## State ofUtah Department of Environmental Quality

Richard W. Sprott Executive Director DIVISION OF AIR QUALITY Cheryl Heying

Director

March 13, 2008 JON M. HUNTSMAN, JR Governor GARY HERBERT Lieutenant Governor

Reginald Soepnel, Managing Director PacifiCorp, Hunter Power Plant 3 miles South Highway 10 P.O. Box 569 Castle Dale, Utah 84513 Dear Mr. Soepnel: DAQE-ANO 102370012-08

Re: Approval Order: Installation ofPollution Control Equipment, Established Plantwide Applicability Limitations and Approval Orders Consolidation, Emery County- CDS A; NSPS; PSD; Title IV; Title V Major; HAPs Project Code: N010237-0012 The attached document is the Approval Order for the above-referenced project. Future correspondence on this Approval Order should includethe engineer's name as well as the DAQE number as shown on the upper right-hand comer ofthis letter. Please direct any technical questions you may have on this project to Mr. John Jenks. He may be reached at (801) 536-4459. Sincerely,

M. Cheryl Heying, Executive Secretary Utah Air Quality Board MCH:JJ:sa

cc: Southeastern Utah District Health Department Mike Owens. EPA Region VIII

150 North 1950 West• PO Box 144820 •Salt Lake City, UT 84114-4820 •phone (801)536-4000 • fax(801)536-4099 T.D.D. (801) 536-4414 • www.deq.utah.gov

# STATE OFUTAH Department ofEnvironmental Quality Division ofAir Quality APPROVAL ORDER: Installation ofPollution Control Equipment, EstablishingPlantwide Applicability Limitations andApproval Orders Consolidation

Prepared By: John Jenks, Engineer (801) 536-4459 Email: jjenks@utah.gov



### APPROVAL ORDERNUMBER

DAQE-ANOl02370012-08

Date: March 13, 2008 

# PacifiCorp,HunterPowerPlant Source Contact William Lawson (801) 220-4581

M. Cheryl Heying Executive Secretary Utah Air Quality Board

### Abstract PacifiCorp is installingnew emissions controlequipmentat the Hunter PowerPlanton Units #1, #2 and #3 boilers in order to substantially reduceplantemissions, main(vsulfurdioxide (SOz), HiS04 , HCl, HFI, particulate matter (PM) andnitrogen oxides (NO:J. PacifiCorp willinstallon Units#1, #2 and#3 aNOx reduction system consistingof two general components: (1) two levels of separatedoverjireair and (2) new low-NOx burners. These changes willresult in reduction of NOx emissions andpossibly result in an increase in CO emissionsgreaterthan the PSD significance level PacifiCorp willalso replace the existingelectrostaticprecipitators (ESP) on Units #1 and#2 with a newpulse jet fabricfilter (baghouse) system This will result in a reduction of HzS04 andPMemissions. Finally, PacifiCorp will upgrade the existing fluegas desulfurization system on Units #1 and#2 to achievegreatersulfurdioxide removal, which willsignificantly reduce the amountof S02, HCI, andHF/emissions. In addition, PacifiCorp is requesting existingapprovalorders (AO) be consolidated;plantwide applicability limits (PALs)forS02andNOxemissions and/or Unit#3 theS02 

### emission limit besetat 0.12 lblMMBtu. Asindicatedin theAODAQE-1189-97, Unit#3 wassubjectto an emission limit/or S02o/0.12/b/MMBtupriorto implementation of the existing limitof 0.10 lblMMBtu. Opaci(v limitlanguage/orthe Unit #1, #2, and#3 boilerstacksis expandedto clarify the opacity limit during startup andshutdown events. Asa result of theproposedchanges, the source is subject to carbon monoxide (CO) PSD major modification review .'lince the rest of theplant emission changes are reductions. Unit #1 and#2 boilers are subjectto New Source PerformanceStandards (NSPS), Part 60SubpartD, andthe Unit #3 boileris subjectto Subpart Da. Title IVand Title Vof the 1990 CleanAirActapply to thissource. The Title V Operating Permit willbe updatedpriorto operatingthe modifiedequipment. The source is located in Emery County, which is an attainmentarea/ortheNationalAmbientAir QualityStandards (NAAQS) for allpollutants. ThisA0 hasgone through the enhancedNSRprocess. Afterthe installation andupgrades of the control equipment, the emissions from theplant, in tonsper year, will change asfollows: PM/IJ

