The California Air Resources Board has scheduled several public workshops to discuss ideas to reduce emissions from existing diesel-fueled trucks, buses, and other vehicles operating in the state, along with its proposed requirement that an estimated 1.5 million in-use trucks meet 2007 emission standards by the year 2012.

The proposed plan would force at least 1.5 million trucks to be replaced or retrofitted in order to cut diesel particulate matter and oxides of nitrogen.

CARB announced a proposed in-use truck rule in August 2007 that would have forced truck operators to replace engines twice in a nine-year span. The current proposal requires truck fleets to meet 2007 emission standards by the year 2010.

CARB redrafted the language after outcry from trucking industry representatives about the regulation’s potential costs and plans to consider approval of its in-use diesel retrofit rule later this fall.

CARB estimates the proposed in-use truck regulation will cost private businesses between $3.6 and $5.5 billion, although the California Trucking Association reportedly have said that estimate is low.

For more information about the upcoming workshops, visit http://www.arb.ca.gov/msprog/onrdiesel/onrdiesel.htm.