21.70.080 Noise and vibration.
   (a)   Purpose. Certain noise levels have been scientifically demonstrated to be detrimental to the health and welfare of individuals. A goal of the city is to minimize noise in residential areas and to prevent excessive exposure of all persons to harmful noise. This chapter establishes regulations that prohibit unnecessary, excessive, and annoying noises and vibration from all sources.
   (b)   Applicability and Exemptions. The standards provided in this chapter apply to all land uses in all zoning districts unless otherwise specified. The following are exempted from the maximum noise standards specified in this section:
      (1)   Sporting events, festivals, and other events which otherwise conform with applicable zoning requirements and have appropriate temporary use and/or noise permits.
      (2)   Sounds emanating from the operation of mobile and stationary equipment, including motor vehicles on a public highway; aircraft; outdoor implements such as power lawn mowers, power hedge clippers, and power saws; and pile drivers or jackhammers and other construction equipment.
      (3)   Sounds emanating from lawful and proper activities on school grounds, playgrounds, parks, or places wherein athletic contests take place are exempt from the provisions of this title.
      (4)   Sounds emanating from emergency equipment, air raid sirens, and other apparatus used solely for public purposes.
   (c)   Noise Measurement. Noise shall be measured with a sound level meter that meets the standards of the American National Standards Institute (ANSI Section S1.4-1979, Type 1 or Type 2). Noise levels shall be measured in decibels at the property line of the receptor property, and at least four feet above the ground and five feet from the nearest structure or wall. The unit of measure shall be designated as dBA. A calibration check shall be made of the instrument at the time any noise measurement is made.
   (d)   Maximum Noise Level.
      (1)   Residential areas. Noise levels from any property or any use shall not exceed sixty dBA as measured in any portion of any surrounding or adjacent residentially zoned property.
      (2)   Non-residential areas. Noise levels generated within any property by any use shall not exceed seventy dBA in any portion of any surrounding or adjacent property with nonresidential zoning.
   (e)   Vibration. Any use on any property within the city that generates vibration that is discernable without instruments at any lot line adjacent to an area with a residential use or residential zoning district is prohibited. The ground vibration caused by moving vehicles, trains, aircraft, or temporary construction or demolition is exempted.
(Ord. 612 Exhibit A (part), 2008).