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ENVIRONMENTAL IMPACT ASSESSMENT

for the proposed

NATIONAL ROAD 3: KEEVERSFONTEIN TO WARDEN (DE BEERS PASS SECTION)

DEA ref. no. 12/12/20/1992

Noise Specialist Report

Prepared for

Cave Klapwijk and Associates PO Box 11651

HATFIELD 0028

Prepared by

F le R Malherbe Pr Eng 220 Long Avenue WATERKLOOF

0181

On behalf of

SOUTH AFRICAN NATIONAL ROADS AGENCY (SOC) LTD.

Date 20/07/2013

PROPONENT The South African National Roads Agency (SOC) Ltd is the project proponent who has commissioned this EIA. Contact details are as follows.

Proponent South African National Roads Agency (SOC) Ltd

Contact Person Ms Mpati Makoa or Mr Ron Harmse

Physical address 48 Tamboti Avenue, Val de Grace, Pretoria, 0184

Postal address PO Box 415 Pretoria 0001

Telephone 012 844 8000

Fax 012 844 8200

Email [email protected]

ENVIRONMENTAL ASSESSMENT PRACTITIONER

Consultant Cave Klapwijk and Associates

Contact Person Mr Alan Cave

Physical address 891 Duncan Street, Brooklyn, Pretoria

Postal address PO Box 11651

Telephone 012 3624684

Fax 012 3620394


INDEPENDENT NOISE SPECIALIST

Consultant François Malherbe Acoustic Consulting cc

Contact Person François Malherbe

Physical address 220 Long Avenue, Waterkloof, Pretoria

Postal address 220 Long Avenue, Waterkloof, 0181

Telephone (012) 346 8278; 082 469 8063


mailto:[email protected]

mailto:[email protected]

DECLARATION OF INDEPENDENCE I, François le Roux MALHERBE hereby confirm my independence as a specialist and declare that I do not have any interest, be it business, financial, personal or other, in any proposed activity, application or appeal in respect of which I was appointed as wetland specialist in terms of the National Environmental Management Act, 1998 (Act No. 107 of 1998), other than fair remuneration for worked performed, specifically in connection with the noise specialist study for the N3: Keeversfontein to Warden (De Beers Pass Section) Environmental Impact Assessment. I further declare that I am confident in the results of the studies undertaken and conclusions drawn as a result of it – as is described in my attached report.

Signed...... Date…2013-07-20

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TABLE OF CONTENTS

TABLE OF CONTENTS .......................................................................................................................................... i GLOSSARY OF ACOUSTIC TERMINOLOGY ................................................................................................. iii EXECUTIVE SUMMARY ....................................................................................................................................... v

1. INTRODUCTION .................................................................................................................................................. 1

2. TERMS OF REFERENCE FOR THE NOISE STUDY.................................................................................................... 1

3. REGULATORY FRAMEWORK ............................................................................................................................... 1

4. METHODOLOGY OF THE NOISE STUDY ............................................................................................................... 2

4.1 MEASUREMENT OF AMBIENT NOISE LEVELS ........................................................................................................ 2 4.2 SECTIONS OF THE DE BEERS PASS ROUTE AND THE ALTERNATIVES STUDIED ....................................................... 3 4.3 MODELLING OF NOISE EMISSION LEVELS .............................................................................................................. 5 4.4 EXPRESSION OF THE NOISE IMPACTS .................................................................................................................... 8 4.5 ASSESSMENT OF THE NOISE IMPACTS................................................................................................................... 9

5. RESULTS OF THE NOISE STUDY: BASELINE MEASUREMENTS ............................................................................ 10

5.1 AMBIENT NOISE LEVEL MEASUREMENTS............................................................................................................ 10

6. RESULTS OF THE NOISE STUDY: SECTION 1: ALTERNATIVES A & C .................................................................... 11

6.1 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND VAN REENEN: ALTERNATIVE A ...................................... 11 6.2 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND VAN REENEN: ALTERNATIVE C ....................................... 18 6.3 THE NOISE IMPACT AT VAN REENEN: ALTERNATIVE A ........................................................................................ 22 6.4 THE NOISE IMPACT AT VAN REENEN: ALTERNATIVE C ........................................................................................ 31


7.1 THE NOISE IMPACT AT SWINBURNE: ALTERNATIVE A ......................................................................................... 39 7.2 THE NOISE IMPACT AT SWINBURNE: ALTERNATIVE C ......................................................................................... 46


8.1 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE A (SOUTH) .......................................................................... 51 8.2 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE A (NORTH) .......................................................................... 56 8.3 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE C (SOUTH) .......................................................................... 65 8.4 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE C (NORTH) .......................................................................... 73 8.5 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE C/N3 (CENTRE) ................................................................... 78

9. RESULTS OF THE NOISE STUDY: SECTION 1: DE BEERS PASS ROUTE AND ALTERNATIVES ................................. 85

9.1 GENERAL ASPECTS .............................................................................................................................................. 85 9.2 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND THE KWAZULU - NATAL BORDER: THE ORIGINAL DE BEERS

PASS ROUTE .................................................................................................................................................................. 85 9.3 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND THE KWAZULU - NATAL BORDER: DBPR + KLIPRIVIER

DEVIATION .................................................................................................................................................................... 92 9.4 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND THE KWAZULU - NATAL BORDER: DBPR + GORGE

DEVIATION – OPTION A .................................................................................................... ERROR! BOOKMARK NOT DEFINED. 9.5 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND THE KWAZULU - NATAL BORDER: DBPR + GORGE

DEVIATION – OPTION A3 .............................................................................................................................................. 97

10. RESULTS OF THE NOISE STUDY: SECTION 2: DE BEERS PASS ROUTE AND ALTERNATIVE ................................. 102

10.1 THE NOISE IMPACT BETWEEN THE KWAZULU - NATAL BORDER AND TANDJIESBERG: THE ORIGINAL DE

BEERS PASS ROUTE ..................................................................................................................................................... 102 10.2 THE NOISE IMPACT BETWEEN THE KWAZULU - NATAL BORDER AND TANDJIESBERG: DBPR + OPTION A .... 107

11. RESULTS OF THE NOISE STUDY: SECTION 3: DE BEERS PASS ROUTE AND ALTERNATIVES ............................... 112

11.1 THE NOISE IMPACT BETWEEN TANDJIESBERG AND THE LINCOLN INTERCHANGE: DBPR ............................. 112

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11.2 THE NOISE IMPACT BETWEEN TANDJIESBERG AND THE LINCOLN INTERCHANGE: DBPR + ALEXANDER PAN

