It is declared to be the policy of the city, in the exercise of its police power, to prohibit unnecessary, excessive and annoying noise levels from all sources. At certain levels, noises are detrimental to the health and welfare of the citizenry and, in the public interest, shall be systematically proscribed. It is the purpose of this chapter to prescribe standards for and to prohibit such unacceptable noises and to provide an effective and readily available remedy for violations of this chapter. The provisions of this chapter and the remedies contained herein shall be cumulative and are not intended to replace any otherwise available remedies for public, private or mixed nuisances, nor any other civil or criminal remedies otherwise available.
(Ord. 1380 § 1)
As used in this chapter, unless the context otherwise clearly indicates, certain words and phrases used herein are defined as follows:
Ambient, local.
"Local ambient" is the all-encompassing noise associated with a given environment, being usually a composite of sounds from many sources, near and far. The ambient noise level is the level obtained when the noise level is averaged over a period of 15 minutes without inclusion of noise from isolated identifiable sources, at the location and time of day near that at which a comparison is to be made. For the purpose of this chapter, in no case shall the local ambient be considered or determined to be less than:
1. 
Thirty dBA for interior noise in Section 9.20.030(B); or
2. 
Forty dBA in application to all other sections hereof.
dB.
"dB" means decibel as herein defined.
dBA.
"dBA" means decibels measured on an A-weighted scale, as herein defined in the definition of "Noise level measurement."
Decibel.
The "decibel" is a unit measure of sound (noise) level relative to a standard reference sound on a logarithmic scale. The decibel level of a given sound is determined as 20 times the logarithm to the base 10 of the ratio of the pressure in micronewtons per square meter of the sound being measured to the standard reference sound pressure of 20 micronewtons per square meter (0.0002 microbar).
Emergencies.
Essential activities necessary to restore, preserve, protect or save lives or property from imminent danger of loss or harm.
Noise level measurement.
For the purpose of enforcement of the provisions of this chapter, noise level shall be measured in decibels on the A-weighted scale with a sound level meter satisfying at least the applicable requirements for Type 1 or Type 2 sound-level meters as defined in the most recent American National Standard Specifications. The meter shall be set for slow response speed, except that for impulse noises or rapidly varying sound levels, fast response speed may be used.
For outside measurements the microphone shall not be less than 4 feet above the ground, at least 4-1/2 feet distant from walls or similar large reflecting surfaces, and shall be protected from the effects of wind noises and other extraneous sounds by the use of screens, shields or other appropriate devices; for inside measurements, the microphone shall be at least 3 feet distant from any wall, and the average measurement of at least 3 microphone positions throughout the room shall be determined.
Property plane.
A vertical plane including the property line which determines the property boundaries in space.
(Ord. 1380 § 2)
A. 
No person shall produce, suffer or allow to be produced by any machine, animal or device, or any combination of same, on residential property, a noise level more than 5 dB above the local ambient at any point outside of the property plane.
B. 
No person shall produce, suffer or allow to be produced by any machine, animal, or device, or any combination of same, on multifamily residential property, a noise level more than 5 dB above the local ambient 3 feet from any wall, floor, or ceiling inside any dwelling unit on the same property, when the windows and doors of the dwelling unit are closed, except within the dwelling unit in which the noise source or sources may be located.
(Ord. 1380 § 3)
No person shall produce, suffer or allow to be produced by any machine or device, or any combination of same, on commercial or industrial property, a noise level more than 8 dB above the local ambient at any point outside of the property plane.
(Ord. 1380 § 4)
A. 
No person shall produce, suffer or allow to be produced by any machine or device, or any combination of same, on public property, a noise level more than 15 dB above the local ambient at a distance of 25 feet or more from the source unless otherwise provided in this chapter.
B. 
Sound performances and special events not exceeding 80 dBA measured at a distance of 50 feet from the source are exempt from this chapter when approval therefor has been obtained from the city.
C. 
Vehicle horns, or other devices primarily intended to create a loud noise for warning purposes, shall not be used when the vehicle is at rest, or when a situation endangering life, health, or property is not imminent.
(Ord. 1380 § 5)
A. 
Daytime Exceptions. Any noise source which does not produce a noise level exceeding 70 dBA at a distance of 25 feet from the source under its most noisy condition of use shall be exempt from the provisions of Sections 9.20.030, 9.20.040 and 9.20.050 between the hours of 7:00 a.m. and 9:00 p.m. daily except Saturdays, Sundays and holidays, when the exemption herein shall apply between 10:00 a.m. and 6:00 p.m.
B. 
Safety Devices. Aural warning devices which are required by law to protect the health, safety, and welfare of the community shall not produce a noise level more than 3 dB above the standard or minimum level as provided by state law.
C. 
Construction and Alteration of Structures. Notwithstanding any other provision of this chapter, between the hours of 7:00 a.m. and 9:00 p.m. daily except Saturdays, Sundays and holidays, when the exemption herein shall apply between 10:00 a.m. and 6:00 p.m., construction, alteration or repair of structures shall be allowed if it meets at least one of the following noise limitations:
1. 
No individual piece of equipment shall produce a noise level exceeding 83 dBA at a distance of 25 feet from the source. If the device is housed within a structure on the property, the measurement shall be made outside the structure at a distance as close to 25 feet from the equipment as possible;
2. 
The noise level at any point outside of the property plane of the project shall not exceed 86 dBA;
3. 
