DAQE

- AN 125290003

- 12

October 2 5 , 2012

Bruce Taylor Sevier Power Company

620 S Main Bountiful, UT 84010

Dear Mr. Taylor:

Re: Approval Order: N otice of Intent to Construct a 580 MW Combined Cycle, Natural Gas,

Combustion Turbine Power Plant Project Number: N 012529

- 0003

The attached document is the Approval Order for the abo ve

- referenced project. Future correspondence

on this Approval Order should include the engineer's name as well as the DAQE number as shown on the upper right

- hand corner of this letter. The project engineer for this action is John Jenks, who may be reached at (801) 536

- 4459.

Sincerely,

Bryce C. Bird

Director

BCB:JJ:kw

cc: Mike Owens Central Utah Health Department

195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 1448 20 • Salt Lake City, UT 84114

- 4820 Telephone (801) 536

- 4000 • Fax (801) 536

- 4099 • T.D.D. (801) 536

- 4414

www.deq.utah.gov
Printed on 100% recycled paper 

## State of Utah

GARY R. HERBERT

Governor

GREG BELL

Lieutenant Governor 

### Department of

Environmental Quality

Amanda Smith

Executive Director

DIVISION OF AIR QUALITY Bryce C. Bird

Director

## STATE OF UTAH

Department of Environmental Quality

Division of Air Quality

APPROVAL ORDER: N otice of Intent to Construct a 580 MW Combined Cycle, Natural Gas, Combustion Turbine Power Plant

Prepared By: John Jenks, Engineer Phone: (801) 536

- 4459 Email: jjenks@utah.gov

APPROVAL ORDER NUMBER

DAQE

- AN 125290003

- 12

Date: October 2 5 , 2012



## Sevier Power Company

Power Plant

Source Contact: Bruce Taylor Phone: (801) 916

- 7341

Bryce C. Bird

Director

## Abstract

On September 8, 2011, Sevier Power Company (SPC) submitted a NOI to construct and operate a 580 MW, combined

- cycle, natural gas

- fired power plant located near Sigurd, Utah ; an attainment area for all criteria pollutants. In response to a request for additional information, SPC submitted a revision to its NOI on January 19, 2012. As proposed in this revised NOI, the plant will consist of two natural gas

- fired, combustion turbines (CT); two

, natural gas duct

- fired, heat recovery steam generators (HRSG); a natural

gas

- fired auxiliary boiler; diesel emergency generator; and other associated equipment. The CT/HRSG units are dry lo w

- NO

x units controlled with both selective catalytic reduction (SCR) and oxidation catalysts (oxy

- cat). The auxiliary boiler shall be equipped with ultra

- low

- NO

x burners (ULNB) and flue gas recirculation (FGR). The SPC power plant shall be subject to the provisions of 40 CFR 60 Subparts A, Dc, IIII and KKK K; and 40 CFR 63 Subparts A and ZZZZ. The proposed source emissions are estimated at the following TPY values: PM 10 106, PM 2.5 (a subset of PM 10 ) 106, NO

x 168.3, SO 2 25.7, CO 577, VOC 91.6, combined HA Ps 8.5, and GHG 2,019,226.1 (expressed as CO 2 e).

This source is a new major source under PSD. The proposed emissions of NO

x , PM 10 and PM 2.5 exceed

the emission thresholds outlined in R307

- 406

- 5 and R307

- 410

- 4, and so an air quality impact analysis (AQIA) of the proposed project’s impact on federal air quality standards a nd air quality related values is required.

This air quality AO authorizes the project with the following conditions and failure to comply with any of the conditions may constitute a violation of this order. This AO is issued to, and applies to the following:

Name of Permittee:

Sevier Power Company

620 S Main Bountiful, UT 84010 Permitted Location:

Power Plant 414,332 m Easting 4,300,261 Northing

Zone 12 Sigurd, UT 84657

UTM coordinates: 414332 m Easting, 4300261 m Northing, UTM Zone 12

SIC code: 4911 (Electric Services)

Section I: GENERAL PROVISIONS

I.1 The limits set forth in this AO shall not be exceeded without prior approval. [R307

- 401]

I.2 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.3 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

oth erwise 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.4 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,DAQE

- AN 1252 90003

- 12

Page 3

including associated air pollution control equipment, in a manner consistent with good air

pollution control practice for minimizing emissions. Determination of whether accept able 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 inspecti on of the source. All maintenance performed on equipment authorized by this AO shall be recorded. [R307

- 401

- 4]

I.5 The owner/operator shall comply with UAC R307

- 107. General Requirements: Breakdowns.

[R307

- 107]

I.6 The owner/operator shall comply with UAC R307

- 150 Series. Inventories, Testing and

Monitoring. [R307

- 150]

I.7 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]

Section II: SPECIAL PROVISIONS

II.A The approved installations shall consist of the following equipment:

II.A.1 Power Plant

Nominal 580 MW natural gas

- fired combustion turbine power plant

II.A.2 Turbine 1

F

- Class combustion turbine with dry low

- NO

x

II.A.3 HRSG 1

Heat recovery steam generator with duct burners, SCR and catalytic oxidation

II.A.4 Turbine 2

F

- Class combustion turbine with dry low

- NO

x

II.A.5 HRSG 2

Heat recovery steam generator with duct burners, SCR and catalytic oxidation

II.A.6 Auxiliary Boiler

85 MMBtu/hr auxiliary boiler with ULNB and FGR

II.A.7 Convection Fuel Heaters

Two (2) 22.3 MMBtu/hr fuel heaters

II.A.8 Emergency Generator

1,250 kWe emergency diesel generator

II.A.9 Emergency Fire Water Pump

300 kWe diesel

- fired fire water pump

II.A.10 Water Treatment

Water treatment and storage facilities

II.A.11 Ammonia Storage and Handling

Aqueous ammonia storage and handling equipmentDAQE

- AN 1252 90003

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Page 4

II.B Requirements and Limitations

II.B.1 Conditions on Permitted Source

II.B.1.a SPC shall notify the Director in writing when the installation of the equipment listed in II.A

has been completed and is operational. To ensure proper credit when notifying the Director

, send your correspondence to the Director , attn: Compliance Section.

The pr ovisions of R307

- 405

- 19. Source Obligation apply to this source

.

II.B.1.b The owner/operator shall install, calibrate, maintain, and operate a continuous emissions

monitoring system on each of the HRSG stacks. The owner/operator shall record the output of the system, for measuring the NO

x and CO emissions. The monitoring system shall comply with all applicable sections of R307

- 170; 40 CFR 60.13; and 40 CFR 60, Appendix B. Th e NO

x monitor shall comply with 40 CFR 75, Appendix A and B.

All continuous emissions monitoring devices as required in federal regulations and state rules shall be installed prior to placing the affected source in operation. These devices shall be
certi fied within 90 days of achieving full load, not to exceed 180 days after startup.

Except for system breakdown, repairs, calibration checks, and zero and span adjustments required under paragraph (d) 40 CFR 60.13, the owner/operator of an affected source s hall continuously operate all required continuous monitoring systems and shall meet minimum frequency of operation requirements as outlined in R307

- 170 and 40 CFR 60.13. [R307

- 170, 40 CFR 60.13]

II.B.1.c Visible emissions shall not exceed the following values:

All natural gas combustion exhaust stacks

- 10% opacity All other emission points

- 20% opacity

Opacity observations of emissions from stationary sources shall be conducted according to 40 CFR 60, Appendix A, Method 9. [R307

- 401

- 8]

II.B.1.d Th e owner/operator shall use natural gas as fuel in the combustion turbines, duct burners and

auxiliary boiler. [R307

- 401

- 8]

II.B.1.e SPC shall conduct post

- construction PM 2.5 ambient air monitoring for a period of no less than

three years or until the Director determines that ambient monitoring for PM 2.5 is no longer warranted. SPC will submit a post

- construction PM 2.5 ambient air quality monitoring plan for approval by the Di rector no less than 180 days prior to the start of operations.

