Mohave power plant to install scrubbers, cut pollution clouding Grand Canyon

Scott Thomsen

Wednesday, Oct. 6, 1999 | 11:02 a.m.

PHOENIX - Owners of a coal-burning power plant, often blamed by environmentalists for clouding the view of the Grand Canyon, agreed to install pollution equipment to settle a lawsuit.

The agreement among the owners of the Mohave Generating Station in Laughlin, Nev., the Grand Canyon Trust and the Sierra Club includes installation of smokestack scrubbers, a filter system and new burners for the plant's boilers.

"This is going to be one of the largest cleanups of one of the old coal-powered plants in the West," said Rick Moore, air quality program officer for the Grand Canyon Trust. "This plant regularly belches enormous plumes of soot and smoke."

Improvements at the plant are designed to cut sulfur dioxide emissions by at least 85 percent and to reduce nitrogen oxides and soot. The project could cost $300 million and is to be finished by April 1, 2006.

Bob Wyman, an attorney for the owners, said the plant has stayed within federal emissions guidelines, but settling the lawsuit makes it easier to continue operations in an increasingly competitive energy market. "We've done what we can to give it the best chance possible."

Mohave, located in Laughlin, Nev., 75 miles from the Grand Canyon, is the last large power plant operating in the Southwest without equipment to control sulfur pollution, said to Chris Leshock, a coal consultant with Research Data International in Boulder, Colo.

The 28-year-old Mohave plant has been blamed for contributing to the haze over the Grand Canyon. Environmental groups contend it routinely exceeded federal emissions standards for sulfur dioxide, a clear emission that combines with other atmospheric chemicals to cloud the sky.

In 1998, the Grand Canyon Trust and the Sierra Club filed a federal lawsuit trying to force a cleanup. The environmental groups and the plant's owners submitted a consent decree to the U.S. District Court in Las Vegas today to resolve the suit. A judge now has 45 days to review the settlement agreement in deciding whether to accept it.

The plant is owned by Southern California Edison, the Los Angeles Department of Water & Power, the Nevada Power Co. and the Salt River Project in Phoenix. It produces 1,580 megawatts of energy each year - enough to serve up to 1.5 million households in California, Arizona and Nevada.

It also produces a lot of pollution.

The plant is fueled by coal-slurry pumped through a 273-mile pipeline from the Hopi and Navajo reservations in northeast Arizona. Each year, the plant burns about 6 million tons of coal. It emits about 40,000 tons of haze-creating sulfur dioxide, 10,000 tons of soot and 20,000 tons of nitrogen oxide, the pollution that stains the air over many large cities brown.

Once the scrubbers are in place, they will spray dry lime into Mohave's smokestacks, which then will react with the sulfur dioxide to create a form of gypsum. The gypsum falls into collection traps for disposal. The equipment is expected to cut sulfur dioxide emissions to about 6,000 tons per year.

That is the equivalent of removing the exhaust of 6 million cars, said Rob Smith of the Sierra Club. "This plant will go from one of the dirtiest to one of the cleanest in the Southwest."

A bag house - which operates much like the dust bag on a vacuum cleaner - will filter exhaust gases to reduce soot and smoke.

Additionally, the new, more efficient burners are expected to reduce the amount of nitrogen oxides.

"You've gone from a filthy rich company to a clean rich company and we appreciate that," Jack Ehrhardt, the Mohave Valley resident who helped bring the lawsuit, told the owners during a press conference this morning.

The Mohave project follows recent improvements at another coal-burning plant affecting the Grand Canyon. A wet-scrubbing system now is operating at the Navajo Generating Station near Page as part of a $420 million upgrade.

Moore said it is difficult to say how much the cleanup will improve visibility at the Grand Canyon because weather conditions and many other pollution sources, including cars in Los Angeles and Phoenix, affect the amount of haze. But he said the air will be noticeably clearer.

"Both of these plants are examples of corporations stepping up to the plate and taking care of their environmental responsibilities," Moore said. "Cleaning up these two plants is definitely going to improve visitors' experiences at the Grand Canyon."