DAQ-2025-001139

DAQE-AN103550018-25

{{$d1 }}

Josh Sewell
PacifiCorp
1407 West North Temple, Suite 330
Salt Lake City, UT 84116
[e-mail]

Dear Mr. Sewell:

Re: Approval Order: Administrative Amendment to Approval Order DAQE-AN0103550015-09 for a
10-Year Review and Permit Updates
Project Number: N103550018

The attached Approval Order (AO) is issued pursuant to the Division of Air Quality conducting a 10-year
administrative review of this source and its respective AO. PacifiCorp must comply with the requirements
of this AO, all applicable state requirements (R307), and Federal Standards.

The project engineer for this action is Stockton Antczak, who can be contacted at [phone] or
[e-mail]. Future correspondence on this AO should include the engineer's name as well as the
DAQE number shown on the upper right-hand corner of this letter.

Sincerely,

{{$s }}

Bryce C. Bird
Director

BCB:SA:jg

cc: Salt Lake County 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

Kimberly D. Shelley
Executive Director

DIVISION OF AIR QUALITY
Bryce C. Bird
Director

February 25, 2025

STATE OF UTAH
Department of Environmental Quality
Division of Air Quality

{{#s=Sig_es_:signer1:signature}}
{{#d1=date1_es_:signer1:date:format(date, "mmmm d, yyyy")}}
{{#d2=date1_es_:signer1:date:format(date, "mmmm d, yyyy"):align(center)}}

APPROVAL ORDER
DAQE-AN103550018-25
Administrative Amendment to Approval Order
DAQE-AN0103550015-09 for a 10-Year Review
and Permit Updates

Prepared By
Stockton Antczak, Engineer
[phone]
[e-mail]

Issued to
PacifiCorp - Gadsby Power Plant

Issued On
{{$d2 }}

Issued By

{{$s }}

Bryce C. Bird
Director
Division of Air Quality

February 25, 2025
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
SECTION I: GENERAL PROVISIONS .................................................................................... 4
SECTION II: PERMITTED EQUIPMENT .............................................................................. 5
SECTION II: SPECIAL PROVISIONS ..................................................................................... 5
PERMIT HISTORY ................................................................................................................... 11
ACRONYMS ............................................................................................................................... 12

DAQE-AN103550018-25
Page 3

GENERAL INFORMATION

CONTACT/LOCATION INFORMATION

Owner Name Source Name
PacifiCorp PacifiCorp - Gadsby Power Plant

Mailing Address Physical Address
1407 West North Temple, Suite 330 1407 West North Temple
Salt Lake City, UT 84116 Salt Lake City, UT 84116

Source Contact UTM Coordinates
Name: Josh Sewell 421638 m Easting
Phone: [phone] 4513505 m Northing
Email: [e-mail] Datum NAD83
UTM Zone 12
SIC code 4911 (Electric Services)

SOURCE INFORMATION
General Description
The PacifiCorp Gadsby Power Plant is a natural gas-fired electric generating plant consisting of three (3)
steam boilers and three (3) combustion gas turbines. Boiler #1 is a 65 MW unit constructed in 1951,
Boiler #2 is an 80 MW unit constructed in 1952, and Boiler #3 is a 105 MW unit constructed in 1955.
Boilers #1 and #2 are equipped with low NOx burners. Three (3) natural gas-fueled simple cycle gas
turbine engines, each with a rating of 43.5 MW, were added in 2002. A diesel-fired, 1,350 hp emergency
generator engine was added in 2006.

NSR Classification
10-Year Review

Source Classification
Located in Northern Wasatch Front O3 NAA, Salt Lake City UT PM2.5 NAA, Salt Lake County SO2
NAA
Salt Lake County
Airs Source Size: A

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), GG: Standards of Performance for Stationary Gas Turbines
MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
Title IV (Part 72 / Acid Rain)
DAQE-AN103550018-25
Page 4

Project Description
A 10-year review to update contact information and requirement language.

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)
Carbon Monoxide 0 558.00
Nitrogen Oxides 0 2598.00
Particulate Matter - PM10 0 74.00
Sulfur Dioxide 0 75.00
Volatile Organic Compounds 0 23.00

SECTION I: GENERAL PROVISIONS

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 five-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 five (5) 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]
DAQE-AN103550018-25
Page 5

I.7 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-150]

SECTION II: PERMITTED EQUIPMENT
II.A THE APPROVED EQUIPMENT
II.A.1 Gadsby Power Plant
II.A.2 Boiler #1
65 MW Gadsby 1 - Dual Fuel Boiler #1 with six (6) Todd Combustion, Inc. Low-NOx burners rated at 726 x 10^6 Btu/hr II.A.3 Boiler #2 80 MW Gadsby 2 - Dual Fuel Boiler #2 with six (6) Todd Combustion, Inc. Low-NOx burners rated at 825 x 10^6 Btu/hr
II.A.4 Boiler #3 105 MW Gadsby 3 - Dual Fuel Boiler #3 rated at 1,155 x 10^6 Btu/hr II.A.5 Emergency Black Start Generator Diesel-fired, rated at 1,350 bhp (1007 kW)
II.A.6 Turbine #1 (Unit 4) GE LM6000 PC Sprint natural gas simple cycle turbine with water injection, NOx Selective Catalytic Reduction (SCR) catalyst, and CO oxidation catalyst II.A.7 Turbine #2 (Unit 5) GE LM6000 PC Sprint natural gas simple cycle turbine with water injection, NOx SCR catalyst, and CO oxidation catalyst
II.A.8 Turbine #3 (Unit 6) GE LM6000 PC Sprint natural gas simple cycle turbine with water injection, NOx SCR catalyst, and CO oxidation catalyst

