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HomeMy WebLinkAboutDAQ-2025-002532 195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone (801) 536-4000 • Fax (801) 536-4099 • T.D.D. (801) 903-3978 www.deq.utah.gov Printed on 100% recycled paper State of Utah Department of Environmental Quality Tim Davis Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director Air Quality Board Kim Frost, Chair Michelle Bujdoso, Vice-Chair Tim Davis Seth Lyman Colton Norman Sonja Norton John Rasband Jeff Silvestrini Dave Spence Bryce C. Bird, Executive Secretary SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor DAQ-048-25 UTAH AIR QUALITY BOARD MEETING TENTATIVE AGENDA Wednesday, June 4, 2025 - 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 Meetings: July 2, 2025, and August 6, 2025 III. Approval of the Minutes for the May 7, 2025, Board Meeting. IV. Propose for Final Adoption: Amend R307-150. Emission Inventories. Presented by Greg Mortensen. V. Informational Items. A. Air Toxics. Presented by Leonard Wright. B. Compliance. Presented by Harold Burge, Rik Ombach, and Chad Gilgen. C. Monitoring. Presented by Thomas Greene. 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 (385) 226-4881, TDD (801) 536-4284 or by email at leannjohnson@utah.gov. ITEM 4 195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone (801) 536-4000 • Fax (801) 536-4099 • T.D.D. 800 346-3128 www.deq.utah.gov Printed on 100% recycled paper State of Utah Department of Environmental Quality Tim Davis Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor DAQ-047-25 M E M O R A N D U M TO: Air Quality Board THROUGH: Bryce C. Bird, Executive Secretary THROUGH: Jazmine Lopez, Rules Coordinator FROM: Greg Mortensen, Inventory Section Manager DATE: May 20, 2025 SUBJECT: PROPOSE FOR FINAL ADOPTION: Amend R307-150. Emission Inventories. ______________________________________________________________________________________ On February 5, 2025, Division of Air Quality staff proposed changes to R307-150, Emission Inventories, for public comment. The Air Quality Board subsequently approved a 30-day public comment period which was then extended another 15 days by the division after receiving an extension request from the Utah Petroleum Association. The proposed amendments included: • Clarification of rule language which erroneously implied that sulfur dioxide (SO2) requirements would lapse in 2018; • An added section and definition pertaining to mobile source reporting on point source facilities; • The removal of decades-old HAPs reporting thresholds which were not documented and could not be reproduced; and • Clerical language, rule reference corrections, and formatting adjustments. The division has reviewed and evaluated all comments submitted in writing during the associated 45-day public comment period from March 1 to April 15, 2025, 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 and a more detailed summary with specific responses may be reviewed in Appendix A of the board packet. Below is a summary of comments received and responses from the division. DAQ-047-25 Page 2 No comments were received in opposition to the proposed change for SO2 reporting. Various comments focused on the mobile source emissions reporting requirements. As the division reviewed the comments and the rule language itself, it became clear that there is confusion on the applicability, process, and on the need for specifying mobile emissions reporting in the rule. Comments also suggested prepared guidance coupled with public outreach on these submissions would be preferred and/or sufficient. The division agrees that it would be best to remove the mobile emissions reporting proposal at this time to allow for guidance development and outreach. The division is, therefore, removing the proposed section and definition. Regarding hazardous air pollutants (HAPs), comments noted that other states have HAPs thresholds while the division seems arbitrary in setting no threshold for HAPs reporting. Some comments preferred mirroring a threshold set by other states or continuing with the current rule method. Comments expressed concerns with regulatory uncertainty and asked the division if the use of templates for reporting would be affected. At least two other states (West Virginia and Oklahoma) also have no threshold for reporting HAPs. Staff contacted states that do have a threshold, and they all noted that thresholds were set based on a Title V HAPs permitting threshold or a figure set decades ago, and they are also uncertain why that figure was chosen. Ultimately, all states noted that the thresholds were essentially arbitrary as they do not account for the different impacts individual HAPs concentrations have on human health and/or air quality chemistry. A static threshold also cannot account for future changes in scientific knowledge of a pollutant’s impacts. It is noteworthy that the division’s historic threshold method likely attempted to account for each HAP type having vastly different impacts on human health and the environment at varying concentrations. This is reflected in the multitude of thresholds as each HAP has its own threshold and weighted by American Conference of Governmental Industrial Hygienists (ACGIH) factors. Unfortunately, not only is this individual calculation daunting and unwieldy for many sources, but when asked by an Air Quality Board member to review these factors, the division was unable to. Continuing with an undocumented method that cannot be replicated and whose factors are in question is also arbitrary and cannot be justified in the division’s opinion. By removing threshold requirements, the division can continue to acknowledge that different HAPs affect human health and air quality chemistry differently without setting an arbitrary threshold. The division believes that, for most reporting facilities (particularly smaller permitted sources), the State and Local Emissions Inventory System (SLEIS) auto population feature saves facilities time and effort in researching the required pollutants for each unit process. Sources should also experience reduced regulatory uncertainty as they do not need to calculate a threshold for each HAP, estimate all their HAP emissions, and verify they are below the calculated threshold (this is very challenging for smaller sources who often rely on administrative staff to do so). The rule eases regulatory burden on the sources by allowing the division’s software (SLEIS) to calculate HAPs emissions. This process is also supported by the certification language sources agree to in SLEIS and R307-150 that the emissions inventory is to the “best knowledge” of the person submitting coupled with EPA’s definition that an emissions inventory is “a comprehensive and detailed estimate of air emissions.”1 1 United States Environmental Protection Agency. (2025, April 16). National Emissions Inventory (NEI). https://www.epa.gov/air-emissions-inventories/national-emissions-inventory-nei DAQ-047-25 Page 3 Furthermore, setting no threshold also aligns this rule with the current Division of Air Quality Notice of Intent (NOI) permitting requirements under UAC R307-410-5(1)(c) Submittal Requirements. The division requires all increases to be examined or evaluated. Therefore, there is no reporting threshold for HAPs and all HAPs above zero should be included in the NOI. Some sources use templates and upload them into SLEIS and asked if this option would be affected. The division can confirm that this feature is not affected by SLEIS’s upgrades. As a matter of fact, sources successfully used template uploads after the autopopulation feature was added to SLEIS in 2024. Finally, comments included some clerical adjustments to rule references if the rule is adopted by the Board. The division appreciates the additional review and has adjusted the final rule proposal with technical adjustments where appropriate. The Utah Office of Administrative Rules also identified some additional changes to bring rule R307-150 into compliance with Executive Order 2021-12. Recommendation: Staff recommends the Board approve the proposed amendments to rule R307-150, Emission Inventories, for final adoption. Page 1 of 7 APPENDIX A 1 2 2024 Amendment to R307-150. Emission Inventories. Response to Public Comment. 3 4 5 The Utah Division of Air Quality (the Division, UDAQ) has reviewed and evaluated all comments 6 submitted in writing during the associated 45-day public comment period in accordance with section 63G-7 3-301(11)(b) of Chapter 3 of the Utah Administrative Rulemaking Act. All written comments received by 8 the Division have been posted on its webpage where they can be viewed in their entirety. Below is a 9 summary of comments received and responses from the Division, divided by the topic of the amendment. 