Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 21735 

(2) You must use this service information 

as applicable to do the actions required by 

this AD, unless this AD specifies otherwise. 

(i) UTC Aerospace Systems Service 

Bulletin 300723–28–03 (V–1577), Revision 

01, dated July 20, 2015. 

(ii) Reserved. 

(3) For service information identified in 

this AD, contact Simmonds Precision 

Products, Inc., A UTC Aerospace Company, 

100 Panton Road, Vergennes, VT 05491; 

phone 802–877–2911; fax 802–877–4444; 

Internet http://www.utcaero

spacesystems.com. 

(4) You may view this service information 

at the FAA, Transport Airplane Directorate, 

1601 Lind Avenue SW., Renton, WA. For 

information on the availability of this 

material at the FAA, call 425–227–1221. 

(5) You may view this service information 

that is incorporated by reference at the 

National Archives and Records 

Administration (NARA). For information on 

the availability of this material at NARA, call 

202–741–6030, or go to: http://www.archives.

gov/federal-register/cfr/ibr-locations.html. 

Issued in Renton, Washington, on March 

30, 2016. 

Victor Wicklund, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2016–08352 Filed 4–12–16; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 71 

[Docket No. FAA–2015–3771; Airspace 

Docket No. 15–ANM–28] 

Establishment of Class E Airspace, 

South Bend, WA 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule, correction. 

SUMMARY: This action corrects 

administrative errors in a final rule 

published in the Federal Register of 

March 8, 2016, that establishes Class E 

airspace at Willapa Harbor Heliport, 

South Bend, WA, by amending the 

assigned paragraph for rule 

incorporation within FAA Order 

7400.9Z, by correcting format errors in 

the text header of the airspace legal 

description, and by correcting 

inconsistent airport name information 

in the airspace legal description. These 

changes do not affect the boundaries or 

operating requirements of the airspace. 

DATES: Effective 0901 UTC, May 26, 

2016. The Director of the Federal 

Register approves this incorporation by 

reference action under Title 1, Code of 

Federal Regulations, part 51, subject to 

the annual revision of FAA Order 

7400.9 and publication of conforming 

amendments. 

FOR FURTHER INFORMATION CONTACT: Tom 

Clark, Federal Aviation Administration, 

Operations Support Group, Western 

Service Center, 1601 Lind Avenue SW., 

Renton, WA 98057; Telephone: (425) 

203–4511. 

SUPPLEMENTARY INFORMATION: 

History 

The FAA published a final rule in the 

Federal Register establishing Class E 

airspace extending upward from 700 

feet above the surface at Willapa Harbor 

Heliport, South Bend, WA (81 FR 12001 

March 8, 2016) Docket No. FAA–2015– 

3771. Subsequent to publication the 

FAA identified errors in the assigned 

paragraph for incorporation, text header 

format, and airport name information. 

This action corrects the errors. 

Correction to Final Rule 

Accordingly, pursuant to the 

authority delegated to me, in the 

Federal Register of March 8, 2016 (81 

FR 12001) FR Doc. 2016–05059, 

Establishment of Class E airspace, South 

Bend, WA, is corrected as follows: 

§ 71.1 [Amended] 

On page 12002, column 1, line 17, 

remove ‘‘Paragraph 5000 Class D 

Airspace’’, and add in its place 

‘‘Paragraph 6005. Class E airspace Areas 

Extending Upward from 700 feet or 

more Above the Surface of the Earth.’’ 

On page 12002, column 1, line 19 and 

20, remove ‘‘ANM WA E5 Willapa 

Harbor Heliport, South Bend, WA 

[New]’’ and add in its place ‘‘ANM WA 

E5 South Bend, WA [New].’’ 

On page 12002, column 1, lines 27, 

28, 34 and 35, after the word ‘Harbor’ 

add the word ‘Heliport’. 

Issued in Seattle, Washington, on April 5, 

2016. 

Tracey Johnson, 

Manager, Operations Support Group, Western 

Service Center. 

[FR Doc. 2016–08395 Filed 4–12–16; 8:45 am] 

BILLING CODE 4910–13–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R09–OAR–2015–0165; FRL–9944–68– 

Region 9] 

Promulgation of Air Quality 

Implementation Plans; Arizona; 

Regional Haze Federal Implementation 

Plan; Reconsideration 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is revising portions of the 

Arizona Regional Haze Federal 

Implementation Plan (FIP) applicable to 

the Coronado Generating Station 

(Coronado) and the Cholla Power Plant 

(Cholla). In response to a petition for 

reconsideration from the Salt River 

Project Agricultural Improvement and 

Power District (SRP), the owner and 

operator of Coronado, we are replacing 

a plant-wide compliance method with a 

unit-specific compliance method for 

determining compliance with the best 

available retrofit technology (BART) 

emission limits for nitrogen oxides 

(NOX) from Units 1 and 2 at Coronado. 

While the plant-wide limit for NOX

emissions from Units 1 and 2 was 

established as 0.065 lb/MMBtu, we are 

now setting a unit-specific limit of 0.065 

lb/MMBtu for Unit 1 and 0.080 lb/

MMBtu for Unit 2. In addition, we are 

revising the work practice standard in 

the FIP for Coronado. Finally, we are 

removing the affirmative defense for 

malfunctions, which applied to both 

Coronado and Cholla. 

DATES: Effective date: This rule will be 

effective May 13, 2016. 

ADDRESSES: The EPA has established a 

docket for this action under Docket ID 

No. EPA–R09–OAR–2015–0165. All 

documents in the docket are listed on 

the http://www.regulations.gov Web 

site. Although listed in the index, some 

information is not publicly available, 

e.g., confidential business information 

(CBI) or other information whose 

disclosure is restricted by statute. 

Certain other material, such as 

copyrighted material, is not placed on 

the Internet and will be publicly 

available only in hard copy form. 

Publicly available docket materials are 

available electronically through http://

www.regulations.gov. 

FOR FURTHER INFORMATION CONTACT: 

Vijay Limaye, U.S. EPA, Region 9, 

Planning Office, Air Division, Air–2, 75 

Hawthorne Street, San Francisco, CA 

94105; telephone number: (415) 972– 

3086; email address: limaye.vijay@

epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this document, ‘‘we,’’ ‘‘us,’’ 

and ‘‘our’’ refer to the EPA. 

Table of Contents 

I. Definitions 

II. Background 

III. Proposed Action 

IV. Public Comments and EPA Responses 

V. Final Action 

VI. Environmental Justice Considerations 

VII. Statutory and Executive Order Reviews 


jstallworth on DSK7TPTVN1PROD with RULES
21736 Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 

1 42 U.S.C. 7491(a)(1). 

2 40 CFR 51.301. 

3See CAA section 169B, 42 U.S.C. 7492. 

4Areas designated as mandatory Class I Federal 

areas consist of national parks exceeding 6000 

acres, wilderness areas, and national memorial 

parks exceeding 5000 acres, and all international 

parks that were in existence on August 7, 1977. 42 

U.S.C. 7472(a). When we use the term ‘‘Class I area’’ 

in this action, we mean a ‘‘mandatory Class I 

Federal area.’’ 

5See generally 40 CFR 51.308. 

6 40 CFR 51.308(e). 

7 77 FR 42834. 

8Boiler-operating day is defined as ‘‘a 24-hour 

period between 12 midnight and the following 

midnight during which any fuel is combusted at 

any time in the unit.’’ 40 CFR 52.145(f)(2). 

9 77 FR 72555. 

10 Id. 

I. Definitions 

For the purpose of this document, we 

are giving meaning to certain words or 

initials as follows: 

• The initials AAC mean or refer to 

the Arizona Administrative Code. 

• The initials ADEQ mean or refer to 

the Arizona Department of 

Environmental Quality. 

• The initials AMPD mean or refer to 

Air Markets Program Data. 

• The words Arizona and State mean 

the State of Arizona. 

• The initials CAM mean or refer to 

Compliance Assurance Monitoring. 

• The word Cholla refers to the 

Cholla Power Plant. 

• The word Coronado refers to the 

Coronado Generating Station. 

• The initials BART mean or refer to 

Best Available Retrofit Technology. 

• The initials BOD mean or refer to 

boiler operating day. 

• The initials CAA mean or refer to 

the Clean Air Act. 

• The initials CBI mean or refer to 

Confidential Business Information. 

• The initials EGU mean or refer to 

Electric Generating Unit. 

• The words EPA, we, us, or our mean 

or refer to the United States 

Environmental Protection Agency. 

• The initials FIP mean or refer to 

Federal Implementation Plan. 

• The initials LNB mean or refer to 

low-NOX burners. 

• The initials MMBtu mean or refer to 

million British thermal units. 

• The initials MOT mean or refer to 

minimum operating temperature. 

• The initials MW mean or refer to 

megawatts. 

• The initials NAAQS mean or refer 

to National Ambient Air Quality 

Standards. 

• The initials NESHAP mean or refer 

to National Emission Standards for 

Hazardous Air Pollutants. 

• The initials NSPS mean or refer to 

Standards of Performance for New 

Stationary Sources. 

• The initials NOX mean or refer to 

nitrogen oxides. 

• The initials OFA mean or refer to 

over fire air. 

• The initials RHR mean or refer to 

the EPA’s Regional Haze Rule. 

• The initials RMB mean or refer to 

RMB Consulting and Research. 

• The initials S&L mean or refer to 

Sargent & Lundy. 

• The initials SCR mean or refer to 

Selective Catalytic Reduction. 

• The initials SIP mean or refer to 

State Implementation Plan. 

• The initials SRP mean or refer to 

the Salt River Project Agricultural 

Improvement and Power District. 

• The initials SSM mean or refer to 

startup, shutdown, and malfunction. 

• The initials UPL mean or refer to 

Upper Prediction Limit. 

