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10 - Bullrock_GrotonSouthMain1_NoiseStudy_May2025
GROTON SOUTH MAIN 1 SOLAR PROJECT NOISE ASSESSMENT May 2025 Prepared for Bullrock Renewables Report Title: Groton South Main 1 Solar Project Noise Assessment Report Prepared by: RSG Report Prepared for: Bullrock Renewables For additional information regarding this report, or for questions about permissions or use of findings contained therein, please contact: RSG (Headquarters) 55 Railroad Row, Suite 200 White River Junction, VT 05001 (802) 295-4999 www.rsginc.com © 2025 RSG GROTON SOUTH MAIN 1 SOLAR PROJECT NOISE ASSESSMENT May 2025 i CONTENTS EXECUTIVE SUMMARY .......................................................................... 3 1.0 INTRODUCTION ................................................................................ 4 1.1 PROJECT DESCRIPTION .......................................................................4 NOISE SOURCES ..................................................................................4 1.2 NOISE IMPACT CRITERIA ......................................................................7 2.0 BACKGROUND SOUND LEVELS .................................................... 8 3.0 SOUND PROPAGATION MODELING ............................................... 9 3.1 DESCRIPTION .........................................................................................9 3.2 OPERATIONAL NOISE SOURCES ....................................................... 10 INVERTERS ......................................................................................... 10 TRANSFORMERS ................................................................................ 10 TRACKERS .......................................................................................... 10 OPERATIONAL EQUIPMENT SUMMARY ........................................... 11 3.3 RESULTS............................................................................................... 12 GROTON SOUTH MAIN 1 .................................................................... 12 CUMULATIVE RESULTS ..................................................................... 12 4.0 CONSTRUCTION NOISE ................................................................. 15 5.0 CONCLUSION .................................................................................. 16 APPENDIX A. ACOUSTICS PRIMER .................................................... 17 ACCOUNTING FOR CHANGES IN SOUND OVER TIME.................... 21 THE DIFFERENCE BETWEEN SOUND PRESSURE AND SOUND POWER .................................................................................. 23 SOUND PROPAGATION OUTDOORS ................................................ 23 APPENDIX B. MODEL INPUT DATA .................................................... 25 APPENDIX C. RECEIVER RESULTS TABLE ....................................... 35 ii LIST OF FIGURES FIGURE 1: MAP OF GROTON SOUTH MAIN 1 AND 2 WITH SURROUNDING RESIDENCES ............................................................................................................ 5 FIGURE 2: PROJECT SITE MAP WITH EQUIPMENT LAYOUT ....................................... 6 FIGURE 3: SOUND CONTOURS FROM GROTON SOUTH MAIN 1 ............................... 13 FIGURE 4: CUMULATIVE SOUND LEVEL CONTOURS (GROTON SOUTH MAIN 1 AND 2) ........................................................................................................ 14 FIGURE 5: A SCALE OF SOUND PRESSURE LEVELS FOR TYPICAL SOUND SOURCES ............................................................................................................... 18 FIGURE 6: AN EXAMPLE OF A SOUND SPECTROGRAM WITH ANNOTATIONS ....................................................................................................... 19 FIGURE 7: EXAMPLE OF DESCRIPTIVE TERMS OF SOUND MEASUREMENT OVER TIME ................................................................................. 22 LIST OF TABLES TABLE 1: ESTIMATED BACKGROUND EQUIVALENT CONTINUOUS SOUND LEVELS ..................................................................................................................... 8 TABLE 2: PROJECT NOISE SOURCE INFORMATION .................................................. 11 TABLE 3: GROTON SOUTH MAIN 2 SOLAR ARRAY NOISE SOURCE INFORMATION (CUMULATIVE MODELING) .......................................................... 11 TABLE 4: SUMMARY OF THE HIGHEST SOUND LEVEL FROM THE PROJECT ................................................................................................................ 12 TABLE 5: SUMMARY OF THE HIGHEST SOUND – CUMULATIVE MODEL ................. 12 TABLE 6: MAXIMUM SOUND LEVELS FROM VARIOUS TYPES OF CONSTRUCTION EQUIPMENT ASSUMING NO ATTENUATION FROM TREES OR TERRAIN .............................................................................................. 15 TABLE 7: MODEL PARAMETER INPUTS ...................................................................... 25 TABLE 8: MODEL SOURCE INPUTS ............................................................................. 25 TABLE 9: SOUND LEVELS AT NEARBY RESIDENCES FROM THE PROJECT AND CUMULATIVE WITH GROTON SOUTH MAIN 2. ............................................ 35 Groton South Main 1 Solar Project Noise Assessment 3 EXECUTIVE SUMMARY RSG performed a noise assessment for the Groton South Main 1 (Project), a 5 MW solar project planned in Tompkins County in Groton, New York. The Project will consist of 25 acres of solar panels, twenty inverters, and two pad-mounted site transformers. The noise design goal for the Project is 40 dBA at non-participating residences and 55 dBA at non-participating property lines. Although the Project does not fall within the jurisdiction of the Office of Renewable Energy Siting because its nameplate capacity value is less than 25 MW, Title 19, Chapter XVIII, Part 900 provides quantitative noise limit criteria that can be applied as reasonable design goals: a limit of 45 dBA Leq at residences and 55 dBA at nonparticipating property lines with an additional 5 dB penalty applied to the residential limit to account for tonal sound from the Project. To assess the operational noise emitted from the planned facility, sound emissions from each equipment type were quantified and sound pressure levels at nearby residences and property lines were calculated. Spectral equipment sound data indicate that sound emissions from the Project are tonal at the source. Because noise with prominent discrete tones is more noticeable than broadband sound at the same overall level, the 5 dB penalty is added to the sound design goal. Sound levels from the Project-only and also cumulative with the nearby planned Groton South Main 2 solar project, were calculated to ensure that the Project remains under the suggested limit. The highest modeled residential sound level is 30 dBA at a residence to the southwest of the Project. The highest property sound level from the Project is 44 dBA along the eastern side of the project. For the cumulative model, sound levels are projected to be up to 33 dBA at the nearest residence and a maximum of 44 dBA along the Eastern property line. All sound levels are at least 7 dB below their respective noise design limits. Sound levels due to construction are projected to be above background sound levels. Construction noise will include road construction, substation construction, trenching, inverter installation, piling and racking. Construction noise from any piece of equipment is calculated to range from 54 to 72 dBA Leq when located adjacent to the nearest residence. Sound levels would be lower as construction activities move away from sensitive locations. Project sound emissions are expected to be below estimated background sound levels in the area: 39 to 42 dBA at night and 45 to 47 dBA during the day. Based upon the results from the analysis completed in this report and the information presented in this report, we conclude that the Project, as designed, does not have a significant adverse impact on the environment with respect to noise. Groton South Main 1 Solar Project Noise Assessment 4 1.0 INTRODUCTION The Groton South Main 1 Solar Project (Project) is a 5 MW AC solar energy project proposed by Bullrock Renewables in Tompkins County in Groton, New York. An acoustics primer that presents the various concepts and terms used in the report is provided in Appendix A. 1.1 PROJECT DESCRIPTION The Groton South Main 1 Solar Project is a 5 MW photovoltaic project located in Groton, New York. The Project site is located on South Main Street Extension, one mile (1.6 kilometers) southeast of the Groton town center, west of Lick Street, and south of Elm Street (Figure 1). The fenceline contains about 25 acres. The land usage surrounding the Project area varies with distance from the Groton town center, with commercial properties residing to the northwest of the Project and agricultural use becoming more abundant toward the eastern side of the Project site. Another planned photovoltaic project (Groton South Main 2) is shown located to the southwest. Both projects are included in the cumulative model. Noise Sources The Project noise sources and the closest residences to the Project are identified in Figure 2. The Project consists of two main solar arrays: one to the northeast and the other to the southwest. The solar arrays will include tracking motors at the center of each solar rack. The primary sources of sound from Project operation include the trackers, which are distributed throughout the solar array, and inverters and transformers, which are located in groups towards the center of the array layout. The closest residence, R255, is located about 425-feet (130-meters) southwest of the Project fenceline and about 900-feet (275-meters) from the closest group of inverters. Sound levels from temporary construction noise sources are also calculated at the distance corresponding to the the closest residence. The next closest residence, R254, is across South Main Street to the southwest of the