A Virginia company has proposed building an electricity generating plant near the Charles County landfill in eastern Waldorf, county and company officials said last week.

The Columbia Electric Corp. facility would burn natural gas to produce up to 550 megawatts of power for sale to regional utilities, executives with the Herndon-based company said.

County officials said the so-called Kelson Ridge plant would be environmentally benign, since burning natural gas emits little air pollution and the facility would rely on treated sewage effluent for its water supply.

The plant would produce 35 permanent jobs, with as many as 700 to 800 construction jobs at peak points during a two-year building period that could start in 2001, county and company officials said.

The proposal faces eight months or more of review by state agencies that will hold public hearings as they examine the plant's likely environmental consequences and its impact on electricity consumers.

Plants like the one proposed are "one of the more benign types of generation facilities," said Pete Dunbar, director of power plant assessment for the state Department of Natural Resources, which coordinates state agencies' review.

The plant also needs approval from county planners, said Roy E. Hancock, Charles County's director of planning and growth management.

County officials have been striving to enrich an employment base dominated by low-paying retail jobs, and they reacted gleefully to Columbia's proposal.

"We are very excited about this," said Charles County Commissioners President Murray D. Levy (D-At Large). "This is a major, major investment in Charles County."

Plants the size of the proposed facility typically represent a $300 million investment, Columbia Electric President Michael Gluckman said in a telephone interview. He did not have an estimate of what the Kelson Ridge facility would cost.

The publicly funded Charles County Economic Development Commission said it had worked for 20 months "to bring Columbia Electric to Charles County."

In a speech to business leaders and government officials gathered Tuesday for the county's annual economic summit, development commission Chairman John Dockery called the power plant "perhaps the biggest thing that has happened this year."

The proposed plant would sit on 70 acres on the south side of Billingsley Road, just west of the county landfill.

It would draw natural gas from a nearby pipeline. The fuel, when burned, would turn an electricity-producing turbine that is much like a jet engine. Hot exhaust gases are used to make steam that turns a second electricity-producing turbine.

The nearest comparable facility is the Panda Brandywine power plant in southern Prince George's County, although the Waldorf plant would be larger, Gluckman said.

The Waldorf plant probably would feature two 200-foot-tall stacks to vent gases produced when natural gas is burned, as well as an undetermined number of shorter cooling towers to evaporate water, Gluckman said.

He said the plant likely would operate using only treated effluent from the county's Mattawoman Wastewater Treatment Plant, about 12 miles away in western Charles County.

However, Gluckman said, other water sources could be used, depending on final plans that haven't been drawn up yet.

The region's ground-water supplies are under strain from rapid residential development, and using such underwater sources for industrial processes has provoked criticism in the past.

Gluckman said engineers would muffle the roar produced by the plant's spinning turbines. Any noise, Gluckman said, "will not be noticeable by the local residents at all."