II . Background 

A. Summary of Statutory and 

Regulatory Requirements 

Congress created a program for 

protecting visibility in the nation’s 

national parks and wilderness areas in 

1977 by adding section 169A to the 

Clean Air Act (CAA). This section of the 

CAA establishes as a national goal the 

‘‘prevention of any future, and the 

remedying of any existing, impairment 

of visibility in mandatory Class I 

Federal areas which impairment results 

from man-made air pollution.’’ 1 It also 

directs states to evaluate the use of 

retrofit controls at certain larger, often 

uncontrolled, older stationary sources in 

order to address visibility impacts from 

these sources. Specifically, section 

169A(b)(2)(A) of the CAA requires states 

to revise their State Implementation 

Plans (SIPs) to contain such measures as 

may be necessary to make reasonable 

progress towards the national visibility 

goal, including a requirement that 

certain categories of existing major 

stationary sources built between 1962 

and 1977 procure, install, and operate 

best available retrofit technology 

(BART) controls. These sources are 

referred to as ‘‘BART-eligible’’ sources.2

In the 1990 CAA Amendments, 

Congress amended the visibility 

provisions in the CAA to focus attention 

on the problem of regional haze, which 

is visibility impairment produced by a 

multitude of sources and activities 

located across a broad geographic area.3

We promulgated the Regional Haze Rule 

(RHR) in 1999, which requires states to 

develop and implement SIPs to ensure 

reasonable progress toward improving 

visibility in mandatory Class I Federal 

areas 4 by reducing emissions that cause 

or contribute to regional haze.5 Under 

the RHR, states are directed to conduct 

BART determinations for BART-eligible 

sources that may be anticipated to cause 

or contribute to any visibility 

impairment in a Class I area.6

B. History of BART Determination for 

Coronado Generating Station 

The Arizona Department of 

Environmental Quality (ADEQ) 

submitted a Regional Haze SIP 

(‘‘Arizona Regional Haze SIP’’) under 

Section 308 of the RHR to EPA Region 

9 on February 28, 2011. The Arizona 

Regional Haze SIP included BART 

determinations for NOX, particulate 

matter (PM), and sulfur dioxide (SO2) 

for Units 1 and 2 at Coronado. We 

proposed on July 20, 2012, to approve 

ADEQ’s BART determinations for PM 

and SO2, but to disapprove its 

determination for NOX at Coronado.7 In 

the same notice, we also proposed a FIP 

that included a NOX BART emission 

limit of 0.050 lb/MMBtu for Unit 1 and 

0.080 lb/MMBtu for Unit 2 based on a 

30-boiler-operating-day (BOD) rolling 

average.8 These limits correspond to the 

use of Selective Catalytic Reduction 

(SCR) and low-NOX burners (LNB) with 

over fire air (OFA) to reduce NOX

emissions. We noted that a consent 

decree between SRP and the EPA 

required the installation of SCR and 

compliance with a NOX emission limit 

of 0.080 lb/MMBtu (30–BOD rolling 

average) at Coronado Unit 2 by June 1, 

2014. In its comments on our proposal, 

SRP asserted that a NOX emission rate 

of 0.050 lb/MMBtu was not achievable 

at either of the Coronado units, due to 

their startup/shutdown operating 

profile. In support of this assertion, SRP 

submitted reports by two consultants, 

Sargent & Lundy (S&L) and RMB 

Consulting and Research (RMB), which 

indicated that the Coronado units could 

achieve a 30–BOD rolling average 

emission rate in the range of 0.053 to 

0.072 lb/MMBtu per unit.9 The S&L 

report also examined potential measures 

to improve the performance of the 

current SCR design for Unit 2, including 

installation of a ‘‘low load temperature 

control system,’’ (i.e., steam reheat) 

which would allow the SCR system to 

operate during periods of low load. 

In the final Arizona Regional Haze 

FIP, we set a plant-wide NOX emission 

limit for Coronado of 0.065 lb/MMBtu 

on a 30–BOD rolling average, which 

SRP could meet by installing a low-load 

temperature control system on Unit 2 

and an SCR system including a low-load 

temperature control system on Unit 1.10

We structured the compliance 

determination method for this limit 


jstallworth on DSK7TPTVN1PROD with RULES
Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 21737 

11 Id. (codified at 40 CFR 52.145(f)(10)). 

12Petition of Salt River Project Agricultural 

Improvement and Power District for Partial 

Reconsideration and Stay of EPA’s Final Rule: 

‘‘Approval, Disapproval and Promulgation of Air 

Quality Implementation Plans; Arizona; Regional 

Haze State and Federal Implementation Plans’’ 

(February 4, 2013). 

13Letters from Jared Blumenfeld, EPA, to Norman 

W. Fichthorn and Aaron Flynn, Hunton and 

Williams (April 9, 2013). 

14 80 FR 17010 (March 31, 2015). 

15The Cholla Power Plant (also known as the 

Cholla Generating Station) is operated by the by 

Arizona Public Service Company (APS). APS owns 

Cholla Units 1–3, while PacifiCorp owns Unit 4. 

16 80 FR 17013–17016. 

17Letter from Kelly J. Barr, SRP, to Deborah 

Jordan, EPA (November 18, 2013), Attachment 1, 

Sargent and Lundy LLC Report SL–011754, Salt 

River Project Coronado Generating Station Unit 1 

SCR NOX Emissions Modeling (November 14, 2013) 

(‘‘2013 S&L Report’’). 18 Id. Attachment 2, Technical Memorandum 

from RMB to SRP, NOX Limits Compliance 

Monitoring Consideration on Coronado Unit 1 

(October 28, 2013) (‘‘2013 RMB Report’’) at 1. 

19 80 FR 17016. 

such that, when one of the two units 

was not operating, its emissions from 

the preceding 30 boiler operating days 

would continue to be included in the 

two-unit average. Please refer to our 

final rule published on December 5, 

2012, for further information on the 

BART determinations and compliance 

methodology. 

In addition, we included in the FIP 

two additional requirements that apply 

to all affected sources, including 

Coronado. First, we promulgated a work 

practice standard that requires that 

pollution control equipment be 

designed and capable of operating 

properly to minimize emissions during 

all expected operating conditions.11

Second, we incorporated by reference 

into the FIP certain provisions of the 

Arizona Administrative Code (AAC) 

that establish an affirmative defense for 

excess emissions due to malfunctions. 

C. Petition for Reconsideration and Stay 

We received a petition from SRP on 

February 4, 2013, requesting partial 

reconsideration and administrative stay 

of our final rule under section 

307(d)(7)(B) of the CAA and section 705 

of the Administrative Procedure Act.12

EPA Region 9 sent a letter on April 9, 

2013, to representatives of SRP 

informing the company that we were 

granting partial reconsideration of the 

final rule for the Arizona Regional Haze 

FIP.13 In particular, we stated that we 

were granting reconsideration of the 

compliance method for NOX emissions 

from Units 1 and 2 at Coronado and that 

we would issue a notice of proposed 

rulemaking seeking comment on an 

alternative compliance methodology. 

We also noted that, because we initially 

proposed different NOX emission limits 

for the two units, we would seek 

comment on the appropriate emission 

limit for each of the units. 

III. Proposed Action 

On March 31, 2015, the EPA proposed 

action on reconsideration of the 

compliance method and NOX emissions 

limits for Coronado in the Arizona 

Regional Haze FIP.14 In particular, we 

proposed a unit-specific compliance 

method and separate numerical 

emission limits for NOX at Coronado 

Units 1 and 2. We also proposed to 

revise the work practice requirement 

that applies to Coronado and to remove 

the affirmative defense for malfunctions 

that is currently included in the FIP for 

Coronado and Cholla.15 Finally, we 

proposed to determine that these 

revisions to the FIP would comply with 

CAA section 110(l). 

A. Proposed Compliance Method for 

Unit-Specific Emission Limits 

We proposed to set a separate rolling 

30–BOD lb/MMBtu limit for each of the 

two Coronado Units, based on the 

following compliance method: 

The 30-day rolling average NOX emission 

rate for each unit shall be calculated in 

accordance with the following procedure: 

First, sum the total pounds of NOX emitted 

from the unit during the current boiler 

operating day and the previous twenty-nine 

(29) boiler-operating days; second, sum the 

total heat input to the unit in MMBtu during 

the current boiler operating day and the 

previous twenty-nine (29) boiler-operating 

days; and third, divide the total number of 

pounds of NOX emitted during the thirty (30) 

boiler-operating days by the total heat input 

during the thirty (30) boiler-operating days. 

A new 30-day rolling average NOX emission 

rate shall be calculated for each new boiler 

operating day. Each 30-day rolling average 

NOX emission rate shall include all 

emissions that occur during all periods 

within any boiler operating day, including 

emissions from startup, shutdown, and 

malfunction. 

We proposed that this method would 

replace the plant-wide method 

promulgated in the final rule at 40 CFR 

52.145(f)(5)(B)(ii), but that all other 

compliance-related requirements, 

including the monitoring, 

recordkeeping, and reporting 

requirements, would remain as 

promulgated. 

B. Proposed Emission Limits for 

Coronado Units 1 and 2 

1. Proposed Emission Limit for 

Coronado Unit 1 

In developing a proposed emission 

limit for Unit 1, we considered 

information and analyses provided by 

SRP, including two reports prepared by 

S&L and RMB concerning the 

achievability of various NOX emission 

limits at Coronado Unit 1, as well as 

emission data for Unit 1 as reported to 

the Air Markets Program Data (AMPD) 

system.16 The 2013 S&L Report 

presented modeling results intended to 

predict NOX emissions from Unit 1 

under various operating scenarios.17

The 2013 RMB Report applied an 

‘‘upper prediction limit’’ (UPL) 

technique to the results of the S&L 

report in order to account for ‘‘the 

impact of measurement uncertainty and 

other process variation.’’ 18

In our evaluation of the 2013 S&L 

report, we found that the scenarios 

examined by S&L were realistic 

depictions of load profile scenarios 

historically experienced by the 

Coronado units. In particular, we found 

that S&L’s scenario 5c, which consists of 

low-load cycling operations (with SCR 

and steam reheat assumed) and three 

cold startups within a 30-day period 

was a reasonable and conservative 

representation of expected future 

operations at Coronado Unit 1, in light 

of the number of startup events that 

have historically occurred and SRP’s 

expectation that the Coronado units will 

experience greater periods of operation 

in load-following service or 

nonoperation in the future. Accordingly, 

we proposed to find that an emission 

rate of 0.065 lb/MMBtu, which 

corresponds to S&L’s scenario 5c, was a 

reasonable estimate of average SCR 

performance for Unit 1. 

We were unable to evaluate fully the 

RMB Report because it lacked 

documentation regarding many of its 

components. In addition, we found that 

the data set for NOX emissions from 

Coronado Unit 1 ‘‘is much more 

extensive, represents continuous data 

collected over a long period of time, and 

covers a wider range of unit operations’’ 

relative to the data sets for which the 

EPA has previously employed a UPL 

analysis.19 This better dataset means 

that use of the UPL analysis method is 

not necessary and use of the actual data 

from the unit is more representative. 

Accordingly, we proposed to find that 

the use of the UPL method was not 

appropriate for setting an emission limit 

for Coronado Unit 1. We also proposed 

to find that it was not necessary to raise 

the numerical emission limit in order to 

provide an additional compliance 

margin due to the conservative 

assumptions in the 2013 S&L Report. 

Based on these proposed findings, we 

proposed to set an emission limit for 

Coronado Unit 1 of 0.065 lb/MMBtu on 

a rolling 30–BOD basis. Please refer to 


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21738 Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 

20 Id. 

21Although the preamble referred to this work 

practice standard specifically in relation to the SCR 

on Unit 2, the proposed regulatory text applied to 

all controls devices on both units, which was the 

intended effect of the proposed revision. 

22See 40 CFR 52.145(f)(11) (incorporating by 

reference AAC R–18–2–101, paragraph 65; AAC 

R18–2–310, sections (A), (B), (D) and (E); and AAC 

R18–2–310.01). 

23See NRDC v. EPA, 749 F.3d 1055 (D.C. Cir. 

2014). 

24 79 FR 55920, 55947 (September 17, 2014). 

25 80 FR 17017–17018. 

26The ECO letter was dated April 28, 2015, but 

was not transmitted to the EPA until June 1, 2015. 

our proposal for more information 

concerning the 2013 S&L and RMB 

Reports, our evaluation of those reports, 

and the basis for our proposed emission 

limit for Unit 1. 

2. Proposed Emission Limit for 

Coronado Unit 2 

In proposing an emission limit for 

Coronado Unit 2, we considered 

information provided by SRP 

concerning Unit 2’s design parameters 

and the installation of a low-load 

temperature control system for Unit 2. 

