California Air Resources Board

SACRAMENTO - The California Environmental Protection Agency's Air Resources Board (ARB) is offering a free outreach and educational program to help diesel truck and bus owners reduce air pollutants from their vehicles and to familiarize them with proposed new smoke standards for diesel vehicles.

        Under Project Outreach, ARB staff will visit diesel bus or trucking fleet facilities to provide information about the proposed new standards. ARB staff will also offer to check diesel trucks or busses to see if they meet the proposed new vehicle smoke standards. Project Outreach is without cost to users and no citations or penalties will be issued in connection with ARB visits or inspections under the program.

        "The goal of Project Outreach is to help the trucking and transit industries become familiar with the proposed new smoke standards and to offer information on reducing smoke from heavy-duty diesel vehicles," said ARB Chairman John Dunlap. The ARB Board is scheduled to consider new heavy duty vehicle smoke standards, including an inspection program, December 11. If the Board approves the standards, the inspection program will go into effect in early 1998.

        The goal of the inspection program is to improve California's air quality by reducing emissions from heavy-duty vehicles. "While heavy-duty diesel vehicles comprise only 2 percent of the state's on-road vehicle fleet, they contribute 65 percent of the fleet's particulate emissions and 30 percent of the oxides of nitrogen," Dunlap said. The ARB Chairman pointed out that oxides of nitrogen, which sunlight converts to to ozone, and the particulate emissions from diesel exhaust have been linked to respiratory disease.

        Another facet of the proposed standards would require fleet operators to have their vehicles inspected annually for excessive smoke as a normal part of vehicle maintenance and to repair any trucks that do not meet the smoke standards.

        "One of the most frequent complaints we hear from average citizens concerns trucks being allowed to pour out diesel smoke and face no inspections while gasoline-powered passenger cars are subject to routine smog checks," Dunlap said. "We believe these new standards will help improve California's air quality while not placing an excessive burden on the trucking or transit industries," he added.

        ARB research has shown that excessive smoke from diesel vehicles generally results from not properly maintaining the vehicle fuel system or because of deliberate tampering with the engine. An ARB study of about 70 trucks that were emitting excessive smoke resulted in an average repair cost of about $600 to bring the vehicles into compliance with the proposed smoke standards. Routinely following manufacturers' repair and maintenance guidelines generally would assure passage of the smoke test.

        Trucking or transit companies interested in receiving more information about Project Outreach or the proposed excessive smoke standards can reach ARB staff by telephoning (916) 322-7061 in Northern California or (626) 450-6158 in Southern California.