Document ID: EPA-R09-OAR-2010-0683-0242
Agency: epa
Document Type: Rule
Title: Source Specific Federal Implementation Plans: Implementing Best Available Retrofit Technology for Four Corners Power Plant; Navajo Nation
Posted Date: 2012-08-24T04:00Z

[Federal Register Volume 77, Number 165 (Friday, August 24, 2012)]
[Rules and Regulations]
[Pages 51619-51648]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-19793]

[[Page 51619]]

Vol. 77

Friday,

No. 165

August 24, 2012

Part II

Environmental Protection Agency

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40 CFR Part 49

 Source Specific Federal Implementation Plan for Implementing Best 
Available Retrofit Technology for Four Corners Power Plant: Navajo 
Nation; Final Rule

  Federal Register / Vol. 77, No. 165 / Friday, August 24, 2012 / Rules 
and Regulations  

[[Page 51620]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 49

[EPA-R09-OAR-2010-0683; FRL-9715-9]

Source Specific Federal Implementation Plan for Implementing Best 
Available Retrofit Technology for Four Corners Power Plant: Navajo 
Nation

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is promulgating a 
source-specific Federal Implementation Plan (FIP) requiring the Four 
Corners Power Plant (FCPP), a coal-fired power plant located on the 
Navajo Nation near Farmington, New Mexico, to achieve emissions 
reductions required by the Clean Air Act's (CAA) Best Available 
Retrofit Technology (BART) provision. In this final action, EPA is 
requiring FCPP to reduce emissions of oxides of nitrogen 
(NOX) and is setting emission limits for particulate matter 
(PM) based on emission rates already achieved at FCPP. These pollutants 
contribute to visibility impairment in the numerous mandatory Class I 
Federal areas surrounding FCPP. For NOX emissions, EPA is 
requiring FCPP to meet a plant-wide emission limit of 0.11 lb/MMBtu on 
a rolling 30-day heat input-weighted average. This represents an 80 
percent reduction from the current NOX emission rate and is 
expected to provide significant improvement in visibility. EPA is also 
finalizing an alternative emission control strategy that gives the 
owners of FCPP the option to close Units 1-3 and install controls on 
Units 4 and 5 to each meet an emission limit of 0.098 lb/MMBtu, based 
on a rolling average of 30 successive boiler operating days. For PM, 
EPA is requiring Units 4 and 5 at FCPP to meet an emission limit of 
0.015 lb/MMBtu, and retaining the existing 20 percent opacity limit. 
These PM limits are achievable through the proper operation of the 
existing baghouses. EPA is also requiring FCPP to comply with a 20 
percent opacity limit on its coal and material handling operations.

DATES: Effective Date: This rule is effective on October 23, 2012.

FOR FURTHER INFORMATION CONTACT: Anita Lee, EPA Region 9, (415) 972-
3958, r9air_fcppbart@epa.gov.

SUPPLEMENTARY INFORMATION: EPA has established a docket for this action 
under Docket ID No. EPA-R09-OAR-2010-0683. The index to the docket for 
this action is available electronically at http://www.regulations.gov 
and in hard copy at EPA Region 9, 75 Hawthorne Street, San Francisco, 
California. While all documents in the docket are listed in the index, 
some information may be publicly available only at the hard copy 
location (e.g. copyrighted material), and some may not be publicly 
available in either location (e.g. Confidential Business Information 
(CBI)). To inspect the hard copy materials, please schedule an 
appointment during normal business hours with the contact listed in the 
FOR FURTHER INFORMATION CONTACT section. A reasonable fee may be 
charged for copies.
    Throughout this document, ``we'', ``us'', and ``our'' refer to EPA.

Table of Contents

I. Background of the Final Rule
II. Summary of Final Federal Implementation Plan (FIP) Provisions
III. Analysis of Major Issues Raised by Commenters
    A. Comments on Factor One--Cost of Controls
    1. Comments on the Analysis of the Cost of SCR at FCPP
    2. Comments on Top-Down Analysis Versus Incremental Cost 
Effectiveness
    B. Comments on Factor Two--Economic, Energy, and Non-Air Quality 
Environmental Impacts
    1. Comments on Economic Impacts
    a. General Comments on Economic Impacts
    b. Comments on EPA's Economic Analysis
    2. Comments on Energy and Non-Air Quality Environmental Impacts
    C. Comments on Factor Three--Existing Controls at FCPP
    D. Comments on Factor Four--Remaining Useful Life at FCPP
    E. Comments on Factor Five--Anticipated Visibility Improvements
    F. Comments on BART Determinations
    1. Comments on the Proposed BART Determination for 
NOX
    2. Comments on the Proposed BART Determination for PM
    3. Comments on BART for SO2
    4. Other Comments on BART
    G. Comments on Arizona Public Service's Alternative and EPA's 
Supplemental Proposal
    H. Other Comments
IV. Administrative Requirements
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Congressional Review Act
    L. Petitions for Judicial Review

I. Background of the Final Rule

    FCPP is a privately owned and operated coal-fired power plant 
located on the Navajo Nation Indian Reservation near Farmington, New 
Mexico. Based on lease agreements signed in 1960, FCPP was constructed 
and has been operating on real property held in trust by the Federal 
government for the Navajo Nation. The facility consists of five coal-
fired electric utility steam generating units with a total capacity of 
2060 megawatts (MW). Units 1, 2, and 3 at FCPP are owned entirely by 
Arizona Public Service (APS) which serves as the facility operator, and 
are rated to 170 MW (Units 1 and 2) and 220 MW (Unit 3). Units 4 and 5 
are each rated to a capacity of 750 MW, and are co-owned by six 
entities: Southern California Edison \1\ (48 percent), APS (15 
percent), Public Service Company of New Mexico (13 percent), Salt River 
Project (SRP) (10 percent), El Paso Electric Company (7 percent), and 
Tucson Electric Power (7 percent).
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    \1\ Arizona Public Service is currently seeking regulatory 
approvals to purchase Southern California Edison's share of Units 4 
and 5.
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    EPA's proposed BART determination for FCPP, published on October 
19, 2010, provided a thorough discussion of the statutory and 
regulatory framework for addressing visibility through application of 
BART for sources located in Indian country, and of the factual 
background for BART determinations at FCPP. 75 FR 64221.
    On February 25, 2011, as a result of additional information 
provided by stakeholders, EPA published a Supplemental Proposal. FR 76 
10530. We briefly summarize the provisions of our Proposal and our 
Supplemental Proposal below.
    Part C Subpart II of the 1977 CAA establishes a visibility 
protection program that sets forth ``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 manmade air pollution.'' 42 U.S.C. 7491A(a)(1). EPA promulgated 
regional haze regulations on April 22, 1999. 64 FR 35765. Consistent 
with the statutory requirement in 42 U.S.C. 7491(b)(2)(a), EPA's 1999 
regional haze

[[Page 51621]]

regulations include a provision requiring States to require certain 
major stationary sources to procure, install and operate BART. This 
provision covers sources ``in existence on August 7, 1977, but which 
ha[ve] not been in operation for more than fifteen years as of such 
date'' and which emit pollutants that are reasonably anticipated to 
cause or contribute to any visibility impairment. EPA has determined 
that FCPP is a BART-eligible source (75 FR 64221).
    In determining BART, States are required to take into account five 
factors identified in the CAA and EPA's regulations. 42 U.S.C. 
7491(g)(2) and 40 CFR 51.308. Those factors are: (1) The costs of 
compliance, (2) the energy and non-air quality environmental impacts of 
compliance, (3) any pollution control equipment in use or in existence 
at the source, (4) the remaining useful life of the source, and (5) the 
degree of improvement in visibility which may reasonably be anticipated 
to result from the use of such technology. 40 CFR 51.308(e)(1)(ii)(A). 
EPA's guidelines for evaluating BART are set forth in Appendix Y to 40 
CFR Part 51.
    In 1998, EPA promulgated the Tribal Authority Rule (TAR) relating 
to implementation of CAA programs in Indian country. See 40 CFR part 
49; see also 59 FR 43956 (Aug. 25, 1994) (proposed rule); 63 FR 7254 
(Feb. 12, 1998) (final rule); Arizona Public Service Company v. EPA, 
211 F.3d 1280 (DC Cir. 2000), cert. den., 532 U.S. 970 (2001) 
(upholding the TAR).
    In the TAR, EPA determined that it has the discretionary authority 
to promulgate ``such federal implementation plan provisions as are 
necessary or appropriate to protect air quality'' consistent with CAA 
sections 301(a) and 301(d)(4) when a Tribe has not submitted or EPA has 
not approved a Tribal Implementation Plan (TIP). 40 CFR 49.11(a).
    EPA has previously promulgated FIPs under the TAR to regulate air 
pollutants emitted from FCPP. In 1999, EPA proposed a FIP for FCPP. 
That FIP proposed to fill the regulatory gap that existed because New 
Mexico permits and State Implementation Plan (SIP) rules are not 
applicable or enforceable in the Navajo Nation, and the Tribe had not 
sought approval of a TIP covering the plant. 64 FR 48731 (Sept. 8, 
1999).
    Before EPA finalized the 1999 FIP, the operator of FCPP began 
negotiations to reduce SO2 emissions from FCPP by making 
upgrades to improve the efficiency of its SO2 scrubbers. The 
parties to the negotiations requested EPA to make those SO2 
reductions enforceable through a source-specific FIP. Therefore, EPA 
proposed a new FIP for FCPP in September 2006. 71 FR 53631 (Sept. 12, 
2006). In the final FIP, EPA indicated that the new SO2 
emissions limits were close to or the equivalent of the emissions 
reductions that would have been required in a BART determination. 72 FR 
25698 (May 7, 2007). The FIP also required FCPP to comply with a 20 
percent opacity limit on both the combustion and fugitive dust 
emissions from material handling operations.
    APS, the operator of FCPP, and Sierra Club each filed Petitions 
seeking judicial review of EPA's promulgation of the 2007 FIP for FCPP 
on separate grounds. The Court of Appeals for the Tenth Circuit 
rejected both Petitions. The Court agreed with EPA's request for a 
voluntary remand of a single narrow aspect of the 2007 FIP: The opacity 
limit for the fugitive dust for the material handling operations. Id. 
At 1131.
    On October 19, 2010 (75 FR 64221) EPA proposed a second FIP under 
40 CFR 49.11(a) finding it is necessary or appropriate to establish 
BART requirements for NOX and PM emissions from FCPP, and 
proposed specific NOX and PM limits as BART. For 
NOX, EPA proposed a plant-wide emission limit of 0.11 lb/
MMBtu, representing an 80 percent reduction from current NOX 
emission rates, achievable by installing and operating SCR technology 
on Units 1-5. For PM, EPA proposed an emission limit of 0.012 lb/MMBtu 
for Units 1-3 and 0.015 lb/MMBtu for Units 4 and 5 achievable by 
installing and operating any of several equivalent controls on Units 1-
3, and through proper operation of the existing baghouses on Units 4 
and 5. EPA also proposed a 10 percent opacity limit from Units 1-5 and 
a 20 percent opacity limit to apply to FCPP's material handling 
operations to respond to the voluntary remand EPA took on this issue 
from the 2007 FIP.
    On November 24, 2010, APS, acting on behalf of FCPP's owners, 
submitted a letter to EPA offering an alternative to reduce visibility-
impairing pollution. APS proposed to close Units 1-3 by 2014 and 
install and operate SCR on Units 4 and 5 to each meet an emission limit 
of 0.11 lb/MMBtu by the end of 2018. On February 25, 2011, we published 
a Supplemental Proposal (76 FR 10530) with a technical evaluation of 
APS' alternative. Our Supplemental Proposal also provides a detailed 
summary of the legal background for proposing an alternative emission 
control strategy as achieving better progress towards the national 
visibility goal (76 FR 10530).
    In our Supplemental Proposal, EPA proposed to allow APS the option 
to comply with the alternative emission control strategy in lieu of 
complying with our October 19, 2010, proposed BART determination. EPA's 
alternative emission control strategy involved closure of Units 1-3 by 
2014 and installation and operation of add-on post combustion controls 
on Units 4 and 5 to each meet a NOX emission limit of 0.098 
lb/MMBtu by July 31, 2018. EPA proposed that this alternative emission 
control strategy represents reasonable progress towards the national 
visibility goal, under CAA Section 169A(b)(2), because it would result 
in greater visibility improvement in surrounding Class I areas at a 
lower cost than our October 19, 2010, BART proposal. The proposal to 
require PM and opacity limits on Units 1-5, as well as 20 percent 
opacity limits for controlling dust from coal and ash handling and 
storage facilities, was unchanged.

II. Summary of Final FIP Provisions

    EPA is finding today that it is necessary or appropriate to 
promulgate a source-specific FIP requiring FCPP to achieve emissions 
reductions required by the CAA's BART provision. Specifically, EPA is 
requiring FCPP to meet new emissions limits for NOX and PM. 
These pollutants contribute to visibility impairment in the 16 
mandatory Class I Federal areas surrounding FCPP. For NOX 
emissions, EPA is finalizing a BART determination as well as an 
optional alternative to BART. FCPP can choose which emissions control 
strategy to follow and must notify EPA of its choice by July 1, 2013. 
Our final BART determination requires FCPP to meet a plant-wide heat 
input-weighted emission limit of 0.11 lb/MMBtu on a rolling 30-calendar 
day average which represents an 80 percent reduction from current 
NOX emission rates. This NOX limit is achievable 
by installing and operating add-on post-combustion controls on Units 1-
5. Installation and operation of the new NOX controls on one 
750 MW unit must be within 4 years of October 23, 2012. NOX 
controls on the remaining units must be installed and operated within 5 
years of October 23, 2012.
    Alternatively, FCPP may choose to comply with an alternative 
emission control strategy for NOX in lieu of complying with 
EPA's final BART determination for NOX. This alternative 
emission control strategy requires permanent closure of Units 1-3 by 
January 1, 2014, and installation and operation of add-on post 
combustion controls on Units 4 and 5 to meet a NOX emission 
limit of 0.098 lb/MMBtu each, based on a rolling average of 30

[[Page 51622]]

successive boiler operating days, by July 31, 2018.
    For PM, EPA is requiring Units 4 and 5 to meet a BART emission 
limit of 0.015 lb/MMBtu within 60 days after restart following the 
scheduled major outages for Units 4 and 5 in 2013 and 2014. This 
emission limit is achievable through the proper operation of the 
existing baghouses. EPA is determining that it is not necessary or 
appropriate to finalize our proposed PM BART determination for Units 1-
3 or our proposed opacity limit of 10 percent on Units 1-5. FCPP must 
continue to meet the existing 20 percent opacity limit on Units 1-5.
    To address our voluntary remand of the material handling 
requirements from the 2007 FIP, EPA is finalizing our proposal to 
require FCPP to comply with a 20 percent opacity limit on its material 
handling operations, including coal handling.
    In our final rule, EPA has made several revisions to the proposed 
rule and Supplemental Proposal based on comments we received during the 
public comment period. These revisions include: revising the compliance 
date under BART from within 3 to 5 years \2\ of the effective date of 
the final rule to within 4 to 5 years \3\ of the effective date; 
revising the interim limits to only include an interim limit for one 
750 MW unit rather than all units to match the revised compliance 
timeframes; adding 6 months to the notification dates to EPA on APS's 
plans to implement BART or the BART Alternative; revising the averaging 
time for the NOX limit under the BART Alternative from a 30-
day average to a rolling average of 30 successive boiler operating 
days; retaining the existing opacity limit of 20 percent instead of 
setting a new 10 percent opacity limit on Units 1-5; determining that 
it is not necessary or appropriate at this time to finalize a BART 
determination for PM for Units 1-3; and revising the effective date of 
the PM emission limit for Units 4 and 5 to the next schedule major 
outage rather than following installation of new post-combustion 
NOX controls. We include the rationale for these revisions 
in our responses to comments. All comments we received are included in 
the docket and EPA has summarized and responded to all comments in a 
separate Response to Comments (RTC) document that is also included in 
the docket for this final rulemaking. In this Federal Register notice, 
EPA is including a summary of the major comments we received and a 
summary of our responses.
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    \2\ We proposed to require phased installation of add-on 
NOX controls on at least 560 MW of generation within 3 
years of the effective date of the final rule, on at least 1310 MW 
of generation within 4 years of the effective date, and plant-wide 
within 5 years of the effective date.
    \3\ We are finalizing the rule to require phased installation of 
add-on NOX controls on at least 750 MW of generation 
within 4 years of the effective date and on the remaining units 
within 5 years of the effective date.
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III. Summary of Major Issues Raised by Commenters

    Our October 19, 2010, proposal included a 60-day public comment 
period that ended on December 20, 2010. On November 12, 2010, EPA 
published a notice of public hearings to be held in the Four Corners 
area on December 7-9, 2010 (75 FR 69374). On December 8, 2010, EPA 
published in the Federal Register a notice that EPA received an 
alternative proposal from APS and would be extending the public comment 
period to March 18, 2011, and postponing the previously scheduled 
public hearings in order to evaluate that alternative proposal (75 FR 
76331). Notices of public hearings and rescheduled hearings were 
published in three newspapers near the Four Corners Power Plant \4\. 
Our supplemental proposal on February 25, 2011, subsequently extended 
the public comment period until May 2, 2011, and announced four public 
hearings on the proposed BART determination and supplemental proposal 
in the Four Corners area on March 29, 30, and 31, 2011. In all, 90 oral 
testimonies were presented at the public hearings.
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    \4\ Notices of scheduled public hearings were published in the 
Farmington Daily Times and the Durango Herald on November 3, 2010 
and February 17, 2011, and the Navajo Times on November 4, 2010 and 
February 17, 2011. Notices of the extended public comment period and 
postponement of the December public hearings were published in the 
Farmington Daily Times and the Durango Herald on November 24, 2010 
and in the Navajo Times on December 2, 2010.
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    We received nearly 13,000 written comments. Of these, over 12,800 
comments came from private citizens who submitted substantially similar 
comments. We received an additional 110 unique written comments (not 
including duplicates, requests for extension of the public comment 
period, or requests for additional hearings). We do not consider or 
address letters or comments unrelated to the rulemaking in this notice 
or in our response to comments document. The unique comments can be 
broken down by general type as follows: 78 from private citizens, eight 
from environmental advocacy groups, four from the owners of FCPP, five 
from state/local government entities, four from public interest 
advocacy groups, two from tribes, four from utility industry 
associations, three from federal agencies, one from a U.S. Senator, and 
one from the operator of the Navajo Mine.

A. Comments on Factor One--Cost of Controls

    We received a number of comments on our approach for estimating the 
cost of SCR at FCCP, the incremental cost effectiveness of controls, 
and on our top-down approach for evaluating controls.
1. Comments on the Analysis of the Cost of SCR at FCPP
    Comment: Some of the owners of FCPP and a utility industry 
association stated that in analyzing the cost of SCR at FCPP, EPA 
improperly reworked and reduced the SCR cost estimates submitted for 
FCPP by eliminating line item costs that are not explicitly included in 
the EPA Control Cost Manual (citing 75 FR 64227). Commenters noted that 
APS' estimate was prepared by B&V, an engineering firm with extensive 
experience with the installation and operation of pollution control 
equipment and that the prices used in the cost analysis were based on 
quotes from equipment vendors that reflected current pricing.
    Response: EPA disagrees with the comment that EPA improperly 
reworked and reduced the SCR cost estimates. EPA used a hybrid approach 
for our cost analysis that relied primarily on the highest of several 
cost estimates provided by APS, but also followed the BART Guidelines 
that state ``[i]n order to maintain and improve consistency, cost 
estimates should be based on the OAQPS Control Cost Manual, where 
possible'',\5\ to determine whether APS included cost estimates for 
services or equipment associated with SCR that were either not needed 
(e.g., mitigation for increased sulfuric acid emissions or catalyst 
disposal), or not allowed under the EPA Control Cost Manual (e.g., 
legal fees).
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    \5\ The OAQPS Control Cost Manual is now called the EPA Control 
Cost Manual. The EPA Control Cost Manual is available from the 
following Web site: http://www.epa.gov/ttncatc1/products.html#cccinfo.
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    Our cost analysis relied primarily on the highest cost estimates 
submitted by APS. EPA accepted all site-specific costs provided by APS 
for cost categories (e.g., purchased equipment, installation) that are 
typically included in a cost estimate conducted in accordance with the 
EPA Control Cost Manual, and only excluded line item costs that are not 
explicitly included in the EPA Control Cost Manual or in a limited 
number of cases where EPA determined alternative

