King County, WA Noise Ordinances: Decibel Limits (2026)
Key Facts
- Industrial-to-industrial cap
- 70 dB(A) maximum
- Industrial-to-commercial cap
- 65 dB(A) maximum
- Industrial-to-residential cap
- 60 dB(A) maximum
- Peak allowance (Lmax)
- +15 dB(A) over limit
- First-violation fine
- up to $125
Summary
Unincorporated King County limits industrial-source sound to 70 dB(A) reaching other industrial land, tapering to 65 dB(A) into commercial areas, 60 dB(A) into residential zones and 57 dB(A) into rural districts, under King County Code § 12.86.110.
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.
C. Sounds created by auxiliary equipment operated on watercraft for the purposes of operation of a marina and clam and oyster harvesting, shall be governed by this section. (Ord. 3139 § 302, 1977. Formerly K.C.C. 12.88.020).
Full Breakdown
King County Code chapter 12.86 sets zone-based decibel ceilings for sound crossing property lines in unincorporated areas. Sound is measured with a Type 1 or Type 2 meter using the Leq over at least a one-minute interval. Under the table at K.C.C. 12.86.110.A, sound from an industrial-district source is capped at 57 dB(A) reaching rural property, 60 dB(A) reaching residential property, 65 dB(A) reaching commercial property and 70 dB(A) reaching other industrial property. Momentary peaks (Lmax) may run 15 dB(A) higher. Nighttime limits drop 10 dB(A) for sound reaching rural or residential receivers between 10 p.m. and 7 a.m. weekdays, 9 a.m. weekends, per K.C.C. 12.86.120. The sheriff and Local Services enforce the chapter.
Violations & Fines
A first violation within 12 months is a civil infraction punishable by up to $125; a second up to $250; each subsequent violation up to double the prior fine, under K.C.C. 12.86.700.
Frequently Asked Questions
Does this limit apply inside Seattle or other cities?
Are the limits stricter at night?
Sources & Official References
Other rules in King County
Compare King County to another location·View the Washington noise ordinances overview
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