Post

- construction PM 2.5 monitoring will begin within 30 days of the start of the SPC operations. SPC will provide post

- construction monitoring reports to the DAQ on a schedule
outlined in the plan approved by the Director. [R307

- 401

- 8]

II.B.2 Conditions on Combustion Turbines and HRSGs

II.B.2.a Emissions to the atmosphere from the indicated emission point(s) shall not exceed the

following rates and concentrations:

Source: Each Turbine/HR SG Stack

Pollutant Limitations Averaging Period
PM 10 /PM 2.5 14 lb/hour (with duct firing) 30

- day rolling average
NO

x 2.0 ppmvd at 15% O 2 * 3

- hourDAQE

- AN 1252 90003

- 12

Page 5

CO 3.0 ppmvd at 15% O 2 * 3

- hour

VOC 3.0 ppmvd at 15% O 2 * 3

- hour

* Under steady state operation

[R307

- 401

- 8]

II.B.2.b Stack testing to show compliance with the emission limitations stated in the above condition

shall be performed as specified below:

Emissions Point Pollutant Status Frequency

HRSG Stacks PM 10 /PM 2.5 * $

NO

x * # CO * #
VOC * %

Testing Status (To be applied t o the sources listed above)

* Initial compliance testing is required. The initial test date shall be performed as soon as possible and in no case later than 180 days after the start up of a new emission

sou rce, an existing source without an AO, or the granting of an AO to an existing emission source that has not had an initial compliance test performed. If an existing source is modified, a compliance test is required on the modified emission point that
h as an emissio n rate limit.

$ Test every year or testing may be replaced with parametric monitoring if approved by
the Director

% Test every five (5) years or testing may be replaced with parametric monitoring if approved by the Director

# Compliance shall be demonstrated through use of a Continuous Emissions Monitoring System (CEM S ) as outlined in Condition II.B.1.b. The Director may require testing at any time.

[R307

- 165]

II.B.2.c For all emissions testing the following shall apply:

Notification:

The Director shall be notified at least 30 days prior to conducting any required emission testing. A source test protocol shall be submitted to DAQ when the testing notification is
submitted to the Director

.

The source test protocol sha ll be approved by the Director prior to performing the test(s). The source test protocol shall outline the proposed test methodologies, stack to be tested, and procedures to be used. A pretest conference shall be held, if directed by the Director

.

Sampl e Location:

The emission point shall be designed to conform to the requirements of 40 CFR 60, Appendix A, Method 1, or other methods as approved by the Director . An Occupational Safety and Health Administration (OSHA) or Mine Safety and Health Administra tion (MSHA) approved access shall be provided to the test location.DAQE

- AN 1252 90003

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Page 6

Volumetric Flow Rate:

40 CFR 60, Appendix A, Method 2 or EPA Test Method No. 19 "SO 2 Removal & PM, SO 2 , NO

x Rates from Electric Utility Steam Generators" or other testing methods approve d by the
Director

.

PM 10 /PM 2.5 :

For stacks in which no liquid drops are present, the following methods shall be used: 40 CFR 51, Appendix M, Methods 201, 201a and 202, or other testing methods approved by the
Director . All particulate captured shall be c onsidered PM 10 /PM 2.5 . The back half condensibles shall be used for compliance demonstration as well as for inventory purposes.

For stacks in which liquid drops are present, methods to eliminate the liquid drops should be explored. If no reasonable metho d to eliminate the drops exists, then the following methods shall be used: 40 CFR 60, Appendix A, Method 5, 5a, 5d, or 5e as appropriate, or other testing methods approved by the Director . The back half condensibles shall also be tested using the
method specified by the Director . The portion of the front half of the catch considered PM 10 shall be based on information in Appendix B of the fifth edition of the EPA document, AP

- 42, or other data acceptable to the Director

.

NO

x :

40 CFR 60, Appendix A, Meth od 7, 7A, 7B, 7C, 7D, 7E, or other testing methods approved by
the Director

.

CO:

40 CFR 60, Appendix A, Method 10, or other testing methods approved by the Director

.

Calculations:

To determine mass emission rates (lb/hr, etc.) the pollutant concentrati on as determined by the appropriate methods above shall be multiplied by the volumetric flow rate and any necessary conversion factors determined by the Director , to give the results in the specified units of the emission limitation. [R307

- 165]

II.B.2.d Compliance with the 3

- hour NO

x and CO emission limitations specified in Condition II.B.2.a

shall not be required during short

- term excursions, limited to a cumulative total of 160 hours annually. Short

- term excursions are defined as 15

- minute periods des ignated by the owner/operator that are the direct result of transient load conditions, not to exceed four
consecutive 15

- minute periods, when the 15

- minute average NO

x and CO concentrations exceed 2.0 ppmv and 3.0 ppmv, dry @ 15% O 2 , respectively. Transie nt load conditions include the following:

1. Initiation/shutdown of combustion turbine inlet air

- cooling
2. Rapid comb ustion turbine load changes
3. Initiation/sh utdown of HRSG duct burners
4. Provision of Ancillary Services and Automatic Generation Contr ol

During periods of transient load conditions, the NO

x concentration shall not exceed 25 ppmv and the CO concentration shall not exceed 50 ppmv, dry @ 15% O 2 . All NO

x and CO emissions during these events shall be included in all calculations of annual m ass emissions as required by this permit. [R307

- 401

- 8]DAQE

- AN 1252 90003

- 12

Page 7

II.B.2.e Steady state operation means all periods of combustion turbine operation, except for periods of

startup and shutdown as defined below, and periods of transient load conditions as defined i n Condition II.B.2.d. Startup is defined as the period beginning with turbine initial firing until the unit meets the ppmvd emission limits in Condition II.B.2.a for steady state operation. Shutdown is defined as the period beginning with the initiation of turbine shutdown sequence and ending with the cessation of firing of the gas turbine engine.

1. Emissions of NO

x from each CT/HRSG unit shall not exceed 126 lb/hr during startup or shutdown operations
2. Emissions of CO from each CT/HRSG unit shall not exceed 959 lb/hr during startup or shutdown operations.

