SEC. 7-185.  EXTERIOR SOUND STANDARDS.
   (A)   The following standards, unless otherwise specifically indicated, shall apply to all property within the designated sound zone:
 
Sound Zone
Type of Land Use
Allowable Exterior Sound Level
7:00 a.m. to 10:00 p.m.
10:00 p.m. to 7:00 a.m.
I
Residential
55 dBA
50 dBA
II
Commercial
65 dBA
60 dBA
III
Industrial
70 dBA
70 dBA
IV
As identified in Figure IX-2 of the 2020 General Plan
 
   (B)   Each of the sound levels specified shall be reduced by five dBA for impulse sound and simple tone noise, or for sounds consisting of speech or music, provided, however, that if the ambient sound level exceeds the allowable exterior sound level, the ambient sound level shall be the standard.
   (C)   No person at any location within the city shall create, maintain, cause or allow any sound on property which causes the sound level, when measured on any other property, to exceed:
      (1)   The allowable exterior sound level for a cumulative period of more than 30 minutes in any hour;
      (2)   The allowable exterior sound level plus five dBA for a cumulative period of more than 15 minutes in any hour;
      (3)   The allowable exterior sound level plus ten dBA for a cumulative period of more than five minutes in any hour;
      (4)   The allowable exterior sound level plus 15 dBA for a cumulative period of more than one minute in any hour; or
      (5)   The allowable exterior sound level plus 20 dBA for any period of time.
   (D)   In the event the ambient sound level exceeds any of the first four sound level categories in subsection (C) above, the allowable exterior sound level applicable to the category shall be increased to reflect ambient sound level. In the event the ambient sound level exceeds the fifth category, the maximum allowable exterior sound level under the category shall be increased to reflect the maximum ambient sound level.
   (E)   If the measurement location is on a boundary between two different sound zones, the lower allowable exterior sound level applicable to the sound zone shall apply.
   (F)   If the intruding sound level is continuous and cannot be reasonably discontinued or stopped for a time period whereby the ambient sound level may be determined, then the measured sound level obtained while the sound source is in operation shall be compared directly to the allowable exterior sound level.  The allowable exterior sound level shall be the one applicable to the type of land use at the location of the measurement and the time of day.
   (G)   The reasonableness of temporarily discontinuing the sound generated by an intruding sound source shall be determined by the director for the purpose of establishing the existing ambient sound level at the measurement location.
(`64 Code, Sec. 19-60.6)  (Ord. No. 2292)