We found that this information 

supported SRP’s assertion that the 

emission limit in the Consent Decree of 

0.080 lb/MMBtu represents BART for 

Unit 2. In particular, we noted that ‘‘the 

fact that SRP has already installed a 

low-load temperature-control system at 

this unit in order to meet the 0.080 lb/ 

MMBtu limit suggests that a lower limit 

would not be achievable on a 30–BOD 

basis.’’ 20 Therefore, we proposed to set 

a unit-specific NOX limit for Unit 2 of 

0.080 lb/MMBtu on a rolling 30–BOD 

basis. 

C. Proposed Revision to Work Practice 

Standard 

In addition to the revisions to the 

continuously applicable numeric 

emission limits for each unit, we 

proposed to revise the work practice 

standard at 40 CFR 52.145(f)(10) to 

require continuous operation of 

pollution control equipment at each 

unit at all times the unit is in service ‘‘in 

a manner consistent with technological 

limitations, manufacturer’s 

specifications, and good engineering 

and good air pollution control practices 

for minimizing emissions.’’ 21

D. Proposed Removal of Affirmative 

Defense for Malfunctions 

As noted in our proposal, the Arizona 

Regional Haze FIP incorporates by 

reference certain provisions of the ACC 

that establish an affirmative defense that 

sources may seek to assert in an 

enforcement action for violations that 

result from excess emissions due to 

malfunctions.22 Subsequent to the 

EPA’s promulgation of the FIP, the 

United States Court of Appeals for the 

D.C. Circuit ruled that CAA sections 113 

and 304 prohibit the inclusion of 

affirmative defense provisions in the 

EPA’s regulations imposing emission 

limits on sources.23 We explained that 

the logic of the court’s decision applies 

to the promulgation of a FIP, and 

precludes the EPA from including an 

affirmative defense provision in a FIP. 

In addition, we noted that the EPA had 

proposed to find AAC R18–2–310(B) 

and AAC R18–2–310(C) substantially 

inadequate to meet CAA requirements 

and to issue a SIP call with respect to 

these provisions (‘‘SSM SIP Call’’).24

Therefore, we proposed to remove the 

affirmative defense for malfunctions 

from the Arizona Regional Haze FIP. 

E. Non-Interference With Applicable 

Requirements 

The final element of our proposed 

action on reconsideration was an 

analysis of whether the proposed 

revisions to the FIP would interfere with 

any applicable requirement concerning 

attainment, reasonable further progress, 

or any other applicable requirement of 

the CAA.25 We explained that the 

proposed revision to the FIP would 

allow for an increase in NOX emissions 

of 233 tons per year (tpy) compared to 

the existing FIP, but that this increase 

represented less than one percent of the 

projected total NOX emission reductions 

required under the FIP. We also noted 

that Coronado is located in an area that 

is designated as Unclassifiable/

Attainment for all of the current 

National Ambient Air Quality Standards 

(NAAQS). We proposed to find that a 

revision to the BART emission limits for 

NOX would not interfere with 

attainment or reasonable further 

progress for any air quality standard. We 

also proposed to find that the revisions 

would not interfere with the applicable 

requirements of the National Emission 

Standards for Hazardous Air Pollutants 

(NESHAP), Standards of Performance 

for New Stationary Sources (NSPS), or 

Compliance Assurance Monitoring 

(CAM) requirements. Finally, we 

explained that, while the proposed 

revisions would alter the specific 

emission limits that constitute BART for 

NOX at Coronado, the effect of the 

proposed changes on visibility and 

overall NOX emissions reductions under 

the FIP would be very small. Therefore, 

we proposed to find that the proposed 

revisions would not interfere with any 

applicable requirement of the CAA. 

IV. Public Comments and EPA 

Responses 

Our proposed action provided a 45- 

day public comment period. During this 

period, we received two comment 

letters: one from Earthjustice on behalf 

of National Parks Conservation 

Association and Sierra Club and one 

from SRP. In addition, after the close of 

the comment period, we received a 

comment letter from the Eastern 

Arizona Counties Organization (ECO).26

The significant comments and our 

responses are summarized below. 

A. Comments on Proposed Compliance 

Method for Unit-Specific Emission 

Limits 

Comment: SRP expressed support for 

the proposed compliance method. 

Response: We acknowledge SRP’s 

support for the proposed compliance 

method. We are finalizing the 

compliance method as proposed. 

B. Comments on Proposed Emission 

Limits for Coronado Units 1 and 2 

1. General Comments on Proposed 

Emission Limits for Coronado Units 1 

and 2 

Comment: Earthjustice noted that the 

proposed emission limits are based on 

an approach that is ‘‘wholly dependent 

on many assumptions’’ and expressed 

concern over several elements of the 

S&L analysis. First, the commenter 

objected to breaking up a continuous 

load profile into ill-defined ‘‘modes.’’ 

Second, the commenter asserted that the 

EPA should not have accepted S&L’s 

scenarios, as listed in Table 2 of the 

proposal, specifically citing a lack of 

support for NOX rates used by S&L for 

the various modes of operation. The 

commenter noted that the EPA 

indicated only that the emission rates 

are ‘‘reasonable and generally 

consistent’’ with data reported to the Air 

Markets Program Data (AMPD). The 

commenter indicated that it could not 

find support for some of the assumed 

rates in the record. Third, Earthjustice 

stated that there were insufficient data 

on how many and what combinations of 

the operation modes can actually occur 

in a given future 30-day period. Finally, 

the commenter argued that the EPA (or 

the permit-issuing authority) should set 

separate limits for each scenario and 

asserted that, in the absence of such 

limits ‘‘this bottom-up approach is 

clearly open for abuse whereby the limit 

is set by making up a worst case 

assumption that may or may not occur— 

or may occur, but with very low 


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Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 21739 

27See spreadsheet ‘‘Startup & Shutdown 

Data.xls.’’ 

28 80 FR 33840, 33980 (June 11, 2015). 

29Excess emissions from malfunctions events are, 

by definition, unforeseeable and extremely variable, 

and therefore generally cannot be specifically 

accounted for within an emission limit. Sources are 

required to meet the normally applicable emission 

limits during malfunctions. Regulators may elect to 

exercise enforcement discretion in such 

circumstances, and sources retain the ability to 

assert any legal or equitable defenses to liability or 

remedies that they may have in an enforcement 

proceedings, consistent with CAA sections 113 and 

304. 

30See 1.1.1 SCR Reactor.pdf, Unit 2 Temperature 

vs. Load PI Data.xlsx, and email from Barbara 

Sprungl, SRP, to Eugene Chen, EPA, regarding SCR 

MOT (February 19, 2016). 

frequency—allowing the operator to 

have a high NOX limit at all times.’’ 

Earthjustice further asserted that 

‘‘inclusion of startup, shutdown, and 

malfunctions cannot be an excuse to 

obtain a high emission limit simply by 

assuming a ‘worst case’ future scenario 

with several of these mode—regardless 

of the low frequency of such a 

scenario.’’ 

Response: We partially agree with this 

comment. With regard to the 

information supporting the assumptions 

made in the S&L analysis, we have 

requested and received additional 

documentation from SRP. The full 

details are included as a spreadsheet in 

the docket of this final rule.27 To 

summarize, SRP examined historical 

operating data from startup and 

shutdown events over a period 

extending from 2009 to 2012 and 

identified multiple cold starts, warm 

starts, and shutdowns. The listed modes 

reflect actual events and operating 

modes from Unit 1 and 2’s history and 

the emission rates associated with these 

events. 

We are cognizant of the commenter’s 

concern that accounting for operating 

events and conditions that occur 

relatively infrequently could result in an 

emission limit that is higher than what 

would be warranted based solely on 

normal, steady-state operations. Such a 

limit provides a larger compliance 

margin during periods of normal, 

steady-state operations, when these 

operating events and conditions are not 

occurring. However, we disagree with 

the commenter’s argument that separate 

limits for each mode of operation or 

load profile are needed. We recognize 

that the EPA’s SSM SIP Policy as of 

2015 contemplates the potential use of 

‘‘. . . special, alternative emission 

limitations that apply during startup or 

shutdown if the source cannot meet the 

otherwise applicable emission 

limitation . . .’’ 28 The EPA’s SSM SIP 

Policy as of 2015 reflects the EPA’s 

interpretation of the CAA to allow 

continuous emission limitations in SIPs 

that are composed of, for instance, (i) 

specific numerical limits that apply 

during most of the operations at the 

affected source, and (ii) other specific 

numerical limits that apply during 

modes of operation such as startup and 

shutdown. This policy thus 

contemplates that the ‘‘otherwise 

applicable’’ numerical limit might be 

based on steady-state operation, which 

reflects the best degree of emission 

control during that mode of operation. 

The 2015 SSM Policy recommends 

seven factors that would be relevant to 

developing an alternative numerical 

limit for specific modes of operation, if 

that were appropriate. 

The commenter is suggesting that the 

FIP should take this approach for 

Coronado. We acknowledge that in 

general this approach would be 

consistent with our 2015 SSM SIP 

Policy, but our SSM Policy also 

contemplates the use of a single 

appropriately set numerical limit with a 

relatively long averaging period that is 

a weighted average of the levels of 

emission control during steady-state 

operation, startup, and shutdown. The 

EPA notes, however, that the averaging 

period for an emission limitation must 

be appropriate for the type of SIP 

provision at issue, e.g., a 30 day 

averaging period appropriate for 

purposes of Regional Haze could be 

inappropriate in an attainment plan for 

a 24-hour NAAQS. In this instance, 

Coronado Unit 1 can meet the 

applicable emission limitation imposed 

in this FIP, precisely because that 

limitation accounts for emissions from 

startup and shutdown. Therefore, an 

alternative emission limit for startup 

and shutdown is not necessary or 

appropriate in this instance.29

Furthermore, the FIP’s approach of 

setting a single continuously applicable 

BART emission limit that applies during 

all modes of operation is consistent with 

the CAA, the RHR and the BART 

Guidelines. We are not aware of any 

instance of BART being implemented 

through separate emission limits that 

apply to different modes of operation. 

Comment: In addition to the 

assumptions noted in the previous 

comment, Earthjustice also asserted that 

the assumptions regarding the design 

and operation of the low-load 

temperature control system are 

unsupported. Earthjustice quoted the 

following passage from the EPA’s 

proposal: 

As described in the S&L report, periods of 

low load operation generally consist of 

operation between loads of 138 MW to 270 

MW (operation above 270 MW can be 

considered ‘‘high’’ load). Broadly speaking, 

the temperature in the SCR system will fall 

below 599 degrees F during these periods of 

low load operation, which is the minimum 

temperature required for effective NOX

control. A low load temperature control 

system increases the temperature at the SCR 

inlet in order to maintain 599 degrees F, 

allowing operation of the SCR system during 

periods of low load. Without this control 

system, the Coronado Unit 2 SCR system will 

not operate during periods of low load. 

The commenter asserted that these are 

‘‘critical and unsupported 

assumptions.’’ Specifically, the 

commenter stated that ‘‘the minimum 

operating temperature (MOT) is a 

function of SCR catalyst design and 

parameters such as the sulfur content of 

the fuel,’’ and that neither the proposal 

nor the S&L analysis explained why the 

MOT is assumed to be 599 degrees F for 

the SCRs at Units 1 and 2. The 

commenter noted that the record 

contains no documentation regarding 

SCR design from the actual designer of 

the Unit 2 SCR. The commenter also 

asserted that the correspondence 

between MOT and unit load (i.e., that 

the 599 degrees F MOT corresponds to 

unit load of 270 MW) is not supported. 

