.  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 Receiver (measured at property line)
Zone Categories of Source Residential Open Space Commercial Industrial
Residential 55 55 60 65
Open Space 55 55 60 65
Commercial 60 60 70 70
Industrial 65 65 70 75

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 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.

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.