Enviros threaten lawsuit against coal plant dubbed 'worst in the West'

A pair of environmental groups threatened yesterday to sue the owners of the Colstrip power station in southeastern Montana, adding to the pressure on the second-largest coal-burning plant west of the Mississippi River.

The Montana Environmental Information Center and the Sierra Club sent a notice yesterday to PPL Montana LLC, Portland General Electric Co., NorthWestern Energy, Puget Sound Energy, Avista Corp. and PacifiCorp, saying their 2,100-megawatt power plant has undergone upgrades over the past 20 years that should have triggered tougher air pollution limits under the Clean Air Act.

Colstrip has been a major source of power across the Pacific Northwest since it started operations in 1975, sending electricity to customers in Montana, Oregon and Washington. It is also the ninth-largest source of carbon dioxide emissions nationwide and releases more air pollution than all other industrial sources in Montana combined, said Derf Johnson, a program associate at the Montana Environmental Information Center.

"It is by far the largest source of air pollution in Montana," he said.

The plant has recently drawn intense opposition from the Sierra Club, which has dubbed the plant "the worst in the West" and tried to shut it down. The group has also challenged permits for Montana coal mines and the rail lines that carry their fuel.

David Hoffman, director of external affairs at PPL Montana, said Colstrip's owners have spent more than $100 million since 2000 to cut its pollution. Mercury controls were added to each of the plant's four boilers in 2009 and 2010 to comply with Montana law, and new burners were added to two of the four units to cut down on nitrogen oxides, which cause soot, smog and haze.

Yesterday's notice claims that Colstrip underwent eight modifications with the potential to cause higher emissions of soot, sulfur dioxide and nitrogen oxides. Hoffman said the company is still reviewing the claims in the letter, but the changes seem to be "fairly routine" maintenance events, which do not trigger tougher pollution limits under the New Source Review program.

"It's a lot like taking a car in every 3,000 miles for an oil change," Hoffman said. "Sometimes you need spark plugs changed, too."

He said all four boilers at the Colstrip plant should meet the mercury limits in U.S. EPA's new rules for toxic air emissions, and wet scrubbers should put these boilers in a good position to meet limits on acid gases. Two of the boilers may have a harder time meeting the stricter limits on fine particles, but that is still being figured out, Hoffman said.

Any plans for future controls on these two boilers also rest on EPA, which was asked by Montana officials to step in with a federal plan to clean up haze at nearby national parks and wilderness areas (Greenwire, March 22).

EPA proposed earlier this year to require more controls for nitrogen oxides at the two Colstrip boilers without the special burners, though environmentalists say the plan should be stricter.

A final plan is due next month.