April 22, 2008 Mr. Geoff Carnegie Canadian Hydro Developers, Inc. 34 Harvard Road Guelph, ON N1G 4V8 Re: Winter 2008 Acoustic Audit Amaranth Transformer Station, Melancthon I Wind Plant Certificate of Approval (Air) Number 2233-6X9NBQ Dear Mr. Carnegie,

As requested, Howe Gastmeier Chapnik Limited (HGC Engineering) has undertaken an acoustic audit of the Amaranth Transformer Station (TS) associated with the Melancthon I Wind Plant. This audit represents the second of four seasonal audits that will be conducted of the TS noise, as a condition of Certificate of Approval (Air) Number 2233-6X9NBQ issued October 17, 2007 by the Ministry of the Environment (MOE).

In summary, the results of the winter 2008 audit are: 1) The data indicate that the noise contribution from the TS at the three closest residences was

in compliance with the MOE sound level limits during the measurement period. 2) In contrast to the measurements conducted during the autumn 2007 audit, there were no

periods when the sound levels on the switch side of the acoustic barrier wall were unexplainably high. The 2007 phenomenon will be investigated further during the spring 2008 acoustic audit.

The acoustic audit is presented in the following sections. We trust that this information is sufficient for your current needs and we look forward to working with you on the spring 2008 acoustic audit of the Amaranth TS. Howe Gastmeier Chapnik Limited Ian Bonsma, BASc, EIT Brian Howe, MEng, PEng

Canadian Hydro Developers, Inc., Page 2 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 Introduction

This winter 2008 acoustic audit of the Amaranth Transformer Station (“TS”), situated in the Township of Amaranth, County of Dufferin, followed the requirements of the Ministry of the Environment’s (“MOE”) technical publication NPC-233 “Information to be Submitted for Approval of Stationary Sources of Sound”. The audit also employed the additional methodology described in a letter prepared by HGC Engineering, dated September 17, 2007, as agreed to by Dr. Al Lightstone of Valcoustics Canada Ltd. (“Valcoustics”) as the Township’s acoustical specialist and John Kowalewski of the MOE. This letter, developed with input from the surrounding residents, is attached as Appendix A for continued reference.

The audit methodology was revised based on the results of the autumn 2007 audit. The revisions to the methodology are described in a letter prepared by HGC Engineering, dated January 24, 2008 and is attached as Appendix B.

As per the audit methodology prescribed for the Amaranth TS, the acoustic audit was based upon a complex series of attended and unattended sound measurements and other data recorded between February 7 and February 20, 2008. These included:

• attended and automated unattended sound level measurements conducted on the TS site, on both sides of the acoustic barrier;

• attended and automated unattended sound level measurements conducted at the three principal receptors adjacent to the TS;

• electrical power data provided by Canadian Hydro Developers, Inc. (“Canadian Hydro”) and verified against Independent Electrical System Operator (“IESO”) data for the same period;

• meteorological data monitored at one of the residences during the measurement period; and • the residents’ own logs of observations made during the measurement period. Throughout this acoustic audit report the acronym ‘TS’ is used to refer to the Amaranth Transformer Station as a whole. However, there are times when the transformer itself is meant, and at these times the word ‘transformer’ is used.

Certificate of Approval – Air

Certificate of Approval – Air (“CofA”) Number 2233-6X9NBQ requires that Canadian Hydro undertake four seasonal, post-abatement acoustical measurements of the Amaranth TS. In this regard, Canadian Hydro has retained HGC Engineering to independently carry out the measurements.

HGC Engineering completed the first of the four seasonal acoustical measurements in the autumn of 2007. This report, which can be viewed on the project website (www.melancthonwind.com), should be read in conjunction with this report as it provides the background and basis for the

Canadian Hydro Developers, Inc., Page 3 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 measurements. This audit represents the second of four seasonal audits that will be conducted at the Amaranth TS.

The audit conducted in the autumn of 2007 indicated that the Amaranth TS was operating in compliance with the applicable MOE sound level limits. During the autumn 2007 audit the measurements showed an intermittent and unexplained increase in sound on the west side of the TS that was not correlated to an increase in sound on the east side. This audit, as well as future audits will attempt to investigate this phenomenon.

Site Description

The TS is located on the east side of 10th Line, south of 15th Side Road, in Amaranth Township, County of Dufferin. There is one 100 MVA GE Prolec transformer on the TS site, along with supporting ancillary facilities. Figure 1A shows the TS in relation to the surrounding roads and residences, and Figure 1B illustrates the TS itself. Photo Plate 1 shows the acoustic barrier wall shielding the nearest residences from the transformer.

