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

Monterey County's primary tool for industrial and stationary-source noise is Section 10.60.030 (Operation of noise-producing devices restricted). It prohibits any person from operating, allowing, or causing to be operated any machine, mechanism, device, or contrivance that produces a noise level above the code's cap measured 50 feet away, at any time of day. The original cap was 85 dBA, reduced to 70 dBA by the February 2024 amendment (Ordinance 5411). Two important limits on the prohibition appear in the same section: it does not apply to aircraft, and it does not apply to a device operated more than 2,500 feet from any occupied dwelling unit, which accommodates remote industrial and resource-extraction equipment. During the nighttime period, stationary sources are additionally subject to Section 10.60.040's 'loud and unreasonable sound' prohibition and the Table 1 exterior standards of 45 Leq dBA (hourly) and 65 dBA maximum at the property line. Commercial agricultural operations (excluding activities at farm-related housing) are exempt from the Sec. 10.60.040 nighttime rules, which matters for ag-processing equipment. Larger industrial uses are also conditioned through HCD Planning Conditions of Approval and the County General Plan.