Noise Impact Assessment Study by iiw15426

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									Noise Impact Assessment Study

    Salem Transfer Station
         Salem, MA


          Swampscott Road
            Salem, MA



             Prepared for:

           Northside Carting
             210 Holt Road
       North Andover, MA 01845



             Prepared by:

         Epsilon Associates, Inc.
     3 Clock Tower Place, Suite 250
          Maynard, MA 01754



            March 21, 2008
Noise Impact Assessment Study



    Salem Transfer Station
         Salem, MA


          Swampscott Road
            Salem, MA



             Prepared for:

           Northside Carting
             210 Holt Road
       North Andover, MA 01845



             Prepared by:

         Epsilon Associates, Inc.
     3 Clock Tower Place, Suite 250
          Maynard, MA 01754



            March 21, 2008
TABLE OF CONTENTS

1.0     INTRODUCTION AND SUMMARY                                                  1-1

2.0     NOISE METRICS                                                             2-1

3.0     RELEVANT NOISE REGULATIONS AND CRITERIA                                   3-1
        3.1   Massachusetts State Regulations                                     3-1
        3.2   Local Regulations                                                   3-1

4.0     EXISTING CONDITIONS                                                       4-1
        4.1    Baseline Noise Environment                                         4-1
        4.2    Sound Level Measurement Locations                                  4-1
        4.3    Measurement Methodology                                            4-3
        4.4    Measurement Equipment                                              4-4
        4.5    Baseline Ambient Noise Levels                                      4-5

5.0     REFERENCE SOUND LEVEL DATA                                                5-1

6.0     FUTURE CONDITIONS                                                         6-1
        6.1  Traffic Noise Model (TNM)                                            6-3
        6.2  CadnaA Computer Software Sound Model                                 6-3
        6.2  Predicted Sound Level Results                                        6-4

7.0     CONCLUSIONS AND CONTROL MEASURES                                          7-1



Appendix A          Beverly Airport Weather Data, March 11, 2008
Appendix B          Cadna/A Noise Model Output




2329 Salem Transfer Noise\report.doc            i                        Table of Contents
                                                                   Epsilon Associates, Inc.
List of Figures
Figure 1       Sound Levels in the Environment                                                                     2-2

Figure 2        Aerial Site Locus and Sound Level Measurement Locations                                            4-2

Figure 3        Hourly Sound Level Plot of Continuous Sound Level Data                                             4-8

Figure 4        Predictive Sound-Level Modeling Locations                                                          6-2



List of Tables
Table 1:        Baseline Ambient Noise Measurements ............................................................... 4-6

Table 2:        Location CM Continuous 9-Hour Sound Measurement Data ................................ 4-7

Table 3:        Measured Equipment Sound Levels (at 50 feet) .................................................... 5-1

Table 4:        Equipment Sound Power Levels, dB (re 1 pW) ..................................................... 5-2

Table 5:       Predicted Noise Levels – MA Noise Policy Criteria .............................................. 6-5




2329 Salem Transfer Noise\report.doc                    ii-2                                       Table of Contents
                                                                                             Epsilon Associates, Inc.
1.0     INTRODUCTION AND SUMMARY

        This report presents an analysis of potential community noise impacts associated with the
        proposed expansion and processing-rate increase at the Salem Transfer Station in Salem,
        Massachusetts. The analysis has been prepared to address the requirements of the
        Massachusetts DEP noise regulations. The report discusses the potential noise levels in the
        surrounding community due to operations within the facility. A sound level measurement
        program was conducted at potentially sensitive locations around the proposed site. The
        goal was to determine existing background sound levels during transfer-station operating
        hours. The existing background levels were then compared with predicted sound levels
        associated with a future increase in processing volume. The modeling results were
        compared against existing conditions and regulatory standards. Community noise
        attributable to the recycling facility may arise from the following sources:

        ♦ Trucks operating onsite and within the property boundary

        ♦ Front-end loaders used to move materials, occurring inside the tipping-floor building

        ♦ Back-up alarms from trucks on the site

        The equipment expected to be used at the facility will operate at noise levels within the MA
        DEP noise regulations, and without substantial impact to the surrounding ambient noise
        environment.




2329 Salem Transfer Noise\report.doc            1-1                                      Introduction
                                                                              Epsilon Associates, Inc.
2.0    NOISE METRICS

        There are several metrics with which sound (noise) levels are measured and quantified. All
        of them use the logarithmic decibel (dB) scale. The following information defines the noise
        measurement terminology used in this analysis.

        The decibel scale is logarithmic, to accommodate the wide range of sound intensities found
        in the environment. A property of the decibel scale is that the sound pressure levels of two
        separate sounds are not directly additive. For example, if a sound of 50 dB is added to
        another sound of 50 dB, the total is only a 3-decibel increase (to 53 dB), not a doubling to
        100 dB. Thus, every 3 dB change in sound levels represents a doubling/halving of sound
        energy. Related to this is the fact that a change in sound levels of less than 3 dB is
        imperceptible to the human ear.