Response: We agree with this 

comment and have requested and 

received additional documentation from 

SRP regarding these issues. Included in 

the docket is a functional description of 

the Unit 2 SCR system prepared by 

Riley Power.30 It indicates that the Unit 

2 SCR was designed for a catalyst MOT 

of 599 degrees F. Also included in the 

docket is a record of Unit 2’s gross load 

and air preheater temperature readings 

over an 18-month period from January 

2011 to July 2012. As indicated in the 

spreadsheet and chart attached to this 

documentation, the majority of these 

data point to an air preheater 

temperature of 599 degrees F being 

achieved at a gross load of 270 MW. 

2. Comments on Proposed Emission 

Limits for Coronado Unit 1 

Comment: Earthjustice commented 

that the proposed emission limit of 

0.065 lb/MMBtu was based on Scenario 

5c of the S&L analysis, as listed in Table 

2 of the proposed rule, which 

corresponds to a 30-day period of 

continuous low-load cycling with three 

cold startup events. The commenter 

noted that the EPA did not identify a 

historical 30-day period that 

corresponded to this scenario. The 

commenter further asserted that it had 

‘‘examined Unit 1 hourly operating data 

for a three year time period, 2012–2014, 

from AMPD and found no instances of 

scenario 5c or even 5b—i.e., two or three 


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31See November 2011, April 2011, July 2009 in 

‘‘Coronado NOX Emission Data (daily).’’ 

32See spreadsheet Coronado 2015–09 

(hourly).xls. 

33Specifically, three cold startup events and 30 

days of low-load cycling operations. 

34See Letter from Kelly Barr, SRP, to Deborah 

Jordan, EPA (April 28, 2014). 

35One of the assumptions underlying Scenario 5c 

is low-load cycling for 30 days, which, for purposes 

of developing a rolling 30–BOD limit, represents 

continuous operation at low-load cycling. 

36Technical Memorandum from RMB to SRP, 

Comments on Proposed Revisions to the Regional 

Haze Federal Implementation Plan for Arizona 

(May 15, 2015). 

cold-starts along with significant low 

load cycling.’’ The commenter 

concluded that the highest NOX limit 

that could be supported by S&L’s 

analysis was Scenario 5a, i.e., 0.0550 lb/ 

MMBtu. Accordingly the commenter 

requested that the EPA ‘‘either fully 

support Scenario 5c or accept the NOX

limit associated with 5a—0.0550 lb/

MMBtu.’’ 

Response: We partially agree with this 

comment. As we stated in our proposed 

rule, the particular scenario that the 

proposed emission limit of 0.065 lb/

MMBtu is based upon, Scenario 5c of 

the S&L analysis, includes unit 

operating conditions (30 days of 

continuous low-load cycling and three 

cold startup events) that have not 

historically occurred in a single 30 BOD 

period. We disagree with the 

commenter’s assertion, however, that an 

emission limit of 0.055 lb/MMBtu 

would be the appropriate emission 

limit. 

The commenter noted that it was 

unable to identify a 30-day period with 

two or three cold starts along with 

significant low-load cycling at Unit 1 

during the period from 2012–2014. We 

reviewed operating data beyond the 

most recent 3-year period and found 

three 30-day periods with multiple 

startup events.31 As indicated in AMPD 

data and the information provided by 

SRP in its April 24, 2014, letter, Unit 1 

has experienced 30-day periods that 

included two cold starts, as well as one 

cold start with multiple warm starts 

(approximately three to six). In general, 

the total amount of NOX emissions from 

a warm startup is smaller than a cold 

startup, in large part due to the longer 

duration of cold startup events. In this 

case, the total amount of NOX generated 

by the actual historical operating 

scenario of one cold startup and 

multiple warm startups (approximately 

three to six) is similar to the total 

amount that would be generated under 

Scenario 5c (i.e., three cold startups), 

and supports the use of three cold 

startups as a conservative assumption 

concerning future operations at Unit 1. 

Similarly, the commenter asserted 

that it had not identified a 30-day 

period of significant low-load cycling at 

Unit 1 during the period from 2012– 

2014. We agree that historical 

operations at the Coronado units do not 

reflect 30 consecutive days of low-load 

cycling operations. As noted in our 

proposed rule, this assumption is based 

on SRP’s expectation that the Coronado 

units will experience greater periods of 

low-load cycling operation in the future, 

as well as nonoperation, given the 

expanded role of renewable energy and 

reduced reliance on fossil fuels in 

electricity generation. More recent data 

from the first 9 months of 2015 indicate 

increased low-load cycling operations 

and startup events relative to historical 

patterns.32 At most, however, this 

represents 3 to 5 days of continuous 

low-load cycling, not 30. Therefore, 30 

days of low-load cycling is likely to be 

an overestimate of the number of lowload cycling days that will be exhibited 

in future operations at Unit 1. 

In sum, based upon historical 

operations, particularly the modest 

amount of low-load cycling operations 

engaged in by the Coronado units, 

Scenario 5c (i.e., an operating scenario 

of three cold startups and 30 days of 

low-load cycling), represents an upperend estimate of low-load Unit 1 

operations and startups at Unit 1. 

However, for the reasons described in 

response to comments from SRP below, 

we do not agree with Earthjustice that 

a rolling 30–BOD limit of 0.065 lb/

MMBtu for Unit 1, which is based upon 

Scenario 5c, is insufficiently stringent. 

Comment: SRP asserted that the EPA’s 

statement that an additional compliance 

margin was not appropriate for 

Coronado Unit 1, given the conservative 

nature of the assumptions in the S&L 

analysis, was inconsistent with the 

EPA’s acknowledgment that S&L’s 

analysis provided a reasonable estimate 

of average SCR performance. The 

commenter argued that ‘‘an emission 

limit that reflects ‘average’ SCR 

performance—even coupled with a 30- 

day averaging period—does not 

adequately account for performance on 

either end of the spectrum—minimum 

emissions as well as maximum 

emissions’’ and that the EPA ‘‘must 

establish a BART emission limit that 

SRP can comply with at all times (i.e., 

a limit that is closer to the maximum 

emissions that can be anticipated).’’ 

Response: We disagree with this 

comment. The commenter is correct, in 

literal terms, that an ‘‘average’’ emission 

rate of 0.065 lb/MMBtu is not the same 

as the maximum emission rate, and an 

emission limit based on an ‘‘average’’ 

emission rate will not account for all 

possible expected emission profiles. We 

do not agree, however, that this 

demonstrates that the proposed limit 

does not adequately account for the 

expected emissions on the upper end of 

the Unit 1’s operating spectrum. 

Although the proposed limit of 0.065 lb/ 

MMBtu is based upon an average 

emission rate, it represents the average 

emission rate of a very conservative 

operating scenario. As described in 

previous responses to comments, the 

specific set of circumstances that form 

the basis for the proposed limit have not 

historically occurred at either of the 

Coronado units.33 Although SRP has 

provided information indicating that it 

expects the Coronado units to be 

engaged in expanded amounts of loadfollowing service,34 it has provided no 

evidence that the units are likely to 

continuously operate at low-load 

cycling.35 Given the conservative nature 

of these assumptions, we consider the 

proposed rolling 30–BOD emission limit 

of 0.065 lb/MMBtu to account 

adequately for the operations of Unit 1 

and, as explained further below, to 

address sources of uncertainty in SRP’s 

emission analysis that may not have 

been accounted for in the S&L analysis. 

Comment: SRP expressed agreement 

with the EPA’s finding that S&L’s 

analysis produced a reasonable estimate 

of average SCR performance for Unit 1, 

but asserted that the S&L report was 

‘‘inadequate to determine an emission 

limit that SRP can meet on a continuous 

basis’’ because it only addressed 

variability due to changes in load and 

‘‘failed to address other factors that can 

and do affect emission rates.’’ SRP 

indicated that it had submitted 

evidence, including the 2013 RMB 

Report showing that ‘‘the 30-day average 

emissions rates from comparable units 

(i.e., same furnace design, comparable 

size, equipped with SCR) regularly 

exceed the proposed SRP limit of 0.065 

lb/MMbtu.’’ Specifically, SRP asserted 

that ‘‘the RMB analysis plainly shows 

that emissions from Unit 1 reasonably 

should be expected to exceed the 

proposed 0.065 lb/MMbtu emission 

limit, even with a 30-day averaging 

period.’’ The commenter argued that 

‘‘failing to address the impact that 

process and measurement variability 

can have on the reported emissions 

would be inconsistent with how EPA 

has handled the issue in other 

rulemakings.’’ Based on the 2013 RMB 

Report and an additional memo from 

RMB enclosed with the comment 

letter,36 the commenter concluded that 

‘‘a value of 0.080 lb/MMbtu is a 


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Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 21741 

37See Table 4 in 2013 RMB Report. To 

summarize, the mean NOX emission rates of the 

similar SCR-equipped units identified by RMB 

range from 0.063 to 0.092 lb/MMBtu. 

38See 2013 RMB Report starting at page 7. To 

summarize, RMB’s analysis asserts that a 15% 

upward adjustment is appropriate, followed by an 

additional upward rounding to the next numerical 

interval, which represents an additional 10%. 

39See Table 1 in 2013 S&L Report. 

40 2013 S&L Report Table 1. 

42See Specific Condition II.E.2.c, Title V 

Operating Permit No. 52693, issued December 6, 

2011 (‘‘The Permittee shall continuously operate 

each NOx control at all times the unit it serves is 

in operation consistent with technological 

limitations, manufacturer’s specifications, and good 

engineering and maintenance practices for 

minimizing emissions to the extent practicable’’ 

(emphasis added)). 

reasonable estimate of the lowest 

achievable BART NOX limit for Unit 1.’’ 

SRP also commented that RMB 

provided a UPL statistical analysis 

‘‘merely as a check against its primary 

analysis, which is analytical assessment 

of years of available emissions data from 

comparable units.’’ The commenter 

noted that: 

In its analytical assessment, RMB simply 

determined the 99th percentile value of 

hundreds of 30-day average emission rates 

that it was able to calculate from the 

available emission data. There was no need 

to rely on a statistical tool such as the UPL 

to predict what the 99th percentile would be 

because there are adequate data to calculate 

that value directly. 

The commenter concluded that the UPL 

was in fact not appropriate because the 

99th percentile emissions rate could be 

analytically derived. 

Response: We disagree with this 

comment. There are two separate issues 

arising from the RMB report: The NOX

emission rates achieved by comparable 

SCR-equipped units 37 and the 

variability derived from the RMB report 

(and inclusion of an appropriate 

compliance margin).38 With regard to 

the former issue, although similar SCRequipped units examined by RMB 

exhibited NOX emission rates that were 

routinely above 0.065 lb/MMBtu, we 

disagree that this represents clear 

evidence that Unit 1 will exceed the 

proposed 30–BOD limit of 0.065 lb/

MMBtu. While the units selected by 

RMB for review had similar design 

characteristics to Coronado Unit 1, the 

analysis did not examine one crucial 

variable: The design emission rate of the 

SCR systems. For example, S&L stated 

that the design target of the Pleasant 

Prairie Unit 1 SCR was 0.050 lb/MMBtu. 

By contrast, the stated design target of 

the Coronado Unit 1 SCR is 0.030 lb/

MMBtu.39 Because the SCR on the 

Coronado Unit 1 is designed to achieve 

a lower NOX emission rate, we do not 

consider the fact the actual NOX

emission rates of these other SCRequipped units exceed 0.065 lb/MMBtu 

to be directly relevant to Coronado Unit 

1’s ability to meet a rolling 30–BOD 

limit of 0.065 lb/MMBtu. 

