The California Air Resources Board (CARB) in November plans to revise its off-road diesel emissions regulations that would impact the fleets of equipment rental companies in California. CARB is currently holding a series of workshops to discuss new inventory estimates after it was determined that CARB’s initial emissions inventory estimates were wrong.

The American Rental Association (ARA) has been involved in the process, with Dr. Michael Graboski, a consulting engineer to the ARA, and John McClelland, ARA’s vice president for government affairs, representing the equipment rental industry and working directly with CARB staff.

“CARB will propose changes to the regulation this month. These are a result of CARB’s admission that they have significantly overestimated diesel fuel use by off-road equipment and thus the emissions,” Graboski said.

“We have worked with CARB staff to insure that the emission inventory is correct and consistent with diesel fuel consumption in California. However, any new regulatory proposals from CARB are likely to be based on the state’s perceived need to meet the pledge for emissions reductions in the South Coast area — Los Angeles — as required by the federal fine particulate standard that must be met in 2015. At this time, CARB has reported that the emissions from on-road trucks are higher in the South Coast and emissions from construction equipment are lower. Even so, there seems to be room for regulatory relief. We just don’t know exactly what they will propose, but we are carefully following the issue and representing the rental industry’s unique situation,” he said.

The Associated General Contractors of America (AGC) last week called on CARB members to repeal the off-road diesel emissions rule “quickly and completely.”

“The fact that this agency has been willing to find and fix the significant flaws in its original estimates is a victory for sound science over rash regulation,” said Mike Kennedy, AGC’s general counsel. “As the agency’s own data now makes clear, it is time for the board to repeal its costly and unneeded rule.”

Kennedy said the state’s new forecasts are for emissions of nitrogen oxide from the regulated fleets to fall well below the levels that the state has targeted in each and every year through 2025. The state now predicts that emissions of particulate matter will fall below the targeted levels through 2015 and will remain close to those targets through 2025.