DAQ-2024-011286

195 North 1950 West • Salt Lake City, Utah
Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of
Environmental Quality
Kimberly D. Shelley
Executive Director
DIVISION OF AIR QUALITY
Bryce C. Bird
Director
Air Quality Board
Kim Frost, Chair
Michelle Bujdoso, Vice-Chair
Kevin R. Cromar
Cassady Kristensen
Randal S. Martin
Sonja Norton
John Rasband
Kimberly D. Shelley
Jeff Silvestrini
Bryce C. Bird,
Executive Secretary
SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor
DAQ-087-24
UTAH AIR QUALITY BOARD MEETING
TENTATIVE AGENDA
Wednesday, November 6, 2024 - 1:30 p.m.
195 North 1950 West, Room 1015
Salt Lake City, Utah 84116
Board members may be participating electronically. Interested persons can participate telephonically by
dialing 1-475-299-8810 using access code: 449-801-632#, or via the Internet at meeting link:
meet.google.com/dpm-oqgm-nzk
I. Call-to-Order
II.Date of the Next Air Quality Board Meeting: December 4, 2024
III.Approval of the Minutes for the October 2, 2024, Board Meeting.
IV.Propose for Final Adoption: Amendment to R307-110-13. General Requirements: State
Implementation Plan. Incorporation of Utah State Implementation Plan, 2015 Ozone NAAQS
Northern Wasatch Front Moderate Nonattainment Area, Section IX.D.11.
Presented by Ryan Bares.
V.Propose for Public Comment: Amend Utah State Implementation Plan, Section X, Vehicle
Inspection and Maintenance Program, Part F, Cache County; and R307-110-36. Section X,
Vehicle Inspection and Maintenance Program, Part F, Cache County. Presented by Mat Carlile.
VI.Propose for Public Comment: New Rule R307-209. Portable Aggregate Processing Plants.
Presented by Alan Humpherys.
VII.Propose for Public Comment: Amend R307-401. Permit: New and Modified Sources.
Presented by Alan Humpherys.
VIII.Propose for Final Adoption: Amend R307-101. General Requirements; including R307-101-3.
Version of Code of Federal Regulations Incorporated by Reference. Presented by Erica Pryor.
IX.Five-Year Review: R307-302. Solid Fuel Burning Devices. Presented by Erica Pryor.
DAQ-087-24
Page 2

X. Informational Items.
A. Air Toxics. Presented by Leonard Wright.
B. Compliance. Presented by Harold Burge, Rik Ombach, and Chad Gilgen.
C. Monitoring. Presented by Lucas Bohne.
D. Other Items to be Brought Before the Board.
E. Board Meeting Follow-up Items.

In compliance with the Americans with Disabilities Act, individuals with special needs (including auxiliary communicative aids
and services) should contact LeAnn Johnson, Office of Human Resources at [phone], TDD [phone] or by email
at [e-mail].

ITEM 4

195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
DAQ-090-24
M E M O R A N D U M TO: Air Quality Board THROUGH: Bryce C. Bird, Executive Secretary THROUGH: Erica Pryor, Rules Coordinator FROM: Ryan Bares, Environmental Scientist DATE: October 23, 2024 SUBJECT: PROPOSE FOR FINAL ADOPTION: Amendment to R307-110-13. General
Requirements: State Implementation Plan. Incorporation of Utah State Implementation Plan, 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment Area, Section IX.D.11.
______________________________________________________________________________________ On August 3, 2018, the U.S. Environmental Protection Agency (EPA) designated Utah’s Northern Wasatch
Front (NWF) as a marginal nonattainment area (NAA) for the 2015 national ambient air quality standard (NAAQS) for 8-hour ozone concentrations (83 FR 25776). On October 7, 2022, EPA finalized the reclassification of the NWF NAA from marginal to moderate status (87 FR 60897) since the area failed to attain the standard by the attainment date of August 3, 2021. The reclassification to moderate status became effective on November 7, 2022. As a result of this designation, under Section 182(b) of the Clean Air Act (CAA), the state of Utah was required to submit a revision to Utah’s State Implementation Plan (SIP) outlining specific provisions implemented in order for the NWF NAA to attain the NAAQS as expeditiously as practicable. On September 12, 2023, the Utah Air Quality Board adopted amendments to the Utah SIP titled Section IX.D.11: 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment Area, which aimed to
fulfill all CAA requirements for a moderate NAA. While this SIP revision demonstrated compliance with a number of CAA requirements, it failed to fully implement Reasonable Further Progress (RFP) requirements as required under CAA Section 182(b)(1)(A)(i). Specifically, the RFP requirements for a
moderate NAA requires a 15% reduction in VOC emissions. However, the 2015 ozone implementation rule states that a moderate NAA that has implemented federally enforceable VOC emission reductions
DAQ-090-24 Page 2
equal to or greater than the current 15% requirement as part of a previous ozone SIP revision shall be granted the opportunity to substitute a comparable amount of NOx emission reductions, as long as those reductions deliver an equivalent improvement in air quality (83 FR 63004). The proposed amendments to Section R307-110-13 results in the incorporation of revisions to Chapter 7 of the NWF moderate ozone SIP which demonstrate compliance with RFP requirement through the substitution of NOx emission reductions in place of the VOC emission reduction requirement. Additionally, these amendments provide the analysis necessary to demonstrate the NOx emission reductions achieved as part of the moderate SIP revision demonstrate an equal or greater improvement to air. The ability to pursue compliance through the use of NOx substitutions is possible due to the substantial past VOC emission
reductions achieved throughout the NWF NAA as part of the state’s efforts to reduce fine particulate matter (PM2.5) pollution.
On July 9, 2024, the Utah Air Quality Board approved a 30-day public comment period for the proposed amendments. This public comment period ran from August 1, 2024, to September 3, 2024. During this time, staff at the Utah Division of Air Quality (the division) received three sets of comments. These
comments spanned an array of positions regarding the support and approvability of the amendments, as well as suggestions for additional amendments that could be added to further strengthen the amendments. The division reviewed and evaluated all comments submitted in writing during this 30-day public comment period in accordance with section 63G-3-301(11)(b) of Chapter 3 of the Utah Administrative Rulemaking Act. A detailed summary of comments received and responses from the division can be found in APPENDIX A of this memorandum. After reviewing and considering the comments received, the division is proposing the following changes to the originally proposed amendments: The addition of two sentences to Section 7.1 providing further legal clarification of precedents and interpretations. Adjustments to the values reported in Section 7.5.1 and Table 66 removing the proportion of emissions associated with Box Elder County. Updating the public notice information found in Section
12.5 of the SIP to accurately reflect the associated public comment period and public hearing opportunity. Recommendation: Staff recommend the Board approve the amendment to section R307-110-13;
Incorporation of Utah State Implementation Plan, Section IX.D.11: 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment Area, for final adoption.

DAQ-090-24 Page 3
APPENDIX A
2024 Amendments to Northern Wasatch Front Moderate Ozone State Implementation Plan Reasonable Further Progress. Response to Public Comment.
The Utah Division of Air Quality (the Division, UDAQ) has reviewed and evaluated all comments submitted in writing during the associated 30-day public comment period in accordance with section 63G-3-301(11)(b) of Chapter 3 of the Utah Administrative Rulemaking Act. All written comments
received by the Division have been posted on its webpage where they can be viewed in their entirety. Below is a summary of comments received and responses from the Division. Comments from U.S Environmental Protection Agency, Region 8 (EPA) 1) EPA Comment #1: The EPA provided a comment stating, “The CAA and the EPA’s implementing
regulations do not allow reliance on NOx emission reductions for a Moderate RFP ozone plan unless the EPA has previously approved a Moderate RFP ozone plan for the nonattainment area. Utah does not have a previously approved Moderate RFP ozone plan and therefore cannot rely on NOx emission reductions to satisfy the requirement. The volatile organic compound (VOC) reductions achieved under the particulate matter (PM2.5) SIP do not substitute for a previously approved Moderate RFP ozone plan. If the state submits a SIP revision that relies on NOx reductions, as in the proposed revisions,
EPA does not currently see a basis for proposing approval of such a SIP revision.” UDAQ Response: The Division appreciates the early engagement and feedback throughout the development of the proposed amendments with the EPA as the Division developed the proposed amendments containing the pathway toward fulfilling RFP requirements. The Division disagrees that there is not currently a pathway for approving the amendments as proposed. Utah is not aware of, and EPA has not cited, language in the CAA that expressly prohibits consideration of NOx emission reductions for meeting reasonable further progress requirements for the current SIP, nor has it cited
language that prohibits an agency from crediting reductions that occurred under a previously approved PM2.5 SIP. Instead, the EPA seems to infer a prohibition based on the CAA’s inclusion of a previously approved Moderate RFP ozone plan (and by deduction of the exclusion of Particulate Matter plans).
This approach is inconsistent with a fair reading of the CAA and EPA’s past policy to credit reductions under an ozone SIP to a separate ozone SIP. Nonetheless, EPA also references its current regulations generally as the justification for disapproving the SIP revision. EPA has likewise not identified federal
regulations that expressly bar credit of reductions between SIPs. The Division urges the EPA to consider a more accurate interpretation of the CAA, which would better align with the purpose of the CAA to reduce ozone forming emissions.
Initially, the EPA’s current position to discredit NOx reductions is not in line with a fair reading of the CAA and frustrates the purpose of an RFP ozone SIP. The CAA requires a 15% reduction in emissions. It does not limit from where those reductions must originate. The emission reductions highlighted in the amendments, and achieved under the previously approved NAAQS SIP, are a common sense approach within EPA’s expertise to adopt, for demonstrating compliance with RFP requirements in line with the intent of the 172(c)(2)1 pathway contained in the CAA and described in

1 42 U.S.C. § 7502.
DAQ-090-24 Page 4
the 20082 and 20153 implementation rules. The EPA’s current interpretation results in it arbitrarily selecting which VOC reductions are creditable while ignoring the reality that year-round (not only wintertime) VOC reductions achieved under PM2.5 NAAQS SIPs have the direct benefit of reducing summertime ozone concentrations, in the same manner that VOC reductions achieved under a previous ozone NAAQS SIP would. The CAA interpretation that the Division urges the EPA to adopt is a more accurate interpretation of the statute than what EPA is proposing in its comments. The Division’s admonition to adopt its reading of the CAA should not be foreign to the EPA because EPA has already, in the past, accepted similar or nearly identical reductions achieved under different NAAQS (ozone). If EPA were to accept the validity of past VOC reductions achieved under NAAQS
(PM2.5), it would be substantially the same as its past acceptance of similar or nearly identical reductions achieved under different NAAQS (ozone). The reductions in VOC emissions are the same, regardless of which section of the CAA those reductions were implemented under. This is a valid
interpretation and consistent with EPA’s historic position. Even in the absence of Chevron4 deference to EPA, this interpretation is appropriate under Loper
Bright5 as “the best reading of a statute”6 because it is “reasoned decisionmaking.”7 Loper Bright preserves what is known as Skidmore8 deference, where the courts consider and rely on the knowledge of the expert agencies in aiding the court to interpret the statute. And where the weight of an expert agency’s judgment “depends upon the thoroughness evident in its consideration, the validity of its reasoning, its consistency with earlier and later pronouncements, and all those factors which give it power to persuade.”9 In preserving Skidmore, the U.S. Supreme Court ruled, “And although an agency's interpretation of a statute cannot bind a court, it may be especially informative to the extent it rests on factual premises within the agency's expertise.”10 Further, the courts “exercising independent judgment in determining the meaning of statutory provisions . . . may—as they have from the start—seek aid from the interpretations of those responsible for implementing particular statutes.”11 Under Skidmore, the EPA’s interpretation that the Division advocates for will similarly be afforded substantial weight of persuasion. In contrast, the EPA’s distinction between ozone NAAQS and PM2.5 NAAQS in its comments appears
to be arbitrary, resulting in the unnecessary penalization of the state of Utah for having successfully complied with directly comparable requirements of the CAA in the past. The Division continues to think that the NOx substitution approach taken in the amendments is a reasonable and common sense
approach for fulfilling RFP requirements and is the better interpretation of the CAA, and urges the EPA to reconsider how it intends to arbitrarily and inconsistently apply its interpretation of the NOx substitution pathway. Given the importance of fulfilling RFP requirements, and the importance of the
fair and equitable application of the NOx substitution pathways allowed for nonattainment areas under

2 Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements, 80 Fed. Reg. 12,264 (March 6, 2015).
3 Implementation of the 2015 National Ambient Air Quality Standards for Ozone: Nonattainment Area State Implementation Plan Requirements, 83 Fed. Reg. 62,998 (Dec. 6, 2018).
4 Chevron, U.S.A., Inc. v. Nat. Res. Defense Council, Inc., 467 U.S. 837 (1984). 5 Loper Bright Enterprises v. Raimondo, 144 S. Ct. 2244 (2024).
6 Id. at 2247. 7 Id. citing Michigan v. EPA, 576 U.S. 743, 750 (2015) (internal quotation marks and citations omitted).
8 Skidmore v. Swift & Co., 323 U.S. 134 (1944). 9 Id. at 140.
10 Loper Bright, 144 S. Ct. at 2267 (cleaned up). 11 Id. citing Skidmore, 323 U.S. at 140.
DAQ-090-24 Page 5
Section 172(c)(2), the state of Utah intends to move forward with the submission of the amendments as originally proposed, and urges the EPA to reexamine its basis for approving this pathway for the NWF NAA and for future nonattainment areas that could be in the same situation. 2) EPA Comment #2: The EPA also provided comment regarding alternative pathways for meeting moderate NAA RFP requirements, stating “For areas that cannot satisfy the 15% VOC reduction requirement, the CAA permits a state to pursue an “RFP waiver,” under which areas may show less than a 15% VOC reduction if they meet the requirements of CAA section 182(b)(1)(A)(ii). This includes requirements to significantly tighten the major source threshold and impose higher emissions offset requirements for new sources (see CAA section 182(b)(1)(A)(ii)).”
UDAQ Response: The Division has previously provided comment regarding the infeasibility of pursuing the “RFP waiver” pathway as well as the challenges the NWF faces in meeting RFP
requirements as part of a response to a similar comment from the EPA during the initial finalization of the moderate SIP.12 This response stated:
“as a result of the state's previous emission reduction efforts addressing wintertime PM2.5, the identification and implementation of viable and meaningful emission reductions has become extremely difficult in the NWF area. Realistically, the VOC emission reduction options available to the state at this time are few and are increasingly costly. The very fact that the state has been in close coordination with the EPA in efforts to identify emissions reduction strategies for several years now is evidence of the exceedingly difficult position the state of Utah is in. The failure to implement RFP is not due to a lack of willingness or desire, but instead is due to the lack of available and cost effective options. This is, in part, why the state must consider the availability of emissions reduction strategies as it examines the reasonable level of cost effectiveness for controls. This holds true for emission reduction strategies for area or point source emissions. As for the EPA’s suggestion the state pursues [sic] an “RFP waiver” under Section 82(b)(1)(A)(ii) of the CAA, the state deems this option to be an overly burdensome pathway to effectively implement in an area with the extensive economic activities and growth in the NWF. The sheer number or [sic]
sources that would be brought into the SIP process would exceed the state's ability to effectively manage the RACT process, and the added regulatory burden including Title V requirements to sources as small as 5 tpy is currently viewed as excessive for sources that size. The evidence that this approach
is exceptionally burdensome is clear in the fact that in the 53 years since the CAA passed, no state or nonattainment area to our knowledge, has found Section 182(b)(1)(A)(ii) to be a meaningful pathway to fulfilling RFP requirements. At this time, the Division does not view Section 182(b)(1)(A)(ii) as a viable option. However, this does not preclude the state from pursuing a “waiver” under 182(b)(1)(A)(ii) in the future if this pathway is necessary to alleviate repercussions of a disapproved RFP element such as conformity freezes… The Division recognizes that the EPA is tasked with implementing the CAA as it is written, but requests that the state’s extensive efforts to address ozone pollution in the NWF are kept in mind when punitive measures such as those included in 40 CFR 93.120(a)(2) and 40 CFR 93.101 are considered. The NWF faces a substantial challenge in identifying viable VOC emission reductions, as well as

12 Utah Air Quality Board Meeting: September 12, 2023, Propose for Final Adoption: Amendment to Section R307-
110-13; Incorporation of Utah State Implementation Plan, Section IX.D.11: 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment Area. (https://lf-public.deq.utah.gov/WebLink/DocView.aspx?id=395711&repo=Public&searchid=811ab908-d212-4af8-84a0-2fdf314605f4).
DAQ-090-24 Page 6
significant regionally specific challenges in addressing ozone pollution, but nonetheless has proceeded with every reasonable option available at this time. The Division requests that these efforts and challenges are taken into consideration when the EPA makes its final determination.”13 The Division continues to hold the view that the cited RFP waiver is not a viable pathway to fulfill RFP requirements for the NWF NAA, especially given the fact that it can demonstrate fulfilling RFP requirements under past NAAQS as shown in the proposed amendments. The Division similarly continues to urge EPA to take into consideration the unique challenges facing the NAA in meeting RFP requirements given the substantial VOC reduction achieved in the past, as highlighted by the amendments to the RFP chapter.
3) EPA Comment #3: “EPA encourages Utah to thoroughly assess how long it would take the state to achieve the full 15% in VOC reductions from the 2017 base year, even if doing so will take longer than
the six years contemplated under CAA section 182(b)(1)(A)(i). EPA historically has approved such an RFP demonstration, provided the state has included robust technical support that demonstrates that the state would achieve the 15% VOC reductions as soon as practicable, i.e., that there are no additional
measures the state could implement to achieve the full 15% VOC reductions more expeditiously.” UDAQ Response: The Division greatly appreciates this comment, as well as the provided citations demonstrating when this “as soon as practicable” approach has been accepted by the EPA in the past. The Division appreciates any additional pathways and guidance on how an area such as the NWF NAA can successfully demonstrate RFP requirements while avoiding the punitive sanctions associated with a disapproved RFP plan. The Division will examine this approach in detail, however cannot provide this level of technical analysis on the timeframe available to the state for the current amendments. The Division will continue to examine this approach and consider it as a possible alternative avenue for fulfilling RFP requirements if the EPA continues to disagree with the currently proposed NOx substitution amendments and intends to disapprove the state’s amended SIP. Joint comments from the Utah Petroleum Association and the Utah Mining Association (joint associations)
4) Joint Association General Comment: The joint associations provided a general comment in support of the proposed amendments stating, “The Associations support the proposed changes to the Moderate ozone SIP for the NWF. While EPA’s ozone implementation regulations for the 2105 ozone NAAQS at 40 CFR §51.1310 suggest that the initial 15% VOC reduction must be met through a prior ozone SIP, the Clean Air Act (CAA) does not make this distinction for subsequent ozone NAAQS after the original 1-hour ozone NAAQS that was in place with the CAA Amendments of 1990... We concur that UDAQ made a reasonable and appropriate interpretation... Furthermore, Utah should not be penalized for making early reductions in ozone precursor emissions. Utah could have easily limited emission reductions in the PM2.5 Moderate SIP to wintertime, with equal benefit to PM2.5 air quality but no benefit to ozone air quality. Instead, it chose to extend the reductions year-round to benefit ozone.” UDAQ Response: The Division appreciates the comment and agrees with the interpretation that the NWF NAA has previously fulfilled RFP requirements and thus can pursue NOx substitutions as part of the moderate SIP for the 2015 standard. Furthermore, the Division also agrees with the comment
regarding the penalization of the state for making early and year-round VOC reductions in efforts to attain the PM2.5 NAAQS as expeditiously as possible.

13 Id., App’x B at 6.
DAQ-090-24 Page 7
5) Joint Associations Recommendation #1: The joint associations also provided five recommendations for changes to strengthen the SIP revision. The first recommendation is to “[a]dd a discussion referring to the lack of specificity in the CAA regarding whether the initial 15% reduction must be part of an ozone SIP. In the era post the Supreme Court decision in the Loper Bright case, [federal] agencies will now need to defend their interpretations as the best interpretation, not just a reasonable interpretation. Adding this CAA discussion will help towards showing that the interpretation to rely on PM2.5 SIP reductions of VOC is the best interpretation.” UDAQ Response: The Division agrees with the comment that the addition of a discussion referring to the lack of specificity in the CAA regarding the initial 15% must be part of an ozone SIP as is currently
interpreted by the EPA. As a result, the Division has added text to Section 7.1 which reads, “It is important to note that the CAA does not specify whether this one-time requirement must be met as part of an ozone SIP revision. EPA has previously interpreted the statute relative to the ozone SIPs, but that
does not preclude the interpretation that Utah is proposing here because it is the “best reading” of the statute and a “reasoned decisionmaking” consistent even with post-Loper Bright review of the EPA’s decisions.
6) Joint Associations Recommendation #2: The joint associations’ second recommendation suggests that the Division “[i]nclude mention that Utah should not be penalized for attempting to benefit ozone air quality as part of the PM2.5 SIP, prior to being required to submit an ozone SIP.” UDAQ Response: The Division appreciates the joint associations for providing this comment and making this point part of the public record. The Division agrees with the sentiment behind the comment, which is a central part of the Division’s response to EPA’s Comment #1 in this document. However, the Division thinks that the documentation of this point in the received public comments and the response to those comments is sufficient. While the Division is not adding the requested text, it does want to note that it is in full agreement with this comment, and again appreciates the commenter entering this point into the record. 7) Joint Associations Recommendation #3: Further, the joint associations provided a recommendation
suggesting that “[i]n section 7.5.1 Past SIP Emission Reductions, provide a county-by-county table of VOC reductions from the Moderate PM2.5 SIP to demonstrate that a 15% VOC reduction occurred in the counties of the NWF. This will clarify that UDAQ is not attempting to take credit for any
reductions in Box Elder County since the Salt Lake City PM2.5 nonattainment area includes a portion of Box Elder County, but the NWF does not contain any portion of Box Elder County. Considering EPA’s approach to ensuring that the initial 15% VOC reduction occurs throughout an entire ozone
nonattainment area,10 reductions in Box Elder County would not be approvable as part of the initial 15% VOC reduction for the ozone SIP RFP.” UDAQ Response: The Division greatly appreciates this comment and agrees with the commenters that the emission reductions achieved under the PM2.5 SIPs in Box Elder County should not be included in the RFP demonstration for the NWF Moderate ozone SIP. The values reported in the originally proposed amendments (Table 66) did indeed include emissions from Box Elder County, which is not part of the NWF NAA. As a result, the Division has adjusted the emission reductions reported in the amended RFP chapter associated with past PM2.5 SIPs to remove Box Elder County’s emission reductions. In order to quantify the proportion of emissions attributed to Box Elder County, the Division leveraged EPA’s 2011ek platform.14 EPA's 2011ek platform is based on the same 2011 NEI

14 https://www.epa.gov/sites/default/files/2016-09/documents/2011v6_3_2017_emismod_tsd_aug2016_final.pdf
DAQ-090-24 Page 8
as was used for PM2.5 moderate SIP demonstration. Emissions summary reports from the 2011ek platform include county-level breakouts of emissions as both tons per year (TPY) and tons per month (TPM) by sector and pollutant. Emissions were summarized for the sectors that were included in the moderate SIP PM2.5 platform including area fugitive dust, agricultural emissions (not biogenic), nonpoint, nonroad, onroad, point, oil and gas, rail, and residential wood combustion. Emissions from fires and vegetation (BEIS) were not summarized for these efforts as they are non-anthropogenic. The proportion of emissions from Box Elder County was compared to the sum of total anthropogenic emissions from Box Elder, Weber, Davis, Salt Lake, and Tooele counties. This analysis identified that Box Elder has an annual contribution of 9% of NOx emissions and 9% of VOC emissions throughout all included counties. As a result, the Division has updated all emission reduction numbers found in the
amendments removing 9% of the total emission reductions originally reported to account for Box Elder County’s proportion. Additional text has also been added to the amendments where necessary to explain this process and the results.
8) Joint Associations Recommendation #4: The joint associations also provided a recommendation to “[u]pdate sections 12.5.3 Public Commenting Period and 12.5.4 Public Hearing according to this SIP
revision.” UDAQ Response: The Division appreciates this comment, and now that the public comment period has closed and the option for hosting a public hearing has passed, the Division has updated Sections 12.5.3 and 12.5.4 accordingly. 9) Joint Associations Recommendation #5: The joint associations' final recommendation includes a comment to “[i]nclude a copy of the Governor’s letter as an appendix or attachment to the SIP revision and refer to it in an appropriate part of Chapter 7 Reasonable Further Progress.” Specifically, the joint associations are referring to Governor Cox’s letter sent to EPA administrator Michael S. Regan on July 2, 2024, in which the proposed NOx substitution pathway was outlined in detail, including details on the necessity of finding a pathway for EPA to approve this approach. UDAQ Response: The Division appreciates this comment, however feels that much of the information
included in the Governor’s letter and the SIP amendments are duplicative. Similar to the Division’s response to the joint associations’ recommendation #2 (DAQ response #6), the Division views the Governor's letter as an important part of the record related to the development and reasoning behind the
amendments. Therefore, the Division anticipates including the letter as part of the final packet of documents when submitting the RFP amendments to the EPA, and also thanks the joint associations for including this reference in their comments as part of the record.
Comments from Western Resources Advocates (WRA)
10) WRA Comment #1: WRA provided comments in opposition to the proposed amendments, stating, “Division cannot claim credit for emission reductions made in response to the designation of some portion of the NWF as a nonattainment area for the 24-hour PM2.5 NAAQS. EPA has repeatedly
confirmed that for an ozone nonattainment area’“that has not previously adopted and implemented a SIP providing for a 15 percent reduction in VOC emissions consistent with CAA section 182(b)(1)’ an air quality agency ‘must provide for a 15 percent reduction in VOC emissions in the 6 years following the baseline emissions inventory year.’ 80 Fed. Reg. 12264, 12275 (March 6, 2015); see also Draft Ozone SIP at 110 (Because ‘the NWF does not have a previously approved ROP plan related to ozone, the state must meet the 182(b)(1)(A) requirements for this moderate SIP’).”
DAQ-090-24 Page 9
UDAQ Response: The Division disagrees with this comment, as the Division continues to hold the view that VOC emission reductions, greater than or equal to the amount required under the current RFP, implemented within the same nonattainment area under a different NAAQS is the best interpretation of Section 182(b)(1)(A) RFP requirements. It also carries the weight of a valid and well-reasoned interpretation consistent with past pronouncements. Therefore, the NWF NAA should be allowed to substitute NOx reductions in place of VOC reductions as would any other nonattainment area that has achieved comparable past VOC reductions. The arbitrary distinction between which NAAQS past VOC reductions were achieved should not preclude the NWF NAA from being able to pursue NOx substitutions to fulfill moderate RFP requirements.
11) WRA Comment #2: “The Division is wrong to suggest that in its Moderate Ozone SIP it be credited from VOC emissions achieved in its PM2.5 SIPs. Because no relevant changes have been made as a result of the amended Reasonable Further Progress Demonstration, we hereby reference and reassert
the comments we made on the draft Ozone SIP. We have attached those comments.” UDAQ Response: The Division refers the commenter to the original response to each of these
comments received during the public comment period for the initial adoption of the 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment Area SIP.15

15 Utah Air Quality Board Meeting: September 12, 2023, Propose for Final Adoption: Amendment to Section R307-
110-13; Incorporation of Utah State Implementation Plan, Section IX.D.11: 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment Area. (https://lf-public.deq.utah.gov/WebLink/DocView.aspx?id=395711&repo=Public&searchid=811ab908-d212-4af8-84a0-2fdf314605f4)
State of Utah
Administrative Rule Analysis
Revised May 2024
NOTICE OF SUBSTANTIVE CHANGE
TYPE OF FILING: CPR (Change in Proposed Rule)
Rule or Section Number: R307-110-13 Filing ID: Office Use Only
Date of Previous Publication (Only for CPRs): 08/01/2024
Agency Information
1. Title catchline:Environmental Quality, Air Quality
Building: Multi Agency State Office Building
Street address: 195 N 1950 W
City, state: Salt Lake City, UT
Mailing address: PO BOX 144820
City, state and zip: Salt Lake City, UT 84114-4820
Contact persons:
Name: Phone: Email:
Ryan Bares 801-536-4216 [e-mail]
Erica Pryor 385-499-3416 [e-mail]
Please address questions regarding information on this notice to the persons listed above.
General Information
2. Rule or section catchline:
R307-110-13. General Requirements: State Implementation Plan
3. Purpose of the new rule or reason for the change:
The proposed amendments to Subsection IX.D.11: 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment
Area revise Chapter 7 of the State Implementation Plan, the Reasonable Further Progress section, which requires the state to
demonstrate compliance with Section 182(b)(1)(A)(i) of the Clean Air Act. Minor changes are being proposed after a 30-day
public comment period.
4. Summary of the new rule or change:
Based on feedback received during a 30-day public comment period, three minor changes are being proposed.
1) The addition of two sentences to section 7.1 providing further legal clarification of precedents and interpretations.
2) Adjustments to the values reported in Table 66 removing the proportion of emissions associated with Box Elder County.
3) Updating the public notice section of the SIP to accurately reflect the associated public comment period and public hearing
opportunity.
Fiscal Information
5. Provide an estimate and written explanation of the aggregate anticipated cost or savings to:
A) State budget:
The amendments to Section R307-110-13 and proposed changes are not expected to create any additional costs or savings for
the state budget because the proposed amendments demonstrate how existing state administrative rules and actions fulfill the
Clean Air Act requirements. Additionally, the changes in the CPR do not result in any costs or savings beyond those identified
with the originally proposed amendments.
B) Local governments:
This rule amendment is not expected to impact local governments; therefore, no cost or savings are anticipated. The proposed
changes to this section of the SIP do not result in any additional regulatory requirements. Additionally, the changes in the CPR
do not result in any costs or savings beyond those identified with the originally proposed amendments.
C) Small businesses ("small business" means a business employing 1-49 persons):
This rule amendment is not expected to impact small businesses employing between 1 and 49 persons; therefore, no cost or
savings are anticipated. The proposed changes to this section of the SIP do not result in any additional regulatory
requirements. Additionally, the changes in the CPR do not result in any costs or savings beyond those identified with the
originally proposed amendments.
D) Non-small businesses ("non-small business" means a business employing 50 or more persons):
This rule amendment is not expected to impact non-small businesses employing more than 50 persons; therefore, no cost or
savings are anticipated. The proposed changes to this section of the SIP do not result in any additional regulatory
requirements. Additionally, the changes in the CPR do not result in any costs or savings beyond those identified with the
originally proposed amendments.
E) Persons other than small businesses, non-small businesses, state, or local government entities ("person" means
any individual, partnership, corporation, association, governmental entity, or public or private organization of any character
other than an agency):
This rule amendment is not expected to impact persons other than small businesses, non-small businesses, state, or local
government entities; therefore, no cost or savings are anticipated. The proposed changes to this section of the SIP do not result
in any additional regulatory requirements. Additionally, the changes in the CPR do not result in any costs or savings beyond
those identified with the originally proposed amendments.
F) Compliance costs for affected persons (How much will it cost an impacted entity to adhere to this rule or its changes?):
This rule amendment does not impact any entities and does not result in any additional regulatory requirements; therefore,
there are no anticipated compliance costs. Additionally, the changes in the CPR do not result in any costs or savings beyond
those identified with the originally proposed amendments.
G) Regulatory Impact Summary Table (This table only includes fiscal impacts that could be measured. If there are
inestimable fiscal impacts, they will not be included in this table. Inestimable impacts will be included in narratives above.)
Regulatory Impact Table
Fiscal Cost FY2025 FY2026 FY2027
State Government $0 $0 $0
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $0 $0 $0
Other Persons $0 $0 $0
Total Fiscal Cost $0 $0 $0
Fiscal Benefits FY2025 FY2026 FY2027
State Government $0 $0 $0
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $0 $0 $0
Other Persons $0 $0 $0
Total Fiscal Benefits $0 $0 $0
Net Fiscal Benefits $0 $0 $0
H) Department head comments on fiscal impact and approval of regulatory impact analysis:
The Executive Director of the Department of Environmental Quality, Kimberly D. Shelly, has reviewed and approved this
regulatory impact analysis.
Citation Information
6. Provide citations to the statutory authority for the rule. If there is also a federal requirement for the rule, provide a
citation to that requirement:
Utah Code 19-2-104 U.S.C. Title 42 Chapter 85 Subchapter I
Part A Section 7410 (a)(1)2(A)
Incorporations by Reference Information
7. Incorporations by Reference (if this rule incorporates more than two items by reference, please include additional tables):
A) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)
Utah State Implementation Plan, Section IX.D.11: 2015 Ozone NAAQS Northern
Wasatch Front Moderate Nonattainment Area
Publisher Division of Air Quality, Utah Department of Environment Quality
Issue Date 11/06/2024
Issue or Version
B) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)
Publisher
Issue Date
Issue or Version
Public Notice Information
8. The public may submit written or oral comments to the agency identified in box 1. (The public may also request a
hearing by submitting a written request to the agency. See Section 63G-3-302 and Rule R15-1 for more information.)
A) Comments will be accepted until:No Formal Comment Period
B)A public hearing (optional) will be held:
Date (mm/dd/yyyy): Time (hh:mm AM/PM): Place (physical address or URL):
To the agency: If more than one hearing will take place, continue to add rows.
9. This rule change MAY become effective on:12/31/2024
NOTE: The date above is the date the agency anticipates making the rule or its changes effective. It is NOT the effective date.
Agency Authorization Information
To the agency: Information requested on this form is required by Sections 63G-3-301, 63G-3-302, 63G-3-303, and 63G-3-
402. Incomplete forms will be returned to the agency for completion, possibly delaying publication in the Utah State Bulletin
and delaying the first possible effective date.
Agency head or
designee and title:
Bryce C. Bird, Director, Division of Air
Quality
Date: 10/21/2024
R307. Environmental Quality, Air Quality. 1
R307-110. General Requirements: State Implementation Plan. 2
R307-110-13. Section IX, Control Measures for Area and Point Sources, Part D, Ozone. 3
4
The Utah State Implementation Plan, Section IX, Control Measures for Area and Point Sources, 5
Part D, Ozone, as most recently amended by the Utah Air Quality Board on [October 2]November 6, 6
2024, pursuant to Section 19-2-104, is incorporated by reference and made a part of Rule R307-110. 7
8
KEY: air pollution, PM10, PM2.5, ozone 9
Date of Last Change: 2024 10
Notice of Continuation: December 1, 2021 11
Authorizing, and Implemented or Interpreted Law: 19-2-104 12
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Utah Division of Air Quality 3
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State Implementation Plan 5
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2015 Ozone NAAQS Northern Wasatch Front 7
Moderate Nonattainment Area 8
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2024 10
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Section IX Part D.11 12
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Contents 1
List of Acronyms .................................................................................................................................. 8 2
Chapter 1 – Background and State Implementation Plan (SIP) Requirements ..................................... 10 3
1.1 How Ozone is Formed ....................................................................................................................... 10 4
1.2 Health Effects of Ozone ..................................................................................................................... 10 5
1.3 History of Ozone NAAQS in the Northern Wasatch Front ................................................................ 11 6
1.4 2015 NAAQS Ozone NAAs ................................................................................................................. 12 7
1.5 Responsible Air Agencies ................................................................................................................... 15 8
1.6 Moderate SIP Elements ..................................................................................................................... 15 9
1.7 Moderate Area SIP Development Process ........................................................................................ 17 10
Chapter 2 – NWF Monitoring Network ............................................................................................... 18 11
2.1 Monitoring Network .......................................................................................................................... 18 12
2.2 Ozone Monitoring Data ..................................................................................................................... 20 13
2.3 Data Quality Assurance ..................................................................................................................... 22 14
Chapter 3 - Baseline and Future Year Emission Inventories ................................................................ 25 15
3.1 Emission Inventory Background ........................................................................................................ 25 16
3.2 Baseline 2017 Emission Inventory and Projected 2023 Emission Inventory ..................................... 25 17
Chapter 4 – Reasonably Available Control Technology (RACT) Analysis and Nonattainment New Source 18
Review (NNSR) ................................................................................................................................... 34 19
4.1 Reasonably Available Control Technology (RACT) Overview ............................................................ 34 20
4.2 Utah RACT Process ............................................................................................................................ 35 21
4.3 Big West Oil LLC - Refinery ................................................................................................................ 36 22
4.4 Chevron Products Company – Salt Lake Refinery ............................................................................. 40 23
4.5 Hexcel Corporation ............................................................................................................................ 45 24
4.6 Hill Air Force Base .............................................................................................................................. 48 25
4.8 Kennecott Utah Copper Bingham Canyon Mine and Copperton Concentrator ................................ 56 26
4.9 KUC Smelter and Refinery ................................................................................................................. 60 27
4.10 LHoist North America of Arizona, Inc. ............................................................................................. 66 28
4.11 Pacificorp Energy Gadsby Power Plant ........................................................................................... 67 29
4.12 Tesoro Refining & Marketing Company LLC dba Marathon Refinery ............................................. 70 30
4.13 Utah Municipal Power Agency West Valley Power Plant ................................................................ 75 31
4.14 University of Utah ........................................................................................................................... 77 32
4.15 US Magnesium LLC .......................................................................................................................... 80 33
4.16 Chevron Salt Lake Marketing Terminal ........................................................................................... 85 34

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4.17 Holly Energy Partners Woods Cross Terminal ................................................................................. 87 1
4.18 Tesoro Logistics Operations LLC Truck Loading Rack and Remote Tank Farm ................................ 89 2
4.19 CTG and ACT .................................................................................................................................... 92 3
4.20 RACT Conclusions ............................................................................................................................ 92 4
4.21 Nonattainment New Source Review (NNSR) ................................................................................... 95 5
Chapter 5 - Reasonably Available Control Measures (RACM) Analysis ................................................ 96 6
5.1 Overview ........................................................................................................................................... 96 7
5.2 RACM Analysis ................................................................................................................................... 97 8
5.3 RACM Analysis Conclusion .............................................................................................................. 104 9
Chapter 6 – Inspection and Maintenance (I/M) Program .................................................................. 106 10
6.1 Overview of I/M Programs .............................................................................................................. 106 11
6.2 Federal Requirements ..................................................................................................................... 106 12
6.3 I/M Testing ...................................................................................................................................... 107 13
6.4 Utah I/M Program History and General Authority .......................................................................... 107 14
6.5 UDAQ Evaluation of Current I/M Program ...................................................................................... 108 15
6.6 Implementation of I/M Program in Tooele County ......................................................................... 110 16
Chapter 7 – Reasonable Further Progress (RFP) ................................................................................ 112 17
7.1 Reasonable Further Progress .......................................................................................................... 112 18
7.2 Methodology ................................................................................................................................... 113 19
7.3 RFP and Anthropogenic VOC Emission Reductions ......................................................................... 114 20
7.4 Anthropogenic NOx Emissions ......................................................................................................... 115 21
7.5 CAA Section 172(c)(2) and NOx Substitutions ................................................................................. 119 22
7.6 Future SIP Emission Reductions ...................................................................................................... 124 23
7.7 RFP Conclusions ............................................................................................................................... 127 24
Chapter 8 - Attainment Demonstration and Weight of Evidence ...................................................... 128 25
8.1 Background ...................................................................................................................................... 128 26
8.2 Photochemical Modeling Platform.................................................................................................. 128 27
8.3 Weight of Evidence (WOE) .............................................................................................................. 137 28
8.4 Conclusion ....................................................................................................................................... 150 29
Chapter 9 - 179B(a) Prospective Demonstration ............................................................................... 151 30
9.1 Overview ......................................................................................................................................... 151 31
9.2 Ozone Source Apportionment (OSAT) Modeling ............................................................................ 152 32
9.3 Ozone Source Apportionment Modeling Results ............................................................................ 155 33

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9.4 Future Design Values after Removal of Contributions from International Anthropogenic Emissions1
............................................................................................................................................................... 157 2
9.5 Conclusion ....................................................................................................................................... 158 3
Chapter 10 - Transportation Conformity and Motor Vehicle Emission Budget .................................. 161 4
10.1 Introduction ................................................................................................................................... 161 5
10.2 Transportation Conformity ........................................................................................................... 161 6
10.3 – Consultation ............................................................................................................................... 161 7
10.4 Motor Vehicle Emission Budgets (MVEB) ..................................................................................... 162 8
10.5 Emission Budgets for the Northern Wasatch Front NAA .............................................................. 163 9
10.6 Implementation of MVEB in Transportation Conformity Determinations ................................... 163 10
Chapter 11 - Contingency Measures ................................................................................................. 164 11
11.1 Overview ....................................................................................................................................... 164 12
11.2 Contingency Measures .................................................................................................................. 164 13
Chapter 12 - Environmental Justice & Title VI Considerations ........................................................... 166 14
12.1 Environmental Justice ................................................................................................................... 166 15
12.2 Title VI of the Civil Rights Act ........................................................................................................ 166 16
12.3 Screening-Level Analysis ............................................................................................................... 167 17
12.4 Identified Stakeholders ................................................................................................................. 168 18
12.5 Stakeholder Outreach, Meaningful Involvement, and Information Distribution ......................... 168 19
20
21

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List of Tables 1
Table 1: NWF NAA marginal requirements under the CAA. ....................................................................... 14 2
Table 2: Ozone values in ppm from sites in NWF NAA from 2018 - 2020. Values calculated in accordance 3
with 40 CFR Part 50, Appendix U. ............................................................................................................... 14 4
Table 3: SIP Requirements .......................................................................................................................... 16 5
Table 4: NWF 4th Maximum 8-Hour Ozone Values reported in ppm......................................................... 20 6
Table 5: NWF 8-Hour Ozone Three-Year Average 4th Maximum Ozone Values. ....................................... 21 7
Table 6: NWF Ozone Data Recovery Rates shown as percentages. ............................................................ 23 8
Table 7: 2017 Nonattainment Area Emission Inventory (tons per day) ..................................................... 26 9
Table 8: 2023 Projected Nonattainment Area Emission Inventory (tons per day) ..................................... 27 10
Table 9: Biogenic Emissions (tons per day) ................................................................................................. 27 11
Table 10: Solvent Emissions Inventory ....................................................................................................... 28 12
Table 11: 2023 Solvent Emissions Inventory .............................................................................................. 28 13
Table 12: 2017 Area Source Emission Inventory ........................................................................................ 29 14
Table 13: Area Source Emission Inventory ................................................................................................. 29 15
Table 14: Non-Road, Rail and Airports Emission Inventory ........................................................................ 30 16
Table 15: 2023 Non-Road, Rail and Airports Emission Inventory ............................................................... 30 17
Table 16: 2017 Point Sources and EGUs Emission Inventory...................................................................... 31 18
Table 17: 2023 Point Sources and EGUs Emission Inventory...................................................................... 32 19
Table 18: 2017 On-road emission inventory for ozone weekday ............................................................... 32 20
Table 19: 2023 On-road emission inventory for ozone weekday ............................................................... 32 21
Table 20: 2017 ERC Bank Emission Inventory ............................................................................................. 33 22
Table 21: 2023 ERC Bank Emission Inventory ............................................................................................. 33 23
Table 22: Big West Oil LLC Refinery Facility-Wide Emissions...................................................................... 37 24
Table 23: Big West Oil LLC - Refinery .......................................................................................................... 37 25
Table 24: Chevron Products Company – Salt Lake Refinery Facility-Wide Emissions ................................ 40 26
Table 25: Chevron Products Company – Salt Lake Refinery ....................................................................... 41 27
Table 26: Hexcel Corporation Facility-Wide Emissions ............................................................................... 45 28
Table 27: Hexcel Corporation ..................................................................................................................... 45 29
Table 28: Hill Air Force Base Facility-Wide Emissions ................................................................................. 48 30
Table 29: Hill Air Force Base ........................................................................................................................ 50 31
Table 30: Holly Frontier Sinclair Woods Cross Refinery Facility-Wide Emissions ....................................... 53 32
Table 31: Holly Frontier Sinclair Woods Cross Refinery .............................................................................. 54 33
Table 32: KUC Bingham Canyon Mine and Copperton Concentrator Facility-Wide Emissions .................. 57 34
Table 33: Kennecott Utah Copper (KUC): Bingham Canyon Mine and Copperton Concentrator .............. 57 35
Table 34: KUC Smelter and Refinery Facility-Wide Emissions .................................................................... 61 36
Table 35: Kennecott Utah Copper: Smelter and Refinery .......................................................................... 61 37
Table 36: LHoist North America of Arizona Facility Facility-Wide Emissions .............................................. 66 38
Table 37: Lhoist North America of Arizona, Inc. ......................................................................................... 67 39
Table 38: Pacificorp Energy Gadsby Power Plant Facility-Wide Emissions ................................................. 68 40
Table 39: PacifiCorp Energy: Gadsby Power Plant ...................................................................................... 68 41
Table 40: Tesoro Marathon Refinery Facility-Wide Emissions ................................................................... 70 42
Table 41: Tesoro Refining and Marketing Company LLC dba Marathon Refinery ...................................... 70 43
Table 42: West Valley Power Plant Facility-Wide Emissions ...................................................................... 75 44
Table 43: Utah Municipal Power Agency West Valley Power Plant ........................................................... 76 45
Table 44: University of Utah Facility-Wide Emissions ................................................................................. 77 46

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Table 45: University of Utah ....................................................................................................................... 78 1
Table 46: US Magnesium LLC Facility-Wide Emissions ............................................................................... 81 2
Table 47: US Magnesium RACT Determination .......................................................................................... 81 3
Table 48: Chevron Salt Lake Marketing Terminal Facility-Wide Emissions ................................................ 86 4
Table 49: Chevron Salt Lake Marketing Terminal ....................................................................................... 86 5
Table 50: Holly Energy Partners Woods Cross Terminal Facility-Wide Emissions ...................................... 88 6
Table 51: Holly Energy Partners Woods Cross Terminal ............................................................................. 88 7
Table 52: Tesoro Logistics Operations LLC TLR and RTF Facility-Wide Emissions ....................................... 90 8
Table 53: Tesoro Logistics Operations LLC TLR and RTF ............................................................................. 90 9
Table 54: Controls identified by RACT analysis for the NWF NAA. ............................................................. 94 10
Table 55: Existing area source VOC rules in the NWF NAA ......................................................................... 97 11
Table 56: VOC RACM Assessment Summary .............................................................................................. 98 12
Table 57: NOX RACM Assessment Summary ............................................................................................. 102 13
Table 58: RACM Identified Control Strategies .......................................................................................... 104 14
Table 59: 2023 Davis County Summer Basic Performance Modeling ....................................................... 109 15
Table 60: 2023 Salt Lake Summer Basic Performance Modeling .............................................................. 109 16
Table 61: 2023 Utah County Summer Basic Performance Modeling ....................................................... 110 17
Table 62: 2023 Weber County Summer Basic Performance Modeling .................................................... 110 18
Table 63: I/M Program Implementation Evaluation for Tooele County in 2023 ...................................... 111 19
Table 64: Anthropogenic VOC Emission Reductions from 2017 to 2023 for the NWF ............................. 114 20
Table 65: Anthropogenic NOx Emission Reductions from 2017 to 2023 for the NWF ............................. 116 21
Table 66: VOC reductions in the NWF NAA during past SIPs timeline demonstrating a 15% VOC reduction 22
relative to NAAQS base years………………………………………………………………………………………………………………120 23
Table 67: VOC and NOx reduction in the NWF NAA during the moderate SIP timeline………………………..121 24
Table 68: Performance statistics for maximum daily average 8-hour (MDA8) ozone on all days of the 25
modeling episode. Results are shown for monitors in the 1.33 km modeling domain. ........................... 131 26
Table 69: Performance statistics for maximum daily average 8-hour (MDA8) ozone on high O3 days 27
(observed MDA8 > 60 ppb). Results are shown for monitors in the 1.33 km modeling domain. ............ 132 28
Table 70: Baseline design values (BDV), relative response factors (RRF), future design values (FDV) at 29
Bountiful, Hawthorne and Herriman monitoring locations. Design values before and after exclusion of 30
days impacted by wildfire smoke are shown.* indicates design value after removal of wildfire smoke-31
impacted ozone exceedance values. ........................................................................................................ 136 32
Table 71: Baseline design values (BDV), relative response factors (RRF), future design values (FDV) at 33
monitors within the northern Wasatch Front ozone non-attainment area. ............................................ 136 34
Table 72: 2023 contributions from upwind states to NWF NAA (ppb) as identified by EPA 2016v2 35
modeling ................................................................................................................................................... 140 36
Table 73: NOx and VOC reductions resulting from PM2.5 SIPs. ................................................................. 143 37
Table 74: Emission reductions associated with incentive programs in and around the NWF NAA ......... 147 38
Table 75: Emission source categories considered in 2023 ozone source apportionment modeling. ...... 154 39
Table 76: Future design values (FDV), source contribution estimates for international anthropogenic 40
emissions (IAE) and adjusted future design values (FDV adj) at monitoring locations within the northern 41
Wasatch Front non-attainment area. ....................................................................................................... 158 42
Table 77: NWF Ozone 2023 NAA MVEB .................................................................................................... 163 43
Table 78: Percent Emission Reductions Based on 2017 Base Year Inventory .......................................... 165 44
Table 79: Environmental Justice Indexes Over the 80th Percentile in the NWF NAA .............................. 167 45

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List of Figures 1
Figure 1: Wasatch Front Ozone Nonattainment Areas. .............................................................................. 13 2
Figure 2: Monitoring sites in the NWF NAA ................................................................................................ 19 3
Figure 3: Ozone 4th Highest 8-Hour Concentration in Wasatch Front ....................................................... 22 4
Figure 4: NWF Anthropogenic VOC Emission Inventories ........................................................................ 115 5
Figure 5: NWF Anthropogenic NOx Emission Inventories ......................................................................... 117 6
Figure 6: NOx-attributable (brown) and VOC-attributable (green) ozone at Hawthorne (left panel) and 7
Bountiful (right) monitoring stations on average over all days of the modeling episode. ....................... 118 8
Figure 7: 12/4/1.33 km CAMx Modeling Domains ................................................................................... 130 9
Figure 8: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone 10
concentration (O3_8hrmax) at the Bountiful monitoring station. ........................................................... 132 11
Figure 9: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone 12
concentration (O3_8hrmax) at the Hawthorne monitoring station. ........................................................ 133 13
Figure 10: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone 14
concentration (O3_8hrmax) at the Erda monitoring station. ................................................................... 133 15
Figure 11: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone 16
concentration (O3_8hrmax) at the Herriman monitoring station. ........................................................... 133 17
Figure 12: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone 18
concentration (O3_8hrmax) at the Harrisville monitoring station. .......................................................... 134 19
Figure 13: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone 20
concentration (O3_8hrmax) at the Ogden monitoring station. ............................................................... 134 21
Figure 14: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone 22
concentration (O3_8hrmax) at Gothic Colorado monitoring station. ...................................................... 134 23
Figure 15: Ozone Attributed to Domain-Wide Sources at Hawthorne as simulated 8-hour mean daily 24
ozone concentrations along the Wasatch Front. ...................................................................................... 139 25
Figure 16: Episode average of simulated 8-hour mean daily ozone concentrations at Hawthorne along 26
the Wasatch Front. ................................................................................................................................... 139 27
Figure 17: Ozone Attributed to Domain-Wide Sources ............................................................................ 142 28
Figure 18: MDA8 ozone source apportionment exceedance vs. non-exceedance days .......................... 142 29
Figure 19: Map of source regions used in 2023 ozone source apportionment modeling for the 4 and 1.33 30
km domains. Each color represents a different source region. ................................................................ 153 31
Figure 20: Source contributions by region and emission sector to maximum daily 8-hr average (MDA8) 32
ozone concentration (ppb) at the Hawthorne monitoring station for each day of the modeling episode 33
(left panel) and on average over all days of the modeling episode (right panel). Results are based on 34
2023 OSAT model outputs for the 1.33 km modeling domain and spin-up days are excluded. .............. 156 35
Figure 21: Source contributions by region and emission sector to maximum daily 8-hr average (MDA8) 36
ozone concentration (ppb) at the Hawthorne monitoring station for each day of the modeling episode 37
(upper panel) and on average over all days of the modeling episode, exceedance days, top 10 38
exceedance days and non-exceedance days (lower panel). Results are based on 2023 OSAT model 39
outputs for the 1.33 km modeling domain and spin-up days are excluded. ............................................ 157 40
Figure 22: International contributions at Hawthorne monitor site on exceedance and non-exceedance 41
days. .......................................................................................................................................................... 159 42
Figure 23: EJ Indexes >80th percentile in Each NWF NAA Census Block .................................................. 166 43
44

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List of Acronyms 1
ACT = Alternative Control Techniques 2
AO = Approval Order 3
BDV = Base Design Value 4
CAA = Clean Air Act 5
CAMx = Comprehensive Air Quality Model with Extensions 6
CFR = Code of Federal Register 7
CO = Carbon Monoxide 8
CTG = Control Techniques Guidelines 9
DERA = Diesel Emissions Reduction Act 10
DV = Design Value 11
EGU = Electric Generating Units 12
EMP = Enhanced Monitoring Program 13
EPA = U.S. Environmental Protection Agency 14
EV = Electric Vehicles 15
FDV = Future Design Value 16
FHWA = Federal Highway Administration 17
FIP = Federal Implementation Plan 18
FR = Federal Register 19
HAP = Hazardous Air Pollutants 20
HYSPLIT = Hybrid Single–Particle Lagrangian Integrated Trajectory 21
ICT = Interagency Consultation Team 22
I/M = Inspection and Maintenance 23
MDA8 = Maximum Daily Average Ozone Over an 8-Hour period 24
MOVES3 = Motor Vehicle Emission Simulator (2014 Release) 25
MPE = Model Performance Evaluation 26
MPO = Metropolitan Planning Organization 27
MVEB = Motor Vehicle Emissions Budgets 28
NAA = Nonattainment Area 29
NAAQS = National Ambient Air Quality Standard 30
NESHAP = National Emission Standards for Hazardous Air Pollutants 31
NMOG – Non-Methane Organic Gases 32
NOx = Nitrogen Oxides 33
NSPS = New Source Performance Standards 34
NNSR = Nonattainment New Source Review 35
OBD = On-Board Diagnostics 36
OSAT = Ozone Source Apportionment 37
PPB = Parts per Billion 38
PPM = Parts per Million 39
PPMV = Parts Per Million by Volume 40
RACM = Reasonably Available Control Measures 41
RACT = Reasonably Available Control Technology 42
RFP = Reasonable Further Progress 43
RRF = Relative Response Factor 44
SIP = State Implementation Plan 45
SMOKE = Sparse Matrix Operator Kernel Emissions 46

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TIP = Transportation Improvement Program 1
TPD = Tons per Day 2
TPY = Tons per Year 3
TSD = Technical Support Document 4
UDAQ = Utah Division of Air Quality 5
VMT = Vehicle Miles Traveled 6
VOC = Volatile Organic Compounds 7
WOE = Weight of Evidence 8
WRF = Weather Research and Forecasting 9
ZEV = Zero Emission Vehicles 10
11

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Chapter 1 – Background and State Implementation Plan (SIP) 1
Requirements 2
1.1 How Ozone is Formed 3
Ozone is a highly unstable and oxidative gas made up of three atoms of oxygen covalently 4
bonded together. Tropospheric ozone is not directly emitted but is formed in the atmosphere through a 5
complex series of secondary and tertiary reactions. In short, Volatile Organic Compounds (VOCs) from a 6
variety of natural and anthropogenic sources react in the atmosphere with Nitrogen Oxides (NOx), and 7
to a lesser extent Carbon Monoxide (CO), in the presence of sunlight and heat to form ozone (Equation 8
1). 9
10
Equation 1 11
VOC + NOx + Sunlight + Heat = O3 12
13
Anthropogenic sources of VOCs and NOx include, but are not limited to automobile exhaust, 14
refueling vapors, solvents, complete and incomplete combustion of fuels, and industrial activities. 15
Natural sources include wildfires, biogenic activities, and soil respiration. 16
In the Northern Wasatch Front (NWF), elevated concentrations of ground-level ozone are 17
predominantly a summertime phenomenon associated with extended periods of high-pressure 18
coinciding with high temperatures, low relative humidity, limited cloud cover, and intense incoming 19
solar radiation. In addition to favorable atmospheric conditions for the local formation of ozone, the 20
high elevation of the NWF and its location within the Intermountain West contribute to the observed 21
elevated ozone concentrations. 22
1.2 Health Effects of Ozone 23
Exposure to elevated levels of ozone is linked to an array of respiratory and pulmonary 24
problems, primarily among susceptible populations and those participating in outdoor activities.1 These 25
health problems can include increased susceptibility to respiratory illnesses like pneumonia and 26
bronchitis, chest pain, inflammation of the respiratory tract, irritated and or permanently damaged lung 27
tissues, and cardiac impacts and aggravation of preexisting respiratory issues like asthma or chronic 28
obstructive pulmonary disease (COPD). 29
The Clean Air Act (CAA) requires the US Environmental Protection Agency (EPA) to set air quality 30
standards for certain criteria air pollutants, known as the National Ambient Air Quality Standards 31
(NAAQS), to protect both public health and the environment. States must develop plans to attain and 32
maintain these health-based standards called State Implementation Plans (SIPs). If an area is determined 33
to not meet these standards, then the SIP must be revised with plans on how the area will achieve the 34
standard by deadlines established in the CAA. 35

1 Devlin BR, Raub AJ, Folinsbee JL. (1997). Health effects of ozone. Science & Medicine;(3):8-17.

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1.3 History of Ozone NAAQS in the Northern Wasatch Front 1
Significant efforts have been made in reducing precursor emissions, primarily NOx and VOCs, 2
throughout the NWF over the last 40 years. Much of the more recent efforts have been targeted at 3
reducing Utah’s wintertime fine particulate matter (PM2.5), however, there is a long history of efforts to 4
combat ozone directly. 5
1.3.1 1979 1-Hour Ozone Standard 6
In 1977 EPA designated parts of the Wasatch Front including Davis, Salt Lake, Utah, and Weber 7
Counties as nonattainment for the 1-hour ozone standard of 0.120 parts per million (ppm). In 1981 both 8
Weber and Utah Counties were re-designated as attainment. In April of 1981, an ozone SIP was 9
submitted to EPA that demonstrated attainment of the standard for both Davis and Salt Lake Counties 10
by May 1, 1984. This ozone SIP submittal was fully approved by the EPA. 11
In November of 1990, Congress amended the CAA. Under the 1990 Amendments, each area of 12
the country that was designated nonattainment for the 1-hour ozone NAAQS, including Salt Lake County 13
and Davis County, was classified by operation of law as marginal, moderate, serious, severe, or extreme 14
nonattainment depending on the severity of the area's air quality problem. The ozone nonattainment 15
designation for Salt Lake County and Davis County continued by operation of law according to section 16
107(d)(1)(C)(i) of the CAA, as amended in 1990. Furthermore, this area was classified by operation of law 17
as moderate for ozone under CAA section 181(a)(1). On November 12, 1993, Utah submitted a formal 18
request to EPA that the Salt Lake/Davis County nonattainment area (NAA) be redesignated to 19
attainment of the 1-hour ozone NAAQS, and the State, in accordance with the CAA, submitted a 20
maintenance plan. In July of 1997, the EPA approved the Ozone Maintenance Plan for Salt Lake and 21
Davis Counties, effective August 18, 1997, and redesignated both counties to attainment for 1-hour 22
ozone NAAQS. 23
1.3.2 1997 8-Hour Ozone Standard 24
In July 1997, the EPA established a new, more rigorous standard for the 8-hour ozone NAAQS. 25
The new 8-hour standard was set at a level of 0.080 ppm averaged over an eight-hour period. To better 26
account for variable meteorological conditions that can influence ozone formation, a violation of the 27
standard occurs when the three-year average of the fourth-highest maximum value at a monitor 28
exceeds the federal standard. On April 30, 2004, EPA published the first phase of its final rule (Phase 1 29
Rule) to implement the 8-hour ozone NAAQS.2 At the same time, EPA also published 8-hour ozone 30
designations for all areas of the country. All areas of Utah were designated attainment or unclassifiable. 31
These designations became effective on June 15, 2004. The Phase 1 Rule provided that the 1979 1-hour 32
ozone NAAQS would be revoked following the effective date of the 8-hour ozone NAAQS, or June 15, 33
2005. This revocation action was affirmed on August 3, 2005.3 On November 29, 2005, EPA published 34
the Final Rule to Implement the 8-hour Ozone NAAQS - Phase 2.4 35

2 Final Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard—Phase 1, 69 Fed. Reg. 23,951 (April 30, 2004).
3 Identification of Ozone Areas for Which the 1-Hour Standard Has Been Revoked and Technical Correction to Phase 1 Rule, 70 Fed. Reg. 44,470 (Aug. 3, 2005).
4 Final Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard—Phase 2; Final Rule to Implement Certain Aspects of the 1990 Amendments
Relating to New Source Review and Prevention of Significant Deterioration as They Apply in Carbon Monoxide, Particulate Matter and Ozone NAAQS; Final Rule for
Reformulated Gasoline, 70 Fed. Reg. 71,612 (Nov. 29, 2005).

UTAH DIVISION OF AIR QUALITY
12

The Utah Air Quality Board adopted a revised maintenance plan on January 3, 2007. Salt Lake 1
and Davis Counties were found to be in attainment on July 18, 1995, under the 1-hour ozone NAAQS5 2
and had been operating under an approved maintenance plan (62 Federal Register [FR] 38213) since July 3
17, 1997.6 This maintenance plan demonstrated that Salt Lake and Davis Counties had achieved the 8-4
hour ozone standard and could maintain compliance with the standard through 2014. 5
1.3.3 2008 8-Hour Ozone Standard 6
In March, 2008, the EPA revised the 1997 8-hour NAAQS from 0.080 to 0.075 ppm averaged 7
over an 8-hour period. In 2012, EPA finalized the standard and issued rulemaking relevant to the 8
implementation of the rule.7 In 2015, EPA finalized the SIP requirements and NAA classifications and 9
determinations for this standard.8 Monitoring data indicated that all areas of Utah were attaining the 10
standard, and thus no SIP revisions were required for the state of Utah for this NAAQS. 11
1.4 2015 NAAQS Ozone NAAs 12
On October 26, 2015, the EPA promulgated a revision to the primary NAAQS for ground-level 13
ozone in accordance with Section 107(d) of the CAA. This revision lowered the standard from 0.075 to 14
0.070 ppm for the 4th highest daily maximum 8-hour concentration (MDA8) averaged over three years.9 15
As a result of the more stringent standard, effective on August 3, 2018, the EPA designated two areas 16
along the Wasatch Front as marginal NAA including the Northern Wasatch Front and Southern Wasatch 17
Front.10 The NWF NAA includes Salt Lake and Davis counties as well as portions of Tooele and Weber 18
counties (Figure 1). 19

5 Determination of Attainment of Ozone Standard for Salt Lake and Davis Counties, Utah, and Determination Regarding Applicability of Certain Reasonable Further
Progress and Attainment Demonstration Requirements, 60 Fed. Reg. 36,723 (July 18, 1995).
6 Approval and Promulgation of Air Quality Implementation Plans; State of Utah; Salt Lake and Davis Counties Ozone Redesignation to Attainment, Designation of
Areas for Air Quality Planning Purposes, Approval of Related Elements, Approval of Partial NOX RACT Exemption, and Approval of Weber County I/M Program, 62
Fed. Reg. 38,213 (July 17, 1997).
7 77 FR 30160
8 FR 80 12264
9 National Ambient Air Quality Standards for Ozone, 80 Fed. Reg. 65,292 (Oct. 26, 2015).
10 Additional Air Quality Designations for the 2015 Ozone National Ambient Air Quality Standards, 83 Fed. Reg. 25,776 (June 4, 2018).

UTAH DIVISION OF AIR QUALITY
13

1
Figure 1: Wasatch Front Ozone NAAs 2
1.4.1 Northern Wasatch Front Ozone NAA 3
The boundaries for the NWF NAA include three valleys that are part of the Intermountain West’s 4
basin and range geological province: Tooele Valley, the North Salt Lake Valley, and the Salt Lake Valley. 5
The majority of the approximately 1.8 million residents within the NAA reside in the Salt Lake valleys 6
situated along the base of the Wasatch Mountains. The three valleys consist of a variety of complex 7
topography including low and large valleys bordered by steep mountain terrain and a large body of 8
water—the Great Salt Lake. The average elevation of the three valleys is 4,327 feet above sea level with 9
the bordering Wasatch Mountains rising to elevations over 11,000 feet. The area experiences a dry-10
summer continental climate with hot and dry summers dominated by persistent high-pressure systems. 11
The relatively high baseline elevation of over 4,000 feet, coupled with its warm and dry climate, and its 12
prominent location in the Intermountain West, results in a naturally high contribution of background 13
ozone in the NWF NAA11 during the typical summer ozone season. 14
15
1.4.2 NWF Marginal Ozone NAA Requirements 16
The NWF NAA failed to attain the standard by the marginal attainment date but has met all 17
statutory requirements for a marginal NAA under the CAA Section 182(a) as shown in Table 1. 18

11 Scientific assessment of background ozone over the U.S.: Implications for air quality management. Jaffe et al.

UTAH DIVISION OF AIR QUALITY
14

1
Table 1: NWF NAA marginal requirements under the CAA. 2
CAA Requirement Federal Register Approval
2017 Base Year Emission Inventory 86 FR 35404, July 6, 2021
Emission Inventory Statement Rule 87 FR 24273, April 25, 2022
Nonattainment New Source Review 87 FR 24273, April 25, 2022
3
The design value (DV) calculated from data collected from 2018-2020 was used to determine if 4
the area attained the standard by the attainment date of August 3, 2021. Validated data in EPA’s Air 5
Quality System (AQS) shows a 3-year average of the 4th high maximum daily 8-hour ozone value at the 6
NWF Bountiful monitor of 0.077 ppm, with exceedances also observed at all other monitoring sites in 7
the NAA except Erda in Tooele County (Table 2). 8
9
Table 2: Ozone values in ppm from sites in NWF NAA from 2018 - 2020. Values calculated in accordance with 40 CFR Part 50, 10
Appendix U. 11
12
On October 7, 2022, the EPA finalized rulemaking where it determined that the NWF did not 13
attain by the attainment date and reclassified the area to moderate with a new attainment date of 14
August 3, 2024.12 The effective date of this rulemaking was November 7, 2022, marking the effective 15
date of moderate designation for the NWF NAA. 16
17
1.4.3 Utah’s Request to Adjustment the NWF NAA Boundary 18
On February 27, 2023, Governor Spencer J. Cox submitted a letter13 and supporting 19
documentation14 to EPA Region 8 administrator Kathleen Becker. In this letter, Governor Cox used his 20
authority under Section 107(d)(3)(D) of the CAA to request an adjustment to the existing NWF NAA 21
boundary (figure 1). The requested modification would extend the western edge of the existing 22
boundary in Tooele County 7.6 miles further west. This adjustment would result in the inclusion of US 23

12 Determinations of Attainment by the Attainment Date, Extensions of the Attainment Date, and Reclassification of Areas Classified as Marginal for the 2015 Ozone
National Ambient Air Quality Standards, 87 Fed. Reg. 60,897 (Oct. 7, 2022).
13 Utah’s Request for Boundary Adjustment for the Northern Wasatch Front NAA. Feb. 27, 2023: https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-
002065.pdf
14 Request for Adjustment of the Northern Wasatch Front NAA Boundary for the 2015 8-hour Ozone National Ambient Air Quality Standard. Feb. 27, 2023:
https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-002086.pdf

Ozone Summary
Site ID Site Name County Annual 4th Highest
(ppm)
Three Year Average (ppm)
2018 2019 2020 2018-2020
49-057-1003 Harrisville Weber 0.077 0.064 0.074 0.071
49-011-0004 Bountiful Davis 0.080 0.073 0.080 0.077
49-035-2005 Copperview Salt Lake 0.079 0.067 0.075 0.073
49-035-3006 Hawthorne Salt Lake 0.074 0.073 0.075 0.074
49-035-3010 Rose Park Salt Lake 0.080 0.071 0.080 0.077
49-035-3013 Herriman Salt Lake 0.078 0.070 0.073 0.073
49-045-0004 Erda Tooele 0.074 0.065 0.070 0.069

UTAH DIVISION OF AIR QUALITY
15

Magnesium LLC (section 4.15) into the NWF NAA. US Magnesium’s Rowley plant is currently one of the 1
largest point sources of VOCs and NOx in the greater Wasatch Front. US Magnesium is also a unique 2
source of halogen emissions which have been shown to impact both summer and wintertime pollution.15 3
Upon the receipt of the letter, EPA has 18 months to either approve or deny the state’s request. EPA has 4
not formally acted on this request and thus the extent of the NWF NAA remains as described in section 5
1.4.3 (Figure 1). However, given the magnitude of emissions from US Magnesium LLC, and their impacts 6
on the NWF NAA, the Utah Division of Air Quality (UDAQ) has included US Magnesium LLC in this SIP 7
revision where it is appropriate. 8
1.5 Responsible Air Agencies 9
1.5.1 Utah Division of Air Quality (UDAQ) 10
Section 19-2-104 of the Utah Code gives the Utah Air Quality Board the authority to promulgate 11
rules “regarding the control, abatement, and prevention of air pollution from all sources and the 12
establishment of the maximum quantity of air pollutants that may be emitted by an air pollutant 13
source.”16 The UDAQ develops, prepares, and submits SIPs to the Utah Air Quality Board for 14
consideration and promulgation. UDAQ is the primary state agency responsible for the development and 15
implementation of SIPs once they are approved by the Utah Air Quality Board, and associated 16
administrative rules, as required by the CAA. 17
1.5.2 Interagency Consultation Team 18
UDAQ works in close coordination with local Metropolitan Planning Organizations (MPOs) on 19
relevant traffic and travel-related aspects of SIP and transportation conformity activities. The 20
Interagency Consultation Team17 (ICT) is a group of MPOs and transportation planning agencies, that 21
undertake the interagency consultation process as it relates to the development of the SIP, applicable 22
control measures related to transportation included in the SIP, transportation plans, the Transportation 23
Improvement Program (TIP), and Transportation Conformity determinations. Within the NWF NAA, the 24
Wasatch Front Regional Council (WFRC) serves as the MPO for Box Elder, Davis, Salt Lake, Tooele, and 25
Weber Counties. The Utah Department of Transportation (UDOT), Federal Highway Transportation 26
Administration, Federal Transit Administration, and the EPA, are all part of the ICT as well. 27
1.6 Moderate SIP Elements 28
As part of the reclassification to a moderate NAA, EPA has required that Utah submit a SIP 29
revision.18 A moderate SIP revision requires mandatory planning elements per CAA section 182(b) which 30
are outlined in the final SIP Requirements Rule as well as in Table 3.19 31
32

15 Womack CC, Chace WS, Wang S, Baasandorj M, Fibiger DL, Franchin A, Goldberger L, Harkins C, Jo DS, Lee BH, Lin JC, McDonald BC, McDuffie EE, Middlebrook
AM, Moravek A, Murphy JG, Neuman JA, Thornton JA, Veres PR, Brown SS. Midlatitude Ozone Depletion and Air Quality Impacts from Industrial Halogen Emissions
in the Great Salt Lake Basin. Environ Sci Technol. 2023 Feb 7;57(5):1870-1881. doi: 10.1021/acs.est.2c05376. Epub 2023 Jan 25. PMID: 36695819.
16 Utah Code Ann. § 19-2-104(1)(a).
17 Utah State Implementation Plan Section XII; Transportation Conformity Consultation (May 2, 2007), available at https://documents.deq.utah.gov/legacy/laws-
and-rules/air-quality/sip/docs/2007/05May/SECXII.PDF
18 87 Fed. Reg. 60,897.
19 Implementation of the 2008 National Ambient Air Quality Standards for Ozone: NAA Classifications Approach, Attainment Deadlines and Revocation of the 1997
Ozone Standards for Transportation Conformity Purposes, 77 Fed. Reg. 30,160 (May 21, 2012).

UTAH DIVISION OF AIR QUALITY
16

Table 3: SIP Requirements 1
Category Requirement Reference Addressed in Section
Reasonable
Further Progress
(RFP)
Demonstrate a 15% reduction of
VOCs from the base year inventory to
the attainment year.
CAA
§182(b)(1)(A)(i)
and 40 CFR
§51.1310
Chapter 7 (IX D.11)
Base Year and
Projected
Emission
Inventories
Establish the base year emission
inventory (2017) and attainment year
inventory (2023) for use in
establishing RFP and demonstration
of attainment.
CAA
§182(b)(1)(B) and
40 CFR §51.1315
Chapter 3 (IX D.11)
Attainment
Demonstration
Demonstration that the NAA will
attain the standard using a
photochemical model and methods
approved in EPA modeling guidance.
CAA §182(c)(2)(A)
and 40 CFR
§51.1308
Chapter 8 (IX D.11)
Reasonable
Available Control
Technology
(RACT)
Evaluation of the application of
reasonable control technology
(technically and economically
feasible) at major sources.
CAA §182(b)(2)
and 40 CFR
§51.1312
Chapter 4 (IX D.11)
Reasonable
Available Control
Measure (RACM)
Evaluation of application of RACM for
all other sources of ozone precursors.
CAA §182(b)(2)
and 40 CFR
§51.1312
Chapter 5 (IX D.11)
Motor Vehicle
Inspection and
Maintenance
(I/M) Program
Evaluate if current I/M program
meets CAA requirements. CAA §182(b)(4) Chapter 6 (IX D.11)
Nonattainment
New Source
Review (NNSR)
Program
General offsets for VOCs shall be a
ratio of at least 1.15 to 1.0.
CAA §182(b)(5)
and 40 CFR
§51.1314
Chapter 4 (IX D.11)
Contingency
Measures
Emission reduction measure triggered
if the NAA fails to attain the standard
by the attainment date.
CAA §182(c)(9) Chapter 11 (IX D.11)

UTAH DIVISION OF AIR QUALITY
17

Motor Vehicle
Emission Budgets
Establishment of maximum allowable
emissions from on-road mobile sector
for ozone precursor emissions used in
transportation conformity analysis.
CAA §182(c)(5) Chapter 10 (IX D.11)
1.7 Moderate Area SIP Development Process 1
UDAQ led the development of the moderate SIP and coordinated with the MPOs and EPA on the 2
development of the various SIP elements. Work began in September 2019 in anticipation of the 3
reclassification of the area from marginal to moderate status. Throughout the SIP development, public 4
stakeholder meetings were held to solicit comment and engagement from interested parties as detailed 5
in Chapter 10 of this SIP revision. The UDAQ holds regular bi-monthly meetings with both industry 6
representatives and environmental advocates. These meetings provide the opportunity to maintain 7
open dialogue and transparency in the development of a SIP with interested parties. Once aspects of the 8
SIP were developed to the point where they could be shared, UDAQ scheduled public outreach meetings 9
to present data and information to the public, and the public was provided with the opportunity to 10
comment or make suggestions. UDAQ also posted all documents related to the development of this SIP 11
revision, including all technical supporting documentation, to its public webpage20 as soon as they 12
became available. 13
14

20 https://deq.utah.gov/air-quality/northern-wasatch-front-moderate-ozone-sip-technical-support-documentation#supporting-tsd

UTAH DIVISION OF AIR QUALITY
18

Chapter 2 – NWF Monitoring Network 1
2.1 Monitoring Network 2
The UDAQ maintains a highly reliable, continuous near-surface ambient air monitoring network 3
that meets the requirements of 40 CFR Parts 50, 53, and 58.21 The 1970 CAA and subsequent 4
amendments provide the framework for an ambient air monitoring network that is designed to collect 5
data addressing five basic needs to: 6
7
1. Activate emergency control procedures that prevent or alleviate air pollution episodes. 8
2. Provide air pollution data to the public in a timely manner. 9
3. Judge compliance with and progress towards meeting ambient air quality standards. 10
4. Observe pollution trends throughout the region, including non-urban areas. 11
5. Provide a database for research evaluation of the following effects: urban, land-use, transportation 12
planning, development and evaluation of abatement strategies, and development and validation of 13
diffusion models. 14
15
The UDAQ collects monitoring data for five NAAQS criteria pollutants including: sulfur dioxide 16
(SO2), CO, ozone (O3), nitrogen dioxide (NO2) and particulate matter (PM10 and PM2.5). In addition, UDAQ 17
currently operates one continuous gas chromatograph for the collection and analysis of ozone precursor 18
data for the Photochemical Assessment Monitoring Station (PAMS) program. Each year, a network 19
review is performed by staff and the Annual Monitoring Network Plan is submitted as a separate 20
document to EPA Region 8 for approval. In addition, Utah has established a comprehensive 21
meteorological monitoring network to supply data for modeling activities, including measurements of 22
temperature, relative humidity, wind speed, and wind direction. 23
As part of the air monitoring network, the UDAQ specifically operates an extensive network of 24
ground level in-situ ambient air quality monitoring stations throughout the NWF NAA. The network 25
consists of eight active sites that monitor atmospheric concentrations of ozone that are used for 26
regulatory purposes, as well as two historic sites which help provide context for the extent and length of 27
UDAQs monitoring network (Figure 2). Beyond the UDAQ operated network of sites, there are several 28
research grade ozone monitoring stations within the NAA boundary that are supported by UDAQ 29
including: The Red Butte Ozone Monitoring Network, the mobile based TRAX Air Quality Observation 30
Project platform and the Mobile Electric Bus Air Quality Monitoring Project. While these projects are not 31
regulatory and are not included in the EPA’s Air Quality System and determination of a DV for the NAA, 32
they significantly contribute to the understanding of transport, production, and the spatiotemporal 33
patterns of ozone throughout the NAA. 34

21 Title 40 Protection of the Environment, Chapter 1 Environmental Protection Agency, Subchapter C Air Programs, Part 50 National Primary and Secondary Ambient
Air Quality Standards, Part 53 Ambient Air Monitoring Reference and Equivalent Methods and Part 58 Ambient Air Quality Surveillance.

