Aging coal-fired power plants across the West could be forced to install costly pollution-control equipment under an agreement between federal regulators and environmentalists aimed at jump-starting a delayed clean-air initiative.

Many utilities already cut emissions sharply over the past decade to meet federal health standards. Next up are even deeper cuts, to improve visibility in 156 national parks and wilderness areas by clearing the air of pollutants that cause haze.

The reductions are required under the Clean Air Act. First announced more than a decade ago, they have yet to be widely enacted.

Now, a deal reached between the Environmental Protection Agency and three groups would require the agency to adopt plans by 2012 to reduce haze-causing pollution from plants in Colorado, Montana, North Dakota and Wyoming. The agreement is subject to approval from a federal judge in Colorado after a 30-day comment period that ends July 15.

An even broader agreement in the works would set deadlines for haze-pollution plans in dozens more states and U.S. territories, according to agency officials and environmentalists.

Putting the plans into action nationwide could cost up to $1.5 billion a year, according to the EPA. Spinoff benefits from reduced health-care spending on pollution-related illnesses were estimated at $8.4 billion or more annually.

“We’re getting the low-hanging fruit, and we expect huge reductions from that effort,” said Gail Fallon, an EPA haze program manager based in Denver. “It doesn’t mean we have to shut all these plants down. But if it’s determined that a man-made source of pollution continues to cause visibility problems, it needs to be addressed.”

It remains unresolved how utilities will meet the mandates. Already some states and utilities are pushing back, saying the haze rule could prove too costly and a five-year timeline for compliance is too short.

Haze is caused by sunlight hitting small particles of pollution, scattering light rays and making it harder to see over distances.

In Western states, haze is blamed for reducing visibility by half compared with natural conditions at a maximum of 60 to 90 miles. In most of the United States, the phenomenon is even more acute, with visibility reduced to just 15 to 30 miles.

To change that, officials have identified 18 coal plants in the four states named in the court agreement that would have to be retired, retrofitted with new pollution-reduction equipment or otherwise reduce emissions. Nationwide, more than 300 old coal plants could face required upgrades if the broader agreement is finalized, said Stephanie Kodish, a lawyer with the National Parks Conservation Association.

Those plants were largely exempted from other air pollution initiatives aimed at newly constructed industrial plants. The thinking when those exemptions were granted was the problem would take care of itself as older plants were retired, said Pat Cummins of the Western Regional Air Partnership, established in 1997 to support state and tribal efforts to address haze pollution.

But many of the old plants have continued to operate, in part
because less pollution-control equipment makes them cheaper than new plants.

The EPA’s haze rules were
adopted in 1999 in part to reduce emissions of sulfur dioxide and nitrogen oxides — byproducts of burning coal that react with the atmosphere to form the particles that cause haze.

The first phase of the program was aimed at plants built between 1962 and 1977 that churn out at least 250 tons of pollutants annually. The goal was to eliminate haze in parks and wilderness areas by 2064.

Combined, the 18 Western coal plants emit more than 200,000 tons of sulfur dioxide and 150,000 tons of nitrogen oxides a year, according to WildEarth Guardians, a plaintiff in the Colorado case along with the Environmental Defense Fund and National Parks Conservation Association. Several cement and soda ash plants also would have to make changes.

“This is the biggest rule affecting coal-fired power plants to be adopted in the West perhaps since the Clean Air Act Amendments in 1990,” said Jeremy Nichols of WildEarth Guardians. “We were literally losing some of our most scenic vistas in the West.”

David Eskelsen of PacifiCorp, which operates four coal plants in Wyoming that fall under the haze rule, said his company has spent $1.2 billion on air quality controls since 2005. He said it would take 12 years, not five, to meet the haze requirements.

“We are making excellent progress,” Eskelsen said. “If there is a more aggressive reduction schedule, policymakers need to understand this is going to result in significant cost increases to electricity.”

Oklahoma Attorney General Scott Pruitt sued the EPA over the issue in May, citing costs of up to $2.5 billion to install “scrubbers” that would reduce pollution from the state’s coal -fired plants.

Pruitt said that could drive up utility rates by as much as 20 percent.

“There’s a requirement to retrofit those plants. That’s clear. But it’s essentially a case-by-case basis,” Cummins said.

— Associated Press