ZONING BOARD OF APPEALS Town Of Philipstown 238 Main Street Cold Spring NY MEETING AGENDA October 1, :30 p.m.

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1 ZONING BOARD OF APPEALS Town Of Philipstown 238 Main Street Cold Spring NY MEETING AGENDA October 1, :30 p.m. CONSIDERATION OF FINAL APPROVAL AND SEQRA DETERMINATION 1.) JAMES GLEICK SP-13-1 TM# Long And Winding Rd. Special Use Permit/ Site Plan Approval Residential Wind Energy Conversion System RR Zone District 2.) New/ Old Business * ITEMS MAY NO BE TAKEN IN ORDER AS LISTED

2 Environmental and Planning Consultants 34 South Broadway Suite 401 White Plains, NY tel: fax: Memorandum To: From: Town of Philipstown Zoning Board of Appeals Susan Jainchill, AICP Date: September 25,2013 Re: Gleick Special Permit Application - Noise Below is AKRF's review and analysis of the information related to expected noise levels resulting from the Applicant's proposed installation of a Bergey Excel-S 10 kw wind turbine. This analysis takes into consideration information submitted by the Applicant as part of the special permit application and by members of the public during the September 9,2013 Public Hearing. GENERAL BACKGROUND The proposed Bergey Excel-S 10 kw Wind Turbine would have the potential to generate noise at nearby locations as a result of its operation. The perceived noise effects of the proposed wind turbine would depend on the wind speed, the existing background noise levels, and the character of the noise generated by the turbine. Below we have provided an evaluation of the noise associated with the proposed wind turbine according to the noise level limits in the Town Code of the Town of Philipstown. Chapter 175, Article VII, of the Code addresses noise. Section C (2) states: "No person, firm, or corporation shall allow the emission ofsound which, as measured at the property lines, has a sound level in excess of (a) Fifty decibels on the A-weighted scale between the hours of 7:00 a.m. and 8:00 p.m.; or (b) Forty decibels on the A-weighted scale between the hours of8:00 p.m. and 7:00a.m.; or (c) Five decibels above the ambient noise at the point on the boundary ofthe lot where measured, whichever is greater. PROPOSED PROJECT SITE The shortest distance from the location of the proposed wind turbine to the property line would be 170 feet to the southern property line. Since the nearest noise sensitive receptor location to the proposed wind turbine is located to the west of the proposed wind turbine, the western property line, at a distance of 1,450 feet from the location of the proposed wind turbine, was also evaluated. The distances used for the evaluation of expected noise levels was 170 feet and 1569 feet based on the topography of the site and the height of the wind turbine. AKRF has not been provided with ambient noise level information for either point on the property line. AKRF, Inc. New York City. Hudson Valley Region. Long Island. Baltimore I Washington Area. New Jersey. Connecticut

