uplands community college lower high street, …

UPLANDS COMMUNITY COLLEGE

LOWER HIGH STREET, WADHURST, EAST SUSSEX

PROPOSED 3G SYNTHETIC SPORTS PITCH

NOISE IMPACT ASSESSMENT

Report No. MRL/100/698.1v1

July 2014

Report No. MRL/100/698.1v1

July 2014

UPLANDS COMMUNITY COLLEGE

LOWER HIGH STREET, WADHURST, EAST SUSSEX

PROPOSED 3G SYNTHETIC SPORTS FACILITIES

NOISE IMPACT ASSESSMENT

Report prepared by:

MRL Acoustics Ltd

2 Kestrel Close

Kingsnorth

Ashford

Kent

TN23 3RB

On behalf of:

MUGA - UK Ltd

Mill Farm

Hathern Road

Shepshed

Leicestershire

LE12 9RP

Report prepared by:

Matthew Lawrence MSc MIOA – Principal Consultant

CONTENTS

Page

1.0 INTRODUCTION 1

2.0 NOISE LEVEL SURVEYS 2

3.0 ASSESSMENT OF NOISE IMPACT 5

4.0 NOISE MITIGATION MEASURES 7

5.0 SUMMARY AND CONCLUSIONS 9

APPENDIX I – NOISE UNITS AND INDICES 12

APPENDIX II – RESULTS OF NOISE LEVEL SURVEYS 14

APPENDIX III – CALCULATIONS 16

MUGA UK-Ltd Uplands Community College, Wadhurst

E-mail: [email protected] Report No: MRL/100/698.1v1

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1.0 INTRODUCTION

1.1 MRL Acoustics was commissioned by MUGA – UK Ltd to carry out an assessment of the

noise impact of a proposed sport development scheme at Uplands Community College,

Lower High Street, Wadhurst, East Sussex.

1.2 The proposal is to provide a new all-weather 3G synthetic sports pitch on the existing

college sports field.

1.3 The location of the new sports pitch is shown in the site layout plan at the end of this

report. We understand that the new pitch is to have floodlighting and may be used up to

9pm in the evenings during the week and up to 6pm at the weekends.

1.4 Our assessment has involved the following scope of work:-

i) Carrying out a background noise survey at the nearest residential properties in the

immediate vicinity of the proposed pitch;

ii) An assessment of the noise impact from the pitch based on typical measured noise

levels and BS 4142 : 1997;

iii) Providing recommendations for any additional noise mitigation measures, if

necessary.

1.5 This report details our findings and our recommendations. Noise levels referred to in the

text have been rounded to the nearest whole decibel (dB), as fractions of decibels are

imperceptible.

1.6 An explanation of acoustical terms used in this report is provided in Appendix I.



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2.0 NOISE LEVEL SURVEYS

Background Noise Survey

2.1 It is understood that the proposed synthetic sport pitch may be used up to 9pm at the

latest during the weekday evenings.

2.2 Therefore, a background noise survey was carried out on a typical weekday evening from

7.52pm – 9.37pm to represent the current noise climate experienced at nearby residential

properties during periods when the new pitch will be in use and when the background

noise climate should be at its lowest level.

2.3 The measurement location chosen is considered to be representative of the nearest

residential properties to the proposed 3G synthetic sports pitch:-

• Location 1: Rear residential boundaries of the dwellings along the Lower High

Street (approximately 30m from the edge of the 3G pitch).

2.4 The noise measurement location is shown in Figure 1 at the end of this report.

2.5 The background noise levels were measured over consecutive 15-minute periods at the

monitoring location. The noise measurements were recorded using a Rion NA-28 Type 1

sound level meter (serial no. 00370312).

2.6 The meter was mounted on a tripod with the microphone approximately 1.5m above

ground level and a windshield was fitted to the microphone at all times. The calibration of

the meter was checked before and after the survey with no variation in level noted.

2.7 The weather conditions for the survey were warm, dry and calm which represented good

conditions for noise measurements.

