DAQ-2025-002769

San Juan Record
Publication Name:
San Juan Record
Publication URL:
Publication City and State:
Monticello, UT
Publication County:
San Juan
Notice Popular Keyword Category:
Notice Keywords:
Northwest Pipeline
Notice Authentication Number:
202505010915373561329
2273419277
Notice URL:
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Notice File:Notice Publish Date:
4-23 legal Utah Air Quality pipeline.pdf Wednesday, April 23, 2025
Notice Content
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the most accurate information.
NOTICE
A Notice of Intent for the following
project submitted in accordance with
R307-401-1, Utah Administrative
Code
(UAC), has been received for con-
sideration by the Director:
Company Name: Northwest Pipe-
line LLC
Department of Environmental
Quality
Tim Davis, Interim Executive Direc-
tor
DIVISION OF AIR QUALITY
Bryce C. Bird, Director
State of Utah
SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor
Location: Northwest Pipeline LLC
- Cisco Compressor Station – Re-
mote, 3 miles south of I-70, Exit 202
on Highway 128, Cisco, UT
Project Description: Northwest
Pipeline LLC (NWP) owns and oper-
ates the Cisco Compressor Station in
Grand County, Utah. The facility
moves natural gas along a transmis-
sion pipeline and is operated to meet
the demand of the pipeline system.
The facility consists
Web display limited to 1,000 characters. Please view the PDF for the complete Public Notice.
Back
DAQE-IN102590005-25
April 17, 2025
Derek Forsberg
Northwest Pipeline LLC
650 South Main Street, Suite 300
Salt Lake City, UT 84101
[e-mail]
Dear Mr. Forsberg:
Re: Intent to Approve: Minor Modification to Approval Order DAQE-AN102590004-23 to Replace
Equipment
Project Number: N102590005
The attached document is the Intent to Approve (ITA) for the above-referenced project. The ITA is
subject to public review. Any comments received shall be considered before an Approval Order (AO) is
issued. The Division of Air Quality is authorized to charge a fee for reimbursement of the actual costs
incurred in the issuance of an AO. An invoice will follow upon issuance of the final AO.
Future correspondence on this ITA should include the engineer's name, Christine Bodell, as well as the
DAQE number as shown on the upper right-hand corner of this letter. Christine Bodell can be reached at
[phone] or [e-mail] if you have any questions.
Sincerely,
{{$s }}
Alan D. Humpherys, Manager
New Source Review Section
ADH:CB:jg
cc: Southeastern Utah District Health Department
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
SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor
Department of
Environmental Quality
Tim Davis
Executive Director
DIVISION OF AIR QUALITY
Bryce C. Bird
Director
STATE OF UTAH
Department of Environmental Quality
Division of Air Quality

INTENT TO APPROVE
DAQE-IN102590005-25
Minor Modification to Approval Order DAQE-AN102590004-23 to
Replace Equipment

Prepared By
Christine Bodell, Engineer
[phone]
[e-mail]

Issued to
Northwest Pipeline LLC - Cisco Compressor Station

Issued On
April 17, 2025

{{$s }}

New Source Review Section Manager
Section Manager NSR
{{#s=Sig_es_:signer1:signature}}

TABLE OF CONTENTS

TITLE/SIGNATURE PAGE ....................................................................................................... 1
GENERAL INFORMATION ...................................................................................................... 3
CONTACT/LOCATION INFORMATION ............................................................................... 3
SOURCE INFORMATION ........................................................................................................ 3
General Description ................................................................................................................ 3
NSR Classification .................................................................................................................. 3
Source Classification .............................................................................................................. 3
Applicable Federal Standards ................................................................................................. 3
Project Description.................................................................................................................. 4
SUMMARY OF EMISSIONS .................................................................................................... 4
PUBLIC NOTICE STATEMENT............................................................................................... 5
SECTION I: GENERAL PROVISIONS .................................................................................... 5
SECTION II: PERMITTED EQUIPMENT .............................................................................. 6
SECTION II: SPECIAL PROVISIONS ..................................................................................... 7
PERMIT HISTORY ..................................................................................................................... 9
ACRONYMS ............................................................................................................................... 10

DAQE-IN102590005-25
Page 3

GENERAL INFORMATION

CONTACT/LOCATION INFORMATION

Owner Name Source Name
Northwest Pipeline LLC Northwest Pipeline LLC - Cisco Compressor Station

Mailing Address Physical Address
650 South Main Street, Suite 300
Salt Lake City, UT 84101
Remote, 3 miles south of I-70 Exit 202 on
Highway 128
Cisco, UT 84515

Source Contact UTM Coordinates
Name: Derek Forsberg 642,850 m Easting
Phone: [phone],310,720 m Northing
Email: [e-mail] Datum NAD83
UTM Zone 12
SIC code 4922 (Natural Gas Transmission)

SOURCE INFORMATION
General Description
Northwest Pipeline LLC (NWP) owns and operates the Cisco Compressor Station in Grand County, Utah.
The facility moves natural gas along a transmission pipeline and is operated to meet the demand of the
pipeline system. The facility consists of two (2) turbines, an emergency engine, and associated equipment.
Operations are controlled from NWP's headquarters in Salt Lake City.

NSR Classification
Minor Modification at Major Source

Source Classification
Located in Attainment Area
Grand County
Airs Source Size: B

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), JJJJ: Standards of Performance for Stationary Spark Ignition Internal
Combustion Engines
NSPS (Part 60), KKKK: Standards of Performance for Stationary Combustion Turbines
NSPS (Part 60), OOOOb: Standards of Performance for Crude Oil and Natural Gas Facilities
for which Construction, Modification or Reconstruction Commenced After December 6, 2022
MACT (Part 63), A: General Provisions
DAQE-IN102590005-25
Page 4

MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
Title V (Part 70) Area Source

Project Description
Northwest Pipeline is requesting a minor modification to AO DAQE-AN102590004-23, dated November
30, 2023, for the following:

- Replace the two (2) existing 5,500 hp and 4,375 hp natural gas-fired turbines (currently permitted under
Equipment ID# II.A.2) with two (2) 4,906 hp natural gas-fired turbines. Unlike the existing turbines, the
new turbines will each be equipped with SoLoNOx combustors to minimize emissions of NOx, CO, and
VOC.

- Replace the existing 350 hp natural gas-fired emergency generator engine (currently permitted under
Equipment ID# II.A.3) with a 374 hp natural gas-fired emergency engine.

The proposed changes will result in an emissions decrease of NOx, CO, SO2, and VOCs such that the
facility's potential to emit (PTE) will no longer exceed PSD and Title V major source thresholds. While
PM10, PM2.5, and HAPs emissions are also expected to remain below PSD and Title V major source
thresholds, the proposed changes will result in an emissions increase in PM10, PM2.5, and HAPs.
Therefore, the NWP Cisco Compressor Station will be reclassified as an NSR minor source.

SUMMARY OF EMISSIONS

The emissions listed below are an estimate of the total potential emissions from the source. Some
rounding of emissions is possible.

Criteria Pollutant Change (TPY) Total (TPY)
CO2 Equivalent 8847 52736.00
Carbon Monoxide -1.91 52.69
Nitrogen Oxides -120.93 38.81
Particulate Matter - PM10 0.04 2.67
Particulate Matter - PM2.5 0.04 2.67
Sulfur Dioxide -4.03 1.33
Volatile Organic Compounds -5.58 6.10

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Acetaldehyde (CAS #75070) 0 40
Benzene (Including Benzene From Gasoline) (CAS #71432) 20 40
Formaldehyde (CAS #50000) 20 2260
Generic HAPs (CAS #GHAPS) 240 280
Hexane (CAS #110543) 100 140
PAH, Total (CAS #234) 0 40
Toluene (CAS #108883) 40 140
Xylenes (Isomers And Mixture) (CAS #1330207) 40 80
Change (TPY) Total (TPY)
Total HAPs 0.23 1.51
DAQE-IN102590005-25
Page 5

PUBLIC NOTICE STATEMENT

The NOI for the above-referenced project has been evaluated and has been found to be consistent with the requirements of UAC R307. Air pollution producing sources and/or their air control facilities may not be constructed, installed, established, or modified prior to the issuance of an AO by the Director. A 30-day public comment period will be held in accordance with UAC R307-401-7. A notification of the intent to approve will be published in the San Juan Record on April 23, 2025. During the public comment period the proposal and the evaluation of its impact on air quality will be available for the public to review and provide comment. If anyone so requests a public hearing within 15 days of publication, it will be held in accordance with UAC R307-401-7. The hearing will be held as close as practicable to the location of the source. Any comments received during the public comment period and the hearing will be evaluated. The proposed conditions of the AO may be changed as a result of the comments received.

SECTION I: GENERAL PROVISIONS

The intent is to issue an air quality AO authorizing the project with the following recommended
conditions and that failure to comply with any of the conditions may constitute a violation of the AO.

I.1 All definitions, terms, abbreviations, and references used in this AO conform to those used in
the UAC R307 and 40 CFR. Unless noted otherwise, references cited in these AO conditions refer to those rules. [R307-101]

I.2 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]
I.3 Modifications to the equipment or processes approved by this AO that could affect the
emissions covered by this AO must be reviewed and approved. [R307-401-1]
I.4 All records referenced in this AO or in other applicable rules, which are required to be kept by the owner/operator, shall be made available to the Director or Director's representative upon request, and the records shall include the two-year period prior to the date of the request. Unless otherwise specified in this AO or in other applicable state and federal rules, records shall be kept for a minimum of two (2) years. [R307-401-8]
I.5 At all times, including periods of startup, shutdown, and malfunction, owners and operators shall, to the extent practicable, maintain and operate any equipment approved under this AO,
including associated air pollution control equipment, in a manner consistent with good air
pollution control practice for minimizing emissions. Determination of whether acceptable operating and maintenance procedures are being used will be based on information available to
the Director which may include, but is not limited to, monitoring results, opacity observations,
review of operating and maintenance procedures, and inspection of the source. All maintenance performed on equipment authorized by this AO shall be recorded. [R307-401-4]
I.6 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns. [R307-107]
I.7 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-150]
DAQE-IN102590005-25
Page 6

I.8 The owner/operator shall submit documentation of the status of construction or modification to the Director within 18 months from the date of this AO. This AO may become invalid if construction is not commenced within 18 months from the date of this AO or if construction is discontinued for 18 months or more. To ensure proper credit when notifying the Director, send the documentation to the Director, attn.: NSR Section. [R307-401-18]

SECTION II: PERMITTED EQUIPMENT

The intent is to issue an air quality AO authorizing the project with the following recommended
conditions and that failure to comply with any of the conditions may constitute a violation of the AO.
II.A THE APPROVED EQUIPMENT II.A.1 Cisco Compressor Station
II.A.2 Two (2) Turbines (New) Maximum Rating: 4,906 hp @ 0oF (4,527 hp @ 59oF), each Maximum Heat Rating: 46.8 MMBtu/hr each Fuel: pipeline-quality natural gas 40 CFR 60 (NSPS) Applicability: Subpart KKKK, Subpart OOOOb II.A.3 One (1) Emergency Generator Engine (New) Rating: 374 hp Fuel: pipeline-quality natural gas 40 CFR 60 (NSPS) Applicability: Subpart JJJJ 40 CFR 63 (MACT) Applicability: Subpart ZZZZ
II.A.4 One (1) Boiler Rating: 2.5 MMBtu/hr Fuel: pipeline-quality natural gas II.A.5 Three (3) Storage Tanks TK-01 Capacity: 4,200 gallons Contents: Used Oil, Condensate NSPS/MACT Applicability: None TK-02 Capacity: 500 gallons Contents: Lube Oil NSPS/MACT Applicability: None
TK-03 Capacity: 500 gallons
Contents: Lube Oil NSPS/MACT Applicability: None

DAQE-IN102590005-25
Page 7

SECTION II: SPECIAL PROVISIONS

The intent is to issue an air quality AO authorizing the project with the following recommended
conditions and that failure to comply with any of the conditions may constitute a violation of the AO. II.B REQUIREMENTS AND LIMITATIONS II.B.1 Operational Requirements
II.B.1.a The owner/operator shall not allow any visible emissions on-site to exceed 10% opacity. [R307-401-8] II.B.1.a.1 Opacity observations of emissions from stationary sources shall be conducted in accordance with 40 CFR 60, Method 9. [R307-401-8]
II.B.1.b The owner/operator shall use only natural gas as fuel in the turbines, emergency generator engine, and boiler. [R307-401-8] II.B.2 Turbine Stack Testing Requirements
II.B.2.a Before November 1, 2025, the owner/operator shall not emit more than the following rates from each turbine: Pollutant lb/hr NOx 17.9 CO 5.8 On or after November 1, 2025, the owner/operator shall not emit more than the following rates from each turbine: Pollutant lb/hr ppmdv NOx 4.26 25 CO 5.19 50 VOCs 0.30 5 Concentration (ppmdv) is corrected to 15% oxygen, dry basis. [R307-401-8] II.B.2.a.1 Compliance Demonstration To demonstrate compliance with the emission limitations above, the owner/operator shall perform stack testing on each turbine according to the stack testing conditions contained in this AO. [R307-165-2, R307-401-8]
II.B.2.a.2 Initial Test The owner/operator shall conduct an initial stack test on each turbine within 180 days after startup of the emission units. [R307-165-2] II.B.2.a.3 Test Frequency The owner/operator shall conduct a stack test on each turbine for NOx and CO emissions within five (5) years after the date of the most recent stack test of the emission unit. The Director may require the owner/operator to perform a stack test at any time. [R307-165-2, R307-401-8]
II.B.2.a.4 Testing & Test Conditions The owner/operator shall conduct testing according to the approved source test protocol and according to the test conditions contained in R307-165-4. [R307-165-4, R307-401-8]
DAQE-IN102590005-25
Page 8

II.B.2.a.5 Access The owner/operator shall provide Occupational Safety and Health Administration (OSHA)- or Mine Safety and Health Administration (MSHA)-approved access to the test location. [R307-401-8]
II.B.2.a.6 Reporting No later than 60 days after completing a stack test, the owner/operator shall submit a written report of the results from the stack testing to the Director. The report shall include validated
results and supporting information. [R307-165-5, R307-401-8]
II.B.2.a.7 Notification At least 30 days prior to conducting a stack test, the owner/operator shall submit a source test protocol to the Director. The source test protocol shall include the items contained in R307-165-3. If directed by the Director, the owner/operator shall attend a pretest conference. [R307-165-3, R307-401-8] II.B.2.a.8 Possible Rejection of Test Results
The Director may reject stack testing results if the test did not follow the approved source test
protocol or for a reason specified in R307-165-6. [R307-165-6, R307-401-8]
II.B.2.a.9 Standard Conditions A. Temperature - 68 degrees Fahrenheit (293 K) B. Pressure - 29.92 in Hg (101.3 kPa) C. Averaging Time - As specified in the applicable test method. [40 CFR 60 Subpart A, 40 CFR 63 Subpart A, R307-401-8]
II.B.2.a.10 NOx
40 CFR 60, Appendix A, Method 7; Method 7E; or other EPA-approved testing method as acceptable to the Director. [R307-401-8]

II.B.2.a.11 CO 40 CFR 60, Appendix A, Method 10, or other EPA-approved testing method as acceptable to the Director. [R307-401-8]
II.B.2.b VOC 40 CFR 60, Appendix A, Method 18; Method 25; Method 25A; 40 CFR 63, Appendix A,
Method 320; or other EPA-approved testing method as acceptable to the Director. [R307-401-8]

II.B.3 Centrifugal Compressor Seal Requirements II.B.3.a The owner/operator shall comply with the applicable centrifugal compressor dry seal
requirements in 40 CFR 60 Subpart OOOOb. [40 CFR 60 Subpart OOOOb, R307-401-8]

II.B.4 Emergency Generator Engine Requirements
II.B.4.a The owner/operator shall not operate the emergency generator engine on site for more than 100
hours per calendar year for maintenance checks and readiness testing. The emergency generator
engine on-site may be operated for up to 50 hours per calendar year in non-emergency situations.
Any operation in non-emergency situations shall be counted as part of the 100 hours per calendar
year for maintenance and testing. There is no time limit on the use of the engine during
emergencies. [40 CFR 63 Subpart ZZZZ, R307-401-8]

DAQE-IN102590005-25
Page 9

II.B.4.a.1 Records documenting the operation of the emergency engine shall be kept in a log and shall include the following: A. The date the emergency engine was used B. The duration of operation in hours C. The reason for the emergency engine usage. [40 CFR 63 Subpart ZZZZ, R307-401-8]
II.B.4.a.2 To determine the duration of operation, the owner/operator shall install a non-resettable hour meter for the emergency engine. [40 CFR 63 Subpart ZZZZ, R307-401-8]
II.B.4.b The owner/operator shall not operate the emergency generator engine for non-emergency purposes before 8:00 am or after 6:00 pm each day. [R307-401-8]
II.B.4.b.1 The owner/operator shall keep and maintain the following records of operation for all periods the
emergency generator engine is in operation for non-emergency purposes:
A. Time operations begin each day
B. Time operations end each day.

[R307-401-8]

PERMIT HISTORY

This Approval Order shall supersede (if a modification) or will be based on the following documents:
Supersedes AO DAQE-AN102590004-23 dated November 30, 2023 Is Derived From NOI dated February 17, 2025
DAQE-IN102590005-25
Page 10

ACRONYMS

The following lists commonly used acronyms and associated translations as they apply to this document:

40 CFR Title 40 of the Code of Federal Regulations
AO Approval Order
BACT Best Available Control Technology
CAA Clean Air Act
CAAA Clean Air Act Amendments
CDS Classification Data System (used by Environmental Protection Agency to classify
sources by size/type)
CEM Continuous emissions monitor
CEMS Continuous emissions monitoring system
CFR Code of Federal Regulations
CMS Continuous monitoring system
CO Carbon monoxide
CO2 Carbon Dioxide
CO2e Carbon Dioxide Equivalent - Title 40 of the Code of Federal Regulations Part 98,
Subpart A, Table A-1
COM Continuous opacity monitor
DAQ/UDAQ Division of Air Quality
DAQE This is a document tracking code for internal Division of Air Quality use
EPA Environmental Protection Agency
FDCP Fugitive dust control plan
GHG Greenhouse Gas(es) - Title 40 of the Code of Federal Regulations 52.21 (b)(49)(i)
GWP Global Warming Potential - Title 40 of the Code of Federal Regulations Part 86.1818-
12(a)
HAP or HAPs Hazardous air pollutant(s)
ITA Intent to Approve
LB/YR Pounds per year MACT Maximum Achievable Control Technology MMBTU Million British Thermal Units NAA Nonattainment Area NAAQS National Ambient Air Quality Standards NESHAP National Emission Standards for Hazardous Air Pollutants NOI Notice of Intent
NOx Oxides of nitrogen
NSPS New Source Performance Standard
NSR New Source Review
PM10 Particulate matter less than 10 microns in size
PM2.5 Particulate matter less than 2.5 microns in size
PSD Prevention of Significant Deterioration
PTE Potential to Emit
R307 Rules Series 307
R307-401 Rules Series 307 - Section 401
SO2 Sulfur dioxide
Title IV Title IV of the Clean Air Act
Title V Title V of the Clean Air Act
TPY Tons per year
UAC Utah Administrative Code
VOC Volatile organic compounds

DAQE-NN102590005-25

April 17, 2025

San Juan Record
Legal Advertising Dept.
49 S Main
Monticello, UT 84535

RE: Legal Notice of Intent to Approve

This letter will confirm the authorization to publish the attached NOTICE in the San Juan Record on
April 23, 2025.

Please mail the invoice and affidavit of publication to the Utah State Department of Environmental
Quality, Division of Air Quality, P.O. Box 144820, Salt Lake City, Utah 84114-4820. If you have any
questions, contact Jeree Greenwood, who may be reached at [phone].

Sincerely,

{{$s }}

Jeree Greenwood
Office Technician

Enclosure

cc: Grand County
cc: Southeastern Association of Governments

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

SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor

Department of
Environmental Quality

Tim Davis
Interim Executive Director

DIVISION OF AIR QUALITY
Bryce C. Bird
Director

DAQE-NN102590005-25
Page 2
NOTICE

A Notice of Intent for the following project submitted in accordance with R307-401-1, Utah
Administrative Code (UAC), has been received for consideration by the Director:

Company Name: Northwest Pipeline LLC
Location: Northwest Pipeline LLC - Cisco Compressor Station – Remote, 3 miles south of
I-70, Exit 202 on Highway 128, Cisco, UT
Project Description: Northwest Pipeline LLC (NWP) owns and operates the Cisco Compressor
Station in Grand County, Utah. The facility moves natural gas along a
transmission pipeline and is operated to meet the demand of the pipeline system.
The facility consists of two (2) turbines, an emergency engine, and associated
equipment. Operations are controlled from NWP's headquarters in Salt Lake
City. NWP is requesting a minor modification to Approval Order
DAQE-AN102590004-23, dated November 30, 2023, for the following:

- Replace the two (2) existing 5,500 hp and 4,375 hp natural gas-fired turbines
(currently permitted under Equipment ID# II.A.2) with two (2) 4,906 hp natural
gas-fired turbines. Unlike the existing turbines, the new turbines will each be
equipped with SoLoNOx combustors to minimize emissions of NOx, CO, and
VOC.

- Replace the existing 350 hp natural gas-fired emergency generator engine
(currently permitted under Equipment ID# II.A.3) with a 374 hp natural gas-fired
emergency engine.

The proposed changes will result in an emissions decrease of NOx, CO, SO2, and
VOCs such that the facility's potential to emit (PTE) will no longer exceed PSD
and Title V major source thresholds. While PM10, PM2.5, and HAPs emissions are
also expected to remain below PSD and Title V major source thresholds, the
proposed changes will result in an emissions increase in PM10, PM2.5, and HAPs.
Therefore, the NWP Cisco Compressor Station will be reclassified as an NSR
minor source.

The completed engineering evaluation and air quality impact analysis showed the proposed project meets
the requirements of federal air quality regulations and the State air quality rules. The Director intends to
issue an Approval Order pending a 30-day public comment period. The project proposal, estimate of the
effect on local air quality, and draft Approval Order are available for public inspection and comment at
the Utah Division of Air Quality, 195 North 1950 West, Salt Lake City, UT 84116. Written comments
received by the Division at this same address on or before May 23, 2025, will be considered in making
the final decision on the approval/disapproval of the proposed project. Email comments will also be
accepted at [e-mail]. If anyone so requests to the Director in writing within 15 days of
publication of this notice, a hearing will be held in accordance with R307-401-7, UAC.

Under Section 19-1-301.5, a person who wishes to challenge a Permit Order may only raise an issue or
argument during an adjudicatory proceeding that was raised during the public comment period and was
supported with sufficient information or documentation to enable the Director to fully consider the
substance and significance of the issue. Date of Notice: April 23, 2025
{{#s=Sig_es_:signer1:signature}}
DAQE-

RN102590005 April 8, 2025 Derek Forsberg
Northwest Pipeline LLC 650 South Main Street, Suite 300 Salt Lake City, UT 84101
[e-mail] Dear Derek Forsberg,
Re: Engineer Review: Minor Modification to Approval Order DAQE-AN102590004-23 to Replace Equipment Project Number: N102590005 Please review and sign this letter and attached Engineer Review (ER) within 10 business days. For this document to be considered as the application for a Title V administrative amendment, a Title V Responsible Official must sign the next page. Please contact Christine Bodell at [phone] if you have any questions or concerns about the ER. If you accept the contents of this ER, please email this signed cover letter to Christine Bodell at [e-mail]. After receipt of the signed cover letter, the DAQ will prepare an Intent to Approve (ITA) for a 30-day public comment period. When the public comment period ends, the DAQ will consider any comments received and will issue the Approval Order. If you do not respond to this letter within 10 business days, the project will move forward without your approval. If you have concerns that we cannot resolve, the DAQ Director may issue an Order prohibiting
construction. Approval Signature _____________________________________________________________
(Signature & Date)
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
Department of Environmental Quality
Tim Davis Interim Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
State of Utah
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor

Engineer Review N102590005: Northwest Pipeline LLC- Cisco Compressor Station April 8, 2025 Page 1
UTAH DIVISION OF AIR QUALITY
ENGINEER REVIEW

SOURCE INFORMATION
Project Number N102590005 Owner Name Northwest Pipeline LLC Mailing Address 650 South Main Street, Suite 300
Salt Lake City, UT, 84101 Source Name Northwest Pipeline LLC- Cisco Compressor Station
Source Location Remote, 3 miles south of I-70 Exit 202 on Highway 128 Cisco, UT 84515
UTM Projection 642,850 m Easting, 4,310,720 m Northing UTM Datum NAD83 UTM Zone UTM Zone 12 SIC Code 4922 (Natural Gas Transmission) Source Contact Derek Forsberg Phone Number [phone] Email [e-mail] Billing Contact Derek Forsberg
Phone Number 801-673-1334 Email [e-mail]
Project Engineer Christine Bodell, Engineer Phone Number [phone] Email [e-mail]
Notice of Intent (NOI) Submitted February 17, 2025 Date of Accepted Application March 3, 2025

Engineer Review N102590005: Northwest Pipeline LLC- Cisco Compressor Station April 8, 2025 Page 2
SOURCE DESCRIPTION General Description
Northwest Pipeline LLC (NWP) owns and operates the Cisco Compressor Station in Grand County, Utah. The facility moves natural gas along a transmission pipeline and is operated to meet the demand of the pipeline system. The facility consists of two turbines, an emergency
engine, and associated equipment. Operations are controlled from NWP's headquarters in Salt Lake City. NSR Classification: Minor Modification at Major Source Source Classification Located in Attainment Area Grand County Airs Source Size: B
Applicable Federal Standards NSPS (Part 60), A: General Provisions NSPS (Part 60), JJJJ: Standards of Performance for Stationary Spark Ignition Internal
Combustion Engines NSPS (Part 60), KKKK: Standards of Performance for Stationary Combustion Turbines NSPS (Part 60), OOOOb: Standards of Performance for Crude Oil and Natural Gas Facilities
for which Construction, Modification or Reconstruction Commenced After December 6, 2022 MACT (Part 63), A: General Provisions MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines Title V (Part 70) Area Source
Project Proposal Minor Modification to Approval Order DAQE-AN102590004-23 to Replace Equipment Project Description Northwest Pipeline is requesting a minor modification to Approval Order DAQE-AN102590004-23, dated November 30, 2023 for the following: - Replace the two (2) existing 5,500 hp and 4,375 hp natural gas-fired turbines (currently
permitted under Equipment ID# II.A.2) with two (2) 4,906 hp natural gas-fired turbines. Unlike the existing turbines, the new turbines will each be equipped with SoLoNOx combustors to minimize emissions of NOx, CO and VOC.
- Replace the existing 350 hp natural gas-fired emergency generator engine (currently permitted under Equipment ID# II.A.3) with a 374 hp natural gas-fired emergency engine.
The proposed changes will result in an emissions decrease of NOx, CO, SO2, and VOCs such that the facility's potential to emit (PTE) will no longer exceed PSD and Title V major source
thresholds. While PM10, PM2.5 and HAPs emissions are also expected to remain below PSD and Title V major source thresholds, the proposed changes will result in an emissions increase in PM10, PM2,5 and HAPs. Therefore, the NWP Cisco Compressor Station will be reclassified as an NSR minor source.

Engineer Review N102590005: Northwest Pipeline LLC- Cisco Compressor Station April 8, 2025 Page 3
EMISSION IMPACT ANALYSIS
The criteria pollutant and HAP emissions increases do not exceed any modeling thresholds as defined by Utah Administrative Code (UAC) R307-410. Therefore, modeling is not required at this time. [Last updated March 3, 2025]

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SUMMARY OF EMISSIONS
The emissions listed below are an estimate of the total potential emissions from the source. Some rounding of emissions is possible.
Criteria Pollutant Change (TPY) Total (TPY) CO2 Equivalent 8847 52736.00 Carbon Monoxide -1.91 52.69
Nitrogen Oxides -120.93 38.81
Particulate Matter - PM10 0.04 2.67
Particulate Matter - PM2.5 0.04 2.67
Sulfur Dioxide -4.03 1.33
Volatile Organic Compounds -5.58 6.10 Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Acetaldehyde (CAS #75070) 0 40
Benzene (Including Benzene From Gasoline) (CAS #71432) 20 40
Formaldehyde (CAS #50000) 20 2260
Generic HAPs (CAS #GHAPS) 240 280
Hexane (CAS #110543) 100 140 PAH, Total (CAS #234) 0 40 Toluene (CAS #108883) 40 140
Xylenes (Isomers And Mixture) (CAS #1330207) 40 80
Change (TPY) Total (TPY)
Total HAPs 0.23 1.51
Note: Change in emissions indicates the difference between previous AO and proposed modification.