[[Page 51623]]

costs were more appropriate (e.g., costs of catalysts, interest rates). 
We note that EPA's cost estimate presented in the Technical Support 
Document (TSD)\6\ ($718 million total for Units 1-5) is only 18 percent 
lower than the highest B&V cost estimate and less than 0.6 percent 
lower than the lowest and most recent B&V cost estimate.
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    \6\ See ``TSD Proposal--Technical Support Document 10-6-10'', 
Document No. EPA-R09-OAR-2010-0683-0002.
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    Our detailed, line-by-line analysis \7\ was included in the docket 
for our proposed rulemaking and provided an explanation for why we 
retained, modified, or rejected each line item in the SCR cost estimate 
for each of the five units at FCPP.
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    \7\ See ``TSD ref [40] Four Corners SCR Cost Analysis (EPA) 8-
26-10'', Document No. EPA-R09-OAR-2010-0683-0033.
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    Comment: One of the owners of FCPP asserted that EPA's estimate of 
the average cost effectiveness of SCR at FCPP is significantly higher 
than the level ($1,600 per ton of NOX removed) that EPA 
determined was not cost effective in the 2005 BART rules for 
presumptive BART limits. The commenter asserted that there is no basis 
for EPA to depart from its own rules by concluding that SCR is BART for 
FCPP when this technology is many times more expensive than the costs 
EPA rejected as presumptive BART in the 2005 BART rules. The commenter 
noted that its cost analysis estimated that the average cost 
effectiveness of combustion controls for the five units at FCPP would 
range from $524 to $1,735 per ton of NOX removed, while the 
average cost effectiveness of SCR would range from $4,215 to $5,283 per 
ton. The commenter also noted that EPA's estimate of average cost 
effectiveness for SCR at FCPP ranged from $2,515 to $3,163 per ton. The 
commenter stated that, at the low end, only the estimate of the average 
cost effectiveness of combustion controls is in line with EPA's 
estimates of cost-effective controls for presumptive BART limits, while 
the estimate of average cost effectiveness of SCR is significantly 
higher.
    Response: EPA disagrees with this comment. Although the commenters 
argue that the BART guidelines established a threshold for cost 
effectiveness against which future BART determinations must be 
compared, the BART Guidelines did not establish a cost effectiveness 
threshold for all BART determinations. In developing the presumptive 
NOX limits for BART in 2005, EPA did not set the cost 
effectiveness values estimated for combustion controls as the threshold 
for determining whether a given control technology was or was not cost 
effective. The BART Guidelines do not set a numerical definition for 
``cost effective'', and the analysis of presumptive limits uses cost 
effectiveness as a means to broadly compare control technologies, not 
as threshold for rejecting controls for an individual unit or facility 
that exceed the average cost effectiveness of combustion controls.
    Additionally, a comparison of the average cost effectiveness 
estimates in the 2005 BART guidelines against EPA's cost effectiveness 
estimates in 2010 for FCPP is not an ``apples to apples'' comparison. 
The technical support documentation for the 2005 BART guidelines 
indicate that cost effectiveness of controls was not determined based 
on site-specific cost estimates developed for each BART-eligible 
facility; rather, cost estimates for existing facilities were 
determined using assumptions for capital and annual costs per kilowatt 
(kW) \8\ or kilowatt-hour (kW-hr), and then scaled according to boiler 
size at the existing facilities. The supporting information for the 
2005 BART Guidelines estimated SCR costs \9\ for FCPP Units 4 and 5 
that are comparable to SCR cost estimates generated by the National 
Park Service (NPS) in 2009 using the EPA Control Cost Manual.\10\ The 
same commenters have previously dismissed the NPS SCR cost estimates 
based on the EPA Control Cost Manual because it does not include site-
specific costs.\11\ In short, the commenter's recommendation to use 
generalized cost estimates from the 2005 BART Guidelines as a bright 
line threshold for comparison with site-specific 2010 cost estimates is 
inconsistent with its own criticisms of the EPA Control Cost Manual.
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    \8\ In the 2005 BART presumptive limit analysis, EPA estimated 
capital costs at all facilities nationwide assuming that SCR costs 
were $100/kW, and then scaling by the size of the facility (kW).
    \9\ The 2005 BART guidelines estimated SCR capital costs at FCPP 
to be $64 million and total annual costs to be $11 million. Cost 
effectiveness calculations rely on total annual costs and annual 
NOX reductions from the control technology.
    \10\ In the ANPRM, in addition to reporting APS' cost estimates 
and EPA's revisions to APS' cost estimates, for reference, EPA also 
reported cost estimates developed by NPS using the EPA Control Cost 
Manual and provided to EPA during consultations with the FLMs prior 
to our ANPRM. NPS estimated SCR capital costs to be $53 million and 
total annual costs to be $10 million. See Table 9 in the October 
2010 TSD for the proposed BART determination for FCPP. In its 
comments on the ANPR, NPS revised its cost estimates for SCR on 
Units 4 and 5 to $114 million (capital cost) and $18 million (total 
annual cost)--see Table 12 in the TSD for the proposed BART 
determination.
    \11\ APS and other entities provided comments to EPA on the NPS 
cost estimates reported in the ANPRM, see document titled ``Comments 
on ANPRM 09 0598 APS Comments and Exhibits'' document ID number EPA-
R09-OAR-2009-0598-0195.
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    In determining that a different level of control than the 
presumptive limit was warranted as BART for FCPP, EPA evaluated the 
five statutory factors in our assessment for FCPP. This evaluation was 
detailed in the Technical Support Document for our proposed BART 
determination and included an analysis of cost effectiveness, energy 
and non-air quality impacts of controls, existing controls at the 
facility, the remaining useful life of the facility, and the visibility 
improvement reasonably anticipated to result from controls. Therefore, 
EPA has not improperly disregarded the BART guidelines in our analysis 
for FCPP.
    Comment: A number of commenters stated that EPA's BART analysis for 
FCPP was inconsistent with its own regulations in that it failed to 
consider control costs as a function of visibility improvement. These 
commenters typically stated that EPA's BART determination for FCPP must 
consider the cost effectiveness of control technology options in terms 
of dollars per deciview-improved.
    Response: The BART Guidelines require that cost effectiveness be 
calculated in terms of annualized dollars per ton of pollutant removed, 
or $/ton.\12\ The commenters are correct in that the BART Guidelines 
list the $/deciview ratio as an additional cost effectiveness metric 
that can be employed along with $/ton for use in a BART evaluation. 
However, the use of this metric further implies that additional 
thresholds or notions of acceptability, separate from the $/ton metric, 
would need to be developed for BART determinations. We have not used 
this metric for BART purposes at FCPP because (1) it is unnecessary in 
judging the cost effectiveness of BART, (2) it complicates the BART 
analysis, and (3) it is difficult to judge. In particular, the $/
deciview metric has not been widely used and is not well-understood as 
a comparative tool. In our experience, $/deciview values tend to be 
very large because the metric is based on impacts at one Class I area 
on one day and does not take into account the number of affected Class 
I areas or the number of days of improvement that result from 
controlling emissions. In addition, the use of the $/deciview suggests 
a level of precision in the CALPUFF model that may not be warranted. As 
a result, the $/deciview can be misleading. We conclude that it is 
sufficient to analyze the cost

[[Page 51624]]

effectiveness of potential BART controls for FCPP using $/ton, in 
conjunction with an assessment of the modeled visibility benefits of 
the BART control.
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    \12\ 70 FR 39167.
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    EPA considered cost of controls, including the total capital costs, 
annual costs, and $/ton of NOX pollution reduced in our 
proposed BART determination. Additionally, in response to comments 
received on our proposal, EPA included calculations and consideration 
of incremental cost effectiveness (see Section 3.2 of the Response to 
Comments document in the docket for this final rulemaking). EPA 
considered visibility impacts, including the degree of impairment, the 
number of Class I areas affected by FCPP, the deciview improvement 
resulting from controls, and the percent change in improvement. EPA 
determined that these metrics are sufficient in completing our five-
factor analysis for FCPP.
    Comment: One commenter stated that BART must be determined in the 
context of reasonable progress rather than in isolation and that the 
cost effectiveness metric used by EPA (i.e., $/ton of NOX 
reduced) does not satisfy the statutory requirement to consider the 
cost to comply with the Regional Haze program because it does not 
include compliance costs related to requirements for reasonable 
progress.
    Response: Congress identified BART as a key measure for ensuring 
reasonable progress. We disagree that BART must be determined in the 
context of reasonable progress. If anything, reasonable progress 
depends on BART. Because the Class I areas affected by emissions from 
FCPP are not achieving the glidepath, it is important that states, 
tribes, and EPA require reasonable measures to be implemented to ensure 
that progress is made towards the national visibility goal.
    The BART guidelines specify that the cost of controls be estimated 
by identifying the emission units being controlled, defining the design 
parameters for emission controls, and developing a cost estimate based 
on those design parameters using the EPA Control Cost Manual while 
taking into account any site-specific design or other conditions that 
affect the cost of a particular BART control option. The BART 
guidelines do not require the costs of compliance under BART to 
consider costs that may be associated with reasonable progress.
    Comment: The Navajo Nation commented that EPA should analyze the 
affordability of controls under the supplemental proposal by performing 
a detailed analysis, rather than an approximation, of the cost of 
compliance for installing SCR on Units 4 and 5, including a 
consideration of the impacts of closing Units 1-3.
    Response: EPA disagrees that we should perform a detailed cost 
analysis of the alternative emission control strategy put forth in the 
Supplemental Proposal. The Regional Haze Rule, in assessing an 
alternative measure in lieu of BART (40 CFR 51.308(e)(2)) requires 
several elements in the alternative plan (e.g., a demonstration that 
the alternative will achieve greater reasonable progress than BART, and 
that reductions are surplus to the baseline date of the SIP), but does 
not require an analysis of the cost of the alternative plan.
    Similarly, an affordability analysis of the alternative emission 
control strategy is not required under the Regional Haze Rule; however, 
at the request of the Navajo Nation, pursuant to EPA's customary 
practice of engaging in extensive and meaningful consultation with 
tribes, EPA commissioned a study to estimate potential adverse impacts 
to the Navajo Nation of APS's option to close Units 1-3 and will 
provide the report to the Navajo Nation by letter as a follow-up to our 
consultation.
2. Comments on Top-Down Analysis Versus Incremental Cost Effectiveness
    Comment: A number of commenters note that EPA's proposed BART 
analysis was inconsistent with its own regulations in that it used a 
top-down analytic approach and failed to conduct an incremental cost 
evaluation. Commenters indicated that in using the top-down analysis, 
EPA failed to carry out the five-factor analysis for each of the 
technically feasible retrofit technologies as required by the BART 
Guidelines (citing 40 CFR part 51, Appendix Y, section I.F.2.c), 
including combustion control technology which the BART Guidelines 
identify as presumptive BART.
    Response: EPA disagrees with these comments. In the preamble to the 
final BART guidelines, EPA discusses two options presented in the 2001 
proposal and 2004 reproposal of the guidelines for evaluating ranked 
control technology options (See discussion at 70 FR 39130). Under the 
first option, States would use a sequential process for conducting the 
analysis, beginning with a complete evaluation of the most stringent 
control option. The process described is a top-down approach analogous 
to the analysis we used in our proposed BART determination for FCPP. If 
the analysis shows no outstanding issues regarding cost or energy and 
non-air quality environmental impacts, the analysis is concluded and 
the top level of technically feasible controls is identified as the 
``best system of continuous emission reduction''. Therefore, in 
conducting our BART determination for FCPP, EPA's top-down approach for 
assessing the five factors was consistent with the discretion allowed 
under the BART guidelines. EPA additionally notes that the TSD for our 
proposed rulemaking included analyses of the costs, non-air impacts, 
and visibility improvements associated with combustion controls at 
FCPP, but that there is no requirement for a five-factor analysis on 
all potentially available control options if the top down approach is 
used and the top level of technically feasible controls is selected (70 
FR 39130).
    Comment: One of the owners of FCPP asserted that the BART rules 
require an incremental cost analysis and provided an analysis comparing 
the costs of combustion controls to the costs of SCR. According to the 
commenter's analysis, the incremental cost effectiveness of moving from 
combustion controls to SCR ranges from $6,553 to $8,605 per ton of 
NOX reduced for the five units at FCPP. This commenter and 
another FCPP owner asserted that this ``extraordinarily high'' 
incremental cost highlights the fact that combustion controls, not SCR, 
satisfy the cost effectiveness test applied by EPA in adopting the 
presumptive BART limits in the BART rules.
    Response: EPA agrees that the BART Guidelines recommend 
consideration of both average and incremental cost effectiveness, 
however, EPA disagrees with the commenter that the incremental cost 
effectiveness should be a comparison between combustion controls and 
SCR for this particular facility. As discussed at length in the TSD for 
our proposed BART determination for FCPP, Region 9 has determined that 
combustion controls (burner modifications and overfire air, including 
ROFA) will not be effective at significantly reducing emissions at Four 
Corners without potential operational difficulties due to inherent 
design and physical limitations of the boilers. Therefore, in 
estimating incremental cost, it is inappropriate and misleading to 
include combustion controls in the analysis for this particular 
facility. To respond to this comment, EPA conducted an incremental cost 
effectiveness analysis and included it in our docket for this final 
rulemaking.\13\ Based on our incremental cost analysis, EPA has 
determined that the incremental cost of SCR compared to

[[Page 51625]]

selective non-catalytic reduction (SNCR), the next most stringent 
option ($2,500 per ton to $3,300 per ton), is reasonable and does not 
support the commenter's conclusion that SCR is not BART for FCPP.
---------------------------------------------------------------------------

    \13\ See ``Incremental cost.xlsx'' in the docket for this final 
rulemaking.
---------------------------------------------------------------------------

    EPA estimated the total capital cost of BART for NOX to 
be $718 million and total annual costs (annualized capital costs plus 
additional operating costs) to be $93 million per year. This final BART 
determination is expected to reduce emissions of NOX by 80 
percent, from 43,000 tons per year to 8,500 tons per year, resulting in 
a facility-wide average cost effectiveness of about $2,700 per ton of 
NOX removed. EPA anticipates that this investment will 
reduce the visibility impairment caused by FCPP by an average of 57 
percent at 16 Class I areas within 300 km of the facility. A detailed 
summary of the cost and visibility benefits were provided in the 
Technical Support Document for the proposed rulemaking. As discussed in 
our Supplemental Proposal, although APS did not provide a cost estimate 
for the BART Alternative and the RHR does not require an evaluation of 
costs associated with a BART Alternative, if APS chooses to implement 
the Alternative, EPA anticipates those costs to be approximately 39 
percent lower than the cost of BART. The BART Alternative is expected 
to reduce emissions of NOX by 87 percent, from 43,000 tons 
per year to 5,600 tons per year, resulting in a facility-wide average 
cost effectiveness of roughly $1,600 per ton of NOX 
removed.\14\ EPA anticipates that implementation of the BART 
Alternative will reduce visibility impairment caused by FCPP by an 
average of 72 percent at 16 Class I areas within 300 km of the 
facility.
---------------------------------------------------------------------------

    \14\ EPA estimates facility-wide average cost effectiveness of 
the BART Alternative to be lower than BART because under the BART 
Alternative, Units 1-3 can be closed instead of retrofitted with new 
air pollution controls. On a per unit basis, the cost effectiveness 
of Units 4 and 5 is not expected to differ between BART or the BART 
Alternative.
---------------------------------------------------------------------------

B. Comments on Factor Two--Economic, Energy, and Non-Air Quality 
Environmental Impacts

    We received a number of comments on the economic impacts and on the 
energy and non-air quality environmental impacts.
1. Comments on Economic Impacts
a. General Comments on Economic Impacts
    Comment: Several commenters stated that EPA's analysis of 
historical and expected costs of electricity from FCPP neglect to 
include public health costs related to air pollution and the negative 
impacts to tourism resulting from loss of visibility. The commenters 
concluded that the cost effectiveness metric used to determine BART 
must account for health costs related to poor air quality.
    Response: EPA disagrees with the comment that the cost 
effectiveness of BART must account for public health costs associated 
with poor air quality. Neither Section 169A of the CAA, nor the BART 
Guidelines, require the BART analysis to include or quantify benefits 
to health or tourism. Moreover, an analysis of health and tourism 
benefits is unlikely to alter the outcome of our BART determination, 
which already requires the most stringent control technology available 
for NOX.
    Comment: The Navajo Nation, one federal agency, and two of the 
owners of FCPP stated that EPA must consider the collateral adverse 
effects on the Navajo Nation and the surrounding communities of its 
BART determination. The commenters provided background on the 
substantial interest that the Navajo Nation has in the continued 
operation of FCPP. The commenters indicated that FCPP and its coal 
supplier, the Navajo Mine operated by BHP Billiton (BHP), together 
provide income to the Navajo Nation that contributes substantially to 
the Nation's economic viability and its sustainability as an 
independent sovereign nation. The commenters added that this resource 
extraction-based economy is the result of a conscious effort of the 
United States dating from the 1950s to develop the Nation's coal 
resources. According to the commenter, if FCPP and the Navajo Mine were 
to close as the result of the imposition of cost-prohibitive emission 
controls, the resulting revenue and job losses would be significant for 
the Navajo Nation.
    Response: EPA agrees with commenters that the operation of FCPP and 
the Navajo Mine contribute significantly to the economy of the Navajo 
Nation and the Four Corners Region.
    It is not EPA's intention to cause FCPP to shut down, nor is it 
within our regulatory authority under the Regional Haze Rule to require 
shutdown or redesign of the source as BART. As expressed in comments 
from the Navajo Nation to our Advanced Notice of Proposed 
Rulemaking,\15\ EPA understands that the Navajo Nation's primary 
concern regarding the BART determination is the potential for FCPP 
closure. Therefore, as discussed in our proposed BART determination, 
EPA conducted an affordability analysis not typically included in a 
BART five-factor analysis in order to assess whether requiring SCR on 
all five units at FCPP would cause the power plant to close.
---------------------------------------------------------------------------

    \15\ Comment letter from President Joe Shirley, Jr. dated March 
1, 2010 in the docket for the ANPR: EPA-R09-OAR-2009-0583-0209.
---------------------------------------------------------------------------

    The model was designed to determine which future alternative 
results in lower power costs: (a) Power produced at FCPP after 
installation of SCR or, (b) replacing the power from FCPP with the 
appropriate amount of wholesale power purchases. As discussed in the 
TSD for our proposed BART determination, the model results suggested 
that even if the owners of FCPP installed and operated SCR on all five 
units, the facility could still produce power at a lower cost than the 
cost to purchase replacement wholesale power on the open market. Thus, 
EPA concluded in our proposed BART determination that requiring SCR as 
BART on all five units would not likely result in plant closure. No 
information was provided by the commenter to change this conclusion in 
the proposal.
    Comment: The Navajo Nation asserted that EPA failed to consult with 
the Nation prior to publishing the supplemental proposal and failed in 
its trust responsibility to consider the economic impacts of closing 
Units 1-3. A federal agency commenter noted that EPA's current analysis 
focuses primarily on increased costs to rate payers and the companies' 
profitability, and stated that the analysis needs to incorporate the 
loss in revenue, jobs, and royalties resulting from the closure of 
Units 1-3 under the supplemental proposal.
    Response: A timeline of correspondence and consultation with the 
Navajo Nation and other tribes for EPA actions on FCPP and Navajo 
Generating Station is included in the docket for the final 
rulemaking.\16\ EPA notes that the Regional Administrator of EPA Region 
9 called President Joe Shirley on February 9, 2011 to inform him of 
EPA's Supplemental Proposal. However, government-to-government 
consultation with the Navajo Nation on FCPP did not occur until May 19, 
2011, with additional consultation occurring on June 13, 2012, prior to 
issuing our final rulemaking. The Navajo Nation raised concerns about 
the potential adverse impacts of the BART Alternative and requested 
that EPA conduct an analysis to estimate those impacts.
---------------------------------------------------------------------------

    \16\ See document titled: ``Timeline of all tribal consultations 
on BART.docx'' in the docket for this final rulemaking.
---------------------------------------------------------------------------

    Although the Regional Haze Rule does not require a cost analysis of 
a BART alternative, at the request of the Navajo Nation, as part of 
EPA's customary

[[Page 51626]]

practice of engaging in extensive and meaningful consultation with 
tribes and tribal authorities with regard to relevant Agency actions, 
EPA did commission an analysis to estimate potential adverse impacts on 
the Navajo Nation, with respect to coal- and power plant-related 
revenues, of the optional BART Alternative to retire Units 1-3. The 
report will be provided to President Shelly by letter as a follow-up to 
our consultation with the Navajo Nation.
    Comment: One owner of FCPP stated that EPA's proposal to require 
SCR at FCPP presents significant challenges and risks with regard to 
its resource planning. The commenter pointed out that implementation of 
the BART proposal would require the commenter to make a significant 
capital investment in FCPP, which could only be recovered through long-
term operation of the plant. According to the commenter, this would 
have the effect of locking FCPP into the commenter's generation 
portfolio for a considerable period or risk stranding those 
investments.
    Response: EPA appreciates the perspectives shared in this comment, 
but we disagree that our five-factor BART analysis should consider the 
potential loss of an owner's flexibility to respond to possible future 
economic or regulatory scenarios. EPA cannot give substantial 
consideration in our BART analysis to external factors that are of 
uncertain magnitude and that may or may not occur. EPA further notes 
that the RHR allows for the development of BART alternatives that 
achieve greater reasonable progress than BART and EPA appreciates the 
fact that the owners of FCPP put forth an alternative that gives them 
more flexibility and results in greater emission reductions at FCPP.
b. Comments on EPA's Economic Analysis
    Comment: One public interest advocacy group concurred with the 
EPA's analysis that the potential increase to APS rate payers as a 
result of SCR is expected to be less than 5 percent, as described in 
the TSD. The commenter stated that EPA's estimates are reasonable and 
that the average increase in the cost of generation at FCPP as a result 
of SCR implementation would be 22 percent, or $0.0074 per kWh, as 
stated in the TSD.
    One of the owners of FCPP stated that installation of BART controls 
would increase its average residential customer monthly bills by $5.10 
(3.8 percent) and larger industrial customer monthly bills by $17,400 
(6.4 percent). The commenter also indicated that installing SCR and 
baghouses on Units 1-3 would increase the cost of electricity 
production on a $/MWh basis by more than 50 percent which, in 
conjunction with other market and regulatory uncertainties, may make 
the units uneconomical. The commenter also raised concerns related to 
the economic viability of Units 4 and 5 if SCR were installed on those 
units.
    Another of the owners of FCPP, who also owns part of San Juan 
Generating Station and Navajo Generating Station, indicated that if SCR 
was required on all three power plants, its customers would face a rate 
increase of 4 to 6 percent, which would be significant because the 
local economy is fragile and has endured an 8 percent rate increase 
(not adjusted for inflation) since 1992.
    Response: EPA agrees with the first commenter that based upon our 
analysis the potential increase to APS rate payers as a result of SCR 
is expected to be less than 5 percent. EPA cannot assess the estimated 
residential and industrial rate increase claimed by the second and 
third commenters with our economic analysis because the commenters did 
not provide information for us to evaluate their conclusions. However, 
EPA notes that the installation of baghouses on Units 1-3 is no longer 
relevant because EPA has determined that it is not necessary or 
appropriate at this time to set new PM limits for Units 1-3. This is 
because the Mercury and Air Toxics Standard (MATS) rule, which sets a 
filterable PM limit of 0.03 lb/MMBtu, is now final \17\ and EPA is 
finalizing in this rulemaking the option to allow APS to comply with 
either BART or the BART alternative, which involves closure of Units 1-
3.
---------------------------------------------------------------------------

    \17\ See 77 FR 9304, February 16, 2012.
---------------------------------------------------------------------------

    Comment: One of the owners of FCPP expressed concern that EPA's 
analysis focuses on the effects on APS and Southern California Edison 
ratepayers, and not on the other owners of FCPP. This commenter's 
specific concerns include that the use of a ``return on rate''-based 
methodology would not apply to organizations of the commenter's type (a 
publicly owned utility) because it is not an investor-owned utility. In 
addition, the commenter stated that the EPA analysis did not attempt to 
determine the impact of different assumptions, such as an uncertainty 
with the future price of coal, on the conclusions of the analysis. 
Specifically, the ``small difference'' that EPA estimates between FCPP 
with SCR installed and the cost of purchasing power to replace FCPP 
generation suggests that a small change in an underlying assumption 
(return on rate, coal price, carbon pricing, etc.) could result in 
model results that show SCR to be a higher cost option than purchasing 
power. The commenter also raised the concern that EPA's analysis did 
not examine different ``payback periods,'' but instead relied on a 
payback period of 25 years, which may be inappropriate because the 
useful life of the plant is far from certain. The commenter said that 
EPA should recognize that there is a real risk that one or more owners 
may decide not to invest in SCR, which would force the shutdown of FCPP 
unless another owner could be found in a timely manner. The commenter 
also said that shutdown of FCPP would have significant adverse 
consequences on the Navajo Nation.
    Response: The commenter is correct that EPA calculated rate impacts 
for only two of the four investor-owned utilities that own FCPP and 
excluded others, including an owner that operates as a publicly owned 
utility. The analysis estimating the increase in electricity generation 
costs is applicable to all owners of FCPP, but the rate impact analysis 
provided in the model was not intended to capture the rate impacts of 
all owners. APS and Southern California Edison (SCE) were selected 
because their combined ownership shares account for nearly 75 percent 
of the plant's output. In addition to our expectation that the 
utilities with the largest ownership share in FCPP would generally 
experience greater ratepayer impacts from capital expenditure projects 
like SCR installation, we also assumed that ratepayers of investor-
owned utilities would likely experience larger impacts than public 
power customers due to the fundamental difference between their 
respective approaches to setting rates. Specifically, rates for public 
power utilities, in contrast to investor-owned utilities, do not 
include recovery for a margin above cost allowed as part of a regulated 
rate of return. Thus, all other variables being equal, one would expect 
the same capital investment to result in a larger rate impact for 
customers of investor-owned utilities than for customers of public 
power entities. Therefore, EPA continues to believe that our analysis 
of ratepayer impacts for only APS and SCE are appropriately 
conservative to demonstrate worst-case impacts to ratepayers of all six 
owners.
    EPA agrees with the commenter that there are many company-specific 
factors and a wide range of assumptions that would affect a given 
owner's decision to make further substantial investments (such as SCR) 
at FCPP. Although many of those factors were outside the focus of the 
modeling because they were either unrelated to BART or were related to 
regulatory uncertainties in the