2.8 It was noted that during these measurements of the background noise, the dominant noise

source was from intermittent road traffic, birds and occasional aircraft noise.



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2.9 The results of the background noise survey are detailed in Appendix II and are

summarised in Table 1 below:-

Table 1: Summary of Ambient Noise Levels at Nearest Dwellings

Noise Levels, dB(A) Measurement

Location Average

LAeq

Average

LA90

Average

LAmax

Location 1 41 36 52

Football Pitch Noise Levels

2.10 MRL Acoustics has carried out a previous noise level survey of an existing all-weather

pitch for a similar project to the one proposed at Uplands Community College. The results

obtained from this previous survey can be used as representative typical source noise

levels of the proposed synthetic pitch at this new development site.

2.11 The pitch was located at Cheriton Road Sports Ground, Folkestone, Kent and at the time it

was being used as 2 no. 5-a-side pitches and as such is considered to represent an occasion

when the maximum levels of noise would be generated. Noise levels at the site could be

measured in unobstructed free-field conditions up to 15m from the perimeter fence of the

pitch.

2.12 The measurements demonstrated that the pitch perimeter should be considered to be the

‘source’ location and attenuation with distance should be calculated using a ‘20 log’ (6 dB

per doubling of distance) relationship. Typical noises included in the measurements were

balls impacting the perimeter fencing, referees’ whistles and players’/spectators’ voices.

2.13 General noise measurements indicate that the noise levels around sports pitches are

generally reasonably constant for a typical match; there is little difference between noise

levels measured behind the goals and near the half-way line. There is also only a very

small difference in noise levels created by adult’s and children’s matches.



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2.14 It is also worth noting that these noise levels are representative of ‘full-blown’ games being

played on a pitch, rather than school teaching classes / sports lessons under instruction,

which might typically be quieter.

2.15 A summary of the source noise levels used in the assessment is shown in Table 2 below:-

Table 2: Sports Pitch Source Noise Levels

Location LAeq LAmax Comments

Football Pitch Noise

Approximately 15m from

Pitch Perimeter Fence

55 dB 72 dB Whistles, voices and ball

impacts



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3.0 ASSESSMENT OF NOISE IMPACT

3.1 We have assessed the likely noise impact from the proposed new all-weather sports pitch

at the site boundary of the nearest residential properties along the Lower High Street at

Location 1.

3.2 The noise impact assessment has been based on our noise data for the 2 no. 5-a-side

football pitches as being representative of the noise levels generated by the new synthetic

sports pitch.

3.3 Using the measured source noise levels (from Table 2 above), of 55 dB LAeq at 15m distance,

we have calculated the noise levels at the property boundaries of the nearest dwellings,

taking into account attenuation of sound over distance. The results of our calculations are

shown in Table 3 below:-

Table 3: Predicted Noise Levels (without noise mitigation), dB

Predicted Pitch

Noise Levels

Existing Noise

Levels Assessment

Location LAeq LAmax LA90 LAmax

Difference Between

Predicted LAeq and

Existing LA90

Location 1 49 66 36 52 + 13 dB

3.4 The predicted pitch LAeq noise level at the rear boundary of the nearest affected dwellings

at Location 1 is 13 dB(A) higher than the existing measured LA90 background noise level at

this location. The predicted pitch LAmax noise level at Location 1 is 14 dB(A) higher than

the existing measured LAmax levels at this location.

3.5 It is generally considered that a change in noise level of 3 dB(A) is the minimum change

perceptible to the human ear and therefore the noise impact from the pitch will be

noticeable.



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3.6 When assessing the potential noise impact of a new noise source upon existing dwellings,

it is appropriate to refer to British Standard 4142 ‘Method for rating industrial noise

affecting mixed residential and industrial areas’, 1997.

3.7 BS 4142 requires the noise from the equipment (in LAeq) to be compared with the

background noise level (LA90) in the absence of the activity noise. If the rated noise level

exceeds the LA90 background noise level by 10 dB or more then complaints would be likely.

