HomeMy WebLinkAbout2001-09-20 Air Quality Analysis SPR RUG 29 2000 3: 12PM MODELING SPECIALTIES 978-392-5818 p. 2
Q pModeling Specialties
Air Quality - Noise w Visual
August 30,2001
North Andover Planning Board
Ms. Heidi Griffin,North Andover Planning Director
RE: Environmental Sound Assessment—Merrimack Building
Members of the Board;
Modeling Specialties, an environmental consulting firm located in Westford, Massachusetts,
has conducted an assessment of environmental sound that could result from the installation of
the Merrimack Building commercial office on Lot 4N in North Andover. The analysis was
requested by Mr. Peter Hingorani in response to item#3 of your July 26, 2001 letter re; Berry
Strect/Route 114 Site flan. The proposed office building is in an early stage of design, so a
detailed analysis of site specific equipment is not possible. However, sound power level data
for generic cooling equipment are available in the acoustics literature and have been used for
this early estimate.
The ambient baseline sound levels were established by field measurements using the sound
level metric specified by the DEP at the property line and nearby residences. Figure 1 shows a
USGS aerial view of the project area and illustrates the relationship between the site and
nearest residences, The existing sound was measured at two locations to characterize the sound
level along Route 114 and also at residences that are more distant from the roadway. One was
on the site at the approximate setback of the nearest residence to the northwest, The other
location was near the intersection of Ash Street and Berry Street. The measured levels are
summarized in Table 1. Daytime levels were measured, since the project equipment will only
be routinely active during workday hours. Based on the results of the measurements, the
corresponding DEP daytime noise limit:at these areas are 63 dBA to 52 dBA,respectively,
Table 1: Measured Ambient Sound Levels in Decibels
Octave Band Center Frequency
Time A wild 31.5 63 125 250 500 1000 2000 4000 8000
site 4:33 PM 53 57 67 48 44 47 51 47 38 31
North 5:02 PM 42 50 46 38 33 34 35 34 36 26
The only significant sources of expected project sound are rooftop cooling equipment, Based
on generic scaling of ventilation requirements, a total cooling capacity of up to 30 tons may be
used at the site. Generic sound power estimates were obtained from the acoustics literature.
Since modern equipment of a similar capacity tends to be quieter than the historic equipment
documented in the literature, this is believed to be a conservative estimate of the sound levels
for the proposed equipment. The sound levels expected at the nearest residential locations were
estimated based on cormnon noise modeling methods, These methods have routinely been
reviewed and accepted by the Massachusetts DEP for the prediction of equipment sound at
30 Maple Road,WeStrord,MA 01896 Ph:{A78}392.5817 Fax:(878)392-N16 smallAsheadel@fflodsper.com
RUG 29 2000 9a15PM MODELING SPECIRLTIES 978-332-w5018 P,3
sensitive locations. The results of the sound level estimates are summarized in Table 2. Please
note that the sound level at the property line is also provided, since the DEP policy applies at
both the site property line and the nearest residences. The results are provided as octave band
spectra to allow the review of the DEP's prohibition of tones. Based on the DEP definition,no
pure tones are expected from the proposed facility.
Table 2: Sound Levels Predicted at Nearby Sensitive Receptors from Typical Equipment
Octave Band Center Frequency
A wtd 31.5 63 125 250 500 1000 2000 4000 8000
Properly Line 49 40 45 45 45 48 45 42 37 26
Residence NW 47 38 43 42 43 44 43 40 34 21
Residence North 42 34 39 38 39 40 38 35 27 10
Even under these conservative modeling assumptions,the installation will produce sound levels
that are well below the DEP criteria, Since sound levels decrease with increased distance,the
levels will be lower at more distant locations. For your convenience, the :results of the study
are summarized in the following table.
Table 3: Summary of Predicted Project Sound Level Impacts
Receptor Location Approx,Distance Expected Baseline Ambient Increase
from Equipment Equipment Level Ambient with Equipment (dBA)
(Ft) (L",dBA) (1-9o,deA) (L.4,d8A)
Property Line NW 300 49 53 55 +2
Residence,Northwest 380 47 53 54 +1
Residence,North 600 42 42 45 +3
I certify that the analysis of sound levels is accurate and consistent with prediction methods that
are common to the acoustic analysis of such sources. Based on the analysis, the equipment
operating sound levels will meet the noise standards provided by the Commonwealth of
Massachusetts (310 CMR 7.10) and defined by the Massachusetts DEP in their noise policy
(DAQC Policy 90-001), 1 ant qualified to make this statement based on training and experience
in conducting analyses of environmental sounds.
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AUG 2S 2000 3: 12PM MODELING SPECIALTIES 378-382-5818 p. 4
I ani a Certified Consulting Meteorologist with approximately 20 years experience conducting
environmental analyses in the technical areas of air quality,noise,and visual aesthetics. I am a
technical expert on the noise comnuttee of Air & Waste Management. Association
headquartered in Pittsburgh, Pennsylvania, I have published many refereed papers on various
aspects of environmental noise. I have analyzed the noise emissions of major industrial
projects such as power plants, wastewater treatment plants and manufacturing facilities.
Related to these analyses,I have testified as a technical expert before the Energy Facility Siting
Hoards of Massachusetts and Rhode Island. I have also testified before many regional and
municipal approval boards in Massachusetts, Rhode Island, New Hampshire, Maine, New
York,Michigan,Illinois, and California.
Thank you for your attention,
Respectfully,
Modeling Specialties
a a,,& �;e c�
Douglas L. Sheadel, CCM
Principal
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HUG 29 2000 3: 15PM MODELING SPECInL7IES 978-392-5818 p. 2
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Figure 1
USGS Aerial View of Project Area Showing Nearby Sensitive Receptors
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