There are five residences adjacent to the general area of the TS. One of these is the participating landowner and is not considered in this assessment given their association with the facility. The three closest residences are the key receptor locations, described in Table 1, with the Receptor ID following the nomenclature used in the original acoustical report prepared by Aercoustics Engineering Ltd. (August 2006).

Table 1. Summary of Receptors.

ID Description Distance from Substation [m]

R01 214292 10th Line – northwest of TS 390 R02 214242 10th Line – southwest of TS 360 R04 214215 10th Line – south of TS 490

Sound Level Limits

As described in the autumn acoustical audit, after accounting for the tonality aspects of the transformers, the applicable MOE sound level limits for the Amaranth TS are:

• daytime (07:00 – 23:00 hrs): 40 dBA

• night-time (23:00 – 07:00 hrs): 35 dBA.

Canadian Hydro Developers, Inc., Page 4 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 These criteria apply to the Amaranth TS as a whole, including any new transformer(s) or equipment that is added in the future. It is important to realize that the guideline documents of the MOE do not require that noise from sound sources be inaudible at a residence. In fact, it should be understood that in a very quiet rural environment, a sound level of 35 dBA will likely be audible at times.

The sound level limits of the MOE guidelines are presented in terms of hourly energy equivalent average sound levels, designated LEQ. This means that if sound levels vary somewhat over an hour, it is the average sound level rather than the maximum or minimum sound levels which is relevant.

Sound levels are sometimes usefully quantified by determining the ninetieth percentile (L90) sound level. An L90 sound level represents the level which was exceeded 90% of the time during a measurement. Technical publication NPC-232 indicates that it is appropriate to use the background one hour ninetieth percentile sound level (L90) plus 10 dB if it results in a more stringent sound level limit than that obtained by considering the background one hour equivalent sound level (LEQ). L90 sound levels are useful as they allow some separation of steady sound from an overall, aggregate measured sound level. That is: when a continuous sound such as the sound of an operating transformer is masked at times by a louder transient sound such as those caused by wind gusts, birds, vehicles, and animals, the L90 sound level tends to more accurately reflect the sound level contribution of the steady sound by itself, than does the LEQ sound level.

Measurement Methodology

The study is based on a complex collection of data series, obtained during the period from Friday, February 7 to Wednesday, February 20, 2008. More than a week-long period was chosen to collect data under a variety of weather conditions, and to include periods of different ambient sound conditions including day and night periods, and weekday and weekend periods.

Non-acoustic Data

Various measurements of non-acoustic quantities such as wind speed and power production were required to conduct this audit. To acquire this information a number of actions were taken:

• On February 7th, an automatic meteorological station was deployed at receptor R02 to record wind speed, wind direction, temperature, and humidity. This data is attached to this audit as Appendix C. Note that data from February 7th to 13th was lost due to a poor power connection.

• The residents agreed to record observations regarding the subjective contribution of the TS sound throughout the measurement period. Summaries of the residents logs are attached to this report as Appendix D;

• Following the measurements, power production data was also acquired from the IESO and Canadian Hydro. The data are attached as Appendices E and F, respectively. It is noted that

Canadian Hydro Developers, Inc., Page 5 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008

based upon HGC Engineering’s review, the data obtained directly from Canadian Hydro agreed with the IESO data.

Unattended Acoustic Measurements

Seven unattended sound level meters were deployed and configured to record LEQ sound levels in 10-minute intervals. L90 sound levels were also recorded. The locations of these instruments are shown on Figures 1A and 1B. Descriptions of the sound level meters are provided in the Instrumentation section of this report and records of the LEQ and L90 measurements are included in Appendixes G and H, respectively.

Two sound level meters were deployed inside the TS fenceline, about two metres west of the east fence and thus about 30 metres from the centre of the transformer. These two locations are identified as Locations 1 and 3 on Figure 1B and shown in Photo Plate 2. These monitors were on the transformer side of the acoustic barrier wall, with a direct line of sight to the equipment. Two instruments were used at this location, rather than a single instrument, in order to provide some spatial averaging of the sound levels near the transformer.

One sound level meter was placed on the switch side of the acoustic barrier wall (Location 4), approximately 30 metres from the centre of the transformer, monitoring noise from the switchgear (Photo Plate 3). Observations indicated that during the measurement period, the transformer audibility was very low at this location.