[R307

- 401

- 8]

II.B.2.f Emissions of GHG from both CT/HRSG units combined shall not exceed 1,958,552.1 metric

tons of CO 2 e per rolling 12

- month period. Compliance with the rolling 12

- month period shall be determined through use of the CO 2 CEM as outlined in condition II.B.1.b above. Non

- CO 2 GHGs shall use Emission factors from Table C

- 2 of 40 CFR Part 98 and global warming potentials from Table A

- 1 of 40 CFR part 98, along with the actual me asured heat input to the combustion turbines. [R307

- 401

- 8, R307

- 170]

II.B.2.g The height of the CT/HRSG stacks shall be no less than 165 feet, as measured from ground

level at the base of the stack. [R307

- 410

- 6]

II.B.3 Conditions on Auxiliary Boiler

II.B.3.a Emissions to the atmosphere from the indicated emission point(s) shall not exceed the

following rates and concentrations:

Source: Auxiliary Boiler #2

Pollutant Limitations Averaging Period
PM 10 /PM 2.5 0.01 lb/MMBtu 3

- hour
NO

x 0.017 lb/MMBtu 3

- hour
CO 0.0375 lb/MMBtu 3

- hour

[R307

- 401

- 8]

II.B.3.b Stack testing to show compliance with the emission limitations stated in the above condition

shall be performed as specified below:

Emissions Point Pollutant Status Frequency

Auxiliary Boiler PM 10 /PM 2.5 * %

NO

x * % CO * %

Testing Status (To be applied t o the sources listed above)

* Initial compliance testing is required. The initial test date shall be performed as soon as possible and in no case later than 180 days after the start up of a new emission source, an existing source without an AO, or the granting of an AO to an existing emission source that has not had an initial compliance test performed. If an existing source is modified, a compliance test is required on the modified emission point that
has an emission rate limit.DAQE

- AN 1252 90003

- 12

Page 8

% Test every five (5) years or testing may be replaced with parametric monitoring if

approved by the Director

[ R307

- 165]

II.B.3.c For all emissions testing the following shall apply:

Notification:

The Director shall be notified at least 30 days prior to conducting any required emission testing. A source test protocol shall be submitted to DAQ when the testing notification is
submitted to the Director

.

The source test proto col shall be approved by the Director prior to performing the test(s). The source test protocol shall outline the proposed test methodologies, stack to be tested, and procedures to be used. A pretest conference shall be held, if directed by the Director

.

Sample Location:

The emission point shall be designed to conform to the requirements of 40 CFR 60, Appendix A, Method 1, or other methods as approved by the Director . An Occupational Safety and Health Administration (OSHA) or Mine Safety and Health Adm inistration (MSHA) approved access shall be provided to the test location.

Volumetric Flow Rate:

40 CFR 60, Appendix A, Method 2 or EPA Test Method No. 19 "SO 2 Removal & PM, SO 2 , NO

x Rates from Electric Utility Steam Generators" or other testing methods approved by the
Director

.

PM 10 /PM 2.5 :

For stacks in which no liquid drops are present, the following methods shall be used: 40 CFR 51, Appendix M, Methods 201, 201a and 202, or other testing methods approved by the
Director . All particulate captured shall be considered PM 10 /PM 2.5 . The back half condensibles shall be used for compliance demonstration as well as for inventory purposes.

For stacks in which liquid drops are present, me thods to eliminate the liquid drops should be explored. If no reasonable method to eliminate the drops exists, then the following methods shall be used: 40 CFR 60, Appendix A, Method 5, 5a, 5d, or 5e as appropriate, or other testing methods approved by t he Director . The back half condensibles shall also be tested using the method specified by the Director . The portion of the front half of the catch considered PM 10 shall be based on information in Appendix B of the fifth edition of the EPA document, AP

- 4 2, or other data acceptable to the Director

.

NO

x :

40 CFR 60, Appendix A, Method 7, 7A, 7B, 7C, 7D, 7E, or other testing methods approved by
the Director

.

CO:

40 CFR 60, Appendix A, Method 10, or other testing methods approved by the Director

.DAQE

- AN 1252 90003

- 12

Page 9

Calcula tions:

To determine mass emission rates (lb/hr, etc.) the pollutant concentration as determined by the appropriate methods above shall be multiplied by the volumetric flow rate and any necessary conversion factors determined by the Director , to give the r esults in the specified units of the emission limitation. [R307

- 165]

II.B.4 Conditions on Emergency Generator

II.B.4.a Emergency generators shall be used for electricity producing operation only during the periods

when electric power from the public u tilities is interrupted, and for regular maintenance and testing. Records documenting generator usage shall be kept in a log and they shall show the date the generator was used, the duration in hours of the generator usage, and the reason for each generat or usage. [R307

- 401

- 8]

II.B.5 Conditions on Diesel

- Fired Equipment

II.B.5.a The owner/operator shall use a combination of #1 or #2 fuel oil or diesel fuel in the emergency

generators and fire pump.

The sulfur content of any #1 or #2 fuel oil or diesel fuel burned shall not exceed 0.0015 percent by weight. Sulfur content shall be determined by ASTM Method D

- 4294

- 89, or approved equivalent. Certification of fuels shall be either by the owner/operator's own testing or test reports from the fuel ma rketer or supplier. For purposes of demonstrating compliance with this limitation, the owner/operator may obtain the above specifications by testing each purchase of fuel in accordance with the required methods; by inspection of the specifications provide d by the vendor for each purchase of fuel; or by inspection of summary documentation of the fuel sulfur content from the vendor; provided that the above specifications are available from the vendor for each purchase if requested. [R307

- 401

- 8]

Section III: A PPLICABLE FEDERAL REQUIREMENTS

In addition to the requirements of this AO, all applicable provisions of the following federal programs have been found to apply to this installation. This AO in no way releases the owner or operator from any liability for compliance with all other applicable federal, state, and local regulations including UAC
R307.

NSPS (Part 60), A: General Provisions NSPS (Part 60), Dc: Standards of Performance for Small Industrial

- Commercial

- Institutional Steam Generating Units NSPS (Part 60), IIII: Standards of Performance for Stationary Compression Ignition Internal Combustion Engines NSPS (Part 60), KKKK: Standards of Performance for Stationary Combustion Turbines
M ACT (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) Title V (Part 70) major sourceDAQE

- AN 12529000 3

- 12

Page 10

PERMIT HISTORY

This AO is based on the following documents:

Is Derived From Source submitted NOI dated September 8, 2011 Incorporates Additional information received dated January 19, 2012

ADMINISTRATIVE CODING

The following information is for UDAQ internal classification use only:

Sevier County
CDS A NSR, PSD, MACT (Part 63), Attainment Area, Title IV (Part 72 / Acid Rain), Compliance Assurance Monitoring (CAM), Title V (Part 70) major source, Major criteria source, NSPS (Part 60),DAQE

- AN 125290003

- 12

Page 11

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
CO 2 Carbon Dioxide
CO 2 e Carbon Dioxide Equivalent

- 40 CFR Part 98, Subpart A, Table A

- 1
COM Continuous opacity monitor DAQ Division of Air Quality (typically interchangeable with UDAQ) 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
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

NO

x Oxides of nitrogen

NSPS New Source Performance Standard

NSR New Source Review

PM 10 Particulate matter less than 10 microns in size

PM 2.5 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

SO 2 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 UDAQ Utah Division of Air Quality (typically interchangeable with DAQ)

VOC Volatile organic compoundsEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 1 

## UTAH DIVISION OF AIR QUALITY

SOURCE PLAN REVIEW

Bruce Taylor Sevier Power Company

620 S Main Bountiful, UT 840100 Project Number: N0125290003

RE: NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant Sevier County; CDS A; NSR, PSD, MACT (Part 63), Attainment Area, Title IV (Part 72 / Acid Rain), Compliance Assurance Monitoring (CAM), Title V (Part 70) major source, Major criteria source, NSPS (Part 60),

Review Engineer: John Jenks Date: March 30, 2012

Notice of Intent Submitted: September 8, 2011

Plant Contact: Bruce Taylor Phone Number: (801) 916-7341

Source Location: 414,332 m Easting 4,300,261 Northing, Zone 12, Sigurd,

UT Sevier County

4300261 m Northing, 414332 m Easting, UTM Zone 12

UTM Datum: NAD83

DAQ requests that a company/corporation official read the attached draft/proposed Plan Review with Recommended Approval Order Conditions. If this pers on does not understand or does not agree with the conditions, the review engineer should be contacted within five days after receipt of the Plan Review. If this person agrees with the Plan Review and R ecommended Approval Order Conditions, this person should sign below and return (FAX # 801-536-4099) with in 10 days after receipt of the conditions. If the review engineer is not contacted within 10 da ys, the review engineer shall assume that the company/corporation official agrees with this Plan Review and will process the Plan Review towards final approval. A public comment period will be re quired before the Approval Order can be issued.