Project, 1130-feet (345-meters) from the nearest inverter. Groton South Main 1 Solar Project Noise Assessment 5 A FIGURE 1: MAP OF GROTON SOUTH MAIN 1 AND 2 WITH SURROUNDING RESIDENCES Groton South Main 1 Solar Project Noise Assessment 6 FIGURE 2: PROJECT SITE MAP WITH EQUIPMENT LAYOUT Groton South Main 1 Solar Project Noise Assessment 7 1.2 NOISE IMPACT CRITERIA The United States of America, New York State, Tompkins County, and the Town of Groton do not have quantitative noise standards that apply to 5 MW solar projects. However, for larger (> 25 MW) renewable energy projects, the Office of Renewable Energy Siting regulates noise under Title 19, Chapter XVIII, Part 900. Although the State regulations are not directly applicable to this project, they provide an accepted quantitative noise design goal for similar land use cases in the State of New York. The Official Compilation of Codes, Rules and Regulations of the State of New York in 19 CRR- NY 900-2.8 Exhibit 7 (b) states that a solar facility must comply with the following: (i) a maximum noise limit of 45 dBA Leq (8-hour), at the outside of any existing non- participating residence, and 55 dBA Leq (8-hour) at the outside of any existing participating residence; (ii) a maximum noise limit of 40 dBA Leq (1-hour) at the outside of any existing non- participating residence from the collector substation equipment; (iii) prominent tones are as defined by using the constant level differences listed under ANSI/ASA S12.9-2005/part 4 annex C (sounds with tonal content) (see section 900- 15.1[a][1][iii] of this Part), at the outside of any existing non-participating residence. Should a prominent tone occur, the broadband overall (dBA) noise level at the evaluated non- participating position shall be increased by 5 dBA for evaluation of compliance with subparagraphs (i) and (ii) of this paragraph; and (iv) a maximum noise limit of 55 dBA Leq (8-hour), short-term equivalent continuous average sound level from the facility across any portion of a non-participating property except for portions delineated as NYS-regulated wetlands pursuant to section 900-1.3(e) of this Part and utility ROW to be demonstrated with modeled sound contours drawings and discrete sound levels at worst-case locations. No penalties for prominent tones will be added in this assessment. Inverters produce prominent discrete tones. In lieu of background sound levels to assess if nearby residences would experience prominent discrete tones from the inverters, we conservatively assume that prominent discrete tones could be present at nearby residences and apply the tonal penalty as described in 19 CRR-NY 900-2.8 (b)(iii). As a result, we establish a Project noise design goal of 40 dBA at nearby non-participating residences and 50 dBA at participating residences. The property line limit is 55 dBA and is independent of the tonal penalty. Sound level limits are assessed as maximum 1-hour Leq (L1h). Measurement of the background sound level at receptors in the vicinity of the Project is not required, as there are no noise standards applicable to the Project that incorporate this metric. However, the background sound level is important to help frame the impact of the Project relative to the existing soundscape. Groton South Main 1 Solar Project Noise Assessment 8 2.0 BACKGROUND SOUND LEVEL S The background sound level is the level of sound that currently exists in the environment in the absence of the Project. This would include sounds from anthropogenic sources, such as vehicular traffic, aircraft, and existing mechanical equipment, as well as natural sound sources such as wind rustling leaves, birdsong, and insect sounds. Further, background sound levels vary both spatially and temporally. That is, the level of sound pressure varies from location to location and also over time at a single location. Background sound is commonly described using metrics that define the averaging period and the statistic used for averaging. These metrics are described in detail in Appendix A. For context with projected Project sound levels, we estimate the background sound levels in the area using two methods. The first method is based on RSG’s database of sound measurements throughout the U.S. and the second method follows the procedures outlined in American National Standard ANSI S12.9 Part 3 Annex C. The RSG database includes sound levels at 63 rural agricultural locations measured over the last 20 years. These measurements typically extended over one week or more. The ANSI S12.9 Part 3 Annex C method estimates background sound as a function of population density. The ANSI standard states that the 95% prediction interval is on the order of ±10 dB. In this case, the population density of the project area (400 to 1000 persons per square mile) fits within the “quiet suburban residential” residential land use category in the ANSI standard. The equivalent continuous sound levels (Leq) estimated from these methods for the daytime and nighttime periods are shown in Table 1. TABLE 1: ESTIMATED BACKGROUND EQUIVALENT CONTINUOUS SOUND LEVELS RSG DATABASE NATIONAL AVERAGE ANSI S12.9 PART 3 ANNEX C Day 47 dBA 45 dBA Night 42 dBA 39 dBA Groton South Main 1 Solar Project Noise Assessment 9 3.0 SOUND PROPAGATION MODELING 3.1 DESCRIPTION Modeling for the assessment was conducted in accordance with the standard ISO 9613-2, “Acoustics – Attenuation of sound during propagation outdoors, Part 2: General Method of Calculation.” ISO 9613-2 is: “an engineering method for calculating the attenuation of sound during propagation outdoors in order to predict the levels of environmental noise at a distance from a variety of sources. The method predicts the equivalent continuous A-weighted sound pressure level … under meteorological conditions favorable to propagation from sources of known sound emissions. These conditions are for downwind propagation … or, equivalently, propagation under a well-developed moderate ground-based temperature inversion, such as commonly occurs at night.” The model considers source sound power levels, surface reflection and absorption, atmospheric absorption, geometric divergence, meteorological conditions, walls, barriers, berms, ground factors, and terrain. ISO 9613-2 assumes downwind sound propagation between every source and every receiver. The acoustical modeling software used here was CadnaA, from Datakustik GmbH, a widely accepted acoustical propagation modeling tool. Parameters and receiver heights were set according to 19 CRR-NY 900-2.8 Exhibit 7 (d): • The temperature and relative humidity were 10 degrees Celsius and 70%, respectively; • Land area was set to a ground absorption factor of 0.5 and bodies of water were set to 0; • Four receivers were placed along the Project’s property line as worst-case property line sound levels; and • All assessment points were calculated 1.5-meters above ground height. A full list of modeling parameters is provided in Appendix B. Groton South Main 1 Solar Project Noise Assessment 10 3.2 OPERATIONAL NOISE SOURCES All equipment was modeled at maximum operational sound level emissions. Sound emissions from temporary construction for the Project are described in Section 4.0. Inverters The twenty 250 kW string inverter converts between direct current (DC) power produced by photovoltaic (PV) panels and the alternating current (AC) power used on the grid. Inverters may be used for reactive power management and during frequency regulation, so their operation is not necessarily limited to daytime. Inverter noise is characterized by the combination of mid- to high-frequency electrical sounds and cooling fans. The manufacturer (CHINT) provides that the inverters shall not exceed 80 dBA from a distance of one meter. For a more precise representation of inverter sound emissions, 1/3 octave band sound power level test results from a similar yet slightly larger inverter, the 275 kW-rated CPS SCH275KTL-DO, leads to a sound power level of 84 dBA. The inverter has a prominent discrete tone at the 630 Hz 1/3 octave band, and since it has not been stated otherwise, the 250 kW model is assumed to have similar tonal qualities. Transformers A total of two three-phase pad-mounted 2,500 kVA transformers will be installed with each group of inverters. The transformers will be energized at all times and without cooling fan operation (ONAN only). Based on the NEMA TR-1 standard1 and the size of the unit, sound power levels of the Project transformers were calculated to be 76 dBA from a NEMA TR-1 level of 62 dBA. Transformer sound is tonal at 120 Hz and integer multiples thereof. Trackers The project utilizes single-axis trackers to pivot the rows of PV panels to match the sun’s azimuth and elevation. The Nevados Solar Trackers specified for the project are positioned at the center of each 300-foot (90-meter) solar rack. The manufacturer of the tracking motor states that the sound level from the trackers does not exceed 65 dBA when measured from 3.3-feet (1- meter) away. This results in a sound power of 76 dBA and represents the maximum continuous sound level emitted by a tracker motor. However, trackers do not operate continuously. Typical operations may be three to four minutes per hour with 7 minutes per hour maximum during a sundown reset cycle, for example. To account for the maximum hourly duty cycle of 12% (7 minutes per hour), the equivalent hourly sound power level is 67 dBA for each tracking motor. The tracking motors are installed integrally on the racking beneath the panels at about 7 feet (2.1 meters) above ground level. The panels physically screen most trackers from most receivers, which impedes sound propagated from the trackers. Further, the condition where the 1 NEMA TR 1-2013 (R2019), Transformers, Regulators and Reactors. National Electrical Manufacturers Association. Groton South Main 1 Solar Project Noise Assessment 11 panels are offering the least screening (parallel to the ground) is also when conditions in the atmosphere are not conducive to sound propagation along