The California Air Resources Board (CARB) has voted unanimously to require that emissions for diesel engines be cut as much as 90% over the next few years.
CARB will mandate particulate traps on new diesel engines sold in California, as well as retrofitting of traps on most existing diesel engines. The plan also requires production of low-sulfur diesel fuel, which is necessary for the particulate traps to work.
Details of the plan, which the agency says will cut emissions 75% over the next decade, will be covered in a series of regulations on which CARB will act in the next three years.
The vote was applauded by at least two groups: the Engine Manufacturers Association (EMA) and the Diesel Technology Forum (DTF). The EMA cautions, however, that the program must be carefully developed to ensure that the emissions goals are achievable, that technology is available to meet the challenge, and that the need for durable, reliable, and fuel-efficient products is not compromised.
EMA also warns CARB against basing diesel emission reduction policy solely on estimated health risks that have been called into question by scientists and health experts.
The DTF said it will assist CARB with implementation of its clean diesel engine management plan.
California has more than 1.2 million vehicles with diesel engines, which produce about 28,000 tons of air pollution each year, according to CARB. California is the only state with power to adopt emissions control stricter than federal standards.
CARB estimates the cost to retrofit a 475-horsepower truck engine could run from $4,750 to $9,500.