Revised Noise Assessment Report – Transformer

Zephyr North Ltd.

850 LEGION ROAD UNIT 20BURLINGTON ON L7S 1T5CANADA

Phone: 905-335-9670Fax: 905-335-0119Internet: [email protected]

Originals printed onRecycled 20% post-consumer content

ST. COLUMBAN WIND PROJECT

TRANSFORMER NOISE ASSESSMENT

REPORTRevision 1

For

J. R. SalmonS. J. Corby

2013 March 25

J. Menéndez, P.Eng.

For St. Columban Energy LP

By

ST. COLUMBAN WIND PROJECT— Transformer Noise Assessment Report Revision 1

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DISCLAIMER OF WARRANTIESAND

LIMITATION OF LIABILITIES

This Report was prepared by Zephyr North Ltd. of Burlington Ontario Canada as an account of work sponsored by St. Columban Energy LP (St. Columban). Neither Zephyr North Ltd. nor any person acting on its behalf:

(a) Makes any warranty or representation whatsoever, express or implied, (i) with respect to the use of any information, apparatus, method, process, or similar item disclosed in this report, including merchantability and fitness for a particular purpose, or (ii) that such use does not infringe on or interfere with privately owned rights, including any party's intellectual property, or (iii) that this report is suitable to any particular user's circumstance, or

(b) Assumes responsibility for any damages or other liability whatsoever (including any consequential damages, even if Zephyr North Ltd. or its representatives have been advised of the possibility of such damages) resulting from your selection or use of this report or any information, apparatus, method, process or similar item disclosed in this report.


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Table of Contents

1 INTRODUCTION............................................................................................6 1.1 Purpose.....................................................................................................6 1.2 Revision 0.................................................................................................6 1.3 Revision 1.................................................................................................6 1.4 Brief Project Description.........................................................................6 1.5 Reporting Details.....................................................................................7 1.6 Sound Level Limits for Wind Farms.......................................................7

2 PROJECT LAYOUT........................................................................................9 2.1 Project Site...............................................................................................9 2.2 Project Details — Turbines......................................................................9 2.3 Municipal Zoning.....................................................................................9 2.4 Adjacent Projects...................................................................................11 2.5 Substations.............................................................................................11

2.5.1 St. Columban Wind Project............................................................11 3 DESCRIPTION OF RECEPTORS................................................................12

3.1 Definition................................................................................................12 3.2 Determination of Receptors and Participants......................................12 3.3 Vacant Lots............................................................................................13 3.4 Methodology...........................................................................................13 3.5 Concordance Table.................................................................................13

4 DESCRIPTION OF SOURCES.....................................................................14 4.1 Wind Turbines........................................................................................14

4.1.1 St. Columban Wind Project............................................................14 4.2 Sub-Stations...........................................................................................14

4.2.1 St. Columban Wind Project............................................................14 4.2.1.1 Transformer............................................................................14

5 NOISE EMISSION RATINGS......................................................................15 5.1 Wind Turbines........................................................................................15

5.1.1 Turbine Noise Definition Standard...............................................15 5.1.2 St. Columban Wind Project............................................................15

5.2 Site-Specific Vertical Wind Shear Exponent........................................15 5.3 Sub-Stations...........................................................................................15

5.3.1 St. Columban Wind Project............................................................15 6 IMPACT ASSESSMENT...............................................................................17

6.1 Methodology...........................................................................................17


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6.2 Specific Parameters...............................................................................17 6.3 Additional parameters and conditions..................................................18 6.4 Results....................................................................................................18

7 NOISE LEVEL SUMMARY TABLES..........................................................20 8 NOISE LEVEL ISOPLETH MAP.................................................................21 9 EXAMPLE CALCULATION.........................................................................23

9.1 Method of Calculation............................................................................23 9.2 Example..................................................................................................24

10 CONCLUSIONS..........................................................................................26 11 REFERENCES............................................................................................27 12 APPENDIX A — TURBINE, RECEPTOR,

VACANT LOT AND PARTICIPANT LOCATIONS...................................29 13 APPENDIX B — ADDITIONAL DOCUMENTATION..............................31


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List of Figures

Figure 1-1 Project location map................................................................7Figure 2-1 Transformer sub-station details map...................................10Figure 8-1 40 dBA noise isopleth map for 1.5 and 4.5 m receptor

heights....................................................................................22

List of Tables

Table 5-1 Project transformer station acoustic emissions summary.....16Table 6-1 Highest noise levels at receptors............................................19Table 7-1 Receptor noise level summary table.......................................20Table 7-2 Participant noise level summary table...................................20Table 9-1 Sample calculation for receptor and turbine..........................25Table 9-2 Sample calculation for single receptor R2011 and transformer

Tr100.......................................................................................25


1 INTRODUCTION

1.1 PurposeThis Noise Assessment Report (NAR) describes the results of a noise impact assessment for the transformer sub-station associated with the St. Columban Energy LP (St. Columban) proposed St. Columban Wind Project. The transformer sub-station is located approximately 35 km north-northeast of the project turbines. Separate reports (Zephyr North, 2012a, 2012b, 2012c, 2012d) describe noise assessment of the project turbines.

