. No party owning, leasing,
controlling or otherwise occupying a facility within the (DEZ) shall be allowed
to cause pronounced, multiple patterns of noise or vibration nuisance to or
interference with any receptor.
No party owning, leasing or otherwise controlling a facility
within the DEZ shall be allowed to:
(a) Produce a broadband sound pressure level
which exceeds an existing background sound pressure level by the following
margins:
1. 5 dBA as measured at any
residential property line or receptor within the DEZ;
2. 10 dBA as measured at any commercial or
industrial property line or receptor within the DEZ;
3. 5dBA as measured at any DEZ perimeter
boundary abutting a residential External Receptor;
4. 10 dBA as measured at any DEZ perimeter
boundary abutting a commercial or industrial External Receptor.
(b) Produce a broadband sound
pressure level which exceeds the following levels:
1. 45 dBA Nighttime/55 dBA Daytime, as
measured at any residential property line or receptor within the DEZ;
2. 60 dBA as measured at any commercial or
industrial property line or receptor within the DEZ;
3. 45 dBA Nighttime/55 dBA Daytime, as
measured at any DEZ perimeter boundary abutting a residential External
Receptor;
4. 60 dBA as measured at
any DEZ perimeter boundary abutting any commercial or industrial External
Receptor.
(d) Produce "impulsive" noise in excess of
decibel limits and durations established herein (definition to follow);
1. Background sound pressure level is defined
as the A-weighted sound pressure level that is exceeded 90% of the quietest
one-hour time interval during the equipment operating hours.
2. Residential receptors shall be defined to
included Churches (During hours of service), Nursing Homes, Hospitals, Rest
Homes, Schools, Day Care centers, and any property in use as a
residence.
3. Daytime hours are
7:00 A.M.. to 6:00 P.M. weekdays. Nighttime hours are all other times,
including legal holidays.
4. All
sound pressure level measurements are to be performed with slow sound level
meter response.
5. All complaints
regarding perceived noise violations shall be directed to the Devens Building
Inspector, or other duly authorized DEC Official. Upon investigation, said
official shall work to identify the source. Any facility found to be in
violation shall measure the existing background sound pressure level, and
mitigate the problem as soon as it is reasonably possible. Measurement may
include, but not be limited to establishing existing background sound levels,
or noise modeling. Mitigation may include, but not be limited to the following:
Constructing appropriate housing for building systems, adding mufflers, or
other devices to engines used exclusively for handling material on site; or
adaptation of any other noise control devices and procedures for noise
producing equipment and activities. All expenses incurred for on-site
mitigation measures shall be the responsibility of the facility found to be in
violation.
6. All measured noise
readings and mitigation efforts shall correspond to the time of day for which
the complaint was reported.
7. A
"pure-tone" is sound concentrated in a narrow frequency range, and is perceived
as a humming, buzzing, whirring, or other such distinctive continuous sound.
Pure-tone sound is often produced by industrial equipment such as fans,
blowers, grinders, and transformers. A pure-tone condition is defined to exist
when the sound pressure level in a one-third octave band exceeds the sound
pressure levels in both adjacent one-third octave bands, and if the average
amount exceeded in both adjacent bands is greater than the following:
1/3 Octave Band mid Frequency adjacent
(Hz)
|
Amount by which the average of both adjacent
bands is exceeded
|
1/3 Octave Band mid
Frequency
(Hz)
|
Amount by which the average of both bands
is exceeded
|
100
|
16
|
1250
|
4
|
125
|
14
|
1600
|
4
|
160
|
12
|
2000
|
3
|
200
|
11
|
2500
|
3
|
250
|
9
|
3150
|
3
|
315
|
8
|
4000
|
3
|
400
|
7
|
5000
|
4
|
500
|
6
|
6300
|
4
|
630
|
6
|
8000
|
5
|
800
|
5
|
10000
|
6
|
1000
|
4
|
8.
"Impulsive" noises are sounds which occur intermittently rather than
continuously. Impulsive noise may exceed existing background sound levels for a
cumulative duration of not more than one minute within any given one hour
period, and subject to the following limits: 10 dBA as measured at any
residential property line or receptor, or 15 dBA as measured by any
commercial/industrial property line or receptor. Impulsive noise, as measured
at any residential receptor shall only be allowed to occur during normal
daytime hours. Readings for impulsive noise shall be recorded with fast sound
level meter response.
9. Equipment
employed in landscape and open space maintenance, or any construction related
activity shall be kept in good repair so as to minimize noise and vibration
beyond the DEZ perimeter. In all cases, such equipment shall meet or exceed
industry standards for noise muffling.
10. All terms not defined herein shall be
understood to comply with those definitions established by the American Noise
Standards Institute (ANSI).