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6560-50-P

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 49

[EPA-R09-OAR-2013-0009; FRL-]

Approval of Air Quality Implementation Plans; Navajo Nation; 

Regional Haze Requirements for Navajo Generating Station; 

Extension of Public Comment Period

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of Extended Comment Period.

SUMMARY: On February 5, 2013, EPA proposed a Best Available 

Retrofit Technology (BART) determination for oxides of nitrogen 

(NOX) for the Navajo Generating Station (NGS), located on the 

Navajo Nation, and provided a three-month period to accept

public comments that was scheduled to close on May 6, 2013. At 

the request of interested stakeholders, EPA extended the comment 

period on two occasions, first on March 19, 2013, and again on 

July 9, 2013. The comment period was scheduled to close October 

4, 2013. Additionally, on June 19, 2013, EPA announced our 

intention to hold five public hearings to accept written and 

oral comment on our proposed BART determination for NGS. On July 

26, 2013, a group of stakeholders, known as the Technical Work 

Group (TWG), submitted its recommendation for an additional BART 

Alternative to EPA for consideration (TWG Alternative). EPA is 

in the process of evaluating this alternative. Because EPA has 
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not yet announced the schedule for the public hearings, and 

because EPA is still evaluating the TWG Alternative and may 

supplement our February 5, 2013 proposal, EPA is extending the 

comment period an additional three months. EPA intends to hold 

the public hearings prior to the close of this extended comment 

period and to announce the schedule shortly.

DATES: Comments on the proposed rulemaking for NGS must be 

postmarked no later than January 6, 2014.

ADDRESSES: Submit comments, identified by docket number EPA-R09-

OAR-2013-0009, by one of the following methods: 

(1) Federal eRulemaking Portal: www.regulations.gov. Follow the 

on-line instructions.

(2) E-mail: r9ngsbart@epa.gov.

(3) Mail or deliver: Anita Lee (Air-2), U.S. Environmental 

Protection Agency Region 9, 75 Hawthorne Street, San Francisco, 

CA 94105-3901. 

For more detailed instructions concerning how to submit 

comments on this proposed rule, and for more information on our 

proposed rule, please see the notice of proposed rulemaking, 

published in the Federal Register on February 5, 2013 (78 FR 

8274).

Instructions: All comments will be included in the public 

docket without change and may be made available online at 

www.regulations.gov, including any personal information 
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provided, unless the comment includes Confidential Business 

Information (CBI) or other information whose disclosure is 

restricted by statute. Information that you consider CBI or 

otherwise protected should be clearly identified as such and 

should not be submitted through www.regulations.gov or e-mail. 

www.regulations.gov is an “anonymous access” system, and EPA 

will not know your identity or contact information unless you 

provide it in the body of your comment. If you send an e-mail 

directly to EPA, your e-mail address will be automatically 

captured and included as part of the public comment. If EPA 

cannot read your comment due to technical difficulties and 

cannot contact you for clarification, EPA may not be able to 

consider your comment. 

Hearings: EPA intends to schedule five public hearings to 

accept oral and written comments on the proposed rulemaking. EPA 

intends to hold the public hearings at locations on the Navajo 

Nation and the Hopi Tribe, as well as in Page, Phoenix, and 

Tucson, Arizona. EPA will provide notice and additional details 

related to the hearings in the Federal Register, on our website, 

and in the docket for this proposed rulemaking. 

Docket: The index to the docket for this action is 

available electronically at www.regulations.gov and in hard copy 

at EPA Region 9, 75 Hawthorne Street, San Francisco, California. 

While documents in the docket are listed in the index, some 
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information may be publicly available only at EPA Region 9 

(e.g., maps, voluminous reports, copyrighted material), and some 

may not be publicly available in either location (e.g., 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.

FOR FURTHER INFORMATION CONTACT: Anita Lee, EPA Region 9, (415) 

972-3958, r9ngsbart@epa.gov. 

SUPPLEMENTARY INFORMATION: Throughout this document, “we”, “us”, 

and “our” refer to EPA.