SECTION II: SPECIAL PROVISIONS II.B REQUIREMENTS AND LIMITATIONS II.B.1 Site-Wide Requirements
II.B.1.a Unless otherwise specified in this AO, the owner/operator shall not allow visible emissions from any stationary sources on site to exceed 10% opacity. [R307-401] II.B.1.a.1 Opacity observations of emissions from stationary sources shall be conducted in accordance with 40 CFR 60, Appendix A, Method 9. [R307-401]
II.B.1.b In addition to the requirements of this AO, the owner/operator shall comply with all applicable provisions of 40 CFR Parts 72, 73, 75, 76, 77, and 78 - federal regulations for the Acid Rain Program under Clean Air Act Title IV. [40 CFR 75]
DAQE-AN103550018-25
Page 6

II.B.2 Emergency Engine Requirements II.B.2.a The owner/operator shall not allow visible emissions from the black start emergency generator
exhaust to exceed 20% opacity. [R307-401]
II.B.2.b The owner/operator shall not operate each emergency engine on site for more than 100 hours per calendar year during non-emergency situations. There is no time limit on the use of the engines during emergencies. [40 CFR 63 Subpart ZZZZ, R307-401-8] II.B.2.b.1 To determine compliance with a calendar year total, the owner/operator shall calculate a new
annual total by the 20th day of the first month of the year using data from the previous calendar year. Records documenting the operation of each 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.2.c The owner/operator shall only use diesel fuel (e.g., fuel oil #1, #2, or diesel fuel oil additives) as fuel in each emergency engine. [R307-401-8]
II.B.2.c.1 The owner/operator shall only combust diesel fuel that meets the definition of ultra-low sulfur
diesel (ULSD), which has a sulfur content of 15 ppm or less. [R307-401-8]
II.B.2.c.2 To demonstrate compliance with the ULSD fuel requirement, the owner/operator shall maintain records of diesel fuel purchase invoices or obtain certification of sulfur content from the diesel fuel supplier. The diesel fuel purchase invoices shall indicate that the diesel fuel meets the ULSD requirements. [R307-401-8]
II.B.3 Natural Gas Combustion Turbines Requirements
II.B.3.a Emissions to the atmosphere from the turbine stacks shall not exceed the following rates and concentrations: Pollutant lb/hr* ppmvd** ppmvd*** (15% O2 dry) (15% O2 dry) (15% O2 dry) NOx 22.2 5 116 (30-day (30-day (4-hour rolling average) rolling average) rolling average) CO 26.9 10 NA (8-hour block (8-hour block average) average) * Total emissions for all three (3) turbines under steady-state operation, not including startup and shutdown. ** Emissions from an individual turbine under steady-state operation not including startup and shutdown. ***Emissions from an individual turbine, 40 CFR 60 Subpart GG requirement. [R307-401]
DAQE-AN103550018-25
Page 7

II.B.3.b The owner/operator shall not exceed the following amounts from the three (3) natural gas-fired turbines. A. PM10 - 29.5 tons per rolling 12-month period B. NOx - 81.0 tons per rolling 12-month period C. CO - 98.30 tons per rolling 12-month period D. SO2 - 6.12 tons per rolling 12-month period. [R307-401] II.B.3.b.1 The owner/operator shall use the following formula to calculate the above annual emissions
limitations:
Turbine heat input (10^6 Btu/month) x emissions factor (lb/10^6 Btu) x 1 ton/2000 lb =
tons/month.
[R307-401]

II.B.3.c The owner/operator shall determine turbine heat input data using natural gas consumption readings from each turbine flow meter or CEMs data and natural gas caloric value provided by local distribution company. [R307-401] II.B.3.d The owner/operator shall determine emission factors as follows:

A. PM10 shall be obtained from EPA's Compilation of Air Pollutant Emission Factors, AP- 42 (Supplement F EPA, April 2000)

B. NOx monthly average emission factor in lb/10^6 Btu shall be calculated from the ppmvd CEMs recorded data using 40 CFR 60 App. A. Method 19

C. CO monthly average emission factor in lb/10^6 Btu shall be calculated from the ppmvd CEMs recorded data based on 40 CFR 60 App. A. Method 19

D. SO2 emission factor shall be calculated with local distribution company natural gas sulfur content data and the EPA's Compilation of Air Pollutant Emission Factors, AP-42
(Supplement F EPA, April 2000).
[R307-401]

II.B.3.d.1 The owner/operator shall: A. Determine fuel consumption using a fuel meter provided for each turbine from CEMS data B. Keep consumption records on a continuous basis C. Use the consumption data to calculate a new rolling 12-month total by the 10th day of each month using data from the previous 12 months D. Keep the consumption records for all periods the plant is in operation. [R307-401]
DAQE-AN103550018-25
Page 8

II.B.3.e The owner/operator shall install, calibrate, maintain, and operate a continuous monitoring system for measuring nitrogen oxides and carbon monoxide emissions discharged to the atmosphere from each turbine stack and record the output of the system. The monitoring system shall be used for measuring and determining compliance. The continuous monitoring system shall comply with applicable provisions of UAC, R307-170, and applicable federal regulations for the Acid Rain Program under Clean Air Act Title IV. [R307-170] II.B.3.f The owner/operator shall maintain a CEMs monitoring plan. Such a plan shall be made available
to the Director or the Director's representative upon request, or at any time the plan is changed. The plan shall address the number of monitors to be used, the method of measuring the rate in tons per hour, and the method of calculating emissions during the CEMs breakdowns.
[R307-401]
II.B.3.g The owner/operator shall use only pipe-line quality natural gas as fuel in the turbines. [R307-401] II.B.4 Boiler Requirements
II.B.4.a Emissions to the atmosphere from the indicated emission point shall not exceed the following rates and concentrations: A. Gadsby 1 boiler stack Pollutant lbs/hr ppmdv (3% O2, dry) NOx 179 336 B. Gadsby 2 boiler stack Pollutant lbs/hr ppmdv (3% O2, dry) NOx 204 336 C. Gadsby 3 boiler stack 1. Winter (November 1st through February 28th): Pollutant lbs/hr ppmdv (3% O2, dry) NOx 142 168 2. Summer (March 1st through October 31st): Pollutant lbs/hr ppmdv (3% O2, dry) NOx 203 168 [R307-401]
DAQE-AN103550018-25
Page 9

