A11. Noise and Vibration · PDF file11/9/2014 · SgurrEnergy Linfairn Wind Farm Addendum Chapter A11: Noise and Vibration 14/7048/001/GLA/O/R/001 Revision B1 Page 2

SgurrEnergy Linfairn Wind Farm Addendum Chapter A11: Noise and Vibration

14/7048/001/GLA/O/R/001 Revision B1 Page 1 of 33

Certified to ISO 9001, ISO 14001 and OHSAS 18001

A11. Noise and Vibration

11.1 Introduction

Noise can have an effect on the environment and on the quality of life enjoyed by

individuals and communities. This assessment considers the noise impact at noise

sensitive receptors (NSRs) through the construction, operation and decommissioning of

the Linfairn Wind Farm (“the Project”). The assessment has been carried out by

SgurrEnergy Ltd.

For this Addendum, new background noise data was gathered which informed the

assessment of the revised Project layout. This Addendum chapter therefore

supersedes ES Chapter 11.

11.2 Scope of the Assessment

11.2.1 Study Area

The study area considered in this chapter of the Addendum considers the likely

significant effects in terms of noise of the Project wind turbine generators (WTGs) at

NSRs. This chapter provides details on the assessment methodology; the baseline

conditions currently existing at the Project site and surroundings; the likely significant

noise effects during the construction, operation and decommissioning phases of the

Project; the mitigation measures required to prevent, reduce or offset any significant

adverse effects; and the likely residual effects after these measures have been

employed.

Construction noise effects are normally of a temporary nature and result from both

moving and static sources. Assessment allows the temporary impact of construction

noise to be understood and for suitable mitigation measures to be identified to minimise

any potential adverse effects.

When operational, WTGs emit two types of noise – mechanical noise and aerodynamic

noise. The main sources of mechanical noise are from internal components housed

within the nacelle, such as gearbox and generator. Mechanical noise from a modern

WTG is negligible as designs are highly refined. Aerodynamic noise occurs from the

movement of the blades passing through the air. At high wind speeds, that aerodynamic

noise is usually masked by the increasing sound of wind blowing through trees and

around buildings, and turbulent noise within the air itself. The level of masking

determines the perceived audibility of the wind farm. The noise impact assessment

establishes the relationship between WTG noise and the natural masking noise and

assesses levels against established standards.




11.2.2 Scoping and Consultation

The initial Section 36 application was submitted to the Scottish Government Energy

Consents and Deployment Unit (ECDU) on 27 September 2013 with responses

received in November / December 2013. Set out below is a summary of relevant

consultation responses with details of how these have been taken into consideration

within the revised measurements and assessments presented here.

Table A11-1: Summary of Consultation Responses

Consultee Summary of

Response Comment / Action

Relevant Section

of This Chapter

South

Ayrshire

Council

Environmental

Health Officer

(Fiona Grant)

The proposed

monitoring locations

and the intended

monitoring periods were

confirmed during a

telephone call between

SgurrEnergy personnel

and the South Ayrshire

Council Environmental

Health Officer. It was

agreed upon that four

receptors would be

considered, these being

Balbeg Cottage/Balbeg

House, Genoch

Cottage, Linfairn and

Tairlaw Farm, though

the precise location of

the instruments would

be determined (and

agreed) on the

installation day.

The EHO requested

that she accompany

SgurrEnergy personnel

on site when deploying

the equipment to agree

the locations and assist

with any queries

residents may have.

The installation of the

noise monitoring

instruments was carried

out by SgurrEnergy

personnel and overseen

by the South Ayrshire

Council EHO at each of

the agreed upon

monitoring locations on

15 October 2014. The

locations were deemed

mutually satisfactory by

the EHO and

SgurrEnergy personnel.

Monitoring locations were

agreed upon as:

Balbeg Cottage.

Genoch Cottage.

Linfairn Farm.

Tairlaw Farm.

Section 11.4

(Baseline Data

Collection)






Relevant Section

of This Chapter

Save Straiton

for Scotland

(SSfS)

Community

Group

ETSU-R-97 does not

fulfil the requirement of

a description of the

likely significant effects

in the EU Directive.

ETSU-R-97 is the method

approved by the UK and

Scottish Governments.

Section 11.3.1

(Regulatory and

Policy Context)

For example (in relation

to the above comment)

at night the lower

ETSU- R-97 limit is

43dB. At a wind speed

of around 6m/s when

turbines might have

reached more or less

their maximum noise

output they could be

running at this limit of

43dB. At one site,

perhaps near a main

road system, the

background noise level

could be 38dB and so

the margin of turbine

noise over background

noise is 5dB. At another

site the background

noise might be 28dB

and the margin 15dB.

Clearly the significance

of the impact is more in

the second case than in

the first but ETSU-R-97

does not take this into

account.

The 43dB limit is

reiterated in the Institute

of Acoustics’ (IOA’s) good

practice guide (GPG),

issued May 2013, which

has been endorsed by the

Scottish Government, as

well as by DECC.

Section 11.3.1

(Regulatory and

Policy Context)






Relevant Section

of This Chapter

The background noise

levels are surprisingly

high for the area, which

I have visited, and are

not representative of

typical background

noise levels likely to be

found at local

residences in such a

rural location.

New background noise

measurements were

carried out for the revised

layout of the Project in

October 2014. The

background noise levels

gathered are generally

similar to, or higher than,

those previously gathered

in 2013.

Section 11.4.1

(Baseline Data

Collection - Current

Conditions)

One of the reasons for

the high background

noise level is almost

certainly that the wind

speed was not

measured on the wind

farm site. It was

measured at Grid

Reference

37929/01165. This is at

a height of about 182m

AOD compared with the

nearest turbine which is

at about 220m AOD and

the height of most of the

turbines at around 250

to 300m AOD. It is also

over 600m from the

nearest turbine.

The wind speeds at this

location are likely to be

less than those on the

wind farm site and this

would result in a higher

background noise level

curve.