        Another property of decibels is that if one source of noise is 10 dB (or more) louder than
        another source, then the total sound level is simply the sound level of the higher source.
        For example, a source of sound at 60 dB plus another source of sound at 47 dB is 60 dB.

        Sound level meters used to measure noise are standardized instruments. They contain
        “weighting networks” to adjust the frequency response of the instrument to approximate
        that of the human ear under various circumstances. The network used for community noise
        surveys is the A-weighting network. Sounds detected with the A-weighting network of the
        sound level meter are reported in decibels designated as “dBA.” The A-weighted scale
        (dBA) most closely approximates how the human ear responds to sound at various
        frequencies: it emphasizes the middle frequency (i.e., middle pitched - around 1,000 Hertz
        - sounds), and de-emphasizes lower and higher frequency sounds. Figure 1 presents an
        example of some common indoor and outdoor activities, and their typical sound levels in
        our environment.

        Because the sounds in the environment vary with time, they cannot simply be described
        with a single number. Two methods are used for describing variable sounds: the percent-
        exceeded levels (Ln) and the equivalent level (Leq). Both are derived from a large number
        of moment-to-moment A-weighted sound level measurements. Percent-exceeded levels are
        values from the cumulative amplitude distribution of all of the sound levels observed during
        a measurement period. Percent-exceeded levels are designated Ln, where n can have a
        value of 0 to 100 percent. Some common metrics reported in community noise monitoring
        studies are described below.

        ♦ L90 is the sound level in dBA exceeded 90 percent of the time during the measurement
          period. The L90 is close to the lowest sound level observed. It is essentially the same as
          the residual sound level, which is the sound level observed when there are no obvious
          nearby intermittent noise sources.




2329 Salem Transfer Noise\report.doc            2-1                                    Noise Metrics
                                                                              Epsilon Associates, Inc.
                                                   Sound Pressure
      COMMON INDOOR SOUNDS                           Level, dBA                 COMMON OUTDOOR SOUNDS
                                                        120         Jet takeoff at 300 feet




                                                        110

                                     Rock Ba nd

                                                                    Jet flyover at 1000 feet
                                                        100
                    Inside Subway train (NYC)
                                                                    Gas lawnmo wer at 3 feet

                                                         90


                          Food Blender at 3 feet                    Heavy truck at 50 feet
                    Garbage disposal at 3 feet
                                                         80


                              Shouting at 3 feet
                                                                    Noisy urban daytime


                    Vacuum cleaner at 10 feet            70         Gas lawnmo wer at 100 feet


                                                                    Auto (60 mph ) at 100 feet
                      Normal speech at 3 feet
                                                         60
                                                                    Heavy traffic at 300 feet




                        Quiet speech at 3 feet
                                                         50
                       Dishwasher next room                         Quiet urban daytime




                          Soft whisper at 3 feet         40         Quiet urban nighttime

                                                                    Quiet suburban nighttime
                                        Library

                                                         30
                              Bedroom at night

                                                                    North rim of Grand Canyon
                                                                    Quiet rural nighttime

                                                         20


               Broadcast and recording studio

                                                         10




                                                                      References:
                          Threshold of hearing           0            1. Harris, Cyril, "Handbook of Noise Acoustical Measurements and
                                                                         Noise Control", p 1-10., 1998
                                                                      2. "Controlling Noise", USAF, AFMC, AFDTC, Elgin AFB, Fact Sheet, August 1996.
                                                                      3. California Dept. of Trans., "Technical Noise Supplement", Oct, 1998
Northside Carting, Inc.

                                                                                                                                               Figure 1
                                                                                                          Sound Levels in the Environment
        ♦ L50 is the median sound level, which is the sound level in dBA exceeded 50 percent of
          the time during the measurement period.

        ♦ L10 is the sound level in dBA exceeded only 10 percent of the time. It is close to the
          maximum level observed during the measurement period. The L10 is sometimes called
          the intrusive sound level because it is caused by occasional louder noises like those
          from passing motor vehicles.

        ♦ Leq, the equivalent level, is the level of a hypothetical steady sound that would have the
          same energy (i.e., the same time-averaged mean square sound pressure) as the actual
          fluctuating sound observed. The equivalent level is designated Leq; and is also A-
          weighted. The equivalent level represents the time average of the fluctuating sound
          pressure, but because sound is represented on a logarithmic scale and the averaging is
          done with linear mean square sound pressure values, the Leq is most often determined
          by occasional loud, intrusive noises.

        ♦ The maximum sound level during a given time is designated as the Lmax. The Lmax are
          typically due to discrete, identifiable events such as an airplane overflight, car or truck
          passby, or a dog barking for example.

        By using various noise metrics it is possible to separate prevailing, steady sounds (the L90)
        from occasional, louder sounds (L10 or Lmax) in the noise environment.

        The frequency content of noises are also stated in terms of octave band sound pressure
        levels, in dB, with the octave frequency bands being those established by standard. If noise
        control treatments are required for a source, it is very useful to know something about the
        frequency spectrum of the noise of interest. Noise control treatments do not function like
        the human ear, so simple A-weighted levels are not useful for noise-control design. In the
        event that noise-control is necessary for this project, the estimates of noise levels due to
        equipment operation are also presented in terms of octave band sound pressure levels.




