The U.S. Energy Department yesterday dealt a setback to opponents of a proposed high-voltage electric transmission line that would pass through Washington and Greene counties, and to critics of similar projects elsewhere.

The department designated a large swath of the northeastern United States as a National Interest Electric Transmission Corridor, giving the federal government the ability to override state decisions on placement of transmission lines and to take private property through eminent domain.

Energy Secretary Samuel Bodman approved the designation, which includes eight states, the District of Columbia, and 52 of Pennsylvania's 67 counties. A similar corridor was approved for the southwest United States.

Power companies that want to build multistate transmission lines to improve the nation's aging electricity grid have faced local and state opposition that has stalled the projects, sometimes for years.

Mr. Bodman said the designations "serve as an important indication by the federal government that significant transmission constraint or congestion problems exist. By designating these national corridors, we are encouraging stakeholders in these regions to identify solutions and take prompt action."

The federal transmission corridor was opposed locally because of a plan by Greensburg-based Allegheny Power to construct a 37-mile, 500-kilovolt power line through Washington and Greene counties. In a related project, the company plans to build an additional transmission line from Greene County through West Virginia and Maryland, ending in northern Virginia.

"It's almost as if the hearings never took place," said Robert Lazaro, director of communications for the Piedmont Environmental Council, referring to a series of public hearings at which the Energy Department gathered input over its draft corridor, proposed in May. Hundreds of local residents turned out to one of the hearings in South Park in June.

No changes to the draft corridor were made, despite more than 2,000 public comments and letters.

Opponents, including Gov. Ed Rendell, mostly questioned the size of the corridor and its necessity. A report released last year by the Energy Department declared much of the East Coast, from southern New York to northern Virginia, in "critical" need of new energy sources.

According to the Energy Department, the corridor needed to be large to accommodate as many electric transmission options as possible.

Allegheny Power has said the Washington-Greene line is meant to serve Pennsylvania customers only, but opponents have questioned that, saying they believe the company will tap local coal-fired generation plants to supply the energy-strapped East.

The project is under consideration now by the state Public Utility Commission. Yesterday's designation means that if the state denies a construction permit, makes no decision within a year or places too many restrictions on the company, it would have the right to seek a permit from the federal government.

Allegheny Power spokesman Allen Staggers said the company remains committed to the state process.

"We've said all along we intend to work with state regulators," he said.

He said yesterday's decision is a recognition from federal officials and policy makers that the electric grid in the mid-Atlantic region is in serious need of an upgrade.

Local groups said the decision promotes an outmoded solution for a problem that needs contemporary thinking toward demand-side management, conservation and alternative energy sources.

"There is overwhelming opposition to this in Pennsylvania," said Will Burns, attorney for the Energy Conservation Council of Pennsylvania, a grass-roots organization representing local property owners. "They ignored thousands and thousands of criticisms. They essentially ignored everything that everyone said."

U.S. Sens. Arlen Specter, R-Pa., and Bob Casey, D-Pa., said they were disappointed by the Energy Department's action.

"It is disheartening that after strong opposition from local and state governments and a public outcry of opposition that the department plans to proceed with no changes," they said in a letter yesterday to Mr. Bodman.

American Electric Power Co., owner of the largest U.S. transmission system, plans to build as much as $15 billion worth of new power lines. The Columbus, Ohio-based company last month joined with Warren Buffett's MidAmerican Energy Holdings Co. to form a company aimed at investing in high-voltage transmission lines.

"All of us have chosen to shy away" from new transmission lines in the past, Michael Morris, chief executive officer of American Electric, told an investor conference in New York in September.

"They are almost impossible to build."

American Electric completed a $306 million, 90-mile power line from West Virginia to Virginia in 2006. The project took two years to build after 14 years to obtain permits, Mr. Morris said.

Congress gave the Energy Department new authority two years ago to designate the corridors in an effort to boost investment in the power grid.

"Much of the system in place today is 30 to 50 years old, and while it served our last century very well, it is not going to serve the next century very well," Kevin Kolevar, assistant U.S. secretary for electricity delivery and energy reliability, told reporters on a conference call yesterday.

The finalized mid-Atlantic corridor would run from Virginia and Washington, D.C., north to include most of Maryland, all of New Jersey and Delaware and large sections of New York, Ohio, Pennsylvania and West Virginia.

The Southwest corridor is composed of seven counties in southern California and three in Arizona.

In New York, the corridor plan has generated opposition from local community activists, preservationists and environmentalists fighting a proposed power line running nearly 200 miles from the center of the state toward the more populous suburbs surrounding New York City.

U.S. Rep. Maurice Hinchey, D-N.Y., who has lobbied against the construction of that line, called yesterday's announcement "just ridiculous."

"They're using two blackouts to try and make an excuse for setting up these transmission lines. We're going to fight them both in Congress and in the courts," Mr. Hinchey said.