Airborne Noise Measurement Study

Airborne Noise Measurement Study for DRven

Corporations Proposed Ladd Marine Coal Terminal

Prepared for

DRven Corporation 711 H Street, Suite 350 Anchorage, AK 99501

Version 1

May 29, 2007

Airborne Noise Measurement Study for DRven Corporations Proposed Ladd Marine Coal Terminal

Prepared by

Christopher Whitt, Alex MacGillivray, David Hannay and Holly Sneddon

2101 4464 Markham Street

Victoria, British Columbia, Canada V8Z 7X8

Prepared for

DRven Corporation 711 H Street, Suite 350 Anchorage, AK 99501

Version 1.0

May 29, 2007

Release Version #

Date Author/Editor Comment

1 May 29, 2007 Holly Sneddon Final release version to be sent to M Link.

Suggested format for citation: Whitt, C., A. MacGillivray, D. Hannay and H. Sneddon. 2007. Airborne Noise Measurement Study for DRven Corporations Proposed Ladd Marine Coal Terminal. Unpublished report prepared by JASCO Research, Ltd. for DRven Corporation, Anchorage, AK, 40 p.

Airborne Noise Study Westshore Terminal & Ladd Proposed Terminal

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Table of Contents Table of Contents............................................................................................................ 1 List of Tables .................................................................................................................. 2 List of Figures................................................................................................................. 3 1 Introduction............................................................................................................. 5 2 Noise Measurements at the WestShore Coal Terminal, Roberts Bank, British Columbia, September 2006 ............................................................................................. 6

2.1 General............................................................................................................ 6 2.2 Study Location ................................................................................................ 6 2.3 Methods........................................................................................................... 9

2.3.1 Measurement Apparatus........................................................................... 9 2.3.2 Source Level Measurements................................................................... 10 2.3.3 Data Analysis......................................................................................... 10

2.4 Results........................................................................................................... 11 2.4.1 Long Range Coal Loading Noise ........................................................... 11 2.4.2 Conveyor Drive System Noise ............................................................... 14 2.4.3 Coal Car Dumping Noise ....................................................................... 16 2.4.4 Stacker Reclaimer Noise ........................................................................ 19 2.4.5 Summary of Measurements.................................................................... 22

3 In-Air Noise Measurements at the Proposed Ladd Terminal Location, Upper Cook Inlet, Alaska, October 2006........................................................................................... 24

3.1 General.......................................................................................................... 24 3.2 Study Locations............................................................................................. 24

3.2.1 Beluga Airstrip ...................................................................................... 26 3.2.2 Freemans Barge.................................................................................... 26 3.2.3 Ladd Landing Beach .............................................................................. 27 3.2.4 Ladd Landing Bluff................................................................................ 27

3.3 Methods......................................................................................................... 28 3.3.1 Measurement Apparatus......................................................................... 28 3.3.2 Data Analysis......................................................................................... 28

3.4 Results........................................................................................................... 28 3.4.1 Beluga Airstrip ...................................................................................... 28 3.4.2 Freemans Barge Launch ....................................................................... 31 3.4.3 Ladd Landing Beach .............................................................................. 33 3.4.4 Ladd Landing Bluff................................................................................ 35

3.5 Summary ....................................................................................................... 37 4 Discussion of Results ............................................................................................ 38 5 Literature Cited ..................................................................................................... 39 Appendix A Tables of 1/3 Octave Band Source Levels .............................................. 40


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List of Tables Table 1: Summary of flat-weighted and A-weighted source levels measured at Westshore Terminal coal yard. ....................................................................................................... 23 Table 2: Latitude and longitude of Ladd area in-air measurement study locations.......... 26 Table 3: Flat-weighed and A-weighted LN percentile level statistics for the Beluga airstrip ambient noise measurements. ........................................................................................ 31 Table 4: Flat-weighed and A-weighted LN percentile level statistics for the Freemans barge launch ambient noise measurements. ................................................................... 33 Table 5: Flat-weighed and A-weighted LN percentile level statistics for the Ladd Landing beach ambient noise measurements. .............................................................................. 35 Table 6: Flat-weighed and A-weighted LN percentile level statistics for the Ladd Landing bluff ambient noise measurements................................................................................. 37 Table 7: Summary of L10, L50, and L90 percentile ambient noise levels for all four measurement sites. ........................................................................................................ 38


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List of Figures Figure 1: Aerial photographs of Westshore marine coal terminal in Delta, BC, Canada. a) Overview of Westshore, Deltaport and Tsawwassen Ferry Terminal, b) Close-up of Westshore terminal note Berth 1 and 2 and stacker reclaimers (3). ............................... 7 Figure 2: Photographs of the equipment for which in-air measurements were taken at Westshore terminal on September 16, 2006..................................................................... 8 Figure 3: Acoustic monitoring equipment: Larson Davis Sound Level Meter with Marantz PMD690 digital recorder, laser rangefinder and GPS....................................... 10 Figure 4: Diagram showing the work boat GPS track during the acoustic measurements of coal loading aboard the bulk carrier Pierre LD.......................................................... 13 Figure 5: Flat-weighted and A-weighted sound pressure level versus range from the coal loading operation. ......................................................................................................... 13 Figure 6: Estimated 1/3-octave band source levels for the coal loading operation .......... 14 Figure 7: Broadband sound pressure levels and time-frequency spectrogram of the loading operation at 150-200 meters distance. ............................................................... 14 Figure 8: Broadband sound pressure levels and spectrogram plots of the conveyor drive system measured at 16 meters distance.......................................................................... 16 Figure 9: Estimated 1/3 octave band source levels for the conveyor drive system. ......... 16 Figure 10: Broadband sound pressure level and spectrogram plots for the coal car dumping operation. ....................................................................................................... 18 Figure 11: Back-propagated 1/3-octave band source levels of coal car dumping, averaged over the entire 3:45 minute coal dumping cycle............................................................. 18 Figure 12: Back-propagated1/3-octave band source levels for the loudest 30 seconds of the coal car dumping operation...................................................................................... 19 Figure 13: Broadband sound pressure level and spectrogram plots while the stacker reclaimer was stacking coal........................................................................................... 20 Figure 14: Back-propagated 1/3-octave band source levels for the stacker reclaimer during coal stacking. ..................................................................................................... 21 Figure 15: Broadband sound pressure level and spectrogram plots recorded while the stacker reclaimer was moving. ...................................................................................... 21 Figure 16: Back-propagated 1/3-octave band source levels for the moving stacker reclaimer. ...................................................................................................................... 22 Figure 17: Map of the Tyonek area showing the location of the ambient noise measurement sites near the proposed Ladd coal terminal. The position of a nearby oil platform (Phillips-A) is also indicated. .......................................................................... 25 Figure 18: View offshore from Freemans barge launch. Note the offshore platform in the upper left of the photo. .................................................................................................. 26 Figure 19: Photograph of Ladd landing beach measurement location. Note the offshore platform (right). ............................................................................................................ 27 Figure 20: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at the Beluga Airstrip measurement site.... 30 Figure 21: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Beluga Airstrip measurement site. .............................................. 30 Figure 22: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at Freemans barge launch. ....................... 32


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Figure 23: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Freemans barge launch measurement site. ................................. 32 Figure 24: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at the Ladd Landing beach measurement site. ............................................................................................................................... 34 Figure 25: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Ladd Landing beach measurement site........................................ 34 Figure 26: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at the Ladd Landing bluff measurement site...................................................................................................................................... 36 Figure 27: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Ladd Landing bluff measurement site. ........................................ 36


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1 Introduction Development of a marine coal terminal by DRven Corporation at Ladd in Upper

Cook Inlet would introduce new industrial activity into the area that would generate airborne noise. Ladd is approximately 2.5 km (1.5 mi) north of the Village of Tyonek on the west side of Upper Cook Inlet, Alaska. The proposed terminal would include an over water pile-supported trestle to carry conveyor systems that transport coal from the onshore coal yard to the vessel berths, approximately 3 km (2 miles) offshore. The primary sources of airborne noise will be large machinery operating in the coal yard and the conveyor system that extends from the coal yard to the offshore berth. The large coal carrier vessels generate relatively low levels of airborne noise during loading. Their noise emission levels while moored at berth should be similar to noise produced by other large vessel traffic already transiting in Upper Cook Inlet.