10 11 12 Amendments to Sulfur Dioxide Milestone Inventory Requirements: 13 14 The Division received one comment mentioning the Sulfur Dioxide Milestone amendments: 15 16 RTK Comment 1: “KUC understands that UDAQ opened up R307-150 for revisions in order to make 17 necessary administrative changes to the rule related to the SO2 reporting language1.” 18 19 UDAQ Response: As stated in the February 5, 2025, Board memorancum, the Division is amending 20 R307-150 due to Board member questions from 2020 regarding the HAPs exemptions and definitions. 21 The SO2 reporting language is outdated, and since the Division is proposing to amend this rule, it 22 includes changes to the Sulfur Dioxide Milestone requirements. 23 24 25 Amendments to the Hazardous Air Pollutants (HAPs) Exemptions and Definitions: 26 27 The Division received comments from three entities regarding the amendments to HAPs reporting. 28 29  Rio Tinto Kennecott 30  Utah Petroleum Association 31  Utah Mining Association 32 33 Comments from Rio Tinto Kennecott (RTK) 34 35 RTK Comment 2: “For proposing to remove the HAPs thresholds from the rule, UDAQ outlines that 36 they cannot recreate the thresholds. As a replacement, they assert that having no threshold is appropriate 37 because: 38 39 SLEIS is now able to automatically populate any HAPs emission factors with standard, well-40 defined methodology, therefore negating the need for exemption limits. 41 42 This feature of SLEIS is not a justification for removing the thresholds. SLEIS is a tool for submitting 43 inventory data. The use of the tool does not guarantee compliance and UDAQ is assuming user reliance 44 on the tool.” 45 46 UDAQ Response: The Division appreciates this point of view. This quoted statement is from the Notice 47 of Substantive Change for the rule amendments. The previous sentence says, “DAQ is removing the 48 HAPs exemption limits as staff were unable to replicate the calculation methodology employed in the 49 existing rule.” This feature in SLEIS is not the justification for removing the thresholds; they are being 50 Page 2 of 7 removed because there is no evidence of where the factors in R307-150-7(2)(b)-(d) originated, nor the 1 explicit exemption levels in R307-150-7(1). This feature in SLEIS provides the solution to this issue, and 2 since SLEIS can calculate to 15 places past the decimal point, there is no need to retain exemption 3 thresholds. 4 5 The Division is responsible for collecting emissions inventories from a wide variety of facilities, and the 6 automatic population feature is a prompt for most facilities to display the pollutants that should be 7 reported for the particular piece of equipment. In 2023, 88% of reporting facilities utilized the built-in 8 emission factors, resulting in 53% of emissions reported in SLEIS calculated this way. Therefore, the 9 Division believes it is correct to assume that users are relying on this tool. 10 11 There are many aspects to consider in “guaranteeing compliance,” but part of the quality control process 12 conducted by Division staff is comparing reported pollutants to those with available emission factors. 13 When these two items match, that is one aspect of the inventory staff can consider complete. 14 Additionally, a facility should review what has been pre-populated; if a facility feels additional HAPs 15 should be added to the list of those pre-populated by SLEIS, they can add those pollutants or delete them 16 if they feel the unit process does not create that pollutant. A facility ultimately agrees the report is 17 compliant when they check the box “I have reviewed the electronic report being submitted in its entirety, 18 and agree to the validity and accuracy of the information contained within it to the best of my knowledge” 19 during the submission process. 20 21 RTK Comment 3: “KUC uses the template upload feature to populate the data into SLEIS for submittal. 22 It is unclear if UDAQ considered this feature in their review.” 23 24 UDAQ Response: UDAQ did not specifically address this during the initial proposal, as the template 25 upload feature is not affected by the proposed change nor by the SLEIS HAPs auto-calculation feature, 26 but how the upload feature is used could impact the autopopulation process. When a facility downloads 27 the template, it will show what pollutants were reported in the most recently submitted report, and auto 28 populate any other pollutants that have an emission factor based on the Source Classification Code (SCC) 29 and throughput combination. 30 31 Ideally, facilities download the template, modify it, and upload it back into SLEIS. However, if a facility 32 only uploads the document, meaning they bypass SLEIS’s downloadable template and upload a different 33 spreadsheet, then the facility would miss any auto populated pollutants SLEIS suggests. The facility can 34 submit this, and if Division staff have questions about pollutants that would have auto populated, they 35 will contact the facility. 36 37 Joint comments from Utah Petroleum Association and Utah Mining Association 38 39 Joint Association Comment 1: “Sources can now use process knowledge to determine if reporting may 40 be required, especially if they have information that the process does not contain or does not emit a 41 particular HAP. In the absence of reporting thresholds, sources must certify that the emissions of many 42 HAPs are zero, a difficult certification to make because, even with process knowledge that a certain HAP 43 may not be expected to be emitted, it may be emitted in a trace or very small quantity.” 44 45 UDAQ Response: The Division believes that for the majority of reporting facilities, the autopopulation 46 feature saves time and effort in researching the required pollutants for each unit process. For those 47 facilities that did use the exemption guidelines to determine if a pollutant needed to be reported, they will 48 have a number to report since they had to determine if it was exempt. Again, SLEIS is capable of 49 reporting to 15 places past the decimal point, and if a facility believes a HAP is present at a trace amount, 50 Page 3 of 7 then they can estimate that in SLEIS. Division staff would not question a facility for not reporting a 1 pollutant if there is no expected emission factor based on the SCC and throughput combination. 2 3 Facilities can also rely on their submitted Notice of Intent (NOI), which should consider any HAPs a unit 4 process would create, as permitting has no HAPs reporting threshold and requires all HAPs to be 5 submitted as part of the application. 6 7 Joint Association Comment 2: “Incorporating the calculations into SLEIS will reduce the workload but 8 is not part of the rulemaking. Eliminating the thresholds, which is part of the rulemaking, will likely 9 increase the workload for many facilities, especially those subject to the certification requirement of 10 existing R307-150-9.” 11 12 UDAQ Response: If a facility is utilizing the listed exemptions, then it is already calculating or 13 estimating its HAPs, so that workload should not increase much more than now they must enter the 14 calculated HAPs into SLEIS. In addition, this would be a one-time work task, since once a pollutant is 15 reported for a unit process, it will populate for the next report. If the facility enters the emission factor 16 using an _1 or _2 calculation method, that pollutant will be automatically calculated in future years. 17 Additionally, if a facility needs to revise its calculation method for a particular HAP, that should also be a 18 one-time work task, as the same method will likely be used in the following years. 19 20 The certification language in R307-150-9(2)(a) “a certification that the information contained in the 21 statement is accurate to the best knowledge of the individual certifying the statement” is similar to the 22 SLEIS submissions check box “I have reviewed the electronic report being submitted in its entirety, and 23 agree to the validity and accuracy of the information contained within it to the best of my knowledge.” 24 Therefore, facilities subject to R307-150-9 are not held to any higher standard than all users in SLEIS. 25 26 Joint Association Comment 3: “SLEIS bases its calculations on AP-42 emission factors or similar 27 information (unless the reporting facility adds additional detail of emissions for its specific equipment) 28 and as discussed earlier in this letter, AP-42 factors are known to have inherent inaccuracies. 