An excess of 5 dB over the background noise level is viewed as being ‘of marginal

significance’. A noise rating level of 10 dB below the background noise is a positive

indication that complaints will be unlikely.

3.8 From the above, and taking into account the character of noise from a sports pitch, we

consider that it will be necessary to implement a scheme of noise mitigation measures in

order to protect residential amenity at Location 1 and along the Lower High Street.

3.9 Our recommended noise mitigation measures are outlined in Section 4.0.



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4.0 NOISE MITIGATION MEASURES

4.1 We understand that from our site inspection and information provided by MUGA – UK

Ltd, the proposed sports pitch will have a finished playing level that is approximately the

same as that of the ground level of the nearby residential properties at Location 1.

4.2 Therefore the following noise control measures are recommended to reduce noise levels

from the proposed all-weather pitch at the nearest affected residential properties:-

• The north-eastern perimeter of the proposed 3G sports pitch is to be provided with

an acoustic screen of at least 2.5m in height, as shown in Figure 2 at the end of this

report;

• The south-eastern perimeter of the pitch is to be provided with a 1.5m high earth

bund with a 1m acoustic screen on top, as shown in Figure 2 at the end of this

report;

• We calculate that such a screen should provide around 11 dB(A) attenuation in

noise levels if it is located approximately 3m from the perimeter edge of the

proposed pitch.

• The screens should be constructed from solid material with a minimum mass per

unit area of at least 15 kg/m2. It may therefore be typically constructed from solid

timber of nominal 25mm thickness and density of at least 600 kg/m3 and with no

holes or gaps in its construction, e.g. Jacksons Fencing ‘Jakoustic’ Environmental

Reflective Noise Barrier (or any similar performing acoustic barrier manufacturer

that meets the performance criteria outlined above);

• The screen may also be constructed in the form of a solid earth bund or solid

masonry.

4.3 These measures are designed to provide a significant reduction in the noise levels from the

sports pitch, although the precise level of attenuation will depend on the exact location of



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the noise source on the pitch at any one given time. The acoustic screens will be high

enough so that screening will be provided for voices of both players and spectators.

4.4 The noise assessment with the 2.5m high acoustic screens in place is shown in Table 4

below:-

Table 4: Predicted Noise Levels with 2.5m High Acoustic Screening, dB

Predicted Pitch

Noise Levels

Existing Noise

Levels Assessment

Location LAeq LAmax LA90 LAmax

Difference Between

Predicted LAeq and

Existing LA90

Location 1 38 55 36 52 + 2 dB

4.5 It is envisaged that the measures will reduce the predicted LAeq level to around 38 dB

which is 2 dB higher than the existing LA90 background level at the rear site boundary of

the nearest affected residential properties in the Lower High Street.

4.6 As a result of the recommended acoustic screening, the predicted LAmax noise levels from

the sports pitch should be approximately 3 dB higher than the measured existing LAmax

levels at the nearest residential properties.

4.7 This level of noise impact is less than ‘of marginal significance’ in accordance with the

assessment methodology set out in BS 4142 : 1997 and is therefore considered to be within

acceptable limits.

4.8 Our calculations for the noise attenuation provided by the proposed 2.5m high acoustic

barrier and the resultant noise impact at the nearest dwellings are shown in Appendix III

at the end of this report.



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5.0 SUMMARY AND CONCLUSIONS

5.1 MRL Acoustics has carried out an assessment of the noise impact of a proposal to provide

a new synthetic all-weather sports pitch at Uplands Community College, Lower High

Street, Wadhurst, East Sussex.

5.2 The assessment has included monitoring of existing ambient noise levels at nearby

residential properties adjacent to the development site and calculating likely noise levels

from the proposed sports pitch using measured source noise data for an existing similar

sports pitch.

5.3 Recommendations have been made for appropriate noise control measures, namely

acoustic screening along the north-east and south-east perimeters of the pitch.

