Notwithstanding any other provision of this chapter, and in addition thereto, it shall be unlawful for any person to willfully or negligently make or continue, or cause to be made or continued, any loud, unnecessary, or unusual noise which disturbs the peace and quiet of any neighborhood or which causes any discomfort or annoyance to any reasonable person of normal sensitiveness residing in the area. Noncommercial public speaking and public assembly activities conducted on any public space or public right-of-way shall be exempt from the operation of this section.
(Ord. 90-03 §1, 1990)
If it is determined by the responding agency that a sound level in excess of the levels prescribed by this chapter exists, the following procedures shall be followed:
A. 
A written warning shall be issued by the Noise Control Officer or his or her agent to the person responsible for the event causing the disturbance.
B. 
If the disturbance persists for more than fifteen minutes following the notice, or recurs within an eight-hour period, then the person responsible for the event causing the disturbance shall be guilty of a violation of this chapter. Any such violation shall be an infraction.
(Ord. 90-03 §1, 1990)
The factors which will be considered in determining whether a violation of the provisions of this chapter exists shall include, but not be limited to, the following:
A. 
The sound level of the alleged objectionable noise;
B. 
The sound level of the ambient noise;
C. 
The proximity of the noise to residential sleeping facilities;
D. 
The nature of zoning of the area within which the noise emanates;
E. 
The number of persons affected by the noise source;
F. 
The time of day or night the noise occurs;
G. 
The duration of the noise and its tonal, musical, or informational content; and
H. 
Whether the noise is continuous, recurrent, or intermittent.
(Ord. 90-03 §1, 1990)
Upon the receipt of a complaint from a citizen, the noise control officer or his or her agent, equipped with a sound level meter, shall investigate the complaint. The investigation shall consist of a measurement taken according to the Enforcement Manual and the gathering of data to adequately define the noise problem and shall include the following:
A. 
Non-Acoustic Data.
1. 
The type of the noise source;
2. 
The location of the noise source relative to the complainant's property;
3. 
The time period during which the noise source is considered by the complainant to be intrusive;
4. 
The total duration of the noise produced by the noise source; and
5. 
The date and time of the noise measurement survey.
B. 
Acoustic Data. Utilizing the A-weighting scale of the sound level meter and the "slow" meter response, the noise control officer or his or her agent shall measure the sound level at any point on the receiver's property.
(Ord. 90-03 §1, 1990)
The provisions of this section address noise intrusions over and above the noise normally associated with a given location (intrusions over the ambient level). The ambient noise varies throughout the community, depending upon proximity to highways, population density, and land use. Different standards are set for various segments of the community which reflect the existing day and nighttime ambient noise levels. The ambient noise level is defined in terms of statistical parameters which describe the total noise occurring over any hourly time period.
A noise intrusion is judged by comparing such noise statistics with the noise source on versus such statistics with the noise source off (the ambient). Violations of the provisions of this chapter may be cited in terms of particular levels exceeded or in terms of the length of time the intrusive noise exceeded such standards. Compliance with the noise emission standards as set forth in this section shall constitute the elimination of a noise disturbance.
A. 
Exterior Noise Standards.
Exterior Noise Limits
(Levels Not to be Exceeded More Than Thirty Minutes in any Hour)
Noise Level (dBA) Noise Zone Classification
Receiving Land Use Category
Time Period
Rural/ Suburban
Suburban
Urban
One-and Two-Family
10:00p.m.—7:00a.m.
40
45
50
Residential
7:00a.m.—10:00p.m.
50
55
60
Multiple Dwelling
Residential
10:00p.m.—7:00a.m.
45
50
55
Public Space
7:00a.m.—10:00p.m.
50
55
60
Limited Commercial
Some Multiple Dwellings
10:00p.m.—7:00a.m.
 
55
 
7:00a.m.—10:00p.m.
 
60
 
Commercial
10:00p.m.—7:00a.m.
 
60
 
7:00a.m.—10:00p.m.
 