## =(-) 1,441.02, NOx

## =(-) 9,298, S01

## =(-) 3,609, CO=(+) 17,278,**SO~**

## =(-) 33.1, HF/=(-) 7.5, andHCI= (-) 27.9. The change in emissions, afterthe replacement, addition andupgrades of controlequipment, willresult in the following, in tonsperyear,potentialto emit totals/ortheplant: PM10

## =1,218.1, NOx 

## =19,319, S02

## =7,187, CO= 18,449, VOC

## =163, H:;S04

## =3.5, HF=44.6, HCl

## =13.41, Lead=0.12 andother HAPs = 

### 43.15. PALs are now established/orNOx

## =19,319 tons/yearandS02

## =7,187tons/yearbasedon a 12-month rolling average.DAQE-ANOl02370012-08 Page 3

General Conditions: 1. This AO applies to the following PacifiCorp: Site Office PacifiCorp Hunter Plant 3 miles South Highway 10 P.O. Box 569 CastleDale, Utah 84513 PhoneNumber (435) 748-5114 Fax Number (435) 748-6579 Corporate Office Location PacifiCorp 1407 West North Temple Salt Lake City, Utah 84140 (801) 220-2235 (801) 220-4307 The equipment listed in this AO shall be operated at the following location: Approximately three (3) miles south ofCastle Dale, Utah on State Highway I0, Emery County Universal Transverse Mercator (UTM) Coordinate System: 4,335.8 kilometers Northing; 497.8 kilometers Easting; Zone 12 UTM Datum NAD27 2. All definitions, terms, abbreviations, and references used in this AO conform to those used in the Utah Administrative Code (UAC) Rule 307 (R307) and Title 40 ofthe Code ofFederal Regulations (40 CFR). Unless noted otherwise, references cited in these AO conditions refer to those rules. 3. The limits set forth in this AO shall not be exceeded without prior approval in accordance with R307-40I. 4. Modificationsto the equipment or processes approved by this AO that could affect the emissions covered by this AO must be reviewed and approved in accordance with R307-40I. 5. All records referenced in this AO or in applicableNSPS and/orNESHAP and/or MACT standards, which are required to be kept by the owner/operator, shall be made available to theExecutive Secretary orExecutive Secretary's representative upon request. Records shall be kept for a minimum offive year periods. 6. PacifiCorp shall install and operatethe new Low NOx burners, overtire air system, main boiler stack baghouse and upgrade ofthe existing flue gas desulfurization system on Unit#I 

### & #2 (each) and new Low NOx burner system with OFA on Unit #3. PacifiCorp shall conduct its operations ofthe Hunter Power Plant in accordance with the terms and conditions ofthis AO, which was written pursuant to PacifCorp'sNotice ofIntent submitted to the Division ofAir Quality (DAQ) on May 2, 2007, July 19, 2007, September 17, 2007, September 21, 2007, October 26, 2007, November 27, 2007, December 5, 2007 and December 26, 2007.DAQE-ANOI02370012-08 Page 4

7. This AO shall replace the following AOs : DAQE-1189-97 dated December 18, 1997 Unit#1dated April 3, 1986 Unit #2 dated July 27, 1987 Unit #3 dated August 31, 1983 and additional letters dated October27, 1983 and September 6, 1985 8. The approved installations shall consist ofthe following equipment or equivalent*: A. Steam Generating Unit#1 Unit Description: Nominal 480 MW gross capacity, dry bottom, tangentially-fired boiler fired on subbituminous 