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2 Noise Measurements at the WestShore Coal Terminal, Roberts Bank, British Columbia, September 2006

2.1 General The purposes of the study outlined in this report were to quantify acoustic source

levels of machinery that would be used at the terminal, and to determine the noise levels at distance produced by overall operations of the coal yard and conveyor systems. To satisfy this requirement, JASCO Research Ltd made airborne sound level measurements at a similar marine terminal, the Westshore marine coal terminal, located in Delta, British Columbia, Canada. The measurements were performed on 15 and 16 September 2006 and comprised both source level measurements on individual pieces of equipment and longer range noise level measurements from distances between 100 m and 900 m from the Southern Westshore terminal Berth 1. The longer range measurements were made over water from a small boat as it drifted away from this loading berth.

The source level measurements were performed 16 September 2007 within 20 m of each piece of equipment monitored. These measurements included a coal rail car dumping station, a stacker-reclaimer and a conveyor drive. The dumping station and conveyor drive were measured at 16 meters distance. The stacker reclaimer was moving on its tracks during the measurement; the closest distance being 21 meters.

2.2 Study Location The Westshore marine coal terminal is located on an artificial island off Delta,

British Columbia, Canada, approximately 35 km south of Vancouvers inner harbor. The island is shared by the Westshore coal terminal, situated on the southwest section (shown in Figure 1), and the TSI Deltaport container shipping terminal, situated to the northeast. The terminal is connected to the mainland by a 4 km long constructed causeway with roadway and railway access. British Columbias Tsawwassen ferry terminal is located 1.75 km south and east of the Westshore terminal. The marine area between the island and the ferry terminal is used by ferries, fishing and private vessels, tug boats and large container and coal carrier vessels.


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Figure 1: Aerial photographs of Westshore marine coal terminal in Delta, BC, Canada. a) Overview of Westshore, Deltaport and Tsawwassen Ferry Terminal, b) Close-up of Westshore terminal note Berth 1 and 2 and stacker reclaimers (3).

All of the coal that Westshore handles arrives by train via two rail loops. Each day on average, six unit coal trains up to 125 cars long arrive on the island and are unloaded within two to four hours within the enclosed dumper sheds (Figure 2a) located near the southwest corner of the coal stockpile yard. Three pieces of equipment called stacker reclaimers (Figure 2c & d), service the stockpile area by moving up and down the site to add or remove coal from the storage piles. A series of high capacity, high volume conveyors joined by conveyor drives (Figure 2b) are then used to transfer the coal to one of Westshores two shipping berths. The conveyor drives transfer coal from one conveyor belt to another and drive each conveyor. Other equipment that would contribute to the overall noise output of the Westshore coal terminal include bulldozers, loaders, cranes and water trucks. (Westshore Terminals Ltd.)

Berth 1

Berth 2


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a) Photograph of Coal Car Dumping Station

b) Photograph of Conveyor Hopper

c) Photograph of Stacker Reclaimer Base

d) Photograph of Stacker Reclaimer

Figure 2: Photographs of the equipment for which in-air measurements were taken at Westshore terminal on September 16, 2006

Westshore terminal uses two berths (see Figure 1) to load coal carrier vessels. the carrier vessels Pierre LD and Hanjin Richards Bay were being loaded throughout the time period of this study. Berth 1, located at the end of a 600 meter pile-supported trestle off the south corner of the yard, uses a single rail-mounted Krupp shiploader capable of 7,000 tonnes per hour. Berth 2, situated to the east, adjacent to the coal pile yard uses Twin quadrant shiploaders capable of a combined loading rate of 7,000 tonnes per hour. The conveyors transport the coal from the stockpile yard to the vessels where it is loaded directly into the carrier holds.


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The noise measurements made for the present study were made off the south berth (Berth 1), as well as near the coal car dumping station, the main conveyor drive, and a stacker-reclaimer machine. Berth 1 is most closely representative of the proposed Ladd terminal berth in terms of water depth and its pile-supported conveyor belt system.

2.3 Methods

2.3.1 Measurement Apparatus The field study was performed to measure noise emission levels of the equipment

associated with the Westshore Coal terminals activities. Sound level measurements were made using a Larson Davis System 824 Type-1 Logging Sound Level Meter (SLM) that monitored and logged Flat-weighted and A-weighted sound levels on the slow time integration (1-second) setting. At the same time, digital recordings of broadband flat-weighted acoustic pressure were made on a Marantz PMD690 digital recorder at 48kHz sample rate with 16-bit samples. Refer to Figure 3 for a photograph of the recording system and associated equipment. A Larson Davis CAL200 calibrator was used in the field to perform calibrations of both the SLM and digital recorder before and after each measurement. A laser range finder and GPS were used to determine the distance between the recording system and the equipment measured. Timing of calibrations and noise source events, such as coal car dumps, were logged throughout each measurement.


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Figure 3: Acoustic monitoring equipment: Larson Davis Sound Level Meter with Marantz PMD690 digital recorder, laser rangefinder and GPS.

2.3.2 Source Level Measurements Source level measurements were made on the coal rail car dumper, the stacker-

reclaimer, and a conveyor hopper-drive system. These measurements were made at distances less than 30 m from the respective equipment. For each measurement the sound measurement equipment was set up with the microphone of the sound level meter facing the equipment, and placed at a height of 1.5 m (5 feet). The digital recorder was started and the CAL200 calibrator placed over the microphone for 30 seconds. The calibrator was removed while operations of the equipment were monitored. A continuous written log of the environment was kept during the recording to log non-related noise sources such as passing vehicle traffic and to accurately note the time of events such as the actual dumping of a coal car. The calibrator was placed over the microphone again during the last 30 seconds of each recording. Calibrator signals were processed for each measurement to ensure system gain changes were properly accounted for in each measurement.

2.3.3 Data Analysis Digital waveform recordings were analyzed using custom data processing

software written in IDL programming language. For each recording, the data processing


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routines computed the following sound level metrics versus time inside a sliding 1-second analysis window:

1. Broadband sound pressure level (SPL)

2. A-weighted sound pressure level

3. 1/3-octave band pressure levels (BPLs)

4. Spectrum levels in 1 Hz frequency bins

Broadband SPL was computed from the rms sound pressure level inside each 1-second analysis window. Spectrum levels from 1 Hz to 24 kHz, in 1 Hz frequency bins, were computed from the FFT (Fast Fourier Transform) of each analysis window. A-weighted sound pressure levels were computed by integrating spectral levels using a standard A-weighting filter network. 1/3-octave band pressure levels were computed by integrating spectral levels inside standard 1/3-octave bands. Sound pressure levels, band pressure levels and spectral levels were computed from the start to the end of each recording on a 100 msec time base (the overlap of consecutive analysis windows was 90%). Absolute sound levels in the recordings were calibrated using a 94 dB, 1 kHz calibration tone at the beginning of each recording. Source levels were computed by back-propagating sound pressure levels and band pressure levels to a reference distance of 1 meter assuming spherical (i.e., 20 log10 r) spreading.

