Orange County, CA Noise Ordinances: Industrial Noise (2026)

The Noise Control ordinance expressly contemplates industrial and commercial sources. Section 4-6-2 defines a 'fixed noise source' as a stationary device that creates sound while motionless, 'including but not limited to industrial and commercial machinery and equipment, pumps, fans, compressors, generators, air conditioners and refrigeration equipment.' Such sources are bound by the same residential exterior limits in Section 4-6-5: 55 dB(A) from 7 a.m. to 10 p.m. and 50 dB(A) from 10 p.m. to 7 a.m. when measured on any residential property, with the graduated allowances of Section 4-6-5(b) (the standard may not be exceeded for more than 30 cumulative minutes per hour, and never by 20 dB(A) for any period). If the offending sound is a simple tone (a predominant frequency that stands out, common in motors and fans), the limit is reduced by a further 5 dB(A). The ordinance gives one historic accommodation: Section 4-6-9 temporarily increased the standard by 8 dB(A) for air-conditioning or refrigeration systems installed before the article's effective date, but only for a five-year window that has long since closed. Emergency machinery and utility-restoration work are exempt under Section 4-6-7(d).