DEVIATION OPTION 1 ...................................................................................................................................................... 117 11.3 THE NOISE IMPACT BETWEEN TANDJIESBERG AND THE LINCOLN INTERCHANGE: DBPR + ALEXANDER PAN

DEVIATION OPTION 2 ...................................................................................................................................................... 122

12. RESULTS OF THE NOISE STUDY: SECTION 4: DE BEERS PASS ROUTE AND ALTERNATIVES ............................... 127

12.1 EFFECT OF THE BUCKLAND DOWNS ADJUSTMENT ...................................................................................... 127 12.2 THE NOISE IMPACT BETWEEN THE LINCOLN INTERCHANGE AND WARDEN: DBPR ...................................... 128

13. CONCLUSIONS OF THE NOISE IMPACT STUDY ................................................................................................ 134

13.1 THE EFFECT OF THE ENVIRONMENT ON THE NOISE IMPACT SIGNIFICANCE ................................................ 134 13.2 THE EFFECT OF MITIGATION MEASURES ON THE NOISE IMPACT ................................................................. 134

14. IMPACT ASSESSMENT PER SECTION FOR EACH ROUTE ALTERNATIVE ............................................................ 136

14.1 IMPACT AND MITIGATION DESCRIPTION: DBPR ALTERNATIVE A ................................................................. 136 14.2 IMPACT AND MITIGATION DESCRIPTION: DBPR ALTERNATIVE C ................................................................. 137 14.3 IMPACT AND MITIGATION DESCRIPTION: DBPR ........................................................................................... 138 14.4 IMPACT AND MITIGATION DESCRIPTION: DBPR + DEVIATIONS ................................................................... 139

15. SUMMARY OF THE NOISE IMPACT RATINGS .................................................................................................. 140

16. REFERENCES ................................................................................................................................................... 140

17. APPENDIX A: MEASUREMENT INSTRUMENTATION ........................................................................................ 143

18. APPENDIX B: THE CKA ASSESSMENT METHODOLOGY .................................................................................... 145

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GLOSSARY OF ACOUSTIC TERMINOLOGY Absorption The process by which a fluid (such as air),

material or structure absorbs sound by dissipating the impinging or transmitted sound energy as heat.

A-weighting An electronic filter that simulates the

human hearing characteristic which is less sensitive to sounds at low frequencies than at high frequencies.

Broad band noise Noise that contains a wide range of

frequencies and cannot be associated with a specific frequency or tone. ‘White noise’ (like the sound of a radio that is not tuned on a station) is a typical example of broad band noise.

Decibel (dB) A descriptor that is used to indicate a level

determined as 10 times the logarithmic ratio of two quantities of the same physical unit.

dBA A descriptor that is used to indicate that 10

times the logarithmic ratio of two quantities of the same physical unit has been A-weighted.

Equivalent noise level A single value noise level that has the

same energy content as a time varying noise level measured over a given period of time. Therefore, it is in essence a time-and energy averaged noise level.

Frequency The characteristic of a time varying signal

that describes the number of cycles per second, expressed in Hertz, Hz.

Integrated noise level A time- and energy averaged measure of a

noise signal varying as a function time LAeq The A-weighted equivalent sound pressure

level. This descriptor is internationally used for quantifying and evaluating noise in human-related circumstances. A vast amount of research links this parameter to human physiological and psychological responses.

iv LAeq (T) The A-weighted equivalent sound pressure

level, where T indicates the time over which the noise is averaged, i.e. LAeq (10 min) indicates that the LAeq was measured over a period of 10 min.

Level The property of any parameter that

expresses it’s magnitude as 10x the logarithm of the ratio of the value of the parameter to a reference value of the same physical unit. The reference value is 20 µPa (micro- or 20x10-6 Pascal, or N/m2) for a sound pressure level and 1 pW (pico or 1x10-12 Watt) for a sound power level.

Medium The substance or material through which

sound propagates, e.g. air in most cases. Noise Unwanted sound Noise emission The noise energy that is emitted by a

noise source into the environment. Noise immission The noise energy that impinges on a

receiver. Sound level meter An instrument used to measure

sound/noise Sound power level The level of the sound energy radiated by

a given source per unit time. The magnitude does not depend on physical surroundings, e.g. distance, screening, weather. Cannot be directly measured, but has to be calculated from sound pressure level measurements.

Sound pressure level The level of the varying sound pressure

caused by a sound/noise source. The magnitude depends on the physical parameters of the surroundings.

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EXECUTIVE SUMMARY Introduction N3 Toll Concession (Pty) Ltd. (N3TC) is responsible for the Design, Construction, Financing, Operating and Maintenance of a portion of National Route 3 from Cedara in KwaZulu Natal to the Heidelberg South Interchange in Gauteng. This includes the requirement to construct a new route known as the De Beers Pass Route (DBPR), between Keeversfontein and Warden. Completion of the DBPR has a completion date, linked to a traffic volume based on the annual average daily traffic (AADT) on the portion of the N3 between Keeversfontein and Harrismith. N3TC embarked on an analysis process to compare alternative alignments with the DBPR. During this process, N3TC established through the use of new road design software, an alternative geometrically compliant route in the vicinity of the existing Van Reenen’s Pass, with various alternatives to re-join the DBPR at appropriate positions. Therefore, regardless of the viability of alternative routes satisfying the engineering constraints, a comparison of environmental impacts was required. Internationally road traffic is considered to be one of the most serious noise pollutants. Therefore, the noise impact caused by road traffic on the different alternatives is an important aspect of the Environmental Impact Assessment. The aim of the present study was to quantify and assess the noise emissions from road traffic of the different alternatives on the receiving environment. Terms of reference for the noise study The terms of reference for this noise study were to:

Create a baseline noise level for areas on the existing road at each of the four towns – Van Reenen, Swinburne, Harrismith and Warden and rural communities;

Predict the noise levels caused by traffic on the identified route alternatives for the specified trigger traffic volumes;

Identify mitigation measures to reduce noise levels on each of the Alternative routes and outline the effectiveness of these; and