During the autumn 2007 audit the measurements showed an intermittent and unexplained increase in sound on the west side of the TS that was not correlated to an increase in sound on the east side. As such, an additional sound level meter was placed on the switch side of the acoustic barrier, on the berm, outside the transformer fencing (Location 11) to assist in investigating the unexplained increase. The location of this sound level meter is shown in Photo Plate 3.

One sound level meter was also placed at each of the three residences described in Table 1, near to the dwellings. Locations were selected in conjunction with discussions with the residents, and were generally near the houses themselves, with little to no acoustic screening from the TS to represent the same exposure the homes experienced.

Attended Acoustic Measurements

Attended measurements conducted over a series of one minute periods were made at the three receptors during the afternoon of February 13, 2008 and during the overnight hours between February 13 and 14, 2008. Observations as well as sound level measurements were made. The instrumentation used for the attended measurements is described in the Instrumentation section of this report.

Canadian Hydro Developers, Inc., Page 6 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 A variety of attended measurements were also conducted at various locations around the TS on February 13, 2008. These measurements, each conducted over a period of five minutes, were intended to:

• investigate the spectrum of the noise radiated by the TS; • verify typical sound levels emitted by the TS and radiated in different directions; • investigate propagation of sound with distance from the TS; • ensure that the acoustic barrier wall is providing attenuation to the noise from the transformer;

and • investigate the potential significance of power production at the wind plant on the noise of the

transformer. Measurements were conducted simultaneously at three locations to the south, east, and northwest of the transformer at a distance of about 30 to 40 metres. These locations are identified in Figure 1B as Location 8 through Location 10, respectively. At this distance, the sound of the TS was clearly the dominant source of noise. The three locations were then moved further from the transformer to investigate propagation with distance. As requested by the MOE, the microphones were manually swept in a continuous fashion over as large an area as practical while standing in one spot in an attempt to minimize any local effects of acoustic radiation patterns, modal interference, small-scale shielding phenomena, etc. which might cause variations in measured sound level from location to location. Several cycles of microphone location changes occurred during each of the five minute measurements. Larger swept areas were not used as footsteps were found to generate excessive noise.

Specific TS operating conditions were investigated by shutting down all wind plant turbines for a period of about 15 minutes during the measurements.

Instrumentation

MOE technical publication NPC-102, “Instrumentation” provides specifications for sound level measurement instrumentation. All equipment used in the Audit meets these requirements.

Unattended Acoustic Measurements

Six Bruel & Kjaer and one Larson Davis Integrating Sound Level Meters were used for the unattended monitoring. The instruments are described in Table 2 below.

Canadian Hydro Developers, Inc., Page 7 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008

Table 2: Instrumentation used For Unattended Sound Level Measurements

Measurement Location Instrument Make and Model Instrument Serial Number

Inside fenceline, NE location Bruel and Kjaer Type 2238 2562612 Inside fenceline, E location Larson Davis LxT 0001724 Inside fenceline, SW location Bruel and Kjaer Type 2236 2151071 Outside fenceline, SW location Bruel and Kjaer Type 2236 2047261 Receptor R01 Bruel and Kjaer Type 2238 2448501 Receptor R02 Bruel and Kjaer Type 2238 2562611 Receptor R04 Bruel and Kjaer Type 2238 2343948

Both of the Bruel and Kjaer 2236 and 2238 sound level meters meet the specifications contained in technical publication NPC-102, however, the newer Type 2238 sound level meter has replaced Type 2236 in the Bruel and Kjaer catalogue. The Larson Davis LxT also meets the specifications of technical publication NPC-102. The clocks of all seven instruments were synchronized before being deployed.

Correct calibration of the acoustic instrumentation was verified using Bruel and Kjaer and Rion acoustic calibrators. Wind screens were used on all microphones, consistent with the requirements of technical publication NPC-103, “Procedures”.

Meteorological data was collected using a Davis Instruments Corp. Vantage Pro2 weather station, equipped with an anemometer, wind vane, thermometer, hygrometer, and barometer. The system was configured to record data in 10 minute intervals; consistent with the 10 minute interval recordings of the sound level meters.

The MOE guidelines indicate that sound level measurements should not be conducted during periods with high wind speeds. Specifically, technical publication NPC-102 indicates that measurements of low sound levels should not be undertaken when winds exceed 15 km/h. However, as the winds in Amaranth Township are frequently strong, making the area the subject of interest for wind plants, some consideration of the sound level during higher wind speeds is appropriate. The data from the weather station is presented in Appendix C.