A lidar was deployed on

site in the location of the

proposed WTGs during

the same time as noise

equipment was installed

at the four receptors.

The previous wind speed

data gathered have not

been used for this

assessment and therefore

this comment is no longer

applicable.

Section 11.4.1

(Baseline Data


Conditions)






Relevant Section

of This Chapter

From the photographs

some of the locations

appear to be in exposed

locations and not, as

required in ETSU-R-97,

in garden areas

available for rest and

recreation.

The background noise

measurements, as stated

above, were redone for

this Addendum with the

locations agreed in

advance by the EHO and

during an accompanied

site visit for installation of

equipment.

Section 11.4.1

(Baseline Data


Conditions)

At Little Garroch, there

appears to be a change

in the sensitivity of the

equipment after the visit

of 06 September. This

results in levels of more

than 10dB greater in the

second period

compared with the first.

As above. This comment

is no longer applicable.

Section 11.4.1

(Baseline Data


Conditions)

At Dyke there is strong

banding of noise and

this appears to be due

to water in a nearby

watercourse producing

high levels after rainfall.

In accordance with

ETSU-R-97 this period

of water noise should

have been removed

(not just periods when it

was raining).


measurements have been

made and great care

taken to minimise noise

from watercourses.

Locations were agreed by

the EHO.

Section 11.4.1

(Baseline Data


Conditions)






Relevant Section

of This Chapter

At Linfairn there is also

banding, some of which

appears to be water

noise but other high

noise levels may be

activity typical of a

working farm,

particularly during the

night and possibly

including plant or

machinery.



Section 11.4.1

(Baseline Data


Conditions)

At Tairlaw the levels are

similarly high day and

night but do not show

obvious signs of plant

and machinery. Again

this is a working farm.

The graphs in the ES

state that the dawn

chorus has been

removed. However, I

cannot see any

significant evidence of

dawn chorus and,

indeed it is unlikely in

such a location at this

time of year.








Relevant Section

of This Chapter

I believe there are a few

properties that would be

considered as having

concave ground (see

4.3.9 of the IOAGPG)

from some turbines and

would therefore have

higher noise levels than

quoted in the table. This

appears to apply to

Craigencallie and

Craigard from the three

nearest turbines.

Noted. This has now

been applied.

Section 11.6.3

(Description and

Evaluation of Effects

- Operation)

In Appendix 1 I have set

out some omissions,

errors and clarifications

to the applicant’s list of

properties. I have also

supplied Table 1, a

table of properties I

believe to be within the

35dB noise contour.

There are 34 such

properties of which, I

understand, four have

occupants who are

financially involved.

The names of properties

used in this assessment

have been updated.

Section 11.3.3

(Assessment

Methodology -

Operational)






Relevant Section

of This Chapter

In the absence of what I

believe to be reliable


I have based my own

assessment on the

average of all the

background noise

measurements carried

out for Assel Valley.

In Tables 6 and 7 I have

set out the margin of

turbine noise over

background noise. It

can be seen that, during

the day 12 properties

will suffer a major loss

of amenity and others a

significant loss. At night

22 locations (27

properties) will suffer a

major loss of amenity

and all the others on my

list a significant loss.


measurements were

carried out for the revised

layout of the Project in

October 2014. The


gathered are generally

similar to, or higher than,

those previously gathered

in 2013.

Section 11.4.1

(Baseline Data


Conditions)

11.3 Assessment Methodology

11.3.1 Regulatory and Policy Context

An overview of key guidance with respect to construction and operational noise is

outlined below, and further details of legislation, policy and guidance specifically for

operational noise (ETSU-R-971) are set out in Section 11.3.3.

1 ETSU-R-97 (2007) The Assessment and Rating of Noise from Wind Farms, ETSU for the Department of Trade and

Industry




The effect of construction noise has been assessed in accordance with British Standard

(BS) 5228 Part 1: 2009 Code of Practice for Basic Information and Procedures for Noise

and Vibration Control2. BS 5228 provides best practice guidance on the control of noise

from construction activities.

Noise propagation has been modelled in accordance with International Standard ISO

9613-2: 1996 Acoustics – Attenuation of Sound Propagation Outdoors – Part 2: General

Method of Calculation3.

PAN 1/2011: Planning and Noise4 provides advice on how the planning system can be

used to reduce the adverse impact of noise without placing unreasonable restrictions on

development or adding unduly to the costs and administrative burdens of business.

The Scottish Government’s online planning advice5 and in particular, the page on

onshore WTGs, recommends the framework set out in the report The Assessment and

Rating of Noise from Wind Farms (ETSU-R-97) for the measurement of WTG noise. It

gives indicative noise levels calculated to offer a reasonable degree of protection to

those living near to WTGs, without placing unreasonable restrictions on wind farm

development. It also states that well-specified and well-designed wind farms should be

located so that increases in ambient noise levels around noise sensitive receptors are

kept to acceptable levels in relation to existing background noise. This will normally be

achieved through good design of the WTGs and through allowing sufficient distance

between the WTGs and any existing noise-sensitive development so that noise from the

wind farm will not normally be significant. Noise levels from WTGs are generally low,

and under most operating conditions it is likely that WTG noise would be completely

masked by wind-generated background noise.

The impact of operational noise has been assessed in accordance with ETSU-R-97,

taking cognisance of the most recent good practice guide (GPG) of the Institute of

Acoustics6, and Supplementary Guidance Notes7. This is acknowledged by the Scottish

Government's online guidance on onshore wind turbines:

2 British Standard 5228: Parts 1 and 2 (2009) Code of practice for noise and vibration control on construction and open

sites, BSI, 2009

3 International Standard ISO 9613-2: 1996, Acoustics – Attenuation of Sound during Propagation Outdoors

4 Planning Advice Note 1/2011, Planning and Noise, http://www.scotland.gov.uk/Resource/Doc/343210/0114180.pdf,

(Scottish Government, last viewed 11 September 2014)

5 Renewable Energy, http://www.scotland.gov.uk/Topics/Built-Environment/planning/National-Planning-

Policy/themes/renewables (Scottish Government, last viewed 01 July 2013)

6 A Good Practice Guide to the Application of ETSU-R-97 for the Assessment and Rating of Wind Turbine Noise, Institute

of Acoustics, May 2013

http://www.scotland.gov.uk/Resource/Doc/343210/0114180.pdf

http://www.scotland.gov.uk/Topics/Built-Environment/planning/National-Planning-Policy/themes/renewables

http://www.scotland.gov.uk/Topics/Built-Environment/planning/National-Planning-Policy/themes/renewables




"The Scottish Government accepts that the guide represents current industry good

practice".

