CHAPTER 51

NOISE NUISANCES

51.01 Purpose; Definitions

51.02 Measuring Noise Levels

51.03 General Noise Restriction; Exceptions

51.04 Permits for Exception

51.05 Enforcement

51.01 PURPOSE; DEFINITIONS. The purpose of this chapter is to control excessive noise that interferes with the comfortable enjoyment of life, property, recreation or conduct of business as defined and described in this chapter. The following words and terms are defined as used in this chapter:

“Ambient noise” means background or surrounding noise.

“A-weighted sound level” means the sound pressure level in decibels as measured on a sound level meter using the A-weighted filter network. The A-weighted filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the response of the human ear. Such sound measurement is a numerical method of rating human judgment of loudness.

“Construction” means any site preparation, assembly, erection, substantial repair, alteration or similar action, for or of public and private rights-of-way, structures, utilities or similar property demolition.

“Noise measurement location” means the property line of the noise-producing property, or beyond.

“Noise measurement method” means the measurement of the

“Noise nuisance” means:
- A. Any loud, irritating, vexing, disturbing or unreasonable sound which causes distress, annoyance, discomfort or injury to or which interferes with the comfort or repose of any reasonable person of ordinary nervous sensibilities in the vicinity or hearing thereof, or any sound which endangers or injures the safety or health of humans or animals, or any sound which interferes with the physical well-being of humans or animals, or any sound which endangers or injures persons or real property.
- B. Any noise measured in excess of 50 dBA for a residentially zoned property, or 60 dBA for any non-residentially zoned property, between the hours of 10:00 p.m. and 6:00 a.m.

“Receiving land use” means the use or occupancy of the property which receives the transmission of sound.

“Sound level” or “noise level” means the weighted sound pressure level obtained by use of a sound level meter having a standard frequency filter for attenuating part of the sound spectrum as specified in American National Standards Institute specifications for sound level meters (ANSI S1.4-1971).

“Sound level meter” means an instrument which includes a microphone, amplifier, RMS detector, integrator or time averages, output meter and weighing network used to measure sound pressure levels.

51.02 MEASURING NOISE LEVELS. The measurement of noise shall be made with a decibel meter meeting the standards prescribed by the American Standards Association and using the A-weighted, fast response. Measurements shall be taken so as to provide a proper representation of the noise being measured. The microphone shall be placed three to five feet above ground level, when possible, and positioned so as not to create any unnatural enhancement or diminution of the measured noise. Traffic, aircraft and other transportation noise shall not be considered in taking measurements, except where such background noise interferes with the primary noise being measured.

51.03 GENERAL NOISE RESTRICTION; EXCEPTIONS. A person may not create, generate, produce, cause, permit or emanate a noise nuisance.

The following exceptions to the above restriction shall apply to the activities listed below at all times:
- A. Sound produced by a vehicle motor while the vehicle is moving on a public right-of-way, public waterway, airport runway or railway;
- B. Sound produced by any governmental body in the performance of a governmental function to include work performed by or for public or private utilities;
- C. Sound generated at or by a parade route during a lawful and permitted parade, a scheduled stadium event, or at outdoor celebrations sponsored or co-sponsored by the City or any governmental body in the performance of its duty or as otherwise allowed by law;
- D. The emission of sound made by safety signals, warning devices, and sound resulting from any authorized emergency vehicle when responding to an emergency call or acting in time of an emergency;
- E. The emission of sound during nonprofessional athletic and school events or practices;
- F. The emission of sound from the use of snow removal equipment.

The following exceptions to the above restriction shall only apply to the activities listed below between the hours of 6:00 a.m. to 10:00 p.m.:

. The emission of sound through the un-amplified human voice;

The activity, operation or noise source which emanates from an operation or activity (including, by way of example only, and not limited to construction, reconstruction, remodeling and rebuilding of any structure or place in conformity with applicable provisions of this Code of Ordinances and State law) that cannot reasonably be done in an alternative manner, time or place so as to otherwise comply with the chapter;

The emission of sound from the use of lawn and garden equipment and chainsaws;

The conduct of one-day auction/sale events;

Downtown background music on Central Avenue between 7th and 10th Streets;

Agricultural activities associated with the raising and harvesting of crops, exclusive of those involving the ownership or possession of animals or birds;

Religious organizations conducting worship services outdoors with musical components.