With regard to the variability derived 

by the RMB report, we agree that 

measurement and process variability 

should be accounted for in establishing 

an emission limit that is achievable, and 

that incorporates an appropriate 

compliance margin. The UPL 

methodology would be one way to 

account for the possible impact of 

process and measurement variability. As 

explained in our proposed rule, 

however, we do not believe it is 

necessary or appropriate to use the UPL 

methodology in this instance, given the 

size and scope of the data set available. 

The commenter provided no assertions 

or arguments that contradict our finding 

that use of the UPL methodology is 

inappropriate in this instance. Indeed, 

the commenter actually acknowledges 

that use of the UPL is not appropriate 

in this instance given the available data. 

For similar reasons, we disagree with 

SRP’s suggestion that we should simply 

have used the 99th percentile emissions 

rate. As with UPL analyses, the EPA has 

previously used the 99th percentile 

(described in some contexts as the 99th 

confidence level) when establishing 

emission limits for entire source 

categories based on emission data set 

collected from a subset of the sources in 

each category. In such cases, it is 

appropriate to take additional measures, 

such as use of the 99th confidence level, 

to address concerns about variations not 

captured or accounted for in the 

development of the data set. In this 

instance, by contrast, the proposed 

0.065 lb/MMBtu emission limit was 

developed from emission data from the 

specific unit in question—either from 

CEMS data collected from Unit 1 or 

from SCR vendor estimates developed 

specifically for Unit 1. Although we 

recognize that this does not eliminate all 

concerns regarding variability and 

uncertainty, we do not consider the 

measures proposed by the commenter to 

be appropriate in this instance given the 

substantially site-specific nature of the 

data underlying the proposed emission 

limit. Moreover, neither S&L nor RMB 

calculated a 99th percentile emission 

rate for Coronado Unit 1 based on the 

use of SCR. Accordingly, we do not 

agree that use of the 99th percentile 

emissions is necessary to account for 

process and measurement variability. 

More broadly, while we have not 

explicitly quantified a portion of the 

compliance margin specifically to 

account for process and measurement 

variability (e.g., the additional 15–25 

percent proposed by the commenter), 

we consider the conservative nature of 

the operating assumptions underlying 

the 0.065 lb/MMbtu limit to be 

sufficient to account for this variability. 

As noted in previous responses, 0.065 

lb/MMbtu is based on operating 

assumptions that have not historically 

occurred for either of the Coronado 

units and that have not been 

demonstrated to be likely to occur on a 

regular basis in the future. In addition, 

0.065 lb/MMBtu is based on an 

assumption of a steady-state full load 

emission rate of 0.040 lb/MMBtu, which 

is 0.01 lb/MMBtu higher than the 

performance guarantee of the SCR 

system of 0.030 lb/MMBtu.40 As noted 

in the S&L report, this increase above 

the performance guarantee is intended 

to account for variations that will occur 

with actual controlled emissions.41 We 

consider the conservatism built into this 

assumption and the previously 

described assumptions concerning 

startups and low-load cycling to be 

sufficient to account for process and 

measurement variability and provide an 

adequate compliance margin. 

Accordingly, we are finalizing a 

rolling 30–BOD NOX emission limit of 

0.065 lb/MMBtu for Coronado Unit 1, as 

proposed. 

3. Comments on Proposed Emission 

Limits for Coronado Unit 2 

Comment: SRP expressed support for 

the EPA’s proposed emission limit of 

0.080 lb/MMbtu for Coronado Unit 2. 

SRP noted that it had already installed 

SCR and a low-load temperature control 

system on Unit 2 and that it was unable 

to meet an emission limit lower than the 

0.080 lb/MMbtu limit in the Consent 

Decree. SRP also expressed support for 

the proposed work practice standard 

and additional language addressing 

operation using the low-load 

temperature control system. 

Response: We acknowledge SRP’s 

support. We wish to clarify that the 

revised work practice standard applies 

to both Coronado units, as does the 

analogous language in Coronado’s 

existing Title V Permit.42

Comment: Earthjustice stated that it 

had examined emission data for Unit 2 

from the APMD for the period following 

installation of SCR (i.e., roughly June 1 

to December 31, 2014). The commenter 

provided a table of hourly reported NOX

rates for Unit 2, sorted by gross load in 

the range of 138 to 270 MW, which is 

the load range in which the low-load 

temperature control system would be 

expected to operate. The commenter 

identified several periods of time in 

which Unit 2 operated in this load 


jstallworth on DSK7TPTVN1PROD with RULES
21742 Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 

43By comparison, a typical low-load cycling 

operation would consist of the boiler starting at 

gross load levels above 270 MW, dropping to below 

270 for several hours, and finally returning to load 

levels above 270 MW. 

44See Coronado 2015–09 (hourly).xls. May 24, 

May 27, May 28, June 8, August 25, September 7, 

September 11, September 14, and September 15, 

2015. NOX emission rates observed during these 

periods of low-load cycling range from 0.028 to 

0.060 lb/MMBtu, which based on the corresponding 

heat rates are emission rates that indicate operation 

of the SCR system. 

45See Letter from Kelly J. Barr, SRP, to Deborah 

Jordan, EPA (April 28, 2014) page 4 and 2013 S&L 

Report page 6. 

46 In particular, the commenter cited EPA’s 1999 

SSM Guidance (Memorandum to EPA Regional 

Administrators, Regions I–X from Steven A. 

Herman and Robert Perciasepe, USEPA, Subject: 

State Implementation Plans: Policy Regarding 

Excess Emissions During Malfunctions, Startup, 

and Shutdown (September 20, 1999). 

range, but emitted higher NOX rates that 

indicated that the SCR was not 

operating in this load range. Based on 

this information, the commenter 

asserted that the low-load temperature 

control system is not operating as 

intended. 

Further, the commenter asserted that 

had the low-load temperature control 

system operated at this load range, the 

corresponding NOX rates would have 

been much lower and the resulting 30- 

day average NOX rates for these periods 

would also be lower. Earthjustice also 

stated that, in order to simulate proper 

low-load temperature control system 

operation, it had substituted the NOX

value of 0.049 lb/MMBtu (the average of 

0.039 and 0.059, the lowest and highest 

NOX rates corresponding to 270 MW) for 

all loads in the 138–270 MW range and 

computed the 30-day average NOX rate, 

including startup, shutdown, and 

malfunctions (excluding some 

anomalous data). Based upon the results 

of this substitution, the commenter 

asserted that the highest 30-day average 

using these results was 0.0621 lb/

MMBtu, and that the appropriate NOX

limit for Unit 2 would be 0.0650 lb/

MMBtu, allowing for a reasonable 

compliance margin. 

Response: We disagree with the 

commenter’s assertion that the noted 

instances indicate that the low-load 

temperature control system was not 

operating as intended. The commenter 

has accurately identified certain 

operating hours with load values that 

fall within a range of 138 to 270 MW. 

We agree that these instances exhibit 

NOX emission rates that are consistent 

with nonoperation of the SCR system. 

We note, however, that these instances 

do not correspond to periods of lowload cycling (i.e., periods of extended 

operation at low-load electricity 

generation). Rather, the instances 

identified by the commenter correspond 

to startup/shutdown events. 

For example, the first instance listed 

by the commenter (hours 13 to 15 on 

June 1, 2014) are the final 3 hours of a 

15-hour-long startup event, in which 

Unit 2 starts at zero load, proceeds to 

full load, and engages in high-load 

cycling on a continuous basis for the 

next 5 weeks.43 The 3 hours of low load 

are part of the process of ramping the 

boiler up to high load and/or full load, 

and are not part of a period of actual 

low-load operation. The other instances 

identified by the commenter on July 13, 

July 18, July 22, September 11, 

September 15, November 13, and 

November 17, 2014, are similarly all 

startup/shutdown events. As described 

in our 2015 proposed rulemaking, the 

low-load temperature control systems 

on the Coronado units function during 

periods of low-load cycling by the 

boilers. During these periods of low 

load, the boiler exhaust falls below the 

600 degree F minimum operating 

temperature of the SCR system. By using 

a portion of the steam generated by the 

boiler to reheat the exhaust stream up to 

600 degrees F, the low-load temperature 

control system allows operation of the 

SCR system during periods of low-load 

cycling. The availability of steam reheat 

is a crucial element of this system. In a 

boiler startup event, boiler steam may 

not be available in sufficient quantity or 

temperature to allow operation of the 

temperature control system, because the 

boiler is starting up. 

More broadly, the commenter raises 

concerns regarding whether these 

instances of SCR nonoperation are 

indicative of the low-load temperature 

control system being improperly 

installed or operated. The 2014 AMPD 

data supplied by the commenter do not 

appear to contain any periods of 

operation that correspond to low-load 

cycling. Therefore, it is not possible to 

readily evaluate the effectiveness of the 

low-load temperature control system 

based on these data alone. In preparing 

our final action on reconsideration, we 

have reviewed 2015 AMPD data in order 

to determine if the low-load temperature 

control system is being operated during 

periods of low-load cycling. We have 

identified several periods of low-load 

cycling in 2015, and note that the 

emission rates achieved during these 

periods are consistent with operation of 

the SCR system.44 This is consistent 

with the analyses provided by SRP, 

which indicate that the low-load 

temperature control system is intended 

to operate during periods of low-load 

cycling.45

We also disagree with the 

commenter’s second assertion, that 30- 

day NOX emission rates for Unit 2 

would be lower had the low-load 

temperature control system operated in 

these load ranges, and that the 

appropriate NOX limit for Unit 2 is 

0.065 lb/MMBtu. As described in the 

previous paragraphs, we note that the 

instances identified by the commenter 

correspond to startup/shutdown events 

and not periods of low-load cycling. As 

a result, we do not consider the 

information provided to be sufficient to 

demonstrate that the SCR should have 

operated during the instances identified 

by the commenter, and that a lower 

0.065 lb/MMBtu limit is achievable by 

Unit 2. 

In sum, in our 2015 proposed action 

on reconsideration, we proposed a 

BART limit of 0.080 lb/MMBtu for Unit 

2 based on information and analysis 

provided by SRP indicating that the 

Unit 2 SCR system was designed to meet 

the 2012 Consent Decree emission limit 

of 0.080 lb/MMBtu, and that SRP had 

since installed a low-load temperature 

control system on Unit 2 to meet that 

emission limit. Because the information 

provided by the commenter does not 

alter the data, analysis, or reasoning 

underlying this proposed limit, we are 

finalizing a rolling 30–BOD limit of 

0.080 lb/MMBtu for Unit 2. 

C. Comments on Proposed Removal of 

Affirmative Defense for Malfunctions 

Comment: SRP urged the EPA to 

retain the affirmative defense for excess 

emissions due to malfunctions as part of 

the Arizona Regional Haze FIP. The 

commenter made several arguments in 

support of its position. 

First, the commenter argued that the 

court’s decision in NRDC v. EPA, 749 

F.3d 1055 (D.C. Cir. 2014) does not 

compel the EPA to remove the 

affirmative defense provision from the 

Arizona Regional Haze FIP because the 

decision applies only to an EPA 

rulemaking under section 112 and is not 

binding precedent in the Ninth Circuit. 