2.4 Results

2.4.1 Long Range Coal Loading Noise Long range coal loading noise measurements were obtained at Westshore terminal

Berth 1 during loading of the forward hatches (numbers 1 and 2) of the bulk carrier, Pierre LD. Noise levels were recorded at ranges from 150 meters to 900 meters from the bulk carrier aboard a small work boat drifting downwind from the pier in a south easterly direction; the GPS drift track of the recording vessel is shown in Figure 4. The primary noise source in this recording was identified to be a conveyor drive located near the bow of the bulk carrier. However, at longer ranges, noise from other sources at the coal terminal likely contributed to the overall measured noise levels. Approximately 36 minutes of sound recordings were obtained during the drift measurements.


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Figure 5 shows flat-weighted and A-weighted SPLs for the recording period, plotted versus range from the conveyor drive. This plot illustrates how noise levels diminished with distance from the loading operation. Flat weighted levels shown in Figure 5 were dominated by low-frequency wind noise concentrated below 20 Hz whereas A-weighted levels were almost entirely due to noise from the loading operation. Note that the spike in the A-weighted levels between 750m and 800m was caused by wave noise on the work boat hull from the wake of a passing ferry.

To estimate the source level of the coal loading operation, A-weighted and 1/3-octave band sound levels measured at close range (< 300 meters) were back-propagated to the source assuming spherical (20 log10 r) spreading. Sound refraction due to wind and temperature gradients can generally be neglected at short distances and so spherical spreading was most appropriate for back-propagation at these distances. The A-weighted back-propagated source level of the loading operation was estimated to be 114.7 dB(A) re 20 Pa @ 1-m. The flat-weighted back-propagated source level of the loading operation filtered above 22 Hz was estimated to be 121.7 dB(F) re 20 Pa @ 1-m. Figure 6 shows 1/3-octave band source levels for the coal loading operation; the dominant 1/3-octave bands from the coal loading were observed to be between 20-60 Hz and 250-630 Hz and band levels dropped off rapidly above 1 kHz. Note that bands below 20 Hz in Figure 6 were dominated by wind noise. Figure 7 shows a time-spectrogram for an 80 second section of recording taken at 150-200 meters distance from the loading operation. The strongest tones identified in the recordings were at 235 Hz, 360 Hz and 470 Hz, with weaker tones identified at 1600 Hz and 2100 Hz.

At long range, A-weighted levels diminished with distance approximately according to a 15 log10 r curve, as shown in the Figure 5 trendline. The long range sound decay was weaker than spherical (20 log10 r) spreading for the following two reasons:

1. The long-range noise measurements were taken in the downwind direction. Noise levels measured downwind are usually higher than those measured upwind because sound rays emanating from the source are refracted back down towards the ground in the downwind direction.

2. At ranges beyond approximately 300 meters from the loading pier, noise from other sources at the coal terminal also contributed to measured noise levels. This is because the distance to the loading pier and the distance to other sources at the coal terminal were comparable at measurement ranges greater than 300 meters.


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Figure 4: Diagram showing the work boat GPS track during the acoustic measurements of coal loading aboard the bulk carrier Pierre LD.

Figure 5: Flat-weighted and A-weighted sound pressure level versus range from the coal loading operation.


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Figure 6: Estimated 1/3-octave band source levels for the coal loading operation

Figure 7: Broadband sound pressure levels and time-frequency spectrogram of the loading operation at 150-200 meters distance.

2.4.2 Conveyor Drive System Noise Noise measurements from a conveyor drive system at the coal yard were recorded

at 16 meters range on 16 September. A total of 5.5 minutes of acoustic data were obtained from the conveyor drive system. A two minute section of the recording was selected for analysis that was free of interfering noise from passing vehicles. Note that the conveyor drive from this measurement was different than the pier conveyor drive


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measured in the previous section. Figure 8 shows a plot of flat-weighted and A-weighted SPLs and spectral levels from the conveyor drive measurements. Noise from the conveyor drive was quite steady with no significant transients. Spectral levels from the conveyor drive system were observed to be loudest around 30 Hz, with two additional strong tones at 1600 Hz and 1800 Hz. Many weaker tonal components were observed in the data: one particularly interesting group of tones was observed between 630 Hz and 750 at evenly spaced 30 Hz increments. The conveyor is driven by three identical Toshiba 600 hp, 4160 VAC motors. The specified speed of the motors is 1785 rpm, or 29.75 revolutions per second, which closely corresponds to the large amount of noise energy at 30 Hz.

Source levels for the conveyor drive were estimated by back-propagating sound levels measured at 16 meters range using spherical spreading. The estimated flat-weighted and A-weighted source levels for the conveyor drive were 111.2 dB(F) or 107.2 dB(A) re 20 Pa @ 1-m, respectively. Figure 9 shows 1/3-octave band source levels for the conveyor loader, which were estimated by back-propagating measured 1/3-octave band levels, averaged over the two minute recording period. An occasional high pitched tone was observed from the drive system at 3.7 kHz. When this tone was present, sound levels in the 4 kHz band increased from 60.3 dB to 77.9 dB. Flat-weighted and A-weighted source levels for the conveyor drive increased to 111.8 dB(F) or 108.6 dB(A) respectively while the 3.7 Hz tone was present.


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Figure 8: Broadband sound pressure levels and spectrogram plots of the conveyor drive system measured at 16 meters distance.

Figure 9: Estimated 1/3 octave band source levels for the conveyor drive system.

2.4.3 Coal Car Dumping Noise Noise levels from the coal car dumping station were measured at 8 meters range

on 16 September. A total of 7 minutes of acoustic data were obtained from the coal dumping operation. A 3.75 minute section of the recording was selected for analysis that


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had the least extraneous noise from passing vehicles and other unrelated sources. The analysis period corresponded to one complete cycle of a train car entering the shed, being dumped, and leaving the shed. Figure 10 shows flat-weighted levels, A-weighted levels and spectral levels for the analysis period. The spectral data show that the strongest tones in the coal car dumping noise were observed at 16 Hz and 32 Hz. The increased noise levels from 230 s to 270 s in Figure 10 correspond to the period when coal was being dumped from the car. Figure 10 shows that the flat-weighted SPL was dominated by energy from 10-100 Hz, whereas the A-weighted SPL was dominated by energy between 100-1000 Hz.

Figure 11 shows 1/3 octave band source levels, averaged over the entire 3.75 minute coal car dumping cycle. Coal dumping source levels were estimated by back-propagating sound levels measured at 8 meters range using spherical spreading. Figure 11 clearly shows that the dominant bands from the coal car dumping cycle were at 16 Hz and 35 Hz. The flat-weighted and A-weighted source levels averaged over the entire 3.75 minute dumping cycle were estimated to be 118.3 dB(F) and 103.5 dB(A) re 20 Pa @ 1m, respectively. Figure 12 shows the back-propagated 1/3 octave band source levels for the loudest 30 seconds of the dumping operation, corresponding to when coal was being dumped from the car. Most bands below 500 Hz increased by 3-5 dB during the coal dumping compared to the rest of the cycle. The broadband flat weighted and A-weighted SPLs for the loudest section of the coal dumping were 119.5 dB(F) and 105.9 dB(A) re 20 Pa @ 1m, respectively.


