9.8.104: PERMISSIBLE NOISE LEVELS:
A noise measured or registered as provided in section 9.8.103 of this part from any source other than as provided in section 9.8.109 of this part at a level which is equal to or in excess of the db(A) established for the time period and zones listed in this section, is declared to be excessive and unusually loud and is unlawful.
 
   Zone
7:00 A.M. To Next 7:00 P.M.
7:00 P.M. To Next 7:00 A.M.
Residential
 
55 dB(A)
 
50 dB(A)
Commercial
 
60 dB(A)
 
55 dB(A)
Light industrial
 
70 dB(A)
 
65 dB(A)
Industrial
 
80 dB(A)
 
75 dB(A)
 
For purposes of this section only, these zones shall be defined as follows:
   A.   Residential: An area of single or multi-family dwellings where businesses may or may not be conducted in the dwellings. The zone includes areas where multiple-unit dwellings, high rise apartment districts, and redevelopment districts are located. A residential zone may include areas containing accommodations for transients such as motels and hotels and residential areas with limited office development, but it may not include retail shopping facilities. Residential zone includes educational facilities, hospitals, nursing homes and similar institutions.
   B.   Commercial:
      1.   An area where offices, clinics and the facilities needed to serve them are located;
      2.   An area with local shopping and service establishments located within walking distances of the residents served;
      3.   A tourist oriented area where hotels, motels and gasoline stations are located;
      4.   A large integrated regional shopping center;
      5.   A business strip along a main street containing offices, retail businesses and commercial enterprises;
      6.   A central business district; or
      7.   A commercially dominated area with multiple-unit dwellings.
   C.   Light Industrial:
      1.   An area containing clean and quiet research laboratories;
      2.   An area containing light industrial activities which are clean and quiet;
      3.   An area containing warehousing; or
      4.   An area in which other activities are conducted where the general environment is free from concentrated industrial activity.
   D.   Industrial: An area in which noise restrictions on industry are necessary to protect the value of adjacent properties for other economic activity, but shall not include agricultural operations.
   E.   Adjacent Zones: When a noise source can be measured from more than one zone, the permissible sound level of the more restrictive zone shall govern. (Ord. 96-41; Ord. 01-42)