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Montana Air Plan Falls Short of Protecting Big Sky State

EPA Proposal Sidelines Science, Sacrifices Clean Air for Dirty Energy

Montana—The Big Sky state’s most iconic landscapes will continue to be shrouded in haze from coal-fired power plants under an Environmental Protection Agency air plan proposed today.

“The EPA’s proposal lets dirty energy off the hook when it comes to safeguarding clean air in Montana,” said Jeremy Nichols, WildEarth Guardians’ Climate and Energy Program Director.  “For a state defined by its skies, this proposal is a step backward.”

The EPA’s proposal was spurred by a lawsuit filed by WildEarth Guardians in 2011 over the agency’s failure to clean up haze pollution in National Parks and wilderness areas as required by the Clean Air Act.  Under the law, the EPA is required to ensure the oldest and dirtiest sources of air pollution be retrofitted with up to date emission controls, called “best available retrofit technology.”  Above all, the law requires that reasonable progress be made in reducing haze so that by 2064, natural visibility in restored.

The need to reduce haze is critical in Montana, with some of the states most iconic landscapes—including Glacier National Park, Yellowstone National Park, the Bob Marshall Wilderness Area, and more—are on average nine times hazier than normal.  The same pollutants that form haze also negatively impact public health.

“If the air is so bad you can see it, there’s a major problem,” said Jeremy Nichols, WildEarth Guardians’ Climate and Energy Program Director.  “Air quality in National Parks and wilderness areas is a bellwether for the health of our air everywhere.  When Glacier, Yellowstone, or other pristine landscapes suffer, so do we.”

Unfortunately, under its proposal, the EPA itself admits that the plan will not make reasonable progress in reducing haze in Montana’s National Parks and wilderness areas.  The reason is because the agency proposed to control emissions at only a handful of sources of air pollution, and even then, proposed less stringent emission controls than have been adopted in other states.

At best, the EPA estimates its plan will make only 51% of the required haze reductions in National Parks and wilderness areas.  However, for most areas, the progress will be far less.  In Glacier National Park, only 26% of the required haze reductions will be achieved.

In Montana, the key sources of haze forming pollution are the state’s coal-fired power plants, including the 2,200 megawatt Colstrip power plant, which is the second largest coal-fired power plant west of the Mississippi River.  These plants release thousands of tons of haze forming nitrogen oxides and sulfur dioxide gases. Other sources include cement kilns.

Although the proposal would achieve nominal emission reductions—6,237 tons of nitrogen oxides and 8,615 tons of sulfur dioxide annually—by the EPA’s own admission the proposal is not good enough.  In the case of one source of air pollution, the J.E. Corette coal-fired power plant in Billings, the proposal would actually allow 2,000 tons of more air pollution to be released

Yet according to the EPA’s own proposal, using cost-effective emission controls just at the state’s coal-fired power plants could reduce nitrogen oxide emissions by more than 17,000 tons annually.  Using a technology called “selective catalytic reduction,” which the EPA has required in other states (including New Mexico and Colorado), more than 14,000 tons of nitrogen oxides could be reduced just from the Colstrip power plant.  See table below.


Coal-fired Power Plant Unit

NOx Reductions as Proposed

NOx Reductions Possible Using Cost-effective Controls

Colstrip 1



Colstrip 2



Colstrip 3



Colstrip 4



Colstrip Energy






Lewis and Clark







The EPA’s proposal kicks off a public comment period, including two public hearings, one in Helena on May 1st and one in Billings on May 2nd.  WildEarth Guardians intends to call on the EPA to strengthen its proposal and fully protect Montana from air pollution.


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