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Figure 10: Broadband sound pressure level and spectrogram plots for the coal car dumping operation.

Figure 11: Back-propagated 1/3-octave band source levels of coal car dumping, averaged over the entire 3.75 minute coal dumping cycle.


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Figure 12: Back-propagated1/3-octave band source levels for the loudest 30 seconds of the coal car dumping operation.

2.4.4 Stacker Reclaimer Noise Approximately 8 minutes of acoustic recordings were obtained from the stacker

reclaimer on 16 November. These acoustic recordings included periods when the stacker was actively servicing the stockpile and periods when it transited to a new position in the stockpile area. The stacker reclaimers noise emissions were substantially different while it was servicing the stockpile and while it was in transit. Noise emissions from the stacker while servicing the stockpile were concentrated below 1 kHz and were primarily from the stackers engines and rollers on the stackers boom. When it was moving to a different part of the stockpile, the stacker reclaimers engines were idling and so its noise emissions below 1 kHz were substantially reduced. Noise emissions from the transiting stacker reclaimer were dominated by a loud warning buzzer concentrated at 2.7 kHz. However, noise from the buzzer was only intermittent since the stacker moved only occasionally during its operations.

Figure 13 shows flat-weighted levels, A-weighted levels and spectral levels for a 1 minute section of recording when the stacker was actively stacking coal. The spectral data show that noise from the coal stacking contained several strong, low-frequency tones below 100 Hz, with the loudest tonal component of the noise observed at 26 Hz. Figure 14 shows 1/3-octave band source levels for the stacker reclaimer that were estimated by back-propagating levels measured at 30 meters range using spherical spreading. Figure 14 shows that, while stacking coal, noise levels from the stacker reclaimer were loudest between 20 Hz and 630 Hz. Broadband flat-weighted and A-weighted source levels for


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the stacker reclaimer were 113.5 dB(F) and 105.9 dB(A) re 20 Pa @ 1m, respectively, during coal stacking.

Figure 15 shows flat-weighted levels, A-weighted levels and spectral levels for a section of recording when the stacker reclaimer was moving along its track past the measurement location. The closest point of approach of the stacker reclaimer was at 270 seconds into the recording where the distance was measured to be 8 meters. The tone at 2.7 kHz in the spectrogram data corresponds to a warning buzzer which sounded while the stacker reclaimer was in motion. Figure 16 shows back-propagated 1/3-octave band source levels for the moving stacker reclaimer. The broadband flat weighted and A-weighted SPLs for the moving stacker reclaimer were 107.6 dB(F) and 107.1 dB(A) re 20 Pa @ 1m, respectively.

Figure 13: Broadband sound pressure level and spectrogram plots while the stacker reclaimer was stacking coal.


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Figure 14: Back-propagated 1/3-octave band source levels for the stacker reclaimer during coal stacking.

Figure 15: Broadband sound pressure level and spectrogram plots recorded while the stacker reclaimer was moving.


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Figure 16: Back-propagated 1/3-octave band source levels for the moving stacker reclaimer.

2.4.5 Summary of Measurements Table 1 presents a summary of the estimated flat-weighted and A-weighted source

levels from the various operations measured at Westshore terminal. Composite source levels of in-air noise for all operations at Westshore terminal were computed based on measurements made between 150 m and 900 m from berth 1 during loading of coal aboard the Pierre LD. Flat-weighted and A-weighted source levels from this operation, referred to as coal loading, were estimated at 121.7 dB(F) and 114.7 dB(A), respectively; 1/3-octave band levels from the coal loading showed that noise from this operation was concentrated at low to mid frequencies, from 20-60 Hz and from 250-630 Hz. Wind noise in these data prevented an accurate source level assessment at the lowest frequencies (below 20 Hz). The source levels of coal loading (being a composite noise source) were as expected greater than any of the individual sources measured at the coal terminal. The long-range measurements were taken in the downwind direction. Possible downward focusing of sound energy to the measurement location may have caused higher levels than would have been measured in a no-wind condition. This may have led to a slight overestimation of the true source level.

The A-weighted levels of the conveyor drive were the highest of the three individual sources measured at Westshore terminal, with an estimated source level of 107.2 dB(A). The noise from the conveyor drive was continuous and steady, and 1/3-octave band levels from the conveyor drive were fairly evenly distributed between 20 Hz and 2 kHz.


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The coal dumper was the second loudest A-weighted source but it was the loudest flat-weighted source. Loud tones in the coal dumper spectrum at 16 Hz and 32 Hz would be inaudible or barely perceptible to human beings and most animals. Thus, the A-weighted noise levels from the coal dumping were substantially lower than the flat-weighted levels from this source. Impulsive noise from the dumping station was only present when a coal car was being unloaded, as the coal bumped against the sides of the metal container car. The coal dumper measurements were made through a large doorway in the side of the dumping station. It is likely that sounds in other directions would be partly attenuated by the building. The door to this station faced the sea rather than toward shore and urban areas.

While the stacker reclaimer was servicing the stockpile, its noise emissions were comparable in loudness and frequency distribution to noise from the conveyor drive. However, the stacker occasionally moved to and fro to different between parts of the coal stockpile and during these periods its noise emissions below 1 kHz were substantially reduced. Instead, while it was transiting, the stacker briefly generated a loud warning tone at 2.7 kHz. Such high frequency noise is expected to attenuate much more rapidly with range than low frequency noise.

Table 1: Summary of flat-weighted and A-weighted source levels measured at Westshore Terminal coal yard.

Source Measurement

range (m) Flat-weighted SL

(dB(F) re 20 Pa@1m) A-weighted SL

(dB(A) re 20 Pa@1m) Coal loading

(composite source) 150 121.7 114.7 Conveyor drive 16 111.2 107.2

Coal dumping 8 118.3 103.5 Stacker reclaimer 30 113.5 105.9


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3 In-Air Noise Measurements at the Proposed Ladd Terminal Location, Upper Cook Inlet, Alaska, October 2006

3.1 General This chapter presents the results of an in-air ambient noise study conducted near

the site of the proposed marine coal terminal, in the Ladd area, north of the village of Tyonek in Upper Cook Inlet. The purpose of this study was to measure baseline ambient noise levels in the Ladd area to estimate the region surrounding the proposed coal terminal site that would be exposed to increased noise levels, and to determine whether any increase would have significant impacts on wildlife populations in this area.

One-hour ambient airborne noise recordings were taken at four different locations in the Ladd area on October 20th and 21st, 2006. The noise recordings were subsequently analyzed to determine ambient noise level statistics at each location, including mean A-weighted and flat-weighted sound pressure levels (SPLs), and the frequency distribution of the baseline noise conditions. The recordings were also examined to identify existing sources of noise, both transient and continuous, in the area.

3.2 Study Locations Ambient sound measurements were made at four locations near the proposed

Ladd terminal site: Beluga Airstrip, Freemans Barge Launch, Ladd Landing bluff and Ladd Landing beach. A list of the study areas locations is provided in Table 2 and an overview map is presented in Figure 17. The Ladd area is for the most part uninhabited, the closest settlement being Tyonek, Alaska, 2.5 km to the southwest. Features of the area include boreal forest, marsh habitats, mixed sand and gravel beaches and mudflats.


