United States Environmental Protection Agency

Region9

Prevention of Significant Deterioration Permit Pursuant to 40 CFR 52.21 

and

Minor New Source Review Permit in Indian Country Pursuant to 40 CFR

49.151 through 161

PSD Permit: NN 14-01 

Tribal NSR Permit: T-002-NN 

Permittee:

Arizona Public Service Company 

Four Corners Electric Power Station 

P.O. Box 35 

Fruitland, NM 87416 

Source:

Four Corners Power Plant 

Source Location:

End of San Juan County Road 6675 

Fruitland, NM 

Pursuant to the provisions of the Clean Air Act (CAA) in Subchapter I, parts C and D, and section 110(a), and the 

Code of Federal Regulations (CFR) Title 40, Sections 52.21 and 49.151-161, the United States Environmental 

Protection Agency Region 9 (EPA) is issuing a Prevention of Significant Deterioration (PSD) permit and a Minor 

New Source Review (NSR) permit in Indian Country to Arizona Public Service Company (APS or Permittee). This 

permit applies to the construction and operation of equipment at Four Corners Power Plant (FCPP or Source) for 

the installation of selective catalytic reduction (SCR) systems on two coal-fired steam electric generating units. 

Installation of the SCR systems is causing a significant net emissions increase of one regulated NSR pollutant, 

sulfuric acid mist (SAM). 

APS is authorized to construct and operate the FCPP SCR Project as described herein, in accordance with the 

permit application (and plans submitted with the permit application), the federal PSD regulations at 40 CFR 52.21, 

the Minor NSR in Indian Country regulations at 40 CFR 49.151-161, and other terms and conditions set forth in this 

permit. Failure to comply with any condition or term set forth in this permit may result in enforcement action 

pursuant to section 113 of the CAA. This permit does not relieve APS from the responsibility to comply with any 

other applicable provisions of the CAA (including applicable implementing regulations in 40 CFR parts 51, 52, 60, 

61, 63, and 72 through 75), or other federal, tribal, and local requirements. 

Per 40 CFR 52.21(b) and 40 CFR 49.159(a) this permit becomes effective on [INSERT DATE]. 

___________________________________________________ ____________________________________________ 

Deborah Jordan Date 

Director, Air Division 
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Project Description 

The FCPP SCR Project (Project) consists of:

· Installation of SCR systems on Emissions Units 4 and 5; 

· Increased truck traffic on paved roads for delivery of hydrated lime; 

· Increased truck traffic on paved roads for delivery of urea pellets, aqueous ammonia, or anhydrous 

ammonia; 

· A pneumatic truck unloading system and silo for hydrated lime; and 

· A pneumatic truck unloading system and silo for urea pellets OR a pneumatic truck unloading system and 

storage tank for aqueous ammonia or anhydrous ammonia. 

In addition, minor NSR portion of the permit includes a 220 MMBtu/hr limited-use natural gas auxiliary boiler that 

was approved by EPA on May 15, 2012 pursuant to 40 CFR 49.153(a)(2). 

The Project will be located in an unincorporated area of San Juan County, New Mexico near the town of Fruitland, 

on the Navajo Nation Indian Reservation. 

This permit requires the use of Best Available Control Technology (BACT) to limit emissions of sulfuric acid mist 

(SAM) to the greatest extent feasible. Air pollution emissions from the Project will not cause or contribute to 

violations of any National Ambient Air Quality Standards (NAAQS) or any applicable PSD increments for the 

pollutants regulated under the PSD permit. 

