SMOG Check Exemption

Residents of the Northern Sonoma County Air Pollution Control District are not required to get SMOG checks on their vehicles, provided that the vehicle in question is registered within the district (see map).

However, in some areas where the zip code is shared with Bay Area Air Quality Management District (mainly the Knights Valley area and south Forestville/north Graton area), the DMV may send a SMOG check requirement in error.

If this occurs, you can request an exemption letter from the District, which you can then bring to DMV to have the SMOG requirement erased from your record.

Obtain an Exemption Letter

To receive an exemption letter, please visit the District Office with your Vehicle Registration Notice, PLUS either of the following:

  • Photo ID showing you reside at the address where the vehicle is registered
  • PG&E bill
  • Other bill or document showing that you reside where the vehicle is registered.

Please note that exemption letters are only available if you visit the district office in person.

Contact Information

Northern Sonoma County Air Pollution Control District
Business Hours
Monday – Friday
8:00 AM – 4:30 PM
Contact us by Phone
150 Matheson Street
Healdsburg, CA 95448
38.610885, -122.868283


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