51.04 PERMITS FOR EXCEPTION.

Applications for a permit for relief from the noise restrictions designated in this chapter on the basis of undue hardship may be made to the City Administrator. A letter of request containing the basis for the request and a $10.00 fee must accompany each application. The relief requested may be granted upon a good and sufficient showing:
- A. That additional time is necessary for the applicant to alter or modify the activity or operation to comply with the provisions of this chapter;
- B. That the activity, operation, noise or vibration source will be of temporary duration and cannot reasonably be done in a manner that would comply with this chapter ; or
- C. That no reasonable alternative is available to the applicant.

If granted, the permit shall be in writing and contain all conditions upon which such permit is granted, including, but not limited to, the effective dates, any time-of-day, location, sound-pressure-level, or equipment limitations. The City Administrator may prescribe any reasonable conditions or requirements deemed necessary to minimize adverse effects upon the community or the surrounding area.

In the event the City Administrator denies an application for a permit for relief from the noise restrictions designated in this chapter, or grants relief under conditions the applicant finds unacceptable, the affected party may appeal the decision to the City Council by filing a written letter with the City Administrator within ten (10) calendar days after receiving notice of the City Administrator’s decision. The appeal letter must specifically state each and every point of contention with the City Administrator’s determination. The City Administrator shall immediately cause the appeal to be placed on the next regular meeting agenda of the Council for discussion and action. At that meeting, the Council shall consider the intent contained in this chapter, the City Administrator’s reason for denying a permit or applying conditions, the points raised in the letter of appeal, and relevant surrounding facts.

51.05 ENFORCEMENT.

Responsible Violators. The persons responsible for violations of this chapter are identified as follows:
- A. At Private Residences. Any adult resident present at the time of the offense, and any adult guest or adult trespasser with the ability to control the level of noise at the time of the offense when no adult resident is present at the time of the offense.
- B. At Business Locations. Any business owner, operator, manager, employee in charge, and all persons in control or in possession of the noise nuisance-generating instrument or property at the time of the offense.
- C. Other Locations. Any person who leaves unattended any machine, instrument, device, child, animal, or any combination of same, which thereafter commences producing noise in violation of this chapter.

Warning. Any person violating this chapter shall be first warned of the unlawfulness of such noise activity and be given a reasonable opportunity to peacefully disperse, discontinue or to abate such noise condition prior to being subject to further enforcement action. Only one warning shall be issued per occurrence. Not more than one warning shall be necessary during any 24-hour period for any site.

Determination of Violation. An arrest, citation, summons, or complaint for the violation of any part of this chapter must be based on probable cause arising from:
A. The complainant’s physical sense perceptions and observations of the unreasonable noise as defined herein, at the time such is occurring; or
B. Sound level measurements, taken in accordance with Section 51.02 this chapter, which exceed the stated limits, or
C. A combination of the foregoing two (2) types of evidence.

Enforcement Remedies and Penalties. In the event that the noise violation is not abated as ordered and within the time specified, the City may abate such violation by one or more of the methods listed below. Each time the noise violation is not abated as directed shall be considered a separate violation, with a minimum of 30 minutes between noise violations declared by the enforcement officer. Increased fines for repeat violations may be issued for similar violations at the same location within 30 days.
- A. Issuance of a municipal infraction.
- B. Undertaking the public abatement of the violation and assessment of costs thereof.
- C. Prosecution as a misdemeanor.
- D. Remedy by means of civil court proceeding or any other lawful process pursuant to the Code of Iowa.

Chapter 51

CHAPTER 51

NOISE NUISANCES