### & bituminous coal using distillate fuel oil during startup and flame stabilization currently equipped with LowNOx firing system, ESP and S02 FGD scrubber. Boiler will be equipped with a new advanced combustion Low NOx burner/overtire air system (OFA), new baghouse and upgraded S02WFGD scrubber, with no scrubber bypass. B. Steam Generating Unit#2 Unit Description: Nominal 480 MW gross capacity, dry bottom, tangentially-fired boiler fired on subbituminous and bituminous coal using distillate fuel oil during start-up and flame stabilization currently equipped with LowNOx firing system, ESP and S02 FGD scrubber. Boiler will be equipped with a new advanced combustion LowNOx burner/overtire air system (OFA), new baghouse and upgraded S02 WFGD scrubber, with no scrubber bypass. C. Steam Generating Unit #3 Unit Description: Nominal 495 MW gross capacity, dry bottom, wall-fired boiler fired on subbituminous and bituminous coal using distillate fuel oil during start-up and flame stabilization. Unit is equipped with a new LowNOx burner system with overtire air, baghouse and S02 WFGD scrubber, with no scrubber bypass. D. Circulating Water Cooling Tower for Unit#I steam generating boiler E. Circulating Water CoolingTower for Unit#2 steam generating boiler F. Circulating Water Cooling Tower for Unit#3 steam generating boiler G. Coal Pile and operations and associated fugitive emissions and fugitive dust H. Coal Conveyors for coal transfer operations I. Unpaved Ash Haul Road for ash disposal J. Paved Ash Haul Road for disposal ofashDAQE-AN0102370012-08 Page 

### 5

K. Ash Landfill operations and associated fugitive emissions and fugitive dust 

### L. Unit#I Emergency Diesel Generator M. Unit#2 Emergency Diesel Generator N. Unit#3 Emergency Diesel Generator 0. Emergency Diesel Fire Pump#I P. Emergency Diesel Fire Pump #2 Q. Auxiliary Steam Boiler rated at 211.4 MMBtu/hr fired on fuel oil and constructed in 1976 R. Coal Silo System Exhauster with centrifugal dustcollector for Unit#1coal silos distribution system S. Coal Silo System Exhauster with centrifugal dust collector for Unit #2 coal silo distribution system T. Coal Silo System Exhauster with centrifugal dust collector for Unit #3 coal silo distribution system U. Lime SiloBin Vents (water treatment plant) dust collectors for lime storage silos 

### for water treatment plant V. Lime Silo Bin Vents (S02 scrubber) dust collectors for scrubber lime silos for Units #1, #2, and #3 W. Four70,000 distillate fuel oil tanks for the emergency diesel generators and fire pumps X. Four 10,000 gallon tanks that store lubricating oil 

### Y. Storage area for oil contained in closed 

### 55 gallon drums and totes 

### Z. Three400 gallon electro control hydraulic oil reservoirs AA. Paved access road from the plant entrance to the administration building and parking area BB. Bench-top cold degreasing units using Safety-Kleen or other comparable degreasing agents CC. MiscellaneousElectrical Equipment with some fugitive emission units including transformer insulating oilDAQE-ANOI02370012-08 Page 6

DD. Anhydrous Sulfur Dioxide Tank: Unit Description: I0,000 gallon anhydrous sulfur dioxide tankto generate S03 for ESP flue gas conditioning. After the baghouse installation, Anhydrous Sulfur Dioxide Tank will be removed from service after the baghouses installation on Units #I and #2. EE. WaterTreatment storage tanks including chlorine, aluminum sulfate, lime, sodium sulfite, soda ash, calcium hypochlorite, sodium hydroxide, anti-scale, aqueous ammonia FF. Various storage areas for sealed paint containers GG. Spray Paint Booth for painting parts to maintain plant HH. Gasoline Refueling Station and Storage Tank for fleet vehicles with a 5,500 gallon aboveground tank II. 5,500 gallon aboveground unleaded gasolinetank for fleet vehicle refueling 