Equipment List 

Emissions 

Unit (EU) 

Construction 

Date 

Description 

Control Equipment Authorized by this 

Permit 

EU4 1969 Coal-Fired Electric Generating 

Unit, 750 MW, approximately 

7,411 MMBtu/hr 

SCR, DSI system using hydrated lime 

EU5 1970 Coal-Fired Electric Generating 

Unit, 750 MW, approximately 

7,411 MMBtu/hr 

SCR, DSI Injection using hydrated lime 

EU6 N/A Truck Traffic for Sorbent Delivery Wet suppression 

EU7 N/A Truck Traffic for SCR Reagent 

Delivery 

Wet suppression 

EU8 N/A Pneumatic Delivery System and 

Storage Silo for Hydrated Lime 

Bin vent (fabric filter) 

EU9 N/A Pneumatic Delivery System and 

Storage Silo for SCR Reagent (Urea 

Pellets) 

Bin vent (fabric filter) 

EU10 2012 220 MMBtu/hr Natural Gas-Fired 

Boiler 

Flue Gas Recirculation 

 
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Permit Terms and Conditions

I. General Provisions 

1. Permit Expiration 

As provided in 40 CFR 52.21(r), unless EPA grants an extension pursuant to 40 CFR 52.21(r)(2), this permit 

shall become invalid if: 

a. Construction does not commence (as defined in 40 CFR 52.21(b)(9)) within 18 months after the permit 

becomes effective; 

b. Construction is discontinued for a period of 18 months or more; or 

c. Construction is not completed within a reasonable time. 

2. Permit Notification Requirements

The Permittee shall notify EPA by letter (postmarked by the timelines below) or by email, at AEO_R9@epa.gov , 

of: 

a. The date construction is commenced, within 30 days of such event; 

b. The actual date of initial startup, as defined in 40 CFR 60.2, within 15 days of such event; and 

c. The date upon which initial performance tests will commence, in accordance with the provisions in 

Condition 24, not less than 30 days prior to such date. Notification may be provided with the submittal of 

the performance test protocol(s) required pursuant to Condition 13.b. 

3. Source Operation

At all times, including periods of startup, shutdown, shakedown, and malfunction, the Permittee shall, to the 

extent practicable, maintain and operate the facility that is subject to this permit (Source), including associated 

air pollution control equipment, in a manner consistent with good air pollution control practices for 

minimizing emissions. Determination of whether acceptable operating and maintenance procedures are being 

used will be on information available to EPA which may include, but is not limited to, monitoring results, 

opacity observations, review of operating and maintenance procedures, and inspection of the Source. 

4. Malfunction Report

a. The Permittee shall notify EPA at AEO_R9@epa.gov within two (2) working days following the discovery 

of any failure of equipment listed in this permit (see Equipment List above), or failure of a process listed 

in this permit to operate in a normal manner, which results in an increase in emissions above any 

allowable emission limit stated in Sections II-III of this permit. 

b. The Permittee shall provide an additional notification to EPA in writing or email within 15 days of any 

such failure described in under Condition 4.a. This notification shall include a description of the 

malfunctioning equipment or abnormal operation, the date of the initial malfunction, the period of time 

over which emissions were increased due to the failure, the cause of the failure, the estimated resultant 

emissions in excess of those allowed in Sections II-III, and the methods utilized to mitigate emissions and 

restore normal operations. 

c. Compliance with the malfunction notification requirements in Condition 4 shall not excuse or otherwise 

constitute a defense to any violation of this permit or any law or regulation such malfunction may cause. 

5. Inspection and Entry

The EPA Regional Administrator, and/or an authorized representative, upon presentation of proper 

credentials, shall be permitted to: 

a. Enter upon the premises where the Source is located or emissions-related activity is conducted; or where 

records are required to be kept under the terms and conditions of this permit; 

b. Have access to and copy, at reasonable times, any records that are required to be kept under the conditions 

of the permit; 
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PSD and Minor NSR Permit 

c. Inspect, during normal business hours or while the source is in operation, any facilities, equipment 

(including monitoring and air pollution control equipment), method, practices or operations regulated or 

required under the permit; 

d. Sample or monitor substances or parameters subject to the requirements in this permit; and 

e. Record any inspection by use of written, electronic, magnetic and photographic media. 