Applicant Contact ______________________________________________________________ (Signature & Date)Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 2 OPTIONAL: In order for this Source Plan Review and associated Approval Order conditions to be administratively included in your Operating Permit (App lication), the Responsible Official as defined in R307-415-3, must sign the statement below and th e signature above is not necessary. THIS IS

STRICTLY OPTIONAL!

If you do not desire this Plan Review to be administratively included in your Operating Permit (Application), only the Applicant Contact signature a bove is required. Failure to have the Responsible Official sign below will not delay the Approval Or der, but will require a separate update to your Operating Permit Application or a request for modi fication of your Operating Permit, signed by the Responsible Official, in accordance with R307 --415-5a through 5e or R307-415-7a through 7i.

“Based on reasonable inquiry, I certify that the information provided for this Approval Order has been true, accurate and complete and request that this Approval Order be administratively amended to the Operating Permit (Application).”

Responsible Official _________________________________________________ (Signature & Date)

Print Name of Responsible Official _____________________________________Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 3 

### ABSTRACT

As the abstract is longer than the available space in this field, please see the attached document SPC -

Abstract.docx for additional details.



### SOURCE SPECIFIC DESIGNATIONS

Applicable Programs: NSPS (Part 60), Subpart A: General Provisions applies to Power Plant NSPS (Part 60), Subpart Dc: Standards of Perform ance for Small Industrial-Commercial-Institutional Steam Generating Units applies to Auxiliary Boiler NSPS (Part 60), Subpart Dc: Standards of Perform ance for Small Industrial-Commercial-Institutional Steam Generating Units applies to Convection Fuel Heaters NSPS (Part 60), Subpart IIII: Standards of Performan ce for Stationary Compression Ignition Internal Combustion Engines applies to Emergency Fire Water Pump NSPS (Part 60), Subpart IIII: Standards of Performan ce for Stationary Compression Ignition Internal Combustion Engines applies to Emergency Generator NSPS (Part 60), Subpart KKKK: Standards of Pe rformance for Stationary Combustion Turbines applies to Combustion Turbines MACT (Part 63), Subpart A: General Provisions applies to Power Plant MACT (Part 63), Subpart ZZZZ: National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion E ngines applies to Emergency Fire Water Pump MACT (Part 63), Subpart ZZZZ: National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combusti on Engines applies to Emergency Generator Attainment Area applies to Power Plant Compliance Assurance Monitoring (CAM) applies to Power Plant Major criteria source applies to Power Plant NSR applies to Power Plant PSD applies to Power Plant Title IV (Part 72 / Acid Rain) applies to Power Plant Title V (Part 70) major source applies to Power Plant

Permit History:

When issued, the approval order shall supersede or will be based on the following documents:

Is Derived From Source submitte d NOI dated Sept ember 8, 2011 Incorporates Additional information received dated January 19, 2012



### SUMMARY OF NOTICE OF INTENT INFORMATION

Description of Proposal:

Sevier Power Company (SPC) proposes to construct a nd operate a new natural gas-fired combined-cycle power generating plant to be located approximately 8 miles northeast of Richfield Utah in Sevier County, Utah. The proposed plant upon completion will incl ude a single power block, fired exclusively onEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 4 pipeline-quality natural gas, and will consist of eith er two General Electric (GE) Frame 7FA or Siemens Westinghouse 5000-F(4) gas turbines, two heat recove ry steam generators (HRSGs) with supplemental firing, and one steam turbine in a combined-cycle configuration, with associated equipment including an air-cooled condenser, a natural gas-fired auxiliary boi ler, two natural gas-fired fuel heaters, a diesel engine-driven fire pump, and a diesel engine emergenc y generator. The combined cycle plant will have a nominal electrical generating capacity output of approximately 580 megawatts (MWe).

The proposed plant is considered to be a major Prevention of Significant Deterioration (PSD) source and is listed as one of the 28 major cate gories as defined in 40 CFR Part 52.21. The criteria pollutants that will be emitted from the facility are nitrogen oxides (NO

x ), carbon monoxide (CO), volatile organic compounds (VOCs), particulate matter (PM 10 and PM 2.5 ), and sulfur dioxide (SO 2 ). The proposed electric generating facility has the potential to emit (PTE) regulated pollutants in amounts above significant levels as 40 CFR Part 52.21 (b) 23 for the following: NO

x , PM 10 and PM 2.5 , CO, and VOC.

Summary of Emission Totals:

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

Estimated Criteria Pollutant Potential Emissions

CO 2 Equivalent 2,019,226.1 tons/yr Carbon Monoxide 577.40 tons/yr Nitrogen Oxides 168.30 tons/yr

Particulate Matter - PM 10 106.00 tons/yr

Particulate Matter - PM 2.5 106.00 tons/yr Sulfur Dioxide 25.70 tons/yr Volatile Organic Compounds 91.60 tons/yr

Estimated Hazardous Air Pollutant Potential Emissions Total HAPs (CAS #THAPS) 8.50 tons/yr

Total hazardous air pollutants 8.50 tons/yr

Review of Best Available Control Technology:

1. BACT review regarding Criteria Polluta nt BACT - Combustion Turbines and HRSGs As required under R307-401-8(1)(a) and also under R307-405-11, "the degree of pollution

control for emissions ... is at least best availa ble control technology." Best available control technology or BACT is defined in R307-401-2(d) . SPC submitted a BACT analysis following EPA's recommended "top-down" approach, wh ich is a five-step methodology outlined as

follows:

Step 1 - Identify all control technologies Step 2 - Eliminate technically infeasible options Step 3 - Rank remaining control technologies by control effectiveness Step 4 - Evaluate most effective controls Step 5 - Select BACT

This approach has been well documented a nd discussed, and is the most commonly acceptedEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 5 approach to satisfy the case-by-case requirement for BACT determination. UDAQ will not include an in-depth discussion of the top-dow n methodology here. Rather, UDAQ reviewed SPC's BACT submittal and agrees with the reached conclusions. For the CT/HRSG units those

conclusions are:

NO

x - use of dry low-NO

x (DLN) combustors, SCR, and ammonia injection to achieve an emissions limit of 2.0 ppmdv @ 15% O 2 on a 3-hour average

CO - DLN combustors, good combustion practices, oxidation catalyst (oxy-cat) system with a limit of 3.0 ppmdv @ 15% O 2 on a 3-hour average

VOC - DLN combustors, good combustion practi ces, oxy-cat with a limit of 3.0 ppmdv @ 15%

O 2 on a 3-hour average

PM 10 /PM 2.5 - good combustion practices, natural gas as fuel, limit of 14 lb/hr on a 30-day rolling

average

SO 2 /H 2 SO 4 - good combustion practices, natural gas as fuel, limit of 3.4 lb/hr on a 30-day rolling average [Last updated March 29, 2012]

2. BACT review regarding Criteria Pollutant BACT - Auxiliary Boiler For the Auxiliary Boiler those conclusions are:

NO

x - use of ultra-low-NO

x burners (ULNB) and FGR to achieve an emissions limit of 0.017 lb/MMBtu, 1.45 lb/hr