[[Page 51627]]

future, we included a qualitative discussion in Appendix B to the TSD 
regarding decision variables that EPA assumed each owner must consider 
before making capital expenditures. Additionally, EPA notes that the 
use of low, medium and high future projected prices for the Palo Verde 
Index in Appendix B to the TSD for the proposed rulemaking represents a 
sensitivity analysis for the market comparison.
    With respect to the comment on the ``payback period'', the economic 
analysis for the proposed BART determination did not identify ``payback 
periods''. Rather, the commenter appears to be referring to the 25-year 
period used in the discounted cash flow model. EPA does not disagree 
with the commenter's stated concern that a shorter plant life, and thus 
shorter discounting periods, would yield different economic results. 
However, EPA disagrees with commenters that a shorter useful life 
should be considered in the economic analysis because there is no 
enforceable obligation on APS to cease operations on a given (earlier) 
date.
2. Comments on Energy and Non-Air Quality Environmental Impacts
    Comment: One private citizen stated that no consideration was given 
to the effect of removing FCPP generation from the grid. According to 
the commenter, the events of February 2, 2011, show there are times 
when gas-fired generation cannot replace coal-fired generation because 
there is not enough gas transportation capacity.
    Response: EPA disagrees with the commenter that we should consider 
the effect of removing FCPP generation from the grid. As stated 
elsewhere, it is not EPA's intention, nor is it within our regulatory 
authority, to require closure or require a redefinition of the source, 
in order to comply with the BART requirement of the Regional Haze Rule. 
Furthermore, the owners of FCPP did not provide evidence that the 
installation of SCR would cause FCPP to close.
    EPA also notes that APS proposed to purchase the shares of Units 4 
and 5 currently owned by Southern California Edison in order to close 
Units 1-3 (of which APS is sole owner) and install SCR on Units 4 and 5 
as an alternative to BART. APS has received approval from the Arizona 
Corporation Commission and the California Public Utilities Commission 
to purchase Southern California Edison's share of Units 4 and 5. APS is 
also seeking approval from the Federal Energy Regulatory Commission to 
implement its proposal.\18\ Decisions on investing in pollution 
controls or shutting down units are made by the owners in conjunction 
with their oversight boards or public utility commissions. These 
oversight bodies are also responsible for assuring the adequacy of 
electrical generating capacity, whether from coal, gas or nuclear fuels 
or renewable sources.
---------------------------------------------------------------------------

    \18\ On March 22, 2012, the California Public Utilities 
Commission (PUC) approved the sale of SCE's ownership share in FCPP 
to APS. On April 18, 2012, the Arizona Corporation Commission voted 
to allow APS to purchase SCE's ownership share in FCPP.
---------------------------------------------------------------------------

    Comment: Thirty-seven private citizens commented that FCPP causes 
significant threats to public health due to its effects on air quality. 
In addition, a number of environmental and public interest advocacy 
groups provided comments on health and ecosystem impacts of the 
pollutants emitted by FCPP.
    Regarding health impacts, the commenter noted that the same 
pollutants that contribute to visibility impairment also harm public 
health--the fine particulates that cause regional haze can cause 
decreased lung function, aggravate asthma, and result in premature 
death in people with heart or lung disease. The commenter added that 
NOX and volatile organic compounds (VOCs) can also be 
precursors to ground-level ozone, which is associated with respiratory 
diseases, asthma attacks, and decreased lung function. According to the 
commenter, ozone concentrations in parks in the Four Corners region 
approach the current health standards, and likely violate anticipated 
lower standards.
    The same commenter also contended that consideration of non-air 
quality impacts extends to impacts on wildlife and habitat as well as 
natural and cultural heritage. According to the commenter, haze-causing 
emissions also harm terrestrial and aquatic plants and animals, soil 
health, and water bodies by contributing to acid rain, ozone formation, 
and nitrogen deposition.
    With these health and environmental considerations in mind, in 
addition to visibility and economic considerations discussed in other 
sections of this document, the commenter urged the EPA to finalize more 
stringent BART determinations for FCPP.
    The commenter noted that FCPP is a significant source of mercury 
emissions and provided information on the health and ecosystem effects 
of mercury, as well as on the deposition of mercury and the levels of 
mercury found in the Four Corners area. In addition, the commenter 
stated that FCPP emits more than 16 million tons per year (tpy) of 
CO2, and that such emissions contribute significantly to 
climate change which is likely to result in increasing temperatures and 
increase drought in the Southwest. The commenter noted that the 
supplemental proposal would reduce emissions of both mercury and 
CO2.
    One environmental advocacy group stated that a formal Health Impact 
Assessment should be conducted by independent experts before EPA's 
final decision to answer such questions as whether shutting down Units 
1-3 is sufficient to protect local health, and what health impacts 
would result from delaying pollution controls on Units 4 and 5 until 
2018.
    Response: EPA agrees that there are potential benefits to health 
and the environment from reducing emissions of NOX. However, 
quantifying health benefits is not within the scope of the BART five 
factor analysis required under the CAA (Sec.  169A(g)). The BART 
Guidelines provide additional information on how to analyze ``non-air 
quality environmental impacts, and focuses on adverse environmental 
impacts associated with control technologies, i.e., generation of solid 
or hazardous wastes and discharges of polluted water, that have the 
potential to affect the selection or elimination of a control 
alternative'' (see 70 FR 39169). Thus, although the BART Guidelines do 
state that relative environmental impacts (both positive and negative) 
of alternatives can be compared with each other, they state that ``if 
you propose to adopt the most stringent alternative, then it is not 
necessary to perform this analysis of environmental impacts for the 
entire list of technologies''. EPA agrees with commenters that 
controlling pollutant emissions may have co-benefits for reducing ozone 
production and acid deposition. EPA does not interpret the BART 
Guidelines to require quantification of human health or environmental 
co-benefits in determining BART, particularly if the most stringent 
BART option is finalized. Similarly, EPA does not interpret the BART 
guidelines to require human health or environmental assessments of 
alternative compliance strategies as long as we have determined that 
the alternative strategy achieves better progress towards the national 
visibility goal.
    Comment: The commenter stated that human exposure to environmental 
hazards is an important factor in assessing impacts of FCPP. The 
commenter encouraged EPA to pursue health studies in collaboration with 
the Navajo Nation to study local risks

[[Page 51628]]

associated with exposure to criteria pollutants, indoor air pollutants, 
and other contributing air pollutants, from which improved public 
health and effective rulemakings under the CAA may be achieved.
    Response: Assessing human exposure and quantifying health benefits 
are outside the scope of the requirements of the Regional Haze Rule. 
EPA sets National Ambient Air Quality Standards (NAAQS) to establish 
levels of air quality that are protective of public health, including 
the health of sensitive populations, for a number of pollutants 
including particulate matter. These ``sensitive'' populations include 
asthmatics, children, and the elderly. At this time the Navajo Nation 
is not identified as out of attainment with any of the NAAQS. However, 
EPA recognizes that there are significant concerns about risk and 
exposure to air pollutants on the Navajo Nation and EPA will continue 
discussions with the Navajo Nation and will involve other federal 
agencies, as appropriate, to help address these concerns.

C. Comments on Factor Three--Existing Controls at FCPP

    Comment: One of the owners of FCPP agreed with EPA's summary of the 
existing controls at the plant, but noted that the proposed FIP is only 
the most recent action in a long line of regulatory and voluntary 
efforts to reduce emissions of pollutants that impact visibility, 
including SO2, NOX, and PM emissions. The 
commenter asserted that FCPP has a strong history of retrofitting 
pollution controls and recounted the facility's history of installing 
these controls and reducing emissions.
    Response: EPA agrees that there have been numerous installations of 
pollution controls over the several decades that FCPP has been in 
operation. The most recent voluntary effort by FCPP increased the 
SO2 removal from its long-term level of 72 percent removal 
to 88 percent removal. This was accomplished before the end of 2004 and 
became effective as a regulatory requirement in June 2007. The 
improvement in SO2 removal has resulted in a decrease of 
over 22,000 tons of SO2 per year since that time.

D. Comments on Factor Four--Remaining Useful Life at FCPP

    Comment: One of the owners of FCPP noted that the BART rules state 
that the normal amortization period (20 years for NOX 
control devices) is appropriate to use as the remaining useful life if 
the plant's ``remaining useful life will clearly exceed'' that 
amortization period (citing 70 FR 39169). The commenter asserted, 
however, that as a result of substantial uncertainty related to 
multiple factors, it is not at all clear that the plant's remaining 
useful life is at least 20 years.
    Moreover, according to the commenter, one factor that should not be 
allowed to shorten the useful life under the BART rules is the choice 
of BART itself--EPA cannot use a 20-year amortization period to justify 
a specified technology (e.g., SCR) if the application of the technology 
would be so costly as to make the facility uneconomical and shorten its 
useful life (citing 70 FR 39164, 39171).
    The commenter made a number of arguments related to the possibility 
of a shorter useful life at FCPP that are briefly summarized here. The 
excessive cost of SCR will dramatically increase the energy costs of 
the plant, potentially making it uneconomical. The proposed ``phase-in 
schedule'' for SCR may force closure of units because APS will not have 
certainty by the compliance deadline that the lease will be extended or 
that Southern California Edison's ownership share will have been 
successfully transitioned. Emerging environmental laws and regulations 
present cost and operational uncertainty that may shorten FCPP's useful 
life (including new GHG laws and regulations, MATS, new ash-handling 
requirements, and new requirements for cooling water intake 
structures).
    Response: EPA disagrees that we must consider a shorter useful life 
because of uncertainty related to the factors cited by the commenter. 
It is inappropriate to consider a useful life shorter than 20 years 
based solely on uncertainty or the possibility of shut down. EPA 
further notes that in its cost analysis on behalf of APS, B&V stated 
``the remaining useful life of Units 1 through 5 was at least 20 
years''.\19\ Unless there is an enforceable obligation for APS to cease 
operations or unless APS convincingly demonstrates that controls 
(rather than uncertainty associated with future requirements) will 
cause facility closure, the default 20 year amortization period 
represents the appropriate period for the remaining useful life.
---------------------------------------------------------------------------

    \19\ See B&V Engineering Analysis for Units 1-5 at FCPP dated 
December 2007. Document number 0011 in docket for proposed 
rulemaking: EPA-R09-OAR-2010-0683.
---------------------------------------------------------------------------

    EPA agrees that our proposed ``phase-in'' schedule for installation 
of add-on post-combustion NOX controls on Unit 1-3 for BART, 
which was added in the supplemental proposal, may have allowed less 
than two years for engineering and installation from the date by which 
APS intends to make its decision on continuing operation or shutting 
the units down by 2014. EPA is finalizing a modified schedule for the 
installation of add-on post combustion controls from what was 
originally proposed (phased-in installation of controls within three to 
five years of effective date) by requiring one of the 750 MW units to 
comply with the BART emission limit within 4 years of the effective 
date of this final rule and the remaining units (Units 1-3 and either 
Unit 4 or 5) within 5 years of the effective date of this final rule.
    Comment: One industry commenter stated that EPA, rather than 
evaluate APS' supplemental proposal as an alternative emission control 
strategy, should instead ``re-determine'' BART for each of the five 
units at FCPP based on the APS-proposed shutdown scenario for Units 1-
3, i.e., reducing the remaining useful life of Units 1-3 to 2014 and 
then using the short remaining life of those units to determine that 
BART for Units 1-3 is no additional control. The commenter concluded 
that a ``better-than-BART'' control strategy does not seem to be 
necessary for determining the appropriate requirements for FCPP under 
the APS-proposed shutdown scenario; instead, a BART determination for 
each unit with appropriate weighting of the statutory factors appears 
to present a logical and less-burdensome means of applying section 
169A(b)(2) of the CAA to FCPP.
    Response: EPA disagrees that APS' supplemental proposal should be 
evaluated in terms of a BART re-determination rather than in terms of 
its current status as a ``better-than-BART'' alternative measure. The 
2006 Regional Haze Rule (71 FR 60612) established the procedures 
described in 40 CFR 51.308(e)(2) and (3) for scenarios involving 
programs that may make greater reasonable progress than source-by-
source BART. These provisions were specifically included to allow for 
the flexibility to consider alternative measures such as the one 
proposed by APS, and EPA considers it the most appropriate method for 
evaluating APS' supplemental proposal.
    Comment: One industry commenter discussed the ``remaining useful 
life'' statutory factor, noting that under the BART Guidelines 
remaining useful life is ignored in the majority of BART determinations 
(citing 40 CFR part 51, Appendix Y, section IV.D.4.k), which the 
commenter asserted is inappropriate. According to the commenter, 
Congress designated the remaining useful life of the source as an 
important consideration because it did not want to impose the burdens 
of control technology retrofits on sources

[[Page 51629]]

that were more than 15 years old at the time the statute was enacted. 
Given that it is now 34 years after the BART requirements were enacted, 
the commenter stated that the ``remaining useful life'' statutory 
factor should weigh heavily in BART determinations for older sources 
such as FCPP, instead of being ignored.
    Response: EPA disagrees with the commenter that we ignored the 
``remaining useful life'' statutory factor in our BART decision. EPA 
considered this factor in our BART analysis (see pages 42-43 of the TSD 
for our proposed BART determination). As discussed in the TSD, the 
remaining useful life of an Electric Generating Unit (EGU) subject to 
BART is determined by the utility. EPA cannot arbitrarily decide that 
an EGU has less useful life when it is not within our BART rulemaking 
authority to require closure of an EGU. If a utility used a shorter 
useful life than one that would allow the full amortization of any 
necessary pollution controls, EPA would take that into account in the 
cost analysis, provided that there was an enforceable obligation for 
the facility to cease operation by that time.

E. Comments on Factor Five--Anticipated Visibility Improvements

    Comment: One of the owners of FCPP presented information on 
visibility conditions on the Colorado Plateau and the role of 
NOX emissions in Western visibility impairment. The 
commenter noted that SO2 and NOX emissions have 
been decreasing in recent years. The commenter also presented 
information that purported to show that whether averaged over the 
haziest 20 percent of days, the clearest 20 percent of days, or all 
days, power plant NOX emissions contribute less than 1.5 
percent to the light extinction at Mesa Verde National Park.
    Another commenter questioned EPA's assertion that NOX 
and PM from FCPP are significant contributors to visibility impairment 
in the numerous mandatory Class I areas surrounding FCPP (citing 75 FR 
64221), stating that coal-fired power plants, including FCPP, are 
relatively small contributors to regional haze in the surrounding Class 
I Areas.
    Response: EPA modeling of FCPP showed visibility impacts ranging 
from 1.2 to 6.0 deciviews (dv), depending on the Class I area, with the 
sum of impacts at all sixteen Class I areas totaling 43 dv. This is a 
significant contribution to visibility impairment. Even if an 
individual source category appears small to some commenters, the many 
segments of the emissions inventory together cause significant 
visibility impairment and must be addressed in order to make progress 
towards the national goal of remedying visibility impairment from 
manmade pollution. Section 169A of the CAA requires BART determinations 
on BART-eligible EGUs regardless of trends or ambient visibility 
conditions. Application of BART is one means by which we can ensure 
that downward emission and visibility impairment trends continue. EPA 
identifies stationary sources as an important category to evaluate in a 
BART analysis.
    Comment: Three of the owners of FCPP, the Navajo Nation, and two 
utility industry associations argued that EPA's use of Interagency 
Workgroup on Air Quality Modeling (IWAQM) Phase II default background 
ammonia values is not appropriate. They argued the following points: 
(1) Actual field measurements show lower ammonia concentrations than 
used by EPA; (2) EPA is mistaken in its assumption that background 
ammonia concentrations along the path of the plant's plume determine 
nitrate concentrations and their contribution to haze at the receptor 
site; (3) EPA's ``corroborating'' approach of ``back-calculating'' 
ammonia is flawed because it erroneously assumes that the ammonia 
associated with measured sulfate and nitrate would all be available to 
react with FCPP emissions, whereas in reality those measurements 
reflect emissions from many sources; (4) EPA's analysis of nitrate 
predictions as a check on the ammonia values used is also flawed 
because it erroneously assumes that the resulting measured nitrate 
levels are solely due to FCPP emissions; (5) comparable analysis using 
the EPA ammonia value shows substantial and ``physically impossible'' 
over-predictions of nitrate. The commenters conclude that the use of 
IWAQM values invalidates EPA's BART modeling and the BART determination 
that relied on the modeling.
    Another utility industry association stated that several 
measurement programs on the Colorado Plateau show that actual ammonia 
values in Class I areas near FCPP are significantly lower than the 
IWAQM default value, indicating that these values typically range from 
0.1 to 0.6 ppb. The commenter noted that ammonia concentrations are 
lowest during the cold season when the visibility impacts of 
NOX emissions are the highest. Accordingly, the commenter 
asserted that using a single ammonia value throughout the year is not 
scientifically valid and should be replaced with seasonally variable 
values.
    The Navajo Nation expressed concern regarding discrepancies between 
EPA and APS modeling inputs, given the commenter's understanding that 
APS obtained advance EPA approval for its modeling protocols. Some 
commenters stated that EPA had earlier agreed to lower ammonia 
concentrations, and so should not be using the higher IWAQM value now.
    In contrast, one public interest advocacy group concurred with 
EPA's back-calculation method for ammonia background levels (citing the 
TSD, page 60). The commenter added that the requests to EPA from other 
commenters for additional ammonia monitoring data are unrealistic in 
today's budget environment.
    Response: EPA disagrees with commenter objections to the background 
ammonia concentrations used in our modeling. Our use of the 1 ppb IWAQM 
Phase II default background ammonia value is appropriate. Most of the 
objections have already been discussed in EPA's TSD for the proposal; 
and several of them concern the ``back-calculation'' method that we 
used only as corroboration for using the 1 ppb results we principally 
relied on. Also, even if the lower ammonia concentrations urged by some 
commenters were accepted, EPA's sensitivity modeling results provided 
in the TSD for our proposed BART determination showed the visibility 
benefits would still support EPA's BART determination. EPA also 
provided the results of modeling runs that used the lower ammonia 
background concentrations recommended by some commenters (see TSD Table 
37). The visibility benefits of the NOX controls for BART 
are substantial under all ammonia scenarios, including the lower 
background ammonia concentrations recommended by commenters. For 12 
Class I areas, modeling even with those lower background concentrations 
showed improvements of 0.5 dv or more, an amount recognized in the BART 
Guidelines as significant (e.g. at 70 FR 39120).
    The lack of ammonia and ammonium measurements in the Class I areas 
of concern requires that EPA estimate background ammonia concentrations 
by some method, considering available data and approaches. As discussed 
in the BART proposal and its accompanying TSD, EPA understands that 
there is no single accepted method for estimating the background 
concentration of ammonia, and that any method will have advantages and 
disadvantages. The lack of consensus on a method was a factor in EPA's 
decision to rely on the 1 part per billion (ppb)

[[Page 51630]]

default value in IWAQM, as was the fact that IWAQM is the only 
available guidance on this issue. In summary, there is insufficient 
monitoring information available to use a different value, or to 
support any seasonally varying values and, as described below, these 
values are reasonable to use in this analysis.
    On the first issue, field measurements cited by the commenters were 
not performed in the Four Corners area, nor at the Class I areas near 
FCPP, so they do not give appropriate ammonia background concentrations 
for modeling of FCPP. In addition, the studies provide only gaseous 
ammonia (NH3) and not ammonium (NH4) that has 
reacted with SO2 or NOX emissions. For purposes 
of assessing FCPP impacts relative to natural background, per the BART 
Guidelines, both ammonia and ammonium should be assumed to be available 
to interact with emissions from FCPP. The ammonia-only measurements 
cited by the commenters underestimate the available ammonia. Finally, 
as discussed in the TSD, field measurements in the Four Corners area 
showed ammonia measurements ranging from 1.0 ppb to 1.5 ppb, and 
sometimes as high as 3.5 ppb.\20\ This provides some additional support 
for the 1 ppb used by EPA.
---------------------------------------------------------------------------

    \20\ Mark E. Sather et al., 2008. ``Baseline ambient gaseous 
ammonia concentrations in the Four Corners area and eastern 
Oklahoma, USA''. Journal of Environmental Monitoring, 2008, 10, 
1319-1325, DOI: 10.1039/b807984f.
---------------------------------------------------------------------------