II.B.4.b Monitoring to show compliance with the emission limitations stated in the above condition shall be performed as specified below: Emission Point Pollutant Testing Status Test Frequency Gadsby 1 NOx * ** (Boiler Stack) Gadsby 2 NOx * ** (Boiler Stack) Gadsby 3 NOx * ** (Boiler Stack) Testing Status (To be applied above) * Initial compliance testing was performed. ** Compliance shall be determined using a CEM as outlined below. [R307-150]
II.B.4.b.1 Compliance with the NOx limits listed in II.B.4.a above shall be determined by calculating the
arithmetic average of three (3) contiguous one-hour period NOx emission rates (lb/hr) or concentrations (ppmdv, 3% O2 dry).

A. The owner/operator shall install, calibrate, maintain, and operate CEMs for NOx and CO2 as required by 40 CFR Part 75 for the Acid Rain Program.

B. The hourly average O2 concentration (percent by volume) shall be calculated from CO2 concentration obtained from CO2 CEMS in accordance with 40 CFR Part 75,
Appendix F.
C. The NOx concentration (ppm) obtained from NOx CEMS shall be corrected to 3% O2
on hourly basis using the O2 data calculated above.
D. The emission rate (lb/hr) shall be calculated by multiplying the hourly average
NOx emission rate (lb/MMBtu) by the hourly heat input (MMBtu/hr).
E. The hourly average NOx emission rate (lb/MMBTU) shall be calculated by using NOx
and CO2 concentrations obtained from CEMS in accordance with 40 CFR Part 75,
Appendix F.
F. The heat input shall be calculated by multiplying the measured fuel flow rate
(scf/hr) by the hourly average CO2 concentration (percent by volume) and by any necessary conversion factors in accordance with 40 CFR Part 75, Appendix F.

Each continuous emission monitoring system shall meet the specifications and test procedures
required by 40 CFR Part 75, Appendix A. [R307-150]

II.B.4.c The owner/operator shall implement quality assurance and quality control procedures required by 40 CFR Part 75, Appendix B. [R307-401]
II.B.4.d PM10 emissions combined from the boilers covered in this AO (boiler #1, #2, and #3) shall not
exceed 44.39 tons per rolling 12-month period. [R307-401]

DAQE-AN103550018-25
Page 10

II.B.4.d.1 Compliance with the above emission limitations shall be determined as follows: The amount of fuel used by equipment shall be recorded on a daily basis. The amount of fuel used shall be multiplied by the following emission factors: 5.0 lb/10^6 ft3 for Boiler #1, #2, and #3 when natural gas fired. 3.5 lb/10^3 gal for Boiler #1, #2, and #3 when #2 diesel fuel is fired. [R307-401] II.B.4.d.2 The following equation shall be used to calculate combined one-month emissions:
[(ft^3/month)* x 5.0 (lb/10^6 ft3) x (1 ton/2000 lbs)] + [(gal/month)** x 3.5 (lb/10^3 gal) x (1 ton/2000 lbs)] = tons/month emissions.
* natural gas consumed by all boilers combined during one (1) month
** #2 diesel fuel consumed by all boilers combined during one (1) month.
[R307-401]

II.B.4.d.3 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a new 12-month total by the tenth day of each month using data from the previous 12 months. Records of emissions shall be kept for all periods when the plant is in operation. Fuel consumption shall be determined by examination of the fuel usage records. The consumption recording shall be maintained and kept on a daily basis. [R307-401]
II.B.4.e The owner/operator shall use only natural gas as a primary fuel and No. 2 fuel oil or better as
backup fuel in the boilers. The No. 2 fuel oil may be used only during periods of natural gas curtailment and for maintenance firings. [R307-401]

II.B.4.f The owner/operator shall not exceed one percent of the annual plant Btu requirement during maintenance firings. In addition, maintenance firings shall be scheduled between April 1st and November 30th of any calendar year. [R307-401]
II.B.4.f.1 The owner/operator shall maintain records of fuel oil use. The records shall include
A. The date the fuel oil was fired
B. The duration in hours the fuel oil was fired

C. The amount of fuel oil consumed during each curtailment
D. The reason for each firing.
Records shall be made available to the Director or the Director's representative upon request and
shall include a period of five (5) years ending with the date of the request.