6. Transfer of Ownership

In the event of any changes in the Permittee listed on this permit, the Permittee must submit a written or 

electronic notice to EPA within 30 days after the change in Permittee is effective. In the notice, the succeeding 

Permittee must provide a written agreement containing a specific date for transfer of the Permittee, and an 

effective date on which the new Permittee assumes partial and/ or full coverage and liability under this permit. 

The submittal must identify the previous owner, and update the name, street address, mailing address, contact 

information, and any other information about the Source if it would change as a result of the change of 

ownership. The Permittee shall ensure that the Source remains in compliance with this permit during any such 

transfer of ownership. 

7. Severability 

The provisions of this permit are severable. If any portion of this permit is held invalid, the remaining 

terms and conditions of this permit shall remain valid and in force. 

8. Adherence to Application and Compliance with other Environmental Laws

The Permittee shall construct the Project and operate equipment listed in this permit (see Equipment List 

above) in compliance with this permit, the application on which this permit is based, and all other applicable 

federal, state, and local air quality regulations. This permit does not release the Permittee from any liability for 

compliance with other applicable federal, state, and local environmental laws and regulations, including the 

Clean Air Act. 

9. Compliance 

The Permittee must comply with all provisions of this permit. Noncompliance with any permit provision is a 

violation of the permit and may constitute a violation of the CAA and is grounds for an enforcement action. 

10. Unavailable Defense 

In an enforcement action it shall not be a defense for the Permittee that it would have been necessary to halt or 

reduce the permitted activity in order to maintain compliance with the provisions of this permit. 

11. Property Rights 

The permit does not convey any property rights of any sort or any exclusive privilege. 

12. Credible Evidence

For the purpose of establishing whether the Permittee violated or is in violation of any requirement of this 

permit, nothing shall preclude the use, including the exclusive use, of any credible evidence or information 

relevant to whether a source would have been in compliance with applicable requirements if the Permittee had 

performed the appropriate performance or compliance test or procedure. 

13. Performance Tests 

a. The Permittee shall submit a test report to EPA within 60 days after the completion of any required 

performance test. At a minimum, the test report shall include:

1. A description of the Emissions Unit and sampling location(s); 

2. The time and date of each test; 

3. A summary of test results, reported in units consistent with the applicable standard; 

4. A description of the test methods and quality assurance procedures used; 
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5. A summary of any deviations from the proposed test plan and justification for why the deviation(s) 

was necessary; 

6. The amount of fuel burned, raw material consumed, and/or product produced during each test run; 

7. Operating parameters of the source and control equipment during each test run; 

8. Sample calculations of equations used to determine test results in the appropriate units; and 

9. The name of the company or entity performing the analysis. 

b. For each performance test required by this permit, the Permittee shall submit a performance test 

protocol to EPA no later than 30 days prior to the test to allow review of the test plan and to arrange for 

an observer to be present at the test. The performance test shall be conducted in accordance with the 

submitted protocol, and any changes required by EPA. 

c. Performance tests shall be conducted in accordance with the test methods set forth in 40 CFR 60.8 and 40 

CFR part 60, appendix A, as specified in this permit. In lieu of the specified test methods, equivalent 

methods may be used with prior written approval from EPA. 

d. Upon written request and adequate justification from the Permittee, EPA may waive a specific annual test 

and/or allow for testing to be done at less than maximum operating capacity. 

e. For performance test purposes, sampling ports, platforms, and access shall be provided on the Emissions 

Unit exhaust system in accordance with the requirements of 40 CFR 60.8(e). 