1.2 Revision 0Revision 0 is the original Transformer Noise Assessment Report.

1.3 Revision 1To ensure a conservative approach to this noise assessment, this revision (Revision 1) revises the project transformer source sound power level specifications upwards based on updated information from transformer manufacturers.

In addition, based on comments from the Ontario Ministry of Environment, for the ISO 9613-2 noise propagation analysis the magnitude of the source ground factor (Gs) has been updated to a more conservative value of 0.5. A discussion has been included.

Also, public comments on the receptor height specification of “raised bungalows” were addressed.

None of these changes resulted in material changes in the noise assessment of this transformer. All qualified receptors remain fully noise compliant.

Minor corrections and edits have been included.

1.4 Brief Project DescriptionThe St. Columban Wind Project consists of two Ontario Feed-In Tariff (FIT) wind energy projects with two distinct points of connection into the local distribution

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grid, and a remote transformer sub-station. The two projects and the transformer sub-station are referred to herein and collectively as the St. Columban Wind Project.

The turbines are sited in the Municipality of Huron East in Huron County. They are located in two wind farm clusters — one consisting of 8 turbines for a capacity of approximately 18 MW, and another consisting of 7 turbines for a capacity of approximately 15 MW.

The project power transformer sub-station is located approximately 35 km north-northeast of the project turbines in the Township of Howick. A transmission line running through the Municipality of Huron East, the Municipality of Morris-Turnberry, and the Township of Howick links the turbine site to the transformer sub-station.

Figure 1-1 shows the location of the project within Ontario.

1.5 Reporting DetailsThis report has been prepared to meet all reporting requirements related to wind project noise for a Renewable Energy Approval (REA) under the Green Energy and Green Economy Act 2009 (Government of Ontario, 2009)

A noise impact assessment was carried out for this project under Section 55.(3) of O. Reg 359/09 (Government of Ontario, 2009b) and amendments (O.Reg. 521/10, Government of Ontario, 2010; O.Reg. 231/11, Government of Ontario, 2011; O.Reg. 195/12, Government of Ontario, 2012). The assessment methodology and calculations conform to the ISO 9613-2 International Standard (ISO, 1996). Results of the analysis have been interpreted using Ministry of Environment Guidelines (MoE, 2008). This latter document generally provides guidelines, clarifications and additional requirements for the application of MoE regulations document NPC-232 (MoE, 1995) to wind farm projects.

This report will show that the estimated noise levels generated by the project power transformer meet the MoE (2008) prescribed limits at all qualified receptors.

1.6 Sound Level Limits for Wind FarmsMoE (2008) lists the sound level limits for wind farms (based on the NPC-205 (MoE, 1995a) and NPC-232 (MoE, 1995b) publications and a consideration of the background ambient wind-induced sound level) as follows. Note that noise

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Figure 1-1 Project location map.


contributions from other project hardware, such as switching stations, transformer sub-stations, etc., must be included in the cumulative noise assessment.

Summary of Sound Level Limits for Wind Turbines

Wind speed (ms-1) at 10 m height 4 5 6 7 8 9 10

Wind turbine sound level limits Class 3 Area, dBA 40.0 40.0 40.0 43.0 45.0 49.0 51.0

Wind turbine sound level limits Class 1 Area, dBA 45.0 45.0 45.0 45.0 45.0 49.0 51.0

Reference wind induced background sound level L90, dBA 30.0 31.0 33.0 36.0 38.0 42.0 44.0

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2 PROJECT LAYOUT

2.1 Project SiteThe St. Columban Wind Project power transformer sub-station is located in the Township of Howick in Huron County. Transformer site details along with typical topographic map features are included in Figure 2-1 which shows the project area surrounding the power transformer.

Within the project power transformer domain, the topography can be characterized as very gently rolling to the point of being almost flat. In Figure 2-1, the contour lines (5 m contour interval) confirm this. Note that the topographic elevation in the vicinity of the transformer sub-station is about 345 m above sea level (a.s.l).

The surface roughness of the project domain is typical of Ontario rural terrain with a heterogeneous mixture of agricultural fields, woodlots, farm buildings, dwellings, rural settlements, and small villages and towns.

The primary activity in this area is agriculture.

The St. Columban Wind Project power transformer sub-station site features a population density typical of southern Ontario rural communities — a relatively sparse population in the countryside except for a small number of settlement clusters (villages and towns). The hamlet of Wroxeter is located about 1.7 km to the north-northeast of the transformer site.

2.2 Project Details — TurbinesSince the project turbines are located some 35 km to the south-southwest of the power transformer under consideration in this report, they will not be described here. A full description can be found in Zephyr North (2012a, 2012b, 2012c, 2012d).

2.3 Municipal ZoningTypically, the project area is zoned as Agricultural.

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Figure 2-1 Transformer sub-station details map.


2.4 Adjacent ProjectsSt. Columban Energy LP (St. Columban) has stated that it is not aware of any other planned wind energy projects nor transformer sub-stations in the vicinity of the presently described sub-station.

