Clackamas County, OR Noise from Specific Sources: Generator Noise (2026)

Code 6.05.020(L)(9) lists heat pumps, air conditioning units, generators, blowers and refrigeration units, including those mounted on vehicles, as examples of a regulated SOUND SOURCE, so a generator is squarely inside the chapter's reach. The chapter's general per se rule then applies: under Code 6.05.040(A), no sound source may exceed 50 dBA at any time between 10 p.m. and 7 a.m., or 60 dBA between 7 a.m. and 10 p.m., regardless of what is making the noise.

Generators get an extra, more specific rule. Code 6.05.040(B)(12) makes it a per se violation, between 10 p.m. and 7 a.m., to operate any noise-creating blower, power fan, or any internal combustion engine, the operation of which causes noise due to the explosion of operating gases or fluids, when the noise is unreasonably loud and reaches a dwelling or noise-sensitive area, which squarely describes a gas- or diesel-powered generator engine running at night.

The chapter carves out real exceptions that matter for generators: sounds from emergency work, meaning work to prevent or address actual or imminent physical trauma or property damage, including utility restoration (Code 6.05.060(B)), and sounds from industrial, commercial, timber-harvesting, or utility organizations or workers during their normal operations (6.05.060(F)) are exempt. An owner who expects to run a loud generator outside those exceptions, for a planned event or extended outage, can apply to the county for a variance, which must state the provision at issue, the duration sought and the reason, and which the county must approve, deny, or approve with conditions within ten days (6.05.070).