### JJ. Boiler feed pump lube oil conditioners KK. Lube oil conditioners with vapor extractors LL. Lube oil reservoirs with vapor extractors MM. Three 5,500 gallon aboveground diesel tanks and dispensing equipmentto refuel vehicles and mobile equipment NN. Mobile truck mounted vacuum to clean up spilled material such as ash 00. Unit#I equipment for unloading ash from silos and into trucks for transportto the ash landfill PP. Unit #2 equipment for unloading ash from silos and into trucks for transport to the ash landfill QQ. Unit#3 equipment for unloading ash from silos and into trucks for transportto the ash landfill

• Equivalency shall be determined by the Executive Secretary. 9. PacifCorp shall notify the Executive Secretary in writing when the installation ofthe new equipment listed in Condition #8A, Band Chas been completed and is operational. To insure proper credit when notifying the Executive Secretary, send your correspondence to the Executive Secretary, attn: Compliance Section.DAQE-ANOI02370012-08 Page 7

Ifthe construction and/or installation has not been completed within eighteen months from the date ofthis AO, the Executive Secretary shall be notified in writing on the status ofthe construction and/or installation. At that time, the Executive Secretary shall require documentation ofthe continuous construction and/or installation ofthe operation and may revoke the AO in accordance with R307-401-18. Limitations and Tests Procedures 10. Unit#I and Unit #2 Boilers A Effective upon issuance ofthe AO: I. PM limit

a. Emissions shall not be greaterthan 0.05 lb/MMBtu heat input from each boiler based on 6-hour averaging period. b. Stack testing for the emission limitation shall be performed each year. The source may be tested at any time ifdirected by the Executive Secretary. 2. NOx limits

a. Emissions from each boiler shall be no greater than 0.70 lb/MMBtu heat input based on a 3-hour averaging period. b. Emissions from each boiler shall be no greater than 0.45 lb/MMBtu heat input based on a 12-month rolling averaging period.

c. Measuring ofthe NOx emissions shall be performed by CEMs. 3. S02 limits

a. Emissions from each boiler shall be no greater than 1.2 lb/MMBtu heat input for any 3-hour period. b. Emissions from each boiler shall be no greater than 0.21 lb/MMBtu heat input based on a 12-month rolling average.

c. Emissions ofS02 shall be no greater than 20 percent ofthe potential combustion concentration based on the average inlet and average outlet S02 emissions determined as the arithmetic average ofall hourly emission rates for the 30 successive boiler operating days. d. Measuring ofthe S02 1.2 lb/MMBtu and 0.21 lb/MMBtu emissions shall be performed by CEMs.DAQE-ANOI02370012-08 Page 8

B. Effective upon installation orupgrade ofcontrol equipment: I. PM limit

a. Emissions shall not be greater than 0.015 lb/MMBtu heat input from each boiler based on a 3-test average. b. After the initial stack test is performed, stack testing for the emission limitation shall be performed each year. The source may be tested at any time ifdirected by theExecutive Secretary. 2. NOx limits

a. Emissions from each boiler shall be no greaterthan 0.70 lb/MMBtu heat input based on a 3-hour averaging period. b. Emissions from each boiler shall be no greaterthan 0.26 lb/MMBtu heat input for a 30-day rolling average.

c. After the initial stack test is performed for 0.26 lb/MMBtu measuring ofall NOx emissions shall be performed by CEMs. 3. S02 limits

a. Emissions from each boiler shall be no greater than 1.2 lb/MMBtu heat input for any 3-hour period. b. Emissions from each boiler shall be no greaterthan 0.12 lb/MMBtu heat input based on a 30-day rolling average.