2.5 Substations

2.5.1 St. Columban Wind ProjectThe St. Columban Wind Project turbines are connected into the low voltage electrical distribution system at two different points well to the south of the subject transformer substation. In the case of the St. Columban 1 wind farm (~18 MW capacity), an approximately 43 km buried interconnection line will link the project to the single transformer described here. The host property is located about 1.7 km south-southwest of the hamlet of Wroxeter. The 15/20 MVA transformer will operate at 44 kV/34.5 kV.

Figure 2-1 shows the prospective transformer, point of reception (receptor), and participating point of reception (participant) locations. The transformer is designated with the prefix ‘Tr’, receptors are designated with ‘R’, and participants with ‘P’.

The project transformer substation is located within an agricultural field. It will occupy approximately 0.06 ha (~20 m x 30 m). An access road will run from the adjacent highway (McDonald Line) to the sub-station. The latter will be surrounded by a security fence, but not a noise barrier as the latter is not required to achieve noise compliance.

The Ontario NPC designation for the project property would be Class 3 — Rural. Typical background sound levels for this area would be generated by residential and agricultural activities, ambient sound from wind, and vehicle noise from regional roads. For the purposes of this report, all project areas have been considered to be NPC Class 3.

As specified by O.Reg 359/09, the St. Columban Wind Project (including its power transformer) is a Class 4 Wind Project.

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3 DESCRIPTION OF RECEPTORS

3.1 DefinitionReceptors (non-participating points of reception), vacant lot surrogate receptors (VLSRs), and participants (participating points of reception) are defined in Ontario MoE NPC-232 (MoE, 1995b) and Noise Guidelines publication (MoE, 2008), and in Ontario O.Reg. 359-09 and amendments (Government of Ontario; 2009b, 2010, 2011, 2012).

3.2 Determination of Receptors and ParticipantsReceptors and participants appropriate to the present noise assessment were identified through mapping and aerial photographs of the power transformer portion of the project area. For verification of details, on-site surveys were carried out. All known receptors and participants within 1,000 m of the project transformer were identified.

Typically, for the project area, receptors are residential dwellings of individuals and families not associated with the project. Section 12 (Appendix A) lists limited details for all known receptors and participants situated within the project area. Their locations are shown in Figure 2-1. All receptors within 1,000 m of the project transformer have been included and reported in this noise impact analysis. All receptors have been considered to be designated as rural (NPC Class 3).

For the purposes of noise assessment, participants have been defined as dwellings occupied by landowners who receive financial compensation for the placement of project hardware (turbines, cables, roads, transformers, etc.) on their properties.

For this project, 7 receptors (non-participating points of reception) and 1 participant (participating point of reception) were determined to be within 1,000 m of the project transformer.

Note that public comments have been received with regard to the assignment of heights of 1.5 m to “raised bungalows”. However, as shown in Table 6-1, the predicted sound pressure level at receptor (R2011; designated 2-storey or 4.5 m

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receptor height) nearest the transformer is well within compliance at 33.1 dBA. As a consequence, it would not be possible for any other receptors to be out of compliance, whether they be 1-storey, 2-storey, or “raised bungalows”. Therefore, the issue of “raised bungalows” has not been further considered.

3.3 Vacant LotsThe MoE (2008) Guidelines document also requires prediction of the noise levels on “...vacant lots that have been zoned by the local municipality to permit residential or similar noise-sensitive uses...”. However, for the present assessment, the 40 dBA isopleths (for 1 and 2 storey dwellings) are confined entirely within the transformer host property and the adjacent property to the south. (See Figure 8-1.) Both of these properties contain dwellings — a participant dwelling to the north and a receptor dwelling to the south. There are no other properties that can be impacted by the transformer with noise levels greater than 40 dBA. As a consequence of this, no vacant lots were designated, and no vacant lot surrogate receptors (VLSRs) were assigned.

3.4 MethodologyISO 9613-2 modelling was carried out for all receptors and participants.

A calculated receptor sound pressure level for each receptor was determined as stipulated in Section 6.3.2 of MoE (2008) as the present calculations apply only to the project transformer.

The heights of dwellings designated as 1-, 2-, and 3-storeys are normally set to be 1.5, 4.5, and 7.5 m respectively. However, as noted above, in the present assessment, all dwelling heights have been set to 4.5 m (2-storey).

As noted above, a participating receptor (referred to herein as a participant) has also been surveyed and is shown in Figure 2-1 and listed in Section 12 (Appendix A). An estimate of the sound pressure level was also made for this participant location.

It should be noted that the receptors and participant listed in Section 12 include only those that are closer than or equal to 1,000 m from the project transformer noise source.

3.5 Concordance TableSince there are no existing or proposed neighbouring wind energy projects (including transformer sub-stations), “concordance tables” that rationalize the identification of receptors and VLSRs between the subject and neighbouring projects have not been included.

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4 DESCRIPTION OF SOURCES

4.1 Wind Turbines

4.1.1 St. Columban Wind ProjectSince the project turbines are located some 35 km to the south-southwest of the power transformer sub-station under consideration in this report, they will not be described nor considered here. Should the reader require turbine information, full descriptions can be found in Zephyr North (2012a, 2012b, 2012c, 2012d).