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Figure 17: Map of the Tyonek area showing the location of the ambient noise measurement sites near the proposed Ladd coal terminal. The position of a nearby oil platform is also indicated.


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Table 2: Latitude and longitude of Ladd area in-air measurement study locations.

Location Latitude Longitude Beluga Airstrip 6117'23"N 15104'24"W Freemans Barge Launch 6112'15"N 15108'90"W Ladd Landing Beach 6111'27"N 15109'66"W Ladd Landing Bluff 6111'27"N 15109'73"W

Figure 18: View offshore from Freemans barge launch. Note the offshore platform in the upper left of the photo.

3.2.1 Beluga Airstrip Beluga airstrip is located approximately 8 km to the north of Ladds Landing,

fairly close to the coastline in a boreal forest area, at 6117'23"N 15104'24"W. Measurements were taken on the evening of 21 October 2006. The measurements were made next to a small passenger waiting area at the airstrip. At the time of measurement the prevailing winds were from a bearing of 155 degrees at an average speed of 0.9 km/h.

3.2.2 Freemans Barge Freemans barge launch is a gravel boat launch approximately 1.1 km north of

Ladds Landing. An hour of measurement was done in the morning of 21 October 2006 at 6112'15"N 15108'90"W. There were small waves of approximately 30cm breaking on the shoreline, winds light to none, and clear skies. The tide was outgoing during the measurement period. There is an oil platform approximately 9 km ESE offshore from Freemans barge launch, at approximately 6107'62"N 15095'11"W. This platform is visible in Figure 18, and also in Figure 19 (right).


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3.2.3 Ladd Landing Beach Ladd Landing is a boat launch leading down to a beach located at 6111'27"N

15109'66"W, approximately 5 km north of the village of Tyonek. The landing has a gravel access road at the top of a bluff approximately 15m to 20m above the beach level. An access road parallel to the waterline slopes down to the beach. About an hour of measurement was done in the afternoon of 20 October 2006. The measurement location is shown in Figure 19. At the start of measurement the weather was sunny with a light breeze averaging 5.9 km/h from a bearing of 174 degrees. The winds diminished to 3.9 km/h during the measurement period. There were small waves approximately 10cm to 15 cm in height at the waterline. The waterline was 15m to 20m east of the measurement location at the start of the measurement and receded by approximately 5m over the measurement period as the tide was outgoing. The offshore platform visible from Freemans barge launch can also be seen from Ladd Landing beach (see Figure 19 right).

3.2.4 Ladd Landing Bluff An hour of measurement was done in the early evening of 2006 October 20 from

the gravel access road on the bluff overlooking the beach at Ladds Landing, at 6111'27"N 15109'73"W. At the time of the measurement the weather was very calm with wind averaging 0.4 km/h from a bearing of 186 degrees at the beginning of the measurement, and diminishing over the measurement period.

Figure 19: Photograph of Ladd landing beach measurement location. Note the offshore platform (right).


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3.3 Methods

3.3.1 Measurement Apparatus The measurement apparatus used to obtain the Ladd ambient noise recordings was

identical to the apparatus used for the Westshore coal terminal measurements (see Section 2.3.1).

3.3.2 Data Analysis The ambient noise recordings for the Ladd measurement sites were processed

according to the same methodology as the Westshore data (see Section 2.3.3) to obtain 1-second A-weighted and flat-weighted SPLs versus recording time. The processed SPL data were used to generate histograms of the ambient noise distribution at each measurement site; a SPL histogram bin width of 1 dB was used for this study. Cumulative percentiles from the histograms were used to generate LN percentile sound level statistics for each set of measurements. The LN percentile sound level is the SPL that is exceeded during N% of the total recording time. So, for example, if 60 dB SPL was exceeded 10% of the time during an acoustic recording then L10=60 dB. LN percentile levels for each measurement site were computed at 10%, 30%, 50%, 70%, and 90% intervals.

3.4 Results

3.4.1 Beluga Airstrip Figure 20 shows flat-weighted, A-weighted, decade-band SPLs and spectral

levels for approximately 1 hour of acoustic recording at the Beluga airstrip measurement site. At low frequencies less than 100 Hz, baseline ambient noise levels at this location were dominated by tonal and narrow-band noise, e.g., at 13 Hz, 24 Hz. This noise very likely originated at the offshore oil platform that was approximately 12 km (7.5 miles) south east and directly upwind of the airport. Continuous tonal background noise above 100 Hz was from a gas discharge lamp outside the passenger waiting area building, 5 meters (16 feet) from the recording site. Intermittent spikes in the broadband levels throughout the recording are due to vehicle traffic (mostly pickup trucks) traveling on a road close to the measurement site. Passing vehicles were observed to increase the flat and A-weighted broadband levels by up to 30 dBF and 15 dBA, respectively. Transient noise at the beginning of the recording period (19:21-12:24) was engine noise which may


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have originated from a passing helicopter (c.f., 9:35 in Figure 22), though the actual noise source was not identified in the logs. The temporary increase in both flat and A-weighted SPL from this source was about 10 dB. The descending tones at 19:55-19:59 were from a commercial airplane (most likely a turboprop) which passed by the measurement site at long range. The 20 dB spike in the A-weighted levels at 20:02-20:05 were from a commercial jet flying past the Beluga airstrip site.

Figure 21 shows histograms of flat-weighted (black) and A-weighted (red) background levels at the Beluga airstrip measurement site. These histograms show the time distribution of ambient noise levels for the entire 1 hour sound recording. The concentration of levels below 40 dBA in the A-weighted histogram shows that intermittent noise sources like passing vehicles represented only a small fraction of the total ambient noise, despite large temporary increases in the SPL in Figure 20. Table 3 shows the LN percentile levels computed from the histograms. A-weighted and flat-weighted L50 percentile levels for the Beluga airstrip site were 39.3 dBA and 58.3 dBF, respectively. Mean flat-weighted levels were almost 20 dB higher than mean A-weighted levels at the Beluga airstrip site which indicates that much of the continuous background noise was concentrated at very low frequencies below 100 Hz. The source of this low frequency noise, which would have been largely inaudible to the human observer, was not identified in the measurement logs. Some of it was likely produced by the offshore oil platform.


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Figure 20: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at the Beluga Airstrip measurement site.

Figure 21: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Beluga Airstrip measurement site.


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Table 3: Flat-weighed and A-weighted LN percentile level statistics for the Beluga airstrip ambient noise measurements.

LN percentile level

Flat-weighted level (dBF)

A-weighted level (dBA)

10% (L10) 64.6 52.3 30% (L30) 59.7 41.8 50% (L50) 58.3 39.3 70% (L70) 57.2 38.5 90% (L90) 56.1 37.8

3.4.2 Freemans Barge Launch Figure 22 shows flat-weighted, A-weighted, and decade-band SPLs as well as

spectral levels for approximately 1 hour of acoustic recording at the Freemans barge launch measurement site. Broadband ambient noise at this site was predominantly due to the splashing of small ocean waves at the shoreline; the wave height was approximately 30 cm and winds were light to none at the time of measurement. Ambient noise below 100 Hz was dominated by low to infrasonic tones (e.g., at 13 Hz, 24 Hz and 30 Hz) which are believed to be from the power generator at an oil platform approximately 9 km offshore. The noise spectra in Figure 22 show that most of the ambient noise was concentrated below 100 Hz; consequently the A-weighted SPL is significantly lower than the flat-weighted SPL at this location. Tonal noise at 9:34-9:37 in Figure 22 was from a distant helicopter. Transient noise events at 9:50-9:52 and again at 10:13-10:15 were due to passing aircraft.