11.3.2 Construction

Sound power levels of noise sources associated with the construction activities are

taken from BS 5228. Noise is dominated first by the construction of the access track

and subsequently by the WTG foundation excavation and piling. The aggregate level of

quasi-static noise from the machinery involved in the access track construction, taking

account of duty time, is 115dB(A) (Table A11-2). The aggregate level of static noise

from the machinery involved in the foundation construction, taking account of assumed

duty time, is 115 dB(A) (Table A11-3). Heavy vehicle noise is taken as a worst-case of

an unladen dump truck, producing a sound pressure level (SPL) of 87dB(A) at 10m,

equivalent to a sound power level of 115dB(A), assuming hemispherical spreading to

10m.

7 A Good Practice Guide to the Application of ETSU-R-97 for the Assessment and Rating of Wind Turbine Noise,

Supplementary Guidance Notes 1-5, November 2013 - September 2014




Table A11-2: Access Road Quasi-Static & Compound Static Plant Utilisation

(Sound Power are in decibels relative to 10-12

Watts)

Plant Item No.

Utilisation BS 5228

reference

LAeq at

10m, dB

SWL

% dB(A)

Excavator 1 50% Table C2 No.

19 77 105

Transporter 1 100% Table C2 No.

27 80 108

Dump truck

(tipping) 1 20%

Table C2 No.

30 79 107

Dump truck

(empty) 1 40%

Table C2 No.

31 87 115

Grader 1 50% Table C6 No.

31 86 114

Roller 1 10% Table C2 No.

37 79 107

Equivalent ∑ 115 dB(A) SWL




Table A11-3: WTG Foundation Excavation and Construction Static Plant

Utilisation (Sound Power are in decibels relative to 10-12

Watts)

Plant Item No Off

Utilisation BS 5228

reference LAeq at 10m, dB

SWL

% dB(A)

Excavator 1 50% Table C2 No. 19

77 105

CPA piling rig 1 20% Defra Table

3 No. 21 79 107

Auxiliary crane 1 20% Defra Table

3 No. 48 76 104

Concrete truck 1 20% Defra Table

3 No. 27 79 107

Transporter 1 10% Table C2 No. 27

80 108

Dump truck (tipping)

1 20% Table C2 No. 30

79 107

Dump truck (empty)

1 40% Table C2 No. 31

87 115

Grader 1 50% Table C6 No. 31

86 114

Roller 1 10% Table C2 No. 37

79 107

Excavator 1 50% Table C2 No. 19

77 105

CPA piling rig 1 20% Defra Table

3 No. 21 79 107

Auxiliary crane 1 20% Defra Table

3 No. 48 76 104

Concrete truck 1 20% Defra Table

3 No. 27 79 107

Transporter 1 10% Table C2 No. 27

80 108

Equivalent ∑ 115 dB(A) SWL




There are no legal limits on the noise received at nearby NSRs, only a variety of

sources of guidance. Thus it is necessary to agree criteria with local authorities. The

limiting criteria for construction noise, shown in Table A11-4 have been taken from

BS 5228. Any predicted excesses over these limits will be considered to have significant

effect.

It has been assumed for the purposes of this assessment that the construction activities

will generally take place between 0700 and 1900 Monday to Friday and 0700 to 1300

on Saturdays. WTG assembly may take place at night, but over a relatively short time,

and neighbours will be kept informed well in advance. There will be no working without

prior agreement on Sundays or bank holidays.

Table A11-4: Construction Noise Level Limits at Noise Sensitive Receptors

Period Hours LAeq (Work Period)

Monday to Friday

0700-1900 65

1900-2300 55

2300-0700 45

Saturday

0700-1300 65

1300-2300 55

2300-0700 45

Sunday

0700-2300 55

2300-0700 45

Unattended Plant - 45

11.3.3 Operational

The assessment of operational noise effects was undertaken following the guidance of

ETSU-R-97. This recommends a methodology for measuring prevailing background

noise at a wind farm site and for defining operational noise thresholds. Details of the

ETSU guidance are set out below.

The current practice on controlling wind farm noise imposes noise limits at the NSRs.

Noise limits should be applied to external locations and should apply only to those areas

frequently used for relaxation or activities for which a quiet environment is highly

desirable.




Noise limits set relative to the background noise are more appropriate than fixed limits

in the majority of cases. Generally, the noise limits should be set relative to the existing

background noise at the NSRs and the limits should reflect the variation in both WTG

source noise and background noise with wind speed.

Separate noise limits should apply for day-time and for night-time as during the night the

protection of external amenity becomes less important and the emphasis should be on

preventing sleep disturbance. Absolute noise limits and margins above background

should relate to the cumulative effect of all WTGs in the area contributing to the noise

received at the properties in question. Any existing WTGs should not be considered as

part of the prevailing background noise.

The LA90,10min descriptor should be used for both the background noise and the wind

farm noise, and when setting limits it should be borne in mind that the LA90,10min of the

wind farm is likely to be about 1.5-2.5dB(A) less than the LAeq measured over the same

period. The use of the LA90,10min descriptor for wind farm noise allows reliable

measurements to be made without corruption from relatively loud, transitory noise

events from other sources.