65
 
Light Industrial
Any time
 
70
 
Heavy Industrial
Any time
 
75
 
The classification of different areas of the community in terms of environmental noise zones shall be determined by the noise control officer, based upon the assessment of the community noise survey data and noise contours established by the noise element of the general plan. Additional area classifications should be used as appropriate to reflect both lower and higher existing ambient levels than those shown.
Industrial noise limits are intended primarily for use at the boundaries of industrial zones rather than for noise reduction within the zone.
B. 
Interior Noise Standards.
Maximum Permissible Dwelling Interior Sound Levels
Noise Zone
Type of Land Use
Time Interval
Allowable Interior Noise Level (dBA)
All
Multifamily
10:00p.m.—7:00a.m.
35
Residential
7:00a.m.—10:00p.m.
45
1. 
The interior noise standards for multi-family residential dwellings as set forth in this section shall apply, unless otherwise specifically indicated, within all such dwellings with windows in their normal seasonal configuration.
2. 
No person shall operate, or cause to be operated, within a dwelling unit any source of sound or allow the creation of any noise which causes the noise level when measured inside a neighboring receiving dwelling unit to exceed:
i. 
The noise standard as specified in this section for a cumulative period of more than five minutes in any hour; or
ii. 
The noise standard plus five dB for a cumulative period of more than one minute in any hour; or
iii. 
The noise standard plus ten dB or the maximum measured ambient for any period of time.
(Ord. 90-03 §1, 1990)
The maximum sound levels shall be determined as follows:
A. 
The noise standards for the various categories of land use identified by the noise control officer as set forth in Section 8.22.037 of this article, unless otherwise specifically indicated, shall apply to all such property within a designated zone.
B. 
No person shall operate, or cause to be operated, any source of sound at any location within the incorporated city, or allow the creation of any noise on property owned, leased, occupied, or otherwise controlled by such person, which causes the noise level, when measured on any other property, either incorporated or unincorporated, to exceed:
1. 
The noise standard for that land use as specified in Section 8.22.037 of this article for a cumulative period of more than thirty minutes in any hour; or
2. 
The noise standard plus five dB for a cumulative period of more than fifteen minutes in any hour; or
3. 
The noise standard plus ten dB for a cumulative period of more than five minutes in any hour; or
4. 
The noise standard plus fifteen dB for a cumulative period of more than one minute in any hour; or
5. 
The noise standard plus twenty dB or the maximum measured ambient level for any period of time.
C. 
If the measured ambient level differs from that permissible within any of the first four noise limit categories set forth in subsection B of this section, the allowable noise exposure standard shall be adjusted in five dB increments in each category as appropriate to encompass or reflect such ambient noise level.
In the event the ambient noise level exceeds the fifth noise limit category, the maximum allowable noise level under such category shall be increased to reflect the maximum ambient noise level.
D. 
If the measurement location is on a boundary between two different zones, the noise level limit applicable to the lower noise zone, plus five dB, shall apply.
E. 
If possible, the ambient noise shall be measured at the same location along the property line utilized in subsection B of this section, with the alleged offending noise source inoperative. If for any reason the alleged offending noise source cannot be shut down, the ambient noise shall be estimated by performing a measurement in the same general area of the source but at a sufficient distance such that the noise from the source is at least ten dB below the ambient in order that only the ambient level be measured. If the difference between the ambient and the noise source is five to ten dB, then the level of the ambient itself can be reasonably determined by subtracting a one decibel correction to account for the contribution of the source.
F. 
In noise sensitive zones the maximum permissible sound level shall not be exceeded by:
1. 
Creating or causing the creation of any sound within any noise sensitive zone so as to exceed the specified land use noise standards set forth in Section 8.22.037 of this article provided conspicuous signs are displayed indicating the presence of the zone; or
2. 
Creating or causing the creation of any sound within or adjacent to any noise sensitive zone containing a hospital, nursing home, school, court, or other designated area so as to interfere with the functions of such activity or annoy the occupancy in the activity provided conspicuous signs are displayed indicating the presence of the zone.
(Ord. 90-03 §1, 1990)