the ground due to the upward refraction from daytime solar heating. Modeling conservatively considers the tracker motors as point sources at 7 feet above ground level without any screening and with favorable conditions for sound propagation, i.e., a nighttime temperature inversion. Operational Equipment Summary A list of specifications and associated sound levels is provided in Table 2 for Project noise sources. Specifications of the noise sources associated with the adjacent PV project are provided in Table 3. TABLE 2: PROJECT NOISE SOURCE INFORMATION EQUIPMENT MAKE MODEL QTY. SOUND POWER LEVEL (dBA) NOISE SPEC. (SOUND PRESSURE LEVEL) Inverter CHINT CPS SCH250K-T-US-600 20 84 < 80 dBA at 1 meter Transformer Typical 2,500 kVA 2 76 NEMA TR-1 = 62 dBA Tracker Nevados All Terrain Tracker 183 67 65 dBA at 1 meter TABLE 3: GROTON SOUTH MAIN 2 SOLAR ARRAY NOISE SOURCE INFORMATION (CUMULATIVE MODELING) EQUIPMENT MAKE MODEL QTY. SOUND POWER LEVEL (dBA) NOISE SPEC. (SOUND PRESSURE LEVEL) Inverter CHINT CPS SCH250K-T-US-600 15 84 < 80 dBA at 1 meter Transformer Typical 2,500 kVA 1 76 NEMA TR-1 = 62 dBA Transformer Typical 1,500 kVA 1 73 NEMA TR-1 = 60 dBA Tracker Nevados All Terrain Tracker 138 67 65 dBA at 1 meter Groton South Main 1 Solar Project Noise Assessment 12 3.3 RESULTS Sound pressure levels were modeled and assessed in accordance with 19 CRR-NY 900-2.8 Exhibit 7(b). Appendix C provides a list of the modeled sound pressure levels at each receptor. Groton South Main 1 The highest calculated sound levels from the Project were 30 dBA at a residence and 44 dBA at the property line. As shown in Table 4, all receptors are projected to be less than the design goals. Figure 3 shows sound level contours depicting sound propagation from the Project. TABLE 4: SUMMARY OF THE HIGHEST SOUND LEVEL FROM THE PROJECT LOCATION HIGHEST SOUND LEVEL DESIGN GOAL (dBA) Receiver ID Sound Level (dBA) Property Line Northern 37 55 Property Line Eastern 44 55 Property Line Southern 23 55 Property Line Western 35 55 Closest Residences R254 30 40 Closest Residences R255 29 40 The assumed 12% duty cycle of the trackers reduces the modeled tracker sound levels when averaged over a one-hour period. The highest sound level from the trackers was modeled to be 32 dBA at the eastern property line and up to 26 dBA at a residence (R255) on a 1-hour Leq basis. The trackers were additionally assessed without averaging over the hour period. The maximum sound level from the trackers (Lmax - not averaged over one hour) was 41 dBA at the eastern property line and 35 dBA at the nearest residence. Cumulative Results The highest sound level on each property line and at a residence is listed in Table 5. The sound contours from both projects are shown in Figure 4. The highest predicted cumulative sound level is 33 dBA at a residence and 44 dBA at the eastern property line. TABLE 5: SUMMARY OF THE HIGHEST SOUND – CUMULATIVE MODEL LOCATION HIGHEST SOUND LEVEL DESIGN GOAL (dBA) Receiver ID Sound Level (dBA) Property Line Northern 37 55 Property Line Eastern 44 55 Property Line Southern 26 55 Property Line Western 35 55 Closest Residences R254 31 40 Closest Residences R255 33 40 Groton South Main 1 Solar Project Noise Assessment 13 FIGURE 3: SOUND CONTOURS FROM GROTON SOUTH MAIN 1 Groton South Main 1 Solar Project Noise Assessment 14 FIGURE 4: CUMULATIVE SOUND LEVEL CONTOURS (GROTON SOUTH MAIN 1 AND 2) Groton South Main 1 Solar Project Noise Assessment 15 4.0 CONSTRUCTION NOISE Temporary construction noise will be generated throughout the Project site as the Project is being built. Expected portions include road construction within the project site, trenching along the underground collection line routes, inverter and transformer installation at each transformer pad location, and piling and racking throughout the solar arrays. Equipment used for each activity will vary. Some of the louder pieces of equipment are shown in Table 6 along with the approximate maximum sound pressure levels at a reference distance of 50-feet (15-meters) and 425-feet (130-meters), the closest distance between a solar array where racking and piling will take place and a residence. Sound source information was obtained from FHWA’s Roadway Construction Noise Model and manufacturer data. The sound propagation model used similar parameters to the Project’s operational modeling (Section 2.0), though the construction model utilizes a worst-case ground absorption coefficient of G = 0 in a 15 meters radius around each sound source. The maximum projected sound level at a residence from construction equipment is 72 dBA for a dump truck. TABLE 6: MAXIMUM SOUND LEVELS FROM VARIOUS TYPES OF CONSTRUCTION EQUIPMENT ASSUMING NO ATTENUATION FROM TREES OR TERRAIN EQUIPMENT MAXIMUM SOUND LEVEL (dBA) 50-feet (15-meters) 425-feet (130-meters) Compactor 84 63 Dozer 87 67 Dump Truck 93 72 Excavator 88 68 Flatbed or Boom Truck 76 55 Grader 80 59 Horizontal Bore Drill 89 70 Large Crane 77 57 Man-lift 75 54 Pile Driver (PD10) 89 68 Roller 90 71 Small Crane 84 63 Trencher 85 64 Groton South Main 1 Solar Project Noise Assessment 16 5.0 CONCLUSION RSG performed a sound modeling study of Bullrock Renewable’s proposed Groton South Main 1 Solar Project to determine its compatibility with the surrounding noise area and Project noise design goals. The project will contain 20 inverters, 2 transformers, and 183 tracking motors and have a 5 MW AC generator capacity. Summary and conclusions are as follows: 1. The project design threshold is 40 dBA at non-participating residences. Although the Project does not fall within the jurisdiction of the Office of Renewable Energy Siting because its nameplate capacity value is less than 25 MW, Title 19, Chapter XVIII, Part 900 provides quantitative noise limit criteria that can be applied to the Project. The 40 dBA limit comes from Title 19, Chapter XVIII, Part 900(b): 45 dBA Leq with a 5 dB penalty applied to account for the tonal sound. A property line design limit of 55 dBA is also considered. 2. While the Project transformers are typically the only sources that operate at night from a solar project, there may be times that the inverters will operate at night for VAR support and/or tracking motors are running at dawn. As such, this assessment conservatively assumed all equipment operating at maximum capacity. 3. Sound propagation modeling was conducted in accordance with ISO 9613-2 at 857 receptors within 4,920-feet (1,500 meters) of the Project. 4. The highest modeled residential sound level is 30 dBA at a residence to the southwest of the Project. The highest property sound level from the Project is 44 dBA along the eastern side of the project. 5. Modeled cumulative results (Groton South Main 1 and Groton South Main 2) produced sound levels up to 33 dBA at the nearest residence, which is 7 dBA below the design limit. The highest expected property sound level is 44 dBA along the eastern portion of the Project site, which is 11 dB below the design limit. 6. Sound levels from both Projects are expected to be below estimated nighttime (39 to 42 dBA) and daytime (45 to 47 dBA) background sound levels in the area. 7. Sound levels due to construction are summarized projected to be above background for a temporary basis. The maximum sound level at any residence could be up to 72 dBA from a dump truck. 8. Since maximum expected Project levels are below the design thresholds, the Project will not have a significant adverse impact on the environment with respect to noise. Groton South Main 1 Solar Project Noise Assessment 17 APPENDIX A. ACOUSTICS PRIMER Expressing Sound in Decibel Levels The varying air pressure that constitutes sound can be characterized in many different ways. The human ear is the basis for the metrics that are used in acoustics. Normal human hearing is sensitive to sound fluctuations over an enormous range of pressures, from about 20 micropascals (the “threshold of audibility”) to about 20 pascals (the “threshold of pain”).2 This factor of one million in sound pressure difference is challenging to convey in engineering units. Instead, sound pressure is converted to sound “levels” in units of “decibels” (dB, named after Alexander Graham Bell). Once a measured sound is converted to dB, it is denoted as a level with the letter “L”. The conversion from sound pressure in pascals to sound level in dB is a four-step process. First, the sound wave’s measured amplitude is squared and the mean is taken. Second, a ratio is taken between the mean square sound pressure and the square of the threshold of audibility (20 micropascals). Third, using the logarithm function, the ratio is converted to factors of 10. The final result is multiplied by 10 to give the decibel level. By this decibel scale, sound levels range from 0 dB at the threshold of audibility to 120 dB at the threshold of pain. Typical sound sources, and their sound pressure levels, are listed on the scale in Figure 5. Human Response to Sound Levels: Apparent Loudness For every 20 dB increase in sound level, the sound pressure increases by a factor of 10; the sound level range from 0 dB to 120 dB covers 6 factors of 10, or one million, in sound pressure. However, for an increase of 10 dB in sound level as measured by a meter, humans perceive an approximate doubling of apparent loudness: to the human ear, a sound level of 70 dB sounds about “twice as loud” as a sound level of 60 dB. Smaller changes in sound level, less than 3 dB up or down, are generally not perceptible. 