14. Recordkeeping and Reporting

In addition to the recordkeeping and reporting requirements specified in Sections II-III the Permittee shall: 

a. Maintain a file of all records, data, measurements, reports, and documents related to operation of the 

Source. All records shall be in a permanent form suitable for inspection. 

b. The Permittee shall maintain records and submit a written report of all excess emissions and any other 

noncompliance with permit conditions to EPA for each six-month reporting period from January 1 to June 

30 and from July 1 to December 31, except when more frequent reporting is required by an applicable 

subpart, or EPA, on a case-by-case basis, determines that more frequent reporting is necessary to 

accurately assess the compliance status of the source. Each report shall be postmarked by the 30th day 

following the end of each six-month reporting period and shall include the following: 

1. Time intervals, data, and magnitude of the excess emissions; 

2. Nature and cause of the excess emissions (if known); 

3. Corrective actions taken and preventive measures adopted; 

4. If applicable, a statement in the report specifying that no excess emissions occurred or that the 

monitoring equipment has not been inoperative, repaired, or adjusted,; 

5. Any failure to conduct any required source testing, monitoring, or other compliance activities; and 

6. Any violation of limitations on operation, including but not limited to restrictions on hours of 

operation. 

c. Excess emissions shall be defined as any period in which an Emissions Unit (listed in the Equipment List 

above) exceeds any emissions limits set forth in this permit in Sections II and III. 

d. Excess emissions indicated by performance testing or compliance monitoring shall be considered 

violations of the applicable emission limit for the purposes of this permit. 

e. All records required by this permit shall be retained for not less than five years following the date of such 

measurements, maintenance reports, and/or records. 

f. The Permittee shall maintain a log describing the maintenance and repair activities for Emission Units 6 

through 10 and for the DSI systems and SCR systems for Emissions Units 4 and 5, including the following 

information: 

1. Date of activity; 

2. Description of activity; 

3. For scheduled maintenance, the elapsed time, hours of operation, or other applicable measure since 

the activity was last performed; 

4. For scheduled maintenance, the elapsed time, hours of operation, or other applicable measure until 

the activity should next be performed. 
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15. Shakedown Period

The emission limits and requirements in Conditions 20 and 21 shall not apply during the shakedown period. 

Shakedown is defined as the period beginning with initial startup as defined in Condition 19 and ending no 

later than initial performance testing, during which the Permittee conducts operational and contractual testing 

and tuning to ensure the safe, efficient and reliable operation of the equipment. The shakedown period shall 

not exceed 90 consecutive days. The requirements of Condition 3 shall apply at all times. 

16. Notification of Closure 

The Permittee must submit a report of any permanent or indefinite closure to EPA in writing within 90 days 

after the cessation of any operations at the permitted source. It is not necessary to submit a report of closure 

for regular, seasonal closures. 

17. Signature Verifying Truth, Accuracy, and Completeness 

All reports required by this permit shall be signed by a responsible official as to the truth, accuracy, and 

completeness of the information. The report must state that, based on information and belief formed after 

reasonable inquiry, the statements and information are true, accurate, and complete. If the Permittee discovers 

that any reports or notification submitted to the reviewing authority contain false, inaccurate, or incomplete 

information, the Permittee shall notify the reviewing authority immediately and correct or amend the report as 

soon as is practicable. 

18. Agency Notifications

The Permittee shall send all required reports to EPA at: 

EPA Region 9 

Director, Enforcement Division 

Attn: Air & TRI, ENF-2-1 

75 Hawthorne Street 

San Francisco, CA 94105-3901 

With a copy to: 

Navajo Nation EPA 

Operating Permit Program 

Route 112 N Blg 2837 

Fort Defiance, AZ 86504 

II. Additional requirements for Emissions Units 4 and 5 Pursuant to 40 CFR 52.21 – PSD 

II.a Emissions Limitations and Work Practice Standards 

19. Startup of the SCR

“Initial startup” of the SCR system shall be defined as the first utilization of each SCR system for Emissions 

Units 4 and 5 (EU4 and EU5) upon installation. 

20. Upon initial startup of each SCR system, and after the shakedown period in Condition 15, emissions of sulfuric 

acid mist (SAM) into the atmosphere from EU4 or EU5 shall each not exceed 0.00435 lb/MMBtu. This limit 

shall apply until the emission limit in Condition 21 becomes applicable, or the Permittee submits a report 

according to the requirements in Conditions 30 through 32 demonstrating that the limit in Condition 21 is not 
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achievable. If such a demonstration is submitted, the limit in this condition shall apply until the permit is 

revised to include the limit determined achievable. 

