California state regulators last week released a plan to force owners of diesel-powered tractors, bulldozers, big rigs, school buses and other vehicles to install soot-catching equipment at costs that could total up to thousands of dollars per vehicle.

According to the Los Angeles Times, the California Air Resources Board feels the risk of cancer from diesel exhaust is too high to wait for cleaner-burning diesel engines to hit the market. They want to push for the retrofitting of an estimated 1.25 million engines right away.
According to CARB scientists, a new mandate for low-sulfur diesel fuel in California and strict requirements for new engines, along with the widespread installation of soot traps, could lower diesel particulate pollution in the state by 85% over the next 20 years.
"Diesel engines are the most significant source of air toxic contaminants in California," said Mike Kenny, CARB executive officer.
The board is scheduled to consider adopting the plan in September. If the plan is approved, it would be put into full effect by 2010, with the goal of making existing and new diesel engines in California run 10 times cleaner than they currently do. Regulators offered no overall estimate of the cost of their plan to the farmers, truckers, school districts, refiners and others who it would affect, but they did proved a guesstimate 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, reported the Times.
Late last week, the California Trucking Assn. endorsed the board's draft plan, agreeing that the state needs to cut down on 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 the costs.