2329 Salem Transfer Noise\report.doc             2-3                                    Noise Metrics
                                                                               Epsilon Associates, Inc.
3.0    RELEVANT NOISE REGULATIONS AND CRITERIA

        Noise is officially defined as “unwanted sound”. The principal feature of this definition is
        that there must be sound energy and someone hearing it who considers it unwanted. Noise
        impact is judged on two bases: the extent to which governmental regulations or guidelines
        may be exceeded, and the extent to which it is estimated that people may be annoyed or
        otherwise adversely affected by the sound. Specific regulatory references are as follows.

3.1    Massachusetts State Regulations

        The DEP has the authority to regulate noise under 310 CMR 7.10, which is part of the
        Commonwealth’s air pollution control regulations. Under the DEP regulations, noise is
        considered to be an air contaminant and, thus, 310 CMR 7.10 prohibits “unnecessary
        emissions” of noise.

        DEP administers this regulation through Noise Policy DAQC 90-001 dated
        February 1, 1990. The policy limits a source to a 10-dBA increase in the ambient sound
        measured (L90) at the property line for the Project and at the nearest residences. For
        developed areas, the DEP has utilized a “waiver provision” at the property line in certain
        cases. This is appropriate when are there are no noise-sensitive land uses at the property
        line and the adjacent property owner agrees to waive the 10-dBA limit.

        The ambient level is defined as the background L90 measured when the facility is not
        operating (or, in this case, before an expansion that has not yet occurred), but during a time
        period when it would normally operate. For a source which will or could operate all day,
        the ambient level typically occurs during the quietest period (9 a.m. to 4 p.m.). The DEP
        policy further prohibits “pure tone” conditions where one octave band frequency is 3 dB or
        more greater than an adjacent frequency band. An example of a “pure tone” is a fan with a
        bad bearing that is producing an objectionable squealing sound.

        Although the transfer station currently exists, and the sound level measurement program
        was conducted during operating hours, current operations have been “part of the
        background” for decades.

3.2     Local Regulations

        The City of Salem does have a quantifiable noise standard as part of the Code of
        Ordinances (Article I, Section 22-1 within the Salem Code of Ordinances). The Article does
        not state a specific sound level limit at the property boundary for a commercial operation.




2329 Salem Transfer Noise\report.doc             3-1                        Relevant Noise Regulations
                                                                                Epsilon Associates, Inc.
4.0     EXISTING CONDITIONS

        The facility is located on a parcel of land bordered by Swampscott Road to the east and
        businesses zoned for commercial use to the north, west, and south. The property
        immediately to the northwest contains a bank, a gas station, and a convenience store. To
        the west and southwest, the parcel is bordered by the Forest River and a wooded area
        (immediately beyond which are commercially-zoned properties). The property to the south
        contains a self-storage facility and a health club. Figure 2 is an aerial photograph of the
        area, and it also shows noise measurement locations with an overlay of the site footprint.

        The nearest residential locations are located slightly further to the southwest (in the vicinity
        of Barnes Road) and to the southeast (a development at the intersection of Swampscott Road
        and First Street). There also are a few homes on the north side of Highland Avenue at the
        intersection with Swampscott Road.

        Trucks enter and exit the transfer station through an entrance on Swampscott Road, and this
        will not change in the future. Currently, the facility processes approximately 100 tons of
        construction and demolition debris per day. A traffic study conducted by Vanasse &
        Associates concluded that, during a weekday morning, peak-hour conditions will result in
        approximately 9 trucks entering and 11 trucks exiting per hour.

4.1     Baseline Noise Environment

        An ambient noise level survey was conducted during the daytime hours to characterize the
        existing “baseline” acoustical environment in the vicinity of the site. Existing noise sources
        in the vicinity include: car, bus, and truck traffic on Highland Avenue and Swampscott
        Road; airplane overflights; birds; and existing-condition activity at the transfer station.

4.2     Sound Level Measurement Locations

        The selection of both the continuous and short-term sound monitoring locations was based
        upon a review of the current land use in the area, with emphasis placed on the nearest
        residential locations. The three short-term noise-monitoring locations were selected at the
        nearest residences to the northwest, southwest, and southeast. The measurement locations
        are depicted in Figure 2 are described below.




2329 Salem Transfer Noise\report.doc              4-1                                 Existing Conditions
                                                                                  Epsilon Associates, Inc.
G:\Projects2\MA\Salem\2268\sound_measurement_locations.mxd




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Northside Carting, Inc.                                     Salem, Massachusetts

                                                                                                                                                                                                Figure 2
                                                                                                                                                              Sound Level Measurement Locations
        ♦ Location CM, the continuous 9-hour measurement location, is located along the
          southern property border of the transfer station and is adjacent to the storage facility
          property. The location is approximately 100 feet from Swampscott Road. It was chosen
          due to its close proximity to the nearest residences, which are located at the intersection
          of Swampscott Road and First Street. Location CM is considered to be very
          representative of the current background sound level near the transfer station. The
          primary noise source here was vehicle traffic along Swampscott Road. Truck activity
          within the transfer station was audible here. There was also an excavator operating on
          that day, but it was not a major source of noise (compared to vehicle traffic, the
          excavator was barely audible at location CM).

