PacifiCorp's Jim Bridger Power Plant near Rock Springs is one of the largest industrial sites in Wyoming and, unfortunately, one of the largest sources of air pollution in the nation.

According to PacifiCorp's own monitoring data, emissions from Jim Bridger exceeded permit limits for opacity thousands of times in the last five years. (Opacity is a measure of the density of pollution being released and is an indication of the amount of breathable particles, colored gases, and other light-reflecting and absorbing chemicals in the plant's emissions.)

These pollutants can cause serious human health problems, can be harmful to wildlife, and can contribute to local and regional haze.

The federal Clean Air Act requires major sources of air pollution like Jim Bridger to obtain an operating permit that spells out emission limits and monitoring requirements. Emission monitoring information is available to the public and, under the "citizen suit" provision of the Clean Air Act, citizens may take legal action to stop violations of an air pollution permit.

It is against this backdrop that the Wyoming Outdoor Council and the Sierra Club have filed a federal lawsuit to stop violations of the opacity limits in the permit for the Jim Bridger Power Plant.

PacifiCorp Energy President Bill Fehrman claimed in a press release on Feb. 21 that the Wyoming Outdoor Council/Sierra Club lawsuit "has no merit and does not involve a risk to the health and welfare of the citizens of Wyoming." This statement is both cavalier and untrue. PacifiCorp's own monitoring reports submitted to the Wyoming Department of Environmental Quality show the opacity violations, and opacity is regulated to protect public health.

PacifiCorp's news release also claimed it has plans to spend millions of dollars to upgrade pollution control equipment at Jim Bridger. While we applaud these efforts, we also believe they won't fix the opacity violations.

What's a possible solution? Baghouses have been shown to be an excellent method for minimizing opacity, thereby achieving compliance with the Clean Air Act, protecting the health of citizens, and reducing pollution haze. (Baghouses use a filtration system that removes solids from exhaust streams, chiefly through the use of long fabric tubes called "bags.")

It's interesting to note that PacifiCorp has proposed baghouses for its Hunter and Huntington Power Plants in Utah, yet so far has not proposed the same upgrade at Jim Bridger.

The Wyoming Outdoor Council and the Sierra Club entered into the lawsuit only after good-faith negotiations with PacifiCorp broke down in February.

The two groups are seeking full and prompt compliance with the current opacity provisions in the Jim Bridger operating permit, and penalties payable to the federal government for past opacity violations. Citizens of Wyoming - and indeed the entire Rocky Mountain West - deserve the best air quality protections available.

Tom Bell founded the Wyoming Outdoor Council and High Country News. He is a member of the Wyoming Outdoor Council and the Sierra Club. He lives in Lander, Wyo.