[R307-401]

II.B.4.g The sulfur content of any fuel burned in the boilers shall not exceed 0.45% by weight as determined by ASTM Method D-4294-89 or approved equivalent. The sulfur content shall be tested if directed by the Director. [R307-401]

DAQE-AN103550018-25
Page 11

PERMIT HISTORY

This Approval Order shall supersede (if a modification) or will be based on the following documents: Supersedes AO DAQE-AN0103550015-09 dated January 12, 2009

DAQE-AN103550018-25
Page 12

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

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 1
UTAH DIVISION OF AIR QUALITY
ENGINEER REVIEW

SOURCE INFORMATION

Project Number N103550018
Owner Name PacifiCorp
Mailing Address 1407 W. North Temple
Suite 330
Salt Lake City, UT, 84116

Source Name Gadsby Power Plant
Source Location 1407 West North Temple (rear)
Salt Lake City, UT 84116

UTM Projection 421638 m Easting, 4513505 m Northing
UTM Datum NAD83
UTM Zone UTM Zone 12
SIC Code 4911 (Electric Services)

Source Contact Josh Sewell
Phone Number [phone]
Email [e-mail]

Billing Contact Josh Sewell
Phone Number 801-220-2010
Email [e-mail]

Project Engineer Stockton Antczak, Engineer
Phone Number [phone]
Email [e-mail]

Notice of Intent (NOI) Submitted October 16, 2024
Date of Accepted Application October 23, 2024

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 2
SOURCE DESCRIPTION

General Description
The PacifiCorp Gadsby Power Plant is a natural gas-fired electric generating plant consisting of
three steam boilers and three combustion gas turbines. Boiler #1 is a 65 MW unit constructed in
1951, Boiler #2 is an 80 MW unit constructed in 1952, and Boiler #3 is a 105 MW unit
constructed in 1955. Boilers #1 and #2 are equipped with low NOx burners. Three natural gas-
fueled simple cycle gas turbine engines, each with a rating of 43.5 MW, were added in 2002. A
diesel-fired, 1,350 hp emergency generator engine was added in 2006.

NSR Classification:
10 Year Review

Source Classification
Located in , Northern Wasatch Front O3 NAA, Salt Lake City UT PM2.5 NAA, Salt Lake County
SO2 NAA,
Salt Lake County
Airs Source Size: A

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), GG: Standards of Performance for Stationary Gas Turbines
MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
Title IV (Part 72 / Acid Rain)

Project Proposal
Administrative Amendment to Approval Order DAQE-AN0103550015-09 for a 10-Year Review

Project Description
10-Year review to update contact information and requirement language.

EMISSION IMPACT ANALYSIS
No changes to emissions, equipment, or processes are occurring as a result of this 10-year review. No modeling
is required. [Last updated October 22, 2024]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 3
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)
Carbon Monoxide 0 558.00
Nitrogen Oxides 0 2598.00
Particulate Matter - PM10 0 74.00
Sulfur Dioxide 0 75.00
Volatile Organic Compounds 0 23.00

Note: Change in emissions indicates the difference between previous AO and proposed modification.

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 4
Review of BACT for New/Modified Emission Units

. BACT review regarding No change in BACT
There are no changes to equipment or processes in this project. No BACT analysis is required.
[Last updated November 13, 2024]

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 five (5) 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]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 5
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 Permitted Source

II.A.2 Boiler #1
65 MW Gadsby 1 - Dual Fuel Boiler #1 with six Todd Combustion, Inc. Low-NOx burners
rated at 726 x 10^6 Btu/hr
II.A.3 Boiler #2
80 MW Gadsby 2 - Dual Fuel Boiler #2 with six Todd Combustion, Inc. Low-NOx burners
rated at 825 x 10^6 Btu/hr
II.A.4 Boiler #3
105 MW Gadsby 3 - Dual Fuel Boiler #3 rated at 1,155 x 10^6 Btu/hr
II.A.5 Emergency Black Start Generator
Diesel-fired, rated at 1,350 bhp (1007 kW)
II.A.6 Turbine #1 (Unit 4)
GE LM6000 PC Sprint natural gas simple cycle turbine with: water injection, NOx Selective
Catalytic Reduction (SCR) catalyst and CO oxidation catalyst
II.A.7 Turbine #2 (Unit 5)
GE LM6000 PC Sprint natural gas simple cycle turbine with: water injection, NOx Selective
Catalytic Reduction (SCR) catalyst and CO oxidation catalyst
II.A.8 Turbine #3 (Unit 6)
GE LM6000 PC Sprint natural gas simple cycle turbine with: water injection, NOx Selective
Catalytic Reduction (SCR) catalyst and CO oxidation catalyst

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 Site-Wide Requirements
II.B.1.a Unless otherwise specified in this AO, the owner/operator shall not allow visible emissions
from any stationary sources on site to exceed 10% opacity. [R307-401]

II.B.1.a.1 Opacity observations of emissions from stationary sources shall be conducted in accordance
with 40 CFR 60, Appendix A, Method 9. [R307-401]

II.B.1.b In addition to the requirements of this AO, the owner/operator shall comply with all applicable
provisions of 40 CFR Part 72, 73, 75, 76, 77, and 78 - Federal regulations for the Acid Rain
Program under Clean Air Act Title IV. [40 CFR 75]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 6
II.B.2

Emergency Engine Requirements
II.B.2.a The owner/operator shall not allow visible emissions from the black start emergency generator
exhaust to exceed 20% opacity. [R307-401]

II.B.2.b
NEW
The owner/operator shall not operate each emergency engine on site for more than 100 hours
per calendar year during non-emergency situations. There is no time limit on the use of the
engines during emergencies. [40 CFR 63 Subpart ZZZZ, R307-401-8]

II.B.2.b.1
NEW
To determine compliance with a calendar year total, the owner/operator shall calculate a new
annual total by the 20th day of the first month of the year using data from the previous
calendar year. Records documenting the operation of each 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.2.c
NEW
The owner/operator shall only use diesel fuel (e.g. fuel oil #1, #2, or diesel fuel oil additives)
as fuel in each emergency engine. [R307-401-8]

II.B.2.c.1
NEW
The owner/operator shall only combust diesel fuel that meets the definition of ultra-low sulfur
diesel (ULSD), which has a sulfur content of 15 ppm or less. [R307-401-8]