UTAH DIVISION OF AIR QUALITY
19

1
Figure 2: Monitoring sites in the NWF NAA 2
The UDAQ currently operates one PAMS site at Hawthorne, located in Salt Lake County. The PAMS 3
program is a subset of the State or Local Air Monitoring Stations (SLAMS) network for enhanced 4
monitoring of ozone precursor chemicals at sites located in an area with a population over 1,000,000 5
and in areas of moderate and above nonattainment status. The PAMS program is designed with the 6
objective to produce an air quality database to be used to evaluate and refine ozone prediction models. 7
In addition, the program will assist to identify and quantify the ozone precursors and establish the 8
temporal patterns and associated meteorological conditions to assist and refine the control strategies. 9
UDAQ is measuring the following parameters at the PAMS required site: 10
 Carbonyls 11
 Meteorological parameters: ambient temperature, wind direction, wind speed, atmospheric 12
pressure, relative humidity, precipitation, mixing layer height, solar radiation, and UV radiation 13
 Speciated VOCs 14
 True NO2 15
 NO & NOy 16
 Ozone 17

UTAH DIVISION OF AIR QUALITY
20

Since significant portions of the NWF NAA overlap with the Salt Lake City PM2.5 NAA, the UDAQ 1
operates the PAMS site for the full calendar year to account for both wintertime PM2.5 and summertime 2
ozone seasons. 3
In order to meet the Enhanced Monitoring Plan (EMP) requirements for a moderate NAA the UDAQ 4
is developing an EMP in fulfillment of federal regulations, 40 CFR Part 58, Appendix D 5(h). These 5
regulations require that a state with any area designated moderate or above for the 8-hour ozone 6
standard, and any state within the Ozone Transport Region (OTR), develop, implement, and submit an 7
EMP for ozone to the regional EPA office two years following the effective date of a designation to a 8
classification of moderate or above. The EMP is intended to provide monitoring organizations the 9
flexibility to implement any additional monitoring beyond the minimum requirements for the SLAMS to 10
complement the needs of their area. 11
As part of UDAQ’s proposed EMP, UDAQ plans to expand PAMS monitoring beyond the existing site 12
at Hawthorne to include 5 additional sites throughout the NWF NAA. These sites will represent an array 13
of land use types and will be distributed to provide insight into the underlying atmospheric chemical 14
regimes present at a variety of locations. 15
2.2 Ozone Monitoring Data 16
Table 4 and Table 5 show the monitoring data for the past twelve years for the NWF ozone 17
monitoring sites. The MDA8, and the 3-year averages of the MDA8 at each site are shown, respectively. 18
A trend graph of data from 2002 – 2021 for the key sites in the NWF is presented in Figure 3. 19
20
Table 4: NWF MDA8 reported in ppm. 21
NWF NAA Ozone MDA8 (ppm)
Site ID AQS # 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Bountiful BV 49-011-
0004
0.074 0.068 0.067 0.062* 0.074 0.073* 0.076 0.078 0.080 0.073 0.080 0.082
Copperview CV 49-035-
2005
--- --- --- --- --- --- --- --- 0.079* 0.067 0.075 0.086
Hawthorne HW 49-035-
3006
0.073 0.075 0.078 0.077 0.072 0.081 0.074 0.081 0.074 0.073 0.075 0.081
Rose Park RP 49-035-
3010
--- --- --- --- --- --- --- --- 0.080 0.071 0.080 0.079
Herriman H3 49-035-
3013
--- --- --- --- --- 0.074 0.076 0.078 0.078 0.070 0.073 0.087
Lake Park LP 49-035-
3014
--- --- --- --- --- --- --- --- --- --- 0.062* 0.082
Tech Center UT 49-035-
3015
--- --- --- --- --- --- --- --- --- 0.038* 0.071* 0.083
Near Road NR 49-035-
4002
--- --- --- --- --- --- --- --- --- 0.064 0.072 0.083
Tooele #3 T3 49-045-
0003
0.074 0.071 0.074 0.072 0.069 --- --- --- --- --- --- ---
Erda ED 49-045-
0004
--- --- --- --- --- 0.071* 0.072 0.077 0.074 0.065 0.070 0.075
Harrisville HV 49-057-
1003
0.070 0.074 0.076 0.073 0.070 0.074 0.073 0.073 0.077 0.064 0.074 0.077
Ogden O2 49-057-
0002
0.073 0.074 0.066 0.076 0.070 0.072 0.072 0.075 0.079 0.059* --- ---
* Indicates numbers that do not meet the data completeness requirements
22

UTAH DIVISION OF AIR QUALITY
21

Table 5: NWF 8-Hour Ozone Three-Year Average 4th Maximum Ozone Values. 1
3-yr. Average MDA8 (ppm)
Site ID AQS
#
2010-
2012
2011-
2013
2012-
2014
2013-
2015
2014-
2016
2015-
2017
2016-
2018
2017-
2019
2018-
2020
2019-
2021
Bountiful BV 49-011-
0004 0.069 0.065* 0.067* 0.069* 0.074* 0.075* 0.078 0.077 0.077 0.078
Copperview CV 49-035-
2005 --- --- --- --- --- --- 0.079* 0.073* 0.073* 0.076*
Hawthorne HW 49-035-
3006 0.075* 0.076 0.075 0.076 0.075 0.078 0.076* 0.076 0.074 0.076
Rose Park RP 49-035-
3010 --- --- --- --- --- --- 0.08* 0.075* 0.077* 0.076*
Herriman H3 49-035-
3013 --- --- --- 0.074 0.075 0.076 0.077 0.075 0.073 0.076
Lake Park LP 49-035-
3014 --- --- --- --- --- --- --- --- --- ---
Tech Center UT 49-035-
3015 --- --- --- --- --- --- --- --- --- 0.064*
Near Road NR 49-035-
4002 --- --- --- --- --- --- --- --- --- 0.073*
Tooele #3 T3 49-045-
0003 0.073 0.072 0.071 0.07 --- --- --- --- --- ---
Erda ED 49-045-
0004 --- --- --- 0.071* 0.071* 0.073* 0.074 0.072 0.069 0.07
Harrisville HV 49-057-
1003 0.073 0.074 0.073 0.072 0.072 0.073 0.074 0.071 0.071 0.071
Ogden O2 49-057-
0002 0.071 0.072 0.07 0.072 0.071 0.073 0.075 0.071* --- ---
* Indicates numbers that do not meet the data completeness requirements
2
3

UTAH DIVISION OF AIR QUALITY
22

1
Figure 3: MDA8 in Wasatch Front 2
As shown in Figure 3, the combined state air agency and federal regulatory actions have been 3
successful at reducing ozone values in the NWF. However, the area is still experiencing exceedances of 4
the ozone standard at all regulatory air monitors within the NAA. Ozone represents a unique challenge 5
in the Intermountain West. Despite years of success in reducing precursor emissions of NOX and VOCs, 6
the region still faces significant and unique challenges in meeting ambient ozone concentration health-7
based standards. These regionally specific challenges include significantly elevated background ozone 8
levels,22 increasing instances and contributions of emissions from wildfire events,23 significant biogenic 9
contributions,24 as well as both interstate and international25 transport. 10
2.3 Data Quality Assurance 11
The primary purpose of UDAQ’s ambient air monitoring network is to determine whether the 12
area is meeting the criteria pollutant NAAQS. Other purposes for air monitoring include, but are not 13
limited to, determining the impact of sources on air quality, establishing background concentrations, 14
and determining the extent of regional ozone transport. The goal of UDAQ’s Air Monitoring Section is to 15

22 Scientific Assessment of background ozone over the U.S.: Implications for air quality management
23 Influence of Fires on O3 Concentrations in the Western U.S.; Dan Jaffe, Duli Chand, Will Hafner, Anthony Westerling, and Dominick Spracklen; Environmental
Science & Technology 2008 42 (16), 5885-5891. DOI: 10.1021/es800084k
24 EPA Webinar; Description and preliminary evaluation of BELD 6 and BEIS 4. ORD. Jesse O. Bash and Jeff Vukovich
25 Entrainment of stratospheric air and Asian pollution by the convective boundary layer in the southwestern U.S.; Langford, A.O. et al. (2017), J. Geophysics. Res.
Atmos., 122, 1312-1337, doi:10.1002/2016JD025987

UTAH DIVISION OF AIR QUALITY
23

produce data that are complete, comparable, representative, precise, and accurate in accordance with 1
40 CFR Part 58, Appendix A. Data quality is calculated at least annually according to EPA’s accepted 2
statistical procedures to determine compliance with the recommended limits. Data outside these limits 3
are still reported to Air Quality System (AQS), but UDAQ flags the data internally and attempts to 4
determine the source of the problems. The UDAQ Air Monitoring Quality Assurance Program Plan 5
provides details of how UDAQ meets the requirements of 40 CFR Part 58, Appendix A and is made 6
available to the public for review.26 7
Table 6 shows the data recovery rates for each monitoring site in the NWF NAA as a percentage. 8
The percent of data recovery is the number of valid sampling hours occurring within the ozone season 9
divided by the total number of hours encompassing the ozone season. The ozone season for Utah was 10
defined as from January 1 to December 31, thus is year-round.27 A valid sampling day is one in which at 11
least 75% of the hourly averages are recorded. 12
13
Table 6: NWF Ozone Data Recovery Rates shown as percentages. 14
Site 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Bountiful
49-011-0004
99% 97% 98% 64% 99% 53% 100% 99% 99% 98% 99% 99%
Copperview
49-035-2005
--- --- --- --- --- --- --- --- 96% 93% 98% 97%
Hawthorne
49-035-3006
99% 97% 98% 64% 99% 53% 100% 99% 99% 98% 99% 96%
Rose Park
49-035-3010
--- --- --- --- --- --- --- --- 87% 80% 98% 99%
Herriman
49-035-3013
--- --- --- --- --- 100% 98% 98% 97% 99% 99% 98%
Lake Park
49-035-3014
--- --- --- --- --- --- --- --- --- --- 99% 98%
Tech Center
49-035-3015
--- --- --- --- --- --- --- --- --- 99% 99% 98%
Near Road --- --- --- --- --- --- --- --- --- 99% 98% 99%
Tooele
49-045-0003
64% 98% 99% 100% 99% 100% 83% 83% 97% 99% 92% ---
Erda
49-045-0004
--- --- --- --- --- 61% 100% 99% 93% 97% 99% 99%
Harrisville
49-057-1003
83% 99% 98% 99% 100% 96% 99% 89% 99% 82% 98% 96%
Ogden
49-057-0002
98% 94% 96% 99% 100% 100% 99% 99% 99% 99% --- ---
15
As shown in Table 6, the UDAQ monitoring program is extremely robust with a consistently high 16
level of data recovery. On an annual basis, the monitoring network is evaluated, assessed, and adjusted 17
as necessary to ensure that the agency and the public have an accurate understanding of local air quality 18

26 https://documents.deq.utah.gov/air-quality/planning/air-monitoring/DAQ-2022-007189.pdf
27 83 FR 25776

UTAH DIVISION OF AIR QUALITY
24

concentrations and trends. What these monitoring values represent and how they are impacted will be 1
evaluated and discussed in other SIP chapters. 2
3
4

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25

Chapter 3 - Baseline and Future Year Emission Inventories 1
3.1 Emission Inventory Background 2
3.1.1 2017 Base Year Inventory 3
In accordance with the CAA and 40 CFR §51.1315, when the NWF was designated as a marginal 4
ozone NAA, the UDAQ was required to submit a base year emission inventory 24 months after the 5
effective date of designation. A base year inventory is comprised of a comprehensive, accurate, current 6
inventory of actual emissions from sources of VOCs and NOX emitted within the boundaries of the NAA 7
as required by CAA Section 182(a)(1). The base year for this SIP submittal is 2017, which is the most 8
recent calendar year for which a complete triennial inventory was submitted to the EPA. The inventory 9
is compiled in ozone season day emissions, which is an average day’s emissions for a typical ozone 10
season work weekday. This requirement was met and approved by EPA in 86 FR 35404, on July 6, 2021. 11
As a result of being reclassified as a moderate ozone NAA, the 2017 base year inventory is being 12
resubmitted as part of this NWF moderate SIP as some refinements have been made since the submittal 13
of the marginal base year inventory. The methodology for each inventory source category will be 14
provided in this chapter, with a more detailed description provided in the technical support document 15
(TSD) for this SIP. 16
3.1.2 2023 Projected Year Inventory 17
To support the CAA requirement for a moderate NAA to demonstrate RFP towards attainment, 18
UDAQ has developed a projected emission inventory for 2023 based on the base year inventory 19
described in Section 3.1.1. 2023 is the year prior to the required attainment date of August 3, 2024, thus 20
the state is required to demonstrate a 15% reduction in VOCs between 2017 and 2023 in accordance 21
with 40 CFR § 51.1310. The emission inventory presented here represents the projected inventory for 22
sources with no additional emission controls implemented beyond actions taken under the PM2.5 SIPs. A 23
discussion of proposed or potential emission controls and how they will help achieve the required VOC 24
reductions and demonstration of attainment will be discussed in Chapter 7, RFP. This chapter provides 25
the methodology and results of developing the baseline and future year inventories in accordance with 26
available EPA guidance.28 27
3.2 Baseline 2017 Emission Inventory and Projected 2023 Emission Inventory 28
Both inventories developed for the SIP are reported as an average day’s emissions for a typical 29
ozone season work weekday, in the unit of tons per day (tpd). This is an average summer day for the 30
NWF. The 2017 inventory of actual emissions is the basis for any projections made to represent future 31
years. Emission inventories are generally collected and reported as annual emissions. These annual 32
inventories are processed through the Sparse Matrix Operating Kernel Emissions Model (SMOKE).29 33
SMOKE modeling spatially allocates, temporalizes, and chemically speciates annual emissions 34
estimations from the emissions inventories. Post-SMOKE, annual emissions are temporalized and can be 35
represented in tons per day. Spatial allocation, temporalization, and chemical speciation are SCC-specific 36
operations. UDAQ typically tabulates emissions from area and mobile sources on a county-by-county 37

28 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf
29 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf

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26

basis, however the NAA includes two partial counties. To obtain the typical ozone season day, emission 1
inventories are entered into the SMOKE model such that it is assigned a geographic location (grid cell). 2
To report emissions specific to the NAA, UDAQ cropped the post-SMOKE processed gridded emissions 3
using a Geographic Information System (GIS) tool using polygons representing the boundaries of the 4
NAA. 5
An inventory of emissions was developed for the major source categories as presented in Table 6
7 for the 2017 emission inventory. Residential wood combustion is excluded as this source is not a 7
significant emitter of ozone precursors when compared to more predominant sources in the NAA and is 8
not seasonally relevant to summertime ozone production in the NWF. More detailed post-SMOKE 9
emissions inventory tables can be found in the SMOKE TSD.30 10
11
Table 7: 2017 Nonattainment Emission Inventory (tons per day) 12
NWF NAA 2017 base year
Sector NOx TPD VOC TPD
Solvents 0.56 43.20
Area (non-point) 5.36 8.51
Livestock

0.69
Non-road 10.52 12.53
Rail 9.25 0.47
Airports 3.14 1.25
Electric Generating Units (EGUs) 0.44 0.03
Point Sources 20.43 5.85
On-road Mobile 55.53 20.47
ERC Bank 3.1 0.7
TOTAL ANTHROPOGENIC 108.33 93.7
13
The projection year emissions inventory was prepared for 2023 as this is the year prior to the 14
attainment date of August 3, 2024. The emission projections reflect changes due to growth and existing 15
controls. The 2023 emission inventories presented here do not account for controls put in place 16
specifically from actions taken for this SIP. 17
18

30 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf

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27

Table 8: 2023 Projected Nonattainment Emission Inventory (tpd) 1
NWF NAA 2023 future year
Sector NOX TPD VOC TPD
Solvents 0.71 44.52
Area (non-point) 4.85 8.26
Livestock

0.71
Non-road 8.05 12.62
Rail 8.77 0.44
Airports 3.74 1.42
Electric Generating Units (EGUs) 0.45 0.03
Point Sources 22.00 6.00
On-road Mobile 35.40 15.32
ERC Bank 3.1 0.7
TOTAL ANTHROPOGENIC 87.07 90.02
3.2.1 Fires and Biogenic Sources 2
Emissions from wildland and prescribed fires, and biogenic sources, which are dependent on 3
meteorological conditions, are accounted for during the modeling phase and are not traditionally 4
inventoried.31 Emissions from wildfires are accounted for using the Blue-Sky Framework in the SMOKE 5
model. Biogenic emissions are modeled with the Biogenic Emissions Inventory System (BEIS) version 6
3.6.1. BEIS creates gridded, hourly, model-species emissions from vegetation and soils. Forests are 7
significant sources of VOCs, and the burning of forest material is a source of ozone precursors and 8
particulate matter. These source categories are crucial to include in any ozone modeling demonstration. 9
The emissions from biogenic sources are shown in Table 9 and are held constant between 2017 and 10
2023. 11
12
Table 9: Biogenic Emissions (tons per day) 13
NWF NAA COUNTIES (includes all of Tooele and Weber Counties) 2017 base year
Sector NO TPD VOC TPD
TOTAL NAA COUNTY-WIDE BIOGENIC 5.57 246.88
3.2.2 Solvent Emissions 14
The solvents sector includes VOC emissions from everyday items such as cleaners, personal care 15
products, adhesives, architectural and aerosol coatings, printing inks, asphalt, and pesticides. Emissions 16
estimates were sourced from EPA’s 2016v2 platform, which were generated with the VCPy framework. 17
EPA’s 2017 platform predates EPA’s 2016v2 platform, and it does not include emissions from solvents 18
according to the VCPy framework. The VCPy framework features better VOC emissions estimates than 19
previous platforms, thus UDAQ made every effort to include improved emissions in the solvents 20
inventory.32 Since EPA’s 2016 modeling base year did not align with the NWF SIP 2017 base year, the 21
inventory was projected to 2017. The only relation expected to change between 2016 and 2017 base 22
years is the mass of chemical products used. To determine a change in product used, UDAQ evaluated 23

31 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf
32 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf

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28

the average Producer Price Index (PPI) across the summer months represented during our modeling 1
episode: June, July, and August. In 2016, the average summer PPI for all commodities was 187.3. In 2017 2
the PPI was 193.6. This shows a 3% increase in PPI from 2016 to 2017, so all solvents emissions from the 3
2016v2 platform VCPy inventory were increased by 3% to produce the 2017 base year VCPy inventory 4
used in this modeling demonstration. The 2016v2 platform includes projected emissions inventories for 5
2023 that were utilized by UDAQ. Table 10 and Table 11 provide the 2017 baseline inventory for 6
solvents and the projected 2023 inventory respectively. 7
Emissions from hot mix asphalt (HMA) plants are submitted as point source inventories, 8
however, all HMA plants in the NAA have 2017 NOx and/or VOC emissions less than 100 tons per year 9
(tpy). Point sources with NOx and/or VOC emissions less than 100 tpy are assumed to be represented in 10
nonpoint sectors, but emissions from asphalt plants are technically not represented in the solvents or 11
nonpoint sectors. To accommodate planned rulemaking, UDAQ added emissions from HMA plants to 12
the solvents sector. It is important to note that the emissions associated with HMA facilities discussed in 13
this section represent UDAQ’s best assumptions for actual annual emissions associated with the 14
production of HMA products based on known metrics like annual production. Elsewhere in this SIP 15
revision emissions may be reported based on the combined potential to emit based on permitted 16
maximums from all HMA facilities, and thus represent the upper bounds of potential emissions from 17
HMA facilities. 18
19
Table 10: Solvent Emissions Inventory 20
NWF NAA 2017 base year
Sector NOX TPD VOC TPD
Solvents 0.56 43.20
Consumer Products - 18.23
HMA plants 0.56 0.06
Other Solvents - 24.91
21
Table 11: 2023 Solvent Emissions Inventory 22
NWF NAA 2023 future year
Sector NOX TPD VOC TPD
Solvents 0.71 44.52
Consumer Products - 18.80
HMA plants 0.71 0.11
Other Solvents - 25.62
3.2.3 Area Sources 23
Nonpoint (area) sources are typically smaller, yet pervasive sources that do not qualify as point 24
sources under the relevant emissions cutoffs. Area sources encompass more widespread sources that 25
may be abundant, but that, individually, release small amounts of a given pollutant. These are sources 26
for which emissions are estimated as a group rather than individually. Examples typically include 27
residential heating and residential charcoal grilling. Area sources generally are not required to submit 28
individual emissions estimates, and instead are reported as county totals. 29
Area source calculation methods are consistent with Utah’s methods for reporting the EPA’s tri-30
annual National Emissions Inventory. Area source emissions are calculated based on activity data, which 31

UTAH DIVISION OF AIR QUALITY
29

is gathered from sources such as Departments of Transportation, State Tax Commissions, State Data 1
Centers, State Offices of Planning and Budget, State Energy Commissions, federal agencies such as the 2
U.S. Census Bureau, county and local government agencies, airports, natural gas suppliers, and local 3
trade associations. These data include population, employment, vehicle miles traveled (VMT), fuel 4
usage, animal, crop, and other estimates. Area source calculations are often based on combining these 5
activity data with emission factors. Emission factors were also gathered from similar sources, mostly EPA 6
documents. Area sources were adjusted for potential overlaps and double counts with point sources.33 7
Emission projections for 2023 were based on 2017 data and projected forward. Projection 8
methods were consistent with methods used in past Utah SIPs. Emission projections were based on 9
activity data, similar to their baseline estimates. Depending on the specific source, emissions were 10
projected to scale with population, manufacturing, agricultural, employment data, Energy Information 11
Agency energy use projections, VMT, and other similar data sources. 12
Livestock emissions were calculated using EPA generated emission factors for livestock animals 13
and multiplying them by the respective livestock populations for each county. Future emissions were 14
forecast using a linear regression model to predict future year livestock emissions as based on 15
agricultural employment. 16
17
Table 12: 2017 Area Source Emission Inventory 18
NWF NAA 2017 base year
Sector NOX TPD VOC TPD
Livestock - 0.69
Nonpoint 5.36 8.51
2 - 5 MMBTU boilers 0.91 0.05
Other Nonpoint Sources 4.45 8.46
19
Table 13: Area Source Emission Inventory 20
NWF NAA 2023 future year
Sector NOX TPD VOC TPD
Livestock - 0.71
Nonpoint 4.85 8.26
2 - 5 MMBTU boilers 0.87 0.05
Other Nonpoint Sources 3.99 8.21
3.2.4 Non-Road, Rail, and Airport Sources 21
EPA’s Motor Vehicle Emission Simulator (MOVES3) model was used to obtain emission 22
inventories for non-road mobile vehicles and equipment that operate on unpaved roads and other areas 23
but not on paved roads.34 They include non-road engines and equipment, such as lawn and garden 24
equipment, construction equipment, engines used in recreational activities, portable industrial, 25
commercial, and agricultural engines. Emissions from MOVES3 for the month of July are input to SMOKE 26
to obtain the typical ozone season day value. 27

33 Area Source Inventories; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001348.pdf
34 2017 BASELINE, EPISODIC AND 2023 PROJECTION OZONE EMISSIONS INVENTORY NON-ROAD MOBILE SOURCE; https://documents.deq.utah.gov/air-
quality/planning/DAQ-2023-001585.pdf

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30

Emissions from snow blowers and snowmobiles have been removed from the non-road sector, 1
assuming that these emissions are zero during the summertime modeling episode. Emissions from 2
pleasure craft (personal watercraft and recreational boats with outboard or inboard/sterndrive motors) 3
are allocated to counties according to the number of watercraft registrations in each county. However, 4
along the Wasatch Front, personal watercraft is not operated in the county of residence. Bodies of 5
water on which pleasure craft may be operated exist in mainly rural counties beyond the urban corridor 6
of the Wasatch Front. Assuming that pleasure craft owners transport their recreational vehicles to use 7
them, UDAQ removes any pleasure craft emissions from Salt Lake, Davis, Weber, and Tooele counties. 8
These four counties do not include any bodies of water on which pleasure craft may be operated. 35 9
Emissions in the airports sector include all emissions from aircraft and associated ground 10
support equipment. UDAQ’s platform base year airport emissions are sourced from EPA’s 2017 platform 11
within Utah, and from EPA’s 2016v2 platform outside Utah. All future year 2023 emissions were copied 12
from EPA’s 2016v2 platform future year emissions inventories (2023). Rail emissions within the state of 13
Utah include all locomotives, railway maintenance locomotives, and point source yard locomotives.36 14
15
Table 14: Non-Road, Rail and Airports Emission Inventory 16
NWF NAA 2017 base year
Sector NOx TPD VOC TPD
Non-road 10.52 12.53
2-stoke Lawn/garden Equipment 0.11 3.33
Other Lawn/garden Equipment 1.48 4.35
Other Non-road Sources 8.94 4.86
Rail 9.25 0.47
Airports 3.14 1.25
17
Table 15: 2023 Non-Road, Rail and Airports Emission Inventory 18
NWF NAA 2023 future year
Sector NOx TPD VOC TPD
Non-road 8.05 12.62
2-stoke Lawn/garden Equipment 0.12 3.63
Other Lawn/garden Equipment 1.46 4.42
Other Non-road Sources 6.47 4.57
Rail 8.77 0.44
Airports 3.74 1.42
3.2.5 Point Sources and Electric Generating Units (EGUs) 19
The definition of a Type B Source under Title V of the CAA (as specified in 40 CFR Appendix A to 20
Subpart A of Part 51) includes point source thresholds in the NAA. This definition includes all facilities 21
with the potential to emit 100 tpy or more of VOC or NOX. Emissions from sources under the Type B 22
thresholds are included in the area source baseline inventory, as they do not have large enough 23

35 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf
36 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf

UTAH DIVISION OF AIR QUALITY
31

potential emissions to qualify for the point source inventory. According to the Type B Source definition, 1
Utah had 53 major point sources of NOx and VOC in 2017, 12 of which are located in the NWF NAA. 2
UDAQ has improved emissions inventory data management with the implementation of the 3
State and Local Emissions Inventory System (SLEIS). This system has established an online emissions 4
inventory system, whereby point sources can submit their air emissions inventories to UDAQ. SLEIS 5
includes built-in calculation capabilities which simplify the process and reduce the workload for point 6
sources. SLEIS also contains extensive Quality Assurance and Quality Control (QA/QC) tools which guide 7
point sources as they submit their data, thereby greatly reducing oversight required by UDAQ staff. The 8
2017 triannual emissions inventory was submitted to UDAQ by point sources using the SLEIS online 9
system. The submitted emissions inventories were thoroughly reviewed using additional QA/QC by 10
UDAQ staff before being finalized. The QA/QC contained in the SLEIS online system along with the 11
review performed by UDAQ staff greatly surpasses EPA guidance requiring 10% QA/QC as the minimum 12
criteria necessary for a SIP inventory. 13
The 2017-point source emissions inventory was used for the baseline emissions inventory for 14
the SIP.37 Point source emissions were represented as the actual emissions from the 2017 triannual 15
emissions inventory which coincides with the most recent triannual inventory that has been compiled 16
and reviewed by UDAQ. 17
Point source emissions, as based on annual actual emissions, in the NAA and affecting the NWF 18
NAA was grown on a case-by-case basis for each source and represented in the ozone SIP workbooks for 19
2023. Emission estimates were projected to future years and to display any control technologies that 20
will be applied. Data from Kem C. Gardner Policy Institute County Projections were used for developing 21
projected emissions for all major point sources. 38 More information on how the Kem C. Gardner data 22
was used is found on page 3 of the 2023 Point Source TSD. 23
Point source operators provided a monthly percentage of annual emissions from January to 24
December as part of their emissions inventory submission, which was used to generate source-specific 25
monthly temporal profiles in SMOKE for point sources in Utah’s emissions inventory. Emissions 26
summaries are provided on a per-facility basis in the SMOKE TSD.39 27
28
29
Table 16: 2017 Point Sources and EGUs Emission Inventory 30
NWF NAA 2017 base year
Sector NOx TPD VOC TPD
EGUs 0.44 0.03
Point Sources 20.43 5.85
5+ MMBTU boilers 1.90 0.12
Other Point Sources 18.52 5.74
31
32
33
34

37 Base Year Ozone SIP Point Source Inventory; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001356.pdf
38 Projected Ozone SIP Point Source Inventory; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001361.pdf
39 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf

UTAH DIVISION OF AIR QUALITY
32

Table 17: 2023 Point Sources and EGUs Emission Inventory 1
NWF NAA 2023 future year
Sector NOx TPD VOC TPD
EGUs 0.45 0.03
Point Sources 22.00 6.00
5+ MMBTU boilers 1.48 0.14
Other Point Sources 20.52 5.86
3.2.6 On-Road Mobile 2
On-road mobile source emissions include vehicles that travel on paved roads that produce 3
exhaust, evaporative, and road dust emissions. The on-road mobile inventory was compiled using Motor 4
Vehicle Emissions Simulator (MOVES3) according to the document “MOVES3 Technical Guidance: Using 5
MOVES to Prepare Emissions Inventories for SIPs and Transportation Conformity” November 2020. The 6
baseline year and projection year inventories was compiled through the ICT. The interagency 7
consultation team is primarily used to discuss and decide what MOVES modeling inputs should be used 8
with the SIP modeling domain. The ICT includes representatives from EPA, Federal Highway 9
Administration (FHWA), Federal Transit Authority, Utah Department of Transportation, Utah Transit 10
Authority, Wasatch Front Regional Council (WFRC), Mountainland Association of Governments (MAG), 11
Cache MPO, and UDAQ.40 12
On-road mobile source baseline and projection emission inventories are prepared for an 13
average ozone season weekday based on average hourly temperatures and relative humidity from 2017 14
July data. VMT were reported as an average ozone season day weekday. 15
16
17
Table 18: 2017 On-road emission inventory for ozone weekday 18
NWF NAA 2017 base year
Sector NOx TPD VOC TPD
On-road Mobile 55.53 20.47
Heavy Duty Vehicles 27.21 3.65
Light Duty Vehicles 28.32 16.82
19
Table 19: 2023 On-road emission inventory for ozone weekday 20
NWF NAA 2023 future year
Sector NOx TPD VOC TPD
On-road Mobile 35.40 15.32
Heavy Duty Vehicles 23.41 2.74
Light Duty Vehicles 11.98 12.58

40 2017 THE NORTHERN WASATCH FRONT, UT NONATTAINMENT OZONE AREA SUMMER BASELINE OZONE INVENTORY ON-ROAD TECHNICAL SUPPORT
DOCUMENTATION; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001725.pdf & 2023 NORTHERN WASATCH FRONT, UT NONATTAINMENT
OZONE AREA SUMMER PROJECTION OZONE INVENTORY ON-ROAD TECHNICAL SUPPORT DOCUMENT; https://documents.deq.utah.gov/air-quality/planning/DAQ-
2023-001699.pdf

UTAH DIVISION OF AIR QUALITY
33

3.2.7 Emission Reduction Credit Bank 1
The NAA has Emission Reduction Credit Bank (ERC) from past ozone SIP revisions that include 2
NOx and VOC credits available. Emission credit banks for VOCs and NOx were reviewed for the four NAA 3
counties. All banked credits were reviewed for validity concerning applicable emission credits meeting 4
2017 RACT or better for controlled or reduced emissions. Upon review, the majority of credits were 5
awarded as a result of a unit or facility closure or decommissioning. Credits are valid and remained in 6
the bank if the applicable change was RACT or better. These credits are available in the ERC offset bank 7
moving forward and were included in the ERC portion of both the baseline and projected year 8
inventories to represent all potential emissions within the NAA boundary.41 9
10
Table 20: 2017 ERC Bank Emission Inventory 11
NWF NAA 2017 base year
Sector NOx TPD VOC TPD
ERC Bank 3.10 0.70
12
Table 21: 2023 ERC Bank Emission Inventory 13
NWF NAA 2023 future year
Sector NOx TPD VOC TPD
ERC Bank 3.10 0.70
14
15

41 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf

UTAH DIVISION OF AIR QUALITY
34

Chapter 4 – Reasonably Available Control Technology (RACT) Analysis 1
and Nonattainment New Source Review (NNSR) 2
4.1 Reasonably Available Control Technology (RACT) Overview 3
Under the CAA 182(b)(2), all areas designated moderate nonattainment for the 2015 8-hour 4
ozone NAAQS are required to implement RACT for all existing major sources of VOCs or NOx that emit 5
100 tpy of either pollutant, as well as all VOC sources subject to an EPA Control Technique Guideline 6
(CTG). 7
CTGs are documents issued by the EPA to provide states with recommendations on how to 8
control VOC emissions from specific sources or products in an ozone NAA. When determining what is 9
RACT, in addition to existing CTGs and alternative control techniques (ACTs), states should consider, “all 10
relevant information (including recent technical information and information submitted by the public) 11
that is available at the time they develop the RACT SIPs.”42. “States may require VOC and NOX reductions 12
that are “beyond RACT" if such reductions are needed to provide for timely attainment of the ozone 13
NAAQS.”43 14
A RACT analysis identifies controls that could be implemented at the lowest emission limitation 15
that a source is capable of meeting by the application of a control technology that is reasonably 16
available, considering technological and economic feasibility.44 Implementation of controls identified 17
under the RACT process must be implemented by January 1, 2023, for emission reductions to be 18
creditable towards RFP requirements (section 7).45 A RACT analysis must include the latest information 19
when evaluating control technologies. Control technologies evaluated for a RACT analysis can range 20
from work practices to add-on controls. As part of the RACT analysis, current control technologies 21
already in use for VOCs or NOX sources can be taken into consideration. To conduct a RACT analysis, a 22
top-down analysis is used to rank all control technologies. 23
4.1.1 Top Down RACT Analysis Steps 24
For sources that meet or exceed the applicable emission thresholds, the following steps are 25
followed: 26
 Step 1. Identify all RACT options applicable to the source 27
 Step 2. Eliminate technically infeasible control technologies 28
 Step 3. Rank remaining control technologies based on capture and control efficiencies 29
 Step 4. Evaluate remaining control technologies based on economic, energy, and environmental 30
feasibility 31
 Step 5. Select RACT options 32

42 Implementation of the 2015 National Ambient Air Quality Standards for Ozone: NAA State Implementation Plan Requirements, 83 Fed. Reg. 62,998, 63,007 (Dec.
6, 2018).
43 Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements, 80 Fed. Reg. 12,264, 12,279 (March 6,
2015).
44 40 CFR § 51.1312 Requirements for reasonably available control technology (RACT) and reasonably available control measures (RACM).
45 87 Fed. Reg. 60,897.

UTAH DIVISION OF AIR QUALITY
35

All available control technologies must be included in a RACT analysis for all VOC and NOx 1
sources, with a thorough description and discussion of technological feasibility. Economic feasibility is 2
determined through Step 4 of a RACT analysis using EPA’s Air Pollution Control Cost Manual as 3
guidance.46 4
4.2 Utah RACT Process 5
The UDAQ relied on multiple available analyses when determining if sources within the NWF NAA 6
met RACT requirements, or if the implementation of additional RACT were required to demonstrate that 7
the NWF NAA will attain the standard at the earliest possible date. First, the UDAQ reviewed and 8
reconsidered control options submitted as part of the Salt Lake City, UT PM2.5 serious SIP, which 9
required the implementation of the more stringent Best Available Control Technologies (BACT) for both 10
NOx and VOCs.47 BACT relies on more restrictive emission control requirements than RACT, and thus 11
emission reduction strategies identified and implemented under BACT are more stringent than those 12
identified through the RACT process. Therefore, by reexamining past BACT analyses, the UDAQ relied on 13
a recently conducted analysis which implemented controls that conform to a higher economic and 14
technological standard. In doing so, the UDAQ is remaining consistent with guidance provided by the 15
EPA48, in which the EPA concludes that states may conclude a source has already addressed RACT based 16
on a RACT determination for a previous NAAQS SIP revision. For instance, the EPA proposes that in some 17
instances a RACT analysis submitted for the 1997 NAAQS are appropriate for meeting RACT 18
requirements for the 2008 NAAQS.49 In this example, states are granted the discretion to rely on a like-19
for-like RACT analysis with a substantial time laps between respective SIP revisions under each NAAQS. 20
For this SIP revision, the UDAQ reexamined the more stringent BACT analyses submitted with a shorter 21
time lapse than that provided in the example, with BACT reports being submitted just 4 to 5 years 22
earlier. 23
In addition to reexamining past BACT reports, the UDAQ identified three emission sources that were 24
not evaluated as part of the PM2.5 serious SIP. Those analyses were provided to UDAQ by Tesoro 25
Refining and Marketing Company LLC50, Holly Energy Partners Woods Cross Terminal51, and Chevron Salt 26
Lake Marketing Terminal52. These three RACT reports were later included in facility wide updated RACT 27
analyses by each of the respective sources and therefore were analyzed in multiple rounds of RACT 28
analysis conducted as part of this SIP revision. 29
Beyond the past PM2.5 BACT reports, and three additional RACT reports submitted for review, the 30
UDAQ notified sources that they could opt-in to submitting an updated facility wide RACT analysis for 31
consideration in this SIP revision. Subsequently, 9 sources within the NAA provided UDAQ with new 32
RACT analyses for emissions of both VOCs and NOx. The UDAQ reviewed all analyses submitted in 33

46 EPA’s Air Pollution Control Cost Manual can be found at: https://www.epa.gov/sites/default/files/2020-07/documents/c_allchs.pdf
47 Utah State Implementation Plan; Control Measures for Area and Point Sources, Fine Particulate Matter, Serious Area PM2.5 SIP for the Salt Lake City, Utah NAA;
Section IX. Part A.31: https://deq.utah.gov/air-quality/control-strategies-serious-area-pm2-5-sip
48 80 FR 12264 & 83 FR 62998
49 80 FR 12264 p.12278
50 The RACT analysis from the Tesoro Refinery and Marketing Company can be found at: https://documents.deq.utah.gov/air-quality/planning/air-quality-
policy/DAQ-2022-011275.pdf
51 The RACT analysis for the Holly Energy Partners Woods Cross Terminal can be found at: https://documents.deq.utah.gov/air-quality/planning/air-quality-
policy/DAQ-2022-011295.pdf
52 The RACT analysis for the Chevron Salt Lake Marketing Terminal can be found at: https://documents.deq.utah.gov/air-quality/planning/air-quality-policy/DAQ-
2022-011292.pdf

UTAH DIVISION OF AIR QUALITY
36

conjunction with past BACT reports, and where warranted, requested updated RACT reports with 1
additional or clarifying information. All RACT analyses, and all follow-up reports, were made available for 2
public review at the earliest possible date53. 3
UDAQ determined that one major source located outside the NWF NAA impacts the ability of the 4
NAA to attain the NAAQS, and as such was required to provide a RACT analysis to UDAQ. This source, US 5
Magnesium, its RACT analysis, and identified control options, will be discussed in detail in Section 4.15. 6
4.2.1 Actual Emissions and Potential to Emit (PTE) 7
Utah Administrative Rule R307-101; General Requirements, contains the definitions for the 8
terms “Actual Emissions”, “Potential to Emit”, and “Enforceable”. Thus, the actual emissions of a source 9
refers to the actual rate of emissions of an air pollutant from an emissions unit. Actual emissions are 10
calculated using the unit’s actual operating hours, production rates, and types of materials processed, 11
stored, or combusted during the selected time period. The actual emissions of a source can fluctuate 12
from year-to-year due to changes in a source’s year-to-year operations. 13
The PTE of a source means the estimated maximum capacity of a source to emit an air pollutant 14
under its physical and operational design. A source’s PTE is not an enforceable limitation in itself, but is 15
instead the maximum amount of air pollutants a source could emit if each emission unit operated at 16
100% of its design capacity, 24 hours a day, 365 days a year. Any physical or operational limitation on 17
the capacity of a source to emit an air pollutant, including air pollution control equipment and 18
operational or process restrictions or limitations, are treated as part of a source’s design if the limitation 19
is enforceable. 20
Enforceable limitations and conditions include requirements developed pursuant to 40 CFR 21
Parts 60 and 61, requirements within the Utah SIP and Utah Administrative Rule Series R307, and any 22
permit requirements established pursuant to Utah Administrative Rule R307-401; Permit: New and 23
Modified Sources. 24
4.3 Big West Oil LLC - Refinery 25
4.3.1 Introduction 26
This section specifically serves as an evaluation of Big West Oil LLC – Big West Oil Refinery (Big 27
West). The UDAQ relied on past submitted BACT reports and an additional RACT analysis submitted by 28
Big West for evaluation on January 31, 2023; specific sections from this analysis are referenced in the 29
RACT analysis. Specific ozone SIP conditions for Big West can be found in Section IX, Part H.32.a. 30
4.3.2 Facility Process Summary 31
The Big West Oil Refinery is a petroleum refinery capable of processing 30,000 barrels per day of 32
crude oil. The source consists of a specific type of Fluidized Catalytic Cracking Unit (FCCU), a Millisecond 33
Catalytic Cracker (MSCC); catalytic reforming unit; hydrotreating units; and a sulfur recovery unit. The 34
source also has an assortment of heaters, boilers, cooling towers, storage tanks, flares, and fugitive 35
emissions. 36

53 https://deq.utah.gov/air-quality/northern-wasatch-front-moderate-ozone-sip-technical-support-documentation#supporting-tsd

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37

4.3.3 Facility Baseline Actual Emissions and Current PTE 1
The baseline and current PTE from Big West processes and equipment are summarized in Table 2
22. The 2017 actual emissions were used as the baseline emissions. The current PTE values for Big West 3
were established by the most recent active Approval Orders (AOs) issued to the source. Big West 4
currently has several open AO modifications that will include updating their PTE to more accurately 5
reflect their operations. 6
 AO DAQE-AN101220077-22 issued January 13, 2022 (0077-22) 7
 AO DAQE-AN101220074-19 issued October 23, 2019 (0074-19) 8
 AO DAQE-AN101220072-19 issued July 10, 2019 (0072-19) 9
Table 22: Big West Oil LLC Refinery Facility-Wide Emissions 10
Big West Oil LLC Refinery Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 115.15 195.00
VOC 676.59 432.78
4.3.4 RACT Analysis 11
The RACT evaluations were performed using data from Big West Oil, AOs and supporting 12
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 13
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 14
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 15
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 16
NOx and VOCs are provided in Table 23. 17
18
Table 23: Big West Oil LLC - Refinery 19
Big West Oil LLC - Refinery
RACT
Section
#54
Emission
Unit/Activity
Pollutant RACT
Determination
Enforceability Comments
AO
Conditions
PM2.5 SIP
Conditions
3.1 FCCU
(MSCC)
Regenerator
NOx Low-NOx
regeneration
with low-NOx
promoter
catalyst -
meets MACT
Subpart UUU.
(0077-22)
II.B.3.b
H.12.b.ii &
H.12.b.vi
Current operations
meet RACT, no further
action warranted.
VOCs Good
combustion
practices, no
(0077-22)
I.5
No

54 https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001493.pdf

UTAH DIVISION OF AIR QUALITY
38

additional
controls.
3.2 -
3.4
Process
Heaters and
Boilers
NOx LNB & ULNB
required on
various units,
& refinery-
wide NOx limit.
(0077-22)
II.B.1.d &
II.B.8.d
H.12.b.ii &
H.12.b.vi
Current operations
meet RACT, no further
action warranted.
VOCs Good
combustion
practices, no
additional
controls.
(0077-22)
I.5
No
3.5 Refinery
Flares
NOx Evaluated
through
control of flare
gases, not
through
individual
pollutants,
requirement
to meet New
Source
Performance
Standards
(NSPS)
Subpart Ja and
MACT Subpart
CC for flares.
(0077-22)
II.B.4 &
II.B.7.c
H.11.g.v,
H.12.b.ii,
&
H.12.b.vi
Current operations
meet RACT, no further
action warranted.
VOCs
3.4 SRU NOx Existing tail
gas incinerator
& refinery-
wide NOx limit.
(0077-22)
II.B.8.d
H.12.b.ii &
H.12.b.vi
Current operations
meet RACT, no further
action warranted.
3.13 Cooling
Towers
VOCs MACT Subpart
CC
requirements
on cooling
towers
servicing high
VOC heat
exchangers.
(0077-22)
II.B.7.a
H.11.g.iii Current operations
meet RACT, no further
action warranted.
3.7 Fugitive
emissions
VOCs Low leak LDAR
requirements
of NSPS
Subpart GGGa.
(0077-22)
II.B.1.a &
II.B.7.b
H.11.g.iv Current operations
meet RACT, no further
action warranted.

UTAH DIVISION OF AIR QUALITY
39

3.10 &
3.11
Tanks VOCs Submerged fill
operations &
tank degassing
requirements -
eventual
compliance
with NSPS
Subpart Kb or
MACT Subpart
CC.
(0072-19)
II.B.1.a &
II.B.1.b
H.11.g.vi Current operations
meet RACT, no further
action warranted.
3.12 Wastewater
System
VOCs API separator
with fixed
cover, carbon
canisters for
VOC control,
90% removal
efficiency.
No H.12.b.vi Current operations
meet RACT, no further
action warranted.
3.6 Standby Fire
Pumps
VOCs Proper
maintenance
and operation,
and
compliance
with
applicable
NSPS or MACT
requirements.
(0074-19)
I.5
H.12.b.iv Current operations
meet RACT, no further
action warranted. NOx (0074-19)
II.B.1.c
3.8 Truck
Loading Rack
VOCs Vapor
recovery unit
with carbon
adsorption in
compliance
with MACT
Subpart CC.
(0077-22)
I.5
H.12.b.vi Current operations
meet RACT, no further
action warranted.
3.9 Railcar
Loading Rack
VOCs Vapor
recovery with
vapor
combustion
unit in
compliance
with MACT
Subpart R.
(0077-22)
I.5
H.12.b.vi Current operations
meet RACT, no further
action warranted.
N/A Refinery
General
Approach
NOx Refinery-wide
NOx limit.
(0077-22)
II.B.8.d
H.12.b.ii Current operations
meet RACT, no further
action warranted.

UTAH DIVISION OF AIR QUALITY
40

4.3.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emission limitations are considered RACT for the Big West Oil Refinery. RACT evaluations showed 3
that additional add-on controls or limitations are not technically or economically feasible options at this 4
time. No additional RACT measures were identified, and all RACT determinations are already being 5
implemented. Therefore, there are no additional implementation schedules or requirements for Big 6
West Oil Refinery as required by this SIP revision. 7
4.4 Chevron Products Company – Salt Lake Refinery 8
4.4.1 Introduction 9
This section specifically serves as an evaluation of Chevron Products Company – Salt Lake 10
Refinery (Chevron Refinery). In addition to its past submitted BACT reports, Chevron Refinery submitted 11
an additional RACT analysis for evaluation January 31, 2023, with supporting information submitted 12
February 23, 2023, and February 24, 2023; specific sections from this analysis are referenced in the 13
RACT analysis. Specific Ozone SIP conditions for Chevron Refinery can be found in Section IX, Part 14
H.32.b. 15
4.4.2 Facility Process Summary 16
The Chevron Refinery is a petroleum refinery with a nominal capacity of approximately 50,000 17
barrels per day of crude oil. The source consists of two FCCUs, a delayed coking unit, a catalytic 18
reforming unit, hydrotreating units, and two sulfur recovery units. The source also has an assortment of 19
heaters, boilers, cooling towers, storage tanks, flares, and fugitive emissions. The refinery operates with 20
a flare gas recovery system on its hydrocarbon flares. 21
4.4.3 Facility Baseline Actual Emissions and Current PTE 22
The baseline and current PTE from the Chevron Refinery processes and equipment are 23
summarized in Table 24. The 2017 baseline actual emissions were used as the baseline emissions. The 24
current PTE values for Chevron Refinery were established by the most recent active AOs issued to the 25
source. 26
 AO DAQE-AN101190106-22 issued August 24, 2022 (0106-22) 27
 AO DAQE-AN101190104-22 issued September 26, 2022 (0104-22) 28
Table 24: Chevron Products Company – Salt Lake Refinery Facility-Wide Emissions 29
Chevron Products Company – Salt Lake Refinery Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 265.50 766.50
VOC 339.60 1,242.06

UTAH DIVISION OF AIR QUALITY
41

1
4.4.4 RACT Analysis 2
The RACT evaluations were performed using data from Chevron Refinery, AOs and supporting 3
documentation, and Section IX, Utah SIP Parts H.11 and H.12. Various resources were evaluated to 4
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 5
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 6
regulations; and other state SIPs. The RACT determinations for each emission unit or activity emitting 7
NOx and VOCs are provided in Table 25. 8
9
Table 25: Chevron Products Company – Salt Lake Refinery 10
Chevron Products Company – Salt Lake Refinery
RACT
Section
#55
Emission
Unit /
Activity
Pollutant RACT
Determin
ation
Enforceability Comments
AO Conditions PM2.5 SIP
Conditions
II.A FCCU
Regenerator
NOx Feed
hydrotrea
ting &
refinery-
wide NOx
limit.
(0106-22)
II.B.1.h &
II.B.7.b
H.12.d.ii Current
operations
meet
RACT, no
further
action
warranted. VOCs Good
combustio
n
practices,
no
additional
controls.
(0106-22)
I.5
No
II.B Process
Heaters and
Boilers
NOx LNB, FGR
(Boilers 5,
6,7), &
refinery-
wide NOx
limit,
complianc
e with
NSPS
Subpart
Ja.
(0106-22)
II.B.1.h, II.B.2,
& II.B.3
H.12.d.ii &
H.12.d.vii
Current
operations
meet
RACT, no
further
action
warranted.
VOCs Good
combustio
n
practices,
(0106-22)
I.5
No

55 https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001911.pdf

UTAH DIVISION OF AIR QUALITY
42

no
additional
controls,
complianc
e with
NSPS
Subpart
Ja.
II.B Crude
Heaters
NOx LNB &
refinery-
wide NOx
limit.
(0106-22)
II.B.1.h
H.12.d.ii &
H.12.d.vii

Current
operations
meet
RACT, no
further
action
warranted.
VOCs Good
combustio
n
practices.
(0106-22)
I.5

No
II.C SRU NOx Existing
tail gas
treatment
unit and
thermal
oxidizer &
refinery-
wide NOx
limit.
(0106-22)
II.B.1.h
H.12.d.ii &
H.12.d.vii
Current
operations
meet
RACT, no
further
action
warranted.
II.D Cooling
Towers
VOCs MACT
Subpart
CC
requireme
nts on
cooling
towers
servicing
high VOC
heat
exchanger
s.
(0106-22)
II.B.10.a
H.11.g.iii Current
operations
meet
RACT, no
further
action
warranted.
II.E Fugitive
emissions
VOCs Low leak
LDAR
requireme
nts of
NSPS
Subpart
GGGa.
(0106-22)
II.B.10.b
H.11.g.iv Current
operations
meet
RACT, no
further
action
warranted.
II.F Tanks VOCs Submerge
d fill
(0106-22)
II.B.10.c1
H.11.g.vi Current
operations

UTAH DIVISION OF AIR QUALITY
43

operation
s & tank
degassing
requireme
nts -
complianc
e with
NSPS
Subpart
Kb or
MACT
Subpart
CC.
&
(0104-22)
II.B.2.c2
meet
RACT, no
further
action
warranted.
II.G Wastewater
System
VOCs Induced
air
floatation
& RTO,
complianc
e with
NSPS
Subpart
QQQ and
National
Emission
Standards
for
Hazardous
Air
Pollutants
(NESHAP)
Subpart
FF.
(0104-22)
II.B.2.a &
II.B.2.b
H.12.d.vii Current
operations
meet
RACT, no
further
action
warranted.
II.H Refinery
Flares
NOx Evaluated
through
control of
flare
gases, not
through
individual
pollutants
,
requireme
nt to meet
NSPS
Subpart Ja
for flares.
(0106-22)
II.B.10.d
H.11.g.v,
H.12.d.ii, &
H.12.d.vii
Current
operations
meet
RACT, no
further
action
warranted.
VOCs

UTAH DIVISION OF AIR QUALITY
44

II.I Standby Fire
Pumps and
Emergency
Diesel
Engines
VOCs Proper
maintena
nce and
operation,
and
complianc
e with
NESHAP
Subpart
ZZZZ.
(0106-22)
I.5
H.12.d.iv Current
operations
meet
RACT, no
further
action
warranted.
NOx (0106-22)
II.B.8.c
II.L Reformer
Compressor
Engines
NOx Use of
NSCR
meeting
NOx
emission
limits in
SIP
Section IX,
Part
H.12.d.v.
(0106-22)
II.B.9.a
H.12.d.v &
H.12.d.vii
SCR
incorrectly
required in
SIP Section
IX, Part
H.12.d.vii.
Correct
control
required is
NSCR.
Current
operations
meet
RACT, no
further
action
warranted.
II.J Crude Oil
Loading
Racks
VOCs Vapor
Combusti
on Unit
with a
98% VOC
control
efficiency.
(0104-22)
II.B.3.a
H.12.d.vii Current
operations
meet
RACT, no
further
action
warranted.
N/A

Refinery
General
Approach

NOx

Refinery-
wide NOx
limit.

(0106-22)
II.B.1.h

H.12.d.ii

Current
operations
meet
RACT, no
further
action
warranted.
4.4.5 Conclusion of RACT Implementation 1
The emission units/activities examined in this RACT analysis indicates that all activities currently 2
meet all RACT requirements, and all other existing controls and emissions limitations are considered 3

UTAH DIVISION OF AIR QUALITY
45

RACT for the Chevron Refinery. No other additional add-on controls or limitations are technically or 1
economically feasible options at this time. 2
4.5 Hexcel Corporation 3
4.5.1 Introduction 4
This section specifically serves as an evaluation of Hexcel Corporation (Hexcel). In addition to its 5
past BACT reports, Hexcel submitted an additional RACT analysis for evaluation January 31, 2023. 6
Specific Ozone SIP conditions for Hexcel can be found in Section IX, Part H.32.c. 7
4.5.2 Facility Process Summary 8
Hexcel owns and operates a carbon fiber and fabric pre-impregnation manufacturing plant in 9
West Valley City. Products made at Hexcel are used in commercial aerospace primary and secondary 10
structures, helicopters, defense aircraft, satellites, and sporting equipment. The facility consists of 11
twelve production buildings, two raw material receiving warehouses, and a material testing laboratory. 12
The plant manufactures carbon fibers and hot melt pre-impregnation fabrics. The plant also produces 13
epoxy resins, adhesive films, and solvated fabrics. 14
4.5.3 Facility Baseline Actual Emissions and Current PTE 15
The baseline and current PTE from the Hexcel industrial processes and equipment are 16
summarized in Table 26. The 2017 actual emissions were used as the baseline emissions. The current 17
PTE values for Hexcel were established by the most recent active AOs issued to the source. 18
 AO DAQE-AN113860032-19 issued May 13, 2019 (0032-19) 19
Table 26: Hexcel Corporation Facility-Wide Emissions 20
Hexcel Corporation Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 187.90 197.51
VOC 154.20 168.34
4.5.4 RACT Analysis 21
The RACT evaluations were performed using data from Hexcel, AOs and supporting 22
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 23
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 24
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 25
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 26
NOx and VOCs are provided in Table 27. 27
28
Table 27: Hexcel Corporation 29
30
Hexcel Corporation
Pollutant Enforceability Comments

UTAH DIVISION OF AIR QUALITY
46

RACT
Section
#56
Emission
Unit/Activity
RACT
Determination
AO
Conditions
PM2.5 SIP
Conditions
4.0 -
4.2
All Fiber
Lines
All Consumption
and
production
limits.
(0032-19)
II.B.1.b
H.12.f.i &
H.12.f.vi
Current operations
meet RACT, no
further action
warranted.
4.0 -
4.2
Fiber Lines 2
thru 8, 10
thru 12
VOCs Good
combustion
practices,
natural gas as
fuel,
incineration
and flaring
technology.
(0032-19)
I.5;
II.B.1.d -
II.B.1.l;
II.B.3.a -
II.B.3.d;
II.B.4.a -
II.B.4.c; &
II.B.5.a -
II.B.5.b
No Current operations
meet RACT, no
further action
warranted. Fiber Lines 2,
5, 6, 8, 10
thru 12
NOx
4.0 -
4.2
Fiber Lines 3,
4, and 7
NOx ULNB with
FGR required
to be installed
by December
31, 2024.
No H.12.f.iv Current operations
meet RACT, no
further action
warranted.
4.0 -
4.2
Fiber Lines
13 thru 16
VOCs RTO,
incineration
and flaring
technology.
(0032-19)
I.5;
II.B.1.d -
II.B.1.l;
II.B.6.a; &
II.B.7.a
H.12.f.ii Current operations
meet RACT, no
further action
warranted.
NOx LNB on
thermal
oxidizer and
RTO, good
combustion
practices,
natural gas as
fuel.
H.12.f.ii,
H.12.f.v
4.3 Pilot VOCs Good
combustion
practices,
natural gas as
fuel, proper
maintenance,
incineration
and flaring
technology.
(0032-19)
I.5 &
II.B.1.d -
II.B.1.l
No Current operations
meet RACT, no
further action
warranted.
NOx

56 https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001511.pdf

UTAH DIVISION OF AIR QUALITY
47

5.0 Matrix
(Solvent
Coating
Operations)
VOCs Good
combustion
practices,
natural gas as
fuel, proper
maintenance,
incineration
and flaring
technology.
(0032-19)
I.5;
II.B.1.j;
II.B.1.o; &
II.B.1.p
No Current operations
meet RACT, no
further action
warranted.
NOx
6.0 Boilers VOCs Use of pipeline
quality natural
gas, good
combustion
practices,
good design, &
proper
operation.
(0032-19)
I.5
No Current operations
meet RACT, no
further action
warranted.

NOx Compliance
with a NOx
emission rate
of 9 ppm.
(0032-19)
I.5
No
7.0 Emergency
Generators
VOCs Proper
maintenance
and operation,
Subpart IIII
and Subpart
ZZZZ.
(0032-19)
I.5
No Current operations
meet RACT, no
further action
warranted. NOx
8.0 HVAC VOCs Proper
maintenance
and operation.
(0032-19)
I.5 &
II.B.1.o
No Current operations
meet RACT, no
further action
warranted. NOx
4.5.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emissions limitations are considered RACT for Hexcel. RACT evaluations showed that additional add-3
on controls or limitations are not technically or economically feasible options at this time. No additional 4
RACT measures were identified, and all RACT determinations are already being implemented. Therefore, 5
there are no additional implementation schedules or requirements for Hexcel as required by this SIP 6
revision. 7

UTAH DIVISION OF AIR QUALITY
48

4.6 Hill Air Force Base 1
4.6.1 Introduction 2
This section specifically serves as an evaluation of Hill Air Force Base (Hill AFB). Hill AFB did not 3
submit an additional RACT analysis for evaluation, and thus UDAQ relied on the more stringent BACT 4
analysis submitted for NOx and VOC emissions as evaluated for the Salt Lake City PM2.5 serious SIP. 5
Specific conditions as they relate to this SIP revision for Hill AFB can be found in Section IX, Part H.32.d. 6
4.6.2 Facility Process Summary 7
Hill AFB is a large U.S. Air Force base located in northern Utah, just south of the city of Ogden. 8
Hill AFB is the home of the Air Force Material Command’s Ogden Air Logistics Complex, which is the 9
worldwide manager for a wide range of aircraft, engines, missiles, software, avionics, and accessories 10
components, and provides worldwide logistics support for Air Force and Defense Department weapon 11
systems. Additional tenant units include the Air Combat Command and the Air Force Reserve Command. 12
Hill AFB has extensive industrial facilities for painting, paint stripping, plating, parts 13
warehousing/distribution, wastewater treatment, and manages and maintains air munitions, solid 14
propellants, landing gear, and training devices. 15
4.6.3 Facility Baseline Actual Emissions and Current PTE 16
The baseline and current PTE from the Hill AFB processes and equipment are summarized in Table 17
28. The 2017 actual emissions were used as the baseline emissions. The current PTE values for Hill AFB 18
were established by the most recent active AOs issued to the source. 19
 AO DAQE-AN101210245-16 issued September 1, 2016 (0245-16) 20
 AO DAQE-AN101210200A-09 issued December 17, 2009 (0200A-09) 21
 AO DAQE-AN0121175-06 issued October 16, 2006 (175-06) 22
 AO DAQE-AN101210266-19 issued May 8, 2019 (0266-19) 23
 AO DAQE-AN0101210195-09 issued August 10, 2009 (0195-09) 24
 AO DAQE-AN101210233-12 issued January 27, 2012 (0233-12) 25
 AO DAQE-AN101210225-12 issued April 19, 2012 (0225-12) 26
 AO DAQE-AN101210248-17 issued June 7, 2017 (0248-17) 27
 AO DAQE-AN101210228-12 issued June 13, 2012 (0228-12) 28
 AO DAQE-AN0101210214-11 issued June 28, 2011 (0214-11) 29
 AO DAQE-AN101210229-12 issued October 29, 2012 (0229-12) 30
 AO DAQE-AN101210233-14 issued June 26, 2014 (0233-14) 31
 AO DAQE-AN101210237-15 issued March 9, 2015 (0237-15) 32
 AO DAQE-AN101210241-15 issued November 5, 2015 (0241-15) 33
 AO DAQE-AN101210260-19 issued April 3, 2019 (0260-19) 34
 AO DAQE-AN101210240B-16 issued February 8, 2016 (0240B-16) 35
Table 28: Hill Air Force Base Facility-Wide Emissions 36
Hill Air Force Base Facility Emissions
Pollutant Baseline Emissions PTE

UTAH DIVISION OF AIR QUALITY
49

(TPY) (TPY)
NOx 101.43 279.81
VOC 140.24 330.41
4.6.4 RACT Analysis 1
The RACT evaluations were performed using data from Hill AFB, AOs and supporting 2
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 3
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 4
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 5
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 6
NOx and VOCs are provided in Table 29. 7
8

UTAH DIVISION OF AIR QUALITY
50

1
Table 29: Hill Air Force Base 2
Hill Air Force Base
TSD
Section
#57
Emission
Unit/Activity
Pollutant BACT
Determination
Enforceability Comments
AO
Conditions
PM2.5 SIP
Conditions
2.1.1 Boilers VOCs Use of pipeline
quality natural
gas (low sulfur
fuel), good
combustion
practices,
good design,
and proper
operation.
(0245-16)
I.5
No Current operations
meet RACT, no
further action
warranted.
NOx All boilers
older than
January 1,
1989, will be
removed. The
combined
heat NOx
emissions for
all boilers
(except those
less than 5
MMBtu/hr)
shall not
exceed 95
lb/hr.
(0245-16)
II.B.1.a &
II.B.2.a

H.12.q.ii Current operations
meet RACT, no
further action
warranted.
2.1.2 Surface
Coating,
Cleaning &
Chemically
De-painting
Operations
VOCs Low VOC
coatings, work
practice
standards,
emissions limit
of 0.58 tpd,
and proper
maintenance.
(0200A-
09)
II.B.1.a
through
II.B.1.m

H.12.q.i Current operations
meet RACT, no
further action
warranted.

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2.1.3 Emergency
Equipment
Operations
VOCs Limited hours
of operation
for
maintenance
and testing,
good
combustion
practices, use
of a tier-
certified
engine when
required
under NSPS
Subpart IIII
and JJJJ, the
use of ULSD
and proper
equipment
operation,
maintenance
schedules and
protocols.
(175-06)
I.E & II.C

(0266-19)
I.5 &
II.B.1.b
No Current operations
meet RACT, no
further action
warranted.

NOx
2.1.4 Testing
Operations
VOCs Site-wide fuel
limit and
proper
operation,
maintenance,
and protocols.
(0195-09)
I.5,
II.B.1.a,
II.B.2.a, &
II.B.3.a
(0233-12)
I.5 &
II.B.1.b
(0225-12)
I.5 &
II.B.1.a
(0248-17)
I.4,
II.B.1.a, &
II.B.1.b
No Current operations
meet RACT, no
further action
warranted.

NOx
2.1.5 Degreasing
Operations
VOCs Use of low
volatility
solvents,
proper
operation,
maintenance
and operation
protocols with
(0228-12)
I.6, II.B.1.a
through
II.B.1.f

No Current operations
meet RACT, no
further action
warranted.

UTAH DIVISION OF AIR QUALITY
52

a limit on VOC
emissions.
2.1.6 Misc.
Coating and
Blasting
VOCs Scrubbers,
low-sulfur
fuel, limited
use, proper
operation,
maintenance
and protocols.
(0214-11)
I.5 &
II.B.1.a
(0229-12)
I.5
(0233-14)
I.5 &
II.B.1.a

No Current operations
meet RACT, no
further action
warranted.

NOx Limited use,
proper
operation,
maintenance,
and protocols.
2.1.7 Air Handlers
& Heaters
VOCs LNBs, low
sulfur fuel,
limited use,
proper
operation,
maintenance,
and protocols.
(0237-15)
I.5 &
II.B.1.a

No Current operations
meet RACT, no
further action
warranted. NOx
2.1.8 Fuel
Operations
VOCs Fuel storage:
vapor
balancing
system and
submerged
loading as
required by
R307-328,
limited use,
proper
operation,
maintenance
and protocols.

Distillation:
Limited use,
proper
operation,
Maintenance
and protocols.
(0241-15)
I.5 and
II.B.1.a
(0260-19)
I.5,
II.B.1.a, &
II.B.1.b

No Current operations
meet RACT, no
further action
warranted.

2.1.10 Industrial
Wastewater
Operation
VOCs Limiting VOC
emission,
proper
operation,
(0240B-
16)
I.5,
II.B.1.a, &
II.B.1.b
No Current operations
meet RACT, no
further action
warranted.

UTAH DIVISION OF AIR QUALITY
53

maintenance
and protocols.

4.6.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emissions limitations are considered RACT for Hill AFB. Re-evaluation of BACT showed that 3
additional add-on controls or limitations are not technically or economically feasible options at this time. 4
No additional RACT measures were identified, and all RACT determinations are already being 5
implemented. Therefore, there are no additional implementation schedules or requirements for Hill AFB 6
as required by this SIP revision. 7
8
4.7 Holly Frontier Sinclair Woods Cross Refinery 9
10
4.7.1 Introduction 11
This section specifically serves as an evaluation of Holly Frontier Sinclair Woods Cross Refinery 12
(HF Sinclair Refinery). In addition to its BACT report submitted as part of the Salt Lake City PM2.5 serious 13
SIP, HF Sinclair Refinery submitted an additional RACT analysis for evaluation on January 31, 2023, with 14
supporting information submitted February 23, 2023. Specific conditions related to this SIP revision for 15
HF Sinclair Refinery can be found in Section IX, Part H.32.e. 16
17
4.7.2 Facility Process Summary 18
The HF Sinclair Refinery is a petroleum refinery capable of processing 60,000 barrels per day of 19
crude oil, primarily heavier black wax and yellow wax crudes from eastern Utah. The refinery produces a 20
variety of products including gasoline, natural gas liquids, propane, butanes, jet fuels, fuel oils, and 21
kerosene products. The refinery receives and distributes products by tanker truck, rail car, and pipeline. 22
The source consists of two FCCUs, both controlled with wet gas scrubbers. A single sulfur recovery unit 23
controls the sulfur content of the fuel gas. The source also has an assortment of heaters, boilers, cooling 24
towers, storage tanks, flares, and related fugitive emissions. 25
26
4.7.3 Facility Baseline Actual Emissions and Current PTE 27
The baseline and current PTE from the HF Sinclair Refinery processes and equipment are 28
summarized in Table 28. The 2017 actual emissions were used as the baseline emissions. The current 29
PTE values for HF Sinclair Refinery were established by the most recent active AOs issued to the source. 30
 AO DAQE-AN101230053-22 issued September 1, 2022 (0053-22) 31
Table 30: Holly Frontier Sinclair Woods Cross Refinery Facility-Wide Emissions 32
Holly Frontier Sinclair Woods Cross Refinery Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 170.51 347.10
VOC 217.45 223.63
33
4.7.4 RACT Analysis 34
The RACT evaluations were performed using data from HF Sinclair Refinery, AOs and supporting 35
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 36

UTAH DIVISION OF AIR QUALITY
54

identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 1
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 2
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 3
NOx and VOCs are provided in Table 31. 4
5
Table 31: Holly Frontier Sinclair Woods Cross Refinery 6
Holly Frontier Sinclair Woods Cross Refinery
RACT
Section
#58
Emission
Unit/Activity
Pollutant RACT
Determination
Enforceability Comments
AO
Condition
s
PM2.5 SIP
Conditions
3.4 &
4.5
FCCU
Regenerator
NOx Wet gas
scrubber with
use of LoTOx
add-on &
refinery-wide
NOx limit.
(0053-22)
II.B.4 &
II.B.8.b
H.12.g.ii &
H.12.g.vi
Current
operations meet
RACT, no further
action
warranted.
4.5 VOCs Good
combustion
practices, no
additional
controls.
(0053-22)
I.5
No
3.1 &
4.1
Process
Heaters and
Boilers
NOx LNB, ULNB,
some use of
SCR, &
refinery-wide
NOx limit.
(0053-22)
II.B.4.a &
II.B.6.b
H.12.g.ii &
H.12.g.vi
Current
operations meet
RACT, no further
action
warranted.
4.1 VOCs Good
combustion
practices, no
additional
controls.
(0053-22)
I.5 &
II.B.6.d
No
3.3 &
4.4
Sulfur
Recovery
Unit Tail Gas
incinerator
NOx Wet Gas
Scrubber, Low-
NOx burner &
refinery-wide
NOx limit.
(0053-22)
I.5 &
II.B.4.a
H.12.g.ii &
H.12.g.vi
Current
operations meet
RACT, no further
action
warranted.
4.4 VOCs Wet Gas
Scrubber.
4.3 Cooling
Towers
VOCs MACT Subpart
CC
requirements
on cooling
(0053-22)
II.B.12.a
H.11.g.iii Current
operations meet
RACT, no further

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UTAH DIVISION OF AIR QUALITY
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towers
servicing high
VOC heat
exchangers.
action
warranted.
4.9 Fugitive
emissions/
Equipment
Leaks
VOCs Low leak LDAR
requirements
of NSPS
Subpart GGGa.
(0053-22)
II.B.1.h
H.11.g.iv Current
operations meet
RACT, no further
action
warranted.
4.6 Fixed Roof
Tanks
VOCs Compliance
with NSPS
Subpart Kb,
MACT Subpart
WW, and
LDAR.
(0053-22)
I.5
H.11.g.vi Current
operations meet
RACT, no further
action
warranted.
4.7 Internal
Floating Roof
Storage tanks
VOCs Submerged fill
operations &
tank degassing
requirements -
eventual
compliance
with NSPS
Subpart Kb or
MACT Subpart
CC and MACT
Subpart WW.
(0053-22)
I.5

H.11.g.vi

Current
operations meet
RACT, no further
action
warranted.
4.8 External
Floating Roof
VOCs Compliant with
NSPS Subpart
Kb or MACT
Subpart CC and
MACT Subpart
WW.
(0053-22)
I.5

H.11.g.vi

Current
operations meet
RACT, no further
action
warranted.
4.10 Wastewater
System
VOCs Closed vent
system with
carbon
adsorption.
Compliance
with NSPS
Subpart QQQ
and MACT
Subpart FF.
(0053-22)
I.5
H.12.g.vi Current
operations meet
RACT, no further
action
warranted.
3.2 &
4.2
Refinery
Flares
NOx Flare Gas
recovery
system,
requirement to
(0053-22)
II.B.1.g
H.11.g.v,
H.12.g.ii, &
H.12.g.vi
Current
operations meet
RACT, no further
action
warranted.
4.2 VOCs

UTAH DIVISION OF AIR QUALITY
56

meet NSPS
Subpart Ja.
3.5 &
4.12
Standby
Diesel
Engines
VOCs Proper
maintenance
and operation,
compliance
with MACT
Subpart ZZZZ.
(0053-22)
I.5
H.12.g.iv Current
operations meet
RACT, no further
action
warranted.
4.1 NOx
3.6 &
4.13
Standby
Emergency
Nat Gas
Engines
VOCs Proper
maintenance
and operation,
compliance
with NSPS
Subpart JJJJ
and MACT
Subpart ZZZZ.
(0053-22)
I.5
No Current
operations meet
RACT, no further
action
warranted.
4.1 NOx
4.11 Product
Loading
VOCs Submerged or
bottom loading
as well as
vapor
balancing.
(0053-22)
I.5
No Current
operations meet
RACT, no further
action
warranted.
N/A

Refinery
General
Approach

NOx

Refinery-wide
NOx limit.

(0053-22)
II.B.4

H.12.g.ii

Current
operations meet
RACT, no further
action
warranted.
4.7.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emissions limitations are considered RACT for the HF Sinclair Refinery. RACT evaluations showed 3
that additional add-on controls or limitations are not technically or economically feasible options at this 4
time. No additional RACT measures were identified, and all RACT determinations are already being 5
implemented. Therefore, there are no additional implementation schedules or requirements for the HF 6
Sinclair Refinery as required by this SIP revision. 7
4.8 Kennecott Utah Copper Bingham Canyon Mine and Copperton Concentrator 8
4.8.1 Introduction 9
This section specifically serves as an evaluation of Kennecott Utah Copper (KUC) – Bingham 10
Canyon Mine (BCM) and Copperton Concentrator (CC). In addition to past submitted BACT reports, KUC 11
submitted an additional RACT analysis for evaluation January 30, 2023. Specific conditions for this SIP 12
revision for KUC BCM & CC can be found in Section IX, Part H.32.f. 13

UTAH DIVISION OF AIR QUALITY
57

4.8.2 Facility Process Summary 1
The KUC BCM is an open pit mining operation located in the southwest corner of Salt Lake 2
County. The ore and waste rock at the BCM are transferred from the mining areas to other areas of the 3
mine through a series of transfers using haul trucks and conveyor belts. Ore is crushed in the in-pit 4
crusher. After the ore is crushed, it is conveyed to the KUC CC located approximately five miles north of 5
the open pit. At the CC, semi-autogenous grinding mills and ball mills grind the ore into a slurry. The 6
slurry is sent through cyclone clusters, and the cyclone overflow is fed into flotation circuits and mixed 7
with reagents. The flotation circuits are aerated to float copper and other valuable by-products from the 8
ore. Once the ore is processed at the concentrator, it is transferred to the smelter. 9
4.8.3 Facility Baseline Actual Emissions and Current PTE 10
The baseline and current PTE from the KUC BCM & CC processes and equipment are 11
summarized in Table 31. The 2017 actual emissions were used as the baseline emissions. The current 12
PTE values for KUC BCM & CC were established by the most recent active AOs issued to the source. 13
 AO DAQE-AN105710047-21 issued May 10, 2021 (0047-21) 14
 AO DAQE-AN105710044-18 issued August 21, 2018 (0044-18) 15
Table 31: KUC Bingham Canyon Mine and Copperton Concentrator Facility-Wide Emissions 16
KUC Bingham Canyon Mine & Copperton Concentrator Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 4,209.19 5,852.77
VOC 210.03 318.17
17
4.8.4 RACT Analysis 18
The RACT evaluations were performed using data from KUC, AOs and supporting 19
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 20
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 21
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 22
regulations; and other state SIPs. The RACT determinations for each emission unit or activity emitting 23
NOx and VOCs are provided in Table 33. 24
25
Table 33: Kennecott Utah Copper: Bingham Canyon Mine and Copperton Concentrator 26
Kennecott Utah Copper: Bingham Canyon Mine & Copperton Concentrator
Bingham Canyon Mine
RACT
Section
#59
Emission
Unit/Activity
Pollutant RACT
Determination
Enforceability Comments
AO
Condition
PM2.5 SIP
Conditions

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UTAH DIVISION OF AIR QUALITY
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2.1.1 Tailpipe
Emissions
from Mobile
Sources
NOx Compliance
with non-road
EPA Standards.
(0047-21)
II.B.1.f
H.12.h.i.A Current
operations
meet RACT, no
further action
warranted.
2.1.5 Solvent
Extraction
and
Electrowinni
ng Process
NOx Use of mist
eliminators and
covers in tanks,
mixers, and
settlers.
(0047-21)
II.B.2.f &
II.B.2.g
No Current
operations
meet RACT, no
further action
warranted.
VOCs
2.1.2 Gasoline
Fueling
VOCs Stage I and
Stage 2
recovery
systems.
(0047-21)
I.5
No Current
operations
meet RACT, no
further action
warranted.
2.1.3 Cold Solvent
Degreasing
Washers
VOCs Compliance
with R307-335.
(0047-21)
I.5
No Current
operations
meet RACT, no
further action
warranted.
2.1.4 Propane
Communicati
ons
Generator
VOCs Proper
maintenance
and operation,
and
compliance
with applicable
NSPS or MACT
requirements.
(0047-21)
I.5
No Current
operations
meet RACT, no
further action
warranted.
NOx
PM2.5
BACT
TSD
1.460
Diesel-Fired
Emergency
Generators
VOCs BACT
determination:
proper
maintenance
and operation,
and
compliance
with applicable
NSPS or MACT
requirements.
(0047-21)
I.5
No Equipment not
operated
during
evaluation
period, no
additional
RACT
submitted.
Current
operations
meet RACT, no
further action
warranted.
NOx

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UTAH DIVISION OF AIR QUALITY
59

Copperton Concentrator
RACT
Section
#
Emission
Unit/Activity
Pollutant RACT
Determination
Enforceability Comments
AO
Condition
PM2.5 SIP
Conditions
2.2.1 Tioga
Heaters
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, and
good design
and proper
operation
(0044-18)
I.5
No Current
operations
meet RACT, no
further action
warranted. NOx
2.2.4 Feed and
Product
Dryer Oil
Heaters
VOCs Use of pipeline
quality natural
gas and good
combustion
practices.
(0044-18)
I.5
No Current
operations
meet RACT, no
further action
warranted.
NOx LNBs H.12.h.ii.A
2.2.2 Degreasing
Parts
Washers
VOCs Compliance
with the
requirements
of R307-335.
(0044-18)
I.5
No Current
operations
meet RACT, no
further action
warranted.
2.2.3 Gasoline
Fueling
Stations
VOCs Stage I and
Stage 2
recovery
systems.
(0044-18)
I.5
No Current
operations
meet RACT, no
further action
warranted.
PM2.5
BACT
TSD
1.4

Three
Storage
Tanks
(Sodium
Cyanide)
VOCs BACT
determination:
use of
submerged
pipes.
(0044-18)
I.5
No Equipment not
operated
during
evaluation
period, no
additional
RACT
submitted.
Current
operations
meet RACT, no
further action
warranted.

UTAH DIVISION OF AIR QUALITY
60

2.1.4 Liquid
Propane-
Fired
Emergency
Generator
VOCs Proper
maintenance
and operation,
and
compliance
with applicable
NSPS or MACT
requirements.
(0044-18)
I.5
No Current
operations
meet RACT, no
further action
warranted.
NOx
1
4.8.5 Conclusion of RACT Implementation 2
The emission units/activities currently meet all RACT requirements, and the existing controls 3
and emissions limitations are considered RACT for KUC BCM & CC. RACT evaluations showed that 4
additional add-on controls or limitations are not technically or economically feasible options at this time. 5
No additional RACT measures were identified, and all RACT determinations are already being 6
implemented. Therefore, there are no additional implementation schedules or requirements for KUC 7
BCM & CC as required by this SIP revision. 8
4.9 KUC Smelter and Refinery 9
4.9.1 Introduction 10
This section specifically serves as an evaluation of KUC – Smelter and Refinery. In addition to 11
past BACT reports, KUC submitted an additional RACT analysis for evaluation January 30, 2023. Specific 12
conditions for this SIP revision for the KUC Smelter and Refinery can be found in Section IX, Part H.32.g. 13
4.9.2 Facility Process Summary 14
KUC operates a copper smelter and refinery in Salt Lake County. The Smelter employs flash 15
smelting technology with flash converting technology to produce copper anodes and high concentration 16
sulfur dioxide gases. Copper ore concentrates from the Copperton Concentrator are first dewatered, 17
dried, blended with fluxes and secondary copper-bearing materials, then fed to a flash smelting furnace 18
where the ore is melted and reacts to produce copper matte. The copper matte is converted to blister 19
copper by oxidization, reduced in the anode furnace to produce a high purity copper, and then poured 20
in molds to cast solid copper ingots (anodes). The anodes are moved to the Refinery co-located near the 21
Smelter. The Refinery uses an electrolytic refining process to convert the Smelter-produced anodes to 22
high-purity cathode copper and also recover precious metals from the electrolytic refinery slimes in a 23
precious metals circuit. 24
4.9.3 Facility Baseline Actual Emissions and Current PTE 25
The baseline and current PTE from the KUC Smelter and Refinery processes and equipment are 26
summarized in Table 34. The 2017 actual emissions were used as the baseline emissions. The current 27
PTE values for the KUC Smelter and Refinery were established by the most recent active AOs issued to 28
the source. 29
 AO DAQE-AN103460058-20 issued November 12, 2020 (0058-20) 30
 AO DAQE-AN103460061-22 issued June 23, 2022 (0061-22) 31

UTAH DIVISION OF AIR QUALITY
61

Table 34: KUC Smelter and Refinery Facility-Wide Emissions 1
KUC Smelter and Refinery Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 154.87 198.13
VOC 10.94 20.47
4.9.4 RACT Analysis 2
The RACT evaluations were performed using data from KUC, AOs and supporting 3
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 4
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 5
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 6
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 7
NOx and VOCs are provided in Table 35. 8
9
10
Table 35: Kennecott Utah Copper: Smelter and Refinery 11
Kennecott Utah Copper: Smelter and Refinery
Refinery
RACT
Section
#61
Emission
Unit/Activity
Pollutant RACT
Determination
Enforceability Comments
AO
Conditio
n
PM2.5 SIP
Conditions
3.2.1 Boiler VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0058-
20)
I.5 &
II.B.4.a
No Current
operations meet
RACT, no further
action
warranted.
NOx Installation of
ULNB (9 ppmvd)
on the boiler &
continued use of
FGR.
(0058-
20)
II.B.1.A
H.12.j.ii.A
&
H.12.j.ii.C
3.2.2 CHP VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0058-
20)
I.5 &
II.B.4.d
H.12.j.ii.D Current
operations meet
RACT, no further
action
warranted.

