Diamond Bar Municipal Code Ch. 22.28 Noise Control

The purpose of this chapter is to establish standards in order to protect the health, safety, welfare, and living/working environments of those living and working in the city.

(Ord. No. 02(1998), § 2, 11-3-98)

Excessive noise levels are detrimental to the health and safety of individuals. Noise is considered a public nuisance and the city discourages unnecessary, excessive or annoying noises from all sources. Creating, maintaining, causing or allowing to be created, caused or maintained any noise or vibration in a manner prohibited by the provisions of this chapter is a public nuisance and shall be punishable as a misdemeanor.

(Ord. No. 02(1998), § 2, 11-3-98)

The director shall have responsibility for the enforcement of the noise regulations contained in this chapter. The director shall make all noise level measurements required for the enforcement of this chapter.

(Ord. No. 02(1998), § 2, 11-3-98)

In the event of an initial violation of the provisions of this chapter, a written notice of violation shall be given the alleged violator, specifying the time by which the condition shall be corrected or an application for permit or variance shall be filed. No further action shall be taken if the cause of the violation has been removed, the condition abated, or fully corrected within the time period specified in the written notice.

(Ord. No. 02(1998), § 2, 11-3-98)

The following activities shall be exempt from the provisions of this chapter:

(1) Emergency exemption. The emission of sound for the purpose of alerting persons to the existence of an emergency, or the emission of sound in the performance of emergency work.

(2) Warning device. Warning devices necessary for the protection of public safety (e.g., police, fire and ambulance sirens, and train horns).

(3) Outdoor activities. Activities conducted on public playgrounds and public or private school grounds, including, but not limited to, school athletic and school entertainment events.

(4) Motion picture production and related activities. Activities in connection to production of motion pictures.

(5) Railroad activities. All locomotives and rail cars operated by any railroad which is regulated by the state public utilities commission.

(6) Federal or state preexempted activities. Any activity, to the extent regulation thereof has been preempted by state or federal law.

(7) Public health and safety activities. All transportation, flood control, and utility company maintenance and construction operations at any time on public right-of-way, and those situations that may occur on private real property deemed necessary to serve the best interest of the public and to protect the public's health and well being, including, but not limited to, street sweeping, debris and limb removal, removal of downed wires, restoring electrical service, repairing traffic signals, unplugging sewers, house moving, vacuuming catchbasins, removal of damaged poles and vehicles, repair of water hydrants and mains, gas lines, oil lines, sewers, etc.

(8) Motor vehicles on public right-of-way and private property. All legal vehicles of transportation operating in a legal manner in compliance with local, state and federal vehicle-noise regulations within the public right-of-way or air space, or on private property.

(9) Minor maintenance to residential real property. Noise sources associated with the minor maintenance of residential real property, provided the activities take place between the hours of 7:00 a.m. and 8:00 p.m. on any day except Sunday, or between the hours of 9:00 a.m. and 8:00 p.m. on Sunday.

(Ord. No. 02(1998), § 2, 11-3-98)

Decibel measurements made in compliance with the provisions of this chapter shall be based on a reference sound pressure of 20 micropascals, as measured with a sound level meter using the A-weighted network (scale) at slow response, or at the fast response when measuring impulsive sound levels and vibrations.

(Ord. No. 02(1998), § 2, 11-3-98)

Receptor properties described in this chapter are assigned to the following noise zones:

(1) Noise zone I, noise-sensitive area;

(2) Noise zone II, residential properties;

(3) Noise zone III, commercial properties; and

(4) Noise zone IV, industrial properties.

(Ord. No. 02(1998), § 2, 11-3-98)

(a) Standards for noise zones. Unless otherwise provided in this chapter, the following exterior noise standards shall apply to all receptor properties within a designated noise zone:

TABLE 3-9 EXTERIOR NOISE STANDARDS

(b) Noise standards. No person shall operate or cause to be operated a source of sound location within the city or allow the creation of a noise on property owned, leased, occupied, or otherwise controlled by a person that causes the noise level, when measured on any other property to exceed the following exterior noise standards:

(1) Standard No. 1. Standard No. 1 shall be the exterior noise level that may not be exceeded for a cumulative period of more than 30 minutes in any hour. Standard No. 1 shall be the applicable noise level from subsection (a); or, if the ambient L 50 exceeds the foregoing level, then the ambient L 50 becomes the exterior noise level for Standard No. 1.