4.2 Sub-Stations

4.2.1 St. Columban Wind ProjectAs noted previously, the off-site project sub-station transformer considered in this report is located about 35 km to the north-northeast of the project turbines.

4.2.1.1 Transformer

The following table describes the single sub-station power transformer.

Sub-Station Wind Farm Transformer

Type AC power transformer; details to be finalizedOperating voltages 44kV output / 34.5kV inputRating ~18 MVAHeight ~4 m

Core tank size ~ 3.0mW x 1.2mD x 3.8mH~ 5,200 litres

Source location outsideSound characteristics steady, tonalNoise control measures none

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5 NOISE EMISSION RATINGS

5.1 Wind Turbines

5.1.1 Turbine Noise Definition StandardAs noted previously, since the project turbines are located some 35 km to the south-southwest of the power transformer under consideration in this report, they will not be considered here and, as a consequence the turbine noise definition Standard is not relevant to this report. If required, a description of the Standard can be found in Zephyr North (2012a, 2012b).

5.1.2 St. Columban Wind ProjectAs noted previously, since the project turbines are located some 35 km to the south-southwest of the power transformer under consideration in this report, they will not be considered here.

5.2 Site-Specific Vertical Wind Shear ExponentAs no turbines are under consideration in this noise assessment report, the site-specific vertical wind shear exponent is not relevant here.

5.3 Sub-Stations

5.3.1 St. Columban Wind ProjectBecause it is not fiscally prudent to purchase or even to order a large power transformer such as required for this project before receiving confirmation that the project will be permitted to proceed, only limited information is available for the transformer and its source noise.

In any case, Veresen Inc. has specified an 18 MVA, 34.5 kV (in), 44 kV (out) power transformer for this project. Based on the CAN/CSA-C88-M90 Standard (CAN/CSA, 2009) it was determined that the maximum allowable “Audible Sound

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Level” or “Average sound level, dB A-weighted” (using the Standard’s terminology) for this size of transformer is 72 dBA. In discussions with transformer suppliers, Veresen Inc. further determined that a suitable transformer could be supplied with an audible sound level 10 dB lower (62 dBA) than the 72 dBA specified in the Standard for a small premium in cost. Veresen Inc. has chosen the lower noise option for this project.

Assuming conservative dimensions for this capacity of transformer (4.5 m width by 4.0 m depth x 4.0 m height including cooling fans, if any), an estimate of the broadband source sound power level based on the methodology of the ANSI/IEEE C57.12.90-2010 (Section 13) Standard (IEEE, 2010), as referenced in the CAN/CSA-C88-M90 Standard, would be as follows.

Lw = Lp + 10log10(S)

Lw = 62 dBA + 10log10(101.1 m2)

Lw = 82 dBA

where the notation follows that of the C57.12.90-2010 Standard. Lw is the transformer source broadband sound power level; Lp is the “Audible Sound Level” or “Average sound level, dB A-weighted” specified in the CAN/CSA -C88-M90 Standard (72 dBA minus the 10 dB reduction offered by the transformer manufacturer); and S is the side and top radiating areas and includes a 0.30 or 1.0 m offset from the transformer surface as appropriate and as specified in the ANSI/IEEE C57.12.90-2010 Standard.

For the purpose of this report, octave band source sound power levels characteristic of a typical power transformer were adjusted to reflect the maximum 82.0 dBA broadband level derived above. These are listed in Table 5-1 along with a 5 dB tonal penalty assessed to all frequencies. The net octave band source sound power levels are also shown, as is the resulting broadband source sound power levels before and after assessment of the penalties.

Note that the tonal penalties have been applied for all calculations in this report.

No attenuation due to acoustic barriers has been included in the present calculations.

St. Columban Energy LP (St. Columban) has undertaken to provide full transformer and substation details as soon as they become available.

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Table 5-1 Project transformer station acoustic emissions summary.

Operating voltage: 44kV output; 34.5kV input

Source height (m): ~ 4.0Source location: outsideSound characteristics: steady, tonalNoise control measures: uncontrolled

63 58.9 5.0 63.9125 72.6 5.0 77.6250 78.1 5.0 83.1500 76.3 5.0 81.3

1000 72.7 5.0 77.72000 70.6 5.0 75.64000 62.1 5.0 67.18000 51.2 5.0 56.2

82.0 87.0

Make and Model: AC power transformer; details to be finalized

Rating: ~18 MVACore tank size: ~ 3.0mW x 1.2mD x 3.8mH~ 5,200 litres

Frequency (Hz)

Source sound

power level (dBLin)

Tonal penalty

(dB)

Net source sound power level

(dBLin)

Broadband (dBA)


6 IMPACT ASSESSMENT

6.1 MethodologyCumulative transformer sound pressure levels were estimated at each of the receptors using the ISO 9613-2 Standard (ISO, 1996). Transformer octave band and A-weighted sound power values, standardized meteorological conditions, transformer location, receptor/participant locations, and characteristics were used to determine the A-weighted sound pressure levels at all receptors.