2 The pascal is a measure of pressure in the metric system. In Imperial units, they are themselves very small: one pascal is only 145 millionths of a pound per square inch (psi). The sound pressure at the threshold of audibility is only 3 one-billionths of one psi: at the threshold of pain, it is about 3 one- thousandths of one psi. Groton South Main 1 Solar Project Noise Assessment 18 FIGURE 5: A SCALE OF SOUND PRESSURE LEVELS FOR TYPICAL SOUND SOURCES Groton South Main 1 Solar Project Noise Assessment 19 Frequency Spectrum of Sound The “frequency” of a sound is the rate at which it fluctuates in time, expressed in Hertz (Hz), or cycles per second. Very few sounds occur at only one frequency: most sound contains energy at many different frequencies, and it can be broken down into different frequency divisions, or bands. These bands are similar to musical pitches, from low tones to high tones. The most common division is the standard octave band. An octave is the range of frequencies whose upper frequency limit is twice its lower frequency limit, exactly like an octave in music. An octave band is identified by its center frequency: each successive band’s center frequency is twice as high (one octave) as the previous band. For example, the 500 Hz octave band includes all sound whose frequencies range between 354 Hz (Hertz, or cycles per second) and 707 Hz. The next band is centered at 1,000 Hz with a range between 707 Hz and 1,414 Hz. The range of human hearing is divided into 10 standard octave bands: 31.5 Hz, 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz, 8,000 Hz, and 16,000 Hz. For analyses that require finer frequency detail, each octave-band can be subdivided. A commonly used subdivision creates three smaller bands within each octave band, or so-called 1/3-octave bands. The Spectrogram One method of viewing the spectral sound level is to look at a spectrogram of the sound. As shown in FIGURE 6, the spectrogram shows the level, frequency spectra, and time in one graph. That is, the horizontal axis represents time, the vertical axis is frequency, and the intensity of the color is proportional to the intensity of the sound. FIGURE 6: AN EXAMPLE OF A SOUND SPECTROGRAM WITH ANNOTATIONS The spectrogram is useful for identify the sources of sound. For example, birds show short bursts of high frequency sound, while airplanes are mostly low frequency sound and show slow rise and fall times. In the example above, we can see several of these events. Groton South Main 1 Solar Project Noise Assessment 20 Human Response to Frequency: Weighting of Sound Levels The human ear is not equally sensitive to sounds of all frequencies. Sounds at some frequencies seem louder than others, despite having the same decibel level as measured by a sound level meter. In particular, human hearing is much more sensitive to medium pitches (from about 500 Hz to about 4,000 Hz) than to very low or very high pitches. For example, a tone measuring 80 dB at 500 Hz (a medium pitch) sounds quite a bit louder than a tone measuring 80 dB at 60 Hz (a very low pitch). The frequency response of normal human hearing ranges from 20 Hz to 20,000 Hz. Below 20 Hz, sound pressure fluctuations are not “heard”, but sometimes can be “felt”. This is known as “infrasound”. Likewise, above 20,000 Hz, sound can no longer be heard by humans; this is known as “ultrasound”. As humans age, they tend to lose the ability to hear higher frequencies first; many adults do not hear very well above about 16,000 Hz. Most natural and man-made sound occurs in the range from about 40 Hz to about 4,000 Hz. Some insects and birdsongs reach to about 8,000 Hz. To adjust measured sound pressure levels so that they mimic human hearing response, sound level meters apply filters, known as “frequency weightings”, to the signals. There are several defined weighting scales, including “A”, “B”, “C”, “D”, “G”, and “Z”. The most common weighting scale used in environmental noise analysis and regulation is A-weighting. This weighting represents the sensitivity of the human ear to sounds of low to moderate level. It attenuates sounds with frequencies below 1000 Hz and above 4000 Hz; it amplifies very slightly sounds between 1000 Hz and 4000 Hz, where the human ear is particularly sensitive. The C-weighting scale is sometimes used to describe louder sounds. The B- and D- scales are seldom used. All of these frequency weighting scales are normalized to the average human hearing response at 1000 Hz: at this frequency, the filters neither attenuate nor amplify. When a reported sound level has been filtered using a frequency weighting, the letter is appended to “dB”. For example, sound with A-weighting is usually denoted “dBA”. When no filtering is applied, the level is denoted “dB” or “dBZ”. The letter is also appended as a subscript to the level indicator “L”, for example “LA” for A-weighted levels. A relatively new standard weighting is the ANS weight. ANS stands for A-weighted, natural sounds. The ANS weight is the same as the A-weighting, but it filters out all sound above the 1,000 Hz octave band. Thus, it removes the impact of many high frequency biogenic sound such as insects, birds, and amphibians. The ANS weighting is often used to eliminate the effects of seasonality of sound, as there are fewer insects and birds during the winter than the summer. Time Response of Sound Level Meters Because sound levels can vary greatly from one moment to the next, the time over which sound is measured can influence the value of the levels reported. Often, sound is measured in real time, as it fluctuates. In this case, acousticians apply a so-called “time response” to the sound level meter, and this time response is often part of regulations for measuring sound. If the sound level is varying slowly, over a few seconds, “Slow” time response is applied, with a time constant of one second. If the sound level is varying quickly (for example, if brief events are Groton South Main 1 Solar Project Noise Assessment 21 mixed into the overall sound), “Fast” time response can be applied, with a time constant of one- eighth of a second.3 The time response setting for a sound level measurement is indicated with the subscript “S” for Slow and “F” for Fast: LS or LF. A sound level meter set to Fast time response will indicate higher sound levels than one set to Slow time response when brief events are mixed into the overall sound, because it can respond more quickly. In some cases, the maximum sound level that can be generated by a source is of concern. Likewise, the minimum sound level occurring during a monitoring period may be required. To measure these, the sound level meter can be set to capture and hold the highest and lowest levels measured during a given monitoring period. This is represented by the subscript “max”, denoted as “Lmax”. One can define a “max” level with Fast response LFmax (1/8-second time constant), Slow time response LSmax (1-second time constant), or Continuous Equivalent level over a specified time period Leq.max. Accounting for Changes in Sound Over Time A sound level meter’s time response settings are useful for continuous monitoring. However, they are less useful in summarizing sound levels over longer periods. To do so, acousticians apply simple statistics to the measured sound levels, resulting in a set of defined types of sound level related to averages over time. An example is shown in Figure 7. The sound level at each instant of time is the grey trace going from left to right. Over the total time it was measured (1 hour in the figure), the sound energy spends certain fractions of time near various levels, ranging from the minimum (about 27 dB in the figure) to the maximum (about 65 dB in the figure). The simplest descriptor is the average sound level, known as the Equivalent Continuous Sound Level. Statistical levels are used to determine for what percentage of time the sound is louder than any given level. These levels are described in the following sections. Equivalent Continuous Sound Level - Leq One straightforward, common way of describing sound levels is in terms of the Continuous Equivalent Sound Level, or Leq. The Leq is the average sound pressure level over a defined period of time, such as one hour or one day. Leq is the most commonly used descriptor in noise standards and regulations. Leq is representative of the overall sound to which a person is exposed. Because of the logarithmic calculation of decibels, Leq tends to favor higher sound levels: loud and infrequent sources have a larger impact on the resulting average sound level than quieter but more frequent sounds. For example, in Figure 7, even though the sound levels spends most of the time near about 34 dBA, the Leq is 41 dBA, having been “inflated” by the maximum level of 65 dBA and other occasional spikes over the course of the hour. 3 There is a third-time response defined by standards, the “Impulse” response. This response was defined to enable use of older, analog meters when measuring very brief sounds; it is no longer in common use. Groton South Main 1 Solar Project Noise Assessment 22 FIGURE 7: EXAMPLE OF DESCRIPTIVE TERMS OF SOUND MEASUREMENT OVER TIME Percentile Sound Levels – Ln Percentile sound levels describe the statistical distribution of sound levels over time. “LN” is the level above which the sound spends “N” percent of the time. For example, L90 (sometimes called the “residual base level”) is the sound level exceeded 90% of the time: the sound is louder than L90 most of the time. L10 is the sound level that is exceeded only 10% of the time. L50 (the “median level”) is exceeded 50% of the time: half of the time the sound is louder than L50, and half the time it is quieter than L50. Note that L50 (median) and Leq (mean) are not always the same, for reasons described in the previous section. L90 is the sound that persists for longer periods, and below which the overall sound level seldom falls. It tends to filter out other short-term environmental sounds that aren’t part of the source being investigated. L10 represents the higher, but less frequent, sound levels. These could include such events as barking dogs, vehicles driving by and aircraft flying overhead, gusts of wind, and work operations. L90 represents the background sound that is present when these event sounds are excluded. Note that if one sound source is very constant and dominates the soundscape in an area, all of the descriptive sound levels mentioned here tend toward the same value. It is when the sound is varying widely from one moment to the next