        ♦ Location ST-1 is located on the north side of Highland Avenue, within a small
          development of houses on Thomas Circle. Vehicle noise on Highland was the primary
          audible sound source there.

        ♦ Location ST-2 is within the townhouse development at the intersection of First Street
          and Swampscott Road, approximately 200 feet from the transfer station’s southern
          property line. The townhouses sit at an elevation of approximately 30 feet above the
          Swampscott Road. From that location the entire vicinity can be seen (including the
          transfer station). Vehicular traffic on Swampscott Road and First Street were the primary
          noise sources at ST-2.

        ♦ Location ST-3 was in a residential neighborhood approximately 1,300 feet to the
          southwest of the transfer station. This is a traditional neighborhood of single-family
          homes, and sound levels here were quieter than at the other locations (quiet enough to
          hear birds chirping). It was not possible to single-out sounds from the transfer station,
          since vehicular traffic on Highland Avenue was the primary audible source of
          background noise.

4.3    Measurement Methodology

        Daytime sound level measurements were made for 30 minutes per short-term location on
        Tuesday March 11, 2008, from approximately 9:00 a.m. to 12:00 p.m. In addition to the
        sampling data, one continuous programmable unattended sound level meter was placed at
        Location CM. This monitor continuously measured and stored hourly sound level statistics
        for 9 consecutive hours, to determine the temporal variation of the background noise levels,
        and to confirm that the short-term sampling was indeed representative. The monitor ran
        from 7:00 a.m. until 4:00 p.m. on Tuesday March 11. These hours were selected to match
        the operating hours of the transfer station. Field personnel checked on the integrity of the
        continuous equipment intermittently throughout the 9-hour period. Noise sources at each
        location were observed and noted throughout the day.



2329 Salem Transfer Noise\report.doc             4-3                               Existing Conditions
                                                                               Epsilon Associates, Inc.
        The sound levels were measured at a height of five feet above the ground and at locations
        where there were no large reflective surfaces to affect the measured levels. The
        measurements were made under low wind conditions and with dry roadway surfaces. Wind
        speed measurements were made with a Davis Instruments TurboMeter electronic wind
        speed indicator, and temperature and humidity measurements were made using a Mannix
        digital psychrometer. Unofficial observations about meteorology or land use in the
        community were made solely to characterize the existing sound levels in the area and to
        estimate the noise sensitivity at properties near the proposed Project.

        Wind speeds were measured several times throughout the day at microphone height.
        Speeds were calm between 7 a.m. and 12 p.m. and ranged between 3 to 5 mph during the
        rest of the measurement period. National Weather Service (NWS) observations from Beverly
        Municipal Airport meteorological station were obtained for the 9-hour period and are
        provided as Appendix A. The wind speeds at the airport (measured at a height of 33 feet
        above ground level) ranged between 5 and 13 mph between 7 a.m. and 4 p.m. However,
        conditions near the transfer station were much less windy, and it is not believed that wind
        significantly affected the measurement equipment or data.

4.4    Measurement Equipment

        A CEL Instruments Model 593.C1 Precision Sound Level Analyzer (serial number
        3/0162197) equipped with a CEL-257 Type 1 Preamplifier, a CEL-250 half-inch electret
        microphone (serial number 6259) and a four-inch foam windscreen were used to collect the
        short-term broadband and octave band ambient sound pressure level data. The
        instrumentation meets the “Type 1 - Precision” requirements set forth in American National
        Standards Institute (ANSI) S1.4-1983 for acoustical measuring devices, as well as IEC
        Publication 804 (1985). The meter was equipped with an internal octave band filter set
        along with automatic data logging capabilities conforming to ANSI S1.11-1986. The meter
        time-weighting was set for the “slow” response (1 second) and the data were logged every
        one second. Octave band levels for this study correspond to the same data set processed for
        the broadband levels.

        The CEL sound level meter was calibrated in the field before and after the surveys with a
        CEL-110/1 acoustical calibrator, which meets the standards of IEC 942 Class 1L and ANSI
        S1.40-1984. The calibration frequency is 1000 Hz with an accuracy of +/- 0.25 dB at the
        calibration level of 114.0 dB. The calibrator and analyzer were certified as accurate, to
        standards set by the US National Institute of Standards and Technology by an independent
        laboratory within the past 12 months. A calibration check was performed before and after
        each measurement program. All calibration level changes were 0.5 dB or less, thus
        validating the data precision.

        A Larson Davis model 812 sound level meter (serial number 0632) was used for the
        continuous monitoring. This meter meets Type 1 ANSI S1.4-1983 standards for sound level
        meters. The meter was calibrated immediately before and after the measurement with a

2329 Salem Transfer Noise\report.doc            4-4                               Existing Conditions
                                                                              Epsilon Associates, Inc.
        Larson Davis CAL200 acoustical calibrator which meets the standards of IEC 942 Class 1L
        and ANSI S1.40-1984. The model 812 meter has been calibrated and certified as accurate
        to standards set by the National Institute of Standards and Technology by an independent
        laboratory within the past 12 months. The model 812 has data logging capability and was
        programmed to log statistical data every hour for the following parameters: L1, L10, L50, L90,
        Lmax, Lmin, and Leq.