Table of Contents

I. Background

II. Today’s Action

I. Background

NGS is a coal-fired power plant located on the Navajo 

Nation Indian Reservation, just east of Page, Arizona, 

approximately 135 miles north of Flagstaff, Arizona. Emissions 

of NOX from NGS affect visibility at 11 National Parks and 

Wilderness Areas that are designated as Class I federal areas

(Class I areas), mandated by Congress to receive heightened 

protection. NGS is subject to the BART requirement of the CAA 

and the Regional Haze Rule (RHR) based on its age and its 

effects on visibility in Class I areas. 
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On February 5, 2013, EPA proposed a BART determination to 

require NGS to achieve a nearly 80 percent reduction of its 

current overall NOX emission rate. EPA also proposed an 

alternative to BART that would provide flexibility to NGS in the 

schedule for the installation of new post-combustion control 

equipment. As discussed in more detail in our proposed 

rulemaking, EPA proposed to exercise its authority and 

discretion under section 301(d)(4) of the CAA (42 U.S.C. §

7601(d)(4)), and the Tribal Authority Rule (40 CFR 49.11(a)), to

credit NGS for its early and voluntary installation of new 

combustion controls and to propose an extended timeframe for NGS 

for alternative measures to BART under the RHR. 

In recognition that there may be other approaches that 

could result in better visibility benefits than BART, as well as 

the importance of NGS to the Navajo Nation, Hopi Tribe, the Gila 

River Indian Community, and numerous other tribes located in 

Arizona, EPA also outlined a framework for evaluating other BART 

alternatives (“better than BART” alternatives) that provide 

greater emission reductions than EPA’s proposed BART alternative 

in exchange for greater flexibility. 

EPA encouraged a robust public discussion of our proposed 

BART determination and alternative, as well as other possible 

alternatives, and recognized the potential need for a 
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supplemental proposal if approaches developed by other parties 

are identified as meeting the requirements of the CAA. 

EPA received requests for a 90-day extension of the public 

comment period from the Navajo Nation, the Gila River Indian 

Community (Gila River, or the Community), Salt River Project 

Agricultural Improvement and Power District (SRP), and the 

Central Arizona Water Conservation District (CAWCD), in order to 

allow stakeholders time to develop alternatives to BART for 

EPA’s consideration. On March 19, 2013, EPA extended the close 

of the public comment period to August 5, 2013 (78 FR 16825). 

On June 10, 2013, EPA signed a notice, published on June 

19, 2013, of our intent to hold five public hearings throughout 

the state of Arizona (78 FR 36716). EPA intends to hold hearings 

at one location each on reservation lands of the Navajo Nation 

and Hopi Tribe, and in Page, Phoenix, and Tucson, Arizona.

On June 20, 2013, SRP submitted a letter, on behalf of six 

stakeholders, requesting another extension of the comment period 

for NGS. On July 9, 2013, EPA extended the close of the public 

comment period to October 4, 2013 (78 FR 41012).

On July 26, 2013, a group of stakeholders known as the 

Technical Work Group (TWG) and consisting of the CAWCD, the 

Environmental Defense Fund (EDF), Gila River, Navajo Nation, 

SRP, on behalf of itself and the other non-federal Participants, 

Interior, and Western Resource Advocates, submitted a document 
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to EPA memorializing a multi-party agreement (the TWG 

Agreement).1 The TWG Alternative to BART was included as Appendix 

B to the TWG Agreement. EPA is currently evaluating the TWG 

Alternative to determine if it is consistent with the RHR and 

the framework for “better than BART” Alternatives put forth in 

our February 5, 2013 proposed rulemaking.

Because EPA has not yet scheduled the public hearings for 

NGS and because we are still evaluating the TWG Alternative, EPA 

is extending the close of the comment period to accept written 

and oral comment on our proposed rulemaking for NGS.

II. Today’s Action

In today’s action, EPA is extending the close of the 

comment period for our proposed rulemaking for NGS by three 

months, to January 6, 2014. EPA intends to announce the schedule 

for public hearings in a forthcoming notice in the Federal

Register.

List of Subjects in 40 CFR Part 49

 Environmental protection, Air pollution control, Indians, 

Intergovernmental relations, Nitrogen Dioxide.

 

1 See “Technical Work Group Agreement Related to Navajo 

Generating Station (NGS)” dated July 25, 2013, and submitted to 

EPA on July 26, 2013, in the docket for this proposed rulemaking 

at EPA-R09-OAR-2013-0009-0122.
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Authority: 42 U.S.C. 7401 et seq.

September 16, 2013 /s/

Dated: Elizabeth Adams,

Acting Air Division Director, Region 9.