Engineer Review N102590005: Northwest Pipeline LLC- Cisco Compressor Station April 8, 2025 Page 5
Review of BACT for New/Modified Emission Units 1. BACT review regarding New Natural Gas-Fired Turbines
The new natural gas-fired turbines will emit NOx, CO, PM10, PM2.5, SO2, VOCs, and HAPs.
Emission controls include lean premix combustors, oxidation catalysts, water/steam injection, low-NOx combustors, and an SCR catalyst. Oxidation catalysts are best suited for lean burn engines, which is not applicable to the turbines within this application. SCR and SNCR require specific exhaust temperatures for the optimal destruction, but since the turbines within this application do not meet the required range for either NOx control method, it is not technically feasible. The water/steam option would require modifications to the existing turbine and is considered comparable to the currently installed SoLoNOx dry low NOx combustor. The SoLoNOx technology ensures a uniform air/fuel mixture and is considered BACT for the turbine. As per manufacturer's specifications, the SoLoNOx dry low NOx combustor will limit NOx emission concentration to 25 ppm at 15% oxygen (4.26 lb/hr). This emission concentration is equal to the limit of 25 ppm at 15% oxygen NOx specified in 40 CFR 60 Subpart KKKK. The SoLoNOx
dry low NOx combustor will also limit CO emissions to 50 ppm at 15% oxygen (5.19 lb/hr) and limit VOC emissions to 5 ppm at 15% oxygen (0.30 lb/hr). DAQ is unaware of any other add-on control technologies that can further reduce emissions and agrees that the concentration/emission rates are considered BACT for the proposed turbine. BACT is also to limit visual emissions to below 10% opacity. [Last updated March 3, 2025] 2. BACT review regarding New Natural Gas-Fired Emergency Engine NWP has proposed to install one (1) 374 hp natural gas-fired emergency engine. The new engine will emit 0.16 tpy of CO, and negligible amounts of NOx, PM10, PM2.5, VOCs, SO2, and HAPs (<0.10 tpy each). The engine will not exceed 100 hours of operation per year for maintenance and testing purposes. The potential to emits are based on 100 hours of emergency. Due to the inconsistent and low volume of air pollutants emitted from the engine during testing and maintenance, the installation of add-on control technology is cost prohibitive. The new engine is certified to comply with Part 60 Subpart JJJJ Table 1 NOx, CO, and VOC Emission Standards for Stationary Emergency Engines >25 HP. For the emergency 374 hp engine,
this corresponds to limiting NOx, CO, and VOC emission rates to 2.0 g/hp-hr, 4.0 g/hp-hr, and 1.0 g/hp-hr, respectively. SO2 emissions are a result of sulfur present in the fuel. BACT to control sulfur emissions is the exclusive use of natural gas fuel.
Therefore, BACT for the new emergency engine is good combustion practices, exclusive use of natural gas fuel, installing an engine certified to the Part 60 Subpart JJJJ emission standards, and limiting visible emissions to 10% opacity. [Last updated February 26, 2025]

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SECTION I: GENERAL PROVISIONS
The intent is to issue an air quality AO authorizing the project with the following recommended conditions and that failure to comply with any of the conditions may constitute a violation of the AO. (New or Modified conditions are indicated as “New” in the Outline Label):
I.1 All definitions, terms, abbreviations, and references used in this AO conform to those used in the UAC R307 and 40 CFR. Unless noted otherwise, references cited in these AO conditions refer to those rules. [R307-101]

I.2 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]
I.3 Modifications to the equipment or processes approved by this AO that could affect the emissions covered by this AO must be reviewed and approved. [R307-401-1]
I.4 All records referenced in this AO or in other applicable rules, which are required to be kept by
the owner/operator, shall be made available to the Director or Director's representative upon request, and the records shall include the two-year period prior to the date of the request. Unless otherwise specified in this AO or in other applicable state and federal rules, records
shall be kept for a minimum of two (2) years. [R307-401-8] I.5 At all times, including periods of startup, shutdown, and malfunction, owners and operators shall, to the extent practicable, maintain and operate any equipment approved under this AO,
including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions. Determination of whether acceptable operating and maintenance procedures are being used will be based on information available
to the Director which may include, but is not limited to, monitoring results, opacity observations, review of operating and maintenance procedures, and inspection of the source. All maintenance performed on equipment authorized by this AO shall be recorded. [R307-
401-4] I.6 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns. [R307-107]

I.7 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-150] I.8 The owner/operator shall submit documentation of the status of construction or modification to the Director within 18 months from the date of this AO. This AO may become invalid if
construction is not commenced within 18 months from the date of this AO or if construction is discontinued for 18 months or more. To ensure proper credit when notifying the Director, send the documentation to the Director, attn.: NSR Section. [R307-401-18]

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SECTION II: PERMITTED EQUIPMENT The intent is to issue an air quality AO authorizing the project with the following recommended conditions and that failure to comply with any of the conditions may constitute a violation of the
AO. (New or Modified conditions are indicated as “New” in the Outline Label): II.A THE APPROVED EQUIPMENT
II.A.1 Cisco Compressor Station
II.A.2 Two (2) Turbines (New) Maximum Rating: 4,906 hp @ 0oF (4,527 hp @ 59oF), each Maximum Heat Rating: 46.8 MMBtu/hr, each Fuel: pipeline-quality natural gas 40 CFR 60 (NSPS) Applicability: Subpart KKKK, Subpart OOOOb II.A.3 One (1) Emergency Generator Engine (New) Rating: 374 hp Fuel: pipeline-quality natural gas
40 CFR 60 (NSPS) Applicability: Subpart JJJJ
40 CFR 63 (MACT) Applicability: Subpart ZZZZ II.A.4 One (1) Boiler Rating: 2.5 MMBtu/hr
Fuel: pipeline-quality natural gas II.A.5 Three (3) Storage Tanks TK-01 Capacity: 4,200 gallons Contents: Used Oil, Condensate NSPS/MACT Applicability: None TK-02 Capacity: 500 gallons Contents: Lube Oil
NSPS/MACT Applicability: None
TK-03 Capacity: 500 gallons Contents: Lube Oil
NSPS/MACT Applicability: None

Engineer Review N102590005: Northwest Pipeline LLC- Cisco Compressor Station April 8, 2025 Page 8
SECTION II: SPECIAL PROVISIONS The intent is to issue an air quality AO authorizing the project with the following recommended conditions and that failure to comply with any of the conditions may constitute a violation of the
AO. (New or Modified conditions are indicated as “New” in the Outline Label): II.B REQUIREMENTS AND LIMITATIONS
II.B.1 Operational Requirements
II.B.1.a The owner/operator shall not allow any visible emissions on site to exceed 10% opacity.
[R307-401-8] II.B.1.a.1 Opacity observations of emissions from stationary sources shall be conducted in accordance with 40 CFR 60, Method 9. [R307-401-8]

II.B.1.b The owner/operator shall use only natural gas as fuel in the turbines, emergency generator engine, and boiler. [R307-401-8] II.B.2 NEW Turbine Stack Testing Requirements
II.B.2.a
NEW
Before November 1, 2025, the owner/operator shall not emit more than the following rates
from each turbine:
Pollutant lb/hr NOx 17.9 CO 5.8 On or after November 1, 2025, the owner/operator shall not emit more than the following rates from each turbine:
Pollutant lb/hr ppmdv NOx 4.26 25 CO 5.19 50 VOCs 0.30 5
Concentration (ppmdv) is corrected to 15% oxygen, dry basis. [R307-401-8]
II.B.2.a.1
NEW
Compliance Demonstration
To demonstrate compliance with the emission limitations above, the owner/operator shall perform stack testing on each turbine according to the stack testing conditions contained in this AO. [R307-165-2, R307-401-8]
II.B.2.a.2 NEW Initial Test The owner/operator shall conduct an initial stack test on each turbine within 180 days after startup of the emission units. [R307-165-2]

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II.B.2.a.3 NEW Test Frequency The owner/operator shall conduct a stack test on each turbine for NOx and CO emissions within five (5) years after the date of the most recent stack test of the emission unit. The
Director may require the owner/operator to perform a stack test at any time. [R307-165-2, R307-401-8]
II.B.2.a.4 Testing & Test Conditions The owner/operator shall conduct testing according to the approved source test protocol and according to the test conditions contained in R307-165-4. [R307-165-4, R307-401-8] II.B.2.a.5 Access The owner/operator shall provide Occupational Safety and Health Administration (OSHA)- or Mine Safety and Health Administration (MSHA)-approved access to the test location. [R307-401-8]
II.B.2.a.6 Reporting
No later than 60 days after completing a stack test, the owner/operator shall submit a written report of the results from the stack testing to the Director. The report shall include validated results and supporting information. [R307-165-5, R307-401-8]
II.B.2.a.7 Notification At least 30 days prior to conducting a stack test, the owner/operator shall submit a source test protocol to the Director. The source test protocol shall include the items contained in
R307-165-3. If directed by the Director, the owner/operator shall attend a pretest conference. [R307-165-3, R307-401-8]
II.B.2.a.8 Possible Rejection of Test Results The Director may reject stack testing results if the test did not follow the approved source test protocol or for a reason specified in R307-165-6. [R307-165-6, R307-401-8] II.B.2.a.9 Standard Conditions A. Temperature - 68 degrees Fahrenheit (293 K) B. Pressure - 29.92 in Hg (101.3 kPa) C. Averaging Time - As specified in the applicable test method
[40 CFR 60 Subpart A, 40 CFR 63 Subpart A, R307-401-8]
II.B.2.a.10 NOx 40 CFR 60, Appendix A, Method 7; Method 7E; or other EPA-approved testing method as acceptable to the Director. [R307-401-8]

II.B.2.a.11 CO 40 CFR 60, Appendix A, Method 10 or other EPA-approved testing method as acceptable to the Director. [R307-401-8]

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II.B.2.b NEW VOC 40 CFR 60, Appendix A, Method 18; Method 25; Method 25A; 40 CFR 63, Appendix A, Method 320; or other EPA-approved testing method as acceptable to the Director. [R307-401-
8] II.B.3 NEW Centrifugal Compressor Seal Requirements
II.B.3.a NEW The owner/operator shall comply with the applicable centrifugal compressor dry seal requirements in 40 CFR 60 Subpart OOOOb. [40 CFR 60 Subpart OOOOb, R307-401-8]

II.B.4 NEW Emergency Generator Engine Requirements
II.B.4.a The owner/operator shall not operate the emergency generator engine on site for more than 100 hours per calendar year for maintenance checks and readiness testing. The emergency generator engine on site may be operated for up to 50 hours per calendar year in non-emergency situations. Any operation in non- emergency situations shall be counted as part of the 100 hours per calendar year for maintenance and testing. There is no time limit on the use of the engine during emergencies. [40 CFR 63 Subpart ZZZZ, R307-401-8]
II.B.4.a.1 Records documenting the operation of the emergency engine shall be kept in a log and shall include the following: A. The date the emergency engine was used B. The duration of operation in hours C. The reason for the emergency engine usage
[40 CFR 63 Subpart ZZZZ, R307-401-8]
II.B.4.a.2 To determine the duration of operation, the owner/operator shall install a non-resettable hour meter for the emergency engine. [40 CFR 63 Subpart ZZZZ, R307-401-8]
II.B.4.b The owner/operator shall not operate the emergency generator engine for non-emergency
purposes before 8:00 am or after 6:00 pm each day. [R307-401-8] II.B.4.b.1 The owner/operator shall keep and maintain the following records of operation for all periods the emergency generator engine is in operation for non-emergency purposes: A. Time operations begin each day B. Time operations end each day [R307-401-8]

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PERMIT HISTORY When issued, the approval order shall supersede (if a modification) or will be based on the
following documents: Supersedes Approval Order DAQE-AN102590004-23 dated November 30, 2023
Is Derived From NOI dated February 17, 2025
REVIEWER COMMENTS

1. Comment regarding November 1, 2025 date in Condition II.B.2.a: The source is requesting to replace the two (2) existing 5,500 hp and 4,375 hp natural gas-fired turbines (currently permitted under Equipment ID# II.A.2 in the 2023 AO) with two (2) 4,906 hp natural gas-fired turbines through a "core replacement" process. The bodies of the existing turbines will remain unchanged, but the cores will each be replaced to improve performance, extend lifespan, and reduce air pollutant emissions. Therefore, the two (2) 4,906 hp natural gas-fired turbines are considered "new" for New Source Review permitting purposes. To provide the source with flexibility to conduct the core replacement, the source and DAQ has agreed that the turbines will meet the new emission limitations outlined in II.B.2.a no later than November 1, 2025. Prior to this date, the source shall continue to limit the turbine emissions to the
limits outlined in the 2023 AO. [Last updated March 18, 2025] 2. Comment regarding Source Emission Estimates and DAQ Acceptance: Emission Estimates: One (1) natural gas-fired, 374 hp, emergency engine: Emission estimates are based EPA guidance as published in Compilation of Air Pollution Emission Factors, Volume I: Stationary Point and Area Sources or AP-42, Section 3.2, Natural Gas-fired Reciprocating Engines Tables 3.2-1,-2, and -3. The engine will operate a maximum of 100 hours per year for maintenance and testing purposes and with no hourly limits on emergency use.
Two (2) natural gas-fired, 4,906 hp turbines:
Emission estimates are based on vendor data and EPA guidance as published in Compilation of Air Pollution Emission Factors, Volume I: Stationary Point and Area Sources or AP-42, Section 3.1 Stationary Gas Turbines tables 3.1-1,-2a, and -3. Emissions are calculated assuming operation 24
hours per day, 365 hours per year. As per manufacturer's specifications, the SoLoNOx dry low NOx combustor will limit NOx emission concentration to 25 ppm at 15% oxygen (4.26 lb/hr), CO emissions to 50 ppm at 15% oxygen (5.19 lb/hr), and VOCs emissions to 5 ppm at 15% oxygen (0.30 lb/hr). Three (3) oil storage tanks: EPA TANKS 4.0.9d was used to determine working and breathing losses from each storage tank. One (1) natural gas-fired, 2.5 MMBtu/hr boiler: For the reboilers, emission estimates are based on manufacturer data and AP-42, Section 1.4, Natural Gas Combustion using tables 1.4-1,-2 and -3. Emissions are calculated assuming operation 24 hours per day, 365 hours per year. [Last updated March 18, 2025]

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3. Comment regarding NSPS Federal Subpart Applicability: 40 CFR Part 60 (NSPS) Subpart 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) applies is each storage vessel with a capacity greater than or equal to 75 cubic meters (19,813 gallons) that is used to store volatile organic liquids (VOL) for which construction, reconstruction, or modification is commenced after July 23, 1984. Each tank
has a capacity less than 19,813 gallons. Therefore, NSPS Subpart Kb does not apply to the tanks.
40 CFR 60 Subpart GG (Standards of Performance for Stationary Gas Turbines) applies to all stationary gas turbines with a heat input at peak load equal to or greater than 10.7 gigajoules (10 million Btu) per hour, based on the lower heating value of the fuel fired. The two new turbines each have a maximum heat input ≥ 10 MMBtu/hr and a construction, modification, or reconstruction commenced date after February 18, 2005. Therefore, the turbines are subject to 40 CFR 60 Subpart KKKK (Standards of Performance for Stationary Combustion Turbines). Stationary combustion
turbines regulated under NSPS Subpart KKKK are exempt from the requirements of NSPS Subpart GG. Therefore, NSPS Subpart KKKK applies to the new turbines. 40 CFR 60 NSPS Subpart JJJJ (Standards of Performance for Stationary Spark Ignition Internal Combustion Engines) applies to emergency engines that were manufactured on or after January 1,
2009. Therefore, NSPS Subpart JJJJ applies to the Cisco new emergency engine.
40 CFR 60 NSPS OOOOb (Crude Oil and Natural Gas Facilities for Which Construction, Modification or Reconstruction Commenced After December 6, 2022) applies to the centrifugal compressors driven by the turbines because the facility is located within the Crude Oil and Natural Gas source category and the compressors commenced construction or modification after December 6, 2022. This rule does apply to the electrically driven reciprocating compressor (associated with turbines' recompression system) because it was constructed after December 6, 2022. Requirements for the centrifugal compressors include one of the following options: volumetric flow rate monitoring of the dry gas seals, routing the seal gas to control, or routing the seal gas to process. Additionally, repairing dry gas seals (as applicable) on a specified schedule and recordkeeping and reporting. As the electrically driven reciprocating compressor is a self-contained reciprocating compressor, the closed vent system is subject to the monitoring, recordkeeping and reporting
requirements.
This rule does not apply to the Process Piping and Equipment Leaks (FUG) because the facility has not been "modified" as defined in NSPS Subpart OOOOb. As stated in §60.5365b(i)(3), a modification to a compressor station occurs when an additional compressor is installed, or one or
more compressors are replaced with compressors of greater total horsepower. The compressor horsepower does not increase with this project. This rule does not apply to any storage tank at the facility because each tank does not meet the definition of "storage vessel" (§60.5430b). This rule may apply to the collection of natural gas-driven process controllers if there is an increase in the number of natural gas-driven process controllers at the facility or reconstruction of more than

Engineer Review N102590005: Northwest Pipeline LLC- Cisco Compressor Station April 8, 2025 Page 13
50% of the existing natural gas process controllers. Therefore, NSPS Subpart OOOOb applies to the centrifugal compressors driven by the turbines and the electrically driven reciprocating compressor (associated with turbines' recompression system). [Last updated April 1, 2025]
4. Comment regarding MACT Federal Subpart Applicability: 40 CFR 63 Subpart ZZZZ (National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines) is applicable to owners/operators of stationary RICE at a major or area sources of HAP emissions. MACT Subpart ZZZZ applies to the Cisco Facility as the emergency engine generator is a RICE. Therefore, MACT Subpart ZZZZ applies to the new Cisco emergency engine. [Last updated March 18, 2025]
5. Comment regarding Title V Applicability: Title V of the 1990 Clean Air Act (Title V) applies to the following:
1. Any major source
2. Any source subject to a standard, limitation, or other requirement under Section 111 of the Act, Standards of Performance for New Stationary Sources; 3. Any source subject to a standard or other requirement under Section 112 of the Act, Hazardous Air Pollutants. 4. Any Title IV affected source. This facility is not a major source nor a Title IV source. The facility is not subject to 40 CFR 61 (NESHAP) regulations. It is subject to 40 CFR 60 (NSPS) Subparts A, JJJJ, KKKK, and OOOOb
and to 40 CFR 63 (MACT) Subparts A and ZZZZ. Therefore, Title V applies to this facility as an area source. [Last updated March 18, 2025]

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ACRONYMS The following lists commonly used acronyms and associated translations as they apply to this document:
40 CFR Title 40 of the Code of Federal Regulations AO Approval Order BACT Best Available Control Technology
CAA Clean Air Act CAAA Clean Air Act Amendments CDS Classification Data System (used by EPA to classify sources by size/type) CEM Continuous emissions monitor CEMS Continuous emissions monitoring system CFR Code of Federal Regulations CMS Continuous monitoring system CO Carbon monoxide CO2 Carbon Dioxide CO2e Carbon Dioxide Equivalent - 40 CFR Part 98, Subpart A, Table A-1 COM Continuous opacity monitor
DAQ/UDAQ Division of Air Quality DAQE This is a document tracking code for internal UDAQ use EPA Environmental Protection Agency
FDCP Fugitive dust control plan GHG Greenhouse Gas(es) - 40 CFR 52.21 (b)(49)(i) GWP Global Warming Potential - 40 CFR Part 86.1818-12(a)
HAP or HAPs Hazardous air pollutant(s) ITA Intent to Approve LB/HR Pounds per hour
LB/YR Pounds per year MACT Maximum Achievable Control Technology MMBTU Million British Thermal Units
NAA Nonattainment Area NAAQS National Ambient Air Quality Standards NESHAP National Emission Standards for Hazardous Air Pollutants NOI Notice of Intent NOx Oxides of nitrogen NSPS New Source Performance Standard NSR New Source Review PM10 Particulate matter less than 10 microns in size
PM2.5 Particulate matter less than 2.5 microns in size PSD Prevention of Significant Deterioration PTE Potential to Emit
R307 Rules Series 307 R307-401 Rules Series 307 - Section 401 SO2 Sulfur dioxide
Title IV Title IV of the Clean Air Act Title V Title V of the Clean Air Act TPY Tons per year
UAC Utah Administrative Code VOC Volatile organic compounds
DAQE-
RN102590005
April 8, 2025
Derek Forsberg
Northwest Pipeline LLC
650 South Main Street, Suite 300
Salt Lake City, UT 84101
[e-mail]
Dear Derek Forsberg,
Re:Engineer Review:
Minor Modification to Approval Order DAQE-AN102590004-23 to Replace Equipment
Project Number: N102590005
Please review and sign this letter and attached Engineer Review (ER) within 10 business days. For this
document to be considered as the application for a Title V administrative amendment, a Title V Responsible
Official must sign the next page.
Please contact Christine Bodell at [phone] if you have any questions or concerns about the ER. If you
accept the contents of this ER, please email this signed cover letter to Christine Bodell at [e-mail].
After receipt of the signed cover letter, the DAQ will prepare an Intent to Approve (ITA) for a 30-day public
comment period. When the public comment period ends, the DAQ will consider any comments received and
will issue the Approval Order.
If you do not respond to this letter within 10 business days, the project will move forward without your
approval. If you have concerns that we cannot resolve, the DAQ Director may issue an Order prohibiting
construction.
Approval Signature _____________________________________________________________
(Signature & Date)
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
Department of
Environmental Quality
Tim Davis
Interim Executive Director
DIVISION OF AIR QUALITY
Bryce C. Bird
Director
State of Utah
SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor
Lieutenant Governor
Docusign Envelope ID: 3A808A09-D607-4A72-9968-6942817B8103
4/10/2025 | 1:36 PM CDT
Equipment Details
Rating 4,906 hp = (3661.2 kw)44.44 MMBtu/hr (Typ @ 59oF) (Max)
Operational Hours 8,760 hours/year 88.88 2 TurbinesEngine Type
Criteria Pollutant
EmissionStandards
(g/hp-hr)
Emission Factor
(lb/MMBtu)
EmissionRate
(lbs/hr)
EmissionTotal
(tons/year)Reference
NOX 0.1 8.89 38.93CO0.122 10.84 47.49
PM10 7.00E-03 0.62 2.73PM2.5 7.00E-03 0.62 2.73
VOC 7.00E-03 0.62 2.73SO23.00E-03 0.27 1.17HAP0.31 1.34 See Below
Green House Gas Pollutant
Global
Warming Potential Emission Factor(lb/MMBtu)
Emission
Rate(lbs/hr)
Emission
Total(tons/year)ReferenceCO2 (mass basis)1 1.10E+02 48 210Methane (mass basis)25 1.50E-02 0 1CO2e228
Hazardous Air Pollutant
EmissionRate
(lbs/hr)
EmissionTotal
(tons/year)Reference
1,3-Butadiene 4.30E-07 0.00 1.67E-04
Acetaldehyde 4.00E-05 0.00 1.56E-02Acrolein6.40E-06 0.00 2.49E-03
Benzene 9.10E-07 0.00 3.54E-04
Ethylbenzene 3.20E-05 0.00 1.25E-02
Formaldehyde 2.88E-03 0.26 1.12E+00 0.30Hexane2.54E-04 0.02 9.89E-02 0.030.00
Naphthalene 1.30E-06 0.00 5.06E-04 0.00PAH3.47E-05 0.00 1.35E-02 0.00
Toluene 1.30E-04 0.01 5.06E-02 0.01
Xylene 6.40E-05 0.01 2.49E-02 0.01
Emission Factor(lb/MMBtu)
AP-42 Table 3.2-1,Table 3.2-2, &
Table 3.2-3
(Some HAP do not popluate based on the type of engine
selected. AP-42 does not list certain HAP for certain types of engines.)
Turbine (Normal Operations)
Manufacturer Data,AP-42 Table 3.2-1,
Table 3.2-2, &Table 3.2-3
AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
Page 1 of Version 1.1 February 21, 2019
Equipment Details
Rating 4,906 hp = (3661.2 kw)
Operational Hours 8,760 hours/yearEngine Type
Criteria Pollutant
Emission
Standards
(g/hp-hr)
Emission Factor
(lb/MMBtu)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
NOX 0.03 0.13
CO 0.70 3.07
PM10 0.00 0.00PM2.5 0.00 0.00
VOC 0.12 0.53SO20.00 0.00
HAP 0.01 0.03 See Below
Green House Gas Pollutant
Global Warming
Potential
Emission Factor
(lb/MMBtu)
EmissionRate
(lbs/hr)
EmissionTotal
(tons/year)ReferenceCO2 (mass basis)1 1.10E+02 6 26
Methane (mass basis)25 1.50E-02 1 3CO2e94
Hazardous Air Pollutant
EmissionRate
(lbs/hr)
EmissionTotal
(tons/year)Reference
1,3-Butadiene 0.00E+00 0.00E+00
Acetaldehyde 0.00E+00 0.00E+00Acrolein0.00E+00 0.00E+00
Benzene 7.00E-04 3.07E-03
Ethylbenzene 7.00E-04 3.07E-03
Formaldehyde 0.00E+00 0.00E+00Hexane2.00E-03 8.76E-03
Methanol 3.00E-03 1.31E-02Naphthalene0.00E+00 0.00E+00
PAH 0.00E+00 0.00E+00
Toluene 7.00E-04 3.07E-03
Xylene 7.00E-04 3.07E-03
AP-42 Table 3.2-1,Table 3.2-2, &
Table 3.2-3
Emission Factor
(lb/MMBtu)
AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
(Some HAP do not popluate based on
the type of engine
selected. AP-42 does not list certain HAP for certain types
of engines.)
Turbine SUSD (Per Turbine)
Manufacturer Data,
AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
Page 2 of Version 1.1 February 21, 2019
Equipment Details
Rating 4,906 hp = (3661.2 kw)
Operational Hours 8,760 hours/yearEngine Type
Criteria Pollutant
Emission
Standards
(g/hp-hr)
Emission Factor
(lb/MMBtu)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
NOX 0.00
CO 0.00
PM10 0.00 0.00PM2.5 0.00 0.00
VOC 0.18 0.79SO20.00 0.00
HAP 0.02 0.08 See Below
Green House Gas Pollutant
Global Warming
Potential
Emission Factor
(lb/MMBtu)
EmissionRate
(lbs/hr)
EmissionTotal
(tons/year)ReferenceCO2 (mass basis)1 1.10E+02 1 3
Methane (mass basis)25 1.50E-02 22 96CO2e2,412
Hazardous Air Pollutant
EmissionRate
(lbs/hr)
EmissionTotal
(tons/year)Reference
1,3-Butadiene 0.00E+00 0.00E+00
Acetaldehyde 0.00E+00 0.00E+00Acrolein0.00E+00 0.00E+00
Benzene 2.00E-03 8.76E-03
Ethylbenzene 2.00E-03 8.76E-03
Formaldehyde 0.00E+00 0.00E+00Hexane3.00E-03 1.31E-02
Methanol 1.00E-02 4.38E-02Naphthalene0.00E+00 0.00E+00
PAH 0.00E+00 0.00E+00
Toluene 1.00E-03 4.38E-03
Xylene 1.00E-03 4.38E-03
AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
(Some HAP do not popluate based on
the type of engine
selected. AP-42 does not list certain HAP for certain types
of engines.)
Turbine Leaks (Per Turbine)
Manufacturer Data,
AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
AP-42 Table 3.2-1,Table 3.2-2, &
Table 3.2-3
Emission Factor
(lb/MMBtu)
Page 3 of Version 1.1 February 21, 2019
7,000 BTU/hp-hrEquipment Details 1387 MMscf/yrRating374hp = (279.2 kw)3.8 MMscf/dayOperational Hours 100 hours/year 1343 Btu/scfEngine Type lb/MMBtu lb/hp-hr lb/hr Ton/year Check lb/MMBtu lb/hp-hr lb/hr Ton/year Check lb/MMBtu lb/hp-hr lb/hr Ton/year Check
Criteria Pollutant
EmissionStandards(g/hp-hr)Emission Factor(lb/MMBtu)
EmissionRate(lbs/hr)
EmissionTotal(tons/year)Reference NOX @ 90-105% Load 3.17E+00 2.22E-02 8.30 0.41 4.08E+00 2.86E-02 10.68 0.53 2.21E+00 1.55E-02 5.79 0.29NOX2.00 1.65 0.08 NOX @ <90% Load 1.94E+00 1.36E-02 5.08 0.25 8.47E-01 5.93E-03 2.22 0.11 2.27E+00 1.59E-02 5.94 0.30CO4.00 3.30 0.16 CO @ 90-105% Load 3.86E-01 2.70E-03 1.01 0.05 3.17E-01 2.22E-03 0.83 0.04 3.72E+00 2.60E-02 9.74 0.49PM107.16E-02 0.06 0.00 CO @ <90% Load 3.53E-01 2.47E-03 0.92 0.05 5.57E-01 3.90E-03 1.46 0.07 3.51E+00 2.46E-02 9.19 0.46PM2.5 7.16E-02 0.06 0.00 CO2 1.10E+02 7.70E-01 287.98 14.40 Match 1.10E+02 7.70E-01 287.98 14.40 Match 1.10E+02 7.70E-01 287.98 14.40 Match
VOC 1.00 0.82 0.04 SO2 5.88E-04 4.12E-06 0.00 0.00 5.88E-04 4.12E-06 0.00 0.00 5.88E-04 4.12E-06 0.00 0.00SO20.00 3.13E-03 0.67 0.03 TOC 1.64E+00 1.15E-02 4.29 0.21 1.47E+00 1.03E-02 3.85 0.19 3.58E-01 2.51E-03 0.94 0.05HAP0.05 0.00 See Below Methane 1.45E+00 1.02E-02 3.80 0.19 1.25E+00 8.75E-03 3.27 0.16 Match 2.30E-01 1.61E-03 0.60 0.03VOC1.20E-01 8.40E-04 0.31 0.02 1.18E-01 8.26E-04 0.31 0.02 2.96E-02 2.07E-04 0.08 0.00
Green House Gas Pollutant
Global Warming Potential Emission Factor(lb/MMBtu)
EmissionRate(lbs/hr)
EmissionTotal(tons/year)Reference PM10 - filterable 3.84E-02 2.69E-04 0.10 0.01 7.71E-05 5.40E-07 0.00 0.00 9.50E-03 6.65E-05 0.02 0.00CO2 (mass basis)1 1.10E+02 288 14 PM2.5 - filterable 3.84E-02 2.69E-04 0.10 0.01 7.71E-05 5.40E-07 0.00 0.00 9.50E-03 6.65E-05 0.02 0.00
Methane (mass basis)25 1.25E+00 3 0 PM - Condensable 9.91E-03 6.94E-05 0.03 0.00 9.91E-03 6.94E-05 0.03 0.00 9.91E-03 6.94E-05 0.03 0.00CO2e18PM10 - Total 4.83E-02 0.13 0.01 9.99E-03 0.03 0.00 1.94E-02 0.05 0.00PM2.5 - Total 4.83E-02 0.13 0.01 9.99E-03 0.03 0.00 1.94E-02 0.05 0.00
Hazardous Air Pollutant
EmissionRate(lbs/hr)
EmissionTotal(tons/year)Reference HAP lb/MMBtu lb/hp-hr lb/hr Ton/year Check lb/MMBtu lb/hp-hr lb/hr Ton/year Check lb/MMBtu lb/hp-hr lb/hr Ton/year Check1,1,2,2-Tetrachloroethane 4.00E-05 1.05E-04 5.24E-06 1,1,2,2-Tetrachloroethane 6.63E-05 4.64E-07 1.74E-04 8.68E-06 4.00E-05 2.80E-07 1.05E-04 5.24E-06 Match 2.53E-05 1.77E-07 6.62E-05 3.31E-061,1,2-Trichloroethane 3.18E-05 8.33E-05 4.16E-06 1,1,2-Trichloroethane 5.27E-05 3.69E-07 1.38E-04 6.90E-06 3.18E-05 2.23E-07 8.33E-05 4.16E-06 Match 1.53E-05 1.07E-07 4.01E-05 2.00E-061,3-Butadiene 2.67E-04 6.99E-04 3.50E-05 1,3-Butadiene 8.20E-04 5.74E-06 2.15E-03 1.07E-04 2.67E-04 1.87E-06 6.99E-04 3.50E-05 Match 6.63E-04 4.64E-06 1.74E-03 8.68E-051,3-Dichloropropene 2.64E-05 6.91E-05 3.46E-06 1,3-Dichloropropene 4.38E-05 3.07E-07 1.15E-04 5.73E-06 2.64E-05 1.85E-07 6.91E-05 3.46E-06 Match 1.27E-05 8.89E-08 3.32E-05 1.66E-062,2,4-Trimethylpentane 2.50E-04 6.55E-04 3.27E-05 2,2,4-Trimethylpentane 8.46E-04 5.92E-06 2.21E-03 1.11E-04 2.50E-04 1.75E-06 6.55E-04 3.27E-05 Match2-Methylnaphthalene 3.32E-05 8.69E-05 4.35E-06 2-Methylnaphthalene 2.14E-05 1.50E-07 5.60E-05 2.80E-06 3.32E-05 2.32E-07 8.69E-05 4.35E-06 MatchAcenaphthene1.25E-06 3.27E-06 1.64E-07 Acenaphthene 1.33E-06 9.31E-09 3.48E-06 1.74E-07 1.25E-06 8.75E-09 3.27E-06 1.64E-07 MatchAcenaphthylene5.53E-06 1.45E-05 7.24E-07 Acenaphthylene 3.17E-06 2.22E-08 8.30E-06 4.15E-07 5.53E-06 3.87E-08 1.45E-05 7.24E-07 MatchAcetaldehyde8.36E-03 2.19E-02 1.09E-03 Acetaldehyde 7.76E-03 5.43E-05 2.03E-02 1.02E-03 8.36E-03 5.85E-05 2.19E-02 1.09E-03 Match 2.79E-03 1.95E-05 7.30E-03 3.65E-04Acrolein5.14E-03 1.35E-02 6.73E-04 Acrolein 7.78E-03 5.45E-05 2.04E-02 1.02E-03 5.14E-03 3.60E-05 1.35E-02 6.73E-04 Match 2.63E-03 1.84E-05 6.89E-03 3.44E-04Anthracene7.18E-07 5.03E-09 1.88E-06 9.40E-08 Match MatchBenz(a)anthracene 3.36E-07 2.35E-09 8.80E-07 4.40E-08 Match MatchBenzene4.40E-04 1.15E-03 5.76E-05 Benzene 1.94E-03 1.36E-05 5.08E-03 2.54E-04 4.40E-04 3.08E-06 1.15E-03 5.76E-05 Match 1.58E-03 1.11E-05 4.14E-03 2.07E-04Benzo(a)pyrene 5.68E-09 3.98E-11 1.49E-08 7.44E-10 Match MatchBenzo(b)fluoranthene 1.66E-07 4.35E-07 2.17E-08 Benzo(b)fluoranthene 8.51E-09 5.96E-11 2.23E-08 1.11E-09 1.66E-07 1.16E-09 4.35E-07 2.17E-08 MatchBenzo(e)pyrene 4.15E-07 1.09E-06 5.43E-08 Benzo(e)pyrene 2.34E-08 1.64E-10 6.13E-08 3.06E-09 4.15E-07 2.91E-09 1.09E-06 5.43E-08 Matchbenzo(g,h,i)perylene 4.14E-07 1.08E-06 5.42E-08 benzo(g,h,i)perylene 2.48E-08 1.74E-10 6.49E-08 3.25E-09 4.14E-07 2.90E-09 1.08E-06 5.42E-08 MatchBenzo(k)fluoranthene 4.26E-09 2.98E-11 1.12E-08 5.58E-10 Match MatchBiphenyl2.12E-04 5.55E-04 2.78E-05 Biphenyl 3.95E-06 2.77E-08 1.03E-05 5.17E-07 2.12E-04 1.48E-06 5.55E-04 2.78E-05 MatchCarbon Tetrachloride 3.67E-05 9.61E-05 4.80E-06 Carbon Tetrachloride 6.07E-05 4.25E-07 1.59E-04 7.95E-06 3.67E-05 2.57E-07 9.61E-05 4.80E-06 Match 1.77E-05 1.24E-07 4.63E-05 2.32E-06Chlorobenzene3.04E-05 7.96E-05 3.98E-06 Chlorobenzene 4.44E-05 3.11E-07 1.16E-04 5.81E-06 3.04E-05 2.13E-07 7.96E-05 3.98E-06 Match 1.29E-05 9.03E-08 3.38E-05 1.69E-06Chloroform2.85E-05 7.46E-05 3.73E-06 Chloroform 4.71E-05 3.30E-07 1.23E-04 6.17E-06 2.85E-05 2.00E-07 7.46E-05 3.73E-06 Match 1.37E-05 9.59E-08 3.59E-05 1.79E-06Chrysene6.93E-07 1.81E-06 9.07E-08 Chrysene 6.72E-07 4.70E-09 1.76E-06 8.80E-08 6.93E-07 4.85E-09 1.81E-06 9.07E-08 MatchEthylbenzene3.97E-05 1.04E-04 5.20E-06 Ethylbenzene 1.08E-04 7.56E-07 2.83E-04 1.41E-05 3.97E-05 2.78E-07 1.04E-04 5.20E-06 Match 2.48E-05 1.74E-07 6.49E-05 3.25E-06Ethylene Dibromide 4.43E-05 1.16E-04 5.80E-06 Ethylene Dibromide 7.34E-05 5.14E-07 1.92E-04 9.61E-06 4.43E-05 3.10E-07 1.16E-04 5.80E-06 Match 2.13E-05 1.49E-07 5.58E-05 2.79E-06Fluoranthene1.11E-06 2.91E-06 1.45E-07 Fluoranthene 3.61E-07 2.53E-09 9.45E-07 4.73E-08 1.11E-06 7.77E-09 2.91E-06 1.45E-07 MatchFluorene5.67E-06 1.48E-05 7.42E-07 Fluorene 1.69E-06 1.18E-08 4.42E-06 2.21E-07 5.67E-06 3.97E-08 1.48E-05 7.42E-07 MatchFormaldehyde0.001 5.28E-02 0.00 4.12E-05 Formaldehyde 5.52E-02 3.86E-04 1.45E-01 7.23E-03 5.28E-02 3.70E-04 1.38E-01 6.91E-03 2.05E-02 1.44E-04 5.37E-02 2.68E-03Indeno(1,2,3-c,d)pyrene 9.93E-09 6.95E-11 2.60E-08 1.30E-09 Match MatchMethanol2.50E-03 6.55E-03 3.27E-04 Methanol 2.48E-03 1.74E-05 6.49E-03 3.25E-04 2.50E-03 1.75E-05 6.55E-03 3.27E-04 Match 3.06E-03 2.14E-05 8.01E-03 4.01E-04Methylene Chloride 2.00E-05 5.24E-05 2.62E-06 Methylene Chloride 1.47E-04 1.03E-06 3.85E-04 1.92E-05 2.00E-05 1.40E-07 5.24E-05 2.62E-06 Match 4.12E-05 2.88E-07 1.08E-04 5.39E-06n-Hexane 1.11E-03 2.91E-03 1.45E-04 n-Hexane 4.45E-04 3.12E-06 1.17E-03 5.83E-05 1.11E-03 7.77E-06 2.91E-03 1.45E-04 MatchNaphthalene7.44E-05 1.95E-04 9.74E-06 Naphthalene 9.63E-05 6.74E-07 2.52E-04 1.26E-05 7.44E-05 5.21E-07 1.95E-04 9.74E-06 Match 9.71E-05 6.80E-07 2.54E-04 1.27E-05PAH2.69E-05 7.04E-05 3.52E-06 PAH 1.34E-04 9.38E-07 3.51E-04 1.75E-05 2.69E-05 1.88E-07 7.04E-05 3.52E-06 Match 1.41E-04 9.87E-07 3.69E-04 1.85E-05Perylene4.97E-09 3.48E-11 1.30E-08 6.51E-10 Match MatchPhenanthrene1.04E-05 2.72E-05 1.36E-06 Phenanthrene 3.53E-06 2.47E-08 9.24E-06 4.62E-07 1.04E-05 7.28E-08 2.72E-05 1.36E-06 MatchPhenol2.40E-05 6.28E-05 3.14E-06 Phenol 4.21E-05 2.95E-07 1.10E-04 5.51E-06 2.40E-05 1.68E-07 6.28E-05 3.14E-06 MatchPyrene1.36E-06 3.56E-06 1.78E-07 Pyrene 5.84E-07 4.09E-09 1.53E-06 7.64E-08 1.36E-06 9.52E-09 3.56E-06 1.78E-07 MatchStyrene2.36E-05 6.18E-05 3.09E-06 Styrene 5.48E-05 3.84E-07 1.43E-04 7.17E-06 2.36E-05 1.65E-07 6.18E-05 3.09E-06 Match 1.19E-05 8.33E-08 3.12E-05 1.56E-06Tetrachloroethane2.48E-06 6.49E-06 3.25E-07 Tetrachloroethane 2.48E-06 1.74E-08 6.49E-06 3.25E-07 MatchToluene4.08E-04 1.07E-03 5.34E-05 Toluene 9.63E-04 6.74E-06 2.52E-03 1.26E-04 4.08E-04 2.86E-06 1.07E-03 5.34E-05 Match 5.58E-04 3.91E-06 1.46E-03 7.30E-05Vinyl Chloride 1.49E-05 3.90E-05 1.95E-06 Vinyl Chloride 2.47E-05 1.73E-07 6.47E-05 3.23E-06 1.49E-05 1.04E-07 3.90E-05 1.95E-06 Match 7.18E-06 5.03E-08 1.88E-05 9.40E-07Xylene1.84E-04 4.82E-04 2.41E-05 Xylene 2.68E-04 1.88E-06 7.02E-04 3.51E-05 1.84E-04 1.29E-06 4.82E-04 2.41E-05 Match 1.95E-04 1.37E-06 5.11E-04 2.55E-05
Total HAP 0.21 0.01 0.19 0.01 0.08 0.00
2-Stroke Lean-Burn 4-Stroke Lean-Burn 4-Stroke Rich-Burn
Manufacturer Data,AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
Emission Factor(lb/MMBtu)
AP-42 Table 3.2-1,Table 3.2-2, &Table 3.2-3
(Some HAP do not popluate based on the type of engine selected. AP-42 does not list certain HAP for certain types of engines.)
Natural Gas-Fired Engines
Emergency Engines should equal 100 hours of operation per year4-Stroke Lean-Burn
Page 4 of Version 1.1 February 21, 2019
Equipment Details
Rating 3 MMBtu/hour
Operational Hours 8,760 hours/yearFiringNormal
Criteria Pollutant
Concentration
(ppm)
Emission
Factor
(lb/10^6 scf)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
NOX 100 0.25 1.07
CO 84 0.21 0.90
PM10 7.6 0.02 0.08
PM2.5 7.6 0.02 0.08
SO2 0.6 0.00 0.01
VOC 5.5 0.01 0.06
Lead 0.0005 0.00 0.00
HAP 0.00 0.02 See Below
Green House Gas Pollutant
Global
Warming
Potential
Emission
Factor
(lb/10^6 scf)
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
CO2 (mass basis)1 120,000 294 1,288
Methane (mass basis)25 2.3 0.01 0.02
N2O (mass basis)298 2.2 0.01 0.02
CO2e 1,296
Hazardous Air Pollutant
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)Reference
2-Methylnaphthalene 2.40E-05 5.88E-08 2.58E-073-Methylchloranthrene 1.80E-06 4.41E-09 1.93E-08
7,12-Dimethylbenz(a)anthracene 1.60E-05 3.92E-08 1.72E-07
Acenaphthene 1.80E-06 4.41E-09 1.93E-08
Acenaphthylene 1.80E-06 4.41E-09 1.93E-08
Anthracene 2.40E-06 5.88E-09 2.58E-08
Benz(a)anthracene 1.80E-06 4.41E-09 1.93E-08Benzene2.10E-03 5.15E-06 2.25E-05
Benzo(a)pyrene 1.20E-06 2.94E-09 1.29E-08Benzo(b)fluoranthene 1.80E-06 4.41E-09 1.93E-08
Benzo(g,h,i)perylene 1.20E-06 2.94E-09 1.29E-08Benzo(k)fluoranthene 1.80E-06 4.41E-09 1.93E-08
Chrysene 1.80E-06 4.41E-09 1.93E-08
Dibenzo(a,h)anthracene 1.20E-06 2.94E-09 1.29E-08
Dichlorobenzene 1.20E-03 2.94E-06 1.29E-05
Fluoranthene 3.00E-06 7.35E-09 3.22E-08Fluorene2.80E-06 6.86E-09 3.01E-08
Formaldehyde 7.50E-02 1.84E-04 8.05E-04Hexane1.80E+00 4.41E-03 1.93E-02
Indeno(1,2,3-cd)pyrene 1.80E-06 4.41E-09 1.93E-08Naphthalene6.10E-04 1.50E-06 6.55E-06
Phenanathrene 1.70E-05 4.17E-08 1.83E-07Pyrene5.00E-06 1.23E-08 5.37E-08
Toluene 3.40E-03 8.33E-06 3.65E-05Arsenic2.00E-04 4.90E-07 2.15E-06
Beryllium 1.20E-05 2.94E-08 1.29E-07Cadmium1.10E-03 2.70E-06 1.18E-05
Chromium 1.40E-03 3.43E-06 1.50E-05
Cobalt 8.40E-05 2.06E-07 9.02E-07
Manganese 3.80E-04 9.31E-07 4.08E-06
Mercury 2.60E-04 6.37E-07 2.79E-06Nickel2.10E-03 5.15E-06 2.25E-05Selenium2.40E-05 5.88E-08 2.58E-07
AP-42 Table 1.4-4
Natural Gas-Fired Boilers & Heaters
Manufacturer Data
or AP-42 Table 1.4-1
AP-42 Table 1.4-2
AP-42 Table 1.4-2
&
Table A-1 to
Subpart A of Part 98
Emission Factor
(lb/10^6 scf)
AP-42 Table 1.4-3
Page 5 of 7 Version 1.0
November 29, 2018
Pnematic Devices, Pigging Operations, Storage Tank
Criteria
Pollutant
Emission
Rate
(lbs/hr)
Emission
Total
(tons/year)
NOX 0.00 0.00
CO 0.00 0.00
PM10 0.00 0.00
PM2.5 0.00 0.00
VOC 0.00 0.17
SO2 0.00 0.00
HAP 0.00 0.00
Criteria
Pollutant
DAQ
Emission
Total
(tons/year)
in NOI
(tons/year)Difference
NOX 40.35 38.81 -1.5
CO 54.69 52.69 -2.0
PM10 2.81 2.67 -0.1
PM2.5 2.81 2.67 -0.1
SO2 1.21 1.33 0.1
VOC 5.62 6.10 0.5
HAP 1.60 1.51 -0.1
Differences are due to rounding and
source being more accurate. NOI values
are accepted by the DAQ
Application Supplement – Page 2 of 19
C. Potential-to-Emit (PTE) (Major Source Classification) 40CFR§50.1-§50.19 [Not Applicable]
Following modification, the Cisco Compressor Station will qualify as a true minor (or area)
source under Prevention of Significant Deterioration (PSD), Hazardous Air Pollutant (HAP),
Greenhouse Gas (GHG), and Title V Operating Permit (TVOP) regulations, as summarized
below.