Attended Acoustic Measurements

Three Hewlett Packard Type 3569A Real Time Frequency Analyzers (serial numbers 3222A00134, 3222A00199, and 3442A00141), in conjunction with Bruel & Kjaer Microphones, were used for the attended measurements. Correct calibration of the acoustic instrumentation was verified using Bruel and Kjaer and Rion acoustic calibrators. Wind screens were used on all microphones, consistent with the requirements of technical publication NPC-103.

Canadian Hydro Developers, Inc., Page 8 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 Assessment and Discussion

Unattended Acoustic Measurements – Transformer Station

This acoustic audit was conducted during the winter where the weather is less predictable and frequently changes compared to the other seasons, making it challenging to conduct long-term monitoring. High winds (i.e., > 15 km/hr) affected the unattended acoustic measurements from the evening of February 9th to the early morning hours of February 11th and from noon on February 17th to noon on February 19th. These periods are highlighted in grey on Figures 2 and 4 through 8. Data from the weather station at R02 was lost during the first week of measurements due to a poor power connection and the sound level monitor at Location 11 was blown over by the wind sometime between February 15th and February 20th; negating effective measurements during this period.

Figure 2 shows the sound levels measured at three points around the transformer, within the fenced area and the sound levels measured on the berm, within about 50 metres of the transformer. The northeast and southeast locations (i.e., Locations 1 and 3) are near the transformer, and on the transformer side of the acoustic barrier wall. The sound levels spike during the daytime and evening hours on February 12th and 14th on the switch side, possibly due to activity from Hydro One personnel currently upgrading the transmission lines in the area. Additionally, the sound levels increased briefly in the late afternoon on February 11th and around noon on February 13th due to our presence on site.

Measurements at Location 1 show steady sound levels of 55 dBA during the measurement period when wind speeds were less than 15 km/hr. The sound level meter stationed at Location 3 was affected by the lower temperatures and did not have the longevity of the other meters (i.e., the cold weather shortened the battery life). During the period of operation of the sound level meter at Location 3, when wind speeds were less than 15 km/hr, sound levels ranged from 45 to 55 dBA. As expected, given the close proximity to the transformers, site observations indicate that sound from the TS is clearly the dominant noise at these locations.

The southwest monitor location (i.e., Location 4) was sited near the switch gear, on the opposite side of the acoustic barrier wall from the transformer. As such, any noise generated here would not be appreciably shielded from the residences. During the autumn 2007 audit the sound levels on this side of the barrier were higher than on the transformer side of the barrier; sound levels of up to 70 dBA were recorded. However, during this audit, sound levels at this location were recorded up to 54 dBA, except during known periods of higher winds.

As suggested in the autumn 2007 report, the higher sound levels recorded on the switch side of the transformer wall, could have been attributed to corona noise on the existing 230 kV wires, the TS switch gear, insects, and/or the wind in the trees located on the nearby berm. This winter acoustic audit provided no new insight into this anomaly. During the spring 2008 audit, a sound level meter will be established at Location 11 again, to further investigate what, if anything unusual is occurring at this location.

Canadian Hydro Developers, Inc., Page 9 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 Figure 2 also shows the background (L90) sound levels recorded at the residences at times corresponding with the time of day noted in the residents’ observation logs. The L90 sound level is cited in this case as it is a better indicator of the steady sound at the measurement location, rather than the aggregate sound of all sound sources. The logs are summarized in Appendix C. The comments in the logs, together with the corresponding times and measured sound levels, indicate that the residents typically notice the TS noise when the background sound levels are low (e.g., less than 30 dBA), not when the overall sound levels, including all sounds at the receptor, are high.

Figure 3a is a spectrogram of the unattended spectral measurements conducted at the southeast unattended measurement location (i.e., Location 3). The Figure confirms that the Leq sound levels vary with time, but that the dominant A-weighted frequency bands (i.e., 400 and 500 Hz) do not appreciably vary with time. Figure 3b represents the same measurement location, with the instrument temporarily reconfigured for greater temporal resolution (i.e., one minute intervals) for this time period (i.e., 12:07 to 14:06 on February 13).

Figure 4 integrates the record of the electrical power monitored at the wind plant to the TS sound level data shown in Figure 2. This Figure shows that there is correlation between the wind plant power output and the sound levels at the transformer when the wind is high. Note, however, that the higher sound levels recorded by the sound level meters at the TS are likely due to wind induced noise on the microphones and not related to power production of the wind plant.