For single WTGs or wind farms with very large separation distances between the WTGs

and the nearest properties, a simplified noise condition may be suitable. If the noise is

limited to a LA90,10min of 35dB(A) up to wind speeds of 10 m/s at 10m height, then this

condition alone would offer sufficient protection of amenity, and background noise

surveys would be unnecessary.

In this case, the construction and operational noise impact assessment considered 26

receptors which cover a range of directions from the Project WTGs. They are listed in

Table A11-5. Those marked with an asterisk (*) have a financial interest in the Project.

Background noise levels were measured at those in bold.




Table A11-5: Noise Sensitive Receptors (NSRs)

ID Receptor Easting (m) Northing (m)

Approximate Distance from

nearest Project WTG (km)

A Balbeg 238156 602428 1.9

B Balbeg Cottage 238195 602330 1.8

C Craigfad 238428 602727 2.2

D Dalrowan 238239 602117 1.6

E Little Garroch 238323 602685 2.2

F Craigencallie Cottage 238884 601489 1.4

G Genoch Farm* 239081 601092 1.3

H Genoch Cottage 239049 600791 1.0

I Craigard 239025 601390 1.4

J Bennan Farm* 237902 604531 3.8

K Craig 238730 602657 2.3

L Dalmorton* 238260 601906 1.4

M Knockskae 237279 601396 0.7

N Linfairn Farm* 238159 601207 0.8

O Pulmullen Cottage* 238216 601662 1.2

P Glenlinn Cottage* 238134 601548 1.1

Q Duncawin 238192 602290 1.7

R Glengill Cottage 239881 600889 1.7

S Sunnyside 240239 600664 2.0

T Tairlaw Farm 240316 600903 2.2

U Tairlaw Toll Cottage 239762 599541 1.4

V Tallaminoch 240021 598257 2.0

W Knockgardner* 235159 603471 3.5

X Shawsknowe 233903 603253 4.1

Y Cullochknowes 2 233390 602664 4.1

Z Glenalla Farm 234709 600152 2.1




It is noted that receptors J, W, X and Y are more than three kilometres from the Project

WTGs and are therefore unlikely to be affected by noise during either the construction

or operational phase of the Project. These receptors are considered only to allow the

assessment to be carried out for receptors in all directions from the Project WTGs.

11.4 Baseline Data Collection

The operational noise of wind farms is assessed by comparison with existing

background noise. Background noise is usually measured in the external amenity of

nearby NSRs. Measurements are made in ten-minute intervals over an extended

period.

Background noise monitoring was undertaken at four locations, each representing a

group of NSRs that are acoustically similar. (Highlighted in Table A11-5). The

monitoring locations were discussed between SgurrEnergy and the South Ayrshire EHO

prior to the installation of sound level meters. As noted in Table A11-1, the exact

locations of the noise monitoring kit were determined on the day of installation and

overseen by the South Ayrshire Council EHO.

Background noise measurements were obtained between 15 October 2014 and 20

November 2014 at Balbeg Cottage, Genoch Cottage and Linfairn Farm and from 23

October 2014 to 20 November 2014 at Tairlaw Farm. The slight difference in monitoring

period was due to construction works on the roof of Tairlaw Farm which were on-going

at the beginning of the measurement period. Appendix A11.1 shows photographs of the

microphone positions in the environment of the background noise monitoring receptors.

Other existing wind farms are over 10 km away, and would not be expected to

contribute significantly to the background noise at that distance. Hence no corrections

were made to the recorded data.

Of the four receptors, Balbeg Cottage (B) was chosen to represent receptors A-E,

Genoch Cottage(H) was chosen to represent receptors F-I, Linfairn Farm (N) was

chosen to represent J-Q and Tairlaw Farm (T) was chosen to represent receptors R-Z.

The reasoning for choice of receptor is based mainly on proximity to the monitoring

location or acoustic similarity to the receptor of interest. For receptors W-Z, Tairlaw

Farm was chosen to be representative as this receptor recorded the lowest background

noise measurements over the monitoring period and is deemed to be a conservative

approach for these more distant receptors.

Measurements were made in accordance with best practice set out in ETSU-R-97, (i.e.

at a height of 1.2 m to 1.5 m above ground level and not less than 3.5 m from any

reflective façade). The instruments used were Rion NL-32 and Rion NL-52 sound level

meters, Rion UC-53A microphones, Rion NH-21 preamplifiers and Rion WS-10 wind

shields. The sound level meters were calibrated at the initial deployment, at each

subsequent maintenance visit and upon decommissioning. The meters read correctly

each time.




Care was also taken to position the microphones as far as reasonably practicable from

potentially noisy trees, bushes and watercourses.

The measurement locations were as shown in Table A11-6 and Appendix 11.1.

Table A11-6: Measurement Locations

ID Receptor Easting (m) Northing (m)

B Balbeg Cottage 238223 602331

H Genoch Cottage 239054 600804

N Linfairn Farm 238184 601226

T Tairlaw Farm 240328 600903

- Lidar 238156 600021

Rainfall was measured on site using a Campbell Scientific ARG100 tipping bucket rain

gauge and a Campbell Scientific CR10X data logger. Periods of rainfall were excluded

from the analysis.

Wind speed measurements were also carried out over the duration of the noise

measurements, using a Galion lidar remote sensing device. The measurement height,

amongst others, was 76m which matches the revised proposed hub height of the

Project. The wind speed was then referenced back to 10m using a hypothetical surface

roughness length of 0.05m, as recommended by the GPG Sound power levels of WTGs

have historically been referenced to 10m with a 0.05m surface roughness; this ensures

a consistent treatment of wind speeds and noise levels.

Ten minute consecutive noise measurements of LA90 were undertaken throughout the

measurement period. Noise levels were measured in conjunction with wind speed data

in order to correlate background noise levels with changes in wind speed.

11.4.1 Current Conditions

The noise monitoring results have been analysed in accordance with the procedures

outlined in ETSU-R-97.

The measured LA90 noise levels at 10-minute intervals have been correlated with the

wind speed measurements at 10 minute intervals standardised to a height of 10m

following the procedure recommended by the GPG for the period of the noise

measurement survey.

