4.05 Noise and Vibration

1. Overview. The purpose of the noise and vibration performance standards is to preclude or significantly mitigate conditions that could cause nuisance to any receptor within or without Devens. More detailed definitions of interference sources and potential receptors follow herein under "Noise Limits and Standards".

   While it is the intent of 974 CMR 4.05 to provide a local complaint mechanism for receptors that might be experiencing nuisance from the generation of noise or vibration, it is recognized that complaints can often be minimized by identifying and acting upon potential problems before they become contentious. For this reason, the complaint mechanism is supplemented and enhanced by a process which attempts to minimize or preclude potential noise and vibration issues at the time of application for site plan approval with respect to facilities in proximity to the perimeter boundary of Devens or at the time of application for a building permit with respect to facilities that have the potential of exceeding the performance standards within Devens.

2. Complaint and Enforcement Process
   (a) Upon receipt of a noise or vibration complaint from a receptor, the Building Inspector or other duly authorized Devens Enterprise Commission (DEC) official shall respond to said complaint and attempt, by means of circumstantial and field investigative evidence, to attribute the potential nuisance to a point source. Where such attempts fail to reliably identify a point source and where the pattern of interference is judged by the Inspector to be of a repeated and pronounced nature, then the inspection official may, at his or her discretion and with the concurrence of the Land Use Administrator, require the likely violator to engage technical expertise for the purpose of documenting noise and vibration conditions at strategic locations.

   Once there is reasonable certainty of the nuisance source, the violator shall be subject to providing reasonable mitigation measures that essentially resolve the difficulty. Refer to 974 CMR 4.05(2)(b) for a description of procedures relative to enforcement.

   (b) Potential violators will be given thirty (30) days in which to respond to a complaint or otherwise provide reasonable confirmation to the DEC inspection official, that the problem did not exist or has been eliminated. If probable cause is determined, a second thirty (30) day time period will be granted in which to correct the interference or to demonstrate that good faith efforts have been initiated to correct the objectionable circumstances. If such efforts are not initiated, the violator may be subject to remedies in the Devens By-Laws, including levying or fines, requirements to post performance guarantees, permit reconsideration by the DEC, or legal action. Emergency nuisance conditions may, at the discretion of the DEC inspection official, require more expeditious remediation.

3. Noise Limits and Standards.

   No party owning, leasing, controlling, or otherwise occupying a facility within Devens 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 Devens 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 Devens;

   2. 10 dBA as measured at any commercial or industrial property line or receptor within Devens.

   3. 5 dBA as measured at any Devens perimeter boundary abutting a residential External Receptor

   4. 10 dBA as measured at any Devens 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 Devens

   2. 60 dBA as measured at a commercial or industrial property line or receptor within Devens

   3. 45 dBA nighttime / 55 dBA daytime as measured at any Devens perimeter boundary abutting a residential External Receptor

   4. 60 dBA as measured at any Devens perimeter boundary abutting a commercial or industrial External Receptor.

   (c) Produce a "pure tone" condition. (definition to follow)

   (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 include 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 am to 6:00 pm 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:

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 perimeter of Devens. 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).

4. Vibration Limits and Standards
   (a) No party owning, leasing, or otherwise controlling a facility within Devens shall be allowed to:
   1. Produce vibration which exceeds the combine-axis one-third octave band vibration accelerations of ANSI §3.29, Guide to the evaluation of human exposure to vibration in buildings. (Table one, as read in (meters/second)).

   2. Produce sound levels in the 31.5 Hz octave band, and in lower bands, that exceed 65dB.

   (b) Exceptions: The above performance standards shall not apply to noise and vibration emitted during and associated with the following:
   1. Parades, public gatherings, sporting or special short duration events for which permits have been issued, provided that said parades, public gatherings, sporting, or special events within Devens do not cause noise in an adjacent community

   2. Emergency, police, fire and ambulance vehicles

   3. Police, fire, and civil and national defense activities

   4. Maintenance equipment such as lawn mowers and power saws between the hours of 7:00 am and 8:00 pm.

   5. Temporary construction activity associated with a permitted facility, operating within normal daytime hours.

5. Internal Impacts. As a supplement and enhancement to the complaint process, the noise and vibration performance standards might require that the inspection official attempt to preclude or minimize potential nuisance to the maximum possible degree to Internal Receptors at the beginning of the process, or the building permit application stage. Accordingly, the following process is described. Prior to the issuance of a building or occupancy permit, the applicant proposing the construction or use of a potentially nuisance generating facility, as defined by the applicable "Noise Limits and Standards" set forth in 974 CMR 4.05(3), with potential to impact only Internal Receptors, shall be required to demonstrate the unlikelihood of noncompliance with such Noise Limits and Standards, or that proper mitigation measures will be taken as a condition of permit issuance.

6. External Impacts. As a supplement and enhancement to the complaint process, the noise and vibration performance standards as they apply to External Receptors require procedures at the site plan approval stage to preclude or minimize potential nuisance to the maximum possible degree. Accordingly, the following process is described. Prior to the issuance of site plan approval of any potentially nuisance generating facility as defined by the applicable "Noise Limits and Standards" set forth in 974 CMR 4.05(3), with potential to impact any External Receptors and located within 500 feet of any perimeter boundary of Devens, the applicant shall be required to demonstrate the unlikelihood of noncompliance with such Noise Limits and Standards at or beyond the perimeter of Devens, or that proper mitigation measures will be taken as a condition of permit issuance.