HomeMy WebLinkAbout1998-04-10 Noise Study SPR Tech Environmental, Inc. 1601 Trapela Road
Waltham, MA 02451
(781) 890-2220 Fax (781) 890.9451
www.techenv.com
October 19, 1999
Ref 1833
Mr, Gregory G. Wiech
Channel Building Company,Inc.
355 Middlesex Avenue
Wilmington,MA 01887
Re: Noise Study for Lots 4 and S
North Andover Business Park
Dear Greg:
This letter presents the background noise measurements and the predicted increases above
background associated with the proposed 31,111 ftz facility for Lots 4 and 5. The noise study
results demonstrate that the proposed facility for Lots 4 and 5 will be in compliance with
the restrictive covenant regarding noise levels.
Existing Sound Levels
Ambient sound level monitoring was conducted near the southwest corner of the property line
for these lots between 1 and 2 am. on the morning of Wednesday, November 19, 1997.
Concurrent broadband and octave band measurements were taken. Background noise levels for
the nearest residence on Marian Drive are taken from our monitoring program conducted in the
early morning of Friday, May 24, 1996, The measurements show no existing pure tones and the
background L90 levels were:
Lot 2 Property Line 43 dBA
Marian Drive Residence 33 dBA
Background sound levels at the property line were dominated by HVAC equipment noise from
the nearby Kenics building,with distant highway traffic noise being the secondary source.
F ture Sound Levels
The sources of sound associated with the new building on Lots 4 and 5 are as follows: two 1200
cfiu rooftop exhaust fans and nine HVAC units ranging in size from 5 to 12.5 tons of capacity.
Reference sound pressure levels for these units were taken from manufacturer's data, Maximum
future sound levels are calculated as follows:
Mr, Gregory;Wieeh 2 October 19, 1999
At Nearest Property At Nearest Marian
Piroposed Facility Line Drive Residence
Building Mechanical Equipment 43.5 dBA 30.9 dBA
Existing Nighttime Background +43 dBA +33 dBA
Total Future'Sound Level 45.3 dBA 35.1 dBA
Increase Over Existing Background 3.3 dBA 2.1 dBA
The predicted increases are less than the 10 dBA limit set in DEP's Noise Regulation and based
on manufacturer's octave band data, no "pure tone" condition will be created by the proposed
building on Lots 4 and 5. Thus, the new building will fully comply with the restrictive covenant
regarding noise levels.
Please call if you have any questions.
Sincerely yours,
TECH ENVIRONMENTAL, INC,
Peter H, Guldber C.
President
mrwlgf u