DATE U.S. Environmental Protection Agency EPA Docket Center (EPA/DC) Mail Code 28221T Attn: Docket ID No. EPA-HQ-OAR-2013-0602 1200 Pennsylvania Avenue, NW Washington, DC 20460 RE: EPA-HQ-OAR-2013-0602 As part of its Clean Power Plan, on October 28, 2014, the U.S. Environmental Protection Agency (EPA) released a Supplemental Proposal to address greenhouse gas emissions at existing power plants on Indian lands. This letter is written in support of the Supplemental Proposal on behalf of the [INSERT YOUR ORGANIZATION HERE. In a following sentence, you may wish to also include demographic information and other specifics about your organization. For example: Founded in _____, the City of _________ is one of Arizona's largest cities and serves a population of more than 200,000 people.] Our interest in EPA's recent action stems from its applicability to the Navajo Generating Station (NGS) located in northern Arizona. NGS is critical to the operation of the Central Arizona Project (CAP), providing more than 90-percent of the power CAP needs to deliver Colorado River water to central and southern Arizona populations. In turn, the [your organization] relies on CAP to reliably and affordably deliver this water. [Here you may wish to include information about how much CAP water you take, percentage of water portfolio, and other reliances.] [Your organization] supports the Supplemental Proposal because it specifies critical goals to improve air quality, rather than mandating specific requirements on tribal governments. Importantly, it recognizes that these goals are attainable through compliance with NGS' Best Available Retrofit Technology (BART) rule finalized by the EPA in September. In acknowledging this, the EPA states that it does not expect additional emission reductions from areas of Indian Country with affected power plants, including the Navajo Nation's lands, because of expected compliance with the BART rule. We strongly encourage the EPA to continue to maintain this determination in the final rule because the possible imposition of additional requirements to control carbon emissions and resulting costs will otherwise have a devastating impact on water use in the state. The cost of CAP water already is on the rise in part due to compliance with BART. [Include here how your organization is affected by rising CAP water costs: impact on your budget, customers, rates, etc.] The BART rule drew an extraordinary balance between NGS constituents and the EPA to find a mutually acceptable solution for the continued operation of NGS. Likewise, the Supplemental Proposal strikes a similar balance and is further evidence of the EPA's commitment to achieve air quality standards while ensuring the continued economic vitality of CAP and, consequently, its water customers and stakeholders like the [your organization]. We appreciate the opportunity to provide comment, and urge the EPA to adopt the Supplemental Proposal as part of the Clean Power Plan final rulemaking. Sincerely,