Figure 5 overlays the weather data on the sound levels near the transformer. During periods of higher wind speeds the monitors indicate higher sound levels. No obvious correlations with temperature or humidity exist with the monitored sound levels.

Unattended Acoustic Measurements – Residences

Figure 6a illustrates the LEQ unattended sound levels measured at the residences. The recorded sound levels vary significantly over time and are obviously influenced by wind and local activities (e.g., traffic), and include the sound of aircraft, animals, and voices as well as any sound from the TS. In particular, the heavily treed nature of R04 results in significant wind-induced noise even in relatively light wind conditions. This, combined with the animal activities at R04, likely explain the many short-duration spikes in the measured sound level data at this location.

Figure 6b illustrates the L90 unattended sound levels measured at the residences. These sound levels show the steady source contributions. As shown on the Figure, the L90 sound levels are generally well below 30 dBA during night-time hours.

The data summarized in Figure 6a and 6b show that the night-time sound levels (i.e., when local activity is relatively low) at the residences are below 30 dBA on several occasions when the TS is producing noise. This fact indicates compliance with the MOE sound level limits during these times.

Canadian Hydro Developers, Inc., Page 10 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 Figure 7 adds the unattended measurement data from the TS to the unattended data at the residences. As shown, there is little correlation between the sound on the transformer side of the acoustic barrier wall and the sound levels at the residences; although there may be some limited correlation with the sound on the switch side of the barrier wall. This tends to suggest that while the sound levels at the residences are varying, the contribution of the transformer by itself was not a dominant contributor to the sound levels measured at the residences.

Figure 8 illustrates the sound levels at the residences against the recorded weather data. Local wind correlates closely with the measured sound levels, rather than with the TS sound levels. This correlation demonstrates that the wind is a key contributing source of noise at the residences.

The fact that the sound levels at the residences were not correlated with the sound levels at the TS, the sound levels at the residences were at most times less than 30 dBA when the TS was operating and producing noise, and the fact that the sound levels at the residences seems to correlate closely with the wind speed rather than the TS noise, indicates that the sound contribution of the TS was in compliance with the MOE sound level limits during the measurement period.

Attended Acoustic Measurements – Transformer Station

Figure 9 illustrates the results of the measurements conducted simultaneously over a five minute period at three locations (i.e., Locations 8 through 10) around the TS, 30 to 40 metres from the centre of the transformer. Recall that Location 9 is not shielded from the transformer by the acoustic barrier wall, but is partially screened by fixed site equipment, whereas Locations 8 and 10 are shielded by the barrier wall, as are the residences.

The distances were somewhat forced by the site geometry; any closer and Location 9 would have been affected by acoustic reflections off of a large concrete retaining wall, and any further and Location 8 would have been behind an earthen berm (i.e., shielded from the transformer). Figure 9 represents the LEQ spectra of the five minute measurement. The Figure indicates tonal noise, with principal frequencies in the 50, 125, and 400 Hz 1/3 octave bands, and with the tone in the 400 Hz band as the dominant audible frequency.

During these measurements the microphones were continuously swept over as wide an area as practical, while standing still, with several cycles of microphone location occurring during each measurement.

Figure 10 illustrates how the noise of the transformer, represented by the 400 Hz octave band, varied with time and microphone location at the measurement locations. As shown on the Figure, there is variation at all three locations. The variations are the result of differences in location screening, refractions, and reflections from moment to moment as the microphones are swept.

Figures 11 and 12 summarize a similar set of measurements made when all wind turbine generators at the wind plant had been shut off. A comparison of these Figures with Figures 9 and

Canadian Hydro Developers, Inc., Page 11 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 10 indicates that the transformer noise at the locations most exposed to the transformer, such as Location 9, does not noticeably change when the wind plant is not producing power. Subjectively, no audible difference in sound was noted when the wind plant was shutdown versus when it was in operation.

Figure 13 shows sound level spectra obtained by approximately doubling the distance between the instruments and the transformer (i.e., Locations 12, 13, and 14). In the east and south directions, the sound levels fell off markedly with geographic separation from the transformer. The fact that the northwest direction did not fall off as significantly is explained by the fact that this location was nearer and more exposed to road traffic on Amaranth 10th Line.