CO - good combustion practices with a limit of 0.0375 lb/MMBtu

PM 10 /PM 2.5 - good combustion practices, natural gas as fuel, limit of 0.01 lb/MMBtu

SO 2 /H 2 SO 4 - natural gas as fuel [Last updated March 9, 2012]

3. BACT review regarding Criteria Po llutant BACT - Miscellaneous Sources

For the convection heaters those conclusions are:

NO

x - use of low-NO

x burners (LNB) utilizing low excess air and FGR to achieve an emissions limit of 0.036 lb/MMBtu, 0.81 lb/hr

CO - good combustion practices with a limit of 0.074 lb/MMBtu

PM 10 /PM 2.5 - good combustion practices, natural gas as fuel, limit of 0.01 lb/MMBtu

SO 2 /H 2 SO 4 - natural gas as fuel

For the diesel fired engines (emergency gene rator and emergency fire water pump) those

conclusions are:

NO

x - use of Tier II (emergency generator) and Tier III (fire water pump) engines, hours of operation for testing and maintenance limite d to 100 hrs/yr as per 40 CFR 63 Subpart ZZZZEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 6 CO - use of Tier II and Tier III engines, hours of operation for testing and maintenance limited to 100 hrs/yr

SO 2 /H 2 SO 4 - ultra low sulfur diesel (15 ppm sulfu r) as fuel [Last updated March 9, 2012]

4. BACT review regarding Startup / Shutdown BACT While post-combustion controls work extr emely well during normal operations, catalytic oxidation and reduction systems (SCR and oxy- cat) are of limited use during startup and shutdown periods. While some degree of emissi on control is possible, catalytic systems are designed to operate within specific temperature ranges and care must be taken to avoid thermal stresses during heating or cooling. Therefore, during startup and shutdown there will be periods when the catalyst beds have reduced or limited c ontrol efficiency. For this reason, the optimal control technique is to limit the number and du ration of startup and shutdown events, as this limits the amount of operation under these periods of reduced efficiency.

SPC estimates that a maximum of 12 cold starts (equipment is cold prior to startup), lasting approximately 8 hours, 50 warm starts (equipment is warm), las ting approximately 4 hours, and 230 hot starts (equipment is near normal opera ting temperature), lasting approximately 1-3 hours, will occur annually.

Limits on emissions of 126 lb/hr for NO

x and 959 lb/hr for CO shall apply during all startup and shutdown periods. [Last updated March 23, 2012]

5. BACT review regarding GHG BACT At this point in time, the only practical way to reduce the amount of CO 2 generated is to minimize the amount of fuel combustion required to produce the desired amount of electricity. This is achieved by operating the equipment efficiently in accordance with manufacturer standards and conducting periodic maintenance on the equipment to keep it at its optimum performance. In comparison to other fuels, natural gas generates a lower amount of CO 2 and will be used exclusively by SPC for the CTs/HRSGs.

To determine an appropriate CO 2 emissions limit for the CT/HRSGs, a search of state and EPA's RBLC databases for recent issued permits was conducted to proposed a BACT emission limit for the CTs/HRSGs, the auxiliary boiler, and c onvection heaters. Two permits were identified, PacifiCorp Lakeside in Utah County, Utah and Russell Energy Center in Alameda County,

California with a CO 2 BACT limit which was 1,100 pounds CO 2 per net megawatt-hour. This

CO 2 limit is comparable to the average emissions ra te for all natural gas fired power plants of 1135 lbs/MW-hr that was published by EPA.

However, in the Response to Comments Document for Russell City Energy Center's project, EPA suggested that a proper BACT value should be established based on: 1) output based; 2) efficiency-based; 3) and include reasonable assumptions on degradation factors such as a compliance design margin and performance degradation from normal wear and tear. UDAQ pointed out to the EPA, however, that two factors also need to be accounted in establishing a proper BACT value which include: (1) An adjustme nt of power output for sources located at a much higher elevation; and (2) a discussion of rela tive percentage of duct firing since duct firing has a different emissions profile than that of the combustion turbine.

The Russell City Energy Center established a final efficiency rating of 7730 Btu/kWhr (HHV).Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 7 This was based on the maximum efficiency of 6, 852 Btu/kWhr for each turbine, readjusting to 7,080 Btu/kWhr for an "as installed" rating, and then readjusting again for normal degradation. Russell City is located at an elevation of 16 feet above sea level. The proposed heat input rate for the Russell City Energy Center was 2,038. 6 MMBtu/hr for each turbine and an additional 200 MMBtu/hr for duct firing in the HRSG.

Lake Side II followed a similar approach a nd established an efficiency rating of 8,095 Btu/kWhr. Lake Side II is located at an elevation of approximately 4,550 feet above sea level with a proposed a heat input rate of 1762 MM Btu/hr for each turbine and an additional 400 MMBtu/hr for duct firing.

The Russell City Energy Center is able to supply more fuel to the turbines given its much lower elevation. The total expected output of the plant is approximately 612 MW w ith 8.9% of its total heat input coming from duct firing. Lakeside II is a 629 MW plant with 18.5% of its heat input from duct firing.

The proposed SPC facility will have an efficiency rating of approximately 7,515 Btu/kWhr and occurs at the extreme low ambient conditions of -17°F. The SPC facility will be located at approximately 5,303 feet above mean sea-level. Th e proposed heat input rate of each turbine is a maximum of 1916.5 MMBtu/hr. The proposed heat input to the duct burners will be as high as 540 MMBtu/hr. The proposed SPC facility will be a nominal 580 MW plant with 8.1% of its total heat input coming from duct firing.

The NSR section recommends that the use of high efficiency CT/HRSG units be accepted as

BACT for GHG emissions. As more than 98% of the GHG emissions are the CO 2 emissions from the CT/HRSG units, a limit of 1,926,426 MT of CO 2 /yr from both CT/HRSG units combined shall be set, with compliance demonstrated by CEM. [Last updated March 27, 2012]

Modeling Results:

Please see Modeling Memorandum MN125290003- 12.docx for UDAQ's analysis and recommendations [Last updated March 8, 2012]Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 8 

### RECOMMENDED APPROVAL ORDER CONDITIONS

The intent is to issue an air quality Approval Or der (AO) authorizing the project with the following recommended conditions and that failure to comply w ith any of the conditions may constitute a violation of the AO. The AO will be issued to and will apply to the following:

Name of Permittee:

Sevier Power Company

620 S Main Bountiful, UT 840100 Permitted Location:

Sevier Power Company: Power Plant 414,332 m Easting 4,300,261 Northing

Zone 12 Sigurd, UT 84657

UTM coordinates: 414332 m Easting, 4300261 m Northing, UTM Zone 12

SIC code: 4911 (Electric Services)

Section I: GENERAL PROVISIONS

I.1 All definitions, terms, abbrevia tions, 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 appr oved 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 app licable rules, which are required to be kept by the owner/operator, shall be made available to th e Executive Secretary or Executive Secretary'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, s hutdown, and malfunction, owne rs 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. Determin ation of whether acceptable operating and maintenance procedures are being used will be based on information available to the Executive Secretary 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: Unavoidable Breakdowns. [R307-107]

I.7 The owner/operator shall comply with UAC R307-150 Series. Inventories, Testing and Monitoring. [R307-150]Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 9 Section II: SPECIAL PROVISIONS

II.A The approved installations shall consist of the following equipment:

II.A.1 Power Plant Nominal 580 MW natural gas-fired combustion turbine power plant