29 30 Thus, relying on SLEIS calculations to show that an emission of a HAP is zero countermands the required 31 certification in existing R307-150-9.” 32 33 UDAQ Response: The cited document EPA Reminder About Inappropriate Use of AP-42 Emission 34 Factors states that the intended use for AP-42 emission factors is for the development of annual or 35 triennial inventories. While AP-42 is considered the least accurate of the listed techniques to quantify 36 emissions, it is the only technique many facilities have available. In the document, EPA urges facilities to 37 “use the most representative emissions data.” Therefore, if a facility has more accurate techniques such as 38 Continuous Emissions Monitoring System (CEMS) or stack tests, those emission factors should be used 39 instead of AP-42, particularly if they are required in the facility’s approval order. Division staff, however, 40 would not expect a facility to use these techniques if they are not listed in their approval order. 41 Also, R307-150-9 only requires facilities to report “the total actual emissions of oxides of nitrogen and 42 volatile organic compounds in tons per year for each emission unit.” Therefore, facilities subject to R307-43 150-9 do not need to certify that any HAPs are zero. 44 45 Joint Association Comment 4: “It is not clear if facilities would need to do sampling to measure 46 concentrations of HAPs that are expected to be low. If yes, then protocols would need to be specified in 47 the rulemaking for sampling in every type of situation and for analyses, and the amount of work and 48 associated costs would increase inordinately.” 49 50 Page 4 of 7 UDAQ Response: R307-150 does not specify sampling for any pollutants; rather, this type of 1 requirement is listed in a facility’s Approval Order. A facility should consider any HAPs emissions when 2 they submit their NOI; therefore, at the step of reporting their emissions, the facility should know which 3 HAPs each unit process is expected to emit. 4 5 Joint Association Comment 5: “Furthermore, although the existing reporting thresholds in R307-150 6 seem to be arbitrary because UDAQ cannot replicate them or find their original bases, eliminating the 7 thresholds entirely is equally arbitrary. Why not move the threshold to ten pounds per year like Louisiana 8 and Wyoming use? Why not choose 200 pounds per year like South Carolina uses?25 With the 9 information currently in hand, any change to the reporting thresholds is arbitrary.” 10 11 UDAQ Response: At least two other states (West Virginia and Oklahoma) also have no threshold for 12 reporting HAPs. South Carolina staff do not know where their 200 lb. threshold originated. They are in a 13 similar situation where their rule has been in place for 20 years, and any staff who knew the threshold 14 origins have retired. Louisiana’s exemption thresholds are similar to the current R307-150 thresholds; 15 they are not a straight 10 lb. exemption but instead were modeled based on available Threshold Limit 16 Values (TLV) and carcinogenic data in 1990 and have not been revisited in 35 years. 17 18 Wyoming’s 10 lb. threshold is not in their regulation; it is just a known guidance that facilities do not 19 need to report HAPs emissions under 10 lbs. Because it is not in the regulation, Wyoming DEQ still can 20 ask for HAPs emissions under 10 lbs. if they determine there is a need. 21 22 Ultimately, states with thresholds noted that the thresholds were essentially arbitrary as they do not 23 account for the different impacts individual HAPs concentrations have on human health and/or air quality 24 chemistry. 25 26 Although HAPs are often a small contributor by mass to total VOC concentrations in an airshed, they are 27 often the most reactive concentrations. The Division quantifies this with the Maximum Incremental 28 Reactivity (MIR), which estimates how much ozone could be generated from a specific VOC. Toluene 29 (MIR of ~4) and Xylenes (MIR ~8) are examples of highly reactive aromatic concentrations, all of which 30 are on the HAPs list. MIRs assume that, under ideal ozone-forming conditions, one molecule of toluene 31 would generate four molecules of ozone. The more we can control the highly reactive concentrations, 32 such as HAPs with elevated MIRs, the less prone our airshed is to ozone formation. 33 34 Finally, it should be remembered that aside from elevated MIRs, HAPs are also harmful to human health. 35 Many are known carcinogens, and it is important to know the origin and amount of these pollutants in our 36 airshed. 37 38 Joint Association Comment 6: “Although UDAQ cannot locate or replicate the basis for current 39 thresholds, the thresholds are sufficiently detailed that UDAQ probably had a basis at the time of adopting 40 them.” 41 42 UDAQ Response: The thresholds are based on R307-410. Permits: Emissions Impact Analysis. 43 44 From the November 15, 1998, Utah State Bulletin: 45 46 In Subsection R307-155-1(2), this proposal establishes a de minimis level for HAP emissions. This level is 47 below the emission threshold value calculated using the worst case factors already established in the 48 HAP modeling rule. The cutoff level will change for an individual HAP if Threshold Limit Value for the 49 chemical is changed. The exact cutoff can be listed in the instructions provided by DAQ and changed as 50 needed without requiring a rule change. 51 Page 5 of 7 1 DAQ cannot provide instructions because we do not understand the reasoning for the factors. We agree 2 there was a basis, but they are indefensible because we have no proof of why they chose these numbers. 3 Also, as noted in the response to Joint Association Comment #5, science evolves over 25+ years. The 4 Division now understands that HAPs, while a lower percentage of VOC emissions in our airshed, have a 5 higher potential for generating ozone. Understanding the origins and amounts of these pollutants provides 6 the Division with additional information to reduce ozone formation. 7 8 It is noteworthy that UDAQ’s current threshold method likely attempted to account for each HAP type 9 having vastly different impacts on human health and the environment at varying concentrations. This is 10 reflected in the multitude of thresholds as each HAP has its own threshold weighted by American 11 Conference of Governmental Industrial Hygienists (ACGIH) factors. 12 13 Unfortunately, not only is this individual calculation daunting and unwieldy for many sources, but when 14 asked by an Air Quality Board member to review these factors, UDAQ was unable to. Continuing with an 15 undocumented method which cannot be replicated with factors that are in question is also arbitrary and 16 cannot be justified in UDAQ’s opinion. 17 18 By removing threshold requirements, UDAQ can continue to acknowledge that different HAPs affect 19 human health and air quality chemistry differently without setting arbitrary thresholds. This also reduces 20 the calculation burden for many sources (particularly smaller permitted sources). 21 22 Joint Association Comment 7: “The Associations recommend that UDAQ not eliminate or change the 23 HAP reporting thresholds at this time.” 24 25 UDAQ Response: The requested review and changes were recommended by two Board members, and 26 upon review, the Division determined that we could not rebuild the historical context for the previous 27 language and can no longer justify it. 28 29 Additionally, if the thresholds are left as-is, facilities will need to make the calculations on their own 30 using the 2003 version of the ACGIH "Threshold Limit Values for Chemical Substances and Physical 31 Agents and Biological Exposure Indices." See the UDAQ response to Joint Association Comment #6 32 above for details. 33 34 Joint Association Comment 8: “...in our estimation, eliminating the threshold will increase the 35 workload and does not reduce uncertainty. Sources can now use process knowledge to determine if 36 reporting may be required, especially if they have information that the process does not contain or does 37 not emit a particular HAP. In the absence of reporting thresholds, sources must certify that the emissions 38 of many HAPs are zero, a difficult certification to make because, even with process knowledge that a 39 certain HAP may not be expected to be emitted, it may be emitted in a trace or very small quantity. Thus, 40 we do not agree with the following statement from the fiscal information section of the rule analysis, 41 ‘there is a strong potential that this will reduce workload for sources as they are already expected to 42 determine if their HAP emissions are above or below the threshold in the current rule which involves a 43 complex calculation for each pollutant’.” 