Several Fast Fourier Transform (“FFT”) measurements were conducted at Location 9, approximately 40 metres from the transformer. These measurements are summarized on Figure 14, which illustrates the frequency makeup of the sound of the transformer in some detail. As expected, the sound is tonal and set by peaks at 120, 240, and 360 Hz, with other harmonics present. These three peaks are contained within the 125, 250, and 400 Hz 1/3 octave bands shown in Figure 9.

Attended Acoustic Measurements – Residences

Attended measurements were also conducted at each of the residences and the results are summarized in Table 3. These are short-duration measurements, generally one minute long, taken at moments when the influence of extraneous noise (e.g., wind noise, dogs, birds, farm animals, speech, cars and aircraft) was low.

Canadian Hydro Developers, Inc., Page 12 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008

Table 3: Summary of Attended Measurements at Receptors

Location Date and Time LEQ [dBA]

L90 [dBA] Comments

33 31 TS inaudible, distant snowblower, Feb 13, 2008 14:40 31 29 Dog barking, distant tractor

dominant. 32 31 Transformer hum faintly audible, 32 31 Minimal local activity.

R01 Feb 14, 2008

00:20 30 29

30 26 Distant aircraft, TS inaudible, Feb 13, 2008 14:30 34 24 Distant Traffic.

30 29 TS inaudible 29 29

R02 Feb 14, 2008

00:45 32 30 29 26 TS inaudible, distant traffic. Feb 13, 2008

15:05 31 29 R04 Feb 14, 2008

00:00 TS inaudible, data accidentally erased.

As shown in Table 3, the measured LEQ sound levels at the three receptors was in the range of 29 to 34 dBA, with the L90 sound levels ranging from 24 to 31 dBA. The measured LEQ sound levels represent the aggregate sound level due to all sound sources in the area including sound from distant vehicles, farm animals, distant and local dogs, birds, talking, and wind-induced noises. As the measurements include the effect of these intermittent and extraneous sound sources, the measured L90 represents a better estimate of the steady sounds, including the noise from the TS.

As Table 3 indicates, the TS noise was noted as being audible during only one of the measurements, and inaudible at others. It is noted that when the TS was not audible, it is not contributing to any meaningful degree to the measured LEQ sound levels, and thus the contribution of the TS by itself was well below the measured 29 to 34 dBA LEQ sound levels.

In an attempt to further quantify the contribution of the TS at the residences, a series of FFT measurements were made at each location during the night-time, when the transformer hum was audible. These are summarized in Figure 15. As shown on the Figure, the tones from the transformer could not be measured by the instrument during the measurement period, implying that any such tones were below the noise floor of the equipment (i.e., less than about 10 to 20 dB).

Canadian Hydro Developers, Inc., Page 13 Winter 2008 Acoustic Audit, Amaranth Transformer Station April 22, 2008 Summary and Conclusions

Similar to the conclusions reached in the autumn 2007 acoustic audit, the following conclusions are reached based upon the measurements conducted for the winter 2008 acoustic audit:

1) The measurements show no particular correlation between the sound levels at the residences and the sound levels near the transformer. It is noted that the sound levels at the residences is at times less than 30 dBA during periods when the TS is operating and producing noise. The sound at the residences correlated more closely with wind speed rather than the TS. These facts indicate that the contribution of the TS was in compliance with the applicable MOE sound level limits during the measurement period.

2) In contrast to the measurement results obtained during the autumn of 2007, there were no periods when the sound levels on the switch side of the acoustic barrier wall were unexplainably high. There were two occasions where activity by Hydro One likely affected the measured sound levels, but such activities did not occur during the autumn measurements. As mentioned in the autumn 2007 audit, the unexplained sound levels measured could have been attributable to the wind, insects, birds in the nearby trees, and/or corona noise. Further investigation of this phenomenon will be made during the spring 2008 measurements to determine if the autumn 2007 results were not as a result of the transformer.

Photo Plate 1: Part of the TS, showing acoustical barrier, Looking East

Photo Plate 2: Monitoring Locations 1 and 3, Transformer Side of Acoustic Barrier

Location 3

Location 1

Photo Plate 3: Monitoring Locations 4 and 11, Switch Side of Acoustic Barrier

Location 4

Location 11

Figure 2: Overall LEQ Sound Level Data Collected Automatically within the Amaranth Transformer Station, February 2008, Plotted Against the Background (L90) Sound Levels

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Figure 4: Overall LEQ Sound Level Data Collected Automatically at the Amaranth Transformer Station, With Electrical Power Data, February 2008