6.2 Specific Parametersa)

Analysis was carried out for transformer source sound power levels in eight octave bands (63 to 8,000 Hz) corresponding to 10 m (a.g.l.) ambient wind speeds of 6, 7, 8, 9, and 10 ms-1.

b)

ISO 9613-2 parameters, as prescribed in the MoE (2008) Noise Guidelines were set as follows:

Ambient air temperature: 10 CAmbient humidity: 70 %

The required atmospheric attenuation coefficients to be used in the ISO 9613-2 modelling of noise propagation are prescribed in MoE (2008). These have been used in the present assessment, and are shown in the following table.

Atmospheric Absorption Coefficients

Centre Octave Band Frequency (Hz) 63 125 250 500 1000 2000 4000 8000

Atmospheric Absorption Coefficient (dB/km) from MoE Oct 2008 document

0.1 0.4 1.0 1.9 3.7 9.7 32.8 117.0

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c)

The ISO 9613-2 term for Ground Attenuation was calculated using the “General” Method (Section 7.3.1 of the ISO 9613-2 Standard). Based on the terrain type, and following MoE (2008), ground factors were assigned the following values.

Source ground factor (Gs): 0.5 (hard/soft ground)Middle ground factor (Gm): 0.8 (soft ground)Receptor ground factor (Gr) 0.5 (hard/soft ground)

With respect to the source ground factor (Gs), the relatively small transformer (approximately 4.5 x 4.0 m dimension) will be located in an agricultural field (soft ground, Gs = 1.0). It will be surrounded by a gravel/screenings area (hard ground, Gs = 0.0) of approximately 3 m width and will be serviced by a gravel/screenings road (hard ground) of approximately 5 m width and 80 m length. Also located within the 120 m (30 x source height of 4.0 m) source region is approximately 175 m of approximately 10 m wide paved road (hard ground; McDonald Line). Therefore, the proportion of hard ground to soft ground within the source region (i.e., out to 120 m from the transformer location) is approximately 2,200 m2 / 45,240 m2 = 4.9%. Using this proportion of hard ground to soft ground to set the proportion in Gs results in a Gs of 1.0 (to a precision of 0.1; 0.95 to a precision of 0.01). Note, too, that the linear proportion of hard ground to soft ground on the line directly between the transformer and nearest dwelling (151 m separation) is approximately 3.5 m / 151 m = 2.3% demonstrating that there is significantly more soft ground than hard ground between the source and the receptor. Thus, it would seem reasonable to assign a source ground factor of 1.0 (to a single decimal precision).

However, it should be noted that the receptor region for the nearest dwelling is 135 m for a dwelling height of 4.5 m. (There is no ISO 9613-2 middle region in this case.) For this receptor region, the MOE 2008 Guidelines for wind farms mandates a maximum ground factor of 0.5. Since there is a significant overlap (104 m out of a separation distance of 151 m) of source and receptor regions, it is perhaps prudent to choose the more conservative of the two ground factors, i.e., Gs = Gr = 0.5. This has been done here.

6.3 Additional parameters and conditionsSound pressure levels were not calculated for any receptor further than 1,000 m from the project transformer.

No additional adjustments were made for wind speed or direction since ISO 9613-2 assumes worst-case conditions for these parameters with respect to noise impact.

6.4 ResultsResults are reported in Tables 7-1 and 7-2 found in Section 7 and the noise level isopleth map of Section 8 (Figure 8-1).

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Table 6-1 briefly summarizes the results of the noise assessment. It is a sorted list of the highest sound pressure levels determined in the analysis for receptors.

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Table 6-1 Highest noise levels at receptors.

Receptor ID SPrL (dBA) Height (m)Nearest Turbine /

Transformer

Project / Other

Distance (m)

R2011 33.1 4.5 Tr100 P 151

R2009 24.1 4.5 Tr100 P 386

R2008 22.6 4.5 Tr100 P 456

R2013 20.9 4.5 Tr100 P 549

R2014 18.7 4.5 Tr100 P 686

R2007 16.0 4.5 Tr100 P 898

R2023 15.3 4.5 Tr100 P 967

R2015 14.1 4.5 Tr100 P 1091

R2005 13.7 4.5 Tr100 P 1125

R2022 13.2 1.5 Tr100 P 1005

R2016 13.1 4.5 Tr100 P 1197

R2021 12.9 4.5 Tr100 P 1224

R2006 12.7 1.5 Tr100 P 1055

R2024 12.4 1.5 Tr100 P 1082

R2026 12.0 4.5 Tr100 P 1324

R2019 11.5 4.5 Tr100 P 1400

R2017 11.2 7.5 Tr100 P 1493

R2025 10.1 1.5 Tr100 P 1341

R2002 9.2 1.5 Tr100 P 1455

R2020 9.1 1.5 Tr100 P 1467

R2012 9.0 1.5 Tr100 P 1476

WindFarm layout file: StC05-Trbn-WFL049.csv


7 NOISE LEVEL SUMMARY TABLES

Table 7-1 Receptor noise level summary table.

