This chapter shall be known as the "City of Norwalk Noise Control
Ordinance."
It is recognized that people have a right to and should be ensured
an environment free from excessive sound and vibration that may jeopardize
their health or safety or welfare or degrade the quality of life.
This chapter is enacted to protect, preserve and promote the health,
safety, welfare and quality of life for the citizens of Norwalk through
the reduction, control and prevention of noise.
The following definitions shall apply in the interpretation
and enforcement of this chapter:
AFFECTED PERSON
Any person who has lodged a noise complaint with the Noise
Control Administrator that he/she is the receptor of noise on property
within the City, and said affected person has an interest in the property
as an owner, tenant, or employee.
AMBIENT SOUND
The sound level at a given location that exists as a result
of the combined contribution in that location of all sound sources,
excluding the contribution of the source or sources under investigation
for violation of this code and excluding the contribution of extraneous
sound sources. Ambient sounds are differentiated from extraneous sounds
by the fact that ambient sounds are being emitted the majority of
the time although they may not be continuous. Examples of ambient
sounds may include steady traffic of properly muffled vehicles, summer
insects in the distance, pedestrians talking, and adjacent commercial/industrial
operations or mechanical equipment.
COMMERCIAL ZONE
All commercial districts, business districts, as defined
in the Zoning Regulations of the City of Norwalk, and all uses associated therewith, either permitted as
a right or as a special use.
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.
CONSTRUCTION EQUIPMENT
Any equipment or device operated by fuel pneumatically or
electric power used in construction or demolition work.
CONTINUOUS SOUND
Sound with a duration of one second or longer measured by
the slow response of a sound level meter. Impulsive sounds that are
rapidly repetitive and have a cumulative duration of one second or
longer shall be measured as continuous sound.
CORRECTED SOURCE SOUND LEVEL
The sound level attributable to the source or sources under
investigation, which is calculated by subtracting the measured ambient
sound level from the measured total sound level.
DAYTIME HOURS
The hours between 7:00 a.m. and 8:00 p.m., Monday through
Friday, the hours between 8:00 a.m. and 8:00 p.m. on Saturday and
the hours 9:00 a.m. through 8:00 p.m. on Sundays and federal and state
holidays.
DECIBEL
The practical unit of measurement for sound pressure level
(SPL); the number of decibels of a measured sound is equal to 20 times
the logarithm to the base 10 of the ratio of the sound pressure of
a reference sound (20 micropascals) abbreviated "dB."
DEMOLITION
Any dismantling, intentional destruction or removal of structures,
utilities, public or private right-of-way surfaces or similar property.
DOMESTIC POWER EQUIPMENT
Not limited to, power saws, drills, grinders, lawn and garden
tools and other domestic power equipment intended for use in residential
areas by a home owner.
EMERGENCY
Any occurrence or set of circumstances involving actual or
imminent physical trauma or property damage which demands immediate
action.
EMERGENCY VEHICLE
Any motor vehicle authorized by the City of Norwalk to have
sound warning devices, such as sirens and bells, which can lawfully
be used when responding to an emergency.
EMERGENCY WORK
Work made necessary at the site of an emergency to restore
property to a safe condition following an emergency, or work required
to protect persons or property from exposure to imminent danger.
EXTRANEOUS SOUND
Any sound that is intense and intermittent, and is neither
ambient sound nor sound attributable to a source or sources under
investigation for a violation of this code. Such sound includes but
is not limited to sirens of emergency vehicles, unusually loud motor
vehicle exhaust or braking, people shouting or talking next to the
meter, animal vocalizations, aircraft or trains passing, car door
slams, etc. When conducting compliance measurements, such extraneous
sound sources may be noted but their sound levels are excluded.
IMPULSE SOUND
Sound of short duration, usually less than one second, with
an abrupt onset and rapid decay. Impulse sound may be measured with
the sound level meter response set to "fast" or "impulse."
INDUSTRIAL ZONE
All industrial districts as defined by the Zoning Regulations
of the City of Norwalk.
MOTOR VEHICLE
Per Section 14-1(59) of the Connecticut General Statutes,
as amended.