II.A.2 Turbine 1 F-Class combustion turbine with dry low-NO

x II.A.3 HRSG 1 Heat recovery steam generator with duct burners, SCR and catalytic oxidation

II.A.4 Turbine 2 F-Class combustion turbine with dry low-NO

x II.A.5 HRSG 2 Heat recovery steam generator with duct burners, SCR and catalytic oxidation

II.A.6 Auxiliary Boiler 85 MMBtu/hr auxiliary boiler with ULNB and FGR

II.A.7 Convection Fuel Heaters Two (2) 22.3 MMBtu/hr fuel heaters

II.A.8 Emergency Generator 1,250 kWe emergency diesel generator

II.A.9 Emergency Fire Water Pump 300 kWe diesel-fired fire water pump

II.A.10 Water Treatment Water treatment and storage facilities

II.A.11 Ammonia Storage and Handling Aqueous ammonia storage and handling equipment

II.B Requirements and Limitations

II.B.1 Conditions on Permitted Source

II.B.1.a SPC shall notify the Executive Secretary in wr iting when the installation of the equipment listed in II.A has been completed and is operational, as an initial compliance inspection is required. To insure proper credit when notifying the Executiv e Secretary, send your correspondence to the Executive Secretary, attn: Compliance Section.

If construction and/or installation has not been completed within eighteen months from the date of this AO, the Executive Secretary shall be notif ied in writing on the status of the construction and/or installation. At that time, the Execu tive Secretary shall require documentation of the

continuous construction and/or installati on of the operation and may revoke the AO. [R307-401-8]

II.B.1.b The owner/operator shall install, calibra te, maintain, and operate a continuous emissions monitoring system on each of the HRSG stacks. The owner/operator shall record the output of the system, for measuring the NO

x and CO emissions. The monitoring system shall comply with all applicable sections of R307-170; 40 CFR 60.13; and 40 CFR 60, Appendix B. The NO

x monitor shall comply with 40 CFR 75, Appendix A and B.Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 10 All continuous emissions monitoring devices as re quired in federal regulations and state rules shall be installed prior to placing the affect ed source in operation. These devices shall be certified within 90 days of achieving full load, not to exceed 180 days after startup.

Except for system breakdown, repairs, calibra tion checks, and zero and span adjustments required under paragraph (d) 40 CFR 60.13, the ow ner/operator of an affected source shall continuously operate all requi red continuous monitoring systems and shall meet minimum frequency of operation requirements as outlined in R307-170 and 40 CFR 60.13. [R307-170, 40 CFR 60.13]

II.B.1.c Visible emissions shall not exceed the following values:

All natural gas combustion exhaust stacks - 10% opacity All other emission points - 20% opacity

Opacity observations of emissions from stationa ry sources shall be conducted according to 40 CFR 60, Appendix A, Method 9. [R307-401-8]

II.B.1.d The owner/operator shall use natural gas as fuel in the combustion turbines, duct burners and auxiliary boiler. [R307-401-8]

II.B.2 Conditions on Combustion Turbines and HRSGs

II.B.2.a Emissions to the atmosphere from the indicat ed emission point(s) shall not exceed the following

rates and concentrations:

Source: Each Turbine/HRSG Stack

Pollutant Limitations Averaging Period

PM 10 /PM 2.5 14 lb/hour (with duct firing) 30-day rolling average

NO

x 2.0 ppmvd at 15% O 2 * 3-hour CO 3.0 ppmvd at 15% O 2 * 3-hour VOC 3.0 ppmvd at 15% O 2 * 3-hour

* Under steady state operation [R307-401-8]

II.B.2.b Stack testing to show compliance with th e emission limitations stated in the above condition shall be performed as specified below:

Emissions Point Pollutant Status Frequency

HRSG Stacks PM 10 /PM 2.5 * $

NO

x * #

CO * #Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 11 VOC * %

Testing Status (To be applied to the sources listed above)

* Initial compliance testing is required. The initial test date shall be performed as soon as possible and in no case later than 180 days after the start up of a new emission source, an existing source without an AO, or the granting of an AO to an existing emission source that has not had an initial compliance test performed. If an existing source is modified, a compliance test is required on the modified emission point that has an emission rate limit.

$ Test every year or testing may be replaced with parametric monitoring if approved by the Executive Secretary % Test every five (5) years or testing may be replaced with parametric monitoring if approved by the Executive Secretary # Compliance shall be demonstrated through use of a Continuous Emissions Monitoring System (CEM) as outlined in Condition II.B.1.b. The Ex ecutive Secretary may require testing at any

time. [R307-165]

II.B.2.c For all emissions testing the following shall apply:

Notification:

The Executive Secretary shall be notified at least 30 days prior to conducting any required emission testing. A source test protocol shall be submitted to DAQ when the testing notification is submitted to the Executive Secretary.

The source test protocol shall be approved by the Executive Secretary prior to performing the test(s). The source test protocol shall outline th e proposed test methodologies, stack to be tested, and procedures to be used. A pretest conferen ce shall be held, if directed by the Executive Secretary.

Sample Location:

The emission point shall be designed to confor m to the requirements of 40 CFR 60, Appendix A, Method 1, or other methods as approved by the Executive Secretary. An Occupational Safety and Health Administration (OSHA) or Mine Safety and Health Administration (MSHA) approved access shall be provided to the test location.

Volumetric Flow Rate:

40 CFR 60, Appendix A, Method 2 or EPA Test Method No. 19 "SO 2 Removal & PM, SO 2 , NO

x Rates from Electric Utility Steam Generators " or other testing methods approved by the Executive Secretary.

PM 10 /PM 2.5 :

For stacks in which no liquid drops are present, the following methods shall be used: 40 CFR 51, Appendix M, Methods 201, 201a and 202, or ot her testing methods approved by the Executive Secretary. All particulate captured shall be considered PM 10 /PM 2.5 . The back half condensiblesEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 12 shall be used for compliance demons tration as well as for inventory purposes.

For stacks in which liquid drops are present, methods to eliminate the liquid drops should be explored. If no reasonable method to eliminate the drops exists, then the following methods shall be used: 40 CFR 60, Appendix A, Method 5, 5a, 5d, or 5e as appropriate, or other testing methods approved by the Executive Secretary. The back half condensibles shall also be tested using the method specified by the Executive Secretary. The portion of the front half of the catch

considered PM 10 shall be based on information in Appe ndix B of the fifth edition of the EPA document, AP-42, or other data acceptable to the Executive Secretary.

NO

x :

40 CFR 60, Appendix A, Method 7, 7A, 7B, 7C, 7D , 7E, or other testing methods approved by the Executive Secretary.

CO:

40 CFR 60, Appendix A, Method 10, or other testing methods approved by the Executive Secretary.

Calculations:

To determine mass emission rates (lb/hr, etc.) th e pollutant concentration as determined by the appropriate methods above shall be multiplied by the volumetric flow rate and any necessary conversion factors determined by the Executive Secretary, to give the results in the specified

units of the emission limitation. [R307-165]

II.B.2.d Compliance with the 3-hour NO

x and CO emission limitations sp ecified in Condition II.B.2.a shall not be required during short-term excursi ons, limited to a cumulative total of 160 hours annually. Short-term excursions are de fined as 15-minute periods designated by the owner/operator that are the direct result of transient load conditions, not to exceed four consecutive 15-minute periods, when the 15-minute average NO

x and CO concentrations exceed 2.0 ppmv and 3.0 ppmv, dry @ 15% O 2 , respectively. Transient load conditions include the following:

1. Initiation/shutdown of combustion turbine inlet air-cooling 2. Rapid combustion turbine load changes

3. Initiation/shutdown of HRSG duct burners 4. Provision of Ancillary Servi ces and Automatic Generation Control

During periods of transient load conditions, the NO

x concentration shall not exceed 25 ppmv and

the CO concentration shall not exceed 50 ppmv, dry @ 15% O 2 . All NO

x and CO emissions during these events shall be included in all calcu lations of annual mass emissions as required by this permit. [R307-401-8]

II.B.2.e Steady state operation means all periods of combustion turbine operation, except for periods of startup and shutdown as defined below, and periods of transient load conditions as defined inEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 13 Condition II.B.2.d. Startup is defined as the pe riod beginning with turbine initial firing until the unit meets the ppmvd emission limits in Condition II .B.2.a for steady state operation. Shutdown is defined as the period beginning with the in itiation of turbine shutdow n sequence and ending with the cessation of firing of the gas turbine engine.