Rank the different alternatives on the basis of their potential noise impacts. Regulatory Framework National Noise Regulations were originally published in 1990 under the Environment Conservation Act, 1989 1 by the then Department of Environmental Affairs. At first they were made non-compulsory with a local authority having to apply to make them compulsory in its area of jurisdiction. Since this lead to an unsatisfactory number of applications, the noise regulations were made compulsory in 1992. However, the arrival of the new Constitution 2 in 1994 voided the legal driving force behind the regulations, since the responsibility for them was devolved from national to provincial level. The Minister of the Environment did circulate sample noise regulations to the provinces in 1997 3, which

vi they could adopt unchanged or adapt to their own requirements. This only happened in three provinces, i.e. the Free State, Gauteng and Western Cape. The original sample noise regulations contained a number of serious flaws and a revision was undertaken by the Department of Environmental Affairs. The resulting new regulations 4 were published on 2 July 2010 under the Air Quality Act, 2005 5. They also are presented as a guide that can be adapted by local authorities for their own purposes. In terms of the setting of standards the new regulations make direct and extensive reference to SANS 10103 6. This document successfully addresses the manner in which environmental noise measurements are to be taken and assessed in South Africa and is in line with the guidelines provided by the World Health Organisation (WHO) 7 and standards ISO 1996-1 8 and ISO 1996-2 9 published by the International Standards Organisation (ISO). It also provides guidelines to typical ambient noise levels that may be expected in different types of districts. Therefore, SANS 10103 6 was followed for the purpose of this noise impact study. Methodology of the noise study The current ambient noise levels in the environments of the investigated route alternatives were estimated by taking measurement samples at altogether 18 locations (see the Figure below). The measurements were taken in accordance with the procedures specified in SANS 10103 6.

vii The different sections that were investigated are summarised in the Table below.

Route Alternative

Section 1 Section 2 Section 3 Section 4

DBPR

Keeversfontein to KZN border

KZN border to Tantjiesberg

Tantjiesberg to Lincoln IC

Lincoln IC to Warden

DBPR with Deviations

Keeversfontein to KZN border (gorge deviation Dev.4 & Klip River Dev. 1)

KZN border to Tantjiesberg (Wilge R Dev. 2 and Alex Pan Dev. 3)


Lincoln IC to Warden (Buckland Downs adjustment)

Alternative A

Keeversfontein to Van Reenen

Van Reenen to Swinburne

Swinburne to 42nd Hill

42nd Hill to Warden

Alternative C




42nd Hill to Warden

Do Nothing. (Existing N3)




42nd Hill to Warden

Detailed three dimensional models were developed for each of the sections, specifically for inhabited areas or single noise sensitive receptors. In the case of towns, e.g. Harrismith and van Reenen, noise contours were generated, whereas in the rural areas the noise immissions were calculated for specific receptors that were identified from satellite images and which were assumed to be inhabited. Noise impact contours were specifically calculated for:

Section 1: Van Reenen;

Section 2: Swinburne;

Section 3: Harrismith and 42nd Hill The noise emissions caused by road traffic were calculated in accordance with the procedures specified in SANS 10210 10. The models took account of:

The traffic flow on the highway in terms of the total number of vehicles, average speed of the traffic and the percentage heavy vehicles;

Road conditions, i.e. surface texture and gradient;

viii

The acoustic screening provided by the topography, significant cuts and housing fronts in residential areas; and

Ground conditions. The noise impact was expressed in terms of two characteristics:

The total ambient noise level resulting from the noise emissions from traffic on the N3 alternatives; and

The increase in the estimated present ambient noise levels as a result of the noise emissions.

The noise impacts along the various alternatives were assessed in terms of the guidelines provided in SANS 10103 6 and the assessment methodology specified by the lead consultant Cave Klapwijk and Associates (CKA). Discussion of the measurement results As can be expected traffic on the existing N3 clearly has an impact on ambient noise levels in its environment. However, the measurement results generally are around 55 dBA during the day, even in relatively close proximity to the highway. This noise level corresponds to the guideline limit given by SANS 10103 6 for ‘urban districts’ and is recommended by the WHO 7 for residential developments. During the night the ambient noise level measured at Van Reenen is well below the 45 dBA recommended by both SANS 10103 6 and the WHO 7. At the measuring points located in rural areas the measurement results are either around or well below the 45 dBA listed by SANS 10103 6 as typical for ‘rural districts’. During the night the corresponding noise level is 35 dBA. Based on the measurement results it was decided to use 55 dBA and 45 dBA (urban districts) and 45 dBA and 35 dBA (rural districts) during the day and night, respectively, as reference levels for calculating the noise impacts. Conclusions There will be a very marked difference in the significance rating of the noise impact depending on the type of environment through which the highway will pass:

In areas where the present ambient noise levels are already determined by the noise emissions from localised road traffic or the existing N3 the additional noise intrusion due to an increased traffic flow, the noise impact will be relatively benign and only affect a small area.

However, ambient noise levels generally are very low in an environment previously undisturbed by the intrusion of major noise sources and the introduction of a new major source of noise will necessarily result in a very significant increase in ambient noise levels covering a large area.

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Another factor to consider is that in an environment with a high population density, such as in and around Warden and Harrismith, considerably more people will be affected by a less significant noise impact than by a very significant one in a rural area with a very low population density.

The effect of three possible noise mitigation measures was investigated:

The erection of noise barriers: Noise barriers can provide effective reduction of intruding noise, but their effectiveness largely depends on numerous environmental factors, e.g. the relative heights of the noise source and receiver, meteorological and other atmospheric conditions. The attenuation due to soft ground conditions between the road and the observer can be decreased by the presence of a noise barrier. This is due to the fact that the top edge of the barrier presents a new line source to the observer and, depending on the relative height of this source to the observer the ground effect is reduced. Although proper design can account for topographical and structural factors the final reduction achieved in practice in most cases has an upper limit, sometimes considerably less than the design value. A realistic upper limit typically falls in the interval from 6 dB to 10 dB. There also are situations where the erection of noise barriers simply is not a viable option. For this noise study a noise barrier height of 3.5 m above ground level was assumed since this should provide sufficient line-of-view screening for heavy vehicles fitted with a raised exhaust system. However, it must be noted that any noise barriers must be specifically designed for specific locations.