Point of Reception ID Description Height (m)

Distance to Nearest

Trbn/Trnsfrmr (m)

Nearest Trbn/Trnsfrmr

IDCalculated Sound Level at Selected Wind

Speeds (dBA) Sound Level Limit (dBA)

6.0 7.0 8.0 9.0 10.0 6.0 7.0 8.0 9.0 10.0R2002 Residence 1.5 1455 Tr100 9.2 9.2 9.2 9.2 9.2 40.0 43.0 45.0 49.0 51.0R2005 Residence 4.5 1125 Tr100 13.7 13.7 13.7 13.7 13.7 40.0 43.0 45.0 49.0 51.0R2006 Residence 1.5 1055 Tr100 12.7 12.7 12.7 12.7 12.7 40.0 43.0 45.0 49.0 51.0R2007 Residence 4.5 898 Tr100 16.0 16.0 16.0 16.0 16.0 40.0 43.0 45.0 49.0 51.0R2008 Residence 4.5 456 Tr100 22.6 22.6 22.6 22.6 22.6 40.0 43.0 45.0 49.0 51.0R2009 Residence 4.5 386 Tr100 24.1 24.1 24.1 24.1 24.1 40.0 43.0 45.0 49.0 51.0R2011 Residence 4.5 151 Tr100 33.1 33.1 33.1 33.1 33.1 40.0 43.0 45.0 49.0 51.0R2012 Residence 1.5 1476 Tr100 9.0 9.0 9.0 9.0 9.0 40.0 43.0 45.0 49.0 51.0R2013 Residence 4.5 549 Tr100 20.9 20.9 20.9 20.9 20.9 40.0 43.0 45.0 49.0 51.0R2014 Residence 4.5 686 Tr100 18.7 18.7 18.7 18.7 18.7 40.0 43.0 45.0 49.0 51.0R2015 Residence 4.5 1091 Tr100 14.1 14.1 14.1 14.1 14.1 40.0 43.0 45.0 49.0 51.0R2016 Residence 4.5 1197 Tr100 13.1 13.1 13.1 13.1 13.1 40.0 43.0 45.0 49.0 51.0R2017 Residence 7.5 1493 Tr100 11.2 11.2 11.2 11.2 11.2 40.0 43.0 45.0 49.0 51.0R2019 Residence 4.5 1400 Tr100 11.5 11.5 11.5 11.5 11.5 40.0 43.0 45.0 49.0 51.0R2020 Residence 1.5 1467 Tr100 9.1 9.1 9.1 9.1 9.1 40.0 43.0 45.0 49.0 51.0R2021 Residence 4.5 1224 Tr100 12.9 12.9 12.9 12.9 12.9 40.0 43.0 45.0 49.0 51.0R2022 Residence 1.5 1005 Tr100 13.2 13.2 13.2 13.2 13.2 40.0 43.0 45.0 49.0 51.0R2023 Residence 4.5 967 Tr100 15.3 15.3 15.3 15.3 15.3 40.0 43.0 45.0 49.0 51.0R2024 Residence 1.5 1082 Tr100 12.4 12.4 12.4 12.4 12.4 40.0 43.0 45.0 49.0 51.0R2025 Residence 1.5 1341 Tr100 10.1 10.1 10.1 10.1 10.1 40.0 43.0 45.0 49.0 51.0R2026 Residence 4.5 1324 Tr100 12.0 12.0 12.0 12.0 12.0 40.0 43.0 45.0 49.0 51.0

Table 7-2 Participant noise level summary table.

Participating Receptor ID Description Height (m)

Distance to Nearest

Trbn/Trnsfrmr (m)

Nearest Trbn/Trnsfrmr

Calculated Sound Level at Selected Wind Speeds (dBA)

6.0 7.0 8.0 9.0 10.0

P2010 Residence 1.5 223 Tr100 28.8 28.8 28.8 28.8 28.8

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8 NOISE LEVEL ISOPLETH MAP

Figure 8-1 is a 40 dBA isopleth map of the sound pressure levels (dBA) due to the project transformer over the project area. The noise levels are calculated for receptors with 1.5 m (1 storey) and 4.5 m (2 storeys) heights.

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Figure 8-1 40 dBA noise isopleth map for 1.5 and 4.5 m receptor heights.


9 EXAMPLE CALCULATION

9.1 Method of CalculationThe calculation of cumulative receptor noise levels from turbines and transformers uses the methodology of ISO 9613-2, ‘Acoustics — Attenuation of sound during propagation outdoors: Part 2: General method of calculation’ (ISO, 1996).

The calculation is based on equation (5) from ISO 9613-2, shown here:

where

LAT (DW) is the equivalent continuous A-weighted downwind sound pressure level at a receptor location,

n is the number of turbines/transformers,

Af (j) is the standard A-weighting for octave band j,

j is an index indicating the eight standard octave-band mid-band frequencies from 63 Hz to 8 kHz,

LfT(ij) ≡ LfT(DW) is the equivalent continuous downwind octave-band sound pressure level at a receptor location for turbine/transformer i and octave band j, and is given by

where

LW is the octave-band sound power level, in decibels, produced by the point sound source relative to a reference sound power of one picowatt,

DC is the directivity correction in decibels,

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LAT DW =10 log10{∑i=1n

[∑j=18

100.1[L fT ij A f j]]}

L ft DW =LWDC−A


A is the octave-band attenuation, in decibels, that occurs during propagation from the turbine/transformer to receptor, and is given by

where

Adiv is the attenuation due to geometrical divergence,

Aatm is the attenuation due to atmospheric absorption,

Agr is the attenuation due to the ground effect,

Abar is the attenuation due to a barrier,

Amisc is the attenuation due to miscellaneous other effects,

Aatm is given by

where

α is the atmospheric attenuation coefficient, in decibels per kilometre, for each octave band at the midband frequency,

d is the distance from the turbine/transformer to the receptor.