(2) Standard No. 2. Standard No. 2 shall be the exterior noise level that may not be exceeded for a cumulative period of more than 15 minutes in any hour. Standard No. 2 shall be the applicable noise level from subsection (a), plus 5 dB; or, if the ambient L 25 exceeds the foregoing level, then the ambient L 25 becomes the exterior noise level for Standard No.2.

(3) Standard No. 3. Standard No. 3 shall be the exterior noise level that may not be exceeded for a cumulative period of more than five minutes in any hour. Standard No. 3 shall be the applicable noise level from subsection (a), plus ten dB; or, if the ambient L 8.3 exceeds the foregoing level, then the ambient L 8.3 becomes exterior noise level for Standard No. 3.

(4) Standard No. 4. Standard No. 4 shall be the exterior noise level that may not be exceeded for a cumulative period of more than one minute in any hour. Standard No. 4 shall be the applicable noise level from subsection (a), plus 15 dB; or, if the ambient L 1.7 exceeds the foregoing level, then the ambient L 1.7 becomes the exterior noise level for Standard No. 4.

(5) Standard No. 5. Standard No. 5 shall be the exterior noise level that may not be exceeded for any period of time. Standard No. 5 shall be the applicable noise level from subsection (a), plus 20 dB; or, if the ambient L 0 exceeds the foregoing level then the ambient L 1.7 becomes the exterior noise level for Standard No. 5.

(c) Noise at zone boundaries. If the measurement location is on a boundary property between two different zones, the exterior noise level used in subsection (b) to determine the exterior standard shall be the arithmetic mean of the exterior noise levels, as specified in subsection (a), of the subject zones. Except as provided for in this subsection, when an intruding noise source originates on an industrial property and is impacting another noise zone, the applicable exterior noise level as designated in subsection (a) shall be the daytime exterior noise level for the subject receptor property.

(d) Measurement of ambient noise histogram. The ambient noise histogram shall be measured at the same location along the property line utilized in subsection (b) of this section, with the alleged intruding noise source inoperative. If for any reason the alleged intruding noise source cannot be turned off, the ambient noise histogram will be estimated by performing a measurement in the same general area of the alleged intruding noise source but at a sufficient distance so that the noise from the alleged intruding noise source is at least ten dB below the ambient noise histogram. If the difference between the ambient noise histogram and the alleged intruding noise source is five to ten dB, then the level of the ambient noise histogram itself can be reasonably determined by subtracting a one decibel correction to account for the contribution of the alleged intruding noise source.

(e) Abatement notice in lieu of citation. If the intrusive noise exceeds the exterior noise standards provided in subsections (b) and (c) of this section at a specific receptor property and the director has reason to believe that this violation was unanticipated and due to abnormal atmospheric conditions, the director shall issue an abatement notice in lieu of a citation. If the specific violation is abated, no citation shall be issued. If the specific violation is not abated, the director may issue a citation.

(Ord. No. 02(1998), § 2, 11-3-98)

(a) Noise standards for residential units. No person shall operate or cause to be operated within a residential unit any source of sound, or allow the creation of any noise, that causes the noise level when measured inside a neighboring receiving residential unit to exceed the following standards:

(1) Standard No. 1. The applicable interior noise level from subsection (b), for a cumulative period of more than five minutes in any hour;

(2) Standard No. 2. The applicable interior noise level from subsection (b), plus five dB for a cumulative period of more than one minute in any hour; or

(3) Standard No. 3. The applicable interior noise level from subsection (b), plus ten dB or the maximum measured ambient noise level for any period of time.

(b) Interior noise levels. The following interior noise levels for residential dwellings shall apply within all single-family and dwellings with windows in their normal seasonal configuration.

