On February 5, 2013, EPA proposed a Best Available Retrofit Technology (BART) determination for oxides of nitrogen (NO X) for the Navajo Generating Station (NGS), located on the Navajo Nation, and provided a 3-month period for public comments, to close on May 6, 2013. The Navajo Nation, Gila River Indian Community, and other affected stakeholders requested a 90-day extension of the comment period to allow time for stakeholders to develop an alternative to EPA's proposed BART determination that achieves greater reasonable progress. On March 19, 2013, EPA extended the close of the public comment period to August 5, 2013. On June 10, 2013, EPA signed a notice, published in the Federal Register on June 19, 2013, of our intent to hold five public hearings in the state of Arizona. On June 20, 2013, Salt River Project (SRP), the operator and co-owner of NGS, submitted a letter on behalf of six stakeholders, including the Navajo Nation and Gila River Indian Community, describing the development of a stakeholder alternative, and requesting another extension of the comment period to allow the stakeholders additional time to finalize their alternative and submit it to EPA for consideration in the rulemaking process. EPA is extending the comment period for this proposed rulemaking by 60 days to October 4, 2013.