Note that Abar and Amisc are not used here.

9.2 ExampleThe following sample calculation presents intermediate octave-band results of calculations for A-weighted sound pressure levels corresponding to a 10 m (a.g.l.) wind speed of 6 ms-1. All model parameters are the same as previously tabulated.

Table 9-1 lists the intermediate sound pressure levels calculated at receptor R2011 due to the single transformer Tr100. Receptor and turbine are separated by 151 m.

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A=AdivAatmAgrAbarAmisc

A= d1000


In the table:

LW is the octave-band sound power level, in decibels (A-weighted), produced by the point sound source relative to a reference sound power of one picowatt,

Adiv is the attenuation due to geometrical divergence,

Aatm is the attenuation due to atmospheric absorption,

Agr is the attenuation due to the ground effect,

LfT(DW) is the equivalent continuous downwind octave-band sound pressure level.

Table 9-2 shows intermediate octave band values of the calculations for the A-weighted sound pressure levels at receptor R2011 due to the single transformer Tr100.

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Table 9-1 Sample calculation for receptor and turbine.

Intermediate calculations for receptor R2011 and transformer Tr100

1 63 63.9 52.8 0.0 -3.0 14.1 2 125 77.6 52.8 0.0 0.2 24.6 3 250 83.1 52.8 0.1 2.6 27.6 4 500 81.3 52.8 0.2 0.8 27.5 5 1000 77.7 52.8 0.5 -1.2 25.7 6 2000 75.6 52.8 1.2 -1.5 23.2 7 4000 67.1 52.8 4.0 -1.5 11.8 8 8000 56.2 52.8 14.3 -1.5 -9.4

Octave band

Mid-band frequency

(Hz) LW (dBA) A

div (dB) A

atm (dB) A

gr (dB)

LfT(DW)

(dBA)

Table 9-2 Sample calculation for single receptor R2011 and transformer Tr100.

Intermediate calculations for single receptor R2011 and multiple turbines/transformers

63 125 250 500 1000 2000 4000 8000Tr100 151 40.3 40.7 36.2 30.7 25.7 22.0 10.8 -8.3 33.1

Turbine/ Transformer

IDDistance

(m)

Turbine/Transformer Lft contribution (dB) in frequency band (Hz) Turbine/

Transformer LAT

(dBA)


10 CONCLUSIONS

This noise impact assessment for the proposed St. Columban Wind Project transformer sub-station has determined that the estimated sound pressure levels at receptors in the project area comply with the Ministry of the Environment sound level limits at all qualified points of reception.

26


11 REFERENCES

CAN/CSA, 2009: Power Transformers and Reactors, CAN/CSA-C88-M90 (R2009) Standard, Published 1990, Reaffirmed 2009. Canadian Standards Association. http://shop.csa.ca/en/canada/electrical-engineering-standards/cancsa-c88-m90-r2009/invt/27002451990

CAN/CSA, 2011b: Three-Phase Pad-Mounted Distribution Transformers with Separable Insulated High-Voltage Connectors, CAN/CSA-C227.4-06 Standard, Published 2006, Reaffirmed 2011. Canadian Standards Association. http://shop.csa.ca/en/canada/electrical-engineering-standards/cancsa-c2274-06-r2011/invt/27003792006

Government of Ontario, 1990: Environmental Assessment Act, R.S.O. 1990, Chapter E.18. http://www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_90e18_e.htm

Government of Ontario, 1990: Environmental Protection Act, R.S.O. 1990, Chapter E.19. http://www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_90e19_e.htm

Government of Ontario, 2009: Green Energy Act, 2009, http://www.search.e-laws.gov.on.ca/en/isysquery/abaf99f7-8e6f-4ea9-b8a4-d6d8b0435bac/1/doc/?search=browseStatutes&context=#BK7

Government of Ontario, 2009b: Ontario Regulation 359/09, made under the Environmental Protection Act, Renewable Energy Approvals under Part V.0.1 of the Act. http://www.search.e-laws.gov.on.ca/en/isysquery/e366a7f1-5b0c-4468-b87d-479b33d386b4/1/frame/?search=browseStatutes&context=

Government of Ontario, 2010: O.Reg. 521/10 made under the Environmental Protection Act amending O.Reg. 359/09. http://www.e-laws.gov.on.ca/html/source/regs/english/2010/elaws_src_regs_r10521_e.htm

Government of Ontario, 2011, O.Reg. 231/11 made under the Environmental Protection Act amending O.Reg. 359/09. http://www.e-laws.gov.on.ca/html/source/regs/english/2011/elaws_src_regs_r11231_e.htm

Government of Ontario, 2012, O.Reg. 195/12 made under the Environmental Protection Act amending O.Reg. 359/09. http://www.e-laws.gov.on.ca/html/source/regs/english/2012/elaws_src_regs_r12195_e.htm

IEEE, 2010: IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers, ANSI/IEEE C57.12.90-2010.