3 Town of Philipstown Zoning Board of Appeals 2 9/25/2013 According to the "Wind Professional Resource Report" submitted by the Applicant, at the location of the proposed wind turbine at 140 feet above ground level the average annual wind speed is 5.11 mls (11.44 mph). More detailed information (see attached "WindCad Turbine Performance Model") was developed by Mark Mayhew, Project Manager at New York State Energy research and Development Authority's (NYSERDA) On-Site Wind Turbine Incentive Program and forwarded by the Applicant. Using NYSERDA's Smallwind Explorer ( the wind at the project site is expected to be at or below 11.2 MPH for 5,209 hours per year (60%). The wind is expected to be at or above 22.4 MPH for 338 hours per year (4%). The wind is expected to be at or above 29.1 MPH for 18 hours per year (0.2%). WIND TURBINE NOISE GENERATION The manufacturer's documentation for the Bergey Excel-S 10 kw wind turbine provided by the Applicant includes noise level data for wind speeds ranging from 4 mls (9mph) to 13 mls (29mph), based on noise level measurements performed by the United States Department of Agriculture (USDA). The data show increased noise levels at increased wind speeds. At 5.11 mls (11.44 mph) the perceived noise level at the southern property line would be 39 db(a) and at the western property line would be 22 db(a). These levels are permitted by code regardless of ambient noise levels. At 29 mph, the perceived noise level at the southern property line would be 63 db(a) and at the western property line would be 44 db(a). These levels exceed those allowed by the code unless the ambient noise levels exceed 54 db(a) at southern property line and 36 db(a) western property line. The maximum wind speed at which there would be no exceedances of the noise code regardless of ambient noise levels at either property line would be 23 mph for daytime regulations and 15 mph for nighttime regulations. It is important to note that while the proposed wind turbine would result in higher noise levels at faster wind speeds, the ambient noise level would also be higher at faster wind speeds. Generally, higher background noise levels at faster wind speeds would tend to result in smaller noise level increments resulting from the wind turbine noise. DISCUSSION OF ADDITIONAL MATERIAL At the September 9, 2013 Public Hearing, an adjacent property owner submitted documents discussing the noise effects of wind power facilities and wind turbines in general, including some specific noise concerns. One such concern discussed in this documentation is infrasound (i.e., sound at frequencies below the range of human hearing), which is sometimes attributed to wind turbines. Noise levels at these frequencies are not generally audible or perceptible to humans, and are included in the A-weighted noise levels discussed above. Geoffrey Leventhal's article, "Concerns about Infrasound from Wind Turbines!," states that "internally generated infrasound from heartbeat and breathing, which enters the inner ear via the cochlear aqueduct, is greater than that received externally from wind turbines at similar frequencies, perhaps by 20 db or more." Consequently, noise at frequencies below 20 Hz generated by wind turbines would not likely be audible. Non-auditory effects of infrasound from wind turbines are not fully understood, but, as discussed in Nancy S. Timmerman's article, "Wind Turbine Noise 2," infrasound must be at a great magnitude to have non-auditory effects on people, and such levels of infrasound would occur as a result of very large wind turbines in the megawatt range, rather than the smaller wind turbine proposed. I Leventhall, Geoff. "Concerns About Infrasound From Wind Turbines." Acoustics Today July 2013; Print. 2 Timmerman, Nancy S. "Wind Turbine Noise." Acoustics Today July 2013; Print.

4 Town of Philipstown Zoning Board of Appeals 3 9/25/2013 Most of the documentation provided by the adjacent property owner pertains to large scale wind power generation facilities rather than a single residential-scale wind turbine. The proposed wind turbine is scaled to provide power for a single residence and consequently produces substantially less noise. This is very different than a power generating array of multiple wind turbines (i.e., sources of noise) generating many times more power than a small 10 kw wind turbine. DISCUSSION OF AMBIENT NOISE Based on our analysis, the proposed project would not meet the requirements of Section (a) and (b) at daytime wind speeds above 23 mph and at nighttime wind speeds above 15 mph. According to NYSERDA's model, wind speeds at the project site would be above mph 4% of the time and above mph 26%. Therefore, any approval for the proposed project would be based on l75-40(c) of the Town Code which allows for "five decibels above the ambient noise at the point on the boundary of the lot where measured". There is little generalized information on background noise levels at increasing wind speeds because each site is different in terms of existing non-wind related noise sources, foliage, ground cover, and structures. Actual ambient noise levels at the project site in the conditions of high wind would be difficult and exceedingly expensive to measure and have not been submitted by the Applicant. According to NYSERDA, "at 29 mph wind related noise will be significant and the background noise would be in the range of db(a)." Some internet-based research reveals that academic research on prediction models for vegetation noise and the relative levels of ambient noise needed to mask wind turbine sound is on-going. Based on a limited review of academic abstracts it is not inconceivable that the ambient noise levels at the project site for wind speeds of 11 mph could be up to 60 db(a). The Applicant has provided information that indicates that previous testing has shown the Excel wind turbine produced a noise level less than 5 db(a) above background noise ("Noise Test Data for the kw Bergey Excel Wind Turbine," June 2007) under test conditions at all tested wind speeds. Specifically, the submitted information indicates that under the experimental conditions with a wind speed of 23mph, which produced 50 db(a) background noise, the measured noise level from the proposed wind turbine was less than 5 db(a) above the background noise level. At the proposed wind turbine location, for wind speeds above 15 mph, the background noise level may be high enough that the level of wind turbine noise is no more than 5 db(a) above the background noise level, but we have not been presented with definitive evidence to show that this is the case. RECOMMENDAnONS Based on our analysis, it is AKRF's recommendation that the ZBA conclude that this project would "not result in excessive off-premises noise" and would fulfill the criteria of Section B(2) in regards to noise. Our analysis established that 74% of the time the noise level at the closest property line will not exceed allowable levels regardless of the ambient noise levels. Although ambient noise levels have not been determined, we are confident that the elevated ambient noise level at faster wind speeds would mask much of the wind turbine noise generated at higher wind speeds and will not "create any public or private nuisances" based on emission of sound. In arriving at this conclusion we have taken into consideration the fact that the proposed project locates the wind turbine in the optimal location to minimize any potential noise disturbance beyond the property lines. It was noted that the property to the south of the proposed project, which is closest to the location of the proposed wind turbine, is currently undeveloped. The irregular shape of the property to the south and its orientation to the access road suggests that a residence would be located some distance from the location of the proposed wind turbine.

