Overview of Proposed California Smog Regulations

Proposed Regulation to Reduce Emissions from In-Use On-Road Diesel Trucks and Buses

Reducing diesel emissions to protect public health

The goal of the proposed regulation is to achieve significant emission reductions which are critical to meeting clean air standards by federally mandated deadlines and protecting public health. The current proposal is still draft, and will continue to be modified prior to consideration by the Air Resources Board in October 2008.

Who would be required to comply with this proposed regulation?

Any person, business, or government agency that owns, operates, or sells diesel-powered on-road vehicles in California. The proposed regulation would apply to in-state companies as well as out-of-state companies whose vehicles operate in California.

What vehicles would be subject to this regulation?

The proposed regulation would apply to diesel-fueled vehicles with a manufacturer’s gross vehicle weight rating greater than 14,000 pounds and to diesel shuttle buses of any weight class that operate in California. This regulation would apply regardless of where the vehicle is registered. Federally owned fleets and privately and publicly owned school buses would also be subject to the regulation. On the other hand, the following diesel vehicles would not be subject to the regulation: motor homes for non-commercial private use, military tactical vehicles, and emergency vehicles.

What would the proposed regulation require for most fleets?

For fleets with 4 or more vehicles, the regulation would require the installation of exhaust retrofits in 2010 and 2011 and accelerated engine or vehicle replacement from 2012 to 2022. The proposed regulation also adds compliance flexibility by allowing fleets to choose among 3 compliance options that best suit their situation. In all cases, fleets can comply by purchasing used vehicles. School buses would be required only to add exhaust retrofits, and generally would not be required to replace engines.

What would the proposed regulation require of small fleets?

Fleets with one to three vehicles would be exempt from the 2010 and 2011 retrofit requirements. By December 31, 2012, small fleets would need to show they have one 2004 model year engine (or newer) with an exhaust retrofit. In 2017 the vehicle would need to be replaced with one meeting the 2010 engine emissions. Any other vehicles in a small fleet would need to be upgraded between 2013 and 2023.

What special considerations would be provided?

The proposal provides considerations to delay replacement of lower use vehicles and for vehicles operated in the less polluted areas of the state. Consideration is also given for various specialized farm vehicles and other less common vehicle types. Finally, options for early actions to reduce particulate matter emissions would delay engine replacement requirements.

What is the timeline for adoption of the proposed regulation?

ARB staff is currently planning further workshops in July and August. Staff will also continue to meet with affected stakeholders to better understand the financial impacts of the proposed regulation on individual businesses. The proposed regulation is scheduled to be considered by the Board in October 2008. The regulation and a staff report detailing the reasons for the regulation would be released for formal public comment by early September.

For More Information

Please contact ARB’s diesel hotline at (866) 6DIESEL (634-3735) or visit the website at: www.arb.ca.gov/dieseltruck

You may also obtain this document in an alternative format by contacting ARB at: (916) 322-4505 (voice); (916) 324-9531 (TDD, Sacramento area only); or (800) 700-8326 (TDD, outside Sacramento). TTY/TDD/Speech-to-Speech users may dial 711 for the California Relay Service.