MUFFLER
A device for abating sounds, such as those produced by escaping
gases.
MULTI-DWELLING-UNIT BUILDING
Any building comprising two or more dwelling units, including,
but not limited to, apartments, condominiums, co-ops, multiple-family
houses, townhouses, and attached residences.
MULTI-USE PROPERTY
Any distinct parcel of land that is used for more than one
category of activity. Examples include, but are not limited to:
A.
A commercial, residential, industrial or public service property
having boilers, incinerators, elevators, automatic garage doors, air
conditioners, laundry rooms, utility provisions, or health and recreational
facilities, or other similar devices or areas, either in the interior
or on the exterior of the building, which may be a source of elevated
sound levels at another category on the same distinct parcel of land;
or
B.
A building, which is both commercial (usually on the ground
floor) and residential property, located above, below or otherwise
adjacent to.
NIGHTTIME HOURS
The hours between 8:00 p.m. and 7:00 a.m., Sunday evening
through Friday morning, Friday evening, 8:00 p.m. through 8:00 a.m.,
Saturday morning and Saturday evening, 8:00 p.m. through 9:00 a.m.
Sunday morning. Saturday nighttime hours apply to state and federal
holidays.
NOISE
Any sound, the intensity of which exceeds the standards set forth in §
68-5B or
C of this chapter, or is otherwise not in conformance with the provisions herein.
NOISE CONTROL ADMINISTRATOR
The Mayor, Chief of Police, and Director of the Board of
Health or person(s) designated to oversee enforcement of this chapter,
to review and act upon applications for variances, and perform other
duties specified herein.
NOISE DISTURBANCE
Any sound which unreasonably annoys, disturbs, injures or
endangers the comport, repose, health, peace or safety of a person,
or which causes injury or damage to property or business.
NOISE-SENSITIVE ZONE
Any area designated by the Norwalk Board of Health as a "noise-sensitive
zone" where noise problems are likely to occur or known to exist.
As a minimum requirement, said zone must include within its boundaries
a school, hospital, house of worship, day-care center, nursing home,
public library, senior citizen center, residence or court.
PERSON
Any individual, firm, partnership, association, syndicate,
company, trust, corporation, municipality, agency or political or
administrative subdivision of the state or other legal entity of any
kind.
PLAINLY AUDIBLE
Any sound that can be detected by an investigator using his
or her unaided hearing faculties of normal acuity. As an example,
if the sound source under investigation is a portable or vehicular
sound amplification or reproduction device, the detection of the rhythmic
bass component of the music is sufficient to verify plainly audible
sound. The investigator need not determine the title, specific words,
or the artist performing the song.
PREMISES
Any buildings, structure, land, or portion thereof, including
all appurtenances, and shall include yards, lots, courts, inner yards
and real properties without buildings or improvements owned or controlled
by a person. The emitter's premises includes contiguous publicly
dedicated street and highway rights-of-way, all road rights-of-way
and waters of the state.
PROPERTY LINE
Either a) the vertical boundary that separates one parcel
of property (i.e., lot and block) from another residential or commercial
property; b) the vertical and horizontal boundaries of a dwelling
unit that is part of a multi-dwelling-unit building; or c) on a multi-use
property as defined herein, the vertical or horizontal boundaries
between the two portions of the property on which different categories
of activity are being performed (e.g., if the multi-use property is
a building which is residential upstairs and commercial downstairs,
then the real property line would be the interface between the residential
area and the commercial area, or if there is an outdoor sound source
such as an HVAC unit on the same parcel of property, the boundary
line is the exterior wall of the receiving unit). Note: This definition
shall not apply to a commercial source and a commercial receptor which
are both located on the same parcel of property (e.g., a strip mall).
PUBLIC RIGHT-OF-WAY
Any street, avenue, boulevard, highway, sidewalk, alley,
park, waterway, railroad or similar place which is owned or controlled
by a governmental entity.
RECREATIONAL VEHICLE
Any internal combustion-engine powered vehicle which is being
used for recreational purposes.