that the statistical descriptors are useful. Groton South Main 1 Solar Project Noise Assessment 23 Sound Levels from Multiple Sources: Adding Decibels Because of the way that sound levels in decibels are calculated, the sounds from more than one source do not add arithmetically. Instead, two sound sources that are the same decibel level increase the total sound level by 3 dB. For example, suppose the sound from an industrial blower registers 80 dB at a distance of 2 meters (6.6 feet). If a second industrial blower is operated next to the first one, the sound level from both machines will be 83 dB, not 160 dB. Adding two more blowers (a total of four) raises the sound level another 3 dB to 86 dB. Finally, adding four more blowers (a total of eight) raises the sound level to 89 dB. It would take eight total blowers, running together, for a person to judge the sound as having “doubled in loudness”. Recall from the explanation of sound levels that a difference of 10 decibels is a factor of 20 in sound pressure and a factor of 10 in sound power. (The difference between sound pressure and sound power is described in the next Section.) If two sources of sound differ individually by 10 decibels, the louder of the two is generating ten times more sound. This means that the loudest source(s) in any situation always dominates the total sound level. Looking again at the industrial blower running at 80 decibels, if a small ventilator fan whose level alone is 70 decibels were operated next to the industrial blower, the total sound level increases by only 0.4 decibels, to 80.4 decibels. The small fan is only 10% as loud as the industrial blower, so the larger blower completely dominates the total sound level. The Difference between Sound Pressure and Sound Power The human ear and microphones respond to variations in sound pressure. However, in characterizing the sound emitted by a specific source, it is proper to refer to sound power. While sound pressure induced by a source can vary with distance and conditions, the power is the same for the source under all conditions, regardless of the surroundings or the distance to the nearest listener. In this way, sound power levels are used to characterize noise sources because they act like a “fingerprint” of the source. An analogy can be made to light bulbs. The bulb emits a constant amount of light under all conditions, but its perceived brightness diminishes as one moves away from it. Both sound power and sound pressure levels are described in terms of decibels, but they are not the same thing. Decibels of sound pressure are related to 20 micropascals, as explained at the beginning of this primer. Sound power is a measure of the acoustic power emitted or radiated by a source; its decibels are relative to one picowatt. Sound Propagation Outdoors As a listener moves away from a source of sound, the sound level decreases due to “geometrical divergence”: the sound waves spread outward like ripples in a pond and lose energy. For a sound source that is compact in size, the received sound level diminishes or attenuates by 6 dB for every doubling of distance: a sound whose level is measured as 70 dBA at 100 feet from a source will have a measured level of 64 dBA at 200 feet from the source and 58 dBA at 400 feet. Other factors, such as walls, berms, buildings, terrain, atmospheric Groton South Main 1 Solar Project Noise Assessment 24 absorption, and intervening vegetation will also further reduce the sound level reaching the listener. The type of ground over which sound is propagating can have a strong influence on sound levels. Harder ground, pavement, and open water are very reflective, while soft ground, snow cover, or grass is more absorptive. In general, sounds of higher frequency will attenuate more over a given distance than sounds of lower frequency: the “boom” of thunder can be heard much further away than the initial “crack”. Atmospheric and meteorological conditions can enhance or attenuate sound from a source in the direction of the listener. Wind blowing from the source toward the listener tends to enhance sound levels; wind blowing away from the listener toward the source tends to attenuate sound levels. Normal temperature profiles (typical of a sunny day, where the air is warmer near the ground and gets colder with increasing altitude) tend to attenuate sound levels; inverted profiles (typical of nighttime and some overcast conditions) tend to enhance sound levels. Groton South Main 1 Solar Project Noise Assessment 25 APPENDIX B. MODEL INPUT DATA TABLE 7: MODEL PARAMETER INPUTS MODEL PARAMETER SETTING Atmospheric Absorption Based on 10°C and 70% RH Foliage No Foliage Attenuation Ground Absorption ISO 9613-2 spectral, G=0.5 for land Receiver Height 1.5 meters for sound level isolines and discrete receptors Search Radius 1,500 meters from each source TABLE 8: MODEL SOURCE INPUTS SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Inverter01 Groton South Main 1 84 1.5 388912 4714599 380 Inverter02 Groton South Main 1 84 1.5 388913 4714599 380 Inverter03 Groton South Main 1 84 1.5 388915 4714599 381 Inverter04 Groton South Main 1 84 1.5 388917 4714599 381 Inverter05 Groton South Main 1 84 1.5 388918 4714598 381 Inverter06 Groton South Main 1 84 1.5 388911 4714597 380 Inverter07 Groton South Main 1 84 1.5 388913 4714597 380 Inverter08 Groton South Main 1 84 1.5 388914 4714597 381 Inverter09 Groton South Main 1 84 1.5 388916 4714597 381 Inverter10 Groton South Main 1 84 1.5 388918 4714597 381 Inverter11 Groton South Main 1 84 1.5 389147 4714605 381 Inverter12 Groton South Main 1 84 1.5 389149 4714605 381 Inverter13 Groton South Main 1 84 1.5 389150 4714605 381 Inverter14 Groton South Main 1 84 1.5 389152 4714605 381 Inverter15 Groton South Main 1 84 1.5 389154 4714605 381 Inverter16 Groton South Main 1 84 1.5 389146 4714603 381 Inverter17 Groton South Main 1 84 1.5 389148 4714603 381 Inverter18 Groton South Main 1 84 1.5 389150 4714603 381 Inverter19 Groton South Main 1 84 1.5 389152 4714603 381 Inverter20 Groton South Main 1 84 1.5 389153 4714603 381 MVT1 2.5 kVA Groton South Main 1 76 1.85 389136 4714604 381 MVT2 2.5 kVA Groton South Main 1 76 1.85 388898 4714598 379 Tracker001 Groton South Main 1 67 2.13 388780 4714580 367 Tracker002 Groton South Main 1 67 2.13 388785 4714565 368 Tracker003 Groton South Main 1 67 2.13 388791 4714565 368 Tracker004 Groton South Main 1 67 2.13 388796 4714565 369 Tracker005 Groton South Main 1 67 2.13 388801 4714565 369 Groton South Main 1 Solar Project Noise Assessment 26 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker006 Groton South Main 1 67 2.13 388807 4714565 369 Tracker007 Groton South Main 1 67 2.13 388812 4714565 370 Tracker008 Groton South Main 1 67 2.13 388818 4714565 370 Tracker009 Groton South Main 1 67 2.13 388823 4714565 370 Tracker010 Groton South Main 1 67 2.13 388829 4714550 370 Tracker011 Groton South Main 1 67 2.13 388834 4714549 370 Tracker012 Groton South Main 1 67 2.13 388839 4714549 371 Tracker013 Groton South Main 1 67 2.13 388845 4714549 371 Tracker014 Groton South Main 1 67 2.13 388851 4714549 372 Tracker015 Groton South Main 1 67 2.13 388856 4714549 372 Tracker016 Groton South Main 1 67 2.13 388862 4714549 374 Tracker017 Groton South Main 1 67 2.13 388867 4714549 375 Tracker018 Groton South Main 1 67 2.13 388873 4714549 376 Tracker019 Groton South Main 1 67 2.13 388878 4714548 377 Tracker020 Groton South Main 1 67 2.13 388884 4714548 378 Tracker021 Groton South Main 1 67 2.13 388889 4714548 378 Tracker022 Groton South Main 1 67 2.13 388895 4714548 379 Tracker023 Groton South Main 1 67 2.13 388900 4714548 379 Tracker024 Groton South Main 1 67 2.13 388905 4714548 380 Tracker025 Groton South Main 1 67 2.13 388911 4714548 381 Tracker026 Groton South Main 1 67 2.13 388917 4714548 381 Tracker027 Groton South Main 1 67 2.13 388922 4714548 382 Tracker028 Groton South Main 1 67 2.13 388927 4714548 382 Tracker029 Groton South Main 1 67 2.13 388933 4714548 383 Tracker030 Groton South Main 1 67 2.13 388938 4714547 383 Tracker031 Groton South Main 1 67 2.13 388944 4714539 383 Tracker032 Groton South Main 1 67 2.13 388955 4714532 383 Tracker033 Groton South Main 1 67 2.13 388960 4714547 383 Tracker034 Groton South Main 1 67 2.13 388966 4714547 383 Tracker035 Groton South Main 1 67 2.13 388971 4714547 383 Tracker036 Groton South Main 1 67 2.13 388977 4714547 383 Tracker037 Groton South Main 1 67 2.13 388982 4714547 383 Tracker038 Groton South Main 1 67 2.13 388988 4714546 384 Tracker039 Groton South Main 1 67 2.13 388993 4714547 384 Tracker040 Groton South Main 1 67 2.13 388999 4714546 384 Tracker041 Groton South Main 1 67 2.13 389004 4714546 384 Tracker042 Groton South Main 1 67 2.13 389010 4714546 384 Tracker043 Groton South Main 1 67 2.13 389015 4714546 385 Tracker044 Groton South Main 1 67 2.13 389021 4714546 385 Tracker045 Groton South Main 1 67 2.13 389026 4714546 385 Groton South Main 1 Solar Project Noise Assessment 27 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker046 Groton South Main 1 67 2.13 389032 4714546 385 Tracker047 Groton South Main 1 67 2.13 389037 4714546 386 Tracker048 Groton South Main 1 67 2.13 389043 4714546 386 Tracker049 Groton South Main 1 67 2.13 389048 4714545 387 Tracker050 Groton South Main 1 67 2.13 389054 4714545 388 Tracker051 Groton South Main 1 67 2.13 389059 4714545 389 Tracker052 Groton South Main 1 67 2.13 389065 4714545 389 Tracker053 Groton South Main 1 67 2.13 389070 4714545 389 Tracker054 Groton South Main 1 67 2.13 389075 4714545 389 Tracker055 Groton South Main 1 67 2.13 389081 4714545 389 Tracker056 Groton South Main 1 67 2.13 389086 4714545 389 Tracker057 Groton South Main 1 67 2.13 389092 4714545 389 Tracker058 Groton South Main 1 67 2.13 389098 4714545 389 Tracker059 Groton South Main 1 67 2.13 389103 4714544 389 Tracker060 Groton South Main 1 67 2.13 389108 4714544 389 Tracker061 Groton South Main 1 67 2.13 389114 4714544 389 Tracker062 Groton South Main 1 67 2.13 389119 4714544 389 Tracker063 Groton South Main 1 67 2.13 389125 4714544 389 