Emissions of NO

x from each CT/HRSG unit shall not exceed 126 lb/hr during startup or shutdown operations

Emissions of CO from each CT/HRSG unit shall not exceed 959 lb/hr during startup or shutdown operations [R307-401-8]

II.B.2.f Emissions of GHG from both CT/HRSG units combined shall not exceed 1,926,426 metric tons

of CO 2 per rolling 12-month period. Compliance with the rolling 12-month period shall be determined through use of the CO 2 CEM as outlined in condition II.B.1.b above. [R307-170, R307-401-8]

II.B.2.g The height of the CT/HRSG stacks shall be no less than 165 feet, as measured from ground level

at the base of the stack. [R307-410-6]

II.B.3 Conditions on Auxiliary Boiler

II.B.3.a Emissions to the atmosphere from the indicat ed emission point(s) shall not exceed the following

rates and concentrations:

Source: Auxiliary Boiler #2

Pollutant Limitations Averaging Period

PM 10 /PM 2.5 0.01 lb/MMBtu 3-hour

NO

x 0.017 lb/MMBtu 3-hour

CO 0.0375 lb/MMBtu 3-hour [R307-401-8]

II.B.3.b Stack testing to show compliance with th e emission limitations stated in the above condition shall be performed as specified below:

Emissions Point Pollutant Status Frequency

Auxiliary Boiler PM 10 /PM 2.5 * %

NO

x * %

CO * %

Testing Status (To be applied to the sources listed above)

* Initial compliance testing is required. The initial test date shall be performed as soon as possible and in no case later than 180 days after the start up of a new emission source, an existing source without an AO, or the granting of an AO to an existing emission source that hasEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 14 not had an initial compliance test performed. If an existing source is modified, a compliance test is required on the modified emission point that has an emission rate limit.

% Test every five (5) years or testing may be replaced with parametric monitoring if approved by the Executive Secretary

[R307-165]

II.B.3.c For all emissions testing the following shall apply:

Notification:

The Executive Secretary shall be notified at least 30 days prior to conducting any required emission testing. A source test protocol shall be submitted to DAQ when the testing notification is submitted to the Executive Secretary.

The source test protocol shall be approved by the Executive Secretary prior to performing the test(s). The source test protocol shall outline th e proposed test methodologies, stack to be tested, and procedures to be used. A pretest conferen ce shall be held, if directed by the Executive Secretary.

Sample Location:

The emission point shall be designed to confor m to the requirements of 40 CFR 60, Appendix A, Method 1, or other methods as approved by the Executive Secretary. An Occupational Safety and Health Administration (OSHA) or Mine Safety and Health Administration (MSHA) approved access shall be provided to the test location.

Volumetric Flow Rate:

40 CFR 60, Appendix A, Method 2 or EPA Test Method No. 19 "SO 2 Removal & PM, SO 2 , NO

x Rates from Electric Utility Steam Generators " or other testing methods approved by the Executive Secretary.

PM 10 /PM 2.5 :

For stacks in which no liquid drops are present, the following methods shall be used: 40 CFR 51, Appendix M, Methods 201, 201a and 202, or ot her testing methods approved by the Executive Secretary. All particulate captured shall be considered PM 10 /PM 2.5 . The back half condensibles shall be used for compliance demons tration as well as for inventory purposes.

For stacks in which liquid drops are present, methods to eliminate the liquid drops should be explored. If no reasonable method to eliminate the drops exists, then the following methods shall be used: 40 CFR 60, Appendix A, Method 5, 5a, 5d, or 5e as appropriate, or other testing methods approved by the Executive Secretary. The back half condensibles shall also be tested using the method specified by the Executive Secretary. The portion of the front half of the catch

considered PM 10 shall be based on information in Appe ndix B of the fifth edition of the EPA document, AP-42, or other data acceptable to the Executive Secretary.Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 15 NO

x :

40 CFR 60, Appendix A, Method 7, 7A, 7B, 7C, 7D , 7E, or other testing methods approved by the Executive Secretary.

CO:

40 CFR 60, Appendix A, Method 10, or other testing methods approved by the Executive Secretary.

Calculations:

To determine mass emission rates (lb/hr, etc.) th e pollutant concentration as determined by the appropriate methods above shall be multiplied by the volumetric flow rate and any necessary conversion factors determined by the Executive Secretary, to give the results in the specified

units of the emission limitation. [R307-165]

II.B.4 Conditions on Emergency Generator

II.B.4.a Emergency generators shall be used for el ectricity producing operation only during the periods when electric power from the public utilities is interrupted, and for regular maintenance and testing. Records documenting generator usage sha ll be kept in a log and they shall show the date the generator was used, the duration in hour s of the generator usage, and the reason for each

generator usage. [R307-401-8]

II.B.5 Conditions on Diesel-Fired Equipment

II.B.5.a The owner/operator shall use a combination of #1 or #2 fuel oil or diesel fuel in the emergency generators and fire pump.

The sulfur content of any #1 or #2 fuel oil or diesel fuel burned shall not exceed 0.0015 percent by weight. Sulfur content shall be dete rmined by ASTM Method D-4294-89, or approved equivalent. Certification of fuels shall be eith er by the owner/operator's own testing or test reports from the fuel marketer or supplier. Fo r purposes of demonstrating compliance with this limitation, the owner/operator may obtain the a bove specifications by testing each purchase of fuel in accordance with the required methods; by inspection of the specifications provided by the vendor for each purchase of fuel; or by inspection of summary documentation of the fuel sulfur content from the vendor; provided that the above sp ecifications are available from the vendor for each purchase if requested. [R307-401-8]Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 16 Section III: APPLICABLE FEDERAL REQUIREMENTS

In addition to the requirements of this AO, all a pplicable provisions of the following federal programs have been found to apply to this installation. Th is AO in no way releases the owner or operator from any liability for compliance with all other applicable fe deral, state, and local regulations including UAC

R307.

