The Cholla, Coronado, and Apache coal power plants together spew out tens of thousands of tons of sulfur and nitrogen oxides each year. This kind of pollution is linked to serious health harms, and also to haze that clouds the skies of national parks and wilderness areas in the southwest.
According to the National Park Service, Arizona Public Service’s (APS’s) Cholla plant, whose first coal unit was built some 50 years ago, has significant cumulative impacts on air quality across 13 ‘Class I’ park and wilderness areas, including Petrified Forest National Park and Grand Canyon National Park.
In rejecting the state’s proposal for the three coal plants as inadequate under the requirements of the Clean Air Act, EPA’s plan will require a total of seven coal boilers at the three plants to be retrofitted with selective catalytic reduction controls, a technology now in wide use at over 200 coal-fired units around the country. Selective catalytic reduction can cut nitrogen oxide pollution by 90 percent.
The EPA proposal comes in response to a lawsuit by Earthjustice and Wyoming attorney Reid Zars on behalf of conservation groups including National Parks Conservation Association, Sierra Club, Grand Canyon Trust, Environmental Defense Fund, San Juan Citizens Alliance, Our Children’s Earth Foundation, Plains Justice, and Powder River Basin Resource Council. The suit was brought after the state and EPA missed legal deadlines for limiting haze-causing pollution from power plants and factories in Arizona. Action to clean up haze pollution in the state is required as part of a court-enforceable settlement of the suit.
“People should not have to breathe and see filthy air when they go to a national park,” said attorney David Baron of Earthjustice. “This proposal takes a big step toward clearing the skies in these majestic places.”
Low levels of exposure to 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. Both nitrogen oxides and sulfur dioxide from coal plant smokestacks are also chemically converted in the atmosphere to form ozone and fine particulate pollution, one of the deadliest air pollutants because it can penetrate deep into the lungs. Particulate matter exposure can cause heart attacks, strokes, asthma attacks, and premature deaths.
In April, the Arizona Corporation Commission required APS to evaluate coal plant retirements as part of a systematic review of the economic and environmental risks throughout its coal fleet. The commission’s order was part of its approval for APS to buy two coal units at Four Corners Power Plant from Southern California Edison (APS has proposed retirement of three units).
“We’re seeing more and more players in energy recognizing the financial, environmental, and public health sense in moving from coal to cleaner sources of power,” said Sandy Bahr with the Sierra Club’s Grand Canyon Chapter. “It’s becoming a different era.”
Grand Canyon Trust’s Roger Clark highlighted the window of opportunity that lies ahead for the state now that coal plants’ fuller costs are coming to light with long overdue requirements to finally curtail air pollution. “There’s absolutely no reason to be polluting our skies and lungs with coal in a place like Arizona with the clean energy potential we have,” Clark said. “Big choices loom for our utilities and regulators and residents about what kind of energy future we want to build now for our younger generation to live with.”
Cholla Generating Station in Joseph City is owned by APS, Coronado Generating Station in St. Johns is owned by Salt River Project (SRP), and Apache Generating Station in Willcox is owned by Arizona Electric Power Coop. A pollution control proposal from EPA for SRP’s Navajo Generating Station near Page, Arizona is also expected this year.