c. Unit#I and Unit#2 boileremissions ofS02 shall be no greaterthan 20 percent ofthe potential combustion concentration based on the average inlet and average outlet S02 emissionsdetermined as the arithmetic average ofall hourly emission rates for the 30 successive boiler operating days. d. After the initial stack test is performed for 0.12 lb/MMBtu limit, measuring ofthe S02emissions for 0.12 lb/MMBtu and 1.2 lb/MMBtu limits shall be performed by CEMs. 4. CO limit

a. Emission shall be no greaterthan 0.34 lb/MMBtu heat input for a 30-day rolling average. b. 3990 lb/hr for an 8-hour block average.

c. After the initial stack test is performed, measuring ofthe CO emissions shall be performed by CEMs.DAQE-ANOI02370012-08 Page 9

11. Unit#3 Boiler A Effective upon issuance ofthe AO: 1. PM limit

a. Emissions shall not be greaterthan 0.02 lb/MMBtu heat input from each boiler based on a 6-hour averaging period. b. Stack testing for the emission limitation shall be performed each year. The source may be tested at any time ifdirected by the Executive Secretary. 2. NOx limits

a. Emissions from the boiler shall be no greater than 0.46 lb/MMBtu heat input for a 30-day rolling average. b. Measuring ofthe NOx emissions shall be performed by CEMs. 3. S02 limits

a. Emissions ofS02from the Unit#3 boiler shall be no greater than 0.12 lb/MMBtu heat input based on a 30-day rolling period. b. Boiler#3 emissions ofS02shall be no greaterthan 10 percent ofthe potential combustion concentration based on the average inlet and average outlet S02emissions determined as the arithmetic average ofall hourly emission rates for the 30 successive boiler operating days.

c. Measuring ofthe S020.10 lb/MMBtu emissions limit shall be performed by CEMs. B. Effective upon installation orupgrade ofcontrol equipment: 1. PM limit

a. Emissions shall not be greaterthan 0.02 lb/MMBtu heat input from each boiler based on a 6-hour averaging period. b. Stack testing for the emission limitation shall be perfom1ed each year. The source may be tested at any time ifdirected by the Executive Secretary. 2. NOx limits

a. Emissions from each boiler shall be no greater than 0.34 lb/MMBtu heat input for a 30-day rolling average.DAQE-ANOl02370012-08 Page 10

b. After the initial stack test is performed, measuring ofNOx emissions shall be performed by CEMs. 3. S02 limits

a. Emissions ofS02 from the Unit#3 boiler shall be no greater than 0.12 lb/MMBtu heat input based on a 30-dayrolling period. b. Boiler#3 emissions ofS02 shall beno greaterthan 10 percent ofthe potential combustion concentration based on the average inlet and average outlet S02emissions determined as the arithmetic average ofall hourly emission rates for the 30 successive boileroperating days.

c. Measuring ofthe S020.12 lb/MMBtu emissions limit shall be performed by CEMs. 4. CO limit

a. Emission shall be no greaterthan 0.2 lb/MMBtu heat input for a 30- day rolling average. b. 2406 lb/hr for 8-hour block average.

c. After the initial stacktest is performed, measuring ofthe CO emissions shall be performed by CEMs. 12. Unit #1, #2 and #3 Boilers Compliance and Monitoring: A. The initial test shall be performed as soon as possible and in no case later than 180 days after the startup ofeach new baghouse on unit#1and #2 boilers, each advanced combustion Low NOx burner/overtire air system, new generation Low NOx burner system and each WFGD upgrade. Initial stack testing for PM, NOx, and S02 shall be performed as specified below. Initial stack testing for the CO, NOx and S02 emissions in the Conditions 10.B.2.a, 10.B.2.b., 10.B.3.a., 10.B.3.b., 10.B.4.a., 10.B.4.b. ,11.B.2.a. and 11.B.4.a. may be substituted with a RATA test if approved by the Executive Secretary. B. Notification The Executive Secretary shall be notified at least 30days priorto conducting any required emission testing. A sourcetest protocol shall be submitted to DAQ when the testing notification is submitted tothe 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 the proposed test methodologies, stack to be tested and procedures to beused. A pretest conference shall be held, ifdirected by the Executive Secretary.