Applying porous paving: The key mechanism responsible for the generation of road traffic noise on highways is the interaction of tyres and the road surface. Road surface texture is a determining factor and compared to a ‘smooth’ surface texture, depending on a number of parameters, a ‘rough’ texture can cause an increase of in excess of 4 dB. In contrast a porous surface texture can cause a reduction of around 3.5 dB. In many cases the application of a porous paving is a more effective noise control measure than noise barriers, since it controls the actual noise emissions at the source. An important factor to consider is that this mitigation measure affects both sides of the highway, whereas noise barriers only the side on which they are installed.

Applying a combination of the mitigation measures: Obviously a combination of the mitigation measures described above can bring about further reductions in the noise impact, depending on the influence of environmental factors.

The calculation results for sections where mitigation measures were investigated clearly indicate that the application of porous paving gives the best results, although the combined measure of barriers and porous paving can bring about further improvements. Based on the findings of this noise impact study the ranking of the different alternatives is summarised in the tables below.

x Summary of the noise impact ratings: Unmitigated

Section Description

No

DBPR DBPR + Deviations

Section Description

No

Alt A Alt C

Keeversfontein – KZN border

1 Medium High Keeversfontein – Van Reenen

1 High High

KZN border – S922 Tandjiesberg

2 Medium Medium Van Reenen – Swinburne S922

2 Low Low

S922 – R722 Lincoln IC

3 Medium Medium Swinburne – 42nd Hill R722

3 Medium High

Lincoln – Warden

4 Medium Medium 42nd Hill to Warden

4 Medium Medium

Overall route ranking relative to each other

1 2 3 4

Summary of the noise impact ratings: Mitigated

Section Description

No

DBPR DBPR + Deviations

Section Description

No

Alt A Alt C


1 Low Low Keeversfontein – Van Reenen

1 Medium Medium


2 Low Low Van Reenen – Swinburne S922

2 Low Low


3 Low Low Swinburne – 42nd Hill R722

3 Medium Medium

Lincoln – Warden

4 Low Low 42nd Hill to Warden

4 Low Low

Overall route ranking relative to each other

1 1 3 4

DE BEERS PASS: NOISE STUDY Page 1

N3 EIA (De Beers Pass Noise Study Draft Report Rev 5 2014_6

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Error! Reference source not found. 1. INTRODUCTION N3 Toll Concession (Pty) Ltd. (N3TC) is responsible for the Design, Construction,

Financing, Operating and Maintenance of a portion of National Route 3 from Cedara in KwaZulu Natal to the Heidelberg South Interchange in Gauteng. This includes the requirement to construct a new route known as the De Beers Pass Route (DBPR), between Keeversfontein and Warden. Completion of the DBPR has a completion date, linked to a traffic volume trigger, based on the annual average daily traffic (AADT) on the portion of the N3 between Keeversfontein and Harrismith.

N3TC embarked on an analysis process to compare alternative alignments with the

DBPR. During this process, N3TC established through the use of new road design software, an alternative geometrically compliant route in the vicinity of the existing Van Reenen’s Pass, with various alternatives to re-join the DBPR at appropriate positions. Therefore, regardless of the viability of alternative routes satisfying the engineering constraints, a comparison of environmental impacts was required.

Internationally road traffic is considered to be one of the most serious noise

pollutants. Therefore, the noise impact caused by road traffic on the different alternatives is an important aspect of the Environmental Impact Assessment.

The aim of the present study was to quantify and assess the noise emissions from

road traffic on the different alternatives. 2. TERMS OF REFERENCE FOR THE NOISE STUDY The terms of reference for this noise study were to:

Create a baseline noise level for areas on the existing road at each of the four towns – Van Reenen, Swinburne, Harrismith and Warden and rural communities;

Predict the noise levels caused by traffic on the identified route alternatives for the specified trigger traffic volumes;

Identify mitigation measures to reduce noise levels and outline the effectiveness of these; and

Rank the different alternatives on the basis of their potential noise impacts. 3. REGULATORY FRAMEWORK National Noise Regulations were originally published in 1990 under the Environment

Conservation Act, 1989 1 by the then Department of Environmental Affairs. At first they were made non-compulsory with a local authority having to apply to make them compulsory in its area of jurisdiction. Since this lead to an unsatisfactory number of applications, the noise regulations were made compulsory in 1992. However, the arrival of the new Constitution 2 in 1994 voided the legal driving force behind the regulations, since the responsibility for them was devolved from national to provincial level. The Minister of the Environment did circulate sample noise regulations to the



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provinces in 1997 3, which they could adopt unchanged or adapt to their own requirements. This only happened in three provinces, i.e. the Free State, Gauteng

and Western Cape.

The original sample noise regulations contained a number of serious flaws and a revision was undertaken by the Department of Environmental Affairs. The resulting new regulations 4 were published on 2 July 2010 under the Air Quality Act, 2005 5. They also are presented as a guide that can be adapted by local authorities for their own purposes. In terms of the setting of standards the new regulations make direct and extensive reference to SANS 10103 6. This document successfully addresses the manner in which environmental noise measurements are to be taken and assessed in South Africa and is in line with the guidelines provided by the World Health Organisation (WHO) 7 and standards ISO 1996-1 8 and ISO 1996-2 9 published by the International Standards Organisation (ISO). It also provides guidelines to typical ambient noise levels that may be expected in different types of districts. Therefore, SANS 10103 6 was followed for the purpose of this noise impact study.

4. METHODOLOGY OF THE NOISE STUDY 4.1 MEASUREMENT OF AMBIENT NOISE LEVELS The current ambient noise levels in the environments of the investigated route

alternatives were estimated by taking measurement samples at altogether 18 locations (see Table and Figure 4.1.1). The measurements were taken in accordance with the procedures specified in SANS 10103 6.

TABLE 4.1.1

Coordinates of the measurement points

Point Coordinates (UTM 35J)

X m Y m

P1 708233 6874707

P2 707598 6872734

P3 709168 6873715

P4 712801 6870491

P5 713982 6868608

P6 710146 6870228

P7 733001 6859933

P8 737862 6858982

P9 793997 6917830

P10 698139 6916968

P11 704309 6910414

P12 707592 6903496

P13 716831 6891582

P14 723173 6883593

P15 729805 6878722

P16 734602 6873872

P17 748448 6863821

P18 749662 6855412



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Figure 4.1.1: Map showing the locations of the measurement points. A list of the measurement equipment is given in Appendix A to this report. 4.2 SECTIONS OF THE DE BEERS PASS ROUTE AND THE ALTERNATIVES

STUDIED

The N3 and the De Beers Pass Route plus their particular alternatives and options were divided into four sections, as described in Table 4.2.1 and illustrated in Figure 4.2.1.