II.B.2.c.2
NEW
To demonstrate compliance with the ULSD fuel requirement, the owner/operator shall
maintain records of diesel fuel purchase invoices or obtain certification of sulfur content from
the diesel fuel supplier. The diesel fuel purchase invoices shall indicate that the diesel fuel
meets the ULSD requirements. [R307-401-8]

II.B.3 Natural Gas Combustion Turbines Requirements

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 7
II.B.3.a Emissions to the atmosphere from the Turbine stacks shall not exceed the following rates and
concentrations:

Pollutant lb/hr* ppmvd** ppmvd***
(15% O2 dry) (15% O2 dry) (15% O2 dry)

NOx 22.2 5 116
(30-day rolling average) (30-day rolling average) (4-hour rolling average)

CO 26.9 10 NA
(8-hour block average) (8-hour block average)

* Total emissions for all three turbines under steady state operation not including startup and
shutdown

** Emissions from an individual turbine under steady state operation not including startup and
shutdown

***Emissions from an individual turbine, 40 CFR 60 Subpart GG requirement. [R307-401]

II.B.3.b The owner/operator shall not exceed the following amounts from the three natural gas-fired
turbine.

A. PM10 29.5 tons per rolling 12-month period

B. NOx 81.0 tons per rolling 12-month period

C. CO 98.30 tons per rolling 12-month period

D. SO2 6.12 tons per rolling 12-month period

[R307-401]

II.B.3.b.1 The owner/operator shall use the following formula to calculate the above annual emissions
limitations:

Turbine heat input (10^6 Btu/month) x emissions factor (lb/10^6 Btu) x 1 ton/2000 lb =
tons/month. [R307-401]

II.B.3.c The owner/operator shall determine turbine heat input data using natural gas consumption
readings from each turbine flow meter or CEMs data and natural gas caloric value provided by
local distribution company. [R307-401]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 8
II.B.3.d The owner/operator shall determine emission factors as follows:

A. PM10 shall be obtained from EPA' s Compilation of Air Pollutant Emission Factors, AP-42
(Supplement F EPA, April 2000)

B. NOx monthly average emission factor in lb/10^6 Btu shall be calculated from the ppmvd
CEMs recorded data using 40 CFR 60App. A. Method 19

C. CO monthly average emission factor in lb/10^6 Btu shall be calculated from the ppmvd
CEMs recorded data based on 40 CFR 60 App. A. Method 19

D. SO2 emission factor shall be calculated with local distribution company natural gas sulfur
content data and the EPA' s Compilation of Air Pollutant Emission Factors, AP-42
(Supplement F EPA, April 2000) . [R307-401]

II.B.3.d.1 The owner/operator shall:

A. Determine fuel consumption using a fuel meter provided for each turbine of from CEMS
data

B. Keep consumption records on a continuous basis

C. Use the consumption data to calculate a new rolling 12-month total by the 10th day of each
month using data from the previous 12 months

D. Keep the consumption records for all periods the plant is in operation

[R307-401]

II.B.3.e The owner/operator shall install, calibrate, maintain, and operate a continuous monitoring
system for measuring nitrogen oxides and carbon monoxide emissions discharged to the
atmosphere from each turbine stack and record the output of the system. The monitoring
system shall be used for measuring and determining compliance. The continuous monitoring
system shall comply with applicable provisions of UAC, R307-170 and applicable Federal
regulations for the Acid Rain Program under Clean Air Act Title IV. [R307-170]

II.B.3.f The owner/operator shall maintain a CEMs monitoring plan. Such plan shall be made
available to the Director or the Director's representative upon request, or at any time the plan
is changed. The plan shall address the number of monitors to be used, the method of
measuring the rate in tons per hour, and the method of calculating emissions during the CEMs
breakdowns. [R307-401]

II.B.3.g The owner/operator shall use only pipe line quality natural gas as fuel in the turbines. [R307-
401]

II.B.4 Boiler Requirements

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 9
II.B.4.a Emissions to the atmosphere from the indicated emission point shall not exceed the following
rates and concentrations:

A. Gadsby 1 boiler stack

Pollutant Lbs/hr ppmdv
(3% O2, dry)

NOx 179 336

B. Gadsby 2 boiler stack

Pollutant Lbs/hr ppmdv
(3% O2, dry)

NOx 204 336

C. Gadsby 3 boiler stack

a. Winter (November 1 through February 28):

Pollutant Lbs/hr ppmdv
(3% O2, dry)

NOx 142 168

b. Summer (March 1 through October 31):

Pollutant Lbs/hr ppmdv
(3% O2, dry)

NOx 203 168

[R307-401]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 10
II.B.4.b Monitoring to show compliance with the emission limitations stated in the above condition
shall be performed as specified below:

Emission Point Pollutant Testing Status Test Frequency

Gadsby 1 NOx * **
(Boiler Stack)

Gadsby 2 NOx * **
(Boiler Stack)

Gadsby 3 NOx * **
(Boiler Stack)

Testing Status (To be applied above)

* Initial compliance testing was performed.

** Compliance shall be determined using a CEM as outlined below. [R307-150]

II.B.4.b.1 Compliance with the NOx limits listed in II.B.4.a above shall be determined by calculating the
arithmetic average of three contiguous one-hour period NOx emission rates (lb/hr) or
concentrations (ppmdv, 3% O2 dry).

A. The owner/operator shall install, calibrate, maintain, and operate CEMs for NOx and
CO2 as required by 40 CFR Part 75 for the Acid Rain Program.

B. The hourly average O2 concentration (percent by volume) shall be calculated from
CO2 concentration obtained from CO2 CEMS in accordance with 40 CFR Part 75,
Appendix F.

