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Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Air Actions, Navajo Nation

Recent Additions

» December 30, 2013: Letter from Arizona Public Service notifying EPA that it intends to implement the Alternative to BART for Four Corners Power Plant

Public Comments

You May Submit Comments on the Proposed Rulemaking on Navajo Generating Station (NGS) Using Any One of the Following Methods:

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Navajo Generating Station

Supplemental Proposal for Best Available Retrofit Technology for Navajo Generating Station, Navajo Nation

September 25, 2013: EPA is supplementing our February 5, 2013 proposed rulemaking with today’s proposal of an additional Alternative to BART submitted by a group of stakeholders known as the Technical Work Group (TWG). The TWG Alternative to BART requires that Navajo Generating Station (NGS), located on the Navajo Nation, reduce emissions of oxides of nitrogen (NOx) over time. These pollutants contribute to visibility impairment in numerous national parks and wilderness areas surrounding NGS. EPA is accepting comment on our February 5, 2013 proposed rulemaking and today’s Supplemental Proposal concurrently until January 6, 2014.

Proposed Federal Implementation Plan - Best Available Retrofit Technology for Navajo Generating Station, Navajo Nation

September 16, 2013: EPA is extending the public comment period for three additional months for the proposed rulemaking on NGS. Because EPA has not yet announced the schedule for the five public hearings we intend to hold in Arizona, and because EPA is still evaluating an Alternative to BART we received from stakeholders on July 26, 2013, EPA is extending the comment period to close on January 6, 2014. EPA intends to hold public hearings prior to the close of this extended comment period and to announce the schedule shortly.

June 26, 2013: EPA is providing a second extension of the public comment period for the proposed rulemaking on NGS based on a request from Salt River Project, the operator of NGS, on behalf of the Navajo Nation, the Gila River Indian Community, the Central Arizona Water Conservation District, the Environmental Defense Fund, and the U.S. Department of the Interior, EPA is extending the comment period an additional 60-days. The public comment period will now close on October 4, 2013.

June 10, 2013: EPA is announcing our intent to hold five public hearings to accept written and oral comments on EPA’s proposed rulemaking on NGS. We intend to hold a hearing at one location each on the Navajo Reservation and the Hopi Reservation, and in Page, Phoenix, and Tucson, Arizona. We will announce the exact dates, times, and locations for the hearings at a later time.

March 19, 2013: EPA is providing a 90-day extension of the public comment period for the proposed rulemaking on NGS, based on requests from the Navajo Nation and other stakeholders. The public comment period will now close on August 5, 2013.

January 17, 2013: EPA is proposing that Navajo Generating Station (NGS), located on the Navajo Nation, reduce emissions of oxides of nitrogen (NOx).These pollutants contribute to visibility impairment in numerous national parks and wilderness areas surrounding NGS.

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Contact Information
Anita Lee (lee.anita@epa.gov)
Air Division
(415) 972-3958


Final action on Source-Specific Federal Implementation Plan for Navajo Generating Station

February 25, 2010: EPA finalized a Federal Implementation Plan (FIP) under the Clean Air Act (CAA) to regulate emissions from the Navajo Generating Station (NGS), located on the Navajo Indian Reservation in Arizona. The purpose of the FIP is to ensure protection of tribal air resources. The plan previously followed emissions limits established in the Arizona State Implementation Plan. However, EPA's promulgation of the Tribal Authority Rule clarified that State air quality regulations generally could not be extended to facilities located on the reservation. This FIP establishes federally enforceable emissions limitations for sulfur dioxide, total particulate matter, and opacity, and sets a control measures requirement for dust.

Contact Information
Colleen McKaughan (mckaughan.colleen@epa.gov)
Air Division
(520) 498-0118

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Four Corners Power Plant

Four Corners Power Plant Will Implement Alternative to BART

December 30, 2013: Arizona Public Service Company notified EPA that it has selected to implement the Alternative to BART for the Four Corners Power Plant. Under this compliance strategy, APS will retire Units 1, 2, and 3 by January 1, 2014 and will comply with the BART emission limit for NOx on Units 4 and 5 by July 31, 2018.

Revision to Four Corners Power Plant Federal Implementation Plan – Final Action to Extend Notification Deadline

September 24, 2013: EPA has extended the date by which the operator of the Four Corners Power Plant must notify EPA of its selected strategy for compliance with the Best Available Retrofit Technology (BART) Federal Implementation Plan (FIP) that was finalized in August 2012. EPA’s 2012 BART FIP for Four Corners Power Plant required the operator to choose between compliance with EPA’s final BART determination, or with an alternative emission control strategy. EPA is extending the notification date from July 1, 2013 to December 31, 2013.


Proposed Revision to Four Corners Power Plant Federal Implementation Plan – Proposal to Extend Notification Deadline

June 25, 2013: EPA is proposing to extend the date by which the operator of the Four Corners Power Plant must notify EPA of its selected strategy for compliance with the Best Available Retrofit Technology (BART) Federal Implementation Plan (FIP) that was finalized in August 2012. EPA’s 2012 BART FIP for Four Corners Power Plant required the operator to choose between compliance with EPA’s final BART determination, or with an alternative emission control strategy. EPA is proposing to extend the notification date from July 1, 2013 to December 31, 2013.

Contact Information
Anita Lee (r9_airplanning@epa.gov)
Air Division
(415) 972-3958


Federal Implementation Plan - Best Available Retrofit Technology for Four Corners Power Plant, Navajo Nation

August 6, 2012: EPA is requiring Four Corners Power Plant (FCPP), located in the Navajo Nation, to reduce emissions of oxides of nitrogen (NOx) and setting emission limits for particulate matter (PM) based on emission rates already achieved at FCPP. These pollutants contribute to visibility impairment in numerous national parks and wilderness areas surrounding FCPP.

Contact Information
Anita Lee (r9_airplanning@epa.gov)
Air Division
(415) 972-3958


Final action on Source-Specific Federal Implementation Plan for Four Corners Power Plant

April 30, 2007: EPA finalized a Federal Implementation Plan (FIP) under the Clean Air Act (CAA) to regulate emissions from the Four Corners Power Plant (FCPP), located on the Navajo Indian Reservation in New Mexico. The purpose of this FIP is to ensure protection of tribal air resources. The plant previously followed emissions limits in the New Mexico State Implementation Plan. However, EPA’s promulgation of the Tribal Authority Rule clarified that State air quality regulations generally could not be extended to facilities located on the reservation. This FIP establishes federally enforceable emissions limitations for sulfur dioxide, nitrogen oxides, total particulate matter, and opacity, and a requirement for control measures for dust. The plan includes significant sulfur dioxide reductions from the facility's historic highs at the 5-unit 2,040 megawatt Four Corners plant, which began operations in 1962. The reductions are the result of a partnership between the Navajo Nation, the Arizona Public Service, the National Park Service, Environmental Defense, Western Resource Advocates, and New Mexico Citizens for Clean Air and Water.

Contact Information
Colleen McKaughan (mckaughan.colleen@epa.gov)
Air Division
(520) 498-0118

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