SACRAMENTO–  A comprehensive plan (https://ww3.arb.ca.gov/diesel/documents/rrpapp.htm)to reduce harmful particulate matter (PM) emissions from diesel equipment was approved Thursday by the California Environmental Protection Agency's Air Resources Board (ARB).

    The Diesel Risk Reduction Plan (Diesel RRP) proposes a three-pronged approach that would require use of low-sulfur diesel fuel; retrofitting existing engines with PM filters; and nearly a 90 percent reduction of PM emissions from all new diesel engines and vehicles.

    "Full implementation of this plan means a reduction in health-damaging diesel PM emissions of 75 percent by 2010 and 85 percent by 2020,' said ARB Chairman Dr. Alan Lloyd.  "This plan will benefit the health of every California resident and every person who visits California," he added.

    While the plan is non-regulatory, its approval today means ARB staff, over the next several years, will develop and bring to the Board for action up to 14 regulatory items related to diesel fuel and diesel engines.  These would include four measures reducing emissions from on-road equipment, four reducing emissions from off-road equipment, five reducing emissions from stationary and portable engines.  There will also be a regulation requiring Phase 2 (low-sulfur) diesel fuel.

    "This is an ambitious but necessary plan to reduce the public's exposure to harmful diesel exhaust," said California Environmental Protection Agency Secretary Winston Hickox.  "As the ARB proceeds with specific regulations, I have communicated my desire that they look for solutions that properly balance the protection of public health with a sense of the economic consequence."

    The proposal to cut diesel PM emissions results from ARB's 1998 action identifying diesel PM as a toxic air contaminant, with the potential to cause more than 500 cancer cases per million persons.  This ruling, made after an exhaustive 10-year scientific assessment process, prompted ARB to begin searching for means to reduce diesel PM emissions.  The Diesel RRP is the result of that search.   Control proposals will also consider the feasibility of other technologies, such as compressed natural gas and electric motors, as possible alternatives to diesel.

    The state's more than 1.2 million diesel-fueled vehicles and engines contribute about 28,000 tons per year of PM to California's air.  These emissions come from more than 1 million on-road and off-road vehicles; about 15,000 stationary engines and about 50,000 portable engines.

    To aid in implementation of the Plan, ARB has formed a committee of more than 40 international experts to assess the best technology for reducing diesel PM.  The Diesel Retrofit Advisory Committee will hold its first meeting in Los Angeles in early November.