4.5    Baseline Ambient Noise Levels

        The existing short-term ambient baseline sound level measurements are summarized below
        and are presented in detail in Table 1. Detailed sound level data from the continuous
        measurement program can be found in Table 2 (Location CM). Figure 3 depicts the hour by
        hour sound level measurements at Location CM for the 9-hour continuous measurement.
        The continuous sound level data confirm the short-term data as a reasonable representation
        of area sound levels. The sound level data shown in Figure 3 demonstrates that noise levels
        were fairly constant throughout the day, most likely due to the steady traffic pattern on
        Swamp.

        ♦ The short-term daytime Leq (equivalent) measurements ranged from 50 to 59 dBA.

        ♦ The short-term daytime L90 (background) measurements ranged from 42 to 50 dBA.

        ♦ The 9-hour continuous Leq (equivalent) measurements ranged from 53 to 57 dBA at
          Location CM, and the L90 (background) measurements ranged from 48 to 50 dBA. The
          arithmetically averaged hourly background sound level (L90) equaled 48 dBA for the
          entire measurement period (7:00 a.m. - 4:00 p.m.).




2329 Salem Transfer Noise\report.doc             4-5                                Existing Conditions
                                                                                Epsilon Associates, Inc.
Table 1:             Baseline Ambient Noise Measurements – Salem Transfer Station, Salem, MA

                                                                                                                       Octave Bands (Hz)
 Receptor I.D            Start         L10   L50   L90   Leq  31.5                      63            125        250          500       1000       2000       4000       8000
                         Time        (dBA) (dBA) (dBA) (dBA) Leq (dB)                 Leq (dB)      Leq (dB)   Leq (dB)     Leq (dB)   Leq (dB)   Leq (dB)   Leq (dB)   Leq (dB)
    Loc ST-1          9:04 A.M.        60       54       50       57        62          62            56          49          46         46         41         30         21

    Loc ST-2          9:33 A.M.        61       57       52       59        57          56            53          51          49         49         43         34         26

    Loc ST-3         10:53 A.M.        49       45       42       50        51          49            43          36          34         33         29         35         24
Notes:
1. Weather:                          Temperature = 35oF, RH = 26%, skies clear, winds from the northwest at 0-4 mph.
2. Road surfaces were dry during all short-term measurements.
3. All sampling periods were approximately 30 minutes duration.
4. Measurements were collected on March 11, 2008




2329 Salem Transfer Noise\report.doc                                                          4-6                                                                Existing Conditions
                                                                                                                                                             Epsilon Associates, Inc.
Table 2:        Location CM Continuous 9-Hour Sound Measurement Data

                              Hour        LEQ1 Hr           L90
                                           (dBA)          (dBA)


                              7:00          57              50
                              8:00          56              50
                              9:00          54              48
                             10:00          55              48
                             11:00          54              48
                             12:00          54              48
                             13:00          55              48
                             14:00          57              49
                             15:00          53              48




2329 Salem Transfer Noise\report.doc         4-7                           Existing Conditions
                                                                       Epsilon Associates, Inc.
                                                   Figure 3: Salem Transfer Station, Salem, MA:
                                  Continuous Sound Levels at Southern Property Line, 7 am - 4 pm, March 11, 2008
                    70



                    65



                    60
Sound Level (dBA)




                    55


                                                                                                                             L90
                    50
                                                                                                                             Leq


                    45



                    40



                    35



                    30
                         6:00




                                7:00




                                          8:00




                                                    9:00




                                                             10:00




                                                                         11:00




                                                                                     12:00




                                                                                             13:00




                                                                                                     14:00




                                                                                                             15:00




                                                                                                                     16:00
                                                             Hour of Day (Starting Hour)
5.0     REFERENCE SOUND LEVEL DATA

        The key potential source of operational noise at the transfer station will be truck traffic
        within the property boundaries. Predictive modeling was conducted with the Traffic Noise
        Model (TNM), in order to determine impact due to increased truck traffic. The method is
        described in more detail within Section 6.1.

        In addition to truck traffic, there will be some noise due to truck back-up alarms and front-
        end loader activity within the tipping-floor building. Reference sound level data for
        operation of such equipment was collected by Epsilon Associates through previous projects.
        Those data were used to estimate impacts at the nearest lot boundaries and residences near
        the transfer station. Although the front-end loader will operate intermittently and at different
        times, a worst-case assumption was used where all equipment would operate continuously
        and simultaneously. Back-up alarms emit sound that is most prominent within the 1,000-
        hertz (Hz) frequency region, but they emit very little at other frequencies. They are safety
        devices designed that way, because the human ear is particularly sensitive to sounds within
        the 1,000-hertz region. Reference sound level data for both sources were measured at 50
        feet and are summarized below in Table 3. The loader was operating at full-throttle during
        the measurement.