21. Except as provided under Condition 20, within 910 days of initial startup of the SCR systems or 730 days after 

the initial performance tests in Condition 23, whichever comes first, emissions of SAM from EU4 or EU5 into 

the atmosphere shall each not exceed 0.0025 lb/MMBtu. 

22. For EU4 and EU5 each, the Permittee shall operate the hydrated lime injection system consistent with 

Condition 23 at all times each Emissions Unit is operating. 

23. After the initial performance test in Condition 24, the rate, in lb/hr/acfm, of hydrated lime injected prior to the 

baghouse shall be no less than the average rate of hydrated lime injected during the most recent performance 

test demonstrating compliance with the limit in Condition 20 or 21, as applicable. The average rate shall be 

determined as prescribed in Condition 28. After the initial performance test in Condition 24, the Permittee may 

vary the hydrated lime injection rate during the performance testing for the demonstration study in Condition 

31. Such variations of the hydrated lime injection rate shall not be a violation of this permit. 

II.b Monitoring and Testing Requirements 

24. Within 60 days of achieving normal operation, but not later than 180 days after initial startup of each SCR 

system, the Permittee shall conduct an initial performance test for SAM emissions using CTM-13A or CTM13B, 

as applicable. Each test run shall be at least 2 hours, or longer, as necessary, to meet the minimum detection 

limits of the test method. 

25. For EU4 and EU5 each, the Permittee shall conduct annual performance testing for SAM emissions (at least 270 

days after the most recent test, unless a different schedule is approved by EPA). 

26. The Permittee shall install, calibrate, and operate a mass flow meter on the injection lines between the sorbent 

storage silos and the injection points for measuring the rate at which hydrated lime is injected prior to the 

baghouses. 

27. The Permittee shall install, calibrate, and operate a volumetric flowmeter prior to the baghouses near the 

hydrated lime injection points for measuring the volumetric airflow prior to the baghouses. 

28. The Permittee shall monitor the mass hydrated lime injection rate (lb/hr) and volumetric airflow rate (in 

actual cubic feet per minute (acfm)) at least once every 15 minutes and determine the 6-hr rolling hourly 

average injection rate in lb/hr/acfm. For each 6-hr rolling average, the lb/hr/acfm injection rate shall be the 6-

hr rolling average hydrated lime injection rate (lb/hr) divided by the 6-hr rolling average air flowrate (acfm). 

II.c Recordkeeping and Reporting Requirements 

29. The Permittee shall maintain records of the hydrated lime injection rates and volumetric airflow rates 

measured in Condition 28. 

30. Prior to commencing construction of the dry sorbent injection systems, the Permittee shall submit to EPA for 

review and approval a Design Report for the dry sorbent injection systems. The Permittee shall specify in the 

Design Report the type(s) of hydrated lime to be used (moisture content and mesh size), the locations selected 

for reagent injection, and other design parameters based on maximum emission reduction effectiveness, good 

engineering judgment, vendor standards, available data, and boiler operation. EPA shall respond within 60 

days of receipt of the Design Report with any comments. If EPA does not respond within 60 days, the Permittee 
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shall assume the Design Report is approved. The Design Report shall be submitted to the Enforcement Division, 

as identified in Condition18 with email copies to AEO_R9@epa.gov and R9AirPermits@epa.gov. 

