Jared Blumenfeld is the EPA’s regional administrator in the Southwest. He said the new rules announced Monday require the Navajo Generating Station to install new pollution controls. He said EPA is allowing the plant’s owners to come up with their own methods to cut nitrogen oxide and other emissions by 80 percent before the year 2030.

"We kind of said go out and come back with a flexible approach and if it’s better than the one that we came up with then you’ll be able to implement it,”  Blumenfield said.

The new rules also give the plant’s owners the choice of either shutting down one of the 750-megawatt units or reducing power generation by an equal amount by 2020. But, some clean-air advocates vowed to fight the EPA’s decision. Sandy Bahr is with the Sierra Club.

“We’re disappointed and we think that the EPA missed an opportunity to ensure that this plant was cleaned up and that the Grand Canyon and the people in Arizona and beyond had better protections in place for their health,” Bahr said.

Stephen Etsitty is a spokesman for the Navajo Nation. He supports the new clean air rules but he’s concerned about the economic impact on the tribe.

“For decades now the Navajo Nation has relied on these coal sales and more recently the taxes from these coal sales to help fund our annual government operations… so we certainly will be keeping an eye on that factor,” Etsitty said.

Members of the Hopi tribe also work at the power plant located outside of Page near the Utah state line. The plant is operated by Salt River Project and it provides electricity to Arizona and utilities in Los Angeles and Nevada. It also provides 90 percent of the power that moves Central Arizona Project water across the state.