Table 3:         Measured Equipment Sound Levels (at 50 feet)

                                                           Octave Bands (Hz)

       Equipment            Leq    31.5      63     125    250    500    1000    2000     4000    8000

                                   Leq       Leq     Leq   Leq     Leq    Leq      Leq     Leq      Leq
                          (dBA)
                                   (dB)      (dB)   (dB)   (dB)   (dB)    (dB)    (dB)    (dB)     (dB)

Volvo Model L60E Front-     68     74        87      74    62      57      60      63      50       44
      end Loader

  Truck Back-up Alarm       83         -      -       -     -       -     83        -       -        -


        The Cadna/A model (Computer Aided Noise Abatement, described in more detail with
        Section 6.2) calculates sound levels based on the sound power levels of the sources. The
        sound power output of a source is the total amount of energy radiated into the atmosphere,
        designated in units of Watts. Sound power data for this equipment was not available, so
        approximate sound power levels were calculated using the measured sound levels listed
        above. The following equation was used to approximate the sound power level of the
        equipment, assuming hemi-spherical spreading over hard ground:

                 L w= L p + 20Log10(r) + 8
        where:


2329 Salem Transfer Noise\report.doc                5-1                      Reference Sound Level Data
                                                                                  Epsilon Associates, Inc.
                Lw = sound power level
                Lp = sound pressure level measured at 50 feet (15.24 meters)
                r = distance from measurement microphone to source
                8 dB = increase in sound level, accounting for hemispherical spreading

        The resulting approximate octave-band sound power levels used in the CadnaA model are
        listed below in Table 4.

Table 4:        Equipment Sound Power Levels, dB (re 1 pW)

                                                         Octave Bands (Hz)

        Equipment          Leq    31.5     63     125    250    500    1000     2000     4000    8000

                          (dBA)   (dB)     (dB)   (dB)   (dB)   (dB)   (dB)      (dB)     (dB)    (dB)

    Volvo Model L60E
     Front-end Loader      99      95      105    101    104    94     91        88       80      74

   Truck Back-up Alarm    115          -    -      -      -      -     115        -        -       -




2329 Salem Transfer Noise\report.doc              5-2                        Reference Sound Level Data
                                                                                  Epsilon Associates, Inc.
6.0    FUTURE CONDITIONS

        Predictive sound level modeling was conducted with the Traffic Noise Model program and
        the Cadna/A program at the nearest lot lines to the facility’s noise-producing activities, as
        required by MA DEP regulation. The sound level modeling was also done for the same
        locations where ambient sound levels were measured. If sound levels are acceptable at
        these evaluation points, then noise at other more distant locations will be even less as
        sound decreases with distance from the source. The evaluation points are listed below. All
        evaluation points were modeled at a height of five feet above the ground.

        ♦ Point A: Nearest the southern property boundary; this was also the location of the
          continuous sound level monitor.

        ♦ Point B: Nearest the northern property boundary shared with the gas
          station/convenience store (a commercially-zoned parcel). This is not a noise-sensitive
          residential location, so background sound levels were not measured here. Due to the
          close proximity of the heavy vehicular traffic on Highland Avenue, it is estimated that
          the L90 background sound level at this location is between 55 and 60 dBA.

        ♦ Point C: Nearest the western property boundary in the woods. The abutting parcel is
          commercially-zoned “Business Park Development” and is not residential. Background
          sound levels were not measured here, but L90 sound levels are probably similar to what
          was measured at Location CM (an average L90 of 48 dBA).

        ♦ Point D: Nearest the eastern property line along Swampscott Road. There are no noise-
          sensitive or residential land use parcels along that section of Swampscott Road.
          Background sound levels were not measured here, but existing L90 sound levels are
          estimated to be between 55 and 60 dBA.

        ♦ Point E: Nearest short-term measurement location ST-1, near the houses on Thomas
          Circle, across from the Swampscott Road/Highland Avenue Intersection.

        ♦ Point F: Nearest short-term measurement location ST-2, near the townhouses at the
          Swampscott Road/First Street intersection.

        ♦ Point G: Nearest short-term measurement location ST-3, near houses on Barnes Road.
          The sound levels were predicted within the wooded area in between the two houses
          that are closest to the transfer station.

        ♦ Point H: Houses on Highland Avenue near Barcelona Avenue. Although sound level
          measurements were not made here, those houses are within 700 feet of the transfer
          station.

        Figure 4 shows the location of the transfer station and the modeled points of evaluation.


2329 Salem Transfer Noise\report.doc             6-1                                 Future Conditions
                                                                                Epsilon Associates, Inc.
G:\Projects2\MA\Salem\2268\predictive_modeling.mxd



                                                                                                                   LEGEND
                                                                                                                                   Predictive Modeling Location

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Northside Carting, Inc.                                      Salem, Massachusetts

                                                                                                                                                                                                  Figure 4
                                                                                                                                                                           Predictive Modeling Locations
6.1     Traffic Noise Model (TNM)

        Predicting increases in sound level due to increased truck activity was an important
        consideration when modeling future conditions. The Federal Highway Administration’s
        (FHWA) Traffic Noise Model (TNM) version 2.5 is used to predict sound levels near
        roadways. TNM predicts the hourly average sound level from vehicular traffic. Input
        information includes roadway width, noise-sensitive evaluation points, the hourly number
        and speed of vehicles, and ground elevations. In this case, the input parameters were
        “heavy trucks” travelling within the transfer station property. It was assumed that trucks
        would travel at a speed of approximately 15 miles per hour. Using data taken from a traffic
        study conducted by Vanasse & Associates, it was possible to determine the sound level
        increase due to increases in truck volume at the facility. The study cites an increase of 6
        trucks during a weekday morning peak hour1 (an additional 3 trucks entering and 3 trucks
        exiting).