### DAQE-ANOI02370012-08 Page 11

C. Sample Location The emission point shall be designed to conform to the requirements of40 CFR 60, Appendix A, Method I, 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. D. Volumetric Flow Rate 40 CFR 60, Appendix A, Method 2 or other testing methods approved by the Executive Secretary E. 

### .PM10 Method SB shall be used for PM emission or other testing methods approved by the Executive Secretary. The back halfcondensibles shall also be tested using the referenced method 202. The back halfcondensibles shall not be used for compliance demonstration but shalI be used for inventory purposes. F. Sulfur Dioxide (S02) 40 CFR 60, Appendix A, Method 6, 6A, 6B, 6C, or other testing methods approved by the Executive Secretary G. Nitrogen Oxides (NOx) 40 CFR 60, Appendix A, Method 7, 7A, 7B, 7C, 7D, 7E, or other testing methods approved by the Executive Secretary H. Carbon Monoxide CCO) 40 CFR 60, Appendix A, Method I0, or other testing methods approved by the Executive Secretary I. 

### PacifiCorp shall perform annual stack testing to show compliance with the CO emission limitation after the initial stack testing. J. 

### PacifiCorp shall install, calibrate, maintain, and operate a continuous monitoring system for measuring carbon monoxide, sulfur dioxide and nitrogen oxides emissions. 13. At all times, the plant-wide applicability limitations for the entire Hunter Plant from all point sources and fugitive emissions shall not exceeded the following:

S02 Limit NOx LimitDAQE-ANO 102370012-08 Page 12

14. S02 and NOx limits in Condition 13 shall be monitored in accordance with 40 CFR Part 52.21.21(aa)(12) and as minimum it shall be done by summingup emissions as follows: A. For Units #1, #2 and #3 main boiler stacks, PacifiCorp's reporting to EPA's Acid Rain Emissions data base for NOx and S02in pounds per hour obtained from the boilers' CEM data shall be used to calculateNOx and S02 emission rates. All reported S02 emissions, including emissions associated with startups, shutdowns, and malfunctions, in pounds per hour, shall be summed to get monthly total emissions. B. For Units#1, #2 and #3 emergency diesel-fired generators, emissions shall be calculated by multiplying the S02and NOx emission factor from the latest edition of EPA's emission factors compilation AP-42 and hours ofoperation. Records documenting generator usage shall be kept in a Jog, and they shall show the date the generator was used and the duration in hours ofgeneratorusage. 

### C. For Units#1, #2 and #3 emergencydiesel-fired fire pumps, emissions shall be calculated by multiplying the S02and NOx emission factor from the latest edition of EPA's emission factors compilation AP-42 and hours ofoperation. Records documenting generator usage shall be kept in a log, and they shall showthe date the pump was used and the duration in hours ofpumpusage. D. Auxiliary steam boiler emissions, including emissions associated with startups, shutdowns, and malfunctions, shall be calculated by multiplying the emission factor for S02and NOx from the latest edition ofEPA's emission factors compilation AP42 and fuel consumption. Records documentingAuxiliary steam boilerusage shall be kept in a log, and they shall showthe date the Auxiliary steam boiler was used and the duration in hours ofthe Auxiliary steam boilerusage. E. The PAL limits in Condition 13 shall be effective for ten years from the date of issuance ofthis AO, in accordance with 40 CFR Subpart52.21 (aa). F IfPacifiCorp applies for PAL renewal, the application in accordance with 40 CFR Subpart 52.21(aa)(IO) shall be submitted before the end ofthe PAL effective date, and the PAL established in this AO will remain until a revised approval order is issued. G. Once the PAL expires, the source is subject to the requirements of40 CFR Subpart 52.21(aa)(9). H. Monitoring for each PAL shall be in accordance with 40 CFR Subpart 52.2l(aa)(12). I. Forthe record keeping requirements ofeach PAL, PacifiCorp shall comply with 40 CFR Subpart 52.2l(aa)(13). 