C. The NOx concentration (ppm) obtained from NOx CEMS shall be corrected to 3% O2
on hourly basis using the O2 data calculated above.

D. The emission rate (lb/hr) shall be calculated by multiplying the hourly average
NOx emission rate (lb/MMBtu) by the hourly heat input (MMBtu/hr).

E. The hourly average NOx emission rate (lb/MMBTU) shall be calculated by using NOx
and CO2 concentrations obtained from CEMS in accordance with 40 CFR Part 75,
Appendix F.

F. The heat input shall be calculated by multiplying the measured fuel flow rate
(scf/hr) by the hourly average CO2 concentration (percent by volume) and by any
necessary conversion factors in accordance with 40 CFR Part 75, Appendix F.

Each continuous emission monitoring system shall meet the Specifications and Test
Procedures required by 40 CFR Part 75, Appendix A. [R307-150]

II.B.4.c The owner/operator shall implement Quality Assurance and Quality Control Procedures
required by 40 CFR Part 75, Appendix B. [R307-401]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 11
II.B.4.d PM10 emissions combined from the boilers covered in this AO (boiler #1, #2, and #3) shall not
exceed 44.39 tons per rolling 12-month period. [R307-401]

II.B.4.d.1 Compliance to the above emission limitations shall be determined as follows:

The amount of the fuel used by equipment shall be recorded on daily basis. The amount of
fuel used shall be multiplied by the following emission factors:

5.0 lb/10^6 ft3 for Boiler #1, #2, and #3 when natural gas fired
3.5 lb/10^3 gal for Boiler #1, #2, and #3 when #2 diesel fuel fired. [R307-401]

II.B.4.d.2 The following equation shall be used to calculate combined one month emissions:

[(ft^3/month)* x 5.0 (lb/10^6 ft3) x (1 ton/2000 lbs)] + [(gal/month)** x 3.5 (lb/10^3 gal) x (1
ton/2000 lbs)] = tons/month emissions

* natural gas consumed by all boilers combined during one month
** #2 diesel fuel consumed by all boilers combined during one month. [R307-401]

II.B.4.d.3 To determine compliance with a rolling 12-month total the owner/operator shall calculate a
new 12-month total by the tenth day of each month using data from the previous 12 months.
Records of emissions shall be kept for all periods when the plant is in operation. Fuel
consumption shall be determined by examination of the fuel usage records. The consumption
recording shall be maintained and kept on a daily basis. [R307-401]

II.B.4.e The owner/operator shall use only natural gas as a primary fuel and No. 2 fuel oil or better as
back-up fuel in the boilers. The No. 2 fuel oil may be used only during periods of natural gas
curtailment and for maintenance firings. [R307-401]

II.B.4.f The owner/operator shall not exceed one-percent of the annual plant Btu requirement during
maintenance firings. In addition, maintenance firings shall be scheduled between April 1 and
November 30 of any calendar year. [R307-401]

II.B.4.f.1 The owner/operator shall maintain records of fuel oil use. The records shall include

A. The date the fuel oil was fired

B. The duration in hours the fuel oil was fired

C. The amount of fuel oil consumed during each curtailment

D. The reason for each firing.

Records shall be made available to the Director or the Director's representative upon request,
and shall include a period of five years ending with the date of the request.

[R307-401]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 12
II.B.4.g The sulfur content of any fuel burned in the boilers shall not exceed 0.45% by weight as
determined by ASTM Method D-4294-89 or approved equivalent. The sulfur content shall be
tested if directed by the Director. [R307-401]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 13
PERMIT HISTORY

When issued, the approval order shall supersede (if a modification) or will be based on the
following documents:

Supersedes DAQE-AN0103550015-09 dated January 12, 2009

REVIEWER COMMENTS

1. Comment regarding Summary of Changes:
No equipment changes were made as part of this review. The requirement for the existing equipment
and processes were updated to reflect current permitting language. These changes include updating
the general conditions, updating the emergency engine language, and updating the contact
information for the site. [Last updated November 21, 2024]

2. Comment regarding Applicability of MACT:
The two permits originally issued for the addition of the combustion turbines (DAQE-204-02) and
the black start generator (DAQE-AN0355012-05) did not discuss the applicability of 40 CFR 63
(commonly known as MACT) to these sources. After review, 40 CFR 63 Subpart YYYY is found to
be currently non-applicable. The turbines are natural gas-fired, and aside from initial reporting no
other requirements presently exist in that subpart. It may be that in the future EPA will update
YYYY to incorporate new requirements - and a new applicability determination will need to be
made at that time.

Conversely, the requirements of 40 CFR 63 Subpart ZZZZ (also known as the RICE MACT) are
applicable to the black start generator. The listing of applicable federal requirements has been
updated to incorporate this change. [Last updated November 21, 2024]

3. Comment regarding Applicability of MACT (continued):
An internal DAQ review prior to the start of the public comment period suggested that 40 CFR 60
subpart IIII or JJJJ might apply to the blackstart generator. A more thorough review has shown that
they do not. The blackstart generator is an existing RICE at an area source of HAPs. Currently 40
CFR 63 does apply, although there are no applicable requirements at this time. Subparts IIII and
JJJJ have applicability dates that fall after the date of construction of the generator in question - the
date of construction being defined as the date the engine is ordered.

