Rule 250 Ag Engine Registration


The California Air Resources Board’s (ARB) Air Toxic Control Measure (ATCM) for Stationary Compressions Ignition Engines was revised by ARB in 2006. The revision added requirements for diesel engines used in agricultural operations. In general, these requirements apply to nearly all diesel engines used to power irrigation pumps; however, they do not apply to diesel engines used to power farm equipment such as trucks and tractors. These requirements have both administrative requirements and emission control requirements. An ARB fact sheet provides additional information and details on these new requirements.

To implement these agricultural diesel engine requirements, the District adopted Rule 250, "Registration of Agricultural Engines" on September 11, 2007.

As of March 1, 2008, all agricultural engines 50 horsepower and greater were required to be registered with Air Pollution Control District. New engines installed after September 11, 2007, must be registered within 90 days after installation. This registration program is not a permitting program, but requires application forms and fees similar to a permitting program. These fees are significantly less than permitting fees. The District recently issued a Compliance Assistance Advisory regarding enforcement of the registration requirements and advising agricultural engine operators of upcoming deadlines for older (“Tier 0”) agricultural engines.

As a part of the registration program, emission control requirements are determined for each engine on a case-by-case basis. The emission control requirements have been set by the California Air Resources Board. Newer engines may already comply with the requirements, however, older engines may need to be retrofitted or replaced to comply with the new requirements. Any diesel pump engine replaced with an electric motor or natural gas engine will not be required to register with the District. Grant money may be available from the District to replace older diesel engines with newer, compliant diesel engines, natural gas engines or electric motors.

More information on the ARB plans for diesel engines used in agricultural operations is available at "In-Use Stationary Diesel Agricultural Engines".


For questions on the District’s plans to implement these new ARB requirements, please contact Ali Ghasemi at (805) 303-4016.


For information on District grant programs, please contact Tyler Harris at (805) 303-3661


Click here to obtain a copy of the registration application form and instructions.