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http://www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_90e19_e.htm


International Electrotechnical Commission (IEC), 2002: International Standard, Wind turbine generator systems – Part 11: Acoustic noise measurement techniques. Second edition 2002-12. http://webstore.iec.ch/preview/info_iec61400-11%7Bed2.0%7Den.pdf

International Standards Organization (ISO), 1993: 9613-1 International Standard: Acoustics — Attenuation of sound during propagation outdoors — Part 1: Calculation of the absorption of sound by the atmosphere. http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=17426

International Standards Organization (ISO), 1996: 9613-2 International Standard: Acoustics — Attenuation of sound during propagation outdoors — Part 2: General method of calculation. http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=20649

Ontario Ministry of the Environment (MoE), Date unknown: Sound Level Adjustments, Publication NPC-104. http://www.ene.gov.on.ca/stdprodconsume/groups/lr/@ene/@resources/documents/resource/std01_079360.pdf

Ontario Ministry of the Environment (MoE), 1995a: Sound Level Limits for Stationary Sources in Class 1 & 2 Areas (Urban), Publication NPC-205. October 1995. http://www.ene.gov.on.ca/stdprodconsume/groups/lr/@ene/@resources/documents/resource/std01_079360.pdf

Ontario Ministry of the Environment (MoE), 1995b: Sound Level Limits for Stationary Sources in Class 3 Areas (Rural), Publication NPC-232. October 1995. http://www.ene.gov.on.ca/envision/gp/3405e.pdf

Ontario Ministry of the Environment (MoE), 2008: MoE Noise Guidelines for Wind Farms; Interpretation for Applying MOE NPC Publications to Wind Power Generation Facilities (October 2008). http://www.ene.gov.on.ca/publications/4709e.pdf. 20 pp.

Zephyr North, 2012a: St. Columban Wind Project, Noise Assessment Report, Revision 5-101. Dated: 2012/06/12. By Zephyr North Ltd. – [email protected].

Zephyr North, 2012b: St. Columban Wind Project, Noise Assessment Report, Revision 5-113. Dated: 2012/06/12. By Zephyr North Ltd. – [email protected].

Zephyr North, 2012c: St. Columban Wind Project, Noise Assessment Report, Revision 5-101 Addendum 1. Dated: 2012/07/09. By Zephyr North Ltd. – [email protected].

Zephyr North, 2012d: St. Columban Wind Project, Noise Assessment Report, Revision 5-113 Addendum 1. Dated: 2012/07/09. By Zephyr North Ltd. – [email protected].

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12 APPENDIX A — TURBINE, RECEPTOR, VACANT LOT AND PARTICIPANT LOCATIONS

This appendix contains lists of transformer, receptor, and participant locations. Coordinates are given in the Universal Transverse Mercator (UTM) Zone 17N projection. The datum is North American Datum 1983 (NAD83, Canada).

For reference, the project (turbine/transformer) layout identifier is StC05-WFL049.csv.

TransformerTable: Transformer Location

Project Name: St. Columban Wind Project (Transformer NAR)Datum: NAD83 (Canada) Projection: UTM 17N

Equipment Identifier Make and Model X(E,m) Y(N,m) Transformer To be determined 487630 4854885

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Points of Reception (Receptors)Table - Point of Reception Locations


Point of Reception Height NPC ID Description (m) Class X(E,m) Y(N,m) R2002 Residence 1.5 3 487661 4856340 R2005 Residence 4.5 3 488391 4855714 R2006 Residence 1.5 3 488534 4855429 R2007 Residence 4.5 3 488383 4855375 R2008 Residence 4.5 3 487553 4855334 R2009 Residence 4.5 3 487452 4855227 R2011 Residence 4.5 3 487677 4854741 R2012 Residence 1.5 3 486211 4854478 R2013 Residence 4.5 3 487447 4854367 R2014 Residence 4.5 3 488098 4854384 R2015 Residence 4.5 3 487839 4853814 R2016 Residence 4.5 3 487625 4853688 R2017 Residence 7.5 3 487884 4853414 R2019 Residence 4.5 3 486536 4854012 R2020 Residence 1.5 3 486211 4854514 R2021 Residence 4.5 3 486409 4854799 R2022 Residence 1.5 3 486635 4855029 R2023 Residence 4.5 3 487291 4855791 R2024 Residence 1.5 3 487411 4855945 R2025 Residence 1.5 3 487375 4856202 R2026 Residence 4.5 3 487111 4856103

Participating Receptors (Participants)

Table: Participating Receptor Locations


Point of Reception Height NPC ID Description (m) Class X(E,m) Y(N,m) P2010 Residence 1.5 3 487682 4855102

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13 APPENDIX B — ADDITIONAL DOCUMENTATION

There is no additional documentation associated with this noise assessment report at this time.

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Revised Noise Assessment Report – Transformer

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