        The transfer station will have newly-paved surfaces, so the pavement types modeled within
        TNM are valid. The width and location of the truck driveways were determined from an
        AutoCAD file of the site plan. Also, the site plan provided the elevations of the driveway
        sections. With all of the necessary parameters known, it was possible to predict the
        increase in sound levels resulting from an additional 6 trucks per hour. Location CM was
        used as the point of reference.

        Using the input assumptions above, TNM predicted that the hourly sound level would
        increase by no more than 2 dBA at the nearest locations. This 2 dBA increase was then
        assumed for all predictive modeling locations, to be added to the sound levels predicted by
        Cadna/A. This is described in Section 6.3.

6.2     Cadna/A Computer Software Sound Model

        The sound modeling for the front-end loader and back-up alarms was conducted using the
        Cadna/A sound calculation model (DataKustik Corporation, 2005). This physics-based
        computer software model uses the ISO 9613-2 industrial standard for sound propagation
        (Acoustics - Attenuation of sound during propagation outdoors - Part 2: General method of
        calculation). The Cadna/A model allows for octave band calculation of noise from multiple
        sources, as well as computation of diffraction around building edges, and multiple
        reflections off parallel buildings and solid ground areas. In this manner, all significant noise
        sources and geometric propagation effects are accounted for in the noise modeling.
        Shielding credit from onsite structures was taken in the modeling where appropriate.




1
  “Traffic Impact And Access Study: Proposed Transfer Station Expansion, Salem, MA”, Vanasse & Associates,
Inc., December 2007


2329 Salem Transfer Noise\report.doc               6-3                                  Future Conditions
                                                                                   Epsilon Associates, Inc.
        The front-end loader was assumed to operate inside the tipping-floor building. However,
        the side of the building facing the gas station (northern property line) was assumed to be
        open to the outside, which is where trucks will back in. This was determined from the
        building elevation plans dated October 2007.

        Additionally, noise radiating from the other three walls (eastern, southern, and western
        elevations) of the tipping-floor building were modeled within Cadna/A. Though those three
        walls will not have windows, this is anticipated to be a metal building with limited sound
        insulation. It is reasonable to assume that sound from the front-end loader may transmit
        through the walls somewhat. Trucks were assumed to operate at low idle while inside the
        building. Furthermore, it was assumed that the front-end loader would be considerably
        louder than the sound of refuse emptying from the trucks. It should also be remembered
        that the front-end loader was modeled at high-idle conditions and assumed to operate
        continuously throughout the day. This will not be the case under actual conditions.

        The back-up alarm was modeled outdoors near the northern side of the tipping-floor
        building, where the trucks will back up. The Vanasse & Associates traffic study stated that
        an additional 3 trucks would enter the facility during a weekday morning peak hour (the
        largest number of trucks for any hour of the day). The Cadna/A model allows the user to
        input the total amount of time (throughout the entire day) during which a sound source is
        expected to operate. It was assumed that each truck’s back-up alarm would operate for 30
        seconds during a drop-off. The three (3) additional back-up alarm events per hour result in
        a 1-dBA sound level increase for any given hour. Note: it was assumed that exiting trucks
        would not operate a back-up alarm. This corresponds approximately to an additional 15
        minutes per day during which alarms might operate (3 additional truck alarms for 30
        seconds during each of the 9 hours of operation). As with the TNM results, the increases
        due to back-up alarms were added to the overall Cadna/A results. This will be shown in
        Section 6.3.

        The Cadna/A model was run using standard meteorological conditions of 20 degrees C (68
        degrees F), 50% relative humidity, and no wind. To be conservative, no ground attenuation
        credit was taken by the model. The maximum order of reflections was set to seven in
        Cadna/A. The reflection type of the building wall was modeled as a smooth façade/reflective
        barrier. That calculates a loss of 1 dB for sound reflecting off of the building.

6.3     Predicted Sound Level Results

        The model output is shown in Appendix B, produced directly from Cadna/A with the results
        at the evaluation points. The sound level results at each point are shown in Table 5. Note
        that the results account for the presence of back-up alarms and truck traffic in incremental
        terms. Even with the back-up alarm increase and the 2-dBA increase from truck activity, all
        equipment operation will meet the MA DEP noise policy.