    On the second issue, in using a 1 ppb background EPA did not rely 
on an assumption about the importance of background ammonia along the 
path of the plume, as claimed by the commenters. The 1 ppb background 
is a representative value for areas in the west under existing EPA 
guidance, in the IWAQM document. The commenters' objection is based on 
the rapidity of the nitrate-nitric acid equilibrium, which they state 
implies that ammonium nitrate can only be estimated using ammonia 
measurements right at the Class I area, and not the ammonia that occurs 
earlier along the plume's path to the area. EPA's TSD for the proposed 
rulemaking did state (TSD p.62) that the Federal Land Managers partly 
relied on this assumption as one of the rationales for the back-
calculation method, discussed below; EPA also expressed support for the 
idea that the method can be viewed as a 24-hour temporal integration, 
not just a spatial integration over the plume path, and that this 
aspect can be viewed as desirable for the 24-hour average visibility 
estimate that CALPUFF provides (TSD pp.71-72). This plausibility 
argument applies despite the rapid nitrate-nitric acid equilibrium 
cited by the commenters, and in any case was not relied on by EPA in 
using the 1 ppb default ammonia background.
    As the commenters stated under the third issue, EPA used a back-
calculation ammonia estimation method as an alternative means of 
corroboration for the 1 ppb IWAQM method, which is more fully explained 
in the TSD for the proposed rulemaking. Essentially, it uses measured 
particulate ammonium sulfate and nitrate to estimate the amount of 
ammonia that must have been present to form those ammonia compounds. 
The commenters object that the method assumes that all the calculated 
ammonia is available to interact with the FCPP plume as background 
ammonia. However, this assumption is reasonable for the single-source 
CALPUFF modeling performed under the BART Guidelines. It estimates 
ammonia concentrations that would be monitored at the Class I area if 
only this single source existed; it includes ammonia that is currently 
in the form of ammonium because of interaction with other sources' 
emissions. It remains true that some portion of the calculated ammonia 
would in reality not be available for FCPP, because it arrives at the 
monitor from a different direction than FCPP's pollutant plume; on the 
other hand, the data would also include directions contributing below-
average ammonia, reducing that effect.
    In addition, the back-calculated ammonia is based on measurements 
only of particulate ammonium, the form associated with measured sulfate 
and nitrate; it does not include any gaseous ammonia that may also be 
present. In this sense, the back-calculated ammonia is a lower bound on 
the ammonia that may be available to interact with source emissions; 
that is, the method may underestimate ammonia concentrations. This 
possible underestimation tends to offset possible overestimation 
discussed above.
    EPA does not claim that the back-calculation method is dispositive; 
it incorporates various assumptions and imperfections that make clear 
it is only an estimate. However, it is based on real measured data at 
Class I areas, and has some counterbalancing tendencies for over- and 
under-estimation. After weighing various lines of argument about the 
back-calculation method, EPA disagrees with the commenters who 
recommended that it be rejected altogether. The method provides a 
useful estimate of ammonia for BART modeling, by providing 
concentrations representative of the high values that would be observed 
at the Class I areas in the absence of other sources. The back-
calculation method, therefore, is used to corroborate that it is 
appropriate to use the 1 ppb IWAQM default for background ammonia 
concentrations.
    In the fourth issue raised by commenters, the commenters claim that 
the assumption of full availability to FCPP of the back-calculated 
ammonia invalidates EPA's comparison of monitored nitrate levels with 
those modeled using the back-calculated ammonia (TSD p.73). As just 
discussed for the third issue, EPA disagrees that the assumption is 
invalid for corroboration of single-source BART assessment modeling. 
For single-source BART modeling, on balance, it is reasonable to assume 
all the ammonia is available to the source, given the counterbalancing 
tendencies for over- and underestimation inherent in the back-
calculation method discussed above. In any case, this method mainly 
provided corroboration for the results from using the 1 ppb ammonia 
default.
    The fifth issue about ``physically impossible'' nitrate over-
predictions does not account for the fact that any model evaluation is 
expected to have under- and over-predictions, depending on the 
meteorological conditions and the geographic location modeled, as well 
as on the location of the monitor used for comparison. The commenter's 
apparent requirement for no over-predictions whatsoever would require a 
model with the converse problem, a bias toward underprediction. While 
consistent over-prediction in a full model performance evaluation would 
indeed raise concerns over its validity, as EPA stated, our nitrate 
comparison was not intended as a model performance evaluation, but 
rather as a ``rough check'' for the back-calculation corroboratory 
method (TSD p.73). EPA found that the modeled and monitored values, for 
both the maximum values and the 98th percentiles, were generally in 
agreement.
    Finally, contrary to the commenter's assertion, EPA did not receive 
a modeling protocol in advance of modeling by APS's contractor. EPA 
disagrees with commenters that EPA committed to use the same ammonia 
concentrations used by APS's contractor in our own modeling analysis 
for our BART determination.
    Comment: Three of the owners of FCPP and a utility industry 
association asserted that CALPUFF version 5.8 used in EPA's BART 
analysis is outdated. Because of enhancements to the model's chemistry, 
the commenters asserted that CALPUFF version 6.4 represents the best 
application that is currently available. A number of the commenters

[[Page 51631]]

mentioned a December 2010 meeting between the CALPUFF developer and the 
FLMs where the FLMs reportedly supported an expedited review and 
approval of CALPUFF version 6.4.
    Another owner of FCPP stated that the version of CALPUFF used by 
EPA has a tendency to over-predict nitrate concentrations, which is 
compounded by EPA's use of what the commenter stated are overestimated 
ammonia background values. The commenter asserted that this combination 
of errors results in a significant over-prediction of visibility 
improvements for more stringent NOX BART control options. 
Further, the commenter stated that this disproportionately affects the 
incremental visibility benefits predicted for SCR over Low 
NOX Burners (LNB) compared to LNB over baseline.
    In contrast, one federal agency was generally supportive of the 
modeling methods employed by EPA with the regulatory approved version 
5.8 of the CALPUFF modeling system.
    Response: EPA disagrees with the commenters that any new CALPUFF 
version should be used for the BART determination. EPA relied on 
version 5.8 of CALPUFF because it is the EPA-approved version in 
accordance with the Guideline on Air Quality Models (``GAQM'', 40 CFR 
51, Appendix W, section 6.2.1.e); EPA updated the specific version to 
be used for regulatory purposes on June 29, 2007, including minor 
revisions as of that date; the approved CALPUFF modeling system 
includes CALPUFF version 5.8, level 070623, and CALMET version 5.8 
level 070623. CALPUFF version 5.8 has been thoroughly tested and 
evaluated, and has been shown to perform consistent with the version 
from the time of the initial 2003 promulgation, in the analytical 
situations CALPUFF has been approved for. Any other version would be 
considered an ``alternative model'', subject to the provisions of GAQM 
section 3.2.2(b), requiring full model documentation, peer-review, and 
performance evaluation. No such information for the later CALPUFF 
versions that meet the requirements of section 3.2.2(b) has been 
submitted to or approved by EPA. Experience has shown that when the 
full evaluation procedure is not followed, errors that are not 
immediately apparent can be introduced along with new model features. 
For example, changes introduced to CALMET to improve simulation of 
over-water convective mixing heights caused their periodic collapse to 
zero, even over land, so that CALPUFF concentration estimates were no 
longer reliable.
    In addition, the latest version of CALPUFF, 6.4, incorporates a 
detailed treatment of chemistry. EPA's promulgation of CALPUFF (68 FR 
18440, April 15, 2003) as a ``preferred'' model approved it for use in 
analyses of Prevention of Significant Deterioration increment 
consumption and for complex wind situations, neither of which involve 
chemical transformations. For visibility impact analyses, which do 
involve chemical transformations, CALPUFF is considered a ``screening'' 
model, rather than a ``preferred'' model; this ``screening'' status is 
also described in the preamble to the BART Guidelines (at 70 FR 39123, 
July 6, 2005). The change to CALPUFF 6.4 is not a simple model update 
to address bug fixes, but a significant change in the model science 
that requires its own rulemaking with public notice and comment.
    Furthermore, it should be noted that the U.S. Forest Service and 
EPA review of CALPUFF version 6.4 results for a limited set of BART 
applications showed that differences in its results from those of 
version 5.8 are driven by two input assumptions and not associated with 
the chemistry changes in 6.4. Use of the so-called ``full'' ammonia 
limiting method and finer horizontal grid resolution are the primary 
drivers in the predicted differences in modeled visibility impacts 
between the model versions. These input assumptions have been 
previously reviewed by EPA and the FLMs and have been rejected based on 
lack of documentation, inadequate peer review, and lack of technical 
justification and validation.
    EPA intends to conduct a comprehensive evaluation of the latest 
CALPUFF version along with other ``chemistry'' air quality models in 
consultation with the Federal Land Managers, including a full 
statistical performance evaluation, verification of its scientific 
basis, determination of whether the underlying science has been 
incorporated into the modeling system correctly, and evaluation of the 
effect on the regulatory framework for its use, including in New Source 
Review permitting. CALPUFF version 5.8 has already gone through this 
comprehensive evaluation process and remains the EPA-approved version, 
and is thus the appropriate version for EPA's BART determination for 
FCPP.
    Comment: Some commenters argued against the visibility metrics that 
EPA introduced in the BART proposal. One commenter noted that none of 
the metrics (percent improvement in dv impacts, cumulative changes in 
dv, and dv impacts scaled by the geographic area of the affected Class 
I area) is addressed in the BART rules, and posited that their 
introduction into the BART process is intended to inflate the estimated 
visibility benefits of the control options at FCPP. Regarding the 
percent improvement metric, the commenter stated that these values 
(unlike values of the haze index in dv) have no consistent relationship 
to the human perception of haze changes and no consistent relationship 
to changes in ambient visibility-impairing particle concentrations.
    Similarly, one of the owners of FCPP stated that cumulative change 
in dv is not an appropriate metric to describe visibility improvement 
and should be withdrawn. This commenter made a number of points which 
are briefly described here. The peak impact from a source occurs at 
different times in different Class I areas because a facility's 
emissions cannot result in peak concentrations in all directions at 
once. Thus, this metric really does not represent a cumulative regional 
impact of the source (and hence the benefit of controls); rather it 
simply produces a mathematical summation of the peak impacts occurring 
at different times at various Class I areas. It is inappropriate to add 
improvements over all Class I areas. A 0.5 dv improvement in one Class 
I area and a 0.5 dv improvement in another area does not result in a 1 
dv improvement--the improvement is a 0.5 dv improvement, which occurs 
in two different locations. Any one observer would experience only a 
0.5 dv improvement; he or she can only experience the visibility 
improvement in the Class I area being visited.
    Conversely, one environmental advocacy group commenter supported 
the use of a cumulative impact analysis. The commenter asserted that 
the cumulative impact of a source's emissions on visibility, as well as 
the cumulative benefit of emission reductions, is a necessary 
consideration as part of the fifth step in the BART analysis, 
particularly in cases such as FCPP where the source causes or 
contributes to visibility impairment at a significant number of Class I 
areas. The commenter stated that failing to account for a source's 
cumulative impairment and the cumulative pollution control benefit 
would result in a failure to acknowledge the regional approach to 
reducing haze.
    Response: EPA believes that it is important to consider the 
visibility impact on multiple Class I areas. The goal of the visibility 
program is to remedy visibility impairment at all Class I areas. CAA 
169A(a)(1). One approach to account for the benefits to

[[Page 51632]]

all affected Class I areas is the cumulative ``total dv'' metric. EPA 
relied on the modeled impacts and benefits at each Class I area 
individually, the number of Class I areas affected, and also 
considered, but did not rely on, the sum of visibility impacts and 
benefits across all 16 Class I areas.
    Comment: Two commenters questioned EPA's use of 0.5 dv as the 
threshold of a humanly perceptible change in visibility (citing 75 FR 
64228). One commenter added that the establishment of a specific 
deciview threshold as a ``bright line'' to define whether a certain 
control will be imposed as BART is contrary to the intent of the BART 
rules and the objectives of the Regional Haze program, which require 
EPA to consider the cost of each control option in relation to the 
associated visibility benefit.
    One of the owners of FCPP expressed the belief that application of 
SCR at FCPP would result in no perceptible visibility improvement and 
therefore cannot be BART.
    Response: EPA disagrees with the commenters that the visibility 
benefit from the proposed BART controls is too small to warrant 
requiring the controls; in addition, EPA is not using a perceptibility 
threshold in this BART determination. EPA agrees that thresholds should 
not be considered a ``bright line'' in making BART decisions. In the 
BART Guidelines, EPA described 1 dv as the threshold for an impact that 
``causes'' visibility impairment, and 0.5 dv as a threshold for an 
impact that ``contributes'' to visibility impairment, for determining 
whether a source is subject to BART, though States were accorded 
discretion to use different thresholds (70 FR 39118, July 6, 2005; also 
39120-39121). These thresholds do not apply to BART determinations for 
sources that have been found subject to BART; States or EPA could 
consider visibility impacts less than 0.5 dv to warrant BART controls. 
To the extent that the comment is questioning the BART eligibility of 
FCPP, EPA has already established that FCPP is BART eligible and the 
commenter did not provide evidence to the contrary.
    Even if the commenters are correct that 0.5 dv change is not 
perceptible, EPA noted that ``[e]ven though the visibility improvement 
from an individual source may not be perceptible, it should still be 
considered in setting BART because the contribution to haze may be 
significant relative to other source contributions in the Class I area. 
Thus, we disagree that the degree of improvement should be contingent 
upon perceptibility. Failing to consider less-than-perceptible 
contributions to visibility impairment would ignore the CAA's intent to 
have BART requirements apply to sources that contribute to, as well as 
cause, such impairment.'' (70 FR 39129) That is, impacts smaller than 
0.5 dv do contribute to impairment. Conversely, an improvement of 0.5 
dv or even less contributes to improvement in visibility impairment. As 
stated in the proposal, the modeled improvements in visibility are 
large enough to warrant requiring the proposed BART controls. While the 
actual improvements may be larger, from 0.6 to 2.8 dv, even as small an 
improvement as 0.5 dv is a contribution toward improving visibility, 
especially when the benefits at multiple Class I areas are considered. 
In conjunction with improvements from other sources, this will help and 
is necessary for progress toward the CAA goal of remedying manmade 
visibility impairment.
    Comment: One environmental advocacy group commenter stated that EPA 
underestimated visibility improvement from installing NOX 
controls because it overestimated the production of sulfuric acid by 
the SCR and underestimated the amount of sulfuric acid removed 
downstream of the SCR. The commenter cited reports attached to the 
comments to argue that sulfuric acid does not limit SCR NOX 
control efficiency. The reports also state that modeling shows that 
greater NOX removal rates are not offset by sulfuric acid 
emissions but instead yield greater visibility improvements than those 
proposed by EPA. The commenter states that this would result in a 
significant visibility benefit from increasing the SCR NOX 
efficiency from 80 percent to 90 percent and therefore concludes that a 
higher level of NOX control than 80 percent should be 
determined BART.
    Response: EPA disagrees that we overstated the production of 
sulfuric acid from the SCR catalyst and underestimated the amount of 
sulfuric acid removed downstream of the SCR. In the TSD for our 
proposed BART determination, we estimated sulfuric acid emissions using 
the Electric Power Research Institute (EPRI) methodology and provided 
detailed explanations for all of the assumptions we applied (see TSD p. 
55-59, 64-65, and 68). While we fully acknowledge and understand that 
the generalized EPRI methodology does not precisely represent true 
sulfuric acid emissions for a given facility, this method is a commonly 
used calculation methodology for estimating sulfuric acid emissions 
under a future operating scenario involving SCR.
    EPA assumed in our BART proposal that a 3+1 system (four layers of 
catalyst) would achieve 80 percent NOX removal. Greater 
reduction efficiencies would likely require an additional layer of 
catalyst, which models indicate would increase sulfuric acid emissions. 
Based on the SO2 to SO3 conversion rate guarantee 
we received from Hitachi for its CX series catalyst (ultra-low 
conversion) of 0.167 percent per layer, the use of an additional 
catalyst layer would equal five layers of catalyst and a 0.835 percent 
conversion rate. EPA is not aware of SCR systems that use five layers 
of catalyst, and the addition of a fifth layer would also affect the 
cost and operation of the unit.
    Although EPA agrees that the modeling referenced by the commenter 
indicates greater visibility improvement from an SCR system achieving 
90 percent removal compared to 80 percent removal despite higher 
sulfuric acid emissions,\21\ EPA does not agree that this requires EPA 
to determine that a greater level of control is required as BART. The 
level of control recommended by the commenter is equivalent to those 
required as the Best Available Control Technology (BACT) for new 
facilities. As discussed in responses to other comments, the Regional 
Haze Rule requires a case-by-case BART determination, which need not be 
equivalent to BACT for new facilities. As discussed in our proposed 
BART determination and in our Supplemental proposal, given the boiler 
size and configuration at FCPP that limit use of combustion controls, 
and other considerations related to ash content of coal, EPA is 
finalizing its determination that 80 percent control is appropriate as 
BART for FCPP.
---------------------------------------------------------------------------

    \21\ EPA notes that the baghouses on Units 4 and 5 are assumed 
to provide a significant amount of control of sulfuric acid 
emissions, therefore, such slight increases in sulfuric acid 
emissions would not be expected on units that are not equipped with 
baghouses.
---------------------------------------------------------------------------

F. Comments on BART Determinations

1. Comments on the Proposed BART Determination for NOX
    Comment: A number of commenters, including owners of FCPP, the 
Navajo Nation, and a utility industry association, assert that EPA's 
BART analysis was inconsistent with its own regulations in that it did 
not give proper weight to the ``presumptive BART'' limits for 
NOX that it established for EGUs through notice-and-comment 
rulemaking (generally citing 70 FR 39104, July 6, 2005). The commenters 
noted that these presumptive BART limits are based on the use of

[[Page 51633]]

combustion controls, and that EPA had considered and rejected 
establishing presumptive BART limits based on SCR. A brief summary of 
these comments follows.
    In establishing presumptive BART limits for NOX 
emissions from EGUs, EPA concluded that combustion control-based 
presumptive limits ``are extremely likely to be appropriate for all 
greater than 750 MW power plants subject to BART'' (a category that 
includes FCPP), that they are ``highly cost-effective controls,'' and 
that they ``would result in significant improvements in visibility and 
help to ensure reasonable progress toward the national visibility goal 
(citing 70 FR 39131). Additionally, EPA has made clear that ``the 
presumptions represent a reasonable estimate of a stringent case BART * 
* *'' (citing 71 FR 60612, 60619, Oct. 13, 2006).
    Commenters argue that EPA was not correct in stating in the 
proposed BART determination for FCPP that in setting presumptive BART 
limits, it ``did not consider the question of what more stringent 
control technologies might be appropriately determined to be BART'' 
(citing 75 FR 64226). Rather, EPA's 2005 rules were clear that the 
Agency had considered--and rejected--establishing presumptive BART 
limits based on SCR (citing 70 FR 39136). Thus, EPA established through 
rulemaking that SCR is not an appropriate basis for presumptive BART 
limits and that combustion controls should generally be deemed BART.
    Commenters also argue that a BART analysis must begin with and take 
into account the presumptive BART limits and EPA's rationale for 
setting them. If a source is able to meet the limit through the 
application of combustion controls, there should be an exceedingly 
strong presumption that such controls constitute BART.
    Commenters state that EPA's analytical approach disregarded the 
presumptive limits entirely. By using a top-down approach in which it 
started its analysis by evaluating SCR and then determined that SCR is 
BART for FCPP, EPA never undertook an assessment of combustion 
controls.
    Commenters further argue that in its BART analysis, APS 
demonstrated that each unit at FCPP can meet the presumptive BART 
limits through the application of advanced combustion control 
technologies.
    Under the BART rules, a deviation from presumptive BART, either 
upwards or downwards, is authorized if an alternative control level is 
justified based on ``careful consideration of the statutory factors'' 
(citing 70 FR 39131). Commenters argue that EPA did not carefully 
consider the BART factors and then conclude that an alternative to 
presumptive BART limits is appropriate. Instead, commenters state that 
EPA dismissed the presumptive BART limits before even considering the 
BART factors.
    Response: EPA disagrees with the commenters' assertions that we did 
not give sufficient weight to presumptive BART NOX limits, 
or that the BART determination for FCPP was performed in a manner 
inconsistent with the RHR.
    As noted in other responses in this document, the presumptive 
NOX limits established in the BART Guidelines are determined 
to be cost effective and appropriate for most units. The establishment 
of presumptive BART limits, and the corresponding technology upon which 
those limits are based, does not preclude States or EPA from setting 
limits that differ from those presumptions. Indeed, the five statutory 
factors enumerated in the BART Guidelines provide the mechanism for 
establishing different requirements. We note the RHR states:

    States, as a general matter, must require owners and operators 
of greater than 750 MW power plants to meet these BART emission 
limits. We are establishing these requirements based on the 
consideration of certain factors discussed below. Although we 
believe that these requirements are extremely likely to be 
appropriate for all greater than 750 MW power plants subject to 
BART, a State may establish different requirements if the State can 
demonstrate that an alternative determination is justified based on 
a consideration of the five statutory factors.\22\
---------------------------------------------------------------------------

    \22\ 70 FR 39131.

---------------------------------------------------------------------------
The RHR also states:

    If, upon examination of an individual EGU, a State determines 
that a different emission limit is appropriate based upon its 
analysis of the five factors, then the State may apply a more or 
less stringent limit.\23\
---------------------------------------------------------------------------

    \23\ 70 FR 39132.

    Therefore, the presumptive emission limits in the BART Guidelines 
are rebuttable.\24\ The presumptive emission limits apply to power 
plants with a total generating capacity of 750 MW or greater insofar as 
these sources are required to adopt emission limits at least as 
stringent as the presumptive limits, unless after considering the five 
statutory factors, the State determines that the presumptive emission 
limits are not appropriate. Moreover, the RHR and BART Guidelines do 
not exempt States from a five factor BART analysis, and that BART 
analysis may result in a determination of BART emission limits that are 
more or less stringent than the presumptive emission limits for subject 
to BART sources. The RHR states:
---------------------------------------------------------------------------

    \24\ 71 FR 60619.

    For each source subject to BART, 40 CFR 51.308(e)(1)(ii)(A) 
requires that States identify the level of control representing BART 
after considering the factors set out in CAA section 169A(g), as 
follows:
    States must identify the best system of continuous emission 
control technology for each source subject to BART taking into 
account the technology available, the costs of compliance, the 
energy and non-air quality environmental impacts of compliance, any 
pollution control equipment in use at the source, the remaining 
useful life of the source, and the degree of visibility improvement 
that may be expected from available control technology.\25\
---------------------------------------------------------------------------

    \25\ 70 FR 39158.

    EPA's site-specific five-factor analysis performed for FCPP 
demonstrates that, in considering the expected remaining useful life of 
FCPP and the existing controls, SCR is cost effective, results in the 
most visibility improvement of all feasible control technologies, and 
does not cause energy or non-air quality environmental impacts that 
warrant its elimination as the top control option. As a result, 
regardless of the appropriateness of SCR as a control technology for 
most units on a national scale, or the extent to which EPA considered 
SCR in establishing the presumptive limits, the site-specific five-
factor analysis performed for FCPP justifies a different NOX 
BART limit than the presumptive NOX BART limit.
    EPA disagrees with commenters' assertions that we disregarded 
presumptive NOX BART limits. Although we do not rely upon 
the numerical values of the presumptive NOX limits listed in 
the BART Guidelines, the technological basis for presumptive 
NOX BART limits, such as the use of combustion control 
technology, boiler type, and coal type, were considered in the site-
specific five-factor analysis. Combustion control technology was 
specifically considered as a potential retrofit technology, and costs 
and visibility improvements associated with combustion controls were 
calculated and included in the TSD in order to provide a comparison to 
other NOX control technologies.
    In addition, EPA disagrees that the rule directs authorities to 
consider non-combustion control technology only when presumptive limits 
cannot be met using combustion control technology. While a BART 
determination deviating from presumptive BART must be supported by the 
results of the five-factor analysis, the rule does not restrict the 
ability of States (or in this case, EPA) to initiate a five-factor 
analysis.