The commenter further argued that by 

removing the affirmative defense 

provision, the EPA ‘‘ignores its own 

longstanding policy supporting 

affirmative defenses in situations 

beyond the owner’s or operator’s 

control, as well as decisions from other 

Courts of Appeals upholding affirmative 

defenses.’’ Referring to the EPA’s 1999 

SSM Guidance,46 the commenter stated 

that ‘‘[s]ince the early 1980s, EPA has 

consistently maintained the imposition 

of penalties for exceedance of an 

emission standard that is caused by 

circumstances beyond the owner’s or 

operator’s control is not appropriate.’’ 

Citing Arizona Public Service Co. v. 


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47 80 FR 33851–33852. 

48 666 F.3d at 1192–93. 

49 Id. at 1193. The EPA’s position in that case was 

based on the 1999 SSM Policy, which has now been 

replaced by the EPA’s SSM SIP Policy as of 2015. 

See 80 FR 33977–33982. 

50 Id. 

EPA, 562 F.3d 1116, 1129–30 (10th Cir. 

2009), Montana Sulphur & Chemical Co. 

v. EPA, 666 F.3d 1174, 1192–93 (9th Cir. 

2012), and Luminant Generation v. EPA, 

714 F.3d 841, 851–53 (5th Cir. 2013), 

the commenter asserted that the EPA’s 

prior SSM policy, which interpreted the 

CAA to allow affirmative defense 

provisions in SIPs, had been upheld by 

three separate U.S. Courts of Appeals. 

The commenter further argued that the 

EPA should not apply the D.C. Circuit 

decision in NRDC ‘‘where controlling 

precedent from the U.S. Court of 

Appeals for the Ninth Circuit condones 

EPA’s use of affirmative defenses.’’ 

Second, SRP noted that, in the 

proposed SSM SIP Call, the EPA had 

only proposed to interpret the CAA to 

bar affirmative defense type provisions 

in SIPs and had also proposed to 

provide states 18 months to submit SIP 

revisions to remove affirmative defenses 

for exceedances due to malfunctions. 

The commenter thus asserted that the 

EPA should allow the SSM SIP Call 

rulemaking to proceed, rather than 

‘‘predetermine the outcome of that 

rulemaking by removing the affirmative 

defense from the Arizona Regional Haze 

FIP far in advance of [the] timeline 

applicable to the SIP call rulemaking.’’ 

Third, SRP asserted that ‘‘[t]he U.S. 

Constitution also supports retention of 

the affirmative defense for 

malfunctions.’’ In particular, the 

commenter noted that the U.S. Supreme 

Court has held that the Eighth 

Amendment, including protections 

against excessive fines and 

punishments, may apply to government 

action in a civil context as well as in a 

criminal context. SRP claimed that 

significant penalties are not 

proportional to an offense caused by 

unavoidable events, such as excess 

emissions during malfunction events. 

Furthermore, the commenter argued that 

‘‘imposing liability for ‘unavoidable’ 

and therefore innocent conduct would 

infringe on substantive due process 

principles under the Fifth 

Amendment.’’ SRP asserted that 

affirmative defense provisions ‘‘avoid 

unjust punishment while at the same 

time placing on the source the burden 

of demonstrating that the offense 

actually was ‘unavoidable’ (and that 

punishment therefore would be 

unjust).’’ Again citing Montana Sulphur, 

the commenter asserted that providing 

an affirmative defense is the ‘‘minimum 

protection EPA or the state must 

provide to avoid infringing 

constitutional rights.’’ 

Finally, SRP stated that the 

affirmative defense ‘‘was an integral part 

of the agreed-upon emission limits 

established in the [Coronado] Consent 

Decree’’ and ‘‘was integral to the 

analyses submitted by SRP in support of 

its Petition for Reconsideration and the 

proposed emission limits SRP submitted 

to EPA for NOX.’’ The commenter 

asserted that without such an 

affirmative defense, ‘‘the emission limits 

identified as feasible and appropriate by 

S&L and RMB would have undoubtedly 

been higher.’’ The commenter argued 

that ‘‘[i]f EPA now removes the 

affirmative defense from the Arizona 

Regional Haze FIP for [Coronado], EPA 

must modify upward the emission 

limits for NOX to account for that 

action.’’ 

Response: We do not agree with SRP’s 

arguments in favor of retaining the 

affirmative defense for violations due to 

malfunctions in the Arizona Regional 

Haze FIP or its assertion that the 

emission limits should be revised 

upward in light of removal of the 

affirmative defense. 

First, we do not agree with the 

commenter’s suggestion that we are free 

to ignore the NRDC decision in the 

context of promulgating or revising a 

FIP. The fact that the decision pertained 

to a rulemaking by the EPA under 

section 112 is irrelevant. As explained 

in our proposal, NRDC turned on an 

analysis of CAA sections 113 and 304. 

These provisions apply with equal force 

to a civil action brought to enforce the 

provisions of a FIP. The logic of the 

court’s decision thus applies to the 

promulgation of a FIP, and precludes 

the EPA from including an affirmative 

defense provision in a FIP. As explained 

in the final SSM SIP Call: 

The EPA is revising its interpretation of the 

CAA with respect to affirmative defenses 

based upon a reevaluation of the statutory 

provisions that pertain to enforcement of SIP 

provisions in light of recent court opinions. 

Section 113(b) provides courts with explicit 

jurisdiction to determine liability and to 

impose remedies of various kinds, including 

injunctive relief, compliance orders and 

monetary penalties, in judicial enforcement 

proceedings. This grant of jurisdiction comes 

directly from Congress, and the EPA is not 

authorized to alter or eliminate this 

jurisdiction under the CAA or any other law. 

With respect to monetary penalties, CAA 

section 113(e) explicitly includes the factors 

that courts and the EPA are required to 

consider in the event of judicial or 

administrative enforcement for violations of 

CAA requirements, including SIP provisions. 

Because Congress has already given federal 

courts the jurisdiction to determine what 

monetary penalties are appropriate in the 

event of judicial enforcement for a violation 

of a SIP provision, neither the EPA nor states 

can alter or eliminate that jurisdiction by 

superimposing restrictions on that 

jurisdiction and discretion granted by 

Congress to the courts. Affirmative defense 

provisions by their nature purport to limit or 

eliminate the authority of federal courts to 

determine liability or to impose remedies 

through factual considerations that differ 

from, or are contrary to, the explicit grants of 

authority in section 113(b) and section 

113(e).47

Therefore, the EPA cannot include any 

such affirmative defense provision in a 

FIP. 

The commenter has offered nothing to 

refute this interpretation of the CAA. 

Instead, the commenter suggests that the 

EPA should not apply the NRDC 

decision in this instance because of 

‘‘controlling precedent’’ from the Ninth 

Circuit, namely the Montana Sulphur 

decision. As relevant here, that decision 

involved a challenge by Montana 

Sulphur to the EPA’s imposition of 

limits on flaring emissions during SSM 

events. In responding to Montana 

Sulphur’s argument that these limits 

were infeasible, ‘‘the EPA 

acknowledge[d] that violations are 

likely inevitable, but relie[d] on the 

provision of an affirmative defense to 

compensate for the infeasibility 

problem.’’ 48 Significantly, however, 

Montana Sulphur did not involve a 

challenge to inclusion of the affirmative 

defense in a FIP. On the contrary, 

Montana Sulphur argued that the 

affirmative defense in the FIP should 

have been extended to cover injunctive 

relief in addition to monetary 

penalties.49 The court rejected this 

argument and concluded that the EPA 

had reasonably interpreted the CAA to 

limit the extent of the affirmative 

defense as part of imposing continuous 

limits on emissions.50 However, because 

no party directly challenged the legal 

basis for the affirmative defense itself, 

the court did not have occasion to 

consider whether the affirmative 

defense in the FIP contravened CAA 

sections 113 and 304. Therefore, we do 

not agree that Montana Sulphur 

constitutes controlling precedent on the 

issue of whether the EPA may 

promulgate an affirmative defense in a 

FIP. 

With regard to the other judicial 

decisions cited by the commenter, the 

Luminant decision did not involve a FIP 

at all, but concerned the EPA’s 

evaluation of affirmative defense 

provisions in a SIP context. In that 

decision, the court upheld the EPA’s 

disapproval of an affirmative defense 

provision applicable to violations due to 

emissions during startup, shutdown and 


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51See 79 FR 55920, 55931–55934 (September 17, 

2014) and 80 FR 33856–33857. 

52Arizona Public Service Co. v. EPA, 562 F.3d 

1116, 1130 (10th Cir. 2009). 

53 Id. (internal quotations omitted). 

54 80 FR 33840, 33971 (June 12, 2015). 55AAC R18–2–310(B)(1) and (8). 

maintenance events, and the EPA’s 

approval of an affirmative defense 

provision applicable to violations due to 

emissions during malfunctions. In both 

instances, the court deferred to the 

EPA’s then current interpretation of the 

CAA as a reasonable reading of 

ambiguous provisions. Subsequent to 

that decision, however, the DC Circuit 

issued its opinion in NRDC. In our 

Supplemental Proposal and Final SSM 

SIP Call, we explained at length why we 

now consider the court’s reasoning in 

the NRDC decision to be the better 

reading of the CAA.51 Thus, the EPA has 

now changed its interpretation of the 

CAA with respect to the permissibility 

of affirmative defense provisions in SIPs 

and has directed the affected state to 

remove the affirmative defense 

provision at issue in the Luminant 

decision from its SIP in the final SSM 

SIP call. 

Finally, while the Arizona Public 

Service case did involve a challenge to 

an affirmative defense in a FIP, it did 

not involve a challenge to the statutory 

basis for such a defense.52 Rather, 

Arizona Public Service argued that ‘‘the 

EPA must justify inclusion of the 

affirmative defense with a factual basis 

for presuming that excess emissions are 

the fault of APS, and requiring APS to 

prove otherwise’’ and that ‘‘the EPA 

offered no defense to this burdenshifting affirmative defense.’’ 53 The 

court rejected both of these arguments. 

However, as with Montana Sulphur, no 

party argued that the affirmative defense 

at issue was inconsistent with the 

enforcement structure of CAA sections 

113 and 304, so the Arizona Public 

Service court did not have occasion to 

consider this question. Accordingly, the 

Arizona Public Service decision is not 

directly on point with regard to whether 

the EPA is authorized to include an 

affirmative defense in a FIP. Therefore, 

none of the cases cited by the 

commenter compel or persuade the EPA 

to adopt an interpretation of the CAA 

with regard to affirmative defenses that 

differs from the interpretation set forth 

in the SSM SIP Call Final Rule 

preamble, as quoted previously. 

Second, as noted previously, the EPA 

has finalized the SSM SIP Call and 

determined that AAC R18–2–310(B) and 

AAC R18–2–310(C) are substantially 

inadequate to meet CAA 

requirements.54 Arizona must submit a 

SIP revision to remove or revise these 

provisions by November 22, 2016. To 

the extent that the commenter disagrees 

with the EPA’s interpretation of the 

CAA in the SSM SIP Call, and disagrees 

with the EPA’s application of that 

interpretation to AAC R18–2–310(B) 

and AAC R18–2–310(C), that decision 

may be challenged in the DC Circuit. 