2329 Salem Transfer Noise\report.doc            6-4                                Future Conditions
                                                                              Epsilon Associates, Inc.
Table 5: Predicted Noise Levels Due to Tipping-Floor Building Operations vs. Baseline Ambient
          Background Sound Levels – MA Noise Policy Criteria

                                                                           TNM:           Increase        Increase
                          Tipping-       Baseline         Total:
                                                                          Increase         Due to           Over
                           Floor         L90 Back-      Project +
         Location                                                          Due to          Alarms           Back-
                          Activity        ground        Lowest L90
                                                                           Trucks        (+ 1 dBA)         ground
                           (dBA)           (dBA           (dBA)
                                                                         (+ 2 dBA)                          (dBA)
              A              42             481                49             51                52            4

              B              50             552                56             58                59            4

              C              43             481                50             52                53            4

              D              55             552                58             60                61            6
              E
                             41             503                50             52                53            3
        (residential)
              F
                             39             524                52             54                55            3
        (residential)
              G
                             37             425                43             45                46            4
        (residential)
              H
                             40             506                50             52                53            3
        (residential)
        Point A: Nearest the southern property boundary and continuous sound level monitor.
        Point B: Nearest the northern property boundary shared with the gas station
        Point C: Nearest the western property boundary in the woods
        Point D: Nearest the eastern property line along Swampscott Road.
        Point E: Nearest short-term measurement location ST-1, near the houses on Thomas Circle
        Point F: Nearest short-term measurement location ST-2, near the townhouses
        Point G: Nearest short-term measurement location ST-3, near houses on Barnes Road
        Point H: Nearest houses on Highland Avenue near Barcelona Avenue.


        1. 48 dBA was the average L90 sound level for the entire 9-hour continuous measurement period at Location CM
        2. 55 dBA is an estimated L90 sound level and is conservative. The actual daytime L90 sound level near the gas
        station at the intersection of Highland Ave and Swampscott Street is probably higher.
        3. Measured L90 sound level at Location ST-1
        4. Measured L90 sound level at Location ST-2
        5. Measured L90 sound level at Location ST-3
        6. The L90 sound level here was assumed to be the same as Location ST-1, since the locations are very close to
        one another.




2329 Salem Transfer Noise\report.doc                     6-5                                         Future Conditions
                                                                                                Epsilon Associates, Inc.
7.0   CONCLUSIONS AND CONTROL MEASURES

      The sound level impact assessment for the proposed expansion at the Salem Transfer Station
      indicates that predicted noise levels will comply with the most stringent daytime noise
      regulations. Expected worst-case future sound levels from increased truck volumes, loader
      activity within the tipping-floor building, and truck back-up alarms will be slightly above
      current property-line noise levels to the north, east, south, and west. Sound levels at the
      closest residential locations are also predicted to be slightly above the existing ambient
      (background) sound level.

      However, the transfer station will be far enough away from all residential zones, such that
      worst-case increases in background sound levels will range from 3-4 dBA at the nearest
      residences. This is well within the MA DEP criteria. Also, the tipping-floor building was
      intentionally situated such that the open end of the building would face in the direction of
      Highland Avenue. This will help considerably to shield the townhouses on First Street from
      tipping-floor activity.

      When they are operating, the back-up alarms may temporarily result in “pure-tone”
      conditions at locations to the north and west. However, as described earlier, these events
      will be very brief (less than 30 seconds during each back-up). Alarms will not operate
      continuously throughout the day. Also, actual alarm sound levels will probably be much
      lower than what was assumed in the modeling. The total increase in the occurrence of
      back-up alarms will be 15 minutes per day compared to current conditions.
                             Appendix A
Beverly Airport Weather Data, March 11, 2008
Observations for Beverly, MA (BVY)
                                                                        Relative         Wind
          STN   Date         Time        PMSL     ALTM     Temp   DEW   Humidity   DIR   Speed   VIS    CLOUDS
                                         hPa      inches Hg F     F     %          deg   knots   mile

      1   BVY    11-Mar-08     6:50 AM   1021.1   30.16    20     9     62         300   5       10     CLR
      2   BVY    11-Mar-08     7:50 AM   1021.2   30.16    22     9     57         290   5       10     CLR
      3   BVY    11-Mar-08     8:50 AM   1020.7   30.15    26     9     48         290   5       10     CLR
      4   BVY    11-Mar-08     9:50 AM   1020.5   30.14    29     7     39         290   10      10     CLR
      5   BVY    11-Mar-08    10:50 AM   1019.8   30.12    31     6     34         300   9       10     CLR
      6   BVY    11-Mar-08    11:50 AM   1018.7   30.09    33     5     30         270   8       10     CLR
      7   BVY    11-Mar-08    12:50 PM   1017.8   30.06    35     5     28         260   11      10     CLR
      8   BVY    11-Mar-08     1:50 PM   1016.9   30.04    36     5     27         270   5       10     CLR
      9   BVY    11-Mar-08     2:50 PM   1015.9   30.01    39     7     26         240   10      10     CLR
     10   BVY    11-Mar-08     3:50 PM   1014.8   29.98    40     7     25         260   9       10     CLR
     11   BVY    11-Mar-08     4:50 PM   1014.1   29.95    41     6     23         220   7       10     CLR
     12   BVY    11-Mar-08     5:50 PM   1013.7   29.94    36     17    46         160   8       10     CLR
 Appendix B
Cadna/A Output

								
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