Twentynine Palms Municipal Code Ch. 19.80 Noise Control

This Chapter establishes standards to reduce unnecessary, excessive and annoying noise and vibration in the City, maintain quiet in those areas which exhibit low noise levels, and implement programs aimed at reducing noise in those areas in the City where noise levels are above acceptable values.

A. The standards and requirements contained in this Chapter shall apply to all areas within the City limits of Twentynine Palms.

B. Exemptions. The following sources of noise are exempt:

1. Temporary construction, repair or demolition activities between 7:00 a.m. and 7:00 p.m. except Sundays and federal holidays.

2. During the months of May through September of each year, temporary construction, repair or demolition activities shall be permitted during the hours of 6:00 a.m. to 7:00 p.m.

All terminology used in this Chapter, not defined below, shall be in conformance with applicable publications of the American National Standards Institute (ANSI) or its successor body. The following words, phrases and terms as used in this Chapter shall have the meaning as indicated below:

A. A Weighted Sound Level. The sound level in decibels as measured on a sound level meter using the A-weighting network. The level so read is designated dBA.

B. Ambient Noise Level. The composite of noise from all sources near and far. In this context, the ambient noise level constitutes the normal or existing level of environmental noise at a given location.

C. Community Noise Equivalent Level (CNEL). CNEL is a noise rating scale. CNEL is similar to the LDN scale (see Day Night Noise Level, below) except that it includes an additional 5 dBA penalty for events that occur during the evening (7 p.m. to 10 p.m.) time period.

D. Construction. Any site preparation, assembly, erection, substantial repair, alteration, or similar action, for or of public or private rights-of-way, structures, utilities or similar property.

E. Cumulative Period. An additive period of time.

F. Day Night Noise Level (LDN). A 24-hour, time-weighted annual average noise level. Time-weighted refers to the fact that noise which occurs during certain sensitive time periods is penalized for occurring at these times. In the LDN scale, those events that take place during the night (10 p.m. to 7 a.m.) are penalized by 10 dB. This penalty was selected to attempt to account for increased human sensitivity to noise during the quieter period of a day, where sleep is the most probable activity. LDN is composed of individual time segments which may be continuous or interrupted.

G. Decibel (dBA). A unit for measuring the amplitude of a sound, equal to 20 times the logarithm to the ratio of the sound measured to the reference pressure, which is 20 micropascals.

H. Demolition. Any dismantling, intentional destruction or removal of structures, utilities, public or private rights-of-way surfaces, or similar existing development.

I. Equivalent Noise Level (LEQ). The "energy" average noise level during the time period of the sample. It is a number that represents a decibel sound level. This constant sound level would contain an equal amount of energy as a fluctuating sound level over a given period of time. LEQ can be measured for any time period, but is typically measured for 15 minutes, 1 hour or 24 hours.

J. Motor Vehicle. Any and all self-propelled vehicles as defined in the California Motor Vehicle Code, including all on-highway type motor vehicles subject to registration under said Code, and all off-highway type motor vehicles subject to identification under said Code.

K. Sound Level Meter. An instrument, including a microphone, an amplifier, an output meter, or frequency weighting networks, for the measurement of sound levels. Such instrument shall meet or exceed the pertinent requirements for type S2A meters contained in the ANSI specifications for sound level meter, S1.4-1971, or the most recent revision thereof.

A. Lead Agency. The Community Development Director shall designate a control program established by this Chapter. Such program may designate a specific staff person or persons to administer the noise monitoring and review on behalf of the City.

B. Powers. In order to implement and enforce this Chapter and for the general purpose of noise abatement and control, the City shall have, in addition to any other vested authority, the power to:

1. Conduct or cause to be conducted studies, research, and monitoring related to noise including joint cooperative investigation with public or private agencies, and the application for, and acceptance of, grants.

2. Review all public and private projects which are likely to cause noise in violation of this Chapter and which are subject to mandatory review or approval by other departments. Such review may include, but shall not be limited to:

a. Review for compliance with the intent and provisions of this Chapter.

b. Require sound analyses which identify existing and projected noise sources and associated noise levels.

c. Require the usage of adequate mitigation measures to avoid violation of any provision of this Chapter.

3. Upon presentation of proper credentials, enter and/or inspect any private property, place, report or records at any time when granted permission by the owner or by some other person with authority to act for the owner. When permission is refused or cannot be obtained, a search warrant may be obtained from a court of competent jurisdiction upon a showing of probable cause to believe that a violation of this Chapter may exist. Such inspection may include the administration of any necessary tests.

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 enjoyment of any neighborhood or which causes any discomfort or annoyance to any reasonable person of normal sensitivity residing in the area. The factors which shall be considered in determining whether a violation of the provisions of this Section exists shall include, but not limited to, the following:

A. The sound level of the objectionable noise.

B. The sound level of the ambient noise.

C. The proximity of the noise to residential sleeping facilities.

D. The nature and zoning of the area within which the noise emanates.

E. The number of persons affected by the noise source.

F. The duration of the noise and its tonal, informational or musical content.

G. Whether the noise is continuous, recurrent or intermittent.

H. Whether the noise is produced by a commercial or noncommercial activity.

A. Upon receipt of a signed complaint from a citizen or upon direction from the City Council, the City shall investigate the complaint. The investigation shall consist of a measurement of the offending noise and the gathering of data to adequately define the noise problem and shall include the following:

1. Type of noise source.

2. Location of noise source relative to complainant's property.

3. Time period during which noise source is considered by complainant to be intrusive.

4. Total duration of noise produced by noise source.

5. Date and time of noise measurement survey.

B. The following procedures shall be followed when taking noise measurements:

1. Utilizing the A weighting scale of the sound level meter and the "slow-meter response" (use "fast" response for impulsive type sounds), the noise level shall be measured at a position(s) at any point on the receiver's property.