Tracker064 Groton South Main 1 67 2.13 388860 4714488 376 Tracker065 Groton South Main 1 67 2.13 388866 4714488 376 Tracker066 Groton South Main 1 67 2.13 388871 4714488 377 Tracker067 Groton South Main 1 67 2.13 388877 4714488 377 Tracker068 Groton South Main 1 67 2.13 388882 4714488 378 Tracker069 Groton South Main 1 67 2.13 388888 4714488 378 Tracker070 Groton South Main 1 67 2.13 388893 4714487 378 Tracker071 Groton South Main 1 67 2.13 388899 4714487 378 Tracker072 Groton South Main 1 67 2.13 388904 4714472 378 Tracker073 Groton South Main 1 67 2.13 388910 4714472 378 Tracker074 Groton South Main 1 67 2.13 388915 4714472 378 Tracker075 Groton South Main 1 67 2.13 388920 4714472 378 Tracker076 Groton South Main 1 67 2.13 388926 4714472 378 Tracker077 Groton South Main 1 67 2.13 388932 4714472 378 Tracker078 Groton South Main 1 67 2.13 388937 4714472 378 Tracker079 Groton South Main 1 67 2.13 388943 4714478 378 Tracker080 Groton South Main 1 67 2.13 388953 4714456 378 Tracker081 Groton South Main 1 67 2.13 388958 4714456 378 Tracker082 Groton South Main 1 67 2.13 388964 4714456 378 Tracker083 Groton South Main 1 67 2.13 388969 4714456 378 Tracker084 Groton South Main 1 67 2.13 388975 4714456 379 Tracker085 Groton South Main 1 67 2.13 388980 4714456 379 Groton South Main 1 Solar Project Noise Assessment 28 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker086 Groton South Main 1 67 2.13 388986 4714456 378 Tracker087 Groton South Main 1 67 2.13 388992 4714456 377 Tracker088 Groton South Main 1 67 2.13 388997 4714455 377 Tracker089 Groton South Main 1 67 2.13 389002 4714455 377 Tracker090 Groton South Main 1 67 2.13 389008 4714455 377 Tracker091 Groton South Main 1 67 2.13 389013 4714455 378 Tracker092 Groton South Main 1 67 2.13 389019 4714455 379 Tracker093 Groton South Main 1 67 2.13 389024 4714455 379 Tracker094 Groton South Main 1 67 2.13 389030 4714455 379 Tracker095 Groton South Main 1 67 2.13 389035 4714455 380 Tracker096 Groton South Main 1 67 2.13 389041 4714455 380 Tracker097 Groton South Main 1 67 2.13 389046 4714454 381 Tracker098 Groton South Main 1 67 2.13 389052 4714454 381 Tracker099 Groton South Main 1 67 2.13 389057 4714454 381 Tracker100 Groton South Main 1 67 2.13 389063 4714454 381 Tracker101 Groton South Main 1 67 2.13 389068 4714454 381 Tracker102 Groton South Main 1 67 2.13 389074 4714454 381 Tracker103 Groton South Main 1 67 2.13 389079 4714454 381 Tracker104 Groton South Main 1 67 2.13 389084 4714454 382 Tracker105 Groton South Main 1 67 2.13 389091 4714453 382 Tracker106 Groton South Main 1 67 2.13 389096 4714454 382 Tracker107 Groton South Main 1 67 2.13 389101 4714453 383 Tracker108 Groton South Main 1 67 2.13 389107 4714453 383 Tracker109 Groton South Main 1 67 2.13 389112 4714453 384 Tracker110 Groton South Main 1 67 2.13 389118 4714453 384 Tracker111 Groton South Main 1 67 2.13 389123 4714453 384 Tracker112 Groton South Main 1 67 2.13 389131 4714640 378 Tracker113 Groton South Main 1 67 2.13 389137 4714640 378 Tracker114 Groton South Main 1 67 2.13 389142 4714640 378 Tracker115 Groton South Main 1 67 2.13 389148 4714639 378 Tracker116 Groton South Main 1 67 2.13 389153 4714639 378 Tracker117 Groton South Main 1 67 2.13 389159 4714639 378 Tracker118 Groton South Main 1 67 2.13 389164 4714639 377 Tracker119 Groton South Main 1 67 2.13 389170 4714639 377 Tracker120 Groton South Main 1 67 2.13 389175 4714639 377 Tracker121 Groton South Main 1 67 2.13 389181 4714639 378 Tracker122 Groton South Main 1 67 2.13 389186 4714639 378 Tracker123 Groton South Main 1 67 2.13 389192 4714639 378 Tracker124 Groton South Main 1 67 2.13 389197 4714639 378 Tracker125 Groton South Main 1 67 2.13 389203 4714638 378 Groton South Main 1 Solar Project Noise Assessment 29 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker126 Groton South Main 1 67 2.13 389208 4714638 378 Tracker127 Groton South Main 1 67 2.13 389214 4714638 378 Tracker128 Groton South Main 1 67 2.13 389219 4714638 378 Tracker129 Groton South Main 1 67 2.13 389225 4714638 378 Tracker130 Groton South Main 1 67 2.13 389230 4714638 378 Tracker131 Groton South Main 1 67 2.13 389236 4714638 378 Tracker132 Groton South Main 1 67 2.13 389241 4714638 378 Tracker133 Groton South Main 1 67 2.13 389246 4714638 378 Tracker134 Groton South Main 1 67 2.13 389252 4714637 378 Tracker135 Groton South Main 1 67 2.13 389257 4714637 378 Tracker136 Groton South Main 1 67 2.13 389263 4714637 379 Tracker137 Groton South Main 1 67 2.13 389268 4714637 379 Tracker138 Groton South Main 1 67 2.13 389274 4714637 379 Tracker139 Groton South Main 1 67 2.13 389279 4714637 379 Tracker140 Groton South Main 1 67 2.13 389285 4714637 380 Tracker141 Groton South Main 1 67 2.13 389290 4714637 380 Tracker142 Groton South Main 1 67 2.13 389296 4714637 380 Tracker143 Groton South Main 1 67 2.13 389301 4714637 380 Tracker144 Groton South Main 1 67 2.13 389307 4714636 380 Tracker145 Groton South Main 1 67 2.13 389312 4714636 381 Tracker146 Groton South Main 1 67 2.13 389318 4714636 381 Tracker147 Groton South Main 1 67 2.13 389323 4714636 381 Tracker148 Groton South Main 1 67 2.13 389329 4714636 381 Tracker149 Groton South Main 1 67 2.13 389334 4714636 381 Tracker150 Groton South Main 1 67 2.13 389340 4714636 381 Tracker151 Groton South Main 1 67 2.13 389345 4714636 381 Tracker152 Groton South Main 1 67 2.13 389350 4714636 381 Tracker153 Groton South Main 1 67 2.13 389188 4714715 373 Tracker154 Groton South Main 1 67 2.13 389193 4714715 373 Tracker155 Groton South Main 1 67 2.13 389199 4714714 374 Tracker156 Groton South Main 1 67 2.13 389204 4714714 374 Tracker157 Groton South Main 1 67 2.13 389210 4714714 374 Tracker158 Groton South Main 1 67 2.13 389215 4714714 374 Tracker159 Groton South Main 1 67 2.13 389221 4714714 375 Tracker160 Groton South Main 1 67 2.13 389226 4714714 375 Tracker161 Groton South Main 1 67 2.13 389231 4714714 376 Tracker162 Groton South Main 1 67 2.13 389237 4714714 376 Tracker163 Groton South Main 1 67 2.13 389242 4714714 376 Tracker164 Groton South Main 1 67 2.13 389248 4714714 376 Tracker165 Groton South Main 1 67 2.13 389253 4714713 377 Groton South Main 1 Solar Project Noise Assessment 30 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker166 Groton South Main 1 67 2.13 389259 4714713 377 Tracker167 Groton South Main 1 67 2.13 389264 4714713 377 Tracker168 Groton South Main 1 67 2.13 389270 4714713 378 Tracker169 Groton South Main 1 67 2.13 389275 4714713 378 Tracker170 Groton South Main 1 67 2.13 389281 4714713 378 Tracker171 Groton South Main 1 67 2.13 389286 4714713 379 Tracker172 Groton South Main 1 67 2.13 389292 4714713 379 Tracker173 Groton South Main 1 67 2.13 389297 4714713 379 Tracker174 Groton South Main 1 67 2.13 389303 4714713 379 Tracker175 Groton South Main 1 67 2.13 389308 4714712 380 Tracker176 Groton South Main 1 67 2.13 389314 4714712 380 Tracker177 Groton South Main 1 67 2.13 389319 4714712 380 Tracker178 Groton South Main 1 67 2.13 389325 4714712 380 Tracker179 Groton South Main 1 67 2.13 389330 4714712 380 Tracker180 Groton South Main 1 67 2.13 389336 4714712 380 Tracker181 Groton South Main 1 67 2.13 389341 4714712 381 Tracker182 Groton South Main 1 67 2.13 389347 4714712 381 Tracker183 Groton South Main 1 67 2.13 389352 4714712 381 Inverter01 Groton South Main 2 84 1.5 388593 4713943 329 Inverter02 Groton South Main 2 84 1.5 388560 4713943 326 Inverter03 Groton South Main 2 84 1.5 388562 4713943 327 Inverter04 Groton South Main 2 84 1.5 388563 4713943 327 Inverter05 Groton South Main 2 84 1.5 388565 4713943 327 Inverter06 Groton South Main 2 84 1.5 388592 4713943 329 Inverter07 Groton South Main 2 84 1.5 388590 4713943 329 Inverter08 Groton South Main 2 84 1.5 388590 4713942 329 Inverter09 Groton South Main 2 84 1.5 388592 4713942 329 Inverter10 Groton South Main 2 84 1.5 388564 4713942 327 Inverter11 Groton South Main 2 84 1.5 388563 4713942 327 Inverter12 Groton South Main 2 84 1.5 388561 4713942 327 Inverter13 Groton South Main 2 84 1.5 388560 4713942 326 Inverter14 Groton South Main 2 84 1.5 388593 4713942 329 Inverter15 Groton South Main 2 84 1.5 388589 4713943 329 MVT1 2.5 kVA Groton South Main 2 76 1.85 388573 4713945 328 MVT2 1.5 kVA Groton South Main 2 73 1.85 388584 4713945 328 Tracker001 Groton South Main 2 67 2.13 388455 4713976 325 Tracker002 Groton South Main 2 67 2.13 388460 4713976 325 Tracker003 Groton South Main 2 67 2.13 388466 4713976 325 Tracker004 Groton South Main 2 67 2.13 388471 4713976 325 Tracker005 Groton South Main 2 67 2.13 388477 4713976 325 Groton South Main 1 Solar Project Noise Assessment 31 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker006 Groton South Main 2 67 2.13 388482 4713976 326 Tracker007 Groton South Main 2 67 2.13 388488 4713976 326 Tracker008 Groton South Main 2 67 2.13 388493 4713976 326 Tracker009 Groton South Main 2 67 2.13 388499 4713982 326 Tracker010 Groton South Main 2 67 2.13 388504 4713984 327 Tracker011 Groton South Main 2 67 2.13 388510 4713987 327 Tracker012 Groton South Main 2 67 2.13 388515 4713990 327 Tracker013 Groton South Main 2 67 2.13 388521 4713993 327 Tracker014 Groton South Main 2 67 2.13 388527 4713994 327 Tracker015 Groton South Main 2 67 2.13 388532 4713996 327 Tracker016 Groton South Main 2 67 2.13 388538 4713996 327 Tracker017 Groton South Main 2 67 2.13 388543 4713996 327 Tracker018 Groton South Main 2 67 2.13 388549 4713996 327 Tracker019 Groton South Main 2 67 2.13 388554 4713996 327 Tracker020 Groton South Main 2 67 2.13 388560 4713996 328 Tracker021 Groton South Main 2 67 2.13 388565 4713996 328 Tracker022 Groton South Main 2 67 2.13 388571 4713995 328 Tracker023 Groton South Main 2 67 2.13 388576 4713995 328 Tracker024 Groton South Main 2 67 2.13 388587 4713996 328 Tracker025 Groton South Main 2 67 2.13 388592 4713996 328 Tracker026 Groton South Main 2 67 2.13 388598 4713996 328 Tracker027 Groton South Main 2 67 2.13 388603 4713989 329 Tracker028 Groton South Main 2 67 2.13 388609 4713989 329 Tracker029 Groton South Main 2 67 2.13 388614 4713989 330 Tracker030 Groton South Main 2 67 2.13 388620 4713989 330 