State Plan Would Require Diesel Soot Traps

Calling the cancer risk from diesel soot too deadly for delay, state regulators Thursday released a first-ever plan to force owners of diesel-powered tractors, bulldozers, big rigs, school buses and other vehicles to install soot-catching equipment at costs of perhaps thousands of dollars per vehicle.

Not content to wait for a new generation of cleaner-burning diesel engines, the state Air Resources Board wants to force the retrofitting of an estimated 1.25 million engines.

Widespread installation of muffler-like soot traps, plus a new mandate for low-sulfur diesel fuel in California and strict requirements for new engines, could shrink diesel particulate pollution in California by 85% over the next two decades, according to air board scientists. The tiny, lung-irritating particles in diesel exhaust make life near busy freeways, truck stops and schools where buses idle potentially dangerous places, researchers say.

“Diesel engines are the most significant source of air toxic contaminants in California,” said Mike Kenny, executive officer of the Air Resources Board.

The board is scheduled to consider adopting the three-pronged plan in September. It set the plan in motion in August 1998, when it declared diesel soot a toxic air contaminant. Workers exposed for long periods to diesel exhaust are more likely to develop lung cancer, according to the air board, and even brief exposure can lead to coughing and bronchitis.

If approved, the plan would be fully implemented by 2010, with the goal of making existing and new diesel engines in California run 10 times cleaner than they do now. Regulators offered no overall estimate of the cost of their plan to the farmers, truckers, school districts, refiners and others who would have to carry it out.

But they did figure that installing equipment to make existing vehicles cleaner would cost from $10 to $50 per horsepower. That could mean $3,750 to $18,750 for the owner of a 375-horsepower long-haul truck.

The California Trucking Assn. on Thursday endorsed the board’s draft plan, agreeing that California must cut diesel soot pollution. Spokeswoman Stephanie Williams said the group intends to seek legislation that would impose a $25 to $50 fee on truck owners to create a board-administered fund to help small trucking company owners offset retrofitting costs.

Cynthia Corey, who monitors the issue for the California Farm Bureau Federation, said her members worry that retrofitting makes no economic sense on farm equipment that may be, for example, 30 years old and used only two months a year. Farmers wonder too about how much time they’ll have to meet new requirements and whether the state will offer financial help.

Such details will be worked out as the air board crafts actual regulations based on the broad plan released Thursday, said spokesman Jerry Martin.

The particle-trapping technology that is the key to the plan dates to the mid-1980s but is untested on a large scale, said Martin. The traps get clogged and work poorly on engines burning diesel fuel rich in the sulfur that is a natural ingredient of crude oil. That’s why another key component of the soot reduction plan is a requirement that refiners begin selling diesel fuel with roughly one-tenth the sulfur content as that now sold.

According to Martin, Arco has said it can produce enough low-sulfur fuel by 2002 to supply several thousand transit buses that must begin using it under a rule recently passed by the air board. Other refiners expect to produce the low-sulfur fuel soon, said Mike Wang, manager of operations and environment for the Western States Petroleum Assn., though it’s not clear yet how much low-sulfur fuel might be required by California or when. The U.S. Environmental Protection Agency recently proposed a national requirement for low-sulfur diesel to take effect in 2006.

Gail Ruderman Feuer, a senior attorney with the Natural Resources Defense Council in Los Angeles, praised the move toward massive retrofitting, an unusual step for an agency that tends to rely upon the evolution of cleaner-burning technology.

“If we really want to do something about pollution levels,” she said, “we have to do something about vehicles now on the road.”

Still, said Feuer, clean-air advocates worry that the diesel soot reduction plan does not do enough to force engine manufacturers to drop diesel altogether in favor of cleaner fuels such as natural gas--something the South Coast Air Quality Management District did last month when it banned the purchase of diesel-powered buses by transit operators in Los Angeles, Orange, Riverside and San Bernardino counties.

“The South Coast keeps pushing for alternative fuels,” said Feuer, “and the state air board needs to catch up.”