If the measured ambient noise level reflected by the L 50 exceeds that permissible within any of the interior noise standards in subsection 22.28.080(a) (Standards for noise zones), the allowable interior noise level shall be increased in five dB increments in each standard as appropriate to reflect the ambient noise level (L 50 ).

(c) Residential design requirements.

(1) Whenever a residential project is to be developed on a site where the existing exterior ambient noise level exceeds 65 dBA, a detailed analysis of noise reduction requirements shall be made and the developer shall incorporate noise mitigation features into the design of the structure(s) that will ensure interior noise levels at, or below, 40 dBA.

(2) All residential developments shall consider the following noise mitigation measures whenever appropriate:

a. Increase the distance between the noise source and receiver;

b. Locate land uses not sensitive to noise (i.e., parking lots, garages, utility areas, etc.) between the noise source and the receiver;

c. Locate bedrooms on the side/rear of the structure away from major rights-of-way; and

d. Provide quiet outdoor spaces in multifamily projects next to a noisy right-of-way by creating a U-shaped development that faces away from the noise source.

(Ord. No. 02(1998), § 2, 11-3-98)

For any source of sound that emits a pure tone or impulsive noise, the noise levels provided in sections 22.28.080 (Exterior noise standards) and 22.28.090 (Interior noise standards) shall be reduced by five decibels.

(Ord. No. 02(1998), § 2, 11-3-98)

(a) A-weighting scale. The noise level shall be measured at positions on the receiver's property utilizing the A-weighting scale of the sound-level meter and the slow meter response (use fast response for impulsive type sounds).

(b) Microphone location. The microphone shall be located four to five feet above the ground and ten feet or more from the nearest reflective surface except in those cases where another elevation is deemed appropriate.

(c) Interior noise. Interior noise measurements shall be made within the affected residential unit. The measurements shall be made at a point at least four feet from the wall, ceiling or floor nearest the noise source, with windows in their normal seasonal configuration. Calibration of the measurement equipment, utilizing an acoustic calibrator, shall be performed immediately prior to recording any noise data.

(Ord. No. 02(1998), § 2, 11-3-98)

The following acts are a violation of this chapter:

(1) Construction noise.

a. Operating or causing the operation of any tools or equipment used in construction, drilling, repair, alteration, or demolition work between weekday hours of 7:00 p.m. and 7:00 a.m., or at any time on Sundays or holidays, so that the sound creates a noise disturbance across a residential or commercial property line, except for emergency work of public service utilities is prohibited.

b. Construction activities shall be conducted in a manner that the maximum noise levels at the affected structures will not exceed those listed in the following schedule:

1. Residential structures:

(a) Mobile equipment. Maximum noise levels for nonscheduled, intermittent, short-term operation (less than ten days) of mobile equipment shall be as follows:

(b) Stationary equipment. Maximum noise level for repetitively scheduled and relatively long-term operation (periods of ten days or more) of stationary equipment shall be as follows:

2. Nonstructures. Mobile equipment. Maximum noise levels for nonscheduled, intermittent, short-term operation of mobile equipment. Daily, including Sundays and legal holidays, all hours: Maximum of 85 dBA.

c. All mobile or stationary internal combustion engine powered equipment or machinery shall be equipped with suitable exhaust and air-intake silencers in proper working order.

d. In case of a conflict between this chapter and any other ordinance regulating construction activities, the provisions of a more specific ordinance regulating construction activities shall control.

(b) Forced-air blowers in tunnel car washes. Operating or permitting the operation of a forced-air blower in a tunnel car wash between the hours of 7:00 a.m. and 8:00 p.m. in a manner that exceeds the following sound levels is prohibited:

(c) Loading and unloading operations. Loading, unloading, opening, closing or other handling of boxes, crates, containers, building materials, garbage cans or similar objects between the hours of 10:00 p.m. and 6:00 a.m. in a manner to cause a noise disturbance is prohibited.

(d) Noise disturbances in noise-sensitive zones. Creating or causing the creation of a noise disturbance within a noise-sensitive zone is prohibited, provided that conspicuous signs are displayed indicating the presence of the zone. Noise-sensitive zones shall be indicated by the display of conspicuous signs in at least three separate locations within 500 feet of the institution or facility.

