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))