### J. Forrecord submittal, PacifiCorp shall comply with 40 CFR Subpart 52.21(aa)(14).DAQE-ANO 102370012-08 Page 13

15. To determine compliance with the applicable 12-month rollingNOx and S02PAL limits, the owner/operator shall calculate new 12-month total NOx and S02 emissions by the twentieth day ofeach month using data from the previous 12 months. Records ofemissions shall be kept for all periods when the plant is in operation. 16. Visible emissions from HunterUnit#1, Unit#2 and Unit #3 boilers shall be limited as follows:During boiler operation, no greaterthan 20 percent opacity, except as provided in R307-201-3(7). During startup and shutdown events Condition 18 and Condition 26 shall apply. 17. PacifiCorp shall develop, maintain, and implement a written Hunter Emissions Minimization Plan (HunterPlan) thatdescribes, in detail, procedures for operating and maintaining the Units#l, #2 and #3 boilers, including associated air pollution control and monitoring equipment, during events ofstartup and shutdown. The Plan shall be submitted to the Executive Secretary no later than 180 days after the issuance ofthis AO. 18. Definition ofstartup and shutdown events for Unit#I, Unit#2 and Unit #3 boilers and the HunterPlan minimum requirements: A. Startup is defined as the period beginning with the introduction offuel into the boiler and ending no later than when two coal feeders have been proven in service and the flue gas temperature at the outlet ducts to both sides ofthe electrostatic precipitator (Units#1 and #2) or the baghouse outlet (Units#I, #2 or#3 boilers) have reached a temperature of220"F and less than 20 percent ofthe boiler heat input is being furnished by fuel oil. B. Bypass ofassociated control equipment shall only be used to prevent loss oflife, personal injury, or severe property damage. C. Shutdown is defined as the period beginning when the unit load or output is reduced with the intent ofremoving the unit from service, or when the unit trips as the result ofa sudden and unforeseen failure or malfunction and ending when fuel flow to the boiler ceases. D. The Hunter Plan shall contain detailed steps to minimize, to the maximum extent practicable, the frequency and duration ofoperation in startup or shutdown and shall be followed at all times. The Hunter Plan shall contain steps to minimize, to the maximum extent practicable, the frequency and duration ofoperation in startup or shutdown mode. This shall include, but not necessarily be limited to, careful and detailed design, planning, operation, and maintenance so as to avoid unnecessary, preventable, or unreasonably frequent or lengthy startups and shutdowns. E. The duration ofa boiler startup event shall not extend beyond 20 hours per startup period or 300 hours per year per boiler and 750 hours per year combined for the Unit #I, #2 and #3 boilers.DAQE-ANOI02370012-08 Page 14

F. During periods ofstartup and shutdown, PacifiCorp shall operate and maintain the boilers, including associated air pollution control and monitoring equipment, in accordance with procedures specified in the HunterPlan based on equipment manufacturer/plant operating procedures. G. PacifiCorp shall maintain records demonstrating that the procedures in the Hunter Plan were followed. These records shall include the date and time ofoccurrence and duration ofeach startup and shutdown, include emissions during startup and shutdown as well as other pertinent information. H. PacifiCorp may periodically revise the Hunter Plan for the affected source as necessary to satisfy the requirements ofthis Condition orto reflect changes in equipment or procedures at the affected source. Each such revision must be submitted to the Executive Secretary. 19. Unless otherwise specified in this AO, visible emissions from any stationary point, other than main stacks, or fugitive emission source associated with the source or with the control facilities shall not exceed 20% opacity. Opacity observations ofemissions from stationary sources shall be conducted in accordance with 40 CFR60, Appendix A, Method 9. For those sources that are subject to NSPS, opacity shall be determined by conducting observations in accordance with 40 CFR 60.11(b) and 40 CFR60, Appendix A, Method 9. 20. Visible fugitive dust emissions from haul-road traffic and mobile equipment in operational areas shall not exceed 20% opacity. Visible emission determinations for traffic sources shall use procedures similar to Method 9. The normal requirement for observations to be made at 15-second intervals over a six-minute period, however, shall not apply. 21. Fugitive dust and emissions shall be minimized by the following techniques: A. All conveyors and drop points shall be enclosed in a structure. B. The live coal handling and storage shall be enclosed in a structure.