NSPS (Part 60), A: General Provisions NSPS (Part 60), Dc: Standards of Performance for Sma ll Industrial-Commercial-Ins titutional Steam Generating

Units NSPS (Part 60), IIII: Standards of Performance for St ationary Compression Ignition Internal Combustion Engines NSPS (Part 60), KKKK: Standards of Performance for Stationary Combustion Turbines MACT (Part 63), A: General Provisions MACT (Part 63), ZZZZ: National Emissions Standard s for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines Title IV (Part 72 / Acid Rain) Title V (Part 70) major sourceEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 17 REVIEWER COMMENTS

The AO will be based on the following documents:

Is Derived From Source submitte d NOI dated Sept ember 8, 2011 Incorporates Additional information received dated January 19, 2012

1. Comment regarding PSD Applicability: Because the SPC power plant is defined as a fossil fuel-fired steam electric plant of greater than 250 MMBtu/hr heat input, it falls into one of the 28 listed source categories with a 100 tpy emission threshold for determination as a majo r stationary source under PSD. The SPC power plant will be a major source for at least one PSD regulated pollutant as found under 40 CFR 52.21(b)(1)(i)(a). Therefore, any pollutant with emissions greater than the significance level will also be subject to PSD review. An analysis of SPC's emissions reveals that NO 2 , CO, PM 10 and

PM 2.5 are all subject to PSD review (GHG emissi ons will be covered under a separate review comment).

In addition to the application of BACT (covered elsewhere) and an analysis of air quality impacts, a source subject to PSD must also submit an Additional Impacts Analysis which addresses the impact to visibility; acid deposition; the impact on soils, vegetation and w ildlife; and the general commercial, residential, industrial and ot her growth associated with the source.

For purposes of this review, visibility and acid deposition are both addressed in the associated (and attached) modeling memorandum MN125290003-12.docx.

The soils vegetation and wildlife analysis was submitted under Appendix P of the September 8, 2012 NOI. After review of the expected emissi ons from the SPC power plant, modeled impacts on Air Quality Related Values (AQRVs) were below, and in most cases far below, the significant impact levels established by EPA. Therefore, no adve rse impact to soils, vegetation or wildlife is expected.

The growth analysis is found in section 8.2 of the NOI. No new commercial construction, housing, or industrial construction would be necess ary during the construction period. Similarly, no new housing, commercial or i ndustrial construction is expected as a result of operating the power plant. The full-time permanent positions re quired are estimated at 20-25, with some of these positions filled by local residents. Given these growth expectations, no new significant emissions are anticipated from secondary growth du ring either construction or operation of the power plant. [Last updated March 27, 2012]

2. Comment regarding NSPS Applicability: The following New Source Performance Standards we re determined to be applicable to the SPC power plant:

40 CFR 60 Subpart A - General Provisions. This subpart outlines general provisions applicable to a source subject to any other subpart under 40 CFR 60.

40 CFR 60 Subpart Dc - Standards of Performance for Small Industrial-Commercial-Institutional Steam Generating Units. This subpart applies to both the auxiliary boiler and the two convectionEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 18 heaters. As these units are all natural gas fired, only the recordkeeping and reporting requirements of Subpart Dc are applicable. Although the HRSGs are steam generating units, they are not subject to the requirements of Subpart Da, Db or Dc , because they are considered to be integral to the combined cycle CT/HRSG affected unit un der Subpart KKKK (see below) and are therefore regulated under that NSPS.

40 CFR 60 Subpart IIII - Standards of Performance for Stationary Compression Ignition Internal Combustion Engines. This subpart applies to both the diesel-fired emergency generator, and the diesel-fired emergency fire water pump. Both units shall comply with the provisions of this subpart.

40 CFR 60 Subpart KKKK - Standards of Performance for Stationary Combustion Turbines. As the two CT/HRSG units are both greater than 10 MMBtu/hr heat input, this subpart applies. A stationary combustion turbine is defined as all equipment associated with the physical turbine; including (but not limited to) the turbine, heat recovery systems, ancillary equipment, any combined-cycle turbine, and any combined heat and power combustion system. Therefore, the HRSGs and duct burners are considered to be part of the stationary combustion turbine, and are exempt from the NSPS requirements of Subparts Da, Db or Dc. Subpart KKKK also supersedes the older Subpart GG, which, therefore, does not apply. [Last updated March 9, 2012]

3. Comment regarding NESHAP/MACT Applicability: The following NESHAP/MACT requirements were found to be applicable to the SPC power plant:

40 CFR 63 Subpart A - General Provisions: This subpart outlines general provisions applicable to a source subject to any other subpart under 40 CFR 63.

40 CFR 63 Subpart ZZZZ - National Emissions St andards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion E ngines. This subpart applies to both the emergency generator and emergenc y fire water pump. An affected compression ignition source

that meets the criteria outlined in 40 CFR 63.6590 paragraphs (c)(1) through (7) must meet the requirements of Subpart ZZZZ by meeting the requirements of 40 CFR 60 Subpart IIII. Therefore, while Subpart ZZZZ applies to these two units, there are no additional applicable requirements.

While the CT/HRSGs are a source of HAP emissi ons, the total expected HAP emissions from the power plant is less than 10 tpy. This categori zes the SPC power plant as an area source for HAP emissions. Therefore the requirements of 40 CFR 63 Subpart YYYY do not apply to this plant. [Last updated March 29, 2012]

4. Comment regarding Title IV and Title V: The SPC power plant will be subject to both Title IV (Acid Rain Provisions) and Title V (Operating Permits) of the CAA.

Title IV requires, in part, the installation of a CEMS to demonstrate compliance with the acid rain requirements of 40 CFR 75. This CEMS requireme nt is also included in this permitting action.

Title V requires, in part, that the applicant subm it a timely and complete Title V application within one year of commencing operations. It also requires the application of CAM (complianceEngineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 19 assurance monitoring) on those emitting units me eting specific requirements. The CT/HRSG units will require the application of CAM. SPC has proposed to meet this requirement by installing and operating a CEMS for both NO

x and CO emissions (the CAM-applicable pollutants). [Last updated March 9, 2012]

5. Comment regarding GHG Emissions: As part of its request for additional informa tion, UDAQ asked SPC to recalculate GHG emissions using a consistent methodology. In summary, that strategy was to apply the same ambient temperature conditions to each source of GHG emissions and then pick the highest emitting scenario with all other factors being unchanged. This results in a lower but more accurate and realistic estimate of GHG emissions from the pl ant. Using this revised methodology the GHG emissions from the SPC plant are calculated as follows:

SPC operating case #11(GE operating case #14) turbine emissions:

CO 2 = 1926425.5 metric tons (MT)/yr, global warming potential (GWP) x1 = 1926425.5 MT/yr

CO 2 e N2O = 101.43 MT/yr, GWP x310 = 31443.3 MT/yr CO 2 e CH4 = 32.60 MT/yr, GWP x21 = 684.6 MT/yr CO 2 e

Turbine CO 2 e = 1958552.1 MT/yr

Adding in the auxiliary boiler at 39816 MT/yr CO 2 e and convection heaters at 20858 MT/yr CO 2 e for this same operating case gives a grand total of 2,019,226.1 MT/yr CO 2 e.

A discussion of GHG BACT is found in the BACT se ction of this source plan review document. [Last updated March 9, 2012]Engineering Review NSR0125290003: Sevier Power Company: Powe r Plant - NOI to construct a 580 MW combined cycle, natural gas, combustion turbine power plant March 30, 2012 Page 20 

### ACRONYMS

The following lists commonly used acr onyms 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

CO 2 Carbon Dioxide

CO 2 e Carbon Dioxide Equivalent - 40 CFR Part 98, Subpart A, Table A-1 COM Continuous opacity monitor DAQ Division of Air Quality (typically interchangeable with UDAQ) 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 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

NO

x Oxides of nitrogen

NSPS New Source Performance Standard

NSR New Source Review

PM 10 Particulate matter less than 10 microns in size

PM 2.5 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

SO 2 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 UDAQ Utah Division of Air Quality (typically interchangeable with DAQ) VOC Volatile organic compounds