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UTAH DIVISION OF AIR QUALITY
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NOx Use of SoLoNOx
burner
technology (9
ppmv) on
turbine.
(0058-
20)
II.B.1.A
H.12.j.ii.A
3.1.8 Space
Heaters
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0058-
20)
I.5
No Current
operations meet
RACT, no further
action
warranted. NOx
3.1.6 Gasoline
Fueling
VOCs Stage I and Stage
2 recovery
systems.
(0058-
20)
I.5
No Current
operations meet
RACT, no further
action
warranted.
PM2.5
BACT
TSD
1.462

Degreasing VOCs BACT
determination:
compliance with
R307-335.
(0058-
20)
I.5
No Equipment not
operated during
evaluation
period, no
additional RACT
submitted.
Current
operations meet
RACT, no further
action
warranted.
3.2.8 Paint VOCs Enclosures. (0058-
20)
I.5
No Current
operations meet
RACT, no further
action
warranted.
3.2.7 Prime Diesel
Generators
VOCs Proper
maintenance and
operation, and
compliance with
applicable NSPS
or MACT
requirements.
(0058-
20)
I.5
No Current
operations meet
RACT, no further
action
warranted. NOx
3.1.4 Refinery LPG
Emergency
VOCs Proper
maintenance and
operation, and
(0058-
20)
No Current
operations meet
RACT, no further

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63

Communicati
on Generator
NOx compliance with
applicable NSPS
or MACT
requirements.
I.5 &
II.B.4.e
action
warranted.
Smelter
RACT
Section
#
Emission
Unit/Activity
Pollutant RACT
Determination
Enforceability Comments
AO
Conditio
n
PM2.5 SIP
Conditions
3.1.1 Main Stack NOx Controls are
described for
each source that
vents to the Main
Stack. The
following sources
vent to the Main
Stack: anode
furnaces,
secondary gas
system, matte
grinding,
concentrate
dryer, acid plant,
and vacuum
cleaning system.
Compliance with
MACT Subpart
EEEEEE.
(0061-
22)
II.B.1.a &
II.B.3.a
H.12.j.i.A.I.
3
Current
operations meet
RACT, no further
action
warranted.
3.1.1.1 Anode
Furnaces
NOx LNB (30 ppmvd) (0061-
22)
II.B.1.a &
II.B.3.a
No Current
operations meet
RACT, no further
action
warranted. VOCs Use of pipeline
quality natural
gas and oxy-fuel,
good combustion
practices, good
design, & proper
operation.
(0061-
22)
I.5
3.1.1 Concentrate
Dryer
NOx Use of LNB &
good combustion
practices.
(0061-
22)
II.B.1.a &
II.B.3.a
No Current
operations meet
RACT, no further
action
warranted. VOCs Use of pipeline
quality natural
gas and oxy-fuel,
(0061-
22)
I.5

UTAH DIVISION OF AIR QUALITY
64

good combustion
practices, good
design, & proper
operation.
3.1.2 Powerhouse
Holman
Boiler
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, proper
operation, &
limited natural
gas consumption.
(0061-
22)
I.5
No Current
operations meet
RACT, no further
action
warranted.
NOx Use of
continuous
monitoring to
ensure NOx
emissions do not
exceed 14 lbs/hr
(calendar-day
average); FGR.
(0061-
22)
II.B.1.a &
II.B.2
H.12.j.i.A.II
3.1.3 Powerhouse
Foster
Wheeler
Boiler (Now
Rentech
Boiler)
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, proper
operation, &
limited natural
gas consumption.
(0061-
22)
I.5
No Replaced by
Rentech Boiler in
AO DAQE-
AN103460056-20
issued January
10, 2020. Current
operations meet
RACT, no further
action
warranted. NOx ULNB, 15 ppm (0061-
22)
II.B.1.a &
II.B.2
3.1.5 Cold Solvent
Degreaser
VOCs Compliance with
R307-335
(0061-
22)
I.5
No Current
operations meet
RACT, no further
action
warranted.
3.1.8 Space
Heaters
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0061-
22)
I.5
No Current
operations meet
RACT, no further
action
warranted.
NOx

UTAH DIVISION OF AIR QUALITY
65

3.1.6 Fueling VOCs Stage I and Stage
2 recovery
systems.
(0061-
22)
I.5
No Current
operations meet
RACT, no further
action
warranted.
3.2.7,
3.1.7
Emergency
Backup
Power
Generators
VOCs Proper
maintenance and
operation, and
compliance with
applicable NSPS
or MACT
requirements.
(0061-
22)
I.5
No Current
operations meet
RACT, no further
action
warranted. NOx
PM2.5
BACT
TSD
1.4

Diesel
Compressor
VOCs BACT
determination:
proper
maintenance and
operation.
(0061-
22)
I.5
No Equipment not
operated during
evaluation
period, no
additional RACT
submitted.
Current
operations meet
RACT, no further
action
warranted.
NOx
3.1.4 Smelter LPG
Emergency
Communicati
on Generator
VOCs Proper
maintenance and
operation, and
compliance with
applicable NSPS
or MACT
requirements.
(0061-
22)
I.5
No Current
operations meet
RACT, no further
action
warranted. NOx
3.1.9 Hot Water
Boilers
VOCs Proper
maintenance and
operation.
(0061-
22)
I.5
No Current
operations meet
RACT, no further
action
warranted.
NOx
1
4.9.5 Conclusion of RACT Implementation 2
The emission units/activities currently meet all RACT requirements, and the existing controls 3
and emissions limitations are considered RACT for the KUC Smelter and Refinery. RACT evaluations 4
showed that additional add-on controls or limitations are not technically or economically feasible 5
options at this time. No additional RACT measures were identified, and all RACT determinations are 6
already being implemented. Therefore, there are no additional implementation schedules or 7
requirements for the KUC Smelter and Refinery as required by this SIP revision. 8

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66

4.10 LHoist North America of Arizona, Inc. 1
2
4.10.1 Introduction 3
This section specifically serves as an evaluation of LHoist North America of Arizona, Inc. (LHoist). 4
LHoist did not submit an additional RACT analysis for evaluation. UDAQ referenced the more stringent 5
BACT for NOx and VOCs evaluated as part of the Salt Lake City PM2.5 serious SIP. Specific conditions for 6
this SIP revision for LHoist can be found in Section IX, Part H.32.h. 7
4.10.2 Facility Process Summary 8
LHoist operates a lime production facility near Grantsville that consists of a Quarry and Lime 9
Plant. Kiln operations were placed in temporary care and maintenance mode November 14, 2008, with 10
support operations having had limited operation since that date. Activities at the facility include mining 11
of limestone ore, limestone processing through various crushing and screening processes, operation of a 12
rotary kiln that heats the crushed limestone ore and converts it into quicklime, lime hydration 13
equipment to create hydrated lime, bagging facilities, and load-out operations. When operating, the 14
facility produces a variety of products including quicklime, hydrate, aggregate kiln-grade limestone, 15
overburden/low-grade limestone, and limestone chat. 16
4.10.3 Facility Baseline Actual Emissions and Current PTE 17
The baseline and current PTE from the LHoist processes and equipment are summarized in Table 18
36. The 2017 actual emissions were used as the baseline emissions. The current PTE values for LHoist 19
were established by the most recent active AOs issued to the source. 20
 AO DAQE-AN0707015-06 issued August 14, 2006 (015-06) 21
22
23
24
Table 36: LHoist North America of Arizona Facility Facility-Wide Emissions 25
LHoist North America of Arizona Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 0.11 328.66
VOC 0.07 3.01
4.10.4 RACT Analysis 26
The RACT evaluations were performed using data from LHoist, AOs and supporting 27
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 28
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 29
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 30
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 31
NOx and VOCs are provided in Table 37. 32
33

UTAH DIVISION OF AIR QUALITY
67

Table 37: Lhoist North America of Arizona, Inc. 1
LHoist North America of Arizona, Inc.
TSD
Section
#63
Emission
Unit/Activity
Pollutant BACT
Determination
Enforceability Comments
AO
Conditions
PM2.5 SIP
Conditions
4.0 Rotary Kiln
System
NOx SNCR required
upon facility
startup.
No H.12.c.i &
H.12.c.ii
Current operations
meet RACT, no
further action
warranted.

VOCs Good
combustion
practices and
burner/process
optimization.
(015-06)
#22
No
5.0 Pressure
Hydrator
NOx Good
combustion
practices and
natural gas as
fuel.
(015-06)
#22
No Current operations
meet RACT, no
further action
warranted.
VOCs
7.0 Kiln Shaft
Motor
NOx Good
combustion
practices and
proper
maintenance.
(015-06)
#22
No Current operations
meet RACT, no
further action
warranted. VOCs
2
4.10.5 Conclusion of RACT Implementation 3
The emission units/activities currently meet all RACT requirements, and the existing controls 4
and emissions limitations are considered RACT for LHoist. Re-evaluation of BACT showed that additional 5
add-on controls or limitations are not technically or economically feasible options at this time. No 6
additional RACT measures were identified, and all RACT determinations are already being implemented. 7
Therefore, there are no additional implementation schedules or requirements for LHoist as required by 8
this SIP revision. 9
4.11 Pacificorp Energy Gadsby Power Plant 10
4.11.1 Introduction 11
This section specifically serves as an evaluation of Pacificorp Energy – Gadsby Power Plant 12
(Pacificorp Gadsby). Pacificorp Gadsby did not opt to submit an additional RACT analysis for evaluation, 13
therefore UDAQ referenced the more stringent BACT for NOx and VOCs evaluated as part of the PM2.5 14
serious SIP, with support information submitted by Pacificorp Gadsby March 10, 2023. Specific 15
conditions for this SIP revision for Pacificorp Gadsby can be found in Section IX, Part H.32.i. 16

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4.11.2 Facility Process Summary 1
Pacificorp Energy operates the Gadsby Power Plant located in Salt Lake City. The Gadsby Power 2
Plant is a natural gas-fired electric generating plant consisting of three steam boilers (Units #1-3) and 3
three simple-cycle combustion turbines (Units #4-6). Unit #1 is a 65 MW unit equipped with low NOx 4
burners; Unit #2 is an 80 MW unit equipped with low NOx burners; and Unit #3 is a 105 MW unit. All 5
three units are capable of using fuel oil as a back-up fuel during natural gas curtailments. Units #4-6 are 6
43.5 MW combustion turbine engines. The plant also has small emergency generators, cooling towers, 7
and small storage tanks. 8
4.11.3 Facility Baseline Actual Emissions and Current PTE 9
The baseline and current PTE from Pacificorp Gadsby processes and equipment are summarized 10
in Table 38. The 2017 actual emissions were used as the baseline emissions. The current PTE values for 11
Pacificorp Gadsby were established by the most recent active AOs issued to the source. 12
 AO DAQE-AN103550015-09 issued January 12, 2009 (0015-09) 13
Table 38: Pacificorp Energy Gadsby Power Plant Facility-Wide Emissions 14
Pacificorp Energy Gadsby Power Plant Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 38.81 716.10
VOC 2.26 23.00
4.11.4 RACT Analysis 15
The RACT evaluations were performed using data from Pacificorp Gadsby, AOs and supporting 16
documentation, and SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to identify all 17
existing and potential controls and emission rates, including EPA’s RBLC; technical documents, EPA fact 18
sheets, applicable CTGs, and other applicable literature; state and federal regulations; and other state 19
SIPS. The RACT determinations for each emission unit or activity emitting NOx and VOCs are provided in 20
Table 39. 21
22
Table 39: PacifiCorp Energy: Gadsby Power Plant 23
PacifiCorp Energy: Gadsby Power Plant
TSD
Section
#64
Emission
Unit/Activity
Pollutant BACT
Determination
Enforceability Comments
AO
Conditions
PM2.5 SIP
Conditions
4.0 Steam Generating
Units (Boilers 1-3)
NOx Natural gas as
fuel, good
combustion
practices, ULSD as
backup fuel, NOx
emission limits.
(0015-09)
II.B.4
H.12.l.i,
H.12.l.ii,
H.12.l.iii,
& H.12.l.iv
Current
operations
meet RACT,
no further
action
warranted.

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69

VOCs Good combustion
practices, proper
design.
(0015-09)
I.5
No
5.0 Combustion
Turbines (Units 4-
6)
NOx SCR, water/steam
injection.
(0015-09)
II.B.3
H.12.l.v Current
operations
meet RACT,
no further
action
warranted.
VOCs GCP and
oxidation
catalysts.
(0015-09)
I.5
No
6.3 Fuel Storage
Tanks
VOCs Submerged fill
operations, no
additional
controls.
(0015-09)
I.5
No Current
operations
meet RACT,
no further
action
warranted.
6.5 Misc. Painting
Operations
VOCs Use of low-VOC
compliant
coatings, high
transfer efficiency
applications, &
proper operation.
(0015-09)
I.5
No Current
operations
meet RACT,
no further
action
warranted.
6.2 Standby
Emergency
Engines
VOCs Proper
maintenance and
operation.
(0015-09)
I.5
No Current
operations
meet RACT,
no further
action
warranted.
NOx
5.5 Startup/Shutdown
at Combustion
Turbines
NOx Limitation of
hours of
operation for
startup/shutdown
to limit NOx,
alternative
operating
scenarios
included.
(0015-09)
I.5
H.12.l.vi Current
operations
meet RACT,
no further
action
warranted.
4.11.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emissions limitations are considered RACT for Pacificorp Gadsby. Re-evaluation of BACT showed 3
that additional add-on controls or limitations are not technically or economically feasible options at this 4
time. No additional RACT measures were identified, and all RACT determinations are already being 5
implemented. Therefore, there are no additional implementation schedules or requirements for 6
Pacificorp Gadsby as required by this SIP revision. 7

UTAH DIVISION OF AIR QUALITY
70

4.12 Tesoro Refining & Marketing Company LLC dba Marathon Refinery 1
4.12.1 Introduction 2
This section specifically serves as an evaluation of Tesoro Refining and Marketing Company LLC 3
dba Marathon Refinery (Marathon Refinery). In addition to past BACT reports, Marathon Refinery 4
submitted an additional RACT analysis for evaluation January 31, 2023, with a subsequent submission 5
including additional information submitted on March 31, 2023. Specific conditions for this SIP revision 6
for Marathon Refinery can be found in Section IX, Part H.32.j. 7
4.12.2 Facility Process Summary 8
The Marathon Refinery is a petroleum refinery capable of processing 57,500 barrels per day of 9
crude oil. The source consists of one FCCU, a catalytic reforming unit, hydrotreating units, a sulfur 10
recovery unit, and cogeneration units. The source also has assorted heaters, boilers, cooling towers, 11
storage tanks, flares, and similar fugitive emissions. 12
4.12.3 Facility Baseline Actual Emissions and Current PTE 13
The baseline and current PTE from the Marathon Refinery processes and equipment are 14
summarized in Table 40. The 2017 actual emissions were used as the baseline emissions. The current 15
PTE values for Marathon Refinery were established by the most recent active AOs issued to the source. 16
 AO DAQE-AN103350075-18 issued January 11, 2018 (0075-18) 17
 AO DAQE-AN103350081A-21 issued January 12, 2021 (0081A-21) 18
19
20
Table 40: Tesoro Marathon Refinery Facility-Wide Emissions 21
Tesoro Marathon Refinery Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 313.27 638.05
VOC 230.77 769.88
22
4.12.4 RACT Analysis 23
The RACT evaluations were performed using data from Marathon Refinery, AOs and supporting 24
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 25
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 26
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 27
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 28
NOx and VOCs are provided in Table 41. 29
30
Table 41: Tesoro Refining and Marketing Company LLC dba Marathon Refinery 31
Tesoro Refining and Marketing Company LLC dba Marathon Refinery
Pollutant Enforceability Comments

UTAH DIVISION OF AIR QUALITY
71

RACT
Section
#65
Emission
Unit/Activity
RACT
Determination
AO
Conditions
PM2.5 SIP
Conditions
4.0 FCCU
Regenerator
& CO Boiler
NOx Wet gas
scrubber with
use of LoTOx
add-on &
refinery-wide
NOx limit.
(0075-18)
II.B.1.g,
II.B.4.a,
II.B.4.f, &
II.B.7.a
H.12.m.ii
&
H.12.m.vi
Current operations
meet RACT, no
further action
warranted.
VOCs Good
combustion
practices, no
additional
controls.
(0075-18)
I.5
No
5.0 Process
Heaters and
Boilers
NOx LNB & ULNB
required on
various units,
& refinery-
wide NOx limit.
(0075-18)
II.B.1.g,
II.B.3.a, &
II.B.7.a
H.12.m.ii
&
H.12.m.vi
Current operations
meet RACT, no
further action
warranted.
VOCs Good
combustion
practices, no
additional
controls.
(0075-18)
I.5
No

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6.0 Cogeneration
Turbines
NOx Good
combustion
practices, use
of gaseous
fuels, &
refinery-wide
NOx limit. SCR
installation
required.
(0075-18)
II.B.1.g &
II.B.7.a
H.12.m.ii Installation of SCR
that meets a 5 ppm
NOx limit by
October 1, 2028.
Required by SIP
Section IX, Part
H.32.j.
VOCs Good
combustion
practices, no
additional
controls.
(0075-18)
I.5
No
7.0 SRU NOx Good
combustion
practices &
refinery-wide
NOx limit.
(0075-18)
II.B.1.g
H.12.m.ii
&
H.12.m.vi
Current operations
meet RACT, no
further action
warranted.
13.0 Cooling
Towers
VOCs MACT Subpart
CC
requirements
on cooling
towers
servicing high
VOC heat
exchangers.
(0075-18)
I.5

H.11.g.iii Current operations
meet RACT, no
further action
warranted.

UTAH DIVISION OF AIR QUALITY
73

8.0 Fugitive
emissions
VOCs Low leak LDAR
requirements
of NSPS
Subpart GGGa.
(0075-18)
I.5
H.11.g.iv Current operations
meet RACT, no
further action
warranted.
16.0 -
18.0
Tanks VOCs Submerged fill
operations,
and tank
degassing
requirements -
eventual
compliance
with NSPS
Subpart Kb or
MACT Subpart
CC. Secondary
seal
installation on
Tank 321
required.
(0075-18)
II.B.9
H.11.g.vi &
H.12.m.vi
Installation of
secondary seal on
Tank 321 by May 1,
2026. Required by
SIP Section IX, Part
H.32.j. All other
current operations
meet RACT, no
further action
warranted.
9.0 Wastewater
System
VOCs API separator
unit with fixed
cover;
installation of
closed vent
system to
carbon
adsorption
required.
(0075-18)
I.5

H.12.m.vi Installation of a
closed vent system
to carbon
adsorption by
December 31, 2025
in compliance with
NSPS Subpart QQQ.
Required by SIP
Section IX, Part
H.32.j.
11.0 &
12.0
Refinery
Flares
NOx Evaluated
through
control of flare
gases, not
through
individual
pollutants,
requirement
to meet
Subpart Ja for
flares.
(0075-18)
II.B.1.f
H.11.g.v &
H.12.m.vi
Current operations
meet RACT, no
further action
warranted.
VOCs

UTAH DIVISION OF AIR QUALITY
74

19.0 Standby
Emergency
Engines
VOCs Proper
maintenance
and operation,
and
compliance
with
applicable
NSPS or MACT
requirements.
(0075-18)
I.5
H.12.m.vi Current operations
meet RACT, no
further action
warranted.
NOx
15.0 K1
Compressors
(natural gas
engines)
VOCs Catalytic
converters,
proper
maintenance
and operation,
& refinery-
wide NOx limit
(0075-18)
I.5
(0075-18)
II.B.4.a,
II.B.7.a, &
II.B.7.c
H.12.m.ii Current operations
meet RACT, no
further action
warranted.
NOx
N/A Refinery
General
Approach
NOx Refinery-wide
NOx limit.
(0075-18)
II.B.1.g &
II.B.7.a
H.12.m.ii Current operations
meet RACT, no
further action
warranted.
1
4.12.5 Conclusion of RACT Implementation 2
The RACT analysis determined that all emission units/activities currently meet all RACT 3
requirements, and all other existing controls and emissions limitations are considered RACT for the 4
Marathon Refinery. The evaluations showed that the following control options are technically feasible: 5
 Installation of selective catalytic reduction (SCR) that meets a NOx emission rate of 5 ppm on the 6
Cogeneration Turbines 7
 Installation of a secondary seal on Tank 321 8
 Installation of a closed vent system controlled by carbon adsorption on the Wastewater System 9
The UDAQ has determined that these controls are necessary for the NWF NAA to demonstrate 10
attainment of the 2015 8-hour ozone NAAQS as expeditiously as practicable. While the financial 11
feasibility of the identified controls may be beyond previously established RACT thresholds, the CAA 12
provides states with “discretion to require beyond-RACT reductions from any source” if those reductions 13
are necessary to “demonstrate attainment as expeditiously as practicable”. 66 14
No other additional add-on controls or limitations are technically or economically feasible options at 15
this time. The installation of SCR on the Cogeneration Turbines will control total emissions from these 16
two turbines by approximately 68.7%. The installation of SCR will result in an annual emission reduction 17
of 68.78 tpy of NOx. The SCR shall be installed and operational by October 1, 2028. The installation of a 18
secondary seal on Tank 321 will result in 2.30 TPY of VOC emission reductions. The secondary seal shall 19
be installed and operational by May 1, 2026. The installation of a closed vent system with carbon 20

66 80 FR 12279 & 83 FR 62998

UTAH DIVISION OF AIR QUALITY
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adsorption on the Wastewater System is a planned refinery modification that shall be installed and 1
operational by December 31, 2025, and result in approximately 10 TPY of VOC emission reductions. 2
All requirements for the Cogeneration Turbines, Tank 321, and the Wastewater System are 3
incorporated into SIP Section IX, Part H.32.j. No additional RACT measures were identified, and all other 4
identified RACT determinations are already being implemented. 5
4.13 Utah Municipal Power Agency West Valley Power Plant 6
4.13.1 Introduction 7
This section specifically serves as an evaluation of Utah Municipal Power Agency (UMPA) West 8
Valley Power Plant (WVPP). In addition to past BACT reports, UMPA submitted an additional RACT 9
analysis for evaluation January 31, 2023, with supporting information submitted March 1, 2023. Specific 10
conditions for this SIP revision for UMPA WVPP can be found in Section IX, Part H.32.l. 11
4.13.2 Facility Process Summary 12
UMPA operates the WVPP in West Valley City. The WVPP is a natural gas-fired electric 13
generating plant consisting of 5 natural gas simple cycle turbines. Each turbine has a power output rated 14
at 43.4 MW and is equipped with water injection, evaporative spray mist inlet air cooling, selective 15
catalytic reduction catalyst, and CO oxidation catalyst. The primary purpose of the plant is to produce 16
electricity for sale via the utility power distribution system to meet the demands of the Salt Lake Valley 17
service area. 18
4.13.3 Facility Baseline Actual Emissions and Current PTE 19
The baseline and current PTE from the WVPP processes and equipment are summarized in Table 20
42. The 2017 actual emissions were used as the baseline emissions. The current PTE values for the WVPP 21
were established by the most recent active AOs issued to the source. 22
 AO DAQE-282-02 issued April 18, 2002 (282-02) 23
24
Table 42: West Valley Power Plant Facility-Wide Emissions 25
UMPA West Valley Power Plant Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 10.09 162.06
VOC 1.47 18.33
4.13.4 RACT Analysis 26
The RACT evaluations were performed using data from UMPA WVPP, AOs and supporting 27
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 28
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 29
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 30
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 31
NOx and VOCs are provided in Table 43. 32

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76

1
Table 43: Utah Municipal Power Agency West Valley Power Plant 2
Utah Municipal Power Agency West Valley Power Plant
RACT
Section
#67

Emission Unit/Activity Pollutant RACT
Determination
Enforceability Comments
AO
Conditions
PM2.5 SIP
Conditions
4.1 & 4.2
Combustion Turbines

NOx
SCR,
water/steam
injection and
maintenance
of NOx
emissions at or
below 5 ppmv
for each
turbine.
(282-02)
#10, #17
H.12.o.i, ii, iii,
iv Current
operations
meet RACT,
no further
action
warranted.
4.2 VOCs
Good
combustion
practices and
oxidation
catalysts.
(282-02)
#14, #19 No
PM2.5
BACT TSD
5.068
Startup/Shutdown at
Combustion Turbines

NOx
BACT
determination:
limitation of
hours of
operation for
startup/shutd
own to limit
NOx,
alternative
operating
scenarios
included.
(282-02)
#19 No
No
additional
RACT
submitted
.
Current
operation
s meet
RACT, no
further
action
warranted
.
4.13.5 Conclusion of RACT Implementation 3
The emission units/activities currently meet all RACT requirements, and the existing controls 4
and emissions limitations are considered RACT for the UMPA WVPP. RACT evaluations showed that 5
additional add-on controls or limitations are not technically or economically feasible options at this time. 6
No additional RACT measures were identified, and all RACT determinations are already being 7

67 https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-002084.pdf
68 https://documents.deq.utah.gov/air-quality/pm25-serious-sip/DAQ-2018-006862.pdf

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implemented. Therefore, there are no additional implementation schedules or requirements for the 1
UMPA WVPP as required by this SIP revision. 2
4.14 University of Utah 3
4.14.1 Introduction 4
This section specifically serves as an evaluation of the University of Utah (U of U). In addition to 5
past BACT reports, the U of U submitted an additional RACT analysis for evaluation January 31, 2023. 6
Specific conditions for this SIP revision for the U of U can be found in Section IX, Part H.32.m. 7
4.14.2 Facility Process Summary 8
The U of U is a higher education institution in Salt Lake City. The U of U campus consists of 9
several different types of buildings and facilities, including classroom buildings, hospitals and clinics, 10
research facilities, and housing. The emission sources at the U of U are primarily boilers, comfort heating 11
equipment, emergency generator engines, and miscellaneous small VOC sources. Industrial high 12
temperature boilers that provide hot water for distribution heating systems are located in the two main 13
heating plants on campus: the Upper Campus High Temperature Water Plant (UCHTWP) and the Lower 14
Campus High Temperature Water Plant (LCHTWP). A cogeneration turbine with waste heat recovery unit 15
is also located at the LCHTWP. 16
4.14.3 Facility Baseline Actual Emissions and Current PTE 17
The baseline and current PTE from the U of U processes and equipment are summarized in Table 18
44. The 2017 actual emissions were used as the baseline emissions. The current PTE values for the U of 19
U were established by the most recent active AOs issued to the source. 20
 AO DAQE-AN103540030-22 issued December 22, 2022 (0030-22) 21
22
23
24
Table 44: University of Utah Facility-Wide Emissions 25
University of Utah Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 41.65 126.50
VOC 8.13 13.53
4.14.4 RACT Analysis 26
The RACT evaluations were performed using data from the U of U, AOs and supporting 27
documentation, and Utah SIP Section IX, Parts H.11 and H.12. Various resources were evaluated to 28
identify all existing and potential controls and emission rates, including EPA’s RBLC; technical 29
documents, EPA fact sheets, applicable CTGs, and other applicable literature; state and federal 30
regulations; and other state SIPS. The RACT determinations for each emission unit or activity emitting 31
NOx and VOCs are provided in Table 45. 32

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78

1
Table 45: University of Utah 2
University of Utah
RACT
Section
#69
Emission
Unit/Activity
Pollutant RACT
Determination
Enforceability Comments
AO
Conditions
PM2.5 SIP
Conditions
4.0 Building 302
UCHWTP
Boilers
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0030-22)
I.5
H.12.p.iv. Current operations
meet RACT, no
further action
warranted.
NOx Boilers limited
to back-
up/peaking
boilers with
natural gas
limitations and
FGR.
(0030-22)
II.B.1.b
5.0 Building 303
LCHWTP
Boilers
NOx Boiler 4 required
to be
decommissioned
and replaced by
Boiler 9, use of
ULNB (9ppmvd)
on Boiler 9, &
use of LNBs and
FGR (9 ppmvd)
for boilers 6 and
7.
(0030-22)
II.b.2.a
H.12.p.i.,
H.12.p.ii.,
&
H.12.p.iii.
Current operations
meet RACT, no
further action
warranted.
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0030-22)
I.5
No Current operations
meet RACT, no
further action
warranted.
6.0 Building 303
LCHWTP
Cogeneration
Plant
NOx SoLoNOx
burners and
compliance with
NSPS Subpart
KKKK.
(0030-22)
II.B.2.a
No Current operations
meet RACT, no
further action
warranted.

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VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0030-22)
I.5
7.0 Dual Fuel
Boilers
NOx LNBs on various
boilers; the use
of specialized
mixing heads
and mixing
assemblies.
(0030-22)
I.5 &
II.B.3.a
H.12.p.v. Current operations
meet RACT, no
further action
warranted.
VOCs Use of pipeline
quality natural
gas with diesel
fuel as backup,
good
combustion
practices, good
design, & proper
operation.
(0030-22)
I.5
No
8.0 Backup
Diesel Boiler
NOx Meet a NOx
emission rate of
30 ppm.
(0030-22)
I.5 &
II.B.3.a
No Current operations
meet RACT, no
further action
warranted. VOCs Use of diesel
fuel, good
combustion
practices, good
design, & proper
operation.
(0030-22)
I.5
No
9.0 Small Boilers VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, & proper
operation.
(0030-22)
II.B.1.b &
II.B.3.a
No Current operations
meet RACT, no
further action
warranted.
NOx LNBs on various
boilers.
(0030-22)
II.B.3.c
H.12.p.v
10.0 Diesel
Emergency
Generator
Engines
VOCs Proper
maintenance
and operation,
and compliance
with applicable
(0030-22)
I.5
No Current operations
meet RACT, no
further action
warranted.
NOx

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NSPS or MACT
requirements.
11.0 Natural Gas
Emergency
Generator
Engines
VOCs Use of pipeline
quality natural
gas, good
combustion
practices, good
design, proper
operation, and
compliance with
applicable NSPS
or MACT
requirements.
(0030-22)
I.5
No Current operations
meet RACT, no
further action
warranted.
NOx
12.0 Paint Booth
and Parts
Washer
VOCs Good
housekeeping
practices,
routine
inspections, &
compliance with
R307-351.
(0030-22)
I.5
No Current operations
meet RACT, no
further action
warranted.
12.0 Fuel Storage
Tanks
VOCs Good operating
and
maintenance
practices.
(0030-22)
I.5
No Current operations
meet RACT, no
further action
warranted.
N/A Ethylene
Oxide
Sterilizer
VOCs Preparing to
decommission.
(0030-22)
I.5
No Current operations
meet RACT, no
further action
warranted.
4.14.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emissions limitations are considered RACT for the U of U. RACT evaluations showed that additional 3
add-on controls or limitations are not technically or economically feasible options at this time. No 4
additional RACT measures were identified, and all RACT determinations are already being implemented. 5
Therefore, there are no additional implementation schedules or requirements for the U of U as required 6
by this SIP revision. 7
4.15 US Magnesium LLC 8
4.15.1 Introduction 9
This section specifically serves as an evaluation of US Magnesium LLC (US Magnesium) RACT. 10
UDAQ identified US Magnesium as a major stationary source with the potential to impact the ozone 11
formation in the NWF NAA. The UDAQ required US Magnesium to submit a RACT analysis under CAA 12
172(c)(6) Other Measures for all major stationary sources located outside a NAA but impacting the NAA, 13

UTAH DIVISION OF AIR QUALITY
81

which applied to one source. US Magnesium submitted a NOx-specific RACT analysis for evaluation May 1
17, 2021, with a supporting VOC-specific RACT analysis submitted May 20, 2022, and an updated VOC-2
specific RACT analysis submitted January 31, 2023. Specific conditions for this SIP revision for US 3
Magnesium can be found in Section IX, Part H.32.k. While US Magnesium was included in the RACT 4
process, the emissions from this facility were not included in the point source inventories found in 5
section 3 of this SIP revision as the facility was located outside of the NAA. 6
4.15.2 Facility Process Summary 7
US Magnesium operates a primary magnesium production facility at its Rowley plant located in 8
Tooele County. US Magnesium produces magnesium metal from the waters of the Great Salt Lake, using 9
a system of solar evaporation ponds to create a brine solution. This brine solution is purified and dried 10
to a powder in spray dryers. The powder is melted and further purified in the melt reactor before going 11
through an electrolytic process to separate magnesium metal from chlorine. The magnesium is then 12
refined and/or alloyed and cast into molds. The separated chlorine is combusted in the chlorine 13
reduction burner and converted into hydrochloric acid, which is removed through a scrubber train. The 14
chlorine generated at the electrolytic cells is collected and piped to the chlorine plant. The on-site 15
lithium carbonate plant recovers lithium from cell salt created through the magnesium plant production. 16
4.15.3 Facility Baseline Actual Emissions and Current PTE 17
The baseline and current PTE from the US Magnesium processes and equipment are 18
summarized in Table 46. The 2017 actual emissions were used as the baseline emissions. The current 19
PTE values for US Magnesium were established by the most recent active AOs issued to the source. 20
 AO DAQE-AN107160050-20 issued April 20, 2020 (0050-20) 21
22
23
24
25
Table 46: US Magnesium LLC Facility-Wide Emissions 26
US Magnesium LLC Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 1,061.59 1,260.99
VOC 660.26 894.25
4.15.4 RACT Analysis 27
The RACT evaluations were performed using data from US Magnesium, AOs, and supporting 28
documentation. Various resources were evaluated to identify all existing and potential controls and 29
emission rates, including EPA’s RBLC; technical documents, EPA fact sheets, applicable CTGs, and other 30
applicable literature; state and federal regulations; other state SIPS; and UDAQ’s Appendix A – PM2.5 31
serious SIP BACT for Small Sources. The RACT determinations for each emission unit or activity emitting 32
NOx and VOCs are provided in Table 47. 33
34
Table 47: US Magnesium RACT Determination 35

UTAH DIVISION OF AIR QUALITY
82

US Magnesium LLC
RACT
Section
#70
Emission
Unit/Activity
Pollutant RACT
Determination
AO
Conditions
Comments
5.1 Turbines and
Duct Burners
VOCs Use of pipeline
quality natural
gas with fuel
oil as backup,
good
combustion
practices,
good design, &
proper
operation.
(0050-20)
I.4
Current operations meet RACT,
no further action warranted.
NOx Compliance
with a plant-
wide natural
gas
consumption
limit.
(0050-20)
II.B.1.b
5.2 Chlorine
Reduction
Burner
NOx Compliance
with a plant-
wide natural
gas
consumption
limit.
(0050-20)
II.B.1.b
Current operations meet RACT,
no further action warranted.
VOCs Use of pipeline
quality natural
gas, good
combustion
practices,
good design, &
proper
operation.
(0050-20)
I.4
5.3 Riley Boiler NOx Compliance
with a plant-
wide natural
gas
consumption
limit.
Installation of
flue gas
recirculation
required by
(0050-20)
II.B.1.b
Current operations meet RACT,
no further action warranted.

70 https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001863.pdf

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January 1,
2028 under
SIP Section IX,
Part H.23.g.
VOCs Use of pipeline
quality natural
gas, good
combustion
practices,
good design, &
proper
operation.
(0050-20)
I.4
5.5 Hydrochloric
Acid Plant
Burner
VOCs Use of pipeline
quality natural
gas, good
combustion
practices,
good design, &
proper
operation.
(0050-20)
I.4
Current operations meet RACT,
no further action warranted.
NOx Compliance
with a plant-
wide natural
gas
consumption
limit.
(0050-20)
II.B.1.b
5.4 Diesel
Engines
VOCs Proper
maintenance
and operation,
compliance
with
applicable
MACT
requirements,
and
compliance
with a
horsepower-
hour
operational
limitation.
(0050-20)
I.4 &
II.B.4.b
Current operations meet RACT,
no further action warranted.
NOx

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84

5.6 Casting
House
VOCs Use of pipeline
quality natural
gas, good
combustion
practices,
good design, &
proper
operation.
(0050-20)
I.4
Current operations meet RACT,
no further action warranted.
NOx Compliance
with a plant-
wide natural
gas
consumption
limit.
(0050-20)
II.B.1.b
5.7 Lithium
Carbonate
Plant Boilers
& Burners
VOCs Use of pipeline
quality natural
gas, good
combustion
practices,
good design, &
proper
operation.
(0050-20)
I.4
Current operations meet RACT,
no further action warranted.
NOx ULNBs on
boilers and
LNBs on
burners;
compliance
with a plant-
wide natural
gas
consumption
limit.
(0050-20)
II.B.1.b &
II.B.12.d
VOC
RACT71
Boron Plant VOCs Installation of
a steam
stripper and
RTO system
that will
achieve 98%
control
efficiency by
October 1,
2024.
N/A Installation of a steam stripper
and RTO system by October 1,
2024, required by SIP Section IX,
Part H.32.k.

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Small
Source
BACT72
Fuel Storage
Tanks
VOCs Proper
maintenance
and operation.
(0050-20)
I.4
Current operations meet RACT,
no further action warranted.
Small
Source
BACT
Paint Booths VOCs Good
operating
practices and
compliance
with
consumption
and VOC
limitations.
(0050-20)
I.4,
II.B.11.a,
& II.B.11.d
Current operations meet RACT,
no further action warranted.
1
4.15.5 Conclusion of RACT Implementation 2
The UDAQ determined that the emission units/activities currently meet all RACT requirements, 3
and all other existing controls and emissions limitations are considered RACT for US Magnesium. 4
However, RACT evaluations showed that the installation of a steam stripper in series with a regenerative 5
thermal oxidizer (RTO) to control VOC emissions from the Boron Plant Process Wastewater Ponds is 6
technically feasible. 7
The UDAQ has determined that these controls are necessary for the NWF NAA to demonstrate 8
attainment of the 2015 8-hour ozone NAAQS as expeditiously as practicable. While the financial 9
feasibility of the identified controls may be beyond previously established RACT thresholds, the CAA 10
provides states with “discretion to require beyond-RACT reductions from any source” if those reductions 11
are necessary to “demonstrate attainment as expeditiously as practicable”. 73 12
The installation of a steam stripper with RTO on the Boron Plant Process Wastewater Ponds will 13
control emissions from this process by approximately 98% resulting in 161.70 tpy of VOC emissions 14
reductions. The steam stripper with RTO shall be installed and operational by October 1, 2024. All 15
requirements for the Boron Plant are incorporated into SIP Section IX, Part H.32.k. No other additional 16
RACT measures were identified, and all other RACT determinations are already being implemented. 17
4.16 Chevron Salt Lake Marketing Terminal 18
4.16.1 Introduction 19
This section specifically serves as an evaluation of Chevron Salt Lake Marketing Terminal 20
(Chevron Terminal). The emissions units at the Chevron Terminal were not included in the PM2.5 serious 21
SIP. At that time, UDAQ considered the Chevron Terminal as a separate source from the Chevron 22
Refinery. However, recent permitting actions have since established that the Chevron Terminal and 23
Chevron Refinery are considered one stationary source. Therefore, UDAQ requested a RACT analysis for 24
the emission units at the Chevron Terminal. Chevron Terminal submitted a RACT analysis for evaluation 25

72 https://documents.deq.utah.gov/air-quality/pm25-serious-sip/DAQ-2018-007161.pdf
73 80 FR 12279 & 83 FR 62998

UTAH DIVISION OF AIR QUALITY
86

March 30, 2021, with supporting information submitted January 4, 2023. Specific conditions applicable 1
for this SIP revision for Chevron Terminal can be found in Section IX, Part H.32.b. 2
4.16.2 Facility Process Summary 3
The Chevron Terminal is a bulk gasoline terminal, which receives product by pipeline from the 4
Chevron Refinery, as well as ethanol and additives from outside vendors by truck and railcar. Products 5
are dispensed through the primary truck loading rack to cargo tank trucks where the product is 6
delivered to gasoline dispensing facilities. Storage tanks at the site store gasoline, ethanol, Transmix, 7
diesel fuel, water, additives, hydraulic fluid, motor oil, and jet fuel. Ethanol and other additives are 8
blended in line with refined products at the truck loading rack. 9
4.16.3 Facility Baseline Actual Emissions and Current PTE 10
The baseline and current PTE from Chevron Terminal processes and equipment are summarized 11
in Table 48. The 2017 actual emissions were used as the baseline emissions. The current PTE values for 12
Chevron Terminal were established by the most recent active AOs issued to the source. 13
 AO DAQE-AN105560017-15 issued May 18, 2015 (0017-15) 14
Table 48: Chevron Salt Lake Marketing Terminal Facility-Wide Emissions 15
Chevron Salt Lake Marketing Terminal Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx N/A N/A
VOC 13.64 33.60
4.16.4 RACT Analysis 16
The RACT evaluations were performed using data from Chevron Terminal, AOs, and supporting 17
documentation. Various resources were evaluated to identify all existing and potential controls and 18
emission rates, including EPA’s RBLC; technical documents, EPA fact sheets, applicable CTGs, and other 19
applicable literature; state and federal regulations; and other state SIPS. The RACT determinations for 20
each emission unit or activity emitting NOx and VOCs are provided in Table 49. 21
22
Table 49: Chevron Salt Lake Marketing Terminal 23
Chevron Salt Lake Marketing Terminal
RACT
Section
#74
Emission
Unit/Activity
Pollutant RACT
Determination
AO
Conditions
Comments
2.2.1

Transport
Loading Rack

VOCs

Vapor recovery
unit with carbon
adsorption in
compliance with
MACT Subpart R.

(0017-15)
II.B.1.b &
II.B.1.c
Current
operations
meet RACT,
no further
action
warranted.

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2.2.3

Fugitive
Emissions

VOCs

LDAR in
accordance with
MACT Subpart R
and NSPS Subparts
XX and Kb.

(0017-15) I.5
2.2.1

Specialty Rack

VOCs

Bottom loading
with good work
practice standards.

(0017-15) I.5
& II.B.1.c
Current
operations
meet RACT,
no further
action
warranted.

2.2.2

Storage Tanks

VOCs

Top-submerged or
bottom loading of
tanks; good design
methods and
operating
procedures; and
compliance with
applicable NSPS
Subpart Kb
requirements.

(0017-15)
II.B.1.c
Current
operations
meet RACT,
no further
action
warranted.

4.16.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emissions limitations are considered RACT for the Chevron Terminal. RACT evaluations showed that 3
additional add-on controls or limitations are not technically or economically feasible options at this time. 4
No additional RACT measures were identified, and all RACT determinations are already being 5
implemented. Therefore, there are no additional implementation schedules or requirements for the 6
Chevron Terminal as required by this SIP revision. 7
4.17 Holly Energy Partners Woods Cross Terminal 8
4.17.1 Introduction 9
This section specifically serves as an evaluation of Holly Energy Partners Terminal (Holly 10
Terminal). The emissions units at the Holly Terminal were not included in the PM2.5 serious SIP. At that 11
time, UDAQ considered the Holly Terminal as a separate source from the main refinery. However, recent 12

UTAH DIVISION OF AIR QUALITY
88

permitting actions have since established that the Holly Terminal and Woods Cross Refinery are 1
considered one stationary source. Therefore, UDAQ requested a RACT analysis for the emission units at 2
the Holly Terminal. Holly Terminal submitted a RACT analysis for evaluation February 12, 2021. Specific 3
conditions applicable to this SIP revision for Holly Terminal can be found in Section IX, Part H.32.e. 4
4.17.2 Facility Process Summary 5
The Holly Terminal is a petroleum products loading facility located in Woods Cross. The terminal 6
consists of a loading rack and a soil remediation system. The bulk terminal is used by the Holly Terminal 7
to load gasoline and diesel products into tanker trucks. The Holly Terminal receives gasoline, diesel, and 8
jet fuel via pipeline from the HF Sinclair Woods Cross Refinery. The petroleum products are loaded into 9
tanker trucks for offsite transportation. The Holly Terminal doesn’t have aboveground storage tanks. 10
4.17.3 Facility Baseline Actual Emissions and Current PTE 11
The baseline and current PTE from the Holly Terminal processes and equipment are summarized 12
in Table 50. The 2017 actual emissions were used as the baseline emissions. The current PTE values for 13
the Holly Terminal were established by the most recent active AOs issued to the source. 14
 AO DAQE-AN101230023B-07 issued October 17, 2007 (0023B-07) 15
 AO DAQE-AN101230034-10 issued November 18, 2010 (0034-10) 16
Table 50: Holly Energy Partners Woods Cross Terminal Facility-Wide Emissions 17
Holly Energy Partners Woods Cross Terminal Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx 0.32 2.53
VOC 2.14 9.13
18
4.17.4 RACT Analysis 19
The RACT evaluations were performed using data from Holly Terminal, AOs, and supporting 20
documentation. Various resources were evaluated to identify all existing and potential controls and 21
emission rates, including EPA’s RBLC; technical documents, EPA fact sheets, applicable CTGs, and other 22
applicable literature; state and federal regulations; and other state SIPS. The RACT determinations for 23
each emission unit or activity emitting NOx and VOCs are provided in Table 51. 24
25
Table 51: Holly Energy Partners Woods Cross Terminal 26
Holly Energy Partners Woods Cross Terminal
RACT
Section
#75
Emission
Unit/Activity
Pollutant RACT
Determination
AO
Conditions
Comments

75 https://documents.deq.utah.gov/air-quality/planning/air-quality-policy/DAQ-2022-011295.pdf

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5.1 Transport
Loading Rack
VOCs Vapor recovery
unit with carbon
adsorption in
compliance with
MACT Subpart
CC; vapor
combustion unit
backup.
(0023B-
07) #7, #9,
& #16
Current operations meet
RACT, no further action
warranted.
5.2 Fugitive
Emissions
VOCs LDAR required by
NSPS Subpart
VVa.
(0023B-
07) #12
Current operations meet
RACT, no further action
warranted.
5.3 Soil
Remediation
System
VOCs Thermal/catalytic
oxidizer.
(0034-10)
I.5; II.B.1.b
Current operations meet
RACT, no further action
warranted.
1
2
4.17.5 Conclusion of RACT Implementation 3
The emission units/activities currently meet all RACT requirements, and the existing controls 4
and emissions limitations are considered RACT for the Holly Terminal. RACT evaluations showed that 5
additional add-on controls or limitations are not technically or economically feasible options at this time. 6
No additional RACT measures were identified, and all RACT determinations are already being 7
implemented. Therefore, there are no additional implementation schedules or requirements for the 8
Holly Terminal as required by this SIP revision. 9
4.18 Tesoro Logistics Operations LLC Truck Loading Rack and Remote Tank Farm 10
4.18.1 Introduction 11
This section specifically serves as an evaluation of Tesoro Logistics Operations LLC Truck Loading 12
Rack and Remote Tank Farm (Tesoro TLR). The emissions units at the Tesoro TLR were not included in 13
the PM2.5 serious SIP. At that time, UDAQ considered the Tesoro TLR as a separate source from the main 14
refinery. However, recent permitting actions have since established that the Tesoro TLR and Marathon 15

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Refinery are considered one stationary source. Therefore, UDAQ requested a RACT analysis for the 1
emission units at the Tesoro TLR. Tesoro TLR submitted a RACT analysis for evaluation March 31, 2021, 2
with an updated RACT analysis submitted January 31, 2023. Specific conditions applicable to this SIP 3
revision for Tesoro TLR can be found in Section IX, Part H.32.j. 4
4.18.2 Facility Process Summary 5
The Tesoro TLR is a bulk gasoline terminal, which receives products from the Marathon Refinery. 6
Products are dispensed through the primary truck loading rack to cargo tank trucks where the product is 7
delivered to gasoline dispensing facilities. Storage tanks at the site store gasoline, diesel fuel, kerosene, 8
heavy oils, and fuel additives. 9
4.18.3 Facility Baseline Actual Emissions and Current PTE 10
The baseline and current PTE from the Tesoro TLR processes and equipment are summarized in 11
Table 52. The 2017 actual emissions were used as the baseline emissions. The current PTE values for the 12
Tesoro TLR were established by the most recent active AOs issued to the source. 13
 AO DAQE-AN156590008-18 issued March 12, 2018 (0008-18) 14
Table 52: Tesoro Logistics Operations LLC TLR and RTF Facility-Wide Emissions 15
Tesoro Logistics Operations LLC TLR and RTF Facility Emissions
Pollutant Baseline Emissions
(TPY)
PTE
(TPY)
NOx N/A N/A
VOC 18.24 107.92
4.18.4 RACT Analysis 16
The RACT evaluations were performed using data from Tesoro TLR, AOs, and supporting 17
documentation. Various resources were evaluated to identify all existing and potential controls and 18
emission rates, including EPA’s RBLC; technical documents, EPA fact sheets, applicable CTGs, and other 19
applicable literature; state and federal regulations; and other state SIPS. The RACT determinations for 20
each emission unit or activity emitting NOx and VOCs are provided in Table 53. 21
22
Table 53: Tesoro Logistics Operations LLC TLR and RTF 23
Tesoro Logistics Operations LLC Truck Loading Rack and Remote Tank Farm
RACT
Section
#76
Emission
Unit/Activity
Pollutant RACT
Determination
AO
Conditions
Comments

76 https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001507.pdf

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5.1 Transport
Loading Rack
VOCs Vapor
recovery unit
with carbon
adsorption in
compliance
with MACT
Subpart CC.
(0008-18)
II.B.1.l
Current operations meet RACT,
no further action warranted.
4.1 Fugitive
Emissions
VOCs Enhanced
LDAR required
by NSPS
Subpart GGGa
and
maintenance
vent
monitoring.
(0008-18)
I.7
Current operations meet RACT,
no further action warranted.
6.1 Fixed Roof
Tanks
VOCs Good design
methods and
operating
procedures;
closed vent
system to a
carbon
adsorber on
OWS Tank.
(0008-18)
I.7;
II.B.1.c -
II.B.1.k
Current operations meet RACT,
no further action warranted.
7.1 Internal
Floating
Roof Tanks
VOCs Good design
methods and
operating
procedures;
compliance
with
applicable
NSPS Subpart
Kb
requirements;
and tank
degassing
requirements.
(0008-18)
I.7;
II.B.1.c -
II.B.1.k
Current operations meet RACT,
no further action warranted.
1

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4.18.5 Conclusion of RACT Implementation 1
The emission units/activities currently meet all RACT requirements, and the existing controls 2
and emissions limitations are considered RACT for the Tesoro TLR. RACT evaluations showed that 3
additional add-on controls or limitations are not technically or economically feasible options at this time. 4
No additional RACT measures were identified, and all RACT determinations are already being 5
implemented. Therefore, there are no additional implementation schedules or requirements for the 6
Tesoro TLR as required by this SIP revision. 7
4.19 CTG and ACT 8
For all sources located within the NWF NAA examined as part of this RACT analysis, any 9
applicable CTGs or ACTs were found to have been implemented to the relevant source through existing 10
AOs or SIP conditions. Any published CTG or ACT not enacted within the NAA boundary results from the 11
fact that the NWF does not have sources in which those CTGs are applicable. Details regarding this 12
analysis and additional information about source specific CTG and ACT applicability can be found in the 13
CTG VOC Source Categories Analysis TSD.77 14
Thus, the UDAQ conducted no further RACT analysis for CTG source categories not included in 15
AOs or SIP conditions as there are not sources subject to those CTGs within the NWF NAA. Therefore, 16
this SIP revision has met the CTG requirements as required under CAA Section 182(b)(2). 17
4.20 RACT Conclusions 18
Upon completion of RACT analysis for each of the major industrial sources located within the 19
NWF NAA, or nearby in the case of US Magnesium, the UDAQ has concluded that the controls identified 20
in Table 54, with the corresponding emission limitations included in Utah SIP Section IX, Part H.31 and 21
H.32, are necessary for the NWF NAA to demonstrate attainment of the 2015 8-hour ozone NAAQS as 22
expeditiously as practicable. While the financial feasibility of some of these controls may be beyond 23
previously established RACT thresholds, the CAA provides states with “discretion to require beyond-24
RACT reductions from any source” if those reductions are necessary to “demonstrate attainment as 25
expeditiously as practicable”. 78 The precedent for the requirement of “beyond-RACT” controls for an 26
ozone NAA demonstrating attainment at the earliest achievable date has been previously established in 27
2001,79 and further upheld in 2009.80 28
The implementation timeline of controls identified in Table 54 are beyond the implementation 29
deadline of January 1, 202381 and therefore will not count towards RFP under this SIP revision. However, 30
the state of Utah has ongoing obligations under Section 182 of the CAA to demonstrate attainment of 31
the NAAQS. The timing of compliance for states meeting statutory deadlines established in the CAA does 32
not impact or nullify those obligations for future SIP revisions. Thus, a state submitting a SIP revision 33
late, or meeting 182(b)(2) requirements late, does not negate the obligations imposed by the CAA. As a 34
result, the UDAQ has determined that the implementation of the controls identified in Table 54 are 35

77 NWF CTG VOC Source Categories Analysis: https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-005467.pdf
78 80 FR 12279 & 83 FR 62998
79 66 FR 26914
80 74 FR 1927
81 87 Fed. Reg. 60,897.

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required to be implemented on the most expeditiously practicable timelines to comply with these 1
ongoing CAA obligations. 2
While the controls identified in Table 54 have been determined to be beyond-RACT, the UDAQ 3
has concluded that these controls meet the definition of reasonable when considering their cost 4
effectiveness for controls considered beyond-RACT. This determination was made when examining 5
three variables that impact what constitutes reasonable including: 1) the regulatory landscape of the 6
NWF NAA (i.e. availability of control options), 2) other NAA determination of cost thresholds, 3) 7
appropriate adjustments for inflationary and other price pressures. 8
First, as noted in sections 5 and 7 of this SIP revision, Utah has previously implemented an 9
extensive array of emission reduction strategies at the BACT threshold while the state worked to 10
address wintertime PM2.5 pollution. These emission reductions target the same precursor emissions for 11
ozone, i.e. NOx and VOCs. As a result, there are exceedingly few control options available for the State to 12
implement at this time in the regulatory landscape of the NWF. In essence, the supply of available 13
controls is exceptionally low, while the demand to implement controls to comply with CAA 14
requirements is high. This same economic reality—what is considered a reasonable cost in one area will 15
be different than another area based on supply and demand— is seen in a wide array of economic 16
activities, such as housing. Therefore, it is reasonable to conclude that an appropriate cost threshold for 17
controls in the NWF NAA would be higher than that seen in an area with greater control options 18
available to it. This same reasoning follows that a reasonable cost threshold would be more similar to a 19
cost threshold seen in an NAA with fewer control options available. Further, a recent analysis conducted 20
by the UDAQ examining the cost effectiveness of emissions reduced from incentive programs identified 21
a similar scenario, with the cost to reduce emissions increasing as a result of previously implemented 22
incentive programs. In short, as programs (incentive or regulatory) reduce emissions from older, dirtier 23
equipment, the remaining pool of emissions sources are relatively cleaner, and thus the emission 24
reductions are more expensive per ton of pollutant removed. 25
Second, the UDAQ compared and contrasted the RACT cost thresholds with a number of other 26
NAAs, and compared cost thresholds for both RACT and BACT implemented controls. While many 27
contrasting NAAs that have recently implemented RACT determined an appropriate cost thresholds 28
between $5,000 - $10,000 per ton of pollutant removed,82 these areas are doing so with a wider array of 29
emission reduction strategies available to them. In contrast, the UDAQ examined BACT cost thresholds 30
in areas with more similar regulatory frameworks in place to see what the higher end of cost 31
effectiveness could be considered reasonable. The Division found instances of BACT cost thresholds near 32
$43,000 per ton of VOC and $41,000 per ton of NOx emission reductions.83 While these higher end 33
estimates are considered BACT, and thus represent a more stringent standard, the Division has 34
concluded that, given the existing regulatory framework in place in the NWF and the similarities 35
between these higher cost threshold NAAs, that a RACT cost threshold of approximately $10,000 per ton 36
of pollutant removed below that reported on the high end is reasonable for the NWF. The controls 37
outlined in Table 54 all fall near or below this threshold. Additionally, the UDAQ identified instances in 38
which a cost threshold of $10,000 was determined reasonable for Regional Haze SIPs.84 It’s worth noting 39
that Regional Haze SIPs are developed to meet visibility standards, not health-based standards as in this 40

82 Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Reasonably Available Control Technology Determinations for Case-by-Case
Sources Under the 1997 and 2008 8-Hour Ozone National Ambient Air Quality Standards, 85 Fed. Reg. 66,484, 66,486 (Oct. 20, 2020) (examples of benchmarks from
several other states examined by Pennsylvania).
83 2022 South Coast Air Quality Management District BACT Maximum Cost Effectiveness Values.
84 Oregon Regional Haze State Implementation Plan, for the period 2018 – 2028, available at https://www.oregon.gov/deq/rulemaking/Pages/rhsip2028.aspx.

UTAH DIVISION OF AIR QUALITY
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moderate ozone SIP. The Division believes that a reasonable threshold for a control used to protect 1
human health should be considerably higher than that determined reasonable for protecting visibility. 2
Lastly, the UDAQ also considered inflationary forces when determining a reasonable cost-3
effectiveness threshold. Since 2000, the United States has seen a cumulative price increase associated 4
with inflationary pressures of 77.18%.85 Similar upward price pressures have been observed in other 5
parts of the economy that impact the price of pollution controls. For example, the building cost index for 6
construction for nonresidential buildings over the same period cited for inflation above (2000 – 2023) 7
has risen from ~50 to just over 130—a 160% increase.86 If inflationary pressures are not taken into 8
consideration over time when determining reasonable cost-effectiveness thresholds, the ever-increasing 9
costs associated with building and installing controls would result in a diminished ability for responsible 10
air agencies to identify and require effective controls. These same inflationary economic forces have 11
been realized elsewhere in the regulatory world, resulting in an increase in the statutory civil monetary 12
penalties for violations as enforced by the EPA for the CAA violations rising from $25,000 in 1991 to 13
$55,808 in 2023 for each day of continued noncompliance. 14
When all three of these factors (existing regulatory framework, similar NAA thresholds, and 15
inflationary pressures) are taken together, the UDAQ has determined that the controls outlined in Table 16
54 are reasonable for an area in which beyond-RACT controls are necessary to attain the standard.87 A 17
SIP is intended to be a plan that matches the unique characteristics of each NAA, which is why the 18
responsible air agency has primacy to develop and implement the plan it determines best meets the 19
unique challenges of its air shed. When considering appropriate cost thresholds for a NAA, it is 20
important to recognize that the cost effectiveness for controls for that air shed will also be unique to the 21
NAA in question. 22
23
Table 54: Controls identified by RACT analysis for the NWF NAA. 24
Source Control Part H
Reference
Implementation
Timeline
Emission
Reductions
Tesoro Refining &
Marketing
Company LLC
Marathon
Refinery
NOx emission limits on
cogeneration turbines
with heat recovery
steam generation CG1
and CG2
XI.H.32.j.b October 1, 2028 68.78 tpy NOx
Tesoro Refining &
Marketing
Company LLC
Marathon
Refinery

Replacement of
wastewater API
separator and DAF unit
with a closed vent to
carbon adsorption
controls
XI.H.32.j. d December 31,
2025
10.0 tpy VOCs
Tesoro Refining &
Marketing
Company LLC
Secondary seal
installation on Tank
321
XI.H.32.j.c May 1, 2026 2.30 tpy VOCs

85 Bureau of Labor Statistics Consumer Price Index (CPI), available at https://www.bls.gov/cpi/.
86 Construction Analytics, Construction Inflation 2023, available at https://edzarenski.com/2022/12/20/construction-inflation-2023/.
87 42 U.S.C § 7545(d)(1); 40 CFR § 19.4.

UTAH DIVISION OF AIR QUALITY
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Marathon
Refinery

US Magnesium LLC Steam stripper in
series with RTO
XI.H.32.k October 1, 2024 161.70 tpy VOCs
1
Based on all available data including the examination of past submitted BACT reports, newly 2
submitted RACT analyses, and by requiring the implementation of “beyond-RACT” controls as identified 3
in Table 54, the NWF NAA has met all RACT criteria as required under CAA Section 182(b)(2) for this SIP 4
revision. Furthermore, the implementation of technologically feasible “beyond-RACT” controls 5
demonstrates not only completion of RACT requirements, but that the area will demonstrate attainment 6
as expeditiously as practicable. 7
4.21 Nonattainment New Source Review (NNSR) 8
NNSR is a CAA permitting program which requires industrial facilities to install modern pollution 9
control equipment when they are built, or when making a change that increases emissions significantly. 10
The purpose of an NNSR program is to protect public health and the environment, even as new 11
industrial facilities are built, by ensuring that air quality does not worsen in the NAA and air quality is not 12
significantly degraded. This is accomplished through preconstruction permitting. 13
Utah Administrative Rule R307-403; Permits: New and Modified Sources in Nonattainment and 14
Maintenance Areas,88 implements federal NAA permitting programs for major sources as required by 40 15
CFR § 51.165 and contains new source review provisions for some non-major sources in the ozone 16
NAAs. Rule R307-403 is applicable any new major stationary source or major modification that is major 17
for the pollutant or precursor pollutant for which the area is designated nonattainment if the stationary 18
source or modification is located anywhere in the designated NAA. This includes requirements that a 19
major stationary source in the NWF NAA obtain a ratio of total actual emission reductions of VOCs 20
compared to the emission increase of VOCs of at least 1.15:1 prior to commencement of operations and 21
permitting by the UDAQ. EPA determined that rule R307-403 meets the requirement for nonattainment 22
new source review under 40 CFR § 51.131489 on February 02, 202290 Therefore, this SIP revision 23
adequately addresses the CAA NAA requirements for NOx and VOC emission offsets. 24
25
26
27

88 Utah Admin. Code r. R307-403.
89 40 CFR § 51.1314 New source review requirements.
90 Approval and Promulgation of Implementation Plans; Utah; Emissions Statement Rule and Nonattainment New Source Review Requirements for the 2015 8-
Hour Ozone National Ambient Air Quality Standard for the Uinta Basin, Northern Wasatch Front and Southern Wasatch Front NAAs, 87 Fed. Reg. 5,435 (Feb. 1,
2022).

UTAH DIVISION OF AIR QUALITY
96

Chapter 5 - Reasonably Available Control Measures (RACM) Analysis 1
5.1 Overview 2
CAA section 172(c)(1) requires states to implement all RACM as expeditiously as practicable, 3
including RACT, to meet both RFP requirements and to demonstrate attainment of the NAAQS. The CAA 4
requires RACM to be implemented for point, area, non-road, and on-road sources categories to meet 5
the attainment standard. 6
The general approach to the RACM analysis is to evaluate control measures that have been 7
implemented at the federal level, in other states and other local air districts and, if reasonable and 8
practicable, to implement the controls to help the area attain the ozone standard. A RACM analysis 9
determines potential control measures for each source category by considering the following 10
requirements: 11
 technological feasibility of the control measure, 12
 economic feasibility of the control measure, 13
 if the control measure would cause substantial widespread and long-term adverse impacts, 14
 if the control measure is absurd, unenforceable, or impracticable, and 15
 if the control measure can advance the attainment date by at least one year. 16
UDAQ conducted a RACM analysis by analyzing the following materials: 17
 EPA guidance documents and regulations including: 18
o CTG, 19
o ACT, 20
o Ozone Transport Commission model rules. 21
 A comparison of existing Utah administrative rules to other EPA SIP-approved rules of the three 22
western air districts that were moderate nonattainment for the 2008 ozone standard. The 23
rationale for this comparison is that the selected air districts have already implemented ozone 24
controls approved by EPA. The three air districts are Imperial County, CA, Mariposa County, CA, 25
and Phoenix-Mesa (Maricopa County), AZ. These NAAs were selected for comparison since they 26
have comparable climatic conditions to those experienced in the NWF NAA during summer and 27
similar industrial activities present in the NWF NAA. Each area has served as a basis for RACT 28
and RACM comparisons for other ozone NAAs, hence emission reduction strategies adopted in 29
these areas serve as a base for many other current ozone NAAs. 30
 Lastly, an evaluation of newly identified technological and economically feasible controls, or if 31
enhancement of existing controls were available. 32
The RACM analysis for the NWF NAA examined control measures for all potential VOC and NOx 33
emission sources. As part of this analysis, UDAQ reviewed existing Utah administrative rules, many of 34
which were implemented as part of the Salt Lake PM2.5 serious SIP and were developed under the 35
regulatory guidelines of best available control measures (BACM) which allow for more stringent 36
measures to be implemented than those conforming to RACM. The rules adopted under the BACM 37
approach for state efforts to address PM2.5 pollution include 24 VOC-related administrative rules, which 38
are identified in Table 55. Furthermore, as the implementation rules under PM2.5 allow for the 39
implementation of emission reduction strategies beyond the attainment dates, the VOC emission 40

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97

reduction rules implemented during the PM2.5 SIP were not constrained by timelines and further 1
contribute to the exhaustive list of existing regulations in the NWF NAA. As the requirements for BACM 2
are significantly more stringent than for RACM, the majority of this analyses concluded that current 3
control measures are as, or more stringent than, the requirements for the moderate ozone SIP. 4
5
Table 55: Existing area source VOC rules in the NWF NAA91 6
Rule Name
R307-211 Emission Standards: Emission Controls for Existing Municipal Solid Waste Landfills
R307-230 NOx Emission Limits for Natural Gas-Fired Water Heaters
R307-303 Commercial Cooking
R307-304 Industrial Solvent Use
R307-328 Gasoline Transfer and Storage
R307-335 Degreasing
R307-341 Cutback Asphalt
R307-342 Adhesive and Sealants
R307-343 Emission Standards for Wood Furniture Manufacturing Operations
R307-344 Paper, Film & Foil Coating
R307-345 Fabric & Vinyl Coating
R307-346 Metal Furniture Surface Coating
R307-347 Large Appliance Surface Coating
R307-348 Magnet Wire Coating
R307-349 Flat Wood Panel Coating
R307-350 Miscellaneous Metal Parts & Products Coating
R307-351 Graphic Arts
R307-352 Metal Containers, Closure & Coil Coating
R307-353 Plastic Parts Coating
R307-354 Auto Body Refinishing
R307-355 Control of Emissions from Aerospace Manufacturing & Rework Facilities
R307-356 Appliance Pilot Light
R307-357 Consumer Products
R307-361 Architectural Coatings
5.2 RACM Analysis 7
To evaluate the VOC and NOX sources in the NWF NAA, UDAQ first evaluated the 2017 baseline 8
emission inventory described in section 3, examining emission categories with the highest emissions 9
contributions first, then proceeding to examine smaller emission categories, in an attempt to identify 10
the most impactful strategies first. Thus, Tables 56 and 57, which overview the results of UDAQ’s RACM 11
analysis, are presented in descending order of the magnitude of emission category, as is the 12
corresponding TSD for this analysis.92 Next, the UDAQ identified control techniques currently in place for 13

91 All these rules are found in the Utah Administrative Code.
92 Northern Wasatch Front Area Source Reasonable Available Control Measures (RACM) Analysis for Ozone Control. Technical Supporting Document (TSD).
https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001246.pdf

UTAH DIVISION OF AIR QUALITY
98

source categories and determine if existing controls and rules are up to date with federal guidance and 1
other states moderate ozone NAA rules. 2
3
Table 56: VOC RACM Assessment Summary 4
Source Category Utah Existing Rules/Statute and
Federal Rules
Comments
Solvent,
Consumer/commercial Use
Products
R307-357 Consumer Products R307-357 is the most current OTC
model rule, no further action
warranted
Solvent, Graphic Arts R307-351 Graphic Arts UDAQ worked closely with the
national printing trade association to
derive a BACM rule that would be in
line with printing rules found in the
most stringent California air districts.
No further analysis warranted.
Surface Coating, Industrial
Maintenance*
Surface coating rules R307-
343,344, 345,346,
347,348,349,350,352,353,354
and 355.

Surface Coatings, Traffic
Markings –
R307-361 Architectural Coatings
Most current control strategies for
surface coating and deemed to be
BACM by UDAQ.

R307-361 is the most current OTC
model rule and deemed to be BACM
by UDAQ.
Chemical Stripper R307-304 Solvent Cleaning
R307-335 Degreasing
UDAQ created the new rule R307-304
by removing sections of R307-335, in
which the applicability was
dramatically lowered, and a low vapor
pressure solvent option was added.
UDAQ determined that R307-304 was
BACM. No further analysis warranted.
Surface Coatings,
Architectural
R307-361 Architectural Coatings R307-361 is the most current OTC
model rule, no further action
warranted
Gas Pipelines 40 CFR 49 Subtitle B U.S. Dept. of Transportation is
responsible for pipeline safety and
spill prevention. No further action
warranted.
Asphalt R307-341 Cutback Asphalt Imperial and Maricopa counties
require lower VOC limits which were
not considered in this evaluation for
safety reasons. Reducing the VOC
content requires the asphalt to be
heated at a higher temperature
leading to possible flashing and
increase fuel usage negating any
VOC reductions.
Industrial Bakery

UDAQ issued a proposed rule for
public comment in 2016. Commenters
submitted documentation that the
estimated cost would be at least
$19,000/ton, requiring double-walled
stainless-steel stack plus catalytic

UTAH DIVISION OF AIR QUALITY
99

oxidation of ethanol. High capital cost
would require a rule with high
applicability threshold that would
preclude regulating most bakeries that
comprise these emissions. No further
action warranted.
Residential & Commercial
Portable Gas Cans
Evaporation/Spillage etc.
40 CFR Part 59, Subpart F,
Control of Evap. Emission from
New & In-use Portable Fuel
Containers
No further action warranted
Gas Under Ground
Storage Tank

DAQ enforces Federal UST
regulation. No further action
warranted.

Waste Disposal, Treatment,
and Recovery;
Composting;100% Green
Waste
R315-312 Recycling and
Composting Facility Standards
Composting operations are managed
by the Utah Solid Waste Division.
R315-312 includes facility and
material management requirements
to reduce air, soil and groundwater
impairment. The 3 comparative air
districts do not have air quality rules
for compost operations. No further
action warranted.
Leaking Underground
Storage Tanks
Title 19 Chapter 6 Part 4,
Underground Storage Tank Act
UDEQ enforces the EPA UST
regulation, no further action
warranted
Pesticide Application,
Commercial/Consumer
(FIFRA)
R307-357 Consumer Products R307-357 is the most current OTC
model rule, no further action
warranted
Fuel Gas/Gasohol Bulk
Plants
R307-328 Gasoline Transfer and
Storage
Maricopa County has additional EPA
SIP rules for gasoline transfer and
storage based upon federal stage 1
vapor recovery guidance. An
evaluation of Maricopa County’s rules
with Utah’s determined that no
additional control technique would
be beneficial, and our current rules
associated with these processes were
determined to be BACM.

Landfills R307-221 Emission Standards:
Emission Controls for Existing
Municipal Solid Waste Landfills
No further action warranted.
Combustion, Natural Gas,
Residential
R307-356 Appliance Pilot Light R307-356 prohibits appliance from
utilizing a pilot light thereby reducing
VOC’s. No further action warranted.

UTAH DIVISION OF AIR QUALITY
100

Gas Stage 1 R307-328 Gasoline Transfer and
Storage
Refer to discussion in section 5.2.1
Commercial Cooking Researchers in California have
been unable to identify cost
effective technology for this
emission source. Known control
measures have a high capitol cost
(>$50k) and demanding
maintenance such that the
removal cost would likely exceed
$20K/ton. Prohibitive cost would
shutter most sources. No further
action warranted.
Livestock Production

According to local USDA
representatives, most Utah producers
use National Resource Service best
management practices to protect soil,
water and air. No further action
warranted.

Sewer Treatment in Publicly
Owned Treatment Works
(POTW)
Clean Water Act: all POTW’s have
to report to EPA VOC
concentrations in discharges.
All major POTW’s meet Best Available
Technology, no further action
warranted.
Consumer and Commercial,
Miscellaneous Products
R307-357 Consumer Products R307-357 is the most current OTC
model rule, no further action
warranted
Fuel, Jet, Stage 1
(Storage)
Regulated under 40 CFR Subpart
Kb
Not technically feasible for jet fuel due
to low vapor pressure (0.125 psi). No
further action warranted.

Fires, Structural

Uncontrollable, no further action
warranted.

Backyard BBQ

Statutory Exemption, no further action
warranted.

Dairy and Beef Cattle
Composite

According to local USDA
representative, most Utah producers
use national conservation best
management practices.

Gas Tank Truck Transport R307-328 Gasoline Transfer and
Storage
Refer to discussion in section 5.2.1
Solvent, Dry Cleaning

Solvent dry cleaners use no transfer
machines that eliminate vapor loss
during transfer from washing to
drying. Additional built-in controls
include refrigerated condensers.
Some units also include built-in stills

UTAH DIVISION OF AIR QUALITY
101

to further recover vapors. No further
controls would be feasible. No further
analysis warranted.

Poultry According to the Utah Farm Bureau,
operations apply best management
practices to maintain healthy stock.

Fuel, Jet, Stage 2
(Dispensing)

Regulated under 40 CFR Subpart
CC or Subpart R
Not technically feasible for jet fuel due
to low vapor pressure (0.125 psi). No
further action warranted.

Commercial Cooking -
Conveyorized Charbroiling
R307-303 Commercial Cooking R307-303 requires all units to utilize
catalytic oxidizers. UDAQ and a
nonprofit environmental group
worked together to fund and install
catalysts in all units in the Wasatch
Front. No further action warranted.
Industrial Boiler Liquid
Propane Gas (LPG)

No known control measures. Source
may require permit with conditions
under R307-401.
LPG Fuel

No known control measures exist, no
further action warranted.

Fires, Vehicle

Uncontrollable, no further action
warranted.

Combustion, Natural Gas,
Industrial Boilers and IC
Engines

No known control measures exist.
Source may require permit conditions
under air quality permitting R307-401-
4(3) requiring low-NOx burners.

Commercial/institutional
wood Fuels

There are no reasonably cost-
effective control strategies for this de
minimis emission. No further action
warranted.

Residential Oil Fuel

No known control exists, no further
action warranted.

Cremation, Human and
animal

Catalytic oxidizer control cost would
readily exceed $15k/ton, an
unreasonable cost for a de minimis
emission. No further action warranted.

Commercial/institutional
Kerosene Combustion

No known control, no further action
warranted.

Aircraft/Rocket Engine
Firing and Testing

Uncontrollable event for aircraft
maintenance/testing (no rocket
engine). No further action warranted.

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Solvents; Hot Mix Asphalt NEW Administrative Rule:
R307-313; VOC and Blue Smoke
Controls for Hot Mix Asphalt
Plants
The UDAQ has identified blue smoke
controls reducing VOC emissions
associated with blue smoke from Hot
Mix Asphalt plants being RACM. As a
result, the Utah Air Quality Board has
adopted Utah Administrative Rule
R307-313 to fulfill this requirement.
*Surface Coating, Industrial Maintenance: EPA has aggregated coatings of the following surfaces: wood 1
furniture, paper, film, foil, fabric, vinyl, metal furniture, large appliances, magnet wire, wood panel, 2
metal parts, metal containers, plastic parts, autobody and aerospace parts. 3
4
Table 57: NOX RACM Assessment Summary 5
Source Category Utah Existing
Rules/Statute and Federal
Rules
Comments
Combustion, Natural
Gas
R307-356 Appliance Pilot
Light.

R307-230 NOx Emission
Limits for Natural Gas-Fired
Water Heaters

PROPOSED: R307-315 &
R307-316
Prohibits the sale of appliance pilot lights (with
the exception of water heaters) after January 1,
2014. A Canadian study determined that a gas
fireplace pilot light accounts for 48% of the
annualized gas usage for the appliance.
Reduced gas consumption translates to a
reduction in PM2.5, VOC, NOx, SOx and NH3. We
are not aware of other comparable rules.

Ultra-low NOx water heaters reduce emissions to
10 ng/Joule for residential units and slightly
higher limits for commercial units. R307-230 is
consistent with the most stringent California
rules. No further action warranted.

The UDAQ has identified ultra-low NOx burners
(9 ppmv) as being RACM in most instances when
applied to replacement of end-of-life equipment
or replacement burners. Some instances,
particularly for high MMBtu units, may exceed
RACM requirements and require regulatory
flexibility.

UDAQ is proposing the adoption of
administrative rules R307-315 and R307-316 to
fulfill this RACM requirement.

Combustion, Natural
Gas, Commercial &
Institutional Boilers
and IC Engines

May be subject to air quality permitting. R307-
401-4(3) may apply requiring low-NOx burners.

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Industrial Boiler LPG

May be subject to air quality permitting
depending on size of emission sources.

Combustion,
Industrial, Distillate
Oil, All IC Engines
May be subject to air quality permitting
depending on size of emission sources.

Combustion,
Commercial,
Institutional LPG

No known control.

Combustion,
Industrial, Distillate
Oil, All Boilers
May be subject to air quality permitting. R307-
401-4(3) may apply requiring low-NOx burners
depending on the size of emission source.

Residential LPG Fuel

No known control.

Combustion, Natural
Gas, Industrial Boilers
and IC Engines

May be subject to air quality permitting. R307-
401-4(3) may apply requiring low-NOx burners.

Commercial,
institutional wood
Fuels
There are no reasonably cost-effective control
strategies for this de minimis emission. No further
action warranted.

Backyard BBQ

Statutory Exemption, no further action warranted.

Structural fires

Uncontrollable

Residential Oil Fuel

No known control, no further action warranted.

Waste Disposal, Open
Burning, Yard Waste
and Household Waste
R307-202, General Burning
regulates yard waste
burning by permit and
prohibits household waste
burning by homeowners.
No further action warranted.
Cremation, Human
and animal

Catalytic oxidizer control cost would readily
exceed $15k/ton, an unreasonable cost for a de
minimis emission. No further action warranted.

Combustion,
Kerosene
No known control, no further action warranted.

Aircraft/Rocket
Engine Firing and
Testing

Uncontrolled event for aircraft
maintenance/testing (no rocket engine). No
further action warranted.

Motor vehicle fires

Uncontrollable.

1

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Table 58: RACM Identified Control Strategies 1
Source Category New or Proposed
Administrative Rules
Comments
Combustion, Natural Gas Proposed:

R307-315; NOx
Emission Controls for
Natural Gas-Fired
Boilers 2.0-5.0 MMBtu

R307-316; NOx
Emission Controls for
Natural Gas-fired
Boiler greater than 5.0
MMBtu

The UDAQ has identified ultra-low NOx
burners (9 ppmv) as being RACM in most
instances when applied to replacement of
end-of-life equipment or replacement burners.
Some instances, particularly for high MMBtu
units, may exceed previously established
RACM thresholds and require regulatory
flexibility.

UDAQ is proposing the adoption of
administrative rules R307-315 and R307-316
to fulfill this RACM requirement.

Solvents; Hot Mix Asphalt Utah Administrative:
R307-313; VOC and
Blue Smoke Controls
for Hot Mix Asphalt
Plants

The UDAQ has identified blue smoke controls
reducing VOC emissions associated with blue
smoke from Hot Mix Asphalt plants being
RACM. As a result, the Utah Air Quality Board
has adopted Utah Administrative Rule R307-
313 to fulfill this requirement.

