Westminster, CA Noise Ordinances: Industrial Noise (2026)

Westminster does not set a separate manufacturing-zone noise table; industrial and commercial operations are held to the same Chapter 8.28 standards as other sources, measured at the affected (typically adjacent) property line. Under WMC Section 8.28.040, the exterior limit at any point on the affected property is 55 dB(A) in citywide Zone 1 (day and night), while the elevated Zone 2 limits of 60 dB(A) day / 55 dB(A) night apply specifically to property in the R2, R3, R4 and R5 residential districts. Because industrial equipment often produces simple-tone or impact noise (compressors, pumps, presses, HVAC), Section 8.28.040(B) requires the applicable limit to be reduced by 5 dB(A) for such content, effectively tightening the standard for many plants and rooftop units. The graduated duration framework means a continuous source must stay within the base limit; exceeding it by 5 dB(A) is allowed only briefly (more than 15 minutes per hour is unlawful), and exceeding by 20 dB(A) is unlawful for any period. Existing residential air-conditioning units received a limited five-year grace exemption when the ordinance was adopted (Section 8.28.060(K)), but ongoing commercial mechanical noise must comply. Where a facility cannot meet the limits, relief is through the county noise variance board under Section 8.28.080. Vibration is also addressed by the chapter's policy declaration. These are the City of Westminster's own standards and apply throughout the incorporated city.