18.10.010 Land Use Zones.

City Code Section

(Amended by Ordinance Nos. 159276, 163608, 164010, 175775, 184101 and 188959, effective May 24, 2018.)  Except as specifically provided for elsewhere in this Title, no person shall cause or permit sound to intrude into the property of another person which exceeds the limits set forth below in this Section.  For purposes of this Section, “day hours” shall be between 7 a.m. and 10 p.m., and “night hours” shall be between 10 p.m. and 7 a.m.

A.  The sound levels established are as set forth in Figure 1 before any adjustments are applied:

FIGURE 1

PERMISSIBLE SOUND LEVELS

(7 am-10 pm, otherwise minus 5 dBA) 

Zone Categories of SourceZone Categories of Receiver (measured at property line)
-ResidentialOpen SpaceCommercial/ Mixed UseIndustrial
Residential55556065
Open Space55556065
Commercial/ Mixed Use60607070
Industrial65657075

B.  Adjustments to Figure 1.

1.  During the night hours, the sound levels of Figure 1 shall be reduced 5 dBA.

2.  During all hours, the sound levels of Figure 1 shall be decreased 5 dBA for narrow band or steady sound (apply 1 only).

3.  The adjustments provided herein are cumulative.

C.  If a dwelling unit or noise sensitive receiver is in a nonresidential zone of the City, the nonresidential standard shall normally apply, unless:

1.  a complaint is received, and

2.  the dwelling unit or noise sensitive receiver type use predates that of the noise source.  In that case, the permissible sound level, as measured at the lot line of the dwelling unit or other noise sensitive receiver, shall be 65 dBA in a commercial/mixed use zone, and 70 dBA in an employment or industrial zone, each subject to the adjustments of Section 18.10.010 B., F., and G.

D.  Nonconforming use: The maximum permissible sound level that may be emitted from any lot containing a nonconforming use shall be the same as that permitted for the most restrictive zone in which the use would be conforming.

E.  When a sound source can be identified and its sound measured in more than one zone, each of the appropriate sections shall apply at the boundaries between zones.

F.  Impulse sound: Notwithstanding the sound levels of this Section, no person shall cause or permit the operation of an impulsive noise source which has a peak sound pressure level in excess of 100 dB during day hours or 80 dB during night hours.

G.  Octave band measurements: When the Noise Control Officer makes a finding that the frequency characteristics of the sound are such that the A‑scale levels specified in Section 18.10.010 are inadequate to protect the public health, welfare, or safety, octave‑band sound pressure level measurements shall be performed.

1.  Octave‑band measurements shall be compared to the appropriate values indicated in Figure 2 for equivalent permissible dBA land use values; octave‑band sound pressure in excess of these standards shall be considered evidence of a violation of this Title.

FIGURE 2

PERMITTED OCTAVE BAND SOUND PRESSURE LEVELS

FOR GIVEN PERMISSIBLE dBA SOUND LEVELS

When the permissible dBA level is:The Maximum Octave Band Sound Pressure Levels Shall Not Exceed:
-Octave Band Center Frequency, in Hz
-31.5631252505001000200040008000
45645851464239363330
50656256504643403734
55686561555249464340
60726864605654514845
65767268646159565350
70797672696664615855
75827976737169666360

H.  When property of the receiver is unoccupied, as in the case of any undeveloped lot, sound levels in excess of those specified herein, shall be considered only as a technical violation of the standard.  No citation shall be issued in such instances, nor is corrective action required by the noise source.