RESIDENTIAL USE
Any property used for human habitation, unless the habitation
is a condition of employment, including, but not limited to:
A.
Private property used for human habitation;
B.
Commercial living accommodations and commercial property used
for human habitation;
C.
Recreational and entertainment property used for human habitation.
RESIDENTIAL ZONE
All City-owned property used for recreational or educational
purposes and all residential districts and any commercial district
when used for residential purposes, as defined in the Zoning Regulations
of the City of Norwalk, and all uses permitted therewith either as a right or
as a special use.
SITE WORK
Any activities involving the use of heavy equipment, including
but not limited to hydraulic point breaking of rock, pavement breaking
(jack hammering), pile driving, excavation, activities related to
the processing of earth and rock, such as screening, splitting and
crushing, removal of materials and filling.
SOUND
A transmission of energy through solid, liquid or gaseous
media in the form of vibrations which constitute alterations in pressure
or position of the particles in the medium and which, in air, evoke
physiological sensations, including, but not limited to, an auditory
response when impinging on the ear.
SOUND LEVEL
The sound pressure level in decibels as measured with a sound
level meter using the A-weighting network. The level so read is designed
"dB(A)" or "dBA."
SOUND LEVEL METER
An instrument used to take sound level measurements and which
should conform, as a minimum, to the American National Standards Institute
Specifications for Sound Level Meters, S1.4-1984 (or subsequent revisions).
SOUND LEVEL METER CALIBRATOR
An instrument used to conduct field calibration checks of
a sound level meter, and which should conform, as a minimum, to the
American National Standards Institute Specifications and Verification
Procedures for Sound Calibrator, S1.40-2006 (or subsequent revisions).
SOUND PRESSURE LEVEL
Twenty times the logarithm to the base 10 of the ratio of
the pressure of a sound to the reference pressure of 20 micronewtons
per square meter (20 X 10 - 6 Newtons/meter2), and is expressed in decibels (dB).
SOUND-PRODUCTION DEVICE
Any device whose primary function is the production of sound,
including, but not limited to, any musical instrument, loudspeaker,
radio, television, digital or analog music player, public address
system or sound-amplifying equipment.
TOTAL SOUND LEVEL
The measured level which represents the sum of sound from
the source or sources under investigation for violation of this code
and the ambient sound sources, excluding any extraneous sound, when
measured on the property of an affected person or at another specified
location.
For the purpose of determining sound level as set forth in this
chapter, the following guidelines shall be applicable:
A. All personnel conducting sound measurements shall be trained in the
current techniques and principles of sound measuring equipment and
instrumentation.
B. Sound level meters and calibrators used to conduct measurements shall
conform to the definitions of this chapter.
C. The sound level meter and calibrator shall be recertified annually
by the manufacturer or at a laboratory accredited for such calibrations
by either the American Association for Laboratory Accreditation or
the National Institute of Standards and Technology.
D. The general steps listed below shall be followed when conducting
sound level measurements:
(1) A field calibration check of the sound level meter shall be conducted
before and after each set of measurements. If the meter drifts by
more than 0.5 dB between calibrations, all measurements taken since
the last valid calibration shall be voided.
(2) When measurements are taken out of doors, a wind screen shall be
placed over the microphone of the sound level meter as per the manufacturer's
instructions. Wind speed measurements shall be taken at the sound
measurement location, and sound measurements shall not be conducted
when the wind speed exceeds 12 miles per hour. Measurements may be
taken in a location where the microphone is shielded from excess wind
speeds.
(3) The sound level meter shall be placed at an angle to the sound source
as specified by the manufacturer's instructions and at least
four feet above the ground. It shall be so placed as not to be interfered
with by individuals conducting the measurements.
(4) Unless otherwise specified in this chapter, sound level measurements
or observations shall be conducted at or within the property line
of an affected person, at any location or elevation on their property
or within their premises that reasonably represents a location at
which they may be exposed to the noise. This may include but is not
limited to conducting measurements at an elevated balcony or bedroom
window.
