The U.S. Environmental Protection Agency said in a notice to be published in the Sept. 25 Federal Register that it is again extending the comment period on a regional haze plan for the coal-fired Navajo Generating Station (NGS) in Arizona.
On Feb. 5, EPA proposed a Best Available Retrofit Technology (BART) determination for NOx for the NGS, located on the Navajo Nation, and provided a three-month period to accept public comments that was scheduled to close on May 6. At the request of interested stakeholders, EPA extended the comment period twice, first on March 19 and again on July 9. The latest comment period was scheduled to close Oct. 4. Additionally, on June 19, EPA announced its intention to hold five public hearings.
On July 26, a group of stakeholders known as the Technical Work Group (TWG) submitted its recommendation for an additional BART Alternative to EPA for consideration (TWG Alternative). EPA is still evaluating this alternative. Because EPA has not yet announced the schedule for the public hearings, and because it is still evaluating the TWG Alternative and may supplement its Feb. 5 proposal, the agency is extending the comment period by three months, to Jan. 6, 2014. EPA intends to hold the public hearings prior to the close of this extended comment period and to announce the schedule shortly.
NGS is a coal-fired power plant located on the Navajo Nation Indian Reservation, just east of Page, Ariz. Emissions of NOx from NGS affect visibility at 11 National Parks and Wilderness Areas that are designated as Class I federal areas (Class I areas), mandated by Congress to receive heightened protection.
The Feb. 5 EPA called for NGS to achieve a nearly 80% reduction of its current overall NOX emission rate. EPA also proposed an alternative to BART that would provide flexibility to NGS in the schedule for the installation of new post-combustion control equipment.
In recognition that there may be other approaches that could result in better visibility benefits than BART, as well as the importance of NGS to the Navajo Nation, Hopi Tribe, the Gila River Indian Community, and numerous other tribes located in Arizona, EPA also outlined a framework for evaluating other BART alternatives (“better than BART” alternatives) that provide greater emission reductions than EPA’s proposed BART alternative in exchange for greater flexibility.
New alternative would shut one of three units by 2020
On July 26, the Technical Work Group (TWG) made its proposal. The TWG consists of: the Central Arizona Water Conservation District (CAWCD); Environmental Defense Fund (EDF); the Gila River Indian Community; Navajo Nation; the Salt River Project (SRP) on behalf of itself and the other non-federal participants in the power plant; the Interior Dept.; and Western Resource Advocates.
EPA wants NOx emissions reduced by 84% at Navajo through the installation of selective catalytic reduction (SCR) systems on all three units. But the July 26 alternative plan would shut down one of three units by 2020, cutting pollution beyond what the EPA has proposed. The plant’s operator, the SRP, said the plan takes into account potential ownership changes and pushes back the implementation of expensive pollution controls.
Two plant owners, the Los Angeles Department of Water and Power and NV Energy, plan to get rid of their stakes in Navajo in an effort to cut their greenhouse gas emissions. SRP, the U.S. Bureau of Reclamation, Tucson Electric Power and Arizona Public Service also own shares of the power generated at the plant.
Under this new alternative, one 750 MW unit would be shut down by Jan. 1, 2020, and SCR would be installed on the remaining units by 2030 – if the Los Angeles Department of Water & Power (LADWP) and NV Energy exit NGS as expected by 2019, and if the Navajo Nation chooses not to exercise an option to purchase a portion of the plant’s ownership shares. In total, LADWP and NV Energy own the equivalent of almost exactly one unit at NGS, so shutting one unit would essentially be getting rid of their capacity share.