It is declared to be the policy of
the city in its exercise of the police power to prohibit unnecessary,
excessive and annoying sound levels from all sources. At certain levels,
such sounds become noise and are detrimental to the health and welfare
of the citizenry and, in the public interest, are hereby systematically
proscribed. This chapter is intended to work in concert with and supplement
Penal Code Section 370 (Public Nuisances) and Section 415 (Disturbing
the Peace) and to establish local community standards for noise regulation.
(Ord. 3638 §
1, 2001)
The following words, phrases and
terms as used in this chapter shall have the following meanings:
“Acoustic specialist”
means a person or persons trained in acoustic sampling, qualified
to measure sound levels in A-weighted and C-weighted networks and
one-third octave band frequencies.
“Ambient sound level”
means the composite of normal or existing sound from all
sources measured at a given location for a specified time of the day
or night. The ambient sound level shall be measured with a sound level
meter, using slow response and A weighting. The ambient sound level
shall be determined with the sound source at issue silent.
“Approving authority”
means the designated body or persons authorized to grant
approval or deny a discretionary permit or an exception to this chapter.
“A-weighting”
means the standard A-weighted frequency response of a sound
level meter, which de-emphasizes low and high frequencies of sound
in a manner similar to the human ear for moderate sounds.
“C-weighting”
means the standard C-weighted frequency response of a sound
level meter, which de-emphasizes high frequencies of sound in a manner
similar to the human ear for relatively loud sounds.
“Decibel”
means a unit for measuring the relative amplitude of sound
equal approximately to the smallest difference normally detectable
by the human ear, whose range includes approximately 130 decibels
on a scale beginning with zero decibels for the faintest detectable
sound. The sound pressure associated with zero decibels is 20 MicroPascals.
“Discretionary permit”
means a permit issued by the city other than ministerial
permits, including, but not limited to, conditional use permits, tentative
subdivision maps, design review permits and administrative permit.
“Equivalent hourly sound level (Leq)”
means the sound level corresponding to a steady state A-weighted
sound level containing the same total energy as the actual time-varying
sound level over a one-hour period.
“Fixed sound source”
means a device or machine which creates sounds while fixed
or stationary, including, but not limited to, residential, agricultural,
industrial and commercial machinery and equipment, pumps, fans, compressors,
air conditioners and refrigeration equipment also includes motor vehicles
operated on private property.
“Intruding sound level”
means the sound level created, caused, maintained or originating
from an alleged offensive source, measured in decibels, at a specified
location while the alleged offensive source is in operation.
“Noise”
means any loud discordant or disagreeable sound or sounds.
“One-third octave band”
means a band of frequencies, in Hertz (Hz), which is one-third
of an octave wide. The center frequencies of one-third octave bands
increase by a factor of 1.26 (cube root of 2). Examples of one-third
octave band center frequencies in the range of audible sound include
20, 25, 31.5, 40 and 63 Hertz. Describing sound pressure levels in
one-third octave bands provides information as to the tone or pitch,
of noise (low frequency versus high frequency), as well as the amplitude
of the sound.
“Property line or plane”
means a vertical plane including the property line that determines
the property boundaries in space.
“Public property”
means any property owned by a public agency and held open
to the public, including but not limited to parks, streets, sidewalks,
and alleys.
“School”
means institutions conducting regular academic instruction
at preschool, kindergarten, elementary, secondary or collegiate levels.
“Sensitive receptor”
means a land use in which there is a reasonable degree of
sensitivity to noise. Such uses include single-family and multifamily
residential uses, schools, hospitals, churches, rest homes, cemeteries,
public libraries and other sensitive uses as determined by the enforcement
officer.
“Simple tone noise”
means any sound that is distinctly audible as a single pitch
(frequency) or set of pitches, which includes sound consisting of
speech and music.
“Sound level”
means the sound pressure level in decibels as measured with
a sound level meter using the Aweighting and C-weighting networks
or one-third octave band frequency. The unit of measurement is referred
to herein as dBA, dBC or one-third octave band.
“Sound level meter”
means an instrument meeting American National Standard Institute
Standard S1.4A-1985 for Type I or Type 2 sound level meters or an
instrument and the associated recording and analyzing equipment that
will provide equivalent data.
(Ord. 3638 §
1, 2001)
Sound or noise emanating from the
following sources and activities are exempt from the provisions of
this title:
A. Sound sources typically associated with
residential uses (e.g., children at play, air conditioning and similar
equipment, but not including barking dogs);
B. Sound sources associated with property
maintenance (e.g., lawn mowers, edgers, blowers, pool pumps, power
tools, etc.) provided such activities take place between the hours
of 8:00 a.m. and 9:00 p.m.;
C. Safety, warning and alarm devices, including
house and car alarms, and other warning devices that are designed
to protect the health, safety and welfare, provided such devices are
not negligently maintained or operated;
D. The normal operation of public and private
schools typically consisting of classes and other school-sponsored
activities;
E. Maintenance (e.g., lawn mowers, edgers,
aerators, blowers, etc.) of golf courses, provided such activities
take place between the hours of 5:00 a.m. and 9:00 p.m. May through
September, and 6:00 a.m. and 9:00 p.m. October through April;
F. Emergencies involving the execution of
the duties of duly authorized governmental personnel and others providing
emergency response to the general public, including, but not limited
to, sworn peace officers, emergency personnel, utility personnel,
and the operation of emergency response vehicles and equipment;
G. Private construction (e.g., construction,
alteration or repair activities) between the hours of 7:00 a.m. and
7:00 p.m. Monday through Friday, and between the hours of 8:00 a.m.
and 8:00 p.m. Saturday and Sunday; provided, however, that all construction
equipment shall be fitted with factory installed muffling devices
and that all construction equipment shall be maintained in good working
order.