5.3 RACM Analysis Conclusion 2
The evaluation of existing Utah administrative rules, EPA issued CTGs, ACTs, and OTC rules, as 3
well as similar western counties with moderate ozone NAAs determined that the NWF NAA has adopted 4
an expansive list of both VOC and NOx emission reduction rules for area sources. Through this process, 5
and in parallel with UDAQ working groups, two additional control techniques were identified as RACM 6
that will result in the reduction of NOx emissions from natural gas boiler as well as VOC emission 7
reduction from hot mix asphalt facilities (Table 58). These controls were determined to be reasonable 8
and will help the NAA reach attainment as expeditiously as practicable. As a result, the UDAQ has 9
adopted administrative rule R307-313; VOC and Blue Smoke Controls for Hot Mix Asphalt Plants as a 10
RACM strategy to reduce VOC emissions. Additionally, the UDAQ has adopted administrative rules R307-11
315; NOx Emission Controls for Natural Gas-Fired Boilers 2.0-5.0 MMBtu and R307-316: NOx Emission 12
Controls for Natural Gas-fired Boiler greater than 5.0 MMBtu. These reduction strategies, and their 13
implementation timelines, are discussed further in section 7. The UDAQ has determined that the NWF 14
NAA has met RACM requirements with the RACM analysis and the implementation of the two new 15
control strategies. 16
Beyond the RACM controls identified for natural gas-fired boilers and hot mix asphalt facilities, 17
the UDAQ has identified that the application of in-use limitations for small non-road engines, 18
particularly those used in lawn and garden operations, are likely to be reasonable in scope and could 19
result in significant emission reductions of both VOCs and NOx. Section 209 of the CAA prohibits states 20
from regulating mobile sources in certain ways,93 with section 209(e) specifically preempting states from 21
regulating emissions from non-road sources. While section 209 does prohibit a state from regulating 22

93 42 U.S.C. § 7543

UTAH DIVISION OF AIR QUALITY
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mobile source emissions, the prohibition is not absolute. In particular, section 209(d) allows states to 1
impose restrictions on when or where these engines can be operated (i.e., “in use“ restrictions), 2
including for source covered under 209(e). Thus, the UDAQ has identified that states are not preempted 3
from implementing meaningful emission reduction strategies covering non-road mobile sources through 4
in-use requirements. The UDAQ plans to develop and implement policies that address emissions from 5
these sources as the NAA works towards demonstrating attainment as expeditiously as possible. 6
However, the scope of implementing a policy that covers such a large amount of small and distributed 7
sources like non-road engines requires more time than allotted for in this SIP revision. The UDAQ 8
intends to develop and implement a policy aimed at reducing VOC emissions from these sources in 9
subsequent SIP revisions. 10
11
12

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Chapter 6 – Inspection and Maintenance (I/M) Program 1
6.1 Overview of I/M Programs 2
The transportation sector is a major source of both NOx and VOCs in and around the NWF NAA. 3
Although modern vehicles (1996 and newer) emit far less pollution than older vehicles due to improved 4
emission reduction technologies, these reductions depend on the on-board emission control systems 5
being adequately maintained and operating. If not properly maintained, vehicles will not perform as 6
originally designed, resulting in increased emissions. Malfunctions in emission control technologies can 7
cause emissions to increase substantially beyond federal vehicle standards, with even minor 8
malfunctions resulting in increased emissions. Therefore, identifying and repairing malfunctioning 9
vehicles is imperative to reducing vehicle-related emissions in NAAs. 10
Vehicle I/M programs require mandatory and periodic testing of on-road motor vehicles for 11
compliance with emission standards, and the repair of vehicles that do not meet standards. These tests 12
are designed to determine whether a vehicle’s emission controls are functioning properly, and whether 13
emissions levels are acceptable. The goal of an I/M program is to identify and repair high-emitting 14
vehicles to improve air quality in areas not attaining the NAAQS. EPA sets vehicle emission standards to 15
protect public health, however, these regulations do not guarantee proper operation and maintenance 16
of a vehicle’s emission controls over its lifetime. State and local governments implement I/M programs 17
to identify high-emitting vehicles and notify owners and operators to have these vehicles repaired. Once 18
repaired, vehicles must be retested to verify their emissions are within the standards. The 1990 19
amendments to the CAA mandated I/M programs for ozone and CO NAAs based on criteria such as air 20
quality status, population, and/or geographic location. 21
In parallel with CAA requirements, Utah Code requires that, if identified as necessary to attain or 22
maintain any NAAQS, a county must create an I/M program as authorized by the Utah Air Quality Board 23
to formally establish those requirements for county I/M programs after obtaining agreement from the 24
affected counties.94 Similarly, Utah Code also allows any county with an established I/M program to 25
subject individual motor vehicles to I/M testing at times other than the annual inspection.95 26
As a result of the NWF NAA’s previous designation as marginal nonattainment, as well as a CO 27
NAA that overlaps portions of the NWF NAA, under CAA Section 182(a) and Section 187, Utah was 28
previously required to implement and maintain an I/M program in the most populated counties in the 29
NWF NAA including: Davis, Salt Lake, and Weber Counties. Beyond the NWF NAA, Utah was also 30
required to implement an I/M program in the SWF NAA, which includes Utah County, to the south of the 31
NWF NAA (figure 1). These programs are required to be at least as effective as the EPA's Basic 32
Performance Standard.96 33
6.2 Federal Requirements 34
I/M programs are mandatory under CAA Section 182 for ozone NAAs. These programs may be 35
removed if the state can demonstrate that the program is no longer needed. However, the I/M program 36
would still be retained in the SIP as a contingency control measure, which would be triggered if the area 37

94 Utah Code Section 41-6a-1642 & Utah Code Ann. § 19-2-104(1)(g).
95 Utah Code Section 41-6a-1642
96 40 CFR § 51.352

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107

ever exceeds the applicable NAAQS.97 Additionally, states have the flexibility to develop their own I/M 1
programs based on local conditions, if the state can show that impacted areas will continue to meet air 2
quality standards. 3
There are two performance levels of any I/M program—basic or enhanced. Basic I/M programs 4
are a requirement for moderate ozone NAAs98 which requires testing for light-duty cars for any 5
urbanized population over 200,000 residents.99 An enhanced I/M program is required for serious, 6
severe, and extreme ozone NAAs100 with urbanized populations over 200,000. An enhanced I/M 7
program requires inspection of both light duty cars and light duty trucks.101 As a moderate NAA, the 8
NWF is only required to demonstrate that its existing I/M programs meet the basic I/M criteria. Since all 9
counties in the NWF NAA with populations over 200,000 have existing programs, no new I/M programs 10
are required as part of this SIP revision. 11
6.3 I/M Testing 12
There are three types of I/M testing that can be performed on vehicles: 13
14
 Visual Inspections: These inspections discourage tampering by checking for the presence of 15
certain required emission control parts such as catalytic converters. 16
 Tailpipe Testing: This inspection consists of measuring the exhaust emissions when a vehicle is 17
idle or under certain engine loads. This inspection is typically for models made in 1995 and 18
older. 19
 On-Board Diagnostics (OBD): Vehicles made in 1996 or later have been equipped with OBD 20
computerized systems. These systems continuously monitor emission control systems and will 21
activate the “check engine” light if a diagnostic trouble code is detected concerning the vehicle’s 22
emission controls. 23
6.4 Utah I/M Program History and General Authority 24
I/M programs were adopted in the early 1980’s in Utah as a required strategy to attain both the 25
ozone and CO NAAQS.102 These programs have played a critical role in reducing emissions that 26
contribute to ozone and CO and have been highly effective in improving air quality in urbanized parts of 27
the state. Utah's I/M programs are initially authorized in Utah Code Section 41-6-163.61, which was 28
enacted during the First Special Session of the Utah legislature in 1983. 103 I/M programs were initially 29
implemented in Davis and Salt Lake counties in 1984, by Utah County in 1986, and by Weber County in 30
1990. In 1994, Utah Code was amended to authorize the implementation of I/M programs stricter than 31
minimum federal requirements in counties where it is necessary to attain or maintain a NAAQS. 104 32

97 40 CFR § 51.905 (A)(4)(i).
98 CAA Section 182(b)(4), 42 U.S.C. § 7511a(b)(4).
99 40 CFR § 51.350(a)(4).
100 CAA Section 182(c)(3), 42 U.S.C. § 7511a(c)(3).
101 40 CFR § 51.350(7) and (8).
102 Davis, Salt Lake, Utah, and Weber counties are required to have I/M programs under Section 182(b)(4) and/or Section 187(a)(4) of the CAA.
103 This section has been renumbered as section 41-6a-1642 by Laws 2005, c. 2, § 216, eff. Feb. 2, 2005.
104 1994 Utah Code.

UTAH DIVISION OF AIR QUALITY
108

This section of the Utah Code required preference be given to a decentralized program to the 1
extent that a decentralized program would attain and maintain ambient air quality standards and would 2
meet federal requirements. Thus, I/M programs in Utah are implemented at the county level, and not 3
directly by the state of Utah. Utah Code also required affected counties and the Utah Air Quality Board 4
to give preference to the most cost-effective means to achieve and maintain the maximum benefit 5
regarding air quality standards, and to meet federal air quality requirements related to motor vehicles. 6
The Utah legislature indicated preference for a reasonable phase-out period for replacement of air 7
pollution test equipment made obsolete by program in accordance with applicable federal 8
requirements, and if such a phase-out does not otherwise interfere with attainment of ambient air 9
quality standards. 10
By January 1, 2002, OBD inspections and OBD-related repairs were required as a routine 11
component of Utah I/M programs on model year 1996 and newer light-duty vehicles and light-duty 12
trucks equipped with certified OBD systems. The federal performance standard requires repair of 13
malfunctions or system deterioration identified by or affecting OBD systems. In addition, in 2002, the 14
Utah State Legislature amended the Utah Code to allow for biannual inspection of cars six years old or 15
newer.105 This provision is applicable to the extent allowed under the current SIP for each county within 16
the NAA. Meaning the state would need to determine if the I/M programs in counties within the NAA 17
would need to have their testing frequency modified to comply with NAAQS standards. The state would 18
then work with local health departments to alter their requirements. 19
Most recently, in 2005 the Utah State Legislature renumbered and amended Utah Code to allow 20
counties with an I/M program to require college students and employees who park a motor vehicle on 21
college or university campus that is not registered in a county subject to I/M provisions to provide proof 22
of compliance with an emission inspection.106 23
6.5 UDAQ Evaluation of Current I/M Program 24
I/M programs in Utah are currently using OBD and tailpipe testing. However, I/M programs rely 25
mostly on OBD testing because most of the fleet is equipped with OBD systems, but there are still some 26
tailpipe tests being performed. Details on Utah existing I/M programs, relevant county ordinances and 27
regulations, network types and enforceability can be found in the applicable I/M TSD.107 28
In an effort to evaluate if existing I/M programs in the NWF NAA meet the requirements of a 29
moderate NAA, the UDAQ conducted basic performance standard modeling to show how the existing 30
I/M programs of Davis, Salt Lake, and Weber counties meet the applicable performance standard for a 31
basic I/M Program for the summer of 2023. 2023 was chosen as the analysis year to be consistent with 32
the year used for this modeling demonstration. This evaluation used the same MOVES modeling 33
assumptions used to develop the on-road mobile source 2023 projection inventory for the NWF NAA 34
covering Davis, Salt Lake, Weber, and Utah counties.108 Utah County provides reciprocity testing and, 35
given the proximity of Utah County to the NWF, its I/M program was included in the analysis. Tooele 36
County was not included in this analysis since the area does not meet the population threshold of 37
200,000 or more residents in which an I/M program is required.109 38

105 Utah Code Section 41-6-163.6
106 Utah Code Section 41-6a-1642
107 NWF Inspection and Maintenance (I/M) Program; 2015 Ozone NAAQS Moderate Ozone SIP, TSD
108 2023 EXISTING BASIC INSPECTION AND MAINTENANCE PERFROMANCE STANDARD MODELING TECHNICAL SUPPORT DOCUMENT:
https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001726.pdf
109 40 CFR § 51.350(a)(2) and (a)(3).

UTAH DIVISION OF AIR QUALITY
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The performance standard compares the modeling results of the existing program and 1
performance standard benchmark for a basic program for 2023. For a basic I/M program, if the 2
proposed/existing program achieves the same or lower emissions levels for VOC and NOx as the 3
performance standard benchmark program, then the proposed/existing program is considered to have 4
met the basic performance standard. Areas required to operate an I/M program as the result of being 5
classified (or reclassified) as moderate for an 8-hour ozone NAAQS must use the basic performance 6
standard, using the program design elements at 40 CFR § 51.352(e). Emission estimates are confined to 7
the EPA approved MOVES 3.0.3. This model produces emissions daily estimates for on-road vehicles by 8
providing emissions profiles for starts, exhaust, evaporative and hot soak conditions. Inputs include 9
speeds, vehicle fuel profiles and specifications, VMT, I/M profiles, VMT mix, vehicle age distributions, 10
and meteorological conditions. These inputs were chosen to meet EPA and Department of 11
Transportation guidance on updating local planning assumptions every 5 years.110 12
Compliance factors were compiled utilizing local 2017 I/M EPA data covering: Total Vehicles 13
tested, Total Failures, Waivers, and Failure Rate for the following testing procedures: Two Speed Idle, 14
OBD, and Gas Cap. The compliance data is from EPA prepared compliance data dated 2/21/2019. Since 15
this modeling exercise had been completed, 2020 I/M testing compliance factors have become available 16
(EPA prepared compliance data dated 8/12/2021)111. The only difference between the 2017 I/M and 17
2020 I/M compliance factors is in Weber County for light duty trucks model years 1996-2007 creating a 18
difference of 1%. Results of this analysis including county specific I/M program details utilized within 19
MOVES 3.0.3 are included in the Table 59 to Table 62.112 20
21
Table 59: 2023 Davis County Summer Basic Performance Modeling 22
2023 Davis County Summer Basic Performance Modeling (Tons Per Day)

NOx VOC
Davis I/M 7.42 2.77
Basic I/M 7.55 2.91
Difference 0.14 0.13
Table 60: 2023 Salt Lake Summer Basic Performance Modeling 23
2023 Salt Lake County Summer Basic Performance Modeling (Tons Per
Day)

NOx VOC
Salt Lake I/M 20.98 8.51
Basic I/M 21.42 8.94
Difference 0.44 0.43
24

110 EPA420-B-08-901 Dec 2008
111 https://www.epa.gov/compliance-and-fuel-economy-data/annual-certification-data-vehicles-engines-and-equipment
112 Utah’s 2023 Existing Basic Inspection and Maintenance Performance Standard Modeling Technical Support Document can be found on the NWF Moderate
Ozone SIP TSD web page at https://deq.utah.gov/air-quality/northern-wasatch-front-moderate-ozone-sip-technical-support-documentation#supporting-tsd.

UTAH DIVISION OF AIR QUALITY
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Table 61: 2023 Utah County Summer Basic Performance Modeling 1
2023 Utah County Summer Basic Performance Modeling (Tons Per Day)

NOx VOC
Utah I/M 10.39 3.37
Basic I/M 10.56 3.48
Difference 0.16 0.12
2
Table 62: 2023 Weber County Summer Basic Performance Modeling 3
2023 Weber County Summer Basic Performance Modeling (Tons Per Day)

NOx VOC
Weber I/M 5.87 2.12
Basic I/M 5.97 2.22
Difference 0.11 0.10
4
The analysis provided in this section, with the results highlighted in tables 59 – 62, indicates that 5
the existing I/M programs currently in place in the NWF meet the CAA requirements for moderate ozone 6
NAAs. 7
6.6 Implementation of I/M Program in Tooele County 8
9
To determine if the implementation of an I/M program in Tooele County would provide 10
significant benefit for the NWF NAA to demonstrate attainment of the NAAQS, UDAQ conducted an 11
analysis of the effects of implementing an I/M program in Tooele County using MOVES parameters 12
similar to those described in section 6.5. Tooele county has a relatively small population of 13
approximately 76,000 residents, and only a portion of the total county is included within the boundary 14
of the NWF NAA (Figure 1). Tooele county has not previously been required to implement an I/M 15
program since they are below the population threshold of 200,000 residents. 16
The results of this analysis are shown in Table 63. Based on these results, the UDAQ has 17
concluded that the emission reductions associated with implementing a Basic I/M program in Tooele 18
County would yield minimal emission reductions. Thus, the UDAQ has decided not to implement an I/M 19
program in Tooele County especially in light of the fact that the county does not meet the population 20
requirements found in 40 CFR § 51.350(a)(3), and the associated emission reductions would be small. 21
This determination does not exclude the possibility of an I/M program implemented in Tooele County at 22
a later date. 23
24
25

UTAH DIVISION OF AIR QUALITY
111

Table 63: I/M Program Implementation Evaluation for Tooele County in 2023 1

NOx VOC VOC
Refuel
NH3 PM2.5 Vehicle Miles
Traveled
No I/M Program 3.783 0.875 0.13 0.097 0.081 3,476,298
OBD I/M Program 3.74 0.833 0.13 0.097 0.081 3,476,298
Percentage Emission
Reduction
-1.14% -4.80% 0.00% 0.00% 0.00% 0.00%
TPD Emission
Reduction
-0.043 -0.042 0 0 0 0
2

UTAH DIVISION OF AIR QUALITY
112

Chapter 7 – Reasonable Further Progress (RFP) 1
7.1 Reasonable Further Progress 2
CAA section 172(c)(2) requires that SIP provisions include Reasonable Further Progress (RFP)113, 3
which is defined as “annual incremental reductions in emissions of the relevant air pollutant”114, or 4
ozone precursor emissions including NOx and/or VOCs. Section 182(b)(1)(A)(i) of the CAA further states 5
that for a moderate ozone NAA, “the State shall submit a revision to the applicable implementation plan 6
to provide for volatile organic compound emission reductions, within 6 years” after being designated as 7
a nonattainment area.115 This section goes on to say that “such a plan shall provide annual reductions in 8
emissions of volatile organic compounds and oxides of nitrogen as necessary to attain the national 9
primary ambient air quality standard for ozone.”116 Section 182(b)(1)(A)(i) further details RFP 10
requirements for a newly designated moderate NAAs, which is a demonstrated 15% reduction 11
specifically for VOC emissions, known as Rate of Progress (ROP).117 The EPA has consistently interpreted 12
the 15% VOC-only requirements as a one-time requirement throughout several implementation rules. 13
Starting with the 1997 8-hour ozone NAAQS implementation rule,118 which was revised and later 14
replaced by the 2008 NAAQS implementation rule,119 and finally affirming the same approach in the 15
2015 NAAQS implementation. This interpretation has been upheld by the DC Circuit.120 16
It is important to note that the CAA does not specify whether this one-time requirement must 17
be met as part of an ozone SIP revision. EPA has previously interpreted the statute relative to the ozone 18
SIPs, but that does not preclude the interpretation that Utah is proposing here because it is the “best 19
reading”121 of the statute and a “reasoned decisionmaking”122 consistent even with post-Loper Bright 20
review of the EPA’s decisions. Based on this interpretation,[Therefore,] the 15% VOC only component 21
achieved over a 6-year period identified in Section 182(b)(1)(A) of the CAA represents a one-time 22

113 42 U.S.C. § 7502(c)(2).
114 Id. § 7501(1).
115 Id. § 7511a(b)(1)(a)(i).
116 Id.
117 Id.
118 Final Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard—Phase 2; Final Rule To Implement Certain Aspects of the 1990 Amendments
Relating to New Source Review and Prevention of Significant Deterioration as They Apply in Carbon Monoxide, Particulate Matter and Ozone NAAQS; Final Rule for
Reformulated Gasoline, 70 Fed. Reg. 71,612, 71,615 (Nov. 29, 2005) (“Areas that are classified as moderate under the 8-hour standard that have already
implemented their 15 percent plans under their 1-hour ozone SIPs would be considered to have met the statutory 15 percent requirement. Reasonable further
progress for the first 6 years from the baseline year would be covered under the more generic RFP requirements of subpart 1. “).
119 Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements, 80 Fed. Reg. 12,264, 12,271 (March 6,
2015) (“With respect to RFP requirements, we interpret the 15 percent VOC emission reduction requirement in CAA section 182(b)(1) such that an area that has
already met the 15 percent requirement for VOC under either the 1-hour ozone NAAQS or the 1997 ozone NAAQS (for the first 6 years after the RFP baseline year
for the prior ozone NAAQS) would not have to fulfill that requirement again. Instead, such areas would be treated like areas covered under CAA section 172(c)(2) if
they are classified as Moderate for the 2008 ozone NAAQS, and would need to meet the RFP requirements under CAA section 182(c)(2)(B) if they are classified as
Serious or above for the 2008 ozone NAAQS.”).
120 Natural Resources Defense Council v Environmental Protection Agency, 571 F.3d 1245 (D.C. Cir. 2009) (holding that EPA reasonably interpreted the CAA
provision requiring a moderate or greater nonattainment area to provide for VOC emission reductions of at least 15 percent). This decision should not be disturbed
by the holding in Loper Bright Enterprises v. Raimondo, 144 S. Ct. 2244 (2024)[No. 22-1219, 2024 WL 3208360, at *5 (U.S. June 28, 2024)] overruling Chevron, U.S.A.,
Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984) because Loper Bright expressly held that by overruling Chevron the Court “does not call into
question prior cases that relied on the Chevron framework.” Further “[t]he holdings of those cases that specific agency actions are lawful—including the Clean Air
Act holding of Chevron itself—are still subject to statutory stare decisis despite the Court's change in interpretive methodology. Mere reliance on Chevron cannot
constitute a “special justification” for overruling such a holding.” Loper Bright, 144 S.Ct. at 2273[2024 WL 3208360, at *5] (cleaned up).
121 Loper Bright, 144 S. Ct. at 2247.
122 Id. citing Michigan v. EPA, 576 U.S. 743, 750 (2015) (internal quotation marks and citations omitted).

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requirement, and once an area has achieved a 15% reduction of VOCs relative to an established NAAQS 1
baseline year, the area can fulfill subsequent RFP requirements utilizing NOx and/or VOC reductions, as 2
instructed by the CAA. 3
Having previously met the one-time 15% VOC only reduction as part of the substantial VOC 4
emission reductions achieved under previous PM2.5 SIPs, including a 21.2% VOC reduction relative to the 5
2010 PM2.5 base year achieved in a 6-year period,123 and a 43.2% VOC reduction relative to the 1980 1-6
hour ozone standard, the state of Utah is pursuing compliance with RFP / ROP for this SIP revision 7
through both NOx and VOC emission reductions under CAA Section 172(c)(2) and 182(b)(1(A). Therefore, 8
the RFP requirement for this SIP revision is to reduce ozone precursor emissions by 15% relative to the 9
VOC emissions of the established 2017 baseline year within six years for the purpose of ensuring 10
attainment of the NAAQS by the attainment date of August 3, 2024. The state must identify and 11
implement emission reduction strategies equal to or greater than 15% of the 2017 baseline VOC 12
inventory described in Section 3.2 (Table 7) by January 1, 2023. In order for reductions to count towards 13
RFP, they must occur at sources located within the boundary of the NAA, and “have actually 14
occurred”124, meaning they are quantifiable with strategies developed to reduce emissions being 15
enforceable. 16
Details regarding past SIP emission reductions of ozone precursor emissions, including 17
demonstrations of a 15% VOC reduction relative to a base year for multiple primary NAAQS, and an 18
overview of how the state is meeting current RFP requirements, are discussed in detail in Section 7.5. 19
7.2 Methodology 20
The methodology for determining compliance with CAA Section 182(b)(1)(A) RFP requirements 21
are as follows: 22
1) Develop an anthropogenic VOC baseline inventory (2017) for the NAA. 23
2) Develop an anthropogenic VOC projected inventory (2023) for the NAA that incorporates 24
anticipated emission reductions. 25
3) Demonstrate that VOC emissions in the projected year inventory (2023) are at least 15% lower 26
than the baseline (2017) (i.e., 2023 emissions – 2017 emissions >= 15% of 2017 emissions) and 27
meet the criteria described in Section 7.1. 28
Alternatively, if a state is pursuing compliance under Section 172(c)(2) of the CAA, the 15% 29
emission reduction requirement identified in steps 1-3 serve as the NAA wide emission reduction 30
requirement, however NOx reductions can be substituted in place of VOC reductions. Beyond 31
demonstrating the total 15% reduction requirement is fulfilled, a state must also show that the 32
reductions in NOx deliver an equivalent, or greater, improvement to air quality as would have been 33
achieved had RFP been met through VOC reductions alone. This demonstration can include 34
photochemical modeling analysis, as is discussed in sections 7.4.1.125 Lastly, the extent of the current 35
NAA boundary needs to be considered. NOx substitutions are only an available pathway in areas which 36
overlap the same geographic extent in which the previously approved VOC reductions occur. 37

123 Utah State Implementation Plan Section IX, Part A.21: Control Measures for Area and Point Sources, Fine Particulate Matter, PM2.5 SIP for the Salt Lake City, UT
Nonattainment Area. Adopted December 3, 2014.
124 42 USC § 7511a(b)(1)(C).
125 NOx Substitutions Guidance. U.S. EPA. December, 1993.
https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2_old/19931201_oaqps_nox_substitution_guidance.pdf

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7.3 RFP and Anthropogenic VOC Emission Reductions 1
Table 64 shows anthropogenic VOC emission for the NWF NAA for the baseline year of 2017 and 2
the projected year of 2023, as well as the change in emissions from 2017 compared to 2023 (i.e., 2017 – 3
2023 VOC emissions). The total anthropogenic VOC emissions for the NWF NAA in 2017 account for 93.7 4
tpd. As a result, the RFP requirement for the NWF NAA is 14.0 tpd reduction to achieve the 15% 5
reduction. 6
7
Table 64: Anthropogenic VOC Emission Reductions from 2017 to 2023 for the NWF 8
Source Sector
2017 Baseline
Anthropogenic VOC
Emissions (tpd)
2023 Projected
Anthropogenic
VOC Emissions
(tpd)
Δ Anthropogenic
VOC Emissions
(tpd)
% Δ
Anthropogenic
VOC Emissions
Airports 1.3 1.4 0.2 15.4
Livestock 0.7 0.7 ---- ----
Area 8.5 8.3 -0.2 -2.4
Non-Road
Mobile 12.5 12.6 0.1 0.8
On-Road
Mobile 20.5 15.3 -5.2 -25.4
Point 5.9 6 0.1 1.7
Point-Electric
Generating
Units
0 0 ---- ----
Rail 0.5 0.4 -0.1 -20
Solvents 43.2 44.5 1.3 3.0
ERC Bank 0.7 0.7 ---- ----
Total 93.7 90 -3.7 -3.9
9
10

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1
Figure 4: NWF Anthropogenic VOC Emission Inventories 2
As shown in Table 64 and Figure 4, there have been substantial VOC reductions in the on-road 3
mobile sector, resulting in 5.2 tpd of VOC reductions. These reductions are overwhelmingly due to 4
improvements in vehicle emission reduction technologies for personal automobiles and the introduction 5
of cleaner, tier 3 fuels, into the NAA. Other source sectors such as rail and area sources show small 6
emission reductions of 0.2 and 0.1 tpd, respectively. 7
While the area has experienced emission reductions across multiple sectors, the area is also 8
experiencing rapid population growth, with Utah being the fastest growing state in the nation in 2022 9
and projected to add 2.2 million more residents by 2060.126 As a result of this rapid population growth, 10
the NWF NAA has had emission increases in certain source sectors, including the non-road and solvents 11
sectors accounting for an added 0.2 tpd and 1.3 tpd, respectively. 12
The increased emissions in some source sectors that closely track population growth offset the 13
emission reductions in other sectors. As a result, the net total reductions of anthropogenic VOC 14
emissions in the NWF NAA are 3.7 tpd, accounting for a decrease of 3.9% of the baseline 2017 15
emissions. 16
7.4 Anthropogenic NOx Emissions 17
Table 65 shows anthropogenic NOx emissions for the NWF NAA for the baseline year of 2017 18
and the projected year of 2023, as well as the change in emissions from 2017 compared to 2023 (i.e., 19
2017 – 2023 NOx emissions). The area has experienced significant NOx reductions despite the substantial 20

126 Kem C. Gardner Policy Institute research and data, available at https://gardner.utah.edu/utah-population-to-increase-by-2-2-million-people-through-2060/
1.3 0.7
8.5
12.5
20.5
5.9
0 0.5
43.2
0.71.4 0.7
8.3
12.6
15.3
6
0 0.4
44.5
0.7
0
5
10
15
20
25
30
35
40
45
50
To
n
s

P
e
r

D
a
y
NWF Anthropogenic VOC Emission Inventories
2017 Baseline Anthropogenic VOC Emissions (tpd)2023 Projected Anthropogenic VOC Emissions (tpd)

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population growth. These reductions have played an important role in the area progressing towards 1
attaining the standard as expeditiously as possible, which is further discussed in section 7.4.1. 2
3
Table 65: Anthropogenic NOx Emission Reductions from 2017 to 2023 for the NWF 4
Source Sector
2017 Baseline
Anthropogenic NOX
Emissions (tpd)
2023 Projected
Anthropogenic NOX
Emissions (tpd)
Δ Anthropogenic
NOX Emissions
(tpd)
% Δ
Anthropogenic
NOx Emissions
Airports 3.1 3.7 +0.6 19.4
Livestock 0 0.0 ---- ----
Area 5.4 4.9 -0.5 -9.3
Non-Road Mobile 10.5 8.0 -2.5 -23.8
On-Road Mobile 55.5 35.4 -20.1 -36.2
Point 20.4 22.0 +1.6 7.8
Point-Electric
Generating Units 0.4 0.4 ---- ----
Rail 9.2 8.8 -0.5 -5.4
Solvents 0.6 0.7 +0.1 16.7
ERC Bank 3.1 3.1 ---- ----
Total 108.3 87.0 -21.3 -19.7
5
6

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Figure 5: NWF Anthropogenic NOx Emission Inventories 1
As shown in both Table 65 and Figure 5, the total anthropogenic NOx emissions for the NWF 2
NAA in 2017 account for 108.3 tpd, decreasing to 87.0 tpd in 2023, accounting for a 21.3 tpd reduction 3
in daily NOx emissions in this time period from 2017 to 2023. A substantial portion of these emission 4
reductions, much like those observed in VOC emission reductions (Section 7.3), come from the on-road 5
mobile sector because of continued improvements to vehicle engine standards and the introduction of 6
cleaner burning fuels, resulting in 20.1 tpd of emission reductions relative to the baseline year. The NAA 7
has also experienced NOx reductions in other sectors including non-road mobile, rail and area sources, 8
accounting for an additional 2.5, 0.5, and 0.5 tpd respectively. While some sectors have had small 9
amounts of emission growth, such as airports, the majority of emission source sectors are showing 10
reductions of anthropogenic NOx emissions. 11
7.4.1 Effectiveness of NOx emission reductions in the NWF NAA 12
Reductions in NOx have been identified as an effective strategy in reducing ozone formation in 13
the NWF NAA. A source apportionment modeling analysis conducted by the UDAQ using CAMx 14
(Comprehensive Air Quality Model with Extensions) OSAT (Ozone Source Apportionment Tool) (section 15
9.2) at the Hawthorne and Bountiful monitoring stations found that a little more than half of the 16
modeled ozone at both monitoring sites is attributable to NOx sources (Figure 6). Specifically, on 17
average, 54% of the ozone is attributable to NOx sources and 46% is attributable to VOC sources at the 18
Hawthorne station. Similarly, 53% of the ozone is attributable to NOx and 47% is attributable to VOCs at 19
the Bountiful station. These results indicate that ozone at the controlling monitors in the NWF NAA is 20
formed under both NOx- and VOC-limited conditions, with a little more than half of the ozone formed 21
under NOx-limited conditions. 22
3.1
0
5.4
10.5
55.5
20.4
0.4
9.2
0.6 3.13.7
0
4.9
8
35.4
22
0.4
8.8
0.7 3.1
0
10
20
30
40
50
60
To
n
s

P
e
r

D
a
y
NWF Anthropogenic NOx Emission Inventories
2017 Baseline Anthropogenic NOx Emissions (tpd)2023 Projected Anthropogenic NOx Emissions (tpd)

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While the modeling results have some uncertainty, the findings are consistent with those from a 1
VOC/NOx ratio analysis conducted by the UDAQ which utilized VOC measurements collected at the 2
Hawthorne monitoring site during the summer of 2021127. 8-hr time-integrated carbonyls measurements 3
and hourly Gas Chromatograph (GC) data with VOC concentrations weighted by their Maximum 4
Incremental Reactivity (MIR) (i.e. reactivity respective to ozone production/per unit VOC), collected 5
from June-August 2021, were used in this ratio analysis. Results showed that the area is in a transitional 6
regime, with controls on both VOCs and NOx emissions as potentially effective strategies to reduce 7
ozone formation. These findings are consistent with the CAMX results reported in this section. 8
9
10
11
12
Figure 6: NOx-attributable (brown) and VOC-attributable (green) ozone at Hawthorne (left panel) and Bountiful (right) 13
monitoring stations on average over all days of the modeling episode. 14
These findings support the UDAQ’s conclusion that the implementation of NOx reduction 15
controls as identified in section 4 (Table 54) as part of this SIP revision are necessary for the NWF NAA to 16
demonstrate attainment of the NAAQS as expeditiously as practicable. 17
The UDAQ also conducted a High-Order Decoupled Direct Method (HDDM) photochemical 18
analysis examining the predicted reductions in ozone concentrations for a given reduction of 19
anthropogenic NOx or VOC emissions to further assess the effect of NOx and VOC emission reductions 20
within the NAA. This analysis is particularly important as ozone chemistry is non-linear, and therefore a 21
1:1 relationship between NOx and/or VOC reduction and decreased ozone concentrations cannot be 22
assumed. The resulting isopleth plots (Figure 7) shows that much of the NWF NAA is fairly insensitive to 23
VOC emission reductions, especially at the controlling monitor. 24

127 https://harbor.weber.edu/Airqualityscience/docs/conferences/AQSfS-2022/AQSfS2022Posters/sghiatti_sci_4_sol_poster_2022.pdf

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1
2
Figure 7: Average maximum daily 8-hour ozone isopleths representing NOx and VOC reductions and the resulting predicted 3
ozone concentrations at Bountiful (left) and Hawthorne (right) monitoring station. Analysis was conducted using CAMx version 4
7.1 HDDM and demonstrates the sensitivity to NOx reductions vs. VOC reductions at the two monitoring sites. 5
This analysis further identified that much of the NAA is more sensitive to NOx reductions on 6
exceedance days, however significant reductions of greater than 50% of NAA anthropogenic emissions 7
would still be needed to attain 2015 8-hr ozone NAAQS. This analysis highlights that NOx reductions play 8
a critical role in Utah pursuing a reasonable pathway towards attaining the standard, with a NOx heavy - 9
limited VOC reduction pathway being the most beneficial pathway for the NWF NAA to improve 10
summertime air quality. These results confirm the unique characteristics of the NWF NAA airshed and 11
show that an equivalent reduction in NOx emissions provides as great, or greater, of an improvement in 12
air quality than VOC emission reduction alone. Therefore, the 21.5 tpd of NOx reductions implemented 13
as part of the moderate ozone SIP delivers a greater improvement to air quality than would have been 14
seen with a 15% reduction of VOC emissions alone. As a result, the 25.0 tpd of ozone precursor 15
emissions (NOx + VOC) reductions documented in this SIP revision represents the best possible pathway 16
for delivering the maximum improvement in air quality. 17
7.5 CAA Section 172(c)(2) and NOx Substitutions 18
As discussed in Section 7.1, the EPA interprets the 15% VOC reduction requirement of CAA 19
Section 182(b)(1)(A) as a one-time requirement for a nonattainment area. This is supported by the 2015 20
ozone implementation rule stating that a NAA designated as moderate that has implemented federally 21
enforceable VOC emission reductions equal to or greater than the current 15% requirement from a 22
previous ozone NAAQS SIP revision, are granted the opportunity to substitute a comparable amount of 23
NOx emission reductions under Section 172(c)(2), as long as those reductions deliver an equivalent 24
improvement in air quality.128 This section provides the necessary evidence to document past SIP-25

128 83 Fed. Reg. at 63,004 (“Areas classified Moderate for the 2015 ozone NAAQS that had SIPs previously approved to meet the ROP [RFP] requirements for the 1-
hour, 1997 8-hour or 2008 8-hour ozone NAAQS would be treated like areas covered under CAA section 172(c)(2)… the EPA continues to interpret CAA section

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approved VOC reductions in excess of 15% relative to a NAAQS base year in a 6 or less year window, as 1
well as the benefits to air quality associated with NOx reductions within the NWF NAA. Taken together, 2
this demonstrates the requirements needed to comply with CAA Section 172(c)(2) RFP requirements 3
utilizing the substitution of NOx emission reductions in place of VOC reductions. This approach is 4
consistent with the stated intent of RFP requirements, to “provide annual reductions in emissions of 5
volatile organic compounds and oxides of nitrogen as necessary to attain the national primary ambient 6
air quality standard for ozone”.129 Furthermore, as clearly demonstrated in Section 7.4.1, this approach 7
is the most appropriate for the NWF NAA where a combination of both NOx and VOC reductions 8
provides the most effective pathway towards attainment. 9
7.5.1 Past and Current SIP Emission Reductions 10
Table 66 overviews the substantial VOC emissions reductions achieved for both moderate130 and 11
serious131 PM2.5 SIPs for the Salt Lake City, UT nonattainment area, as well as the 1979 1-hour ozone 12
standard for the Davis – Salt Lake NAA. The emission reductions demonstrated in this table account for 13
only those emission reductions achieved in the counties included in the NWF NAA, therefore the 14
emission reductions associated with Box Elder County have been accounted for and removed from these 15
numbers. Emissions from Box Elder county account for 9% of the total NOx and VOC emissions in the 16
five-county area that comprise the Salt Lake PM2.5 NAA, and thus the emission reductions reported in 17
Table 66 were adjusted accordingly. This table demonstrates that in the five-year period from the 18
moderate PM2.5 base year of 2010 to the attainment year of 2015, VOC emissions were reduced from 19
118.3[130] tpd to 93.28[102.5] tpd, a reduction of 25.02[27.5] tpd. To meet the 15% RFP VOC reduction 20
requirements specified in 182(b)(1)(A), a decrease of VOC emissions by 17.75[19.5] tpd would have been 21
necessary. As a result, the [27.6]25.02 tpd of documented VOC emission reductions far exceeds a 15% 22
threshold of [19.5]17.75 tpd, and therefore serves to fulfill a past RFP plan, with more than a 15% 23
reduction occurring within a 6-year period. In fact, this reduction represents a 21[.21]% reduction, far in 24
excess of the 15% required to demonstrate RFP. 25
26
Table 66: VOC reductions in the NWF NAA during past SIPs timelines demonstrating a 15% VOC reduction relative to NAAQS 27
base years. 28
Moderate PM2.5 SIP
(2010 - 2015)+
Combined Moderate and
Serious PM2.5 SIP (2010 -
2020)+
1979 1-hour Ozone SIP
(1980 - 1987)
VOC (tpd
reduced)
[27.6]25.02 tpd [35.7]32.49 tpd 67.7 tpd
15% of base year [19.5]17.75 tpd NA (10-year period) 23.5 tpd
182(b) RFP
fulfilled
Yes (21[.21]%
reduction)*
NA (10-year period) Yes (43.2% reduction)
* The federally approved reductions from the moderate PM2.5 SIP represent an appropriately equivalent 6-year reduction of 29
VOC emission to fulfill a 15% reduction relative to a NAAQS base year. 30
+ Box Elder county emissions removed by proportion. 31

172(c)(2) as requiring Moderate areas with an approved SIP under the 1-hour ozone NAAQS or prior 8-hour ozone NAAQS to achieve 15 percent ozone precursor
(NOX and/or VOC) emission reductions.”).
129 § 7511a(b)(1)(a)(i).
130 Utah State Implementation Plan Section IX, Part A.21: Control Measures for Area and Point Sources, Fine Particulate Matter, PM2.5 SIP for the Salt Lake City, UT
Nonattainment Area. Adopted December 3, 2014.
131 Utah State Implementation Plan Section IX, Part A.31: Control Measures for Area and Point Sources, Fine Particulate Matter, Serious Area PM2.5 SIP for the Salt
Lake City, UT Nonattainment Area. Adopted January 2, 2019.

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1
Additionally, as the entirety of the NWF ozone NAA resides within the slightly larger Salt Lake 2
City PM2.5 NAA boundary, with nearly identical boundaries except for the inclusion of Box Elder County 3
to the north in the PM2.5 boundary, the past VOC reductions highlighted in Table 67 apply to the entire 4
NWF ozone NAA. Therefore, a single RFP plan demonstrating compliance through the utilization of NOx 5
substitutions is suitable for the NWF NAA as all areas of the current boundary can demonstrate past 6
applicable VOC reductions. 7
Furthermore, the state of Utah also implemented significant VOC reductions under the 1979 1-8
hour ozone NAAQS, which resulted in 67.7 tpd of reductions.132 This reduction represents a 43.2% 9
reduction in VOC relative to the 1980 base year, far in excess of the 15% required to demonstrate a 10
successful RFP plan, which additionally serves to fulfill a past 182(b)(1)(A) requirement. However, as air 11
quality subsequently improved, the area was ultimately granted a clean data determination which 12
resulted in the suspension of RFP requirements.133 Therefore, VOC emission reductions achieved under 13
this standard were not federally approved and therefore are not considered a previously approved RFP 14
plan. While this plan was never acted upon by the EPA, such action was unnecessary since the EPA 15
issues a clean data determination instead. The act of issuing a clean data determination serves as 16
verification that the emission reductions were implemented and successful in reducing emissions and 17
improving air quality, demonstrating the continued effectiveness of this RFP plan. 18
19
Table 67: VOC and NOx reduction in the NWF NAA during the moderate SIP timeline relative to RFP requirements for a moderate 20
SIP as 15% of the 2017 base year. 21
RFP Requirements 2017 - 2023 moderate
ozone SIP
% of Moderate Ozone
SIP RFP
VOC (tpd reduced) 14.0 tpd 3.7 tpd 26%
NOx (tpd reduced) -- 21.3 tpd 152%
Combined (tpd reduced) -- 25.0 tpd 178%
22
Lastly, as overviewed in Section 7.3 and Section 7.,4 and shown in Table 67, the state of Utah 23
has been able to account for 3.7 tpd of VOC emission reductions from 2017 to 2023 as part of this 24
moderate ozone SIP revision, as well as a 21.3 tpd reduction of NOx emissions over the same six-year 25
period. Combined, ozone precursor emissions were reduced 25.0 tpd during the 6-year period of this SIP 26
revision, representing 178% of the 14.0 tpd RFP requirement, and therefore fulfilling RFP requirements 27
for this SIP revision. 28
7.5.2 PM2.5 Chemistry and VOC Reductions 29
While northern Utah’s PM2.5 air quality challenges are predominantly a wintertime issue, the 30
emission reductions implemented under these past SIPs to address PM2.5 pollution episodes were largely 31
adopted as year-round emission reduction strategies. As a result, the associated NOx and VOC emission 32
reductions decrease both wintertime PM2.5 and serve to improve summertime ozone throughout the 33
NWF NAA. The interconnectedness of ozone and wintertime PM2.5 in the Wasatch Front is complex, but 34
breaks down into three essential components: 35

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1
1. While the reaction of NO2 with sunlight (hv) initiates the formation of ozone (O3), VOC emissions 2
accelerate the daytime formation of ozone (O3) in both the wintertime and summertime which 3
subsequently drives the availability of hydroxyl radicals (OH) within the troposphere. A 4
simplified cycle of this chemistry is included in the equations below (equations 2 - 4): 5
6
Equation 2 7
NO2 + sunlight(hv) → NO + O3 8
O + O2 + M → O3 + M (M=air) 9
O3 + hv → O2 + O 10
O + H2O → 2OH 11
VOC + OH → RO2 12
RO2 + NO → RO + NO2 13
14
2. The newly formed NO2 at the end of the reactions above subsequently cycles back to form 15
additional ozone. The presence of ozone as formed in the reactions above during the day 16
determines the availability of OH radicals. OH radicals subsequently act as fuel for daytime PM2.5 17
chemistry wherein the NOx-HOx cycle is responsible for daytime production of ozone and nitric 18
acid (HNO3).134 This cycle begins when VOCs are oxidized by OH, generating HO2 or RO2 radicals 19
(equation 3). 20
21
Equation 3 22
OH + VOC → HO2 + RO2 23
HO2 + NO → NO2 + OH 24
OH + NO2 → HNO3 25
26
HNO3 undergoes an acid-based reaction with gas phase ammonia (NH4) to form particulate 27
ammonium nitrate (NH4NO3), the predominant secondary particulate compound found in 28
wintertime Persistent Cold Air Pool (PCAP) events in northern Utah.135 29
30
3. Lastly, the presence of ozone plays a direct instigating (oxidative) force in the nighttime PM2.5 31
chemistry as at night NOx converts to particulate ClNO2 and HNO3 through NO3 and N2O5 32
(equation 4).136 33
34
Equation 4 35
NO2 + O3 → NO3 36
NO3 + NO2 ⇆ N2O5 37

134 Womack, C. C., McDuffie, E. E.,Edwards, P. M., Bares, R., de Gouw, J. A.,Docherty, K. S., et al. (2019). An oddoxygen framework for wintertime ammonium
nitrate aerosol pollution in urban areas: NOx and VOC control as mitigation strategies. Geophysical Research Letters,46, 4971–4979.
https://doi.org/10.1029/2019GL082028.
135 Kelly, K. E.; Kotchenruther, R.; Kuprov, R.; Silcox, G. D. Receptor model source attributions for Utah’s Salt Lake City airshed and the impacts of wintertime
secondary ammonium nitrate and ammonium chloride aerosol. J. Air Waste Manage. Assoc. 2013, 63 (5), 575−590.
136 Munkhbayar Baasandorj, Sebastian W. Hoch, Ryan Bares, John C. Lin, Steven S. Brown, Dylan B. Millet, Randal Martin, Kerry Kelly, Kyle J. Zarzana, C. David
Whiteman, William P. Dube, Gail Tonnesen, Isabel Cristina Jaramillo, and John Sohl. Environmental Science & Technology 2017 51 (11), 5941-5950. DOI:
10.1021/acs.est.6b06603.

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N2O5 + H2O (het.) → 2HNO3 1
N2O5 + HCl (het.) → HNO3 + ClNO2 2
3
As with daytime chemistry, the resulting HNO3 reacts with NH3 to form particulate nitrate 4
NH4NO3, with NO3, N2O5, and ClNO2 converted back to NO2 and O3 the following morning and further 5
contributing to daytime chemistry. 6
7
The importance of ozone in wintertime PM2.5 is reinforced by the fact that tropospheric ozone is 8
completely depleted during PCAP events (0.00 ppb) throughout the Wasatch Front, as ozone acts as a 9
fuel driving secondary particulate formation. Because of the important role ozone plays in both the 10
daytime and nighttime formation of PM2.5, Utah’s PM2.5 SIPs specifically targeted reductions of ozone 11
and its precursor emissions to limit the effectiveness of these pathways. Utah’s most recent PM2.5 SIP 12
explains this interconnectedness of ozone and PM2.5 formation.137 The explicit efforts to target the 13
formation of ozone, even during the wintertime, as well as the year-round nature of the emission 14
reduction policies implemented as part of these efforts, demonstrates why VOC emission reductions 15
achieved under a PM2.5 NAAQS SIP should be applied toward RFP compliance through NOx substitutions 16
under CAA Section 172(c)(2) for this ozone SIP revision. 17
7.5.3 NOx Effectiveness 18
As discussed in detail in section 7.4.1 and highlighted in Figure 7, the airshed of the NWF NAA is 19
more sensitive to reduction in NOx than in VOCs, especially at the controlling monitor. As an example, a 20
50% reduction of VOCs at the Bountiful monitoring site (~46 tpd reduction) results in a 1-2 ppb decrease 21
in modeled 8-hour ozone concentrations. Conversely, the same 50% reduction in NOx (also ~46 tpd 22
reduction) results in a 4-5 ppb decrease, approaching attainment of the standard at that location. 23
However, as demonstrated by the fact that the Hawthorne monitor is far less sensitive to NOx 24
reductions than the Bountiful monitor, the ozone photochemistry in the NWF NAA is highly localized 25
with each monitoring location responding differently to NOx and VOC reductions. Regardless of location, 26
however, all sites respond to paired VOC and NOx reduction strategies well, further demonstrating that a 27
NOx-heavy - limited VOC reduction pathway provides the most reasonable pathway to attainment. 28
Furthermore, these results demonstrate that NOx emission reductions deliver an equivalent, or better, 29
improvement to air quality at the controlling monitor, especially when paired with the VOC reductions 30
documented in this SIP revision. Therefore, the 21.3 tpd NOx emission reductions highlighted in Section 31
7.4 serve to not only fulfill the 14.0 tpd RFP requirement but also to deliver a greater overall benefit to 32
air quality than a 15% reduction in VOC emissions alone. Lastly, the NOx and VOC emission reductions 33
combined in this SIP revision result in a total of 25.0 tpd, representing a 26.7% reduction in ozone 34
precursor emissions, or 178% of the RFP requirement, while delivering the most effective and 35
reasonable pathway towards attaining the standard. 36
7.5.4 Conclusion 37
The significant VOC emission reductions implemented under past PM2.5 SIPs and ozone SIPs in 38
the NWF allow the area to pursue compliance with RFP requirements138 for this SIP revision through the 39

137 https://documents.deq.utah.gov/air-quality/planning/technical-analysis/research/northern-utah-airpollution/utah-winter-fine-particulate-study/DAQ-2018-
004037.pdf (“Aerosol chloride can also contribute to the formation of nitryl chloride (ClNO2), a source of radicals which act to enhance the daytime photochemical
production of ozone and nitrate, both of which are important contributors to PM2.5 formation. This formation of ClNO2 is particularly active in the Salt Lake Valley, as
shown by recent aircraft measurements (2017 Utah Winter Fine Particulate Study (UWFPS)).”)
138 42 U.S.C. § 7511a(b)(1)(A)(i).

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reduction of both NOx and VOC emissions, as is consistent with the EPAs interpretation of Section 1
172(c)(2) of the CAA. As demonstrated in Table 66, under the moderate PM2.5 SIP, the state 2
implemented a 21.1[23]% reduction of VOC emissions relative to the 2010 base year in less than a 6-3
year period, significantly exceeding the 15% requirement for an RFP plan. Furthermore, the state 4
demonstrated a 43.2% reduction in VOCs for the 1979 1-hour ozone standard. As a result, the state has 5
twice, prior to this SIP revision, implemented a full 15% VOC-only reduction in a 6-year period within the 6
NAA, fulfilling the one-time 182(b)(2)(A) VOC-only obligation. As a result, the RFP requirement for this 7
SIP revision, calculated as 15% of the 2017 VOC emission inventory, is a reduction of 14.0 tpd of NOx 8
and/or VOC emissions. From 2017 to 2023, the NWF NAA has seen a combined 25.0 tpd reduction of 9
ozone precursor emissions, representing a a 26.7% reduction in of ozone forming precursor emissions. 10
The combined NOx and VOC emission reductions have also been demonstrated to provide a greater 11
improvement to air quality than a 15% reduction in VOC emissions alone. Therefore, the NWF NAA has 12
met RFP requirements as a moderate NAA for the 2015 ozone NAAQS. 13
7.6 Future SIP Emission Reductions 14
The UDAQ has identified several emission reduction strategies that, once fully implemented, will 15
result in the reduction of both VOC and NOx emissions within the NWF NAA and count towards RFP 16
requirements. However, due to the short implementation timeframe afforded to states under this SIP 17
revision, paired with the added difficulty of finding viable VOC reduction strategies after the extensive 18
emission reductions associated with Utah’s PM2.5 planning efforts, these strategies will not be fully 19
implemented by the implementation deadline of January 1, 2023139 and thus, will not count towards RFP 20
under the moderate SIP. Utah is working to have these strategies fully implemented prior to the 21
summer of 2026 in an effort to count these reductions towards RFP requirements during the state’s 22
submission of a potential serious SIP for the same NAA. The UDAQ is simultaneously implementing NOx 23
emission reductions both in anticipation of future SIP creditability as well as in an effort to demonstrate 24
attainment of the standard at the earliest achievable date. 25
7.6.1 Hot Mix Asphalt; Utah Administrative Code Rule R307-313 26
The UDAQ has identified reducing VOC emissions associated with hot mix asphalt manufacturing 27
as a technologically viable and economically feasible control strategy. UDAQ has proposed R307-313 28
requiring hot mix asphalt (HMA) plants in the NAA to install emission capture and control devices to 29
reduce VOC and blue Smoke emissions associated with the production and loading of HMA and oil 30
storage tanks. Blue smoke is a visible emission generated during the production of HMA plants that 31
results from the process of mixing hot oil with aggregate which consists of oils heated to the point of 32
volatilization resulting in aerosols containing VOCs. Blue Smoke controls work to control both the visible 33
emissions and VOC emissions from HMA plants by capturing the emissions at various points of the 34
production process and routing these emissions through ducting to a destruction point, either using 35
filters and activated carbon, or through post-capture combustion. Emissions from the associated oil 36
tanks can be captured and reduced using similar technologies. 37
The UDAQ identified 15 HMA plants operating in the NWF NAA as well as 48 oil tanks associated 38
with asphalt manufacturing at these plants. UDAQ estimates that the aggregated PTE emissions from 39
these activities result in a combined 0.34 tpd (125.32 tpy) of VOC emissions in the NAA, of which 0.26 40
tpd (95.63 tpy) would be reduced with the implementation of controls as required by R307-313. It is 41

139 87 Fed. Reg. 60,897.

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important to note that these numbers are represented as PTE, and when applied to actual emissions 1
from the sources based on annual production the emission reductions will be lower. This difference 2
explains why associated inventoried emissions described in section 3 do not match those reported here, 3
and thus it is expected that the actual emission reductions will be lower as many facilities are permitted 4
to produce more asphalt per year than what is actually produced annually. 5
Administrative rule R307-313 was adopted by the Utah Air Quality Board on February 1, 2023. 6
However, the lead time for the engineering and installation of these controls, as well as the additional 7
testing and emission destruction verification required for the implementation of a novel emission 8
reduction strategy, mean that the emission reductions associated with this rule will not be creditable 9
under the moderate SIP timeline. As impacted facilities have until May 1, 2025 to install controls, these 10
emissions reductions are expected to be creditable for future SIP reductions. 11
7.6.2 Boilers; Utah Administrative Code Rules R307-315 and R307-316 12
In an effort to reduce NOx emissions in and around the NWF NAA, UDAQ has proposed the 13
adoption of R307-315; NOx Emissions Controls for Natural Gas-Fired Boilers 2.0-5.0 MMBtu and R307-14
316; NOx Emission Controls for Natural Gas-Fired Boilers greater than 5.0 MMBtu. These rules both 15
implement an emission standard of 9ppmv for natural gas-fired boilers in the NAA in the effected 16
MMBtu ranges. In aggregate, these rules will apply to an estimated 2,136 boilers in the NAA which 17
combine to emit an estimated 8.55 tpd (3,122 tpy) of NOx emissions. It is important to note that these 18
emission estimates are independent bottom-up estimates of the total potential emissions from boilers, 19
and were determined using different datasets and methods than those used in the development of the 20
inventories described in section 3. The UDAQ believes that these numbers are a more accurate 21
representation of actual emissions from boilers within the NAA. However, these numbers may be 22
different than those reported in section 3, and any future SIP credited emission reductions associated 23
with the implementation of these rules would rely instead on the numbers reported in the inventory. 24
The implementation of R307-315 and R307-316 has the potential to reduce 6.9 tpd (2,522 tpy) of these 25
combined emissions. However, R307-315 and R307-316 do not require the retrofit or replacement of 26
any boiler currently operating in the NAA, and instead require new boilers or burner replacements to 27
meet the 9ppmv standard. Thus, the implementation of this rule will take place over a long period of 28
time as the average lifespan of this equipment can be greater than 20 years. 29
Since the emission reductions from the implementation of R307-315 and R307-316 will occur 30
beyond the moderate SIP timeline the reductions associated with these rules will not count towards RFP 31
requirements for this SIP revision but are anticipated to be creditable for future SIP reductions. 32
7.6.3 US Magnesium LLC 33
The UDAQ also examined major industrial point sources that contribute to the degradation of 34
the NWF NAA’s airshed but are located outside of the existing boundary. This examination identified 35
one source that met this criteria, US Magnesium LLC, located in Tooele County on the southwestern 36
edge of the Great Salt Lake. This facility produces significant amounts of highly reactive precursor 37
emissions that contribute to both ozone and PM2.5 formation along the Wasatch Front. 38
US Magnesium LLC is the largest producer of primary magnesium in the US and operates the 39
Rowley Plant production facility on the western edge of the Great Salt Lake in Tooele County near the 40
NAA boundary. Here, water from the Great Salt Lake is evaporated to produce a brine solution that is 41
then purified and dried before going through a melt reactor and electrolytic process which separates 42
magnesium metal from chlorine. Byproducts of this industrial process include VOCs and NOx, as well as 43
chlorine which is converted into hydrochloric acid. All of these byproducts contribute to ozone and 44

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secondary particulate matter formation in the NWF NAA. In 2021, US Magnesium’s permitted potential 1
to emit was 894 tpy of VOCs, 1,261 tpy of NOx and 8,522 tpy of Hazardous Air Pollutants (HAPs). These 2
emissions make US Magnesium’s Rowley plant one of the largest point sources of VOCs and NOx in the 3
greater Wasatch Front and the largest point source of HAPs in Utah. 4
As a result of the magnitude of emissions and proximity to the NWF NAA boundary, UDAQ 5
required US Magnesium to perform a RACT analysis for VOC and NOx emissions. As described in detail in 6
section 4.15, the RACT analysis submitted by US Magnesium identified that the installation of a steam 7
stripper and regenerative thermal oxidizer on the wastewater ponds at the boron plant would be 8
feasible. Once installed, this control will result in the reduction of 0.44 tpd (161.7 tpy) of VOC. However, 9
since the source is located outside of the current NAA (see section 1.4.2), and the timeline for the 10
installation of these controls are beyond what is statutorily required, these emission reductions are not 11
creditable towards RFP requirements but will be included as a contingency measure as discussed in 12
section 11.2.2. 13
7.6.4 Tesoro Refining & Marketing Company LLC Marathon Refinery 14
As described in section 4.12, a RACT analysis submitted by Tesoro Refining & Marketing 15
Company LLC Marathon Refinery identified that the installation of selective catalytic reduction for 16
reducing NOx emissions from the cogeneration turbines with heat recovery steam generation CG1 and 17
CG2 would be technologically feasible. As a result, these controls will be required to be installed by 18
October 1, 2028, in order for the NAA to demonstrate attainment of the standard as expeditiously as 19
practicable. The installation of these controls will result in an emission reduction of approximately 0.18 20
tpd (68.78 tpy) of NOx once installed. Since the timeline for the installation of these controls is beyond 21
the implementation timeline for this SIP revision, and the controls will result in the reduction of NOx 22
emissions and not VOC emissions, these emission reductions are not creditable towards RFP 23
requirements but are anticipated to be accounted for in subsequent SIP revisions. 24
In addition to the NOx reductions associated with controls on CG1 and CG2, Tesoro Refining & 25
Marketing Company LLC Marathon Refinery will be required to install a secondary seal on Tank 321 and 26
replace the wastewater system API Separator and DAF unit with a closed vent to a carbon adsorption 27
control system. These controls, once installed, will result in reductions of VOC emissions by 0.006 tpd 28
(2.30 tpy) and 0.027 tpd (10.0 tpy) respectively. Thus, the combined VOC reductions associated with 29
these controls is expected to be .033 tpd (12.3 tpy). 30
7.6.5 Lawn and Garden Small Non-Road Engines 31
As noted in section 5.3, the UDAQ has identified emission reduction policies aimed at reducing 32
VOCs and NOx emissions from small non-road engines used in lawn and garden operations as being 33
reasonable. While there are some substantial limitations on the state in how emissions from these 34
sources can be regulated due to CAA Section 209 preemption, the implementation of in-use restrictions 35
for this class of equipment on ozone exceedance days, colloquially known as “mandatory action days,” 36
complies with Section 209 preemption while simultaneously allowing for significant VOC emission 37
reductions on days in which reductions are the most critical. The state has identified that the 38
implementation of a rule based on these criteria could net a VOC emission reduction of approximately 39
2.84 tpd throughout the NWF NAA. It is the intent of the UDAQ to introduce an administrative rule 40
during subsequent ozone state implementation planning efforts that aligns with reducing emissions 41
from these sources through mandatory action days restrictions. 42

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7.7 RFP Conclusions 1
As described in section 7.5.4, this SIP revision demonstrates compliance with RFP requirements 2
for a moderate NAA under CAA section 172(c)(2) through the utilization of NOx substitutions as allowed 3
for NAAs with previously approved SIPs demonstrating comparable past VOCs emissions reductions. 4
5

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Chapter 8 - Attainment Demonstration and Weight of Evidence 1
8.1 Background 2
CAA Section 182(b)(1)(I) requires SIP revisions for moderate ozone NAAs to contain an 3
attainment demonstration, with the ozone implementation rule140 further specifying that an approvable 4
demonstration rely on a photochemical model, or another equivalent analytical method determined to 5
be at least as effective as that required for a serious NAA. For this SIP revision, the UDAQ has developed 6
a photochemical model following EPA guidance, with supplemental analyses to perform the attainment 7
demonstration modeling. In the previous sections of this SIP revision, ozone concentrations have been 8
reported using the unit ppm to be consistent with CAA and CFR (Code of Federal Regulations) language. 9
In this all subsequent sections (sections 8 – 12), the UDAQ will be reporting ozone concentrations in the 10
unit of parts per billion (ppb), in order to be consistent with literature and EPA technical guidance. 11
The photochemical model developed for this SIP serves as a useful tool for projecting future 12
ozone concentrations, determining source regions that contribute to local ozone levels, and estimating 13
the impacts of emission source categories. This model also represents a significant step forward in 14
understanding the transport and formation of ozone throughout the NWF and the broader state of 15
Utah. Though the predictive ability of this model is scientifically sound and meets established 16
performance criteria, all models have inherent limitations since they are a simplified approximation of 17
complex real-world systems. Therefore, results presented from this modeling analysis should not be 18
considered the sole source of information relied upon when determining if a region will attain the 2015 19
ozone standard by the attainment date. 20
EPA’s modeling guidance141 overviews supplemental analyses, termed “weight of evidence” 21
(WOE), that can be used to further support an attainment determination if the maximum MDA8 ozone 22
DV is close to the 70-ppb (0.070 ppm) standard at one or more monitoring sites. A WOE analysis is “a 23
totality of the circumstances approach, one that considers all available data to evaluate the 24
reasonableness of the modeled result which supplements those results.”142 EPA’s modeling guidance 25
outlines the basic types of analysis that could be included a part of a WOE analysis including: 26
 Additional modeling analyses, 27
 Analysis of trends in ambient air quality and/or emissions, and 28
 Additional unaccounted emission controls or reactions 29
The results of the UDAQ’s photochemical modeling and WOE are presented in section 8.2. 30
8.2 Photochemical Modeling Platform 31
The UDAQ conducted an air quality modeling analysis in support of the NWF NAA attainment 32
demonstration. Modeling was performed following EPA’s modeling guidance143. This modeling platform 33

140 83 FR 62998
141 Modeling Guidance for Demonstrating Air Quality Goals for Ozone, PM2.5, and Regional Haze: https://www.epa.gov/sites/default/files/2020-10/documents/o3-
pm-rh-modeling_guidance-2018.pdf
142 Environmental Defense Fund v. Unites States EPA, 369 F.3d 193, 198 (2d Cir. 204).
143 Modeling Guidance for Demonstrating Air Quality Goals for Ozone, PM2.5, and Regional Haze: https://www.epa.gov/sites/default/files/2020-10/documents/o3-
pm-rh-modeling_guidance-2018.pdf

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includes emissions modeling, meteorological modeling, and photochemical modeling. Photochemical 1
modeling was conducted using the CAMxv7.1 model. Emissions inventories were collected and 2
processed through the Sparse Matrix Operating Kernel Emissions Model (SMOKE) version 4.8.1. With the 3
exception of lightning NOx and oceanic emissions, modeling was based on scripts and data from EPA’s 4
2016v2 modeling platform.144 Sea salt and lightning NOx emissions were calculated in CAMx by running 5
the corresponding CAMx tools (oceanic_v4.2 and lnox_v1.1, respectively). Meteorological fields for 6
input into CAMx were produced using the Weather Research and Forecasting (WRFv4.2) model. A 7
detailed description of each of these models, their configuration, settings, and performance are 8
provided in their respective TSDs.145 9
For this attainment demonstration, the period of June 15 - August 1, 2017, was selected as the 10
modeling episode, where June 15 - 25 corresponds to spin-up days. 2017 was also selected as the base 11
year for modeling and 2023 was selected as the future year with local emissions projected from the 12
2017 inventory as described in section 3. The modeling domain consisted of three nested grid domains 13
at 12/4/1.33 km. The 12 km domain covers the Western United States and is aligned with EPA’s 12US1 14
domain, with the north-south extent of this domain matching the EPA’s domain. The 4 km domain is 15
nested within the 12 km domain and covers the state of Utah as well as parts of neighboring states. The 16
1.33 km domain is nested within the 12/4 km domains and extends over the northern Wasatch Front 17
non-attainment area to provide higher resolution modeling within this area. The 12/4/1.33 km nested 18
grid modeling domain configuration is shown in Figure 8. 19
20

144 EPA 2016v2 Emissions Modeling Platform TSD https://www.epa.gov/system/files/documents/2021-
09/2016v2_emismod_tsd_september2021.pdf
145 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration: https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001603.pdf
& Meteorological Modeling for Wasatch Front O3 SIP Technical Support Documentation and Model Performance Evaluation: https://documents.deq.utah.gov/air-
quality/planning/DAQ-2023-001605.pdf

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1
Figure 8: 12/4/1.33 km CAMx Modeling Domains 2
Time- and space-variable initial and boundary conditions (ICs and BCs, respectively) for the 3
outermost domain (i.e., 12 km domain) were derived from GEOS-Chem global chemistry model outputs 4
for 2017, with the modeling performed by Ramboll under contract with WESTAR.146 Following EPA 5
guidance, the same GEOS-Chem-derived ICs and BCs for the 2017 base case were used for the 2023 6
future case. BCs and ICs for the 4 km domain, which was run in a two-way nested configuration with the 7
1.33 km domain, were extracted from the 3-D CAMx output concentration files for the 12 km domain. 8
Concentrations were extracted along the lateral boundaries of the 4 km domain. 9
CB6r5h (version 6, revision 5 with halogens) gas-phase chemical mechanism, which includes 10
halogens chemistry, was used for all simulations. At the request of the UDAQ, this mechanism was 11
specifically developed and implemented by Ramboll, developer of CAMx, in a special version of CAMx 12
v7.1 as a replacement for CB6r5 (version 6, revision 5). CB6r5h was developed to account for 13
interactions between inorganic halogen species, ozone, VOCs, and NOx, where reactions involving 14
chlorine (Cl) and bromine (Br) were added to CB6r5. Halogens emissions are significant in the valley and 15
play a significant role in PM and ozone formation in the NWF. An aircraft monitoring campaign 16
conducted by the National Oceanic and Atmospheric Administration (NOAA) in winter 2017 indicated 17
that US Magnesium, an industrial plant located on the southwest edge of the Great Salt Lake, emits 18
large quantities of HCl and dihalogens (Cl2, Br2, BrCl), with the facility being the single largest halogen 19
emission source in the US.147 Using a photochemical box model and a 3D chemical transport model, the 20
investigators also showed that, while these halogens induce ozone depletion near the plant, they lead to 21

146 https://views.cira.colostate.edu/docs/IWDW/Modeling/WRAP/2017/Ramboll_WESTAR_GEOS-Chem_Report_8Apr_2021.pdf
147 C. C. Womack, W. S. Chace, S. Wang, M. Baasandorj, D. L. Fibiger, A. Franchin, L. Goldberger, C. Harkins, . S. Jo, B. H. Lee, J. C. Lin, B. C. McDonald, E. E. McDuffie,
A. M. Middlebrook, A. Moravek, J. G. Murphy, J. A. Neuman, J. A. Thornton, P. R. Veres, S. Brown. Midlatitude Ozone Depletion and Air Quality Impacts from
Industrial Halogen Emissions in the Great Salt Lake Basin. Environ. Sci. Technol. 2023, 57, 5, 1870–1881.

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significant increases in the formation of particulate ammonium nitrate, PM2.5, ozone, and other oxidants 1
in populated regions of the Salt Lake Valley located downwind of the plant. Regional PM2.5 increases of 2
10%-25% were attributed to this single industrial halogen source. Given that the chemical cycles leading 3
to ozone and ammonium nitrate are linked148 implementing CB6r5h in our summertime ozone modeling 4
is increasingly important. 5
8.2.1 Model Performance Evaluation (MPE) 6
Model performance was evaluated by comparing the 2017 modeled ozone concentrations to 7
measured concentrations of ozone and ozone precursors, including NOx, NO2 and VOCs. The evaluation 8
was focused on results for the 1.33 km modeling domain and results for spin-up days are excluded from 9
this analysis. Results showed that the CAMx model performs well at simulating ozone at all sites within 10
the NWF NAA. While the model generally underestimates MDA8 ozone concentrations at the local 11
monitors, site-specific performance statistics are within established performance criteria. For all days of 12
the modeling episode, modeled MDA8 ozone concentrations are within established performance criteria 13
for Normalized Mean Bias (NMB), Normalized Mean Error (NME) and correlation coefficient (R). NMB 14
values for all sites are within the performance criteria of ±15% (Table 68). Similarly, NME and R values 15
for all sites are within their respective performance criteria of < 25% and > 0.5 (Table 69). These 16
performance statistics suggest that the model performs well at simulating MDA8 ozone concentrations. 17
On days with elevated ozone (observed MDA8 > 60 ppb), model performance was overall acceptable 18
with NME values falling within their performance thresholds at all sites (< 25%) and NMB performance 19
threshold being slightly exceeded at one of the sampling sites (NMB of -15.86%) (Table 69). At some 20
sites, the correlation coefficient R displayed some values below 0.5, which is likely related to the model 21
switching from an underprediction to an overestimation of MDA8 ozone on a few days (< 8% of high 22
ozone modeling days), which impacted the modeled ozone temporal trend. These days were 23
characterized by a variable cloud cover, which WRF did not simulate completely. More details on this 24
are provided in the CAMx MPE TSD. 25
26
Table 68: Performance statistics for MDA8 ozone on all days of the modeling episode. Results are shown for monitors in the 1.33 27
km modeling domain. 28
AQS Site ID Site Name NMB (%) NME (%) R
49-011-0004 Bountiful -11.36 13.32 0.735
49-035-3006 Hawthorne -9.75 12.48 0.653
49-035-3013 Herriman -13.73 14.46 0.61
49-045-0004 Erda -14.66 16.04 0.663
49-057-0002 Ogden -10.51 12.8 0.652
49-057-1003 Harrisville -14.12 14.56 0.763
29

148 C.C. Womack, E.E. McDuffie, P.M. Edwards, R. Bares, J.A. de Gouw, K.S. Docherty, W.P. Dubé, D.L. Fibiger, A. Franchin, J.B. Gilman, L. Goldberger, B.H. Lee, J.C.
Lin, R. Long, A.M. Middlebrook, D.B. Millet, A. Moravek, J.G. Murphy, P.K. Quinn, T.P. Riedel, J.M. Roberts, J.A. Thornton, L.C. Valin, P.R. Veres, A.R. Whitehill, R.J.
Wild, C. Warneke, B. Yuan, M. Baasandorj, S.S. Brown, An Odd Oxygen Framework for Wintertime Ammonium Nitrate Aerosol Pollution in Urban Areas: NO x and
VOC Control as Mitigation Strategies. Geophys. Res. Lett., 46, 4971-4979 (2019).

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Table 69: Performance statistics for MDA8 ozone on high O3 days (observed MDA8 > 60 ppb). Results are shown for monitors in 1
the 1.33 km modeling domain. 2
AQS Site ID Site Name NMB (%) NME (%) R
49-011-0004 Bountiful -11.49 13.22 0.56
49-035-3006 Hawthorne -9.12 12.22 0.276
49-035-3013 Herriman -13.86 13.9 0.294
49-045-0004 Erda -15.86 16.78 0.565
49-057-0002 Ogden -10.16 12.46 0.318
49-057-1003 Harrisville -14.02 14.57 0.586
3
Moreover, the model generally captures well the temporal variability of MDA8 ozone 4
concentrations, with the timing of peak and low ozone values being well represented (Figure 9 to Figure 5
14). The underestimation in modeled MDA8 ozone concentrations is likely primarily related to an 6
underestimation in local emissions, rather than background emissions. Background ozone is well-7
replicated as indicated by the overall good agreement between modeled and observed MDA8 ozone 8
concentrations at Gothic Colorado, a high-altitude (10,000 ft) monitoring site in the Colorado Rockies 9
that serves as a good indicator of mid-tropospheric air (Figure 15). 10
Overall, the model exhibited a level of agreement with measurements that has typically been 11
achieved for US regulatory modeling for this region.149 These results provide confidence in the ability of 12
the modeling platform to provide a reasonable projection of future year ozone concentrations and 13
source contributions in the NWF NAA. 14
15
16
17 Figure 9: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone concentration 18
(O3_8hrmax) at the Bountiful monitoring station. 19

149 https://www.epa.gov/system/files/documents/2022-03/aq-modeling-tsd_proposed-fip.pdf & Denver Metro/North Front Range 2017 8-Hour Ozone State
Implementation Plan: 2011 Base Case Modeling and Model Performance Evaluation.
https://views.cira.colostate.edu/wiki/Attachments/Source%20Apportionment/Denver/Denver_2017SIP_MPE_Finalv1.pdf

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1
Figure 10: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone concentration 2
(O3_8hrmax) at the Hawthorne monitoring station. 3
4
Figure 11: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone concentration 5
(O3_8hrmax) at the Erda monitoring station. 6
7
Figure 12: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone concentration 8
(O3_8hrmax) at the Herriman monitoring station. 9

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1
Figure 13: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone concentration 2
(O3_8hrmax) at the Harrisville monitoring station. 3
4
Figure 14: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone concentration 5
(O3_8hrmax) at the Ogden monitoring station. 6
7
8
Figure 15: Time series of observed (grey line) and modeled (red line) maximum daily 8-hr average ozone concentration 9
(O3_8hrmax) at Gothic Colorado monitoring station. 10
8.2.2 Determination of Future Year (2023) Design Values 11
The ozone predictions from the CAMx model simulations were used to project ambient ozone 12
DVs for the year 2023 following EPA’s ozone modeling guidance for SIP demonstrations150. Five-year 13
weighted average DVs centered on the base modeling year of 2017 were first calculated by averaging 14
ambient 8-hour ozone DVs for 2015-2017, 2016-2018, and 2017- 2019. The 5-year weighted average 15

150 https://www.epa.gov/sites/default/files/2020-10/documents/o3-pm-rh-modeling_guidance-2018.pdf

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DVs at each site were then projected to 2023 using the Software for Model Attainment Test Software – 1
Community Edition (SMAT-CE version 1.6).151 This program predicts future year ozone DVs (FDVi) for 2
each monitoring site within the NWF NAA by calculating site-specific relative response factors (RRFi) and 3
scaling the 5-year weighted average base year ozone DV (BDVi) at each site (i) using its corresponding 4
RRFi. 5
6
Equation 5 7
𝑭𝑫𝑽𝒊ൌ 𝑹𝑹𝑭𝒊 ൈ𝑩𝑫𝑽𝒊 8
9
The RRFi for each monitoring site corresponds to the fractional change in MDA8 ozone between 10
the base and future year. It is based on the average ozone on model-predicted “high” ozone days in a 11
3x3 grid cell array centered on the grid cell containing the monitor. Following EPA modeling guidance, 12
RRFs were calculated based on the highest 10 modeled ozone days in the base year simulation at each 13
monitoring site. Specifically, the RRF for an individual monitoring site is the ratio of the average MDA8 14
ozone concentration in the future year to the average MDA8 concentration in the 2017 base year. The 15
average values are calculated using MDA8 model predictions in the future year and in 2017 for the 10 16
highest days in the 2017 base year modeling. High ozone days correspond to days when modeled ozone 17
MD8A concentration exceeds, or is or equal, to 60 ppb. For cases in which the base year model 18
simulation does not include 10 days with MDA8 ozone values >= 60 ppb at a site, all days with ozone >= 19
60 ppb are used in the calculation, as long as there were at least 5 days that meet this criterion. At 20
monitor locations with less than 5 days with modeled 2017 base year ozone >= 60 ppb, no RRF or FDV is 21
calculated for the site and the monitor in question is not included in the analysis. A detailed description 22
of SMAT configuration is provided in the SMAT TSD.152 23
Following this approach, FDVs and RRFs were calculated for each monitoring site within the 24
NWF NAA, where FDV for Bountiful, Hawthorne and Herriman were based on an adjusted BDV (Table 25
70). BDV for Bountiful, Hawthorne and Herriman, which correspond to the three highest monitors in the 26
NAA, were adjusted to reflect DVs after exclusion of wildfire smoke-impacted ozone exceedance values. 27
In a separate technical document (“Analysis in Support of Exceptional Event Flagging and Exclusion from 28
Modeling for the Weight of Evidence Analysis”), the UDAQ determined that ozone concentrations 29
exceeding the 2015 ozone NAAQS on August 4, 2016, and September 2, 5 and 6 2017 qualify as wildfire 30
smoke-impacted ozone exceedances. These events were excluded from the 2017 BDV calculations for 31
Hawthorne, Bountiful and Herriman. Excluding these events results in a decrease of 1.7 - 2.0 ppb in the 32
BDV and 2.0 ppb in the FDV for these sites (Table 70). Note that consistent with the truncation and 33
rounding procedures for the 8-hour ozone NAAQS, the projected DVs are truncated to the first decimal 34
place in units of ppb. 35
36
37

151 https://www.epa.gov/scram/photochemical-modeling-tools & UDAQ Ozone SIP SMAT-CE Configuration Utah Division of Air Quality TSD:
https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001838.pdf
152 UDAQ Ozone SIP SMAT-CE Configuration Utah Division of Air Quality: https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001838.pdf

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Table 70: Baseline design values (BDV), relative response factors (RRF), future design values (FDV) at Bountiful, Hawthorne and 1
Herriman monitoring locations. DVs before and after exclusion of days impacted by wildfire smoke are shown.* indicates DV 2
after removal of wildfire smoke-impacted ozone exceedance values. 3
Flagged Data Not Excluded
3x3 grid-cell array Max Paired
in Space
Flagged Data Excluded
3x3 grid-cell array Max Paired in Space
Site Site ID County BDV RRF FDV Final
FDV
BDV RRF FDV Final
FDV
Bountiful 490110
004
Davis 76.7 0.9593 73.5 73 75* 0.9593 71.9* 71
Hawthorne 490353
006
Salt
Lake
76.7 0.9698 74.3 74 75* 0.9698 72.7* 72
Herriman 490353
013
Salt
Lake
76 0.9686 73.6 73 75* 0.9686 72.6* 72
Erda 490450
004
Tooele 73 0.9673 70.6 70 73 0.9673 70.6 70
Harrisville 490571
003
Weber 72.7 0.9676 70.3 70 72.7 0.9676 70.3 70
4
8.2.3 Model Attainment Test 5
Table 71 summarizes the finalized BDV, FDV and RRF at each monitoring site within the NWF 6
NAA, where the BDV for Bountiful, Hawthorne and Herriman, are adjusted to reflect BDV after removal 7
of ozone exceedance values impacted by wildfire smoke. Only sites that had an ozone monitor operating 8
in the 5-year period (2015-2019) were used to calculate the 5-year weighted average ambient BDV and 9
are currently still part of UDAQ air monitoring network were included in this analysis. 10
Results show that the FDV are projected to reach between 70 - 72 ppb by the attainment date 11
across all sites in the non-attainment area, with the Hawthorne monitoring site projected to be the 12
controlling monitor at 72 ppb. It is important to note the way in which ozone DVs are truncated to the 13
lowest whole number when being calculated, a FDV of 70.9 ppb is needed to demonstrate attainment. 14
Therefore, considering the range of projected FDV, monitoring sites that show nonattainment are all 15
demonstrating FDV very near attaining the standard. 16
17
Table 71: Baseline design values (BDV), relative response factors (RRF), future design values (FDV) at monitors within the 18
northern Wasatch Front ozone non-attainment area. 19
3x3 grid-cell array Max Paired in
Space
Site Site ID County BDV RRF FDV Final FDV
Bountiful 490110004 Davis 75 0.9593 71.9 71
Hawthorne 490353006 Salt Lake 75 0.9698 72.7 72
Herriman 490353013 Salt Lake 75 0.9686 72.6 72
Erda 490450004 Tooele 73 0.9673 70.6 70
Harrisville 490571003 Weber 72.7 0.9676 70.3 70

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8.3 Weight of Evidence (WOE) 1
8.3.1 Overview 2
While the modeled attainment demonstration described in section 8.1 (Table 71) indicates that 3
the MDA8 at the Hawthorne monitor will reduce to 72 ppb by the attainment date, slightly above the 4
70.9 ppb required to demonstrate attainment, the UDAQ has implemented substantial additional efforts 5
to combat summertime ozone not accounted for during this modeling effort should be taken into 6
consideration when determining if the area is demonstrating attainment. In this section, as part of a 7
WOE approach153, the UDAQ will present an overview of additional efforts and analysis to provide 8
further insights into to be considered when determining if the area is demonstrating attainment. 9
8.3.2 Uncertainties in Modeling and Inventory 10
While the photochemical modeling results presented in section 8.1 meet EPA performance 11
metrics and represent a significant improvement in past efforts to model ozone in the NWF, there are 12
uncertainties in any modeling effort that may result in an overestimation in future predicted ozone 13
concentrations. 14
These uncertainties can result from a wide array of parameters involved in complex modeling 15
efforts, including the process of compiling the emission inventories modeling efforts rely on. For 16
instance, the mobile on-road sector of the inventory is estimated using models developed by the EPA 17
that have many versions EPA released over the years. Estimations of NOx have differed significantly as 18
one model replaced the next, and changes in the vehicle fleets over time such as the electrification of 19
the mobile sector may be underrepresented (see section 8.3.4). Further, since SIPs are legally binding 20
documents and will be enforced in the event certain conditions are not met, emission reductions 21
associated with past SIP efforts have included conservative estimates of total reductions. Therefore, 22
emission reductions accounted for in inventories may underrepresent the full extent of real-world 23
reductions. 24
Additionally, for the development of the attainment demonstration included in this SIP revision, 25
the UDAQ relied on VOC emissions estimates within the solvent sector from an EPA supplied product. 26
This product, VCPy, has substantial benefits over past methods used in the quantification of emissions 27
within this category. However, some uncertainties remain in the emission estimates produced by VCPy 28
that could result in overestimations of VOC emissions within the NWF NAA. For instance, as described in 29
section 3.2.2, this SIP revision sourced its VOC emissions for the solvents sector from EPA’s 2016v2 30
platform. EPA has subsequently released an updated version (2016v3) of this platform154 in which EPA 31
revised its estimated for Utah statewide VOC emissions as adjusted to account for “indoor usage 32
assumptions” as well as “control assumptions”. These updates resulted in a statewide decrease of 33
estimated VOC emissions by 1,699 tpy. As these emissions are generally allocated in modeling based on 34
population metrics, and the NWF represents a significant proportion of Utah’s population, it stands to 35
reason that the majority of the decrease in VOC emission from 2016v2 to 2016v3 would be observed in 36
the NWF NAA. 37

153 Modeling Guidance for Demonstrating Air Quality Goals for Ozone, PM2.5, and Regional Haze
154 Technical Support Document (TSD): Preparation of Emissions Inventories for the 2016v3 North American Emissions Modeling Platform. U.S. EPA. January 2023

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8.3.3 Background, Interstate, and International Transport 1
8.3.3.1 Background Ozone 2
The EPA identifies “background” ozone in the United States (USB) as ozone formed from sources 3
or processes other than anthropogenic emissions of NOx, VOCs, methane (CH4) and CO originating from 4
within the United States.155 This definition does not include intra or inter-state transport of ozone 5
impacting downwind areas, which are covered by other sections of the CAA including section 6
110(a)(2)(D). NAAs in the Intermountain West face significant and regionally specific challenges meeting 7
ozone standards especially as it relates to the amount of USB present.156 The region faces further 8
challenges due to the increasing instances of wildfire,157 significant regional and local biogenic 9
contributions,158 as well as the influence of internationally transported pollutants,159 all of which 10
contributing to a large proportion of ozone on any given day. These challenges are highlighted in 11
multiple analysis identifying significantly elevated USB ozone concentrations throughout the region 12
when compared to the eastern United States.160 13
The substantial contribution of USB ozone impacting Utah’s total ozone concentrations and can 14
be seen at the remote sites located throughout the state, such as the monitoring sites located in 15
Escalante National Monument, or Bryce and Canyonlands National Parks. These sites are typically free of 16
impacts from localized anthropogenic emissions, and they regularly report 8-hour summertime ozone 17
concentrations above 0.050 ppm. Source apportionment modeling performed by the UDAQ (see section 18
9.2 for details) further found USB ozone concentrations (including interstate anthropogenic emissions) 19
along the Wasatch Front account for up to 85.5% of the ozone comprising the daily 8-hour 20
concentrations observed at the Hawthorne site (Figure 16 and Figure 17), with the remaining 14.5% 21
attributable to Utah anthropogenic emissions. 22
23

155 Implementation of the 2015 Primary Ozone NAAQS: Issues Associated with Background Ozone”. USEPA, December 2015
156 Scientific Assessment of background ozone over the U.S.: Implications for air quality management
157 Buchholz, R.R., Park, M., Worden, H.M. et al. New seasonal pattern of pollution emerges from changing North American wildfires. Nature Communications 13,
2043 (2022). https://doi.org/10.1038/s41467-022-29623-8
158 EPA Webinar; Description and preliminary evaluation of BELD 6 and BEIS 4. ORD. Jesse O. Bash and Jeff Vukovich
159 Entrainment of stratospheric air and Asian pollution by the convective boundary layer in the southwestern U.S.; Langford, A.O. et al. (2017), J. Geophysics. Res.
Atmos., 122, 1312-1337, doi:10.1002/2016JD025987
160 Entrainment of stratospheric air and Asian pollution by the convective boundary layer in the southwestern U.S.; Langford, A.O. et al. (2017), J. Geophysics. Res.
Atmos., 122, 1312-1337, doi:10.1002/2016JD025987 & Implementation of the 2015 Primary Ozone NAAQS: Issues Associated with Background Ozone; USEPA,
December 2015

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1
Figure 16: Ozone Attributed to Domain-Wide Sources at Hawthorne as simulated 8-hour daily ozone concentrations along the 2
Wasatch Front. 3
4
Figure 17: Episode average of simulated 8-hour daily ozone concentrations at Hawthorne along the Wasatch Front. 5

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8.3.3.2 Interstate Transport 1
In 2022, as part of its ongoing efforts to model nationwide ozone and transport of precursor 2
emissions, the EPA released results from its updated North American Emission Modeling Platform 3
2016v2. This analysis identified the contributions from multiple upwind states for the modeled year of 4
2023 to ozone concentrations along the NWF NAA (Table 72).161 The states impacting the NWF NAA 5
include California, Nevada, Arizona, Idaho, Oregon, and Washington. The combined contributions to 6
counties in the NWF from these upwind states result in impacts ranging from 4.0 ppb to 4.91 ppb. Given 7
that the attainment demonstration described in section 8.2 identified the FDV of 72 ppb for Salt Lake, 8
and 71 ppb for Davis counties, the combined upwind contribution from western states accounts for 6 - 9
7% of the total predicted ozone concentrations in the NWF NAA. 10
11
Table 72: 2023 contributions from upwind states to NWF NAA (ppb) as identified by EPA 2016v2 modeling 12
Salt Lake Davis Weber
California 2.46 2.25 2.24
Nevada 0.89 0.86 0.58
Arizona 0.22 0.22 0.13
Idaho 0.55 0.37 0.57
Oregon 0.58 0.44 0.41
Washington 0.21 0.16 0.13
Total 4.91 4.30 4.06
13
Section 110(a)(2)(D)(i)(I) of the CAA, known as the “Good Neighbor” provision, requires states 14
with a contribution more than the EPA’s determined significance threshold to develop a SIP revision 15
with provisions to address contributions to downwind states. This threshold was set at 1% of the 16
NAAQS, or 0.7 ppb for the 2015 ozone NAAQS. Of the six states listed in Table 72, both California and 17
Nevada were identified by the EPA as contributing to Utah’s ability to attain or maintain the NAAQS in a 18
regulatorily significant way (>= 0.7 ppb). On April 4, 2022, the EPA proposed a Federal Implementation 19
Plan (FIP) to address disapprovals or deficiencies in twenty-six states’ Good Neighbor SIPs, including 20
those of California and Nevada.162 The proposed FIP will require emission reductions from an array of 21
industrial activities including fossil fuel-fired power plants, natural gas pipeline transportation, cement 22
production, glass, iron and steel manufacturing, as well as reductions from chemical, petroleum, and 23
paper manufacturing processes. If the proposed FIP becomes final, emission reductions covered under 24
this rule will begin taking effect the summer of 2023, with full implementation of emission reductions by 25
summer 2026. Given that California and Nevada combine to generate upwind contributions of 3.35 ppb 26
of ozone to the NWF NAA, as these proposed controls take effect, they may further aid in the NWF 27
NAA’s ability to attain the standard by the attainment date. 28
29
30
31
8.3.3.3 International Transport 32
The transport of ozone and its precursor emissions from international sources will be discussed 33
in depth in section 9 of this SIP revision. However, international contributions to ozone along the 34

161 Federal Implementation Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air Quality Standard, 87 Fed. Reg. 20,036 (April 6,
2022).
162 Id.