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TABLE 4.2.1 Description of the sections

Route Alternative

Section 1 Section 2 Section 3 Section 4

DBPR

Keeversfontein to KZN border

KZN border to Tantjiesberg


Lincoln IC to Warden

DBPR with Deviations

Keeversfontein to KZN border (gorge deviation Dev.4 & Klip River Dev. 1)

KZN border to Tantjiesberg (Wilge R Dev. 2 and Alex Pan Dev. 3)


Lincoln IC to Warden (Buckland Downs adjustment)

Alternative A



Swinburne to 42

nd Hill

42

nd Hill to

Warden

Alternative C



Swinburne to 42

nd Hill

42

nd Hill to

Warden

Do Nothing. (Existing N3)



Swinburne to 42

nd Hill

42

nd Hill to

Warden

It must be noted that for all the major noise sensitive areas the ‘Do Nothing

Alternative’ is the same as ‘Alternative C’ or the ‘Existing N3 Alternative’. Therefore, all references to ‘Alternative C’ in this report are to be understood as also referring to the ‘Do Nothing’- and ‘Existing N3’- Alternatives.



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Figure 4.2.1: Graphic illustration of the De Beers Pass Route and its different

alternatives, divided into four sections. 4.3 MODELLING OF NOISE EMISSION LEVELS Detailed three dimensional models were developed for each of the sections,

specifically for inhabited areas or single noise sensitive receptors. In the case of towns, e.g. Harrismith and van Reenen, noise contours were generated, whereas in



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the rural areas the noise immissions were calculated for specific receptors that were identified from satellite images and which were assumed to be inhabited.

Noise impact contours were specifically calculated for:

Section 1: Van Reenen;

Section 2: Swinburne;

Section 3: Harrismith and 42nd Hill; and

Section 4: Ezenzeleni near Warden. The noise emissions caused by road traffic were calculated in accordance with the

procedures specified in SANS 10210 10. The models took account of:

The traffic flow on the highway in terms of the total number of vehicles, average speed of the traffic and the percentage heavy vehicles;

Road conditions, i.e. surface texture and gradient;

The acoustic screening provided by the topography, significant cuts and housing fronts in residential areas; and

Ground conditions. It must be noted that, although not explicitly stated by SANS 10210 10, Graph 5 on

page 34 in the document implies a maximum distance of 300 m from the centre line of the road. This primarily is due to the fact that the further the observer is from the road the less its noise contribution will be for the same traffic flow conditions. Therefore, other noise sources in the environment will tend to become more dominant and meteorological and other atmospheric conditions may influence the actual ambient noise levels. However, this does not prevent the experienced user from applying the calculation method to longer distances and obtain a good estimate of road traffic noise contributions.

The assumed parameters are summarised in Table 4.3.1 and 4.3.2.



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TABLE 4.3.1 Summary of the modelling parameters: 2010

Parameter

Period

24 hr Day

06:00 - 22:00 Night

22:00 - 06:00

Duration (hours) 24 16 8

Total number of vehicles 12188 10124 2064

Q (vehicles/hr) - 633 258

% Heavy vehicles 31% 25% 60%

Average traffic speed (km/h) - 90 70

Road texture Smooth

Ground conditions 70% Soft

TABLE 4.3.2

Summary of the modelling parameters: 2016

Parameter

Period

24 hr Day

06:00 - 22:00 Night

22:00 - 06:00

Duration (hours) 24 16 8

Total number of vehicles 14502 11882 2621

Q (vehicles/hr) - 743 328

% Heavy vehicles 31% 30% 65%

Average traffic speed (km/h) - 90 70

Road texture Smooth

Ground conditions 70% Soft

The values summarised in Table 4.3.1 are based on:

Duration of periods: As defined in SANS 10103 6;

Total number of vehicles: Based on the 2010 data supplied by N3RC for van Reenen. It must be noted that the purpose of the noise study was to rank the different alternatives in terms of their potential noise impacts. Therefore, the supplied traffic flow data provides a well-defined reference which can be equally applied to all the alternatives, thereby facilitating their ranking in terms of their respective noise impacts;

% Heavy vehicles: Based on a 24 hour average of approximately 30%. Personal communication with N3TC engineers suggested a much higher percentage, i.e. in excess of 50% during the night. This corroborates the percentages calculated using the actual 2010 traffic flow data supplied by N3RC;

Average traffic speed: Based on speed limits and the slowing effect of high percentages of heavy vehicles;

Road texture: ‘Smooth’ meaning that the protrusion of aggregates are limited; and



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Ground conditions: Based on the general grassland character of the vegetation in the environments of the alternative routes.

4.4 EXPRESSION OF THE NOISE IMPACTS

The noise impact was expressed in terms of two characteristics:

The total ambient noise level resulting from the noise emissions from traffic on the N3 alternatives; and

The increase in the estimated present ambient noise levels as a result of the noise emissions.

The resulting total ambient noise level was expressed as contours of:

35 dBA;

40 dBA;

45 dBA;

50 dBA;

55 dBA; and

60 dBA.

Table 5 of SANS 10103 6 provides a guideline for estimating community response to an increase in the general ambient noise level caused by an intruding noise. If Δ is the increase in noise level, the following criteria are of relevance:

Δ ≤ 0 dB: An increase of 0 dB or less will not cause any response from a community. For a person with average hearing acuity an increase of less than 3 dB in the general ambient noise level will not be noticeable. Therefore, 3 dB is a useful ‘significance indicator’;

0 dB < Δ ≤ 10 dB: An increase of between 0 dB and 10 dB will elicit ‘little’ community response with ‘sporadic complaints’. However, between 5 dB and 15 dB the strength of the response will gradually change to ‘medium’ with ‘widespread complaints’;

5 dB < Δ ≤ 15 dB: An increase of between 5 dB and 15 dB will elicit a ‘medium’ community response with ‘widespread complaints’. It is also worth noting that an increase of 10 dB is subjectively perceived as a doubling in the loudness of a noise. For an increase of more than 15 dB the community reaction will be ‘strong’ with ‘threats of community action’;



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10 dB < Δ ≤ 20 dB: For an increase of between 10 dB and 20 dB the community response will gradually increase in strength to ‘strong’ with ‘threats of community action’; and

15 dB < Δ: For an increase in excess of 15 dB the community response will gradually increase in strength to ‘very strong’ with ‘vigorous community action’

The overlapping ranges of community responses reflect the fact that there is no

clear-cut transition from one community response to another. Instead the transition is more gradual and may differ substantially from one scenario to another, depending on a large number of variables.

