Sonoma County, CA Noise Ordinances: Aircraft Noise (2026)

The only chapter of the Sonoma County Code titled 'Noise Control' (Chapter 3, Article III, sections 3-40 through 3-46) regulates aircraft noise at the Charles M. Schulz–Sonoma County Airport, which the County owns. Section 3-41 makes it unlawful to operate any aircraft at the airport between 6:00 a.m. and 10:00 p.m. that exceeds 83.2 dBA (Lmax) on takeoff, or between 10:00 p.m. and 6:00 a.m. that exceeds 72 dBA (Lmax) on takeoff. Compliance is determined by reference to FAA Advisory Circular 36-3E takeoff noise levels, with no adjustment for gross weight. Section 3-42 lets the Director of Aviation presume that aircraft types unable to meet these limits will violate them and bar them from the airport, subject to rebuttal. Section 3-44 sets penalties: a first violation is an infraction punishable by a $100 fine; a second or further violation within two years is a misdemeanor punishable by a fine of up to $1,000, up to six months in county jail, or both. Section 3-45 exempts government, law-enforcement, firefighting, rescue, medical-emergency and declared-emergency flights. The ordinance (Ordinance No. 4440, 1991) is enforced by the Director of Aviation under California Penal Code section 836.5. Aircraft overflight noise generally — as opposed to airport operations — is primarily a matter of federal (FAA) jurisdiction. An excerpt appears below.