King County, WA Noise from Specific Sources: Generator Noise (2026)
Key Facts
- Rural-to-rural limit
- 49 dB(A)
- Industrial-to-industrial limit
- 70 dB(A)
- Nighttime reduction
- 10 dB(A) quieter
- First-offense fine
- up to $125
- Enforced by
- sheriff and director
Summary
In unincorporated King County, generators count as regulated 'equipment,' so their noise can't exceed the county's maximum permissible sound levels: as low as 49 dB(A) reaching a rural neighbor, and quieter overnight.
It is unlawful for any person to cause sound, or for any person in possession of property to permit sound originating from such property, to intrude into the real property of another person whenever such sound exceeds the maximum permissible sound levels established by this chapter. (Ord. 3139 § 301, 1977. Formerly K.C.C. 12.88.010).
12.86.110 Envrionmental sound levels – maximum permissible sound levels.
A. For purposes of this subsection, sound levels shall be measured by a Type 1 or Type 2 sound level meter. Sound level measurements shall be based on the Leq during the measurement interval, using a minimum measurement interval of one minute for a constant sound source or a thirty-minute measurement for a noncontinuous sound source. For sound sources located within unincorporated King County, the maximum permissible sound levels are as follows:
Receiving Property District Rural Residential Commercial Industrial Sound Source District Rural 49 dB(A) 52 dB(A) 55 dB(A) 57 dB(A) Residential 52 dB(A) 55 dB(A) 57 dB(A) 60 dB(A) Commercial 55 dB(A) 57 dB(A) 60 dB(A) 65 dB(A) Industrial 57 dB(A) 60 dB(A) 65 dB(A) 70 dB(A)
B. During a measurement interval, Lmax may exceed the sound level limits of this section by no more than 15 db(A). For the purposes of this subsection, "Lmax" means the maximum sound over a measurement interval determined by using a sound level meter set to "fast" response time.
Full Breakdown
A generator qualifies as 'equipment' under K.C.C. 12.86.030.F, 'any stationary or portable device or any part thereof capable of generating sound', so its noise is governed by the county's environmental sound-level rules. K.C.C. 12.86.100 makes it unlawful to let sound from your property intrude onto a neighbor's land above the maximum permissible levels in K.C.C. 12.86.110, which range from 49 dB(A) rural-source-to-rural-receiving up to 70 dB(A) industrial-to-industrial. Between 10 p.m. and 7 a.m. weekdays (9 a.m. weekends), those limits drop 10 dB(A) for rural or residential receiving property under K.C.C. 12.86.120.A. A generator can also separately draw a public disturbance noise complaint under K.C.C. 12.86.410.A.2.
Violations & Fines
First violation in 12 months is a civil infraction up to $125; second up to $250; each later violation within that year doubles the prior fine, per K.C.C. 12.86.700.
Frequently Asked Questions
Does unincorporated King County regulate generator noise?
Is a backup generator exempt during a power outage?
Sources & Official References
Other rules in King County
Compare King County to another location·View the Washington noise from specific sources overview
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