NOx 159.74 (120.93)38.81 ---38.81
CO 54.60 (1.90)52.69 ---52.69
VOC 11.68 (5.58)5.51 0.58 6.10
SO2 5.36 (4.03)1.33 ---1.33
PM10/2.5 2.63 0.03 2.67 ---2.67
Acetaldehyde 0.02 (0.00)0.02 ---0.02
Acrolein 5E-03 (0.00)3E-03 ---3E-03
Benzene 0.01 0.01 0.02 3E-03 0.02
Butadiene, 1,3-7E-04 (0.00)3E-04 ---3E-04
Ethylbenzene 0.01 0.02 0.03 3E-03 0.03
Formaldehyde (HCHO)1.12 0.01 1.13 ---1.13
n-Hexane 0.02 0.05 0.06 0.01 0.07
Methanol (MeOH)3E-03 0.09 0.08 0.02 0.09
Polycyclic Organic Matter (POM)0.02 8E-05 0.02 ---0.02
Toluene 0.05 0.02 0.07 3E-03 0.07
2,2,4-Trimethylpentane (i-Octane)2E-04 0.02 0.02 3E-03 0.02
Xylenes 0.02 0.02 0.04 3E-03 0.04
Other/Trace HAP 0.01 8E-05 0.01 ---0.01
Total Hazardous Air Pollutants (HAPs)1.28 0.23 1.473 0.040 1.51
CO2 (GWP=1)---44,192 44,192 0.03 44,192
Methane (CH4) (GWP=28)---293.90 225 69.25 294
Nitrous Oxide (N2O) (GWP=265)---1.19 1.19 ---1.19
Carbon Dioxide Equivalent (CO2e)---52,737 50,798 1,939 52,737
GH
G
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Site-Wide Potential-to-Emit (PTE) Summary (tpy)
Pollutant
Current
Permit
Total
Change
Total
Proposed
Point
Source
Proposed
Fugitive
Source
Proposed
Total
Cr
i
t
e
r
i
a
HA
P
Application Supplement – Page 17 of 19
Table 1

NOx 159.74 (120.93)38.81 ---38.81
CO 54.60 (1.90)52.69 ---52.69
VOC 11.68 (5.58)5.51 0.58 6.10
SO2 5.36 (4.03)1.33 ---1.33
PM10/2.5 2.63 0.03 2.67 ---2.67
Acetaldehyde 0.02 (0.00)0.02 ---0.02
Acrolein 5E-03 (0.00)3E-03 ---3E-03
Benzene 0.01 0.01 0.02 3E-03 0.02
Butadiene, 1,3-7E-04 (0.00)3E-04 ---3E-04
Ethylbenzene 0.01 0.02 0.03 3E-03 0.03
Formaldehyde (HCHO)1.12 0.01 1.13 ---1.13
n-Hexane 0.02 0.05 0.06 0.01 0.07
Methanol (MeOH)3E-03 0.09 0.08 0.02 0.09
Polycyclic Organic Matter (POM)0.02 8E-05 0.02 ---0.02
Toluene 0.05 0.02 0.07 3E-03 0.07
2,2,4-Trimethylpentane (i-Octane)2E-04 0.02 0.02 3E-03 0.02
Xylenes 0.02 0.02 0.04 3E-03 0.04
Other/Trace HAP 0.01 8E-05 0.01 ---0.01
Total Hazardous Air Pollutants (HAPs)1.28 0.23 1.473 0.040 1.51
CO2 (GWP=1)---44,192 44,192 0.03 44,192
Methane (CH4) (GWP=28)---293.90 225 69.25 294
Nitrous Oxide (N2O) (GWP=265)---1.19 1.19 ---1.19
Carbon Dioxide Equivalent (CO2e)---52,737 50,798 1,939 52,737
GH
G
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Site-Wide Potential-to-Emit (PTE) Summary (tpy)
Pollutant
Current
Permit
Total
Change
Total
Proposed
Point
Source
Proposed
Fugitive
Source
Proposed
Total
Cr
i
t
e
r
i
a
HA
P
lb/MMBtu (0oF)lb/hr (0oF)tpy (0oF)lb/hr (0oF)tpy (0oF)
Vendor Data NOx (25 ppm)---4.26 18.68 ---4.26 18.68
Vendor Data CO (50 ppm)---5.19 22.74 ---5.19 22.74
Vendor Data UHC (CH4) (25 ppm)---1.48 6.50 ---1.48 6.50
Vendor Data (PIL 168)VOC (UHC*20%)---0.30 1.30 ---0.30 1.30
4,906 bhp (Max @ 0oF)AP-42 Table 3.1-2b SO2 0.003 0.16 0.66 ---0.16 0.66
4,527 bhp (Avg @ 59oF)AP-42 Table 3.1-2b PM10/2.5 0.007 0.31 1.29 ---0.31 1.29
8,760 hr/yr AP-42 Table 3.1-3 Acetaldehyde 4.00E-05 2E-03 0.01 ---2E-03 0.01
AP-42 Table 3.1-3 Acrolein 6.40E-06 3E-04 1E-03 ---3E-04 1E-03
AP-42 Table 3.1-3 Benzene 9.10E-07 4E-05 2E-04 ---4E-05 2E-04
AP-42 Table 3.1-3 Butadiene, 1,3-4.30E-07 2E-05 8E-05 ---2E-05 8E-05
AP-42 Table 3.1-3 Ethylbenzene 3.20E-05 1E-03 0.01 ---1E-03 0.01
Vendor Data (PIL 168)Formaldehyde 2.88E-03 0.13 0.56 ---0.13 0.56
AP-42 Table 3.1-3 n-Hexane --- --- --- --- --- ---
886 Exhaust Temp (oF)AP-42 Table 3.1-3 Methanol --- --- --- --- --- ---
128,627 Exhaust Flow (lb/hr)AP-42 Table 3.1-3 POM/PAH 3.47E-05 2E-03 0.01 ---2E-03 0.01
AP-42 Table 3.1-3 Toluene 1.30E-04 6E-03 0.03 ---6E-03 0.03
9,537 Btu/bhp-hr (HHV)AP-42 Table 3.1-3 TMP, 2,2,4- --- --- --- --- --- ---
46.79 MMBtu/hr (Max @ 0oF)AP-42 Table 3.1-3 Xylenes 6.40E-05 3E-03 0.01 ---3E-03 0.01
44.44 MMBtu/hr (Typ @ 59oF)AP-42 Table 3.1-3 Other/Trace HAP 2.90E-05 1E-03 0.01 ---1E-03 0.01
45,871 scf/hr (Max @ 0oF)Sum Total HAP 3.22E-03 0.15 0.63 ---0.15 0.63
43,573 scf/hr (Typ @ 59oF)AP-42 Table 3.1-3 CO2 (GWP=1)110 5,147 21,413 ---5,147 21,413
382 MMscf/yr Vendor Data CH4 (GWP=28)0.035 1.64 6.81 ---1.64 6.81
1,020 Btu/scf (HHV)AP-42 Table 3.1-3 N2O (GWP=265)0.003 0.14 0.58 ---0.14 0.58
Weighted Sum CO2e 112 5,230 21,759 ---5,230 21,759
Notes:1 - The emissions shown are based on operation at 100% of rated load for 8,760 hr/yr.
2 - PM10/2.5 is filterable and condensable particulate matter; including PM10 and PM2.5
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Compressor Turbine (CT-01 and CT-02) Emissions
Source
ID Description Reference Pollutant
Controlled Emissions Control
Efficiency
Controlled Emissions
CT-01
CT-02
Compressor Turbine 01 and 02
Solar Centaur 50-5502S
Manufactured ≥ 02/18/05
NSPS KKKK Affected
3 - "Other/Trace HAPs" includes: Carbon Tetrachloride, Chlorobenzene, Chloroform, Dichloropropene, 1,3-Dichloropropene, Ethylene Dibromide, Methylene
Chloride, Phenol, Propylene Oxide, Styrene, 1,1,2,2-Tetrachloroethane, 1,1,2-Trichloroethane, and Vinyl Chloride (as per AP-42).
4 - The fuel heating value will vary, 1,020 Btu/scf (HHV) is at the low end of the range and results in a high (conservative) fuel consumption estimate. (It does NOT impact the emission estimates.)
Cisco Compressor Station Compressor Turbine (CT-01 and CT-02) Emissions Notice of Intent Application
Emission Estimates - Page 04 of 13

Northwest Pipeline LLC
650 S. Main Street, Suite 300
Salt Lake City, UT 84101

February 11, 2025
(Submitted via Email)

Alan Humpherys
Environmental Program Manager
Utah Department of Environmental Quality
Division of Air Quality
195 North 1950 West
Salt Lake City, UT 84116

Subject: Application to Modify Approval Order DAQE-AN102590004-23
Northwest Pipeline LLC
Cisco Compressor Station

Dear Mr. Humpherys:
Northwest Pipeline LLC (NWP) is submitting the attached Notice of Intent application for
a facility modification at Cisco Compressor Station in Grand County, Utah. The two
existing conventional Solar Centaur 50-5502 turbines will be replaced with Solar Centaur
50-5502S SoLoNOx turbines and the existing Cummins GTA-855 emergency generator
engine will be replaced with a Caterpillar DG250 DC emergency generator engine.
Additionally, the centrifugal compressors driven by the turbines will be changed from wet
seal to dry seal units. The project will result in a decrease in pollutant emissions.
Modification of the turbines is scheduled to begin early summer 2025; therefore, your
prompt attention to this matter is appreciated. This facility is a transmission compressor
station, and therefore has a limited window in the year in which the compressors can be
taken off-line for modification. If the work cannot be done during early summer 2025 it
will have to be delayed until the following summer, delaying the beneficial emissions
reductions associated with this project.

Alan Humpherys
Utah DEQ – Division of Air Quality
February 11, 2025
Page 02 of 02
If you have any questions or require additional information, please contact me at (303)
475-0989 or by email at [e-mail].

Sincerely,

Northwest Pipeline LLC
Kirsten Derr
Environmental Specialist

Enclosures:
Application Supplement
Attachment A – Utah DAQ Permit Application Forms
Attachment B – Emission Calculations
Attachment C – Supporting Documents
Utah Division of Air Quality
R307-401 Notice of Intent Application

For the:
Northwest Pipeline LLC
Cisco Compressor Station
Grand County, Utah

Submitted to:
Utah Department of Environmental Quality
Division of Air Quality
195 North 1950 West
Salt Lake City, UT 84116

Submitted by:
Northwest Pipeline LLC
650 S. Main Street, Suite 300
Salt Lake City, UT 84101

Prepared by:
EcoLogic Environmental Consultants, LLC
864 Windsor Court
Santa Barbara, CA 93111

February 2025
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Utah Division of Air Quality
R307-401 Notice of Intent Application

Northwest Pipeline LLC
Cisco Compressor Station
Grand County, Utah

Table of Contents
Cover Letter
Title Page / Table of Contents
Application Supplement
A. Facility Process Description B. Permit Application Scope C. Potential to Emit (PTE) (Minor Source Classification) D. Applicability of New Source Review (NSR) Regulations
E. Applicability of New Source Performance Standards (NSPS)
F. Applicability of National Emission Standards for Hazardous Air Pollutants (NESHAP) G. Compliance Assurance Monitoring (CAM) H. Chemical Accident Prevention Provisions (Risk Management Plan (RMP))
I. Mandatory Greenhouse Gas (GHG) Reporting
J. Maps and Drawings K. Best Available Control Technology Determination L. Air Modeling Analysis
Attachment A – Utah DEQ Permit Application Forms
Attachment B – Emission Calculations
B-1 – Potential to Emit (PTE) Summaries B-2 – Point Source PTE B-3 – Fugitive Source PTE B-4 – AP-42 and GHG Emission Factors
Attachment C – Supporting Documents
C-1 – Representative Gas Analysis C-2 – Vendor Data (Solar Turbines, Caterpillar)
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Application Supplement

A. Facility Process Description
B. Permit Application Scope
C. Potential to Emit (PTE) (Minor Source Classification)
D. Applicability of New Source Review (NSR) Regulations
1. Applicability of Source Aggregation (Single-Source Determination) 2. PSD – Prevention of Significant Deterioration
3. NNSR – Nonattainment New Source Review
4. HAPs – Hazardous Air Pollutants 5. TVOP – Title V Operating Permit
E. Applicability of New Source Performance Standards (NSPS)
1. NSPS A – General Provisions
2. NSPS A – Control Devices-Flares
3. NSPS Dc – Steam Generating Units 4. NSPS Kb – Volatile Organic Liquid Storage Vessels 5. NSPS GG – Stationary Gas Turbines 6. NSPS KKK – Leaks from Natural Gas Processing Plants
7. NSPS LLL – Onshore Natural Gas Processing: SO2 Emissions
8. NSPS IIII – Compression Ignition Reciprocating Internal Combustion Engines (RICE) 9. NSPS JJJJ – Stationary Spark Ignition (SI) Internal Combustion Engines (ICE) 10. NSPS KKKK – Stationary Combustion Turbines
11. NSPS OOOO – Oil and Natural Gas Facilities
12. NSPS OOOOa – Oil and Natural Gas Facilities 13. NSPS OOOOb – Oil and Natural Gas Facilities
F. Applicability of National Emission Standards for Hazardous Air Pollutants (NESHAP)
1. NESHAP Part 61 A – Lists of Pollutants and Applicability of Part 61
2. NESHAP J – Equipment Leaks (Fugitive Emission Sources) of Benzene 3. NESHAP V – Equipment Leaks (Fugitive Emission Sources) 4. NESHAP Part 63 A – General Provisions (aka MACT) 5. NESHAP HH – Oil and Natural Gas Production Facilities
6. NESHAP HHH – Natural Gas Transmission and Storage Facilities
7. NESHAP YYYY – Stationary Combustion Turbines 8. NESHAP ZZZZ – Stationary Reciprocating Internal Combustion Engines (RICE) 9. NESHAP DDDDD – Boilers and Process Heaters – Major Sources 10. NESHAP CCCCCC – Gasoline Dispensing Facilities (GDF)
11. NESHAP JJJJJJ – Boilers and Process Heaters – Area Sources
G. Compliance Assurance Monitoring (CAM)
H. Chemical Accident Prevention (RMP)
I. Mandatory Greenhouse Gases (GHG) Reporting

... Continued
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Application Supplement --- Continued ---

J. Maps and Drawings
1. Process Flow Diagram (PFD) 2. Location/Topo Map 3. Aerial View 4. Plot Plan
K. Best Available Control Technology Determination
L. Air Modeling Analysis

Application Supplement – Page 1 of 19
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Application Supplement
A. Facility Process Description
Northwest Pipeline LLC (NWP) operates the Cisco Compressor Station located approximately
3.2 miles south of I-70, exit 202 on Highway 128 in Grand County, Utah. The facility is used
to move natural gas along a transmission pipeline. The station is operated to meet the demand
of the pipeline system rather than operating on a fixed schedule. The arrangement of pipes
and valves in the Cisco pipe yard allows natural gas to be transmitted in either direction of the
pipeline.
Natural gas entering the station passes through two in-line filters (one for each turbine) that
remove any impurities from the gas stream. The natural gas is compressed through the
compressor and is returned to the transmission pipeline. Fuel for the turbines and other
natural gas combustion equipment enters the station in a separate pipeline. Fuel gas is
lowered from the pipeline pressure to pressures appropriate for the turbines in the fuel gas
building. From the fuel gas building, natural gas is transported to the turbines, the boiler and
the emergency generator engine. The turbines, boiler and emergency generator engine have
their own exhaust stacks.
B. Permit Application Scope
The NWP Cisco Compressor Station will be modified through the replacement of both existing
Solar Centaur 50-5502 conventional turbines with Solar Centaur 50-5502S SoLoNOx turbines
and the existing Cummins GTA-855 emergency generator engine will be replaced with a
Caterpillar DG250 GC emergency generator engine. Additionally, the centrifugal
compressors driven by the turbines will be changed from wet seal to dry seal units.
The requested Approval Order will provide for operation of the following emission sources at
the NWP Cisco Compressor Station:
• Two (2) 4,906 bhp Solar Centaur 50-5502S Turbines CT-01 and CT-02
• Compressor Turbine Start/Stop TSS
• Centrifugal Compressor Dry Gas Seal Leaks DGS
• One (1) 374 hp Caterpillar DG250 GC Emergency Generator Engine GE-01
• One (1) 2.5 MMBtu/hr Sellers Boiler B001
• Compressor Blowdown BD
• Pneumatic Devices PNE
• Pigging Operations PIG
• Three (3) Used Oil/Lube Oil Storage Tanks (124 bbl Total) TKS
• Process Piping and Equipment Leaks FUG

Application Supplement – Page 2 of 19
C. Potential-to-Emit (PTE) (Major Source Classification) 40CFR§50.1-§50.19 [Not Applicable]
Following modification, the Cisco Compressor Station will qualify as a true minor (or area)
source under Prevention of Significant Deterioration (PSD), Hazardous Air Pollutant (HAP),
Greenhouse Gas (GHG), and Title V Operating Permit (TVOP) regulations, as summarized
below.