(e) Places of public entertainment. Operating, playing or permitting the operation or playing of a radio, television, phonograph, drum, musical instrument, sound amplifier or similar device that produces, reproduces, or amplifies sound in a place of public entertainment at a sound level greater than 95 dBA, (read by the slow response on a sound level meter) at any point that is normally occupied by a customer is prohibited, unless conspicuous signs are located near each public entrance, stating "Warning Sound Levels Within May Cause Hearing Impairment."

(f) Powered model vehicles. Operating or permitting the operation of powered model vehicles that create a noise disturbance across a residential property line, or within a noise-sensitive zone between the hours of 8:00 p.m. and 7:00 a.m. the following day is prohibited.

(g) Emergency signaling devices.

(1) The intentional sounding or permitting the sounding outdoors of an emergency signaling device, including fire, burglar or civil defense alarm, siren, whistle, or similar stationary emergency signaling device, except for emergency purposes or for testing, is prohibited.

(2) Testing of a stationary emergency signaling device shall not occur before 7:00 a.m. or after 7:00 p.m. Testing shall use only the minimum cycle test time. Test time shall not exceed 60 seconds. Testing of the complete emergency signaling system, including the functioning of the signaling device, and the personnel response to the signaling device, shall not occur more than once in each calendar month. Testing shall not occur before 7:00 a.m. or after 10:00 p.m.

(3) Sounding or permitting the sounding of an exterior burglar or fire alarm, or motor vehicle burglar alarm is prohibited, unless the alarm is terminated within ten minutes of activation.

(h) Stationary nonemergency signaling devices. Sounding or permitting the sounding of an electronically amplified signal from a stationary bell, chime, siren, whistle, or similar device intended primarily for nonemergency purposes, from any place, for more than ten consecutive seconds in any hourly period is prohibited.

(i) Refuse collection vehicles.

(1) Operating or permitting the operation of the compacting mechanism of any motor vehicle that compacts refuse and which creates, during the compacting cycle, a sound level in excess of 85 dBA when measured at 50 feet from any point of the vehicle is prohibited.

(2) Collecting refuse, or operating or permitting the operation of the compacting mechanism of a motor vehicle that compacts refuse between the hours of 10:00 p.m. and 6:00 a.m. the following day within 500 feet of a residential area or noise-sensitive zone is prohibited.

(j) Residential air conditioning or refrigeration equipment. Operating or permitting the operation of air conditioning or refrigeration equipment in a manner that exceeds the following sound levels is prohibited:

(k) Street sales. Offering for sale, selling anything, or advertising by shouting or outcry within a residential or commercial area or noise-sensitive zone in the city is prohibited.

(l) Vehicle or motorboat repairs and testing. Repairing, rebuilding, modifying or testing any motor vehicle, motorcycle or motorboat in a manner as to cause a noise disturbance across property lines or within a noise-sensitive zone is prohibited.

(m) Vibration. Operating or permitting the operation of any device that creates vibration which is above the vibration perception threshold of any individual at or beyond the property boundary of the source if on private property, or at 150 feet from the source if on a public space or public right-of-way is prohibited. The perception threshold shall be a motion velocity of 0.01 in/sec over the range of one to 100 Hertz.

(Ord. No. 02(1998), § 2, 11-3-98)

The director may grant a delay in the compliance with the requirements of this chapter for a period of not to exceed 60 days. The planning commission, upon conclusion of a public hearing, may grant a delay not to exceed one year, subject to any terms, conditions, or requirements to minimize adverse effects on the surrounding neighborhood. The director or planning commission's decision may be appealed to the city council. A delay in compliance may be granted only if one of the following conditions apply:

(1) Additional time is necessary for the applicant to alter or modify his activity, operation or noise source to comply with this chapter; or

(2) The activity, operation or noise source cannot feasibly be done in a manner that would comply with the provisions of this chapter, and no other reasonable alternative is available to the applicant at this time.

(Ord. No. 02(1998), § 2, 11-3-98)