However, the EPA is not obligated to 

wait until that deadline for SIP revisions 

in response to the SSM SIP Call passes 

to remove these provisions from the 

Arizona Regional Haze FIP. On the 

contrary, having made a final 

determination that affirmative defense 

provisions are inconsistent with CAA 

requirements, we believe it is 

appropriate to expeditiously remove the 

affirmative defense provision from the 

Arizona Regional Haze FIP. The FIP is 

the EPA’s own rulemaking, which it is 

now conforming to the requirements of 

the CAA. 

Third, the commenter’s constitutional 

arguments appear to suggest that the 

existing CAA enforcement provisions 

are facially unconstitutional. We do not 

agree. The CAA does not mandate that 

any penalty be automatically assessed 

for a violation. Rather, the CAA 

establishes a maximum civil penalty in 

section 113(b), but then expressly 

provides in section 113(e) the criteria 

that the EPA (in administrative 

enforcement) or the courts (in judicial 

enforcement) ‘‘shall take into 

consideration (in addition to other 

factors as justice may require).’’ These 

criteria explicitly include consideration 

of ‘‘good faith efforts to comply.’’ 

Whether in administrative enforcement 

or judicial enforcement, there is a 

process through which the alleged 

violator may raise any legal or equitable 

arguments it may have based on the 

facts and circumstances of the violation. 

Thus, the CAA on its face does not 

mandate the imposition of any penalty 

automatically, much less one that is per 

se excessive. Notably, the commenter 

does not elaborate on how or why it 

believes the statutory penalty provisions 

of the CAA are facially unconstitutional. 

To the extent that the commenter is 

raising an ‘‘as applied’’ claim of 

unconstitutionality, any such claim can 

be raised in the future in the context of 

a specific application of the statute in an 

enforcement action. 

Fourth, we acknowledge that, as in 

the Montana Sulphur example cited by 

the commenter, the EPA has previously 

provided affirmative defense provisions 

as a mechanism to mitigate penalties 

where a violation was beyond the 

control of the owner or operator. 

Contrary to the commenter’s suggestion, 

however, the EPA did not indicate that 

such provisions were constitutionally 

mandated. These actions were premised 

upon the EPA’s prior interpretation of 

the CAA to permit such affirmative 

defense provisions under very narrow 

circumstances. More significantly, these 

actions predated the NRDC decision 

and, as explained previously, the EPA 

no longer considers affirmative defense 

provisions to be consistent with the 

enforcement provisions of the CAA. 

Furthermore, the EPA believes that the 

penalty criteria in section 113(e) 

perform a similar function to the 

affirmative defense provisions 

previously promulgated by the EPA. 

The commenter does not explain why 

these explicit statutory factors do not 

provide sufficient protection from the 

imposition of allegedly 

unconstitutionally excessive penalties. 

Finally, we do not agree that removal 

of the affirmative defense from the 

Arizona Regional Haze FIP necessitates 

an increase in the emission limits for 

NOX for Coronado Units 1 and 2. 

Neither the 2013 S&L Report nor the 

2013 RMB Report indicates that it relied 

on the existence of such a defense in 

evaluating what emission limits were 

achievable at the Coronado units. 

Moreover, the affirmative defense in the 

FIP applied only to violations due to 

emissions during malfunctions, which 

(among other criteria) must have 

‘‘resulted from a sudden and 

unavoidable breakdown of process 

equipment or air pollution control 

equipment’’ and ‘‘not stem[med] from 

any activity or event that could have 

been foreseen and avoided, or 

planned.’’ 55 Nothing in the CAA, the 

RHR, or the BART Guidelines indicates 

that BART emissions limits should be 

set at a level that accommodates all 

emissions during such unforeseeable 

events. Finally, we note that, if 

Coronado were to violate a BART 

emission limit due to a malfunction, 

SRP retains the ability to defend itself 

in an enforcement action and to oppose 

the imposition of particular remedies or 

to seek the reduction or elimination of 

monetary penalties, based on the 

specific facts and circumstances of the 

event. To the extent that a violation is 

the result of a genuine malfunction, the 

EPA anticipates that the state, citizen 

suit plaintiffs, and the EPA itself will 

likely exercise enforcement discretion. 

To the extent that any party elects to 

pursue enforcement in such 

circumstances, however, the CAA 

already authorizes the courts to 

determine whether parties should be 

held responsible for such violations and 

to impose remedies or penalties only as 

may be appropriate, given the relevant 


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56Consent Decree paragraph 107. 

57See, e.g., id. paragraph 106. 

58 80 FR 33840, 33971 (June 12, 2015). 

59 80 FR 17013. 

60 77 FR 42834, 77 FR 72512. 61 80 FR 17010. 

facts and circumstances. As noted 

previously, under CAA section 113(e), 

federal courts are required to consider 

the enumerated statutory factors when 

assessing monetary penalties, including 

‘‘such other factors as justice may 

require.’’ Accordingly, we do not 

consider it necessary or appropriate to 

revise the BART emission limits due to 

the removal of the affirmative defense 

for malfunctions. 

It should also be noted that our 

removal of the affirmative defense from 

the Arizona Regional Haze FIP does not 

alter the terms of the Coronado Consent 

Decree, which includes an affirmative 

defense applicable only to stipulated 

penalties for violations of the Consent 

Decree itself.56 This provision of the 

Consent Decree affects only whether 

SRP must pay stipulated penalties 

under the Consent Decree and does not 

provide a defense to otherwise 

applicable CAA penalties.57 Thus, the 

provision operates as a liquidated 

damages clause applicable only to the 

penalties imposed for violations of the 

Consent Decree and does not purport to 

alter the jurisdiction of the courts to 

impose penalties for violations of CAA 

requirements. Moreover, this provision 

was sanctioned by the United States 

District Court for the District Of 

Arizona, which entered the Consent 

Decree. Therefore, it does not raise the 

same concerns about limiting the 

jurisdiction of courts that are raised by 

the affirmative defense provision in the 

FIP. 

In sum, we do not agree that the 

affirmative defense applicable to 

violations due to malfunctions should 

be retained in the Arizona Regional 

Haze FIP or that the emission limits in 

the FIP should be revised upward in 

light of the removal of the defense. 

Comment: Earthjustice expressed 

support for the EPA’s proposal to 

remove the affirmative defense 

applicable to violations due to 

malfunctions from the FIP. Citing the 

NRDC decision relied upon by the EPA 

in the proposal, the commenter asserted 

that affirmative defenses for violations 

due to malfunctions like that previously 

incorporated into the Arizona Regional 

Haze FIP are prohibited by the plain 

language of the CAA. Earthjustice 

further argued that such affirmatives 

defenses are unnecessary because courts 

do not impose penalties for truly 

unavoidable and unforeseeable 

violations. Finally, the commenter 

urged the EPA to finalize its proposal in 

a separate action to find the affirmative 

defense for violations due to 

malfunctions in AAC Code R18–2– 

310(C) and the similar affirmative 

defense for violations due to startup and 

shutdown in AAC R18–2–310(B) 

substantially inadequate to meet CAA 

requirements as part of the SSM SIP 

Call. 

Response: We agree with the 

commenter for the reasons detailed in 

the previous response. We note that the 

EPA has already finalized the SSM SIP 

Call and determined that AAC R18–2– 

310(B) and AAC R18–2–310(C) are 

substantially inadequate to meet CAA 

requirements.58 Accordingly, the EPA 

has already directed the state to remove 

those existing affirmative defense 

provisions from the SIP, consistent with 

EPA’s action to remove the affirmative 

defense for violations during 

malfunctions from the Arizona Regional 

Haze FIP. 

D. Other Comments 

Comment: SRP asserted that the EPA 

should defer to Arizona’s NOX BART 

determination for Coronado, noting that 

this determination was less stringent 

than the requirements of the Consent 

Decree. 

Response: This comment is outside 

the scope of the proposed action. The 

EPA is not reconsidering our prior final 

action disapproving Arizona’s NOX

BART determinations for Coronado 

Units 1 and 2. Furthermore, as 

explained in our proposal, we are not 

reconsidering our determination that 

BART for Coronado Units 1 and 2 is an 

emission limit consistent with the use of 

SCR, LNB with OFA, and low-load 

temperature control systems.59 Finally, 

even if this comment were relevant to 

this action, we do not agree that 

Arizona’s BART determinations for NOX

at Coronado were reasonable or that 

they complied with the applicable 

statutory and regulatory requirements, 

for the reasons set forth in our prior 

proposed and final actions disapproving 

those determinations.60

Comment: ECO commented that the 

EPA’s proposed action on 

reconsideration was ‘‘a critical step 

toward insuring the economic viability’’ 

of Coronado and urged the EPA to 

finalize the proposal. 

Response: We acknowledge ECO’s 

support for our action on 

reconsideration. 

V. Final Action 

The EPA is taking final action to 

revise the Arizona Regional Haze FIP to 

replace a plant-wide BART compliance 

method and emission limit for NOX on 

Units 1 and 2 at Coronado with a singleunit compliance method and emission 

limit on each of the units. For the 

reasons described in our proposal and 

in our responses to comments above, we 

are finalizing emission limits of 0.065 

lb/MMBtu for Unit 1 and 0.080 lb/

MMBtu for Unit 2 with compliance 

based on a rolling 30–BOD basis. This 

revision constitutes our final action on 

SRP’s petition for reconsideration of the 

FIP. We are also finalizing our proposals 

to remove the affirmative defense for 

malfunctions in the FIP and revise the 

work practice requirement that applies 

to Coronado under the FIP. 

We find that this revision will not 

interfere with any applicable 

requirement concerning attainment, 

reasonable further progress, or any other 

applicable requirement of the CAA. The 

Arizona Regional Haze FIP, as revised 

by this action, will result in a significant 

reduction in emissions compared to 

current levels (roughly 5,000 tpy). 

Although this revision will allow a 

marginal increase in emissions after 

December 2017 from the Coronado 

facility as compared to the prior FIP 

(roughly 233 tpy), the FIP as a whole 

will still result in an overall NOX

reductions from Coronado compared to 

those currently allowed. In addition, the 

area where Coronado is located has not 

been designated nonattainment for any 

NAAQS. Thus, the revised FIP will 

ensure a significant reduction in NOX

emissions compared to current levels in 

an area that has not been designated 

nonattainment for the relevant NAAQS 

at those current levels. Likewise, for the 

reasons explained in our proposal and 

summarized in section III.D, the 

revision will not interfere with any 

other applicable CAA requirements. 

VI. Environmental Justice 

Considerations 

The EPA believes the human health or 

environmental risk addressed by this 

action will not have potential 

disproportionately high and adverse 

human health or environmental effects 

on minority, low-income, or indigenous 

populations. We expect that Coronado 

will install the same control technology 

in order to meet the revised emission 

limits as would have been necessary to 

meet the previously finalized limits. As 

noted previously, this revision to the 

FIP will allow for an increase in NOX

emissions of roughly 233 tpy compared 

to the original Arizona Regional Haze 

FIP.61 Although this is a not a trivial 

amount of emissions, it is relatively 

small compared to the facility’s total 


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62Coronado Consent Decree, paragraph 44. 

emissions. In particular, 233 tpy is 

equivalent to about three percent of the 

7,300 tpy of NOX that the facility is 

currently allowed to emit under the 

Coronado Consent Decree.62

Furthermore, total NOX emissions from 

the facility following full 

implementation of the FIP will be 

roughly 2,275 tpy, a decrease of over 

5,000 tpy compared to the amount the 

facility is presently allowed to emit. In 

sum, while this revision will allow for 

a marginal increase in emissions 

compared to the prior FIP, it will still 

ensure a significant reduction in 

emissions compared to present levels. 

