§ 8.16.070. Restrictions on noise emitted from construction sites
A.
1.
Except as provided for in subsections C and D of this section, it is unlawful for any person to operate any construction device or devices on any construction site if the operation of such device or devices emits noise, measured at the lot line of the affected property, in excess of the values shown below:
Lot Use of Affected L10 Maximum Noise Property Level Level Residential 75 dB(A) 86 dB(A) Business or Office 80 dB(A) — Industrial 85 dB(A) — 2. The same level shall apply to a public way as applies to an industrial use. Measurements should not be taken closer than fifty feet or approximately fifteen meters from the nearest active construction device on the construction site. The maximum noise level shall be measured on the sound level meter at slow response.
B. The L10 level shall be determined in the following manner:
1. Every ten seconds, on the mark, the A-weighted noise level on the sound level meter with slow response is recorded until one hundred observations have been made. If, during any of these observations, a measurement is substantially affected by any source outside the construction site (such as aircraft overflight), measurements made during these periods will not be considered. However, the observation period shall be extended until one hundred valid measurements are obtained. The L10 level will be that level that is equal to the tenth highest level recorded.
2. If, in the estimation of the person taking the measurements, outside noise sources contribute significantly to the noise level, the above procedure shall be repeated (with the same outside noise source contributions) when construction is inactive, in order to determine the existing background L10 level. The L10 level during construction must exceed the background L10 level by 5 dB(A) to be considered a violation of subsection A of this section.
C.
1.
Except as provided for in subsection D of this section, it shall be unlawful to operate a construction device at any street excavation, grading or repair, utility street work installation or repair, which produces a noise level exceeding 86 dB(A) at a distance of fifty feet or approximately fifteen meters from the device.
2. The provisions of subsection A of this section shall not apply to any construction site covered by subdivision C(1). The provisions of this subsection will not be applicable to any construction device used in emergency service work that is necessary to return utility service to an area provided that within twenty-four hours such device is brought into compliance with this section or is not reused within the City until it does comply.
D. The provisions of subsections A and C of this section shall not be applicable to impact devices.
(Ord. 1121 (part), 1991)