5.4 With the mitigation measures recommended in this report, it is considered that noise from

use of the new synthetic all-weather sports pitch should be reduced to acceptable levels

such that there should be no demonstrable harm to any nearby residential amenity.

5.5 It should also be considered that the new sports pitch is only to be used up to 9pm at the

latest which is not considered to be an unreasonable time for a community facility such as

this.



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APPENDIX I – NOISE UNITS AND INDICES

a) Sound Pressure Level and the decibel (dB)

A sound wave is a small fluctuation of atmospheric pressure. The human ear responds to

these variations in pressure, producing the sensation of hearing. The ear can detect a very

wide range of pressure variations. In order to cope with this wide range of pressure

variations, a logarithmic scale is used to convert the values into manageable numbers.

Although it might seem unusual to use a logarithmic scale to measure a physical

phenomenon, it has been found that human hearing also responds to sound in an

approximately logarithmic fashion. The dB (decibel) is the logarithmic unit used to

describe sound (or noise) levels. The usual range of sound pressure levels is from 0 dB

(threshold of hearing) to 120 dB (threshold of pain).

Due to the logarithmic nature of decibels, when two noises of the same level are combined

together, the total noise level is (under normal circumstances) 3 dB(A) higher than each of

the individual noise levels e.g. 60 dB(A) plus 60 dB(A) = 63 dB(A). In terms of perceived

‘loudness’, a 3 dB(A) variation in noise level is a relatively small (but nevertheless just

noticeable) change. An increase in noise level of 10 dB(A) generally corresponds to a

doubling of perceived loudness. Likewise, a reduction in noise level of 10 dB(A) generally

corresponds to a halving of perceived loudness.

b) Frequency and hertz (Hz)

As well as the loudness of a sound, the frequency content of a sound is also very

important. Frequency is a measure of the rate of fluctuation of a sound wave. The unit

used is cycles per second, or hertz (Hz). Sometimes large frequency values are written as

kilohertz (kHz), where 1 kHz = 1000 Hz.

Young people with normal hearing can hear frequencies in the range 20 Hz to 20,000 Hz.

However, the upper frequency limit gradually reduces as a person gets older.



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c) A-weighting

The ear is not equally sensitive to sound at all frequencies. It is less sensitive to sound at

low and very high frequencies, compared with the frequencies in between. Therefore,

when measuring a sound made up of different frequencies, it is often useful to ‘weight’

each frequency appropriately, so that the measurement correlates better with what a

person would actually hear. This is usually achieved by using an electronic filter called the

‘A’ weighting, which is built into sound level meters. Noise levels measured using the ‘A’

weighting are denoted dB(A) or dBLA.

d) Glossary of Terms

When a noise level is constant and does not fluctuate over time, it can be described

adequately by measuring the dB(A) level. However, when the noise level varies with time,

the measured dB(A) level will vary as well. In this case it is therefore not possible to

represent the noise climate with a simple dB(A) value. In order to describe noise where

the level is continuously varying, a number of other indices, including statistical

parameters, are used. The indices used in this report are described below:-

LAeq This is the A-weighted 'equivalent continuous noise level' which is an average of

the total sound energy measured over a specified time period. In other words, LAeq

is the level of a continuous noise which has the same total (A-weighted) energy as

the real fluctuating noise, measured over the same time period. It is increasingly

being used as the preferred parameter for all forms of environmental noise.

LAmax This is the maximum A-weighted noise level that was recorded during the

monitoring period.

LA10 This is the A-weighted noise level exceeded for 10% of the specified time period.

LA10 is most often used as a measure of traffic noise.

LA90 This is the A-weighted noise level exceeded for 90% of the specified time period.

LA90 is used as a measure of ‘background noise’.