Any 10-minute interval in which unusually high noise levels were logged for a given

wind speed has been discarded.




The measurement results have then been separated into the different time periods for

quiet daytime and night-time limits.

The LA90, 10-minute noise levels have been plotted against the corresponding wind

speeds at the reference height of 10m. For each period a polynomial “best-fit”

regression curve is fitted to the data.

The resultant background noise levels against wind speed at the four measurement

locations are shown in Table A11-7 below. The wind speed-background noise scatter

plots associated with these values are provided in Appendix A11.2, Appendix A11.3,

Appendix A11.4 and Appendix A11.5 for Balbeg Cottage, Genoch Cottage, Linfairn

Farm and Tairlaw Farm respectively. The background noise is relatively independent of

wind speed.

In choosing the background noise measurement locations, great care was taken to

avoid running water and, as far as possible, central heating pumps. Final measurement

locations were agreed with the EHO who was present during installation of the

equipment. Nevertheless, the background noise was consistently high, in some cases

higher than that measured during the 2013 baseline noise monitoring.

Table A11-7: Background Noise Levels, L90, dB(A)

Receptor Balbeg Genoch Linfairn Tairlaw

Wind

Speed

(m/s)

Quiet

Day

Night-

time

Quiet

Day

Night-

time

Quiet

Day

Night-

time

Quiet

Day

Night-

time

4 36.4 35.3 37.1 36.4 34.4 33.0 33.8 33.5

5 36.7 35.6 37.0 36.5 34.7 33.0 34.4 34.1

6 37.1 36.3 37.1 36.8 35.4 33.8 35.0 34.8

7 37.8 37.3 37.2 37.3 36.4 35.1 35.8 35.6

8 38.8 38.5 37.5 38.0 37.7 37.0 36.6 36.6

9 40.2 40.0 38.0 39.0 39.4 39.1 37.6 37.8

10 42.1 41.8 38.8 40.1 41.5 41.5 38.7 39.1

11 44.6 43.8 39.9 41.4 44.0 43.9 39.9 40.6

12 47.6 46.0 41.3 42.8 46.9 46.2 41.4 42.2




11.5 Assessment of Effects

11.5.1 Construction & Grid Connection

The results of the calculation of received levels of noise at sensitive receptors during

Stage 1, (construction of access track) are summarised in Table A11-8. The levels have

been assessed on a worst case basis, i.e. with limited attenuation and assuming works

will be done concurrently (rather than consecutively).

Table A11-8: Predicted Noise Levels Received at NSRs for Stage 1 activities,

(Construction of Access Track)

ID Receptor SPL dB(A) LEq

A Balbeg 55.5

B Balbeg Cottage < 57.0

C Craigfad < 55.5

D Dalrowan < 57.0

E Little Garrioch < 55.5

F Craigencallie 51.7

G Genoch 51.5

H Genoch Cottage < 54.3

I Craigard < 51.5

J Bennan < 55.5

K Craig <55.5

L Dalmorton 57.0

M Knockskae 67.8

N Linfairn 61.1

O Pulmullen < 61.1

P Glenlinn < 61.1

Q Duncawin < 61.1

R Glengill < 51.5

S Sunnyside < 51.5

T Tairlaw Farm < 51.5

U Tairlaw Toll Cottage 52.9

V Tallaminoch < 52.9

W Knockgardner < 44.0

X Shawsknowe < 44.0





Y Cullochknowes 2 < 44.0

Z Glenalla 44.0

The results of the calculation of received levels of noise at sensitive receptors during

Stage 2, (installation of WTGs and ancillary equipment) are set out in Table A11-9. The

results assume a worst case basis, i.e. with limited attenuation and assuming works will

be done concurrently (rather than consecutively).

Table A11-9: Predicted Noise Levels Received at NSRs for Stage 2 activities,

Installation of WTGs and Ancillary Equipment


A Balbeg 55.9

B Balbeg Cottage < 57.2

C Craigfad < 55.9

D Dalrowan < 57.2

E Little Garrioch < 55.9

F Craigencallie 54.3

G Genoch 54.1

H Genoch Cottage < 54.4

I Craigard < 54.1

J Bennan < 55.9

K Craig < 55.9

L Dalmorton 57.2

M Knockskae 65.3

N Linfairn 61.0

O Pulmullen < 61.0

P Glenlinn < 61.0

Q Duncawin < 61.0

R Glengill < 54.1

S Sunnyside < 54.1

T Tairlaw Farm < 54.1

U Tairlaw Toll Cottage 47.6

V Tallaminoch < 47.6

W Knockgardner < 48.3





X Shawsknowe < 48.3

Y Cullochknowes 2 < 48.3

Z Glenalla 48.3

11.5.2 Operational Noise

The criteria for operational noise are based on existing background noise, subject to

fixed lower limits. The results of the background noise survey are presented in Table

A11-7.

Based on the ETSU guidance, criteria are 5 dB above local background noise, subject

to various lower limits. Where background noise levels are not available at high wind

speeds, a constant background noise level is assumed; this assumption is very

conservative. At levels above the criteria the noise emissions from the Project would be

considered a significant effect.

ETSU-R-97 defines night time to be the period between 23:00 and 07:00. Quiet day

time is defined as the period between 18:00 – 23:00 every day, as well as 13:00 – 18:00

on a Saturday and 07:00 – 18:00 on a Sunday.

The choice of day time noise criterion is in the range of 35 dB to 40 dB, as the limit of

low wind speeds depends on the number of sensitive receptors, the power output of the

development and the duration and level of exposure. The night time criterion generally

applied is 43 dB. The exception to this is either where the criterion of 5 dB above local

background noise is greater than the defined limit, and/or where appropriate financial

involvement is in place, in which case the appropriate limit is set at 45dB.

The following limits have been applied to the Project for the purposes of this

assessment:

Day time - the 35 dB limit or 5 dB above local background noise (whichever the

greater) limit has been used. For properties with financial interest, the 45 dB limit

is considered the appropriate level.

