The rule implemented a manufacturers' supported program to significantly reduce diesel emissions from heavy-duty trucks and buses. Diesel truck and bus engines will be required to emit 50 percent less oxides of nitrogen beginning in 2004.
In response to manufacturers' requests, the EPA is expected to finalize later this year a separate program to significantly improve the quality of diesel fuel, thus enabling another significant reduction in diesel engine emissions.
The Engine Manufacturers Association (EMA) today announced their support of the 50 percent
reduction. "This ruling is the product of over five years of hard work and cooperation between the diesel industry, the California Air Resources Board and the EPA," said Glenn Keller, EMA Executive Director. "The standards for heavy-duty engines that the agency has developed with industry support are technically challenging but achievable."
"However, EMA remains concerned about the inclusion of supplemental test requirements that will not take effect until 2007. We believe that the inclusion of these requirements in the final 2004 Rule is premature." Keller noted, "Not only would further work on the supplemental requirements have yielded a more effective program, but these requirements won't be applied until the adoption of new fuels and emission control strategies that are part of the ongoing EPA rulemaking. EPA should not separate out test procedures and emission standards in different rulemakings."
With regard to speculation that the final ruling will allow the manufacturers to renege on1998 consent decrees with the Department of Justice (DOJ) Keller said, "the final 2004 regulations have nothing to do with the ongoing dialogue between some consent decree companies and federal officials regarding engine certification procedures. That is a completely separate matter."