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APPENDIX II – RESULTS OF NOISE LEVEL SURVEYS

Date: Friday 4th July 2014

Equipment: Rion NA-28 ‘Type 1’ sound level meter (s/n 00370312)

Weather: Warm, dry and calm

Results: All free-field values in dB(A)

Table A1: Location 1

Noise Levels (dB) Location Time

LAeq LAmax LA90 Comments

19:52 – 20:07 41.7 55.1 37.0

20:07 – 20:22 41.3 52.9 36.7

20:22 – 20:37 40.8 54.3 35.3

20:37 – 20:52 41 50 35.8

20:52 - 21:07 41.8 53.8 35.3

21:07 - 21:22 40.5 50.8 35.9

Rear of

Residential

Properties

21:22 – 21:37 39.8 47.9 35

Noise from intermittent road

traffic and birds, occasional

aircraft noise

Average 41.0 52.1 35.9



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Table A2: Typical Noise Levels 15m from Existing Football Pitch

Time LAeq LA90 LAmax Comments

20:00 - 20:05 54.3 48.8 68.0

20:05 - 20:10 54.6 49.8 69.1

20:10 – 20:15 55.6 49.6 73.6

20:15 – 20:20 55.8 49.8 77.7

20:20 – 20:25 55.9 50.2 72.2

Noise from Football Pitch, including ball

impacts, shouts and whistles

Average 55.3 49.6 72.1

Hockey Activities (Extract from Sandy Brown Associates Report 09136/DR)

In general when all of the measurement data are corrected to sound pressure levels at the same

distance from the noise source, there is good agreement between the various datasets (assuming that

the noise is dominated by activity at the nearest edge of the pitches for the correction).

In summary, noise levels around pitches are typically in the region of 60 dB LAeq and 75 dB LAmax at 10

metres distance.

In the worst case, noise levels of up to around 62 dB LAeq and maximum noise levels up to around 80

dB LAmax have been measured at 10 metres distance during football matches. In the case of hockey, up

to 84 dB LAmax at 10 metres has been observed. The measurements also show that the noise levels

around sports pitches are reasonably constant for a typical match; there is little difference between

noise levels measured behind the goals and near the half-way line.

There is also only a very small difference in noise levels created by adult’s and children’s matches.

There is not a significant difference in noise levels between hockey and football matches, however,

higher maximum noise levels can be created when hockey is played:-

• Striking of the ball, measured at 10m LAmax 72 – 81 dB

• Ball striking wooden goal back board, measured at 10m LAmax 77 – 84 dB

• Ball striking wooden rebound board, corrected to 10m LAmax 71 – 80 dB



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Uplands Community College, Wadhurst - Proposed Sports Pitch

Barrier Attenuation h (Source) h(Reciever) h(Barrier) d(S-B) d(B-R) d(S-B-R)

1.5 1.5 2.5 3.0 27.0 30.0

d(SBR) d(SR)

30.18 30.00

a b c Path Diff Log (Path Diff)

3.16 27.02 30.00 0.180790 -7.43E-01

h(S)-H(R) h(S)-H(R)/SBR Theta h(min shadow) Zone

0 0 0 1.5 Shadow

Frequency (Hz) 500

Barrier Correction dB(A)

CRTN -10.54

Calculation for Railway Noise Reflective Barrier -9.89

Absorptive Barrier -11.82

Fresnel At Frequency (Hz) 500 -11.3

Octave Band 63 -6.4

125 -7.5

250 -9.2

500 -11.3

1000 -13.8

2000 -16.5

4000 -19.4

8000 -22.3

63 125 250 500 1k 2k 4k 8k

Measured Level at 15m 65.2 60.1 55.4 51.6 50.7 46.4 38.6 31.2 55.3 db(A)

Level at 30m Distance 59.2 54.1 49.4 45.6 44.7 40.4 32.6 25.2 49.2 dB(A)

Barrier Attenuation -6.4 -7.5 -9.2 -11.3 -13.8 -16.5 -19.4 -22.3

Resultant Level 52.8 46.6 40.2 34.3 30.9 23.8 13.2 2.8 37.7 db(A)

APPENDIX III – CALCULATIONS

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