Tracker031 Groton South Main 2 67 2.13 388625 4713989 330 Tracker032 Groton South Main 2 67 2.13 388631 4713988 331 Tracker033 Groton South Main 2 67 2.13 388636 4713988 331 Tracker034 Groton South Main 2 67 2.13 388642 4713988 331 Tracker035 Groton South Main 2 67 2.13 388647 4713988 332 Tracker036 Groton South Main 2 67 2.13 388653 4713988 332 Tracker037 Groton South Main 2 67 2.13 388658 4713988 333 Tracker038 Groton South Main 2 67 2.13 388664 4713988 333 Tracker039 Groton South Main 2 67 2.13 388669 4713988 333 Tracker040 Groton South Main 2 67 2.13 388675 4713988 333 Tracker041 Groton South Main 2 67 2.13 388680 4713988 334 Tracker042 Groton South Main 2 67 2.13 388686 4713987 334 Tracker043 Groton South Main 2 67 2.13 388691 4713987 334 Tracker044 Groton South Main 2 67 2.13 388697 4713987 335 Tracker045 Groton South Main 2 67 2.13 388702 4713987 336 Groton South Main 1 Solar Project Noise Assessment 32 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker046 Groton South Main 2 67 2.13 388708 4713987 336 Tracker047 Groton South Main 2 67 2.13 388604 4714050 332 Tracker048 Groton South Main 2 67 2.13 388610 4714050 332 Tracker049 Groton South Main 2 67 2.13 388615 4714050 333 Tracker050 Groton South Main 2 67 2.13 388621 4714050 333 Tracker051 Groton South Main 2 67 2.13 388626 4714050 333 Tracker052 Groton South Main 2 67 2.13 388632 4714049 333 Tracker053 Groton South Main 2 67 2.13 388637 4714049 333 Tracker054 Groton South Main 2 67 2.13 388643 4714049 334 Tracker055 Groton South Main 2 67 2.13 388648 4714049 334 Tracker056 Groton South Main 2 67 2.13 388654 4714049 334 Tracker057 Groton South Main 2 67 2.13 388659 4714049 335 Tracker058 Groton South Main 2 67 2.13 388665 4714049 335 Tracker059 Groton South Main 2 67 2.13 388670 4714049 336 Tracker060 Groton South Main 2 67 2.13 388676 4714048 336 Tracker061 Groton South Main 2 67 2.13 388681 4714048 336 Tracker062 Groton South Main 2 67 2.13 388687 4714048 337 Tracker063 Groton South Main 2 67 2.13 388692 4714048 337 Tracker064 Groton South Main 2 67 2.13 388697 4714048 337 Tracker065 Groton South Main 2 67 2.13 388703 4714048 337 Tracker066 Groton South Main 2 67 2.13 388709 4714048 337 Tracker067 Groton South Main 2 67 2.13 388426 4713899 324 Tracker068 Groton South Main 2 67 2.13 388432 4713899 324 Tracker069 Groton South Main 2 67 2.13 388437 4713899 324 Tracker070 Groton South Main 2 67 2.13 388442 4713899 324 Tracker071 Groton South Main 2 67 2.13 388448 4713899 324 Tracker072 Groton South Main 2 67 2.13 388454 4713899 324 Tracker073 Groton South Main 2 67 2.13 388459 4713899 324 Tracker074 Groton South Main 2 67 2.13 388464 4713899 324 Tracker075 Groton South Main 2 67 2.13 388470 4713898 324 Tracker076 Groton South Main 2 67 2.13 388475 4713898 324 Tracker077 Groton South Main 2 67 2.13 388481 4713898 324 Tracker078 Groton South Main 2 67 2.13 388487 4713898 324 Tracker079 Groton South Main 2 67 2.13 388492 4713898 324 Tracker080 Groton South Main 2 67 2.13 388498 4713898 324 Tracker081 Groton South Main 2 67 2.13 388503 4713898 324 Tracker082 Groton South Main 2 67 2.13 388508 4713900 324 Tracker083 Groton South Main 2 67 2.13 388514 4713901 324 Tracker084 Groton South Main 2 67 2.13 388519 4713903 324 Tracker085 Groton South Main 2 67 2.13 388525 4713905 324 Groton South Main 1 Solar Project Noise Assessment 33 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker086 Groton South Main 2 67 2.13 388530 4713906 324 Tracker087 Groton South Main 2 67 2.13 388536 4713908 325 Tracker088 Groton South Main 2 67 2.13 388541 4713908 325 Tracker089 Groton South Main 2 67 2.13 388547 4713908 325 Tracker090 Groton South Main 2 67 2.13 388552 4713908 326 Tracker091 Groton South Main 2 67 2.13 388558 4713907 326 Tracker092 Groton South Main 2 67 2.13 388563 4713907 327 Tracker093 Groton South Main 2 67 2.13 388569 4713907 328 Tracker094 Groton South Main 2 67 2.13 388574 4713907 328 Tracker095 Groton South Main 2 67 2.13 388580 4713907 329 Tracker096 Groton South Main 2 67 2.13 388585 4713907 329 Tracker097 Groton South Main 2 67 2.13 388591 4713907 330 Tracker098 Groton South Main 2 67 2.13 388596 4713907 331 Tracker099 Groton South Main 2 67 2.13 388602 4713896 332 Tracker100 Groton South Main 2 67 2.13 388607 4713896 333 Tracker101 Groton South Main 2 67 2.13 388613 4713896 333 Tracker102 Groton South Main 2 67 2.13 388618 4713896 333 Tracker103 Groton South Main 2 67 2.13 388623 4713896 334 Tracker104 Groton South Main 2 67 2.13 388629 4713896 334 Tracker105 Groton South Main 2 67 2.13 388635 4713896 334 Tracker106 Groton South Main 2 67 2.13 388640 4713896 334 Tracker107 Groton South Main 2 67 2.13 388645 4713895 335 Tracker108 Groton South Main 2 67 2.13 388651 4713895 335 Tracker109 Groton South Main 2 67 2.13 388656 4713895 335 Tracker110 Groton South Main 2 67 2.13 388662 4713895 336 Tracker111 Groton South Main 2 67 2.13 388667 4713895 336 Tracker112 Groton South Main 2 67 2.13 388673 4713895 336 Tracker113 Groton South Main 2 67 2.13 388678 4713895 336 Tracker114 Groton South Main 2 67 2.13 388684 4713895 336 Tracker115 Groton South Main 2 67 2.13 388689 4713895 336 Tracker116 Groton South Main 2 67 2.13 388695 4713895 337 Tracker117 Groton South Main 2 67 2.13 388700 4713895 337 Tracker118 Groton South Main 2 67 2.13 388706 4713894 337 Tracker119 Groton South Main 2 67 2.13 388600 4713835 334 Tracker120 Groton South Main 2 67 2.13 388606 4713835 336 Tracker121 Groton South Main 2 67 2.13 388611 4713835 337 Tracker122 Groton South Main 2 67 2.13 388617 4713835 337 Tracker123 Groton South Main 2 67 2.13 388622 4713835 337 Tracker124 Groton South Main 2 67 2.13 388628 4713835 337 Tracker125 Groton South Main 2 67 2.13 388633 4713835 338 Groton South Main 1 Solar Project Noise Assessment 34 SOURCE PROJECT OVERALL SOUND POWER LEVEL (dBA) RELATIVE HEIGHT (m) COORDINATES ABSOLUTE ELEVATION (m) UTM NAD83 Z18N X (m) Y (m) Tracker126 Groton South Main 2 67 2.13 388638 4713820 340 Tracker127 Groton South Main 2 67 2.13 388644 4713819 341 Tracker128 Groton South Main 2 67 2.13 388649 4713820 341 Tracker129 Groton South Main 2 67 2.13 388655 4713819 341 Tracker130 Groton South Main 2 67 2.13 388660 4713819 342 Tracker131 Groton South Main 2 67 2.13 388666 4713819 342 Tracker132 Groton South Main 2 67 2.13 388671 4713819 342 Tracker133 Groton South Main 2 67 2.13 388677 4713819 342 Tracker134 Groton South Main 2 67 2.13 388682 4713819 343 Tracker135 Groton South Main 2 67 2.13 388688 4713819 343 Tracker136 Groton South Main 2 67 2.13 388693 4713819 343 Tracker137 Groton South Main 2 67 2.13 388698 4713819 343 Tracker138 Groton South Main 2 67 2.13 388704 4713819 343 Groton South Main 1 Solar Project Noise Assessment 35 APPENDIX C. RECEIVER RESULTS TABLE TABLE 9: SOUND LEVELS AT NEARBY RESIDENCES FROM THE PROJECT AND CUMULATIVE WITH GROTON SOUTH MAIN 2. RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R001 103 Peru Rd Unit 1 17 18 387749 4715544 R002 847 Elm St Extension 17 17 390273 4715544 R003 103 Peru Rd 17 18 387743 4715541 R004 106 S Main St 18 19 387936 4715540 R005 106 1/2 S Main St 18 19 387931 4715540 R006 106 Pasadena Ave 16 17 387458 4715538 R007 103 Peru Rd Unit 2 17 18 387747 4715534 R008 317 Barrows St 15 17 388177 4715533 R009 107 S Main St 17 18 387984 4715529 R010 301 W South St 16 17 387593 4715527 R011 105 Peru Rd Unit 1 17 18 387745 4715525 R012 106 Peru Rd 17 18 387696 4715524 R013 108 S Main St 18 19 387939 4715524 R014 107 Baken Ave 15 17 388069 4715523 R015 105 1/2 Baken Ave 18 19 388051 4715519 R016 105 Baken Ave 18 19 388046 4715519 R017 103 Baken Ave 18 19 388032 4715518 R018 105 Peru Rd Unit 2 17 18 387744 4715517 R019 308 W South St 16 17 387486 4715512 R020 109 S Main St 17 18 387986 4715511 R021 307 W South St 16 17 387565 4715511 R022 105 Peru Rd 16 17 387741 4715508 R023 309 W South St 16 17 387544 4715505 R024 310 W South St 16 17 387463 4715505 R025 823 Elm St Extension 18 18 390050 4715503 R026 106 Mack St 23 24 388796 4715500 R027 319 Barrows St 15 17 388181 4715498 R028 101 Mack St 23 24 388850 4715497 R029 101 Cedar Ln 23 23 389076 4715495 R030 119 Cedar Ln 22 23 389354 4715493 R031 480 Lick St 20 20 389766 4715491 R032 106 Hamilton Sq 17 18 387619 4715491 R033 114 Peru Rd 17 18 387664 4715488 R034 108 Baken Ave 18 19 388064 4715485 R035 108 Baken Ave Unit 1 18 19 388066 4715484 R036 112 S Main St 18 18 387947 4715483 Groton South Main 1 Solar Project Noise Assessment 36 RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R037 106 Baken Ave 18 19 388048 4715482 R038 112 1/2 S Main St 18 18 387942 4715482 R039 112 Peru Rd 17 18 387668 4715482 R040 113 Cedar Ln 23 23 389247 4715480 R041 108 Baken Ave Unit 2 18 19 388066 4715480 R042 117 Cedar Ln 23 23 389308 4715480 R043 115 Cedar Ln 23 23 389278 4715478 R044 103 Cedar Ln 23 24 389108 4715478 R045 111 Cedar Ln 23 23 389219 4715478 R046 105 Cedar Ln 23 24 389135 4715478 R047 107 Cedar Ln 23 23 389161 4715477 R048 109 Cedar Ln 23 23 389191 4715477 R049 107 Peru Rd 16 17 387737 4715477 R050 108 Hamilton Sq 17 18 387591 4715472 R051 102 Corona Ave 16 17 387471 4715471 R052 103 Mack St 23 24 388848 4715470 R053 143 Cedar Ln 23 24 389010 4715468 R054 108 Mack St 23 24 388795 4715468 R055 202 S Main St 18 19 387954 4715463 R056 104 Corona Ave 16 17 387498 4715463 R057 202 1/2 S Main St 18 19 387947 4715461 R058 203 S Main St 18 19 387999 4715459 R059 202 Peru Rd 16 17 387684 4715456 R060 107 Corona Ave 16 17 387543 4715449 R061 203 Peru Rd 16 18 387730 4715447 R062 204 S Main St 17 18 387954 4715445 R063 106 Corona Ave 16 17 387493 4715443 R064 204 1/2 S Main St 17 18 387951 4715442 R065 105 Mack St 24 24 388848 4715439 R066 205 S Main St 18 19 388003 4715439 R067 115 Hamilton Sq 16 17 387627 4715438 R068 204 Peru Rd Apartment C 16 17 387680 4715438 R069 204 Peru Rd Apartment B 16 17 387680 4715438 R070 204 Peru Rd Apartment D 16 17 387680 4715438 R071 204 Peru Rd 16 17 387680 4715438 R072 204 Peru Rd Apartment A 16 17 387680 4715438 R073 110 Mack St 24 24 388796 4715437 R074 471 Lick St 18 18 389818 4715432 R075 407 W South St 15 16 387419 4715431 