[[Page 51634]]

    Comment: Two of the owners of FCPP and the Navajo Nation asserted 
that advanced combustion controls constitute BART for FCPP because such 
controls will result in meaningful emission reductions and will 
contribute to reasonable progress toward visibility improvement.
    One of these commenters noted that EPA has ``determined that 
combustion controls are not likely to be effective control technologies 
at FCPP'' (citing 75 FR 64226). The commenter asserted that EPA's 
determination is based on superficial analysis and is mistaken. This 
commenter cited its comments which contain a detailed analysis of the 
use of LNB and OFA on FCPP's units. According to the commenter, this 
analysis confirms that the use of advanced combustion controls on the 
five units at FCPP will reduce plant-wide NOX emissions by 
34 percent and, for those units that are subject to presumptive BART 
limits, the reductions more than satisfy the presumptive limits in the 
BART rules.
    Two of the commenters added that considering that neither SCR nor 
advanced combustion controls will produce humanly perceptible 
visibility improvements in the nearby Class I areas, control 
technologies that result in limits that meet presumptive BART should be 
determined BART and that these reductions will contribute to reasonable 
progress toward the national visibility goal.
    The Navajo Nation stated that a phased approach to emissions 
controls at FCPP, beginning with combustion controls, is fully 
consistent with both the CAA and the RHR, and is the approach that the 
EPA should take as a prudent trustee of the Navajo Nation.
    This commenter added that the BART component of the CAA and RHR was 
meant to provide for a measured response to emissions from aging power 
plants; thus, requiring the most expensive controls is inconsistent 
with the law and regulations governing the BART process. The commenter 
also asserted that requiring a power plant over which EPA has exclusive 
jurisdiction to bear a greater regulatory burden than similarly 
situated plants regulated by the States is contrary to the purposes of 
the Act, the RHR, and to the economic interests of the Navajo Nation.
    Response: EPA disagrees with the comment that advanced combustion 
controls on all five units at FCPP will reduce plant-wide 
NOX emissions by 34 percent. APS has provided conflicting 
information regarding whether or not advanced combustion controls will 
be effective at significantly reducing NOX emissions at 
FCPP. As outlined in the TSD for our 2010 BART proposal, we have 
concluded that combustion controls will not be effective at 
significantly reducing NOX emissions at FCPP.
    EPA disagrees that installation of SCR will not result in humanly 
perceptible impacts. As noted above, EPA's visibility modeling of the 
impacts of SCR installation at FCPP indicates visibility improvements 
at the sixteen nearby Class I areas ranging from 0.9 to 2.5 dv.
    EPA agrees with certain aspects of comments from the Navajo Nation 
regarding a phased implementation strategy to attaining national 
visibility goals. In 40 CFR 51.308(f), States are required to revise 
their regional haze implementation plans every ten years, which is a 
process that involves evaluating their ability to attain reasonable 
progress goals and potentially updating their long-term strategy for 
regional haze. The periodic revision requirement described in 40 CFR 
51.308(f), however, does not extend to the implementation plan for BART 
requirements. The phased approach described by the Navajo Nation has 
certain benefits, and a phased approach is incorporated into the 
alternative emission control strategy.
    Comment: Two federal agencies and two groups of environmental 
advocacy groups assert that the NOX emission limit for the 
units at FCPP should be 0.05 lb/MMBtu based on the capabilities of SCR. 
The federal agency commenters stated that, given that BART is meant to 
achieve the best possible emissions reductions, EPA should not base its 
emission limits on the ``minimum reduction expected from SCR, estimated 
by Hitachi Power Systems America'' (citing the TSD for our proposed 
rulemaking) because real-world application of SCR indicates that lower 
NOX emission limits are routinely reached. Regarding the 
emission limits for Units 4 and 5, the commenters noted that of the 20 
cell burners with SCR in 2010, 12 had lower NOX limits than 
proposed by EPA for FCPP, with 3 EGUs at less than 0.06 lb/MMBtu. Based 
on this information, the original APS BART analysis of SCR at 0.06 lb/
MMBtu (annual and 24-hour average), and the ``common knowledge'' that 
SCR can achieve at least 90 percent reduction, the commenters concluded 
that the installation of SCR at FCPP is capable of reducing annual 
NOX emissions by 90 percent to 0.05 lb/MMBtu on an annual 
average basis.
    One of the federal agency commenters specifically refuted EPA's 
rationale in the supplemental proposal for its 80 percent SCR 
efficiency estimate. The main points are summarized below.
    EPA took into account the degradation of the SCR catalyst over its 
lifetime and calculated the emission limit to reflect the capability of 
the catalyst just prior to its replacement on a 3-year cycle. 
Commenters assert this issue is not a technical limitation on SCR, but 
is simply a cost item to be accounted for in the proper design and 
operation of the SCR.
    EPA stated that pursuing NOX control efficiencies of 
greater than 80 percent on Units 4 and 5 is limited by formation of 
H2SO4 from the SCR catalyst because the 
additional layers of catalyst needed to increase NOX control 
efficiency would increase emissions of H2SO4, 
most affecting nearby Mesa Verde National Park. The commenter gave 
several reasons why this argument is incorrect.
    EPA stated that the high ash content (approximately 25 percent) of 
the coal burned at FCPP may adversely affect the capability of SCR to 
reach the highest end of the control efficiency range without the use 
of additional layers of catalyst or more frequent catalyst replacement. 
According to the commenter, this is not consistent with previous EPA 
proposals for SCR emissions limits at facilities that use coal with 
similar ash content. Unless the FCCP ash contains some unusual catalyst 
poison, the 25 percent ash content is not a technical feasibility issue 
that would affect SCR effectiveness, but is a matter of proper SCR 
design, operation, and maintenance.
    This federal agency commenter also asserted that NOX 
BART for Units 1-3 should be 0.05 lb/MMBtu on an annual basis. The 
commenter noted that unsuccessful attempts to reduce NOX 
emissions at FCPP with combustion controls occurred over a decade ago 
when this technology was not as fully developed as now, and pointed out 
that APS'S BART analysis concluded that such controls are technically 
feasible and would reduce NOX emissions significantly.
    The commenter evaluated Clean Air Markets Division (CAMD) data for 
2000--2009 and found 33 dry-bottom, wall-fired boilers with 
NOX emissions rates similar to FCPP Units 1-3 (0.6--0.8 lb/
MMBtu) that had been reduced to 0.4 lb/MMBtu or less by application of 
modern combustion controls. The commenter asserted that because the 
typical approach is to first reduce NOX emissions by 
combustion controls before adding SCR, these real-world CAMD data 
support the belief that using combustion controls and SCR could

[[Page 51635]]

reduce NOX at FCPP Units 1-3 to 0.05 lb/MMBtu on an annual 
basis.
    The commenter asserted that modern SCRs are routinely designed and 
operated to achieve 90 percent NOX control and that based on 
this well-accepted industry standard, NOX control of at 
least 90 percent is BART.
    The commenter also contended that LNB and OFA are feasible for all 
five units at FCPP. The commenter rejected EPA's statement that it 
would be difficult to retrofit Units 4 and 5 with modern LNB technology 
(citing 76 FR 10534) and pointed out that the operator of FCPP has 
stated that the combination of LNB and OFA is technically feasible for 
these units. The commenter indicated that the use of LNB/OFA on Units 
1-5 would reduce NOX emissions by 27 to 46 percent, making 
SCR with a removal efficiency of 90 percent sufficient to satisfy a 
0.05 lb/MMBtu NOX limit.
    The commenter stated that a 0.05 lb/MMBtu limit is consistent with 
EPA's determinations elsewhere, such as for the San Juan Generating 
Station (proposed limit of 0.05 lbs/MMBtu, 30-day rolling average) and 
for Desert Rock (final permit limit of 0.035 lbs/MMBtu, 365-day rolling 
average). According to the commenter, an EPA-issued permit containing a 
lower NOX limit creates a presumption of technical 
feasibility for purposes of BART. Commenters also argued that emission 
limits should be based on a 30-boiler operating day rolling average.
    Response: EPA disagrees with the commenter's assertion that 
emission limits associated with BART must meet the lowest emission rate 
achieved with that technology at any coal-fired power plant. The 
Regional Haze Regulations at 40 CFR Sec.  51.308(e)(1)(ii)(A) state 
that:

    The determination of BART must be based on an analysis of the 
best system of continuous emission control technology available and 
associated emission reductions achievable for each BART-eligible 
source that is subject to BART * * *

Additionally, the BART Guidelines state that: ``[i]n assessing the 
capability of the control alternative, latitude exists to consider 
special circumstances pertinent to the specific source under review, or 
regarding the prior application of the control alternative'', (70 FR 
39166) and that ``[t]o complete the BART process, you must establish 
enforceable emission limits that reflect the BART requirements * * *'' 
(70 FR 39172). The five-factor BART analysis described in the 
Guidelines is a case-by-case analysis that considers site specific 
factors in assessing the best technology for continuous emission 
controls. After a technology is determined as BART, the BART Guidelines 
require establishment of an emission limit that reflects the BART 
requirements, but does not specify that the emission limit must 
represent the maximum level of control achieved by the technology 
selected as BART. The BART Guidelines and the Regional Haze Rule do not 
preclude selection of the maximum level of control achieved by a given 
technology as BART, however, the emission limit set to reflect BART 
must be achievable by the specific source and should be determined 
based on consideration of site-specific factors. Therefore, limits set 
as Best Available Control Technology (BACT) during Prevention of 
Significant Determination (PSD) review (e.g., Desert Rock) may provide 
relevant information, but should not be construed to automatically 
represent the most appropriate BART limits representative of a given 
technology for every facility.
    While some commenters asserted that combustion controls would be 
feasible upstream of SCR to further reduce NOX emissions to 
meet a limit of 0.05 lb/MMBtu, in its comment letter, the National Park 
Service (NPS) agreed with EPA that the addition of combustion controls 
may ``not (be) worth the small incremental reduction in NOX 
emissions''. As discussed in the TSD for our proposed BART 
determination, because additional combustion controls at FCPP would not 
achieve significant reductions in NOX and may cause 
operability issues for the boilers, EPA determined that SCR, without 
the addition of new combustion controls, is BART for FCPP.
    Several environmental organizations argued that a 30-day rolling 
average emission limit of 0.05 lb/MMBtu should be determined BART for 
FCPP and provided supporting documentation.\26\ EPA disagrees that an 
emission limit set in association with a BART determination must 
represent the lowest achieved emission rate from the best performing 
unit using that technology. EPA notes that, after further examination 
\27\ of the commenters' supporting documentation, the maximum 30-day 
calendar average emission rates for the 17 top performing units 
exhibited significant variability (0.056--1.1 lb/MMBtu), even though 
the annual average emission rates listed are all below 0.07 lb/MMBtu.
---------------------------------------------------------------------------

    \26\ See items (2 and 3) in collection of documents titled 
``Public Comment--8 Environmental Groups (Barth)--Letter 5-2-11''. 
Document Number EPA-R09-OAR-2010-0182.
    \27\ See the Response to Comments, Section 8.1 in the docket for 
this final rulemaking.
---------------------------------------------------------------------------

    In its comments, the National Park Service provided examples of 3 
cell burner boilers currently equipped with SCR: Cardinal Units 1 and 2 
and Belews Creek Unit 1. Based on NOX data from the Clean 
Air Markets Division (CAMD), EPA notes that over 2009-2011, 
NOX emissions from Cardinal Unit 1 showed an increasing 
trend. Cardinal Unit 2 shows a similar pattern as Unit 1, with an 
increasing trend in minimum and maximum 30-day calendar averages. 
Belews Creek 1 also showed a similar pattern of generally increasing 
minimum and maximum 30-day calendar average emission rates. Although 
commenters are correct in stating that the best performing units can 
achieve 30-day rolling emission rates of 0.05 lb/MMBtu or lower, CAMD 
data show significant variability in emission rates, both over time for 
a given unit, and between the best performing units. Some of this 
variability may be related to catalyst aging, or may be related to the 
participation of these units in trading programs (therefore these units 
operate without an absolute limit on individual boilers). Regardless of 
the cause of this variability, EPA notes that significant variability 
over a 30-day average, even among the best performing units, does 
exist, and EPA disagrees that an emission limit set in association with 
a BART determination must represent the lowest rate achieved on 30-day 
rolling average basis from the best performing unit using that 
technology.
    EPA examined the most recent Clean Air Markets Division (CAMD) 
emission rate data for 12 cell burner boilers currently operating with 
SCR over 2009-June 2011.\28\ In order to determine what might be an 
appropriate percent reduction to represent all cell burner boilers 
currently using SCR, we calculated the average percent reduction from 
the highest emission rate achieved over all 12 units. The percent 
reduction achieved from the monthly calendar average emission rate over 
2009-June 2011 from the 12 units ranged from 48 to 90 percent, with an 
average value of 78 percent.
---------------------------------------------------------------------------

    \28\ See the Response to Comments Section 8.1 in the docket for 
this final rulemaking.
---------------------------------------------------------------------------

    Commenters claim that emissions of sulfuric acid mist and the high 
ash content of coal used by FCPP, and considerations of catalyst life 
are not barriers to achieving higher NOX reduction 
efficiencies than proposed by EPA. EPA disagrees with comments that our 
statement regarding the impact of additional layers of catalyst on 
increasing sulfuric acid emissions is unsupported. EPA understands from 
our

[[Page 51636]]

correspondence with Hitachi Power Systems America that each layer of 
catalyst used results in an incremental increase in the conversion rate 
of SO2 to SO3. The EPRI method used for 
calculating sulfuric acid requires the input of a SCR catalyst 
oxidation rate. This oxidation rate varies depending on catalyst type 
and number of layers used. For the ultra low SO2 to 
SO3 oxidation catalysts offered by Hitachi, each layer 
contributed roughly 0.167 percent conversion, with three layers 
totaling 0.5 percent. The use of an additional layer, such as in a 3+1 
system, would thus increase the conversion rate to nearly 0.7 percent 
when all four catalyst layers are in operation. Further NOX 
reductions achieved from the addition of a 5th layer of catalyst would 
likely exacerbate pluggage and back-pressure concerns related to the 
ash content of the coal and may affect cost and operation of the unit. 
Commenters have not submitted information to refute this.
    The ash content of coal has an important effect on the 
effectiveness of SCR because high ash content in coal can cause 
pluggage and catalyst erosion and thus reduce available catalyst area 
and activity for NOX reduction. Commenters point to San Juan 
Generating Station (SJGS) and Desert Rock as facilities with lower SCR-
based NOX emission limits that use high ash content coal. 
EPA Region 6 recently finalized a FIP for SJGS with a limit of 0.05 lb/
MMBtu, representing an 83 percent reduction in NOX 
emissions. The emission limit EPA Region 6 set for SJGS is lower than 
the limit we set for FCPP because SJGS uses a different boiler type 
than FCPP and modern combustion controls have already been installed 
and have reduced NOX emissions at SJGS by 29-33 percent.\29\ 
EPA has determined that because Units 4 and 5 at FCPP are cell burner 
boilers, modern combustion controls would not significantly reduce 
NOX emissions from FCPP. Even though the emission limit 
differs, the reduction efficiency from the installation and operation 
of SCR at FCPP and SJGS are generally consistent, particularly when 
considering the similarly high ash content of coal (greater than 20 
percent) used at both facilities. In 2008, EPA Region 9 issued a pre-
construction Prevention of Significant Deterioration (PSD) permit to 
allow construction of a new coal-fired power plant on the Navajo 
Nation, known as the Desert Rock Energy Facility (Desert Rock).\30\ If 
constructed, Desert Rock would have used the same coal as FCPP from the 
BHP Navajo Mine and the final PSD permit set a NOX limit of 
0.05 lb/MMBtu (on a rolling 365-day average). Commenters argue that if 
Desert Rock was required to meet a limit of 0.05 lb/MMBtu using the 
same coal as FCPP, the ash content should not hinder FCPP from 
achieving similarly low NOX emission rates. EPA notes that 
if constructed, Desert Rock would have been a new, state-of-the-art 
facility specifically designed with boiler characteristics, combustion 
controls, and post-combustion controls to meet the Best Available 
Control Technology (BACT) requirements for numerous criteria and non-
criteria pollutants. FCPP is an existing, over 40-year-old power plant. 
The Regional Haze Rule requires a case-by-case BART (best available 
retrofit technology) determination, which need not be equivalent to 
BACT for new facilities.
---------------------------------------------------------------------------

    \29\ See page 4-3 of report titled ``PNM BART Report for SJGS--
final to PNM--June 18, 2007.pdf'' in the docket for this final 
rulemaking. Pre-consent decree emission rates on Units 1-4 at SJGS 
ranged from 0.42-0.45 lb/MMBtu. Post-consent decree emission limits 
for those units were 0.30 lb/MMBtu.
    \30\ Desert Rock has not been constructed. EPA requested a 
voluntary remand of the Desert Rock PSD permit in 2009 to 
incorporate new applicable requirements. The developers of Desert 
Rock have not yet submitted a revised PSD application to EPA.
---------------------------------------------------------------------------

    Based on the significant 30-calendar day average variability 
exhibited by the top performing units cited by commenters, and the 
variability in 30-calendar day average and the 2009-June 2011 30-
calendar day average percent NOX reduction of 78 percent 
exhibited by 12 cell burner boilers equipped with SCR, EPA continues to 
affirm that a limit representing an 80 percent reduction in 
NOX emissions reflects what is achievable using the 
technology determined as BART for FCPP.
    Comment: One of the owners of FCPP stated a willingness to support 
a NOX emission limit of 0.098 lb/MMBtu for Units 4 and 5 
under the alternative proposal, but only in the context of an 
alternative emission reduction strategy that includes resolution of the 
related issues.
    The Navajo Nation similarly endorsed the proposed 80 percent 
reduction in NOX emissions from Units 4 and 5, with a limit 
of 0.098 lb/MMBtu, under the supplemental proposal, based on the site-
specific parameters at FCPP.
    Response: EPA agrees that the appropriate limit for Units 4 and 5 
under the alternative strategy is 0.098 lb/MMMtu (based on a rolling 
average of 30 successive boiler operating days). The final rule 
reflects this limit.
    Comment: One of the owners of FCPP opposed EPA's proposal to 
``phase in'' NOX controls at FCPP under a traditional BART 
FIP, commencing 3 years from the date the FIP becomes effective. The 
commenter asserted that this proposal does not afford adequate time to 
properly design, engineer, and construct the controls before the 
compliance deadline.
    Response: EPA partially agrees with this comment. We revised the 
BART compliance date for one 750 MW unit to within 4 years from the 
effective date of this final rule. The remaining 750 MW unit and Units 
1-3 must meet a compliance date of within 5 years of the effective date 
of the final rule. The revised compliance time within 4 and 5 years 
allows time for design, engineer, and construct controls.
    Comment: One environmental advocacy group stated that the proposed 
plant-wide BART limit of 0.11 lb/MMBtu across all five FCPP units 
violates Executive Order 12898 on environmental justice. Specifically, 
the commenter asserted that given the significant differences in 
pollution control systems among FCPP's five units, allowing a plant-
wide average could create pollution ``hotspots'' with respect to co-
pollutants. As an example, the commenter noted that while Units 4 and 5 
have baghouses, Units 1-3 use less efficient venturi scrubbers for 
control of sulfur dioxide, particulate matter, and mercury. The 
commenter asserted that the plant-wide average limit for NOX 
would allow increased emissions from Units 1-3 in the event of a 
temporary outage or reduced output from one or both of the larger 
units. The commenter stated that while this may not increase the total 
NOX emissions from the plant, it would increase the amount 
of mercury and other toxic co-pollutants emitted into the surrounding 
community, which is a low-income community of color.
    Response: EPA disagrees with the commenter that a plant-wide BART 
limit of 0.11 lb/MMBtu across all five FCPP units violates Executive 
Order 12898 on environmental justice. This final rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income population because it increases the 
level of environmental protection for all affected populations in the 
area including any minority or low-income population.
    The commenter is correct that in the event of a temporary outage or 
reduced output from Unit 4 or 5 the operator could continue to operate 
FCPP units 1-3 under the original BART proposal provided that they 
maintain compliance with the plant-wide emission limit of 0.11 lb/MMBtu 
for NOX. In order to maintain compliance with the plant-wide 
emission limit, Units 1-3 would have to operate at a lesser capacity 
than

[[Page 51637]]

they would normally operate if Unit 4 and 5 were functioning because 
units 1-3 have higher NOX emission rates than Units 4 and 5. 
The NOX emission rates from Units 1-3 with SCR, based on 80 
percent control of current emission rates would be 0.16, 0.13, and 0.12 
lb/MMBtu respectively which are higher than the proposed plant-wide 
emission limit. Therefore, to maintain compliance with the plant-wide 
NOX emission limit (which is based upon a 30-calendar day 
rolling average), Units 1-3 would have to operate at a reduced capacity 
in any 30-day period in which Units 4 and 5 are operating a reduced 
capacity, so as to maintain the balance among the five units. This 
reduced capacity would result in an overall lower rate of emission for 
mercury and other co-pollutants from Units 1-3. Therefore, there would 
be no increased emissions of mercury or other co-pollutants and no 
``hot-spots'' or disproportionately high and adverse human health or 
environmental effects on minority or low-income population.
2. Comments on the Proposed BART Determination for PM
    Comment: One of the owners of FCPP asserted that the existing 
controls at FCPP constitute BART for PM emissions. The commenter 
contended that the impact of PM controls on the visibility in the 
neighboring Class I areas would be ``vanishingly small'' while the cost 
would be ``exorbitant'' (resulting in cost effectiveness ranging from 
$51,500-$148,659 per ton reduced and from $1.4 billion-$3.7 billion per 
dv improvement).
    The Navajo Nation stated that EPA acknowledged the high incremental 
cost of new PM controls on Units 1-3 (citing 75 FR 64230), yet 
justified the cost effectiveness of baghouses by comparison with 
similar retrofit projects in EPA Region 9. This commenter asserted that 
EPA failed to properly evaluate the costs associated with installation 
of baghouses using site-specific parameters, thereby deviating from the 
BART Guidelines. The commenter asserted that continued operation of 
venturi scrubbers to meet emission limits of 0.03 lb/MMBtu and an 
opacity limit of 20 percent satisfies BART for Units 1-3.
    The Navajo Nation expressed support for the supplemental proposal 
to require a PM emission limit of 0.015 lb/MMBtu and 10 percent opacity 
limit on Units 4 and 5. The commenter presumed that FCPP can readily 
meet these standards prior to installation of SCR since the limits can 
be achieved with the existing baghouses.
    Regarding the EPA's proposed 10 percent opacity standard for each 
unit, two of the owners of FCPP stated that the EPA has not specified 
any costs or predicted any improvement in visibility that would result 
from such limits. The commenters asserted that without such basis, the 
EPA cannot justify the proposed opacity limits.
    Response: As stated in our proposed BART determination for PM, the 
existing venturi scrubbers on Units 1-3 at FCPP do not constitute BART. 
In our proposed BART determination for FCPP, EPA proposed a PM emission 
limit for Units 1-3 that can be achieved through the installation of 
any of four different PM control options. At the time of our BART 
proposal, the MATS Rule for electric utility steam generating units had 
not yet been proposed, nor had APS suggested its alternative emission 
control strategy to close Units 1-3 in lieu of complying with BART for 
NOX. Because the final MATS rule has been issued \31\ and 
sets filterable PM and mercury limits that would be applicable to the 
units at FCPP, and because EPA is finalizing this rule to allow APS to 
either comply with the alternative emission control strategy or BART 
for NOX, EPA is determining that it is not necessary or 
appropriate at this time to finalize our proposal to set new PM limits 
for Units 1-3.
---------------------------------------------------------------------------

    \31\ See 77 FR 9304, February 16, 2012.
---------------------------------------------------------------------------