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-10

0

10

20

30

40

50

60

70

Win

d Fa

rm P

ower

Pro

duct

ion

[MW

]

Location 4 (Switch Side) Location 11 (Berm) Location 1 (Transformer Side) Location 3 (Transformer Side)Power Data from IESO Power Data from Can Hydro Poor Weather

Figure 5: Summary of Overall LEQ Sound Level Data Collected Automatically Within the Amaranth Transformer Station,

Plotted Against Meterological Data, February 2008

20

30

40

50

60

70

80

90

100

Thu,

Feb

07,

12:

00

Fri,

Feb

08, 1

2:00

Sat,

Feb

09, 1

2:00

Sun,

Feb

10,

12:

00

Mon

, Feb

11,

12:

00

Tue,

Feb

12,

12:

00

Wed

, Feb

13,

12:

00

Thu,

Feb

14,

12:

00

Fri,

Feb

15, 1

2:00

Sat,

Feb

16, 1

2:00

Sun,

Feb

17,

12:

00

Mon

, Feb

18,

12:

00

Tue,

Feb

19,

12:

00

Wed

, Feb

20,

12:

00

Ove

rall

A-W

eigh

ted

Soun

d Pr

essu

re L

evel

[dB

A],

Hum

idity

[%]

-20

-16

-12

-8

-4

0

4

8

12

16

20

24

28

32

Tem

pera

ture

[C],

Gro

und

Leve

l Win

d Sp

eed

[m/s

]

Location 11 (Berm) Location 4 (Switch Side) Location 3 (Transformer Side) Location 1 (Transformer Side)Humidity Precipitation Temperature Wind DirectionWind Speed Poor Weather

Figure 6a: Summary of Overall LEQ Sound Level Data Collected Automatically at the Residences, February 2008

20

30

40

50

60

70

80

Thu,

Feb

07,

12:

00

Fri,

Feb

08, 1

2:00

Sat,

Feb

09, 1

2:00

Sun,

Feb

10,

12:

00

Mon

, Feb

11,

12:

00

Tue,

Feb

12,

12:

00

Wed

, Feb

13,

12:

00

Thu,

Feb

14,

12:

00

Fri,

Feb

15, 1

2:00

Sat,

Feb

16, 1

2:00

Sun,

Feb

17,

12:

00

Mon

, Feb

18,

12:

00

Tue,

Feb

19,

12:

00

Wed

, Feb

20,

12:

00

Ove

rall

A-W

eigh

ted

Soun

d Pr

essu

re L

evel

[dB

A]

Location 5 (R1) Location 6 (R2) Location 7 (R4) Poor Weather

Figure 6b: Summary of Overall L90 Sound Level Data Collected Automatically at the Residences, February 2008

20

30

40

50

60

70

80

Thu,

Feb

07,

12:

00

Fri,

Feb

08, 1

2:00

Sat,

Feb

09, 1

2:00

Sun,

Feb

10,

12:

00

Mon

, Feb

11,

12:

00

Tue,

Feb

12,

12:

00

Wed

, Feb

13,

12:

00

Thu,

Feb

14,

12:

00

Fri,

Feb

15, 1

2:00

Sat,

Feb

16, 1

2:00

Sun,

Feb

17,

12:

00

Mon

, Feb

18,

12:

00

Tue,

Feb

19,

12:

00

Wed

, Feb

20,

12:

00

Ove

rall

A-W

eigh

ted

Soun

d Pr

essu

re L

evel

[dB

A]

Location 5 (R1) Location 6 (R2) Location 7 (R4) Poor Weather

Figure 7: Summary of LEQ Sound Level Data Collected Automatically at the Residences, With LEQ Sound Level Data at the Amaranth Transformer Station, February 2008

Overall sound levels include the effect of all sound sources including wind, vehicles, etc.

20

30

40

50

60

70

80

Thu,

Feb

07,

12:

00

Fri,

Feb

08, 1

2:00

Sat,

Feb

09, 1

2:00

Sun,

Feb

10,

12:

00

Mon

, Feb

11,

12:

00

Tue,

Feb

12,

12:

00

Wed

, Feb

13,

12:

00

Thu,

Feb

14,

12:

00

Fri,

Feb

15, 1

2:00

Sat,

Feb

16, 1

2:00

Sun,

Feb

17,

12:

00

Mon

, Feb

18,

12:

00

Tue,

Feb

19,

12:

00

Wed

, Feb

20,

12:

00

Ove

rall

A-W

eigh

ted

Soun

d Pr

essu

re L

evel

[dB

A]

Location 5 (R1) Location 6 (R2) Location 7 (R4)Location 4 (Switch Side) Location 1 (Transformer Side) Poor Weather

Figure 8: Summary of Overall LEQ Sound Level Data Collected Automatically at the Residences, With Meterological Data, February 2008

Overall sound levels include the effect of all sound sources including wind, vehicles, animals, etc.