5 Town of Philipstown Zoning Board of Appeals The nearest existing noise sensitive receptor is located on the property to the west which is a distance of 1,450 feet from the proposed wind turbine location. Based on our analysis, regardless of the ambient noise, expected noise levels at the western property line resulting from the proposed project will not exceed the daytime levels allowable by code. If ambient noise levels (which are dominated by traffic noise on Route 9D) are taken into consideration it is highly probably that that the noise levels at the western property line will not exceed allowable nighttime noise levels.

6 WindCad Turbine Performance Model BWC EXCEL-S, Grid - Intertie USDA lee Data Prepared For: Gleick Site Location: Data Source: 300 Long and Winding Road N/A Per AWEA Date: 9/25/ kw Inputs: Ave. Wind (m/s) = 5.11 Weibull K = 2.33 Site Altitude (m) = 220 Wind Shear Exp. = Anem. Height (m) = Tower Height (m) = Turbulence Factor = 24.4% Results: Hub Average Wind Speed (m/s) = Air Density Factor = Average Output Power (kw) = % 1.10 Daily Energy Output (kwh) = 26.3 Annual Energy Output (kwh) = 9,612 Monthly Energy Output = Percent ODeratinQ Time = % Weibull Performance Calculations Wind Speed Bin (m/s) Power (kw) Wind Probability (f) NetkW@V Weibull Calculations: MPH No of Hours % Wind speed probabi lity is calculated as a Weibull curve defined by Ihe average wind % speed and a shape faclor, K. To facilitate % piece-wise integration, the wind speed range % is broken down inlo "bins" of 1 mls in widlh (Column 1). For each wind speed bin, % instantaneous wind turbine power (W, % Column 2)) is multiplied by the Weibull wind % 0192 speed probability (f, Column 3). This cross % product (Net W, Column 4) is the contribution to average turbine power outpul % contributed by wind speeds in that bin. The % 0113 sum of these contributions is the average % power outpul of the turbine on a continuous, % hour, basis Besl results are achieved using annual or % monthly average wind speeds. Use of daily % or hourly average speeds is not % recommended % % % % % , BWC I Totals: 99.84% Instructions: Inputs: Use annual or monthly Average Wind speeds. If Weibull K is not known, use K % 2 for inland sites, use 3 for coastal sites, and use 4 fo island sites and trade wind regimes. Site Altitude is meters above sea level. Wind Shear Exponent is best assumed as For rough terrain or high turbulence use For very smooth terrain or open water use Anemometer Height is for the data used for the Average Wind speed. If unknown, use 10 meters. Tower Height is the nominal height of the tower, eg.: 24 melers. Turbulence Factor is a derating for No of hours turbulence, site variability, and other performance influencing factors -- typical turbulence has already been incorporaled inlo Ihe model. Use 0.00 (0%) for level sites with limited obstructions. Use (negative 10%) for flal, clear sites on open water. Use 0.05 to 0.15 (5% 1015%) for rolling 11 MPH or hills or mountainous terrain. less Results: Hub Average Wind Speed is corrected for wind shear and used to calculate the Weibull wind speed probability. Air Density Factor is No of hours the reduction from sea level performance. Average Power Output is the average continuous equivalent output of the turbine. Daily Energy Output is the average energy produced per day. Annual and Monthly Energy Outputs are calculated using the Daily value. Percent Operating 22.4 MPH or Time is the time the lurbine should be producing some power. above Limitations: This model uses a mathmatical idealization of the wind speed probability. The validity of this assumption is reduced as the time period under consideration (ie, the wind speed averaging period) is reduced. This model is best used with annual or monthly average wind speeds. Use of this model with daily or hourly average wind speed data is not recommended because I he wind will nol follow a Weibull distribution over short periods. The data used in creating the power curve was generated at the BWC test site in Norman, OK. Consult Bergey No of hours 29.1 MPH or above 18.20