    Regarding our proposed BART determination for PM for Units 4 and 5, 
we are finalizing the proposed 0.015 lb/MMBtu emission limit based upon 
the proper operation of the existing baghouses. However, we have 
determined based on the comments we received from the operator of FCPP 
that it is not necessary or appropriate to take final action on the 
proposed 10 percent opacity limit. We have determined that imposing a 
10 percent opacity limit will not provide greater assurance that Units 
4 and 5 at FCPP are meeting the PM emission limit of 0.015. We have 
determined previously that a 20 percent opacity limit is sufficient to 
ensure the PM emission limit is being continuously met. The 10 percent 
opacity limit was generally supported by the Navajo Nation and 
environmental groups. EPA has promulgated some recent rules for 
electric generating units that have retained a 20 percent opacity 
standard rather than reducing that limit to 10 percent. Specifically, 
EPA's revised the New Source Performance Standard for large electric 
generating units at 40 CFR Part 60, Subpart Da, to lower the PM 
emission limit for new units to 0.09 lb/MMBtu for gross energy output 
or 0.097 lb/MMBtu for net energy output. For existing units that 
reconstruct or modify, Subpart Da establishes an emissions limit of 
0.015 lb/MMBtu. For both standards, EPA retained a 20 percent opacity 
standard as being sufficient to ensure compliance with either the 0.090 
(0.097) lb/MMBtu or 0.015 lb/MMBtu PM emission limit. EPA's MATS rule, 
which was finalized just a few months ago, also retained a 20 percent 
opacity standard as being sufficient to ensure compliance with the PM 
emission limit that will be required for electric generating units 
subject to that rule.
    The importance of the opacity limit is that a certain percentage 
opacity is an instantaneous demonstration that a unit is in compliance 
with its PM emission limit. If a unit does not install and operate a PM 
continuous emissions monitor, then EPA ensures compliance with the PM 
emission limit by requiring an episodic source test. For the periods 
between episodic source testing, EPA can reasonably assure continuous 
compliance with the PM emission limit by observing that the unit's 
stack emissions do not exceed a set opacity. EPA's recent rulemakings 
have determined that 20 percent opacity is sufficient to ensure 
compliance with a PM emission limit lower than the emission limit we 
have determined is BART for Units 4 and 5. Accordingly, EPA is 
determining the 20 percent opacity limit that we promulgated in our 
2007 FIP for FCPP as being adequate to ensure continuous compliance 
with the PM BART limit or 0.015 lb/MMBtu. EPA concludes that this 
change is a logical outgrowth of the comments received on the proposal.
    Comment: One commenter indicated that EPA has proposed a BART limit 
only for PM, which appears to be only filterable particulate matter. 
The commenter asserted that the BART guidelines specify that BART 
should be evaluated and defined for both PM10 and 
PM2.5 (citing 40 CFR part 51, Appendix Y, section IV.A) and, 
consequently, that EPA must evaluate and define BART limits for both 
PM10 and PM2.5. The commenter also asserted that 
as part of the PM2.5 BART determination, EPA must impose 
emission limits on condensable particulate matter, which is typically 
in the size range of 2.5 micrometers or smaller. Thus, the commenter 
stated that in addition to a filterable PM BART limit, EPA should 
impose a BART limit on total PM2.5.
    One public interest advocacy group supported EPA's proposal and 
supplemental proposal to require a PM limit and a 10 percent opacity 
limit on Units 4 and 5. The commenter indicated

[[Page 51638]]

that these limits should become effective prior to SCR installation, 
regardless of whether the BART or alternative emission control plan is 
implemented.
    Response: EPA disagrees with the commenters' recommendation that 
the condensable fraction must be included in the PM BART limits. EPA 
has previously outlined our rationale for why an 
H2SO4 limit is not appropriate at this time (it 
will be addressed through the pre-construction permitting process if 
needed) and EPA expects that H2SO4 will be the 
main component of condensable PM that would be expected from a coal-
fired EGU with an SCR.
    EPA agrees with commenters that PM limits on Units 4 and 5 should 
become effective prior to SCR installation, as Units 4 and 5 generally 
already meet the 0.015 lb/MMBtu limit.\32\ EPA is finalizing a 
compliance date for PM emission limits on Units 4 and 5 to be within 6 
months after restart following the next scheduled major outages in 2013 
and 2014. As discussed previously, EPA has determined that finalizing 
the proposed opacity limit of 10 percent on Units 4 and 5 is not 
necessary or appropriate at this time.
---------------------------------------------------------------------------

    \32\ See document titled: ``TSD ref. [2-3, 95] FCPP--BART--
Scenarios--Emissions--EPA--Proposal.xlsx'' in the docket for this 
proposed rulemaking at EPA-R09-OAR-2010-0683-0017.
---------------------------------------------------------------------------

3. Comments on BART for SO2
    Comment: Some commenters stated that SO2 BART should be 
required for FCPP, while one commenter simply noted that FCPP is 
subject to BART for SO2. One federal agency commenter stated 
that FCPP is subject to BART for SO2. The commenter stated 
that Units 4 and 5 should be able to meet a limit of 0.12 lb/MMBtu on 
an annual average basis by upgrading the existing scrubbers.
    One set of environmental advocacy groups discussed the Regional 
Haze rules, the TAR, and the SO2 emissions from FCPP and 
concluded that EPA is under a legal obligation to conduct a BART 
analysis for SO2 emissions from FCPP and, to the extent EPA 
has failed to make a finding that it is ``necessary or appropriate'' to 
regulate SO2 emissions from the FCPP, such a failure is 
arbitrary, capricious, and not supported by the administrative record.
    According to the commenter, EPA argues that FCPP's current 
SO2 emissions limits are ``close to or equivalent'' to the 
limit that would be established under BART. The commenter asserted that 
this conclusion is arbitrary and capricious because EPA has failed to 
undertake any scientific or technical analysis to support its 
conclusion.
    A public interest advocacy group stated that the SO2 
limits need to be tightened for FCPP to further reduce visibility 
impairment and to reduce the acidification of rainfall caused by the 
formation of H2SO4. The commenter stated that 
because the damaging effects of H2SO4 in 
precipitation on ancestral Puebloan sandstone dwellings and pictographs 
are not fully understood, it is disappointing for the FCPP proposals 
not to address SO2.
    Response: EPA finalized a FIP in May 2007 that required significant 
SO2 emissions reductions from FCPP and established 
continuous SO2 emissions limits for FCPP. See 72 FR 25698 
(May 7, 2007). The 2007 FIP required FCPP to increase the removal 
efficiency of its SO2 emissions controls from 72 percent to 
88 percent, resulting in an SO2 emissions reduction of 
approximately 22,000 tons per year. EPA had proposed this FIP in 
September 2006. The 2006 proposed FIP stated that ``EPA believes that 
the SO2 controls proposed today for FCPP are close to or the 
equivalent of a regional haze BART determination of SO2. 
This takes into consideration the early reductions this action will 
achieve and the modification to the existing SO2 
scrubbers.'' 72 FR 25700. In finalizing that rulemaking in the 2007 
FIP, EPA stated that it was exercising its authority pursuant to 
Section 49.11 of the TAR to implement measures that are necessary or 
appropriate to protect air quality in Indian country. Id. EPA 
determined that the SO2 emissions reductions would be 
federally enforceable as soon as the 2007 FIP was finalized, which 
would be potentially five years before EPA could achieve enforceable 
SO2 emissions reductions through making a BART 
determination. See id. EPA also considered the Navajo Nation's request 
for EPA to establish enforceable SO2 emissions reductions 
immediately that, in the opinion of the Navajo Nation, ``appear[] to be 
equivalent to BART.'' Id. Therefore, EPA's determination on this issue 
in finalizing the 2007 FIP was ``that it is neither necessary nor 
appropriate at this time to undertake a BART determination for 
SO2 from FCPP given the timing of the substantial 
SO2 reductions resulting from this FIP.'' Id. In addition, 
we stated that ``given that the SO2 controls for FCPP 
immediately achieve significant reductions in SO2 comparable 
to what could ultimately be achieved through a formal BART 
determination, EPA believes that it will not be necessary or 
appropriate to develop a regional haze plan to address SO2 
for the Navajo Nation in the near term.'' Id. 25700-701. Both APS, as 
operator of FCPP, and Sierra Club sought judicial review of our 2007 
FIP.
    The comments on this action essentially repackage the comments we 
received and provided a response for on the 2007 FIP. The comments have 
not presented any new facts or legal considerations that have arisen or 
changed since we responded to comments requesting a BART determination 
for SO2 in 2007.
4. Other Comments on BART
    Comment: One group of environmental advocacy groups stated that as 
an alternative to a condensable PM2.5 limit, EPA could set 
limits on the pollutants which form condensable PM2.5, such 
as sulfuric acid mist (H2SO4) and ammonia, as EPA 
proposed as part of the San Juan Generating Station (SJGS) BART 
rulemaking (citing 76 FR 503-4, January 5, 2011). If EPA adopts this 
approach, the commenter urged EPA to set an emission limit for 
H2SO4 no higher than the limit of 1.06 x 
10-4 lb/MMBtu for each unit as proposed for SJGS based on 
the use of low reactivity catalyst and the most current information 
from the Electric Power Research Institute. If CEMS are unavailable for 
this pollutant, the commenter urged EPA to require stack test 
monitoring for H2SO4 on a more frequent basis 
than annual monitoring.
    The commenter also requested that EPA set emission limits for 
ammonia at a rate no higher than the 2.0 parts per million as proposed 
at SJGS, to be monitored with CEMs.
    Response: EPA disagrees with the comment that Region 9 should set 
the same emission limits for ammonia and sulfuric acid as Region 6 in 
its proposed BART determination for SJGS.
    In its January 5, 2011 proposed rulemaking for SJGS, Region 6 
proposed an ammonia slip limit of 2.0 ppmvd on an hourly average and 
requested comment on a range from 2.0 ppmvd to 6.0 ppmvd. In its final 
BART rulemaking (76 FR 52388, August 22, 2011), Region 6 determined 
that an emission limit and monitoring were not warranted for ammonia 
and did not finalize its BART determination for SJSG with the proposed 
2.0 ppmvd ammonia limit.
    In its proposal for SJGS, Region 6 proposed an emission limit for 
sulfuric acid of 1.06 x 10-4 lb/MMBtu on an hourly average, 
and requested comment on a range from 1.06 x 10-4 to 7.87 x 
10-4 lb/MMBtu. In its final rulemaking, Region 6 finalized 
an emission limit for sulfuric acid of 2.6 x 10-4 lb/MMBtu 
to minimize its contribution to visibility impairment. Region 6 
calculated this emission limit using an estimation

[[Page 51639]]

methodology from EPRI, assuming the use of an ultra-low activity 
catalyst (0.5 percent total conversion of SO2 to 
SO3), zero ammonia slip, no sorbent injection, and EPRI-
recommended values for removal by existing downstream control 
equipment.
    Actual measurements of baseline sulfuric acid emissions have not 
yet been determined at FCPP and the calculation of projected sulfuric 
acid emissions after installation and operation of SCR using the EPRI 
methodology is dependent on future decisions made by the facility on 
the type of SCR catalyst and number of layers used, as well as numerous 
assumptions about loss to downstream components, such as air preheaters 
and baghouses, the true values of which are currently not yet defined 
or known for FCPP. Furthermore, EPA Region 9 is the permitting 
authority for preconstruction permits on the Navajo Nation, and an 
increase in sulfuric acid emissions from the installation of SCR may 
trigger major modification PSD permit requirements at a low threshold 
of 7 tpy (see 40 CFR 52.21) or Tribal minor new source review (NSR) 
permit requirements at a threshold of 2 tpy (see 40 CFR Part 49 Subpart 
C). Preconstruction permitting review may also be triggered from 
significant emissions increases of PM2.5 from SCR 
installation at FCPP. If one of these pollutant triggers PSD, the 
permitting authority must provide an Additional Impact Analysis under 
the PSD program. The PSD program also requires the permitting authority 
to determine BACT for pollutants that triggered PSD. A similar control 
technology review may also be required at the discretion of the 
permitting authority under the Tribal Minor NSR program. For these 
reasons, Region 9 has determined that for FCPP, emission limits and 
monitoring requirements for sulfuric acid are more appropriately 
reviewed in the preconstruction permitting process.
    Comment: Citing the BART Guidelines at 40 CFR part 51, Appendix Y, 
section V, one environmental advocacy group stated that BART emission 
limits and compliance schedules must be based on ``boiler operating 
day.''
    The commenter asserted that the ``very high'' proposed BART 
emission limits suggest that EPA set these limits to encompass spikes 
that occur during startups and shutdowns. The commenter asserted that 
setting and enforcing limits based on boiler operating day would 
necessarily exclude spikes that occur before and after outages, such as 
startups, shutdowns, and malfunctions. According to the commenter, such 
periods should be subject to separate limits set at the pre-SCR 
uncontrolled level to encourage good work practice standards during 
these periods while allowing the SCR and other emission control 
technologies to be operated at an efficient and continuous capacity in 
compliance with BART.
    Response: EPA agrees that the NOX limit under the 
alternative emission control strategy should be set for 30 successive 
boiler operating days and that a ``boiler operating day'' should be 
defined as any day in which the boiler fires fossil fuel. Because the 
NOX emission limit under the alternative emission control 
strategy already includes periods of startup and shutdown, separate 
limits are not required. The final rule reflects this approach.
    For the original proposed BART determination, EPA does not find it 
necessary to define boiler operating day because the BART limit is a 
heat input-weighted plant-wide limit. Only operating hours for any of 
the five units would be included. When a unit is not operating, those 
hours are not included in the plant-wide 30-day average. Additionally, 
the heat input-weighted plant-wide limit also includes periods of 
startup and shutdown; therefore, separate limits are not required.
    Comment: One environmental advocacy group stated that EPA should 
require FCPP to install all control equipment within 3 years of the 
date of a final FIP, as EPA did at SJGS. The commenter stated that 
there is ample data to support the contention that all this emission 
control technology can be installed and operational within 3 years or 
less.
    Response: EPA disagrees with the comment that Region 9 should set a 
3-year compliance timeframe because Region 6 proposed a 3-year 
compliance timeframe for SJGS. In its proposed rulemaking for SJGS,\33\ 
Region 6 proposed a 3-year timeframe for SJGS to comply with the 
proposed limits but requested comment on a compliance range of 3-5 
years. In its final rulemaking,\34\ Region 6 finalized a compliance 
timeframe of 5 years and determined that because of site congestion at 
SJGS, a longer timeframe than average (37-43 months) to install SCR on 
the 4 units at SJGS would be required. The final BART determination for 
FCPP requires retrofit of five existing units at FCPP. In the final 
rule for FCPP, Region 9 is requiring installation and operation of SCR 
controls for one 750 MW unit within 4 years of the effective date, and 
the remaining 750 MW unit and Units 1-3 within 5 years of the effective 
date. Based on all of the factors that will be involved in the design, 
purchase and operation of the SCR controls, Region 9 considers this 
schedule to be appropriate and expeditious.
---------------------------------------------------------------------------

    \33\ See 76 FR 491, January 5, 2011.
    \34\ See 76 FR 52388, August 22, 2011.
---------------------------------------------------------------------------

G. Comments on APS's Alternative and EPA's Supplemental Proposal

    Comment: One of the owners of FCPP pointed out that the November 
2010 APS proposal included two critical components: (1) A proposal to 
close Units 1-3 and install SCRs on Units 4 and 5; and (2) EPA's 
contemporaneous agreement that these activities resolve any liability 
FCPP may have under regional haze BART, Reasonably Attributable 
Visibility Impairment Best Available Retrofit Technology (RAVI BART), 
NSR, and New Source Performance Standard (NSPS). The commenter asserted 
that EPA's supplemental proposal addresses only half of APS'S 
proposal--the half that achieves better than BART emission reductions, 
plant-wide reductions of all other emissions, and greater visibility 
improvement at nearby Class I areas--but ignores the other half of the 
APS proposal--the half that provides APS and the FCPP co-owners with 
needed regulatory certainty. Unless there is a contemporaneous 
resolution of these key issues with EPA, the commenter cannot and does 
not support EPA's supplemental proposal.
    Response: EPA understands that the owners of FCPP were seeking to 
resolve any potential regulatory noncompliance issues simultaneously. 
However, EPA must use different mechanisms for promulgating rules and 
resolving enforcement issues. The comment requests resolution of 
potential past non-compliance with NSR and NSPS requirements. Potential 
past non-compliance can be resolved through entering into a Consent 
Decree containing a judicially approved release from liability. Such a 
Consent Decree under the CAA must be approved by the United States 
Department of Justice and must also be lodged in a United States 
District Court where the public is allowed to comment on it. Consent 
Decrees must be entered by the United States District Court for a 
release of liability of potential past non-compliance to be effective. 
Accordingly, this rulemaking action cannot effectuate any release of 
liability for potential past non-compliance with NSR or NSPS.
    EPA is aware that several environmental groups have petitioned the 
Department of Interior to make a

[[Page 51640]]

finding that impairment at Class I areas is reasonably attributable to 
FCPP.\35\ The NPS, on behalf of Department of Interior, has declined to 
make such a finding based on EPA's work in this rulemaking.\36\ The 
environmental groups also filed a Complaint in the United States 
District Court for the District of Columbia \37\ contending that the 
Department of Interior was unreasonably delaying making a finding of 
reasonable attribution from FCPP. On June 30, 2011, the Court dismissed 
the Complaint \38\ holding that the NPS's letters refusing to make the 
finding of reasonable attribution constituted denying the Petitioners' 
request for a RAVI finding. Therefore, there are no pending petitions 
with the Department of Interior requesting a finding that visibility 
impairment at any Class I areas is reasonably attributable to FCPP. In 
any event, a BART determination under RAVI would likely be the same as 
under this BART determination.
---------------------------------------------------------------------------

    \35\ See National Parks Conservation Association, et al., 
Petition to United States Department of Interior, United States 
Department of Agriculture, and United States Forest Service, 
February 16, 2010, in the docket for this rulemaking.
    \36\ See letter from Will Shafroth, Department of Interior to 
Stephanie Kodish, NPCA, March 8, 2011 in the docket for this 
proposed rulemaking.
    \37\ See National Parks Conservation Association, et al., 
Petition to United States District Court for the District of 
Columbia, January 20, 2011, in the docket for this final rulemaking.
    \38\ See National Parks Conservation Association, et al., 
Plaintiffs, v. United States Department of Interior and United 
States Department of Agriculture, Defendants. Civil Action No. 11-
130 (GK). United States District Court for the District of Columbia, 
June 30, 2011, 794 F. Supp. 2d 39; 2011 U.S. Dist. LEXIS 70170; 74 
ERC (BNA) 1015. In the docket for this final rulemaking.
---------------------------------------------------------------------------

    Comment: One of the owners of FCPP stated that it is imperative to 
note that its support of the supplemental proposal (if other potential 
liabilities are resolved as discussed above) is based solely on the 
rationale that this achieves a result better than the proposed BART 
FIP, and that this ``better than BART'' outcome is a result of the 
closure of Units 1, 2, and 3. The commenter stressed that in no case--
either in the original BART FIP proposal or in the supplemental 
proposal--does the commenter support any determination that SCR 
constitutes BART for FCPP. A second FCPP owner stated that its 
acceptance of the supplemental proposal upon resolution of the other 
potential issues would be a voluntary action based on its own business 
interests; the commenter does not support any BART determination that 
calls for installation of SCR at FCPP.
    Response: EPA disagrees with the commenters that SCR is not BART. 
Based on our five-factor analysis, as described in the TSD for our 
proposed BART determination, SCR is cost effective and results in the 
greatest anticipated improvement in visibility. One of the owners of 
FCPP notes that the ``better-than-BART'' outcome is a result of the 
closure of Units 1, 2, and 3. However, the closure of Units 1-3 alone 
does not result in greater emission reductions than EPA's proposed BART 
determination, and represents only a roughly 30 percent reduction from 
baseline emissions. The closure of Units 1-3, in combination with SCR 
on Units 4 and 5, results in the ``better-than-BART'' outcome.
    The voluntary nature of the alternative emission control strategy 
does not negate EPA's BART determination because (1) EPA must first 
determine what BART is in order to fulfill the requirements of the 
alternative program to BART as prescribed in the Regional Haze Rule, 
and (2) EPA cannot require the full or partial closure of a facility as 
a BART alternative, therefore the alternative emission control strategy 
remains an optional business choice of the owners of FCPP to implement 
in lieu of BART, if they see fit.
    Comment: One environmental advocacy group and one federal agency 
asserted that the supplemental proposal is not better than BART for 
NOX. Generally, commenters argue that based on the extended 
compliance timeframe for the alternative emission control strategy, the 
use of an artificially inflated baseline, the potential increase in 
output from Units 4 and 5, and assuming that SCR can achieve 0.05 lb/
MMBtu of NOX on an annual basis, the BART alternative fails 
to achieve greater cumulative NOX reductions than would 
installation of BART (SCR) on all five units.
    Response: EPA disagrees with the comment that the alternative 
emission control strategy is not better than BART, but agrees that a 
reexamination of baseline emissions and projected capacity factors in 
the future is warranted. As reported in the TSD for our proposed BART 
determination, facility-wide NOX emissions over 2001-2009 
ranged from 40,331 to 47,300 tpy. While the baseline emissions provided 
by APS and used by EPA in our Supplemental Proposal was within the 
range of annual NOX emissions, in response to these 
comments, we conducted an additional analysis to compare the 
alternative emission control strategy against our final BART 
determination for NOX using the 2001-2010 average as the 
baseline emission rate and an assumed capacity factor of 81 percent 
\39\ for Units 4 and 5 under the alternative emission control 
strategy.\40\ This analysis shows that in 2014 and 2015, the 
alternative emission control strategy results in lower NOX 
emissions than BART due to the closure of Units 1-3 at the end of 2013. 
In 2016, 2017, and 2018, BART results in lower emissions than the 
alternative, and in 2019 and beyond, the alternative emission control 
strategy (5,556 tpy), with phased-in controls on Units 4 and 5 by the 
end of 2018, results in lower emissions than BART (8,479 tpy). In 
total, the BART Alternative results lower emissions from FCPP over more 
calendar years (2014-2015, and 2019 and beyond) than does BART (2016-
2018). Even if APS operated Units 4 and 5 at 100 percent capacity, EPA 
calculates that emissions under the alternative emission control 
scenario in 2019 and beyond to be 6,859 tpy, which is still lower than 
under BART (8,479 tpy). On a cumulative basis, i.e., the sum total of 
NOX emissions over 2011 to 2064, the BART Alternative also 
results in lower emissions than BART, both at an 81 percent capacity 
factor and at 100 percent capacity.
---------------------------------------------------------------------------

    \39\ In testimony to the ACC, Mark Schiavoni of APS testified 
that he anticipates capacity factors over 2015-2030 to range from 
75-81 percent for Units 4 and 5. See document titled ``Schiavoni 
Testimony--TRANSCRIPT.pdf'' in the docket for this final rulemaking.
    \40\ See document titled ``BART vs Alternative.xlsx'' in the 
docket for this final rulemaking.
---------------------------------------------------------------------------

    Commenters argue that if the BART emission limit were lower, the 
alternative would not be better than BART. For example, if EPA required 
an emission limit representing a 90 percent reduction in NOX 
emissions, annual NOX emissions would be lower than 5,000 
tpy. However, as discussed in responses to similar comments, EPA has 
determined that an 80 percent reduction in NOX emissions is 
BART for FCPP. It is inappropriate to compare the alternative emission 
control strategy against a target for BART that commenters would like 
to see based on maximum emission reductions achieved without 
consideration of site-specific characteristics of FCPP that EPA has 
determined are not appropriate for FCPP.
    Commenters further argue that by offering FCPP a BART compliance 
deadline of July 2018, EPA is illegally extending a mandatory deadline 
under the CAA, and that installation of SCR at Units 4 and 5 can easily 
be accomplished within 2 years. EPA disagrees and notes that the 
compliance timeframe for EPA's BART determination requiring SCR

[[Page 51641]]

installation on all 5 units is within 5 years of the effective date of 
the final rule, consistent with the maximum time allowed under the CAA 
Sec.  169A(g)(4) in the definition of ``as expeditiously as 
practicable''. The commenter is confusing requirements under BART and 
requirements under the alternative to BART. EPA is not extending the 
BART compliance deadline beyond a 5-year period. Rather, EPA is 
allowing additional time to implement the alternative emission control 
strategy, as allowed under the provisions of the RHR for the 
implementation of ``other alternative measure rather than to require 
sources subject to BART to install, operate, and maintain BART'' (See 
40 CFR 51.308(e)(2)). In our Supplemental Proposal, EPA cited the 
requirement (under 40 CFR 51.308(e)(2)(iii)) that ``all necessary 
emission reductions take place during the period of the first long-term 
strategy for regional haze''.
    EPA disagrees with commenters that reductions under the alternative 
to BART violates 40 CFR 51.308(e)(2)(iii). The requirement simply 
states the reductions take place during the period of the first long 
term strategy and does not specifically prescribe that those reductions 
must take place at the beginning, middle, or end of the period of the 
first long-term strategy.

