Agricultural Engine Registration

Placer County Air Pollution Control District requires owners/operators of new and existing agricultural diesel engines rated at 50 horsepower or greater to register their engines with the District. Agricultural engines are either stationary or portable and are commonly used for pumping water. This does not include engines used to propel vehicles such as trucks, tractors and forklifts.


New engines can be registered with the District using the following forms:

An application fee will apply.

Compliance Dates

California Air Resources Board regulations require retirement of diesel engines by a date that is based on the engine horsepower rating and the year of manufacture. This compliance date is listed on your registration certificate. The engine can no longer be used in normal service after the compliance date listed. Many Tier 1 engines have a compliance date of December 31, 2015. View compliance dates (PDF).

The District has two limited-use options for further use of these engines beyond the compliance date:

  • Low-Use Engine - Allows continued use of the engine not to exceed 200 hours per year with a cumulative total of 2,400 hours.
  • Intermittent-Use Engine - Allows a cumulative total of 2,000 hours without a yearly limit.

The owner/operator may apply to the District (PDF) to modify the registration to a limited use engine of one of the two types. An application fee will apply.