22. The sulfur content ofany fuel oil shall not exceed 0.85 lbs/MMBtuheat input. The sulfur content shall be determined by ASTM Methods 02015-77 or 03286-85 or approved equivalent. Federal Limitations and Requirements 23. In addition to the requirements ofthis AO, all applicable provisions of40 CFR Part 60, NSPS Subparts A, 40 CFR60.1 to 60.I8, Subpart D, 40 CFRPart 60.40 to 60.46 (Standards ofPerformance for Fossil-Fuel-Fired Steam Generators for Which Construction is Commenced After August 17, 1971), Subpart Oa (Standards ofPerformance for Electric Utility Steam Generating Units for Which Construction Commenced After September 18, 1978) and SubpartHHHH (Emission Guidelines and Compliance Times for Coal-fired Electric Steam Generating Units) apply to this installation.DAQE-ANO 102370012-08 Page 15

24. In addition to the requirements ofthis AO, all applicable provisions of40 CFR Part 72. 73, 75, 76, 

### 77 and 78

- Federal regulations for the Acid Rain Program under Clean Air Act Title IV apply to this installation. 25. In addition to the requirements ofthis AO, all applicable provisions of40 CFR Part 52.21 (aa)-Actuals Pals (incorporated by reference in the UAC, R307-405-2) apply to this installation. Monitoring - General Process 26. The owner/operator shall install, calibrate, maintain, and operate a continuous emissions monitoring system (CEMs) on the main boilers stacks for CO, S02, and NOx. TI1e owner/operator shall record the output ofthe system, for measuring the opacity, CO, S02. and NOx emissions. The monitoring system shall comply with all applicable sections of R307-170, UAC; and 40 CFR 60, Appendix B. All continuous emissions monitoring devices as required in federal regulations, and state rules shall be installed and operational prior to placingthe affected source in operation. Except for system breakdown, repairs, calibration checks, and zero and span adjustments required under paragraph (d) 40 CFR 60.13, the owner/operator ofan affected source shall continuously operate all required continuous monitoring devices and shall meet minimum frequency ofoperation requirements as outlined in 40 CFR 60.13 and Section UAC R307- 

### l70. Records & Miscellaneous 27. At all times, including periods ofstartup, 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 ofwhether acceptable operating and maintenance procedures are being used will be based on the information available to the Executive Secretary which may include, but is not limited to, monitoring results, opacity observations, review ofoperating and maintenance procedures, and inspection ofthe source. All maintenance performed on the equipment authorized by this AO shall be recorded. 28. The owner/operator shall comply with R307-l50 Series. Inventories, Testing and Monitoring. 29. The owner/operator shall comply with R307-107. General Requirements: Unavoidable Breakdowns. The Executive Secretary shall be notified in writing ifPacifiCorp is sold or changes its name. This AO in no way releases the owner or operatorfrom any liability for compliance with all other applicable federal, state, and local regulations including R307.DAQE-ANO 

### 102370012-08 Page 16

A copy ofthe rules, regulations and/or attachments addressed in this AO may be obtained by contacting the DAQ. The UAC 

### R307 rules used by DAQ, theNotice ofIntent (NOi) guide, and other air quality documents and forms may also be obtained on the Internet at the following web site:

http://www.airquality.utah.gov/ TI1e DAQ is authorized to charge a fee for reimbursement ofthe actual costs incurred in the issuance ofan AO. An invoice will follow upon issuance ofthe final AO. Approved By:

M. Cheryl Heying, Executive Secretary Utah Air Quality Board