Diesel Rules Pack a Punch

Environmentalists have rightly slammed the Bush administration’s environmental rollbacks, which have reversed or eviscerated rules protecting the nation’s water, air and wilderness areas. So Christie Whitman’s announcement last week of tough new rules to cut diesel emissions is welcome news.

The Environmental Protection Agency, which Whitman heads, has finally gotten religion on the dangers of diesel pollution. Scientists have long recognized that the exhaust from diesel-powered trucks, buses, ships and a host of heavy-construction vehicles can cause cancer and heart and lung illnesses and contribute mightily to foul air.

California air quality officials have already started regulating diesel pollutants, but unyielding industry opponents forced Washington regulators to move far more slowly. The rules Whitman announced focus on so-called off-road vehicles, including tractors, bulldozers and farm machinery. Although these vehicles are few in number compared with automobiles, they account for 44% of soot and 12% of smog-producing nitrogen oxides from all vehicles nationwide.

The new rules, which start to go into effect in 2008, will eventually slash soot from these diesel vehicles by 95% nationwide and smog-forming gases by 90%. The clean-air gains will come from ultralow-sulfur diesel fuel and cleaner-burning engines to be required for new tractors and bulldozers. The EPA expects to finalize this proposal next spring after hearings and public comment.

The heavy-machinery rules mirror Clinton-era regulations that cut diesel pollution from buses, big-rig trucks and recreational vehicles. The off-road vehicle proposals also underscore the wisdom of Los Angeles-area agreements, forged by environmentalists, to cut diesel fumes swirling through the neighborhoods around large warehouses and the Port of Los Angeles.

Whitman deserves credit for leading the agency on this issue. But her resolve comes as she contemplates proposals to exempt aging coal plants that install new equipment from stricter anti-pollution requirements. Progress toward cleaner air in one way doesn’t justify backsliding in another.