NOx 159.74 (120.93)38.81 ---38.81
CO 54.60 (1.90)52.69 ---52.69
VOC 11.68 (5.58)6.10 0.58 6.10
SO2 5.36 (1.30)1.33 ---1.33
PM10/2.5 2.63 (2.70)2.67 ---2.67
Acetaldehyde 0.02 (0.00)0.02 ---0.02
Acrolein 5E-03 (0.00)3E-03 ---3E-03
Benzene 0.01 0.01 0.02 3E-03 0.02
Butadiene, 1,3-7E-04 (0.00)3E-04 ---3E-04
Ethylbenzene 0.01 0.02 0.03 3E-03 0.03
Formaldehyde (HCHO)1.12 0.01 1.13 ---1.13
n-Hexane 0.02 0.05 0.06 0.01 0.07
Methanol (MeOH)3E-03 0.09 0.08 0.02 0.09
Polycyclic Organic Matter (POM)0.02 8E-05 0.02 ---0.02
Toluene 0.05 0.02 0.07 3E-03 0.07
2,2,4-Trimethylpentane (i-Octane)2E-04 0.02 0.02 3E-03 0.02
Xylenes 0.02 0.02 0.04 3E-03 0.04
Other/Trace HAP 0.01 8E-05 0.01 ---0.01
Total Hazardous Air Pollutants (HAPs)1.28 0.23 1.473 0.040 1.51
CO2 (GWP=1)---44,192 44,192 0.03 44,192
Methane (CH4) (GWP=28)---293.90 225 69.25 294
Nitrous Oxide (N2O) (GWP=265)---1.19 1.19 ---1.19
Carbon Dioxide Equivalent (CO2e)---52,737 50,798 1,939 52,737
GH
G
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Site-Wide Potential-to-Emit (PTE) Summary (tpy)
Pollutant
Current
Permit
Total
Change
Total
Proposed
Point
Source
Proposed
Fugitive
Source
Proposed
Total
Cr
i
t
e
r
i
a
HA
P
Application Supplement – Page 3 of 19
D. Applicability of New Source Review (NSR) Regulations
The following New Source Review (NSR) regulations are potentially applicable to natural gas
compressor stations. Applicability to the subject facility has been determined as follows:
1. Applicability of Source Aggregation (Single-Source Determination)
40CFR§52.21(b)(6)(i) [Not Applicable]
This rule does not apply. For the purposes of determination of what constitutes a ‘‘major
source’’ for the PSD, NNSR, and TVOP permitting regulations, emissions from two or
more facilities may be aggregated and considered a single source if they meet all the
following criteria:
• They belong to the same industrial grouping (same two-digit SIC code); and
• They are located on one or more “contiguous or adjacent” properties; and
• They are “under common control” of the same person (or persons).
Operations at the subject facility have not been aggregated with any other facility or
sources because there is no other oil and gas facility that is both “contiguous or adjacent”
and “under common control” to the subject facility.
2. Prevention of Significant Deterioration (PSD)
40CFR§52.21 [Not Applicable]
This rule does not apply because the subject facility is not a new PSD Major Source nor
a PSD Major Modification at an existing PSD Major Source. The subject facility is a “PSD
Minor Source” for each regulated pollutant, as follows:
• NO2: PSD Natural Minor Source with PTE < 250 tpy
• CO: PSD Natural Minor Source with PTE < 250 tpy
• VOC: PSD Natural Minor Source with PTE < 250 tpy
• SO2: PSD Natural Minor Source with PTE < 250 tpy
• PM10/2.5: PSD Natural Minor Source with PTE < 250 tpy
• HAPs: Not Applicable for PSD Major Source Determination
• CO2e: Not Applicable for PSD Major Source Determination
Important Notes:
* Criteria pollutant fugitive emissions are not included in PSD Major Source
determinations because the subject facility is not a “listed source” category
(§52.21(b)(1)(iii)).
* Greenhouse gases (GHG/CO2e) are not treated as air pollutants for PSD Major
Source determinations; however, GHG/CO2e must be included in the permit if
potential emissions exceed 100,000 tpy and the facility is “otherwise” subject to PSD
requirements (US Supreme Court, No. 12-1146, June 23, 2014).
* The designation of PSD Major Source status is determined on a pollutant specific
basis; however, if a facility exceeds a PSD Major Source threshold for a single NSR
regulated pollutant, it becomes PSD Major Source for any other regulated NSR
pollutant emitted at or above its significant level, regardless of whether that pollutant
exceeds the major stationary source threshold.
Application Supplement – Page 4 of 19
3. Non-Attainment New Source Review (NNSR)
40CFR§51.165 [Not Applicable]
This rule does not apply. The operations are in Grand County which is designated as
Attainment/Unclassified/Maintenance for all criteria pollutants.
4. Major Source of Hazardous Air Pollutants (HAPs)
40CFR§63.1-§63.16 [Not Applicable]
This rule does not apply because the subject facility qualifies as a “HAP Area Source” as
follows:
• Each HAP: HAP Area Source with PTE < 10 tpy
• Total HAPs: HAP Area Source with PTE < 25 tpy
Important Note:
* Hazardous air pollutant (HAP) fugitive emissions are included in HAP Major Source
determinations (§63.2).
5. Title V Operating Permit (TVOP)
40CFR§70.1-§70.14 [Not Applicable]
This rule does not apply. The subject facility, after modification, qualifies as a “TVOP Minor
Source” as follows:
• NOx: TVOP Natural Minor Source with PTE < 100 tpy
• CO: TVOP Natural Minor Source with PTE <100 tpy
• VOC: TVOP Natural Minor Source with PTE < 100 tpy
• SO2: TVOP Natural Minor Source with PTE < 100 tpy
• PM10/2.5: TVOP Natural Minor Source with PTE < 100 tpy
• Each HAP: TVOP Natural Minor Source with PTE < 10 tpy
• Total HAPs: TVOP Natural Minor Source with PTE < 25 tpy
• CO2e Not Applicable for Major Source Determination
Important Notes:
* Criteria pollutant fugitive emissions are not included in TVOP Major Source
determinations because the subject facility is not a “listed source” category (§70.2).
* Hazardous air pollutant (HAP) fugitive emissions are included in TVOP Major Source
determinations (§70.2).
* Greenhouse gases (GHG/CO2e) are not treated as air pollutants for TVOP Major
Source determinations; however, GHG/CO2e must be included in the permit if
potential emissions exceed 100,000 tpy and the facility is “otherwise” subject to TVOP
requirements (US Supreme Court, No. 12-1146, June 23, 2014).
Application Supplement – Page 5 of 19
E. Applicability of New Source Performance Standards (NSPS)
The following New Source Performance Standards (NSPS) are potentially applicable to
natural gas compressor stations. Applicability to the subject facility has been determined as
follows:
1. NSPS - Part 60 - A - General Provisions
40CFR§60.1-§60.19 [Applicable]
This rule does apply to the Solar Centaur 50-5502S turbines because they are subject to
NSPS Subpart KKKK (Please Reference E.10 below.)
This rule does apply to the Caterpillar DG250 GC emergency generator engine because
it is subject to NSPS JJJJ (Please Reference E.9 below.)
This rule does apply to the 75 bhp reciprocating compressor (associated with Solar
Turbines’ recompression systems) because it is subject to NSPS OOOOb and the
centrifugal compressors (associated with the Solar Centaur 50-5502S turbines) because
they are subject to NSPS OOOOb (Please Reference E.13 below.)
Requirements may include:
a. Notification and Recordkeeping (§60.7),
b. Performance Testing (§60.8),
c. Standards and Maintenance (§60.11),
d. Monitoring (§60.13),
e. Control Device and Work Practices (§60.18), and
f. Notification and Reporting (§60.19).
This rule does not apply to any other equipment, operation, or pollutant emission source
at the subject facility because no other equipment, operation, or pollutant emission source
is subject to the requirements of NSPS Part 60.
2. NSPS A - Control Devices - Flares
40CFR§60.18(b) [Not Applicable]
This rule does not apply because there is no flare used to comply with any applicable
provisions under a New Source Performance Standard (NSPS) or National Emissions
Standards for Hazardous Air Pollutants (NESHAP).
3. NSPS Dc - Steam Generating Units
40CFR§60.40c-§60.48c [Not Applicable]
This rule does not apply because there is no steam generating unit at the facility with a
maximum design heat input capacity greater or equal to 10 MMBtu/hr and equal or less
than 100 (§60.40c(a)).
(Note: Steam generating unit means a device that combusts any fuel and produces steam
or heats water or heats any heat transfer medium. This term does not include process
heaters used to heat a material to initiate or promote a chemical reaction (§60.41c).)
4. NSPS Kb - Volatile Organic Liquid (VOL) Storage Vessels
40CFR§60.110b-§60.117b [Not Applicable]
This rule does not apply to any storage vessel at the facility because each has a design
capacity less than 75 m3 (19,800 gals, 471 bbl) (§60.110b(a)).
Application Supplement – Page 6 of 19
5. NSPS GG - Stationary Gas Turbines
40CFR§60.330-§60.335 [Not Applicable]
This rule does not apply to the Solar Centaur 50-5502S turbines (CT-01 and CT-02)
because each has a heat input at peak load ≥ 10 MMBtu/hr, and construction, modification,
or reconstruction commenced after February 18, 2005.
6. NSPS KKK - Leaks from Natural Gas Processing Plants
40CFR§60.630-§60.636 [Not Applicable]
This rule does not apply because the subject facility is not located at a natural gas
processing plant that is engaged in the extraction of natural gas liquids from field gas
(§60.630(e)).
7. NSPS LLL - Onshore Natural Gas Processing: SO2 Emissions
40CFR§60.640-§60.648 [Not Applicable]
This rule does not apply because there is no gas sweetening operation at the subject
facility (§60.640(a)).
8. NSPS IIII - Compression Ignition Reciprocating Internal Combustion Engines
40CFR§60.4200-§60.4219 [Not Applicable]
This rule does not apply because there is no stationary compression ignition engine at the
facility (§60.4200(a)).
9. NSPS JJJJ - Stationary Spark Ignition (SI) Internal Combustion Engines (ICE)
40CFR§60.4230-§60.4248 [Applicable]
This rule does apply to the Caterpillar DG250 GC emergency generator engine because
it was manufactured after July 1, 2009 and has a maximum engine power greater than 25
HP (§60.4230(a)(4)(iv)).
Requirements may include:
a. NOx, CO, and VOC emission limits (§60.4233(e-f));
b. Operating limits (§60.4243);
c. Performance testing (§60.4244); and
d. Notification and recordkeeping requirements (§60.4245).
10. NSPS KKKK - Stationary Combustion Turbines
40CFR§60.4300-§60.4420 [Applicable]
This rule does apply to the Solar Centaur 50-5502S turbines (CT-01 and CT-02) because
each has a heat input at peak load ≥ 10 MMBtu/hr, and construction, modification, or
reconstruction commenced after 02/18/05 (§60.4305(a)). Requirements include NOx
emission limits (§60.4320); SOx emission limits (§60.4330); and initial and subsequent
performance testing (§60.4400).
Application Supplement – Page 7 of 19
11. NSPS OOOO - Crude Oil and Natural Gas Facilities for Which Construction,
Modification, or Reconstruction Commenced After August 23, 2011, and on or
Before September 18, 2015
40CFR§60.5360-§60.5430 [Not Applicable]
This rule does not apply because none of the potentially applicable equipment was
constructed, modified, or reconstructed during the applicable time period.
12. NSPS OOOOa - Crude Oil and Natural Gas Facilities for Which Construction,
Modification or Reconstruction Commenced After September 18, 2015 and On or
Before December 6, 2022
40CFR§60.5360a-§60.5430a [Not Applicable]
This rule does not apply because none of the potentially applicable equipment was
constructed, modified, or reconstructed during the applicable time period.
13. NSPS OOOOb, Crude Oil and Natural Gas Facilities for Which Construction,
Modification or Reconstruction Commenced After December 6, 2022
40CFR§60.5360a-§60.5430a [Applicable]
This rule does apply to the centrifugal compressors driven by the Solar Turbines (CT-01
and CT-02) because the facility is located within the Crude Oil and Natural Gas source
category and the compressors commenced construction or modification after December
6, 2022 (§60.5360b and §60.5365b(c)).
This rule does apply to the electrically driven reciprocating compressor (associated with
Solar Turbines’ recompression system used with the Solar Centaur 50-5502S turbines)
because it was constructed after December 6, 2022 (§60.5360b and §60.5365b(c)).
Requirements for the centrifugal compressors include one of the following options:
volumetric flow rate monitoring of the dry gas seals, routing the seal gas to control, or
routing the seal gas to process. Additionally, repairing dry gas seals (as applicable) on a
specified schedule (§60.5380b(a)(6)-(8)) and recordkeeping and reporting (§60.5420(b)).
As the electrically driven reciprocating compressor is a self-contained reciprocating
compressor, the closed vent system is subject to the monitoring, recordkeeping and
reporting requirements.
This rule does not apply to the Process Piping and Equipment Leaks (FUG) because the
facility has not been “modified” as defined in NSPS Subpart OOOOb. As stated in §
60.5365b(i)(3), a modification to a compressor station occurs when an additional
compressor is installed, or one or more compressors are replaced with compressors of
greater total horsepower. The compressor horsepower does not increase with this project.
This rule does not apply to any storage tank at the facility because each tank does not
meet the definition of “storage vessel” (§60.5430b).
This rule may apply to the collection of natural gas-driven process controllers if there is an
increase in the number of natural gas-driven process controllers at the facility or
reconstruction of more than 50% of the existing natural gas process controllers.
(§60.5365b(d)(1)).
Application Supplement – Page 8 of 19
Other requirements of this rule do not apply because the facility is a) not a well, b) is not modifying
natural gas-driven pumps, and c) does not have a process unit associated with the processing of
natural gas.
F. Applicability of National Emission Standard for Hazardous Air Pollutants (NESHAP)
The following National Emissions Standard for Hazardous Air Pollutants (NESHAP) are
potentially applicable to natural gas compressor stations. Applicability to the subject facility
have been determined as follows:
1. NESHAP - Part 61 Subpart A - General Provisions
40CFR§61.01-§61.359 [Not Applicable]
This rule does not apply because there are no equipment, operation, or pollutant emission
sources at the subject facility that is subject to the requirements of NESHAP Part 61.
2. NESHAP J - Equipment Leaks (Fugitive Emission Sources) of Benzene
40CFR§61.110-§63.112 [Not Applicable]
This rule does not apply to the Process Piping and Equipment Leaks (FUG) because all
the fluids (liquid or gas) at the subject facility contain less than 10 wt% volatile hazardous
air pollutants (VHAP) (§61.111).
3. NESHAP V - Equipment Leaks (Fugitive Emission Sources)
40CFR§61.240-110-§61.247 [Not Applicable]
This rule does not apply to the Process Piping and Equipment Leaks (FUG) because all
the fluids (liquid or gas) at the subject facility contain less than 10 wt% volatile hazardous
air pollutants (VHAP) (40CFR§61.245(d)(1)).
4. NESHAP Part 63 Subpart A - General Provisions (aka MACT)
40CFR§63.1-§63.16 [Applicable]
This rule does apply because there are equipment, operations, or pollutant emission
sources at the facility that are subject to the requirements of NESHAP Part 63 (Please
reference F.8-NESHAP ZZZZ, below.)
5. NESHAP HH - Oil and Natural Gas Production Facilities
40CFR§63.760-§63.779 [Not Applicable]
This rule does not apply because the facility is not located within the oil and natural gas
production source category (§63.760(a)).
6. NESHAP HHH - Natural Gas Transmission and Storage Facilities
40CFR§63.1270-§63.1289 [Not Applicable]
This rule does not apply because the facility is not a major HAP source and there is no
dehydrator at the facility (§63.1270).
7. NESHAP YYYY, Stationary Combustion Turbines
40CFR§63.6080-§63.6175 [Not Applicable]
This rule does not apply because the facility is not a major HAP source (§63.6080).
8. NESHAP ZZZZ - Stationary Reciprocating Internal Combustion Engines (RICE)
40CFR§63.6580-§63.6675 [Applicable]
Application Supplement – Page 9 of 19
This rule does apply to the Emergency Generator Engine (GE-01) because it is “New”
(constructed after 06/12/06) and located at an area source of HAP emissions. The engine
meets requirements of NESHAP ZZZZ by meeting the requirements of 40 CFR part 60
subpart JJJJ (NSPS JJJJ) for Spark Ignition (SI) Internal Combustion Engines (ICE).
9. NESHAP DDDDD - Industrial, Commercial, and Institutional Boilers and Process
Heaters – Major Sources
40CFR§63.7480-§63.7575 [Not Applicable]
This rule does not apply because the subject facility is not a major HAP source (§63.7485).
10. NESHAP CCCCCC - Gasoline Dispensing Facilities (GDF)
40CFR§63.11111 [Not Applicable]
This rule does not apply because the subject facility does not dispense gasoline into the
fuel tank of a motor vehicle, motor vehicle engine, nonroad vehicle, or nonroad engine
(§63.11111 (a)).
11. NESHAP JJJJJJ - Industrial, Commercial, and Institutional Boilers – Area Sources
40CFR§63.11193-§63.11237 [Not Applicable]
This rule does not apply because the miscellaneous heaters do not meet the definition of
“boiler”. Specifically, “boiler” means an enclosed device using controlled flame combustion
in which water is heated to recover thermal energy in the form of steam and/or hot water
(§63.11195).
G. Compliance Assurance Monitoring (CAM)
40CFR§64.1-§64.10 [Not Applicable]
This rule does not apply because the modified facility is not a major source required to obtain
a Title V Operating Permit (§64.2(a)).
H. Chemical Accident Prevention Provisions (Risk Management Plan (RMP))
40CFR§68.1-§68.220 [Not Applicable]
This rule does not apply because the subject facility is not considered a “stationary source”
under the Chemical Accident Prevention Provisions. Specifically, the term stationary source
does not apply to transportation, including storage incident to transportation, of any regulated
substance or any other extremely hazardous substance under the provisions of this part.
Transportation includes, but is not limited to, transportation subject to oversight or regulation
under 49 CFR parts 192, 193, or 195, or a state natural gas or hazardous liquid program for
which the state has in effect a certification to DOT under 49 U.S.C. section 60105 (§68.3).
Application Supplement – Page 10 of 19
I. Mandatory Greenhouse Gas Reporting (GHGRP)
The following Mandatory Greenhouse Gas Reporting (GHGRP) rules are potentially
applicable to natural gas compressor stations. Applicability to the subject facility has been
determined as follows:
1. GHGRP - Part 98 - Subpart A - General Provisions
40CFR§98.1-§98.9 [Applicable]
This rule does apply because the subject facility is required to report under GHGRP
Subpart W–Petroleum and Natural Gas Systems (§98.1(c)) (§98.2(a)(2)). (Please
Reference I.2 below.)
Requirements may include:
a. Follow the procedures for emission calculation, monitoring, quality assurance, missing
data, recordkeeping, and reporting that are specified in each relevant GHGRP Subpart
(§98.3(a)); and
b. Submit reports no later than March 31 of each calendar year (§98.3(b)).
2. GHGRP W - Petroleum and Natural Gas Systems
40CFR§98.230-§98.238 [Potentially Applicable]
This rule potentially applies. The facility is not subject to a listed source category; however,
the aggregate maximum heat input capacity of the stationary fuel combustion units is ≥ 30
MMBtu/hr and the facility has the potential to emit ≥ 25,000 metric ton/yr (27,558 tpy) of
CO2e/yr from all stationary fuel combustion sources combined (§98.2(a)).

Records must be kept of actual CO2, CH4 and N2O emissions to determine the actual
CO2e emissions. If such emissions exceed the 25,000 metric ton/yr threshold, then an
annual report must be submitted no later than March 31 of each calendar year thereafter.

Application Supplement – Page 11 of 19
J. Maps and Drawings
1. Process Flow Diagram (PFD)

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Application Supplement – Page 12 of 19
2. Location/Topo Map

Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Application Supplement
Cisco Compressor Station
J.2. Location/Topo Map
J.2. Location/Topo Map Notice of Intent Application
Northwest Pipeline, LLCCisco Compressor StationGrand County, Utah
Lat: 38°55'59.1"N Lon: 109°21'04.5"WElev: ~4,400 ft ASL
Application Supplement – Page 13 of 19
3. Aerial View
J.3. Aerial View
Cisco Compressor Station
Northwest Pipeline LLC
J.3. Aerial View
Cisco Compressor Station
Application Supplement
Notice of Intent Application
Notice of Intent Application
Unit 1 -Centaur 50 Turbine
Unit 2 -Centaur 50 Turbine
Emergency Generator Engine
Boiler
Application Supplement – Page 14 of 19
4. Plot Plan
Notice of Intent ApplicationJ.4. Plot PlanCisco Compressor Station
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Application Supplement
J.4. Plot Plan
Application Supplement – Page 15 of 19
K. Best Available Control Technology Determination

Summary

It is concluded that BACT for NOx, CO, VOC, SO2 and PM10 emissions from the Solar Centaur
50-5502S turbines is lean burn technology (i.e., SoLoNOx combustors), fuel restriction to natural
gas and good combustion practices. It is concluded that BACT for the Caterpillar DG250 GC
emergency generator engine is good combustion practices and exclusive use of natural gas fuel.

Solar Turbines BACT for NOx, CO and VOC Emissions

The Solar Centaur 50-5502S turbines proposed for installation will be a core replacement
equipped with SoLoNOx combustors to minimize emissions of NOx, CO and VOC. Turbines
equipped with SoLoNOx or Dry Low NOx combustion technology are commonly used in the
natural gas industry to reduce emissions and meet standards without the need for add-on control
technology such as Selective Catalytic Reduction or Oxidation Catalyst. Use of SoLoNOx
technology to reduce emissions of NOx, CO and VOC from the modified turbine is considered
BACT.

The Solar Centaur 50-5502S turbines will be permitted for a maximum NOx emission rate of 25
ppmvd @ 15% O2, 50 ppm CO @ 15% O2 and 5 ppm VOC @ 15% O2. These are the lowest
emission rates available for a core replacement and will be met using SoLoNOx technology and
without add-on pollution controls. The proposed emission rates should be considered BACT by
Utah DEQ based on recent permits issued for similar equipment. Note that while a new Solar
Centaur 50-5502S turbine is available at 15 ppmvd NOx @ 15% O2, an entirely new turbine would
need to be installed (rather than a core replacement) and the cost prohibitive (in dollars per ton
of pollutant removed) based on the 25 ppm to 15 ppm NOx emissions reduction.

Solar Turbines BACT for SO2 and PM10 Emissions
SO2 and PM10 emissions are negligible for natural gas-fired turbines. There is no information
available in which add-on technology was imposed under permitting to reduce emissions of these
pollutants from pipeline quality natural gas-fired turbines. The only technically feasible, cost-
effective solution for minimizing SO2 and PM10 emissions for pipeline quality natural gas-fired
turbines is use of natural gas fuel.

Application Supplement – Page 16 of 19
BACT for NOx, CO, VOC, SO2, PM10 and HAP Emissions – Caterpillar DG250 GC Emergency
Generator Engine

Various emission control technologies were reviewed for natural gas-fired emergency generator
engines. The only technically feasible, cost-effective solution for reducing NOx, CO, VOC, SO2,
PM10 and HAP emissions for natural gas-fired emergency generator engines was identified to be
good combustion practices and exclusive use of natural gas fuel. The emergency generator
engine will meet the applicable emission standards of NSPS Subpart JJJJ and have potential
criteria air pollutant emissions less than one ton per year.
L. Air Modeling Analysis

Introduction
This qualitative modeling assessment provides an evaluation of Northwest Pipeline LLC’s Cisco
Compressor Station emissions and includes a demonstration that the modified facility will not
interfere with maintenance of the National Ambient Air Quality Standards (NAAQS) or cause or
contribute to an exceedance of the PSD Increments. The Cisco Compressor Station is located
approximately three miles southwest of Cisco in Grand County, Utah. Grand County is currently
classified as “Attainment, Unclassified, or Maintenance” for all NAAQS.
Facility
Northwest Pipeline LLC's Cisco Compressor Station is a natural gas pipeline compression facility
in Grand County, Utah. Two Solar Centaur gas-fired turbines, a 350 hp emergency generator
engine, and associated equipment are operated to meet the demand of the pipeline system. The
incoming natural gas is compressed by the two Solar turbines and sent down the transmission
pipeline. All equipment is fired on natural gas from the transmission pipeline. Operations are
controlled from Northwest Pipeline's headquarters in Salt Lake City, Utah. There is no air pollution
control equipment at this source. The compressor station is currently a major source of nitrogen
oxide (NOx) emissions and a minor source of carbon monoxide (CO), volatile organic compounds
(VOC) and of hazardous air pollutant (HAP) emissions.
As part of an emissions reduction project, NWP will be replacing the existing Solar Centaur 50
conventional turbines with Solar Centaur 50-5502S SoLoNOx turbines. Additionally, the existing
Cummins GTA-855 emergency generator engine will be replaced with a Caterpillar DG250 DC
emergency generator engine. The project will result in a decrease in pollutant emissions.
Emissions
Natural gas transmission compressor stations typically consist of multiple compressors driven by
turbines or internal combustion engines. These turbines or engines are usually fired with low-
sulfur (sweet) natural gas withdrawn from the stream being compressed. Turbines emit NOx, CO
and VOC. Smaller amounts of sulfur oxides (SO2) and particulate matter (PM) are also emitted;
however, the pollutant of almost exclusive concern for natural gas-fired turbines is NOx.
Table 1 below identifies the current potential-to-emit (PTE), proposed PTE and change in
emissions. The table shows the Cisco Compressor Station modification will result in a substantial
NOx emissions reduction as well as a reduction in other criteria air pollutants.

Application Supplement – Page 17 of 19
Table 1

NOx 159.74 (120.93)38.81 ---38.81
CO 54.60 (1.90)52.69 ---52.69
VOC 11.68 (5.58)6.10 0.58 6.10
SO2 5.36 (1.30)1.33 ---1.33
PM10/2.5 2.63 (2.70)2.67 ---2.67
Acetaldehyde 0.02 (0.00)0.02 ---0.02
Acrolein 5E-03 (0.00)3E-03 ---3E-03
Benzene 0.01 0.01 0.02 3E-03 0.02
Butadiene, 1,3-7E-04 (0.00)3E-04 ---3E-04
Ethylbenzene 0.01 0.02 0.03 3E-03 0.03
Formaldehyde (HCHO)1.12 0.01 1.13 ---1.13
n-Hexane 0.02 0.05 0.06 0.01 0.07
Methanol (MeOH)3E-03 0.09 0.08 0.02 0.09
Polycyclic Organic Matter (POM)0.02 8E-05 0.02 ---0.02
Toluene 0.05 0.02 0.07 3E-03 0.07
2,2,4-Trimethylpentane (i-Octane)2E-04 0.02 0.02 3E-03 0.02
Xylenes 0.02 0.02 0.04 3E-03 0.04
Other/Trace HAP 0.01 8E-05 0.01 ---0.01
Total Hazardous Air Pollutants (HAPs)1.28 0.23 1.473 0.040 1.51
CO2 (GWP=1)---44,192 44,192 0.03 44,192
Methane (CH4) (GWP=28)---293.90 225 69.25 294
Nitrous Oxide (N2O) (GWP=265)---1.19 1.19 ---1.19
Carbon Dioxide Equivalent (CO2e)---52,737 50,798 1,939 52,737
GH
G
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Site-Wide Potential-to-Emit (PTE) Summary (tpy)
Pollutant
Current
Permit
Total
Change
Total
Proposed
Point
Source
Proposed
Fugitive
Source
Proposed
Total
Cr
i
t
e
r
i
a
HA
P
Application Supplement – Page 18 of 19
Ambient Monitoring Data
The US Environmental Protection Agency AirData website was used to access air quality data
collected at monitors across Utah. The data comes primarily from the AQS (Air Quality System)
database.
The closest monitoring stations to the Cisco Compressor Station are the Price and Moab air
quality monitoring stations. The Price station is located approximately ninety (90) miles to the
northeast of the facility and the Moab station is located approximately twenty-seven (27) miles
southwest of the facility. Both monitoring stations collect 1-hour NO2 data.
The typical pollutant of concern from a modeling standpoint for natural gas compressor stations
is NO2. NO2 monitoring data at the Price location from calendar year 2024 are presented below.

The highest monitored 1-hour NO2 concentration at Price, Utah during 2024 was 16.1 ppb. This
is equivalent to 30.3 µg/m3, well below the 1-hour NO2 standard of 188 µg/m3.
NO2 monitoring data at the Moab location from calendar year 2024 are presented below.

The highest monitored 1-hour NO2 concentration at Moab, Utah during 2024 was 26.8 ppb. This
is equivalent to 50.4 µg/m3, well below the 1-hour NO2 standard of 188 µg/m3.
Recent Air Quality Modeling Analysis
The Utah Division of Air Quality performed a modeling analysis for Cisco Compressor Station in
August 2023. The modeling analysis included the two conventional Solar turbines, boiler and
emergency generator engine. Results of the modeling analysis demonstrate compliance with the
1-hour NO2 ambient air quality standard.

State Code County CodeSite NumberLatitude Longitude Datum Parameter Name Duration Description Year Units of Measure First Maximum Value First Maximum DateTime
49 007 1003 39.59575 -110.770111 WGS84 Solar radiation 1 HOUR 2024 Langleys/minute 1.45 6/18/2024 12:00
49 007 1003 39.59575 -110.770111 WGS84 PM2.5 - Local Conditions 1 HOUR 2024 Micrograms/cubic meter (LC)96.5 1/6/2024 20:00
49 007 1003 39.59575 -110.770111 WGS84 PM2.5 - Local Conditions 24-HR BLK AVG 2024 Micrograms/cubic meter (LC)19.5 7/23/2024 00:00
49 007 1003 39.59575 -110.770111 WGS84 PM2.5 - Local Conditions 24-HR BLK AVG 2024 Micrograms/cubic meter (LC)19.5 7/23/2024 00:00
49 007 1003 39.59575 -110.770111 WGS84 Nitric oxide (NO)1 HOUR 2024 Parts per billion 19.1 12/2/2024 09:00
49 007 1003 39.59575 -110.770111 WGS84 Nitrogen dioxide (NO2)1 HOUR 2024 Parts per billion 16.1 3/5/2024 08:00
49 007 1003 39.59575 -110.770111 WGS84 Nitrogen dioxide (NO2)1 HOUR 2024 Parts per billion 16.1 3/5/2024 08:00
49007 1003 39.59575 -110.770111 WGS84 Oxides of nitrogen (NOx)1 HOUR 2024 Parts per billion 32.7 12/17/2024 10:00
49007 1003 39.59575 -110.770111 WGS84 Wind Speed - Scalar 1 HOUR 2024 Knots 37.8 12/27/2024 22:00
49007 1003 39.59575 -110.770111 WGS84 Wind Direction - Scalar 1 HOUR 2024 Degrees Compass 359 12/28/2024 03:0049007100339.59575 -110.770111 WGS84 Outdoor Temperature 1 HOUR 2024 Degrees Fahrenheit 98 7/13/2024 13:0049007100339.59575 -110.770111 WGS84 Relative Humidity 1 HOUR 2024 Percent relative humidity 100 11/26/2024 22:0049007100339.59575 -110.770111 WGS84 Ozone 1 HOUR 2024 Parts per million 0.077 7/8/2024 18:0049007100339.59575 -110.770111WGS84 Ozone 8-HR RUN AVG BEGIN HOUR 2024 Parts per million 0.074 7/23/2024 10:0049007100339.59575 -110.770111WGS84 Barometric pressure 1 HOUR 2024 Millibars 839 1/28/2024 10:00
State CodeCounty CodSite NumbeLatitude Longitude Datum Parameter Name Duration DYear Units of Measure First Maximum ValueFirst Maximum DateTime49019000738.56606 -109.537 WGS84 PM2.5 - Local Conditions 1 HOUR 2024 Micrograms/cubic meter (LC)89 1/14/2024 18:00
49019 0007 38.56606 -109.537 WGS84 PM2.5 - Local Conditions 24-HR BLK A 2024 Micrograms/cubic meter (LC)28.7 7/23/2024 00:00
49019 0007 38.56606 -109.537 WGS84 PM2.5 - Local Conditions 24-HR BLK A 2024 Micrograms/cubic meter (LC)28.7 7/23/2024 00:0049019000738.56606 -109.537 WGS84 Wind Speed - Scalar 1 HOUR 2024 Knots 15.8 3/2/2024 07:00
49019 0007 38.56606 -109.537 WGS84 Wind Direction - Scalar 1 HOUR 2024 Degrees Compass 325 3/8/2024 00:0049019000738.56606 -109.537 WGS84 Outdoor Temperature 1 HOUR 2024 Degrees Fahrenheit 105 7/12/2024 16:00
49019 0007 38.56606 -109.537 WGS84 Solar radiation 1 HOUR 2024 Langleys/minute 1.43 5/19/2024 11:00
49019 0007 38.56606 -109.537 WGS84 Relative Humidity 1 HOUR 2024 Percent relative humidity 100 1/22/2024 00:0049019000738.56606 -109.537 WGS84 Barometric pressure 1 HOUR 2024 Millibars 891 12/18/2024 09:00
49019 0007 38.56606 -109.537 WGS84 Nitric oxide (NO)1 HOUR 2024 Parts per billion 31.2 12/18/2024 08:00
49019 0007 38.56606 -109.537 WGS84 Oxides of nitrogen (NOx)1 HOUR 2024 Parts per billion 49.1 12/18/2024 08:0049019000738.56606 -109.537 WGS84 Nitrogen dioxide (NO2)1 HOUR 2024 Parts per billion 26.8 1/16/2024 17:00
49019 0007 38.56606 -109.537 WGS84 Nitrogen dioxide (NO2)1 HOUR 2024 Parts per billion 26.8 1/16/2024 17:0049019000738.56606 -109.537 WGS84 Ozone 1 HOUR 2024 Parts per million 0.078 7/23/2024 16:00
49019 0007 38.56606 -109.537 WGS84 Ozone 8-HR RUN A 2024 Parts per million 0.072 7/22/2024 11:00
Application Supplement – Page 19 of 19
Formaldehyde and Hazardous Air Pollutants Emissions Modeling
The permit application forms included with the permit application state that all formaldehyde
emissions must be modeled per Utah Administrative Code R307-410-5 using SCREEN3. The
Utah Division of Air Quality Emissions Impact Assessment Guidelines dated June 2024 require
sources proposing to increase a plant-wide HAP emission level by an amount greater than or
equal to the ETV, to submit a modeling analysis which addresses the impact of that specific HAP
(R307-410-5.1c). The ETV is calculated to be the applicable threshold limit value - time weighted
average (TLV-TWA) or the threshold limit value – ceiling (TLV-C) multiplied by the appropriate
emission threshold factor (ETF) found in Table 2 (R307-410-5). The table below presents the
project HAP emission increases and whether the HAP increases are above the calculated ETV.
In summary, the project HAP emission increases do not exceed the ETVs; therefore, HAPs
modeling is not required for this project.