Figure 23 shows histograms of flat-weighted (black) and A-weighted (red) background levels at the Freemans barge launch measurement site. The narrow histogram distributions show that ambient noise levels were fairly constant over the 1 hour recording duration. Table 4 presents LN percentile levels for ambient noise at Freemans barge launch. The A-weighted and flat-weighted L50 percentile levels for this site were 46.1 dBA and 57.0 dBF, respectively. Flat weighted levels at this site were dominated by very low frequency engine noise from passing aircraft and the power generator at the distant oil platform. A-weighted levels were dominated by the noise of splashing waves at the shoreline.


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Figure 22: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at Freemans barge launch.

Figure 23: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Freemans barge launch measurement site.


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Table 4: Flat-weighed and A-weighted LN percentile level statistics for the Freemans barge launch ambient noise measurements.

LN percentile level



10% (L10) 60.1 49.0 30% (L30) 58.1 47.3 50% (L50) 57.0 46.1 70% (L70) 56.1 45.0 90% (L90) 55.0 43.4

3.4.3 Ladd Landing Beach Figure 24 shows flat-weighted, A-weighted, and decade-band SPLs as well as

spectral levels for approximately 1 hour of acoustic recording at the Ladd Landing beach measurement site. Ambient noise at the Ladd Landing beach was observed to be primarily from small waves at the shoreline and small aircraft overhead. Quite a few small aircraft passed by during the ambient noise recordings: the loudest passes were at 14:42, 14:52, 15:05, 15:14, and 15:36. These are clearly visible in the spectral data in Figure 24 as groups of tones that shift down in frequency, due to the Doppler effect, as the noise source approached the measurement position, reached CPA, and then moved away from the measurement position. The A-weighted SPL increased by 20-25 dB during the aircraft passes. The other notable feature of the spectral data was the continuous tones at 30 Hz, 38 Hz and 90 Hz. These are believed to be noise emissions from an oil platform which was approximately 9 km (5.5 miles) offshore from the measurement site.

Figure 25 shows histograms of flat-weighted (black) and A-weighted (red) background levels and Table 5 presents LN percentile levels for ambient noise at the Ladd landing beach measurement site. The A-weighted and flat-weighted L50 percentile levels for this site were 54.4 dBA and 60.8 dBF, respectively. A-weighted levels were closer to the flat weighted levels at this site primarily because the breaking ocean waves were larger than at Ladd Landing and had more sound energy at mid frequencies. Though passing aircraft briefly increased broadband SPLs, average ambient noise levels at this site were dominated by breaking waves at the shoreline and very low frequency noise from the distant oil platform.


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Figure 24: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at the Ladd Landing beach measurement site.

Figure 25: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Ladd Landing beach measurement site.


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Table 5: Flat-weighed and A-weighted LN percentile level statistics for the Ladd Landing beach ambient noise measurements.

LN percentile level



10% (L10) 66.8 59.5 30% (L30) 62.4 56.1 50% (L50) 60.8 54.4 70% (L70) 59.5 52.9 90% (L90) 57.7 51.1

3.4.4 Ladd Landing Bluff Figure 26 shows flat-weighted, A-weighted, and decade-band SPLs and spectral

levels for approximately 1 hour of acoustic recording at the Ladd Landing bluff measurement site. Ambient noise at this location was dominated by low frequency tonal noise believed to be from a power generator at the offshore oil platform 9 km away. Noise from the offshore platform was much more prominent at the bluff than at the beach and continuous audible tones from the platform were clearly noted in the measurement logs; the loudest tones were at 30 Hz, 38 Hz, and 90 Hz, with fainter tones identified at 100 Hz, 110 Hz and 220 Hz. Ocean wave noise at the shoreline was also observed at this location, though mid-frequency wind noise was much lower than at the beach site. Transient spikes in the ambient SPL data were from passing propeller aircraft (at 18:28-18:30 and 18:39-18:41) and a diesel engine pickup truck (at 18:39 and 18:41) that passed by the measurement site. Frequencies below 20 Hz in the Ladd Landing bluff recording were obscured by low frequency ocean wave noise at the shoreline.

Figure 27 shows histograms of flat-weighted (black) and A-weighted (red) background levels and Table 6 presents LN percentile levels for ambient noise at the Ladd landing bluff measurement site. The A-weighted and flat-weighted L50 percentile levels for the bluff were 44.5 dBA and 61.4 dBF, respectively. Ambient levels at this site were clearly dominated by noise from the offshore oil platform, as noted in the field observations logs. A-weighted SPLs at Ladd Landing bluff were about 8 dB lower than at the beach site because mid-frequency breaking wave noise was much lower at this location. The greater prominence of the platform noise at this site was partly due to the higher elevation at the bluff and partly due to decreased masking from breaking wave noise at the shoreline.


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Figure 26: Flat-weighted, A-weighted, and decade-band SPLs (top) and spectral levels (bottom) for ambient noise recordings taken at the Ladd Landing bluff measurement site.

Figure 27: Histogram of flat-weighted and A-weighted SPLs for 1 hour ambient noise recording taken at the Ladd Landing bluff measurement site.


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Table 6: Flat-weighed and A-weighted LN percentile level statistics for the Ladd Landing bluff ambient noise measurements.

LN percentile level



10% (L10) 64.8 47.6 30% (L30) 62.7 45.7 50% (L50) 61.4 44.5 70% (L70) 60.1 43.2 90% (L90) 58.1 41.6

3.5 Summary Table 7 summarizes ambient noise level statistics for all four Ladd in-air

measurement sites. The two most prominent sources of continuous noise in the ambient recordings were breaking ocean waves at the nearby shoreline and by low frequency industrial noise from a distant oil platform, 9 km offshore. Industrial noise from the offshore oil platform, in particular, was concentrated at low frequencies less than 100 Hz, with prominent tones observed at 13, 24, 30, 38, and 90 Hz. Transient events in the ambient noise recordings were identified as passing aircraft and as vehicles traveling on a nearby road.

The quietest location, in terms of the average A-weighted ambient noise level, was the Beluga airstrip measurement site, with L50=39.3 dBA. However, transient noise events from passing vehicles and aircraft were also very frequent at this location. Flat-weighted ambient noise levels at the Beluga airstrip were dominated by low frequency industrial noise from an unknown source which was not identified in the field observation logs. Flat-weighted levels were almost 20 dB higher than A-weighted levels at Beluga airstrip, which was the greatest difference observed at all four measurement sites.

The loudest location, in terms of the average A-weighted ambient noise level, was the beach at Ladd Landing, with L50=54.4 dBA. Noise from breaking ocean waves dominated measured levels at Ladd Landing beach. Breaking wave noise was less prominent, but still significant, at the Ladd Landing bluff and Freemans barge launch measurement sites. Continuous industrial noise, believed to be from an offshore oil platform 9 km away, was identified to be the loudest source of continuous low frequency noise at all three of these sites. Noise from the offshore oil platform was loudest at the Ladd Landing bluff measurement site. However, the low frequency platform noise was below audible frequency range for humans, and consequently did not strongly influence the A-weighted noise levels, which were generally low at all sites.


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Table 7: Summary of L10, L50, and L90 percentile ambient noise levels for all four measurement sites.

