HomeMy WebLinkAbout2012-07-17 Planning Board Supplemental Materials (53)Environmental Noise Assessment Report Site No. [SITE NUMBER]
EBI Project No. [EBI PROJECT NUMBER] 723 Osgood Street North Andover, Massachusetts
21 B Street Burlington, MA 01803 1.800.786.2346
5.0 AMBIENT SOUND LEVEL MEASUREMENTS
Short-term (20 minute) sound monitoring, day and night, was performed in the area surrounding the
proposed location on June 21, 2012 and July 16, 2012. See Figure 1. Nighttime measurements were
taken between 0200 and 0320 and daytime measurements were taken between 1320 and 1410. The
property line measurement (Loc-1) was taken outside the security barrier, with the door open (night)
and closed (day). The nearest residence measurement (Loc-2) was made at the entrance to 723
Osgood Street. The average measured sound levels (Leq) varied from 69.7 dB to 64.8 dB during
daytime hours and from 61.1 dB to 68.3 dB during nighttime hours.
All sound level measurements were taken with a Casella CEL-63X real-time octave-band sound level
analyzer, which was equipped with a precision condenser microphone having an operating range of 5 dB
to 140 dB, and an overall frequency range of 3.5 to 20,000 Hz. The meter meets or exceeds all
requirements set forth in the American National Standards Institute (ANSI) Standards for Type 1 for
quality and accuracy. Prior to and immediately following both measurement sessions, the sound
analyzer was calibrated (no level adjustment was required) with an ANSI Type 1 calibrator, which has an
accuracy traceable to the National Institute of Standards and Technology (NIST). All instrumentation
was laboratory calibrated per ANSI recommendations. For all measurement sessions the microphone
was fitted with an environmental windscreen to negate the effect of air movement and tri-pod mounted
at a height of 1.3 meters above grade, and measurements were made away from any vertical reflecting
surfaces in compliance with ANSI Standards S12.92. All data were downloaded to a computer following
the measurement session. The sound data are shown in Appendix A and are summarized in Table 3.
TABLE 3 – AMBIENT SOUNT LEVEL MONITORING RESULTS
JUNE 21, 2012 AND July 16, 2012
Location Description Time Leq
(dB / dBA)
Loc‐1 Compound entrace
0233‐0253
(security door open) 68.3 / 58.8
1319‐1339
(security door closed) 64.8 / 51.7
Loc‐2 Nearest Propertiy
line
0300‐0320 61.1 / 48.7
1347‐1407 69.7 / 63.0
2 Acoustical Society of America, ANSI Standard S12.9-1992, “Quantities and Procedures for Description and
Measurement of Environmental Sound”
Environmental Noise Assessment Report Site No. [SITE NUMBER]
EBI Project No. [EBI PROJECT NUMBER] 723 Osgood Street North Andover, Massachusetts
21 B Street Burlington, MA 01803 1.800.786.2346
6.0 RESULTS AND CONCLUSIONS
Existing noise conditions at the wireless facilit at 723 Osgood Street were measured on June 21, 2012
and July 16, 2012 during the daytime and nighttime hours. Average measured noise levels included all
sources operating in the area at the time of the site visit, including HVAC equipment, air and road
traffic, and human and wildlife activities. These average measured noise levels ranged from 69.7 dB to
64.8 dB during daytime hours and from 61.1 dB to 68.3 dB during nighttime hours.