40 CFR 63 Subpart ZZZZ has a similar date of construction to determine if the RICE is existing or
new/reconstructed. Based on the date of construction, this engine is considered to be existing. [Last
updated January 8, 2025]

4. Comment regarding Applicability of NSPS:
The natural gas combustion turbines on site have a heat input at peak load greater than 10.7
gigajoules per hour and were constructed after October 3, 1977. 40 CFR 60 (NSPS) Subpart GG is
applicable to this source. [Last updated November 21, 2024]

5. Comment regarding Summary of Emissions:
The emission totals listed in this review are based on the amounts listed in the project file for the
minor modification in 2009. Emissions should be reevaluated in the future when the source
undergoes a modification. [Last updated November 25, 2024]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 14

6. 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 a major source and is a Title IV source. Title V applies to this source. [Last updated
November 25, 2024]

Engineer Review N103550018: Gadsby Power Plant
February 4, 2025
Page 15
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

Contact information for the site was updated after calling the source. Since everything was
discussed over the phone, I don’t have any email communication to add to this folder at this
time.

The following is the updated contact information

Josh Sewell
801-220-2010
[e-mail]

I confirmed that the source address and site name is still accurate.
Stockton Antczak <[e-mail]>
Gadsby Power Plant Air Quality Permit 10-Year Review
15 messages
Stockton Antczak <[e-mail]>Fri, Dec 13, 2024 at 2:00 PM
To: "[e-mail]" <[e-mail]>
Josh,
Here is my finalized engineering review for the 10-year review project I talked to you about a few weeks ago. Please
review the attached document and let me know if you have any questions or concerns. The formatting for the AO when it
is issued will be a bit different from my review, but the information will all be the same.
Thanks,
Stockton
--
Stockton J. Antczak | Permitting Engineer | Major New Source Review
385-306-6724 (cell)
195 North 1950 West, Salt Lake City, UT 84116
RN103550018.rtf
1560K
Stockton Antczak <[e-mail]>Fri, Dec 27, 2024 at 8:54 AM
To: "[e-mail]" <[e-mail]>
Josh,
I just wanted to follow up to make sure this email didn't get missed. Let me know if you have any questions.
Thanks,
Stockton
[Quoted text hidden]
Sewell, Joshua (PacifiCorp) <[e-mail]>Mon, Dec 30, 2024 at 9:19 AM
To: Stockton Antczak <[e-mail]>
Thanks for following up, Stockton. I had missed the reviewed document. I’ll give it a review and get back to
you on any questions.

Best!

2/6/25, 1:13 PM State of Utah Mail - Gadsby Power Plant Air Quality Permit 10-Year Review
https://mail.google.com/mail/u/0/?ik=15596fcb07&view=pt&search=all&permthid=thread-a:r4415031789785488988&simpl=msg-a:r161744229254498…1/6
You don't often get email from [e-mail]. Learn why this is important
Josh Sewell
Sr. Environmental Engineer
Office: [phone]
Cell: [phone]

From: Stockton Antczak <[e-mail]>
Sent: Friday, December 27, 2024 8:55 AM
To: Sewell, Joshua (PacifiCorp) <[e-mail]>
Subject: [INTERNET] Re: Gadsby Power Plant Air Quality Permit 10-Year Review

THIS MESSAGE IS FROM AN EXTERNAL SENDER.
Look closely at the SENDER address. Do not open ATTACHMENTS unless expected. Check for INDICATORS of phishing. Hover over
LINKS before clicking. Learn to spot a phishing message
Josh,

I just wanted to follow up to make sure this email didn't get missed. Let me know if you have any questions.

Thanks,
Stockton

On Fri, Dec 13, 2024 at 2:00 PM Stockton Antczak <[e-mail]> wrote:
Josh,

Here is my finalized engineering review for the 10-year review project I talked to you about a few weeks ago. Please
review the attached document and let me know if you have any questions or concerns. The formatting for the AO when
it is issued will be a bit different from my review, but the information will all be the same.

Thanks,
Stockton

--
Stockton J. Antczak | Permitting Engineer | Major New Source Review
2/6/25, 1:13 PM State of Utah Mail - Gadsby Power Plant Air Quality Permit 10-Year Review
https://mail.google.com/mail/u/0/?ik=15596fcb07&view=pt&search=all&permthid=thread-a:r4415031789785488988&simpl=msg-a:r161744229254498…2/6
385-306-6724 (cell)
[Quoted text hidden]
Sewell, Joshua (PacifiCorp) <[e-mail]>Mon, Dec 30, 2024 at 9:41 AM
To: Stockton Antczak <[e-mail]>
Stockton,

I see that I need to reply within 10 business days of receipt. Do you need a certification within 10 days?
Including the Christmas holiday, that ends up being today. I would prefer to spend a little more time
reviewing to see if there are any questions I have before responding back with a certification. Could you
please call me when you get this: 801-247-4218.

Best regards,

Josh Sewell
Sr. Environmental Engineer
Office: [phone]
Cell: [phone]

[Quoted text hidden]
Sewell, Joshua (PacifiCorp) <[e-mail]>Mon, Dec 30, 2024 at 2:40 PM
To: Stockton Antczak <[e-mail]>
Good afternoon, Stockton. I believe that today marks the 10 business-day deadline for us to provide
feedback. I don’t have any major concerns with the updates you have suggested. I do have a couple of
comments on the conditions listed as new in the attached document as well as a comment on the
comments section. I will be available tomorrow to discuss and again on January 6th. Please let me know if
you have questions about the comments I have left.