The increase in the ambient noise level was expressed as contours of:

Δ = 0 dB *

Δ = 3 dB

Δ = 5 dB

Δ = 10 dB

Δ = 15 dB * When projecting a calculated road traffic noise contribution to the existing ambient

noise level in a given environment the result will always be a level in excess of the latter, even if it may only be by a small fraction of a dB. Therefore, calculating a contour representing Δ = 0 dB exactly is not possible. To overcome this and provide a clearer image any difference between the calculated result and the existing ambient noise level smaller than 0.5 dB is given the value -0.5 dB, enabling the determination of a clear Δ = 0 dB contour. The uncertainty of 1 dB is for practical purposes negligible.

The noise impact contours were calculated for conditions during both the day and

night. 4.5 ASSESSMENT OF THE NOISE IMPACTS By far the largest part of the De Beers Pass Project falls within the Free State

Province. As described in section 3 of this report the province has adapted the model noise regulations distributed by the Minister of the Environment in 19973 to establish the Free State Noise Control Regulations in 1998 11. At the time of writing this report the consultant could not establish whether the province will proceed to adopt the model noise regulations published in 2010 4.

Therefore, the noise impacts along the various alternatives were assessed in terms

of the guidelines provided in SANS 10103 6 and the assessment methodology specified by the EAP Cave Klapwijk and Associates (CKA). The latter is reproduced in Appendix B to this report.



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5. RESULTS OF THE NOISE STUDY: BASELINE MEASUREMENTS 5.1 AMBIENT NOISE LEVEL MEASUREMENTS The ambient noise levels that were measured at the locations identified in section 4.1

are summarised in Table 5.1.1.

TABLE 5.1.1 Ambient noise level measurement results

Point LAeq, dBA

Location Comments Day Night

P1 49.7

Harrismith, intersection of R722 with Alt. A

Distant traffic on the N3. Distant voices.

P2 56.6

Harrismith, Engen Bergview

Traffic on the N3. Vehicles parking, music, people talking.

P3 40.5

Harrismith, on Route A by-pass

Distant traffic on N3. Bird calls.

P4 41.3

Platberg game reserve Rustling vegetation.

P5 39.4

Platberg game reserve Rustling vegetation.

P6 49.6

Harrismith residential Traffic on the N3.clearly audible

P7 52.9 38.2 Van Reenen village N3 traffic

P8 42.0

Old Van Reenen pass N3 traffic

P9 41.6

Warden Ezenzeleni Distant N3 and voices

P10 34.0

Rural area Vegetation rustling, bird calls and insects.

P11 42.5


P12 46.6


P13 43.4


P14 45.7


P15 41.3


P16 43.4 52.9 Rural area Vegetation rustling, bird calls and insects.

P17 40.3 38.2 Rural area Vegetation rustling, bird calls and insects.

P18 36.4


As can be expected traffic on the existing N3 clearly has an impact on ambient noise

levels in its environment. However, the measurement results generally are around 55 dBA during the day, even in relatively close proximity to the highway (P1, P2, P3, P7, P8 and P9). This noise level corresponds to the guideline limit given by SANS 10103 6 for ‘urban districts’ and is recommended by the WHO 7 for residential developments. During the night the ambient noise level measured at P7 (Van Reenen village) is well below the 45 dBA recommended by both SANS 10103 6 and the WHO 7.

At the measuring points located in rural areas (P4, P5 and P10 to P18) the

measurement results are either around or well below the 45 dBA listed by SANS



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10103 6 as typical for ‘rural districts’. During the night the corresponding noise level is 35 dBA. Therefore, the ambient noise level measured at P16 is exceptionally high. However, the measurement officer had noticed that insects in close proximity to the instrument had caused this high noise level. Insects such as crickets emit noise at high frequencies (i.e. in excess of 2 kHz), which dominate the resulting A-weighted noise level in the absence of significant noise contributions at middle and low frequencies. Experience has shown that if the high frequency noise contributions are removed the A-weighted level is reduced by around 20 dB. This would bring the measured 52.9 dBA at P16 to below 35 dBA.

6. RESULTS OF THE NOISE STUDY: SECTION 1: ALTERNATIVES A & C 6.1 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND VAN REENEN:

ALTERNATIVE A The impacts caused by road traffic on Alternative A in the section between

Keeversfontein and Van Reenen are illustrated in Figures 6.1.1 to 6.1.6. The present ambient noise levels were assumed to be 45 dBA (day-time) and 35 dBA (night-time), as recommended by SANS 10103 6 for ‘rural districts’.

Figure 6.1.1: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A between Keeversfontein and Van Reenen during the day.



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Figure 6.1.2: Contours describing the increase in ambient noise levels caused by traffic on Alternative A between Keeversfontein and Van Reenen during the day, compared to present (2010) conditions.



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Figure 6.1.3: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A between Keeversfontein and Van Reenen during the night.



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Figure 6.1.4: Contours describing the increase in ambient noise levels caused by traffic on Alternative A between Keeversfontein and Van Reenen during the night, compared to present (2010) conditions.

The results presented in Figures 6.1.1 to 6.1.4 (Alternative A) indicate that:

It is clear that the noise emissions from road traffic on these alternatives will affect a very substantial area in their environment, both during the day and night. This is due to the low ambient noise levels that were assumed in accordance with SANS 10103 6, i.e. 45 dBA and 35 dBA during the day and night, respectively;

During the day the contours of high impact, i.e. 55 dBA and higher, cover a band of approximately 300 m on each side of the highway (Figure 5.12.1). During the night the distance of the 45 dBA is up to approximately 800 m (Figure 5.12.3);

In terms of the increase in ambient noise levels the noise impact during the day will be significant, i.e. in excess of 3 dB, at distances of approximately 800 m from the highway, depending on the amount of acoustic screening provided by the topography of the area (Figure 5.12.2). During the night this distance can be in excess of 1300m (Figure 5.12.4); and



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However, it must also be kept in mind that in these kind of rural environments only a small number, if any, noise sensitive receptors will be affected.