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Wasatch Front, much like interstate contributions described in section 8.3.3.2, plays an important role in 1
the area’s observed ozone concentrations and the NWF NAA’s ability to meet ozone health-based 2
standards. Thus, it is important to include a discussion of international contributions in a WOE analysis. 3
In short, emissions from international sources have long been shown to impact ozone 4
concentrations throughout the Intermountain West.163 These studies generally identified international 5
contributions in the range of 3 – 4 ppb, predominantly observed as contributing to USB ozone 6
conditions. International contributions tend to be relatively consistent throughout the spring and 7
summer seasons. The range of international contributions reported in these studies are similar in scale 8
to those seen from upwind states impacting the NWF NAA as described in section 8.3.3.2 and shown in 9
Table 71. 10
To examine international contributions to the NWF NAA, the UDAQ conducted source 11
apportionment modeling (see section 9.2 for details), in which international contributions were tagged. 12
The results of this exercise (Figure 18 & Figure 19) identified a contribution of 6.2% of ozone along the 13
Wasatch Front attributable to international transport on non-exceedance days, with a similar but slightly 14
higher contribution identified during exceedance days of 6.7%. While the model underestimates 15
absolute ozone concentrations when compared to monitored values, and thus absolute apportioned 16
contributions should be considered with that limitation in mind, the reported concentrations of 17
international contributions range from 3.74 ppb over the episode and average, up to 4.5 ppb on the top 18
10 modeled exceedance days. This range is well in line with those reported in the literature and is highly 19
similar in scale when compared to inter-state transport contributions. 20
21

163 Langford, A.O., Alvarez, R.J., Brioude, J., Fine, R., Gustin, M.S., Lin, M.Y., Marchbanks, R.D., Pierce, R.B., Sandberg, S.P., Senff, C.J., Weickmann, A.M., Williams,
E.J., 2017. Entrainment of stratospheric air and Asian pollution by the convective boundary lauer in the southern U.S. J. Geophysical Res. Atmos., 122, 1312-1337,
doi:10.1002/2016JD025987 & Jaffe, D.A., O.R. Cooper, A.M. Fiore, B.H. Henderson, G.S. Tonnesen, A.G. Russell, D.K. Henze, A.O. Langford, M. Lin, T. Moore, 2018.
Scientific assessment of background ozone over the U.S.: Implications for air quality management. Elem. Sci. Anth., 6: 56. DOI:
https://doi.org/10.1525/elementa.309.

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1
2
Figure 18: Ozone Attributed to Domain-Wide Sources 3
4
5
Figure 19: Domain-Wide OSAT exceedance vs. non-exceedance days 6

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8.3.3.4 Federal vs. State Regulatory Authority 1
As noted in Utah’s comments164 submitted to EPA on EPA’s proposed FIP for interstate 2
transport,165 “A significant portion of states’ total contribution to downwind areas include emissions that 3
states have limited regulatory authority and, in some cases, no regulatory authority at all, including 4
emissions that are federally regulated.” These federally regulated emission sources include the mobile 5
sector, an area in which the state has significantly limited authority to regulate due to CAA section 209’s 6
preemption. This is particularly relevant for anthropogenic NOx emissions, which are dominated by the 7
mobile sector. For the NWF NAA, the emissions from federally regulated sources account for 55.96 tpd 8
(64%) of the total NAA NOx inventory, and 29.8 tpd (33%) of the VOC inventory (section 3). 9
The discrepancy between regulatory authority can be further seen in Figures 15 – 18, where 10
federally regulated sources account for 59.7% of the ozone attributable to anthropogenic emissions, 11
while emissions under state authority account for the remaining 40.3% of ozone formation. As the state 12
of Utah strives to attain the NAAQS, it is doing so with limited authority to reduce a substantial portion 13
of the emissions contributing to the formation of ozone within the NAA. 14
8.3.4 Trends in Emissions 15
Trends in emission reductions along the Wasatch Front are presented in Table 73, providing 16
further evidence that the area is progressing towards attaining the standard by the attainment date. As 17
described in detail in section 3 and section 7 of this SIP revision, the NWF NAA has experienced 18
substantial emission reductions of both anthropogenic VOCs and NOx during the corresponding years of 19
this implementation timeframe—2017 to 2023. During this time, NOx emissions decreased by 21.3 tpd 20
and VOC emissions decreased by 3.7 tpd in large part due to improvements in the on-road mobile sector 21
and as a result of past SIP efforts. 22
23
Table 73: NOx and VOC reductions resulting from PM2.5 SIPs. 24
State Implementation Plan Years NOx Reduction
(tpd)
VOC Reductions
(tpd)
*Salt Lake City Moderate PM2.5 SIP (2014)166 2010 - 2015 24.86 27.57
*Salt Lake City Serious PM2.5 SIP (2019)167 2016 - 2020 15.75 8.27
Total 40.61 35.84
* Includes portions of Box Elder County which is not included in NWF ozone NAA
25
As shown in Table 73, past SIP efforts have resulted in significant reductions of NOx and VOC 26
emissions along the Wasatch Front. Additionally, as described in detail in section 7.3 and section 7.4, the 27
areas have experienced significant decreases in both precursor pollutants as a result of improvements to 28
the mobile on-road sector associated with lower emissions from Tier 3 fuels and engines. Beyond the 29
inventoried reductions, these reductions likely underestimate the full extent of emission reductions in 30
this sector since they fail to capture Utah’s high adoption rate of zero emission vehicles (ZEV), 31

164 Docket ID No. EPA-HQ-OAR-2021-0668, Federal Implementation Plan Addressing Regional Ozone Transport for the 2015 Primary Ozone National Ambient Air
Quality Standard. Comments Submitted by Utah Department of Environmental Quality (UDAQ). DAQP-055-22. June 21, 2022
165 87 Fed. Reg. 20,0036.
166 Utah State Implementation Plan Section IX. Part A.21; Control Measures for Area and Point Sources, Fine Particulate Matter, PM2.5 SIP for the Salt Lake City, UT
NAA
167 Utah State Implementation Plan Section XI. Part A.31; Control Measures for Area and Point Sources, Fine Particulate Matter, Serious Area PM2.5 SIP for the Sal
Lake City, UT NAA.

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predominantly in the light duty sector. The growth of ZEV and electric-hybrid vehicles has grown 940.3% 1
and 101.6% respectively from 2015 – 2021 in the state of Utah.168 While the total proportion of ZEV and 2
electric-hybrid vehicles in Utah’s fleet was still relatively low, at ~2.4% in 2021169, given the growth rate 3
of electric vehicle (EV) adoption in the state, and the fact that Utah is ranked fifth in the nation for 4
access to EV charging infrastructure per capita,170 the percentage of Utah’s on-road fleet is likely to 5
continue to shift towards ZEV and low emission vehicles which will further advance emission reductions 6
in this sector. 7
In addition to the potential underestimation in the electrification of the on-road mobile sector, 8
further market penetration of Tier 3 fuels is expected to continue. In 1970, the EPA set the first light-9
duty vehicle emission standards. These standards have been updated over time with generations of the 10
standard termed Tier 1, Tier 2, and most recently, Tier 3. The Tier 2 and Tier 3 standards also included 11
sulfur standards for gasoline to help ensure that vehicle emissions control operates optimally. By 2025, 12
NOx emission standards for light-duty vehicles will represent a 98% improvement from 1975 levels, with 13
sizable improvements for VOCs. 14
The UDAQ anticipates that the transition from Tier 2 and older vehicles to Tier 3 vehicles will 15
yield dramatic reductions in ozone precursor emissions. While MOVES modeling attempts to capture 16
these emissions reductions, and thus should be represented to some degree in emissions inventories 17
used for this SIP revision, it is important to note that Utah has taken significant additional steps to 18
ensure that the benefit of the Tier 3 vehicle and fuel standards is fully realized throughout the NWF NAA 19
and thus some emission reductions may be underestimated in this modeling demonstration. 20
Unlike many other metropolitan areas throughout the U.S., the NWF is served by the relatively 21
small number of refineries. Importantly, all but one of these refineries (Sinclair) are considered to be 22
“small volume” under the Tier 3 regulations171 – i.e., they produce less than 75,000 barrels per day. 23
Because of this, and due to the older age of facilities in the NWF, it may be more cost-effective for 24
operators to comply with Tier 3 regulations by upgrading their larger, or newer, refineries elsewhere 25
and using credits generated at these facilities and the averaging, banking, and trading provisions of the 26
Tier 3 rule to comply in Utah. This compliance structure would result in higher-sulfur gasoline being sold 27
throughout the NWF NAA, which would erode the benefits of Tier 3 fuels. 28
Although states are restricted from directly establishing new fuel requirements by the Energy 29
Policy Act of 2005, the State of Utah has used a combination of state-led pressure, public awareness 30
initiatives, and incentives in the form of tax credits, to encourage refineries to produce Tier 3 fuel 31
instead of using credits to comply, giving UDAQ greater confidence that the full benefits of the Tier 3 32
fuels will be realized locally. This is especially important in the early years of the Tier 3 program when 33
most of the emissions reduction benefits stem from using Tier 3 fuels in Tier 2 and older vehicles. In 34
particular, the WFRC found that the use of Tier 3 fuel in existing light-duty vehicles results in a NOx 35
reduction of 14.5% and in a VOC reduction of 3.9% as compared with the same vehicles using Tier 2 fuel 36
(30 ppm sulfur).172 These dramatic benefits begin to accrue almost immediately after the first few 37

168 Adoption of Electric and Alternative Fuel Vehicles. OFFICE OF LEGISLATIVE RESEARCH AND GENERAL COUNSEL; May 18, 2021:
https://le.utah.gov/interim/2021/pdf/00002047.pdf
169 Adoption of Electric and Alternative Fuel Vehicles. OFFICE OF LEGISLATIVE RESEARCH AND GENERAL COUNSEL; May 18, 2021:
https://le.utah.gov/interim/2021/pdf/00002047.pdf
170 https://www.governing.com/next/new-data-shows-states-ith-highest-and-lowest-number-of-ev-charging-stations?utm_campaign=Newsletter%20-
%20GOV%20-%20Daily&utm_medium=email&_hsmi=235987835&_hsenc=p2ANqtz--VWjg_LxXqDi4qNgUMKfC7NQ8O47DG-
58ltMXtUweN0QB986ZcszciRfLRxIBQmqBB1mJcfUdxIrvMrh7tWVVucfX1yw&utm_content=235987835&utm_source=hs_email
171 81 FR 23641: Amendments Related to: Tier 3 Motor Vehicle Emission and Fuel Standards
172 “Improved air quality through the use of Tier 3 fuels in Utah", Utah Clean Air Caucus, June 14, 2016

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refueling cycles once the lower-sulfur fuel is available, making the State’s efforts to bring these cleaner 1
burning fuels to the NWF NAA critical for reducing ozone precursor emissions and ultimately 2
demonstrating attainment of the NAAQS. 3
There are seven refineries that provide the majority of the fuel consumed within the NWF NAA. 4
Five of those refineries are located in the NWF NAA, while two additional facilities – the Sinclair 5
refineries in Sinclair and Casper, WY – are connected to the NWF via a product pipeline. Utah has 6
received public commitments from all but one of these refineries that the fuel provided along the 7
Wasatch Front meets the Tier 3 10-ppm sulfur average requirements. The last remaining refinery is 8
expected to make the full transition to Tier 3 fuels by 2024.173 As the last of Utah’s refineries makes the 9
transition to refining and distributing the cleaner burning Tier 3 fuels, additional potentially 10
underestimated reductions in estimated on-road mobile emissions are possible. 11
In addition to potential underestimations of on-road emission reductions, the state of Utah has 12
taken steps to reduce emissions through improving the effectiveness of existing administrative rules. On 13
February 1, 2023, the Utah Air Quality Board adopted amendments to Utah Administrative Rule R307-14
328; Gasoline Transfer and Storage. These amendments resulted in the addition of clarifying language to 15
the rule which requires all gasoline service stations to install pressure relief valves to underground 16
storage tanks. While the requirement for pressure relief valves was preexisting in R307-328, the 17
language did not adequately explain the requirements. The UDAQ had identified 266 underground 18
storage tanks located in the NWF NAA that either did not have, or could not be confirmed to have, the 19
required pressure relief valve. The resulting emission reductions from these amendments are not 20
represented in the inventory since the inventory assumed compliance with this requirement, however 21
these amendments will result in additional reductions of VOC emissions within the NWF NAA. 22
8.3.5 Unaccounted Controls and Emission Reductions 23
As described in section 7, emissions reductions that are creditable towards RFP, and thus 24
included in a subsequent attainment demonstration, emission reductions have strictly prescriptive 25
requirements attached. While the attainment demonstration in this SIP revision utilized inventories that 26
attempt to quantify emission reductions associated with past SIP work and improvements to the on-27
road sector, the inventory does not account for emission reductions associated with non-RFP creditable 28
reductions. However, the state of Utah has multiple and extensive incentive and non-creditable 29
emission reduction programs that result in substantial emission reductions. As a result, the attainment 30
demonstration outlined in Section 8.2 does not fully account for ongoing emission reduction in, and 31
around, the NWF NAA. This section highlights these programs and, where possible, reports emission 32
reductions associated with these programs. Some of these programs include regions beyond the NWF 33
NAA, however being the most densely populated region in the State, a substantial portion of the 34
emission reductions highlighted in this section are targeted to areas within the NAA boundary. 35
36
8.3.5.1 Utah Clean Diesel Program (UCDP) and Diesel Emission Reduction Act (DERA) 37
Utah’s Clean Diesel Program provides incentives to fleet owners to retire older vehicles and 38
replace them with newer vehicles that meet more stringent emission standards. The program began in 39
2008 and will continue beyond this SIP revision and includes incentives available under the Diesel 40
Emission Reduction Act (DERA)174 and the National Clean Diesel (NCD) program. Table 73 indicates the 41

173 “Four Utah refineries now produce cleaner Tier 3 fuels, and the fifth says it will soon.” Salt Lake Tribune. January 22, 2023: https://www.sltrib.com/renewable-
energy/2023/01/22/four-utah-refineries-now-produce/
174 42 U.S.C. §§ 16131 through 16137.

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annual targeted number of vehicles included in the program and their estimated annual and lifetime 1
emission reductions for both NOx and VOCs for the years associated with this SIP revision. 2
3
8.3.5.2 Volkswagen Settlement Funds 4
In 2016, Volkswagen (VW) entered into a settlement175 as a result of a lawsuit filed against the 5
company for defeating emission testing programs and engine certifications for its light-duty diesel 6
vehicles. The state of Utah was the beneficiary of this settlement and received $35,177,506. The Utah 7
Department of Environmental Quality was designated as the lead agency to administer this funding, 8
which has been used to replace older class 4 – 8 freight trucks, school buses, shuttle and transit buses, 9
fund electrical vehicle supply equipment, and assist the Diesel Emissions Reduction Act (DERA) program 10
described in section 8.2.6.1. The results of this program are highlighted in Table 74. 11
12
8.3.5.3 Vehicle Repair and Replacement Assistance Program (VRRAP) 13
In 2018 the EPA awarded the state of Utah with Targeted Air Shed Grant funding. Targeted Air 14
Shed Grants provide funds to reduce air pollution in the nation’s NAAs with the highest levels of ozone 15
and PM2.5. UDAQ application was for the development of a Vehicle Repair and Replacement Assistance 16
Program (VRRAP) for the Salt Lake PM2.5 NAA. 17
Through the VRRAP, low-income individuals with a vehicle that fails an emissions inspection are 18
offered funding assistance to either repair the vehicle or replace it with a newer, cleaner vehicle. 19
Qualifications for financial assistance are based on a matrix that considers the vehicle owner’s 20
household income as a percent of the national income poverty level, the value of the repairs being done 21
on the vehicle, and the vehicle’s mechanical life expectancy. The program is set up to augment and 22
improve the overall effectiveness of counties’ I/M programs. 23
Since starting in 2020 the VRRAP has repaired 163 and replaced 48 vehicles. UDAQ expects 24
these activities to reduce emissions annually by 1.26 tons of Nonmethane Organic Gas (NMOG) and NOx 25
and reduce lifetime emissions of NMOG and NOx by 11.17 tons (Table 74). 26
27
28
29
30
31
32
33
34
35
36
37
38
39
40

175 VOLKSWAGEN “CLEAN DIESEL” MARKETING, SALES PRACTICES, AND PRODUCTS LIABILITY LITIGATION. Case Number: MDL No. 2672 CRB (JSC)

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Table 74: Emission reductions associated with incentive programs in and around the NWF NAA. * VOC emission reductions not 1
available. ** Combined NOx and NMOG emission reductions 2
Year Vehicles
Replaced
NOx Annual
Reduction (tpy)
NOx Lifetime
Reduction (tpy)
VOC Annual
Reduction (tpy)
VOC Lifetime
Reduction (tpy) Program
2017 95 35.77 144.19 8.68 12.77 DERA / NCD
2018 87 9.66 176.40 0.89 16.91 DERA / NCD
2019 60 20.91 62.73 1.04 3.12 DERA / NCD
2020 44 4.75 14.26 0.55 1.65 DERA / NCD
2021 59 7.2 26.34 0.66 2 DERA / NCD
2019 -
Ongoing 78 23.49 10.34 * * VW
Settlement
2020 -
Ongoing 48 11.17** 1.26** ** ** VRRAP
2022 13 1.54 4.62 NCD
Total 484 103.32 438.88 11.82 36.45
3
8.3.5.4 Diesel I/M Programs 4
In 2018 the Utah State Legislature passed H.B. 101, which established a pilot program to require 5
diesel vehicle emissions inspections in Utah County. This program was made permanent in 2021 when 6
the Utah State Legislature passed S.B. 146. While diesel I/M programs have not historically been 7
awarded SIP emissions reduction credit, UDAQ nevertheless anticipates additional NOx and VOC 8
emissions reductions from this program. Currently, all counties that are required to have an emission 9
inspection program are required to have a diesel emissions program for vehicles model year 2007 or 10
newer with a gross vehicle weight of 14,000 pounds or less (see 41-6a-1642(7)). Salt Lake and Davis 11
Counties also require all diesel vehicles to go have an emission inspection. 12
13
8.3.5.5 Lawn & Garden Equipment Exchange Program 14
Beginning in 2015, as part of the Utah Clean Air Retrofit, Replacement, and Off-Road Technology 15
(CARROT) program,176 the UDAQ has administered a lawn and garden exchange program aimed at 16
replacing gas powered lawn and garden equipment with zero emission alternatives. This equipment 17
includes lawn mowers and string trimmers but is expected to be expanded in the coming years to 18
include a wider array of 2-stroke lawn and garden equipment. Since 2017, this program has replaced an 19
estimated 6,638 pieces of summertime operated lawn and garden equipment resulting in an estimated 20
reduction of 0.13 tpy of NOx and 2.26 tpy of VOCs. 21
22

176 Utah Code Ann. §§ 19-2-201 through 19-2-204.

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8.3.5.6 UCAIR Summer Education Program 1
The Utah Clean Air Partnership (UCAIR) is a statewide non-profit entity created to bring together 2
individuals, business, and communities to help improve Utah’s air. In 2022, UCAIR received a grant from 3
the Utah Department of Environmental Quality to conduct an outreach and education campaign aimed 4
at educating Utah’s population about summertime ozone pollution. The campaign ran from July 5 5
through September 11, 2022. During this time the campaign measured over 45 million unique 6
impressions through a combination of television (2.9 million), outdoor (27.68 million) and online (14.45 7
million) outlets. Post-campaign research identified that 92% of residents were concerned with the air 8
quality where they live during summer ozone season, with 99% of respondents familiar with personal 9
actions they can take to improve air quality. 10
11
8.3.5.7 UCAIR Personal Fuel Can Exchange Program 12
In addition to the education campaign discussed in section 8.3.5.6, UCAIR operates a Personal 13
Fuel Canister (PFC) exchange program, in which UCAIR collects and recycles old PFCs and replaces them 14
with EPA compliant canisters, which reduces VOC emissions associated with the evaporative loss of 15
gasoline. The program began targeting PFCs for replacement in 2019, and since that time has 16
successfully upgraded over 5,000 PFCs in Utah’s NAAs. 17
18
8.3.5.8 UTA Free Fare Days 19
In 2019, Utah enacted H.B. 353: Reductions of Single Occupancy Vehicle Trip Pilot Program.177 20
This bill designated the UDAQ as the lead agency in administering a program to make all public transit 21
free on days associated with poor air quality in an attempt to reduce emissions associated with vehicle 22
emissions. While much of this program was aimed at reducing emissions during Utah’s wintertime PM2.5 23
season, the program has been enacted during two separate periods of high summertime ozone. These 24
“free fare days” were August 12 - 13 of 2021, and September 1 - 2 of 2022. 25
26
8.3.5.9 Surge Teleworking 27
During the 2021 legislative session, Utah adopted S.B. 15: Workforce Solutions for Air Quality. 28
This bill encourages eligible State employees to telecommute on mandatory action days for air quality 29
and on other special circumstances to help decrease on-road emissions. This law covers an estimated 30
10,185 eligible state employees and contributes to reductions of NOx and VOC emissions on ozone 31
exceedance days throughout the NAA. 32
33
8.3.5.10 Emission Reductions Beyond the NAA Boundary 34
On July 6, 2022, the Utah Air Quality Board adopted SIP revisions including Utah’s Second 35
Implementation Period for Regional Haze178 and associated emission limits179. The emission reductions 36
associated with these actions are broad and include the following measures: (1) requiring flue gas 37
recovery on boilers at US Magnesium by summer of 2028; (2) mandating a shutdown of units 1 and 2 at 38
the Intermountain Generation Station by December of 2027; (3) imposing new plantwide NOx emission 39
limits for the coal-fired Hunter and Huntington power plants that phase in between July of 2022 and 40
January of 2028; and (4) making many existing permitted limits across the state federally enforceable. 41
While much of the emission reductions highlighted here are beyond the temporal scope of this SIP 42

177 Id. § 19-2a-104, repealed pursuant to § 63I-1-219, eff. July 1, 2022.
178 Utah State Implementation Plan. Section XX.A, Regional Haze
179 Utah State Implementation Plan, Emission Limits and Operating Practices. Section IX, Part H.21 and Part H.23

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revision, occur outside of the NWF NAA, or make permanent emission reductions that have already 1
occurred, they serve to further demonstrate efforts by the state of Utah to reduce ozone forming 2
precursor emissions. 3
4
8.3.5.11 Science for Solutions Applied Research Grants 5
In 2018, UDAQ received an ongoing annual $500,000 appropriation from the Utah State 6
Legislature specifically intended to fund applied air quality research projects. In response, the UDAQ 7
established the competitive Science for Solutions research grant program. Over the last five years, 8
successful grant applicants have submitted proposals targeting UDAQ’s goals and priorities. In recent 9
years, UDAQ has placed a high emphasis on improving the understanding of summertime ozone 10
pollution throughout the NWF NAA. 11
An abbreviated list of applied research projects funded by the UDAQ’s Science for Solutions 12
research grant are listed below. These projects focus on summertime ozone in the NWF NAA: 13
14
 The Salt Lake Regional Smoke, Ozone and Aerosol Study (SAMOZA); University of Washington 15
 Improving Smoke Detection and Quantifying the Wildfire Smoke Impacts on Local Air Quality 16
Using Modeling and Machine Learning Techniques; University of Utah 17
 Improved Vegetation Data for the Biogenic Emission Inventory of Wasatch Front; Ramboll US 18
Consulting 19
 Impacts of the Great Salt Lake on Summer Ozone Concentrations Along the Wasatch Front; 20
University of Utah 21
 Development of a WRF-based Urban Canopy Model for the Greater Salt Lake City Area; 22
Brigham Young University 23
 Quantitative Attribution of Wildfires on Summertime Ozone Concentrations along the Wasatch 24
Front; San Jose State University 25
These projects, along with others, were specifically funded to improve UDAQ’s SIP model 26
performance and better inform state policy and rulemaking. Science for Solutions projects have already 27
made a difference in improving UDAQ’s model performance. For example, these projects have improved 28
shortwave albedo in the CAMx model to realistically reflect salt-crust and playa surfaces around the 29
Great Salt Lake. UDAQ also learned more about the unique role of halogens in ozone formation in the 30
Salt Lake Valley. Motivated by this information, UDAQ funded the development of an enhanced 31
chemical mechanism (CB6r5h) that includes a broader range of halogen pathways to use in our air 32
quality modeling. These enhancements have led to demonstrable improvements in model performance. 33
Future projects will help UDAQ determine critical factors in summertime ozone formation. 34
Biogenic emissions are a large source of uncertainty in the region. Recent evaluations of BEIS/BELD have 35
shown that isoprene, a key reactive biogenic VOC, is largely underpredicted in regional modeling. 36
Through Science for Solutions, UDAQ is funding a comprehensive project to greatly improve inputs (e.g., 37
leaf area index, tree species) to biogenic models using local information and high-resolution satellite 38
imagery. In addition, UDAQ is funding projects to better understand wildfire impact on ozone pollution. 39
These projects will not only enhance UDAQ’s understanding of wildfire contributions to ozone 40
concentrations throughout the NWF NAA but will also improve the UDAQ’s understanding of local 41
contributions. 42

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8.4 Conclusion 1
Results of any modeled outcome will include some degree of uncertainties. As a result of these 2
uncertainties, it is important to consider additional factors within the range of those uncertainties and 3
consider factors beyond the scope of the analysis. The predicted FDV for ozone concentrations outlined 4
in section 8.2, paired with the additional WOE analysis, results in a strong case that this attainment 5
demonstration adequately demonstrates the NWF NAA attaining the 8-hour ozone NAAQS by the 6
attainment date of August 3, 2024. 7
8
9

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Chapter 9 - 179B(a) Prospective Demonstration 1
9.1 Overview 2
Section 179B(a) of the CAA states that a SIP revision shall be approved by the EPA if the state 3
can demonstrate that the implementation plan is “adequate to attain and maintain the relevant national 4
ambient air quality standards... but for emissions emanating from outside of the United States.”180 As 5
noted in the preambles of both the 2008181 and 2015182 ozone implementation rules, section 179B of the 6
CAA does not prohibit non-international border states from submitting a demonstration. However, as 7
noted in EPA guidance,183 demonstrations from states that do not directly share an international border 8
will require additional technical rigor compared to international border areas. 9
Section 179B of the CAA has two mechanisms to demonstrate that international contributions 10
impact a NAA’s ability to attain or maintain a NAAQS. A state may demonstrate independent of a SIP 11
revision that a NAA would have attained the standard at a past attainment date but for the presence of 12
international emissions, known as a retrospective 179B(b) demonstration, and thus should not be 13
advanced in nonattainment classifications.184 Conversely, a state may demonstrate as part of a SIP 14
revision that a NAA will attain the standard by a future attainment date, but for the presence of 15
international emissions. This is known as a prospective 179B(a) demonstration.185 16
There are also substantial differences in the outcomes of approved prospective and 17
retrospective 179B demonstrations. An approved retrospective 179B(b) acts to prevent a NAA from 18
being further redesignated to a more stringent nonattainment status. A prospective 179B(a) however, 19
acts as additional information used by the EPA in determining if a SIP modeling attainment 20
demonstration adequately demonstrates attainment by the attainment date, but for the presence of 21
international emissions. As a result, a NAA with an approved 179B(a) demonstration that subsequently 22
fails to attain the standard by the attainment date would not be prevented from a further 23
reclassification to a more stringent nonattainment status. 24
On May 28, 2021, the UDAQ submitted to the EPA for consideration a retrospective 179B(b) 25
demonstration for the NWF NAA186 for the marginal attainment date of August 3, 2021. In the 26
demonstration, UDAQ provided three separate analyses examining international contributions including 27
a synoptic weather analysis, Hybrid Single–Particle Lagrangian Integrated Trajectory (HYSPLIT) backward 28
dispersion modeling, and photochemical modeling results performed by a third party showing that the 29
area would have attained the standard by the marginal attainment date, but for the presence of 30
international contributions. 31
Upon publication of the Determination of Attainment by the Attainment Date,187 the EPA found 32
Utah’s demonstration was not approvable and subsequently reclassified the area as a moderate NAA. 33

180 42 U.S.C. § 7509a(a)(2).
181 Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements, 80 Fed. Reg. 12,264 (March 6, 2015).
182 Implementation of the 2015 National Ambient Air Quality Standards for Ozone: NAA State Implementation Plan Requirements, 83 Fed. Reg. 62,998 (Dec. 6,
2018). s
183 Guidance on the Preparation of Clean Air Act Section 179B Demonstrations for NAAs Affected by International Transport of Emissions (Dec. 2020) (179B
Demonstrations Guidance).
184 42 U.S.C. § 7509a(b)-(d); see also 179B Demonstrations Guidance at 15-18.
185 42 U.S.C. § 7509a(a); see also 179B Demonstrations Guidance at 12-15.
186 Retrospective 179B(b) Demonstration for Utah’s Northern Wasatch Front Ozone NAA. May 28, 2021. DAQP-048-21
187 87 Fed. Reg. 60,897.

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The EPA cited four primary reasons for its disapproval188 including: (1) a lack of technical information; (2) 1
a divergence in interpretation of section 179B including the importance of the proportion of local versus 2
international contributions; (3) a failure to demonstrate sufficient implementation of feasible emission 3
reduction measures; and (4) the presence of a nearby NAA that attained the standard despite the 4
presence of international contributions. 5
In this section, the UDAQ will demonstrate attainment under Section 179B(a) prospectively, 6
using an updated and improved photochemical modeling, that the NWF NAA would attain the 2015 8-7
hour ozone NAAQS by the attainment date of August 3, 2024, but for the presence of international 8
emissions. Further, UDAQ will utilize and expand on the wealth of technical information included in this 9
SIP revision to address each of EPA reasons for denying Utah’s previous 179B(b) demonstration. 10
9.2 Ozone Source Apportionment (OSAT) Modeling 11
To determine the contribution of different source emission groups and regions to measured 12
ozone concentrations at individual monitoring sites within the NAA, OSAT modeling was performed 13
using emissions projected to 2023. Modeling was conducted using the OSAT tool in CAMx v7.1, which 14
was used for this SIP demonstration modeling as described in section 8. At the request of the UDAQ, 15
OSAT was integrated by Ramboll (developer of CAMx) with CB6r5h in a special version of CAMx v7.1. 16
CB6r5h (version 6, revision 5 with halogens) gas-phase chemical mechanism, which includes halogens 17
chemistry and was specifically developed by Ramboll for this SIP application, was used for all modeling 18
simulations. Source apportionment was conducted for the 4 and 1.33 km domains, where the two 19
domains were run in a two-way nested configuration. 2023 emission inputs were used for source 20
apportionment modeling.189 Meteorological fields, ozone column values and photolysis rates remained 21
unchanged from those used for the attainment demonstration modeling. Six geographic source regions 22
were used in the source apportionment modeling (Figure 20), where each county within the NAA was 23
considered as an individual region (Salt Lake, Davis, Weber, Tooele counties). Counties within Utah but 24
outside the NAA were considered as a single region (Other Utah). Regions within the 4 km domain but 25
outside the State of Utah were considered as a single region. 25 different source emission sectors were 26
considered for this OSAT simulation and tracer species that track ozone formation from VOC and NOx 27
emissions from these source categories were tagged. Source groups that were considered in OSAT 28
included emissions from consumer solvents, on-road heavy duty mobile source emissions, on-road light 29
duty mobile source emissions, lawn and garden equipment emissions, point source emissions, biogenic 30
emissions, in addition to several other source emission sectors. A complete list of these source emission 31
groups is provided in Table 75. 32
To determine the contribution of international anthropogenic source emissions to local ozone 33
concentrations, initial and boundary conditions (IC and BC) for the 4 km domain were also considered as 34
their own separate source groups. The contribution of international anthropogenic source emissions 35
was determined based on two CAMx simulations for the 12 km domain. These included a base (BASE) 36
simulation and a sensitivity (ZROW) simulation. The BASE case simulation included 2023 emissions from 37
all source emissions while the ZROW simulation included all 2023 emissions with the exception of non-38

188 Technical Support Document (TSD): Northern Wasatch Front (NWF), Utah: Failure to Attain the 2015 Ozone National Ambient Air Quality Standard by the
Attainment Date; Reclassification and Disapproval of International Emission Demonstration, Docket Id. No. EPA-HQ-OAR-2021-0742-0043 (Jan. 2022) (179B NWF
TSD).
189 SMOKE Technical Support Documentation for NWF SIP Attainment Demonstration; https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-
001603.pdf

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US anthropogenic emissions, leaving only US and global natural emissions. This ZROW simulation was 1
based on 2017 ZROW GEOS-Chem global chemistry model outputs, where all anthropogenic emissions 2
outside the US were set to zero190. 3
Source-apportioned boundary and initial conditions for the 4 km domain were then derived 4
using CAMx “saicbc” tool and model outputs from the base and ZROW 12 km simulations. Using IC and 5
BC extracted from model outputs from the base and ZROW 12 km simulations, the tool was used to 6
generate two source apportionment IC and BC groups for the 4 km domain, where one group represents 7
international anthropogenic emissions, and one represents global natural and US emissions within the 8
12 km CAMx domain that are transported into the 4 km domain from the lateral boundaries. 9
10
11
Figure 20: Map of source regions used in 2023 OSAT modeling for the 4 and 1.33 km domains. Each color represents a different 12
source region. 13
14

190 https://views.cira.colostate.edu/docs/IWDW/Modeling/WRAP/2017/Ramboll_WESTAR_GEOS-Chem_Report_8Apr_2021.pdf

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1
Table 75: Emission source categories considered in 2023 OSAT modeling. *Only VOCs and NOx tracer species from US 2
Magnesium are tagged. 3
Source Group ID Source Group Description
1 Solvents: Consumer Products All personal care and household cleaning products
2 Solvents: Other Any non-personal care or household cleaning product
solvents: Surface coatings, dry cleaning, asphalt
paving, degreasing, etc.
3 Non-road: Lawn & Garden All lawn & garden equipment: 2- & 4-stroke gasoline-
powered mowers, trimmers, leaf blowers etc.
4 Non-road: Other Any non-lawn & garden non-road equipment:
construction equipment, aircraft ground support
equipment
5, 7 On-road: Light Duty Passenger vehicles
6, 8 On-road: Heavy Duty Commercial trucks, haul trucks, buses, motor homes
9 Rail
10 Biogenics
11 EGUs
12 Point Oil & Gas
13 Nonpoint Oil & Gas
14 Point: Other All other point sources not specifically tagged
15 Point: US Magnesium* all emissions associated with US Magnesium Rowley
Plant (point source ID = 10716)
16 Point: Mine Trucks Mobile Sources; Off-highway Vehicle Diesel;
Construction and Mining Equipment; Off-highway
Trucks
17 Wildfires, Prescribed Fires
18 Agricultural Fires
19 Lightning NOx
20 Airports
21 ERC Bank Emissions Reduction Credit bank
22 Fertilizer
23 Livestock
24 Nonpoint

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25 Area Fugitive Dust
International
Anthropogenic
Non-US anthropogenic emissions estimated based on
12 km base case and zero-out modeling simulations
that use GEOS-Chem global model outputs
Global Natural + Non-
Utah US
Anthropogenic
Global natural emissions plus any US anthropogenic
emissions that are transported into the 4km domain
(California anthropogenic, etc.). These were
estimated based on 12 km base case and zero-out
modeling simulations that use GEOS-Chem global
model outputs
Top Boundary
Conditions

1
Source group contributions to MDA8 ozone concentrations at each monitoring station and on 2
each day of the modeling episode were determined using modeled hourly contributions from each 3
source sector and region, where, for each group, contributions under “NOx-limited” and “VOC-limited” 4
chemical regimes were combined to obtain the net contribution from each group. For each day and 5
monitoring station, hourly contributions were processed to calculate 8-hour average source group 6
contributions at each individual monitoring site, where the contribution values were calculated using 7
model predictions for the grid cell that includes the monitoring station. For each day and monitoring 8
station, 8-hr average contributions were then summed to calculate total 8-hr average ozone 9
concentrations for each source group and region. Maximum daily 8-hr average ozone concentrations 10
and their contributions were then determined based on these total 8-hr values. 11
9.3 Ozone Source Apportionment Modeling Results 12
Source apportionment modeling results showed that non-Utah natural and non-Utah US 13
anthropogenic emissions contribute to most of the ozone measured at the Hawthorne monitoring 14
station, which corresponds to the monitor with the highest predicted FDV, accounting for about 67% 15
(39.07 ppb) of its modeled maximum daily 8-hour ozone concentrations on average during the modeling 16
episode (Figure 21). Local anthropogenic and biogenic sources had smaller contributions, accounting for 17
nearly 14.5% (8.44 ppb) and 7.4% (4.28 ppb) of ozone at the same location, while international 18
anthropogenic emissions source contribution averaged 6.5% (3.74 ppb). The contributions for 19
background ozone (international anthropogenic emissions, global natural and US anthropogenic 20
emissions) are consistent with contributions reported for the Western US in other modeling 21
studies191,192,193. Contributions from other sources, such as wildfires, prescribed (Rx) fires, lightning NOx, 22
were more minor (<= 4% at 2.3 ppb). Figures in this section represent a low bound of 8-hour ozone 23
source apportionment results and are subject to increase in future modeling. 24
25

191 Denver Metro/North Front Range 2017 Ozone Source Apportionment Modeling. HYPERLINK "https://views.cira.colostate.edu/wiki/wiki/9132/denver-
metronorth-front-range-2017-ozone-source-apportionment-modeling"https://views.cira.colostate.edu/wiki/wiki/9132/denver-metronorth-front-range-2017-
ozone-source-apportionment-modeling
192 2017 Denver Metro/North Front Range Moderate Area 8-Hour Ozone SIP. https://raqc.egnyte.com/dl/uJJfKleU67/FinalModerateOzoneSIP_2016-11-29.pdf_
193 Scientific assessment of background ozone over the U.S.: Implications for air quality management.
https://online.ucpress.edu/elementa/article/doi/10.1525/elementa.309/112835/Scientific-assessment-of-background-ozone-over-the

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1
Figure 21: Source contributions by region and emission sector to 8-hour ozone concentration (ppb) at the Hawthorne monitoring 2
station for each day of the modeling episode (left panel) and on average over all days of the modeling episode (right panel). 3
Results are based on 2023 OSAT model outputs for the 1.33 km modeling domain and spin-up days are excluded. 4
These source contributions displayed some differences across exceedance, top 10 exceedance 5
and non-exceedance days (Figure 21). Compared to contributions on non-exceedance days, the 6
contributions from local anthropogenic and biogenic source emissions are greater on exceedance 7
(modeled MDA8 ozone >= 60 ppb) and top 10 exceedance days, on average, consistent with 8
expectations (Figure 22). Ozone exceedance days are characterized by an upper-level high pressure 9
system that brings warm temperatures, lack of frontal passage, low surface winds and increased solar 10
radiation; all of which are conducive to the build-up of ozone and its precursors. The contribution of 11
international anthropogenic emissions to average ozone also increased on exceedance days compared 12
to non-exceedance days, but the increase was not as significant as that determined for local 13
anthropogenic and biogenic source emissions. Their contribution estimate increased from 3.25 ppb 14
(6.2%) on non-exceedance days to 4.47 ppb (6.7%) on exceedance days. A similar increase is also noted 15
for background natural and US anthropogenic emissions. The upper-level ridge on exceedance days can 16
increase background concentrations within the ridge, where the complex topography of the region can 17
enhance vertical transport and recapture of ozone from aloft.194 18
19

194 Reddy, P. J., & Pfister, G. (2016). Meteorological factors contributing to the interannual variability of midsummer surface ozone in Colorado, Utah, and other
western U.S. states. Journal Of Geophysical Research-Atmospheres, 121, 2434-2456. doi:10.1002/2015JD023840.

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1
Figure 22: Source contributions by region and emission sector ozone concentration (ppb) at the Hawthorne monitoring station 2
for each day of the modeling episode (upper panel) and on average over all days of the modeling episode, exceedance days, top 3
10 exceedance days and non-exceedance days (lower panel). Results are based on 2023 OSAT model outputs for the 1.33 km 4
modeling domain and spin-up days are excluded. 5
9.4 Future Design Values after Removal of Contributions from International 6
Anthropogenic Emissions 7
8
Overall, the source apportionment modeling results show that background ozone emission 9
sources, contribute to the majority of the ozone measured along the Wasatch Front, accounting for about 10
66% of modeled ozone concentrations, on average on modeled top 10 exceedance days. This includes 11
59.3% (40.82 ppb) contribution from natural and US anthropogenic emissions outside Utah and 6.5% (4.5 12
ppb) contribution from international anthropogenic emission sources. Using the source contribution 13
estimate for international anthropogenic emissions, the projected FDV were adjusted to reflect what the 14
FDV would be but for the presence of international emissions. For each site, FDV were adjusted by 15
subtracting the OSAT source contribution estimate for international anthropogenic emissions (IAE) from 16
the FDV calculated in the attainment demonstration (section 8). 17
Average source contribution estimate for international anthropogenic emissions on top 10 18
exceedance days were used for this calculation. For cases in which the model simulation does not include 19
10 days with MDA8 ozone values >= 60 ppb at a site, all days with MDA8 O3 values >= 60 ppb are used in 20
the calculation. Given that the model does well at simulating background ozone (section 8.2), subtracting 21
the OSAT source contribution estimate for international anthropogenic emissions from the FDV calculated 22
in the attainment demonstration is considered adequate. This approach is shown in equation 6. Moreover, 23
since the model tended to be biased low for local ozone production, this approach is more adequate than 24
a scaling technique where the FDV at each monitoring site is scaled by the relative modeled changes in 25

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ozone between a 2023 baseline and a 2023 sensitivity modeling scenario that includes emissions from all 1
sources except for international anthropogenic emissions. 2
3
Equation 6 4
𝑭𝑫𝑽𝒊, 𝒂𝒅𝒋ൌ𝑭𝑫𝑽𝒊െ𝑰𝑨𝑬𝒊, 5
6
where “i” corresponds to a given monitoring site. 7
Resulting adjusted FDV are shown in Table 76. Consistent with the truncation and rounding 8
procedures for the 8-hour ozone NAAQS, the projected DVs are truncated to integers in units of ppb195. 9
All sites demonstrate attainment when the contribution of international anthropogenic emission 10
sources is subtracted from the FDV calculated in the attainment demonstration modeling. 11
12
Table 76: Future design values (FDV), source contribution estimates for international anthropogenic emissions (IAE) and 13
adjusted future design values (FDV adj) at monitoring locations within the northern Wasatch Front non-attainment area. 14
Site Site ID County FDV (ppb) IAE (ppb) FDV_adj
Bountiful 490110004 Davis 71 4.54 66
Hawthorne 490353006 Salt Lake 72 4.50 67
Herriman 490353013 Salt Lake 72 3.81 68
Erda 490450004 Tooele 70 4.06 65
Harrisville 490571003 Weber 70 3.12 66
9.5 Conclusion 15
In its document overviewing the disapproval of Utah’s retrospective 179B(b) demonstration, 16
EPA cited a lack of “sufficient technical information”196 to support the modeled conclusions including: a 17
lack of emission data, observations, and meteorological analyses. Further, EPA noted that the model 18
UDAQ relied on for its submission did not demonstrate adequate model performance to creditably 19
determine the influence of international contributions in the NAAs ability to attain the standard.197 20
The 179B(a) demonstration provided as part of this SIP revision leverages the wealth of 21
information included within the SIP and in the technical supporting documentation. This includes 22
detailed information on the underlying emission inventories (section 3), modeled and observed 23
concentrations (section 8), and meteorological modeling (section 8).198 The improved modeling also 24
conforms with EPA’s modeling performance metrics (section 8). Thus, the analysis and conclusions 25
provided in this 179B(a) demonstration and SIP revision fulfill the technical deficiencies EPA noted in 26
Utah's retrospective submission, and conclusively identifies the role international emissions play in the 27
NWF NAA’s ability to attaining the standard by the attainment date. 28
Beyond the lack of technical information cited by EPA in its disapproval of Utah’s 179B(b) 29
demonstration, EPA noted that the state’s demonstration diverged from EPA’s interpretation of criteria 30

195 40 CFR Part 50, Appendix P to Part 50 – Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone.
196 179B NWF TSD at 2.2
197 Id.
198 Meteorological Modeling for Wasatch Front O3 SIP. Technical Support Documentation and Model Performance Evaluation.

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for a successful demonstration in several ways.199 EPA noted that the states did not demonstrate that 1
international transport is significantly different on ozone exceedance days compared to non-exceedance 2
days and that international contributions appear to contribute less than local ozone production.200 3
As shown in Figure 23, the UDAQ has identified that international emissions contribute to ~6% 4
of ozone in NWF NAA on non-exceedance days. That contribution increases to ~7% of the total modeled 5
ozone across all exceedance days. The observed increase during exceedance days relative to non-6
exceedance days represents a significant additional contribution to the observed ozone concentrations 7
when considering that only 18.5% of the overall ozone contributions are attributed to in-state 8
anthropogenic emissions. Thus, the additional 1% observed international contributions on exceedance 9
days represents excess international contributions relative to modeled non-exceedance day 10
contributions. 11
12
Figure 23: International contributions at Hawthorne monitor site on exceedance and non-exceedance days. 13
As further demonstrated by Figure 22, international emissions represent a significant 14
contribution to the NAA relative to ozone attributable to anthropogenic emissions within the NAA, and 15
thus emissions which this SIP can regulate. For instance, on the top 10 exceedance day during the 16
modeling episode, anthropogenic emissions represent just 19.3% of modeled ozone, with emissions 17
from sources under federal jurisdiction accounting for 11.8% and emissions under state authority 18
accounting for the remaining 7.5%. However, contributions from international anthropogenic emissions 19
account for 6.5% of the modeled ozone concentrations. 20

199 179B NWF TSD at 2-3.
200 Id. at 3.

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The EPA further notes in its disapproval of Utah’s 179B(b) submission that the state failed to 1
adequately demonstrate that all “feasible” emission reduction strategies had been implemented.201 As 2
noted in the ozone implementation rules,202 emission reduction strategies implemented as part of 3
ozone SIPs are to be reasonably available (i.e., RACT or RACM), and thus feasible controls in the context 4
of ozone reductions strategies should be held to a comparable standard. While section 179B of the CAA 5
makes no specific mention of the requirement for implementation of feasible controls, sections 4 and 5 6
of this SIP revision clearly demonstrate that the state of Utah has implemented an exhaustive list of VOC 7
and NOx emission reduction strategies throughout the NAA as a result of past SIPs targeting wintertime 8
PM2.5, many of which go beyond what would be considered reasonably available. Beyond the controls 9
implemented to date, the UDAQ has identified additional emission reduction controls and strategies as 10
outlined in Sections 4, 5 and 7 of this SIP revision, some of which have been determined to be ”beyond-11
RACT”. These emission reductions are planned to be implemented in the coming years and serve as 12
further evidence that the state has implemented feasible controls, and thus the contributions of 13
international emissions should be considered when determining attainment. 14
Lastly, in its disapproval of Utah’s 179B(b) demonstration EPA argued that the presence of a 15
nearby ozone NAA, the Southern Wasatch Front (SWF) (figure 1) which recently attained the standard 16
by the marginal attainment date, is evidence that the NWF NAA can attain the current standard despite 17
the presence of international emissions. However, in the same document, EPA demonstrates that the 18
SWF has an order of magnitude lower anthropogenic NOx emissions and almost a third of the 19
anthropogenic VOC emissions when compared to the NWF203. To this point, the SWF has approximately 20
1.2 million fewer residents than the NWF and a substantially different industrial sector. While the SWF 21
did attain the 2015 ozone NAAQS by the marginal attainment date of August 3, 2021, it did so by just 1.0 22
ppb, and has subsequently exceeded this standard. The fact that a bordering NAA, with fewer residents, 23
fewer emissions, and a substantially different industrial make-up, is marginally attaining the standard 24
further demonstrates why it is critical that the presence of international emissions be appropriately 25
acknowledged as regulatorily significant. Unless it is the intent of the EPA to suggest that the NWF NAA 26
must reduce its NOx and VOC emissions to levels similar to that of the SWF, which is impossible given the 27
lack of reasonably available control options available to the state as demonstrated in sections 4 and 5 of 28
this SIP revision, the state does not see how the attainment status of the SWF is relevant. In fact, 29
comparisons between two substantially different NAAs, both of which are facing the Intermountain 30
West’s regionally specific challenges in addressing ozone, only further supports that international 31
emissions are regulatorily significant to the region. Thus, section 179B of the CAA is an appropriate 32
mechanism to provide regulatory flexibility to NAAs within this unique geographic region. 33
As discussed in the introduction of this section, an approved 179B(a) demonstration would not 34
prevent the NWF NAA from being reclassified to a more stringent nonattainment status if the area fails 35
to attain the standard by the attainment date based on ambient monitoring data. Instead, this 36
demonstration serves as further evidence that the modeling attainment demonstration and WOE 37
analysis provided in section 8.3 of this SIP revision adequately demonstrates the NWF NAA is projected 38
to attain the standard by the attainment date, but for the presence of international emissions. 39
40

201 Id. at 3.
202 83 Fed. Reg. 62,998.
203 179B NWF TSD at 14, Tables 2 and 3.4

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Chapter 10 - Transportation Conformity and Motor Vehicle Emission 1
Budget 2
10.1 Introduction 3
Motor Vehicle Emission Budgets (MVEB) for NOx and VOCs were submitted to the EPA in 1997 as 4
part of Utah’s maintenance plan for the 1979 1-hour ozone standard. EPA approved these MVEB for 5
transportation conformity purposes when it finalized the approval of that maintenance plan,204 further 6
reaffirming this budget in subsequent rulemaking.205 As a result, the local MPO Wasatch Front Regional 7
Council (WFRC) has been using these budgets for subsequent transportation conformity determinations 8
within the ozone NAA. Following this same approach, the UDAQ has developed an updated MVEB for 9
the NWF NAA to be used in future transportation conformity determinations in relation to the 2015 10
NAAQS standard for ozone. As required by Section 176(c) of the CAA, this MVEB is based on the best 11
available data for emissions, population, and travel estimates available during the development of this 12
SIP. 13
10.2 Transportation Conformity 14
Transportation conformity is a requirement under CAA Section 176(c).206 This requirement 15
ensures that any federally funded or approved highway or transportation activity conforms to the 16
relevant promogulated air quality SIPs, in a way that planned transportation activities do not interfere 17
with a SIPs success in reducing the severity or number of exceedances of a NAAQS. The federal level 18
transportation conformity rules establish the criteria and procedures for determining if a metropolitan 19
transportation plan, TIP, or federally supported highway and transportation projects conform to the 20
SIP.207 State level transportation conformity requirements are codified in Utah’s SIP Section XII.208 21
Transportation conformity requirements apply to any designated NAA or maintenance area for a 22
primary NAAQS and must be included in any SIP submitted for these areas. 23
The metropolitan planning responsibilities for the area encompassed by the NWF NAA are 24
covered by a single MPO—Wasatch Front Regional Council (WFRC). WFRC serves as the MPO for Box 25
Elder, Davis, Salt Lake, Tooele, and Weber counties. 26
Upon a finding of adequacy or approval by the EPA, the impacted MPO in the NAA will use these 27
budgets to demonstrate that estimated emissions resulting from the implementation of approved 28
transportation plans and TIPs are less than or equal to the budgets included in this SIP revision. 29
10.3 – Consultation 30
The ICT is an air quality workgroup in Utah that makes technical and policy recommendations 31
regarding transportation conformity issues related to the SIP development and transportation planning 32
process. Section XII of the Utah SIP established the ICT workgroup and defines the roles and 33

204 62 Fed. Reg. 38,213.
205 Approval, Disapproval and Promulgation of Air Quality Implementation Plan; Utah; Maintenance Plan for the 1-Hour Ozone Standard for Salt Lake and Davis
Counties, 77 Fed. Reg. 35,873 (June 15, 2012).
206 42 U.S.C. § 7506(c).
207 40 CFR Part 51; 40 CFR Part 93.
208 Utah State Implementation Plan; Section XII, Transportation Conformity Consultation. Adopted by the Utah Air Quality Board May 2, 2007

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responsibilities of the participating agencies. Members of the ICT workgroup collaborated on a regular 1
basis during the development of the ozone SIP. They also meet on a regular basis regarding 2
transportation conformity and air quality issues. 3
4
The ICT workgroup is comprised of management and technical staff members from the affected 5
agencies associated directly with transportation conformity including the following agencies: 6
 UDAQ 7
 Cache MPO 8
 Mountainland Association of Governments 9
 Wasatch Front Regional Council 10
 Utah Department of Transportation (UDOT) 11
 Utah Local Public Transit Agencies 12
 FHWA 13
 Federal Transit Administration (FTA) 14
 EPA 15
16
The regional emissions analysis is the primary component of transportation conformity and is 17
administered by the lead transportation agency located in the EPA designated air quality NAA. The 18
responsible transportation planning organization for the Salt Lake City, UT NAA is the WFRC. During the 19
SIP development process, the WFRC coordinated with the ICT workgroup and developed ozone SIP 20
motor vehicle emissions inventories using the latest planning assumptions and tools for traffic analysis 21
and the EPA-approved Motor Vehicle Emission Simulator (MOVES2014a) emissions model. The WFRC 22
and the ICT worked cooperatively to develop local MOVES2014a modeling data inputs using EPA 23
recommended methods where applicable. 24
10.4 Motor Vehicle Emission Budgets (MVEB) 25
MVEBs are defined as the “portion of the total allowable emissions defined in the submitted or 26
approved control strategy implementation plan revision or maintenance plan for a certain date for the 27
purpose of meeting reasonable further progress milestones or demonstrating attainment or 28
maintenance of the NAAQS, for any criteria pollutant or its precursors, allocated to highway and transit 29
vehicle use and emissions.”209 30
Thus, a MVEB refers to the maximum allowable emissions originating from the on-road mobile 31
sector for each applicable regulated pollutant (i.e., NOx and VOCs) as defined in the SIP and required by 32
the CAA. The MVEB must be used in all future transportation conformity analysis and areas must 33
demonstrate that the estimated emissions from transportation plans, programs, and projects do not 34
exceed the MVEB. MVEBs were developed in collaboration with the MPO WFRC. Details regarding the 35
development of the budget can be found in the accompanying Technical Supporting Document (TSD).210 36
For the purpose of this SIP revision, MVEBs for precursor emissions of VOC and NOx are 37
established for the attainment year of 2023, and are based on the projected on-road mobile inventory 38

209 40 CFR § 93.101.
210 TECHNICAL SUPPORT DOCUMENT FOR ON-ROAD MOBILE SOURCES: MOTOR VEHICLE EMISSIONS BUDGET DERIVIATION FOR THE NORTHERN WASATCH FRONT,
UT NONATTAINMENT OZONE AREA: https://documents.deq.utah.gov/air-quality/planning/DAQ-2023-001700.pdf

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for the same year as described in section 3.2.6. This MVEB represents a single NAA-wide MVEB to be 1
used in transportation conformity purposes. 2
Within the NWF NAA, both Tooele and Weber counties are not entirely contained within the 3
NAA boundary. Thus, portions of the counties are located outside of the boundary, while most of the 4
population of each county resides within the boundary. To account for the proportion of on-road mobile 5
emissions attributable to the NAA, and thus to be included in a MVEB, 2020 census data was used to 6
determine the percentage of on-road vehicle activity relative to census tracts located within the NAA, 7
and emissions were revised accordingly. For Salt Lake and Davis counties, which are entirely located 8
within the NAA, no such adjustments were made. 9
10.5 Emission Budgets for the Northern Wasatch Front NAA 10
For the purposes of transportation conformity in the NWF NAA, Table 77 includes a MVEB in tpd 11
for daily summertime weekday emissions of both VOCs and NOx. 12
13
Table 77: NWF Ozone 2023 NAA MVEB 14
NWF, UT Ozone 2023 NAA MVEB
Year County NOx (tpd) VOC** (tpd)
2023* Davis (NA) 7.42 2.78
2023* Salt Lake (NA) 20.98 8.53
2023* Tooele (NA) 3.49 0.81
2023* Weber (NA) 5.69 2.06
Total 37.58 14.18
NA = NAA County Portion
* Gasoline 10 PPM Sulfur
**VOC = VOC does not include Refueling Displacement and Spillage
15
It is important to note that the MVEBs presented in Table 77 are somewhat different from the 16
on-road mobile emission inventory presented in Table 8. The emissions established for this MVEB were 17
calculated using MOVES3 to reflect an average summer weekday. The totals presented in the summary 18
emissions inventory in section 3, however, represent a summer average-episode-day. Thus, the 19
temporal averaging used to generate these two different products results in slightly different values. 20
10.6 Implementation of MVEB in Transportation Conformity Determinations 21
The MVEB for the NWF NAA, once determined adequate or approved by the EPA, will be used 22
for purposes of transportation conformity determinations of Regional Transportation Plans (RTPs) and 23
TIPs for the respective MPOs and planning areas. Once the included MVEB is in effect, the local MPO 24
must make a new determination of conformity for their respective RTP and TIP within two years of EPA’s 25
finding of adequacy or SIP approval.211 Throughout the process of determining conformity with the 26
MVEB included in this SIP revision, the impacted MPO shall consult with federal, state, and local air 27
agencies through the normal interagency consultation process established in Section XII of the Utah SIP. 28

211 40 CFR § 93.104(e).

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Chapter 11 - Contingency Measures 1
11.1 Overview 2
Section 172(c)(9) of the CAA requires SIPs to include provisions for specific emission reduction 3
measures to be undertaken if the area fails to demonstrate RFP requirements or attain the NAAQS by 4
the attainment date. These provisions are known as contingency measures. These contingency 5
measures shall take effect “without further action by the State, or the [EPA] Administrator”, thus no 6
further rulemaking activities by the State or EPA would be needed to implement them if the area fails to 7
attain the standard by the attainment date or if a SIP revision fails to demonstrate RFP.212 8
Contingency measures should consist of other available control measures or emission reduction 9
strategies beyond those reasonably required (i.e., RACT or RACM) to expeditiously attain the NAAQS.213 10
The attainment date for the 2015 8-hour ozone NAAQS moderate SIP for the NWF NAA is August 11
3, 2024. Thus, if triggered, contingency measures must result in additional emission reductions after that 12
date, or upon a disapproval of the RFP plan included in this SIP revision by the EPA. Contingency 13
measures shall provide demonstratable emission reductions of one year’s worth of emission reductions, 14
or approximately 3% of the 2017 base year emission inventory.214 Unlike the RFP requirements of a 15
moderate SIP, emission reductions associated with contingency measures can consist entirely, or in part, 16
of NOx emission reduction strategies.215 17
11.2 Contingency Measures 18
11.2.1 NOx Emission Reductions from Boilers 19
The UDAQ has proposed R307-315; NOx Emission Controls for Natural Gas-Fired Boilers 2.0-5.0 20
MMBtu, and R307-316; NOx Emission Controls for Natural Gas-Fired Boilers greater than 5.0 MMBtu, 21
both of which were described in section 5.3, Table 58. These rules were adopted by the Utah Air Quality 22
Board in May of 2023, with an implementation beginning in May of 2024. These rules require new and 23
modified industrial and commercial boilers installed in the NWF NAA to comply with an emission 24
threshold of 9 parts per million by volume (ppmv). The NOx emission reductions from these combined 25
rules are anticipated to result in a total reduction of 7.3 tpd, or 2,689 tpy once the full emission 26
potential of the rules are realized. While these rules do not require retrofits or replacements of existing 27
equipment, when accounting for the useful life span of this equipment it is anticipated that the full 28
emission potential of these rules will be realized in 10 – 20 years. Thus, it is expected that these two 29
rules combined will result in ~0.36 tpd of emission reductions per year, compounding over time to the 30
full 7.3 tpd. Given the implementation timeline of these control strategies, one year of emission 31
reductions (0.36 tpd) should be creditable towards contingency measure requirements. 32

212 State Implementation Plans; General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990, 57 Fed. Reg. 13,498, 13,512 (April 16,
1992).
213 Id. 57 Fed. Reg. at 13,543.
214 83 Fed. Reg. 62,998; 80 Fed. Reg. 12,285.
215 83 Fed. Reg. 62,998.

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11.2.2 US Magnesium 1
As part of this SIP revision, and as overviewed in section 4.15, the UDAQ is requiring US 2
Magnesium to install a steam stripper and thermal oxidizer to reduce VOC emissions from its 3
wastewater and deboronated pond water systems.216 The installation of these controls will reduce 0.44 4
tpd (161.7 tpy) of VOC emissions from the airshed. It is anticipated that these controls will be installed 5
by October of 2024. US Magnesium is located outside of the existing NAA boundary and thus emission 6
reductions are not creditable towards RFP, emission reductions implemented in areas outside of a NAA 7
may count towards contingency measures as long as they improve air quality in the subject NAA.217 8
11.2.3 NAA NOx Emission Reductions 9
As described in detail in section 7.4, the NWF NAA has experienced significant emission 10
reduction of anthropogenic NOx. From the baseline year of 2017 to the attainment year for this SIP 11
revision of 2023, NOx emission decreased from 108.3 tpd down to 87.0 tpd. Thus, the area experienced a 12
21.3 tpd reduction in NOx emissions, representing a 19.6% decrease. These emission reductions are 13
largely the result of the introduction of more stringent vehicle emission reduction tiers and the 14
introduction of cleaner burning Tier 3 fuels into the NWF NAA. Thus, as the market penetration of Tier 3 15
fuels continues throughout the NAA as the local refineries finish the transition to refining fuels at these 16
standards, and older vehicles are replaced with newer cleaner vehicles, the emission reductions seen in 17
this sector are expected to continue without further action required. 18
11.3 Contingency Measures Emission Reduction Demonstration 19
Currently, no rulemaking exists that precludes a state from implementing a contingency 20
measure before they are triggered, but emission reductions credited towards contingency measures 21
may not be accounted for as part of the RFP demonstration. The emission reductions described in 22
sections 11.2.1 and 11.2.2 will be in effect prior to the attainment date but are not counted towards 23
RFP. The emission reductions described section 11.2.3 are already in place and do not count towards 24
RFP or are being used as a control measure for this SIP revision. Table 78 demonstrates how the area 25
has met the contingency measure requirement of reductions of 3% of baseline emissions. 26
27
Table 78: Percent Emission Reductions Based on 2017 Base Year Inventory 28
NOx Emissions (tpd) VOC Emissions (tpd)
2017 Baseline Inventory 108.3 93.7
3% Baseline Inventory 3.2 2.8
Emission Reductions for Contingency
Measures (Percent of 2017 Inventory)
21.66
(20%)
0.44
(0.47%)
Meets Contingency Measure
Requirements?
Yes --
29
30

216 Utah State Implementation Plan; Section IX, Part H.32.k
217 See e.g., Louisiana Env't Action Network v. U.S. E.P.A., 382 F.3d 575, 585 (5th Cir. 2004).

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Chapter 12 - Environmental Justice & Title VI Considerations 1
12.1 Environmental Justice 2
EPA defines Environmental Justice (EJ) 3
as the fair treatment and meaningful 4
involvement of all people regardless of race, 5
color, national origin, or income, with respect 6
to development, implementation, and 7
enforcement of environmental laws, 8
regulations, and policies.218 Fair treatment 9
ensures no group of people are 10
disproportionately burdened by environmental 11
harms or risks, including those resulting from 12
industrial, governmental, and commercial 13
operations, programs, or policies. Meaningful 14
involvement ensures that populations 15
potentially affected by an action have an 16
opportunity to participate in decisions 17
impacting their environment and health. 18
Meaningful involvement also includes the 19
stipulations that the public’s contributions can 20
influence a regulatory agency’s decision, the 21
concerns of the public will be considered in the 22
decision-making process, and the rule-writers 23
and decision-makers will seek out and facilitate the involvements of these potentially-affected 24
populations. Executive Order (E.O.) 12898: Environmental Justice,219 directs federal agencies to 25
incorporate environmental justice initiatives into their missions. E.O. 14008 issued in 2021220 further 26
reiterated a national focus on EJ. As a result, EPA has encouraged states to consider EJ in their SIP 27
development process as their resulting actions may have impacts on disproportionately affected areas. 28
EPA has also issued guidance on incorporating EJ consideration during the development of regulatory 29
actions.221 30
12.2 Title VI of the Civil Rights Act 31
Title VI of the Civil Rights Act is a federal law that prohibits recipients of federal financial 32
assistance (e.g., states, universities, and local governments) from discriminating based on race, color, or 33
national origin in any program or activity.222 This prohibition against discrimination under Title VI has 34
been a statutory mandate since 1964 and EPA has had Title VI regulations since 1973. Title VI allows 35

218 https://www.epa.gov/environmentaljustice
219 Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations, 59 Fed. Reg. 7,629 (Feb. 11, 1994).
220Tackling the Climate Crisis at Home and Abroad, 86 Fed. Reg. 7,619 (Jan. 27, 2021).
221 Guidance on Considering Environmental Justice During the Development of Regulatory Actions (May 2015), available at
https://www.epa.gov/environmentaljustice/guidance-considering-environmental-justice-during-development-action.
222 Title VI, 42 U.S.C § 2000d et seq.
Figure 24: EJ Indexes >80th percentile in Each NWF NAA Census Block

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persons to file administrative complaints with federal departments and agencies alleging discrimination 1
based on race, color, or national origin and EPA has a responsibility to ensure its funds are not being 2
used to subsidize discrimination. Should a complaint be filed, EPA’s Office of Civil Rights is responsible 3
for the Agency’s administration of Title VI, including investigation of such complaints. In accordance with 4
Title VI, federal agencies shall ensure that all programs and activities receiving federal financial 5
assistance that affect human health or the environment do not discriminate based on race, color, or 6
national origin. The NWF NAA SIP revision falls under this category of programs and has potential 7
impacts on such areas. 8
12.3 Screening-Level Analysis 9
Using Utah’s Environmental Interactive Map,223 UDAQ conducted an analysis of the EJ indices 10
surrounding the NWF NAA. UDAQ reviewed all pollution and sources as well as socioeconomic indicators 11
(a total of 20 indices) as percentiles calculated by comparing data from census blocks within the State of 12
Utah. UDAQ notes that this SIP revision does not have the authority to control the following indexes 13
included in this analysis: lead paint, superfund sites, wastewater discharge, RMP facilities, hazardous 14
waste, or underground storage tanks. Figure 24 shows the count of EJ indexes above the 80th percentile 15
in each of the census blocks within the NWF NAA. Table 79 shows the number of census blocks in the 16
NFW NAA at the 80th percentile and above for each EJ index. 17
Table 79: Environmental Justice Indexes Over the 80th Percentile in the NWF NAA 18
EJ Index Number of Census
Blocks >80th Percentile
Superfund Proximity 400
PM2.5 387
Ozone 364
Hazardous Waste Proximity 318
Air Toxics Respiratory Health Index 306
People of Color 294
Diesel PM 291
Air Toxics Cancer Risk 282
Underground Storage Tanks 267
Traffic Proximity 262
RMP Facility Proximity 258
Demographic Index 250
Less than High School Education 244
Lead Paint 236
Limited English Speaking 215
Low Income 181
Wastewater Discharge 153
Unemployment Rate 136
Under Age 5 113
Over Age 64 61
19

223 https://enviro.deq.utah.gov/

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12.3.1 EJ Screening Findings 1
Based on Figure 24, the areas within the NWF NAA with the highest concentrations of indexes 2
above the 80th percentile include Ogden, Salt Lake City, West Valley City, and West Jordan. There is a 3
total of 498 census blocks within the NWF NAA. 4
Table 79 shows a high number of census blocks at the 80th percentile or greater for all EJ 5
indexes, with the most prevalent indexes in the NAA being: 6
 Superfund Proximity
 PM2.5
 Ozone
 Hazardous Waste Proximity
 Air Toxics Respiratory Health Index
 People of Color
 Diesel PM
 Air Toxics Cancer Risk
 Underground Storage Tanks
 Traffic Proximity
12.4 Identified Stakeholders 7
As a result of this EJ analysis, UDAQ has identified the general public and public health 8
departments within the Ogden, Salt Lake City, West Valley City, and West Jordan areas as populations 9
potentially affected by the decisions made in this SIP. UDAQ identified these stakeholders as entities and 10
groups requiring additional facilitation and involvement in the SIP development process. 11
12.5 Stakeholder Outreach, Meaningful Involvement, and Information Distribution 12
UDAQ made it a priority to ensure that the identified stakeholders would have ample and equal 13
opportunity within the division’s ability to participate in this SIP process through the measures described 14
in section 12.5.1 to 12.5.5. 15
12.5.1 Public Informational Meetings 16
UDAQ hosted two virtual public meetings on the subject of “Finding Ozone Emissions Reduction 17
Ideas.” The first meeting took place on Wednesday, March 23, 2022, from 6 to 7 PM MST, and the 18
second meeting took place on Saturday, May 3, 2022, also from 6 to 7 PM MST. These times were 19
selected to maximize attendance from households with traditional working hours. Handouts for this 20
meeting were issued via an interactive webpage224 and potential attendees were invited to submit 21
comments through a public Google Form to be addressed at each of the meetings. 67 individuals 22
attended the first meeting. 45 individuals attended the second meeting. Recordings of each of these 23
meetings are publicly available on YouTube.225 24
UDAQ also presented SIP-related updates to the State of Utah Governance Committee, a joint 25
coordination effort by the Utah Department of Health and local health departments. These 26
presentations took place on September 27, 2022, and on January 24, 2023, to inform the committee of 27
the progress UDAQ has made in the SIP development process and emission reduction strategies 28
employed. 29

224 https://deq.utah.gov/air-quality/northern-wasatch-front-ozone-emissions-inventory
225 https://www.youtube.com/watch?v=ip5D7nRaLTI & https://www.youtube.com/watch?v=b0fHNSFczvE

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12.5.2 Environmental Advocate and Industrial Stakeholder Meetings 1
UDAQ holds regular environmental advocate meetings, industrial stakeholder meetings, and 2
academic stakeholder meetings where UDAQ updated these groups on the development of this SIP and 3
online postings of the SIP-related documents. Members of all groups were provided equal opportunities 4
to ask questions and were encouraged to comment during these meetings as well as follow up 5
afterward. 6
12.5.3 Public Commenting Period 7
Upon the approval of the Air Quality Board on April 5, 2023, this SIP and all relating documents 8
were made available for public comment from June 1 to July 17, 2023. Public notices for the 9
commenting period were issued on the UDAQ webpage, via electronic mail, and in the Utah State 10
Bulletin. Commenters included: 11
 49 private citizens;
 US EPA Region 8;
 Breathe Utah;
 HEAL Utah;
 Utah Petroleum Association and Utah Mining Association;
 Chevron Products Company;
 Marathon Tesoro Refining & Marketing Company LLC;
 Rio Tinto Kennecott;
 Western Resource Advocates; and
 Utah Manufacturers Association

On July 9, 2024, the Utah Air Quality Board proposed amendments to Section 7,
RFP, of this SIP revision for a 30-day public comment. Public notices for the commenting
period were issued on the UDAQ webpage, via electronic mail, and in the Utah State
Bulletin. Commenters included:
 US EPA Region 8;
 Utah Petroleum Association and Utah Mining Association; and
 Western Resources Advocates.

