Local and state air quality regulations and compliance standards for diesel engines effect stationary, portable, off-road (currently not including majority use agricultural equipment) and on-road equipment. Mendocino County Farm Bureau has successfully worked with regulatory agencies, our membership and California Farm Bureau Federation to lessen the impacts on agricultural operations. Emission standards and air quality issues will continue to evolve in California and Farm Bureau will continue to advocate for polices that do not overly burden agriculture and rural areas of the state with compliance mandates.

Emission Compliance Funding Resources

FARMER Program

In March of 2018, at the California Air Resources Board (CARB) meeting, the Funding Agriculture Replacement Measure for Emission Reductions (FARMER) program was approved. The FARMER funding was used to provide $135,000,000 in funding statewide to provide incentives for the replacement of: agricultural harvesting equipment, heavy-duty trucks, agricultural pump engines, tractors and other equipment used in agricultural operations.

Mendocino County Farm Bureau continues to work with the Mendocino County Air Quality Management District staff and our membership to encourage participation in the FARMER program. The annual outreach has been successful and Mendocino County has submitted numerous eligible projects for funding consideration. 

Additional rounds of funding applications are expected and those with diesel engines that need to be replaced for compliance reasons are encouraged to contact the Mendocino County Air Quality Management District for additional information.

Mendocino County Air Quality Management District (MCAQMD)


Carl Moyer Grant Funds

The Carl Moyer Program is a voluntary grant program that reduces air pollution from vehicles and equipment by providing incentive funds to private companies and public agencies to purchase cleaner-than-required engines, equipment, and emission reduction technologies. The program has been implemented since 1998 through a partnership between the California Air Resources Board (CARB) and California’s 35 local air pollution control and air quality management districts.

Projects that reduce emissions from heavy-duty on-road and off-road equipment qualify for Moyer grants. Eligible engines may include on-road trucks over 14,000 lbs. gross vehicle weight, off-road equipment such as construction and farm equipment, marine vessels, locomotives, stationary agricultural equipment, forklifts, light-duty vehicles, airport ground support equipment, lawn and garden equipment, and emergency vehicles.

MCAQMD Carl Moyer Website 

CARB Carl Moyer Website 

CARB Diesel Engine Regulations

On-Road Regulation: Agricultural Vehicle Extension

The current agricultural vehicle exemption is expiring as of January 1, 2023. Once the agricultural vehicle extension expires, agricultural trucks must be upgraded with a 2010 or newer model year engine or claim any remaining flexibility options the vehicle may be eligible to use.

The remaining flexibility options include:

Low Use Exemption: The mileage limit is less than 1,000 miles per year in California.  Vehicles that are designed to power other equipment that can only be used while stationary must be operated less than 100 hours per year and those hours must be reported every compliance year

NOx Exempt Area Extension: Vehicles that operate exclusively in areas defined as NOx Exempt Areas and have a PM filter installed do not need to be replaced. Each January, or within 30 days of purchasing a vehicle, owners must report fleet information and identify which vehicles will operate ONLY in NOx Exempt Areas to take advantage of the extensions. Trucks enrolled into the NOx exempt extension must be labeled with NE on both sides of the vehicle.  MCFB has compliant NE stickers available for purchase at our office if needed.

The following counties make up the NOx Exempt Areas: Alpine, Colusa, Del Norte, Glenn,
Humboldt, Lake, Lassen, Mendocino, Modoc, Monterey, Northern Sonoma, Plumas, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz, Shasta, Sierra, Siskiyou, Tehama, Trinity, and Yuba

On-Road Heavy-Duty Diesel Vehicles (In-Use) Regulation Information and Reporting

CARB Truck Stop: Diesel Regulation Information

CARB Vehicle Smoke Inspection Programs

Sonoma County Air Districts and District Maps (For NOx Exempt Area Reference)

Truck Labels Available for the NOx Exempt (NE) On Road Extensions

Mendocino County Farm Bureau has NE stickers that meet regulation standards (sample above) available at the MCFB office. Stickers are $4/set of two for MCFB members and $5/set of two for non- MCFB Members.

Off-Road Regulation: Vehicles Used in Agricultural Operations

The CARB Off-Road Regulation provides that all off road vehicles used exclusively for agricultural operations, including first processing after harvest, do not need to report, label, or control the emissions from those vehicles under the Off-Road Regulation. San Joaquin Valley is the ONLY area in California with a separate regulation on emissions related to off road mobile agricultural equipment at this time. 

If a vehicle is used over half the time (a majority), but not exclusively, in agricultural operations it is exempt from the performance requirements, but still must comply with the reporting and labeling requirements of the off road regulation. If a vehicle is used less than half the time for agricultural operations, the vehicle must comply with all requirements of the Off-Road Regulation. However, when calculating the hours of usage for the vehicle (for example, to determine low-use status), the hours used in agricultural operations may be excluded from the total number of hours reported to ARB. For more information on the off road regulation in relation to agricultural operations, please visit:

CARB Off Road Diesel Regulation Resource and Reporting Page 

Burn Permits and Smoke Management 

Open outdoor burning is only allowed on permissive burn days with a valid burn permit within specified hours. Permit specifications vary depending on the time of the year and location of the property where the burn will occur. 

MCAQMD Burn Permit Information 

List of Local Agencies to Contact Regarding Burn Permits 

A Smoke Management Plan (SMP) is required for any of these conditions:

  • The burn(s) is a broadcast burn
  • The burn(s) is expected to equal or exceed ten (10) acres.
  • The fuel loading for the burn is equal or exceed fifty (50) tons.
  • The burn has the possibility to impact sensitive receptors.
  • The applicant was previously fined for open burning.
  • The MCAQMD determined a SMP is needed.

Contact the Mendocino County Air Quality Management District to determine if a SMP will be needed.