Only one possible mitigation measure was considered for Alternative A in this section, i.e. applying a porous texture for the paving of the highway.

The results are illustrated in Figures 6.1.5 and 6.1.6 for night-time conditions.

Figure 6.1.5: Contours describing the mitigated total resulting ambient noise levels for Alternative A between Keeversfontein and Van Reenen during the night. The porous paving is indicated by the violet dashed line.



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Figure 5.12.6: Contours describing the mitigated increase in ambient noise levels for

Alternative A between Van Reenen and Keeversfontein during the night. The porous textured paving by the violet dashed line.

Comparing the noise impacts mitigated by paving the highway with porous asphalt

(Figures 6.1.5 and 6.1.6) with the unmitigated situation (Figures 6.1.3 and 6.1.4) it is clear that:

The extents of the contours have been significantly reduced;

The 60 dBA contour has been removed and the distance of the 45 dBA contour has generally been reduced to less than 800 m;

Although the extent of the area that will experience a significant increase in ambient noise levels has been substantially reduced, a large strip of land adjacent to the highway will still experience increases in excess of 10 dB;

The noise impacts for Alternative A are assessed in Tables 6.1.1 to 6.1.2.



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TABLE 6.1.1 Assessment of the noise impact during Construction: Alternative A between

Keeversfontein and Van Reenen Noise

Impact Description The impact manifests itself as an increase in ambient noise levels caused by, in this case construction activities. Noisy equipment includes diesel engine earth moving machinery, power generators and air compressors, drills and road building equipment, e.g. vibrating rollers, rollers and paving machines. It must be noted that at this stage of the project no concise data on construction activities, timing and equipment exists. Therefore, it is not possible to provide any sensible calculation results and the assessment may only serve as a generic indicator.

Mitigation Effective mitigating measures are:

The use of well- and regularly maintained equipment;

A maintenance schedule which includes a noise test; and

Limiting construction activities to day-light hours, i.e. 06:00 to 18:00.

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Without Mitigation

Negative Medium Low Medium Low Low Medium High Medium High

With Mitigation


Cumulative Impact

Noise is in itself a cumulative pollutant, i.e. it necessarily adds to existing ambient noise levels. It is only its cumulative characteristic that can effectively be assessed.

TABLE 6.1.2

Assessment of the noise impact during Operations: Alternative A between Keeversfontein and Van Reenen

Noise

Impact Description The impact manifests itself as an increase in ambient noise levels caused by, in this case, road traffic noise. Next to aircraft, road traffic noise has been recognised as one of the major pollutants of modern society. The impact is mainly assessed in terms of the total resulting and actual increase in ambient noise levels caused by the source.

Mitigation Apart from the development of quieter vehicles and law enforcement, the impact of road traffic noise can be mitigated by either, or a combination of:

Rerouting the road, i.e. increasing the distance between source and receiver;

Well-designed noise barriers; or

The application of noise reducing paving. The latter two measures were considered in the present study.

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Without Mitigation

Negative Medium High Medium Low Low Low High Medium High

With Mitigation

Negative Medium High Low Low Low Low High Low High

Cumulative Impact




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6.2 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND VAN REENEN: ALTERNATIVE C

The impacts caused by road traffic on Alternative A in the section between

Keeversfontein and Van Reenen are illustrated in Figures 6.2.1 to 6.2.4. The present ambient noise levels were assumed to be 45 dBA (day-time) and 35 dBA (night-time), as recommended by SANS 10103 6 for ‘rural districts’.

Figure 6.2.1: Contours describing the total resulting ambient noise levels caused by traffic on Alternative C between Keeversfontein and Van Reenen during the day. The dashed lines represent 2010 and the solid lines 2016 traffic flow conditions.



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Figure 6.2.2: Contours describing the increase in ambient noise levels from 2010 to 2016 caused by traffic on Alternative C between Keeversfontein and Van Reenen during the day.

Figure 6.2.3: Contours describing the total resulting ambient noise levels caused by traffic on Alternative C between Keeversfontein and Van Reenen during the night. The dashed lines represent 2010 and the solid lines 2016 traffic flow conditions.



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Figure 6.2.4: Contours describing the increase in ambient noise levels from 2010 to 2016 caused by traffic on Alternative C between Keeversfontein and Van Reenen during the night. The results in Figures 6.2.1 to 6.2.4 indicate that:

Road traffic noise levels were already high under 2010 traffic flow conditions;

Although the growth in traffic flow up until 2016 will increase the extent of the contours this is less than what may have been expected both during the day and night (see Figures 6.2.1 and 6.2.3);

This is also clearly illustrated by the results in Figures 6.2.2 and 6.2.4. Although the contour during the night extends much further during the night it must also be noted that an increase of less than 1 dBA is not only insignificant but also negligible; and

No 3 dBA contours could be calculated, thereby clearly indicating that the overall noise impact is insignificant.

The noise impacts for Alternative C are assessed in Tables 6.2.1 and 6.2.2.



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TABLE 6.2.1 Assessment of the noise impact during Construction: Alternative C between

Keeversfontein and Van Reenen Noise






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Without Mitigation


With Mitigation


Cumulative Impact




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TABLE 6.1.2 Assessment of the noise impact during Operations: Alternative C between Keeversfontein

and Van Reenen Noise


Mitigation Since the noise impact in this section is insignificant no special mitigation measures were investigated..

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Without Mitigation

Negative Medium High Medium Low Low Medium High Medium High

With Mitigation

Negative Medium High Medium Low Low Low High Medium High

Cumulative Impact


6.3 THE NOISE IMPACT AT VAN REENEN: ALTERNATIVE A The impact caused by road traffic on Alternative A at Van Reenen is illustrated in

Figures 6.3.1 to 6.3.4. Over and above the present traffic noise emissions the ambient noise levels were assumed to be:

In residential areas: 55 dBA (day-time) and 45 dBA (night-time); and

Everywhere else: 45 dBA (day-time) and 35 dBA (night-time).



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Figure 6.3.1: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A in Van Reenen during the day.

Figure 6.3.2: Contours describing the increase in ambient noise levels caused by traffic on Alternative A in Van Reenen during the day



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Figure 6.3.3: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A in Van Reenen during the night.

Figure 6.3.4: Contours describing the increase in ambient noise levels caused by traffic on Alternative A in Van Reenen during the night.