R076 139 Cedar Ln 24 24 389080 4715430 R077 137 Cedar Ln 24 24 389106 4715429 Groton South Main 1 Solar Project Noise Assessment 37 RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R078 131 Cedar Ln 24 24 389191 4715429 R079 133 Cedar Ln 24 24 389162 4715428 R080 129 Cedar Ln 23 24 389218 4715428 R081 125 Cedar Ln 23 24 389276 4715428 R082 114 Hamilton Sq 16 17 387593 4715426 R083 135 Cedar Ln 24 24 389136 4715426 R084 123 Cedar Ln 23 23 389307 4715425 R085 127 Cedar Ln 23 24 389247 4715424 R086 206 Peru Rd 16 17 387658 4715421 R087 121 Cedar Ln 21 21 389349 4715420 R088 116 Hamilton Sq 16 17 387585 4715420 R089 503 W South St 14 17 387378 4715419 R090 208 S Main St 18 19 387960 4715413 R091 207 S Main St Unit 1 18 19 388010 4715411 R092 207 S Main St Unit 2 18 19 388007 4715410 R093 107 Mack St 24 24 388848 4715409 R094 207 S Main St 18 19 388006 4715407 R095 112 Mack St 23 23 388796 4715406 R096 208 Peru Rd 16 18 387668 4715401 R097 141 Cedar Ln 24 25 388999 4715400 R098 112 Corona Ave 15 17 387487 4715395 R099 119 Hamilton Sq 16 17 387634 4715391 R100 118 Hamilton Sq 16 17 387595 4715387 R101 114 Baken Ave 16 18 388142 4715387 R102 210 Peru Rd 16 18 387665 4715380 R103 114 Mack St 23 23 388796 4715380 R104 109 Mack St 25 25 388848 4715380 R105 212 S Main St 18 19 387967 4715373 R106 468 Lick St 19 19 389770 4715367 R107 120 Hamilton Sq 16 17 387598 4715363 R108 212 Peru Rd 16 18 387660 4715361 R109 209 Peru Rd 17 18 387717 4715356 R110 114 Corona Ave 15 17 387490 4715347 R111 216 S Main St 18 19 387977 4715340 R112 216 1/2 S Main St 18 19 387972 4715339 R113 300 Peru Rd 16 18 387645 4715320 R114 217 S Main St 19 20 388029 4715320 R115 218 S Main St 19 19 387956 4715316 R116 109 Dewey Ave 17 18 388140 4715312 R117 107 Dewey Ave 20 20 388122 4715309 R118 201 Dewey Ave 17 19 388200 4715309 Groton South Main 1 Solar Project Noise Assessment 38 RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R119 111 Dewey Ave 17 18 388163 4715308 R120 120 Corona Ave 15 17 387502 4715305 R121 115 Mack St 24 25 388880 4715304 R122 140 Cedar Ln 25 26 389025 4715303 R123 203 Dewey Ave 17 19 388230 4715302 R124 456 Lick St 22 22 389730 4715301 R125 219 S Main St 19 20 388033 4715298 R126 105 Dewey Ave 20 20 388097 4715298 R127 120 Corona Ave Unit 12 15 16 387439 4715298 R128 301 Peru Rd 17 18 387716 4715298 R129 120 Corona Ave Unit 11 15 17 387445 4715298 R130 120 Corona Ave Unit 10 15 17 387451 4715297 R131 120 Corona Ave Unit 9 15 17 387457 4715297 R132 220 S Main St 19 20 387987 4715297 R133 120 Corona Ave Unit 2 15 17 387485 4715296 R134 120 Corona Ave Unit 1 15 17 387491 4715296 R135 120 Corona Ave Unit 3 15 17 387480 4715295 R136 120 Corona Ave Unit 4 15 17 387474 4715295 R137 120 Corona Ave Unit 16 15 16 387439 4715292 R138 120 Corona Ave Laundry 15 17 387463 4715292 R139 120 Corona Ave Unit 15 15 16 387445 4715292 R140 120 Corona Ave Unit 14 15 17 387451 4715291 R141 120 Corona Ave Unit 13 15 17 387457 4715291 R142 120 Corona Ave Unit 7 15 17 387480 4715290 R143 120 Corona Ave Unit 5 15 17 387490 4715290 R144 120 Corona Ave Unit 6 15 17 387484 4715290 R145 120 Corona Ave Unit 8 15 17 387474 4715290 R146 112 Dewey Ave 17 19 388173 4715271 R147 110 Dewey Ave 17 19 388148 4715265 R148 302 S Main St 19 20 387996 4715263 R149 106 Dewey Ave 20 21 388100 4715259 R150 104 Dewey Ave 20 20 388058 4715256 R151 301 S Main St 19 20 388041 4715254 R152 400 Peru Rd 16 17 387547 4715251 R153 303 S Main St 19 20 388042 4715249 R154 304 S Main St 19 20 387999 4715249 R155 119 Washington Ave 18 19 388178 4715240 R156 200 Clinton Ave 18 19 388207 4715238 R157 306 S Main St 19 20 388003 4715237 R158 117 Washington Ave 17 19 388158 4715236 R159 115 Washington Ave 17 19 388144 4715234 Groton South Main 1 Solar Project Noise Assessment 39 RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R160 305 S Main St 20 21 388051 4715225 R161 107 Clinton Ave 18 20 388236 4715217 R162 308 S Main St 19 20 388011 4715216 R163 201 Clinton Ave 18 20 388240 4715205 R164 310 S Main St 20 21 388018 4715200 R165 430 Lick St 23 23 389744 4715195 R166 112 Washington Ave 18 19 388147 4715194 R167 108 Washington Ave 20 21 388096 4715193 R168 110 Washington Ave 20 21 388116 4715193 R169 116 Washington Ave 18 20 388203 4715191 R170 401 S Main St 19 20 388060 4715190 R171 402 S Main St 19 20 388021 4715186 R172 400 Peru Rd 16 18 387579 4715184 R173 114 Washington Ave 18 20 388171 4715182 R174 404 S Main St 19 20 388026 4715170 R175 405 S Main St 20 21 388067 4715163 R176 115 Morton Ave 18 20 388203 4715161 R177 113 Morton Ave 18 20 388173 4715159 R178 400 Peru Rd 16 18 387544 4715157 R179 111 Morton Ave 21 22 388145 4715157 R180 101 Morton Ave 21 21 388100 4715156 R181 109 Morton Ave 21 22 388119 4715155 R182 406 S Main St 20 21 388029 4715151 R183 408 S Main St 19 20 388037 4715131 R184 410 Lick St 23 24 389751 4715125 R185 301 Clinton Ave 19 20 388245 4715124 R186 108 Morton Ave 21 22 388149 4715123 R187 106 Morton Ave 21 22 388121 4715120 R188 112 Morton Ave 22 22 388188 4715119 R189 503 S Main St 21 22 388082 4715117 R190 505 S Main St 21 22 388103 4715094 R191 111 McKinley Ave 22 23 388192 4715091 R192 502 S Main St 20 21 388049 4715087 R193 308 Clinton Ave 22 23 388212 4715087 R194 107 McKinley Ave 21 22 388154 4715086 R195 307 Clinton Ave 19 21 388247 4715085 R196 105 McKinley Ave 21 22 388135 4715081 R197 504 S Main St 21 22 388053 4715073 R198 414 Lick St 24 24 389752 4715067 R199 506 S Main St 21 22 388058 4715058 R200 206 McKinley Ave 20 21 388287 4715055 Groton South Main 1 Solar Project Noise Assessment 40 RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R201 208 McKinley Ave 20 21 388275 4715051 R202 315 Clinton Ave 22 23 388242 4715048 R203 112 McKinley Ave 22 23 388204 4715045 R204 112 1/2 McKinley Ave 22 23 388210 4715045 R205 602 S Main St 21 22 388064 4715045 R206 701 S Main St 22 22 388133 4715043 R207 606 S Main St 21 22 388073 4715011 R208 305 1/2 Elmwood Ave 22 23 388202 4715010 R209 305 Elmwood Ave 22 23 388207 4715008 R210 317 Clinton Ave 23 24 388251 4715003 R211 301 Elmwood Ave 22 23 388166 4715002 R212 412 Lick St 25 25 389727 4714989 R213 410 Lick St 24 25 389770 4714980 R214 404 Lick St 27 28 389548 4714976 R215 101 Elmwood Ave 22 23 388152 4714972 R216 400 Elmwood Ave 23 24 388264 4714967 R217 700 S Main St 22 23 388110 4714949 R218 703 S Main St 22 23 388175 4714942 R219 702 S Main St 22 23 388126 4714924 R220 711 S Main St 22 23 388216 4714921 R221 713 S Main St 23 24 388243 4714912 R222 706 S Main St 21 22 388163 4714908 R223 398 Lick St 26 26 389659 4714903 R224 712 S Main St 22 23 388187 4714882 R225 715 S Main St 22 23 388309 4714871 R226 714 S Main St 20 22 388223 4714866 R227 396 Lick St 24 24 389746 4714859 R228 717 S Main St 22 23 388334 4714853 R229 719 S Main St 22 23 388355 4714841 R230 718 S Main St 21 22 388260 4714840 R231 592 Sovocool Hill Rd 15 17 387173 4714835 R232 720 S Main St 21 23 388284 4714819 R233 410 Peru Rd 18 20 387660 4714809 R234 724 S Main St 21 23 388317 4714797 R235 604 Sovocool Hill Rd 14 17 387118 4714795 R236 753 S Main St 21 23 388393 4714792 R237 393 Lick St 23 24 389831 4714784 R238 409 Peru Rd 19 21 387745 4714777 R239 500 Peru Rd 18 20 387682 4714749 R240 742 S Main St 22 24 388381 4714734 R241 411 Peru Rd 19 21 387765 4714732 Groton South Main 1 Solar Project Noise Assessment 41 RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R242 390 Lick St 26 26 389757 4714720 R243 601 Sovocool Hill Rd 15 17 387170 4714701 R244 756 S Main St 20 23 388278 4714701 R245 501 Peru Rd 19 21 387786 4714662 R246 766 S Main Street Ext 23 26 388440 4714662 R247 510 Peru Rd 19 21 387708 4714640 R248 520 Peru Rd 19 21 387716 4714570 R249 780 S Main Street Ext 25 27 388516 4714569 R250 522 Peru Rd 19 21 387722 4714532 R251 516 Peru Rd 18 22 387651 4714529 R252 526 Peru Rd 19 22 387747 4714478 R253 524 Peru Rd 18 23 387684 4714477 R254 800 S Main Street Ext 30 31 388605 4714441 R255 801 S Main Street Ext 29 33 388680 4714440 R256 610 Peru Rd 19 24 387787 4714399 R257 617 Peru Rd 19 25 387860 4714329 R258 334 Lick St 21 22 389772 4714308 R259 618 Peru Rd 19 25 387778 4714303 R260 834 S Main Street Ext 23 29 388836 4714286 R261 847 S Main Street Ext 23 28 388943 4714250 R262 631 Peru Rd 20 26 387904 4714229 R263 875 S Main Street Ext 22 25 389226 4714156 R264 649 Peru Rd 19 26 387950 4714074 R265 305 Lick St 19 21 389834 4714073 R266 901 S Main Street Ext 21 23 389319 4714039 R267 656 Peru Rd 18 26 387831 4714017 R268 301 Lick St 19 20 389842 4713969 R269 935 S Main Street Ext 21 22 389566 4713952 R270 908 S Main Street Ext 21 24 389347 4713937 R271 670 Peru Rd 18 27 387921 4713909 R272 278 Lick St 18 20 389771 4713848 R273 676 Peru Rd 18 27 387913 4713821 R274 267 Lick St 18 19 389842 4713768 R275 692 Peru Rd 18 27 387944 4713730 R276 253 Lick St 17 19 389844 4713709 R277 251 Lick St 17 19 389842 4713676 R278 702 Peru Rd 17 26 387947 4713654 R279 247 Lick St 16 18 389861 4713599 R280 720 Peru Rd 17 25 387905 4713528 R281 720 Peru Rd Unit B 17 25 387901 4713524 R282 680 Stevens Rd 14 24 388685 4713471 Groton South Main 1 Solar Project Noise Assessment 42 RECEPTOR ID ADDRESS MODELED SOUND LEVEL (dBA) COORDINATES UTM NAD83 Z18N (m) GROTON SOUTH MAIN 1 CUMULATIVE X Y R283 30 Torok Rd 8 13 387089 4713335 R284 670 Stevens Rd 16 22 388884 4713304 R285 690 Stevens Rd 13 22 388530 4713250 R286 614 Stevens Rd 14 16 389844 4713236 R287 600 Stevens Rd 13 16 389955 4713230 R288 610 Stevens Rd 14 16 389888 4713228 R289 590 Stevens Rd 13 15 390090 4713223 R290 756 Peru Rd 15 23 387989 4713218 R291 20 Torok Rd 7 12 386944 4713218 R292 780 Stevens Rd 15 24 388113 4713205 R293 730 Stevens Rd 14 23 388284 4713201 R294 196 Lick St 13 16 389779 4713183 R295 39 Torok Rd 8 13 387158 4713137 R296 31 Torok Rd 7 12 387095 4713120 R297 774 Peru Rd 14 22 387998 4713073 R298 156 Lick St 11 14 389747 4712854 R299 147 Lick St 11 14 389861 4712782 Northern Property Line 37 37 389126 4714799 Eastern Property Line 44 44 389173 4714548 Southern Property Line 23 26 389169 4714286 Western Property Line 35 35 388759 4714488