Conclusion
Based on the nearby monitoring data showing monitored NO2 concentrations well below the
NAAQS, and the substantial NOx emissions reduction (as well as other pollutant emission
reductions) from the Cisco Compressor Station, it can be reasonably concluded that operation of
the modified facility will not interfere with maintenance of the NAAQS.
Hazardous Air Pollutant
ACGIH TLV
(mg/m3)
Utah DEQ ETF
(lb-m3/mg-hr)
Calculated
ETV (lb/hr)
HAP
Emissions
Increase
(lb/hr)
Dispersion
Modeling
Required?
Acetaldehyde 45 0.066 2.970 -0.002 No
Acrolein 0.11 0.066 0.007 -0.002 No
Benzene 0.064 0.198 0.013 0.013 No
Butadiene, 1,3-4.4 0.066 0.290 0.000 No
Ethylbenzene 87 0.066 5.742 0.019 No
Formaldehyde (HCHO)0.12 0.154 0.018 0.006 No
n-Hexane 176 0.154 27.104 0.047 No
Methanol (MeOH)260 0.154 40.040 0.091 No
Toluene 75 0.154 11.550 0.019 No
2,2,4-Trimethylpentane (i-Octane)1401 0.154 215.754 0.019 No
Xylenes 87 0.154 13.398 0.019 No
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Attachment A
Utah DEQ Permit Application Forms

• Form 1 - Notice of Intent (NOI) Application Checklist
• Form 2 - Company Information/Notice of Intent (NOI)
• Form 11 - Internal Combustion Engines (Turbines)
• Form 11 – Internal Combustion Engines (Emergency Generator Engine)

Form 1 Date __________________
Notice of Intent (NOI) Application Checklist Company __________________ Utah Division of Air Quality
New Source Review Section
Source Identification Information [R307-401-5]
1. Company name, mailing address, physical address and telephone number 
2. Company contact (Name, mailing address, and telephone number)
3.Name and contact of person submitting NOI application (if different than 2) 4.Source Universal Transverse Mercator (UTM) coordinates 
5. Source Standard Industrial Classification (SIC) code 
6.Area designation (attainment, maintenance, or nonattainment)
7.Federal/State requirement applicability (NAAQS, NSPS, MACT, SIP, etc.)
8.Source size determination (Major, Minor, PSD) 9. Current Approval Order(s) and/or Title V Permit numbers 
NOI Application Information: [R307-401]










N/A 
N/A 
A.Air quality analysis (air model, met data, background data, source impact analysis) N/A 
1.Detailed description of the project and source process
2.Discussion of fuels, raw materials, and products consumed/produced3.Description of equipment used in the process and operating schedule
4.Description of changes to the process, production rates, etc.
5.Site plan of source with building dimensions, stack parameters, etc.
6.Best Available Control Technology (BACT) Analysis [R307-401-8]A.BACT analysis for all new and modified equipment
7.Emissions Related Information: [R307-401-2(b)]
A.Emission calculations for each new/modified unit and site-wide
(Include PM10, PM2.5, NOx, SO2, CO, VOCs, HAPs, and GHGs)B.References/assumptions, SDS, for each calculation and pollutant
C.All speciated HAP emissions (list in lbs/hr)
8.Emissions Impact Analysis – Approved Modeling Protocol [R307-410]
A.Composition and physical characteristics of effluent(emission rates, temperature, volume, pollutant types and concentrations)
9.Nonattainment/Maintenance Areas – Major NSR/Minor (offsetting only) [R307-403]
A.NAAQS demonstration, Lowest Achievable Emission Rate, Offset requirements
B.Alternative site analysis, Major source ownership compliance certification
10.Major Sources in Attainment or Unclassified Areas (PSD) [R307-405, R307-406]
B.Visibility impact analysis, Class I area impact
11.Signature on Application
N/A 
Note: The Division of Air Quality will not accept documents containing confidential information or data.
Documents containing confidential information will be returned to the Source submitting the application.
Utah Division of Air Quality
New Source Review Section Company _________ _
Site/Source ---------Form 11 Date ------------Internal Combustion Engines
Equipment Information
1.Manufacturer:2.Operating time of Emission Source:
average maximum Model no.: Hours/day Hours/day
The date the engine was constructed or __ Days/week Days/week
reconstructed Weeks/year Weeks/year
3.Manufacturer's rated output at baseload, ISO hp or __ Kw
Proposed site operating range hp or __ Kw
Gas Firing
4.Are you operating site equipment on pipeline quality natural gas: □Yes □No
5.Are you on an interruptible gas supply:6.Annual consumption of fuel:□ Yes D No
If "yes", specify alternate fuel: MMSCF/Year
7.Maximum firing rate:8.Average firing rate:
BTU/hr BTU/hr
Oil Firing
9.Type of oil:
Grade number □1 □2 □4 □5 □6 Other specify
10.Annual consumption:gallons 11 . Heat content: BTU/lb or BTU/gal
12.Sulfur content:% by weight 13.Ash content:% by weight
14.Average firing rate:gal/hr 15.Maximum firing rate:gal/hr
16.Direction of firing: □ horizontal □tangential □other: (specify)
Page 1 of 4
Northwest Pipeline LLC
Cisco Compressor Station
February 2025
Solar Turbines, Inc.
Centaur 50-5502S
2025
24
7
52
24
7
52
4906 @ 0F
4906 @ 0F
X
X
382 (Each Turbine)
46.79 MM 46.79 MM
(NA)
17.Application:
Internal Combustion Engine
Form 11 (Continued)
Operation
18.Cycle□Simple cycle□Electric generation
Base load ---___ Peaking □Regenerative cycle□Emergency Generator □Cogeneration□Driving pump/compressor □Combined cycle□Exhaust heat recovery
□Other (specify) _________ _
Emissions Data
19.Manufacturer's Emissions in grams per hour (gr/hp-hr): ___ NOx co ---
Formaldehyde
voe ---
20.Attach manufacturer's information showing emissions of NOx, CO, VOC, SOx, CH20, PM10, PM 2.5, CO2, CH4 and N20for each proposed fuel at engine loads and site ambient temperatures representative of the range of proposed
operation. The information must be sufficient to determine maximum hourly and annual emission rates. Annualemissions may be based on a conservatively low approximation of site annual average temperature. Provide emissions
in pounds per hour and except for PM10 and PM2.5 parts per million by volume (ppmv) at actual conditions and correctedto dry, 15% oxygen conditions.
Method of Emission Control:
□Lean premix combustors
□Other low-NOx combustor
□Oxidation catalyst □Water injection
□SCR catalyst □Steam injection
Additional Information
21.On separate sheets provide the following:
□Other (specify) ____ _
A.Details regarding principle of operation of emission controls. If add-on equipment is used, provide make and
model and manufacturer's information. Example details include: controller input variables and operationalalgorithms for water or ammonia injection systems, combustion mode versus engine load for variable mode
combustors, etc.
B.Exhaust parameter information on attached form.
C.All calculations used for the annual emission estimates must be submitted with this form to be deemed
complete.
D.All formaldehyde emissions must be modeled as per Utah Administrative Code R307-410-5 usingSCREEN3.
E.If this form is filled out for a new source, forms 1 and 2 must be submitted also.
Page 2 of 4
X
X
(See PTE Calculations)
X
Utah Division of Air Quality
New Source Review Section Company _________ _
Site/Source ---------Form 11 Date ------------Internal Combustion Engines
Equipment Information
1.Manufacturer:2.Operating time of Emission Source:
average maximum Model no.: Hours/day Hours/day
The date the engine was constructed or __ Days/week Days/week
reconstructed Weeks/year Weeks/year
3.Manufacturer's rated output at baseload, ISO hp or __ Kw
Proposed site operating range hp or __ Kw
Gas Firing
4.Are you operating site equipment on pipeline quality natural gas: □Yes □No
5.Are you on an interruptible gas supply:6.Annual consumption of fuel:□Yes D No
If "yes", specify alternate fuel: MMSCF/Year
7.Maximum firing rate:8.Average firing rate:
BTU/hr BTU/hr
Oil Firing
9.Type of oil:
Grade number □1 □2 □4 □5 □6 Other specify
10.Annual consumption:gallons 11 . Heat content: BTU/lb or BTU/gal
12.Sulfur content:% by weight 13.Ash content:% by weight
14.Average firing rate:gal/hr 15.Maximum firing rate:gal/hr
16.Direction of firing: □ horizontal □tangential □other: (specify)
Page 1 of 4
Northwest Pipeline LLC
Cisco Compressor Station
February 2025
Caterpillar
DG250 DC
2025
2
1
52
24
7
52
374
X
X
0.30
3.04 MM 3.04 MM
(NA)
374
17.Application:
Internal Combustion Engine
Form 11 (Continued)
Operation
18.Cycle□Simple cycle□Electric generation
Base load ---___ Peaking □Regenerative cycle□Emergency Generator □Cogeneration□Driving pump/compressor □Combined cycle□Exhaust heat recovery
□Other (specify) _________ _
Emissions Data
19.Manufacturer's Emissions in grams per hour (gr/hp-hr): ___ NOx co ---
Formaldehyde
voe ---
20.Attach manufacturer's information showing emissions of NOx, CO, VOC, SOx, CH20, PM10, PM 2.5, CO2, CH4 and N20for each proposed fuel at engine loads and site ambient temperatures representative of the range of proposed
operation. The information must be sufficient to determine maximum hourly and annual emission rates. Annualemissions may be based on a conservatively low approximation of site annual average temperature. Provide emissions
in pounds per hour and except for PM10 and PM2.5 parts per million by volume (ppmv) at actual conditions and correctedto dry, 15% oxygen conditions.
Method of Emission Control:
□Lean premix combustors
□Other low-NOx combustor
□Water injection□Oxidation catalyst
□NSCR catalyst □Steam injection
Additional Information
21.On separate sheets provide the following:
□Other (specify) ____ _
A.Details regarding principle of operation of emission controls. If add-on equipment is used, provide make and
model and manufacturer's information. Example details include: controller input variables and operationalalgorithms for water or ammonia injection systems, combustion mode versus engine load for variable mode
combustors, etc.
B.Exhaust parameter information on attached form.
C.All calculations used for the annual emission estimates must be submitted with this form to be deemed
complete.
D.All formaldehyde emissions must be modeled as per Utah Administrative Code R307-410-5 usingSCREEN3.
E.If this form is filled out for a new source, forms 1 and 2 must be submitted also.
Page 2 of 4
(See PTE Calculations)
X
X
INTERNAL COMBUSTION ENGINE
FORM 11 (continued)
EMISSION SOURCES
Review of applications and issuance of permits will be expedited by supplying all necessary information requested on this form.
AIR CONTAMINANT DATA EMISSION POINT DISCHARGE PARAMETERS
EMISSION POINT CHEMICAL COMPOSITION AIR UTM COORDINATES OF STACK SOURCES (7) CONTAMINANT (1) OF TOTAL STREAM EMISSION RATE EMISSION PT. (6) EXIT DATA HEIGHT HEIGHT
COMPONENT OR AIR ABOVE ABOVE
NUMBER NAME CONTAMINANT NAME CONG. LB/HR TONS/YR ZONE EAST NORTH GROUND STRUCT. DIA. VELO.
(2) (%V)(3) (4) (5) (METERS) (METERS) (FT) (FT) (FT) (FPS)
GROUND ELEVATION OF FACILITY ABOVE MEAN SEA LEVEL __ � ___ feet. UTAH AIR CONSERVATION BOARD STANDARD CONDITIONS ARE 68° F AND 14.7 PSIA.
General Instructions for this form.
TEMP. (oF)
1. Identify each emission; point with a unique number for this plant site on plot plan, previous permits and emission inventory questionnaire. Limit emission point number to 8 character spaces. For eachemission point use as many lines as necessary to list air contaminant data. Typical emission point names are: heater, vent, boiler, tank, reactor, separator, bag house, fugitive, etc. Abbreviations are OK.2.Typical component names are: air, H2O, nitrogen, oxygen, CO2, CO, NOx, SOx, hexane, particulate matter (PM10and PM2.s), etc. Abbreviations are OK.
3.Concentration data is required for all gaseous components. Show concentration in volume percent of total gas stream.4.Pounds per hour. (#/hr) is maximum emission rate expected by applicant.5. Tons per year (T/Y) is annual maximum emission rate expected by applicant, which takes into account process operating schedule.6.As a minimum applicant must furnish a facility plot plan drawn to scale showing a plant benchmark, latitude and longitude correct to the nearest second for the benchmark, and all emission points dimensioned with respect to the benchmark. Please show emission point UTM coordinates if known.
7. Supply additional information as follows if appropriate: (a) Stack exit configuration other than a round vertical stack. Show length and width for a rectangular stack. Indicate if horizontal discharge with a note. (b) Stack's height above supporting or adjacent structures if structure is within three "stack heights above ground" of stack.
Page 4 of 4
CT-01 Turbine1 12 642909 4310646
12 642890 4310626CT-02 Turbine2
52
53
12.5
13.5
886
886
4400
3.0
3.0
201
201
B001 Boiler 12 642940 4310674 18.5 0 1.33 40 400
GE-01 Generator 12 642932 4310666 9.0 13500.330 312.2
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Attachment B
Emission Calculations

B-1 – Emission Summaries:
• Criteria Pollutants – Controlled
• Hazardous Air Pollutants (HAP) – Controlled
• Greenhouse Gas (GHG) – Controlled
• Regulated Air Pollutants – Pre-Controlled
B-2 – Point Source Emissions:
• Two (2) 4,906 bhp Solar Centaur 50-5502S Compressor Turbines
• Compressor Turbine Start/Stop
• Centrifugal Compressor Dry Gas Seal Leaks
• One (1) 374 bhp Caterpillar DG250 GC Emergency Generator Engine
• One (1) 2.5 MMBtu/hr Sellers Boiler
• Compressor Blowdowns
• Pneumatic Devices
• Pigging Operations
• Storage Tanks
B-3 – Fugitive Emissions:
• Process Piping and Equipment Leaks (Gas/Vapor)
B-4 – Emission Factors:
• AP-42 Emission Factors – Internal and External Combustion
• 40 CFR 98 – Default Greenhouse Gas (GHG) Emission Factors

lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
Existing P001 na Compressor Turbine 01 - Solar Centaur Type H 5,375 bhp 8,760
New CT-01 na Compressor Turbine 01 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 4.26 18.68 5.19 22.74 0.30 1.30 0.16 0.66 0.31 1.29
Existing P002 na Compressor Turbine 02 - Solar Centaur Type H 5,375 bhp 8,760
New CT-02 na Compressor Turbine 02 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 4.26 18.68 5.19 22.74 0.30 1.30 0.16 0.66 0.31 1.29
Update TSS na Compressor Turbine Start/Stop (CT-01 & CT-02)300 Events/yr 8,760 0.07 0.30 1.40 6.15 0.24 1.05 ------------
Update DGS na Centrifugal Compressor Dry Gas Seal Leaks 9,812 bhp 8,760 ------------0.36 1.59 ------------
Existing B001 na Sellers C60 Boiler 2.50 MMBtu/hr 8,760 0.25 1.07 0.21 0.90 0.01 0.06 1E-03 0.01 0.02 0.08
Existing G001 na Backup Generator - Cummins GTA-855 350 bhp 500
New GE-01 na Backup Generator - Caterpillar DG250 DC 374 bhp 100 1.65 0.08 3.30 0.16 0.90 0.05 2E-03 9E-05 0.06 3E-03
Existing PNE na Pneumatic Devices 33 Units 8,760 ------------0.03 0.11 ------------
Existing PIG na Pigging Operations 2 Units 8,760 ------------0.01 0.03 ------------
Existing TKS na Storage Tanks 124 bbl 8,760 ------------0.01 0.03 ------------
10.49 38.81 15.29 52.69 2.15 5.51 0.32 1.33 0.70 2.67
100 100 100 100 100
Existing FUG na Process Piping & Equipment Leaks 2,470 Units 8,760 ------------0.13 0.58 ------------
--- --- --- ---0.13 0.58 --- --- --- ---
10.49 38.81 15.29 52.69 2.29 6.10 0.32 1.33 0.70 2.67
na na na na na
* = lb/hr is based on 8,760 hr/yr (except GE-01), the generator operates less frequently and TSS and BD are event based.
Fugitive Sources:
Cisco Compressor Station - Grand Total
Grand Total:
TVOP Threshold:
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
TVOP Threshold:
Status Site Rating PM10/2.5SO2
Criteria Pollutants - Controlled
Source
ID APCE Description VOC (w/HCHO)CO
Criteria Pollutants - ControlledCisco Compressor Station Emission Estimates - Page 01 of 13 Notice of Intent Application
Cisco Compressor Station - Fugitive Sources
NOx
Cisco Compressor Station - Point Sources
hr/yr
Point Sources:
Unit to be Replaced
Unit to be Replaced
Unit to be Replaced
lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
Existing P001 na Compressor Turbine 01 - Solar Centaur Type H 5,375 bhp 8,760
New CT-01 na Compressor Turbine 01 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 2E-03 0.01 3E-04 1E-03 4E-05 2E-04 2E-05 8E-05 1E-03 0.01 0.13 0.56 --- ---
Existing P002 na Compressor Turbine 02 - Solar Centaur Type H 5,375 bhp 8,760
New CT-02 na Compressor Turbine 02 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 2E-03 0.01 3E-04 1E-03 4E-05 2E-04 2E-05 8E-05 1E-03 0.01 0.13 0.56 --- ---
Update TSS na Compressor Turbine Start/Stop (CT-01 & CT-02)300 Events/yr 8,760 ------------1E-03 0.01 ------1E-03 0.01 ------3E-03 0.01
Update DGS na Centrifugal Compressor Dry Gas Seal Leaks 9,812 bhp 8,760 ------------2E-03 0.01 ------2E-03 0.01 ------0.01 0.02
Existing B001 na Sellers C60 Boiler 2.50 MMBtu/hr 8,760 --- --- --- ---5E-06 2E-05 --- --- --- ---2E-04 8E-04 4E-03 0.02
Existing G001 na Backup Generator - Cummins GTA-855 350 bhp 500
New GE-01 na Backup Generator - Caterpillar DG250 DC 374 bhp 100 0.01 4E-04 0.01 4E-04 5E-03 2E-04 2E-03 1E-04 8E-05 4E-06 0.06 3E-03 --- --
Existing PNE na Pneumatic Devices 33 Units 8,760 ------------1E-04 6E-04 ------1E-04 6E-04 ------4E-04 2E-03
Existing PIG na Pigging Operations 2 Units 8,760 ------------4E-05 2E-04 ------4E-05 2E-04 ------9E-05 4E-04
Existing TKS na Storage Tanks 124 bbl 8,760 ------------------------------------------
0.01 0.02 0.01 3E-03 0.01 0.02 2E-03 3E-04 0.01 0.03 0.33 1.13 0.01 0.06
Exist FUG na Process Piping & Equipment Leaks 2,470 Units 8,760 --- --- --- ---7E-04 3E-03 --- ---7E-04 3E-03 --- ---2E-03 8E-03
--- --- --- ---7E-04 3E-03 --- ---7E-04 3E-03 --- ---2E-03 8E-03
0.01 0.02 0.01 3E-03 0.01 0.02 2E-03 3E-04 0.01 0.03 0.33 1.13 0.02 0.07
10 10 10 10 10 10 10
lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
Existing P001 na Compressor Turbine 01 - Solar Centaur Type H 5,375 bhp 8,760
New CT-01 na Compressor Turbine 01 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 --- ---2E-03 0.01 0.01 0.03 --- ---3E-03 0.01 1E-03 0.01 0.15 0.63
Existing P002 na Compressor Turbine 02 - Solar Centaur Type H 5,375 bhp 8,760
New CT-02 na Compressor Turbine 02 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 --- ---2E-03 0.01 0.01 0.03 --- ---3E-03 0.01 1E-03 0.01 0.15 0.63
Update TSS na Compressor Turbine Start/Stop (CT-01 & CT-02)300 Events/yr 8,760 0.01 0.03 ------1E-03 0.01 1E-03 0.01 1E-03 0.01 ------0.02 0.07
Update DGS na Centrifugal Compressor Dry Gas Seal Leaks 9,812 bhp 8,760 0.01 0.04 ------2E-03 0.01 2E-03 0.01 2E-03 0.01 ------0.03 0.11
Existing B001 na Sellers C60 Boiler 2.50 MMBtu/hr 8,760 --- ---4E-04 2E-03 8E-06 4E-05 --- --- --- ---3E-06 1E-05 0.01 0.02
Existing G001 na Backup Generator - Cummins GTA-855 350 bhp 500
New GE-01 na Backup Generator - Caterpillar DG250 DC 374 bhp 100 0.01 5E-04 7E-04 4E-05 2E-03 8E-05 2E-03 1E-04 6E-04 3E-05 5E-04 3E-05 0.10 0.01
Existing PNE na Pneumatic Devices 33 Units 8,760 7E-04 3E-03 ------1E-04 6E-04 1E-04 6E-04 1E-04 6E-04 ------2E-03 0.01
Existing PIG na Pigging Operations 2 Units 8,760 2E-04 8E-04 ------4E-05 2E-04 4E-05 2E-04 4E-05 2E-04 ------5E-04 2E-03
Existing TKS na Storage Tanks 124 bbl 8,760 ------------------------------------------
0.03 0.08 4E-03 0.02 0.02 0.07 0.01 0.02 0.01 0.04 3E-03 0.01 0.45 1.47
Exist FUG na Process Piping & Equipment Leaks 2,470 Units 8,760 4E-03 0.02 --- ---7E-04 3E-03 7E-04 3E-03 7E-04 3E-03 --- ---0.01 0.04
4E-03 0.02 --- ---7E-04 3E-03 7E-04 3E-03 7E-04 3E-03 --- ---0.01 0.04
0.03 0.09 4E-03 0.02 0.02 0.07 0.01 0.02 0.01 0.04 3E-03 0.01 0.46 1.51
10 10 10 10 10 10 25
* = lb/hr is based on 8,760 hr/yr (except GE-01), the generator operates less frequently and TSS and BD are event based.
Cisco Compressor Station - Fugitive Sources
Fugitive Sources:
Cisco Compressor Station - Grand Total
Grand Total:
TVOP Threshold:
Trace/Other Total HAPPOM/PAH 2,2,4-TMP
Cisco Compressor Station - Point Sources
Methanol TolueneStatusSource
ID APCE Description Site Rating hr/yr*Xylenes
Point Sources:
Unit to be Replaced
Hazardous Air Pollutants (HAP) - Controlled
Emission Estimates - Page 02 of 13Cisco Compressor Station Notice of Intent Application
Unit to be Replaced
Unit to be Replaced
Cisco Compressor Station - Fugitive Sources
Fugitive Sources:
Cisco Compressor Station - Grand Total
Grand Total:
TVOP Threshold:
Cisco Compressor Station - Point Sources
Ethylbenzene
Point Sources:
n-HexaneHCHOSite Rating Butadiene
Unit to be Replaced
Unit to be Replaced
Unit to be Replaced
Northwest Pipeline LLC
hr/yr*BenzeneAcetaldehydeAcrolein
Hazardous Air Pollutants (HAP) - Controlled
Notice of Intent Application
Cisco Compressor Station
Status SourceID APCE Description
CO2 CO2e CH4 CO2e N2O CO2e
GWP:1 GWP:28 GWP:265
MMBtu/hr tpy tpy tpy tpy tpy tpy lb/hr*tpy
Existing P001 na Compressor Turbine 01 - Solar Centaur Type H 5,375 bhp 8,760
New CT-01 na Compressor Turbine 01 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 46.79 21,413 21,413 6.81 190.77 0.58 154.76 4,968 21,759
Existing P002 na Compressor Turbine 02 - Solar Centaur Type H 5,375 bhp 8,760
New CT-02 na Compressor Turbine 02 - Centaur 50-5502S 4,906 bhp @ 0oF 8,760 46.79 21,413 21,413 6.81 190.77 0.58 154.76 4,968 21,759
Update TSS na Compressor Turbine Start/Stop (CT-01 & CT-02)300 Events/yr 8,760 ---53 53 5.40 151.20 --- ---47 204
Update DGS na Centrifugal Compressor Dry Gas Seal Leaks 9,812 bhp 8,760 ---7 7 188.74 5,285 ------1,208 5,292
Existing B001 na Sellers C60 Boiler 2.50 MMBtu/hr 8,760 2.50 1,288 1,288 0.02 0.69 0.02 6.26 296 1,295
Existing G001 na Backup Generator - Cummins GTA-855 350 bhp 500
New GE-01 na Backup Generator - Caterpillar DG250 DC 374 bhp 100 3.04 17 17 0.03 0.98 3E-05 0.01 354 18
Existing PNE na Pneumatic Devices 33 Units 8,760 ---0.49 0.49 13.42 375.76 ------86 376
Existing PIG na Pigging Operations 2 Units 8,760 ---0.12 0.12 3.40 95.10 --- ---22 95
Existing TKS na Storage Tanks 124 bbl 8,760 ------ ------ ------ --- ------
99.12 44,192 44,192 224.65 6,290 1.19 315.79 11,948 50,798
Exist FUG na Process Piping & Equipment Leaks 2,470 Units 8,760 ---0.03 0.03 69 1,939 --- ---442.73 1,939
---0.03 0.03 69 1,939 --- ---442.73 1,939
99.12 44,192 44,192 294 8,229 1 316 12,391 52,737
na na na na na
* = lb/hr is based on 8,760 hr/yr (except GE-01), the generator operates less frequently and TSS and BD are event based.
Cisco Compressor Station - Grand Total
Grand Total:
TVOP Threshold:
Fugitive Sources:
Cisco Compressor Station - Point Sources
Point Sources:
Unit to be Replaced
Unit to be Replaced
Unit to be Replaced
Cisco Compressor Station - Fugitive Sources
Emission Estimates - Page 03 of 13
Greenhouse Gas (GHG) Pollutants - ControlledCisco Compressor Station Notice of Intent Application
Northwest Pipeline LLC
Description Site Rating hr/yrStatusSource
ID
TOTALCO2eHeat Input (HHV)APCE
Greenhouse Gas (GHG) Pollutants - Controlled
Notice of Intent Application
Cisco Compressor Station
lb/MMBtu (0oF)lb/hr (0oF)tpy (0oF)lb/hr (0oF)tpy (0oF)
Vendor Data NOx (25 ppm)0.100 4.26 18.68 ---4.26 18.68
Vendor Data CO (50 ppm)0.122 5.19 22.74 ---5.19 22.74
Vendor Data UHC (CH4) (25 ppm)0.035 1.48 6.50 ---1.48 6.50
Vendor Data (PIL 168)VOC (UHC*20%)0.007 0.30 1.30 ---0.30 1.30
4,906 bhp (Max @ 0oF)AP-42 Table 3.1-2b SO2 0.003 0.16 0.66 ---0.16 0.66
4,527 bhp (Avg @ 59oF)AP-42 Table 3.1-2b PM10/2.5 0.007 0.31 1.29 ---0.31 1.29
8,760 hr/yr AP-42 Table 3.1-3 Acetaldehyde 4.00E-05 2E-03 0.01 ---2E-03 0.01
AP-42 Table 3.1-3 Acrolein 6.40E-06 3E-04 1E-03 ---3E-04 1E-03
AP-42 Table 3.1-3 Benzene 9.10E-07 4E-05 2E-04 ---4E-05 2E-04
AP-42 Table 3.1-3 Butadiene, 1,3-4.30E-07 2E-05 8E-05 ---2E-05 8E-05
AP-42 Table 3.1-3 Ethylbenzene 3.20E-05 1E-03 0.01 ---1E-03 0.01
Vendor Data (PIL 168)Formaldehyde 2.88E-03 0.13 0.56 ---0.13 0.56
AP-42 Table 3.1-3 n-Hexane --- --- --- --- --- ---
886 Exhaust Temp (oF)AP-42 Table 3.1-3 Methanol --- --- --- --- --- ---
128,627 Exhaust Flow (lb/hr)AP-42 Table 3.1-3 POM/PAH 3.47E-05 2E-03 0.01 ---2E-03 0.01
AP-42 Table 3.1-3 Toluene 1.30E-04 6E-03 0.03 ---6E-03 0.03
9,537 Btu/bhp-hr (HHV)AP-42 Table 3.1-3 TMP, 2,2,4- --- --- --- --- --- ---
46.79 MMBtu/hr (Max @ 0oF)AP-42 Table 3.1-3 Xylenes 6.40E-05 3E-03 0.01 ---3E-03 0.01
44.44 MMBtu/hr (Typ @ 59oF)AP-42 Table 3.1-3 Other/Trace HAP 2.90E-05 1E-03 0.01 ---1E-03 0.01
45,871 scf/hr (Max @ 0oF)Sum Total HAP 3.22E-03 0.15 0.63 ---0.15 0.63
43,573 scf/hr (Typ @ 59oF)AP-42 Table 3.1-3 CO2 (GWP=1)110 5,147 21,413 ---5,147 21,413
382 MMscf/yr Vendor Data CH4 (GWP=28)0.035 1.64 6.81 ---1.64 6.81
1,020 Btu/scf (HHV)AP-42 Table 3.1-3 N2O (GWP=265)0.003 0.14 0.58 ---0.14 0.58
Weighted Sum CO2e 112 5,230 21,759 ---5,230 21,759
Notes:1 - The emissions shown are based on operation at 100% of rated load for 8,760 hr/yr.
2 - PM10/2.5 is filterable and condensable particulate matter; including PM10 and PM2.5
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Compressor Turbine (CT-01 and CT-02) Emissions
Source
ID Description Reference Pollutant
Controlled Emissions Control
Efficiency
Controlled Emissions
CT-01
CT-02
Compressor Turbine 01 and 02
Solar Centaur 50-5502S
Manufactured ≥ 02/18/05
NSPS KKKK Affected
3 - "Other/Trace HAPs" includes: Carbon Tetrachloride, Chlorobenzene, Chloroform, Dichloropropene, 1,3-Dichloropropene, Ethylene Dibromide, Methylene
Chloride, Phenol, Propylene Oxide, Styrene, 1,1,2,2-Tetrachloroethane, 1,1,2-Trichloroethane, and Vinyl Chloride (as per AP-42).
4 - The fuel heating value will vary, 1,020 Btu/scf (HHV) is at the low end of the range and results in a high (conservative) fuel consumption estimate. (It does NOT impact the emission estimates.)
Cisco Compressor Station Compressor Turbine (CT-01 and CT-02) Emissions Notice of Intent Application
Emission Estimates - Page 04 of 13
lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
CT-01 150 0.03 0.15 0.70 3.08 0.12 0.53 6.04 26.48 0.62 2.70 23.30 102.08
CT-02 150 0.03 0.15 0.70 3.08 0.12 0.53 6.04 26.48 0.62 2.70 23.30 102.08
TOTAL:300 0.07 0.30 1.40 6.15 0.24 1.05 TOTAL:12.09 52.95 1.23 5.40 46.61 204.15
0.07 0.30 1.40 6.15 0.24 1.05 Pre:12.09 52.95 1.23 5.40 46.61 204.15
0.56%VOC 0.56%VOC 1.39%VOC 2.78%VOC 0.56%VOC 0.56%VOC 0.56%VOC 6.94%VOC
lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
CT-01 7E-04 3E-03 7E-04 3E-03 2E-03 0.01 3E-03 0.01 7E-04 3E-03 7E-04 3E-03 7E-04 3E-03 0.01 0.04
CT-02 7E-04 3E-03 7E-04 3E-03 2E-03 0.01 3E-03 0.01 7E-04 3E-03 7E-04 3E-03 7E-04 3E-03 0.01 0.04
TOTAL:1E-03 0.01 1E-03 0.01 3E-03 0.01 0.01 0.03 1E-03 0.01 1E-03 0.01 1E-03 0.01 0.02 0.07
1E-03 6E-03 1E-03 0.01 3E-03 0.01 7E-03 0.03 1E-03 6E-03 1E-03 6E-03 1E-03 6E-03 0.02 0.07
Notes:
20%
NOX CO VOC CO2 CH4 CO2e %Total %VOC
1.0 21 3 184 17 660 1,290.52 lb/MMscf 1,550.00 lb/MMscf 3.44% ---
1.0 20 4 169 19 701 39,804 lb/MMscf 42,750 lb/MMscf 95.00% ---
2.0 41 7 353 36 1,361 3,535 lb/MMscf 0 lb/MMscf 0.00% ---
299.68 lb/MMscf 360.00 lb/MMscf 0.80%100.00%
44,929 lb/MMscf 45,000 lb/MMscf 100.00% ---
---lb/MMscf 2.00 lb/MMscf 0.004%0.56%
---lb/MMscf 2.00 lb/MMscf 0.004%0.56%
---lb/MMscf 5.00 lb/MMscf 0.011%1.39%
Methanol ---lb/MMscf 10.00 lb/MMscf 0.022%2.78%
---lb/MMscf 2.00 lb/MMscf 0.004%0.56%
---lb/MMscf 2.00 lb/MMscf 0.004%0.56%
---lb/MMscf 2.00 lb/MMscf 0.004%0.56%
---lb/MMscf 25.00 lb/MMscf 0.06%6.94%
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Compressor Turbine Start/Stop (TSS) Emissions
Source
ID
Unit
ID Description Start+Stop
per year
NOx CO VOC CO2 CH4 CO2e
2.0 lb/(Start+Stop)41 lb/(Start+Stop)
Total HAP
TSS
Pre-Control:
Source ID
7 lb/(Start+Stop)353 lb/(Start+Stop)36 lb/(Start+Stop)1,361 lb/(Start+Stop)
TSS Comp Turbine 01
Comp Turbine 02
XyleneUnit ID
Benzene
* lb/hr is tpy averaged over 8,760 hr/yr Pre-Control:
Ethylbenzene n-Hexane Methanol Toluene 2,2,4-TMP
1 - The emission factors for start-up and shutdown events are provided by the vendor in PIL 170, summarized below: (See Attachment C2 - Vendor Data)3 - The results of a representative Inlet (Wet) Gas Analysis were used to determine the following worst- case components (See Attachment C1 - Lab Data):
Total lb/(Start+Stop)N2/Water/Ethane/Etc
Start/Stop Emissions
Rate in lb/Event
Table 2 - Centaur 50-6102S (w/o Enhanced Emissions Control) Minimum Contingency:
Pollutant Wet Gas Worst Case
lb/Start CO2
lb/Stop Methane (CH4)
Ethylbenzene
n-Hexane
2,2,4-TMP
Xylenes
Total HAP
Cisco Compressor Station Compressor Turbine Start/Stop (TSS) Emissions Notice of Intent ApplicationEmission Estimates - Page 05 of 13
Toluene
VOC
TOTAL Gas
BenzeneSolar PIL 170 Rev. 12
dated 25 August 2022
Hours scfm MMscf/yr lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
CT-01 8,760 8.40 4.42 0.18 0.79 0%0.18 0.79 0.78 3.42 21.55 94.37 604.07 2,646
CT-02 8,760 8.40 4.42 0.18 0.79 0%0.18 0.79 0.78 3.42 21.55 94.37 604.07 2,646
TOTAL:0.36 1.59 TOTAL:0.36 1.59 1.56 6.84 43.09 188.74 1,208 5,292
0.36 1.59 1.56 6.84 43.09 188.74 1,208 5,292
lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
1E-03 4E-03 1E-03 4E-03 3E-03 0.01 0.01 0.02 1E-03 4E-03 1E-03 4E-03 1E-03 4E-03 0.01 0.06
1E-03 4E-03 1E-03 4E-03 3E-03 0.01 0.01 0.02 1E-03 4E-03 1E-03 4E-03 1E-03 4E-03 0.01 0.06
TOTAL:2E-03 0.01 2E-03 0.01 0.01 0.02 0.01 0.04 2E-03 0.01 2E-03 0.01 2E-03 0.01 0.03 0.11
2E-03 0.01 2E-03 0.01 0.01 0.02 0.01 0.04 2E-03 0.01 2E-03 0.01 2E-03 0.01 0.03 0.11
Notes:
20%
Wgt%W%VOC
1,290.52 lb/MMscf 1,550.00 lb/MMscf 3.44% ---
39,804 lb/MMscf 42,750 lb/MMscf 95.00%---
3,535 lb/MMscf 0 lb/MMscf 0.00%---
8.40 scfm 300 lb/MMscf 360 lb/MMscf 0.80%100.00%
44,929 lb/MMscf 45,000 lb/MMscf 100.00% ---
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 5.00 lb/MMscf 0.01%1.39%
---lb/MMscf 10.00 lb/MMscf 0.02%0.02%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 25.00 lb/MMscf 0.06%6.94%
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Centrifugal Compressor Dry Gas Seal (DGS) Emissions
Source
ID
Unit
ID
Unit Description
(Compressor Dry Gas Seals)
Operating
Time
Leak Rate
(Solar PIL 251)
Pre-Control VOC CO2e
360 360 1,550 42,750 CH4 GWP = 28lb/MMscf lb/MMscf lb/MMscf lb/MMscf
DGS Comp Turbine 01
Comp Turbine 02
Control
%
VOC CO2 (w/o Control)CH4
Pre-Control:
Source
ID
Unit
ID
Benzene Ethylbenzene n-Hexane Methanol
lb/MMscf lb/MMscf lb/MMscf lb/MMscf
Toluene 2,2,4-TMP Xylene Total HAP
2.00 2.00 5.00 10.00 2.00 2.00 2.00 25.00
lb/MMscf lb/MMscf lb/MMscf lb/MMscf
DGS CT-01
Pre-Control:
1 - The Solar Centaur 50-5502S Compressor Turbines (CT-01 and CT-02) each drive a Solar 307i centrifugal compressor operating at average suction pressure = 600 psi.
4 - The results of a representative Extended Gas Analysis were used to determine the following
worst-case VOC and HAP components (See Attachment C1 - Lab Analysis):
Minimum Contingency:
n-Hexane
2 - Dry gas seal leak rate provided by Solar Turbines and based on PIL 251
and historical suction pressure. A conservative contingency has been added
to the estimate leak rate.
Pollutant Inlet Gas Worst-Case
CO2
Methane (CH4)
N2/Water/Ethane/Etc
7.0 scfm * 120% Contingency =VOC
TOTAL Gas
Benzene
Ethylbenzene
Methanol
Toluene
2,2,4-TMP
Xylenes
Total HAP
Cisco Compressor Station Centrifugal Compressor Dry Gas Seal (DGS) Emissions Notice of Intent ApplicationEmission Estimates - Page 06 of 13
600 psig : 7 scfm
g/bhp-hr lb/MMBtu lb/hr tpy g/bhp-hr lb/hr tpy
NSPS JJJJ NOx ------------ ---2.00 1.65 0.08
NSPS JJJJ CO ------------ ---4.00 3.30 0.16
NSPS JJJJ NMNEHC ------------ ---1.00 0.82 0.04
NSPS JJJJ VOC (w/Aldehydes)------------ ---1.10 0.90 0.05
AP-42 Table 3.2-3 SO2 2.17E-03 5.88E-04 2E-03 9E-05 ---2E-03 2E-03 9E-05
AP-42 Table 3.2-3 PM10/2.5 7.16E-02 1.94E-02 0.06 3E-03 ---0.07 0.06 3E-03
374 bhp AP-42 Table 3.2-3 Acetaldehyde*1.03E-02 2.79E-03 0.01 4E-04 ---1E-02 8E-03 4E-04
100 hr/yr AP-42 Table 3.2-3 Acrolein*9.70E-03 2.63E-03 0.01 4E-04 ---1E-02 8E-03 4E-04
1,800 rpm, 6 cyl AP-42 Table 3.2-3 Benzene 5.83E-03 1.58E-03 5E-03 2E-04 ---6E-03 5E-03 2E-04
865 in3 Displacement AP-42 Table 3.2-3 Butadiene, 1,3-2.45E-03 6.63E-04 2E-03 1E-04 ---2E-03 2E-03 1E-04
144 in3/cyl AP-42 Table 3.2-3 Ethylbenzene 9.15E-05 2.48E-05 8E-05 4E-06 ---9E-05 8E-05 4E-06
AP-42 Table 3.2-3 Formaldehyde*7.56E-02 2.05E-02 0.06 3E-03 ---0.08 0.06 3E-03
1,350 Exhaust Temp (oF)AP-42 Table 3.2-3 n-Hexane --- --- --- --- --- --- --- --
1,602 Exhaust Flow (acfm)AP-42 Table 3.2-3 Methanol 1.13E-02 3.06E-03 0.01 5E-04 ---1E-02 9E-03 5E-04
AP-42 Table 3.2-3 POM/PAH 8.79E-04 2.38E-04 7E-04 4E-05 ---9E-04 7E-04 4E-05
AP-42 Table 3.2-3 Toluene 2.06E-03 5.58E-04 2E-03 8E-05 ---2E-03 2E-03 8E-05
AP-42 Table 3.2-3 TMP, 2,2,4-2.45E-03 6.63E-04 2E-03 1E-04 ---2E-03 2E-03 1E-04
AP-42 Table 3.2-3 Xylenes 7.20E-04 1.95E-04 6E-04 3E-05 ---7E-04 6E-04 3E-05
8,135 Btu/bhp-hr (HHV)AP-42 Table 3.2-3 Other/Trace HAP 6.61E-04 1.79E-04 5E-04 3E-05 ---7E-04 5E-04 3E-05
3.04 MMBtu/hr (HHV)Sum Total HAP 0.12 0.03 0.10 0.01 ---0.12 0.10 0.01
2,983 scf/hr AP-42 Table 3.2-3 CO2 (GWP=1)405.90 110.00 334.67 17 ---405.90 335 17
0.30 MMscf/yr AP-42 Table 3.2-3 CH4 (GWP=28)0.85 0.23 0.70 0.03 ---0.85 0.70 0.03
1,020 Btu/scf (HHV)40CFR98 - Table C2 N2O (GWP=265)8.14E-04 2.20E-04 7E-04 3E-05 ---8E-04 7E-04 3E-05
Weighted Sum CO2e 429.88 116.50 354 17.72 ---429.88 354 17.72
* = Aldehyde
Notes:1 - Pre-controlled and controlled emissions shown are based on operation at 100% of rated load for 100 hr/yr.
2 - As per vendor specifications, NMNEHC (non-methane/non-ethane hydrocarbons) do NOT include aldehydes. VOC is the sum of NMNEHC, Acetaldehyde, Acrolein, and Formaldehyde.
3 - PM10/2.5 is filterable and condensable particulate matter; including PM10 and PM2.5
5 - The fuel heating value will vary, 1,020 Btu/scf (HHV) is at the low end of the range and results in a high (conservative) fuel consumption estimate. (It does NOT impact the emission estimates.)
6 - The Total VOC, HCHO, HAP and CO2e emissions include Engine Operations, Engine Start-up (ESU), Compressor Rod Packing (CRP), and Compressor Blowdown (CBD) emissions:
VOC HCHO Tot HAP CO2e
Engine Operations (See Above)0.05 tpy 0.00 tpy 0.01 tpy 18 tpy
Engine Start-up (ESU)
Compressor Rod Packing (CRP)
Compressor Blowdown (CBD)
0.05 tpy 0.00 tpy 0.01 tpy 18 tpy
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Emergency Generator Engine (GE-01) Emissions
Source
ID Description Reference Pollutant
Pre-ControlledEmissions Control
Efficiency
TOTAL:
ControlledEmissions
GE-01
Emergency Generator Engine 01
Caterpillar DG250 GC (4SRB)
Manufactured After 01/01/2009
NSPS JJJJ Affected
4 - "Other/Trace HAPs" includes: Carbon Tetrachloride, Chlorobenzene, Chloroform, Dichloropropene, 1,3-Dichloropropene, Ethylene Dibromide, Methylene Chloride, Phenol, Propylene Oxide, Styrene, 1,1,2,2-Tetrachloroethane, 1,1,2-Trichloroethane, and Vinyl Chloride (as per AP-42).
Description (Each Engine)
Electric Starter
Generator Engine - No Compressor
Generator Engine - No Compressor
Cisco Compressor Station Emergency Generator Engine (GE-01) Emissions Notice of Intent ApplicationEmission Estimates - Page 07 of 13
lb/MMscf lb/MMBtu lb/hr tpy
NOx 100.00 9.80E-02 0.25 1.07
CO 84.00 8.24E-02 0.21 0.90
NMNEHC 5.50 5.39E-03 0.01 0.06
VOC 5.50 5.39E-03 0.01 0.06
SO2 0.60 5.88E-04 1E-03 0.01
PM10/2.5 7.60 7.45E-03 0.02 0.08
Acetaldehyde --- --- --- ---
Acrolein --- --- --- ---
Benzene 2.10E-03 2.06E-06 5E-06 2E-05
Butadiene, 1,3- --- --- --- ---
Ethylbenzene --- --- --- ---
Formaldehyde 7.50E-02 7.35E-05 2E-04 8E-04
n-Hexane 1.80 1.76E-03 0.00 0.02
Methanol --- --- --- ---
2.50 MMBtu/hr (HHV)POM/PAH 1.72E-01 1.69E-04 4E-04 2E-03
Toluene 3.40E-03 3.33E-06 8E-06 4E-05
TMP, 2,2,4- --- --- --- ---
1,020 Btu/scf (HHV)Xylenes --- --- --- ---
Other/Trace HAP 1.20E-03 1.18E-06 3E-06 1E-05
8,760 hr/yr Total HAP 2.05 2.01E-03 0.01 0.02
CO2 (GWP=1)120,000 117.65 294.12 1,288
2,451 scf/hr CH4 (GWP=28)2.30 2.25E-03 0.01 0.02
21.47 MMscf/yr N2O (GWP=265)2.20 2.16E-03 0.01 0.02
CO2e 120,647 118.28 295.70 1,295
Notes:1 - The emissions shown are based on operation at 100% of rated load for 8,760 hr/yr.
2 - PM10/2.5 is filterable and condensable particulate matter; including PM10 and PM2.5
EPA AP-42 Table 1.4-2
Weighted Sum
3 - "Other/Trace HAPs" includes: Carbon Tetrachloride, Chlorobenzene, Chloroform, Dichloropropene, 1,3-Dichloropropene, Ethylene Dibromide,
Methylene Chloride, Phenol, Propylene Oxide, Styrene, 1,1,2,2-Tetrachloroethane, 1,1,2-Trichloroethane, and Vinyl Chloride (as per AP-42).
Cisco Compressor Station Boiler (B001) Emissions Notice of Intent ApplicationEmission Estimates - Page 08 of 13
B001
Boiler 01
EPA AP-42 Table 1.4-1
EPA AP-42 Table 1.4-1
EPA AP-42 Table 1.4-2
EPA AP-42 Table 1.4-2
Sellers C60
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
Sum
EPA AP-42 Table 1.4-2
EPA AP-42 Table 1.4-3
Capacity:EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-3
EPA AP-42 Table 1.4-2
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Boiler (B001) Emissions
Source
ID Description Reference Pollutant
EmissionFactor Emissions
EPA AP-42 Table 1.4-2
EPA AP-42 Table 1.4-2
EPA AP-42 Table 1.4-3
bhp scf/bhp scf/event Events/yr MMscf/yr lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
4,906 6.56 32,172 150 4.83 0.20 0.87 0.20 0.87 0.85 3.74 23.55 103.15 660.27 2,892
4,906 6.56 32,172 150 4.83 0.20 0.87 0.20 0.87 0.85 3.74 23.55 103.15 660.27 2,892
75 26.67 2,000 12 0.02 1E-03 4E-03 1E-03 4E-03 4E-03 0.02 0.12 0.51 3.28 14.38
--- ---193,031 2 0.39 0.02 0.07 0.02 0.07 0.07 0.30 1.88 8.25 52.82 231.36
TOTAL:314 10.06 0.41 1.81 TOTAL:0.41 1.81 1.78 7.80 49.10 215.07 1,377 6,030
Pre-Control:0.41 1.81 1.78 7.80 49.10 215.07 1,377 5,384
lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy lb/hr*tpy
1E-03 5E-03 1E-03 5E-03 3E-03 0.01 0.01 0.02 1E-03 5E-03 1E-03 5E-03 1E-03 5E-03 0.01 0.06
1E-03 5E-03 1E-03 5E-03 3E-03 0.01 0.01 0.02 1E-03 5E-03 1E-03 5E-03 1E-03 5E-03 0.01 0.06
5E-06 2E-05 5E-06 2E-05 1E-05 6E-05 3E-05 1E-04 5E-06 2E-05 5E-06 2E-05 5E-06 2E-05 7E-05 3E-04
9E-05 4E-04 9E-05 4E-04 2E-04 1E-03 4E-04 2E-03 9E-05 4E-04 9E-05 4E-04 9E-05 4E-04 1E-03 5E-03
TOTAL:2E-03 0.01 2E-03 0.01 0.01 0.03 0.01 0.05 2E-03 0.01 2E-03 0.01 2E-03 0.01 0.03 0.13
0.00 0.01 2E-03 0.01 0.01 0.03 1E-02 0.05 2E-03 0.01 2E-03 0.01 2E-03 0.01 0.03 0.13
Notes:
%Total %VOC
20% ---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
%Total %VOC ---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
1,290.52 lb/MMscf 1,550.00 lb/MMscf 3.44% --- ---lb/MMscf 5.00 lb/MMscf 0.01%1.39%
39,804 lb/MMscf 42,750 lb/MMscf 95.00% ---Methanol ---lb/MMscf 10.00 lb/MMscf 0.02%2.78%
3,535 lb/MMscf 0 lb/MMscf 0.00% --- ---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
299.68 lb/MMscf 360.00 lb/MMscf 0.80%100.00% ---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
44,929 lb/MMscf 45,000 lb/MMscf 100.00% --- ---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 25.00 lb/MMscf 0.06%6.94%
2 - Blowdown volumes estimated as follows:
Vscf = Vacf * 528/(ToF+460) * (Ppsig+14.70)/14.70 / Z
Compressibility Factor (Z) from https://checalc.com/solved/naturalgasZ.html
V (acf)T (oF)P (psig)Z V (scf)
573.0 60 800 1.00 32,172
573.0 60 800 1.00 32,172
3,438.0 60 850 1.00 193,031
3 - Blowdown volume for turbine dry seal gas recovery compressor conservatively estimated at 2,000 scf.
4 - Facility ESD volume estimated at three times the combined compressor blowdown volume.
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Compressor Blowdown (CBD) Emissions
SourceID
Unit Description
(Compressor Blowdown- Raw Natural Gas)
Site
Rating Blowdown and ESD Total Gas
Vented
Pre-Control VOC CO2e
360 360 1,550 42,750 CH4 GWP = 28lb/MMscf lb/MMscf lb/MMscf lb/MMscf
BD
Turbine Compressor 01
naTurbine Compressor 02
Recovery Compressor 01
Emergency Shutdown (ESD) Test
Control %
VOC CO2 (w/o Control)CH4
Total HAP
* lb/hr is averaged
over 8,760 hr/yr
Source
ID
Unit Description
(Compressor Blowdown
- Raw Natural Gas)
Benzene Ethylbenzene
2.00 2.00
lb/MMscf lb/MMscf
n-Hexane Methanol Toluene 2,2,4-TMP Xylene
lb/MMscf lb/MMscf lb/MMscf
5.00 10.00 2.00 2.00 2.00 25.00
* lb/hr is averaged over 8,760 hr/yr Pre-Control:
lb/MMscf lb/MMscf lb/MMscf
BD
Turbine Compressor 01
Turbine Compressor 02
Recovery Compressor 01
Emergency Shutdown (ESD) Test
1 - The results of a representative Inlet Gas Analysis were used to determine the following worst-case components (See Attachment C1 - Lab Data):Pollutant Inlet Gas Worst Case
Minimum Contingency:Benzene
TOTAL Gas Xylenes
Pollutant Inlet Gas Worst Case Ethylbenzene
CO2 n-Hexane
Methane (CH4)
N2/Water/Ethane/Etc Toluene
VOC 2,2,4-TMP
Notice of Intent ApplicationEmission Estimates - Page 09 of 13
Total HAP
Equipment
Turbine 01 Compressor Blowdown
Turbine 02 Compressor Blowdown
ESD Blowdown
Cisco Compressor Station Compressor Blowdown (CBD) Emissions
360 lb/MMscf 1,550 lb/MMscf 42,750 lb/MMscf
hr/yr scf/hr/unit scf/hr MMscf/yr lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy
6 8,760 1.37 ---8.22 0.07 3E-03 0.01 0.01 0.06 0.35 1.54 9.85 43.15
---8,760 18.20 --- --- --- --- --- --- --- --- --- --- ---
27 8,760 2.35 ---63.45 0.56 0.02 0.10 0.10 0.43 2.71 11.88 76.05 333.09
TOTAL:33 TOTAL:71.67 0.63 0.03 0.11 0.11 0.49 3.06 13.42 85.90 376.24
71.67 0.63 0.03 0.11 0.11 0.49 3.06 13.42 85.90 376.24
---
2.00 lb/MMscf 2.00 lb/MMscf 5.00 lb/MMscf 10.00 lb/MMscf 2.00 lb/MMscf 2.00 lb/MMscf 2.00 lb/MMscf 25.00 lb/MMscf
lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy
2E-05 7E-05 2E-05 7E-05 4E-05 2E-04 8E-05 4E-04 2E-05 7E-05 2E-05 7E-05 2E-05 7E-05 2E-04 9E-04
--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
1E-04 6E-04 1E-04 6E-04 3E-04 1E-03 6E-04 3E-03 1E-04 6E-04 1E-04 6E-04 1E-04 6E-04 2E-03 0.01
TOTAL:1E-04 6E-04 1E-04 6E-04 4E-04 2E-03 7E-04 3E-03 1E-04 6E-04 1E-04 6E-04 1E-04 6E-04 2E-03 0.01
1E-04 6E-04 1E-04 6E-04 4E-04 2E-03 7E-04 3E-03 1E-04 6E-04 1E-04 6E-04 1E-04 6E-04 0.00 0.01
Notes:1 - Assumed 8,760 hours per year of pneumatic device operations.
2 - Gas/Vapor emissions calculated using Table W-3B to Subpart W of 40CFR98.20%
%Total %VOC
1,290.52 lb/MMscf 1,550.00 lb/MMscf 3.44% ---
39,804 lb/MMscf 42,750 lb/MMscf 95.00% ---
3,535 lb/MMscf 0 lb/MMscf 0.00% ---
Low Continuous Bleed Pneumatic Device 1.37 scfh/unit 299.68 lb/MMscf 360.00 lb/MMscf 0.80%100.00%
High Continuous Bleed Pneumatic Device 18.20 scf/hr/unit 44,929 lb/MMscf 45,000 lb/MMscf 100.00% ---
Intermittent Bleed Pneumatic Device 2.35 scf/hr/unit ---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 5.00 lb/MMscf 0.01%1.39%
Methanol ---lb/MMscf 10.00 lb/MMscf 0.02%2.78%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 2.00 lb/MMscf 0.00%0.56%
---lb/MMscf 25.00 lb/MMscf 0.06%6.94%
CO2e
GWP = 28
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Pneumatic Device (PNE) Emissions
UnitID Description Device Type Unit Count
Hours of
Operation
Emission
Factor Control Efficiency
Total
Gas/Vapor
VOC CO2 CH4
(Gas)
PNE Pneumatic Devices
Low Bleed
High Bleed
Intermittent
Unit Device Type Benzene Ethylbenzene n-Hexane Tot HAP
(Gas)
Pre-Control:
Current PTE:
Methanol Toluene 2,2,4-TMP Xylenes
PNE
Low Bleed
High Bleed
Intermittent
Pre-Control:
Toluene
3 - The results of a representative Inlet (Wet) Gas Analysis were used to determine the following worst-case components (See Attachment C1 - Lab Data):
Minimum Contingency:
Default Total Hydrocarbon Population Emission Factors
for Onshore Natural Gas Transmission Compression Emission Factor
Pollutant Inlet Gas Worst Case
CO2
Methane (CH4)
N2/Water/Ethane/Etc
VOC
TOTAL Gas
Benzene
Ethylbenzene
n-Hexane
2,2,4-TMP
Xylenes
Total HAP
Cisco Compressor Station Pneumatic Device (PNE) Emissions Notice of Intent ApplicationEmission Estimates - Page 10 of 13
360 Gas 360 Gas 1,550 Gas 42,750 Gas
scf/Event Events/yr Mscf/yr lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy
12,000 7 84 3E-03 0.02 3E-03 0.02 0.01 0.07 0.41 1.80 11.49 50.34
10,700 7 75 3E-03 0.01 3E-03 0.01 0.01 0.06 0.37 1.60 10.25 44.89
Assumes 1 hr/Event TOTAL:14 159 0.01 0.03 TOTAL:0.01 0.03 0.03 0.12 0.78 3.40 21.74 95.22
Pre-Control:0.01 0.03 0.03 0.12 0.78 3.40 19 85
2.00 Gas 2.00 Gas 5.00 Gas 10.00 Gas 2.00 Gas 2.00 Gas 2.00 Gas 25.00 Gas
lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy
2E-05 8E-05 2E-05 8E-05 5E-05 2E-04 1E-04 4E-04 2E-05 8E-05 2E-05 8E-05 2E-05 8E-05 2E-04 1E-03
2E-05 7E-05 2E-05 7E-05 4E-05 2E-04 9E-05 4E-04 2E-05 7E-05 2E-05 7E-05 2E-05 7E-05 2E-04 9E-04
Assumes 1 hr/Event TOTAL:4E-05 2E-04 4E-05 2E-04 9E-05 4E-04 2E-04 8E-04 4E-05 2E-04 4E-05 2E-04 4E-05 2E-04 5E-04 2E-03
Pre-Control:0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
%Total %VOC
1,291 lb/MMscf 1,550 lb/MMscf 3.444 430.556
39,804 lb/MMscf 42,750 lb/MMscf 95.000 11875.000
3,535 lb/MMscf 0 lb/MMscf 0.000 0.000
300 lb/MMscf 360 lb/MMscf 0.800 100.000
44,929 lb/MMscf 45,000 lb/MMscf 100.000 ---
---lb/MMscf 2 lb/MMscf 0.004 0.556
---lb/MMscf 2 lb/MMscf 0.004 0.556
---lb/MMscf 5 lb/MMscf 0.011 1.389
---lb/MMscf 10 lb/MMscf 0.022 2.778
---lb/MMscf 2 lb/MMscf 0.004 0.556
---lb/MMscf 2 lb/MMscf 0.004 0.556
---lb/MMscf 2 lb/MMscf 0.004 0.556
---lb/MMscf 25 lb/MMscf 0.056 6.944
CO2e
CH4 GWP = 28
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Pigging Operation (PIG) Emissions
UnitID Unit Description
BlowdownVolume Blowdown Total GasVented
Pre-Control VOC
lb/MMscf lb/MMscf lb/MMscf lb/MMscf
PIG Pig Launcher ---Pig Receiver
Control %
VOC CO2 (w/o Control)CH4
1 - The results of a representative Gas Analysis were used to determine the following worst-case components (See Attachment C1 - Wet Gas Summary):
Toluene 2,2,4-TMP
Unit Description
Xylene Total HAP
lb/MMscf lb/MMscf lb/MMscf lb/MMscf lb/MMscf lb/MMscf
Benzene Ethylbenzene n-Hexane Methanol
lb/MMscf lb/MMscf
PIG Pig Launcher
Pig Receiver
Unit
ID
Ethylbenzene
Min. Contingency:
Methane (CH4)
N2/Water/Ethane/Etc
VOC
TOTAL Gas
Benzene
20% VOC and GHG
Pollutant Inlet Gas Worst Case
CO2
Cisco Compressor Station Pigging Operation (PIG) Emissions Notice of Intent ApplicationEmission Estimates - Page 11 of 13
n-Hexane
Methanol (MeOH)
Toluene
2,2,4-TMP
Xylenes
Total HAP
Working Breathing Flash 100%VOC
bbl T-O/yr bbl/yr lb/yr lb/yr lb/yr lb/yr tpy lb/hr tpy lb/hr tpy lb/hr tpy
TK-01 Used Oil 100 4 400 11.02 48.76 ---59.78 0.03 0.01 0.03
TK-02 Lube Oil 11.9 10 119 0.00 0.00 ---0.00 0.00 0.00 0.00
TK-03 Lube Oil 11.9 10 119 0.00 0.00 ---0.00 0.00 0.00 0.00
124 ---638 0.03 TOTAL:0.01 0.03 TOTAL:
Pre-Control:0.01 0.03 Pre-Control:0.00 0.00
Notes:1 - EPA TANKS 4.0.9d was used to determine working and breathing losses from each Storage Tank.
2 - There are no changes to storage tank emissions from the previous permitting.
Negligible GHG Negligible GHG
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Storage Tank (TK-01 thru TK-03) Emissions
Source
ID Material Stored Capacity Turnovers T-Put PRE-CONTROL (VOC)Control
Efficiency
VOC CH4 CO2e
Total CH4 GWP = 25
Negligible GHG
Negligible GHG
Negligible GHG
Negligible GHG
Negligible GHG
Negligible GHG
Cisco Compressor Station Storage Tank (TK-01 thru TK-03) Emissions Notice of Intent ApplicationEmission Estimates - Page 12 of 13
na
0.80%Wgt 3.44%Wgt 95.00%Wgt
500%lb/hr/Unit lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy
257 1,285 9.92E-03 ---12.75 55.84 0.10 0.45 0.44 0.02 12.11 53.05 339.54 1,485
--- ---5.29E-03 --- ------ --- --- --- --- --- --- --- ---
30 150 1.94E-02 ---2.91 12.75 0.02 0.10 0.10 4E-03 2.76 12.11 77.51 339
73 365 4.41E-04 ---0.16 0.70 1E-03 0.01 0.01 2E-04 0.15 0.67 4.29 19
120 600 8.60E-04 ---0.52 2.26 4E-03 0.02 0.02 8E-04 0.49 2.15 13.74 60
14 70 4.41E-03 ---0.31 1.35 2E-03 0.01 0.01 5E-04 0.29 1.28 8.22 36
TOTAL:494 2,470 TOTAL:0.13 0.58 0.57 0.03 15.81 69.25 443.30 1,939
PRE-Controlled:0.13 0.58 0.57 3E-02 15.81 69.25 443.30 1,939
0.56%VOC 0.56%VOC 1.39%VOC 2.78%VOC 0.56%VOC 0.56%VOC 0.56%VOC 6.94%VOC
lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy lb/hr tpy
6E-04 2E-03 6E-04 2E-03 1E-03 0.01 3E-03 0.01 6E-04 2E-03 6E-04 2E-03 6E-04 2E-03 0.01 0.03
--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
1E-04 6E-04 1E-04 6E-04 3E-04 1E-03 6E-04 3E-03 1E-04 6E-04 1E-04 6E-04 1E-04 6E-04 2E-03 0.01
7E-06 3E-05 7E-06 3E-05 2E-05 8E-05 4E-05 2E-04 7E-06 3E-05 7E-06 3E-05 7E-06 3E-05 9E-05 4E-04
2E-05 1E-04 2E-05 1E-04 6E-05 3E-04 1E-04 5E-04 2E-05 1E-04 2E-05 1E-04 2E-05 1E-04 3E-04 1E-03
1E-05 6E-05 1E-05 6E-05 3E-05 2E-04 7E-05 3E-04 1E-05 6E-05 1E-05 6E-05 1E-05 6E-05 2E-04 8E-04
TOTAL:7E-04 3E-03 7E-04 3E-03 2E-03 0.01 4E-03 0.02 7E-04 3E-03 7E-04 3E-03 7E-04 3E-03 0.01 0.04
PRE-Controlled:7E-04 3E-03 7E-04 3E-03 2E-03 8E-03 4E-03 2E-02 7E-04 3E-03 7E-04 3E-03 7E-04 3E-03 0.01 0.04
Notes:1 - Assumed 8,760 hours per year of fugitive emissions.
20%
%Total %VOC
1,291 lb/MMscf 1,550 lb/MMscf 3.44%4.306
kg/hr lb/hr/unit 39,804 lb/MMscf 42,750 lb/MMscf 95.00%118.750
Valves 4.5E-03 9.92E-03 3,535 lb/MMscf 0 lb/MMscf 0.00%0.000
Pump Seals 2.4E-03 5.29E-03 300 lb/MMscf 360 lb/MMscf 0.80%100.000
Others 8.8E-03 1.94E-02 44,929 lb/MMscf 45,000 lb/MMscf 100.00% ---
Connectors 2.0E-04 4.41E-04 ---lb/MMscf 2 lb/MMscf 0.00%0.006
Flanges 3.9E-04 8.60E-04 ---lb/MMscf 2 lb/MMscf 0.00%0.006
Open-Ended Lines 2.0E-03 4.41E-03 ---lb/MMscf 5 lb/MMscf 0.01%0.014
---lb/MMscf 10 lb/MMscf 0.02%0.028
3 - "Other” components include pressure relief devices (PRD), compressors, diaphragms, drains, meters, etc. ---lb/MMscf 2 lb/MMscf 0.00%0.006
4 - Component Count is based in GRI-HAPCalc default values for compressor stations, with a safety margin. ---lb/MMscf 2 lb/MMscf 0.00%0.006
---lb/MMscf 2 lb/MMscf 0.00%0.006
---lb/MMscf 25 lb/MMscf 0.06%0.069
Notice of Intent ApplicationEmission Estimates - Page 13 of 13
TOTAL Gas
Benzene
Ethylbenzene
n-Hexane
Toluene
2,2,4-TMP
Methanol (MeOH)
Xylenes
Total HAP
Cisco Compressor Station Process Piping and Equipment Leak (FUG) Emissions
VOC
Flanges
Open-ended Lines
5 - The results of a representative Inlet Gas Analysis were used to determine the following worst-case components (See Attachment C1 - Lab Analysis):
2 - Gas/Vapor emissions calculated using EPA Protocol for Equipment Leak Emission Estimates, EPA-453/R-95-017, Nov 1995; Table 2-4, Oil and Gas Production Operations:Minimum Contingency:
Pollutant Inlet Gas Worst Case
Equipment Type Gas CO2
Methane (CH4)
N2/Water/Ethane/Etc
Toluene 2,2,4-TMP Xylenes Total HAP
(Gas)
FUG
Valves
Pump Seals
Other
Connectors
Source
ID
Component
(Unit) Type
Benzene Ethylbenzene n-Hexane Methanol
CH4
(Gas)
FUG Process Piping and Equipment Leaks
(Gas)
Valves
Pump Seals
Other
Connectors
Flanges
Open-ended Lines
CO2e
CH4 GWP = 28
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Process Piping and Equipment Leak (FUG) Emissions
SourceID Description
Component (Unit) Type Unit Count
SafetyMultiplier LeakFactor LDAR Control Credit
ControlledLeaks
VOC CO2
2SLB 4SLB 4SRB Uncontrolled Lean Pre-Mix#
lb/MMBtu lb/MMBtu lb/MMBtu lb/MMBtu lb/MMBtu
NOx (<90% Load)3.17E+00 4.08E+00 2.27E+00 3.23E-01 9.91E-02
CO (< 90% Load)3.86E-01 3.17E-01 3.51E+00 8.23E-02 1.51E-02
VOC (NMNEHC w/o Aldehydes*)4.93E-02 5.17E-02 6.50E-03 2.06E-03 2.06E-03
VOC (NMNEHC w/ Aldehydes*)1.20E-01 1.18E-01 3.24E-02*2.82E-03 2.13E-03
SO2 (2,000 gr-S/MMscf ≈ 0.0007 W%)5.88E-04 5.88E-04 5.88E-04 3.40E-03 3.40E-03
PM10/2.5 (Condensible and Filterable) 4.83E-02 9.99E-03 1.94E-02 6.63E-03 6.63E-03
Acetaldehyde*7.76E-03 8.36E-03 2.79E-03 4.00E-05 4.00E-05
Acrolein*7.78E-03 5.14E-03 2.63E-03 6.40E-06 6.40E-06
Benzene 1.94E-03 4.40E-04 1.58E-03 1.20E-05 9.10E-07
Butadiene, 1,3-8.20E-04 2.67E-04 6.63E-04 4.30E-07 4.30E-07
Ethylbenzene 1.08E-04 3.97E-05 2.48E-05 3.20E-05 3.20E-05
Formaldehyde (HCHO)*5.52E-02 5.28E-02 2.05E-02 7.10E-04 2.00E-05
n-Hexane 4.45E-04 1.11E-03 --- --- ---
Methanol (MeOH)2.48E-03 2.50E-03 3.06E-03 --- ---
Polycyclic Organic Matter (POM/PAH)2.68E-04 3.74E-04 2.38E-04 3.47E-05 3.47E-05
Toluene 9.63E-04 4.08E-04 5.58E-04 1.30E-04 1.30E-04
Trimethylpentane, 2,2,4- (i-Octane)8.46E-04 2.50E-04 --- --- ---
Xylenes 2.68E-04 1.84E-04 1.95E-04 6.40E-05 6.40E-05
Other/Trace HAP**6.57E-04 3.21E-04 1.79E-04 2.90E-05 2.90E-05
TOTAL HAP 7.95E-02 7.22E-02 3.24E-02*1.06E-03 3.57E-04
CO2 (GWP=1)1.10E+02 1.10E+02 1.10E+02 1.10E+02 1.10E+02
CH4 (GWP=28)1.45E+00 1.25E+00 2.30E-01 8.64E-03 8.64E-03
N2O (GWP=265)Use 40CFR98 Use 40CFR98 Use 40CFR98 3.00E-03 3.00E-03
CO2e Use 40CFR98 Use 40CFR98 Use 40CFR98 Use 40CFR98 Use 40CFR98
Industrial Flares Diesel Engines
13.5-1 06/17 3.3-1; 3.3-2 10/96
Uncontrolled LoNOx Burners Flue Gas Recirc Combustion Uncontrolled
lb/MMBtu lb/MMBtu lb/MMBtu lb/MMBtu lb/MMBtu
NOx (≥ 90% Load)9.80E-02 4.90E-02 3.14E-02 Use Ext. Comb.4.41E+00
CO (≥ 90% Load)8.24E-02 8.24E-02 8.24E-02 3.10E-01 9.50E-01
VOC (NMNEHC w/o Aldehydes*)5.32E-03 5.32E-03 5.32E-03 3.60E-01
VOC (NMNEHC w/ Aldehydes*)5.39E-03 5.39E-03 5.39E-03 3.62E-01
SO2 (2,000 gr-S/MMscf ≈ 0.0007 W%)5.88E-04 5.88E-04 5.88E-04 2.90E-01
PM10/2.5 (Condensible and Filterable) 7.45E-03 7.45E-03 7.45E-03 3.10E-01
Acetaldehyde* --- --- ---7.67E-04
Acrolein* --- --- ---9.25E-05
Benzene 2.06E-06 2.06E-06 2.06E-06 9.33E-04
Butadiene, 1,3- --- --- ---3.91E-05
Ethylbenzene --- --- --- ---
Formaldehyde (HCHO)*7.35E-05 7.35E-05 7.35E-05 1.18E-03
n-Hexane 1.76E-03 1.76E-03 1.76E-03 ---
Methanol (MeOH) --- --- --- ---
Polycyclic Organic Matter (POM/PAH)1.69E-04 1.69E-04 1.69E-04 1.68E-04
Toluene 3.33E-06 3.33E-06 3.33E-06 4.09E-04
Trimethylpentane, 2,2,4- (i-Octane) --- --- --- ---
Xylenes --- --- ---2.85E-04
Other/Trace HAP**1.18E-06 1.18E-06 1.18E-06 ---
TOTAL HAP 2.01E-03 2.01E-03 2.01E-03 3.87E-03
CO2 (GWP=1)1.18E+02 1.18E+02 1.18E+02 1.64E+02
CH4 (GWP=28)2.25E-03 2.25E-03 2.25E-03
N2O (GWP=265)2.16E-03 6.27E-04 6.27E-04
CO2e Use 40CFR98 Use 40CFR98 Use 40CFR98
Weighted Sum
Carbon Dioxide Methane Nitrous Oxide CO2e
lb CO2/MMBtu lb CH4/MMBtu lb N2O/MMBtu lb CO2e/MMBtu
138,000 Btu/gal 1.63E+02 6.61E-03 1.32E-03 1.64E+02
91,000 Btu/gal 1.39E+02 6.61E-03 1.32E-03 1.39E+02
1,026 Btu/scf 1.17E+02 2.20E-03 2.20E-04 1.17E+02
CO2 CH4 N2O
1 28 265
Revised: 01/30/25
** Other/Trace HAPs include: Carbon Tetrachloride, Chlorobenzene, Chloroform, Dichloropropene, ,3-Dichloropropene, Ethylene Dibromide, Methylene Chloride, Naphthalene, Phenol, Propylene, Oxide, Styrene, 1,1,2,2-Tetrachloroethane, 1,1,2-Trichloroethane, and Vinyl Chloride (as per AP-42).
* Aldehyde (not measured in EPA Test Method 25)
Fuel Type
40CFR98 - Default Greenhouse Gas (GHG) Emission Factors
Default HHV
Table C-1 to Subpart C of Part 98 Table C-2 to Subpart C of Part 98
Natural Gas (External) Combustion
Use 40CFR98
AP-42 Table 1.4-1; 1.4-2; 1.4-3 (<100 MMBtu/hr) 07/98
Use Ext. Comb.CR
I
T
E
R
I
A
(*AP-42 shows V-HAP>VOC?)(#Lean Pre-Mix - aka: Dry Low Emissions (DLE or DLN) or SoLoNOx)
Potentially Applicable
AP-42 and GHG EMISSION FACTORS
(Preferentially use test data or vendor data where available)
Pollutant
Natural Gas-Fired Reciprocating Engines Stationary Gas-Fired Turbines
AP-42 Table 3.2-1; 3.2-2; 3.2-3 10/24 AP-42 Table 3.1-1; 3.1-2a; 3.1-3 04/00
CR
I
T
E
R
I
A
HA
P
s
GH
G
HA
P
s
Pollutant
Use Ext. Comb.
Use Ext. Comb.
AP-42 Emission Factors
Natural Gas
Propane
Fuel Oil No. 2 (Diesel)
Table A-1 to Subpart A of Part 98
Global Warming Potential (100 Yr) (GWP)
GH
G
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Attachment C-1
Supporting Documents