44 45 UDAQ Response: The Division disagrees. HAPs should have been considered when submitting the NOI 46 for the equipment. Facilities should know what HAPs are expected from each unit process. If they have 47 not been calculated in the past, this will be a one-time work task to create the calculations that can be 48 replicated each time an inventory is due. 49 50 Page 6 of 7 Joint Association Comment 9: “Furthermore, uncertainties in emission factors will make the important 1 aspect of certifying any emission estimate of zero an untenable task.” 2 3 UDAQ Response: While the Division appreciates the task of generating emissions inventories and the 4 attention to detail required to produce an accurate report, it would like to remind facilities that 5 certification in SLEIS and R307-150 is to the “best knowledge” of the person submitting. By EPA’s 6 definition, an Emissions Inventory is “a comprehensive and detailed estimate of air emissions”.1 7 [Emphasis added] 8 9 10 Amendments to Add Point Source Mobile Emissions Reporting: 11 12 The Division received comments from five entities regarding point source mobile emissions reporting: 13 14  John Rasband, Air Quality Board Member, Petersen Incorporated 15  Chevron Products Company, Salt Lake Refinery 16  Rio Tinto Kennecott 17  Utah Petroleum Association 18  Utah Mining Association 19 20 The Division acknowledges the various comments focused on the mobile source emissions reporting 21 requirements. As UDAQ reviewed the comments and the rule language itself, it became clear that there is 22 confusion on the applicability, process, and on the need for specifying mobile emissions reporting in the 23 rule. Comments also suggested preparing guidance coupled with public outreach on these submissions 24 would be preferred and/or sufficient. UDAQ agrees that it would be best to remove the mobile emissions 25 reporting proposal at this time to allow for guidance development and outreach. UDAQ is, therefore, 26 removing the proposed section. 27 28 29 Clerical/Administrative Amendments: 30 31 Joint Association Comment 10: “UDAQ indicated that a major source or Part 70 source of emissions 32 with Standard Industrial Classification codes in the major group 13 would be subject to major source and 33 Part 70 source reporting under R307-150-6 and also to oil and gas industry reporting under existing 34 R307-150-8.26 R307-150-3(1)(c) indicates that large stationary sources of sulfur dioxide, i.e. those with 35 100 tons per year or more of sulfur dioxide emissions, “may be subject to other sections of Rule R307-36 150-3.” For clarity, we recommend that a similar statement be added in the appropriate location to 37 indicate the same for major sources and Part 70 sources with Standard Industrial Classification codes in 38 the major group 13.” 39 40 UDAQ Response: This first sentence is misinterpreted; R307-150-3(4)(a) means that any facilities, 41 including major sources and Part 70 sources, are excluded from R307-150-8. Therefore, if a facility is in 42 the major group 13, and not one of the listed facilities to which R307-150-5 and -6 are applicable, then it 43 reports in the Crude Oil and Natural Gas Source Category. In plain language, this means if a facility 44 qualifies under R307-150-3(1) through (3), they report to SLEIS; otherwise, they report to UDAQ’s oil 45 and gas inventory lead via the Oil and Gas Emissions Inventory. 46 47 1 United States Environmental Protection Agency. (2025, April 16). National Emissions Inventory (NEI). https://www.epa.gov/air-emissions-inventories/national-emissions-inventory-nei Page 7 of 7 Joint Association Comment 11: Due to eliminating R307-150-7 Exempted Hazardous Air Pollutants, 1 the Proposal renumbers subsequent sections. Therefore, references to subsequent sections need to be 2 renumbered accordingly. We recommend renumbering the references to Section “R307-150-8” to “R307-3 105-7.” The incorrect references appear in R307-150(4) and R307-150(4)(a). Similarly, the reference to 4 “R307-150-9” in R307-150-3(5) should be updated to “R307-150-8.” 5 6 UDAQ Response: The Division appreciates this feedback and will incorporate it in the final version of 7 the rule. 8 9 Joint Association Comment 12: “The rule analysis indicates the statutory authority for the rule to be 10 “Section 19-6a-1642” which needs to be corrected.” 11 12 UDAQ Response: The Division appreciates the associations catching this error. The correct reference is 13 19-2-104. 14 15 16 Comments Regarding Workload: 17 18 The Division received multiple comments from Rio Tinto Kennecott regarding the amount of work and 19 resources necessary to report emissions inventories and the timing of these proposed amendments. The 20 Division appreciates and acknowledges the amount of effort required by facility staff to complete an 21 emissions inventory and the attention to detail required to produce accurate emissions estimates. Division 22 staff know this through working with the nearly 600 facilities reporting triennially, and 200 reporting 23 annually. Through phone calls, emails, and Google Meet screenshare sessions, Division staff assist 24 facilities to help them successfully submit the best inventory possible. Staff regularly work with facilities 25 that have no designated staff to complete this task, who lack computer skills and the knowledge, 26 understanding, and/or purpose of an emissions inventory. 27 28 The Division apologizes that the timing of these proposed amendments coincided with the reporting 29 period. The original due date for public comments did not coincide with the inventory due date, but the 30 Division received a request to extend the public comment period, resulting in these two deadlines falling 31 on the same day. This was not the intention; staff have been working on these proposed amendments for 32 four years, and the due date was truly coincidental. 33 State of Utah Administrative Rule Analysis Revised May 2025 NOTICE OF SUBSTANTIVE CHANGE TYPE OF FILING: CPR (Change in Proposed Rule) Rule or section number: R307-150 Filing ID: OFFICE USE ONLY Date of previous publication (only for CPRs): 03/01/2025 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: Greg Mortensen 385-226-6171 gmortensen@utah.gov Jazmine Lopez 801-536-4050 jazminelopez@utah.gov Please address questions regarding information on this notice to the persons listed above. General Information 2. Rule or section catchline: R307-150. Emission Inventories. 3. Are any changes in this filing because of state legislative action? Changes are not because of legislative action. If yes, any bill number and session: 4. Purpose of the new rule or reason for the change: Rule R307-150 is being updated to continue to collect HAPs without setting an arbitrary one-size-fits-all threshold and reflect what our State and Local Emissions Inventory System (SLEIS) database is capable of. The Division of Air Quality (DAQ) is removing the HAPs exemption limits as staff were unable to replicate the calculation methodology employed in the existing rule which attempted to address different human health and environmental impacts by different HAPs concentrations. By removing threshold requirements, the Division can continue to acknowledge that different HAPs affect human health and air quality chemistry differently without setting arbitrary thresholds. Ultimately, the DAQ needs to catch the rule up on Hazardous Air Pollutants (HAPs) to adhere to scientific realities, reflect what sources are already reporting, and what SLEIS is also already able to do. SLEIS is now able to automatically populate any HAPs emission factors with standard, well-defined methodology. This is a much-simplified means for most facilities to report their HAPs emissions. DAQ staff believe this will also provide more accurate and consistent HAPs data while also streamlining HAPs reporting with criteria pollutants. Staff is also taking the opportunity to update the sulfur dioxide (SO2) reporting requirements by removing a conflicting statement indicating an erroneous end date for SO2 reporting. Additionally, other revisions have been made to correct rule section references and bring the rule into compliance with Executive Order 2021-12. 