¡ª A $1.3 billion coal-fired power plant in eastern Arkansas is expected to be completed two years from now, providing much needed electricity at affordable costs, developers say.

Houston-based Dynegy Inc. and LS Power Development LLC, based in New Jersey, broke ground on Plum Point Energy Station at Osceola in May 2006. They expect to begin operating in 2010.

The 665-megawatt unit would generate power for utilities in eight states from Texas to Illinois. A proposed second unit would boost the output to 1,330 megawatts.

But environmentalists say the plant will be a major new source of pollution.

"If they build all 1,300 megawatts, it will be one of the biggest new sources of global-warming pollution in the U.S. in the last 30 years," says Bruce Nilles, director of the Sierra Club's national coal campaign.

Nilles says Plum Point also will contribute to air quality concerns in the region, regardless of any controls built into the plant.

The plant site is north of Crittenden County and Memphis, Tenn., in Shelby County. The two counties already violate federal standards for ozone pollution.

With the new plant, Nilles says, "it's like smoking with filters. Is that healthy?"

Coal-fired power plants emit carbon dioxide, the chief culprit of global warming. They release nitrogen oxides, which produce smog; sulfur dioxide, which causes acid rain; mercury and particulate matter.

Plum Point officials say the plant will be outfitted with state-of-the-art pollution controls, including equipment to minimize nitrogen-oxides, scrubbers for sulfur-dioxide and filters to trap toxic mercury emissions. The plant will burn low-sulfur coal from the Powder River Basin of Wyoming and Montana.

However, none of the controls will deal with carbon emissions. Supporters of coal point to emerging technology that could capture and store carbon, and the industry supports proposed legislation in Congress to fund research into the technology. The use of capture-and-storage technology likely would greatly increase the cost of coal-fired plants.

Dynegy spokesman David Byford says coal remains an affordable solution to the world's energy demands and a source more available to the U.S. than foreign oil. Coal plants remain cheaper to build and operate than nuclear reactors and natural gas-fired plants.