Best,

Josh Sewell
2/6/25, 1:13 PM State of Utah Mail - Gadsby Power Plant Air Quality Permit 10-Year Review
https://mail.google.com/mail/u/0/?ik=15596fcb07&view=pt&search=all&permthid=thread-a:r4415031789785488988&simpl=msg-a:r161744229254498…3/6
You don't often get email from [e-mail]. Learn why this is important
Sr. Environmental Engineer
Office: [phone]
Cell: [phone]

From: Stockton Antczak <[e-mail]>
Sent: Friday, December 13, 2024 2:01 PM
To: Sewell, Joshua (PacifiCorp) <[e-mail]>
Subject: [INTERNET] Gadsby Power Plant Air Quality Permit 10-Year Review

THIS MESSAGE IS FROM AN EXTERNAL SENDER.
Look closely at the SENDER address. Do not open ATTACHMENTS unless expected. Check for INDICATORS of phishing. Hover over
LINKS before clicking. Learn to spot a phishing message
Josh,
[Quoted text hidden]
RN103550018-JMS Comments.rtf
1566K
Stockton Antczak <[e-mail]>Tue, Jan 7, 2025 at 3:34 PM
To: "Sewell, Joshua (PacifiCorp)" <[e-mail]>
Josh,
It looks like I should be able to change those conditions to be on an annual basis. I'll get that updated and I'll send you the
revised copy of my review tomorrow.
Thanks,
Stockton
[Quoted text hidden]
Sewell, Joshua (PacifiCorp) <[e-mail]>Tue, Jan 7, 2025 at 3:40 PM
To: Stockton Antczak <[e-mail]>
Much appreciated.

Best!
[Quoted text hidden]
Stockton Antczak <[e-mail]>Wed, Jan 8, 2025 at 1:36 PM
To: "Sewell, Joshua (PacifiCorp)" <[e-mail]>
2/6/25, 1:13 PM State of Utah Mail - Gadsby Power Plant Air Quality Permit 10-Year Review
https://mail.google.com/mail/u/0/?ik=15596fcb07&view=pt&search=all&permthid=thread-a:r4415031789785488988&simpl=msg-a:r161744229254498…4/6
Josh,
Here is the updated review. I changed those two conditions on the emergency generator to be on an annual basis. I also
tweaked the language in the engineering comment about Federal Code applicability to clarify that it is not subject to all 3
subparts. Let me know what you think,
Thanks,
Stockton
[Quoted text hidden]
RN103550018.rtf
1554K
Sewell, Joshua (PacifiCorp) <[e-mail]>Wed, Jan 8, 2025 at 3:23 PM
To: Stockton Antczak <[e-mail]>
Received. I’ll send on to the plant for final review. Do you mind if I give them a few business days for
review? I can have a signed approval for you next week if you are ok with that.
[Quoted text hidden]
Stockton Antczak <[e-mail]>Wed, Jan 8, 2025 at 3:24 PM
To: "Sewell, Joshua (PacifiCorp)" <[e-mail]>
Yes, that should be fine. I know the review says 10 business days but that mostly for sources that don't ever respond.
Next week should be fine, especially since this isn't a time sensitive project.
[Quoted text hidden]
Sewell, Joshua (PacifiCorp) <[e-mail]>Wed, Jan 8, 2025 at 3:26 PM
To: Stockton Antczak <[e-mail]>
Thanks so much. Have a great week.
[Quoted text hidden]
Sewell, Joshua (PacifiCorp) <[e-mail]>Tue, Feb 4, 2025 at 10:01 AM
To: Stockton Antczak <[e-mail]>
Good morning, Stockton. I called about some items that I was still curious about and have listed them all out
in the attached document. I have some additional comments and suggestions with changes tracked. Please
let me know if you have any questions about any of them.
[Quoted text hidden]
RN103550018_JMS-2025-02-04.rtf
1565K
Stockton Antczak <[e-mail]>Tue, Feb 4, 2025 at 10:12 AM
To: "Sewell, Joshua (PacifiCorp)" <[e-mail]>
Josh,
I took a quick look at your comments and I should be able to make all of the requested changes. Once I have redrafted
the review I'll send it back to you one more time and have you sign off on it then I can move forward with getting the AO
issued. I should have it ready for you later today.
2/6/25, 1:13 PM State of Utah Mail - Gadsby Power Plant Air Quality Permit 10-Year Review
https://mail.google.com/mail/u/0/?ik=15596fcb07&view=pt&search=all&permthid=thread-a:r4415031789785488988&simpl=msg-a:r161744229254498…5/6
Thanks,
Stockton
[Quoted text hidden]
Stockton Antczak <[e-mail]>Tue, Feb 4, 2025 at 11:05 AM
To: "Sewell, Joshua (PacifiCorp)" <[e-mail]>
Here is the updated review. If it looks good just sign off on the cover page and then I'll move forward with sending the AO
over.
[Quoted text hidden]
RN103550018.rtf
1549K
Sewell, Joshua (PacifiCorp) <[e-mail]>Thu, Feb 6, 2025 at 7:56 AM
To: Stockton Antczak <[e-mail]>
Cc: "Tiberius, Leah (PacifiCorp)" <[e-mail]>, "Shakespear, Brett (PacifiCorp)"
<[e-mail]>, "Kennick, Bill (PacifiCorp)" <[e-mail]>
Stockton,

Attached is a signed version of the Engineer Review of the Administrative Amendment to Approval Order
DAQE-AN0103550015-09 indicating PacifiCorp’s approval and intent for DEQ to move forward with the
issuance of the Administrative Amendment to the Gadsby Plant. Thank you for your work on this.
[Quoted text hidden]
2 attachments
RN103550018 (FINAL).pdf
199K
RN103550018.rtf
1549K
2/6/25, 1:13 PM State of Utah Mail - Gadsby Power Plant Air Quality Permit 10-Year Review
https://mail.google.com/mail/u/0/?ik=15596fcb07&view=pt&search=all&permthid=thread-a:r4415031789785488988&simpl=msg-a:r161744229254498…6/6