5. Summary of the new rule or change: The amendments to Rule R307-150 will remove HAPs threshold calculation and HAPs reporting exemptions, update SO2 reporting language and remove the outdated timeline for SO2 reporting period, and make rule language changes to bring the rule into compliance with Executive Order 2021-12 and make rule section reference corrections. Fiscal Information 6. Provide an estimate and written explanation of the aggregate anticipated cost or savings to: A. State budget: There are no anticipated costs or savings to the state budget associated with the amendments to Rule R307-150. No additional costs are expected as the automated HAPs enhancement is already included in the current SLEIS maintenance agreement and HAPs are already reported by many facilities in SLEIS. All other changes are administrative language changes for portions of the rule already in effect. B. Local governments: There are no savings or negligible costs anticipated for HAPs reporting due to automated processes for local governments associated with the amendments to Rule R307-150. C. Small businesses ("small business" means a business employing 1-49 persons): There are no savings or negligible costs anticipated for HAPs reporting due to automated processes for small businesses associated with the amendments to Rule R307-150. D. Non-small businesses ("non-small business" means a business employing 50 or more persons): There are no savings or negligible costs anticipated for HAPs reporting due to automated processes for non-small businesses associated with the amendments to Rule R307-150. 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): There are no savings or negligible costs anticipated for HAPs reporting due to automated processes for non-small businesses associated with the amendments to Rule R307-150. F. Compliance costs for affected persons: Removing the HAPs reporting thresholds should have negligible workload increase as SLEIS will automatically calculate HAPs based on the already required activity data for their annual emission inventory reports. Additionally, there is a strong potential that this will reduce workload for sources as they are already expected to determine if their HAP emissions are above or below the threshold in the current rule which involves a complex calculation for each pollutant. For smaller sources, it is not uncommon that administrative staff are tasked with submitting the inventory and are confused by these thresholds. This not only expends their time and agency time supporting them but also exposes sources to potential compliance costs if they fail to report a HAP as they guessed or erroneously calculated that they were below the threshold. SLEIS’s HAPs auto-calculation capability alleviates this burden and allows sources to simply populate their processes with already-required activity data. G. Regulatory Impact Summary Table (This table includes only fiscal impacts the agency was able to measure. If the agency could not estimate an impact, it is excluded from this table but described in boxes A through F.) Regulatory Impact Summary Table Fiscal Cost FY2026 FY2027 FY2028 FY2029 FY2030 State Budget $0 $0 $0 $0 $0 Local Governments $0 $0 $0 $0 $0 Small Businesses $0 $0 $0 $0 $0 Non-Small Businesses $0 $0 $0 $0 $0 Other Persons $0 $0 $0 $0 $0 Total Fiscal Cost $0 $0 $0 $0 $0 Fiscal Benefits FY2026 FY2027 FY2028 FY2029 FY2030 State Budget $0 $0 $0 $0 $0 Local Governments $0 $0 $0 $0 $0 Small Businesses $0 $0 $0 $0 $0 Non-Small Businesses $0 $0 $0 $0 $0 Other Persons $0 $0 $0 $0 $0 Total Fiscal Benefits $0 $0 $0 $0 $0 Net Fiscal Benefits $0 $0 $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, Tim Davis, has reviewed and approved this regulatory impact analysis. Citation Information 7. 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 19-2-104 Incorporation by Reference Information 8. Incorporation 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 material incorporated by reference (a copy of the material 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 material incorporated by reference (a copy of the material 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 9. The public may submit written or oral comments to the agency identified in box 1. A. Comments will be accepted until: B. A public hearing (optional) will be held (The public may request a hearing by submitting a written request to the agency, as outlined in Section 63G-3-302 and Rule R15-1.): Date: Time (hh:mm AM/PM): Place (physical address or URL): To the agency: If more than one hearing is planned to take place, continue to add rows. 10. This rule change MAY become effective on: 08/01/2025 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. The office may return incomplete forms to the agency, 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: 05/13/2025 R307. Environmental Quality, Air Quality. 1 R307-150. Emission Inventories. 2 R307-150-1. Purpose and General Requirements. 3 (1) The purpose of Rule R307-150 is to establish:4 (a) by rule, the time frame, pollutants, and information that sources shall include in inventory5 submittals; and 6 (b) consistent reporting requirements for stationary sources in Utah to determine whether sulfur7 dioxide emissions remain below the sulfur dioxide milestones established in the State Implementation Plan 8 for Regional Haze, Section XX.E.1.a, incorporated by reference, in Section R307-110-28. 9 (2) The requirements of Rule R307-150 replace any annual inventory reporting requirements in10 approval orders or operating permits issued before December 4, 2003. 11 (3) Emission inventories shall be submitted on or before April 15 of each year following the12 calendar year for which an inventory is required. The inventory shall be submitted in a format specified by 13 the Division of Air Quality following consultation with each source. 14 (4) The Director may require at any time a full or partial-year inventory upon reasonable notice to15 affected sources when it is determined that the inventory is necessary to develop a state implementation 16 plan, to assess whether there is a threat to public health or safety or the environment, or to determine 17 whether the source is in compliance with Title R307. 18 (5) Recordkeeping requirements include the following:19 (a) each owner or operator of a stationary source subject to this rule shall maintain a copy of the20 emission inventory submitted to the Division of Air Quality and records indicating how the information 21 submitted in the inventory was determined, including any calculations, data, measurements, and estimates 22 used; 23 (i) the records under Section R307-150-4 shall be kept for ten years;24 (ii) other records shall be kept for a period of at least five years from the due date of each25 inventory; 26 (b) the owner or operator of the stationary source shall make these records available for inspection27 by any representative of the Division of Air Quality during normal business hours. 28 29 R307-150-2. Definitions. 30 The following additional definitions apply to Rule R307-150: 31 "Emissions unit" means emissions unit as defined in Section R307-415-3. 32 "Large Major Source" means a major source that emits or has the potential to emit 2,500 tons or 33 more per year of oxides of sulfur, oxides of nitrogen, or carbon monoxide, or that emits or has the potential 34 to emit 250 tons or more per year of PM10, PM2.5, volatile organic compounds, or ammonia. 35 "Lead" means elemental lead and the portion of its compounds measured as elemental lead. 36 "Major Source" means major source as defined in Section R307-415-3. 37 ["Mobile Emissions" means emissions from mobile sources as defined in 40 CFR [§] 51.491 which 38 never leave the property line.] 39 40 R307-150-3. Applicability. 41 (1) Section R307-150-4 applies to stationary sources with actual emissions of 100 tons or more per42 year of sulfur dioxide in calendar year 2000 or any subsequent year unless exempted in Subsection R307-43 150-3(1)(b).44 (a) Stationary sources subject to Subsection R307-150-3(1) that emit less than 100 tons per year of45 sulfur dioxide in any subsequent year shall remain subject to Section R307-150-4. 46 (b) Stationary sources that meet the requirements of Subsection R307-150-3(1) that have47 permanently ceased operation are exempt from the requirements of Section R307-150-4 for the years 48 during which the source did not operate at any time during the year, except for the Carbon Power Plant, 49 which, beginning with 2016 emissions, the Division of Air Quality shall include emissions of 8,005 tons 50 per year of sulfur dioxide in the annual regional sulfur dioxide milestone report required as part of the 51 Regional Haze State Implementation Plan. 52 (c) Sources subject to Section R307-150-4 may be subject to other sections of Rule R307-150.53 (2) Section R307-150-5 applies to large major sources.54 Page 1 of 3 (3) Section R307-150-6 applies to each:1 (a) major source that is not a large major source;2 (b) source with the potential to emit five tons or more per year of lead;3 (c) source not included in Subsection R307-150-3(2), R307-150-3(3)(a), or R307-150-3(3)(b) that4 is located in Davis, Salt Lake, Utah, or Weber Counties and that has the potential to emit 25 tons or more 5 per year of any combination of oxides of nitrogen, oxides of sulfur and PM10, or the potential to emit ten 6 tons or more per year of volatile organic compounds; and 7 (d) Part 70 source not included in Subsection R307-150-3(2), R307-150-3(3)(a), R307-150-8 3(3)(b), or R307-150-3(3)(c). 