New California Air Standards Provide Options for Cleaning Up Diesel Vehicle Exhaust

On December 12, the California Air Resources Board ("ARB") approved stringent operating standards for diesel powered engines. 

As part of California's continuing initiative to reduce air pollutants, the ARB approved stringent operating standards for diesel powered engines applicable to approximately 170,000 businesses in nearly all industry sectors in California.  The standards require fleet owners to employ best available technology to reduce emissions of particulate matter (PM) and nitrogen oxides (NOx).  Trade associations have raised concerns about the costs to retrofit or replace engines or vehicles. 

The regulations provide affected businesses with three options by which to comply with standards for both pollutants.  Although the options provide owners with some flexibility, selecting the option that makes the most cost-effective strategy for owners will take time.  With compliance deadlines beginning in 2011, fleet owners should begin now to determine how they will comply.

Businesses, school districts, and school transportation providers that own, operate, lease or rent any of the following types of vehicles are subject to the regulation:

• On-road heavy-duty diesel fueled vehicles with a gross vehicle weight rating (GVWR) greater than 14,000 pounds.
• Yard trucks with off-road certified engines, and diesel fueled shuttle vehicles of any GVWR.
• Out-of-state trucks and buses that operate in California.

In addition, California sellers of a vehicle subject to the regulation must disclose the regulation’s potential applicability to buyers of the vehicles.

Fleets are required to install exhaust retrofits in 2011 and accelerate replacements of engines or vehicles from 2012 to 2022.  Fleets can choose among 3 compliance options for both pollutants.  School buses are required only to add exhaust retrofits for NOx, and generally would not be required to replace engines.  Small fleets (three or fewer vehicles) have extended deadlines.

In general, the regulation would require owners to reduce emissions in their fleet by upgrading existing vehicles by using one of three compliance options.

• Install PM retrofits and replace vehicles (or engines) according to a prescribed schedule based on the existing engine model year.
• Retrofit a minimum number engines each year with a high level PM exhaust retrofit and to replace a minimum number of engines meeting the 2010 new engine standards.
• Meet a fleet average. A fleet operator could use PM and NOx emission factors established by the regulation to calculate the average emissions of the fleet. Then, by the applicable compliance date each year, the owner would have to demonstrate that the fleet average emissions for PM or NOx did not exceed the PM and NOx fleet average emission rate targets set by the regulation.
  

If a vehicle cannot be safely equipped with the highest level verified PM exhaust retrofit, the fleet owner may request a one-year extension of the PM compliance deadline.  The owner would have to provide documentation to support its claims.  An example of a possible unique circumstance posing a safety concern mentioned by ARB staff would be the claim by some truckers that the only location to install a filter would block the driver's field of vision or would pose a fire hazard because of its location beneath a vehicle.