(Ord. 3638 §
1, 2001)
It is unlawful for any person to
refuse to cooperate with or to obstruct any governmental agent, officer
or employee in determining the ambient sound level of a sound source.
Such cooperation shall include, but is not limited to, the shutting
off or quieting of any sound source so that an ambient sound level
can be measured.
(Ord. 3638 §
1, 2001)
It is unlawful for any person at
any location to create any sound, or to allow the creation of any
sound, on property owned, leased, occupied or otherwise controlled
by such person, which causes the exterior sound level when measured
at the property line of any affected sensitive receptor to exceed
the ambient sound level by three dBA or exceed the sound level standards
as set forth in Table 1, by three dBA, whichever is greater.
Table 1
SOUND LEVEL STANDARDS
(for non-transportation or fixed
sound sources)
|
---|
Sound Level Descriptor
|
Daytime
(7:00 a.m. to 10:00 p.m.)
|
Nighttime
(10:00 p.m. to 7:00 a.m.)
|
---|
Hourly leq, dB
|
50
|
45
|
Maximum level, dB
|
70
|
65
|
A. Each of the sound level standards specified
in Table 1 shall be reduced by five dB for simple tone noises, consisting
of speech and music. However, in no case shall the sound level standard
be lower than the ambient sound level plus three dB.
B. If the intruding sound source is continuous
and cannot reasonably be discontinued or stopped for a time period
whereby the ambient sound level can be measured, the sound level measured
while the source is in operation shall be compared directly to the
sound level standards of Table 1.
(Ord. 3638 §
1, 2001)
In addition to the sound level standards
established in Table 1, it is unlawful for any person at any location
to produce amplified music or sound which causes the exterior sound
level when measured at the property line of any affected sensitive
receptor to exceed the sound level standards as set forth in Table
2, below.
Table 2
SOUND LEVEL STANDARDS
(for amplified sound)
|
---|
Sound Level Descriptor
|
Daytime
(7:00 a.m. to 10:00 p.m.)
|
Nighttime
(10:00 p.m. to 7:00 a.m.)
|
---|
Leq, A weighting
dBA
|
50
|
45
|
Leq, C weighting
dBC
|
75
|
70
|
One-third octave band
|
10 dB increase in any one-third octave
band
|
A. The measurements shall be conducted with
the sound level meter set to A-weighting and fast response. Fast response
shall be used because the duration between low-frequency tones associated
with amplified sound may be considerably less than one second (the
average duration represented by the slow meter response). The fast
meter response represents one-eighth second intervals.
B. If separation of low frequency tones from
the background ambient sound can be determined with the sound level
meter on fast response (a clearly identifiable increase in ambient
sound levels corresponding to the audible bass sounds), sound levels
shall not exceed an Leq of 50 dBA daytime and 45 dBA nighttime for
any one minute period.
C. If separation of low frequency tones cannot
be determined with the sound level meter on A-weighting, the meter
shall be switched to C-weighting to emphasize the low frequency sound.
If separation between low frequency tones and ambient levels can be
observed with the meter set to the C-weighting scale, the sound level
from the low frequency tones shall not exceed an Leq of 75 dBC daytime
and 70 dBC nighttime for any one minute period.
D. If existing background sound levels are
higher than standards identified in Table 2, then the maximum sound
levels due to amplified sound shall not exceed the background sound
levels by more than three dB for A-weighted measurements and five
dB for C-weighted measurements.
E. If separation of low frequency noise cannot
be determined with the meter using either A or C weighting scales
and low frequency tones are clearly audible to the acoustics specialist,
a sound level measurement in terms of onethird octave band frequencies
shall be utilized. If this approach is required, a 10 dB increase
in any one-third octave band due to the amplified sound shall be considered
a violation of this chapter.
(Ord. 3638 §
1, 2001)
Notwithstanding the provisions of Section
9.24.100, it is unlawful for any person to create any sound, or to allow the creation of any sound, on property with an industrial zoning designation that is owned, leased, occupied or otherwise controlled by such person where an industrial land use shares a common property line with a sensitive receptor or is separated from a sensitive receptor by a roadway, which causes the exterior sound level when measured at the property line of any affected sensitive receptor to exceed the ambient sound level by seven dBA, or exceed the sound level standards as set forth in Table 1 by seven dBA, whichever is greater.
(Ord. 3638 §
1, 2001)
Notwithstanding the provisions of Section
9.24.100, sound sources associated with outside activities on public property (e.g. athletic events, sporting events, fairs, and entertainment events) between the hours of 8:00 a.m. and 10:30 p.m., Sunday through Thursday, and between the hours of 8:00 a.m. and 11:00 p.m. on Fridays, Saturdays, and cityrecognized holidays, shall not exceed 80 dBA, Lmax at the property line of the property on which the event is being held.
(Ord. 3638 §
1, 2001)
Notwithstanding any other provisions
of this chapter, city operations and activities are not subject to
the provisions of this chapter. The city council may, by resolution,
adopt operational standards for city activities to effectuate the
purposes of this chapter.
(Ord. 3638 §
1, 2001)
It is unlawful for any person to
operate or sound or cause to be operated or sounded, in the operation
of any railroad train, between the hours of 10:00 p.m. of one day
and 7:00 a.m. of the next day, a train horn or train whistle which
creates a noise in excess of 89 dB at any place or point 300 feet
or more distant from the source of such sound.
(Ord. 3638 §
1, 2001)