9 (4) Section R307-150-[8]7 applies to sources with Standard Industrial Classification codes in the10 major group 13 that have uncontrolled actual emissions greater than one ton per year for a single pollutant 11 of PM10, PM2.5, oxides of nitrogen, oxides of sulfur, carbon monoxide, or volatile organic compounds. 12 These sources include, industries involved in oil and natural gas exploration, production, and transmission 13 operations, well production facilities, natural gas compressor stations, natural gas processing plants, and 14 commercial oil and gas disposal wells, and ponds. Sources that require inventory submittals under 15 Subsections R307-150-3(1) through (3) are excluded from the requirements of Section R307-150-7. 16 [(a) Sources that require inventory submittals under Subsections R307-150-3(1) through (3) are 17 excluded from the requirements of Section R307-150-8.] 18 (5) Section R307-150-[9]8 applies to stationary sources located in a designated ozone19 nonattainment area that have the potential to emit oxides of nitrogen or volatile organic compounds greater 20 than 25 tons per year. 21 22 R307-150-4. Sulfur Dioxide Milestone Inventory Requirements. 23 (1) Annual Sulfur Dioxide Emission Report requirements are as follows.24 (a) Sources identified in Subsection R307-150-3(1) shall submit an annual inventory of sulfur25 dioxide emissions beginning with calendar year 2003 for emissions units including fugitive emissions. 26 (b) The inventory shall include the rate and period of emissions, excess or breakdown emissions,27 startup and shut down emissions, the specific emissions unit that is the source of the air pollution, type and 28 efficiency of the air pollution control equipment, percent of sulfur content in fuel and how the percent is 29 calculated, and other information necessary to quantify operation and emissions and to evaluate pollution 30 control efficiency. The emissions of a pollutant shall be calculated using the source's actual operating 31 hours, production rates, and types of materials processed, stored, or combusted during the inventoried 32 period. 33 (2) Each source subject to Section R307-150-4 that is also subject to 40 CFR Part 75 reporting34 requirements shall submit a summary report of annual sulfur dioxide emissions that were reported to the 35 Environmental Protection Agency under 40 CFR Part 75 in lieu of the reporting requirements in Subsection 36 (1). 37 (3) Changes in Emission Measurement Techniques include:38 (a) each source subject to Section R307-150-4 that uses a different emission monitoring or39 calculation method than was used to report their sulfur dioxide emissions in 2006 under Rule R307-150 or 40 40 CFR Part 75 shall adjust their reported emissions to be comparable to the emission monitoring or 41 calculation method that was used in 2006; and 42 (b) the calculations that are used to make this adjustment shall be included with the annual43 emission report. 44 45 R307-150-5. Sources Identified in Subsection R307-150-3(2), Large Major Source Inventory 46 Requirements. 47 (1) Each large major source shall submit an emission inventory annually beginning with calendar48 year 2002. The inventory shall include PM10, PM2.5, oxides of sulfur, oxides of nitrogen, carbon monoxide, 49 volatile organic compounds, and ammonia for emissions units including fugitive [and mobile] emissions. 50 (2) For every third year beginning with 2005, the inventory shall also include any other chargeable51 pollutants and hazardous air pollutants. 52 (3) For each pollutant specified in Subsection (1) or (2), the inventory shall include the rate and53 period of emissions, excess or breakdown emissions, startup and shut down emissions, the specific 54 Page 2 of 3 emissions unit that is the source of the air pollution, composition of air pollutant, type and efficiency of the 1 air pollution control equipment, and other information necessary to quantify operation and emissions and to 2 evaluate pollution control efficiency. The emissions of a pollutant shall be calculated using the source's 3 actual operating hours, production rates, and types of materials processed, stored, or combusted during the 4 inventoried period. 5 6 R307-150-6. Sources Identified in Subsection R307-150-3(3). 7 (1) Each source identified in Subsection R307-150-3(3) shall submit an inventory every third year8 beginning with calendar year 2002 for emissions units including fugitive [and mobile] emissions. 9 (a) The inventory shall include PM10, PM2.5, oxides of sulfur, oxides of nitrogen, carbon monoxide,10 volatile organic compounds, ammonia, other chargeable pollutants, and hazardous air pollutants [not 11 exempted in Section R307-150-7]. 12 (b) For each pollutant, the inventory shall include the rate and period of emissions, excess or13 breakdown emissions, startup and shut down emissions, the specific emissions unit which is the source of 14 the air pollution, composition of air pollutant, type and efficiency of the air pollution control equipment, 15 and other information necessary to quantify operation and emissions and to evaluate pollution control 16 efficiency. The emissions of a pollutant shall be calculated using the source's actual operating hours, 17 production rates, and types of materials processed, stored, or combusted during the inventoried period. 18 (2) Sources identified in Subsection R307-150-3(3) shall submit an inventory for each year after19 2002 in which the total amount of PM10, oxides of sulfur, oxides of nitrogen, carbon monoxide, or volatile 20 organic compounds increases or decreases by 40 tons or more per year from the most recently submitted 21 inventory. For each pollutant, the inventory shall meet the requirements of Subsections R307-150-6(1)(a) 22 and R307-150-6(1)(b). 23 24 R307-150-7. Crude Oil and Natural Gas Source Category. 25 [(1)]Sources identified in Subsection R307-150-3(4) shall submit an inventory every third year 26 beginning with the 2017 calendar year for emission units. The inventory shall: 27 [(a)](1) include the total emissions for PM10, PM2.5, oxides of sulfur, oxides of nitrogen, carbon 28 monoxide, and volatile organic compounds for each emission unit at the source and the emissions of a 29 pollutant shall be calculated using the emission unit's actual operating hours, product rates, and types of 30 materials processed, stored, or combusted during the inventoried period; 31 [(b)](2) include the type and efficiency of air pollution control equipment; and 32 [(c)](3) be submitted in an electronic format determined by the Director specific to this source 33 category. 34 35 R307-150-8. Annual Ozone Emission Statement. 36 (1) Beginning in the year 2021, sources identified in Subsection R307-150-3(5) shall submit an37 ozone emission statement to the Division of Air Quality annually by April 15 of each year for the previous 38 year's emissions. 39 (2) A source required to submit an emission statement shall provide the following minimum40 information: 41 (a) a certification that the information contained in the statement is accurate to the best knowledge42 of the individual certifying the statement; 43 (b) the physical location where actual emissions occurred;44 (c) the name and address of person or entity operating or owning the source;45 (d) the nature of the source; and46 (e) the total actual emissions of oxides of nitrogen and volatile organic compounds in tons per year47 for each emission unit. 48 (3) Emission statements shall be submitted in an electronic format determined by the Director.49 50 KEY: air pollution, reports, inventories 51 Date of Last Change: 2025 52 Notice of Continuation: November 1, 2023 53 Authorizing, and Implemented or Interpreted Law: 19-2-104(1)(c) 54 Page 3 of 3 ITEM 5 Air Toxics 195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone (801) 536-4000 • Fax (801)536-4099 • T.D.D. (801) 536-4284 www.deq.utah.gov Printed on 100% recycled paper State of Utah Department of Environmental Quality Tim Davis Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor DAQA-326-25 M E M O R A N D U M TO: Air Quality Board FROM: Bryce C. Bird, Executive Secretary DATE: May 5, 2025 SUBJECT: Air Toxics, Lead-Based Paint, and Asbestos (ATLAS) Section Compliance Activities – April 2025 ______________________________________________________________________________________ Asbestos Demolition/Renovation NESHAP Inspections 8 Asbestos AHERA Inspections 8 Asbestos State Rules Only Inspections 4 Asbestos Notification Forms Accepted 199 Asbestos Telephone Calls 417 Asbestos Individuals Certifications Approved 72 Asbestos Company Certifications 11 Asbestos Alternate Work Practices Approved 4 Lead-Based Paint (LBP) Inspections 0 LBP Notification Forms Approved 0 LBP Telephone Calls 57 LBP Letters Prepared and Mailed 9 LBP Courses Reviewed/Approved 0 LBP Course Audits 2 LBP Individual Certifications Approved 21 DAQA-326-25 Page 2 LBP Firm Certifications 8 Notices of Violation Sent 0 Compliance Advisories Sent 13 Warning Letters Sent 5 Settlement Agreements Finalized 0 Compliance 195 North 1950 West • Salt Lake City, Utah Mailing Address: P.O. Box 144820 • Salt Lake City, Utah 84114-4820 Telephone (801) 536-4000 • Fax (801) 536-4099 • T.D.D. 800 346-3128 www.deq.utah.gov Printed on 100% recycled paper State of Utah Department of Environmental Quality Tim Davis Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor DAQC-428-25 M E M O R A N D U M TO: Air Quality Board FROM: Bryce C. Bird, Executive Secretary DATE: May 6, 2025 SUBJECT: Compliance Activities – April 2025 _____________________________________________________________________________________ ACTIVITIES: Activity Monthly Total 36-Month Average Inspections 56 64 On-Site Stack Test & CEM Audits 6 5 Stack Test & RATA Report Reviews 37 38 Emission Report Reviews 28 21 Temporary Relocation Request Reviews 7 6 Fugitive Dust Control Plan Reviews 148 118 Soil Remediation Report Reviews 1 2 Open Burn Permits Issued 3,179 692 Miscellaneous Inspections1 18 17 Complaints Received 44 21 Wood Burning Complaints Received 0 3 Breakdown Reports Received 0 1 Compliance Actions Resulting from a Breakdown 0 0 VOC Inspections (Gas station vapor recovery) 0 0 Warning Letters Issued 2 2 Notices of Violation Issued 0 0 Compliance Advisories Issued 1 6 No Further Action Letters Issued 2 2 Settlement Agreements Reached 2 2 Penalties Assessed $14,918 $93,566.96 1Miscellaneous inspections include, e.g., surveillance, complaint, on-site training, dust patrol, smoke patrol, open burning, etc. DAQC-428-25 Page 2 SETTLEMENT AGREEMENTS: Party Amount NOVVA, Inc. $10,838 Uinta Wax Operating $4,080 UNRESOLVED NOTICES OF VIOLATION: Party Date Issued Citation Oil and Gas (in administrative litigation) 01/15/2020 Ovintiv Production Inc. 07/14/2020 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 Holcim 08/02/2024 Big West Oil 10/01/2024 CKC Operations, LLC 02/18/2025 Green Natural Gas Ventures, LLC – Lisbon Valley 02/24/2025 Monitoring Utah Division of Air Quality 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 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 2. 5 (µ g / m 3) Days Utah 24-Hr PM2.5 Data March 2025 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 Heber Exceedence Value is 35 µg/m3 *Environmental Quality (EQ) previously named Technical Support Center (TSC) * BG BV CV ED HB HV HW LN NR RP RS SF SM EQ V4 Arith Mean 456444667645564 Max 24-hr Avg 29 25 28 25 11 27 24 22 26 26 8 21 27 24 12 98th percentile 19 20 23 15 10 20 21 20 22 21 7 17 20 18 9 Days of Data 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 Days >35 µg/m3 000000000000000 Utah Division of Air Quality 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 12345678910111213141516171819202122232425262728293031 PM 2. 5 (µ g / m 3) Days Utah 24-Hr PM2.5 Data April 2025 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 Heber Exceedence Value is 35 µg/m3 *Environmental Quality (EQ) previously named Technical Support Center (TSC) * BG BV CV ED HB HV HW LN NR RP RS SF SM EQ V4 Arith Mean 566455678756565 Max 24-hr Avg 16 14 14 13 11 14 13 14 15 17 15 14 12 16 15 98th percentile 13 13 13 12 10 13 13 14 15 15 14 14 11 15 14 Days of Data 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 Days >35 µg/m3 000000000000000 Utah Division of Air Quality 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 12345678910111213141516171819202122232425262728293031 PM 2. 5 (µ g / m 3) Days Utah 24-Hr PM2.5 Data May 2025 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 Heber Exceedence Value is 35 µg/m3 *Environmental Quality (EQ) previously named Technical Support Center (TSC) * BG BV CV ED HB HV HW LN NR RP RS SF SM EQ V4 Arith Mean 567555778855564 Max 24-hr Avg 10172114 9 122320273710121126 6 98th percentile 9 14 20 11 9 10 19 17 23 29 9 11 9 20 6 Days of Data 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 Days >35 µg/m3 000000000100000 Utah Division of Air Quality 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 12345678910111213141516171819202122232425262728293031 PM 10 (µ g / m 3) Days Utah 24-hr PM10 Data March 2025 Herriman #3 Hawthorne Harrisville 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) H3 HW HV LN RS EQ Arith Mean 18 17 13 17 12 24 Max 24-hr Avg 108 83 100 79 62 97Days of Data 31 31 31 31 31 31 Days >150 µg/m3 000000 Utah Division of Air Quality 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 123456789101112131415161718192021222324252627282930 PM 10 (µ g / m 3) Days Utah 24-hr PM10 Data April 2025 Herriman #3 Hawthorne Harrisville 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) H3 HW HV LN RS EQ Arith Mean 21 14 15 18 15 22 Max 24-hr Avg 56 30 37 37 46 45 Days of Data 30 30 30 30 30 30 Days >150 µg/m 3 000000 Utah Division of Air Quality 0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031 PM 10 (µ g / m 3) Days Utah 24-hr PM10 Data May 2025 Herriman #3 Hawthorne Harrisville 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) H3 HW HV LN RS EQ Arith Mean 23 17 18 26 16 31 Max 24-hr Avg 104 105 83 177 61 177 Days of Data 19 19 19 19 19 19 Days >150 µg/m 3 000101 14.2 18.7 10.1 10.2 11.4 7.4 5 9.5 16.1 17.6 17.615.6 11.9 6 7.4 15.7 17.5 2.5 8.5 9 13.2 14 15.3 18.8 21.1 25.4 23.7 14.4 11.5 14.1 -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 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H a w t h o r n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 Bountiful Copperview Erda Herriman #3 Harrisville Hawthorne Near Road Red Butte Rose Park Environmental Quality Exceed.TM BV CV ED H3 HV HW NR RB RP EQ * *EnvironmentalQuality (EQ) previously named Technical Support Center (TSC) ** Controlling Monitor ** O3 March 2025 BV CV ED H3 HV HW NR RB RP EQ Arith Mean .046 .046 .045 .048 .045 .041 .041 .046 .045 .045 8 -hr. Ozone 4th Max .051 .051 .050 .052 .050 .045 .045 .049 .050 .051 Days of Data 31 31 31 31 31 31 31 31 31 31 Days > 0.070 0000000000 14.4 16 8.2 11.3 8.5 6.2 5.2 8 11.7 15 15 14.2 10.7 5.7 6.5 13.6 15.3 6.7 7.410 10.1 12.8 14.8 19.4 19.5 22.4 21.9 16.9 10.4 11 14.5 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0 0.02 0.04 0.06 0.08 0.1 0.12 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( R o o s e v e l t ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 Price #2 Roosevelt Vernal Exceed.TM P2 RS V4 Arith Mean .047 .048 .049 8 -hr. Ozone 4th Max .051 .053 .052 Days of Data 31 31 31 Days > 0.070 000 6.9 8.3 5.5 8 8.4 2.6 3.5 4.5 8.9 13.3 14.3 12 10.6 3 2 13.3 14.6 2.5 4 6.6 8.7 9.6 11.3 16.5 19.3 22.4 20.7 12.9 11.8 8.4 7.9 -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 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( S m i t h f i e l d ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 Smithfield Exceed.TM SM Arith Mean .047 8 -hr. Ozone 4th Max .052 Days of Data 31 Days > 0.070 0 15.2 17.6 7.9 8.3 9.6 4.9 4.3 7.6 14.7 16.3 15.8 13.8 10.1 4.2 4.7 15.5 15.7 13.2 12.6 9.9 11.3 11.8 14 17.6 20.4 24.6 22.4 15.2 11.3 13.8 14.7 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( L i n d o n ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 Lindon Spanish Fork Exceed.TM LN SF Arith Mean .046 .043 8 -hr. Ozone 4th Max .051 .047 Days of Data 31 31 Days > 0.070 00 23.2 18.8 7.6 14.6 15.6 8.8 9.7 14.3 18.9 20.1 18.9 14.4 12.1 7.1 12.3 15.5 19.1 11.9 12.4 16.6 18.8 19.3 22.8 25.5 28.2 28.5 26.4 19.7 18.5 19.9 19.8 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 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 i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H u r r i c a n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 Enoch Hurricane Moab Exceed.TM EN HC M7 Arith Mean .048 .047 .045 8 -hr. Ozone 4th Max .056 .054 .053 Days of Data 31 31 31 Days > 0.070 000 14.2 18.7 10.1 10.2 11.4 7.4 5 9.5 16.1 17.6 17.615.6 11.9 6 7.4 15.7 17.5 2.5 8.5 9 13.2 14 15.3 18.8 21.1 25.423.7 14.4 11.5 14.1 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 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 