A-weighted levels (dBA) Flat-weighted levels (dBF) L90 L50 L10 L90 L50 L10

Beluga airstrip 37.8 39.3 52.3 56.1 58.3 64.6 Freemans barge launch 43.4 46.1 49.0 55.0 57.0 60.1

Ladd Landing beach 51.1 54.4 59.5 57.7 60.8 66.8 Ladd Landing bluff 41.6 44.5 47.6 58.1 61.4 64.8

4 Discussion of Results

The present study includes results of sound level measurements at a marine coal terminal representative of the proposed Ladd marine coal terminal, and ambient sound level measurements made at four locations near the proposed terminal site. While overall sound levels from the monitored coal terminal were less than 60 dB(A) at distances greater than 1 km (0.6 mi) from the terminal, the proposed Ladd terminal would be located in a rural setting with relatively little present industrial activity, and consequently quite low existing background sound levels. Terminal sounds in this environment could be audible in some instances to several miles distance.

The long-distance sound level measurements made at the Westshore marine coal terminal found overall sound level was 59 dB(A) at 1 km (0.6 mi) distance, 57 dB(A) at 1.5 km (1 mi) distance and 54 dB(A) at 2 km (1.2 mi) distance. These measurements were made overwater in the downwind direction from the terminal and are expected to be representative of the highest sound level reception conditions. Levels measured overland and in upwind or cross-wind directions are typically less than downwind and overwater. The measured sound level decrease with distance followed a transmission loss rate of 15 log (r), where r is range or distance, meaning that sound levels decrease by 15 dB each time the distance from the source increases by a factor of 10. Transmission loss rates overland in normal wind conditions are typically greater at between approximately 20 log(r) and 25 log(r). Assuming the same (measured) sound level of 64 dB at 500 m distance and 20 log(r) loss rates for greater distances yields predicted levels of 58 dB at 1 km, 52 dB(A) at 2 km, 48 dB(A) at 4 km, 42 dB(A) at 8 km and 39 dB(A) at 11 km. Measurements of background sound levels at locations near the proposed terminal site gave L50 levels between 39.3 dB(A) and 46.1 dB(A). L50 levels are the levels that are exceeded 50% of the time during a sound level measurement. A higher L50 of 54.4 dB(A) was measured at Ladd Landing beach where breaking waves increased the ambient


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levels. A comparison of predicted 20 log(r) sound levels with the measured L50 levels indicates, that in normal conditions away from the beach, terminal sounds would equal background A-weighted sound levels at distances between about 5 km (3 mi) and 11 km (6.6 mi). These are the normal distances that terminal sounds would be barely audible in calm conditions. Certain situations such thermal gradients in calm wind conditions, or light downwind reception locations could experience extended distances. Upwind receptors or high-wind conditions would lead to reduced distances for audibility.

The measurements and predicted audibility distances here are based on the sound levels produced by the Westshore marine coal terminal. That facility does not appear to have implemented significant sound reduction technologies such as acoustic shielding and vibration isolation of noise generating equipment. Those technologies could significantly reduce emitted sound levels and are recommended for machinery installed at the proposed terminal. Reductions of sound levels by 6 decibels, which is quite feasible using these methods, leads to halving of the normal distance to which any given sound level is received.

5 Literature Cited

Westshore Terminals Ltd., Background, < http://www.westshore.com/> (15 February 2007)


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Appendix A Tables of 1/3 Octave Band Source Levels

A.1 Long Range Measurements Wave file name: F:\Documents and Settings\Christopher\My Documents\RobertsBank\Air measurements\Offshore\RawData.WAV Number of channels: 1 Sample rate: 48000 Bits per sample: 16 Number of samples: 110583808 Duration (min:sec): 0038:23 SL range correction: 155.000m Start time for analysis: 76 seconds Duration of analysis: 2 seconds Frequency dB(F) dB(A) SL(F) SL(A) --------------------------------------------- 10.0 68.1 -4.5 111.9 39.3 12.5 68.5 3.0 112.3 46.8 16.0 62.3 3.5 106.1 47.3 20.0 67.0 16.6 110.8 60.4 25.0 68.6 23.9 112.4 67.7 31.5 68.9 29.5 112.7 73.3 40.0 66.6 32.0 110.4 75.8 50.0 65.4 35.2 109.2 79.0 63.0 67.5 41.3 111.3 85.1 80.0 62.8 40.3 106.6 84.1 100.0 61.6 42.5 105.4 86.3 125.0 63.5 47.4 107.3 91.2 160.0 62.8 49.4 106.6 93.2 200.0 62.4 51.5 106.2 95.3 250.0 66.6 58.0 110.4 101.8 315.0 66.2 59.6 110.0 103.4 400.0 65.2 60.4 109.0 104.2 500.0 64.8 61.6 108.6 105.4 630.0 62.9 61.0 106.7 104.8 800.0 61.4 60.6 105.2 104.4 1000.0 61.3 61.3 105.1 105.1 1250.0 60.8 61.4 104.6 105.2 1600.0 59.6 60.6 103.4 104.4 2000.0 58.2 59.4 102.0 103.2 2500.0 54.9 56.2 98.7 100.0 3150.0 52.1 53.3 95.9 97.1 4000.0 48.6 49.6 92.4 93.4 5000.0 45.5 46.0 89.3 89.8 6300.0 42.3 42.2 86.1 86.0 8000.0 40.3 39.2 84.1 83.0 10000.0 39.3 36.8 83.1 80.6 12500.0 37.3 33.0 81.1 76.8 16000.0 36.0 29.4 79.8 73.2 20000.0 36.6 27.3 80.4 71.1 Broadband levels 79.1 70.9 122.9 114.7


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A.2 Conveyor Drive System Wave file name: F:\Documents and Settings\Christopher\My Documents\RobertsBank\Air measurements\Conveyor Loader\ConveyorLoader_Sept16.wav Number of channels: 1 Sample rate: 48000 Bits per sample: 16 Number of samples: 19505152 Duration (min:sec): 0006:46 SL range correction: 16.0000m Start time for analysis: 160 seconds Duration of analysis: 120 seconds Frequency dB(F) dB(A) SL(F) SL(A) --------------------------------------------- 10.0 65.9 -6.7 90.0 17.4 12.5 64.5 -1.0 88.6 23.1 16.0 68.2 9.4 92.3 33.5 20.0 70.9 20.5 94.9 44.5 25.0 71.0 26.3 95.1 50.4 31.5 77.5 38.1 101.5 62.1 40.0 73.3 38.7 97.4 62.8 50.0 70.8 40.6 94.8 64.6 63.0 72.6 46.4 96.7 70.5 80.0 74.0 51.5 98.1 75.6 100.0 71.9 52.8 96.0 76.9 125.0 74.4 58.3 98.5 82.4 160.0 74.3 60.9 98.4 85.0 200.0 70.5 59.6 94.6 83.7 250.0 73.0 64.4 97.1 88.5 315.0 72.6 66.0 96.7 90.1 400.0 74.4 69.6 98.5 93.7 500.0 74.3 71.1 98.4 95.2 630.0 76.2 74.3 100.3 98.4 800.0 73.8 73.0 97.9 97.1 1000.0 71.8 71.8 95.9 95.9 1250.0 70.9 71.5 95.0 95.6 1600.0 76.1 77.1 100.2 101.2 2000.0 73.9 75.1 97.9 99.1 2500.0 66.2 67.5 90.3 91.6 3150.0 64.7 65.9 88.8 90.0 4000.0 60.3 61.3 84.4 85.4 5000.0 56.3 56.8 80.4 80.9 6300.0 54.0 53.9 78.1 78.0 8000.0 50.0 48.9 74.0 72.9 10000.0 46.7 44.2 70.8 68.3 12500.0 45.9 41.6 69.9 65.6 16000.0 41.1 34.5 65.2 58.6 20000.0 38.5 29.2 62.6 53.3 Broadband levels 87.1 83.1 111.2 107.2