12.5.4 Public Hearing 12
As part of the public commenting period, a public hearing was conducted at the State of Utah 13
Multi-Agency State Office Building on July 12, 2023 at 12:00 PM. The public hearing information was 14
advertised in the Utah State Bulletin, and the UDAQ webpage 41 days prior to the event. Attendance to 15
this hearing was available both in-person as well as virtually. Commenters included: 16
 Nick Schou of Western Resource Advocates;
 Alex Veilleux of Heal Utah; and
 Gregor Green a private citizen

All comments made by groups and individuals listed in Sections 12.5.3 and 12.5.4 were duly 17
considered in the decision-making process of this SIP. These comments are summarized and responded 18
to in APPENDIX B with original versions of each group or individual’s comments available at 19

UTAH DIVISION OF AIR QUALITY
170

https://deq.utah.gov/air-quality/northern-wasatch-front-moderate-ozone-sip-technical-support-1
documentation. 2
3
On July 9, 2024, the Utah Air Quality Board proposed amendments to Section 7, RFP, of this SIP 4
revision for a 30-day public comment. The public hearing information was advertised in the Utah State 5
Bulletin, and the UDAQ webpage. The public hearing associated with this public comment period was 6
scheduled to be held on August 26, 2024. In accordance with Utah Section 63G-3-302, no requests for a 7
public hearing for the amendments were received by 2:00 pm on August 22, 2024, therefore the hearing 8
was canceled with public notice of the cancelation posted on the Division’s webpage. 9
10
12.5.5 Information Dissemination 11
All materials related to this SIP have been posted on UDAQ’s public platforms as the division has 12
received and processed them throughout the development of this SIP. UDAQ uses all resources at its 13
disposal to disseminate information to its stakeholders including: 14
 UDAQ webpage 226
 State Bulletin
 Ozone SIP webpage 227
 Stakeholder meetings
 Local newspapers in identified stakeholder
communities.
15

226 https://deq.utah.gov/division-air-quality
227 https://deq.utah.gov/air-quality/northern-wasatch-front-moderate-ozone-sip-technical-support-documentation

ITEM 5

195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
DAQ-091-24
M E M O R A N D U M TO: Air Quality Board THROUGH: Bryce C. Bird, Executive Secretary FROM: Mat Carlile, Environmental Planning Consultant DATE: October 24, 2024 SUBJECT: PROPOSE FOR PUBLIC COMMENT: Amend Utah State Implementation Plan, Section X, Vehicle Inspection and Maintenance Program, Part F, Cache County; and R307-110-36. Section X, Vehicle Inspection and Maintenance Program, Part F, Cache County.
______________________________________________________________________________________ Utah Code Annotated 41-6a-1642 gives authority to each county to design and manage a vehicle inspection
and maintenance (I/M) program when it is required to attain and maintain any national ambient air quality standard (NAAQS). Section X incorporates these county programs into the Utah State Implementation Plan (SIP). Section X, Part A summarizes I/M requirements that are common among all I/M programs. The
other subparts (Parts B through F) contain the requirements for each county’s unique I/M program. Section X, Part F is unique to Cache County’s I/M program. Amendments to Section X, Part F were last adopted by the Air Quality Board (Board) on September 4, 2019. The Division of Air Quality is requesting the Board to approve the proposed amendments to Part F of Utah SIP Section X for public comment. Amendments to Part F update Cache County’s regulation to reflect the activities of the current programs, provide clarity, and ensure that the programs conform to federal requirements. Cache County made the following changes to their ordinance that now need to be amended in the SIP:
• Mobile Emissions Testing Following a successful pilot program beginning in March of 2023, a permanent regulation change to allow for mobile testing was approved by the Bear River Health Department Board of Health and Cache County Council. This change will be possible through the removal of the word "stationary" as applied in the definition of an I/M Program Station.

DAQ-091-24 Page 2

• Emergency Vehicle Exemption
To ensure first responders can assist in times of need, current-use "Authorized Emergency Vehicles," as defined by 41-6a-102 Utah Code Annotated, 1953, as amended, will be exempt from emissions testing in Cache County. This will impact roughly 100 vehicles within Bear River Health Department jurisdiction. Note: This will only apply to current-use emergency vehicles as defined. Upon the sale of such
vehicles, all relevant Environmental Protection Agency (EPA) requirements must be met.
• "Parts" Waiver If emissions components are unavailable for a period exceeding six months, a "parts" waiver may be able to assist in keeping a vehicle on the road. This is achievable through providing each of the following types of documentation:
 a failed emissions test from the last 30 days;
 statement/supplier invoice showing the part is unavailable for at least six months from a mechanic or parts store; and
 additional statement from the vehicle's authorized manufacturer repair station/dealership detailing the part is unavailable for at least six months. Waivers for Part Unavailability was added to the regulation to provide guidance on when these
waivers would be issued. A Clean Air Act 110(l) demonstration is provided as part of this rulemaking package. The EPA requires a
110(l) demonstration when removing control measures from the SIP, to ensure that the revision would not interfere with any applicable requirement concerning attainment or any other applicable requirement of the Clean Air Act.
Staff worked closely with the EPA and Cache County to ensure that these amendments accurately reflect the current I/M programs and that they are approvable by the EPA. Recommendation: Staff recommend the Board approve amendment to SIP Section X, Part F and Section R307-110-36 for a 30-day public comment period.
State of Utah
Administrative Rule Analysis
Revised May 2024
NOTICE OF SUBSTANTIVE CHANGE
TYPE OF FILING: Amendment
Rule or Section Number: R307-110-36 Filing ID: Office Use Only
Date of Previous Publication (Only for CPRs): Click or tap to enter a date.
Agency Information
1. Title catchline:Environmental Quality, Air Quality
Building: Multi-Agency State Office Building
Street address: 195 N 1950 W
City, state: Salt Lake City
Mailing address: PO Box 144820
City, state and zip: Salt Lake City, UT 84114-4820
Contact persons:
Name: Phone: Email:
Erica Pryor 385-499-3416 [e-mail]
Mat Carlile 385-306-6535 [e-mail]
Please address questions regarding information on this notice to the persons listed above.
General Information
2. Rule or section catchline:
R307-110-36. General Requirements: State Implementation Plan
3. Purpose of the new rule or reason for the change:
The Utah Air Quality Board (Board) has proposed for public comment amended Utah State Implementation Plan (SIP), Section
X, Part F. Section R307-110-36 incorporates SIP Section X, Parts F, into the rule and must be amended to change the Board
adoption date to the anticipated adoption date of the amended plan
4. Summary of the new rule or change:
Section R307-110-36 incorporates Section X Part F of the Utah State Implementation Plan (SIP). Section R307-110-36
incorporates Section X Part F of the Utah SIP. Part F contains the requirements of Cache County’s I/M program. Amendments
to Part F update the plan to incorporate changes to Cache County’s I/M regulation to ensure that the SIP reflects the current
program. Section R307-110-36 is amended by changing the date of the last adoption by the Air Quality Board to February 5,
2025. These changes were already legally enforceable, and the amendment is bringing the rule in line with federal law.
Fiscal Information
5. Provide an estimate and written explanation of the aggregate anticipated cost or savings to:
A) State budget:
This rule change will not have any fiscal impact on the state budget because it does not enact or remove any new
requirements.
B) Local governments:
This rule change will not have any fiscal impact on the local governments because it does not enact or remove any new
requirements
C) Small businesses ("small business" means a business employing 1-49 persons):
This rule change will not have any fiscal impact on small businesses because it does not enact or remove any new
requirements.
D) Non-small businesses ("non-small business" means a business employing 50 or more persons):
This rule change will not have any fiscal impact on non- small businesses because it does not enact or remove any new
requirements.
E) Persons other than small businesses, non-small businesses, state, or local government entities ("person" means
any individual, partnership, corporation, association, governmental entity, or public or private organization of any character
other than an agency):
This rule change will have not any fiscal impact on other persons because it does not enact or remove any new requirements.
F) Compliance costs for affected persons (How much will it cost an impacted entity to adhere to this rule or its changes?):
No additional costs for affected persons are anticipated due to this rule change because it does not enact or remove any new
requirements.
G) Regulatory Impact Summary Table (This table only includes fiscal impacts that could be measured. If there are
inestimable fiscal impacts, they will not be included in this table. Inestimable impacts will be included in narratives above.)
Regulatory Impact Table
Fiscal Cost FY2025 FY2026 FY2027
State Government $0 $0 $0
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $0 $0 $0
Other Persons $0 $0 $0
Total Fiscal Cost $0 $0 $0
Fiscal Benefits FY2025 FY2026 FY2027
State Government $0 $0 $0
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $0 $0 $0
Other Persons $0 $0 $0
Total Fiscal Benefits $0 $0 $0
Net Fiscal Benefits $0 $0 $0
H) Department head comments on fiscal impact and approval of regulatory impact analysis:
The Executive Director of the Department of Environmental Quality, Kim D. Shelley, has reviewed and approved this regulatory
impact analysis.
Citation Information
6. Provide citations to the statutory authority for the rule. If there is also a federal requirement for the rule, provide a
citation to that requirement:
Section 19-6a-1642 40 CFR Part 51 Subpart S Inspection and
Maintenance Program Requirements
Incorporations by Reference Information
7. Incorporations by Reference (if this rule incorporates more than two items by reference, please include additional tables):
A) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)
UTAH STATE IMPLEMENTATION PLAN SECTION X VEHICLE INSPECTION
AND MAINTENANCE PROGRAM PART F CACHE COUNTY
Publisher Division of Air Quality, Utah Department of Environmental Quality
Issue Date February 5, 2025
Issue or Version
B) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)

Publisher
Issue Date
Issue or Version

Public Notice Information
8. The public may submit written or oral comments to the agency identified in box 1. (The public may also request a
hearing by submitting a written request to the agency. See Section 63G-3-302 and Rule R15-1 for more information.)
A) Comments will be accepted until: 12/31/2024
B) A public hearing (optional) will be held:
Date (mm/dd/yyyy): Time (hh:mm AM/PM): Place (physical address or URL):
TBD

To the agency: If more than one hearing will take place, continue to add rows.

9. This rule change MAY become effective on: 02/05/2025
NOTE: The date above is the date the agency anticipates making the rule or its changes effective. It is NOT the effective date.

Agency Authorization Information
To the agency: Information requested on this form is required by Sections 63G-3-301, 63G-3-302, 63G-3-303, and 63G-3-
402. Incomplete forms will be returned to the agency for completion, possibly delaying publication in the Utah State Bulletin
and delaying the first possible effective date.
Agency head or
designee and title:
Bryce C. Bird, Director, Division of Air
Quality
Date: 10/23/2024

R307. Environmental Quality, Air Quality. 1
R307-110. General Requirements: State Implementation Plan. 2
3
…. 4
R307-110-36. Section X, Vehicle Inspection and Maintenance Program, Part F, Cache County. 5
The Utah State Implementation Plan, Section X, Vehicle Inspection and Maintenance Program, Part 6
F, Cache County, as most recently adopted by the Utah Air Quality Board on [(September 4, 2019)]February 7
5, 2025, pursuant to Section 19-2-104, is hereby incorporated by reference and made a part of these rules. 8
9
10
…. 11
KEY: air pollution, PM10, PM2.5, ozone 12
Date of Last Change: February 7, 2024 13
Notice of Continuation: December 1, 2021 14
Authorizing, and Implemented or Interpreted Law: 19-2-104 15
Page 1 of 1

Section X Part F, Page i
1
2
3
UTAH STATE IMPLEMENTATION PLAN 4
5
SECTION X 6
7
VEHICLE INSPECTION AND 8
MAINTENANCE PROGRAM 9
10
Part F 11
12
Cache County 13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
Adopted by the Utah Air Quality Board 38
[September 4, 2019]February 5, 2025 39
40
41

Section X Part F, Page ii
Table of Contents 1
2
3
1. Applicability ............................................................................................................................................................. 1 4
2. Description of Cache I/M Programs .......................................................................................................................... 1 5
3. I/M SIP Implementation ............................................................................................................................................ 2 6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
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33
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37
38
39
40
41
42
43
44

Section X Part F, Page iii
SECTION X Part F 1
Cache County Emission Inspection/ Maintenance Program 2
APPENDICES 3
4
5
1. Cache County Emission Inspection/ Maintenance Program Ordinance 2018-15 6
2. Bear River Health Department Regulation 2013-1 Updated July 1, 2024 7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

Section X Part F, Page 1
1
UTAH STATE IMPLEMENTATION PLAN 2
SECTION X, PART F 3
VEHICLE INSPECTION AND MAINTENANCE (I/M) PROGRAM 4
1. Applicability 5
6
Cache County I/M program requirements: Cache County was designated nonattainment for the 7
PM2.5 National Ambient Air Quality Standard (NAAQS) on December 14, 2009 (74 FR 58688, 8
November 13, 2009). Accordingly, Cache County implemented control strategies to attain the 9
PM2.5 NAAQS. A motor vehicle emission inspection and maintenance (I/M) program was 10
identified by the PM2.5 State Implementation Plan (SIP) as a necessary control strategy to attain 11
the PM2.5 NAAQS as expeditiously as practicable. Therefore, pursuant to Utah Code Annotated 12
41-6a-1642, Cache County implemented an I/M program that complies with the minimum 13
requirements of 40 CFR Part 51 Subpart S. Cache County implemented its I/M program county-14
wide. This program was approved by EPA on October 9, 2015 (80 FR 54237 September 9, 15
2019). Parts A and F of Section X demonstrate compliance with 40 CFR Part 51 Subpart S for 16
Cache County. 17
18
2. Description of Cache I/M Programs 19
20
Below is a summary of Cache County’s I/M program. Section X, Part F Appendices 1 and 2 21
contain the essential documents for Cache County’s I/M program. 22
23
Network Type: Cache County’s I/M program will comprise of a decentralized test-and-24
repair network. 25
26
Test Convenience: Cache County will make every effort to ensure that its citizens will 27
have stations conveniently located throughout Cache County. Specific operating hours 28
are not specified by the county; however, its Regulation requires that stations be open and 29
available to perform inspections during a major portion of normal business hours of 8:00 a.m. 30
to 5:00 pm Mondays through Fridays. 31
32
Subject fleet: All model year 1996 and newer vehicles registered or principally-operated 33
in Cache County are subject to the I/M program except for exempt vehicles. 34
35
Station/inspector Audits: Cache County’s I/M program will regularly audit all permitted 36
I/M inspectors and stations to ensure compliance with county I/M ordinances, 37
regulations, and policies. Particular attention will be given to identifying and correcting 38
any fraud or incompetence with respect to vehicle emissions inspections. Compliance 39
with recordkeeping, document security, analyzer maintenance, and program security 40
requirements will be scrutinized. The Cache County I/M program will have an active 41
covert compliance program to minimize potential fraudulent testing. 42

Section X Part F, Page 2

1
Waivers: Cache County’s I/M program allows for the issuance of waivers under limited 2
circumstances. The procedure for issuing waivers is specified in Cache County’s I/M 3
regulation provided in Section 9.5 of Appendix 2 of this part of the SIP and meets the 4
minimum waiver issuance criteria specified in 40 CFR Subparts 51.360. 5
6
Test frequency: Vehicles less than six years old as of January 1 on any given year will be 7
exempt from an emissions inspection. All model year 1996 and newer vehicles are 8
subject to a biennial test. 9
10
Test Equipment: Specifications for the I/M test procedures, standards and analyzers are 11
described in Cache County’s I/M regulation provided in Appendix 2. Specifications for 12
the test procedure and equipment were developed according to good engineering 13
practices to ensure test accuracy. Certified testing equipment and emissions test 14
procedures meet the minimum standards established in Appendix A of the EPA's I/M 15
Guidance Program Requirements, 40 CFR Part 51 Subpart S. 16
17
Test Procedures: 18
19
 The following vehicles are subject to an on-board diagnostic (OBD) II inspection: 20
21
o 1996 and newer light duty vehicles1 and 22
o 2008 and newer medium duty vehicles2 23
24
Test procedures are outlined in Appendix 2 of this part of the SIP 25
26
27
3. I/M SIP Implementation 28
29
The I/M program ordinance, regulations, policies, procedures, and activities specified in 30
this I/M SIP revision shall be implemented by [January 1, 2021] July 1, 2024 and shall 31
continue until a maintenance plan without an I/M program is approved by EPA in 32
accordance with Section 175 of the Clean Air Act. 33
34
35

1 Light duty vehicles have a Gross Vehicle Weight of 8500 lbs or less.
2 Medium duty vehicles have a Gross Vehicle Weight greater than 850[0]1 lbs but less than 14,000 lbs
1
ORDINANCE 2013-04 2
3
IMPLEMENTATION OF A VEHICLE EMISSIONS AND MAINTENANCE 4
PROGRAM IN CACHE COUNTY 5
6
7
1.0 PURPOSE 8
9
The purpose of this ordinance is to reduce air pollution levels in Cache County by 10
requiring emission inspections of on-road motor vehicles and by requiring 11
emission related repairs and/or adjustments for those vehicles that fail to meet the 12
prescribed standards so as to: 13
14
1.1 Protect and promote the public health, safety, and welfare; 15
16
1.2 Improve air quality; 17
18
1.3 Comply with the federal regulations contained in 40 CFR part 51 subpart S; 19
20
1.4 Comply with the law enacted by the Legislature of the State of Utah, 21
Section 41-6a-1642 Utah Code Annotated, 1953, as amended. 22
23
2.0 POWERS AND DUTIES 24
25
2.1 The Cache County Council (hereafter, “Council”) has authority to 26
implement a vehicle inspection and maintenance program under Section 41-27
6a1642, Utah Code Annotated, 1953, as amended. 28
29
2.2 The Council is presently required by the EPA and the State of Utah to 30
implement a vehicle emission inspection and maintenance program. 31
32
2.3 The Council hereby delegates its authority as an administrative body under 33
Section 41-6a-1642, Utah Code Annotated, 1953, as amended, to the Bear River 34
District Board of Health (hereafter “Board”), to address all issues pertaining to the 35
adoption and administration of the vehicle emission inspection and maintenance 36
program. 37
38
2.4 The Council authorizes and directs the Board to adopt and promulgate 39
rules and regulations to ensure compliance with EPA and State Implementation 40
Plan requirements with respect to an emission inspection and maintenance 41
program. 42
43
44
Page 1 of 3

3.0 GENERAL PROVISIONS 1
2
3.1 The Board, in conjunction with its staff, will administer and enforce this 3
ordinance. 4
5
3.2 The Board shall adopt vehicle emission and inspection rules and 6
regulations which meet EPA and State Implementation Plan requirements. 7
8
3.3 The Council shall approve the initial Rules and Regulations established by 9
the Board and all changes in Rules and Regulations. 10
11
12
4.0 GUIDELINES TO BE FOLLOWED BY THE BEAR RIVER BOARD OF 13
HEALTH IN IMPLEMENTING A VEHICLE INSPECTION AND 14
MAINTENANCE PROGRAM IN CACHE COUNTY 15
16
17
4.1 Vehicles registered in Cache County, that are not exempt from inspection 18
requirements, will be inspected on the following schedule: 19
20
4.1.1 All gasoline and non-diesel based Alternative Fuel powered 21
vehicles, including Bi-Fuel vehicles, model year 1996 and newer, with a 22
GVWR 8,500 lbs or less will be subject to inspection. All gasoline and 23
non-diesel based Alternative Fuel powered vehicles, including Bi-Fuel 24
vehicles, model year 2008 and newer, with a GVWR greater than 8,500 25
lbs and less than 14,001 lbs will be subject to inspection. 26
27
4.1.2 All diesel and diesel based Alternative Fuel powered vehicles 28
model year 1998 and newer, with a GVWR less than 14,001 lbs will be 29
subject to inspection. 30
31
4.1.3 No emissions inspection will be required for any vehicle that is 32
less than six years old on January 1 based on the age of the vehicle as 33
determined by the model year identified by the manufacture. 34
35
4.1.4 Emissions inspections will be required in odd-numbered years for 36
a vehicle with an odd-numbered model year. Emissions inspections will 37
be required in even-numbered years for a vehicle with an even-numbered 38
model year. 39
40
4.2 A maximum fee for inspection shall be set by the Board and approved by 41
the Council. Part of this fee will be retained by the entity which performs the test 42
and part may be remitted to the Board as reimbursement for administering the 43
program. The intent of the Council is that this fee be as low as possible, while 44
still maintaining the financial viability of the program. 45
46
47
Page 2 of 3

4.3 If a vehicle fails the emissions inspection, a waiver may be granted that 1
will allow the vehicle to be registered that year. In order to qualify for a 2
waiver, the vehicle owner/operator must spend a minimum of $200.00 on 3
emissions related repairs and meet any other requirements established by 4
the Board. A waiver will be issued once during the lifetime of the vehicle. 5
Any changes to the minimum required repair expenditure to qualify for the 6
waiver shall be approved by the Council. 7
8
9
4.4 Emission inspections in Cache County will be conducted by private firms, 10
or by utilizing remote OBD technology. The Board shall establish criteria 11
to ensure that testing is performed in accordance with state and federal 12
requirements. 13
14
4.5 To fund the administration of the emissions inspection and maintenance 15
program and other air quality improvement programs, the Council 16
authorizes an Air Pollution Control fee to be assessed upon every 17
motorized vehicle registered in Cache County at the time of registration as 18
provide by Section 41-1a-1223, Utah Code Annotated, 1953, amended. 19
20
4.5.1 The fee is set at $3.00 for each vehicle registration within 21
the County under section 41-1a-215, Utah Code Annotated, 1953, 22
as amended and at $2.25 for each vehicle registration within the 23
county for a six month registration period under Section 41-24
1a215.5, Utah Code, 1953, as amended. 25
26
4.5.2 Motor vehicles that are exempt from the registration fee, 27
and commercial vehicles with an apportioned registration shall be 28
exempt from this fee as per Section 41-1a-1223, Utah Code 29
Annotated, 1953 as amended. 30
31
4.5.3 The fee shall be assessed beginning January 1, 2014. 32
33
5.0 REVIEW OF NEED FOR PROGRAM 34
35
The Council shall review the vehicle emissions and maintenance program at least 36
every five years to evaluate the continuing need for the program. 37
38
6.0 EFFECTIVE DATE 39
40
These changes will take effect on January 1, 2021. 41
42
This ordinance takes effect on March 27, 2013. Following its passage, but prior to 43
the effective date, a copy of the Ordinance shall be deposited with the County 44
Clerk and a short summary of the ordinance shall be published in a newspaper of 45
general circulation within the County as required by law. 46
Page 3 of 3
Regulation No. 2013-1
VEHICLE EMISSIONS INSPECTION
AND MAINTENANCE PROGRAM
Adopted by the Bear River Board of Health
May 9, 2013
Updated May 27, 2015
Updated April 10, 2019
Updated January 5, 2023
Updated July 1, 2024
Under Authority of Section 26A-1-121
Utah Code Annotated, 1953, as amended
1Page 1 of 38
Table of Contents
1.0 DEFINITIONS......................................................................................................................3
2.0 PURPOSE.............................................................................................................................6
3.0 AUTHORITY AND JURISDICTION OF THE DEPARTMENT.......................................6
4.0 POWERS AND DUTIES..................................................................................................... 7
5.0 SCOPE..................................................................................................................................9
6.0 GENERAL PROVISIONS...................................................................................................9
7.0 PERMIT REQUIREMENTS OF THE VEHICLE EMISSIONS I/M PROGRAM
STATION.......................................................................................................................................
14
8.0 TRAINING AND CERTIFICATION OF INSPECTORS..................................................15
9.0 INSPECTION PROCEDURE............................................................................................ 17
10.0 ENGINE SWITCHING......................................................................................................20
11.0 SPECIFICATIONS FOR CERTIFIED TESTING EQUIPMENT..................................... 21
12.0 QUALITY ASSURANCE..................................................................................................21
13.0 DISCIPLINARY PENALTIES AND RIGHT TO APPEAL..............................................21
14.0 PENALTY...........................................................................................................................23
15.0 SEVERABILITY................................................................................................................23
16.0 EFFECTIVE DATE............................................................................................................24
APPENDIX A – FEE SCHEDULE...............................................................................................25
APPENDIX B - RESERVED........................................................................................................ 26
APPENDIX C – PENALTY SCHEDULE.................................................................................... 27
APPENDIX D – TEST PROCEDURES.......................................................................................28
APPENDIX E – CERTIFIED TESTING EQUIPMENT STANDARDS......................................34
APPENDIX F – WAIVERS FOR “NOT READY” VEHICLES..................................................37
Page 2 of 38
1.0 DEFINITIONS
For the purpose of this Regulation, the following terms, phrases, and words shall have the
following meanings, unless otherwise defined:
Alternative Fuel: A fuel that is derived from resources other than petroleum.
This includes but is not limited to: natural gas, propane, ethanol, and bio-diesel.
Bi-fuel Vehicle: A vehicle that has two separate fueling systems that enables the
vehicle to run on one or the other (ex. Gasoline and natural gas). These vehicles
may be switchable or non-switchable.
Board: See Board of Health.
Board of Health: The Bear River Board of Health.
Cache County Council: The elected Cache County Council representatives.
Certificate of Compliance: Proof that a vehicle meets all applicable requirements
of the I/M Program. This proof may be sent in an electronic format to the Utah
State Tax Commission.
Certification: Assurance by an authorized source, whether it be a laboratory, the
manufacturer, the State, or the Department, that a specific product or statement is
in fact true and meets all required requirements.
Certified Emissions Inspector: A person who has successfully completed all
certification requirements and has been issued a current, valid Certified Emissions
Inspector Certification by the Department.
Certified Testing Equipment: An official test instrument that has been approved
by the Department to test motor vehicles for compliance with this Regulation.
Compliance: Verification that certain submission data and hardware submitted by
a manufacturer for accreditation consideration, meets all required accreditation
requirements.
Compliance Assurance Inspection: A more detailed emissions inspection
performed at the I/M Technical Center. Details of this inspection are found in
Appendix D, Test Procedures.
Compliance Assurance List: A list created and maintained by the Department that
identifies vehicles for Compliance Assurance Inspections. Vehicles placed on this
list, as required in Section 6.8 and Appendix D, Test Procedures, shall be
inspected at the I/M Technical Center.
Page 3 of 38
Contractor: The emission inspection system contractor selected by the
Department to provide specialized services related to the I/M Program in Cache
County.
Council: See Cache County Council.
County: Cache County, Utah.
Department: The Bear River Health Department.
Director: The Director of the Bear River Health Department or his authorized
representative.
DLC: Data Link Connector used in OBD applications is a 16 pin connector used
by scan tools and other emission diagnostic equipment to communicate with the
vehicle’s computer for the purpose of collecting emissions related data.
DTC: Diagnostic Trouble Code is a standardized 5 digit code that is used to
identify a specific fault that has occurred or is occurring in a vehicle.
Dual Fuel Vehicle: See Flexible Fuel Vehicle.
Emissions Control Systems: Parts, assemblies or systems originally installed by
the manufacturer in or on a vehicle for the sole or primary purpose of reducing
emissions.
EPA: The United States Environmental Protection Agency.
Flexible Fuel Vehicle: Also called Flex-Fuel Vehicle. A vehicle that is designed
to run on more than one fuel, usually gasoline blended with ethanol (0-85%), and
both fuels are stored in the same common tank.
I/M Program: See Vehicle Emissions Inspection and Maintenance Program.
I/M Program Station: A vehicle Emissions Inspection and Maintenance Station
that qualifies and has a valid permit, issued by the Department, to operate as an
emissions inspection and maintenance station in the I/M Program.
I/M Technical Center: A facility operated by the Department for technical or
administrative support of the I/M Program.
Inspection: An official vehicle emissions test performed for the purpose of
issuing a Certificate of Compliance or Waiver.
Inspector: A Certified Emissions Inspector.
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MIL: Malfunction Indicator Light is an indicator located on the instrument panel
that notifies the operator of an emissions fault.
Motor Vehicle: A self-propelled motorized vehicle with an internal combustion
powered engine which is licensed for operation on public roads and/or streets.
Motor Vehicles exempted from the inspection requirements of this Regulation are
listed in Section 6.4 of this Regulation.
Non-certified Inspector: Any person who has not been certified by the
Department to perform official emissions tests.
OBD: On Board Diagnostic refers to a vehicle’s monitoring and diagnostic
capabilities of its emissions systems.
Publicly-owned Vehicles: A motor vehicle owned by a government entity,
including but not limited to the federal government or any agency thereof, the
State of Utah or any agency or political subdivision thereof.
Readiness: Readiness is used to identify the state of a vehicle’s emissions
monitors as they are tested. Readiness does not indicate whether the monitors
passed or failed the test, it only indicates whether or not the test has been run for
any particular monitor.
Referee Inspection: An emissions inspection performed at the I/M Technical
Center for the purpose of resolving disputes or overriding inspection criteria for
cause.
Regulation: A regulation of the Bear River Health Department for a vehicle
emissions inspection and maintenance program.
Rejection: A condition where a vehicle subject to an OBD inspection has not met
the Readiness requirements as set forth by this Regulation. The vehicle has not
failed the inspection but it must be driven additional miles until Readiness
monitors are set “ready” or repairs have been made allowing readiness flags to set
ready.
Station: An I/M Program Station.
Training Program: A formal program administered, conducted, or approved by
the Department for the education of emission inspectors in basic emission control
technology, inspection procedures, I/M Program policies, procedures, and this
Regulation.
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Vehicle Emission Control Information Label (VECI Label): An EPA required
label found on a vehicle that contains the manufacturer’s name and trademark,
and an unconditional statement of compliance with EPA emission regulations.
The label often contains a list of emissions control devices found on the vehicle.
Vehicle Emissions Inspection and Maintenance Program: The program
established by the Department pursuant to Section 41-6a-1642 Utah Code
Annotated, 1953, as amended, and Cache County Code Chapter 10.20.
Waiver: Documentation of proof that a vehicle which has not been able to meet
applicable test requirements, has met the applicable repair and/or adjustment
requirements of Section 9.5 of this Regulation.
2.0 PURPOSE
It is the purpose of this Regulation to reduce air pollution levels in Cache County by
requiring inspections of in-use motor vehicles and by requiring emission related repairs
and/or adjustments for those vehicles that fail to meet the prescribed standards so as to:
2.1 Protect and promote the public health, safety, and welfare;
2.2 Improve air quality;
2.3 Comply with the applicable federal requirements for I/M Programs as defined in
40 CFR Part 51, Subpart S;
2.4 Comply with the law enacted by the Legislature of the State of Utah, Sections 41-
6a-1642 Utah Code Annotated, 1953, as amended; and
2.5 Comply with Cache County Code Chapter 10.20, Vehicle Emissions and
Maintenance Program, as amended.
3.0 AUTHORITY AND JURISDICTION OF THE DEPARTMENT
3.1 Under Chapter 10.20.020(C) of Cache County Code, the Cache County Council
(hereafter, Council) delegates its authority as an administrative body under Section 41-
6a-1642, Utah Code Annotated, 1953, as amended, to the Bear River Board of Health
(hereafter Board), to address all issues pertaining to the adoption and administration of
the Vehicle Emissions Inspection and Maintenance Program (hereafter I/M Program).
3.2 Under Chapter 10.20.020(D) of Cache County Code, the Council directs the
Board to adopt and promulgate regulations to ensure compliance with State
Implementation Plan requirements with respect to an I/M Program.
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3.3 The Board is authorized to make standards and regulations pursuant to Section
26A-1-121(1) of the Utah Code Annotated, 1953, as amended.
3.4 The Board is authorized to establish and collect fees pursuant to Section 26A-1-
114(1)(h)(i) of the Utah Code Annotated, 1953, as amended.
3.5 All aspects of the I/M Program within Cache County enumerated in Section 2.0 of
this Regulation shall be subject to the direction and control of the Bear River Health
Department (hereafter Department).
4.0 POWERS AND DUTIES
4.1 The Department shall be responsible for the enforcement and administration of
this Regulation and any other powers vested in it by law and shall:
4.1.1 Make policies and procedures necessary to ensure that the provisions of
this Regulation are met and that the purposes of this Regulation are accomplished;
4.1.2 Require the submission of information, reports, plans, and specifications
from I/M Program Stations as necessary to implement the provisions,
requirements, and standards of this Regulation;
4.1.3 Issue permits, certifications, and charge fees as necessary to implement the
provisions, requirements, and standards of this Regulation; and
4.1.4 Perform audits of any I/M Program Station, issue orders and/or
notices, hold hearings, and levy administrative penalties, as necessary to effect
the purposes of this Regulation.
4.2 The Department may suspend, revoke, or deny a permit, subject to the Penalty
Schedule in Appendix C, of an I/M Program Station and/or require the surrender of
the permit of such I/M Program Station upon showing that:
4.2.1 A vehicle was inspected and issued a Certificate of Compliance by the
station personnel that did not, at the time of inspection, comply with all applicable
policies, procedures, and this Regulation;
4.2.2 A vehicle was inspected and failed by the I/M Program Station when, in
fact, the vehicle was determined by the Department to be in such condition that it
did comply with the requirements of this Regulation;
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4.2.3 The I/M Program Station has violated any provisions of this Regulation, or
any rule, regulation, or Department policy properly promulgated for the operation
of an I/M Program Station;
4.2.4 The I/M Program Station is not operating from a location specified on the
permit;
4.2.5 An official inspection was done by a Non-certified Inspector or a Non-
certified Inspector has gained access to the official testing portion of the Certified
Testing Equipment;
4.2.6 The Certified Emissions Inspector logged in to the official testing portion
of the Certified Testing Equipment did not perform the inspection;
4.2.7 The Certified Testing Equipment has been tampered with or altered in any
way contrary to the certification and maintenance requirements of the Certified
Testing Equipment;
4.2.8 The I/M Program Station denies access to a representative of the
Department to conduct an audit or other necessary business during regular
business hours;
4.2.9 The I/M fee has been determined by the Department to be discriminatory
in that different fees are assessed dependent upon vehicle ownership, vehicle
make or model, owner residence, etc; or
4.2.10 The I/M Program Station that also contracts with the State of Utah as an
On the Spot Station renewed a vehicle registration without a valid Certificate of
Compliance for that vehicle. This is considered an intentional pass.
4.3 The Department may suspend, revoke, or deny the certificate of a Certified
Emissions Inspector, subject to the Penalty Schedule in Appendix C, and require the
surrender of this certificate upon showing that:
4.3.1 The Certified Emissions Inspector caused a Certificate of Compliance to
be issued without an approved inspection being made;
4.3.2 The Certified Emissions Inspector denied the issuance of a Certificate of
Compliance to a vehicle that, at the time of inspection, complied with the law for
issuance of said certificate;
4.3.3 The Certified Emissions Inspector issued a Certificate of Compliance to a
vehicle that, at the time of issuance, was in such a condition that it did not comply
with this Regulation;
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4.3.4 Inspections were performed by the Certified Emissions Inspector, but not
in accordance with applicable policies, procedures, and this Regulation;
4.3.5 The Certified Emissions Inspector allowed a Non-certified Inspector to
perform an official Inspection or gain access to the official testing portion of the
Certified Testing Equipment;
4.3.6 The Certified Emissions Inspector logged in to the official testing portion
of the Certified Testing Equipment did not perform the inspection;
4.3.7 The Certified Emissions Inspector signed an inspection form or certificate
stating that he had performed the emissions test when, in fact, he did not; or
4.3.8 The Certified Emissions Inspector employed at an I/M Program Station
that also contracts with the State of Utah as an On the Spot Station renewed a
vehicle registration without a valid Certificate of Compliance for that vehicle.
This is considered an intentional pass.
4.4 The Department shall respond, according to the policies and procedures of the
Department, to public complaints regarding the fairness and integrity of the inspections
they receive and shall provide a method that inspection results may be challenged if there
is a reason to believe them to be inaccurate.
5.0 SCOPE
It shall be unlawful for any person to fail to comply with any policy, procedure, or
regulation promulgated by the Department, unless expressly waived by this Regulation.
6.0 GENERAL PROVISIONS
Subject to the exceptions in Section 6.4 and pursuant to the schedule in Section 6.1,
motor vehicles that are registered in Cache County, or principally operated within Cache
County shall be subject to an emission inspection. Owners of vehicles that meet the
requirements of Section 6.2 or 6.3 shall comply with the inspection requirements
regardless of the county of registration.
6.1 Motor vehicles are subject to a biennial emissions inspection. Emissions
inspections will be required in odd-numbered years for a vehicle with an odd-numbered
model year. Emissions inspections will be required in even-numbered years for a vehicle
with an even-numbered model year.
6.1.1 A Certificate of Compliance, or evidence that the motor vehicle is exempt
from the I/M Program requirements (as defined in Section 6.4) shall be presented
to the Cache County Assessor or the Utah State Tax Commission as conditions
Page 9 of 38
precedent to registration or renewal of registration of a motor vehicle in odd-
numbered years for a vehicle with an odd-numbered model year. Persons who
register a vehicle without meeting the requirements listed may be subject to the
penalties referenced in Section 14 of this Regulation.
6.1.2 A Certificate of Compliance, or evidence that the motor vehicle is exempt
from the I/M Program requirements (as defined in Section 6.4) shall be presented
to the Cache County Assessor or the Utah State Tax Commission as conditions
precedent to registration or renewal of registration of a motor vehicle in even-
numbered years for a vehicle with an even-numbered model year. Persons who
register a vehicle without meeting the requirements listed may be subject to the
penalties referenced in Section 14 of this Regulation.
6.1.3 The Air Pollution Control Fee shall be paid annually, as per Chapter
10.20.040(E) of Cache County Code, (see also Section 6.7 of this Regulation) as
conditions precedent to registration or renewal of registration of a motor vehicle.
6.1.4 A Certificate of Compliance shall be valid for a period of time in
accordance with Section 41-6a-1642(10) Utah Code Annotated, 1953, as
amended.
6.2 Publicly-Owned Vehicles. Owners of publicly-owned vehicles shall comply with
the inspection program requirements. Federally-owned vehicles and vehicles of
employees operated on a federal installation that do not require registration in the State of
Utah shall comply with the emissions testing requirements.
6.3 Vehicles of employees and/or students parked at a college or university that do
not require registration in Cache County shall comply with the emissions testing
requirements as authorized by 41-6a-1642(5)(a) Utah Code Annotated, 1953, as
amended.
6.3.1 College or university parking areas that are metered or for which payment
is required per use are not subject to the requirements in Section 6.3.
6.4 Vehicle Exemption. The following vehicles are exempt from these emissions
testing requirements:
6.4.1 An implement of husbandry as provided in Section 41-1a-102 Utah Code
Annotated, 1953, as amended;
6.4.2 A motor vehicle that meets the definition of a farm truck as provided in
Section 41-1a-102 Utah Code Annotated, 1953, as amended, and has a gross
vehicle weight rating of 12,001 pounds or more;
6.4.3 A vintage vehicle as defined in Section 41-21-1 Utah Code Annotated,
1953, as amended;
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6.4.4 A custom vehicle as defined in Section 41-6a-1507 Utah Code Annotated,
1953, as amended;
6.4.5 A pickup truck, as defined in Section 41-1a-102 Utah Code Annotated,
1953, as amended, with a gross vehicle weight rating of 12,000 pounds or less
that meets the requirements provided in Section 41-6a-1642(4)(f) Utah Code
Annotated, 1953, as amended;
6.4.6 A motorcycle as defined in Section 41-1a-102 Utah Code Annotated,
1953, as amended;
6.4.7 A motor vehicle powered solely by electric power;
6.4.8 Any gasoline or non-diesel based Alternative Fuel powered vehicle of
model year 1995 or older;
6.4.9 Any gasoline or non-diesel based Alternative Fuel powered vehicle, with a
gross vehicle weight rating greater than 8,500 pounds, and of model year 2007 or
older;
6.4.10 Any gasoline or non-diesel based Alternative Fuel powered vehicle, with a
gross vehicle weight rating greater than 14,000 pounds, and of model year 2008
or newer;
6.4.11 Any vehicle that is less than six years old on January 1 based on the age
of the vehicle as determined by the model year identified by the manufacturer;
6.4.12 Any diesel or diesel based Alternative Fuel powered vehicle 1997 and
older;
6.4.13 Any diesel or diesel based Alternative Fuel powered vehicle with a gross
vehicle weight rating greater than 14,000 pounds; and
6.4.14 Any vehicle that qualifies for exemption under Section 41-6a-1642 Utah
Code Annotated, 1953, as amended;
6.4.15 Any current use “Authorized emergency vehicle” as defined by Section
41-6a-102 Utah Code Annotated,1953, as amended
6.5 If a vehicle exempted by Section 6.4 of this Regulation is brought to the Certified
Emissions Inspector for an official Inspection it shall be the responsibility of the Certified
Emissions Inspector to inform the owner/operator of the vehicle that the vehicle is not
required to have an official Inspection.
6.6 Official Signs.
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6.6.1 All I/M Program Stations shall display in a conspicuous location on the
premises an official sign provided and approved by the Department; The
readiness requirements for an OBD test as referenced in Appendix D
shall be posted in a conspicuous place on the station’s premises;
6.6.2 The station shall post on a clear and legible sign and in a conspicuous
place at the station, the fees charged by that station for the performance of the
emissions inspection;
6.6.3 The free re-inspection policy as referenced in Section 9.4 shall be posted
in a conspicuous place on the station’s premises;
6.6.4 The signs required by Sections 6.6.1 through 6.6.4 shall be located so as to
be easily in the public view.
6.7 Fees.
6.7.1 The fees assessed upon I/M Program Stations and Certified Emissions
Inspectors shall be determined according to a fee schedule adopted by the Board.
The fee schedule is referenced in Appendix A to this Regulation and may be
amended by the Board as necessary.
6.7.2 An Air Pollution Control Fee is hereby assessed upon every motor vehicle
registered in Cache County as per Chapter 10.20.040 of Cache County Code. The
fee will be assessed annually at the time of registration of the vehicle.
6.7.2.1 This fee assessment is included upon all motorized vehicles
including those that are exempted from the inspection
requirements of this Regulation by Section 6.4.
6.7.2.2 A motor vehicle that is exempt from the registration fee,
and a commercial vehicle with an apportioned registration
shall be exempt from this fee as per Section 41-1a-1223,
Utah Code Annotated, 1953, as amended and Chapter
10.20.040 of Cache County Code.
6.7.3 I/M Program Stations may charge a fee for the required service. The fee
may not exceed, for each vehicle inspected, the amount set by the Board and
referenced in Appendix A of this Regulation.
6.7.3.1 The inspection fee pays for a complete inspection leading
to a Certificate of Compliance, a Rejection, or a failure. If
a vehicle fails, or is rejected from an inspection, the
owner/operator is entitled to one free re-inspection if he
returns to the I/M Program Station that performed the
original inspection within fifteen (15) calendar days from
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the date of the initial inspection. The I/M Program Station
shall extend the fifteen day free re-inspection to
accommodate the vehicle owner/operator if the I/M
Program Station is unable to schedule the retest of the
vehicle within the fifteen day time period. The inspection
fee shall be the same whether the vehicle passes or fails the
emission test.
6.7.4 If a vehicle fails the inspection and is within the time and mileage
requirements of the federal emissions warranty contained in section 207 of the
Federal Clean Air Act, the Certified Emissions Inspector shall inform the
owner/operator that he may qualify for warranty coverage of emission related
repairs as provided by the vehicle manufacturer and mandated by the Federal
Environmental Protection Agency (see 40 CFR Part 85, Subpart V).
6.8 Compliance Assurance List.
6.8.1 The Department reserves the right to recall a vehicle and perform a
Compliance Assurance Inspection at the I/M Technical Center for the following
reasons:
6.8.1.1 Suspected fraudulent registration;
6.8.1.2 Suspected fraudulent emissions inspection;
6.8.1.3 Suspected tampering of emissions control devices;
6.8.1.4 Violations of Section 41-6a-1626, Utah Code Annotated, 1953, as
amended, regarding visible emissions; and
6.8.1.5 Any item listed in Appendix D, Test Procedures, that cause the
vehicle to be flagged during an emissions inspection.
6.8.2 The Department shall create and maintain a list of vehicles that are subject
to a Compliance Assurance Inspection at the I/M Technical Center.
6.8.2.1 The Compliance Assurance Inspection criteria listed in Appendix
D, Test Procedures, shall be followed.
6.8.2.2 A vehicle that passes the Compliance Assurance Inspection may be
removed from the Compliance Assurance List by Department personnel.
6.8.2.3 A vehicle that fails the Compliance Assurance Inspection may be
subject to penalties as described in Section 14 of this regulation.
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7.0 PERMIT REQUIREMENTS OF THE VEHICLE EMISSIONS
I/M PROGRAM STATION
7.1 Permit Required.
7.1.1 No person shall in any way represent any place as an official I/M Program
Station unless the station is operated under a valid permit issued by the
Department.
7.1.2 The Department is authorized to issue or deny permits for I/M Program
Stations.
7.1.3 No permit for any official I/M Program Station may be assigned,
transferred, or used by any person other than the original owner identified on the
permit application for that specific I/M Program Station.
7.1.4 The permit shall be posted in a conspicuous place within public view on
the premises.
7.1.5 Application for an I/M Program Station permit shall be made to the
Department upon a form provided by the Department. No permit shall be issued
unless the Department finds that the facilities, and equipment of the applicant
comply with the requirements of this Regulation and that competent personnel,
certified under the provisions of Section 8.0, are employed and will be available
to make inspections, and the operation thereof will be properly conducted in
accordance with this Regulation.
7.1.5.1 An I/M Program Station shall notify the Department and
cease any emission testing if the station does not have a
Certified Emissions Inspector employed.
7.1.5.2 An I/M Program Station shall notify the Department upon
termination and/or resignation of any Certified Emissions
Inspector employed by the station.
7.1.5.3 An I/M Program Station shall comply with all the terms
stated in the permit application and all the requirements of
this Regulation.
7.1.5.4 An I/M Program Station shall provide a dedicated internet
connection for the Certified Testing Equipment. A wireless
internet connection may be required by the Contractor.
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7.2 Permit Duration and Renewal
7.2.1 The permit for I/M Program Stations shall be issued annually and shall
expire on the last day of the month, one year from the month of issue. The permit
shall be renewable sixty days prior to the date of expiration.
7.2.2 It is the responsibility of the owner/operator of the I/M Program Station to
pursue the permit renewal through appropriate channels.
7.3 I/M Program Station to hold Department Harmless
7.3.1 In making application for a permit or for its renewal, such action shall
constitute a declaration by the applicant that the Department shall be held
harmless from liability incurred due to action or inaction of I/M Program Station’s
owners or their employees.
7.4 An I/M Program Station shall be kept in good repair and in a safe condition for
inspection purposes free of obstructions and hazards.
8.0 TRAINING AND CERTIFICATION OF INSPECTORS
8.1 Certified Emissions Inspector Certification Required.
8.1.1 No person shall perform any part of the inspection for the issuance of a
Certificate of Compliance unless the person possesses a valid Certified Emissions
Inspector Certification issued by the Department.
8.1.2 Applications for a Certified Emissions Inspector Certification shall be
made upon an application form prescribed by the Department. No certification
shall be issued unless:
8.1.2.1 The applicant has shown adequate competence by
successfully completing all portions of the Certified
Emissions Inspector Certification requirements as specified
in this Regulation; and
8.1.2.2 The applicant has paid the required permit fees as set by the
Board and referenced in Appendix A of this Regulation.
8.1.3 An applicant shall comply with all of the terms stated in the application
and with all the requirements of this Regulation.
8.1.4 An applicant shall complete a Department approved training course and
shall demonstrate knowledge and skill in the performance of emission testing and
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use of the Certified Testing Equipment. Such knowledge and skill shall be shown
by passing at minimum:
8.1.4.1 Operation and purposes of emission control systems;
8.1.4.2 Inspection procedures as outlined in this Regulation and
prompted by the Certified Testing Equipment ;
8.1.4.3 Operation of the Certified Testing Equipment;
8.1.4.4 The provisions of Section 207(b) warranty provisions of the
Federal Clean Air Act, and other federal warranties;
8.1.4.5 The provisions of this Regulation and other applicable
Department policies and procedures; and
8.1.4.6 A performance qualification test including but not limited
to the following:
(a)Demonstration of skill in proper use, care,
and maintenance, of the Certified Testing
Equipment;
(b)Demonstration of ability to conduct the inspection; and
(c)Demonstration of ability to accurately enter data in
the Certified Testing Equipment.
8.1.5 The Department shall issue a Certified Emissions Inspector Certificate
to an applicant upon successful completion of the requirements of this section.
8.1.6 The Certified Emissions Inspector Certificates are and remain the property
of the Department, only their use and the license they represent is tendered.
8.1.7 Certified Emissions Inspector Certifications shall not be transferred from
one person to another person.
8.2 Recertification Requirements for Certified Emissions Inspectors
8.2.1 The Department may renew certifications for an existing Certified
Emissions Inspector after a properly completed renewal form is submitted,
reviewed, and approved, the recertification requirements have been completed,
the fees are paid and the Certified Emissions Inspector has complied with this
Regulation.
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8.2.2 Certified Emissions Inspectors shall be required to recertify annually.
Failure to recertify shall result in suspension or revocation of the Certification as
described in this Regulation.
8.2.3 Certified Emissions Inspectors shall complete a Department approved
refresher course every 2 years. Applicants for recertification shall complete a
Department approved refresher course no more than sixty days prior to the date of
expiration.
8.3 Certification Expiration
8.3.1 The Certified Emissions Inspector Certification shall be issued annually
and shall expire on the last day of the month one year from the month of issue.
The certification shall be renewable sixty days prior to the date of expiration.
8.3.2 It is the responsibility of the Certified Emissions Inspector to pursue
the renewal of the Certification.
8.4 Certified Emissions Inspector Certification Denial, Suspension and Revocation
8.4.1 Certified Emissions Inspector Certifications may be suspended or revoked
by the Department for violations of this Regulation.
8.4.2 Suspension or revocation of Certified Emissions Inspector Certifications
shall follow the provisions of Appendix C of this Regulation.
8.4.3 The Department may deny issuance of a Certified Emissions Inspector
Certification to an individual that works as an emissions inspector in another
county in Utah and is currently under suspension or revocation in that program.
9.0 INSPECTION PROCEDURE
9.1 The official emissions inspection shall be solely performed by a Certified
Emissions Inspector at an I/M Program Station, and Department approved inspection
procedures, as referenced in this section and Appendix D, Test Procedures, are to be
followed.
9.2 A complete official test must be performed any time an inspection is requested.
The Certified Emissions Inspector shall not perform any part of the inspection without
initiating an official test on the Certified Testing Equipment.
9.3 The Certified Emissions Inspector shall perform the official vehicle emissions test
using the proper testing procedure.
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9.3.1 All gasoline, and non-diesel based Alternative Fuel powered vehicles,
including Bi-Fuel vehicles, model year 1996 and newer, with a gross vehicle
weight rating 8,500 pounds or less, shall be tested as specified in Appendix D,
OBDII Test Procedures, unless specifically exempted by this Regulation.
9.3.2 All gasoline and non-diesel based Alternative Fuel powered vehicles,
including Bi-Fuel vehicles, model year 2008 and newer with a gross vehicle
weight rating greater than 8,500 pounds and less than 14,001 pounds shall be
tested as specified in Appendix D, OBDII Test Procedures, unless specifically
exempted by this Regulation.
9.3.3 All diesel and diesel based Alternative Fuel powered vehicles model year
1998 and newer with a gross vehicle weight rating less than 14,001 pounds shall
be tested as specified in Appendix D, Diesel Test Procedures, unless specifically
exempted by this Regulation.
9.4 Retesting Procedures
9.4.1 If the vehicle fails the initial emissions inspection, the
owner/operator shall have fifteen calendar days in which to
have repairs or adjustments made and return the vehicle to
the I/M Program Station that performed the initial
inspection for one (1) free re-inspection.
9.4.2 If the vehicle is Rejected from the initial emissions
inspection for failure to complete Readiness requirements,
the owner/operator shall have fifteen calendar days in
which to return the vehicle to the I/M Program Station that
performed the initial inspection for one (1) free re-
inspection.
9.4.3 If the vehicle owner/operator does not return to the I/M Program Station
that performed the initial inspection within fifteen calendar days the I/M Program
Station is under no obligation to offer a free re-inspection.
9.5 Waivers
9.5.1 A Waiver may be granted and a Certificate of Compliance issued for 1996
and newer model year vehicles if all of the following requirements are met:
9.5.1.1 Air pollution control devices identified in the VECI Label
are in place and apparently operable on the vehicle. If the
VECI Label is missing, the Department may use reference
material to identify the air pollution control devices
required for the vehicle. If the devices have been removed
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or rendered inoperable, they shall be replaced or repaired
before a Waiver is granted;
9.5.1.2 The vehicle continues to fail the inspection after $200.00
has been spent on acceptable emissions related repair costs
for that specific vehicle, and proof of repair costs for that
specific vehicle have been provided to the Department in
the form of an itemized bill, invoice, work order, manifest,
or statement in which emissions related parts are
specifically identified. If repairs are made at a repair
station that employs individuals with current ASE L1, ASE
A8, or another certification approved by the Department,
the cost of labor may be included in the $200.00;
9.5.1.3 The vehicle is not within the time and mileage
requirements of the federal emissions warranties. Any
vehicle that is within time and mileage requirements of the
federal emissions warranties shall not be eligible for a
Waiver, but shall be repaired to pass the testing
requirements; and
9.5.1.4 A vehicle that is Rejected from the OBD Inspection may
qualify for a Waiver if it meets requirements set forth in
Appendix F, Waivers for “Not Ready” Vehicles.
9.5.2 As used in 9.5.1, acceptable emissions related repairs:
9.5.2.1 May include repairs performed up to 60 days prior to the
official emissions test, provided appropriate documentation
is supplied to the Department;
Diagnostic work performed, including Diagnostic Trouble
Codes if applicable, must be properly documented to justify
any repairs performed;
9.5.2.2 Does not include the fee paid for the test;
9.5.2.3 Does not include costs associated with the repairs or
replacements of air pollution control equipment on the
vehicle if the need for such adjustment, maintenance,
replacement, or repair is due to disconnection of, tampering
with, or abuse of the emissions control systems;
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9.5.2.4 Refers to repairs, maintenance, and diagnostic evaluations
done in accordance with manufacturer’s specifications, to
the extent that the purpose is to reduce emissions;
9.5.2.5 Repairs performed on OBD compliant vehicles should be
directly related to the diagnostic trouble codes identified by
the vehicle and by further diagnostic tests on the vehicle;
9.5.2.6 Does not include parts replaced on OBD compliant vehicles
that cannot be justified through diagnostic trouble codes or
further diagnostic tests on the vehicle.
9.5.3 A Waiver shall only be issued by the Department. A Waiver shall only be
issued after determining that the vehicle complies with the requirements of this
Section.
9.5.4 A Waiver shall only be issued once to any vehicle that qualifies,
throughout the lifetime of the vehicle.
9.5.5 A vehicle must meet the requirements of Section 41-6a-1626, Utah Code
Annotated 1953, as amended, regarding visible emissions in order to qualify for a
Waiver.
9.6 The Department shall explore new technologies related to emissions inspections.
As part of this exploration the Department may perform studies, run pilot projects, collect
and analyze data, and make recommendations to the Board. If a new technology can be
shown to be as effective as current technologies in reducing emissions and preventing
fraud, the Department shall present these findings to the EPA. The Department shall then
work with the EPA, the Board, and the Council to seek approval to incorporate the new
technology as a testing method.
10.0 ENGINE SWITCHING
10.1 Engine switching shall be allowed only in accordance with EPA policy, as
detailed in EPA’s Engine Switching Fact Sheet, dated March 13, 1991, and EPA’s
Addendum to Mobile Source Enforcement Memorandum 1A, dated September 4, 1997.
10.2 Vehicles subject to an emissions inspection, as referenced in Section 6.0 of this
Regulation, that do not meet the requirements of Section 10.1 shall be deemed as
tampered and are not eligible for a Waiver, unless they are restored to the original engine
and emission control configuration.
Page 20 of 38
11.0 SPECIFICATIONS FOR CERTIFIED TESTING EQUIPMENT
11.1 Approval of Certified Testing Equipment
11.1.1 Certified Testing Equipment shall meet the specifications as detailed in
Appendix E.
11.1.2 It shall be illegal for any person to modify the hardware or software of
Certified Testing Equipment without approval by the Department and/or
Contractor.
11.1.3 It shall be illegal for any person to gain access to any Department or
Contractor controlled portions of Certified Testing Equipment without approval
by the Department and/or Contractor.
12.0 QUALITY ASSURANCE
12.1 A quarterly inspection shall be made by a representative of the Department to
verify compliance with this Regulation for each I/M Program Station. During the time of
the inspection by the Department, the Department’s representative shall have exclusive
access to the Certified Testing Equipment. Inspections may be performed utilizing
technology integrated into the Certified Testing Equipment.
12.2 An annual covert inspection and audit shall be made by a representative of the
Department to verify compliance with this Regulation for each I/M Program Station.
12.3 The Department may increase the frequency of inspections for I/M Program
Stations and/or Certified Emissions Inspectors if the Department receives information of
a violation of this Regulation.
12.4 The Department shall regularly monitor I/M Program Stations and/or Certified
Emissions Inspectors through inspection records and/or technology integrated into the
Certified Testing Equipment.
13.0 DISCIPLINARY PENALTIES AND RIGHT TO APPEAL
13.1 When the Department, or its representative(s), receives information of a violation
of any regulation contained herein which may result in a permit denial, revocation, or
suspension, the Department shall notify the affected entity, in writing, informing the
entity of the violation and penalties to be enforced. The affected entity may request a
hearing within ten calendar days of the Department giving notice of the potential permit
denial, revocation, or suspension. Only a written request for a hearing shall be honored
by the Department. No appeal may be made on a formal warning.
Page 21 of 38
13.1.1 In considering the appropriate administrative action to be taken as
indicated in Appendix C, the Director shall consider the following:
13.1.1.1 whether the violation was unintentional or careless;
13.1.1.2 the frequency of the violation or violations;
13.1.1.3 the inspection and covert inspection history of the I/M
Program Station and the Certified Emissions Inspector;
13.1.1.4 whether the fault lies with the I/M Program Station or the
Certified Emissions Inspector.
13.1.2 After consideration of the factors in Section 13.1.1 the Director may take
appropriate administrative action as indicated in Appendix C against either the
I/M Program Station, the Certified Emissions Inspector, or both.
13.2 Appeals Hearing Procedure:
13.2.1 An appeals hearing shall be held at the request of the affected entity in
order to determine the accuracy of information obtained by the Department and
whether there are mitigating factors which would justify a reduction of the
imposed penalties.
13.2.2 The requesting party may bring to the hearing any witnesses and any
evidence believed to be pertinent to the disciplinary action.
13.2.3 The appeal shall be heard by the Vehicle Inspection and Maintenance
Appeal Board, hereafter I/M Board, consisting of at least three persons, who are
not employees of Bear River Health Department, appointed by the Board. The
I/M Board shall have the discretion to determine which witnesses shall be heard
and what evidence is relevant.
13.2.4 Violations determined to be intentional or flagrant shall result in the
maximum enforcement of the penalty schedule pursuant to Appendix C.
13.2.5 In considering whether to reduce a penalty indicated by Appendix C, the
I/M Board and the Department shall consider the following:
13.2.5.1 whether the violation was unintentional or careless;
13.2.5.2 the frequency of the violation or violations;
13.2.5.3 the inspection and covert inspection history of the I/M
Program Station and the Certified Emissions Inspector;
Page 22 of 38
13.2.5.4 whether the fault lies with the I/M Program Station, the
Certified Emissions Inspector, or both.
13.3 Written notice of the final determination of the I/M Board, including the I/M
Board’s finding under Section 14.2.5, shall be made within ten calendar days after the
conclusion of the appeals hearing.
14.0 PENALTY
14.1 Any person who is found guilty of violating any of the provisions of this
Regulation, either by failing to do those acts required herein or by doing a prohibited act,
shall be guilty of a class B misdemeanor pursuant to Section 26A-1-123, Utah Code
Annotated, 1953, as amended. If a person is found guilty of a subsequent similar
violation within two years, he shall be guilty of a class A misdemeanor pursuant to
Section 26A-1-123, Utah Code Annotated, 1953, as amended.
14.2 Each day such violation is committed or permitted to continue shall constitute a
separate violation.
14.3 The Cache County Attorney’s Office may initiate legal action, civil or criminal,
requested by the Department to abate any condition that exists in violation of this
Regulation.
14.4 In addition to other penalties imposed by a court of competent jurisdictions, any
person(s) found guilty of violating any of this Regulation shall be liable for all expenses
incurred by the Department.
14.5 A Penalty Schedule for permit warning, suspension, or revocation is adopted as
Appendix C and may be amended by the Board as the Board deems necessary to
accomplish the purposes of this Regulation.
14.6 The Department shall request that the Utah Division of Motor Vehicles suspend
or revoke a registered vehicle’s registration if the vehicle is unable to meet emissions
standards or if the vehicle has not complied with the required emission testing
requirements pursuant to Section 41-1a-110(6), Utah Code Annotated, 1953, as amended.
15.0 SEVERABILITY
If any provision, clause, sentence, or paragraph of this Regulation or the application
thereof to any person or circumstances shall be held to be invalid, such invalidity shall
not affect the other provisions or applications of this Regulation. The valid part of any
clause, sentence, or paragraph of this Regulation shall be given independence from the
invalid provisions or application and to this end the provisions of this Regulation are
hereby declared to be severable.
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16.0 EFFECTIVE DATE
This Regulation shall become effective on July 1, 2024 as adopted by the Bear River Board
of Health.
Executive Director/Health Officer
Bear River Health Department
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APPENDIX A - FEE SCHEDULE
Permitting of an official I/M Program Station $250.00
Annual Renewal of I/M Program Station $50.00
Expired I/M Program Station Renewal $75.00
I/M Program Station Re-location $75.00
Permitting of a Certified Emissions Inspector $25.00
Renewal of Certified Emissions Inspector $15.00
Expired Certified Emissions Inspector Renewal $25.00
Official Station Sign Cost
APC Fee for 12 month registration $3.00
APC Fee for 6 month registration $2.25
Emissions Inspection Fee – OBD Test Market
Emissions Inspection Fee –Tampering Market
Page 25 of 38
APPENDIX B - RESERVED
Page 26 of 38
APPENDIX C - PENALTY SCHEDULE
Violation
(resets after 2 years of no
similar violations unless
revoked)
1st Occurrence 2nd Occurrence 3rd Occurrence 4th Occurrence
Failure to inspect
or substituting a
vehicle other than
the vehicle on the
test record –
Registering a
Tech: 180 day
suspension and
mandatory retraining
Tech: Revocation of
permit for up to 5 years
Station: 180 day
suspension
Station: 270 day
suspension
Station: Revocation of
inspection station permit
for up to 5 years
failing vehicle
(intentional pass)
Passing a failing
vehicle or
Tech: 30 day suspension
and mandatory retraining
Tech: 60 day suspension
and mandatory retraining
Tech: Revocation of
permit for up to 5 years
recording pass for Station: 15 day Station: 30 day Station: 60 day Station: Revocation of
tampering on a
suspension suspension suspension permit for up to 5 years
tampered vehicle
(gross negligence)
Falsifying an
inspection record
or emissions
certificate or
Failing a passing
vehicle
Tech: 180 day
suspension and
mandatory retraining
Tech: Revocation of
permit for up to 5 years
Station: 180 day
suspension
Station: 270 day
suspension
Station: Revocation of
inspection station permit
for up to 5 years
(intentional)
Non-certified
person performing
Tech: 60 day suspension Tech: 180 day
suspension
Tech: Revocation of
permit for up to 5 years
test – Using
Station: 60 day Station: 180 day Station: Revocation of
another inspector’s
access
suspension suspension inspection station permitfor up to 5 years
(gross negligence
table)
Inaccurate or
incomplete data
Tech: Formal warning
and mandatory retraining
Tech: 30 day suspension
and mandatory retraining
Tech: 90 day suspension
and mandatory retraining
Tech: Revocation of
permit for up to 5 years
entry Station: Formal warning Station: 15 day Station: 45 day Station: Revocation of
(incompetence)suspension suspension inspection station permit
for up to 5 years
Failure to follow
proper test
Tech: Formal warning
and mandatory retraining
Tech: 30 day suspension
and mandatory retraining
Tech: 90 day suspension
and mandatory retraining
Tech: Revocation of
permit for up to 5 years
procedures – Other Station: Formal warning Station: 15 day Station: 45 day Station: Revocation of
regulation
violations
suspension suspension inspection station permit
for up to 5 years
(incompentence)
Page 27 of 38
APPENDIX D - TEST PROCEDURES
OBDII Test Procedures for gasoline and non-diesel based Alternative Fuel powered
vehicles
1 The Certified Emissions Inspector shall verify the following items from the vehicle
and accurately record them in the Certified Testing Equipment:
1.1 Vehicle Identification Number (VIN)
1.2 Gross Vehicle Weight Rating (GVWR)
1.3 Model year
1.4 Make
1.5 Model
1.6 Fuel Type
1.7 Engine size
1.8 Number of cylinders
1.9 Certification standard (EPA or California)
2 The Certified Emissions Inspector shall visually examine the instrument panel to
determine if the Malfunction Indicator Light (MIL) illuminates, at least briefly, when the
ignition key is turned to the “key on, engine off” (KOEO) position. The visual result
shall be accurately recorded in the Certified Testing Equipment.
3 The Certified Emissions Inspector shall locate the Diagnostic Link Connector (DLC)
on the vehicle being tested. The vehicle should be connected to the Certified Testing
Equipment when prompted.
3.1 If the DLC is missing, has been tampered with, or is otherwise inoperable, the
vehicle fails the test and shall be repaired.
3.2 If the DLC is inaccessible, the problem must be remedied before the test can
continue.
4 When prompted by the Certified Testing Equipment the Certified Emissions Inspector
should start the engine so the vehicle is in the “key on, engine running” (KOER)
condition and follow the screen prompts until the test is complete.
5 For 1996-2000 model year vehicles two (2) supported readiness monitors are allowed to
be “not ready”. For 2001 and newer vehicles one (1) supported readiness monitor is
allowed to be “not ready”. If the “not ready” status exceeds these numbers the vehicle
must be driven additional miles or have appropriate repairs made.
5.1 A vehicle that fails the initial inspection for a catalyst related fault (i.e., P0420-
P0439) must have the catalyst monitor set to “ready” upon re-inspection.
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6 If the MIL is commanded on while the engine is running, regardless of the presence of
Diagnostic Trouble Codes (DTC), the vehicle will fail the test and will require repairs.
7 Certain vehicles have been determined to be OBDII deficient. The Certified Testing
Equipment software will maintain a list of these vehicles and perform a modified OBDII
test.
8 A vehicle must meet the requirements of Section 41-6a-1626, Utah Code Annotated
1953, as amended, regarding visible emissions in order to qualify for a Certificate
of Compliance.
9 Certain vehicles will be flagged by the testing software during the inspection and may be
recalled to the I/M Technical Center for a Compliance Assurance Inspection. Vehicles
will be flagged for the following items:
9.1 Mismatch between entered VIN and OBD VIN;
9.2 Any of the following readiness monitors being unsupported: Misfire, fuel system,
component, catalyst, and/or oxygen sensor;
9.3 A change in supported readiness monitors since the last inspection;
9.4 A change in communication protocol since the last inspection;
9.5 A change in OBD VIN since the last inspection;
9.6 The presence of an OBD VIN in a vehicle that does not support OBD VINs;
9.7 The absence of an OBD VIN in a vehicle that supports OBD VINs; or
9.8 A change in PID count since the last inspection.
10 Certain vehicles might not communicate with the Certified Testing Equipment. These
vehicles will be referred to the I/M Technical Center for a Referee Inspection.
11 A vehicle owner/operator that challenges the results of an official emissions inspection
may request a Referee Inspection at the I/M Technical Center.
Page 29 of 38
Diesel and diesel based Alternative Fuel Powered Vehicles Test Procedures
All diesel powered vehicles 2007 and newer, with a gross vehicle weight rating less than 14,001
pounds, shall be tested as follows:
1 The Certified Emissions Inspector shall verify the following items from the vehicle
and accurately record them in the Certified Testing Equipment:
1.1 Vehicle Identification Number (VIN)
1.2 Gross Vehicle Weight Rating (GVWR)
1.3 Model year
1.4 Make
1.5 Model
1.6 Fuel Type
1.7 Engine size
1.8 Number of cylinders
1.9 Certification standard (EPA or California)
2 The Certified Emissions Inspector shall visually examine the instrument panel to
determine if the Malfunction Indicator Light (MIL) illuminates, at least briefly, when the
ignition key is turned to the “key on, engine off” (KOEO) position. The visual result
shall be accurately recorded in the Certified Testing Equipment.
3 The Certified Emissions Inspector shall locate the Diagnostic Link Connector (DLC)
on the vehicle being tested. The vehicle should be connected to the Certified Testing
Equipment when prompted.
3.1 If the DLC is missing, has been tampered with, or is otherwise inoperable, the
vehicle fails the test and shall be repaired.
3.2 If the DLC is inaccessible, the problem must be remedied before the test can
continue.
4 When prompted by the Certified Testing Equipment the Certified Emissions Inspector
should start the engine so the vehicle is in the “key on, engine running” (KOER)
condition and follow the screen prompts until the test is complete.
5 Two supported readiness monitors are allowed to be “not ready”. If the “not ready”
status exceeds these numbers the vehicle must be driven additional miles or have
appropriate repairs made.
5.1 A vehicle that fails the initial inspection for a catalyst related fault (i.e., P0420-
P0439) must have the catalyst monitor set to “ready” upon re-inspection.
6 If the MIL is commanded on while the engine is running, regardless of the presence of
Diagnostic Trouble Codes (DTC), the vehicle will fail the test and will require repairs.
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7 Certain vehicles have been determined to be OBDII deficient. The Certified Testing
Equipment software will maintain a list of these vehicles and perform a modified OBDII
test.
8 A vehicle must meet the requirements of Section 41-6a-1626, Utah Code Annotated
1953, as amended, regarding visible emissions in order to qualify for a Certificate
of Compliance.
9 Certain vehicles will be flagged by the testing software during the inspection and may be
recalled to the I/M Technical Center for a Compliance Assurance Inspection. Vehicles
will be flagged for the following items:
9.1 Mismatch between entered VIN and OBD VIN;
9.2 Any of the following readiness monitors being unsupported: Misfire, fuel system,
component, NMHC, and/or NOx/SCR;
9.3 A change in supported readiness monitors since the last inspection;
9.4 A change in communication protocol since the last inspection;
9.5 A change in OBD VIN since the last inspection;
9.6 The absence of an OBD VIN; or
9.7 A change in PID count since the last inspection.
10 Diesel powered vehicles shall be subject to a visual anti-tampering inspection. The air
pollution control devices identified in the Vehicle Emissions Control Information (VECI)
label shall be in place and apparently operable on the vehicle. If the decal is missing,
reference material may be used to identify the air pollution control devices required for
the vehicle.
11 Certain vehicles might not communicate with the Certified Testing Equipment. These
vehicles will be referred to the I/M Technical Center for a Referee Inspection.
12 A vehicle owner/operator that challenges the results of an official emissions inspection
may request a Referee Inspection at the I/M Technical Center.
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All diesel powered vehicles 1998-2006, with a gross vehicle weight rating less than 14,001
pounds, shall be tested as follows:
1 The Certified Emissions Inspector shall verify the following items from the vehicle and
accurately record them in the Certified Testing Equipment:
1.1 Vehicle Identification Number (VIN)
1.2 Gross Vehicle Weight Rating (GVWR)
1.3 Model year
1.4 Make
1.5 Model
1.6 Fuel Type
1.7 Engine size
1.8 Number of cylinders
1.9 Certification standard (EPA or California)
2 Diesel powered vehicles shall be subject to a visual anti-tampering inspection. The air
pollution control devices identified in the Vehicle Emissions Control Information (VECI)
label shall be in place and apparently operable on the vehicle. If the decal is missing,
reference material may be used to identify the air pollution control devices required for
the vehicle.
3 A vehicle must meet the requirements of Section 41-6a-1626, Utah Code Annotated
1953, as amended, regarding visible emissions in order to qualify for a Certificate
of Compliance.
4 If the OBDII System is identified on the VECI label, the procedure in Section 2 through 5
shall be followed.
4.1 An inspection of the OBDII System shall be for informational purposes only and
will not determine whether a vehicle passes or fails the emission inspection.
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Compliance Assurance Inspection
1 A vehicle that is referred to the I/M Technical Center for a Compliance Assurance
Inspection shall be subject to an official emissions inspection. A visual anti-tampering
inspection shall also be included in every Compliance Assurance Inspection. The air
pollution control devices listed in the Vehicle Emissions Control Information (VECI)
label shall be in place and apparently operable on the vehicle. If the VECI label is
missing, reference material may be used to identify the air pollution control devices
required for the vehicle.
1.1 A vehicle that has missing or tampered air pollution control devices will fail the
Compliance Assurance Inspection and will not be issued a Certificate of
Compliance.
1.2 A vehicle that has missing or tampered air pollution control devices and has
already been issued a Certificate of Compliance will be required to replace or
repair the devices. Owners/operators of vehicles that do not comply will be
subject to the penalties in this Regulation.
2 The Department will use data obtained by the Utah Division of Motor Vehicles and
inspection data to determine if a vehicle should be subject to a Compliance Assurance
Inspection.
3 The owner/operator of a vehicle subject to a Compliance Assurance Inspection will be
notified in writing of the requirement to present the vehicle for inspection.
Referee Inspection
1 Vehicles may be referred to the I/M Technical Center for a Referee Inspection. During a
Referee Inspection the Department may override the normal testing criteria and issue a
Certificate of Compliance for the following reasons:
1.1 The vehicle will not communicate with the Certified Testing Equipment but will
communicate with other scan tools. The vehicle must meet all other testing requirements
including readiness status and MIL status; or
1.2 The vehicle has met the criteria to be issued a Waiver.
2 A Referee Inspection may also be performed when an owner/operator believes the
emissions inspection performed at an I/M Program Station was not done correctly.
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APPENDIX E - CERTIFIED TESTING EQUIPMENT STANDARDS
1 General
This appendix contains specifications for Contractors to design Certified Testing
Equipment to be used in the Cache County I/M Program.
1.1 Design Goals
Certified Testing Equipment must be designed and constructed to provide reliable and
accurate service in the automotive service environment. The software must be designed
for maximum operational simplicity. The software must prevent users from clearing
Diagnostic Trouble Codes (DTC), changing readiness status, or performing other actions
that could change the results of an official emissions test. In addition, the Certified
Testing Equipment must include security measures that will prevent unauthorized
modifications to the software or inspection data.
These technical specifications contain the minimum requirements for Certified Testing
Equipment used to perform official emissions inspections in Cache County, UT.
1.2 Manuals
All Certified Testing Equipment sold or leased by the Contractor must be provided with a
current copy of a manual that contains, at a minimum, operating instructions,
maintenance instructions, and initial startup instructions. The manual may be provided in
electronic format and shall be accessible from the Certified Testing Equipment.
1.3 Warranty Coverage and Extended Service Agreements
A written warranty coverage agreement, signed by an authorized representative of the
Contractor and the I/M Program Station, which provides a complete description of
coverage for all systems and components and all Contractor provided services listed
below in Contractor Provided Services, must accompany the sale or lease of each unit of
Certified Testing Equipment.
The Contractor shall provide a minimum of one-year warranty coverage on each unit of
Certified Testing Equipment sold or leased. The one-year warranty coverage shall begin
on the date of purchase and shall be included in the unit pricing for the Certified Testing
Equipment. An extended warranty shall be made available to the I/M Program Stations
that purchase or lease Certified Testing Equipment.
1.4 Contractor Provided Services
The Contractor shall provide the following services to the I/M Program Station as part of
any sale, lease, or loan of Certified Testing Equipment:
Page 34 of 38
- Delivery, set-up, and verification of proper functionality of the Certified
Testing Equipment; and
- Training on the use and maintenance of the Certified Testing Equipment.
The Contractor shall provide the following services to the I/M Program Station during the
initial one-year warranty coverage period and thereafter to any I/M Program Station that
purchases an extended warranty:
-Full system support and repair as detailed in the warranty coverage
agreement; and
-Appropriate service response, either on-site or remote, by a Contractor
authorized repair technician within one business day (Saturday shall be
considered a business day), excluding Sundays, and national/state holidays
(New Year’s Day, Human Rights Day, President’s Day, Memorial Day,
Independence Day, Pioneer Day, Labor Day, Veteran’s Day, Thanksgiving,
and Christmas), of a request from the I/M Program Station. All system
repairs, component replacements, and/or Certified Testing Equipment
adjustments must be accomplished within a minimum average response time
of 8 business hours after a service request has been initiated. If the
completion of this work is not possible within this time period, Certified
Testing Equipment of equal quality and specifications must be provided until
the malfunctioning unit is properly repaired and returned to service.
1.5 Tamper Resistance
The Certified Testing Equipment operators, Department personnel, and Contractor
authorized service technicians shall be prevented from changing any inspection results,
programs, or data contained on the Certified Testing Equipment. The Contractor shall
use appropriate software and/or hardware provisions to protect files and programs.
2 – Hardware/Software Requirements
2.1 Accessing the OBD System
The Certified Testing Equipment must include hardware and software necessary
to access the on-board computer systems of vehicles subject to OBD inspections.
This includes the following:
-1996 and newer gasoline and non-diesel based alternative fuel vehicles
with a gross vehicle weight rating of 8,500 pounds or less
-2008 and newer gasoline and non-diesel based alternative fuel vehicles
with a gross vehicle weight rating of 14,000 pounds or less
-2007 and newer diesel and diesel based alternative fuel vehicles with
a gross vehicle weight rating of 14,000 pounds or less
Page 35 of 38
The Certified Testing Equipment shall be compliant with the recommended
practices regarding OBD inspections contained in J1962, J1978, and J1979 as
published by the Society of Automotive Engineers (SAE). The Certified Testing
Equipment must be able to connect to the vehicle’s data link connector (DLC) and
access, at a minimum, the following OBD data:
-Service modes $01, $03, $06, $07, $09, $0A
The Certified Testing Equipment must be capable of communicating with all
OBD vehicles that use, at a minimum, the following communications protocols:
-International Organization for Standardization (ISO) 9141
-Variable Pulse Width (VPW)
-Pulse Width Modulation (PWM)
-Keyword Protocol 2000 (KWP)
-Controller Area Network (CAN)
2.2 Barcode Scanner
The Certified Testing Equipment must include a bar code scanner capable of
reading both 1D and 2D barcodes. The bar code scanner must be able to read the
barcode through a windshield. The barcode scanner must be able to withstand
multiple 6.5 foot (2 meter) drops to concrete and be environmentally sealed to
withstand the normal operating conditions of an automotive service environment.
The bar code scanner may be a stand alone device or may be integrated into the
Certified Testing Equipment.
2.3 Camera
Certified Testing Equipment shall be equipped with video capturing equipment.
The video capturing equipment must capture video from each official emissions
inspection.
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APPENDIX F - WAIVERS FOR "NOT READY" VEHICLES
A vehicle owner may be eligible for a Waiver when their gasoline powered vehicle is “Not
Ready” and the following conditions are met:
1 The vehicle is not subject to a modified OBDII test because of OBD deficiencies;
2 The vehicle has an official test performed showing a “Not Ready” status. The MIL is
functioning properly and is not commanded on. No pending codes are stored in the
vehicle’s computer.
3 A second inspection has been performed showing the following:
3.1 Readiness monitors have not changed from “Not Ready” to “Ready”;
3.2 The test dates are separated by at least 7 days and the vehicle has traveled a
minimum of 200 miles;
3.3 The MIL is functioning properly and is not commanded on. No pending codes
are stored in the vehicle’s computer; and
3.4 A statement is included from a repair station, stating the appropriate diagnostics
and manufacturer recommended drive cycles have been performed and the
readiness monitors have not been set.
4 A third inspection has been performed by a second repair station showing the following:
4.1 Readiness monitors have not changed from “Not Ready” to “Ready”;
4.2 The initial and third test dates are separated by at least 14 days and the vehicle has
traveled a minimum of 400 miles;
4.3 The MIL is functioning properly and is not commanded on. No pending codes
are stored in the vehicle’s computer; and
4.4 A statement is included from a repair station, stating the appropriate diagnostics
and manufacturer recommended drive cycles have been performed and the
readiness monitors have not been set.
5 At least one of the statements must come from the vehicle manufacturer’s dealership
repair station. This statement must indicate that the appropriate drive cycles and
diagnostics have been performed and the vehicle will not reach a “Ready” status. The
dealership must also document that the vehicle’s computer is up to date and functioning
properly. The computer must be updated if required or recommended by the
manufacturer. If the computer is updated the vehicle must complete the appropriate drive
cycles following the update.
6 The cost requirements as set forth by this Regulation must be met in order to qualify for a
Waiver. In order to count labor the repair station must employ individuals with current
ASE L1, ASE A8, or other certifications approved by the Department.
Page 37 of 38
APPENDIX G - WAIVERS FOR PART UNAVAILABILITY
A vehicle owner may be eligible for a “Parts” Waiver when their vehicle is unable to pass an
emissions test with a valid error code and the following conditions are met:
1.The vehicle is not subject to a modified OBDII test because of OBD deficiencies;
2.The vehicle has an official test, performed within the prior 30 days, showing a failing status.
3.The MIL is functioning properly. Pending and/or permanent codes are stored in the vehicle’s
computer.
4.A written, signed statement is provided from an ASE certified, currently licensed I/M station stating the
part(s) are unavailable for a time exceeding six (6) months
5.A second, separate I/M Station meeting the above criteria issues a written and signed statement detailing the
part is unavailable for a time exceeding six (6) months.
6.At least one of the statements must come from the vehicle manufacturer’s dealership repair station.
This statement must indicate that the part is either backordered or out of production. The
dealership must also document that the vehicle’s computer is up to date and functioning properly.
The computer must be updated if required or recommended by the manufacturer.
Page 38 of 38
Clean Air Act 110(l) Demonstration
Air Quality Impact of Amendment to
Bear River Health Department Inspection and Maintenance Program

UTAH DIVISION OF AIR QUALITY 1

Introduction

Section 110(l) of the Clean Air Act (CAA) states that the Environmental Protection Agency
(EPA) cannot approve a state implementation plan (SIP) revision if the revision would interfere
with any applicable requirement concerning attainment and reasonable further progress, or any
other applicable requirement of the CAA. When revisions to these rules are made, the CAA
requires that an analysis is made to verify that the rule will not be relaxed in a way that would be
impermissible under Section 110(l).

