The Environmental Protection Agency (EPA) is promulgating a source-specific Federal Implementation Plan (FIP) requiring the Navajo Generating Station (NGS), a coal-fired power plant located on the Navajo Nation near Page, Arizona, to achieve reductions in oxides of nitrogen (NO<INF>X</INF>) required under the Best Available Retrofit Technology (BART) provisions of the Clean Air Act (CAA) and the Regional Haze Rule (RHR). On February 5, 2013, EPA issued a proposed BART determination for NGS and an alternative to BART. In a supplemental proposal on October 22, 2013, EPA proposed to approve a new alternative plan, based on an agreement developed by a group of stakeholders known as the Technical Work Group (TWG). EPA is finalizing the alternative to BART described in our supplemental proposal. This rule is consistent with the TWG Agreement, including a lifetime cap in total emissions of NO<INF>X</INF> from NGS over 2009-2044 (2009-2044 NO<INF>X</INF> Cap). Our final action will achieve greater emissions reductions than BART and is expected to significantly reduce the impact of NGS on visibility at 11 mandatory Class I Federal areas. The operator of NGS must implement one of several alternative operating scenarios to achieve the necessary emission reductions to comply with the 2009-2044 NO<INF>X</INF> Cap.