WASHINGTON, D.C. – The U.S. Environmental Protection Agency (EPA) now requires (as of Jun. 1) that U.S. refineries begin making ultra-low-sulfur diesel (ULSD), a fuel with 97 percent less sulfur than ordinary diesel, according to the Christian Science Monitor. The rule, which mandates that 80 percent of the diesel produced for highway use be ULSD-compliant, was just the first step. By Oct. 15, all filling stations now selling diesel will be required to sell ULSD instead of or in addition to diesel. Upon shifting to ULSD, the diesel vehicles will immediately emit about 10 percent less pollution. But the biggest pollution abatement — as much as 90 percent cleaner — will come with the EPA-mandated debut of “clean diesel” engines, probably late next year or early in 2008. The new EPA rule “is the biggest step toward cutting vehicle pollution since lead was taken out of gasoline two decades ago,” says Richard Kassel, as quotes in the Christian Science Monitor. Kassel is the director of the Clean Fuels and Vehicles Project at the Natural Resources Defense Council, an environmental group based in Washington. Heavy-duty trucks and buses will be first to take full advantage of the new fuel, with new clean-diesel engines slated to hit the road in early 2007. Some city bus fleets, like New York’s, already use ULSD. Off-road diesel vehicles — including farm and construction equipment — won’t be required to shift to ULSD immediately. Their emissions requirements will be phased in from 2007 to 2010. The new clean-diesel vehicles are expected to be no louder or dirtier than gasoline engines, but they get 20 to 40 percent better mileage per gallon. Once the new diesel rule is fully implemented in 2030, it is expected to yield a 90 percent cut in pollution from the nation’s 13 million diesel trucks and buses. That would mean more than 8,000 premature deaths averted each year and about $70 billion annually in health benefits as a result of cleaner air, the EPA estimates, as reported in the Christian Science Monitor.