An option to curb NOx emissions from the Navajo Generating Station (NGS) near Page, Ariz., put forth by the Environmental Protection Agency (EPA) last October has been endorsed by a coalition of the plant’s stakeholders.

The EPA’s supplemental proposal incorporates in large part a Best Available Retrofit Technology (BART) alternative that was submitted by a Technical Working Group (TWG), which comprises parties with various interests in the plant.

The 2.3-GW coal-fired power plant located near the Grand Canyon on the Navajo Indian Reservation, close to Page, Ariz., delivers more than 90% of the power needed for pumping Colorado River water to central and southern Arizona for the Central Arizona Project. Meanwhile, the Navajo Nation’s economy is soundly invested in the power plant and its coal supplier, the nearby Kayenta Mine, both which support more than 1,000 private sector jobs and thousands of public sector jobs in the semiautonomous Navajo Nation government.

The EPA last February proposed a BART rule for the Navajo plant that would require its owners—the U.S. Bureau of Reclamation and five utilities: Salt River Project (SRP), Los Angeles Department of Water & Power (LADWP), Arizona Public Service Co., Nevada Power Co. and Tucson Electric Power Co.—to install selective catalytic reduction (SCR) technology on all three units by 2018 to reduce NOx emissions. But according to plant operator SRP, installing SCR on all three units could cost about $544 million and would exceed $1.1 billion if additional equipment is required to remove airborne particulates created by the SCR.

The TWG countered the EPA’s proposal by essentially calling for closure of one 750-MW unit by January 2020 and for SCR to be installed on the remaining units by 2030—but only if the LADWP and NV Energy divest ownership in the plant 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.

“The TWG supports the EPA’s proposed adoption of the TWG BART Alternative, and recommends EPA adopt a final BART rule for NGS that is based on its October 2013 Supplemental Proposal, with the minor modifications described in their comments. The group will continue to work together on these important issues,” the TWG said in a joint statement on Tuesday.

Sonal Patel, associate editor (@POWERmagazine, @sonalcpatel)