The provisions of paragraphs 1 and 2 of this subsection shall not be applicable to impact tools and equipment, provided that on and after a date 6 months after the effective date of this chapter, such impact tools and equipment shall have intake and exhaust mufflers recommended by the manufacturers thereof and approved by the city's director of public works as best accomplishing maximum noise attenuation, and that pavement breakers and jackhammers shall also be equipped with acoustically attenuating shields or shrouds recommended by the manufacturers thereof and approved by the city's director of public works as best accomplishing maximum noise attenuation. In the absence of manufacturer's recommendations, the director of public works may prescribe such means of accomplishing maximum noise attenuation as he or she may determine to be in the public interest.
D. 
Emergencies and Emergency Vehicles. Emergencies and emergency vehicles are exempt from the provisions of this chapter.
E. 
Outdoor Gatherings and Entertainments. Except during the hours of 10:00 p.m. to 9:00 a.m. Sunday through Thursday nights, and 12:30 a.m. through 9:00 a.m., Saturday and Sunday mornings, and any night preceding a holiday established as such by the state or city, the provisions of this chapter shall not apply to occasional outdoor gatherings, public or private dances, shows and sporting and entertainment events; provided, that the events are conducted by or pursuant to a permit or license issued by the city or other public entity relative to the staging of the events, and provided further that in issuing any such permit or license the city or other public entity shall be empowered to impose as conditions upon the issuance of such a permit or license such conditions as may be necessary to effectuate the intent of this chapter and to prevent the conduct of a public nuisance or violation of this section, and all applicable conditions imposed upon the permittee or licensee are strictly adhered to by such permittee or licensee. Any such conditions imposed pursuant to the authority of this subsection E shall not be more restrictive than the requirements for issuance of a registration statement or comparable activities not eligible for exemption under this subsection.
F. 
Power Tools. The operation of power tools for noncommercial purposes shall be exempt from the provisions of Sections 9.20.030, 9.20.040 and 9.20.050 between the hours of 9:00 a.m. and 8:00 p.m.; provided, that such operations shall be subject to the provisions of Section 9.20.080. For the purpose of this subsection, a noncommercial use shall be any use for which a business license is not required pursuant to Chapter 5.04 of this Code.
(Ord. 1380 § 6)
Where the applicant can show that notwithstanding the application of all available noise-abatement techniques, immediate compliance with the requirements of this chapter would be impractical or unreasonable, a conditional and/or limited noise permit may be granted an applicant, excepting the particular project or activity from the provisions of this chapter for a limited period, not to exceed 6 months, subject to renewal upon a further showing of good cause conditioned by a schedule for compliance and details of methods therefor in appropriate cases. Applications for such permits shall be made to the department assigned by the city administrator to process such permits upon a form provided therefor. Such application shall be processed in the following manner:
A. 
The city administrator or the assigned department is empowered to deny any such application.
B. 
The city administrator or the assigned department is empowered to approve an application subject to such conditions or limitations he or she or it deems advisable, taking into consideration the purpose and intent of this chapter, which approval he or she or it shall submit to the city council at its next meeting. If the city council does not reject the conditional approval by the city administrator or the assigned department, then following the council meeting the city administrator or the assigned department will issue to the applicant the proposed noise permit.
C. 
This section shall apply to public agencies, including the city, provided that in the case of public agencies, the city administrator or the assigned department shall have power and authority to issue a noise permit, conditional or limited, to a public agency upon good cause being shown therefor, forthwith, where the proposed activity involves public health, safety, welfare and benefit, without reference to the city council.
(Ord. 1380 § 7)
Consistent with other provisions of this chapter, and in addition thereto, it shall be unlawful for any person to wilfully make, produce, suffer or allow to be produced by any machine, animal or device, or any combination of same, any loud, unnecessary, or unusual noise which causes discomfort or annoyance to any reasonable person of normal sensitivity residing in the area.
(Ord. 1380 § 10)
The standards which shall be considered in determining whether a violation of the provisions of Section 9.20.080 exists shall include, but shall not be limited to, the following criteria:
A. 
The frequency of the noise;
B. 
The intensity of the noise;
C. 
Whether the nature of the noise is usual or unusual;
D. 
Whether the origin of the noise is natural or unnatural;
E. 
The frequency and intensity of the background noise, if any;
F. 
The proximity of the noise to residential sleeping facilities;
G. 
The nature and zoning of the area within which the noise emanates;
H. 
The density of the inhabitation of the area within which the noise emanates;
I. 
The time of the day or night the noise occurs;
J. 
The duration of the noise;
K. 
Whether the noise is recurrent, intermittent, or constant; and
L. 
Whether the noise is produced by a commercial or noncommercial activity.
(Ord. 1380 § 11)
Any person aggrieved by the decision of any administrative officer empowered to administer the provisions of this chapter shall have the right to appeal the decision of any such officer, to the city council, by filing with the city clerk a verified, written appeal no later than 10 days after decision has been rendered.
(Ord. 1380 § 8)
The city administrator shall assign to an appropriate department or departments the duty of enforcing the provisions of this chapter, and such departments are empowered to issue citations for violations.
(Ord. 1380 § 9)
A. 
A person violating any of the provisions of this chapter shall be deemed guilty of an infraction and shall be subject to the penalties provided by this Code for infractions.
B. 
Each hour a violation is committed or permitted to continue shall constitute a separate offense.
(Ord. 1380 § 12)
As an additional remedy, the operation or maintenance of any machine, animal or device, or any combination of the same, which operation or maintenance causes discomfort or annoyance to reasonable persons of normal sensitivity, or which endangers the comfort, repose, health, or peace of residents in the area, shall be deemed and is declared to be a public nuisance and may be subject to abatement summarily by a restraining order or injunction issued by a court of competent jurisdiction.
(Ord. 1380 § 13)