Arizona Proposal Allows Aging Coal Plant to Increase Air Pollution for Decades

Cholla Power Plant bypasses strong pollution controls, threatens air quality


Michael Hiatt, Earthjustice, (303) 519-9727

Arizona recently proposed a new regional haze plan for the aging coal-fired Cholla Power Plant that would weaken current regulations and put communities, national parks and other resources at risk.

The Environmental Protection Agency’s (EPA) current regional haze plan requires Cholla to install highly-effective pollution controls in 2017, which will significantly improve air quality at Arizona’s world-renowned national parks and wilderness areas. However, a new Arizona Department of Environmental Quality (ADEQ) proposal allows two units at Cholla to continue operating for the next 10 years without updated pollution controls. The proposal discards additional controls despite showing that the facility could cost-effectively install them before the utilities stop burning coal at Cholla in 2025.

Compared to EPA’s existing plan, Arizona’s proposal would lead to increased air pollution and worse visibility impairment for nearly two decades. The Cholla Power Plant, owned by utilities Arizona Public Service Company (APS) and PacifiCorp, is currently one of the nation’s worst sources of visibility impairment at national parks and wilderness areas, according to the National Park Service. Cholla impairs air quality at 13 national parks and wilderness areas, including Petrified Forest National Park and Grand Canyon National Park.

“While we are encouraged by the utilities’ commitment to stop burning coal at Cholla, the APS and ADEQ proposal would result in increased air pollution for nearly two decades compared to EPA’s existing plan,” said Sandy Bahr, chapter director for Sierra Club’s Grand Canyon Chapter. “That additional pollution is at the expense of Arizona’s renowned national parks and public health. Arizona should require APS and PacifiCorp to promptly install additional, cost-effective pollution controls on units 3 and 4 at Cholla.”

“After Arizona Public Service committed last year to closing or at least cleaning up energy for three of the Cholla plant’s coal-fired generators, it is disappointing to see the state take a step backwards with this new regional haze plan,” said Kevin Dahl, Arizona Senior Program Manager for the National Parks Conservation Association. “Cholla is the nation’s worst park polluter, and it also impacts communities throughout northern Arizona. Allowing more time for the plant to continue to harm Arizona’s residents and visitors is unacceptable.”

“We applaud the utilities’ decision to stop burning coal at Cholla in the future,” said Michael Hiatt, an attorney at Earthjustice. “But the utilities’ pledge to do so cannot allow Cholla to evade its Clean Air Act obligations by subjecting national park visitors to worse air pollution for decades.”

Today, Earthjustice submitted comments on ADEQ’s proposal on behalf of the National Parks Conservation Association and Sierra Club. 


In 2012, EPA took action to reduce Cholla’s pollution when it rejected the State’s inadequate regional haze plan and submitted a stronger federal plan in its place. EPA’s plan requires three units at Cholla to be retrofitted with selective catalytic reduction pollution controls, a highly-effective technology now in wide use at more than 200 coal-fired units around the country that can cut smog-forming nitrogen oxide pollution by 90 percent. The National Parks Conservation Association, Sierra Club, and Earthjustice support EPA’s plan and have defended it in court against legal challenges by the State of Arizona, Arizona Public Service Company, and PacifiCorp.

At the request of APS and PacificCorp, the State of Arizona recently released its “reassessment” of the haze plan for the Cholla Power Plant. Rather than require Cholla to install highly-effective pollution controls, Arizona’s new plan would require Cholla Unit 2 to retire in 2016, but allow Cholla Units 3 and 4 to continue operating without any additional pollution controls until 2025. Then, in 2025, the utilities would either switch Units 3 and 4 to natural gas, or retire the units. Compared to EPA’s existing plan, Arizona’s proposal would cause increased air pollution and worse visibility impairment for decades.

Low levels of exposure to dangerous smog-causing nitrogen oxides can irritate the eyes, nose, throat, and lungs, and cause shortness of breath; high levels of exposure can cause serious respiratory system damage. Nitrogen oxide (NOx) emissions are a significant contributor to the formation of smog pollution and are pumped out of vehicle tailpipes and dirty power plants. Doctors compare inhaling smog to getting a sunburn on your lungs. According to the Clean Air Task Force, pollution from the Cholla Power Plant contributes to 10 deaths and 190 asthma attacks every year.



Haze obscures a view of the Grand Canyon.
Haze obscures a view of the Grand Canyon. (Photo courtesy of Alex Berger)

Additional Resources

About Earthjustice

Earthjustice is the premier nonprofit environmental law organization. We wield the power of law and the strength of partnership to protect people's health, to preserve magnificent places and wildlife, to advance clean energy, and to combat climate change. We are here because the earth needs a good lawyer.