Additionally, EPA has given draft guidance that “For example, for certain pollutants such as CO,
the Agency could determine that an increase in emissions is not interfering with attainment if
ambient levels in an attainment area were well below the National Ambient Air Quality Standard
(NAAQS) and not trending upward. Under these conditions, the Agency could conclude that
ambient levels are so low that a slight emissions increase is not likely to cause a violation of the
NAAQS, hence noninterference has been demonstrated (p.12).” 1 The proposed amendments
impact such a small number of vehicle emissions within Cache County that it is not likely to
cause a violation.

This demonstration is being submitted for public comment because the Utah Division of Air
Quality is proposing amendments to Bear River Health Department’s Inspection and
Maintenance Program (I/M) to align with ordinance changes already approved by Bear River
Health Department’s Board of Health.

Proposed Amendment Summary

1. This change creates the addition of a Part Unavailability Waiver which would be utilized if a
vehicle part was unable to be obtained due to the following described circumstances. The
Bear River Health Department I/M may issue a waiver if it can be verified that the part in
question or one similar to it is no longer available for sale or unobtainable due to
manufacturing circumstances.

Air Quality Impact Analysis: This change might result in an additional 4-10 vehicle waivers
per year. Due to the small number of vehicles impacted, this change will have no noticeable
impact on air quality, air quality modeling for the SIP or attainment of the PM2.5 NAAQS.

2. This change creates the addition of a Mobile Inspection Service option. The amendment
includes the deletion of the word “stationary” in the Bear River Health Department’s I/M
regulation. The new language in the I/M regulation states: "I/M Program Station: A vehicle

1 U.S. Environmental Protection Agency. (2005). Demonstrating noninterference under Section 110(l) of the Clean Air Act when revising a State
Implementation Plan (Draft).
Clean Air Act 110(l) Demonstration
Air Quality Impact of Amendment to
Bear River Health Department Inspection and Maintenance Program

UTAH DIVISION OF AIR QUALITY 2

Emissions I/M Station that qualifies and has a valid permit, issued by the Department, to
operate as an emissions inspection and maintenance station in the I/M Program."

Air Quality Impact Analysis: Modifying the I/M regulation to reflect this business innovation
has no impact on air quality. It improves the convenience of the inspection process for the
customer and may have a positive impact on air quality.

3. This change creates the addition of an exemption for emergency vehicles within the I/M
program. The new language in the I/M regulation within the Vehicle Exemption section
states: "Any current use “Authorized emergency vehicle” as defined by Section 41-6a-102
Utah Code Annotated,1953, as amended". Codifying this exemption within the Bear River
Health Department I/M further allows for the emergency departments to exempt emergency
vehicles from inspection. This change is to address issues surrounding the availability of
emergency response vehicles in Cache County where the vehicle is running into
performance issues. The change is necessary to prevent the decommissioning of critical
emergency response vehicles when a part may not be accessed in a timely fashion.

Air Quality Impact Analysis: This exemption would impact approximately 102 vehicles
within Cache County. To put this number into context the total number of registered vehicles
in Cache County as of 2024 is 124,718. Due to the small number of vehicles impacted, this
change will have no noticeable impact on air quality, air quality modeling for the SIP or
attainment of the 24-hour PM2.5 NAAQS.

Table 1. PM2.5 values compared to the 24-hour PM2.5 NAAQS between 2015-2023.
Cache County Air Quality Monitor Data
24 hour PM2.5 Values
Year
Annual average of
24-hour PM2.5
value for listed year
3 year DV centered
on listed year
2015 28.9 33.9
2016 34.0 32.9
2017 36.0 32.6
2018 27.9 33.0
2019 35.1 30.5
2020 28.6 32.4
2021 33.5 30.6
2022 29.9 33.8
2023 38.0 31.0

Clean Air Act 110(l) Demonstration
Air Quality Impact of Amendment to
Bear River Health Department Inspection and Maintenance Program

UTAH DIVISION OF AIR QUALITY 3

Conclusion: The proposed amendments to the Bear River Health Department I/M will not
impact the area's ability to maintain the PM2.5 NAAQS. Table 1 indicates that the design value in
Cache County has been consistently lower than the NAAQS over the last 8 years. The Cache
County monitor is not likely to be influenced by the minor amendment and is predicted to
continue to maintain the NAAQS. The ambient levels are so low that a slight emissions increase
is not likely to cause a violation of the NAAQS, hence noninterference has been demonstrated.

ITEM 6

195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
DAQ-092-24
M E M O R A N D U M TO: Air Quality Board THROUGH: Bryce C. Bird, Executive Secretary THROUGH: Erica Pryor, Rules Coordinator FROM: Alan Humpherys, Minor New Source Review Section Manager DATE: October 24, 2024 SUBJECT: PROPOSE FOR PUBLIC COMMENT: New Rule R307-209. Portable Aggregate
Processing Plants. ______________________________________________________________________________________
The Utah Division of Air Quality (DAQ) currently issues approval orders to portable aggregate processing plants. These plants include nonmetallic mineral processing plants, hot mix asphalt plants, and concrete batch plants. These portable aggregate processing plants can temporarily relocate to locations throughout
the state under section R307-401-17. These sources must comply with the issued approval orders and temporary relocation letters. New rule R307-209 seeks to codify the requirements in portable approval orders, and amendments to existing section R307-401-10 will allow these sources to temporarily relocate aggregate equipment without first obtaining an approval order. These rules will not add any new requirements to sources, but save sources the time and money from first obtaining a portable approval order. In addition, DAQ staff will be saved time from needing to issue portable approval orders to these sources. As a courtesy, stakeholders were provided with an opportunity to comment on proposed changes from August 14 to September 16, 2024. Industry groups and other known stakeholders were emailed a copy of
proposed rule language with an accompanying fact sheet. The advance notice period was also posted on the DAQ website. No comments were received, but staff did address a few questions.
Recommendation: Staff recommend the Board approve new rule R307-209, Portable Aggregate Processing Plants, for a 30-day public comment period.
State of Utah
Administrative Rule Analysis
Revised May 2024

NOTICE OF SUBSTANTIVE CHANGE
TYPE OF FILING: New
Rule or Section Number: R307-209 Filing ID: Office Use Only
Date of Previous Publication (Only for CPRs): Click or tap to enter a date.

Agency Information
1. Title catchline: Environmental Quality, Air Quality
Building: Multi-Agency State Office Building
Street address: 195 N 1950 W
City, state: Salt Lake City
Mailing address: PO BOX 144820
City, state and zip: Salt Lake City, UT 84114-4820
Contact persons:
Name: Phone: Email:
Alan Humpherys 801-536-4142 [e-mail]
Erica Pryor 385-499-3416 [e-mail]

Please address questions regarding information on this notice to the persons listed above.

General Information
2. Rule or section catchline:
R307-209. Portable Aggregate Processing Plants.

3. Purpose of the new rule or reason for the change:
Rule R307-209 will allow portable aggregate processing plants to submit a notice of temporary relocation without first
obtaining an approval order under Rule R307-401.

4. Summary of the new rule or change:
Rule R307-209 establishes standards and limitations for portable aggregate processing plants and exempts portable aggregate
processing plants from the requirement to obtain an approval order.

Fiscal Information
5. Provide an estimate and written explanation of the aggregate anticipated cost or savings to:
A) State budget:
Rule R307-209 will codify existing requirements contained in Air Quality Approval Orders; therefore, no new impacts are
anticipated. It is anticipated that Rule R307-209 will not impact the state budget.

B) Local governments:
Rule R307-209 will codify existing requirements contained in Air Quality Approval Orders; therefore, no new impacts are
anticipated. It is anticipated that Rule R307-209 will not impact local governments.

C) Small businesses ("small business" means a business employing 1-49 persons):
Rule R307-209 will codify existing requirements contained in Air Quality Approval Orders; therefore, no new impacts are
anticipated. It is anticipated that Rule R307-209 will not impact small businesses.

D) Non-small businesses ("non-small business" means a business employing 50 or more persons):
Rule R307-209 will codify existing requirements contained in Air Quality Approval Orders; therefore, no new impacts are
anticipated. It is anticipated that Rule R307-209 will not impact non-small businesses.

E) Persons other than small businesses, non-small businesses, state, or local government entities ("person" means any
individual, partnership, corporation, association, governmental entity, or public or private organization of any character other
than an agency):
Rule R307-209 will codify existing requirements contained in Air Quality Approval Orders; therefore, no new impacts are
anticipated. It is anticipated that Rule R307-209 will not impact other persons.

F) Compliance costs for affected persons (How much will it cost an impacted entity to adhere to this rule or its changes?):
Rule R307-209 will codify existing requirements contained in Air Quality Approval Orders; therefore, no new impacts are
anticipated. It is anticipated that Rule R307-209 will not impose any new compliance costs to affected persons.

G) Regulatory Impact Summary Table (This table only includes fiscal impacts that could be measured. If there are
inestimable fiscal impacts, they will not be included in this table. Inestimable impacts will be included in narratives above.)
Regulatory Impact Table
Fiscal Cost FY2025 FY2026 FY2027
State Government $0 $0 $0
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $0 $0 $0
Other Persons $0 $0 $0
Total Fiscal Cost $0 $0 $0
Fiscal Benefits FY2025 FY2026 FY2027
State Government $0 $0 $0
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $0 $0 $0
Other Persons $0 $0 $0
Total Fiscal Benefits $0 $0 $0
Net Fiscal Benefits $0 $0 $0
H) Department head comments on fiscal impact and approval of regulatory impact analysis:
The Executive Director of the Department of Environmental Quality, Kim D. Shelley, has reviewed and approved this
regulatory impact analysis.

Citation Information
6. Provide citations to the statutory authority for the rule. If there is also a federal requirement for the rule, provide a
citation to that requirement:
Utah Code 19-2-104 U.S.C. Title 42 Chapter 85 Subchapter I
Part A Section 7410 (a)(1)2(A)

Incorporations by Reference Information
7. Incorporations by Reference (if this rule incorporates more than two items by reference, please include additional tables):
A) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)

Publisher
Issue Date
Issue or Version

B) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)

Publisher
Issue Date
Issue or Version

Public Notice Information
8. The public may submit written or oral comments to the agency identified in box 1. (The public may also request a
hearing by submitting a written request to the agency. See Section 63G-3-302 and Rule R15-1 for more information.)
A) Comments will be accepted until: 12/31/2024
B) A public hearing (optional) will be held:
Date (mm/dd/yyyy): Time (hh:mm AM/PM): Place (physical address or URL):

To the agency: If more than one hearing will take place, continue to add rows.

9. This rule change MAY become effective on: 02/05/2025
NOTE: The date above is the date the agency anticipates making the rule or its changes effective. It is NOT the effective date.

Agency Authorization Information
To the agency: Information requested on this form is required by Sections 63G-3-301, 63G-3-302, 63G-3-303, and 63G-3-
402. Incomplete forms will be returned to the agency for completion, possibly delaying publication in the Utah State Bulletin
and delaying the first possible effective date.
Agency head or
designee and title:
Bryce C. Bird, Director, Division of Air
Quality
Date: 10/23/2024

R307. Environmental Quality, Air Quality. 1
R307-209. Portable Aggregate Processing Plants. 2
R307-209-1. Purpose. 3
Rule R307-209 establishes requirements for portable aggregate processing plants including 4
concrete batch plants, asphalt plants, and nonmetallic mineral processing plants. 5
6
R307-209-2. Definitions. 7
“Asphalt Plant” means any equipment used to produce, process, or store hot-mix, warm-mix, or 8
cold-mix asphalt and its ingredients. Equipment in this definition includes dryers, mixers, screens, 9
conveyors, storage bins or silos, storage tanks, and loading stations. 10
“Concrete Batch Plant” means any equipment used to produce, process, or store concrete and its 11
ingredients. Equipment in this definition includes mixers, screens, conveyors, storage bins or silos, and 12
loading stations. 13
“Nonmetallic Mineral Processing Plant” means any equipment used to produce, process, or store 14
nonmetallic minerals. Equipment in this definition includes crushers, grinding mills, screens, conveyors, 15
storage bins or silos, and loading stations. 16
“Portable Aggregate Processing Plant” means any nonmetallic mineral processing plant, asphalt 17
plant, or concrete batch plant that temporarily operates for a period of not more than 180 working days or 18
365 consecutive calendar days at a single source. Engines, boilers, and storage tanks used to support 19
concrete batch plants, asphalt plants, or nonmetallic mineral processing plants are included in this 20
definition. 21
22
R307-209-3. Applicability. 23
(1) Rule R307-209 applies to each portable aggregate processing plant including each concrete24
batch plant, asphalt plant, and nonmetallic mineral processing plant. 25
(2) Rule R307-209 does not apply to concrete batch plants, asphalt plants, or nonmetallic mineral26
processing plants that are subject to an approval order issued under Section R307-401-8. 27
(3) Rule R307-209 does not apply to a concrete batch plant, asphalt plant, or nonmetallic mineral28
processing plant that plans to or will operate at a single source longer than 180 operating days or remains 29
at a source longer than 365 calendar days. These sources shall submit a notice of intent and obtain an 30
approval order under Rule R307-401 before beginning actual construction unless the source qualifies for 31
an exemption under Section R307-401-9. 32
33
R307-209-4. Notice of Temporary Relocation. 34
(1) An owner or operator of a portable aggregate processing plant shall submit a Notice of35
Temporary Relocation to the director and obtain a Temporary Relocation Approval Letter before 36
operating a portable source at any location. 37
(2) A Notice of Temporary Relocation shall include the following:38
(a) the address and driving directions of the proposed location;39
(b) a list of the equipment to be operated at the proposed location, including the:40
(i) type of equipment;41
(ii) rated capacity of the equipment; and42
(iii) date of manufacture of the equipment;43
(c) a site diagram showing the general equipment location on site to scale; and44
(d) the distance to the nearest houses, barns, or commercial operations to scale if the plant45
boundary is located within one mile of these buildings; 46
(e) the expected startup and completion dates for operating at the proposed location;47
(f) the expected hours of operation, including start and stop times;48
(g) the emission control measures that the owner or operator proposes to adopt for each emission49
point at each location, including a fugitive dust control plan specific to the proposed location; and 50
(h) if relocating an asphalt plant, either:51
(i) the results and the date of the most recent stack test for the asphalt plant; or52
(ii) the anticipated stack test date and the stack test protocol for an asphalt plant that has not been53
stack tested. 54
55
R307-209-5. Operations at a Temporary Location. 56
Page 1 of 3
(1) An owner or operator of a portable aggregate processing plant may not exceed 180 working 1
days and may not exceed 365 calendar days at a single location. 2
(2) An owner or operator of a portable aggregate processing plant may not operate the portable 3
aggregate processing plant before 6:00 a.m. or after 10:00 p.m. each day at each temporary location. 4
(3) An owner or operator of a portable aggregate processing plant shall operate in accordance 5
with the terms and conditions of the Temporary Relocation Approval Letter issued by the director for 6
each location. 7
8
R307-209-6. Recordkeeping & Reporting Requirements. 9
(1) Following the end of operations at each temporary location, an owner or operator of a 10
portable aggregate processing plant shall submit the following records to the director at the end of 11
operation at each temporary location, and shall retain the records for at least two years: 12
(a) the initial relocation date at each location; 13
(b) number of working days at each location; 14
(c) consecutive days at each location; 15
(d) the production for each day of operation at each location; 16
(e) the total production at each location; 17
(f) the time operations started and ended each day at each location; and 18
(g) the last day of operation at each location. 19
(2) An owner or operator of a portable aggregate processing plant shall keep records and submit 20
emissions inventories according to Rule R307-150. 21
22
R307-209-7. Fugitive Dust Requirements. 23
Unless otherwise specified in Rule R307-209, an owner or operator of a portable aggregate 24
processing plant shall comply with the following for fugitive dust: 25
(1) the opacity limits and control measures in Section R307-309-5; and 26
(2) the fugitive dust control plan submitted with the Notice of Temporary Relocation for each 27
respective location. 28
29
R307-209-8. Concrete Batch Plant Requirements. 30
An owner or operator of a concrete batch plant shall comply with the following: 31
(1) ensure opacity does not exceed the limits in Section R307-312-4; and 32
(2) control particulate emissions from each storage silo and each mixer with a fabric filter, a 33
baghouse, a bin vent, or a dust collector. 34
35
R307-209-9. Nonmetallic Mineral Processing Plant Requirements. 36
An owner or operator of a nonmetallic mineral processing plant shall comply with the following: 37
(1) ensure opacity does not exceed the limits in Section R307-312-4; and 38
(2) use water sprays and water application to control particulate emissions from each crusher, 39
screen, and conveyor. 40
41
R307-209-10. Asphalt Plant Requirements. 42
(1) An owner or operator of an asphalt plant shall comply with the following: 43
(a) ensure opacity does not exceed 10% opacity and opacity observations shall be conducted in 44
accordance with 40 CFR 60, Method 9; 45
(b) use natural gas, propane, fuel oil, on-specification used oil as defined in Rule R315-15, or 46
any combination thereof as fuel; 47
(c) maintain records of fuel use; 48
(d) control particulate emissions from each storage silo with a fabric filter, a baghouse, a bin 49
vent, or a dust collector; 50
(e) control particulate emissions from each asphalt mixer with a baghouse; 51
(f) maintain the pressure drop of the asphalt plant baghouse between 3.0 and 7.0 inches of water 52
during operation and additionally the owner or operator shall comply with the following: 53
(i) install a pressure gauge on each baghouse; 54
(ii) ensure the pressure gauge measures the pressure drop in 1-inch water column increments or 55
less; 56
Page 2 of 3
(iii) calibrate the pressure gauge according to the manufacturer's instructions at least once every 1
12 months; and 2
(iv) record the reading of the pressure gauge at least once per operating day. 3
(2) The owner or operator shall: 4
(a) ensure filterable PM2.5 emissions do not exceed 0.024 grains per dry standard cubic foot; 5
(b) conduct an initial stack test on each asphalt plant within 180 days after startup; 6
(c) conduct a stack test on each asphalt plant within three years after the date of the most recent 7
stack test; 8
(d) conduct stack testing according to Rule R307-165; and 9
(e) determine PM2.5 emissions by 40 CFR 60, Appendix A, Method 5. 10
11
R307-209-11. Diesel-Fired Engine Requirements. 12
An owner or operator of a diesel-fired engine associated with a portable aggregate processing 13
plant shall comply with the following. 14
(1) Maintain opacity at or below 20% opacity. Opacity observations shall be conducted in 15
accordance with 40 CFR 60, Method 9. 16
(2) Use Ultra-Low Sulfur Diesel (ULSD) as defined in 40 CFR 1090.305 as fuel. 17
(3) Maintain records of ULSD use. 18
Page 3 of 3

ITEM 7

195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
DAQ-093-24
M E M O R A N D U M TO: Air Quality Board THROUGH: Bryce C. Bird, Executive Secretary THROUGH: Erica Pryor, Rules Coordinator FROM: Alan Humpherys, Minor New Source Review Section Manager DATE: October 24, 2024 SUBJECT: PROPOSE FOR PUBLIC COMMENT: Amend R307-401. Permit: New and Modified
Sources. ______________________________________________________________________________________
In response to the new rule R307-209, Portable Aggregate Processing Plants, an amendment to rule R307-401, Permit: New and Modified Sources, is necessary. A revision to section R307-401-10 will allow these sources to temporarily relocate aggregate equipment without first obtaining an approval order. The
amendment to rule R307-401 will not add any new requirements to sources but save sources the time and money from first obtaining a portable approval order. In addition, division staff will be saved time from needing to issue portable approval orders to these sources. Recommendation: Staff recommend the Board approve amendment to rule R307-401, Permit: New and Modified Sources, for a 30-day public comment period.
State of Utah
Administrative Rule Analysis
Revised May 2024

NOTICE OF SUBSTANTIVE CHANGE
TYPE OF FILING: Amendment
Rule or Section Number: R307-401 Filing ID: Office Use Only
Date of Previous Publication (Only for CPRs): Click or tap to enter a date.

Agency Information
1. Title catchline: Environmental Quality, Air Quality
Building: Multi-Agency State Office Building
Street address: 195 N 1950 W
City, state: Salt Lake City
Mailing address: PO BOX 144820
City, state and zip: Salt Lake City, UT 84114-4820
Contact persons:
Name: Phone: Email:
Alan Humpherys 801-536-4142 [e-mail]
Erica Pryor 385-499-3416 [e-mail]

Please address questions regarding information on this notice to the persons listed above.

General Information
2. Rule or section catchline:
R307-401. Permit: New and Modified Sources.

3. Purpose of the new rule or reason for the change:
The Division of Air Quality (DAQ) will be proposing a new rule R307-209, Portable Aggregate Processing Plants, which will
impact Rule R307-401 Permit: New and Modified Sources by necessitating an additional exemption under Subsection R307-
401-10(8).

4. Summary of the new rule or change:
This filing adds an additional source listed as a new Subsection, R307-401-10(8) portable aggregate processing plant, to the list of
exemptions under Section R307-401-10 Source Category Exemptions. This change is because of the introduction of new Rule
R307-209, Portable Aggregate Processing Plants.

Fiscal Information
5. Provide an estimate and written explanation of the aggregate anticipated cost or savings to:
A) State budget:
On average, DAQ issues around four portable Approval Orders a year. The average cost of a portable approval order is
$3,075. It is anticipated that the DAQ will not receive around $12,300 a year in permitting fees by implementing this rule.

B) Local governments:
DAQ is not aware of any local governments that have a portable Approval Order, so it is anticipated that this rule change will
not have an impact on local governments.

C) Small businesses ("small business" means a business employing 1-49 persons):
The proposed changes to Rule R307-401 are anticipated to provide a total fiscal savings of $12,300 per year to all impacted
companies, with no negative fiscal impacts anticipated. At this time DAQ is unable to estimate how many of the total
companies impacted by this rulemaking are small businesses, however the anticipated savings would apply to all small
businesses impacted.

D) Non-small businesses ("non-small business" means a business employing 50 or more persons):
The proposed amendments to Rule R307-401 are anticipated to provide a total fiscal savings of $12,300 per year to all
impacted companies, with no negative fiscal impacts anticipated. At this time DAQ is unable to estimate how many of the
total companies impacted by this rulemaking are non-small businesses, however the anticipated savings would apply to all
non-small businesses impacted.

E) Persons other than small businesses, non-small businesses, state, or local government entities ("person" means any
individual, partnership, corporation, association, governmental entity, or public or private organization of any character other
than an agency):
It is anticipated that amendments to Rule R307-401 would not impact other persons.

F) Compliance costs for affected persons (How much will it cost an impacted entity to adhere to this rule or its changes?):
Rule R307-401 will exempt sources from the requirement to obtain Air Quality Approval Orders; therefore, it is anticipated
that these amendments will not impose any new compliance costs to affected persons.

G) Regulatory Impact Summary Table (This table only includes fiscal impacts that could be measured. If there are
inestimable fiscal impacts, they will not be included in this table. Inestimable impacts will be included in narratives above.)
Regulatory Impact Table
Fiscal Cost FY2025 FY2026 FY2027
State Government $6,150 $12,300 $12,300
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $0 $0 $0
Other Persons $0 $0 $0
Total Fiscal Cost $0 $12,300 $12,300
Fiscal Benefits FY2025 FY2026 FY2027
State Government $0 $0 $0
Local Governments $0 $0 $0
Small Businesses $0 $0 $0
Non-Small Businesses $6,150 $12,300 $12,300
Other Persons $0 $0 $0
Total Fiscal Benefits $6,150 $12,300 $12,300
Net Fiscal Benefits $0 $0 $0
H) Department head comments on fiscal impact and approval of regulatory impact analysis:
The Executive Director of the Department of Environmental Quality, Kim D. Shelley, has reviewed and approved this
regulatory impact analysis.

Citation Information
6. Provide citations to the statutory authority for the rule. If there is also a federal requirement for the rule, provide a
citation to that requirement:
Utah Code 19-2-104 U.S.C. Title 42 Chapter 85 Subchapter I
Part A Section 7410 (a)(1)2(A)

Incorporations by Reference Information
7. Incorporations by Reference (if this rule incorporates more than two items by reference, please include additional tables):
A) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)

Publisher
Issue Date
Issue or Version

B) This rule adds or updates the following title of materials incorporated by references (a copy of materials incorporated
by reference must be submitted to the Office of Administrative Rules; if none, leave blank):
Official Title of Materials Incorporated
(from title page)

Publisher
Issue Date
Issue or Version

Public Notice Information
8. The public may submit written or oral comments to the agency identified in box 1. (The public may also request a
hearing by submitting a written request to the agency. See Section 63G-3-302 and Rule R15-1 for more information.)
A) Comments will be accepted until: 12/31/2024
B) A public hearing (optional) will be held:
Date (mm/dd/yyyy): Time (hh:mm AM/PM): Place (physical address or URL):

To the agency: If more than one hearing will take place, continue to add rows.

9. This rule change MAY become effective on: 02/05/2025
NOTE: The date above is the date the agency anticipates making the rule or its changes effective. It is NOT the effective date.

Agency Authorization Information
To the agency: Information requested on this form is required by Sections 63G-3-301, 63G-3-302, 63G-3-303, and 63G-3-
402. Incomplete forms will be returned to the agency for completion, possibly delaying publication in the Utah State Bulletin
and delaying the first possible effective date.
Agency head or
designee and title:
Bryce C. Bird, Director, Division of Air
Quality
Date: 10/23/2024

R307. Environmental Quality, Air Quality. 1
R307-401. Permit: New and Modified Sources. 2
R307-401-1. Purpose. 3
This rule establishes the application and permitting requirements for new installations and 4
modifications to existing installations throughout the State of Utah. Additional permitting requirements apply 5
to larger installations or installations located in nonattainment or maintenance areas. These additional 6
requirements can be found in Rules R307-403, R307-405, R307-406, R307-420, and R307-421. Modeling 7
requirements in Rule R307-410 may also apply. Each of the permitting rules establishes independent 8
requirements, and the owner or operator must comply with all of the requirements that apply to the 9
installation. Exemptions under R307-401 do not affect applicability of the other permitting rules. 10
11
R307-401-2. Definitions. 12
"Actual emissions" (a) means the actual rate of emissions of an air pollutant from an emissions unit, 13
as determined in accordance with Subsections R307-401-2(b) through R307-401-2(d). 14
(b) In general, actual emissions as of a particular date shall equal the average rate, in tons per year, at15
which the unit actually emitted the air pollutant during a consecutive 24-month period which precedes the 16
particular date and which is representative of normal source operation. The director shall allow the use of a 17
different time period upon a determination that it is more representative of normal source operation. Actual 18
emissions shall be calculated using the unit's actual operating hours, production rates, and types of materials 19
processed, stored, or combusted during the selected time period. 20
(c)The director may presume that source-specific allowable emissions for the unit are equivalent to21
the actual emissions of the unit. 22
(d) For any emissions unit that has not begun normal operations on the particular date, actual23
emissions shall equal the potential to emit of the unit on that date. 24
"Best available control technology" means an emissions limitation (including a visible emissions 25
standard) based on the maximum degree of reduction for each air pollutant which would be emitted from any 26
proposed stationary source or modification which the director, on a case-by-case basis, taking into account 27
energy, environmental, and economic impacts and other costs, determines is achievable for such source or 28
modification through application of production processes or available methods, systems, and techniques, 29
including fuel cleaning or treatment or innovative fuel combustion techniques for control of such pollutant. 30
In no event shall application of best available control technology result in emissions of any pollutant which 31
would exceed the emissions allowed by any applicable standard under 40 CFR parts 60 and 61. If the 32
director determines that technological or economic limitations on the application of measurement 33
methodology to a particular emissions unit would make the imposition of an emissions standard infeasible, a 34
design, equipment, work practice, operational standard or combination thereof, may be prescribed instead to 35
satisfy the requirement for the application of best available control technology. Such standard shall, to the 36
degree possible, set forth the emissions reduction achievable by implementation of such design, equipment, 37
work practice or operation, and shall provide for compliance by means which achieve equivalent results. 38
Air Strippers" are systems designed to pump groundwater to the surface for treatment, usually by 39
aeration. 40
"Building, structure, facility, or installation" means all of the pollutant-emitting activities which 41
belong to the same industrial grouping, are located on one or more contiguous or adjacent properties, and are 42
under the control of the same person (or persons under common control) except the activities of any vessel. 43
Pollutant-emitting activities shall be considered as part of the same industrial grouping if they belong to the 44
same Major Group (i.e., which have the same two-digit code) as described in the Standard Industrial 45
Classification Manual, 1972, as amended by the 1977 Supplement (U.S. Government Printing Office stock 46
numbers 4101-0066 and 003-005-00176-0, respectively). 47
"Construction" means any physical change or change in the method of operation (including 48
fabrication, erection, installation, demolition, or modification of an emissions unit) that would result in a 49
change in emissions. 50
"Emissions unit" means any part of a stationary source that emits or would have the potential to emit 51
any air pollutant. 52
"Fugitive emissions" means those emissions which could not reasonably pass through a stack, 53
chimney, vent, or other functionally equivalent opening. 54
"Indirect source" means a building, structure, facility, or installation which attracts or may attract 55
mobile source activity that results in emissions of a pollutant for which there is a national standard. 56
Page 1 of 10
"Potential to emit" means the maximum capacity of a stationary source to emit an air pollutant under 1
its physical and operational design. Any physical or operational limitation on the capacity of the source to 2
emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the 3
type or amount of material combusted, stored, or processed, shall be treated as part of its design if the 4
limitation or the effect it would have on emissions is enforceable. Secondary emissions do not count in 5
determining the potential to emit of a stationary source. 6
"Secondary emissions" means emissions which occur as a result of the construction or operation of a 7
major stationary source or major modification, but do not come from the major stationary source or major 8
modification itself. Secondary emissions include emissions from any offsite support facility which would not 9
be constructed or increase its emissions except as a result of the construction or operation of the major 10
stationary source or major modification. Secondary emissions do not include any emissions which come 11
directly from a mobile source, such as emissions from the tailpipe of a motor vehicle, from a train, or from a 12
vessel. 13
"Soil Aeration" is an ex-situ treatment process where excavated soil from a remediation project is 14
spread in a thin layer to encourage biodegradation of soil contamination. Biodegradation may be stimulated 15
through aeration or the addition of minerals, nutrients, and/or moisture. 16
"Soil Vapor Extraction", or SVE, is a system designed to extract vapor phase contaminants from the 17
subsurface. SVE systems are often combined with other technologies, such as air sparging or vacuum-18
enhanced recovery systems. 19
"Stationary source" means any building, structure, facility, or installation which emits or may emit an 20
air pollutant. 21
"Vapor Mitigation System", or VMS, is a sub-slab system whose primary purpose is mitigating 22
vapor intrusion into an occupied, or occupiable, structure and is not intended or designed for the remediation 23
of contaminated soil or groundwater. This definition includes both active and passive systems. Passive 24
systems consist of a vapor barrier either below or above the slab of a structure and a venting system 25
installed under a structure to divert vapor from beneath the structure to the sides or roofline of a structure. 26
Active systems are similar to passive systems but incorporate a blower or fan to actively extract air from 27
beneath the structure. 28
29
R307-401-3. Applicability. 30
(1)Rule R307-401 applies to any person planning to:31
(a) construct a new installation that will or might reasonably be expected to bea source or an indirect32
source of air pollution; 33
(b) make modifications to or relocate an existing installation that will or might reasonably be34
expected to increase the amount of or change the character or effect of air pollutants discharged, so that the 35
installation may be expected to be a source or indirect source of air pollution; or 36
(c)install an air cleaning device or other equipment intended to control emission of air pollutants.37
(2) Rules R307-403, R307-405 and R307-406 may establish additional permitting requirements for38
new or modified sources. 39
(a) Exemptions contained in Rule R307-401 do not affect applicability or other requirements under40
Rules R307-403, R307-405 or R307-406. 41
(b) Exemptions contained in Rules R307-403, R307-405 or R307-406 do not affect applicability or42
other requirements under Rule R307-401, unless specifically authorized in this rule. 43
44
R307-401-4. General Requirements. 45
The general requirements in Subsections R307-401-4(1) through R307-401-4(4) apply to all new and 46
modified installations, including installations that are exempt from the requirement to obtain an approval 47
order. 48
(1) Any control apparatus installed on an installation shall be adequately and properly maintained.49
(2) If the director determines that an exempted installation is not meeting an approval order or State50
Implementation Plan limitation, is creating an adverse impact to the environment, or would be injurious to 51
human health or welfare, the director may require the owner or operator to submit a notice of intent and 52
obtain an approval order in accordance with Sections R307-401-5 through R307-401-8. The director will 53
complete an appropriate analysis and evaluation in consultation with the owner or operator before 54
determining that an approval order is required. 55
(3) Low Oxides of Nitrogen Burner Technology.56
Page 2 of 10
(a) Except as provided in Subsection R307-401-4(3)(b), whenever existing fuel combustion burners 1
are replaced, the owner or operator shall install low oxides of nitrogen burners or equivalent oxides of 2
nitrogen controls, as determined by the director, unless such equipment is not physically practical or cost 3
effective. The owner or operator shall submit a demonstration that the equipment is not physically practical or 4
cost effective to the director for review and approval prior to beginning construction. 5
(b) The provisions of (a) above do not apply to non-commercial, residential buildings. 6
(4) A person shall not operate a source of air pollution that is required to have a permit under Rule 7
R307-401 unless the person has obtained a permit for the source under the procedures of Rule R307-401. 8
9
R307-401-5. Notice of Intent. 10
(1) Except as provided in Sections R307-401-9 through R307-401-17, any person subject to Rule 11
R307-401 shall submit a notice of intent to the director and receive an approval order precedent to the 12
construction, modification, installation, establishment, or relocation of an air pollutant source or indirect 13
source. The notice of intent shall be in a format specified by the director. 14
(2) The notice of intent shall include the following information: 15
(a) A description of the nature of the processes involved; the nature, procedures for handling and 16
quantities of raw materials; the type and quantity of fuels employed; and the nature and quantity of finished 17
product. 18
(b) The expected composition and physical characteristics of effluent stream both before and after 19
treatment by any control apparatus, including emission rates, volume, temperature, air pollutant types, and 20
concentration of air pollutants. 21
(c) The size, type, and performance characteristics of any control apparatus. 22
(d) An analysis of best available control technology for the proposed source or modification. When 23
determining best available control technology for a new or modified source in an ozone nonattainment or 24
maintenance area that will emit volatile organic compounds or nitrogen oxides, the owner or operator of the 25
source shall consider EPA Control Technique Guidance (CTG) documents and Alternative Control 26
Technique documents that are applicable to the source. Best available control technology shall be at least as 27
stringent as any published CTG that is applicable to the source. 28
(e) The location and elevation of the emission point and other factors relating to dispersion and 29
diffusion of the air pollutant in relation to nearby structures and window openings, and other information 30
necessary to appraise the possible effects of the effluent. 31
(f) The location of planned sampling points and the tests of the completed installation to be made by 32
the owner or operator when necessary to ascertain compliance. 33
(g) The typical operating schedule. 34
(h) A schedule for construction. 35
(i) Any plans, specifications and related information that are in final form at the time of submission 36
of notice of intent. 37
(j) Any additional information required by: 38
(i) Rule R307-403, Permits: New and Modified Sources in Nonattainment Areas and Maintenance 39
Areas; 40
(ii) Rule R307-405, Permits: Major Sources in Attainment or Unclassified Areas (PSD); 41
(iii) Rule R307-406, Visibility; 42
(iv) Rule R307-410, Permits: Emissions Impact Analysis; 43
(v) Rule R307-420, Permits: Ozone Offset Requirements in Davis and Salt Lake Counties; or 44
(vi) Rule R307-421, Permits: PM10 Offset Requirements in Salt Lake County and Utah County. 45
(k) Any other information necessary to determine if the proposed construction, modification, 46
installation, or establishment will be in accord with Title R307. 47
(l) The payment of a new source review fee established under Subsection 19-1-201(6)(i). 48
(3) Notwithstanding the exemptions in Sections R307-401-9 through R307-401-16, any person that 49
is subject to Rules R307-403, R307-405, or R307-406 shall submit a notice of intent to the director and 50
receive an approval order precedent to the construction, modification, installation, establishment, or 51
relocation of an air pollutant source or indirect source. 52
53
R307-401-6. Review Period. 54
(1) Completeness Determination. Within 30 days after receipt of a notice of intent, or any additional 55
information necessary to the review, the director will advise the applicant of any deficiency in the notice of 56
Page 3 of 10
intent or the information submitted. 1
(2) Within 90 days after the receipt of a complete application including all the information described 2
in Section R307-401-5, the director will 3
(a) issue an approval order for the proposed construction, installation, modification, relocation, or 4
establishment pursuant to the requirements of Section R307-401-8, or 5
(b) issue an order prohibiting the proposed construction, installation, modification, relocation or 6
establishment if it is determined that any part of the proposal will not be in the accord with the requirements 7
of Title R307. 8
(3) The review period under Subsection R307-401-6(2) may be extended by up to three 30-day 9
extensions if more time is needed to review the proposal. 10
11
R307-401-7. Public Notice. 12
(1) Issuing the Notice. Prior to issuing an approval or disapproval order of the proposed 13
construction, installation, modification, relocation or establishment, the director shall: 14
(a) publish a legal notice of the intent to approve or disapprove on the public legal notice website 15
under Subsection 45-1-101(2); 16
(b) notify the public of the intent to approve or disapprove on the Division's website; and 17
(c) post the draft permit and administrative record for the draft permit, or information on how to 18
access the administrative record for the draft permit, on the Division's website for the duration of the 19
public comment period. 20
(2) Opportunity for Review and Comment. 21
(a) At least one location will be provided where the information submitted by the owner or 22
operator, the director's analysis of the notice of intent proposal, and the proposed approval order 23
conditions will be available for public inspection. 24
(b) Public Comment. 25
(i) A 30-day public comment period will be established. 26
(ii) A request to extend the length of the comment period, up to 30 days, may be submitted to the 27
director within 15 days of the date the legal notice in Subsection R307-401-7(1)(a) is published. 28
(iii) Public Hearing. A request for a hearing on the proposed approval or disapproval order may 29
be submitted to the director within 15 days of the date the legal notice in Subsection R307-401-7(1)(a) is 30
published. 31
(iv) The hearing will be held in the area of the proposed construction, installation, modification, 32
relocation or establishment. 33
(v) The public comment and hearing procedure shall not be required when an order is issued to 34
extend the time required by the director to review plans and specifications. 35
(3) The director will consider comments received during the public comment period and at the 36
public hearing and, if appropriate, will make changes to the proposal in response to comments before 37
issuing an approval order or disapproval order. 38
39
R307-401-8. Approval Order. 40
(1) The director will issue an approval order if the following conditions have been met: 41
(a) The degree of pollution control for emissions, to include fugitive emissions and fugitive dust, is 42
at least best available control technology. When determining best available control technology for a new or 43
modified source in an ozone nonattainment or maintenance area that will emit volatile organic compounds or 44
nitrogen oxides, best available control technology shall be at least as stringent as any Control Technique 45
Guidance document that has been published by EPA that is applicable to the source. 46
(b) The proposed installation will meet the applicable requirements of: 47
(i) Rule R307-403, Permits: New and Modified Sources in Nonattainment Areas and Maintenance 48
Areas; 49
(ii) Rule R307-405, Permits: Major Sources in Attainment or Unclassified Areas (PSD); 50
(iii) Rule R307-406, Visibility; 51
(iv) Rule R307-410, Permits: Emissions Impact Analysis; 52
(v) Rule R307-420, Permits: Ozone Offset Requirements in Davis and Salt Lake Counties; 53
(vi) Rule R307-210, Standards of Performance for New Stationary Sources; 54
(vii) National Primary and Secondary Ambient Air Quality Standards; 55
(viii) Rule R307-214, National Emission Standards for Hazardous Air Pollutants; 56
Page 4 of 10
(ix) Rule R307-110, General Requirements: State Implementation Plan; and 1
(x) all other provisions of Title R307. 2
(2) The approval order will require that all pollution control equipment be adequately and properly 3
maintained. 4
(3) Receipt of an approval order does not relieve any owner or operator of the responsibility to 5
comply with the provisions of Title R307 or the State Implementation Plan. 6
(4) To accommodate staged construction of a large source, the director may issue an order 7
authorizing construction of an initial stage prior to receipt of detailed plans for the entire proposal provided 8
that, through a review of general plans, engineering reports and other information the proposal is determined 9
feasible by the director under the intent of Title R307. Subsequent detailed plans will then be processed as 10
prescribed in this paragraph. For staged construction projects the previous determination under Subsections 11
R307-401-8(1) and (2) will be reviewed and modified as appropriate at the earliest reasonable time prior to 12
commencement of construction of each independent phase of the proposed source or modification. 13
(5) If the director determines that a proposed stationary source, modification or relocation does not 14
meet the conditions established in (1) above, the director will not issue an approval order. 15
16
R307-401-9. Small Source Exemption. 17
(1) A small stationary source is exempt from the requirement to obtain an approval order in Sections 18
R307-401-5 through R307-401-8 if the following conditions are met. 19
(a) its actual emissions are less than 5 tons per year per air pollutant of any of the following air 20
pollutants: sulfur dioxide, carbon monoxide, nitrogen oxides, PM10, ozone, or volatile organic compounds; 21
(b) its actual emissions are less than 500 pounds per year of any hazardous air pollutant and less than 22
2000 pounds per year of any combination of hazardous air pollutants; 23
(c) its actual emissions are less than 500 pounds per year of any air pollutant not listed in (a) or (b) 24
above and less than 2000 pounds per year of any combination of air pollutants not listed in (a) or (b) above. 25
(d) Air pollutants that are drawn from the environment through equipment in intake air and then are 26
released back to the environment without chemical change, as well as carbon dioxide, nitrogen, oxygen, 27
argon, neon, helium, krypton, xenon should not be included in emission calculations when determining 28
applicability under (a) through (c) above. 29
(2) The owner or operator of a source that is exempted from the requirement to obtain an approval 30
order under (1) above shall no longer be exempt if actual emissions in any subsequent year exceed the 31
emission thresholds in (1) above. The owner or operator shall submit a notice of intent under Section R307-32
401-5 no later than 180 days after the end of the calendar year in which the source exceeded the emission 33
threshold. 34
(3) Small Source Exemption - Registration. The director will maintain a registry of sources that are 35
claiming an exemption under Section R307-401-9. The owner or operator of a stationary source that is 36
claiming an exemption under Section R307-401-9 may submit a written registration notice to the director. 37
The notice shall include the following minimum information: 38
(a) identifying information, including company name and address, location of source, telephone 39
number, and name of plant site manager or point of contact; 40
(b) a description of the nature of the processes involved, equipment, anticipated quantities of 41
materials used, the type and quantity of fuel employed and nature and quantity of the finished product; 42
(c) identification of expected emissions; 43
(d) estimated annual emission rates; 44
(e) any control apparatus used; and 45
(f) typical operating schedule. 46
(4) An exemption under Section R307-401-9 does not affect the requirements of Section R307-401-47
17, Temporary Relocation. 48
(5) A stationary source that is not required to obtain a permit under Rule R307-405 for greenhouse 49
gases, as defined in Subsection R307-405-3(9)(a), is not required to obtain an approval order for greenhouse 50
gases under Rule R307-401. This exemption does not affect the requirement to obtain an approval order for 51
any other air pollutant emitted by the stationary source. 52
53
R307-401-10. Source Category Exemptions. 54
The source categories described in Section R307-401-10 are exempt from the requirement to obtain 55
an approval order found in Sections R307-401-5 through R307-401-8. The general provisions in Section 56
Page 5 of 10
R307-401-4 shall apply to these sources. 1
(1) Fuel-burning equipment in which combustion takes place at no greater pressure than one inch of 2
mercury above ambient pressure with a rated capacity of less than five million BTU per hour using no other 3
fuel than natural gas or LPG or other mixed gas that meets the standards of gas distributed by a utility in 4
accordance with the rules of the Public Service Commission of the State of Utah, unless there are emissions 5
other than combustion products. 6
(2) Comfort heating equipment such as boilers, water heaters, air heaters and steam generators with 7
a rated capacity of less than one million BTU per hour if fueled only by fuel oil numbers 1 - 6, 8
(3) Emergency heating equipment, using coal or wood for fuel, with a rated capacity less than 9
50,000 BTU per hour. 10
(4) Exhaust systems for controlling steam and heat that do not contain combustion products. 11
(5) A well site as defined in 40 CFR 60.5430a, including centralized tank batteries, that is not a 12
major source as defined in Section R307-101-2, and is registered with the Division as required by Rule R307-13
505. 14
(6) A gasoline dispensing facility as defined in 40 CFR 63.11132 that is not a major source as 15
defined in Section R307-101-2. These sources shall comply with the applicable requirements of Rule R307-16
328 and 40 CFR 63 Subpart CCCCCC: National Emission Standards for Hazardous Air Pollutants for 17
Source Category: Gasoline Dispensing Facilities. 18
(7) A Vapor Mitigation System as defined in R307-401-2. 19
(8) A Portable Aggregate Processing Plant as defined in Subsection R307-209-2. 20
21
22
R307-401-11. Replacement-in-Kind Equipment. 23
(1) Applicability. Existing process equipment or pollution control equipment that is covered by an 24
existing approval order or State Implementation Plan requirement may be replaced using the procedures in 25
(2) below if: 26
(a) the potential to emit of the process equipment is the same or lower; 27
(b) the number of emission points or emitting units is the same or lower; 28
(c) no additional types of air pollutants are emitted as a result of the replacement; 29
(d) the process equipment or pollution control equipment is identical to or functionally equivalent to 30
the replaced equipment; 31
(e) the replacement does not change the basic design parameters of the process unit or pollution 32
control equipment; 33
(f) the replaced process equipment or pollution control equipment is permanently removed from the 34
stationary source, otherwise permanently disabled, or permanently barred from operation; 35
(g) the replacement process equipment or pollution control equipment does not trigger New Source 36
Performance Standards or National Emissions Standards for Hazardous Air Pollutants under 42 U.S.C. 7411 37
or 7412; and 38
(h) the replacement of the control apparatus or process equipment does not violate any other 39
provision of Title R307. 40
(2) Replacement-in-Kind Procedures. 41
(a) In lieu of filing a notice of intent under Section R307-401-5, the owner or operator of a stationary 42
source shall submit a written notification to the director before replacing the equipment. The notification shall 43
contain a description of the replacement-in-kind equipment, including the control capability of any control 44
apparatus and a demonstration that the conditions of (1) above are met. 45
(b) If the replacement-in-kind meets the conditions of (1) above, the director will update the source's 46
approval order and notify the owner or operator. Public review under Section R307-401-7 is not required for 47
the update to the approval order. 48
(3) If the replaced process equipment or pollution control equipment is brought back into operation, 49
it shall constitute a new emissions unit. 50
51
R307-401-12. Reduction in Air Pollutants. 52
(1) Applicability. The owner or operator of a stationary source of air pollutants that reduces or 53
eliminates air pollutants is exempt from the requirement to submit a notice of intent and obtain an approval 54
order prior to construction if: 55
(a) the project does not increase the potential to emit of any air pollutant or cause emissions of any 56
Page 6 of 10
new air pollutant, and 1
(b) the director is notified of the change and the reduction of air pollutants is made enforceable 2
through an approval order in accordance with (2) below. 3
(2) Notification. The owner or operator shall submit a written description of the project to the 4
director no later than 60 days after the changes are made. The director will update the source's approval order 5
or issue a new approval order to include the project and to make the emission reductions enforceable. Public 6
review under Section R307-401-7 is not required for the update to the approval order. 7
8
R307-401-13. Plantwide Applicability Limits. 9
A plantwide applicability limit under Section R307-405-21 does not exempt a stationary source from 10
the requirements of R307-401. 11
12
R307-401-14. Used Oil Fuel Burned for Energy Recovery. 13
(1) Definitions. 14
"Used Oil" is defined as any oil that has been refined from crude oil, used, and, as a result of such 15
use contaminated by physical or chemical impurities. 16
(2) An emission unit that burns used oil, as defined in Section R315-15-1, for energy recovery is 17
exempt from the requirement to obtain an approval order in Sections R307-401-5 through R307-401-8 if 18
the owner or operator complies with Section R315-15-6 and the heat input design of the emission unit is 19
not more than 0.5 MMBtu/hr. 20
21
R307-401-15. Air Strippers and Soil Vapor Extraction Systems. 22
R307-401-15 applies to remediation systems with the potential to generate air emissions, such as air 23
strippers and soil vapor extraction (SVE) as defined in R307-401-2. 24
(1) The owner or operator of an air stripper or SVE remediation system is exempt from the notice of 25
intent and approval order requirements of Sections R307-401-5 through R307-401-8 if the following 26
conditions are met: 27
(a) actual emissions of volatile organic compounds from a given project are less than 5 tons per year; 28
and 29
(b) emission rates of hazardous air pollutants are below their respective threshold values contained 30
in R307-410-5(1)(c)(i)(C). 31
(2) The owner or operator shall submit documentation to the director that demonstrates the project 32
meets the exemption criteria in R307-401-15(1). Required documentation includes, but is not limited to: 33
(a) project summary, including location, system description, operational schedule, and schedule for 34
construction; 35
(b) emission calculations and any laboratory sampling data used in calculations; and 36
(c) plans and specifications for the system and equipment. 37
(3) After beginning the soil remediation project, the owner or operator shall conduct testing to 38
demonstrate compliance with the exemption levels in R307-401-15(1)(1) and (b). Monitoring and reporting 39
shall be conducted as follows: 40
(a) Emissions for air strippers shall be based on the following: 41
(i) influent and effluent water samples analyzed for volatile organic compounds and hazardous air 42
pollutants using the most recent version of USEPA Test Method 8260, Method 8021, or other EPA approved 43
testing methods acceptable to the director; and 44
(ii) design water flow rate of the system or the water flow rates measured during the sample period. 45
(b) Emissions for SVE systems shall be based on the following: 46
(i) Air samples collected from a sample port in the exhaust stack of the SVE system and analyzed 47
for volatile organic compounds and hazardous air pollutants using USEPA test method TO-15, or other EPA 48
approved testing methods acceptable to the director. 49
(ii) Design air flow rate of the system or the air flow rates measured at the outlet of the SVE system 50
during the sample period. Flow rates should be measured and reported at actual conditions. 51
(c) Within one month of sampling, the owner or operator shall submit to the director the sample 52
results, estimated emissions of volatile organic compounds, and estimated emission rates of hazardous air 53
pollutants. 54
(d) Samples shall be collected at the following frequencies or more frequently as determined 55
necessary by the director: 56
Page 7 of 10
(i) no less than twenty-eight days and no more than thirty-one days (i.e., monthly) after startup for 1
the first quarter; 2
(ii) quarterly for the remainder of the first year; and 3
(iii) semi-annually thereafter for the life of the project or as allowed in R307-401-15(3)(f). 4
(e) If an SVE or air stripper system is restarted after rehabilitation or an extended period of 5
shutdown, the owner or operator shall recommence the sampling schedule in R307-415(3)(d), unless 6
otherwise approved by the director. 7
(f) The owner or operator may request to discontinue sampling after three years of operation. To 8
discontinue sampling, the owner or operator must submit to the director a request to discontinue monitoring. 9
(i) The request must include documentation demonstrating emissions have remained below the 10
exemption levels in R307-401-15(1)(a) and (b) since startup of the system. 11
(ii) The request is subject to approval from the director upon consultation with other regulatory 12
agencies involved in the project, such as Division of Environmental Response and Remediation or Division 13
of Waste Management and Radiation Control. 14
(4) The following control devices do not require a notice of intent or approval order when used in 15
relation to an air stripper or soil vapor extraction system that is exempted under Section R307-401-15: 16
(a) thermodestruction unit with a rated input capacity of less than five million BTU per hour using 17
no other auxiliary fuel than natural gas or LPG, or 18
(b) carbon adsorption unit. 19
20
R307-401-16. Soil Aeration Projects. 21
R307-401-16 applies to soil aeration projects used to conduct soil remediation. 22
(1) The owner or operator of a soil aeration project is not subject to the notice of intent and approval 23
order requirements of Sections R307-401-5 through R307-401-8, if the following conditions are met: 24
(a) emissions of volatile organic compounds from a given soil aeration project are less than 5 tons 25
per year; and 26
(b) emission rates of hazardous air pollutants are below their respective threshold values contained 27
in R307-410-(1)(c)(i)(C). 28
(2) The owner or operator shall submit documentation to the director demonstrating the project 29
meets the exemption criteria in R307-401-16(1). The owner or operator shall receive approval from the 30
director for the exemption prior to beginning the remediation project. Required documentation includes, but 31
is not limited to: 32
(a) calculated emissions of volatile organic compounds and estimated emission rates of hazardous 33
air pollutants from all soils to be treated from the soil aeration project. 34
(b) Emission calculations shall be based on soil samples of the soils to be remediated. Samples shall 35
be analyzed for volatile organic compounds and hazardous air pollutants using the most recent version of 36
USEPA Test Method 8260, Method 8021, or other EPA approved testing methods acceptable to the director. 37
Emission calculations should be based on the methodology in EPA guidance "Air Emissions from the 38
Treatment of Soils Contaminated with Petroleum Fuels and Other Substances" (EPA-600/R-92-124) or other 39
methodology acceptable to the director. 40
(c) Location where soil aeration will occur and where the remediated material originated. 41
(3) The owner or operator is exempt from the reporting requirements in R307-401-16(2) if 42
excavated soils are disposed of at a disposal or treatment facility, such as a landfill, solid waste management 43
facility, or a landfarm facility, that is owned or operated by a third party and operates under an existing 44
approval order. 45
46
R307-401-17. Temporary Relocation. 47
The owner or operator of a stationary source previously approved under Rule R307-401 may 48
temporarily relocate and operate the stationary source at any site for up to 180 working days in any calendar 49
year not to exceed 365 consecutive days, starting from the initial relocation date. The director will evaluate 50
the expected emissions impact at the site and compliance with applicable Title R307 rules as the basis for 51
determining if approval for temporary relocation may be granted. Records of the working days at each site, 52
consecutive days at each site, and actual production rate shall be submitted to the director at the end of each 53
180 calendar days. These records shall also be kept on site by the owner or operator for the entire project, and 54
be made available for review to the director as requested. Section R307-401-7, Public Notice, does not apply 55
to temporary relocations under Section R307-401-17. 56
Page 8 of 10
1
R307-401-18. Eighteen Month Review. 2
Approval orders issued by the director in accordance with the provisions of Rule R307-401 will be 3
reviewed eighteen months after the date of issuance to determine the status of construction, installation, 4
modification, relocation or establishment. If a continuous program of construction, installation, modification, 5
relocation or establishment is not proceeding, the director may revoke the approval order. 6
7
R307-401-19. General Approval Order. 8
(1) The director may issue a general approval order that would establish conditions for similar 9
new or modified sources of the same type or for specific types of equipment. The general approval order 10
may apply throughout the state or in a specific area. 11
(a) A major source or major modification as defined in Rules R307-403, R307-405, or R307-420 12
for each respective area is not eligible for coverage under a general approval order. 13
(b) A source that is subject to the requirements of Section R307-403-5 is not eligible for 14
coverage under a general approval order. 15
(c) A source that is subject to the requirements of Section R307-410-4 is not eligible for 16
coverage under a general approval order unless a demonstration that meets the requirements of Section 17
R307-410-4 was conducted. 18
(d) A source that is subject to the requirements of Subsection R307-410-5(1)(c)(ii) is not eligible 19
for coverage under a general approval order unless a demonstration that meets the requirements of 20
Subsection R307-410-5(1)(c)(ii) was conducted. 21
(e) A source that is subject to the requirements of Subsection R307-410-5(1)(c)(iii) is not eligible 22
for coverage under a general approval order. 23
(2) A general approval order shall meet applicable requirements of Section R307-401-8. 24
(3) The public notice requirements in Section R307-401-7 shall apply to a general approval 25
order. 26
(4) Application. 27
(a) After a general approval order has been issued, the owner or operator of a proposed new or 28
modified source may apply to be covered under the conditions of the general approval order. 29
(b) The owner or operator shall submit the application on forms provided by the director in lieu 30
of the notice of intent requirements in Section R307-401-5 for equipment covered by the general approval 31
order. 32
(c) The owner or operator may request that an existing, individual approval order for the source 33
be revoked, and that it be covered by the general approval order. 34
(d) The owner or operator that has applied to be covered by a general approval order shall not 35
initiate construction, modification, or relocation until the application has been approved by the director. 36
(5) Approval. 37
(a) The director will review the application and approve or deny the request based on criteria 38
specified in the general approval order for that type of source. If approved, the director will issue an 39
authorization to the applicant to operate under the general approval order. 40
(b) The public notice requirements in Section R307-401-7 do not apply to the approval of an 41
application to be covered under the general approval order. 42
(c) The director will maintain a record of stationary sources that are covered by a specific general 43
approval order and this record will be available for public review. 44
(6) Exclusions and Revocation. 45
(a) The director may require any source that has applied for or is authorized by a general 46
approval order to submit a notice of intent and obtain an individual approval order under Section R307-47
401-8. Cases where the director will require an individual approval order include the following: 48
(i) the director determines that the source does not meet the criteria specified in the general 49
approval order; 50
(ii) the director determines that the application for the general approval order did not contain all 51
necessary information to evaluate applicability under the general approval order; 52
(iii) modifications were made to the source that were not authorized by the general approval 53
order or an individual approval order; 54
(iv) the director determines the source may cause a violation of a national ambient air quality 55
standard; 56
Page 9 of 10
(v) the director determines that an approval order is required based on the compliance history and 1
current compliance status of the source or applicant; or 2
(vi) the director determines that an approval order is required for any other reason. 3
(b)(i) Any source authorized by a general approval order may request to be excluded from the 4
coverage of the general approval order by submitting a notice of intent under Section R307-401-5 and 5
receiving an individual approval order under Section R307-401-8. 6
(ii) When the director issues an individual approval order to a source subject to a general 7
approval order, the applicability of the general approval order to the individual source is revoked on the 8
effective date of the individual approval order. 9
(7) Modification of General Approval Order. The director may modify, replace, or discontinue 10
the general approval order. 11
(a) Administrative corrections may be made to the existing version of the general approval order. 12
These corrections are to correct typographical errors or similar minor administrative changes. 13
(b) All other modifications or the discontinuation of a general approval order shall not apply to 14
any source authorized under previous versions of the general approval order unless the owner or operator 15
submits an application to be covered under the new version of the general approval order. Modifications 16
under Subsection R307-401-19(7)(b) shall meet the public notice requirements in Subsection R307-401-17
19(3). 18
(c) A general approval order shall be reviewed at least every three years. The review of the 19
general approval order shall follow the public notice requirements of Subsection R307-401-19(3). 20
(8) Modifications at a source covered by a general approval order. A source may make 21
modifications only as authorized by the approved general approval order. Modifications outside the scope 22
authorized by the approved general approval order shall require a new application for either an individual 23
approval order under Section R307-401-8 or a general approval order under Section R307-401-19. 24
25
KEY: air pollution, permits, approval orders, greenhouse gases 26
Date of Last Change: September 26, 2022 27
Notice of Continuation: May 4, 2022 28
Authorizing, and Implemented or Interpreted Law: 19-2-104(3)(b)(iii); 19-2-108 29
Page 10 of 10

ITEM 8

195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
DAQ-089-24
M E M O R A N D U M TO: Air Quality Board THROUGH: Bryce C. Bird, Executive Secretary FROM: Erica Pryor, Rules Coordinator DATE: October 22, 2024 SUBJECT: PROPOSE FOR FINAL ADOPTION: Amend R307-101. General Requirements; including R307-101-3. Version of Code of Federal Regulations Incorporated by Reference. ______________________________________________________________________________________
On August 7, 2024, the Utah Air Quality Board proposed for public comment amendments to rule R307-101, General Requirements, including R307-101-3, Version of Code of Federal Regulations
Incorporated by Reference. R307-101-3 has been amended to incorporate the most recent version of 40 CFR with the July 1, 2024, as
the version that is incorporated throughout the Utah Air Quality Rules. Published changes to 40 CFR that are relevant to the Utah Air Quality Rules from July 1, 2020, to July 1, 2024, are listed in the attached documents including:
• Summary of incorporations through R307-101-3
• Summary of relevant 40 CFR Part 63 Updates for incorporation through R307-214
• Summary of relevant 40 CFR Part 60 Updates for incorporation through R307-210 Additionally, it is important to note that the Standards of Performance for New, Reconstructed, and Modified Sources and Emissions Guidelines for Existing Sources: Oil and Natural Gas Sector Climate Review rules (commonly known as OOOOb and OOOOc) were finalized March 8, 2024, and made effective May 7, 2024. It is important to have these new standards referenced in the Utah Air Quality Rules
to have consistency with management of oil and natural gas sources by the state of Utah and the EPA. Ensuring compliance with these new standards will help ensure continued air quality improvements in the state and especially the Uinta Basin nonattainment area.

DAQ-089-24 Page 2
Finally, we are including additional necessary amendments to rule R307-101 to update certain definitions as well as bring the rule into compliance with Executive Order 2021-12 requiring all departments to update their respective rules to align with the state rule writing manual standards. The public comment period was open from September 1, 2024, through October 1, 2024. No comments were received. The public hearing tentatively scheduled for September 23, 2024, was cancelled because a hearing was not requested. Recommendation: Staff recommend the Board approve amendments to rule R307-101 for final adoption.
Page 1 of 11

R307. Environmental Quality, Air Quality. 1
R307-101. General Requirements. 2
R307-101-1. Foreword. 3
Chapter 19-2 and the rules adopted by the Air Quality Board constitute the basis for control of air 4
pollution sources in the state. Title R307 applies and shall be enforced throughout the state and are 5
recommended for adoption in local jurisdictions where environmental specialists are available to 6
cooperate in implementing rule requirements. 7
National Ambient Air Quality Standards (NAAQS), National Standards of Performance for New 8
Stationary Sources (NSPS), National Prevention of Significant Deterioration of Air Quality (PSD) 9
standards, and the National Emission Standards for Hazardous Air Pollutants (NESHAPS) apply 10
throughout the nation and are legally enforceable in Utah. 11
12
R307-101-2. Definitions. 13
Except where specified in individual rules, definitions in Section R307-101-2 are applicable to 14
any rules adopted by the Air Quality Board. 15
"Actual Emissions" means the actual rate of emissions of a pollutant from an emissions unit 16
determined as follows: 17
(1) In general, actual emissions as of a particular date shall equal the average rate, in tons per 18
year, at which the unit actually emitted the pollutant during a two-year period which precedes the 19
particular date and which is representative of normal source operations. The director shall allow the use 20
of a different period upon a determination that it is more representative of normal source operation. 21
Actual emissions shall be calculated using the unit's actual operating hours, production rates, and types of 22
materials processed, stored, or combusted during the selected period. 23
(2) The director may presume that source-specific allowable emissions for the unit are equivalent 24
to the actual emissions of the unit. 25
(3) For any emission unit, other than an electric utility steam generating unit specified in 26
Subsection (4), which has not begun normal operations on the date, actual emissions shall equal the 27
potential to emit of the unit on that date. 28
(4) For an electric utility steam generating unit, other than a new unit or the replacement of an 29
existing unit, actual emissions of the unit following the physical or operational change shall equal the 30
representative actual annual emissions of the unit, provided the source owner or operator maintains and 31
submits to the director, on an annual basis for a period of five years from the date the unit resumes regular 32
operation, information demonstrating that the physical or operational change did not result in an 33
emissions increase. A longer period, not to exceed ten years, may be required by the director if the 34
director determines a period to be more representative of normal source post-change operations. 35
"Acute Hazardous Air Pollutant" means any noncarcinogenic hazardous air pollutant for which a 36
threshold limit value - ceiling (TLV-C) has been adopted by the American Conference of Governmental 37
Industrial Hygienists (ACGIH) in its "Threshold Limit Values for Chemical Substances and Physical 38
Agents and Biological Exposure Indices, (2009)." 39
"Air pollutant" means a substance that qualifies as an air pollutant as defined in 42 U.S.C. Sec. 40
7602. 41
"Air Pollutant Source" means private and public sources of emissions of air pollutants. 42
"Air Pollution" means the presence of an air pollutant in the ambient air in quantities and duration 43
and under conditions and circumstances, that are injurious to human health or welfare, animal or plant 44
life, or property, or would unreasonably interfere with the enjoyment of life or use of property as 45
determined by the standards, rules adopted by the Air Quality Board, Section 19-2-104. 46
"Allowable Emissions" means the emission rate of a source calculated using the maximum rated 47
capacity of the source, unless the source is subject to enforceable limits which restrict the operating rate, 48
or hours of operation, or both, and the emission limitation established pursuant to Section R307-401-8. 49
"Ambient Air" means that portion of the atmosphere, external to buildings, to which the general 50
public has access. See Subsection 19-2-102(4). 51
"Appropriate Authority" means the governing body of any city, town, or county. 52
Page 2 of 11

"Atmosphere" means the air that envelops or surrounds the earth and includes any space outside 1
of buildings, stacks, or exterior ducts. 2
"Authorized Local Authority" means: 3
(1) city, county, city-county, or district health department; 4
(2) a city, county, or combination fire department; 5
(3) other local agency designated by appropriate authority, with approval of the Utah Department 6
of Health and Human Services; or 7
(4) other lawfully adopted ordinances, codes, or regulations not in conflict with. 8
"Board" means Air Quality Board. See Subsection 19-2-102(8)(a). 9
"Breakdown" means any malfunction or procedural error, to include any malfunction or 10
procedural error during start-up and shutdown, which will result in the inoperability or sudden loss of 11
performance of the control equipment or process equipment causing emissions in excess of those allowed 12
by approval order or Title R307. 13
"BTU" means British Thermal Unit, the quantity of heat necessary to raise the temperature of one 14
pound of water one degree Fahrenheit. 15
"Calibration Drift" means the change in the instrument meter readout over a stated period of 16
normal continuous operation when the VOC concentration at the time of measurement is the same known 17
upscale value. 18
"Carbon Adsorption System" means a device containing adsorbent material including activated 19
carbon, aluminum, silica gel, an inlet and outlet for exhaust gases, and a system for the proper disposal or 20
reuse of any VOC adsorbed. 21
"Carcinogenic Hazardous Air Pollutant" means any hazardous air pollutant that is classified as a 22
known human carcinogen (A1) or suspected human carcinogen (A2) by the American Conference of 23
Governmental Industrial Hygienists (ACGIH) in its "Threshold Limit Values for Chemical Substances 24
and Physical Agents and Biological Exposure Indices, (2009)." 25
"Chargeable Pollutant" means any regulated air pollutant except the following: 26
(1) carbon monoxide; 27
(2) any pollutant that is a regulated air pollutant solely because it is a Class I or II substance 28
subject to a standard promulgated or established by Title VI of the Act, Stratospheric Ozone Protection; 29
or 30
(3) any pollutant that is a regulated air pollutant solely because it is subject to a standard or 31
regulation under Section 112(r) of the Act, Prevention of Accidental Releases. 32
"Chronic Hazardous Air Pollutant" means any noncarcinogenic hazardous air pollutant for which 33
a threshold limit value - time weighted average (TLV-TWA) having no threshold limit value - ceiling 34
(TLV-C) has been adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) 35
in its "Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure 36
Indices, (2009)." 37
"Clean Air Act" means federal Clean Air Act as found in 42 U.S.C. Chapter 85. 38
"Clean Coal Technology" means any technology, including technologies applied at the 39
precombustion, combustion, or post combustion stage, at a new or existing facility which will achieve 40
significant reductions in air emissions of sulfur dioxide or oxides of nitrogen associated with the 41
utilization of coal in the generation of electricity, or process steam which was not in widespread use as of 42
November 15, 1990. 43
"Clean Coal Technology Demonstration Project" means a project using funds appropriated under 44
the heading "Department of Energy-Clean Coal Technology," up to a total amount of $2,500,000,000 for 45
commercial demonstration of clean coal technology, or similar projects funded through appropriations for 46
the Environmental Protection Agency. The federal contribution for a qualifying project shall be at least 47
20% of the total cost of the demonstration project. 48
"Clearing Index" means an indicator of the predicted rate of clearance of ground level pollutants 49
from a given area. This number is provided by the National Weather Service. 50
"Coating" means a material that can be applied to a substrate and which cures to form a 51
continuous solid film for protective, decorative, or functional purposes. Materials include paints, 52
varnishes, sealants, adhesives, caulks, maskants, inks, and temporary protective coatings. 53
Page 3 of 11

"Commence" as applied to construction of a major source or major modification means that the 1
owner or operator has any necessary pre-construction approvals or permits and either has: 2
(1) begun, or caused to begin, a continuous program of actual on-site construction of the source, 3
to be completed within a reasonable time; or 4
(2) entered into binding agreements or contractual obligations, which cannot be canceled or 5
modified without substantial loss to the owner or operator, to undertake a program of actual construction 6
of the source to be completed within a reasonable time. 7
"Composite vapor pressure" means the sum of the partial pressures of the compounds defined as 8
VOCs. 9
"Condensable PM2.5" means material that is vapor phase at stack conditions, but which 10
condenses or reacts upon cooling and dilution in the ambient air to form solid or liquid particulate matter 11
immediately after discharge from the stack. 12
"Compliance Schedule" means a schedule of events, by date, which shall result in compliance 13
with this rule. 14
"Construction" means any physical change or change in the method of operation including 15
fabrication, erection, installation, demolition, or modification of a source which would result in a change 16
in actual emissions. 17
"Control Apparatus" means any device which prevents or controls the emission of any air 18
pollutant directly or indirectly into the outdoor atmosphere. 19
"Department" means Utah State Department of Environmental Quality. See Subsection 19-1-20
103(1). 21
"Director" means the Director of the Division of Air Quality. See Subsection 19-1-103(1). 22
"Division" means the Division of Air Quality. 23
"Electric Utility Steam Generating Unit" means any steam electric generating unit that is 24
constructed to supply more than one-third of its potential electric output capacity and more than 25 MW 25
electrical output to any utility power distribution system for sale. Any steam supplied to a steam 26
distribution system for providing steam to a steam-electric generator that would produce electrical energy 27
for sale is also considered in determining the electrical energy output capacity of the affected facility. 28
"Emission" means the act of discharge into the atmosphere of an air pollutant or an effluent which 29
contains or may contain an air pollutant, or the effluent so discharged into the atmosphere. 30
"Emissions Information" means any source operation, equipment, or control apparatus: 31
(1) information necessary to determine the identity, amount, frequency, concentration, or other 32
characteristics related to air quality of any air pollutant which has been emitted by the source operation, 33
equipment, or control apparatus; 34
(2) information necessary to determine the identity, amount, frequency, concentration, or other 35
characteristics to the extent related to air quality, of any air pollutant which, under an applicable standard 36
or limitation, the source operation was authorized to emit including, to the extent necessary for such 37
purposes, a description of the manner or rate of operation of the source operation, or any combination of 38
the foregoing; and 39
(3) a general description of the location or nature of the source operation to the extent necessary 40
to identify the source operation and to distinguish it from other source operations including, to the extent 41
necessary for such purposes, a description of the device, installation, or operation constituting the source 42
operation. 43
"Emission Limitation" means a requirement established by the Board, the director or the 44
Administrator, EPA, which limits the quantity, rate or concentration of emission of air pollutants on a 45
continuous emission reduction including any requirement relating to the operation or maintenance of a 46
source to ensure continuous emission reduction. See Section 302(k). 47
"Emissions Unit" means any part of a stationary source which emits or would have the potential 48
to emit any pollutant subject to regulation under the Clean Air Act. 49
"Enforceable" means any limitations and conditions which are enforceable by the Administrator, 50
including those requirements developed pursuant to 40 CFR Parts 60 and 61, requirements within the 51
State Implementation Plan and Title R307, any permit requirements established pursuant to 40 CFR 52.21 52
or Rule R307-401. 53
Page 4 of 11

"EPA" means Environmental Protection Agency. 1
"EPA Method 9" means 40 CFR Part 60, Appendix A, Method 9, "Visual Determination of 2
Opacity of Emissions from Stationary Sources," and Alternate 1, "Determination of the opacity of 3
emissions from stationary sources remotely by LIDAR." 4
"Executive Director" means the Executive Director of the Utah Department of Environmental 5
Quality. See Subsection 19-1-103(2). 6
"Existing Installation" means an installation, construction of which began before the effective 7
date of any regulation having application to it. 8
"Filterable PM2.5" means particles with an aerodynamic diameter equal to or less than 2.5 9
micrometers that are directly emitted by a source as a solid or liquid at stack or release conditions and can 10
be captured on the filter of a stack test train. 11
"Fireplace" means any devices both masonry or factory built units, free standing fireplaces with a 12
hearth, fire chamber or similarly prepared device connected to a chimney which provides the operator 13
with little control of combustion air, leaving its fire chamber fully or at least partially open to the room. 14
Fireplaces include those devices with circulating systems, heat exchangers, or draft reducing doors with a 15
net thermal efficiency of no greater than 20% and are used for aesthetic purposes. 16
"Fugitive Dust" means particulate, composed of soil, industrial particulates, or both including ash, 17
coal, and minerals which becomes airborne because of wind or mechanical disturbance of surfaces. 18
Natural sources of dust and fugitive emissions are not fugitive dust within the meaning of this definition. 19
"Fugitive Emissions" means emissions from an installation or facility which are neither passed 20
through an air cleaning device nor vented through a stack or could not reasonably pass through a stack, 21
chimney, vent, or other functionally equivalent opening. 22
"Garbage" means any putrescible animal and vegetable matter resulting from the handling, 23
preparation, cooking and consumption of food, including wastes attendant thereto. 24
"Gasoline" means any petroleum distillate, used as a fuel for internal combustion engines, having 25
a Reid vapor pressure of four pounds or greater. 26
"Hazardous Air Pollutant (HAP)" means any pollutant listed by the EPA as a hazardous air 27
pollutant in conformance with Section 112(b) of the Clean Air Act. A list of these pollutants is available 28
at the Division of Air Quality. 29
"Household Waste" means any solid or liquid material normally generated by the family in a 30
residence in the course of ordinary day-to-day living, including garbage, paper products, rags, leaves, and 31
garden trash. 32
"Incinerator" means a combustion apparatus designed for high temperature operation in which 33
solid, semisolid, liquid, or gaseous combustible wastes are ignited and burned efficiently and from which 34
the solid and gaseous residues contain little or no combustible material. 35
"Installation" means a discrete process with identifiable emissions which may be part of a larger 36
industrial plant. Pollution equipment may not be considered a separate installation or installations. 37
"LPG" means liquified petroleum gas including propane or butane. 38
"Maintenance Area" means an area that is subject to the provisions of a maintenance plan that is 39
included in the Utah State Implementation Plan, and that has been redesignated by EPA from 40
nonattainment to attainment of any National Ambient Air Quality Standard. 41
(1) Provo City is considered a maintenance areas for carbon monoxide effective January 3, 2006. 42
(2) The following areas are considered maintenance areas for PM10: 43
(a) Salt Lake County, effective on the date that EPA approves the maintenance plan that was 44
adopted by the Board on December 2, 2015; 45
(b) Utah County, effective on the date that EPA approves the maintenance plan that was adopted 46
by the Board on December 2, 2015; and 47
(c) Ogden City, effective on the date that EPA approves the maintenance plan that was adopted 48
by the Board on December 2, 2015. 49
(3) The following area is considered a maintenance area for sulfur dioxide: Salt Lake County 50
and the eastern portion of Tooele County above 5,600 feet, effective on the date that EPA approves the 51
maintenance plan that was adopted by the Board on January 5, 2005. 52
(4) The following areas are considered maintenance areas for PM2.5: 53
Page 5 of 11

