The Environmental Protection Agency released its final requirement for emissions reductions at the Navajo Generating Station in northern Arizona.

The plant's co-owners will shut down one of three generators at the facility to comply with a requirement that it reduce emissions by one-third by 2020.

Scott Harelson, spokesperson for the Salt River Project, which operates the plant, said two out-of-state co-owners have plans to divest by that time.

The departure of the Los Angeles Department of Water and Power and NV Energy, which together export about one-third of the power generated at NGS to consumers in California and Nevada, means the reduced output won’t cut supply to Arizonans.

The plant produces power customers across Arizona and for the Central Arizona Project.

NGS’s owners have until 2030 to install pollution controls that would cut nitrogen-oxide emissions by 80 percent.

The plant is scheduled to close in 2044.

Jared Blumenfeld, EPA’s regional administrator, said the ruling is significant and will result in better air quality.

“And at the same time it gives enough flexibility that the tribes, the utilities, the CAP water users, and many others will be able to continue functioning as they were," he said.

Stephen Etsitty, executive director of the Navajo Nation’s Environmental Protection Agency, said the final rule incorporated input from the Navajo Nation and others.

“The Navajo nation, one of our primary concerns was ensuring the continued operations of the facility…and it looks like we have a path to move forward."

The EPA says the emissions reductions requirement aims to improve visibility and air quality at the Grand Canyon, which is about 20 miles away from the Navajo Generating Station.