H. Other Comments

    Comment: Forty-five private citizens and several private citizens 
who submitted written comments at a public hearing explicitly stated 
that they support EPA's efforts to clean up FCPP. Many of these 
commenters asked for the strictest regulations. Another private citizen 
implied that EPA should act to clean up emissions from FCPP and noted 
that cleaner air will result in a cleaner Colorado snow pack, which 
will result in cleaner water in the Colorado River.
    Twelve private citizens and a few private citizens who submitted 
written comments at a public hearing stated that FCPP should be de-
commissioned. Several of these commenters asserted that the plant 
should only be shut down if it cannot cease emitting pollutants, while 
others stated the plant should be shut down immediately.
    Nine private citizens and some of the private citizens who 
submitted written comments at a public hearing stated that renewable 
energy sources can be used in place of coal-fired power plants.
    Response: EPA acknowledges the comments supportive of our proposals 
but disagrees with commenters that suggest that FCPP should be de-
commissioned or shut down immediately.
    In addition to other CAA programs, EPA assesses air quality with 
respect to NAAQS. The Four Corners area is designated attainment for 
each of the NAAQS.\41\ This means that the air quality in the Four 
Corners area is meeting the national health-based standards set by EPA.
---------------------------------------------------------------------------

    \41\ Please see http://www.epa.gov/region09/air/maps/maps_top.html for EPA Region IX air quality designations.
---------------------------------------------------------------------------

    For this action, EPA finds that under 40 CFR 49.11, it is necessary 
or appropriate to achieve emissions reductions of NOX from 
FCPP required by the CAA's Regional Haze program. NOX is a 
significant contributor to visibility impairment in the numerous 
mandatory Class I Federal areas surrounding FCPP. The emission 
reductions finalized will help achieve the goals of the Regional Haze 
Rule. The Regional Haze Rule however does not require nor does it 
authorize EPA to de-commission or shut down facilities to achieve the 
goals of the rule.
    EPA agrees with commenters who stated that renewable energy sources 
can be used in place of coal-fired power plants. However, the Regional 
Haze Rule does not require that coal-fired facilities use or switch to 
renewable energy sources to meet the goals of the rule.
    Comment: The Navajo Nation pointed out that as a federal agency, 
EPA has a trust responsibility to the Navajo Nation that requires it to 
give special consideration to the Nation's best interests in any 
action.\42\ Because of the significant economic interest of the Navajo 
Nation in FCPP the commenter asserted that the BART proposal clearly 
implicates the Nation's tribal trust interests. The commenter further 
contended that since EPA is adopting a FIP for BART in lieu of a TIP by 
the Navajo Nation, the EPA is essentially ``standing in the shoes'' of 
the Nation for purposes of making the BART determination and should, 
therefore, defer to tribal views when making environmental policy 
decisions and give the same weight to the BART factors that the Navajo 
Nation would in determining BART for FCPP; that is, to the extent that 
the Nation recommends a particular control technology as BART for power 
plants located on the Nation's lands, EPA should give substantial 
weight to that recommendation as part of its decision-making process. 
(The commenter asserted that advanced combustion controls, rather than 
SCR, properly represent BART for FCPP.) Thus, the commenter stated that 
as the Nation's trustee and ``stand-in'' for the BART determination for 
FCPP, the EPA should not select a more stringent BART than the 
commenter stated is required by the Regional Haze Rule to achieve 
``reasonable progress'' where doing so would likely have substantial 
adverse impacts on the Navajo Nation.
---------------------------------------------------------------------------

    \42\ To support this assertion, the commenter cited Executive 
Order 13175 (65 FR 67249, November 6, 2000; EPA Policy on 
Consultation and Coordination With Indian Tribes, section IV 
``Guiding Principles,'' May 4, 2011 (EPA Tribal Policy); and the 
1984 EPA Indian Policy.
---------------------------------------------------------------------------

    The commenter also stated that EPA has a duty to undertake 
government-to-government consultations with the Navajo Nation, and that 
EPA must coordinate with the Navajo Nation in its relationship with, 
and reliance on, other federal agencies. The commenter pointed out that 
EPA relies on data provided by the NPS, another federal trustee of the 
Nation, but has not coordinated consultation between NPS and the Navajo 
Nation on this rulemaking. The commenter indicated that the May 2011 
EPA Tribal Policy recognizes that such coordination is required under 
Executive Order 13175 and asserted that EPA should coordinate 
consultation with the U.S. Forest Service (who provided data used in 
the proposed rulemaking) as well as various Department of the Interior 
(DOI) agencies that have an interest in this rulemaking, including NPS, 
the Bureau of Indian Affairs, the U.S. Fish and Wildlife Service, the 
Office of Surface Mining Reclamation and Enforcement, and potentially 
the Bureaus of Land Management and Reclamation. The commenter added 
that consultation with Department of Energy (DOE) may be important in 
regard to including FCPP in a study that DOE is proposing to carry out 
for NGS, which also is located on the Navajo reservation and uses 
Navajo coal.
    Response: It is EPA's policy (EPA Policy on Consultation and 
Coordination with Indian Tribes, May 4, 2011, (EPA Tribal Consultation 
Policy)) \43\ to consult on a government-to-government basis with 
federally recognized tribal governments when EPA actions and decisions 
may affect tribal interests. Consultation is a process of meaningful 
communication and coordination between EPA and tribal officials prior 
to EPA taking actions or implementing decisions that may affect tribes. 
One of the primary goals of the EPA Tribal Policy is to fully implement 
both Executive Order 13175 and the 1984 Indian Policy, with the 
ultimate

[[Page 51642]]

goal of assuring tribal concerns and interests are considered whenever 
EPA's actions may affect tribes by strengthening the consultation, 
coordination, and partnership between tribal governments and EPA.
---------------------------------------------------------------------------

    \43\ See ``EPA Policy on Consultation and Coordination with 
Indian Tribes'', May 4, 2011, in the docket for this final 
rulemaking.
---------------------------------------------------------------------------

    For this action, EPA consulted with Navajo Nation in accordance 
with the Executive Order and EPA's Indian Policies on numerous 
occasions. A record of all consultations with tribes is included in the 
Docket for this final rulemaking.\44\ As stated in the 2011 EPA Tribal 
Consultation Policy, as a process, consultation includes several 
methods of interaction that may occur at different levels.\45\ EPA 
consulted with the Navajo Nation at various times throughout the 
process at various levels of government, including in-person meetings 
with the President of the Navajo Nation on May 19, 2011, and June 13, 
2012.
---------------------------------------------------------------------------

    \44\ See document ``Timeline of all Tribal Consultations on 
BART.docx'' in the docket for this final rulemaking.
    \45\ See ``EPA Policy on Consultation and Coordination with 
Indian Tribes'', May 4, 2011, in the docket for this final 
rulemaking.
---------------------------------------------------------------------------

    EPA acknowledges the significant interest of the Navajo Nation in 
FCPP. Based on the results from the original analysis for the proposed 
BART determination, EPA concluded that the installation and operation 
of SCR on all five units at FCPP would not adversely affect the 
competitiveness of FCPP's cost to generate electricity compared to the 
cost to purchase electricity on the open market. Thus, EPA infers that 
a BART determination requiring SCR on all five units, in itself, should 
not force the closure of FCPP. EPA notes that we do not expect adverse 
impacts to the Navajo Nation if FCPP continues operating all units and 
complies with BART. However, potential adverse impacts to the Navajo 
Nation may result if the owners of FCPP choose to implement the 
optional BART Alternative. At the request of the Navajo Nation during 
consultation, EPA commissioned a study to examine potential adverse 
impacts to Navajo Nation from the BART Alternative. The results of this 
analysis were discussed with President Shelly during a consultation 
meeting on July 13, 2012 and will be provided to President Shelly by 
letter as a follow-up to our consultation.
    EPA agrees that we are acting to implement the BART requirements 
for a facility located on the Navajo Reservation in circumstances in 
which the Tribe has not applied, or been approved, to administer the 
applicable CAA program. EPA is mindful of the Navajo Nation's views and 
recommendations, particularly where there is a potential substantial 
adverse economic impact to the Navajo Nation. We disagree however that 
the Agency must ``defer to tribal views when making environmental 
policy decisions''. EPA is carrying out the requirements of the CAA and 
the Regional Haze Rule pursuant to our authority to implement these 
requirements in the absence of an EPA-approved program. EPA notes that 
the CAA and the TAR provide mechanisms for eligible Indian tribes to 
seek approval of tribal programs should they wish to administer CAA 
requirements.
    For this action EPA carefully considered the unique location of 
FCPP with respect to proximate Class I areas as well as its economic 
importance to Navajo Nation. We conducted a detailed analysis of 
available emission control technologies against the five-factors 
specified in the BART Guidelines. EPA also conducted extensive air 
modeling (included in the Supplemental Proposal). Additionally, we have 
considered the numerous comments we received on our proposals. In 
making our final decision we have had to balance the findings of our 
analysis along with the interests of various stakeholders, our unique 
government-to-government relationship with tribes, and our 
responsibility to carry out the requirements of the CAA and Regional 
Haze Rule to achieve reasonable progress towards visibility 
improvements.
    This final FIP strikes a reasonable balance between reducing 
emissions to improve visibility while allowing for the facility to 
implement those reductions in a manner that is consistent with its 
continued operation and economic viability.
    EPA has received information and comments from numerous federal 
agencies for this rulemaking and considered these in our final decision 
(all information and comments are included in the docket). EPA plans to 
coordinate with the Department of Interior or other federal agencies, 
as appropriate, in any future tribal consultations related to BART for 
FCPP or the Navajo Generating Station, the other coal-fired power plant 
located in Navajo Nation.
    EPA acknowledges that the Department of Interior has contracted 
with the National Renewable Energy Lab (NREL) of the Department of 
Energy to examine renewable energy options for the Navajo Generating 
Station, which is also located on the Navajo Nation and uses coal from 
the Kayenta Mine, located on Navajo and Hopi land. Information on the 
NREL study is available from DOI \46\ and will be included in the 
docket for EPA's upcoming proposed rulemaking for NGS.
---------------------------------------------------------------------------

    \46\ http://www.doi.gov/navajo-gss/index.cfm.
---------------------------------------------------------------------------

    Comment: One public interest advocacy group, the Navajo Nation, and 
one environmental advocacy group supported establishment of a 20 
percent opacity limit for material handling. The public interest 
advocacy group stated that the FCPP site is subject to numerous dust-
storm events originating in northwestern Arizona, and the additional 
fugitive dust that could be picked up by these strong winds at the FCPP 
property added to the incoming dust from the west makes breathing and 
outdoor activity miserable on from 4 to 12 days per year for residents 
of Montezuma County, CO and San Juan County, NM.
    One of the owners of FCPP noted that in addition to the proposed 
BART requirements, EPA proposed separate fugitive dust control 
requirements and a 20 percent opacity limitation for certain material 
handling operations, which are unrelated to the CAA visibility program. 
The commenter laid out the history of EPA's past attempt to apply 
fugitive dust controls to FCPP. The commenter argued that the proposed 
requirements are arbitrary and should not be finalized because the 
facts upon which EPA relies are inadequate to support the conclusion 
that fugitive dust control requirements are ``necessary or 
appropriate'' to protect air quality at FCPP.
    Response: EPA acknowledges support for establishing a 20 percent 
opacity limit for material handling and a Dust Control Plan at FCPP. 
EPA has finalized both these requirements. EPA notes that the Dust 
Control Plan shall include a description of the dust suppression 
methods for controlling dust from site activities including coal 
handling and storage facilities, ash handling, storage, and landfills, 
and road sweeping activities. The 20 percent opacity standard will 
apply to any crusher, grinding mill, screening operation, belt 
conveyor, or truck loading or unloading operation.
    EPA agrees with the commenter that the fugitive dust and 20 percent 
opacity limit are unrelated to the CAA visibility program. EPA also 
agrees with the history laid out by the commenter on fugitive dust 
controls at FCPP. EPA included these dust control requirements in the 
previous FIP finalized in 2007 because EPA considered them necessary or 
appropriate under the TAR to assure that dust from this facility does 
not

[[Page 51643]]

contribute to possible violations of the NAAQS for PM10. The 
commenter is correct that EPA withdrew the 2007 FIP requirements on 
dust when APS appealed the rule. EPA had not adequately documented in 
the record for the 2007 FIP our basis for establishing the 20 percent 
opacity regulation. For the 2007 FIP, EPA chose not to defend our 
position based on the record for that rulemaking and instead chose to 
address the issue in a subsequent FIP action, such as this one.
    EPA disagrees with the commenter that the fugitive dust and opacity 
requirements are arbitrary or that our argument is inadequate to 
support our conclusion that fugitive dust control requirements are 
necessary or appropriate to protect air quality at FCPP.\47\
---------------------------------------------------------------------------

    \47\ For example, see document titled ``Four Corners Power Plant 
Complaint to MSHA'' in the docket for this final rulemaking.
---------------------------------------------------------------------------

    EPA's basis for finding that it is necessary or appropriate for 
FCPP to comply with a requirement to limit its material handling 
emissions to 20 percent or less is being set forth in this rulemaking. 
FCPP receives approximately 10 million tons of coal per year for 
combusting in Units 1-5. This massive quantity of coal moves by 
conveyor belt across FCPP's property line through numerous transfer 
points before the coal is loaded into the storage silos that feed the 
individual combustion units. Each of these transfer points along with 
the conveyor belts has the potential for PM emissions. The PM can be 
minimized through the use of collection devices or dust suppression 
techniques such as covered conveyors or spraying devices at the 
transfer points. EPA first promulgated dust control requirements for 
new coal handling equipment on January 15, 1976 (41 FR 2232). This rule 
affected equipment constructed or modified after the 1970s that 
affected facilities built or modified after October 24, 1974. The 
purpose of these New Source Performance Standards (NSPS) was:

    NSPS implement CAA section 111(b) and are issued for categories 
of sources which have been identified as causing, or contributing 
significantly to, air pollution which may reasonably be anticipated 
to endanger public health or welfare. The primary purpose of the 
NSPS are to help States attain and maintain ambient air quality by 
ensuring that the best demonstrated emission control technologies 
are installed as the industrial infrastructure is modernized.

See 74 FR 51951 (October 8, 2009).

    EPA's basis for finding that it is necessary or appropriate for 
FCPP to comply with a requirement to limit its material handling 
emissions to 20 percent or less is being set forth in this rulemaking. 
EPA has promulgated a 20 percent opacity limit for all new coal 
handling operations built after the mid 1970s in the New Source 
Performance Standards. This NSPS standard applied to any coal handling 
equipment processing more than 200 tons per day of coal. Because FCPP 
receives approximately 10 million tons of coal per year for combusting 
in Units 1-5, it may be processing more than 27,000 tons per day. This 
is more than 100 times the smallest size coal handling operation 
subject to the NSPS, and which EPA considered necessary for protecting 
public health and welfare. As mentioned before, FCPP's massive quantity 
of coal moves by conveyor belt across FCPP's property line, passing 
through numerous transfer points before the coal is loaded into the 
storage silos that feed the individual pulverizers and combustion 
units. Each of these transfer points along with the conveyor belts has 
the potential for PM emissions. The PM can be minimized by collection 
devices or dust suppression techniques such as covered conveyors or 
spraying devices at the transfer points.
    FCPP and the BHP Navajo Mine that provides FCPP's coal are within 
close proximity to Morgan Lake which is a recreational lake with public 
access just beyond the FCPP's property line. Excess dust can blow over 
the FCPP property line to Morgan Lake and adjacent properties. EPA and 
Navajo Nation EPA receive numerous complaints from Navajo Tribal 
members concerning excess dust emissions generated from the ash 
landfill FCPP maintains, as well as from the other material handling 
and storage operations.
    EPA concludes that it is necessary or appropriate to set 
enforceable fugitive dust/PM suppression measures to protect ambient 
air quality because (1) there is a large potential for dust emissions 
from the facility coal and ash operations to be emitted and blow across 
the property line, (2) EPA and Navajo Nation EPA have received numerous 
complaints concerning excess dust from the ash landfill and other 
operations, and (3) these activities are occurring in close proximity 
to a public access area.
    EPA disagrees with the commenter that the 20 percent opacity limit 
is arbitrary and capricious. While EPA acknowledges that New Mexico 
does not have a general opacity limit that applies to dust, the other 
three Four Corners States do. In Arizona and Colorado a general 20 
percent opacity limit applies at all facilities including 
``grandfathered'' coal-fired EGUs. In Utah the general opacity limit 
for facilities built before the CAA in 1971 is a 40 percent opacity 
limit. However, all of Utah's large coal-fired EGUs were constructed 
after 1971 and are subject to a 20 percent general opacity limit, i.e., 
the NSPS. Therefore, if FCPP had been built a few years later or a few 
miles in a different direction, it would be subject to the NSPS or a 
SIP provision limiting its coal material handling and storage 
operations to 20 percent opacity.
    Because FCPP is located on the Navajo Nation where generally 
applicable limits that often are included in SIPs do not exist and 
because it was constructed nearly 40 years ago, and because dust 
control measures at coal-fired power plants are important for 
maintaining the PM10 NAAQS in the areas adjacent to the 
power plant properties, EPA finds that it is necessary or appropriate 
to impose measures to limit the amount of PM emissions from these 
material handling and storage emission sources. EPA recently imposed 
similar dust control requirements at the Navajo Generating Station, 
which is also on the Navajo Nation. 75 FR 10174.
    Comment: One environmental advocacy group stated that the EPA must 
consult in accordance with sections 7(a)(1) and 7(a)(2) of the 
Endangered Species Act (ESA) with regards to the proposed FIP because 
of the impacts of FCPP on threatened and endangered fish, wildlife, and 
plants and their designated critical habitats, which the commenter 
discussed at some length. The commenter added that EPA has discretion 
under the TAR to limit emissions of mercury, selenium, and other 
pollutants that may adversely affect the razorback sucker and Colorado 
pikeminnow, and these species' critical habitats. According to the 
commenter, this discretion is part of what triggers the Agency's 
obligation to consult pursuant to sections 7(a)(1) and 7(a)(2) of the 
ESA.
    Response: EPA disagrees with the commenter that determining BART 
and promulgating this FIP for FCPP necessitates ESA Section 7 
consultation. EPA understands that the U.S. Fish and Wildlife Service 
(FWS) is primarily concerned about the effects of mercury and selenium 
on endangered fish species in the San Juan River. EPA notes that under 
the BART Alternative, mercury and selenium emissions will be reduced 
from FCPP due to the closure of Units 1-3. Additionally, EPA's national 
MATS rule set new emission limits for mercury that would apply to Units 
1-3 at FCPP if those units continue operation. EPA further notes that 
the goal of the Regional Haze Rule is to reduce emissions of 
visibility-

[[Page 51644]]

impairing pollutants in order to restore visibility to natural 
conditions at the mandatory Federal Class I areas, and mercury and 
selenium do not affect visibility. Therefore, EPA does not have 
authority to regulate emissions of mercury or selenium under BART.
    Comment: The coal supplier for FCCP questioned the legality of 
EPA's approach to the Regional Haze program at FCPP. According to the 
commenter, EPA's BART and better-than-BART proposals are not authorized 
because BART is not ``reasonably separable'' from the remainder of a 
regional haze implementation plan for the Navajo Nation under the TAR. 
The commenter concluded that the minimum amount of reasonable progress 
that BART needs to achieve in a given Class I area cannot be determined 
until the amount of reasonable progress achieved by other CAA and state 
programs is subtracted from that area's reasonable progress goal. The 
commenter asserted that the NOX emission reductions that 
would be achieved under the supplemental proposal are in excess of the 
amount required to achieve the reasonable progress goals in the area.
    The commenter added that EPA must consider the reasonable progress 
already achieved by past FCPP emission reductions. The commenter 
concluded that any necessary reasonable progress remaining to be 
achieved by NOX BART at FCPP cannot be determined until the 
reasonable progress achieved by prior emissions reductions at FCPP is 
considered.
    The commenter stated that EPA's BART determination did not properly 
weigh the statutory factors. Specifically, the commenter indicated that 
individual Class I area visibility improvements from SCR have not been 
compared with respect to the statutory factors to visibility 
improvements from LNB, and the actual amounts of those improvements 
have not been measured against the amounts of improvements needed to 
meet reasonable progress goals.
    Response: EPA disagrees with the commenter who questioned the 
legality of our approach and that stated that EPA's BART and ``better-
than-BART'' proposals are not authorized because BART is not 
``reasonably separable'' from the remainder of a regional haze 
implementation plan for the Navajo Nation under the TAR. We also 
disagree that our approach to the Regional Haze program impermissibly 
isolates BART from the context of the overall reasonable progress goal 
in violation of the CAA, and that our proposed BART for FCPP should be 
withdrawn.
    EPA's authority to promulgate a source-specific FIP in Indian 
County is based on CAA sections 301(a) and (d)(4) and section 49.11 of 
the TAR provides EPA with broad discretion to promulgate regulations 
directly for sources located in Indian country, including on Indian 
reservations if we determine such Federal regulations are ``necessary 
or appropriate'' and the Tribe has not promulgated a TIP. Specifically, 
in 40 CFR 49.11, EPA interpreted CAA section 301(d)(4) to authorize EPA 
to promulgate ``such Federal implementation plan provisions as are 
necessary or appropriate to protect air quality''. As such, because the 
Navajo Nation has not adopted a TIP for Regional Haze, the TAR provides 
discretion to EPA to determine which requirements of the Regional Haze 
Rule are necessary or appropriate to protect air quality, and to 
promulgate just those implementation plan provisions accordingly. 
Because two stationary sources on the Navajo Nation meet the BART 
eligibility criteria, EPA has determined that it is necessary or 
appropriate at this time to evaluate source-specific FIPs to implement 
the BART requirement of the RHR for each BART-eligible facility located 
on the Navajo Nation. The basis for our determination is discussed in 
several prior responses (See, e.g., Sections 2.1, 4.1.2, and 8.1). The 
Courts have agreed with EPA that it may implement requirements that are 
necessary or appropriate without providing for all aspects of the CAA 
programs at a single time. See Arizona Public Service v. EPA, 562 F.3d 
1116 (10th Cir. 2009).
    EPA disagrees with the comment that BART must be established in 
relation to reasonable progress goals. State or Tribal Implementation 
Plans for Regional Haze must establish goals that provide for 
reasonable progress towards achieving natural visibility conditions for 
each mandatory Class I Federal area located within its borders (40 CFR 
51.308(d)(1). FCPP and NGS are both located within the Navajo Nation 
Indian Reservation, and for the reasons outlined above, EPA is 
conducting BART determinations for each facility. There are no 
mandatory Class I Federal areas as designated by Congress located 
within the Navajo Nation.\48\ EPA further notes that the five-factor 
analysis outlined in the BART Guidelines, which were promulgated as a 
notice and comment rulemaking, does not require consideration of 
reasonable progress goals in determining BART for a given facility.
---------------------------------------------------------------------------

