In a move that signaled the state’s recognition of the economic realities facing the construction industry and the state, the California Air Resources Board (CARB) announced on Oct. 7 that it will delay for five years the implementation of a controversial emissions regulation for diesel construction equipment. 

In comments submitted earlier this year, NAHB had advised the agency that the rule should not be adopted as proposed.

CARB’s “Off-Road Diesel Emission Rule,” adopted in 2007, established strict deadlines that would have required diesel equipment owners to begin replacing existing equipment with new equipment that achieved higher federal emissions standards or to retrofit existing construction equipment with after-market filters.

CARB proposed the rule to help meet overall emissions reductions that the state needed to comply with federal Clean Air Act emission reductions targets for nitrogen oxides (NOx) and particulate matter (PM). 

Only the U.S. Environmental Protection Agency (EPA) can regulate emission standards for new construction equipment. However, any state can establish emissions controls on existing construction equipment. 

CARB also claimed that implementing the diesel emission rule would help reduce greenhouse gas emissions from the 250,000 pieces of diesel equipment operating within the state.

Because CARB’s regulation represented the first state rule requiring retrofits of existing diesel construction equipment, NAHB and other construction trade groups submitted comments to the board opposing implementation of the emissions rule as proposed.

NAHB pointed out that the technical difficulties and costs of up to $8,000 per piece of equipment would have too great an impact on the construction industry. 

Citing the decrease in the state’s new construction projects, NAHB also questioned the presumed emissions reduction benefits that CARB claimed would be achieved.

Earlier this year, CARB admitted that its projected emissions reductions for PM and NOx over-estimated the emissions benefit of the rule. The profound downturn in California’s housing market further undermined CARB’s emission reduction projections. 

CARB’s decision to delay implementation of the rule — as well as to increase the number of exemptions for owners of small fleets — is expected to reduce, but not completely eliminate, the rule’s impact on the residential construction industry.

CARB is scheduled to officially amend the “Off-Road Diesel Emission Rule” when its Air Resources Board meets on Dec. 17-18.

For more information, e-mail Matt Watkins at NAHB, or call him at 800-368-5242 x8327.