Senators from both parties have been asking the Environmental Protection Agency for months to supply them with analyses of air-pollution bills to determine the health benefits and costs of the proposals but have been unsuccessful, it was reported yesterday, as the administration pushes its own version of a plan affecting coal-fired power plants.

The refusal of the agency to cooperate imperils the ability of Congress to make fair decisions and costs lives as the plants are allowed to dump tons more pollution than they could affordably clean up. When it reconvenes next week, the Senate should quickly send a letter to the White House requesting cooperation from the EPA.

The Washington Post reported Tuesday that leaked documents showed a bill sponsored by Sen. Thomas Carper of Delaware would reduce power plant emissions of sulfur dioxide, nitrogen oxide and mercury earlier and by larger amounts than would the president’s bill. The documents were not made available to the senator but were leaked to the press, apparently by EPA staff members unhappy with the administration’s decision to withhold analyses of comparisons to the president’s Clear Skies proposal. The documents show the proposal by Sen. Carper would cost a negligible amount, increasing electricity prices by two-tenths of a cent per kilowatt-hour over the Clear Skies plan, while by 2020 resulting in 17,800 fewer premature deaths from power plant air pollution and saving $140 billion a year in health costs, according to The Post.

An administration official last week said the EPA had been discouraged from providing the analysis because it would show Clear Skies to be the weaker plan. If so, the administration would really dislike the Clean Power Act, sponsored by Sen. Susan Collins and co-sponsored by Sen. Olympia Snowe. That plan demands even deeper cuts in pollutants on a faster timetable than the Carper proposal. On mercury emissions, for instance, the Clean Power Act would reduce it from 48 tons currently to five tons by 2008; the Carper bill goes to 25 tons by then; and Clear Skies, which begins in 2010 would cut the toxin only to 26 tons.

It hardly needs to be said that the agency with the computer models and the experts able to interpret complex data must do so honestly and promptly. Out of principle and a determination to identify actual benefits and costs of competing air-pollution plans, the Senate should demand an end to the delays and obfuscation that is putting lives at risk for the sake of power-industry interests.