20

30

40

50

60

70

80

90

100

Thu,

Feb

07,

12:

00

Fri,

Feb

08, 1

2:00

Sat,

Feb

09, 1

2:00

Sun,

Feb

10,

12:

00

Mon

, Feb

11,

12:

00

Tue,

Feb

12,

12:

00

Wed

, Feb

13,

12:

00

Thu,

Feb

14,

12:

00

Fri,

Feb

15, 1

2:00

Sat,

Feb

16, 1

2:00

Sun,

Feb

17,

12:

00

Mon

, Feb

18,

12:

00

Tue,

Feb

19,

12:

00

Wed

, Feb

20,

12:

00

Ove

rall

A-W

eigh

ted

Soun

d Pr

essu

re L

evel

[dB

A],

Hum

idity

[%]

-20

-16

-12

-8

-4

0

4

8

12

16

20

24

28

32

Tem

pera

ture

[C],

Gro

und

Leve

l Win

d Sp

eed

[m/s

]

Location 5 (R1) Location 6 (R2) Location 7 (R4) HumidityPrecipitation Temperature Wind Speed Poor Weather

Figure 9. Attended A-Weighted LEQ Sound Level Spectra Measured 30 to 40 metres from Transformer

Measurements Conducted February 13, 2008Wind Farm Producing Electricity

10

20

30

40

50

60

70

80

2531

.5 40 50 63 80 100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

6300

8000

1000

012

500

1600

020

000

dBA

1/3 Octave Band Centre Frequency [Hz]

Soun

d Pr

essu

re L

evel

[dB

A]

Location 9 Location 8 Location 10

Figure 10: A-Weighted Time Signals - 400 Hz 1/3 Octave Band,Measurements Conducted 30 to 40 metres from Transformer, February 13, 2008

Wind Farm Producing ElectricityFluctuations in Sound Level due to Microphone Movement

10

20

30

40

50

60

70

80

1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298

Time [s]

Soun

d Pr

essu

re L

evel

[dB

]

Location 9 Location 8 Location 10

Figure 11. Attended A-Weighted LEQ Sound Level Spectra Measured 30 to 40 metres from Transformer

Measurements Conducted February 13, 2008Wind Farm Not Producing Electricity

10

20

30

40

50

60

70

80

2531

.5 40 50 63 80 100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

6300

8000

1000

012

500

1600

020

000

dBA

1/3 Octave Band Centre Frequency [Hz]

Soun

d Pr

essu

re L

evel

[dB

A]

Location 9 Location 8 Location 10

Figure 12: A-Weighted Time Signals - 400 Hz 1/3 Octave Band,Measurements Conducted 30 to 40 metres from Transformer, February 13, 2008

Wind Farm Not Producing ElectricityFluctuations in Sound Level due to Microphone Movement

10

20

30

40

50

60

70

80

1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298

Time [s]

Soun

d Pr

essu

re L

evel

[dB

]

Location 9 Location 8 Location 10

Figure 13. Attended A-Weighted LEQ Sound Level Spectra Measured 70 to 80 metres from Transformer

Measurements Conducted February 13, 2008Fluctuations in Sound Level due to Microphone Movement

10

20

30

40

50

60

70

80

2531

.5 40 50 63 80 100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

6300

8000

1000

012

500

1600

020

000

dBA

1/3 Octave Band Centre Frequency [Hz]

Soun

d Pr

essu

re L

evel

[dB

A]

80 m East of Transformer 70 m South of Transformer 70 m North of Transformer

Figure 14: Discrete Frequency (FFT) Sound Spectra Measured at Location 9,Measurements Conducted February 13, 2008

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500

Frequency [Hz]

Soun

d Pr

essu

re L

evel

[dB

]

48 dB, 360 Hz

Figure 15: Discrete Frequency (FFT) Sound Spectra Measured at Location 9 and At Residences

Measurements Conducted February 13, 2008

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500

Frequency [Hz]

Soun

d Pr

essu

re L

evel

[dB

]

Location 9 (TS) Location 5 (R01) Location 7 (R04) Location 6 (R02)