i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H a w t h o r n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 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 * ZZ LP Arith Mean .045 .045 8 -hr. Ozone 4th Max .050 .051 Days of Data 31 31 Days > 0.070 00 6.9 8.3 5.5 8 8.4 2.6 3.5 4.5 8.9 13.3 14.312 10.6 3 2 13.3 14.6 2.5 4 6.6 8.7 9.6 11.3 16.5 19.3 22.4 20.7 12.9 11.8 8.4 7.9 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( S m i t h f i e l d ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 Brigham city Exceed.TM BG Arith Mean .045 8 -hr. Ozone 4th Max .051 Days of Data 31 Days > 0.070 0 14.0 14.9 5.1 6.4 7.4 3.3 2.9 6.8 12.7 13.9 12.811.8 8.0 1.6 2.9 11.9 13.4 2.2 3.7 7.6 8.5 9.0 12.0 16.5 19.9 21.7 19.9 14.9 9.1 10.5 10.3 -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 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H e b e r ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature March 2025 Heber Exceed.TM HB Arith Mean .050 8 -hr. Ozone 4th Max .055 Days of Data 31 Days > 0.070 0 6.8 8.2 8.7 10.1 12.5 16.7 21.7 20.5 21.3 27.1 28.6 23.1 15 18.4 22.3 20.3 13.3 8.6 12.7 18.7 17.5 19.9 21.5 18.8 23.4 23.8 17.5 14.5 18.9 16.3 -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 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H a w t h o r n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Bountiful Copperview Erda Herriman #3 Harrisville Hawthorne Near Road Red Butte Rose Park Environmental Quality Exceed.TM BV CV ED H3 HV HW NR RB RP EQ * *Environmental Quality (EQ) previously named Technical Support Center (TSC) ** Controlling Monitor ** O3 March 2025 BV CV ED H3 HV HW NR RB RP EQ Arith Mean .053 .053 .051 .055 .052 .048 .047 .052 .052 .053 8 -hr. Ozone 4th Max .059 .059 .055 .061 .058 .053 .051 .058 .057 .059 Days of Data 30 30 30 30 30 30 30 30 30 30 Days > 0.070 0000000000 5.6 6 6.9 8.4 9.6 14.8 19.4 19.520.8 21.3 25.5 24.3 19.1 17 21.1 19.5 12.8 6.2 10.5 16.8 17.6 20.3 20.8 18.9 21.4 21.8 15.7 15.3 17.8 17.6 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0.000 0.020 0.040 0.060 0.080 0.100 0.120 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( R o o s e v e l t ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Price #2 Roosevelt Vernal Exceed.TM P2 RS V4 Arith Mean .055 .056 .055 8 -hr. Ozone 4th Max .061 .064 .065 Days of Data 30 30 30 Days > 0.070 000 4.6 6.5 8.7 9.8 12.9 15.1 18.3 17.2 19 22.3 23.8 20 13.1 17.6 21 20.8 12 7.5 12.1 15.8 14.9 17.1 19 15.7 19.5 21.1 13.3 12.4 16.6 14.7 -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 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( S m i t h f i e l d ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Smithfield Exceed.TM SM Arith Mean .052 8 -hr. Ozone 4th Max .057 Days of Data 30 Days > 0.070 0 4.5 7.5 6 8.9 12 15 19.9 19.7 21.1 25.5 26.8 23.3 15.1 18.2 22.6 19.6 13.2 8.6 12.3 18.2 18 20.7 22 18.3 21.8 23.3 14.4 13.7 18.9 15.5 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 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 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( L i n d o n ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Lindon Spanish Fork Exceed.TM LN SF Arith Mean .053 .050 8 -hr. Ozone 4th Max .060 .057 Days of Data 30 30 Days > 0.070 00 14.9 11.4 11.7 14.8 16.9 20.7 23.7 26 28.5 30.7 30.3 27.8 26.2 27 27.1 25.7 19.3 11.5 17.7 22.5 25.4 26.4 25.8 26 24.7 22.6 16.5 18.1 22.8 24.9 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H u r r i c a n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Enoch Hurricane Moab Exceed.TM EN HC M7 Arith Mean .053 .052 .052 8 -hr. Ozone 4th Max .060 .058 .058 Days of Data 30 30 30 Days > 0.070 000 6.8 8.2 8.7 10.1 12.5 16.7 21.7 20.5 21.3 27.1 28.6 23.1 15 18.4 22.3 20.3 13.3 8.6 12.7 18.7 17.5 19.9 21.518.8 23.4 23.8 17.5 14.5 18.9 16.3 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H a w t h o r n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Stations Monitoring the Inland Port Development ZZ Lake Park Exceed.TM *ZZis located at the New Utah State Prison (1480 North 8000 West, SLC). This site was previously named IP * ZZ LP Arith Mean .049 .053 8 -hr. Ozone 4th Max .055 .059 Days of Data 30 30 Days > 0.070 00 4.6 6.58.7 9.8 12.9 15.1 18.3 17.2 19 22.3 23.8 20 13.1 17.6 21 20.8 12 7.5 12.1 15.8 14.9 17.1 1915.7 19.5 21.1 13.3 12.4 16.6 14.7 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( S m i t h f i e l d ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Brigham city Exceed.TM BG Arith Mean .055 8 -hr. Ozone 4th Max .060 Days of Data 30 Days > 0.070 0 3.5 4.7 5.8 6.2 10.0 13.6 17.2 17.5 18.8 23.5 24.3 21.1 14.9 19.6 19.6 18.9 7.8 5.7 10.8 15.1 15.8 17.2 19.516.8 18.6 20.2 13.0 13.5 16.6 14.6 -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 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H e b e r ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature April 2025 Heber Exceed.TM HB Arith Mean .056 8 -hr. Ozone 4th Max .063 Days of Data 30 Days > 0.070 0 19.0 23.5 27.0 20.5 15.0 16.8 21.5 25.3 27.5 29.8 29.3 30.2 12.7 11.4 16.3 17.7 21.5 13.2 13.1 -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 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H a w t h o r n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 Bountiful Copperview Erda Herriman #3 Harrisville Hawthorne Near Road Red Butte Rose Park Environmental Quality Exceed.TM BV CV ED H3 HV HW NR RB RP EQ * *EnvironmentalQuality (EQ) previously named Technical Support Center (TSC) ** Controlling Monitor ** O3 May 2025 BV CV ED H3 HV HW NR RB RP EQ Arith Mean .055 .057 .053 .057 .054 .050 .050 .054 .054 .056 8 -hr. Ozone 4th Max .065 .066 .062 .065 .063 .061 .060 .065 .062 .065 Days of Data 19 19 19 19 19 19 19 19 19 19 Days > 0.070 0000000000 18.8 20.2 24.5 19.7 16.3 15.4 19.5 23.325.5 27.3 24.9 28.2 22.8 14.616.0 18.9 19.9 15.4 14.4 -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 0.020 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 i l y M a x i m u m T e m p e r a t u r e ( 0C) ( R o o s e v e l t ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 Price #2 Roosevelt Vernal Exceed.TM P2 RS V4 Arith Mean .057 .058 .055 8 -hr. Ozone 4th Max .061 .061 .060 Days of Data 19 19 19 Days > 0.070 000 19.3 21.8 25.3 18.5 13.1 16.2 21.3 24.0 26.4 27.9 24.9 27.9 13.2 9.0 14.0 15.1 19.7 10.7 11.7 -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 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( S m i t h f i e l d ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 Smithfield Exceed.TM SM Arith Mean .052 8 -hr. Ozone 4th Max .060 Days of Data 19 Days > 0.070 0 19.0 23.126.3 20.5 15.2 16.6 21.3 24.2 26.9 28.6 27.728.6 19.6 10.8 15.8 17.7 21.1 13.1 11.9 -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 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( L i n d o n ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 Lindon Spanish Fork Exceed.TM LN SF Arith Mean .055 .052 8 -hr. Ozone 4th Max .061 .059 Days of Data 19 19 Days > 0.070 00 25.0 28.3 26.8 19.5 14.2 15.8 23.2 28.2 32.1 32.8 32.230.3 22.4 20.3 24.0 26.7 24.7 20.0 23.0 -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 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 i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H u r r i c a n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 Enoch Hurricane Moab Exceed.TM EN HC M7 Arith Mean .054 .053 .056 8 -hr. Ozone 4th Max .060 .058 .061 Days of Data 19 19 19 Days > 0.070 000 19.0 23.527.0 20.5 15.0 16.8 21.5 25.3 27.5 29.8 29.3 30.2 12.7 11.4 16.3 17.7 21.5 13.2 13.1 -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 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H a w t h o r n e ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 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 * ZZ LP Arith Mean .051 .056 8 -hr. Ozone 4th Max .060 .066 Days of Data 19 19 Days > 0.070 00 19.3 21.8 25.3 18.5 13.1 16.2 21.3 24.0 26.4 27.9 24.9 27.9 13.2 9.0 14.0 15.1 19.7 10.7 11.7 -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 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( S m i t h f i e l d ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 Brigham city Exceed.TM BG Arith Mean .054 8 -hr. Ozone 4th Max .065 Days of Data 19 Days > 0.070 0 17.5 21.223.7 16.5 12.0 13.1 19.6 22.8 25.4 26.0 25.6 26.9 19.0 8.9 12.3 14.8 18.7 10.0 11.1 -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 12345678910111213141516171819202122232425262728293031 Da i l y M a x i m u m T e m p e r a t u r e ( 0C) ( H e b e r ) Oz o n e ( p p m ) Days Highest 8-hr Ozone Concentration & Daily Maximum Temperature May 2025 Heber Exceed.TM HB Arith Mean .057 8 -hr. Ozone 4th Max .063 Days of Data 19 Days > 0.070 0