Representative Gas Analysis

• Inlet Gas – Summary

Sampled:2018-2024 Avg.NWP Moab Compressor Station Chromatagraph Gas Analysis GPSA-Sec 23
Water 109-86-4 H2O 18.015 --- --- --- --- --- --- --- --- ---
Carbon Dioxide 124-38-9 CO2 44.010 1 1.1128 0.4897 1,290.52 2.8724 --- --- --- ---
Hydrogen Sulfide 2148-87-8 H2S 34.086 2 --- --- --- --- --- ---637.6 ---
Nitrogen 7727-37-9 N2 28.013 3 0.4858 0.1361 358.64 0.7982 --- --- --- ---
Methane*75-82-8 CH4 16.042 4 94.1559 15.1049 39,804.07 88.5934 91.9692 ---1,010.0 950.975
Ethane*74-84-0 C2H6 30.069 5 4.0083 1.2052 3,176.04 7.0690 7.3384 ---1,769.7 70.934
Propane**74-98-6 C3H8 44.096 6 0.1855 0.0818 215.53 0.4797 0.4980 71.9208 2,516.2 4.667
iso-Butane**75-28-5 i-C4H10 58.122 7 0.0194 0.0113 29.71 0.0661 0.0686 9.9137 3,252.0 0.631
n-Butane**106-97-8 n-C4H10 58.122 8 0.0212 0.0124 32.55 0.0724 0.0752 10.8605 3,262.4 0.693
iso-Pentane**78-78-4 i-C5H12 72.149 9 0.0054 0.0039 10.27 0.0229 0.0237 3.4271 4,000.9 0.216
n-Pentane**109-66-0 n-C5H12 72.149 10 0.0033 0.0023 6.19 0.0138 0.0143 2.0644 4,008.9 0.130
Cyclopentane**287-92-3 C5H10 70.100 11 --- --- --- --- --- ---3,763.6 ---
Cyclohexane**110-82-7 C6H12 84.162 13 --- --- --- --- --- ---4,481.6 ---
Other Hexanes**Various C6H14 86.175 14 0.0024 0.0021 5.43 0.0121 0.0126 1.8135 4,750.3 0.114
Methylcyclohexane**108-87-2 C7H14 98.186 16 --- --- --- --- --- ---5,215.9 ---
C8+ Heavies**Various C8+138.00 est.22 --- --- --- --- --- ---7,000.0 ---
Benzene***71-43-2 C6H6 78.112 18 --- --- --- --- --- ---3,741.9 ---
Ethylbenzene***100-41-4 C8H10 106.165 20 --- --- --- --- --- ---5,222.0 ---
n-Hexane***110-54-3 C6H14 86.175 12 --- --- --- --- --- ---4,756.0 ---
Methanol***67-56-1 CH3OH 32.040 --- --- --- --- --- --- ---866.9 ---
Toluene***108-88-3 C7H8 92.138 19 --- --- --- --- --- ---4,474.9 ---
2,2,4-Trimethylpentane***540-84-1 C8H18 114.229 17 --- --- --- --- --- ---6,213.6 ---
Xylenes***1330-20-7 C8H10 106.165 21 --- --- --- --- --- ---5,208.7 ---
100.000 17.0497 44,928.95 100.00 --- ---1,028
98.401 16.4239 43,279.78 96.33 100.00 ---
0.237 0.1137 299.68 0.67 0.69 100.00
--- --- --- --- --- ---
20%
Mole %Wgt %lb/MMscf Wgt %lb/MMscf % VOC
1.1128 2.872 1,290.52 3.44%1,550.00 --- ---Margin
94.1559 88.593 39,804 95.00%42,750 --- ---Margin
4.4941 7.867 3,535 0.00%0 --- ---Margin
0.2372 0.667 299.68 0.80%360.00 100.00%20.1%Margin
100.0000 100.000 44,929 100.00%45,000 ---0.2%Margin
--- --- ---0.004%2.00 0.56% ---Margin
--- --- ---0.004%2.00 0.56% ---Margin
--- --- ---0.011%5.00 1.39% ---Margin
--- --- ---0.022%10.00 2.78% ---Margin
--- --- ---0.004%2.00 0.56% ---Margin
* = Hydrocarbon (HC) --- --- ---0.004%2.00 0.56% ---Margin
** = also Volatile Organic Compound (VOC) --- --- ---0.004%2.00 0.56% ---Margin
*** = also Hazardous Air Pollutant (HAP) --- --- ---0.06%25.00 6.94% ---Margin
Weight %VOC Component Btu/scf (HHV)
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Inlet Gas - Summary
Component CAS Formula Molecular Weight (MW) GRI #Mole %(M% = V%)
Margin for Changesin Future Gas CompositionMinimum VOC/HAP Margin:
CO2
GasBtu/scf (HHV)
#UGC (Universal Gas Constant) = 379.482 scf/lb-mol @ 60 oF and 14.6959 psia.
Calculated
Btu/scf
(HHV):
Totals:
THC:
lb "X"/scf =
(M% of "X") x (MW of "X") / #UGC
Total VOC:
Total HAP:
Wgt Sum(MW*MF)lb/MMscf(WS/UGC#)Weight %Total Weight %THC
Benzene***
Component Representative Inlet Gas Analysis Assumed "Worst-Case"
2,2,4-Trimethylpentane***
Methane*
Other (N2, C2, O2, CO, H2O)
VOC**
TOTAL GAS
Ethylbenzene***
n-Hexane***
Methanol***
Toluene***
Xylenes***
Total HAP***
Cisco Compressor Station Attachment C1 - Gas Analysis Notice of Intent ApplicationInlet Gas - Summary
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application
Attachment C-2
Supporting Documents

Vendor Data

Compressor Turbine
• Solar Centaur 50-5502S Compressor Turbine Specifications
o PIL 168 – VOC, SO2, and HCHO Emission Estimates
o PIL 170 – Emission Estimates at Start-up, Shutdown, and Commissioning
o PIL 171 – Particulate Matter Emission Estimates
o PIL 251 – Emissions from Gas Seal Systems
Emergency Generator Engine
• Caterpillar DG250 DC Emergency Generator Engine Specifications

Solar Turbines Emissions Estimates
C50-5502S
Assumptions: pipeline nat gas, 4390' elevation, 4/4" inlet/outlet losses
Load%
Amb.
Temp.
NOx
(ppm)
NOx
(lb/hr)CO (ppm)CO (lb/hr)
UHC
(ppm)
UHC
(lb/hr)
100 0 25 4.3 50 5.2 25 1.5
100 40 25 4.1 50 5.0 25 1.4
100 59 25 4.0 50 4.9 25 1.4
100 80 25 3.7 50 4.5 25 1.3
# Caterpillar: Confidential Green
Solar Turbines Incorporated Product Information Letter 187
PIL 168 Revision 9.1 1 20 June 2022

Caterpillar Non-Confidential

Volatile Organic Compound, Sulfur Dioxide,
and Formaldehyde Emission Estimates
Leslie Witherspoon

PURPOSE
This Product Information Letter (PIL) summarizes emission factors commonly utilized to estimate emissions of
volatile organic compounds (VOC), sulfur dioxide (SO2), and formaldehyde from gas turbines.
Volatile Organic Compounds
Many permitting agencies require gas turbine users to include emissions of VOC, a subpart of the unburned
hydrocarbon (UHC) emissions, during the air permitting process. Volatile organic compounds, non-methane
hydrocarbons (NMHC), and reactive organic gases (ROG) are different ways of referring to the non-methane (and
non-ethane) portion of an “unburned hydrocarbon” emission estimate.
For natural gas fuel, Solar’s customers often use 10-20% of the UHC emission rate to conservatively estimate VOC
emissions. Solar can offer a 5 ppm VOC warranty level upon request. For liquid fuel, it is appropriate to estimate
that 100% of the UHC estimate is VOC. The emissions estimates are assumed valid for natural gas at ambient
temperatures >-4°F (-20C) from 50-100% load (80-100% load for the Saturn® 20 and >-20°F (-29C) and 40-100%
for the Titan™ 250) and for liquid fuel from 65-100% load (80-100% for the Saturn 20 and Centaur® 40).
Environmental Protection Agency (EPA’s) AP-421 document and WebFIRE2 database also contain VOC emission
estimates for gas turbines. These sources are not commonly used by Solar’s customers.
Sulfur Dioxide
Sulfur dioxide emissions are produced by conversion of any sulfur in the fuel to SO2. Solar customers usually either
use a mass balance calculation or reference AP-42 to estimate SO2 emissions. Because Solar does not control the
amount of sulfur in the fuel, no SO2 emissions warranty is available.
The mass balance method assumes that any sulfur in the fuel converts to SO2. For reference, the typical mass
balance equation is shown below.
lb SO2
hr  = �wt% Sulfur
100 ��lb fuel
Btu ��106 Btu
MMBtu��MMBtu fuel
hr ��MW SO2
MW Sulfur�
Variables: wt% of sulfur in fuel
Btu/lb fuel (LHV)
MMBtu/hr fuel flow (LHV)

As an alternative to the mass balance calculation, EPA’s AP-42 document can be used. AP-42 (Table 3.1-2a, April
2000) suggests emission factors of 0.94S lb/MMBtu (HHV) (where S=Sulfur % in fuel) or 0.0034 lb/MMBtu (HHV)
for gas fuel and 1.01S lb/MMBtu (HHV) (where S=Sulfur% in fuel) or 0.33 lb/MMBtu (HHV) for liquid fuel.
__________________
1AP-42 is an EPA document containing a compilation of air pollutant emission factors by source category.
2 WebFIRE is an EPA electronic based repository and retrieval tool for emission factors.
PIL 168 Product Information Letter
Solar Turbines Incorporated
PIL 168 Revision 9.1 2 20 June 2022

Caterpillar Non-Confidential
Formaldehyde
For gas turbines, formaldehyde emissions are a result of incomplete combustion and are unstable in the exhaust
stream. In this section, regulatory background, recommended emission factors, and testing considerations are
discussed.
Regulatory Background and Emissions Factors – U.S. and EU
In 2004 the U.S. EPA published a Maximum Achievable Control Technology (MACT) standard (40 CFR 63 Subpart
YYYY) for natural gas fired combustion turbines with a formaldehyde limit of 91 ppb (15% O2). The standard was
stayed a few months later for the natural gas subcategories essentially rendering the regulation “on hold”. The
stay was lifted on March 9, 2022. After ~18 years of not having to comply with the MACT standard, natural gas
fired combustion turbines located at major sources of hazardous air pollutants need to comply with the standard.
The initial compliance date is September 4, 2022. With the lifting of the stay, four of the eight subcategories
outlined in the Subpart YYYY must comply with the MACT standard. They are:
- stationary lean premix combustion turbines when firing gas and when firing oil at sites
where all turbines fire oil no more than an aggregate total of 1,000 hours annually
- stationary lean premix combustion turbines when firing oil at sites where all turbines fire oil
more than an aggregate total of 1,000 hours annually
- stationary diffusion flame combustion turbines when firing gas and when firing oil at sites
where all turbines fire oil no more than an aggregate total of 1,000 hours annually
- stationary diffusion flame combustion turbines when firing oil at sites where all turbines fire
oil more than an aggregate total of 1,000 hours annually
For U.S. customers with a combustion turbine that must comply with Subpart YYYY, an emission factor of 91 ppb
@ 15% O2 (~0.00021 lb/MMBtu HHV) is recommended.
The formaldehyde emissions estimate of 91 ppb @15%O2 (~0.00021 lb/MMbtu HHV) can be used for all new,
current production, SoLoNOx models and ratings when firing pipeline quality natural gas or ultra-low sulfur (ULSD)
diesel fuel. The emissions estimate is valid for natural gas from 50-100% load (40-100% load for Titan 250) or for
liquid fuel from 65-100% load (80-100% load for the Centaur 40) and at ambient temperatures >-4°F (-20C) [> -20
°F (-29C) for Titan 250].
Alternative emission factors for combustion turbines not affected by Subpart YYYY (or non-U.S. based combustion
turbines) are from U.S. EPA’s AP-42 document and are 0.00071 lb/MMBtu (HHV) for natural gas and 0.00028
lb/MMBtu (HHV) for distillate oil0F3. Note that both of the aforementioned formaldehyde emission factors are higher
than the MACT standard. Since ~2003 many gas turbine users have used the emission factors found in an EPA
memo Revised HAP Emission Factors for Stationary Combustion Turbines1F4 for estimating hazardous air pollutant
emissions. The memo presents hazardous air pollutant emission factor data in several categories. While the
memo presents several formaldehyde emissions factors, the most common formaldehyde emission factor used
to estimate emissions from gas turbines from this document is 0.00288 lb/MMBtu HHV (Table 16). Note that this
emission factor is an order of magnitude higher than the MACT standard.
In the EU, Germany has established a formaldehyde limit of 5 mg/Nm3 for combustion turbines (13.BlmSchV
Section 33). This limit applies for operation at 70-100% load and it is anticipated that something similar will be
adopted in other EU member states. The 5 mg/Nm3 limit is equivalent to ~0.0038 kg/GJ or ~3.7 ppm.
Formaldehyde Emissions Testing Considerations
Actual emissions of formaldehyde from Solar’s gas turbines, in the SoLoNOx operating range, are predicted to be
less than 91 ppb @15%O2. However, the 91 ppb level can only be verified if the proper testing equipment is
utilized. To properly measure formaldehyde emissions, Fourier Transform Infrared (FTIR) instrumentation with
limits of detection well below the standard must be utilized. Most “traditional” FTIR systems have formaldehyde

3 AP-42, Table 3.1-3 for Natural Gas and Table 3.1-4 for Distillate Oil, 4/00. 4 Revised HAP Emission Factors for Stationary Combustion Turbines, OAR-2002-0060, IV-B-09,8/22/03.
Solar Turbines Incorporated
PIL 168 Revision 9.1 3 20 June 2022

Caterpillar Non-Confidential
limits of detection in the 120-150 ppb range and are not suitable to measure formaldehyde from combustion
turbines.
Solar recommends the MKS Multi Gas 2030 FTIR with StarBoost™ System, the Spectrum WaveRunIR-EXT or an
equivalent system with similar path lengths and detection levels.
EPA Method 320 (or equivalent method for non-U.S. testing) should be used to measure formaldehyde. Testing
should include three – 120-minute test runs. To ensure accurate formaldehyde measurements, the testing
company, in addition to following the requirements of Method 320 (or equivalent method), should take necessary
steps to optimize signal-to-noise, verify the FTIR is fully temperature stabilized and purged, ensure the FTIR signal
is optimized before testing by maximizing alignment and cleanliness of optics, minimize sampling line bias by using
clean sample lines at 250°F to prevent off-gassing and minimize contamination with other compounds, verify
absence of sampling system bias via system zero measurements, measure a source specific moisture spectrum
while at the test site using a water/N2 delivery systems at +/-10% of turbine moisture content, and use the source
specific water spectrum as an interferent in the analysis.

Neither Solar Turbines Incorporated nor its affiliates shall be held liable for any improper, unauthorized, or incorrect use of the information
described and/or contained herein and assumes no responsibility for anyone’s use of the information contained herein. No warranty, express
or implied, is made regarding accuracy, adequacy, completeness, legality, reliability or usefulness of any information. Solar Turbines
Incorporated provides this information on an “as is” basis. Any and all warranties of any kind, express or implied, including but not limited to
the implied warranties of merchantability, fitness for a particular purpose, and non-infringement of proprietary rights are disclaimed.
Caterpillar is a registered trademark of Caterpillar Inc. Solar, Titan, Mars, Taurus, Mercury, Centaur, Saturn, SoLoNOx, InSight Platform and
Turbotronic are trademarks of Solar Turbines Incorporated. All other trademarks are the intellectual property of their respective companies.
© 2022 Solar Turbines Incorporated. Specifications subject to change without notice. All rights reserved.
Solar Turbines Incorporated Product Information Letter 187
PIL 170 Revision 12 1 25 August 2022

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Emission Estimates at Start-up, Shutdown, and
Commissioning for SoLoNOx™ Combustion Products
Leslie Witherspoon

PURPOSE
The purpose of this Product Information Letter (PIL) is to provide emission estimates for start-up and shutdown
events for Solar® gas turbines with SoLoNOx™ dry low emissions combustion systems.1 For start-up and shutdown
emissions estimates for conventional combustion turbines, landfill gas, digester gas, or other alternative fuel
applications, contact Solar’s Environmental Programs team.
INTRODUCTION
The information presented in this document is representative for both generator set (GS) and compressor
set/mechanical drive (CS/MD) SoLoNOx combustion turbine applications. Operation of duct burners and/or any
add-on control equipment is not accounted for in the emissions estimates. Emissions estimates related to the
start-up, shutdown, and commissioning of combustion turbines will not be warranted. The estimates in this
document are based on limited engine testing and analysis. The engine testing was conducted at idle and other
non-SoLoNOx mode load points. An actual start-up/shutdown event was not measured.
The start-up and shutdown estimates are most commonly used for potential to emit calculations to determine air
permitting status. Solar discourages customers from accepting the estimates in this document as permit limits,
with or without source testing requirements. Accurately measuring emissions during a – non-steady state – start-
up or shutdown event with steady state source test methods may prove to be very challenging. In the event
customers take permit limits and accept compliance testing permit conditions, Solar recommends adding
significant margin to the estimates in this document.
START-UP PROCESS
The duration of a nominal start-up is the same for a cold start, warm start, or hot start (e.g., a Solar Turbine is
programmed to start-up in “x” minutes whether it’s a cold, warm, or hot start).
The start-up and shutdown time for a Solar turbine in a simple-cycle or combine heat and power application is the
same. Heat recovery steam generator (HRSG) steam pressure is usually 250 psig or less. At 250 psig or less,
thermal stress within the HRSG is minimized and, therefore, firing ramp-up/ramp-down is not limited. However,
some combined heat and power plant applications will desire or dictate longer start-up/shutdown times due to
external requirements.
The start-up sequence and attaining SoLoNOx combustion mode takes three steps:
1. Purge-crank
2. Ignition and acceleration to idle
3. Loading/thermal stabilization

________________
1Start-up and shutdown emissions for the Mercury™50 engine are found in PIL 205
PIL 170

Product Information Letter
Solar Turbines Incorporated
PIL 170 Revision 12 2 25 August 2022

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar
During the “purge-crank” step, rotation of the turbine shaft is accomplished with a starter motor to remove any
residual fuel gas in the engine flow path and exhaust. During “ignition and acceleration to idle,” fuel is introduced
into the combustor and ignited in a diffusion flame mode and the engine rotor is accelerated to idle speed.
The third step consists of applying up to 50% load2 while allowing the combustion flame to transition and stabilize.
Once 50% load is achieved, the turbine transitions to SoLoNOx combustion mode and the engine control system
begins to maintain the combustion primary zone temperature and limit pilot fuel to achieve the targeted nitrogen
oxides (NOx), carbon monoxide (CO), and unburned hydrocarbons (UHC) emission levels.
SHUTDOWN PROCESS
Normal, planned cool down/shutdown duration varies by engine model. Once the shutdown process starts the
engine unloads and moves into a cooldown mode.
START-UP AND SHUTDOWN EMISSIONS ESTIMATES
Tables 1 through 5 summarize the estimated pounds of emissions per start-up and shutdown event for SoLoNOx
products. The mass emissions estimates are calculated using exhaust characteristics at ISO conditions in
conjunction with ppm emissions estimates at various load points. The estimates in Tables 1 and 2 are
representative of new production units ordered from 2006 up until the implementation of Enhanced Emissions
Control (EEC). Tables 3 and 4 summarize emissions estimates for turbine models and ratings equipped with EEC.
Enhanced Emission Control is a control regime that will result in lower CO and UHC values at lower loads thus
reducing the estimated emissions per start-up and shutdown sequence. The Titan™ 250 and the Titan 130
23001/23502 (and 22401/22402) ratings have always been equipped with EEC. As testing is completed and other
models/ratings are qualified and able to be equipped with the updated controls PIL170 will be updated. Reference
PIL 220, specifically pages 7 and 8, for additional information about Enhanced Emission Control. Table 5
summarizes start-up and shutdown emissions estimates for liquid fuel applications.
Please contact Solar Environmental Programs, Leslie Witherspoon (858.694.6609) or Anthony Pocengal
(858.505.8554) for support.
COMMISSIONING EMISSIONS
Commissioning generally takes place over a two-week period. Static testing, where no combustion occurs, usually
requires one week and no emissions are expected. Dynamic testing, where combustion will occur, typically
includes a number of engine start and shutdown cycles and a variety of loads will be placed on the system. It is
impossible to predict how long the turbine will run and in what combustion/emissions mode it will be running. The
dynamic testing period is generally followed by one to two days of final commissioning during which the turbine is
running at various loads.

