No loudspeaker, bells, gongs, buzzers, mechanical equipment or other sounds, attention attracting, or communication device associated with any use shall be discernible beyond any boundary line of the parcel, except fire protection devices, burglar alarms and church bells. The following provisions shall apply:
A. In residential areas, no exterior noise level shall exceed 65dBA and no interior noise level shall exceed 45dBA.
B. All residential developments shall incorporate the following standards to mitigate noise levels:
1. Increase the distance between the noise source and receiver.
2. Locate land uses not sensitive to noise (i.e., parking lots, garages, maintenance facilities, utility areas, etc.) between the noise source and the receiver.
3. Bedrooms should be located on the side of the structure away from major rights-of-way.
4. Quiet outdoor spaces may be provided next to a noisy right-of-way by creating a U-shaped development which faces away from the right-of-way.
C. The minimum acceptable surface weight for a noise barrier is 4 pounds per square foot (equivalent to 3/4-inch plywood). The barrier shall be of a continuous material which is resistant to sound including: (1) masonry block; (2) precast concrete; or (3) earth berm or a combination of earth berm with block concrete.
D. Noise barriers shall interrupt the line of sight between noise source and receiver.
(Prior code § 159.20.030(15))