(a) the Salt Lake City, Utah 24-hr PM2.5 nonattainment area, as defined in the July 1, 2019 1
version of 40 CFR 81.345, effective on the date that EPA redesignates the area to attainment for PM2.5; 2
(b) the Provo, Utah 24-hr PM2.5 nonattainment area, as defined in the July 1, 2019 version of 40 3
CFR 81.345, effective on the date that EPA redesignates the area to attainment for PM2.5; and 4
(c) the Utah portion of the Logan, Utah-Idaho 24-hr PM2.5 nonattainment area, as defined in the 5
July 1, 2019 version of 40 CFR 81.345, effective on the date that EPA redesignates the area to attainment 6
for PM2.5. 7
"Major Modification" means any physical change in or change in the method of operation of a 8
major source that would result in a significant net emissions increase of any pollutant. A net emissions 9
increase that is significant for volatile organic compounds shall be considered significant for ozone. 10
Within Salt Lake and Davis Counties or any nonattainment area for ozone, a net emissions increase that is 11
significant for nitrogen oxides shall be considered significant for ozone. Within areas of nonattainment 12
for PM10, a significant net emission increase for any PM10 precursor is also a significant net emission 13
increase for PM10. A physical change or change in the method of operation may not include: 14
(1) routine maintenance, repair, and replacement; 15
(2) use of an alternative fuel or raw material by reason of an order under Section 2(a) and (b) of 16
the Energy Supply and Environmental Coordination Act of 1974, or by reason of a natural gas curtailment 17
plan pursuant to the Federal Power Act; 18
(3) use of an alternative fuel by reason of an order or rule under Section 125 of the federal Clean 19
Air Act; 20
(4) use of an alternative fuel at a steam generating unit to the extent that the fuel is generated 21
from municipal solid waste; 22
(5) use of an alternative fuel or raw material by a source: 23
(a) which the source was capable of accommodating before January 6, 1975, unless such change 24
would be prohibited under any enforceable permit condition; or 25
(b) which the source is otherwise approved to use; 26
(6) an increase in the hours of operation or in the production rate unless the change would be 27
prohibited under any enforceable permit condition; 28
(7) any change in ownership at a source; 29
(8) the addition, replacement, or use of a pollution control project at an existing electric utility 30
steam generating unit, unless the director determines that the addition, replacement, or use renders the 31
unit less environmentally beneficial, or except: 32
(a) when the director has reason to believe that the pollution control project would result in a 33
significant net increase in representative actual annual emissions of any criteria pollutant over levels used 34
for that source in the most recent air quality impact analysis in the area conducted for Title I of the Clean 35
Air Act, if any; and 36
(b) the director determines that the increase will cause or contribute to a violation of any national 37
ambient air quality standard or PSD increment, or visibility limitation; 38
(9) the installation, operation, cessation, or removal of a temporary clean coal technology 39
demonstration project, provided that the project complies with: 40
(a) the Utah State Implementation Plan; and 41
(b) other requirements necessary to attain and maintain the national ambient air quality standards 42
during the project and after it is terminated. 43
"Major Source" means, to the extent provided by the federal Clean Air Act as applicable to Title 44
R307: 45
(1) any stationary source of air pollutants which emits, or has the potential to emit, 100 tons per 46
year or more of any pollutant subject to regulation under the Clean Air Act; or 47
(a) any source located in a nonattainment area for carbon monoxide which emits, or has the 48
potential to emit, carbon monoxide in the amounts outlined in Section 187 of the federal Clean Air Act 49
with respect to the severity of the nonattainment area as outlined in Section 187 of the federal Clean Air 50
Act; 51
(b) any source located in Salt Lake or Davis Counties or in a nonattainment area for ozone which 52
emits, or has the potential to emit, VOC or nitrogen oxides in the amounts outlined in Section 182 of the 53
Page 6 of 11

federal Clean Air Act with respect to the severity of the nonattainment area as outlined in Section 182 of 1
the federal Clean Air Act; or 2
(c) any source located in a nonattainment area for PM10 which emits, or has the potential to 3
emit, PM10 or any PM10 precursor in the amounts outlined in Section 189 of the federal Clean Air Act 4
with respect to the severity of the nonattainment area as outlined in Section 189 of the federal Clean Air 5
Act. 6
(2) any physical change that would occur at a source not qualifying under Subsection (1) as a 7
major source, if the change would constitute a major source by itself; 8
(3) the fugitive emissions and fugitive dust of a stationary source may not be included in 9
determining for any of the purposes of Title R307 rules whether it is a major stationary source, unless the 10
source belongs to one of the following categories of stationary sources: 11
(a) coal cleaning plants with thermal dryers; 12
(b) Kraft pulp mills; 13
(c) Portland cement plants; 14
(d) primary zinc smelters; 15
(e) iron and steel mills; 16
(f) primary aluminum or reduction plants; 17
(g) primary copper smelters; 18
(h) municipal incinerators capable of charging more than 250 tons of refuse per day; 19
(i) hydrofluoric, sulfuric, or nitric acid plants; 20
(j) petroleum refineries; 21
(k) lime plants; 22
(l) phosphate rock processing plants; 23
(m) coke oven batteries; 24
(n) sulfur recovery plants; 25
(o) carbon black plants or furnace process; 26
(p) primary lead smelters; 27
(q) fuel conversion plants; 28
(r) sintering plants; 29
(s) secondary metal production plants; 30
(t) chemical process plants; 31
(u) fossil-fuel boilers, or combination thereof, totaling more than 250 million British Thermal 32
Units per hour heat input; 33
(v) petroleum storage and transfer units with a total storage capacity exceeding 300,000 barrels; 34
(w) taconite ore processing plants; 35
(x) glass fiber processing plants; 36
(y) charcoal production plants; 37
(z) fossil fuel-fired steam electric plants of more than 250 million British Thermal Units per hour 38
heat input; or 39
(aa) any other stationary source category which, as of August 7, 1980, is being regulated under 40
Section 111 or 112 of the federal Clean Air Act. 41
"Modification" means any planned change in a source which results in a potential increase of 42
emission. 43
"National Ambient Air Quality Standards (NAAQS)" means the allowable concentrations of air 44
pollutants in the ambient air specified by the federal government, see Title 40, Code of Federal 45
Regulations, Part 50. 46
"Net Emissions Increase" means the amount by which the sum of the following exceeds zero: 47
(1) any increase in actual emissions from a particular physical change or change in method of 48
operation at a source; and 49
(2) any other increases and decreases in actual emissions at the source that are contemporaneous 50
with the particular change and are otherwise creditable. For purposes of determining a "net emissions 51
increase": 52
Page 7 of 11

(a) an increase or decrease in actual emissions is contemporaneous with the increase from the 1
particular change only if it occurs between the date five years before construction on the particular change 2
commences; and the date that the increase from the particular change occurs; 3
(b) An increase or decrease in actual emissions is creditable only if it has not been relied on in 4
issuing a prior approval for the source which approval is in effect when the increase in actual emissions 5
for the particular change occurs; 6
(c) An increase or decrease in actual emission of sulfur dioxide, nitrogen oxides or particulate 7
matter which occurs before an applicable minor source baseline date is creditable only if it is required to 8
be considered in calculating the amount of maximum allowable increases remaining available and with 9
respect to particulate matter, only PM10 emissions will be used to evaluate this increase or decrease; 10
(d) an increase in actual emissions is creditable only to the extent that the new level of actual 11
emissions exceeds the old level. 12
(e) a decrease in actual emissions is creditable only to the extent that: 13
(i) the old level of actual emissions or the old level of allowable emissions, whichever is lower, 14
exceeds the new level of actual emissions; 15
(ii) it is enforceable at and after the time that actual construction on the particular change begins; 16
(iii) it has about the same qualitative significance for public health and welfare as that attributed 17
to the increase from the particular change; and 18
(iv) it has not been relied on in issuing any permit under Rule R307-401 nor has it been relied on 19
in demonstrating attainment or reasonable further progress. 20
(f) an increase that results from a physical change at a source occurs when the emissions unit on 21
which construction occurred becomes operational and begins to emit a particular pollutant and any 22
replacement unit that requires shakedown becomes operational only after a reasonable shakedown period, 23
not to exceed 180 days. 24
"New Installation" means an installation, construction of which began after the effective date of 25
any regulation having application to it. 26
"Nonattainment Area" means an area designated by the Environmental Protection Agency as 27
nonattainment under Section 107, Clean Air Act for any National Ambient Air Quality Standard. The 28
designations for Utah are listed in 40 CFR 81.345. 29
"Offset" means an amount of emission reduction, by a source, greater than the emission limitation 30
imposed on the source by this rule, the State Implementation Plan, or both. 31
"Opacity" means the capacity to obstruct the transmission of light, expressed as percent. 32
"Open Burning" means any burning of combustible materials resulting in emission of products of 33
combustion into ambient air without passage through a chimney or stack. 34
"Owner or Operator" means any person who owns, leases, controls, operates or supervises a 35
facility, an emission source, or air pollution control equipment. 36
"PSD Area" means an area designated as attainment or unclassifiable under Section 107(d)(1)(D) 37
or (E) of the federal Clean Air Act. 38
"PM2.5" means particulate matter with an aerodynamic diameter less than or equal to a nominal 39
2.5 micrometers as measured by an EPA reference or equivalent method. 40
"PM2.5 Precursor" means any chemical compound or substance which, after it has been emitted 41
into the atmosphere, undergoes chemical or physical changes that convert it into particulate matter, 42
specifically PM2.5. 43
(1) Specifically, Sulfur dioxide, Nitrogen oxides, Volatile organic compounds and Ammonia are 44
precursors to PM2.5 in any PM2.5 nonattainment area, except where the Administrator of the EPA has 45
approved a demonstration satisfying 40 CFR 51.1006(a)(3) which has, for a particular PM2.5 46
nonattainment area, determined otherwise. 47
(2) The following subparagraphs denote specific nonattainment areas, as defined in the July 1, 48
2017 version of 40 CFR 81.345, within which certain pollutants identified in Subsection (1) are exempted 49
from the definition of PM2.5 precursor for the purposes of 40 CFR 51.165 50
(a) In the Logan UT-ID PM2.5 nonattainment area, Ammonia is exempted. 51
"PM10" means particulate matter with an aerodynamic diameter less than or equal to a nominal 52
ten micrometers as measured by an EPA reference or equivalent method. 53
Page 8 of 11

"PM10 Precursor" means any chemical compound or substance which, after it has been emitted 1
into the atmosphere, undergoes chemical or physical changes that convert it into particulate matter, 2
specifically PM10. 3
"Part 70 Source" means any source subject to the permitting requirements of Rule R307-415. 4
"Person" means an individual, trust, firm, estate, company, corporation, partnership, association, 5
state, state or federal agency or entity, municipality, commission, or political subdivision of a state. See 6
Subsection 19-2-103(4). 7
"Pollution Control Project" means any activity or project at an existing electric utility steam 8
generating unit for purposes of reducing emissions from a unit. Activities or projects are limited to: 9
(1) the installation of conventional or innovative pollution control technology, including 10
advanced flue gas desulfurization, sorbent injection for sulfur dioxide and nitrogen oxides controls, and 11
electrostatic precipitators; 12
(2) an activity or project to accommodate switching to a fuel which is less polluting than the fuel 13
used before the activity or project, including natural gas or coal reburning, or the cofiring of natural gas 14
and other fuels for controlling emissions; 15
(3) a permanent clean coal technology demonstration project conducted under Title II, Section 16
101(d) of the Further Continuing Appropriations Act of 1985 (sec. 5903(d) of title 42 of the United States 17
Code), or subsequent appropriations, up to a total amount of $2,500,000,000 for commercial 18
demonstration of clean coal technology, or similar projects funded through appropriations for the 19
Environmental Protection Agency; or 20
(4) a permanent clean coal technology demonstration project that constitutes a repowering 21
project. 22
"Potential to Emit" means the maximum capacity of a source to emit a pollutant under its physical 23
and operational design. Any physical or operational limitation on the capacity of the source to emit a 24
pollutant including air pollution control equipment and restrictions on hours of operation or on the type or 25
amount of material combusted, stored, or processed shall be treated as part of its design if the limitation or 26
the effect it would have on emissions is enforceable. Secondary emissions do not count in determining 27
the potential to emit of a stationary source. 28
"Primary PM2.5" means the sum of filterable PM2.5 and condensable PM2.5. 29
"Process Level" means the operation of a source, specific to the kind or type of fuel, input 30
material, or mode of operation. 31
"Process Rate" means the quantity per unit of time of any raw material or process intermediate 32
consumed, or product generated, through the use of any equipment, source operation, or control 33
apparatus. For a stationary internal combustion unit or any other fuel burning equipment, this term may 34
be expressed as the quantity of fuel burned per unit of time. 35
"Reactivation of a Very Clean Coal-Fired Electric Utility Steam Generating Unit" means any 36
physical change or change in the method of operation associated with the commencement of commercial 37
operations by a coal-fired utility unit after a period of discontinued operation where the unit: 38
(1) has not been in operation for the two-year period before the enactment of the Clean Air Act 39
Amendments of 1990, and the emissions from the unit continue to be carried in the emission inventory at 40
the time of enactment; 41
(2) was equipped before shutdown with a continuous system of emissions control that achieves a 42
removal efficiency for sulfur dioxide of no less than 85% and a removal efficiency for particulates of no 43
less than 98%; 44
(3) is equipped with low-NOx burners before operations begin following reactivation; and 45
(4) is otherwise in compliance with the requirements of the Clean Air Act. 46
"Reasonable Further Progress" means annual incremental reductions in emission of an air 47
pollutant which are sufficient to provide for attainment of the NAAQS by the date identified in the State 48
Implementation Plan. 49
"Refuse" means solid wastes, such as garbage and trash. 50
"Regulated air pollutant" means any of the following: 51
(a) nitrogen oxides or any volatile organic compound; 52
(b) any pollutant for which a national ambient air quality standard has been promulgated; 53
Page 9 of 11

(c) any pollutant that is subject to any standard promulgated under Section 111 of the Act, 1
Standards of Performance for New Stationary Sources; 2
(d) any Class I or II substance subject to a standard promulgated under or established by Title VI 3
of the Act, Stratospheric Ozone Protection; or 4
(e) any pollutant subject to a standard promulgated under Section 112, Hazardous Air Pollutants, 5
or other requirements established under Section 112 of the Act, including Sections 112(g), (j), and (r) of 6
the Act, including any of the following: 7
(i) Any pollutant subject to requirements under Section 112(j) of the Act, Equivalent Emission 8
Limitation by Permit. If the Administrator fails to promulgate a standard by the date established pursuant 9
to Section 112(e) of the Act, any pollutant for which a subject source would be major shall be regulated 10
on the date 18 months after the applicable date established pursuant to Section 112(e) of the Act; 11
(ii) Any pollutant for which the requirements of Section 112(g)(2) of the Act, Construction, 12
Reconstruction and Modification, have been met, but only with respect to the individual source subject to 13
Section 112(g)(2) requirement. 14
"Repowering" means replacement of an existing coal-fired boiler with one of the following clean 15
coal technologies: 16
(a) atmospheric or pressurized fluidized bed combustion; 17
(b) integrated gasification combined cycle; 18
(c) magnetohydrodynamics; 19
(d) direct and indirect coal-fired turbines; 20
(e) integrated gasification fuel cells; or 21
(f) as determined by the Administrator, in consultation with the Secretary of Energy, a derivative 22
of one or more of these technologies, and any other technology capable of controlling multiple 23
combustion emissions simultaneously with improved boiler or generation efficiency and with 24
significantly greater waste reduction relative to the performance of technology in widespread commercial 25
use as of November 15, 1990. 26
(1) Repowering shall also include any oil or gas-fired unit which has been awarded clean coal 27
technology demonstration funding as of January 1, 1991, by the Department of Energy. 28
(2) The director shall give expedited consideration to permit applications for any source that 29
satisfies the requirements of this definition and is granted an extension under Section 409 of the Clean Air 30
Act. 31
"Representative Actual Annual Emissions" means the average rate, in tons per year, at which the 32
source is projected to emit a pollutant for the two-year period after a physical change or change in the 33
method of operation of unit, or a different consecutive two-year period within ten years after that change, 34
where the director determines that the period is more representative of source operations, considering the 35
effect any change will have on increasing or decreasing the hourly emissions rate and on projected 36
capacity utilization. In projecting future emissions, the director shall: 37
(1) consider any relevant information, including historical operational data, the company's own 38
representations, filings with the State of Federal regulatory authorities, and compliance plans under title 39
IV of the Clean Air Act; and 40
(2) exclude, in calculating any increase in emissions that results from the particular physical 41
change or change in the method of operation at an electric utility steam generating unit, that portion of the 42
unit's emissions following the change that could have been accommodated during the representative 43
baseline period and is attributable to an increase in projected capacity utilization at the unit that is 44
unrelated to the particular change, including any increased utilization due to the rate of electricity demand 45
growth for the utility system as a whole. 46
"Residence" means a dwelling in which people live, including all ancillary buildings. 47
"Residential Solid Fuel Burning" device means any residential burning device except a fireplace 48
connected to a chimney that burns solid fuel and is capable of, and intended for use as a space heater, 49
domestic water heater, or indoor cooking appliance, and has an air-to-fuel ratio less than 35-to-1 as 50
determined by the test procedures prescribed in 40 CFR 60.534. It shall also have a useable firebox 51
volume of less than 6.10 cubic meters or 20 cubic feet, a minimum burn rate less than 5 kilograms per 52
hour or 11 pounds per hour as determined by test procedures prescribed in 40 CFR 60.534, and weigh less 53
Page 10 of 11

than 800 kilograms or 362.9 pounds. Appliances that are described as prefabricated fireplaces and are 1
designed to accommodate doors or other accessories that would create the air starved operating conditions 2
of a residential solid fuel burning device shall be considered as such. Fireplaces are not included in this 3
definition for solid fuel burning devices. 4
"Road" means any public or private road. 5
"Salvage Operation" means any business, trade or industry engaged in whole or in part in 6
salvaging or reclaiming any product or material, including metals, chemicals, shipping containers, or 7
drums. 8
"Secondary Emissions" means emissions which would occur as a result of the construction or 9
operation of a major source or major modification, but do not come from the major source or major 10
modification itself. 11
Secondary emissions shall be specific, well defined, quantifiable, and impact the same general 12
area as the source or modification which causes the secondary emissions. Secondary emissions include 13
emissions from any off-site support facility which would not be constructed or increase its emissions 14
except as a result of the construction or operation of the major source or major modification. Secondary 15
emissions do not include any emissions which come directly from a mobile source including emissions 16
from the tailpipe of a motor vehicle, from a train, or from a vessel. 17
Fugitive emissions and fugitive dust from the source or modification are not considered 18
secondary emissions. 19
"Secondary PM2.5" means particles that form or grow in mass through chemical reactions in the 20
ambient air well after dilution and condensation have occurred. Secondary PM2.5 is usually formed at 21
some distance downwind from the source. 22
"Significant" means: 23
(1) In reference to a net emissions increase or the potential of a source to emit any of the 24
following pollutants, a rate of emissions that would equal or exceed any of the following rates: 25
Carbon monoxide: 100 ton per year (tpy); 26
Nitrogen oxides: 40 tpy; 27
Sulfur dioxide: 40 tpy; 28
PM10: 15 tpy; 29
PM2.5: 10 tpy; 30
Particulate matter: 25 tpy; 31
Ozone: 40 tpy of volatile organic compounds; or 32
Lead: 0.6 tpy. 33
"Solid Fuel" means wood, coal, and other similar organic material or combination of these 34
materials. 35
"Solvent" means organic materials which are liquid at standard conditions, Standard Temperature 36
and Pressure, and which are used as dissolvers, viscosity reducers, or cleaning agents. 37
"Source" means any structure, building, facility, or installation which emits or may emit any air 38
pollutant subject to regulation under the Clean Air Act and which is located on one or more continuous or 39
adjacent properties and which is under the control of the same person under common control. A building, 40
structure, facility, or installation means any of the pollutant-emitting activities which belong to the same 41
industrial grouping. Pollutant-emitting activities shall be considered as part of the same industrial 42
grouping if they belong to the same "Major Group" which have the same two-digit code as described in 43
the Standard Industrial Classification Manual, 1972, as amended by the 1977 Supplement, US 44
Government Printing Office stock numbers 4101-0065 and 003-005-00176-0, respectively. 45
"Stack" means any point in a source designed to emit solids, liquids, or gases into the air, 46
including a pipe or duct but not including flares. 47
"Standards of Performance for New Stationary Sources" means the federally established 48
requirements for performance and record keeping, Title 40 Code of Federal Regulations, Part 60. 49
"Temporary" means not more than 180 calendar days. 50
"Temporary Clean Coal Technology Demonstration Project" means a clean coal technology 51
demonstration project that is operated for a period of five years or less, and which complies with the Utah 52
Page 11 of 11

State Implementation Plan and other requirements necessary to attain and maintain the national ambient 1
air quality standards during the project and after it is terminated. 2
"Threshold Limit Value - Ceiling (TLV-C)" means the airborne concentration of a substance 3
which may not be exceeded, as adopted by the American Conference of Governmental Industrial 4
Hygienists in its "Threshold Limit Values for Chemical Substances and Physical Agents and Biological 5
Exposure Indices, (2009)." 6
"Threshold Limit Value - Time Weighted Average (TLV-TWA)" means the time-weighted 7
airborne concentration of a substance adopted by the American Conference of Governmental Industrial 8
Hygienists in its "Threshold Limit Values for Chemical Substances and Physical Agents and Biological 9
Exposure Indices, (2009)." 10
"Total Suspended Particulate (TSP)" means minute separate particles of matter, collected by high 11
volume sampler. 12
"Toxic Screening Level" means an ambient concentration of an air pollutant equal to a threshold 13
limit value - ceiling (TLV- C) or threshold limit value -time weighted average (TLV-TWA) divided by a 14
safety factor. 15
"Trash" means solids not considered to be highly flammable or explosive including clothing, 16
rags, leather, plastic, rubber, floor coverings, excelsior, tree leaves, yard trimmings, and other similar 17
materials. 18
"VOC content" means the weight of VOC per volume of material and is calculated by the 19
following equation in gram/liter, pound/gallon, or pound/pound: 20
Grams of VOC per Liter of Material = Ws - Ww - Wes / Vm 21
Where: 22
Ws = weight of volatile organic compounds 23
Ww = weight of water 24
Wes = weight of exempt compounds 25
Vm = volume of material 26
"Volatile Organic Compound (VOC)" means VOC as defined in 40 CFR 51.100(s), effective as 27
of the date referenced in Section R307-101-3, is incorporated by reference. 28
"Waste" means any solid, liquid or gaseous material, including garbage, trash, household refuse, 29
construction or demolition debris, or other refuse including that resulting from the prosecution of any 30
business, trade or industry. 31
"Zero Drift" means the change in the instrument meter readout over a stated period of normal 32
continuous operation when the VOC concentration at the time of measurement is zero. 33
34
R307-101-3. Version of Code of Federal Regulations Incorporated by Reference. 35
Except as specifically identified in an individual rule, the version of the Code of Federal 36
Regulations (CFR) incorporated throughout Title R307 is dated July 1, 2024. 37
38
KEY: air pollution, definitions 39
Date of Last Change: 2024 40
Notice of Continuation: November 1, 2023 41
Authorizing, and Implemented or Interpreted Law: 19-2-104(1)(a) 42

October 22, 2024 Page 1 of 3
R307-101-3:
Summary of Code of Federal Regulations (CFR) Changes from July 1, 2020, to July 1, 2024

Rule CFR Section Incorporated Summary of Changes to CFR
R307-101-2 40 CFR 51.100(s)
Definitions
Added trans-1,1,1,4,4,4-hexafluorobut-2-ene (HFO-1336mzz(E)) to VOCs
R307-115-1 40 CFR Part 93, Subpart B No changes.
R307-170-7 40 CFR 75, Appendix A, Section 6.2 No changes.
R307-210-1 40 Code of Federal Regulations (CFR) Part 60,
except for Subparts Cb, Cc, Cd, Ce, BBBB,
DDDD, and HHHH
See R307-210 Table for most relevant changes. This includes all OOOOb updates.
R307-214-1 40 CFR Part 61
National Emission Standards for Hazardous Air
Pollutants
61.04. Address. These changes were for new addresses and specific authority delegation
throughout the country for different air agencies and several state-specific changes, not
including Utah.

61.18. Incorporations by Reference for other states.

Appendix B to Part 61 – Test Methods
Added:
Method 114 – Test Methods for Measuring Radionuclide Emissions From Stationary
Sources
Method 115 – Monitoring for Radon-222 Emissions
Method 101 – Determination of Particulate and Gaseous Mercury Emissions From Chlor-
Alkali Plants (Air Streams)
12.0 Calculations and Data Analysis
12.3 Residual Vinyl Chloride Monomer Concentration, (Crvc) or Vinyl Chloride Monomer
Concentration. Calculate Crvc in ppm or mg/kg as follows:
R307-214 40 CFR Part 63 See CFR Table R307-214
R307-221-2 Definitions 40 CFR 60.751 No changes.
R307-221-3 40 CFR 60.752 through 60.759, including
Appendix A
No changes.
307-221-4 Section 40 CFR Part 60.18 No changes.
R307-222-2 40 CFR 60.31e No changes.
R307-222-2 40 CFR 60.51c No changes.

October 22, 2024 Page 2 of 3
R307-101-3:
Summary of Code of Federal Regulations (CFR) Changes from July 1, 2020, to July 1, 2024
R307-222-3 40 CFR 60.52c(b), 40 CFR 60.53c, 40 CFR
60.54c, 40 CFR 60.55c, 40 CFR 60.58c(b)
excluding (b)(2)(ii) and (b)(7), and 40 CFR
60.58c(c) through (f)
No changes.
R307-222-4 Table 1A and Table 1B in 40 CFR Part 60,
Subpart Ce; 40 CFR 60.57c; and 40 CFR
60.56c, excluding 56c(b)(12) and 56c(c)(3)
No changes.
R307-222-5(2) Table 2 in 40 CFR Part 60, Subpart Ce
(40CFR60.30e-39e)
No changes.
R307-222-5(3) 40 CFR 60.36e(a)(1) and (a)(2) No changes.
R307-222-5(4) Testing requirements of 40 CFR 60.37e(b)(1)
through (b)(5)
No changes.
R307-222-5(5) 40 CFR 60.37e(d)(1) through (d)(3) No changes.
R307-222-5(6) 40 CFR 60.38e(b)(1) and (b)(2) No changes.
R307-223-1(2) 40 CFR 60.1555(a) through (k) No changes.
R307-223-2(1) 40 CFR 60.1940
Equations found in 40 CFR 60.1935
No changes.
R307-223-2(2) Equations found in 40 CFR 60.1935 No changes.
R307-223-3(1) 40 CFR 60.1540 and 60.1585 through 60.1905,
and with the requirements and schedules set
forth in Tables 2 through 8 that are found
following 40 CFR 60.1940 for operator training
and certification
40 CFR Part 60, subpart HHHH, Sections
60.4101 through 60.4124; (b) Sections 60.4142
paragraph (c)(2) through paragraph (c)(4); (c)
Sections 60.4150 through 60.4176.
No changes.
R307-224-2 40 CFR Part 60, subpart HHHH, Sections
60.4101 through 60.4124; (b) Sections 60.4142
paragraph (c)(2) through paragraph (c)(4); (c)
Sections 60.4150 through 60.4176.
No changes.

R307-310-2

40 CFR Part 93.101 No changes.

October 22, 2024 Page 3 of 3
R307-101-3:
Summary of Code of Federal Regulations (CFR) Changes from July 1, 2020, to July 1, 2024

R307-328 40 CFR Parts 63.421, 63.425(e), 63.425(i) While there were changes to 40 CFR 63.421 in 2021, there are no changes to the definition
of "Gasoline Cargo Tank" as referenced in the CFR.
63.425(e), 63.425(i) - no changes.
R307-415 40 CFR Parts 72.2, 72, 61.145, 720.3(ee),
70.8(d), 70.7(g)
 For 40 CFR Part 72, Chapter 1, Subchapter N, Section 402, appears currently in
"reserved" status.
 40 CFR Parts 72.2. No changes.
 40 CFR Part 61.145: No changes.
 40 CFR 720.3(ee): Last amended 2022, however no revisions were made to (ee).
 40 CFR 70.8(d): Last amended April 2020 (which was addressed on the prior CFR
Table submission to the Board.)
 40 CFR 70.7(g): Last amended April 2020 (which was addressed on the prior CFR
Table submission to the Board.)
R307-417-1 40 CFR Part 72 No changes.
R307-417-2 40 CFR Part 75
Continuous Emission Monitoring
67 FR 40394, Wednesday, July 12, 2002: Revisions to the Definition sand the Continuous
Emission Monitoring Provisions of the Acid Rain Program and the NOx Budget Trading
Program.

This rulemaking established additional flexibility and options for sources in meeting the
continuous emission monitoring system (CEMS) requirements under programs to reduce
sulfur dioxide and nitrogen oxides emissions. These revisions may apply to sources that
monitor and report emissions only during the ozone season, as well as to sources that
monitor and report emissions for the entire year. The provisions in this final rule benefit the
environment by ensuring that sulfur dioxide (S02), nitrogen oxides (NOX), and carbon
dioxide (CO2) emissions are accurately monitored and reported, even as they benefit the
affected industrial sources by creating opportunities to adopt cost saving procedures.
R307-417-3 40 CFR Part 76 No changes.
R307-801-4 40 CFR 763 Subpart E, and appendices No changes.
October 22, 2024 Page 1 of 6
FR Number Title Effective
Date
Summary
85 FR 57018 OOOO,
OOOOa
Oil and Natural Gas Sector: Emission Standards
for New, Reconstructed, and Modified Sources
Review
9/14/2020 This action finalizes amendments to the oil and natural gas new source
performance standards (NSPS) promulgated in 2012 and 2016. These
amendments remove sources in the transmission and storage segment from
the source category, rescind the NSPS (including both the volatile organic
compounds (VOC) and methane requirements) applicable to those sources,
and separately rescinds the methane-specific requirements of the NSPS
applicable to sources in the production and processing segments.
Furthermore, the U.S. Environmental Protection Agency (EPA) adopts an
interpretation of Clean Air Act (CAA) section 111 under which the EPA, as a
predicate to promulgating NSPS for certain air pollutants, must determine that
the pertinent pollutant causes or contributes significantly to dangerous air
pollution.
85 FR 57398 OOOO,
OOOOa
Oil and Natural Gas Sector: Emission Standards
for New, Reconstructed, and Modified Sources
Reconsideration
11/16/2020 This action finalizes amendments to the new source performance standards
(NSPS) for the oil and natural gas sector. The Environmental Protection
Agency (EPA) granted reconsideration on the fugitive emissions requirements,
well site pneumatic pump standards, requirements for certification of closed
vent systems (CVS) by a professional engineer (PE), and the provisions to
apply for the use of an alternative means of emission limitation (AMEL). This
final action includes amendments as a result of the EPA's reconsideration of
the issues associated with the above mentioned four subject areas and other
issues raised in the reconsideration petitions for the NSPS, as well as
amendments to streamline the implementation of the rule. This action also
includes technical corrections and additional clarifying language in the
regulatory text and/or preamble where the EPA concludes further clarification
is warranted85 FR 70487 BBa National Emission Standards for Hazardous Air
Pollutants for Chemical Recovery Combustion
Sources at Kraft, Soda, Sulfite, and Stand-Alone
Semichemical Pulp Mills; Standards of
Performance for Kraft Pulp Mill Affected
Sources for Which Construction,
Reconstruction, or Modification Commenced
After May 23, 2013
11/12/2020 The U.S. Environmental Protection Agency (EPA) is finalizing amendments to
the National Emission Standards for Hazardous Air Pollutants (NESHAP) for
Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-
alone Semichemical Pulp Mills, and the New Source Performance Standards
(NSPS) for Kraft Pulp Mills constructed, reconstructed, or modified after May
23, 2013. The final rule clarifies how to set operating limits for smelt dissolving
tank (SDT) scrubbers used at these mills and corrects cross-reference errors
in both rules.
New Source Performance Standards (NSPS), Incorporated through R307-210
Summary of 40 Code of Federal Regulations Part 60 Relevant Updates
from July 1, 2020, to July 1, 2024
October 22, 2024 Page 2 of 6
FR Number Title Effective
Date
Summary
New Source Performance Standards (NSPS), Incorporated through R307-210
Summary of 40 Code of Federal Regulations Part 60 Relevant Updates
from July 1, 2020, to July 1, 2024
86 FR 5013 Kb Standards of Performance for Volatile Organic
Liquid Storage Vessels (Including Petroleum
Liquid Storage Vessels) for Which Construction,
Reconstruction, or Modification Commenced
After July 23, 1984
1/19/2021 The U.S. Environmental Protection Agency (EPA) is finalizing amendments to
the Standards of Performance for Volatile Organic Liquid Storage Vessels
(Including Petroleum Liquid Storage Vessels) for Which Construction,
Reconstruction, or Modification Commenced After July 23, 1984. We are
finalizing specific amendments that would allow owners or operators of storage
vessels subject to the Standards of Performance for Volatile Organic Liquid
Storage Vessels and equipped with either an external floating roof (EFR) or
internal floating roof (IFR) to voluntarily elect to comply with the requirements
specified in the National Emission Standards for Storage Vessels (Tanks)--
Control Level 2, as an alternative standard, in lieu of the requirements
specified in the Standards of Performance for Volatile Organic Liquid Storage
Vessels, subject to certain caveats and exceptions for monitoring,
recordkeeping, and reporting.
86 FR 2542 TTTT Pollutant-Specific Significant Contribution
Finding for Greenhouse Gas Emissions From
New, Modified, and Reconstructed Stationary
Sources: Electric Utility Generating Units, and
Process for Determining Significance of Other
New Source Performance Standards Source
Categories
3/15/2021 In this final action, the U.S. Environmental Protection Agency (EPA) is
finalizing a significant contribution finding (SCF) for purposes of regulating
source categories for greenhouse gas (GHG) emissions, under section 111(b)
of the Clean Air Act (CAA) for electric generating units (EGUs), and in doing
so, reaffirming that EGUs remain a listed source category. The EPA has
reached that conclusion by articulating a framework under which source
categories are considered to contribute significantly to dangerous air pollution
due to their GHG emissions if the amount of those emissions exceeds 3
percent of total U.S. GHG emissions. The EPA is applying the 3-percent
threshold to the EGU source category to demonstrate that GHG emissions
from the EGU source category would contribute significantly to dangerous air
pollution. While EGU GHG emissions exceed this threshold by a sufficient
magnitude to warrant an SCF without more ado, the EPA has also, for
completeness, analyzed EGU emissions under a secondary criteria framework,
which also demonstrates the propriety of the SCF.
October 22, 2024 Page 3 of 6
FR Number Title Effective
Date
Summary
New Source Performance Standards (NSPS), Incorporated through R307-210
Summary of 40 Code of Federal Regulations Part 60 Relevant Updates
from July 1, 2020, to July 1, 2024
87 FR 48603 IIII, JJJJ National Emission Standards for Hazardous Air
Pollutants for Reciprocating Internal Combustion
Engines; New Source Performance Standards
for Stationary Internal Combustion Engines;
Court Vacatur
8/10/2022 The Environmental Protection Agency (EPA) is amending the Code of Federal
Regulations (CFR) to reflect a 2015 court decision regarding the National
Emission Standards for Hazardous Air Pollutants (NESHAP) for Stationary
Reciprocating Internal Combustion Engines (RICE) and the New Source
Performance Standards (NSPS) for Stationary Internal Combustion Engines
(ICE). The court vacated provisions in the regulations specifying that
emergency engines could operate for emergency demand response or during
periods where there is a deviation of voltage or frequency. This ministerial rule
revises the RICE NESHAP and ICE NSPS to conform to the court's decision.
88 FR 11556 KK, KKa New Source Performance Standards Review for
Lead Acid Battery Manufacturing Plants and
National Emission Standards for Hazardous Air
Pollutants for Lead Acid Battery Manufacturing
Area Sources Technology Review
1/23/2023 This action finalizes the results of the Environmental Protection Agency's
(EPA's) review of the New Source Performance Standards (NSPS) for Lead
Acid Battery Manufacturing Plants and the technology review for the National
Emission Standards for Hazardous Air Pollutants (NESHAP) for Lead Acid
Battery Manufacturing Area Sources as required under the Clean Air Act
(CAA). The EPA is finalizing revised lead emission limits for grid casting, paste
mixing, and lead reclamation operations for both the area source NESHAP and
under a new NSPS subpart (for lead acid battery manufacturing facilities that
begin construction, reconstruction, or modification after February 23, 2022). In
addition, the EPA is finalizing the following amendments for both the area
source NESHAP and under the new NSPS subpart: performance testing once
every 5 years to demonstrate compliance; work practices to minimize
emissions of fugitive lead dust; increased inspection frequency of fabric filters;
clarification of activities that are considered to be lead reclamation activities;
electronic reporting of performance test results and semiannual compliance
reports; and the removal of exemptions for periods of startup, shutdown, and
malfunctions (SSM). The EPA is also finalizing a revision to the applicability
provisions in the area source NESHAP such that facilities which make lead-
bearing battery parts or process input material, including but not limited to grid
casting facilities and lead oxide manufacturing facilities, will be subject to the
area source NESHAP. In addition, the EPA is finalizing a requirement in the
new NSPS for new facilities to operate bag leak detection systems for emission
points controlled by a fabric filter that do not include a secondary fabric filter.
October 22, 2024 Page 4 of 6
FR Number Title Effective
Date
Summary
New Source Performance Standards (NSPS), Incorporated through R307-210
Summary of 40 Code of Federal Regulations Part 60 Relevant Updates
from July 1, 2020, to July 1, 2024
88 FR 18056 TTT, TTTa New Source Performance Standards Review for
Industrial Surface Coating of Plastic Parts for
Business Machines
3/27/2023 The Environmental Protection Agency (EPA) is finalizing amendments to the
new source performance standards for Industrial Surface Coating of Plastic
Parts for Business Machines pursuant to the review required by the Clean Air
Act. For affected facilities that commence construction, modification, or
reconstruction after June 21, 2022, the EPA is, in a new subpart, finalizing
volatile organic compound (VOC) emission limitations for prime, color, texture,
and touch-up coating operations. We are also finalizing a requirement for
electronic submission of periodic compliance reports.88 FR 58442 AA, AAa,
AAb
New Source Performance Standards Review for
Steel Plants: Electric Arc Furnaces and Argon-
Oxygen Decarburization Vessels
8/25/2023 The Environmental Protection Agency (EPA) is finalizing amendments to the
new source performance standards (NSPS) for electric arc furnaces (EAF) and
argon-oxygen decarburization (AOD) vessels in the steel industry pursuant to
the review required by the Clean Air Act.
88 FR 80594 L, La New Source Performance Standards Review for
Secondary Lead Smelters
11/20/2023 The Environmental Protection Agency (EPA) is finalizing amendments to the
new source performance standards (NSPS) for secondary lead smelters
pursuant to the periodic review required by the Clean Air Act (CAA).
Specifically, the EPA is finalizing revisions to the NSPS that applies to affected
secondary lead smelters constructed, reconstructed, or modified after
December 1, 2022 (NSPS subpart La). The EPA is also finalizing amendments
to the NSPS for secondary lead smelters constructed, reconstructed, or
modified after June 11, 1973, and on or before December 1, 2022, (NSPS
subpart L). In addition, we are finalizing the use of EPA Method 22 (Visual
Determination of Fugitive Emissions from Material Sources and Smoke
Emissions from Flares) as an alternative for demonstrating compliance with the
opacity limit.
October 22, 2024 Page 5 of 6
FR Number Title Effective
Date
Summary
New Source Performance Standards (NSPS), Incorporated through R307-210
Summary of 40 Code of Federal Regulations Part 60 Relevant Updates
from July 1, 2020, to July 1, 2024
88 FR 80480 B, Ba Adoption and Submittal of State Plans for
Designated Facilities: Implementing Regulations
Under Clean Air Act Section 111(d)
12/18/2023 The Environmental Protection Agency (EPA) is finalizing amendments to the
regulations that govern the processes and timelines for state and Federal
plans to implement emission guidelines under Clean Air Act (CAA) New
Source Performance Standards for existing sources (the "implementing
regulations"). The amendments include revisions to the timing requirements for
state and the EPA actions related to plans; the addition of mechanisms to
improve flexibility and efficiency in plan processes; and new requirements for
demonstration of timely meaningful engagement with pertinent stakeholders--
including, but not limited to, industry, small businesses, and communities most
affected by and vulnerable to the impacts of the plan. This action additionally
provides a process for states' consideration of `remaining useful life and other
factors' (RULOF) in applying a standard of performance; amends the definition
of standard of performance in the implementing regulations; and clarifies
compliance flexibilities that states may choose to incorporate into state plans,
including trading or averaging. Finally, this action adds requirements for the
electronic submission of state plans and provides several other clarifications
and minor revisions to the implementing regulations.
89 FR 27392 EEEE,
FFFF
Other Solid Waste Incinerators; Air Curtain
Incinerators Title V Permitting Provisions
4/17/2024 On August 31, 2020, in accordance with requirements under the Clean Air Act
(CAA), the U.S. Environmental Protection Agency (EPA) performed a 5-year
review of the Standards of Performance for New Stationary Sources and
Emissions Guidelines for Existing Sources: Other Solid Waste Incineration
(OSWI) Units, which includes certain very small municipal waste combustion
(VSMWC) and institutional waste incineration (IWI) units. In the same action,
the EPA proposed to remove the title V permitting requirements for air curtain
incinerators (ACI) that burn only wood waste, clean lumber, yard waste, or a
mixture of these three types of waste. In response to supportive comments
received on the August 2020 proposal, this action is finalizing, as proposed, to
remove the title V permitting requirements for ACIs that only burn wood waste,
clean lumber, yard waste, or a mixture of those, and are not located at title V
major sources or subject to title V for other reasons. The EPA is finalizing this
proposed action now to simplify the compliance obligations for owners and
operators of these types of units.
October 22, 2024 Page 6 of 6
FR Number Title Effective
Date
Summary
New Source Performance Standards (NSPS), Incorporated through R307-210
Summary of 40 Code of Federal Regulations Part 60 Relevant Updates
from July 1, 2020, to July 1, 2024
89 FR 16820 OOOO,
OOOOa.
OOOOb,
OOOOc
Standards of Performance for New,
Reconstructed, and Modified Sources and
Emissions Guidelines for Existing Sources: Oil
and Natural Gas Sector Climate Review
5/7/2024 The Environmental Protection Agency (EPA) is finalizing multiple actions to
reduce air pollution emissions from the Crude Oil and Natural Gas source
category. First, the EPA is finalizing revisions to the new source performance
standards (NSPS) regulating greenhouse gases (GHGs) and volatile organic
compounds (VOCs) emissions for the Crude Oil and Natural Gas source
category pursuant to the Clean Air Act (CAA). Second, the EPA is finalizing
emission guidelines (EG) under the CAA for states to follow in developing,
submitting, and implementing state plans to establish performance standards
to limit GHG emissions from existing sources (designated facilities) in the
Crude Oil and Natural Gas source category. Third, the EPA is finalizing several
related actions stemming from the joint resolution of Congress, adopted on
June 30, 2021, under the Congressional Review Act (CRA), disapproving the
EPA's final rule titled, "Oil and Natural Gas Sector: Emission Standards for
New, Reconstructed, and Modified Sources Review," September 14, 2020
("2020 Policy Rule"). Fourth, the EPA is finalizing a protocol under the general
provisions for optical gas imaging (OGI).
October 22, 2024 Page 1 of 5
FR Number Subpart Title Effective Date Summary
85 FR 73854 A, F, G, H, J, L, M, N, O, Q, R, S, T,
U, W, X, Y, AA, BB, CC, DD, EE, GG,
HH, II, JJ, KK, LL, MM, YY, CCC,
DDD, EEE, GGG, HHH, III, JJJ, LLL,
MMM, NNN, OOO, PPP, QQQ, RRR,
TTT, UUU, VVV, XXX, EEEE, FFFF,
GGGG, IIII, JJJJ, KKKK, MMMM,
NNNN, OOOO, PPPP, QQQQ,
RRRR, SSSS, TTTT, UUUU, VVVV,
WWWW, XXXX, YYYY, ZZZZ,
AAAAA, BBBBB, CCCCC, DDDDD,
EEEEE, FFFFF, GGGGG, HHHHH,
IIIII, JJJJJ, KKKKK, LLLLL, MMMMM,
NNNNN, PPPPP, QQQQQ, RRRRR,
SSSSS, TTTTT, WWWWW,
BBBBBB, CCCCCC, HHHHHH,
PPPPPP, RRRRRR, QQQQQQ,
TTTTTT, YYYYYY, WWWWWW,
XXXXXX, AAAAAAA, BBBBBBB,
CCCCCCC, HHHHHHH.
Reclassification of Major Sources as Area
Sources Under Section 112 of the Clean Air Act.
1/19/2021 This rule finalizes amendments to the General Provisions that apply to
National Emission Standards for Hazardous Air Pollutants (NESHAP).
These amendments implement the plain language reading of the "major
source" and "area source" definitions of section 112 of the Clean Air Act
(CAA) and provide that a major source can be reclassified to area source
status at any time upon reducing its potential to emit (PTE) hazardous air
pollutants (HAP) to below the major source thresholds (MST) of 10 tons per
year (tpy) of any single HAP and 25 tpy of any combination of HAP. This rule
also finalizes amendments to clarify the compliance dates, notification, and
recordkeeping requirements that apply to sources choosing to reclassify to
area source status and to sources that revert back to major source status,
including a requirement for electronic notification.
86 FR 13819 A Court Vacatur of Exemption From Emission
Standards During Periods of Startup, Shutdown,
and Malfunction
3/11/2021 The U.S. Environmental Protection Agency (EPA) is amending the Code of
Federal Regulations (CFR) to reflect a court order regarding the General
Provisions for National Emissions Standards for Hazardous Air Pollutants
(NESHAP) issued on December 19, 2008, by the United States Court of
Appeals for the District of Columbia Circuit (the court). The court vacated
two provisions in the General Provisions that exempted sources from
hazardous air pollutant (HAP) non-opacity and opacity emission standards
during periods of startup, shutdown, and malfunction (SSM). The court held
that under the Clean Air Act (CAA), emissions standards or limitations must
be continuous in nature and that the SSM exemptions in these two
provisions violate this requirement. This ministerial action revises these two
NESHAP General Provisions in the CFR to conform to the court's order.
87 FR 393 C Clean Air Act Section 112 List of Hazardous Air
Pollutant: Amendments to the List of Hazardous
Air Pollutants (HAP)
2/4/2022 The U.S. Environmental Protection Agency (EPA) is amending the list of
hazardous air pollutants (HAP) under Clean Air Act (CAA) to add 1-
bromopropane (1-BP) in response to public petitions previously granted by
the EPA. This action amends the list of hazardous air pollutants initially listed
under the CAA.
National Emission Standards for Hazardous Air Pollutants (NESHAP) for Source Categories,
Incorporated through R307-214
Summary of 40 Code of Federal Regulations Part 63 Relevant Updates from July 1, 2020, to July 1, 2024
October 22, 2024 Page 2 of 5
FR Number Subpart Title Effective Date Summary
National Emission Standards for Hazardous Air Pollutants (NESHAP) for Source Categories,
Incorporated through R307-214
Summary of 40 Code of Federal Regulations Part 63 Relevant Updates from July 1, 2020, to July 1, 2024
87 FR 8197 AAAA National Emission Standards for Hazardous Air
Pollutants: Municipal Solid Waste Landfills
Residual Risk and Technology Review;
Correction
2/14/2022 In this action, the U.S. Environmental Protection Agency (EPA) is finalizing
technical revisions and clarifications for the national emission standards for
hazardous air pollutants (NESHAP) for MSW Landfills established in the
March 26, 2020, final rule. This final rule also amends the MSW Landfills
NSPS at 40 CFR part 60, subpart XXX, to clarify and align the timing of
compliance for certain requirements involving installation of a gas collection
and control system (GCCS) under related MSW landfill rules. Additionally,
the EPA is revising the definition of Administrator in the MSW Landfills
Federal Plan that was promulgated on May 21, 2021 to clarify who has the
authority to implement and enforce the applicable requirements. The EPA is
also making some minor typographical corrections.
87 FR 13183 YYYY National Emission Standards for Hazardous Air
Pollutants: Stationary Combustion Turbines;
Amendments
3/9/2022 The U.S. Environmental Protection Agency (EPA) is finalizing amendments
to the National Emission Standards for Hazardous Air Pollutants (NESHAP)
for Stationary Combustion Turbines. This final action removes the stay of the
effectiveness of the standards for new lean premix and diffusion flame gas-
fired turbines that was promulgated in 2004.
87 FR 48603 ZZZZ National Emission Standards for Hazardous Air
Pollutants for Reciprocating Internal Combustion
Engines; New Source Performance Standards
for Stationary Internal Combustion Engines;
Court Vacatur
8/10/2022 The Environmental Protection Agency (EPA) is amending the Code of
Federal Regulations (CFR) to reflect a 2015 court decision regarding the
National Emission Standards for Hazardous Air Pollutants (NESHAP) for
Stationary Reciprocating Internal Combustion Engines (RICE) and the New
Source Performance Standards (NSPS) for Stationary Internal Combustion
Engines (ICE). The court vacated provisions in the regulations specifying
that emergency engines could operate for emergency demand response or
during periods where there is a deviation of voltage or frequency. This
ministerial rule revises the RICE NESHAP and ICE NSPS to conform to the
court's decision.
87 FR 60816 DDDDD National Emission Standards for Hazardous Air
Pollutants for Major Sources: Industrial,
Commercial, and Institutional Boilers and
Process Heaters
12/5/2022 This action finalizes amendments to the national emission standards for
hazardous air pollutants (NESHAP) at major sources from new and existing
industrial, commercial, and institutional (ICI) boilers and process heaters.
Certain aspects of these standards were challenged and subsequently
remanded to the Agency by the United States Court of Appeals for the
District of Columbia Circuit (D.C. Circuit). This action finalizes amendments
to several numeric emission limits for new and existing boilers and process
heaters consistent with the court's opinion and sets compliance dates for
these new emission limits. This action also provides further explanation of
one aspect of the Agency's use of carbon monoxide (CO) as a surrogate for
organic hazardous air pollutants (HAP) and its use of a CO threshold to
represent the application of the maximum achievable control technology
(MACT) for organic HAP. We are also finalizing several technical
clarifications and corrections.
October 22, 2024 Page 3 of 5
FR Number Subpart Title Effective Date Summary
National Emission Standards for Hazardous Air Pollutants (NESHAP) for Source Categories,
Incorporated through R307-214
Summary of 40 Code of Federal Regulations Part 63 Relevant Updates from July 1, 2020, to July 1, 2024
87 FR 78545 GGGGG National Emission Standards for Hazardous Air P 12/22/2022 This action finalizes amendments to the national emission standards for
hazardous air pollutants (NESHAP) for the site remediation source category.
This action finalizes amendments to remove exemptions from the rule for
site remediation activities performed under authority of the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) as a
remedial action or a non- time-critical removal action, and for site
remediation activities performed under Resource Conservation and
Recovery Act (RCRA) corrective actions conducted at treatment, storage,
and disposal facilities.
88 FR 10842 HHHHH National Emission Standards for Hazardous Air
Pollutants: Miscellaneous Coating Manufacturing
Technology Review
2/2/2023 The U.S. Environmental Protection Agency (EPA) is taking final action on
the technology review conducted on the Miscellaneous Coating
Manufacturing (MCM) source category regulated under the National
Emission Standards for Hazardous Air Pollutants (NESHAP). These final
amendments include provisions for inorganic hazardous air pollutant (HAP)
standards for process vessels.
88 FR 11556 PPPPPP New Source Performance Standards Review for
Lead Acid Battery Manufacturing Plants and
National Emission Standards for Hazardous Air
Pollutants for Lead Acid Battery Manufacturing
Area Sources Technology Review
2/23/2023 This action finalizes the results of the Environmental Protection Agency's
(EPA's) review of the New Source Performance Standards (NSPS) for Lead
Acid Battery Manufacturing Plants and the technology review for the National
Emission Standards for Hazardous Air Pollutants (NESHAP) for Lead Acid
Battery Manufacturing Area Sources as required under the Clean Air Act
(CAA). The EPA is finalizing revised lead emission limits for grid casting,
paste mixing, and lead reclamation operations for both the area source
NESHAP and under a new NSPS subpart (for lead acid battery
manufacturing facilities that begin construction, reconstruction, or
modification after February 23, 2022). In addition, the EPA is finalizing the
following amendments for both the area source NESHAP and under the new
NSPS subpart: performance testing once every 5 years to demonstrate
compliance; work practices to minimize emissions of fugitive lead dust;
increased inspection frequency of fabric filters; clarification of activities that
are considered to be lead reclamation activities; electronic reporting of
performance test results and semiannual compliance reports; and the
removal of exemptions for periods of startup, shutdown, and malfunctions
(SSM). The EPA is also finalizing a revision to the applicability provisions in
the area source NESHAP such that facilities which make lead-bearing
battery parts or process input material, including but not limited to grid
casting facilities and lead oxide manufacturing facilities, will be subject to the
area source NESHAP. In addition, the EPA is finalizing a requirement in the
new NSPS for new facilities to operate bag leak detection systems for
emission points controlled by a fabric filter that do not include a secondary
fabric filter.
October 22, 2024 Page 4 of 5
FR Number Subpart Title Effective Date Summary
National Emission Standards for Hazardous Air Pollutants (NESHAP) for Source Categories,
Incorporated through R307-214
Summary of 40 Code of Federal Regulations Part 63 Relevant Updates from July 1, 2020, to July 1, 2024
88 FR 13956 UUUUU National Emission Standards for Hazardous Air
Pollutants: Coal- and Oil-Fired Electric Utility
Steam Generating Units-Revocation of the 2020
Reconsideration and Affirmation of the
Appropriate and Necessary Supplemental
Finding
3/6/2023 After consideration of public comments, the EPA is revoking a May 22, 2020
finding that it is not appropriate and necessary to regulate coal- and oil-fired
electric utility steam generating units (EGUs) under Clean Air Act (CAA)
section 112, and concluding, as it did in its April 25, 2016 finding, that it
remains appropriate and necessary to regulate hazardous air pollutant
(HAP) emissions from EGUs after considering cost.
89 FR 16408 RRRRR National Emission Standards for Hazardous Air
Pollutants: Taconite Iron Ore Processing
3/6/2024 The U.S. Environmental Protection Agency (EPA) is finalizing amendments
to the National Emission Standards for Hazardous Air Pollutants (NESHAP)
for Taconite Iron Ore Processing. Specifically, the EPA is finalizing
maximum achievable control technology (MACT) standards for mercury (Hg)
and establishing revised emission standards for hydrogen chloride (HCl) and
hydrogen fluoride (HF). This final action ensures that emissions of all
hazardous air pollutants (HAP) emitted from the Taconite Iron Ore
Processing source category are regulated.
89 FR 23840 XX, YY, EEEE, FFFF, CC National Emission Standards for Hazardous Air
Pollutants: Ethylene Production, Miscellaneous
Organic Chemical Manufacturing, Organic
Liquids Distribution (Non-Gasoline), and
Petroleum Refineries Reconsideration
4/4/2024 On July 6, 2020, the U.S. Environmental Protection Agency (EPA or the
Agency) finalized the residual risk and technology review (RTR) conducted
for the Ethylene Production source category, which is part of the Generic
Maximum Achievable Control Technology Standards National Emission
Standards for Hazardous Air Pollutants (NESHAP); on July 7, 2020, the EPA
finalized the RTR conducted for the Organic Liquids Distribution (Non-
Gasoline) NESHAP; and on August 12, 2020, the EPA finalized the RTR
conducted for the Miscellaneous Organic Chemical Manufacturing NESHAP.
Amendments to the Petroleum Refinery Sector NESHAP were most recently
finalized on February 4, 2020. Subsequently, the EPA received and granted
various petitions for reconsideration on these NESHAP for, among other
things, the provisions related to the work practice standards for pressure
relief devices (PRDs), emergency flaring, and degassing of floating roof
storage vessels. This action finalizes proposed amendments to remove the
force majeure exemption for PRDs and emergency flaring, incorporate
clarifications for the degassing requirements for floating roof storage
vessels, and address other corrections and clarifications.
October 22, 2024 Page 5 of 5
FR Number Subpart Title Effective Date Summary
National Emission Standards for Hazardous Air Pollutants (NESHAP) for Source Categories,
Incorporated through R307-214
Summary of 40 Code of Federal Regulations Part 63 Relevant Updates from July 1, 2020, to July 1, 2024
89 FR 23294 FFFFF National Emission Standards for Hazardous Air
Pollutants: Integrated Iron and Steel
Manufacturing Facilities Technology Review
6/3/2024 The U.S. Environmental Protection Agency (EPA or the Agency) is finalizing
amendments to the National Emission Standards for Hazardous Air
Pollutants (NESHAP) for Integrated Iron and Steel Manufacturing Facilities
to regulate hazardous air pollutant (HAP) emissions. The amendments
include: HAP from unmeasured fugitive and intermittent particulate (UFIP)
sources previously not regulated by the NESHAP; previously unregulated
HAP for sinter plants:; previously unregulated pollutants for blast furnace
(BF) stoves and basic oxygen process furnaces (BOPFs) primary control
devices; and previously unregulated pollutants for BF primary control
devices. We are also finalizing an update to the technology review for this
source category.

ITEM 9

195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
DAQ-088-24
M E M O R A N D U M TO: Air Quality Board THROUGH: Bryce C. Bird, Executive Secretary FROM: Erica Pryor, Rules Coordinator DATE: October 22, 2024 SUBJECT: FIVE-YEAR REVIEW: R307-302. Solid Fuel Burning Devices. ______________________________________________________________________________________
Utah Code Title 63G-3-305 requires each agency to review and justify each of its rules within five years of a rule’s original effective date or within five years of the filing of the last five-year review. This review process is not a time to revise or amend the rules, but only to verify that the rule is still necessary and
allowed under state and federal statute. As part of this process, we are required to identify any comments received during and since the last five-year review of each rule. This process is not the time to revisit those comments or to respond to them.
DAQ has completed the five-year review for rule R307-302, Solid Fuel Burning Devices. The results of the five-year review are found in the attached Five-Year Notice of Review and Statement of Continuation form. Based on our review of the rule, we believe it is both allowed under federal and state statute and necessary because it reduces pollution during winter temperature inversions and is part of Utah’s State Implementation Plan. Recommendation: Staff recommend that the Board continue rule R307-302, Solid Fuel Burning Devices, by approving the attached Five-Year Notice of Review and Statement of Continuation form to be filed with the Office of Administrative Rules.
State of Utah
Administrative Rule Analysis
Revised May 2024
NOTICE OF FIVE-YEAR REVIEW AND STATEMENT OF CONTINUATION
Rule Number: R307-302 Filing ID: Office Use Only
Effective Date: Office Use Only
Agency Information
1. Title catchline:Environmental Quality, Air Quality
Building: Multi Agency State Office Building
Street address: 195 N 1950 W
City, state Salt Lake City, UT
Mailing address: PO BOX 144820
City, state and zip: Salt Lake City, UT 84114-4820
Contact persons:
Name: Phone: Email:
Rachel Chamberlain 385-414-3390 [e-mail]
Erica Pryor 385-499-3416 [e-mail]
Please address questions regarding information on this notice to the persons listed above.
General Information
2. Rule catchline:
R307-302. Solid Fuel Burning Devices.
3. A concise explanation of the particular statutory provisions under which the rule is enacted and how these
provisions authorize or require this rule:
Rule R307-302 identifies no-burn periods for solid fuel burning devices in areas that sometimes exceed the health standards for
fine particulate. Subsection 19-2-104(1)(a) allows the Air Quality Board to make rules "…regarding the control, abatement, and
prevention of air pollution from all sources and the establishment of the maximum quantity of air contaminants that may be
emitted by any air contaminant source."
4. A summary of written comments received during and since the last five-year review of this rule from interested
persons supporting or opposing this rule:
No written comments have been received since the previous review in April 2020.
5. A reasoned justification for continuation of this rule, including reasons why the agency disagrees with comments
in opposition to this rule, if any:
The provisions to regulate solid fuel burning are part of the requirements to reduce particulates and carbon monoxide that are
included in Utah's state implementation plans for particulate matter and carbon monoxide. Because the provisions in this rule
are necessary to reduce pollution during winter temperature inversions when pollutants build up in the air, and because the rule
is part of Utah's state implementation plan, this rule should be continued.
Agency Authorization Information
To the agency: Information requested on this form is required by Section 63G-3-305. Incomplete forms will be returned to the
agency for completion, possibly delaying publication in the Utah State Bulletin.
Agency head or
designee and title:
Bryce C. Bird, Director, Division of Air
Quality
Date: 10/16/2024
Reminder: Text changes cannot be made with this type of rule filing. To change any text, please file an amendment or a
nonsubstantive change.
R307. Environmental Quality, Air Quality. 1
R307-302. Solid Fuel Burning Devices. 2
R307-302-1. Purpose and Definitions. 3
(1)R307-302 establishes visible emission standards and specifies when it is permissible to burn in4
solid fuel burning devices used to provide comfort heating. 5
(2) The following additional definitions apply to R307-302:6
"Seasoned wood" means wood that has a moisture content of less than or equal to 25%.7
"Sole source of heat" means the solid fuel burning device is the only available source of heat for the8
entire residence, except for small portable heaters. 9
"Solid fuel burning device" means fireplaces, wood stoves and boilers used for burning wood, coal, 10
or any other nongaseous and non-liquid fuel, both indoors and outdoors, but excluding outdoor wood boilers, 11
which are regulated under R307-208. 12
13
R307-302-2. Applicability. 14
(1)R307-302-3 and R307-302-6 shall apply to any solid fuel burning device used to provide15
comfort heating in PM10 or PM2.5 nonattainment or maintenance areas as defined in 40 CFR 81.345 (July 1, 16
2011). Collectively, The PM10 and PM2.5 nonattainment and maintenance plan areas are geographically 17
defined as all regions of Salt Lake and Davis counties; all portions of the Cache Valley; all regions in Weber 18
County west of the Wasatch mountain range; all regions of Utah County; in Box Elder County, from the 19
Wasatch mountain range west to the Promontory mountain range and south of Portage; and in Tooele 20
County, from the northernmost part of the Oquirrh mountain range to the northern most part of the Stansbury 21
mountain range and north of Route 199. 22
(2) R307-302-4 shall apply only within the city limits of Provo in Utah County.23
(3) R307-302-5 shall apply in all portions of Box Elder, Cache, Davis, Salt Lake, Tooele, Utah and24
Weber counties. 25
(4) The following exemptions apply to R307-302:26
(a) R307-302 does not apply to restaurant and institutional food preparation.27
(b)R307-302 does not apply to commercial and industrial boilers subject to an approval order issued28
under R307-401. 29
(c) R307-302-3 does not apply to sources located above 7,000 feet in elevation within Box Elder,30
Davis, Salt Lake, Tooele, Utah and Weber counties. 31
(d)R307-302 does not apply to firefighting training devices that meet the definition of a solid fuel32
burning device. 33
34
R307-302-3. No-Burn Periods for Particulates. 35
(1)A person using a solid fuel burning device as a sole source of heat must register with the director36
in order to be exempt during mandatory no-burn periods. 37
(2)When the ambient concentration of PM10 measured by the monitors in Salt Lake, Davis, Weber,38
or Utah counties reaches the level of 120 micrograms per cubic meter and the forecasted weather for the 39
specific area includes a temperature inversion which is predicted to continue for at least 24 hours, the director 40
will issue a public announcement and will distribute such announcement to the local media notifying the 41
public that a mandatory no-burn period for solid fuel burning devices is in effect. The mandatory no-burn 42
periods will only apply to those areas or counties impacting the real-time monitoring site registering the 120 43
micrograms per cubic meter concentration. A person in the affected areas shall not use a solid fuel burning 44
device unless it is the sole source of heat for an entire residence and registered with the director. 45
(3) PM10 Contingency Plan. If the PM10 Contingency Plan described in Section IX, Part A, of the46
State Implementation Plan has been implemented, the trigger level for no-burn periods as specified in R307-47
302-3(2) will be 110 micrograms per cubic meter for that area where the PM10 Contingency Plan has been48
implemented. 49
(4)When the ambient concentration of PM2.5 measured by monitors in Box Elder, Cache, Davis,50
Salt Lake, Tooele, Utah or Weber counties are forecasted to reach or exceed 25 micrograms per cubic meter, 51
the director will issue a public announcement to provide broad notification that a mandatory no-burn period 52
for solid fuel burning devices is in effect. The mandatory no-burn periods will only apply to those counties 53
identified by the director. A person within the geographical boundaries described in R307-302-2(1) shall not 54
use a solid fuel burning device unless it is the sole source of heat for an entire residence and registered with 55
the director. 56
Page 1 of 2
(5) PM2.5 Contingency Plan. If the PM2.5 contingency plan of the State Implementation Plan has 1
been implemented, the trigger level for no-burn periods as specified in R307-302-3(4) shall be 15 2
micrograms per cubic meter for the area where the PM2.5 contingency plan has been implemented. 3
4
R307-302-4. No-Burn Periods for Carbon Monoxide. 5
(1)Beginning on November 1 and through March 1, the director will issue a public announcement6
and will distribute such announcement to the local media notifying the public that a mandatory no-burn 7
period for solid fuel burning devices is in effect when the running eight-hour average carbon monoxide 8
concentration as monitored by the state at 4:00 PM reaches a value of 6.0 ppm or more. 9
(2) In addition to the conditions contained in R307-302-4(1), the director may use meteorological10
conditions to initiate a no-burn period. These conditions are: 11
(a) A national weather service forecasted clearing index value of 250 or less;12
(b) Forecasted wind speeds of three miles per hour or less;13
(c)Passage of a vigorous cold front through the Wasatch Front; or14
(d)Arrival of a strong high pressure system into the area.15
(3)During the no-burn periods specified in R307-302-4(1) and (2), a person in Provo City shall not16
use a solid fuel burning device unless it is the sole source of heat for an entire residence and is registered with 17
the director. 18
19
R307-302-5. Opacity and Prohibited Fuels for Heating Appliances. 20
(1) Except during no-burn periods as required by R307-302-3 and 4, visible emissions from solid21
fuel burning devices shall be limited to a shade or density no darker than 20% opacity as measured by EPA 22
Method 9, except for the following: 23
(a)An initial fifteen minute start-up period, and24
(b) A period of fifteen minutes in any three-hour period in which emissions may exceed the 20%25
opacity limitation for refueling. 26
(2) Prohibited Fuels: A person shall not cause or allow any of the following materials to be burned27
in a solid fuel burning device at any time: 28
(a) asphaltic products;29
(b) books and magazines;30
(c) garbage;31
(d) paints;32
(e)colored/wrapping paper;33
(f) plastic;34
(g) rubber products;35
(h) treated wood;36
(i)waste petroleum products; or37
(j) any other material not intended by a manufacturer for use as a fuel in a solid fuel burning device.38
(3) A person burning wood in a solid fuel burning device shall only burn seasoned wood.39
40
R307-302-6. Prohibition. 41
(1)No person shall sell, offer for sale, supply, install, or transfer a wood burning stove that is not42
EPA certified or a fireplace that is not EPA qualified. 43
(2) Ownership of a non EPA certified stove within a residential dwelling installed prior to March 6,44
2014 may be transferred as part of a real estate transaction, so long as the unit remains intact within the real 45
property of sale. 46
47
KEY: air pollution, fireplaces, stoves, solid fuel burning 48
Date of Enactment or Last Substantive Amendment: February 1, 2017 49
Notice of Continuation: March 5, 2020 50
Authorizing, and Implemented or Interpreted Law: 19-2-101; 19-2-104 51
Page 2 of 2

ITEM 10

Air Toxics

195 North 1950 West • Salt Lake City, Utah
Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820
Telephone [phone] • Fax [phone] • T.D.D [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

SPENCER J. COX
Governor

DEIDRE HENDERSON
Lieutenant Governor
Department of
Environmental Quality

Kimberly D. Shelley
Executive Director

DIVISION OF AIR QUALITY
Bryce C. Bird
Director

DAQA-680-24

M E M O R A N D U M

TO: Air Quality Board

FROM: Bryce C. Bird, Executive Secretary

DATE: October 7, 2024

SUBJECT: Air Toxics, Lead-Based Paint, and Asbestos (ATLAS) Section Compliance Activities –
September 2024
______________________________________________________________________________________

Asbestos Demolition/Renovation NESHAP Inspections 2
Asbestos AHERA Inspections 8
Asbestos State Rules Only Inspections 4
Asbestos Notification Forms Accepted **
Asbestos Telephone Calls 319
Asbestos Individuals Certifications Approved 77
Asbestos Company Certifications 5
Asbestos Alternate Work Practices Approved 2
Lead-Based Paint (LBP) Inspections 1
LBP Notification Forms Approved 1
LBP Telephone Calls 58
LBP Letters Prepared and Mailed 18
LBP Courses Reviewed/Approved 0
LBP Course Audits 0
LBP Individual Certifications Approved 44
DAQA-680-24
Page 2

LBP Firm Certifications 12
Notices of Violation Sent 0
Compliance Advisories Sent 7
Warning Letters Sent 1
Settlement Agreements Finalized 1
Penalties Agreed to:
Impact Demolition/AJ Kim $250.00

**ATLAS is currently not working properly, so unable to get accurate numbers. The problem is being
worked on, but the information is unavailable at this time. Will update once we can get the correct
numbers.

Compliance

195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144820 • Salt Lake City, UT 84114-4820
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

Department of
Environmental Quality

Kimberly D. Shelley
Executive Director

DIVISION OF AIR QUALITY
Bryce C. Bird
Director

SPENCER J. COX
Governor

DEIDRE HENDERSON
Lieutenant Governor
DAQC-1037-24

M E M O R A N D U M

TO: Air Quality Board

FROM: Bryce C. Bird, Executive Secretary

DATE: October 10, 2024

SUBJECT: Compliance Activities – September 2024
_____________________________________________________________________________________

ACTIVITIES:
Activity Monthly Total 36-Month Average
Inspections 31 60
On-Site Stack Test & CEM Audits 3 5
Stack Test & RATA Report Reviews 33 37
Emission Report Reviews 18 19
Temporary Relocation Request Reviews 7 6
Fugitive Dust Control Plan Reviews 131 124
Soil Remediation Report Reviews 2 2
Open Burn Permits Issued 723 585
Miscellaneous Inspections1 44 16
Complaints Received 33 18
Wood Burning Complaints Received 0 3
Breakdown Reports Received 1 1
Compliance Actions Resulting from a Breakdown 0 0
VOC Inspections (Gas station vapor recovery) 0 0
Warning Letters Issued 4 2
Notices of Violation Issued 2 0
Compliance Advisories Issued 7 6
No Further Action Letters Issued 0 3
Settlement Agreements Reached 4 2
Penalties Assessed $2,773,077 $121,080
1Miscellaneous inspections include, e.g., surveillance, complaint, on-site training, dust patrol, smoke patrol, open
burning, etc.
DAQC-1037-24
Page 2

SETTLEMENT AGREEMENTS:
Party Amount
Ovintiv USA Inc. $2,750,000
Price River Terminal $1,166
DataBank Holdings, Ltd. $21,552
ICU Medical $359

UNRESOLVED NOTICES OF VIOLATION:
Party Date Issued
Citation Oil and Gas (in administrative litigation) 01/15/2020
Uinta Wax Operating (formerly CH4 Finley) 07/24/2020
Finley Resources 09/15/2022
Holcim 12/19/2023
Holcim 03/27/2024
Big West Oil 07/19/2024
Intermountain Regional Landfill 07/31/2024
Holcim 08/02/2024
Flowers Bakeries, LLC 09/17/2024
Winds Exploration and Production 09/17/2024

Monitoring
Utah Division of Air Quality
0
10
20
30
40
50
60
70
80
90
100
12345678910111213141516171819202122232425262728293031
PM
2.
5
(µ
g
/
m
3)
Days
Utah 24-Hr PM2.5 Data August 2024
Brigham City Bountiful Copperview Erda
Harrisville Hawthorne Lindon Near road
Rose Park Roosevelt Spanish Fork Smithfield
Environmental Quality Vernal 24-hr Exceedence Value is 35 µg/m3
Exceedence Value is 35 µg/m3
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
*
Utah Division of Air Quality
0
10
20
30
40
50
60
70
80
90
100
12345678910111213141516171819202122232425262728293031
PM
2.5
(µ
g
/
m
3)
Days
Utah 24-Hr PM2.5 Data September 2024
Brigham City Bountiful Copperview Erda
Harrisville Hawthorne Lindon Near road
Rose Park Roosevelt Spanish Fork Smithfield
Environmental Quality Vernal 24-hr Exceedence Value is 35 µg/m3
Exceedence Value is 35 µg/m3
*EnvironmentalQuality (EQ) previously named Technical Support Center (TSC)
*
Utah Division of Air Quality
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
PM
2.
5
(µ
g
/
m
3)
Days
Utah 24-Hr PM2.5 Data October 2024
Brigham City Bountiful Copperview
Erda Harrisville Hawthorne
Lindon Near road Rose Park
Roosevelt Spanish Fork Smithfield
Environmental Quality Vernal 24-hr Exceedence Value is 35 µg/m3
Exceedence Value is 35 µg/m3
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
*
Utah Division of Air Quality
0
50
100
150
200
250
300
350
400
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
PM
10
(µ
g
/
m
3)
Days
Utah 24-hr PM10 Data August 2024
Harrisville Hawthorne Herriman #3 Lindon Roosevelt Environmental Quality 24-hr Exceedance Value is 150 ug/m3
Exceedance Value is 150 ug/m3
*
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
Utah Division of Air Quality
0
50
100
150
200
250
300
350
400
1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930
PM
10
(µ
g
/
m
3)
Days
Utah 24-hr PM10 Data September 2024
Harrisville Hawthorne Herriman #3 Lindon Roosevelt Environmental Quality 24-hr Exceedance Value is 150 ug/m3
Exceedance Value is 150 ug/m3
*
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
Utah Division of Air Quality
0
50
100
150
200
250
300
350
400
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
PM
10
(µ
g
/
m
3)
Days
Utah 24-hr PM10 Data October 2024
Harrisville Hawthorne Herriman #3 Lindon Roosevelt Environmental Quality 24-hr Exceedance Value is 150 ug/m3
Exceedance Value is 150 ug/m3
*
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
36.5
37.6
36.8 36.2
37.9
38.9
36.8 35.2 34.6 34.9
35.6
29.4
30.5 32.7
33.2
34.8
30.2
31.8
34.0 35.7
33.2 32.4 31.830.7
26.8 26.1
31.2 30.6
27.1
30.1
32.8
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature August 2024
Bountiful Copperview Erda Herriman #3 HV Hawthorne Near Road Red butte Rose Park Environmental Quality Exceed.TM*
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
** Controlling Monitor
**
34.536.0
35.3
31.5
30.7
32.9
32.1 29.8
29.4 30.3 29.1
27.2
22.3
26.0
29.1
32.2
28.1 27.0
28.4
31.7 30.6
25.1 25.1
27.9
22.1
26.1 27.8
30.2
29.6
28.8
30.3
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.020
0.040
0.060
0.080
0.100
0.120
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Da
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(
p
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature August 2024
Price #2 Roosevelt Vernal Exceed.TM
33.4
35.6
33.8
33.1
35.2 34.9
33.1 31.4 31.3
32.6 31.2
26.1 27.5 27.7 30.6
31.3
29.1
31.1
30.9
32.5
30.5
30.3
29.2 28.2
25.4 23.8
27.7 26.5
25.0
28.9
30.4
-10.0
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
Da
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Oz
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(
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature August 2024
Smithfield Exceed.TM
35.8
36.9
36.1
34.6
36.2
37.3
35.0 33.2 33.0 32.8 32.4
27.9 28.7
28.7 31.5
32.7
30.0
31.132.3 33.9 33.3
30.2 30.029.3
26.6 25.2
30.2 31.1
27.3
29.7
32.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
12345678910111213141516171819202122232425262728293031
Da
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(
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature August 2024
Lindon Spanish Fork Exceed.TM
35.9 37.438.9 39.1
40.2
37.4
35.7
37.3 37.8
34.4 34.9
35.3 35.7
35.4
37.0
32.7 32.2
35.9
37.936.4
26.6
33.8
32.229.8
32.9 34.7
34.9 35.3 36.2
36.6
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature August 2024
Enoch Hurricane Moab Exceed.TM
36.5 37.6
36.8 36.2
37.9
38.9
36.8 35.2 34.6
34.9 35.6
29.4 30.5
32.7 33.2 34.8
30.231.8
34.0
35.7 33.2
32.4 31.8
30.7
26.8
26.1
31.2 30.6
27.1
30.1
32.8
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
12345678910111213141516171819202122232425262728293031
Da
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature August 2024
Stations Monitoring the Inland Port Development
ZZ Lake Park Exceed.TM
*ZZ is located at the New Utah State Prison (1480 North 8000 West, SLC).
This site was previously named IP
*
33.4
35.6
33.8 33.1
35.2 34.9
33.1 31.4 31.3
32.6
31.2
26.1
27.5
27.7
30.6 31.3 29.131.1 30.9
32.5 30.5
30.3
29.2
28.2
25.4
23.8
27.7 26.5
25.0
28.9
30.4
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
12345678910111213141516171819202122232425262728293031
Da
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature August 2024
Brigham city Exceed.TM
35.133.4
32.6
26.5
29.7
32.9 34.7
33.8 33.0
31.5
30.7
20.3
24.2
30.4
30.5
27.1
18.6
21.9
24.8 26.5
24.8 25.4 25.3
27.6
32.5
30.9 31.3
36.0
33.2
24.6
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
Da
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature September 2024
Bountiful Copperview Erda Herriman #3 HV Hawthorne Near Road Red butte Rose Park Environmental Quality Exceed.TM
*
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
** Controlling Monitor
**
30.9
30.8
26.6
27.2
26.4
28.029.5
28.8
27.3 26.9
27.6
21.6 22.6
26.9
27.1
26.7
19.1
21.6
24.426.2 25.6
21.8
24.5 25.0
27.8
29.2
29.5 29.2
28.8 29.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.020
0.040
0.060
0.080
0.100
0.120
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature September 2024
Price #2 Roosevelt Vernal Exceed.TM
32.5
32.4
29.4
24.8
28.4 29.5 31.4 30.1 30.7 30.2
28.6
16.7
21.2
26.1 27.9 25.2
15.8
18.0
23.2
25.0
24.4
24.7
23.7
26.6
29.6 28.8 29.4
31.130.7
21.6
-10.0
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature September 2024
Smithfield Exceed.TM
33.6
33.0
30.6
26.6
28.1
30.832.8 31.6 31.3
30.3 29.5
20.5
23.7
28.5
28.7
24.2
19.3
21.7
25.5 25.5 24.2 25.1 24.7
26.5
30.9 30.5
29.9
33.331.9
24.8
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
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Highest 8-hr Ozone Concentration & Daily Maximum Temperature September 2024
Lindon Spanish Fork Exceed.TM
35.7 36.0
36.9 36.1
36.6 37.1
35.2 34.5 34.6
32.8
30.9
31.2 32.0
32.0
28.7
23.7
27.529.6 29.027.5
30.8 32.2 33.1
35.1 35.1 37.0
37.2 35.9 35.9
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature September 2024
Enoch Hurricane Moab Exceed.TM
35.1
33.4
32.6
26.5
29.7
32.9 34.7 33.8 33.0
31.5
30.7
20.3
24.2
30.4 30.5
27.1
18.621.9
24.8
26.5 24.8
25.4 25.3
27.6
32.5
30.9
31.3
36.0
33.2
24.6
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature September 2024
Stations Monitoring the Inland Port Development
ZZ Lake Park Exceed.TM
*ZZ is located at the New Utah State Prison (1480 North 8000 West, SLC).
This site was previously named IP
*
32.5
32.4
29.4
24.8
28.4
29.5 31.4 30.1
30.7
30.2
28.6
16.7
21.2
26.1
27.9
25.2
15.818.0
23.2
25.0
24.4
24.7
23.7
26.6
29.6
28.8
29.4
31.1 30.7
21.6
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature September 2024
Brigham city Exceed.TM
26.4
29.6
26.9
32.2
26.9
30.1
28.3
28.9
30.3 29.3
29.928.6 28.7
28.5
27.5
26.0
17.1
11.1
15.8 17.5
21.6 21.7
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature October 2024
Bountiful Copperview Erda Herriman #3 HV Hawthorne Near Road Red butte Rose Park Environmental Quality Exceed.TM*
*Environmental Quality (EQ) previously named Technical Support Center (TSC)
** Controlling Monitor
**
25.4
26.0
26.1
26.6
26.2
23.5
23.4
22.724.7 24.6
26.2 24.9 24.7
24.9
24.1 21.6
15.2
10.0
11.2
11.0
14.7 16.7
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.020
0.040
0.060
0.080
0.100
0.120
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature October 2024
Price #2 Roosevelt Vernal Exceed.TM
23.7
26.0
25.0
27.9
24.0
25.8 26.6
27.7 27.3
25.8 26.126.3 26.1 26.4
26.2 24.2
12.5
7.9
14.8
17.5 18.7
19.5
-10.0
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
0.110
0.120
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature October 2024
Smithfield Exceed.TM
26.3
27.9
27.7
30.6
25.5
26.727.9
27.6 28.5
27.4
28.0
27.1 27.7
27.2
25.823.6
19.3
8.5
15.9
13.2
20.0
21.4
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature October 2024
Lindon Spanish Fork Exceed.TM
35.0
34.8
34.5 34.0
33.8 34.1
33.6 32.6 31.8
31.6
30.930.2 29.4
29.1 28.2
24.3
13.0
17.3
20.2
23.0
26.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature October 2024
Enoch Hurricane Moab Exceed.TM
26.4
29.6
26.9
32.2
26.9
30.1
28.3
28.9
30.3
29.3 29.928.6 28.7
28.5 27.5
26.0
17.1
11.1
15.8
17.5
21.6
21.7
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
12345678910111213141516171819202122232425262728293031
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature October 2024
Stations Monitoring the Inland Port Development
ZZ Lake Park Exceed.TM
*ZZ is located at the New Utah State Prison (1480 North 8000 West, SLC).
This site was previously named IP
*
23.7
26.0
25.0
27.9
24.0
25.8 26.6
27.7 27.3
25.8 26.1
26.3 26.1
26.4 26.2
24.2
12.5
7.9
14.8
17.5
18.7
19.5
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
12345678910111213141516171819202122232425262728293031
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Days
Highest 8-hr Ozone Concentration & Daily Maximum Temperature October 2024
Brigham city Exceed.TM