________________
240% load for the Titan 250 Engine on natural gas. 65% load for all engines on liquid fuel (except 80% load for the Centaur™ 40).
Solar Turbines Incorporated
PIL 170 Revision 12 3 25 August 2022

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar
Table 1: Estimation of Start-up and Shutdown Emissions (lbs/event) for SoLoNOx Generator Set Applications
Nominal Start-up and Shutdown, Natural Gas Fuel
Production Units from 2006 and without Enhanced Emissions Control
Emissions estimates will NOT be warranted.
Engine Total Emissions Per Start (lbs) Total Emissions Per Shutdown (lbs)
NOx CO UHC VOC CO2 NOx CO UHC VOC CO2
Centaur 40 4701S 1 66 62 12 247 1 67 67 13 228
Centaur 50 6201S 1 67 84 17 333 1 67 88 18 316
Taurus™ 60 7901S 1 86 110 22 338 1 89 119 24 311
Taurus 65 8701S 1 74 67 13 376 1 75 74 15 347
Taurus 70 10801S 1 78 67 13 544 1 58 52 10 411
Mars™ 90 13000S GSC 1 84 41 8 640 1 80 44 9 605
Mars 100 15000S/16000S GSC 1 81 39 8 669 1 76 42 8 616
Titan 130 20501S 3 172 138 28 832 3 174 151 30 768
Assumes ISO conditions: 59°F, 60% RH, sea level, no losses.
Assumes unit is operating at >50% load prior to shutdown.
Assumes natural gas fuel; ES 9-98 (Fuel Air and Water or Steam for Solar Gas Turbine Engines) compliant.

Solar Turbines Incorporated
PIL 170 Revision 12 4 25 August 2022

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar
Table 2: Estimation of Start-up and Shutdown Emissions (lbs/event) for SoLoNOx CS/MD Applications
Nominal Start-up and Shutdown, Natural Gas Fuel
Production Units from 2006 and without Enhanced Emissions Control
Emissions estimates will NOT be warranted.
Engine Total Emissions Per Start (lbs) Total Emissions Per Shutdown (lbs)
NOx CO UHC VOC CO2 NOx CO UHC VOC CO2
Centaur 40 4702S 1 21 17 3 188 1 19 18 4 194
Centaur 50 6102S 1 21 17 3 184 1 20 19 4 169
Taurus 60 7802S 1 22 17 3 180 1 20 18 4 161
Taurus 70 10802S 1 88 88 18 381 1 78 83 17 295
Mars 90 13000S CS/MD 1 45 20 4 437 1 56 28 6 590
Mars 100 15000S/16000S CS/MD 1 46 20 4 385 1 58 28 6 490
Titan 130 20502S 1 55 37 7 662 1 61 43 9 751
Assumes ISO conditions: 59°F, 60% RH, sea level, no losses.
Assumes unit is operating at >50% load prior to shutdown.
Assumes natural gas fuel; ES 9-98 (Fuel Air and Water or Steam for Solar Gas Turbine Engines) compliant.

Solar Turbines Incorporated
PIL 170 Revision 12 5 25 August 2022

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar
Table 3: Estimation of Start-up and Shutdown Emissions (lbs/event) for SoLoNOx Generator Set Applications
Nominal Start-up and Shutdown, Natural Gas Fuel
Production Units with Enhanced Emissions Control
Emissions estimates will NOT be warranted.

Engine Total Emissions Per Start (lbs) Total Emissions Per Shutdown (lbs)
NOx CO UHC VOC CO2 NOx CO UHC VOC CO2
Taurus 60 7901S GSC 1 42 24 5 368 1 50 28 6 345 (Post 9/2020 Orders)
Taurus 70 10801S 1 21 26 5 552 1 16 21 4 419 GSC (Post 2/2018 Orders)
Taurus 70 11101S 1 21 27 5 563 1 17 22 4 427 GSC (Post 2/2018 Orders)
Mars 90 13000S GSC 1 23 20 4 727 1 25 20 4 682 (Post 9/2020 Orders)
Mars 100 15000S GSC 1 40 34 7 760 1 44 36 7 710 (Post 9/2020 Orders)
Mars 100 16000S GSC 1 32 26 5 789 1 35 27 5 733 (Post 8/2017 Orders)
Titan 130 19501S
(Post 9/2020 Orders) 1 15 17 3 842 1 15 17 3 795
Titan 130 20501S 1 18 21 4 839 1 19 22 4 782 (Post 2/2018 Orders)
Titan 130 23001S 1 24 28 6 943 1 26 30 6 885 (All Units)
Titan 250 30000S GSC 2 42 22 4 1502 2 33 17 3 1159 (All Units)
Titan 250 31900S GSC 2 32 18 4 1280 2 26 14 3 975 (All Units)
Assumes ISO conditions: 59°F, 60% RH, sea level, no losses.
Assumes unit is operating at >50% load prior to shutdown.
Assumes natural gas fuel; ES 9-98 (Fuel Air and Water or Steam for Solar Gas Turbine Engines) compliant.

Solar Turbines Incorporated
PIL 170 Revision 12 6 25 August 2022

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar
Table 4: Estimation of Start-up and Shutdown Emissions (lbs/event) for SoLoNOx CS/MD Applications
Nominal Start-up and Shutdown, Natural Gas Fuel
Production Units with Enhanced Emissions Control
Emissions estimates will NOT be warranted.
Engine Total Emissions Per Start (lbs) Total Emissions Per Shutdown (lbs)
NOx CO UHC VOC CO2 NOx CO UHC VOC CO2
Taurus 60 7802S 1 6 5 1 247 1 7 6 1 235 (Post 9/2020 Orders)
Taurus 70 10802S 1 20 28 6 381 1 19 27 5 295 (Post 2/2018 Orders)
Mars 90 13000S CS/MD 1 17 12 2 437 1 24 18 4 564 (Post 9/2020 Orders)
Mars 100 15000S CS/MD 1 20 13 3 474 1 30 18 4 612 (Post 9/2020 Orders)
Mars 100 16000S CS/MD 1 19 13 3 496 1 28 19 4 642 (Post 8/2017 Orders)
Titan 130 20502S 1 11 6 1 682 1 14 8 2 762 (Post 9/2020 Orders)
Titan 130 22402S 1 13 15 3 690 1 15 17 3 775 (All Units)
Titan 130 23502S 1 17 19 4 767 1 20 23 5 869 (All Units)
Titan 250 30000S CS/MD 2 33 13 3 1172 2 28 11 2 1036 (All Units)
Titan 250 31900S CS/MD 1 21 8 2 987 1 18 7 1 880 (All Units)

Assumes ISO conditions: 59°F, 60% RH, sea level, no losses.
Assumes unit is operating at >50% load prior to shutdown.
Assumes natural gas fuel; ES 9-98 (Fuel Air and Water or Steam for Solar Gas Turbine Engines) compliant.

Solar Turbines Incorporated
PIL 170 Revision 12 7 25 August 2022

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Table 5: Estimation of Start-up and Shutdown Emissions (lbs/event) for SoLoNOx Generator Set Applications
Nominal Start-up and Shutdown, Liquid Fuel (Diesel #2)
Emissions estimates will NOT be warranted.
Engine Total Emissions per Start (lbs) Total Emissions per Shutdown (lbs)
NOx CO UHC VOC CO2 NOx CO UHC VOC CO2
Centaur 40 4701S 1 11 1 1 420 1 12 1 1 388
Centaur 50 6201S 1 15 1 1 471 1 17 1 1 439
Taurus 60 7901S 1 14 1 1 510 1 16 1 1 467
Taurus 70 10801S 2 27 2 2 754 1 22 1 1 568
Mars 100 16000S GSC 2 19 1 1 821 2 25 2 2 804
Titan 130 20501S 2 32 2 2 1189 2 35 2 2 1106
Titan 130 23001S 2 27 2 2 1231 2 29 2 2 1132
Titan 250 30000S GSC 5 7 1 1 2188 4 6 1 1 1656
Titan 250 31900S GSC 4 5 1 1 2172 3 4 1 0 1643

Assumes ISO conditions: 59°F, 60% RH, sea level, no losses.
Assumes unit is operating at >50% load prior to shutdown.
Assumes natural gas fuel; ES 9-98 (Fuel Air and Water or Steam for Solar Gas Turbine Engines) compliant.

Neither Solar Turbines Incorporated nor its affiliates shall be held liable for any improper, unauthorized, or incorrect use of the information
described and/or contained herein and assumes no responsibility for anyone’s use of the information contained herein. No warranty, express
or implied, is made regarding accuracy, adequacy, completeness, legality, reliability or usefulness of any information. Solar Turbines
Incorporated provides this information on an “as is” basis. Any and all warranties of any kind, express or implied, including but not limited to
the implied warranties of merchantability, fitness for a particular purpose, and non-infringement of proprietary rights are disclaimed.
Caterpillar is a registered trademark of Caterpillar Inc. Solar, Titan, Mars, Taurus, Mercury, Centaur, Saturn, SoLoNox, InSight Platform and
Turbotronic are trademarks of Solar Turbines Incorporated. All other trademarks are the intellectual property of their respective companies.
© 2022 Solar Turbines Incorporated. Specifications subject to change without notice. All rights reserved.
Solar Turbines Incorporated Product Information Letter 187
PIL 171 Revision 7 1 3 April 2023

Caterpillar Non-Confidential

Particulate Matter Emission Estimates
Leslie Witherspoon

PURPOSE
This Product Information Letter (PIL) summarizes Solar’s recommended PM10/2.5 emission levels for our combustion
turbines. The recommended levels are based on an analysis of emissions tests collected from customer sites.
PARTICULTE MATTER DEFINITION
National Ambient Air Quality Standards (NAAQS) for particulate matter were first set in 1971. Total suspended
particulate (TSP) was the first indicator used to represent suspended particles in the ambient air. Since July 1,
1987, the Environmental Protection Agency (EPA) has used the indicator PM10, which includes only the particles
with aerodynamic diameter smaller than 10 micrometers (µm). PM10 (coarse particles) come from sources such as
windblown dust from the desert or agricultural fields and dust kicked up on unpaved roads by vehicle traffic.
The EPA added a PM2.5 ambient air standard in 1997. PM2.5 includes particles with an aerodynamic diameter less
than 2.5 µm. PM2.5 (fine particles) are generally emitted from industrial and residential combustion and from vehicle
exhaust. Fine particles are also formed in the atmosphere when gases such as sulfur dioxide, nitrogen oxide, and
volatile organic compounds, emitted by combustion activities, are transformed by chemical reactions.
Nearly all particulate matter from gas turbines exhaust is less than one micrometer (micron) in diameter. Thus the
emission rates of TSP, PM10, and PM2.5 from gas turbines are theoretically equivalent although source testing will
show variation due to test method detection levels and processes.
TESTING FOR PARTICULATE MATTER
The turbine combustion process has little effect on the particulate matter generated and measured. The largest
contributor to particulate matter emissions for gas and liquid fired combustion turbines is measurement technique
and error. Other, minor contributing, sources of particulate matter emissions include carbon, ash, fuel-bonded
sulfur, artifact sulfate formation, compressor/lubricating oils, and inlet air.
Historical customer particulate matter source test data show that there is significant variability from test to test.
The source test results support the common industry argument that particulate matter from natural gas fired
combustion sources is difficult to measure accurately. The reference test methods for particulate matter were
developed primarily for measuring emissions from coal-fired power plants and other major emitters of particulates.
Particulate concentrations from gas turbine can be 100 - 10,000 times lower than the “traditional” particulate
sources. The test methods were not developed or verified for low emission levels. There are interferences,
insignificant at higher exhaust particulate matter concentrations that result in emissions greater than the actual
emissions from gas turbines. New methods are being developed to address this problem.
Due to measurement and procedural errors, the measured results may not be representative of actual particulate
matter emitted. There are many potential error sources in measuring particulate matter. Most of these have to do
with contamination of the samples, material from the sampling apparatus getting into the samples, and human
error in samples and analysis. Over the past few years, source test firms are gaining experience in measuring
particulate matter and the historical variability from test to test and the emissions levels measured have decreased.

PIL 171 Product Information Letter
Solar Turbines Incorporated
PIL 171 Revision 7 2 3 April 2023

Caterpillar Non-Confidential
RECOMMENDED PARTICULATE MATTER EMISSION FACTORS
When necessary to support the air permitting process Solar recommends the following PM10/2.5 emission factors
for all models and ratings except for the Mercury™ 50. Please refer to PIL 205 for the Mercury 50. The emission
factors below are intended to include both the front half (filterable) and the back half (condensable).
• Pipeline Natural Gas* and Natural Gas/Hydrogen Blends&: 0.006 lb/MMBtu fuel input (HHV)
• Landfill/Digester Gas+: 0.02 lb/MMBtu fuel input (HHV)
• Liquid Fuel#: 0.01 lb/MMBtu fuel input (HHV)
*Pipeline natural gas emissions factor assumes <1 grains of Sulfur per 100 standard cubic feet.
&Natural Gas/Hydrogen Blends can utilize the same emission factors as 100% natural gas.
+Landfill/digester gas emissions factor assumes <.15lb SO2/MMBtu heat input
#Liquid fuel emission factor assumes fuel Sulfur content is <500 ppm and ash content is <0.005% by wt.
Contact Solar’s Environmental Programs group for particulate matter emissions estimates for fuels not listed
above.
The conversion of particulate matter emissions request from mg/Nm3 to lb/MMBtu (HHV) units involves several
specific turbine parameters. Please contact Solar if you need the calculation performed.

TEST METHOD RECOMMENDATION
Solar recommends that EPA Methods 201/201A1 be used to measure the “front half.” “Front half” represents
filterable particulate matter.
EPA Method 2022 (with Nitrogen purge and field blanks) should be used to measure the “back half.” “Back half”
measurements represent the condensable portion of particulate matter.
EPA Method 53, which measures the front and back halves may be substituted (e.g. where exhaust temperatures
do not allow the use of Method 202).
The turbine should have a minimum of 300 operating hours prior to conducting particulate matter source testing.
The turbine should be running for 3-4 hours prior to conducting a particulate matter source test so that the turbine
and auxiliary equipment is in a sustained “typical” operating mode prior to gathering samples.
Testing should include three 4-hour test runs.
Solar recommends using the aforementioned test methods until more representative test methods are developed
and widely commercially available.
REFERENCES
1EPA Method 201, Determination of PM10 Emissions, Exhaust Gas Recycle Procedure. EPA Method 201A.
Determination of PM10 Emissions, Constant Sampling Rate Procedure, 40 CFR 60, Part 60, Appendix A.
2EPA Method 202, Determination of Condensable Particulate Emissions from Station Sources, 40 CFR 60, Part 60.
Appendix A.
3EPA Method 5, Determination of Particulate Emissions from Station Sources, 40 CFR 60, Part 60, Appendix A.
Neither Solar Turbines Incorporated nor its affiliates shall be held liable for any improper, unauthorized, or incorrect use of the information
described and/or contained herein and assumes no responsibility for anyone’s use of the information contained herein. No warranty, express
or implied, is made regarding accuracy, adequacy, completeness, legality, reliability or usefulness of any information. Solar Turbines
Incorporated provides this information on an “as is” basis. Any and all warranties of any kind, express or implied, including but not limited to
the implied warranties of merchantability, fitness for a particular purpose, and non-infringement of proprietary rights are disclaimed.
Caterpillar is a registered trademark of Caterpillar Inc. Solar, Titan, Mars, Taurus, Mercury, Centaur, Saturn, SoLoNOx, InSight Platform and
Turbotronic are trademarks of Solar Turbines Incorporated. All other trademarks are the intellectual property of their respective companies.
© 2023 Solar Turbines Incorporated. Specifications subject to change without notice. All rights reserved.
Solar Turbines Incorporated Product Information Letter 187
PIL 251 Revision 1 1 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Emissions from Centrifugal Compressor
Dry Gas Seal System
Anthony Pocengal and Sean Garceau

PURPOSE
This product information letter (PIL) provides estimates of methane emitted from the dry gas seal systems installed
in Solar® centrifugal gas compressors.
INTRODUCTION
The standard design of dry seal systems includes characteristic ‘seal leakage’ which in most configurations results
in methane emissions to the atmosphere from the primary seal vent. Figure 1 below shows a cutaway diagram of
a typical compressor shaft and dry seal system showing some of the basic components. The primary seal uses a
high-pressure seal gas to maintain the process gas within the gas compressor body. The seal gas is typically
pressurized process gas, i.e. methane for a typical natural gas compression station, and since the seal gas pressure
is slightly higher than the suction and discharge pressures, most of the seal gas is returned to the compression
process thru the labyrinth seal passage. A portion of the seal gas leaks across the primary seal face per design
and is emitted through the primary vent to atmosphere. The volume of methane emitted from the seal vent is
directly proportional to the operating suction pressure of the gas compressor.

Figure 1: Centrifugal Compressor Dry Gas Seal System – Basic Components
Solar offers a dry seal emissions recompression system which captures the emissions from the primary vent and
allows routing of these emissions back into the compression process or for another beneficial use onsite. Solar PIL
279 has further information on this application which virtually eliminates methane emissions from the dry seal
system.
PIL 251 Product Information Letter
Solar Turbines Incorporated
PIL 251 Revision 1 2 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar
DRY GAS SEAL EMISSIONS DATA
The figures below may be used to estimate dry gas seal emissions (‘seal leakage’) emitted through the primary
vent based on the compressor suction pressure (P1). The charts show the maximum expected leakage rates per
each compressor. Actual emissions are expected to be lower.
For further technical information on Dry Gas Seal systems refer to PIL 140 Dry Gas Face Seals for Solar Gas
Compressors.
Note regarding PIL 140: The maximum dynamic leakage rates from PIL 140 Table 1a are the highest possible
guaranteed flow rates and are based on maximum allowable speed and pressure and should not be utilized for
emission inventories or expected emissions from Solar compressors.
TABLE OF FIGURES
Centrifugal compressor dry gas seal leakage estimates
Figure 1: Centrifugal Compressor Dry Gas Seal System – Basic Components ........................................................ 1
Figure 2: C16, C28 ...................................................................................................................................................... 3
Figure 3: C160K, C166K ............................................................................................................................................. 3
Figure 4: C160R, C160, C166SB, C166V, C168V, C169V .......................................................................................... 4
Figure 5: C31 .............................................................................................................................................................. 4
Figure 6: C304, C306, C33, C33i, C33E, C33EL, C337i, C401 ................................................................................... 5
Figure 7: C33EH, C404A, C404B, C406A, C406B ...................................................................................................... 5
Figure 8: C41 .............................................................................................................................................................. 6
Figure 9: C45 .............................................................................................................................................................. 6
Figure 10: C505J ......................................................................................................................................................... 7
Figure 11: C505U ........................................................................................................................................................ 7
Figure 12: C51 ............................................................................................................................................................ 8
Figure 13: C61 ............................................................................................................................................................ 8
Figure 14: C65 ........................................................................................................................................................... 9
Figure 15: C75 ........................................................................................................................................................... 9
Figure 16: C85 ......................................................................................................................................................... 10
The charts shown below provide estimates for the seal leakage from the two primary dry gas seals on Solar gas
compressors. The dry gas seal leakage flow is a function of the compressor suction pressure. The charts show
seal gas vented flow (scfm) vs compressor suction pressure (psig)

Solar Turbines Incorporated
PIL 251 Revision 1 3 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 2: C16, C28

Figure 3: C160K, C166K

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Solar Turbines Inc.
Compressor Model: C160
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
0 500 1000 15000
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Solar Turbines Inc.
Compressor Model: C160K, C166K
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Solar Turbines Incorporated
PIL 251 Revision 1 4 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 4: C160R, C160, C166SB, C166V, C168V, C169V

Figure 5: C31

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Solar Turbines Inc.
Compressor Model: C160R, C160, C166SB, C166V, C168V. C169V
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
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Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C31
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Solar Turbines Incorporated
PIL 251 Revision 1 5 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 6: C304. C306, C33, C33i, C33E, C33EL, C337i, C401

Figure 7: C33EH, C404A, A404B, C406A, C406B

0 500 1000 15000
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Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C304, C306, C33, C33i, C33E, C33EL, C337i, C401
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
0 500 1000 15000
5
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30
Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C33EH, C404A, C404B, C406A, C406B
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Solar Turbines Incorporated
PIL 251 Revision 1 6 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 8: C41

Figure 9: C45

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Solar Turbines Inc.
Compressor Model: C41
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
0 500 1000 15000
5
10
15
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25
30
Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C45
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Solar Turbines Incorporated
PIL 251 Revision 1 7 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 10: C505J

Figure 11: C505 U

0 100 200 300 400 500 6000
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Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C505J
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
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Solar Turbines Inc.
Compressor Model: C505U
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Solar Turbines Incorporated
PIL 251 Revision 1 8 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 12: C51

Figure 13: C61
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Solar Turbines Inc.
Compressor Model: C51
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
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Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C61
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Solar Turbines Incorporated
PIL 251 Revision 1 9 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 14: C65

Figure 15: C75

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Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C65
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
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Suction Pressure psig
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Solar Turbines Inc.
Compressor Model: C75
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Solar Turbines Incorporated
PIL 251 Revision 1 10 22 May 2020

Caterpillar Confidential Green: Information contained herein is to be treated as Confidential and Proprietary to Caterpillar

Figure 16: C85

SUMMARY
The figures provided in this PIL may be used to estimate dry gas seal emissions (‘seal leakage’) emitted through
the primary vent based on the compressor suction pressure (P1). The charts show the maximum expected leakage
rates per each compressor. Actual emissions are expected to be lower. For further technical information on Dry
Gas Seal systems refer to PIL 140 Dry Gas Face Seals for Solar Gas Compressors.

Neither Solar Turbines Incorporated nor its affiliates shall be held liable for any improper or incorrect use of the information described and/or
contained herein and assumes no responsibility for anyone’s use of the information. No warranty, express or implied, is made regarding
accuracy, adequacy, completeness, legality, reliability or usefulness of any information. Solar Turbines Incorporated provides this information
on an “as is” basis. All warranties of any kind, express or implied, including but not limited to the implied warranties of merchantability, fitness
for a particular purpose, and non-infringement of proprietary rights are disclaimed.
Caterpillar is a registered trademark of Caterpillar Inc. Solar, Titan, Mars, Taurus, Mercury, Centaur, Saturn, SoLoNox, InSight Platform and
Turbotronic are trademarks of Solar Turbines Incorporated. All other trademarks are the intellectual property of their respective companies.
© 2020 Solar Turbines Incorporated. Specifications subject to change without notice. All rights reserved.
0 500 1000 15000
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Solar Turbines Inc.
Compressor Model: C85
Total Gas Seal Gas Vented
SG: 0.59701 - Gas K: 1.2799 - Gas Temperature: 120° F
Results based on the maximum dry gas seal dynamic leakage flow seal
Solar Turbines Incorporated

12-Mar-2020
Williams
Northwest Pipeline
Cisco CS
Caterpillar DG250 GC
250kW Gas Standby
Generator Set
480 Volts, 60 Hertz
For Review
Project Manager: Ken Arsenault – 713-416-7800 – [e-mail]
Submittal # 119027-000_R1 WPO 180003
11/04/2024 1
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
2024 MODEL YEAR
CERTIFICATE OF CONFORMITY
WITH THE CLEAN AIR ACT
OFFICE OF TRANSPORTATION
AND AIR QUALITY
ANN ARBOR, MICHIGAN 48105
Certificate Issued To: Generac Power Systems, Inc.
(U.S. Manufacturer or Importer)
Certificate Number: RGNXB14.22C1-031
Effective Date:
10/25/2023
Expiration Date:
12/31/2024
_________________________
Byron J. Bunker, Division Director
Compliance Division
Issue Date:
10/25/2023
Revision Date:
N/A
Manufacturer: Generac Power Systems, Inc.
Engine Family: RGNXB14.22C1
Mobile/Stationary Certification Type: Stationary
Fuel : Natural Gas (CNG/LNG)
Emission Standards :
Part 60 Subpart JJJJ Table 1
CO ( g/Hp-hr ) : 4.0
NOx ( g/Hp-hr ) : 2.0
VOC ( g/Hp-hr ) : 1.0
Emergency Use Only : Y
Pursuant to Section 213 of the Clean Air Act (42 U.S.C. section 7547) and 40 CFR Part 60, 1065, 1068, and 60 ( stationary only and combined stationary and mobile ) and subject to the terms and conditions
prescribed in those provisions, this certificate of conformity is hereby issued with respect to the test engines which have been found to conform to applicable requirements and which represent the following
nonroad engines, by engine family, more fully described in the documentation required by 40 CFR Part 60 and produced in the stated model year.
This certificate of conformity covers only those new nonroad spark-ignition engines which conform in all material respects to the design specifications that applied to those engines described in the
documentation required by 40 CFR Part 60 and which are produced during the model year stated on this certificate of the said manufacturer, as defined in 40 CFR Part 60. This certificate of conformity does
not cover nonroad engines imported prior to the effective date of the certificate.
It is a term of this certificate that the manufacturer shall consent to all inspections described in 40 CFR 1068.20 and authorized in a warrant or court order. Failure to comply with the requirements of such a
warrant or court order may lead to revocation or suspension of this certificate for reasons specified in 40 CFR Part 60. It is also a term of this certificate that this certificate may be revoked or suspended or
rendered void ab initio for other reasons specified in 40 CFR Part 60.
This certificate does not cover large nonroad engines sold, offered for sale, or introduced, or delivered for introduction, into commerce in the U.S. prior to the effective date of the certificate.
11/04/2024 11
Cat® DG250 GC
SPARK-IGNITED GENERATOR SETS
Image shown may not reflect actual configuration.
Natural Gas
Three-Phase 277/480 VAC @0.8pf 248.4 kW Amps: 376
Standby/Demand Response
250 ekW
313 kVA – 60 Hz
UL2200: Evaluated by ETL to UL Standard for Safety UL2200CSA: Designed in accordance to CSA22.2 standards NFPA: Facilitates compliance with NFPA110Type 10: Product was tested to NFPA110 Type 10
SPECIFICATIONS
Engine
Engine Model 14.2 L, In-line 6, 4-cycle
Bore x Stroke 135 mm x 165 mm (5.31 in x 6.50 in)
Displacement 14.17 L (864.71 in³)
Compression Ratio 9.5:1
Aspiration Turbocharged-Aftercooled
Fuel System Carburetor, Down Draft
Governor Electronic
Fuel Type Natural Gas
Emission Certifications U.S. EPA Certified for Non-Emergency
Rated Engine Speed 1800 rpm
General
Cylinder No.6
Engine Governing
Frequency Regulation
(Steady State)+/- 0.25%
Lubrication System
Oil Pump Type Gear
Oil Filter Type Full-flow Cartridge
Crankcase Capacity – L (qts) 34.3 (36.2)
Cooling System
Cooling System Type Pressurized Closed Recovery
Water Pump Flow – gpm (lpm) 94 (356)
Coolant Heater Standard
Voltage/Wattage 120 V/1500 W
Fuel System
Fuel Type Natural Gas
Carburetor Down Draft
Secondary Fuel Regulator Standard
Fuel Shut Off Solenoid Standard
Operating Fuel Pressure
(Standard)7” – 11” H2O
Engine Electrical System
System Voltage 24 VDC
Battery Charger Alternator Standard
Battery Voltage (2) 12 VDC
ENGINEERED OPTIONS
Engine System Coolant Heater Ball Valves
Fluid Containment Pans
Alternator System 3rd Breaker Systems
Generator Set Special Testing
Battery Box
Enclosure Motorized Dampers
Enclosure Ambient Heaters
Control System EMCP 4.2B
Battery Disconnect Switch
POWER RATINGS – NATURAL GAS
11/04/2024 12
DG250 GC
SPARK-IGNITED GENERATOR SETS
STARTING CAPABILITIES (sKVA)
sKVA vs. Voltage Dip
480 VAC 208/240 VAC
Alternator kW 10% 15% 20% 25% 30% 35% 10% 15% 20% 25% 30% 35%
Standard 250 263 395 527 658 790 922 197 296 395 494 593 692
Upsize 1 300 303 454 605 757 908 1059 227 341 454 568 681 794
FUEL CONSUMPTION RATES*
Natural Gas – ft3/hr (m3/hr)
Percent Load Standby/Demand Response
25%1044 (29.6)
50%1790 (50.7)
75%2417 (68.4)
100%2983 (84.5)
COOLING
Standby/Demand Response
Air Flow (inlet air combustion and radiator)ft3/min (m3/min)10,078 (285.4)
Coolant System Capacity gal (Liters)19 (71.9)
Heat Rejection to Coolant BTU/hr 788,204
Max. Operating Air Temp on Radiator °F (°C)122 (50)
Max. Operating Ambient Temperature (Before derate)°F (°C)104 (40)
Maximum Radiator Backpressure in H2O 0.5
COMBUSTION AIR REQUIREMENTS
Standby/Demand Response
Flow at Rated Power cfm (m3/min)453 (12.8)
ENGINE
Standby/Demand Response
Reated Engine Speed rpm 1800
Horsepower at Rated kW**hp 374
BMEP PSI 190
**Refer to “Emissions Data Sheet” for maximum bhp for EPA and SCAQMD permitting purposes.
Standby/Demand Response
Exhaust Flow (Rated Output) cfm (m
3/min) 1602 (45.4)
Maximum Recommended
Backpressure inHg 0.75
Exhaust Temp (Rated Output) °F (°C) 1350 (732)
Exhaust Outlet Size (Open Set) in 3.5” ID Flex (no muffler)
Deration – For power deration rates reference, please consult Cat LEHE1699-00.
EXHAUST
* Fuel supply installation must accommodate fuel
consumption rates at 100% load.
11/04/2024 13
Northwest Pipeline LLC
Cisco Compressor Station
Notice of Intent Application

*** End of Notice of Intent Application ***