2. In general, the microphone shall be located 4 or 5 feet above the ground, and 10 feet or more from the nearest reflective surface where possible. However, in those cases where another elevation is deemed appropriate, the latter shall be utilized. If the noise complaint is related to interior noise levels, interior noise measurements shall be made within the affected residential unit. The measurements shall be made at a point at least 4 feet from the wall, ceiling or floor nearest the noise source, with windows in the normal seasonal configuration. Calibration of the measurement equipment utilizing an acoustic calibration shall be performed immediately prior to recording any noise data.

A. Table 19.80.070-1 describes the noise standard for emanations from any source, as it affects adjacent properties:

Table 19.80.070-1 Noise Standards

1.Applies to indoor environment excluding bathrooms, toilets, closets and corridors. 2.Applies to single-family residential. Outdoor environment limited to private yard of single-family; normally this is a rear yard. 3.Applies to multi-family residential. Applies to first-floor patio area where there is an expectation of privacy (i.e., not a patio area which also serves as the primary entrance to the unit). 4.Standard recognizes that residential in mixed-use areas may be exposed to noise environments which may have late night noise and may change substantially from time to time. 5.Only applies to neighborhood parks where peace and quiet are determined to be of primary importance. Not applicable to urban parks or active parks.

B. No person shall operate or cause to be operated any source of sound at any location 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 receiving land use, as specified in Table 19.80.070-1, for a cumulative period of more than 30 minutes in any hour; or

2. The noise standard plus 5 dBA for a cumulative period of more than 15 minutes in any hour; or

3. The noise standard plus 10 dBA for a cumulative period of more than five minutes in any hour; or

4. The noise standard plus 15 dBA for a cumulative period of more than one minute in any hour; or

5. The noise standard plus 20 dBA for any period of time.

C. If it is determined that the existing noise level exceeds any of the standards contained in SubSection 19.74.070.B (1-5) above, the allowable noise exposure standard for a new project may be increased by 5 dBA in each category.

D. If the alleged offense consists entirely of impact noise or simple tone noise, each of the noise levels in Table 19.80.070-1 shall be reduced by 5 dBA.

The maximum permissible interior noise level for residential uses, generated from another property, as measured in a residential living area on the receiving property, shall be as specified in Table 19.80.080-1.

Table 19.80.080-1 Residential Interior Noise Limits

A. No person shall unnecessarily make, continue or permit to continue prohibited noise and/or vibration as described herein. Any person(s) so doing shall be in violation of this ordinance.

B. Operating, playing or permitting the operation or playing of any radio, television, sound system, drum, musical instrument or similar device which produces or reproduces sound:

1. Between the hours of 10 p.m. and 7 a.m. in such a manner as to create a noise disturbance across a residential or commercial real property line, except for cases in which an exception has been issued by the City.

2. In such a manner as to exceed the levels set forth for public space in Table 19.80.070-1, measured at a distance of at least 50 feet from such device operating on a public right-of-way or public space.

C. Using or operating for any purpose any loudspeaker system or similar device between the hours of 10 p.m. and 7 a.m. such that the sound therefrom creates a noise disturbance across a residential real property line, except for any noncommercial public speaking, public assembly or other activity for which an exception has been issued by the City.

D. Offering for sale, selling anything, or advertising by shouting or outcry within any residential or commercial area of the City except by variance issued by the City. The provisions of this Section shall not be construed to prohibit the selling by outcry of merchandise, food, and beverages at licensed sporting events, parades, fairs, circuses or other similar licensed public entertainment events.

E. Owning, possessing or harboring any animal or bird which frequently or for long duration, howls, barks, meows, squawks or makes other sounds which create a noise disturbance across a residential or commercial real property line. This provision shall not apply to public zoos.

F. Loading, unloading, opening, closing or other handling of boxes, crates, containers, building materials, garbage cans or similar objects between the hours of 10 p.m. and 7 a.m. in such a manner as to cause a noise disturbance across a residential real property line.

A. Vibration Standard. No ground vibration shall be allowed which can be felt without the aid of instruments at or beyond the lot line; nor will any vibration be permitted which produces a particle velocity greater than or equal to 0.2 inches per second measured at or beyond the lot line.

B. Vibration Measurement. Vibration velocity shall be measured with a seismograph or other instrument capable of measuring and recording displacement and frequency, particle velocity or acceleration. Readings are to be made at points of maximum vibration along any lot line.

C. Exempt Vibrations. The following sources of vibration are not regulated by this Code:

1. Motor vehicles not under the control of an industrial use.

2. Temporary construction, maintenance or demolition activities between 7:00 a.m. and 7:00 p.m. except Sundays and federal holidays.