II.d. Demonstration Study 

31. If the Permittee is unable to meet the limit in Conditions 21, the Permittee shall submit a demonstration study 

to EPA that shall include: 

a. At least 6 SAM performance tests for EU4 and EU5 each; 

b. For each performance test, SAM shall have been measured at the exit of the stack and prior to the 

hydrated lime injection point and after the air preheater; 

c. At least 6 performance tests for filterable PM emissions using Method 5 for EU4 and EU5 each. These 

performance tests must occur when SAM emissions are also being measured; 

d. The injection location(s) of hydrated lime during each performance test; 

e. The type of hydrated lime used during each performance test (moisture content and mesh size); 

f. The six-hour average hydrated lime injection rate (in lb/hr/acfm) during each performance test, 

determined according to Condition 28. 

g. The Permittee shall vary the hydrated lime injection rate and operating conditions (including economize 

bypassing) over the 6 performance tests. The demonstration shall identify when adverse effects were 

observed (e.g., presence of a secondary plume, potential particulate matter noncompliance). The Design 

Report shall identify the appropriate variations in hydrated lime injection rate and operating conditions. 

h. Confirmation and documentation that spray nozzles and delivery systems for hydrated lime were 

operating properly during the performance tests. Including vendor information describing proper 

delivery system operation. 

32. The demonstration study in Condition 31 shall be submitted at least 60 days prior to the limit in Condition 21 

becoming effective. The study shall be submitted to the Enforcement Division as identified in Condition 18, 

with email copies to AEO_R9@epa.gov and R9AirPermits@epa.gov. Upon review, EPA will notify the Permittee 

of the achievable limit based on the demonstration study and provide written notification to the Permittee to 

submit an application to revise the permit accordingly. 

III. Additional requirements for Emissions Units 6 through 9 Pursuant to 40 CFR 49.135(a)(2) – Minor NSR in Indian 

Country 

III.a Emissions Limitations and Work Practice Standards 

33. Vehicle miles traveled (VMT) for truck traffic associated with deliveries of hydrated lime – EU6 – to the Source 

shall not exceed 382.5 miles per 12-month period. 

34. VMT for truck traffic associated with the delivery of urea pellets, aqueous ammonia, or ammonia – EU7 – to the 

Source shall not exceed 270 miles per 12-month period. 

35. Annual operation of the hydrated lime storage silo – EU8 – (for loading and unloading operations) shall not 

exceed 2,000 hours per 12-month period. 

36. Annual operation of the urea pellets storage silo – EU9 – (for loading and unloading) shall not exceed 2,000 per 

12-month period. 

37. Annual operation of the auxiliary boiler – EU9 – shall not exceed 876 hours per 12-month period. 
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III.b Monitoring and Testing Requirements 

38. The Permittee shall monitor on a monthly basis each delivery of hydrated lime and the VMT for each delivery. 

39. The Permittee shall monitor on a monthly basis each delivery of urea pellets, aqueous ammonia, or ammonia, 

and the VMT for each delivery. 

40. The Permittee shall monitor on a monthly basis the hours of operation of EU9. Monthly hours of operation shall 

be determined using a totalizing hour meter. 

III.c – Recordkeeping and Reporting Requirements 

41. The Permittee shall maintain records on a monthly basis of each delivery related to hydrated lime, including 

the VMT for each delivery, and determine the 12-month rolling total. 

42. The Permittee shall maintain records on a monthly basis of each delivery related to urea pellets, aqueous 

ammonia, or ammonia, including the VMT for each delivery, and determine the 12-month rolling total. 

43. For EU7 and EU8 each, the Permittee shall maintain records on a monthly basis of the hours of operation for 

each silo and determine the 12-month rolling total hours of operation. 

44. The Permittee shall maintain records on a monthly basis of the hours of operation of EU9. Monthly hours of 

operation shall be determined using a totalizing hour meter. 

 
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Attachment A: Abbreviations and Acronyms

acfm actual cubic feet per minute 

BACT best available control technology 

CAA or the Act Federal Clean Air Act 

CFR Code of Federal Regulations 

EPA United States Environmental Protection Agency, Region 9 

EU emissions unit 

hr hour 

lb/hr pounds per hour 

NAAQS National ambient air quality standards 

NSR new source review 

PM particulate matter 

PSD prevention of significant deterioration 

SAM sulfuric acid mist 

SCR selective catalytic reduction systems 

VMT vehicle miles traveled