(5) The investigator shall survey the immediate vicinity of the source
under investigation in order to confirm the identity of the source,
and to select suitable locations for the measurement of the total
sound level and the ambient sound level.
(6) Total sound level measurements shall be conducted at or within the
property lines of the affected person, unless otherwise specified
in this chapter. The location of outdoor measurements, at the discretion
of the investigator, must represent a location on that property which
would see regular use by the complainant during the day, or be within
25 feet of the residential structure at night. The sound level meter
reading shall be noted during the period of observation, excluding
extraneous sounds.
(7) When conducting indoor sound level measurements, the measurements
shall be taken at least three feet from any wall, floor or ceiling
and all exterior doors and windows may, at the discretion of the investigator,
be closed. The configuration of the windows and doors shall be the
same when measuring Total and ambient sound levels, and all sound
sources within the dwelling unit must be shut off (e.g., television,
stereo). Measurements shall not be taken in areas which receive only
casual use such as hallways, closets and bathrooms.
(8) Ambient sound level measurements shall be conducted in such a manner as to quantify the contribution of the ambient sound sources to the location at which the total sound measurements were conducted. If sound from the source under investigation can reasonably be discontinued, these measurements shall be conducted at the same location at which the total sound level measurements were conducted, while the source under investigation is not operating. If sound from the source under investigation cannot reasonably be discontinued (per §
68-9B) then for purposes of enforcement of this code, the ambient sound level of a given location may be determined based upon measurements taken at a comparable site (which includes but is not limited to comparable physical locations and time of day) in the nearby area. The choice of an alternate location or time for these measurements must take into consideration the primary source(s) of ambient sound (e.g., a major roadway), and remain the same relative distance from that ambient sound source at the new measurement location when compared to the distance between the ambient source and the location at which the total sound level measurements were conducted, with traffic patterns relatively the same. The sound level meter reading shall be noted during the periods of observation, excluding extraneous sounds.
E. The corrected source sound level shall be calculated by subtracting
the ambient sound level from the total sound level, as per Table 1,
below.
Table 1
|
---|
Correction for Ambient Sound Levels
(dB)
|
---|
Difference between Total Sound Level and Ambient Sound Level
(TSL-ASL) in dB
|
Correction Factor to be Subtracted from Total Sound Level to
Calculate Corrected Source Sound Level
|
---|
0-3
|
Source level < Ambient sound level
|
4,5
|
2
|
6-9
|
1
|
10 or more
|
0
|
Procedure for Using Table 1
|
Step 1: Subtract the ambient sound level from the total sound
level.
|
Step 2: Refer to Table 1 to determine the correction factor
for the difference calculated in Step 1.
|
Step 3: Subtract the correction factor from the total sound
level. The resultant number is the corrected source sound level.
|
F. Compliance determination shall be based upon the corrected source
sound level.
(1) No violation shall be based upon any exceedance that is the result
of numerical rounding.
(2) A violation shall only be confirmed if the corrected source sound
level exceeds both the permissible sound level limits (Tables 1 and
3) and the measured ambient sound levels.
If any clause, sentence, paragraph or part of this chapter,
or the application thereof to any person, firm, corporation or circumstances,
shall for any reason be adjudged by a court of competent jurisdiction
to be unconstitutional or invalid, said judgment shall not affect,
impair or invalidate the remainder of this chapter and the application
of such provision to other persons, firms, corporation or circumstances,
but shall be confined in its operation to the clause, paragraph or
part thereof directly involved in the controversy in which said judgment
shall have been rendered and to the person, firm, corporation or circumstances
involved. It is hereby declared to be the legislative intent of this
body that this chapter would have been adopted had such invalid provisions
not been included.
In the event that provisions or standards of this chapter or
adopted under this chapter shall conflict with regulations or standards
set by the State of Connecticut Department of Environmental Protection,
the more strict standard shall apply.
In construing this chapter, masculine or neutral pronouns shall
be substituted for those of feminine form and vice versa, and the
plural of the singular and the singular of the plural, shall be substituted
in any case which the context may require.
This chapter shall be effective 10 days following approval by
the Connecticut Department of Energy and Environmental Protection.