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A.3 Coal Car Dumping Wave file name: F:\Documents and Settings\Christopher\My Documents\RobertsBank\Air measurements\Coal Car Dumping\CoalCarDumping_Sept16.WAV Number of channels: 1 Sample rate: 48000 Bits per sample: 16 Number of samples: 24535040 Duration (min:sec): 0008:31 SL range correction: 16.0000m Start time for analysis: 131 seconds Duration of analysis: 195 seconds Frequency dB(F) dB(A) SL(F) SL(A) --------------------------------------------- 10.0 70.4 -2.2 94.5 21.9 12.5 73.1 7.6 97.2 31.7 16.0 92.9 34.1 117.0 58.2 20.0 71.9 21.5 96.0 45.6 25.0 75.4 30.7 99.5 54.8 31.5 82.5 43.1 106.6 67.2 40.0 76.4 41.8 100.5 65.9 50.0 78.1 47.9 102.1 71.9 63.0 75.2 49.0 99.3 73.1 80.0 76.8 54.3 100.9 78.4 100.0 75.9 56.8 100.0 80.9 125.0 74.1 58.0 98.2 82.1 160.0 72.7 59.3 96.8 83.4 200.0 72.1 61.2 96.2 85.3 250.0 72.5 63.9 96.6 88.0 315.0 74.4 67.8 98.5 91.9 400.0 72.2 67.4 96.3 91.5 500.0 71.9 68.7 96.0 92.8 630.0 73.7 71.8 97.8 95.9 800.0 73.2 72.4 97.3 96.5 1000.0 69.3 69.3 93.4 93.4 1250.0 68.5 69.1 92.6 93.2 1600.0 65.9 66.9 90.0 91.0 2000.0 63.7 64.9 87.8 89.0 2500.0 62.3 63.6 86.4 87.7 3150.0 60.5 61.7 84.6 85.8 4000.0 58.3 59.3 82.4 83.4 5000.0 55.3 55.8 79.4 79.9 6300.0 52.7 52.6 76.8 76.7 8000.0 49.5 48.4 73.6 72.5 10000.0 47.1 44.6 71.2 68.7 12500.0 43.6 39.3 67.7 63.4 16000.0 38.7 32.1 62.8 56.2 20000.0 36.7 27.4 60.8 51.5 Broadband levels 94.2 79.4 118.3 103.5


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A.4 Stacker

A.4.1 Stacker Stationary Wave file name: F:\Documents and Settings\Christopher\My Documents\RobertsBank\Air measurements\Stacker\Stacker_Sept16.WAV Number of channels: 1 Sample rate: 48000 Bits per sample: 16 Number of samples: 26681344 Duration (min:sec): 0009:15 SL range correction: 30.0000m Start time for analysis: 40 seconds Duration of analysis: 60 seconds Frequency dB(F) dB(A) SL(F) SL(A) --------------------------------------------- 10.0 67.1 -5.5 96.6 24.0 12.5 65.5 -0.0 95.0 29.5 16.0 64.1 5.3 93.7 34.9 20.0 64.9 14.5 94.4 44.0 25.0 73.4 28.7 103.0 58.3 31.5 72.1 32.7 101.6 62.2 40.0 71.2 36.6 100.8 66.2 50.0 70.0 39.8 99.5 69.3 63.0 70.3 44.1 99.8 73.6 80.0 73.1 50.6 102.7 80.2 100.0 71.1 52.0 100.6 81.5 125.0 73.3 57.2 102.9 86.8 160.0 72.3 58.9 101.9 88.5 200.0 69.6 58.7 99.2 88.3 250.0 72.8 64.2 102.3 93.7 315.0 70.2 63.6 99.8 93.2 400.0 70.7 65.9 100.2 95.4 500.0 70.5 67.3 100.1 96.9 630.0 70.7 68.8 100.2 98.3 800.0 68.2 67.4 97.7 96.9 1000.0 66.0 66.0 95.5 95.5 1250.0 65.3 65.9 94.9 95.5 1600.0 62.4 63.4 91.9 92.9 2000.0 60.0 61.2 89.6 90.8 2500.0 59.0 60.3 88.5 89.8 3150.0 56.5 57.7 86.0 87.2 4000.0 53.4 54.4 82.9 83.9 5000.0 51.1 51.6 80.7 81.2 6300.0 48.0 47.9 77.5 77.4 8000.0 45.4 44.3 75.0 73.9 10000.0 46.3 43.8 75.8 73.3 12500.0 41.5 37.2 71.1 66.8 16000.0 36.5 29.9 66.0 59.4 20000.0 36.3 27.0 65.9 56.6 Broadband levels 84.0 76.3 113.5 105.9


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A.4.2 Stacker In Motion Wave file name: F:\Documents and Settings\Christopher\My Documents\RobertsBank\Air measurements\Stacker\Stacker_Sept16.WAV Number of channels: 1 Sample rate: 48000 Bits per sample: 16 Number of samples: 26681344 Duration (min:sec): 0009:15 SL range correction: 8.00000m Start time for analysis: 269 seconds Duration of analysis: 2 seconds Frequency dB(F) dB(A) SL(F) SL(A) --------------------------------------------- 10.0 74.5 1.9 92.5 19.9 12.5 72.9 7.4 91.0 25.5 16.0 68.7 9.9 86.7 27.9 20.0 69.5 19.1 87.5 37.1 25.0 75.8 31.1 93.8 49.1 31.5 74.2 34.8 92.3 52.9 40.0 71.3 36.7 89.4 54.8 50.0 71.3 41.1 89.4 59.2 63.0 73.8 47.6 91.9 65.7 80.0 72.1 49.6 90.2 67.7 100.0 72.6 53.5 90.7 71.6 125.0 72.6 56.5 90.6 74.5 160.0 66.7 53.3 84.8 71.4 200.0 66.5 55.6 84.6 73.7 250.0 69.6 61.0 87.7 79.1 315.0 67.9 61.3 86.0 79.4 400.0 68.5 63.7 86.6 81.8 500.0 70.1 66.9 88.1 84.9 630.0 69.7 67.8 87.8 85.9 800.0 67.9 67.1 86.0 85.2 1000.0 66.4 66.4 84.4 84.4 1250.0 70.3 70.9 88.4 89.0 1600.0 67.4 68.4 85.5 86.5 2000.0 69.3 70.5 87.3 88.5 2500.0 86.8 88.1 104.8 106.1 3150.0 74.1 75.3 92.1 93.3 4000.0 71.9 72.9 90.0 91.0 5000.0 66.9 67.4 85.0 85.5 6300.0 70.4 70.3 88.5 88.4 8000.0 76.4 75.3 94.5 93.4 10000.0 65.6 63.1 83.7 81.2 12500.0 57.1 52.8 75.2 70.9 16000.0 53.4 46.8 71.5 64.9 20000.0 53.1 43.8 71.2 61.9 Broadband levels 89.5 89.1 107.6 107.1 Broadband levels 85.3 79.5 103.4 97.6

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