The night time limit of 43 dB, or 5 dB above local background noise (whichever

the greater), is recommended by ETSU-R-97, unless a receptor has appropriate

financial involvement where a 45 dB limit or 5 dB above local background noise

(whichever the greater) is used.




11.5.2.1 WTG Emission Data

The operational noise has been assessed based on the Siemens SWT-3.2-101

(3.2MW) WTG, using information supplied by Siemens. Both full power (Standard

setting) and noise curtailed modes are included. The sound power level against wind

speed is shown in Table A11-10.

Table A11-10: Candidate WTG Sound Power Level against Wind Speed, dB(A)

WTG Operational

Mode

Wind speed (m/s)

4 5 6 7 8 9 10 11 12+

Standard

Setting 95.1 99.6 104.3 106.5 107.0 107.0 107.0 107.0 107.0

-1dB 95.1 99.6 104.3 106.0 106.0 106.0 106.0 106.0 106.0

-2dB 95.1 99.6 104.1 105.0 105.0 105.0 105.0 105.0 105.0

-3dB 95.1 99.6 103.8 104.0 104.0 104.0 104.0 104.0 104.0

-4dB 95.1 99.6 103.0 103.0 103.0 103.0 103.0 103.0 103.0

-5dB 95.1 99.6 102.0 102.0 102.0 102.0 102.0 102.0 102.0

-6dB 95.1 99.6 101.0 101.0 101.0 101.0 101.0 101.0 101.0

The standard warranty terms are to permit these levels to be exceeded by up to 1.5 dB

or one standard deviation, whichever is greater. Thus a tolerance of 2.0 dB has been

assumed.

Spectral levels are not warranted, but typical octave band spectra for 6 m/s and 8 m/s

are shown in Table A11-11 and Table A11-12.




Table A11-11: Manufacturer’s Typical Sound Power Frequency Distribution at

6 m/s (dB(A))

Octave Band (Hz)

63 125 250 500 1000 2000 4000 8000

Standard setting 85.9 90.0 94.7 97.0 100.0 97.5 92.0 78.0

-1dB 85.9 90.0 94.7 97.0 100.0 97.5 92.0 78.0

-2dB 85.9 90.0 94.5 96.8 99.8 97.3 91.8 77.8

-3dB 85.8 89.9 94.2 96.5 99.5 97.0 91.5 77.5

-4dB 85.3 89.9 93.5 95.7 98.7 96.3 90.7 76.8

-5dB 85.1 89.5 92.4 94.6 97.6 95.2 89.6 75.7

-6dB 84.8 89.1 91.3 93.5 96.5 94.1 88.5 74.6

Table A11-12: Manufacturer’s Typical Sound Power Frequency Distribution at

8 m/s (dB(A))

Octave Band (Hz)

63 125 250 500 1000 2000 4000 8000

Standard setting 87.4 93.8 97.7 99.5 102.5 100.6 94.5 80.9

-1dB 87.2 93.5 96.7 98.5 101.5 99.6 93.5 79.9

-2dB 86.9 93.1 95.6 97.4 100.4 98.5 92.4 78.8

-3dB 86.7 92.7 94.6 96.4 99.4 97.5 91.4 77.8

-4dB 86.5 92.4 93.5 95.3 98.3 96.4 90.3 76.7

-5dB 86.3 92.0 92.4 94.2 97.2 95.3 89.2 75.6

-6dB 86.1 91.6 91.3 93.1 96.1 94.2 88.1 74.5




11.5.2.2 Wind farm operational noise propagation model

The sound propagation over distance, including the effect of atmospheric absorption,

was calculated using the WindPRO model based on ISO 9613-2. In accordance with the

GPG (see Section 11.3.1) a ground factor of 0.5 was used with measured sound power

levels increased by 2.0 dB uncertainty. The receiver height was taken to be 4 m and air

absorption characteristic of 10ºC, 70% relative humidity was used. No screening was

assumed.

11.5.3 Decommissioning

It is considered that the noise effects of the decommissioning phase of the Project will

be similar to those associated with the construction phase and therefore no additional

assessment has been carried out for decommissioning.

11.6 Description and Evaluation of Effects

All NSRs are assessed as being of high sensitivity. The magnitudes of change, and

resulting effects are described in Table A11-13. Those effects above Moderate are

considered significant in terms of the EIA Regulations.

Table A11-13: Magnitude of Change and Resulting Effect

Excess over Criterion Magnitude of Change Effect

> 0 dB Criterion not met Significant

< 0 dB Criterion met Not Significant

11.6.1 Construction

Comparing the contents of Table A11-8 with those of Table A11-4 it will be seen that the

levels of noise attributable to the activities associated with the construction of the

access track, and predicted to be received at the NSRs, are below the threshold for

significant effect, except at Receptor M, Knockskae. It should be noted that the only

time the level there is excessively high is during construction of the access track where

it passes close to the receptor. This work will only take a few days and should be

scheduled in consultation with the residents there to minimise their inconvenience.

Comparison of the contents of Table A11-9 with those of Table A11-4 indicates that the

level of the noise predicted to be received at the nearest NSRs during Stage 2 of the

construction during normal working hours is below the threshold for significant effect,

with the exception again of Receptor M, Knockskae.

Where 24 hour working is needed for WTG installation there are various measures

available to mitigate noise impacts. Night time working will be very brief and infrequent.




11.6.2 Vibration due to Construction

Currently there is no standard source of guidance providing a methodology by which to

predict vibration levels attributable to construction activities other than that for

percussive piling contained in BS 5228. When construction activities are within a few

tens of metres from a sensitive receptor, vibration may just be perceptible. Due to the

hundreds of metres between the construction activities and the sensitive receptors,

perceptible vibrations from these activities will not be transmitted to these receptors. In

summary, the relative significance of the effect of vibration is assessed as being

Negligible and not significant.