Thus, the FIP, as revised by this action, 

increases the level of environmental 

protection for all affected populations 

without having any disproportionately 

high and adverse human health or 

environmental effects on any 

population, including any minority or 

low-income population. 

VII. Statutory and Executive Order 

Reviews 

Additional information about these 

statutes and Executive Orders can be 

found at http://www2.epa.gov/lawsregulations/laws-and-executive-orders. 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

This action is not a significant 

regulatory action and was therefore not 

submitted to the Office of Management 

and Budget (OMB) for review. This rule 

applies to only two facilities and is 

therefore not a rule of general 

applicability. 

B. Paperwork Reduction Act (PRA) 

This action does not impose an 

information collection burden under the 

PRA. This rule applies to only two 

facilities. Therefore, its recordkeeping 

and reporting provisions do not 

constitute a ‘‘collection of information’’ 

as defined under 44 U.S.C. 3502(3) and 

5 CFR 1320.3(c). 

C. Regulatory Flexibility Act (RFA) 

I certify that this action will not have 

a significant economic impact on a 

substantial number of small entities. 

This action will not impose any 

requirements on small entities. Firms 

primarily engaged in the generation, 

transmission, and/or distribution of 

electric energy for sale are small if, 

including affiliates, the total electric 

output for the preceding fiscal year did 

not exceed 4 million megawatt hours. 

Each of the owners of facilities affected 

by this rule, SRP, APS and PacifiCorp, 

exceeds this threshold. 

D. Unfunded Mandates Reform Act 

(UMRA) 

This action does not contain an 

unfunded mandate of $100 million or 

more as described in UMRA, 2 U.S.C. 

1531–1538, and does not significantly or 

uniquely affect small governments. 

E. Executive Order 13132: Federalism 

This action does not have federalism 

implications. It will not have substantial 

direct effects on the states, on the 

relationship between the national 

government and the states, or on the 

distribution of power and 

responsibilities among the various 

levels of government. 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

This action does not have tribal 

implications, as specified in Executive 

Order 13175. It will not have substantial 

direct effects on any Indian tribes, on 

the relationship between the Federal 

Government and Indian tribes, or on the 

distribution of power and 

responsibilities between the Federal 

Government and Indian tribes. Thus, 

Executive Order 13175 does not apply 

to this action. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

The EPA interprets EO 13045 as 

applying only to those regulatory 

actions that concern health or safety 

risks that the EPA has reason to believe 

may disproportionately affect children, 

per the definition of ‘‘covered regulatory 

action’’ in section 2–202 of the 

Executive Order. This action is not 

subject to Executive Order 13045 

because it does not concern an 

environmental health risk or safety risk. 

H. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This action is not subject to Executive 

Order 13211 because it is not a 

significant regulatory action under 

Executive Order 12866. 

I. National Technology Transfer and 

Advancement Act 

This rulemaking does not involve 

technical standards. The EPA is not 

revising any technical standards or 

imposing any new technical standards 

in this action. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations 

The EPA believes the human health or 

environmental risk addressed by this 

action will not have potential 

disproportionately high and adverse 

human health or environmental effects 

on minority, low-income, or indigenous 

populations. The results of this 

evaluation are contained in section VI 

previously. 

K. Determination Under Section 307(d) 

Pursuant to CAA section 307(d)(1)(B), 

this action is subject to the requirements 

of CAA section 307(d), as it revises a FIP 

under CAA section 110(c). 

L. Congressional Review Act (CRA) 

This rule is exempt from the CRA 

because it is a rule of particular 

applicability. 

M. Petitions for Judicial Review 

Under section 307(b)(1) of the Clean 

Air Act, petitions for judicial review of 

this action must be filed in the United 

States Court of Appeals for the 

appropriate circuit by June 13, 2016. 

Filing a petition for reconsideration by 

the Administrator of this final rule does 

not affect the finality of this rule for the 

purposes of judicial review nor does it 

extend the time within which a petition 

for judicial review may be filed, and 

shall not postpone the effectiveness of 

such rule or action. This action may not 

be challenged later in proceedings to 

enforce its requirements. See CAA 

section 307(b)(2). 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Incorporation by 

reference, Nitrogen oxides, Reporting 

and recordkeeping requirements, 

Visibility. 

Authority: 42 U.S.C. 7401 et seq. 

Dated: March 29, 2016. 

Gina McCarthy, 

Administrator. 

Part 52, chapter I, title 40 of the Code 

of Federal Regulations is amended as 

follows: 

PART 52—APPROVAL AND 

PROMULGATION OF 

IMPLEMENTATION PLANS 

■ 1. The authority citation for part 52 

continues to read as follows: 

Authority: 42 U.S.C. 7401 et seq. 

Subpart D—Arizona 

■ 2. In § 52.145: 


jstallworth on DSK7TPTVN1PROD with RULES
Federal Register / Vol. 81, No. 71 / Wednesday, April 13, 2016 / Rules and Regulations 21747 

■ a. Revise paragraphs (f)(3)(i) and 

(f)(5)(ii)(A). 

■ b. Add paragraph (f)(5)(ii)(B). 

■ c. Revise paragraph (f)(10). 

■ d. Remove paragraph (f)(11). 

The revisions and addition read as 

follows: 

§ 52.145 Visibility protection. 

* * * * * 

(f) * * * 

(3) * * * 

(i) NOX emission limitations. The 

owner/operator of each coal-fired unit 

subject to this paragraph (f) shall not 

emit or cause to be emitted NOX in 

excess of the following limitations, in 

pounds per million British thermal 

units (lb/MMBtu) from any coal-fired 

unit or group of coal-fired units. Each 

emission limit shall be based on a 

rolling 30-boiler-operating-day average, 

unless otherwise indicated in specific 

paragraphs. 

Coal fired unit or group of 

coal-fired units 

Federal 

emission 

limitation 

Cholla Power Plant Units 2, 

3, and 4 ............................. 0.055 

Coronado Generating Station 

Unit 1 ................................. 0.065 

Coronado Generating Station 

Unit 2 ................................. 0.080 

* * * * * 

(5) * * * 

(ii) * * * 

(A) Cholla Power Plant. The 30-day 

rolling average NOX emission rate for 

the group of coal-fired units identified 

as Cholla Power Plant, Units 2, 3, and 

4 shall be calculated for each calendar 

day, even if a unit is not in operation 

on that calendar day, in accordance 

with the following procedure: Step one, 

for each unit, sum the hourly pounds of 

NOX emitted during the current boileroperating day (or most recent boileroperating day if the unit is not in 

operation), and the preceding twentynine (29) boiler-operating days, to 

calculate the total pounds of NOX

emitted over the most recent thirty (30) 

boiler-operating day period for each 

coal-fired unit; step two, for each unit, 

sum the hourly heat input, in MMBtu, 

during the current boiler-operating day 

(or most recent boiler-operating day if 

the unit is not in operation), and the 

preceding twenty-nine (29) boileroperating days, to calculate the total 

heat input, in MMBtu, over the most 

recent thirty (30) boiler-operating day 

period for each coal-fired unit; step 3, 

sum together the total pounds of NOX

emitted from the group of coal-fired 

units over each unit’s most recent thirty 

(30) boiler-operating day period (the 

most recent 30 boiler-operating day 

periods for different units may be 

different); step four, sum together the 

total heat input from the group of coalfired units over each unit’s most recent 

thirty (30) boiler-operating day period; 

and step five, divide the total pounds of 

NOX emitted from step three by the total 

heat input from step four for each group 

of coal-fired units, to calculate the 30- 

day rolling average NOX emission rate 

for each group of coal-fired units, in 

pounds of NOX per MMBtu, for each 

calendar day. Each 30-day rolling 

average NOX emission rate shall include 

all emissions and all heat input that 

occur during all periods within any 

boiler-operating day, including 

emissions from startup, shutdown, and 

malfunction. 

(B) Coronado Generating Station. 

Compliance with the NOX emission 

limits for Coronado Unit 1 and 

Coronado Unit 2 in paragraph (f)(3)(i) of 

this section shall be determined on a 

rolling 30 boiler-operating-day basis. 

The 30-boiler-operating-day rolling NOX

emission rate for each unit shall be 

calculated in accordance with the 

following procedure: Step one, sum the 

total pounds of NOX emitted from the 

unit during the current boiler operating 

day and the previous twenty-nine (29) 

boiler operating days; Step two, sum the 

total heat input to the unit in MMBtu 

during the current boiler operating day 

and the previous twenty-nine (29) boiler 

operating days; Step three, divide the 

total number of pounds of NOX emitted 

from that unit during the thirty (30) 

boiler operating days by the total heat 

input to the unit during the thirty (30) 

boiler operating days. A new 30-boileroperating-day rolling average NOX

emission rate shall be calculated for 

each new boiler operating day. Each 30- 

boiler-operating-day average NOX

emission rate shall include all emissions 

that occur during all periods within any 

boiler operating day, including 

emissions from startup, shutdown, and 

malfunction. 

* * * * * 

(10) Equipment operations—(i) Cholla 

Power Plant. At all times, including 

periods of startup, shutdown, and 

malfunction, the owner or operator of 

Cholla Power Plant Units 2, 3 and 4 

shall, to the extent practicable, maintain 

and operate each unit including 

associated air pollution control 

equipment in a manner consistent with 

good air pollution control practices for 

minimizing emissions. Pollution control 

equipment shall be designed and 

capable of operating properly to 

minimize emissions during all expected 

operating conditions. Determination of 

whether acceptable operating and 

maintenance procedures are being used 

will be based on information available 

to the Regional Administrator which 

may include, but is not limited to, 

monitoring results, review of operating 

and maintenance procedures, and 

inspection of each unit. 

(ii) Coronado Generating Station. At 

all times, including periods of startup, 

shutdown, and malfunction, the owner 

or operator of Coronado Generating 

Station Unit 1 and Unit 2 shall, to the 

extent practicable, maintain and operate 

each unit in a manner consistent with 

good air pollution control practices for 

minimizing emissions. The owner or 

operator shall continuously operate 

pollution control equipment at all times 

the unit it serves is in operation, and 

operate pollution control equipment in 

a manner consistent with technological 

limitations, manufacturer’s 

specifications, and good engineering 

and good air pollution control practices 

for minimizing emissions. 

Determination of whether acceptable 

operating and maintenance procedures 

are being used will be based on 

information available to the Regional 

Administrator which may include, but 

is not limited to, monitoring results, 

review of operating and maintenance 

procedures, and inspection of each unit. 

* * * * * 

[FR Doc. 2016–07911 Filed 4–12–16; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R06–OAR–2015–0497; FRL–9944–71– 

Region 6] 

Approval and Promulgation of 

Implementation Plans; Texas; Control 

of Air Pollution From Nitrogen 

Compounds State Implementation Plan 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is approving revisions to 

the State Implementation Plan (SIP) 

submitted by the State of Texas through 

the Texas Commission on 

Environmental Quality (TCEQ) on July 

10, 2015. The Texas SIP submission 

revises 30 Texas Administrative Code 

(TAC) Chapter 117 rules for control of 

nitrogen compounds to assist the DallasFort Worth (DFW) moderate 

nonattainment area (NAA) in attaining 

the 2008 eight-hour ozone (O3) National 


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