The U.S. Environmental Protection Agency in the Oct. 22 Federal Register will release a supplemental proposed rule and a public hearing schedule on that rule related to regional haze requirements for the coal-fired Navajo power plant.
On Feb. 5, EPA had proposed a Federal Implementation Plan requiring major NOx emissions cuts from Navajo to meet the regional haze requirements. On March 19 and June 19, EPA provided two extensions of the public comment period based on requests of several stakeholders who were actively working to develop an alternative to BART. On July 26, a group of stakeholders, known as the Technical Work Group (TWG), submitted to EPA their suggested alternative to BART (the “TWG Alternative”). That group included plant ownership.
The TWG Alternative establishes a lifetime cap in NOX emissions over 2009-2044 (the 2009-2044 NOX Cap) that is equivalent to the cumulative NOX emissions over 2009-2044 that NGS would emit under EPA’s proposed Best Available Retrofit Technology (BART) determination of 0.055 lb/MMBtu achieved within five years of the final rule. Due to on-going lease and ownership uncertainties, the operators of the Navajo Generating Station (NGS) cannot yet commit to a single course of action for maintaining emissions below the 2009-2044 NOX Cap. The TWG Alternative therefore includes several alternative operating scenarios for meeting the 2009-2044 NOX Cap.
EPA did not participate in developing the TWG Alternative, and has independently evaluated it to determine if it meets the requirements of the Clean Air Act and the Regional Haze Rule (RHR). In this new action, EPA is proposing to determine that the TWG Alternative is “better than BART” because maintaining emissions below the 2009-2044 NOX Cap, as provided in the TWG Alternative, achieves greater reasonable progress than EPA’s proposed BART determination towards the national visibility goal.
EPA is accepting comment until Jan. 6, 2014, on both the Oct. 22 Supplemental Proposal and the EPA proposal from Feb. 5. It has scheduled five local public hearings on the issue in November.
Alternative would entail shutdown of one unit, or major plant curtailment
NGS is a coal-fired power plant located on the Navajo Nation Indian Reservation, just east of Page, Ariz. NGS is co-owned by six entities: the U.S. Bureau of Reclamation – 24.3%; Salt River Project (SRP), which also acts as the facility operator – 21.7%; Los Angeles Department of Water and Power (LADWP) – 21.2%; Pinnacle West Capital (NYSE:PNW) unit Arizona Public Service (APS) – 14%; NV Energy (NYSE:NVE) subsidiary Nevada Power – 11.3%; and UNS Energy subsidiary (NYSE:UNS) Tucson Electric Power (TEP) – 7.5%.
The three-unit, 2,250-MW plant is located on the Navajo Nation, less than 20 miles from the Grand Canyon, near Page, Ariz., and the Utah state line. The coal used by NGS is supplied by the Kayenta strip mine in Arizona, operated by Peabody Energy and located on reservation lands of both the Navajo Nation and the Hopi Tribe.
On Feb. 5, EPA proposed a BART determination to require NGS to meet a NOX emission limit of 0.055 pound per million British thermal units of heat input (lb/MMBtu) within five years of the effective date of a final rule. That would be achievable with expensive selective catalytic reduction (SCR) installation on all units. EPA on Feb. 5 did allow for extended deadlines for BART compliance considering the economic importance of the power plant and coal mine to the local tribes.
The TWG Alternative outlines the operating scenarios that would be required based on various future developments, including LADWP’s and Nevada Power’s planned sales of their stakes in the power plant. The alternatives mostly entail shutdown of one 750-MW unit by the end of 2019, or the curtailment of plant operations by at least 561 MW by the end of 2019, and retrofit for NOX control with SCR and other technologies of surviving capacity.
LADWP owns about 477 MW of NGS, while NV Energy owns approximately 254 MW. The sum of their shares is 731 MW, which is 19 MW short of one 750 MW unit at NGS.