11.6.3 Operation

11.6.3.1 Operational Assessment – Project Individually

The noise impact assessment assumes that the sound energy propagates in all

directions from the WTG. Some energy will be absorbed in the air and some by the

ground. On that basis, the predicted levels received at the NSRs, as a function of wind

speed, referenced to 10m above ground level, are as shown as a noise contour map in

Appendix A11.6. The day and night-time criteria are presented in tabular format in Table

11.1 of Appendix A11.7 and graphically in Appendix A11.8. The graphs compare the

prediction (grey) with the quiet daytime criteria (in blue) derived from the quiet daytime

background and the night-time criteria (orange) derived from the night-time background.

The graphs and tables show that the predicted operational noise levels for all NSRs

meet the day- and night-time criteria, with the exception of Receptor M, Knockskae

where the WTG noise exceeds the day-time criteria at 7m/s by 0.5dB. The effect is

assessed as Not Significant for all receptors except Knockskae, where it is Significant.

11.6.4 Infra-sound

Infra-sound is defined as noise occurring at frequencies below that at which sound is

normally audible, i.e. at less than 20Hz, due to the significantly reduced sensitivity of the

ear at such frequencies. In this frequency range, for sound to be perceptible, it has to be

at very high amplitude and it is generally considered that when such sounds are

perceptible then they can cause considerable annoyance.

WTGs have been cited as significant producers of infra-sound. This has, however, been

due to the high levels of such noise, as well as an audible, low frequency, thumping

noise, occurring on older ‘downwind’ WTGs of which many were installed in the USA

prior to the large-scale take up of wind power production in the UK. Downwind WTGs

are configured with the blades downwind of the tower such that the blades pass through

the wake left in the wind stream by the tower resulting in a regular audible thump, with

infra-sonic components, each time a blade passes the tower. All modern WTGs are of

the upwind design, with the blades upwind of the tower, and this effect is eliminated.




A study for the DTI8 concluded that ‘Infrasound noise emissions from WTGs are

significantly below the recognised threshold of perception for acoustic energy within this

frequency range. Even assuming that the most sensitive members of the population

have a hearing threshold which is 12dB lower than the median hearing threshold,

measured infrasound levels are well below this criterion’. It goes on to state that, based

on information from the World Health Organisation, ‘there is no reliable evidence that

infrasound below the hearing threshold produce physiological or psychological effects’ it

may be concluded that ‘infrasound associated with modern WTGs is not a source which

may be injurious to the health of a wind farm neighbour’. Therefore it is concluded that

this effect is Negligible.

11.6.5 Low Frequency Noise

Noise from modern WTGs is essentially broad band in nature in that it contains similar

amounts of noise energy in all frequency bands from low to high frequency. As distance

from a wind farm site increases, the noise level decreases as a result of the spreading

out of the sound energy but also due to air absorption which increases with increasing

frequency. This means that although the energy across the whole frequency range is

reduced, higher frequencies are reduced more than lower frequencies with the effect

that as distance from the site increases, the ratio of low to high frequencies also

increases. This effect may be observed with road traffic noise or natural sources such

as the sea where higher frequency components are diminished relative to lower

frequency components at long distances. At such distances, however, overall noise

levels from WTGs are so low that this effect is Negligible and not significant.

11.6.6 Amplitude Modulation

The RenewableUK research programme on amplitude modulation (AM) has concluded9,

but there remains significant concern about the issue. A recent decision on

Tullymurdoch Wind Farm10 concludes:

8 W/45/00656/00/00 The Measurement of Low Frequency Noise at Three UK Windfarms. Department of Trade and

Industry 2006

9 RenewableUK (2013). Wind Turbine Amplitude Modulation: Research to Improve Understanding as to its Cause and

Effects - Brief Summary. http://www.renewableuk.com/en/publications/reports.cfm/wind-turbine-am-cause-effects-

briefing.

10 http://www.dpea.scotland.gov.uk/Document.aspx?id=213840, last visited 8 December 2014

http://www.renewableuk.com/en/publications/reports.cfm/wind-turbine-am-cause-effects-briefing

http://www.renewableuk.com/en/publications/reports.cfm/wind-turbine-am-cause-effects-briefing

http://www.dpea.scotland.gov.uk/Document.aspx?id=213840




31. The council cites recent research produced by RenewableUK on other

amplitude modulation in support of its contention that a condition is necessary to

deal with this issue if permission is to be granted. As noted above, the Scottish

Government Online Renewables Planning Advice says that the Institute of

Acoustics good practice guide should be used by those undertaking

assessments. In relation to amplitude modulation, the guide states that the

evidence on this issue is still developing and current practice is not to assign a

planning condition to deal with it.

11.6.7 Vibration due to Operation

There is no evidence of vibration due to the operation of WTGs being perceptible

beyond the immediate vicinity of the WTGs. This, together with the considerable

distances between the indicative WTG locations and the nearest sensitive receptor, will

ensure that the effect will be not significant.

Similarly, any effect as a result of operational traffic will be Negligible and not significant,

due to the small numbers of operational vehicles visiting the development.

11.7 Cumulative Effects

ETSU-R-97 states that noise limits should be set relative to the pre-development

background noise levels at the nearest noise sensitive receptor and that other existing

wind farms should be taken into consideration. There are several consented wind farms

within 5km of the Project. Details of the neighbouring wind farms are shown in Table

A11-14 and on the map in Appendix A11.9. Their noise contributions can be predicted

in accordance with ETSU-R-97.

Table A11-14: Cumulative Sites included in the Assessment

Site Name

Number

of

WTGs

Hub Height

(m)

Rotor

Diameter

(m)

Rated

Power (kW)

Project

Status

Dersalloch 23 70 90 3,000 Consented

Burnhead 8 60 82 2,300 Application

Dalmorton 19 80 90 2,500 Scoping

Keirs Hill 17 80 104 3,400 Application

Glenmount 23 80 90 3,000 Application




11.7.1 Operational Assessment –Project Cumulatively

The cumulative noise levels received at the NSRs, as a function of wind speed,

referenced to 10m above ground level, are as shown in tabular format in Appendix

A11.10 and in graphical format in Appendix A11.11. Sound power levels are those

supplied by the manufacturer. Where a receptor has financial involvement, the day and

night-time criteria have been set to 45 dB or background + 5 dB, whichever is greater.