    \48\ EPA notes that Navajo Nation has established its own parks 
and monuments, including Monument Valley, Canyon de Chelly, and the 
Four Corners Monument, however, these parks are not mandatory Class 
I Federal Areas as set by Congress.
---------------------------------------------------------------------------

    EPA also disagrees that the minimum amount of reasonable progress 
that BART needs to achieve in a given Class I area cannot be determined 
until the amount of reasonable progress achieved by other CAA and state 
programs is subtracted from that area's reasonable progress goal. 
Neither the CAA nor Regional Haze regulations set any quantitative 
presumptive targets for the amount of reasonable progress that must be 
achieved. Rather, the regulations allow for flexibility in determining 
the amount of reasonable progress towards the ultimate goal of 
returning to natural background conditions.
    EPA disagrees with the commenter that EPA must consider the 
reasonable progress already achieved by past FCPP emission reductions 
and that previously uncontrolled SO2, NOX, and PM 
emission rates prior to previous FIPs for FCPP should serve as the 
baseline for measuring visibility improvements. In its own five-factor 
BART analysis, APS used actual NOX emissions from 2001-2003 
as baseline emissions for determining visibility improvement from 
NOX controls. NOX emissions from 2001-2003 were 
generally consistent with and representative of NOX 
emissions over the past ten years. EPA agrees with APS in its use of 
actual emissions over a recent time frame, rather than attempting to 
rely on previously uncontrolled emissions emission rates from FCPP as a 
baseline.
    Additionally, nothing in the BART regulations or guidance requires 
that EPA consider past emission reductions in determining BART under 
the RHR. However, as part of the required five-factor analysis for BART 
EPA did evaluate and consider the current pollution control equipment 
in use at FCPP.
    EPA disagrees with the comment that EPA's BART determination did 
not properly weigh the statutory factors. As discussed elsewhere in 
this document, the BART Guidelines allow the reviewing authority 
(State, Tribe, or EPA) the discretion to determine how to weigh and in 
what order to evaluate the statutory factors (cost of compliance, the 
energy and non air quality environmental impacts of compliance, any 
existing pollution control technology in use at the source, the 
remaining useful life of the source, and the degree of improvement in 
visibility which may reasonably be anticipated to result from the use 
of such technology), as long as the reviewing authority justifies its 
selection of the ``best'' level of control and explains the CAA factors

[[Page 51645]]

that led the reviewing authority to choose that option over other 
control levels (see 70 FR 39170, July 6, 2005). EPA provided a detailed 
justification for our BART evaluation process and five-factor analysis 
in the TSD for our proposed BART determination.
    EPA also disagrees with the comment that individual Class I area 
visibility improvements from SCR have not been compared with respect to 
the statutory factors to visibility improvements from LNB. In the 
preamble to our October 19, 2010, proposed BART determination and in 
the accompanying TSD, EPA compared the anticipated visibility 
improvement from SCR with the anticipated improvement from combustion 
controls (LNB or LNB+OFA) (See 75 FR 64230, Table 3, and TSD Tables 36-
39), and noted that EPA modeled the visibility improvement from SCR to 
far exceed the modeled improvement from combustion controls.

IV: Administrative Requirements

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action will finalize a source-specific FIP for a single 
generating source. This type of action is exempt from review under 
Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 
3821, January 21, 2011).

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Under the Paperwork Reduction Act, a ``collection of information'' is 
defined as a requirement for ``answers to * * * identical reporting or 
recordkeeping requirements imposed on ten or more persons * * *'' 44 
U.S.C. 3502(3)(A). Because the final FIP applies to a single facility, 
Four Corners Power Plant, the Paperwork Reduction Act does not apply. 
See 5 CFR 1320(c).
    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a Federal agency. This includes the time 
needed to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR Part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of today's rule on small 
entities, small entity is defined as: (1) A small business as defined 
by the Small Business Administration's (SBA) regulations at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of this action on small 
entities, I certify that this final action will not have a significant 
economic impact on a substantial number of small entities. The Four 
Corners Power Plant is not a small entity and the FIP for Four Corners 
Power Plant being finalized today does not impose any compliance 
requirements on small entities. See Mid-Tex Electric Cooperative, Inc. 
v. FERC, 773 F.2d 327 (D.C. Cir. 1985).

D. Unfunded Mandates Reform Act (UMRA)

    This rule will impose an enforceable duty on the private sector 
owners of FCPP. However, this rule does not contain a Federal mandate 
that may result in expenditures of $100 million (in 1996 dollars) or 
more for State, local, and tribal governments, in the aggregate, or the 
private sector in any one year. EPA's estimate for the total annual 
cost to install and operate SCR on all five units at FCPP does not 
exceed $100 million (in 1996 dollars) in any one year. Thus, this rule 
is not subject to the requirements of sections 202 or 205 of UMRA. This 
action is also not subject to the requirements of section 203 of UMRA 
because it contains no regulatory requirements that might significantly 
or uniquely affect small governments. This rule will not impose direct 
compliance costs on the Navajo Nation, and will not preempt Navajo law. 
This final action will reduce the emissions of two pollutants from a 
single source, the Four Corners Power Plant.

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 in the distribution of power 
and responsibilities among the various levels of government, as 
specified in Executive Order 13132. This final action requires emission 
reductions of NOX at a specific stationary source located in 
Indian country. Thus, Executive Order 13132 does not apply to this 
action.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    Subject to the Executive Order 13175 (65 FR 67249, November 9, 
2000) EPA may not issue a regulation that has tribal implications, that 
imposes substantial direct compliance costs, and that is not required 
by statute, unless the Federal government provides the funds necessary 
to pay the direct compliance costs incurred by tribal governments, or 
EPA consults with tribal officials early in the process of developing 
the proposed regulation and develops a tribal summary impact statement.
    EPA has concluded that this action will have tribal implications. 
However, it will neither impose substantial direct compliance costs on 
tribal governments, nor preempt Tribal law. This final rule requires 
FCPP, a major stationary source located on the Navajo Nation, to reduce 
emissions of NOX under the BART requirement of the Regional 
Haze Rule. The owners of FCPP submitted a BART Alternative to EPA for 
consideration that would provide compliance flexibility to the owners 
and result in greater reasonable progress than BART toward the national 
visibility goal. This BART Alternative involves closure of Units 1-3 at 
FCPP and installation of add-on pollution controls to Units 4 and 5. 
EPA issued a Supplemental Proposal to allow the owners of FCPP the 
option to implement BART or the BART Alternative. Because the BART 
Alternative involves the optional closure of Units 1-3 and an 
associated

[[Page 51646]]

decline in the amount of coal mined and combusted, taxes and royalties 
paid to the Navajo Nation by the owners of FCPP and BHP Billiton, 
operator of the coal mine that supplies FCPP, are expected to decline. 
The closure of Units 1-3 is not expected to result in layoffs, but is 
expected to result in a reduction in workforce at the mine and power 
plant over time through attrition.
    EPA consulted with tribal officials early in the process of 
developing this regulation to permit them to have meaningful and timely 
input into its development. EPA proposed to determine that it was 
necessary or appropriate to implement the BART requirement of the 
Regional Haze Rule for the Navajo Nation to protect air quality and 
improve visibility at the sixteen mandatory Class I Federal areas 
surrounding FCPP and the eleven Class I areas surrounding NGS. EPA 
first put forth an Advanced Notice of Proposed Rulemaking (ANPR) on 
August 28, 2009 to accept comment on preliminary information provided 
by FCPP and NGS and to begin the consultation process with affected 
tribes and the Federal Land Managers. EPA has consulted on numerous 
occasions with officials of the Navajo Nation in the process of 
developing this FIP, including meetings with the President Ben Shelly 
of the Navajo Nation and his staff on May 19, 2011, after the close of 
the public comment period for our proposed BART determination and 
Supplemental Proposal, and on June 13, 2012, prior to our final action. 
The agendas for these two consultation meetings are provided in the 
docket for this final rulemaking.\49\ A timeline of correspondence and 
consultation with tribes on both power plants is included in the docket 
for this final rulemaking.
---------------------------------------------------------------------------

    \49\ See document number 0222 in docket EPA-R09-OAR-2011-0683 
titled ``Agenda May 19, 2011 Meeting; Gov to Gov Consultation with 
Navajo Nation'', and document titled: ``2012--0613 Consultation with 
Navajo Nation agenda and attendees.pdf'' in the docket for this 
final rulemaking.
---------------------------------------------------------------------------

    Several tribes, including the Navajo Nation, submitted comments on 
the ANPR, which we considered in developing our proposal and the 
accompanying Technical Support Document. The main concern expressed by 
the Navajo Nation was that requiring the top NOX control 
option, selective catalytic reduction (SCR) as BART would cause FCPP to 
close. In developing our proposed BART determination, EPA conducted an 
analysis to examine whether requiring SCR on Units 1-5 at FCPP would 
cause electricity generation costs to exceed the cost to purchase power 
on the wholesale market. Based on our analysis, we determined that 
electricity generation costs resulting from installation of SCR would 
not make FCPP uneconomical compared to the wholesale power market; 
therefore, we concluded that our proposed BART determination was 
unlikely to cause FCPP to close.
    The Navajo Nation provided comments on our proposed rule and 
Supplemental Proposal, in consultation and by letter, which EPA 
considered in developing this final rule. The Navajo Nation also 
expressed concern about the potential adverse impacts of the BART 
Alternative to the Navajo Nation and requested that EPA conduct an 
analysis to estimate potential adverse impacts to the Navajo Nation. 
Pursuant to EPA's customary practice of engaging in extensive and 
meaningful consultation with tribes and tribal authorities with regard 
to relevant Agency actions, EPA commissioned an analysis of the 
optional BART Alternative to estimate potential adverse impacts to the 
Navajo Nation if the owners of FCPP chose to retire Units 1-3. EPA 
communicated these potential impacts to the Navajo Nation in our 
consultation meeting with President Shelly on June 13, 2012. The report 
will be provided to President Shelly by letter as a follow-up to our 
consultation with the Navajo Nation.
    The Navajo Nation also expressed support for phased-implementation 
of controls to provide compliance flexibility to FCPP. The final rule 
allows the owners of FCPP to choose between BART or the BART 
Alternative and provides timeframes for phased-implementation of 
control options.
    EPA summarized and responded to comments from the Navajo Nation and 
the Salt River Pima Maricopa Indian Community received on the ANPR in 
the Technical Support Document for our proposed rulemaking. Following 
our meeting with President Shelly on May 19, 2011, EPA sent a follow up 
letter summarizing and responding to the concerns expressed by the 
Navajo Nation.\50\ In coordination with this final rulemaking, EPA will 
also be sending a letter to President Shelly that summarizes and 
responds to the comments raised in his letter to EPA dated June 2, 
2011.
---------------------------------------------------------------------------

    \50\ See document 0231 in docket EPA-R09-OAR-2011-0683 titled 
``EPA response to Navajo Nation dated 09/06/2011''.
---------------------------------------------------------------------------

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks (62 FR 19885, April 23, 1997), applies to 
any rule that: (1) Is determined to be economically significant as 
defined under Executive Order 12866, and (2) concerns an environmental 
health or safety risk that EPA has reason to believe may have a 
disproportionate effect on children. If the regulatory action meets 
both criteria, the Agency must evaluate the environmental health or 
safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    This rule is not subject to Executive Order 13045 because it 
requires emissions reductions of NOX from a single 
stationary source. Because this action only applies to a single source 
and is not a rule of general applicability, it is not economically 
significant as defined under Executive Order 12866, and does not have a 
disproportionate effect on children. However, to the extent that the 
rule will reduce emissions of NOX, which contributes to 
ozone formation, the rule will have a beneficial effect on children's 
health by reducing air pollution that causes or exacerbates childhood 
asthma and other respiratory issues.

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not subject to Executive Order 13211 (66 FR 28355 
(May 22, 2001)), because it is not a significant regulatory action 
under Executive Order 12866.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, 12 (10) (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards (VCS) in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. VCS are technical standards 
(e.g., materials specifications, test methods, sampling procedures and 
business practices) that are developed or adopted by the VCS bodies. 
The NTTAA directs EPA to provide Congress, through annual reports to 
OMB, with explanations when the Agency decides not to use available and 
applicable VCS.
    Consistent with the NTTAA, the Agency conducted a search to 
identify potentially applicable VCS. For the measurements listed below, 
there are a number of VCS that appear to have possible use in lieu of 
the EPA test

[[Page 51647]]

methods and performance specifications (40 CFR part 60, Appendices A 
and B) noted next to the measurement requirements. It would not be 
practical to specify these standards in the current rulemaking due to a 
lack of sufficient data on equivalency and validation and because some 
are still under development. However, EPA's Office of Air Quality 
Planning and Standards is in the process of reviewing all available VCS 
for incorporation by reference into the test methods and performance 
specifications of 40 CFR part 60, Appendices A and B. Any VCS so 
incorporated in a specified test method or performance specification 
would then be available for use in determining the emissions from this 
facility. This will be an ongoing process designed to incorporate 
suitable VCS as they become available.
    Particulate Matter Emissions--EPA Methods 1 though 5;
    Opacity--EPA Method 9 and Performance Specification Test 1 for 
Opacity Monitoring;
    NOX Emissions--Continuous Emissions Monitors.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994), establishes 
federal executive policy on environmental justice. Its main provision 
directs federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    EPA has determined that this final rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it 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. This rule requires emissions reductions of two 
pollutants from a single stationary source, Four Corners Power Plant.

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. Section 804 exempts from section 801 the following types 
of rules (1) rules of particular applicability; (2) rules relating to 
agency management or personnel; and (3) rules of agency organization, 
procedure, or practice that do not substantially affect the rights or 
obligations of non-agency parties. 5 U.S.C 804(3). EPA is not required 
to submit a rule report regarding today's action under section 801 
because this action is a rule of particular applicability. This rule 
finalizes a source-specific FIP for a single generating source.

L. 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 October 23, 2012. 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 49

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Indians, Intergovernmental relations, Reporting 
and recordkeeping requirements.

    Dated: August 6, 2012.
Lisa P. Jackson,
Administrator.
    Title 40, chapter I, of the Code of Federal Regulations is amended 
as follows:

PART 49--[AMENDED]

0
1. The authority citation for part 49 continues to read as follows:

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

0
2. Section 49.5512 is amended by adding paragraphs (i) and (j) to read 
as follows:

Sec.  49.5512  Federal Implementation Plan Provisions for Four Corners 
Power Plant, Navajo Nation.

* * * * *
    (i) Regional Haze Best Available Retrofit Technology limits for 
this plant are in addition to the requirements of paragraphs (a) 
through (h) of this section. All definitions and testing and monitoring 
methods of this section apply to the limits in this paragraph (i) 
except as indicated in paragraphs (i)(1) through (4) of this section. 
The interim NOX emission limit in paragraph (i)(2)(ii) of 
this section shall be effective 180 days after re-start of the unit 
after installation of add-on post-combustion NOX controls 
for that unit and until the plant-wide limit goes into effect. The 
plant-wide NOX limit shall be effective no later than 5 
years after October 23, 2012. The owner or operator may elect to meet 
the plant-wide limit early to remove the individual unit limits. 
Particulate limits for Units 4 and 5 shall be effective 60 days after 
restart following the scheduled major outage for Units 4 and 5 in 2013 
and 2014.
    (1) Particulate Matter from Units 4 and 5 shall be limited to 0.015 
lb/MMBtu for each unit as measured by the average of three test runs 
with each run collecting a minimum of 60 dscf of sample gas and with a 
duration of at least 120 minutes. Sampling shall be performed according 
to 40 CFR Part 60 Appendices A-1 through A-3, Methods 1 through 4 and 
Method 5 or Method 5e. The averaging time for any other demonstration 
of the particulate matter compliance or exceedance shall be based on a 
6-hour average. Particulate testing shall be performed annually as 
required by paragraph (e)(3) of this section. This test with 120 minute 
test runs may be substituted and used to demonstrate compliance with 
the particulate limits in paragraph (d)(2) of this section.
    (2) Plant-wide nitrogen oxide emission limits.
    (i) The plant-wide nitrogen oxide limit, expressed as nitrogen 
dioxide (NO2), shall be 0.11 lb/MMBtu as averaged over a 
rolling 30-calendar day period. NOX emissions for each 
calendar day shall be determined by summing the hourly emissions 
measured as pounds of NO2 for all operating units. Heat 
input for each calendar day shall be determined by adding together all 
hourly heat inputs, in millions of Btu, for all operating units. Each 
day the rolling 30-calendar day average shall be determined by adding 
together that day's and the preceding 29 days' pounds of NO2 
and dividing that total pounds of NO2 by the sum of the heat 
input during the same 30-day period. The results shall be the rolling 
30-calendar day-average pound per million Btu emissions of 
NOX.
    (ii) The interim NOX limit for the first 750 MW boiler 
retrofitted with add-on post-combustion NOX control shall be 
0.11 lb/MMBtu, based on a rolling

[[Page 51648]]

average of 30 successive boiler operating days.
    (iii) Schedule for add-on post-combustion NOX controls 
installation
    (A) Within 4 years of the effective date of this rule, FCPP shall 
have installed add-on post-combustion NOX controls on at 
least 750 MW (net) of generation to meet the interim emission limit in 
paragraph (i)(2)(ii)(A) of this section.
    (B) Within 5 years of the effective date of this rule, FCPP shall 
have installed add-on post-combustion NOX controls on all 
2060 MW (net) of generation to meet the plant-wide emission limit for 
NOX in paragraph (i)(2)(i) of this section.
    (iv) Testing and monitoring shall use the 40 CFR part 75 monitors 
and meet the 40 CFR part 75 quality assurance requirements. In addition 
to these 40 CFR part 75 requirements, relative accuracy test audits 
shall be performed for both the NOX pounds per hour 
measurement and the heat input measurement. These shall have relative 
accuracies of less than 20 percent. This testing shall be evaluated 
each time the 40 CFR part 75 monitors undergo relative accuracy 
testing.
    (v) If a valid NOX pounds per hour or heat input is not 
available for any hour for a unit, that heat input and NOX 
pounds per hour shall not be used in the calculation of the 30 day 
plant-wide rolling average.
    (vi) Upon the effective date of the plant-wide NOX 
average, the owner or operator shall have installed CEMS and COMS 
software that complies with the requirements of this section.
    (3) In lieu of meeting the NOX requirements of paragraph 
(i)(2) of this section, FCPP may choose to permanently shut down Units 
1, 2, and 3 by January 1, 2014 and meet the requirements of this 
paragraph to control NOX emissions from Units 4 and 5. By 
July 31, 2018, Units 4 and 5 shall be retrofitted with add-on post-
combustion NOX controls to reduce NOX emissions. 
Units 4 and 5 shall each meet a 0.098 lb/MMBtu emission limit for 
NOX expressed as NO2 based on a rolling average 
of 30 successive boiler operating days. A ``boiler operating day'' is 
defined as any 24-hour period between 12:00 midnight and the following 
midnight during which any fuel is combusted at any time at the steam 
generating unit. Emissions from each unit shall be measured with the 40 
CFR part 75 continuous NOX monitor system and expressed in 
the units of lb/MMBtu and recorded each hour. A valid hour of 
NOX data shall be determined per 40 CFR part 75. For each 
boiler operating day, every valid hour of NOX lb/MMBtu 
measurement shall be averaged to determine a daily average. Each daily 
average shall be averaged with the preceding 29 valid daily averages to 
determine the 30 boiler operating day rolling average. The 
NOX monitoring system shall meet the data requirements of 40 
CFR 60.49Da(e)(2) (at least 90 percent valid hours for all operating 
hours over any 30 successive boiler operating days). Emission testing 
using 40 CFR part 60 Appendix A Method 7E may be used to supplement any 
missing data due to continuous monitor problems. The 40 CFR part 75 
requirements for bias adjusting and data substitution do not apply for 
adjusting the data for this emission limit.
    (4) By January 1, 2013, the owner or operator shall submit a letter 
to the Regional Administrator updating EPA of the status of lease 
negotiations and regulatory approvals required to comply with paragraph 
(i)(3) of this section. By July 1, 2013, the owner or operator shall 
notify the Regional Administrator by letter whether it will comply with 
paragraph (i)(2) of this section or whether it will comply with 
paragraph (i)(3) of this section and shall submit a plan and time table 
for compliance with either paragraph (i)(2) or (3) of this section. The 
owner or operator shall amend and submit this amended plan to the 
Regional Administrator as changes occur.
    (5) The owner or operator shall follow the requirements of 40 CFR 
part 71 for submitting an application for permit revision to update its 
Part 71 operating permit after it achieves compliance with paragraph 
(i)(2) or (3) of this section.
    (j) Dust. Each owner or operator shall operate and maintain the 
existing dust suppression methods for controlling dust from the coal 
handling and ash handling and storage facilities. Within ninety (90) 
days after promulgation of this paragraph, the owner or operator shall 
develop a dust control plan and submit the plan to the Regional 
Administrator. The owner or operator shall comply with the plan once 
the plan is submitted to the Regional Administrator. The owner or 
operator shall amend the plan as requested or needed. The plan shall 
include a description of the dust suppression methods for controlling 
dust from the coal handling and storage facilities, ash handling, 
storage, and landfills, and road sweeping activities. Within 18 months 
of promulgation of this paragraph each owner or operator shall not emit 
dust with opacity greater than 20 percent from any crusher, grinding 
mill, screening operation, belt conveyor, or truck loading or unloading 
operation.

[FR Doc. 2012-19793 Filed 8-23-12; 8:45 am]
BILLING CODE 6560-50-P