Southern California, home to some of the
dirtiest air in the nation, is dumping diesel engines in favor of
cleaner-burning energy sources such as natural gas and
Last year, a report conducted by the
South Coast Air Quality Management District, a local air pollution
control agency, found that diesel exhaust is responsible for 70
percent of the potential carcinogens in local air pollution. In
June, the district unanimously passed three rules targeting a
reduction in diesel emissions.
The new rules
focus on the gradual replacement of diesel fleets operated by
public agencies. As old garbage trucks and public buses wear out,
agencies will purchase nondiesel models. During this process,
private contractors will build new fueling stations for natural gas
and electric vehicles.
While this is a step in
the right direction, Bill Kelly of the district says, existing
diesel fuel also needs improvement, since hundreds of thousands of
diesel vehicles will continue running for several years. "The
average school bus is anywhere from 10 to 20 years old," he says.
"Only a handful are going to be replaced each year." This month,
the district will review a rule that would require public agencies
to purchase low-sulfur diesel.
environmentalists laud California's efforts, they are also pushing
to reduce diesel emissions in privately owned vehicles. Julie
Masters of the Natural Resources Defense Council says public fleets
should be taking the lead in diesel reduction, but private trucking
companies should follow their examples. The council recently won a
lawsuit against several supermarket chains in California, a
decision that requires the companies to purchase 150