The graphs compare the prediction (in grey) with the quiet daytime criteria (in blue)

derived from the quiet daytime background and the night-time criteria (in orange)

derived from the night-time background. The graphs and tables show that the predicted

levels meet the day- and night-time criteria at all noise sensitive receptors except at

Receptor M, Knockskae where the daytime criterion at 7m/s is exceeded by 0.7dB. The

effect is therefore considered negligible at all receptors barring Knockskae where the

effect is Significant.

11.8 Mitigation Measures

11.8.1 Construction Phase

Construction activities will be scheduled, unless otherwise agreed, from Monday to

Friday 0700 to 1900 or Saturday 0700 to 1300.

Levels of construction noise in excess of the daytime criterion are predicted at Receptor

M, Knockskae, during construction of the access track and erection of WTG 7. This

work will only take a few days and will be scheduled in consultation with the residents at

Knockskae to minimise their inconvenience. Further details will be provided in a

Transport Management Plan (TMP) following consent (see also Chapter A14 (Traffic

and Transportation)). Suitably managed, the effect would be Negligible.

11.8.2 Operational Phase

The potential excess over the noise limits at Knockskae (M) requires that noise

mitigation be applied to some of the WTGs. The proposed candidate WTG has a

number of operational modes to reduce the noise emission.

The modes are assigned to the WTGs as shown in Table A11-14. It should be noted

that this is a worst case curtailment scheme, derived in the original ES (see ES Chapter

11), to meet criteria derived from the lower background noise levels measured at that

time. The actual curtailment scheme to be implemented will be refined should the

application be granted consent.




Table A11-15: Operational Modes of WTGs, L90, dB(A)

WTG Operational Mode

7 -6dB

8 -6dB

9 -6dB

10 Standard setting

13 -6dB

14 -6dB

15 -6dB

16 Standard setting

17 Standard setting

18 Standard setting

19 Standard setting

20 Standard setting

21 Standard setting

22 Standard setting

23 Standard setting

24 Standard setting

25 Standard setting

By operating some of the WTGs in noise-reduced modes (and using a conservative

curtailment scheme) the predicted levels received at the sensitive receptors, as a

function of wind speed, referenced to 10 m above ground level, can be brought below

the daytime criterion levels as shown in Appendices 11.12 and 11.13. Mitigation is only

required during daytime hours (0700 to 2300). The daytime and night-time criteria and

predicted levels are also shown in graphically in Appendix A11.14. The graphs compare

the prediction with the quiet daytime criteria derived from the quiet daytime background

and the night-time criteria derived from the night-time background.




The graphs and tables show that the predicted levels are below the criteria levels at all

noise sensitive receptors.

The effect of operational noise from the WTGs, including cumulative effects of all wind

farms currently operational, consented or applied for, is therefore assessed as Not

Significant.

Procedures for compliance testing in the event of a complaint should be set out in the

planning conditions, and should be based on the guidance in ETSU-R-97.

11.9 Cumulative Review of Sites at Scoping Stage

The local authority (South Ayrshire Council) requested at the pre-gateway meeting on

13 August 2012 that the cumulative effect of wind farms currently in scoping be

considered.

The cumulative assessment has been undertaken in accordance with policy ECON 7D

of the Joint Ayrshire Structure Plan. As a result, sites which are currently not subject to

a valid planning application at the time of submission of the Addendum should not be

considered in the determination of this application. For illustrative purposes the

predicted levels, with this same curtailment scheme, but assuming all other wind farms

currently in scoping were to be built, are shown in Appendix A11.15 to Appendix

A11.17.

It should be noted however that the effect of wind farms only in scoping are not normally

included in cumulative assessments, but have been included here at the request of

South Ayrshire Council.

11.10 Residual Effects

11.10.1 Residual Effects

The residual effects of the noise associated with construction, operation and

decommissioning are summarised below.

11.10.2 Construction Phase

The levels of noise attributable to the activities associated with the construction work,

and predicted to be received at the nearest sensitive receptors are, during daytime

hours, below the threshold for significant effect.

11.10.3 Operational Phase

With a conservative mitigation scheme, the residual predicted levels from the operation

of the Project and the neighbouring wind farms are all below the criterion levels, often

by a significant margin. The effect is assessed as being Negligible.




11.10.4 Decommissioning Phase

Decommissioning noise will be similar to, or less than, construction noise. During

daytime hours, they are below the threshold for significant effect

11.11 Summary of Effects

Table A11-16 provides a summary of the potential effects associated with the

construction, operation and decommissioning of the Project.




Table A11-16: Summary of Effects

Receptor Development Stage

Sensitivity Magnitude of Change

Predicted Effect Prior to Mitigation

Mitigation Residual Effect

D Knockskae Construction High Small Not Significant Schedule work on the section of track nearest property in consultation with residents.

Not Significant

All others Construction High Negligible Not Significant It is assumed that evening and night work will not be permitted.

Not Significant

D Knockskae Operation High Criterion exceeded

Significant Curtail WTGs 7, 8, 9, 13, 14, 15 to Mode -6dB.

Not Significant

D Knockskae Decommissioning High Small Not Significant Schedule work on the section of track nearest property in consultation with residents.

Not Significant

All others Decommissioning High Negligible Not Significant It is assumed that evening and night work will not be permitted.

Not Significant




11.12 Statement of Significance

Overall, the effects of the Project on the acoustic environment are not significant under

the terms of the EIA Regulations.

Documents

A11. Noise and Vibration · PDF file11/9/2014 · SgurrEnergy Linfairn Wind Farm Addendum Chapter A11: Noise and Vibration 14/7048/001/GLA/O/R/001 Revision B1 Page 2