The Bush administration in December proposed tougher rules to cut smog– and soot-forming chemicals from power plants in 30 states, hoping to improve air quality across the eastern half of the country.

The EPA proposal would cap emissions of sulfur dioxide and smog-causing nitrogen oxide at power plants from New England to the Midwest and reduce the amount of pollution that often drifts hundreds of miles across state lines. Nitrogen oxides are a major source of the Bay’s nitrogen pollution.

EPA Administrator Mike Leavitt said at the Dec. 9 Chesapeake Executive Council meeting that the rule would reduce the amount of nitrogen entering the Bay by about 8 million pounds a year by 2010. That’s about 7 percent of the 110 million pound nitrogen reduction the Bay Program estimates is needed to clean up the Chesapeake.

“This will be the largest single investment in air quality in the history of the United States,” Leavitt said. “It will allow us to proceed forward with more progress in cleaning up our air than anything we have done in the past decade, exceeded only by our very successful efforts in acid rain.” He estimated that upgrades to meet the new pollution control requirements would cost the industry as much as $5.5 billion annually when fully put in place. The new pollution ceilings would go into effect beginning in 2015.

Under the rules, sulfur dioxide emissions would drop by 3.7 million tons by 2010 (a cut of 40 percent from current levels) and by another 2.3 million tons when the rules are fully implemented after 2015, for a total reduction of nearly 70 percent from today’s levels. NOx emissions would be cut by 1.4 million tons by 2010, and by a total of 1.7 million tons by 2015, for a total reduction of about 50 percent from today’s levels in the 30 states affected by the rules. Emissions will be capped at the 2015 levels so they cannot increase.

The rules, aimed primarily at reducing long-distance air pollution, will help states, especially in the Northeast, to meet the more stringent federal health-based air quality standards that were issued in 1997 but until recently had been held up in protracted litigation.

While the EPA sets the overall ceiling on future emissions, states and the industry will have to work out how the emissions reductions are achieved. The proposed rule would allow for a trading system by which plant operators would be able to buy pollution allowances from other plants that have exceeded their required reductions.

The proposed reductions mirror the pollution cuts in the Bush administration’s “Clear Skies” legislative proposal that has been bogged down in Congress for more than a year. Leavitt said the administration will continue to pursue approval of the Clear Skies initiative in Congress.