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As can be expected the locations of the noise impact contours have shifted northward and away from Van Reenen village. The exception is the south-eastern settlement where Alternatives A and the existing N3 converge;

During the day the contours of high noise impact, i.e. where the total resulting ambient noise level exceeds 55 dBA, are located in relatively close proximity to the highway on both sides (see Figure 6.3.1). Nonetheless the 55 dBA and 60 dBA contours will cover all the residential properties located north of the main village. As a result these will be exposed to ambient noise levels significantly in excess of the guideline limits of 55 dBA or 50 dBA specified by SANS 10103 6 for ‘urban districts’ or ‘suburban districts with little road traffic’;

The extent of the high-impact contours (55 dBA and 60 dBA) will be reduced during the night.. The entire environment of Van Reenen will experience ambient noise levels in excess of 45 dBA which, according to SANS 10103 6, is the guideline limit for an ‘urban district’ at night; and

Due to the low ambient noise levels assumed for areas north of the Van Reenen main village they will experience a significant increase in ambient noise levels, i.e. between 3 dB and 10 dB during both the day and night. According to SANS 10103

6 the expected community reaction will range between ‘little’ with ‘sporadic complaints’ and ‘medium’ with ‘widespread complaints’.

Two possible mitigation measures were considered for Alternative A at Van Reenen:

Erecting noise barriers along the boundary of the highway opposite inhabited areas (Figures 6.3.5 and 6.3.6). The assumed height of the barrier above ground level is 3.5 m; and

Using a porous texture for the paving of the highway on sections that are close to residential properties in addition to the barriers (Figures 6.3.7 and 6.3.8).

The results are illustrated for night-time conditions only since the maximum extent of

the contours describing the increase in ambient noise levels occur during this period, i.e.:

Figures 6.3.5 and 6.3.6: Barriers only; and

Figures 6.3.7 and 6.3.8: Barriers with porous road surface.



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Figure 6.3.5: Contours describing the mitigated total resulting ambient noise levels for Alternative A during the night. The noise barriers are indicated by the green lines.

Figure 6.3.6: Contours describing the mitigated increase in ambient noise levels for Alternative A during the night. The noise barriers are indicated by the green lines.



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Figure 6.3.7: Contours describing the mitigated total resulting ambient noise levels for Alternative A during the night. The noise barriers are indicated by the green lines and the porous paving is indicated by the violet dashed line.

Figure 6.3.8: Contours describing the mitigated increase in ambient noise levels for Alternative A during the night. The noise barriers are indicated by the green lines and the porous textured paving by the violet dashed line.



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Comparing the noise impacts mitigated by the erection of noise barriers alone (Figures 6.3.5 and 6.3.6) with the unmitigated situation (Figures 6.3.3 and 6.3.4) it is clear that:

The extents of the contours have been effectively reduced;

There is no 60 dBA contour opposite the inhabited premises located between the highway and Van Reenen, and the south-eastern residential area;

However, the increase in ambient noise levels will still be in excess of 10 dB inside a large area adjacent to the highway;

The core areas of Van Reenen will experience a significant reduction in ambient noise levels, compared to the present (2010) conditions; and

In the central portion of Van Reenen the total resulting ambient noise levels will range between 45 dBA and 50 dBA, which is comparable to the guideline limit of 45 dBA recommended by SANS 10103 6 for ‘urban districts’ during the night. For the largest part of the south-eastern residential area the ambient noise level will still be in excess of 50 dBA and 55 dBA, which is far in excess of the guideline limit of 45 dBA.

Comparing the noise impacts mitigated by, in addition to the noise barriers, by paving

the indicated road sections with porous asphalt (Figures 6.3.7 and 6.3.8) with the unmitigated situation (Figures 6.3.3 and 6.3.4) it is clear that:

The extents of the contours have been significantly further reduced;

The central part of Van Reenen and the south-eastern residential area will fall outside the 55 dBA contour;

The increase in ambient noise levels has also been reduced, but a large strip of land adjacent to the highway will still experience increases in excess of 10 dB;

The core areas of the Van Reenen will in experience a significant reduction in ambient noise levels of more than 3 dB; and

The total resulting ambient noise levels will in some areas of Van Reenen still be in excess of 50 dBA, but for a significant part they will be below this level. This is then comparable to the guideline limit of 45 dBA recommended by SANS 10103 6 for ‘urban districts’ during the night.

The noise impacts for Alternative A are assessed in Tables 6.3.1 to 6.3.3.



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TABLE 6.3.1 Assessment of the noise impact during Construction: Alternative A at Van Reenen

Noise






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TABLE 6.3.2

Assessment of the noise impact during Operations (mitigated by noise barriers): Alternative A at Van Reenen

Noise


Mitigation The implementation of noise barriers as indicated in Figures 6.3.5 and 6.3.6. Please note that these results are only intended for purposes of illustration and must not be used for the actual placement of barriers. These have to be custom designed and installed by the necessary experts.

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Negative Medium High High Low Low Medium High High High

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Cumulative Impact




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TABLE 6.3.3 Assessment of the noise impact during Operations (mitigated by noise barriers and porous

asphalt): Alternative A at Van Reenen Noise


Mitigation The implementation of noise barriers and porous asphalt as indicated in Figures 6.3.7 and 6.3.8. Please note that these results are only intended for purposes of illustration and must not be used for the actual placement of barriers. These have to be custom designed and installed by the necessary experts.

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Negative Low High Medium Low Low Low High Medium High

Cumulative Impact




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6.4 THE NOISE IMPACT AT VAN REENEN: ALTERNATIVE C The impact caused by road traffic on Alternative C at Van Reenen is illustrated in




Figure 6.4.1: Contours describing the total resulting ambient noise levels caused by traffic on Alternative C in Van Reenen during the day.



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Figure 6.4.2: Contours describing the increase in ambient noise levels caused by traffic on Alternative C in Van Reenen during the day.

Figure 6.4.3: Contours describing the total resulting ambient noise levels caused by traffic on Alternative C in Van Reenen during the night.



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Figure 6.4.4: Contours describing the increase in ambient noise levels caused by traffic on Alternative C in Van Reenen during the night, compared to present (2010) conditions.

The results presented in Figures 6.4.1 to 6.4.4 (Alternative C) indicate that:

During the day the contours of high noise impact, i.e. in excess of 55 dBA, follow the trajectory of the highway on both sides (see Figure 5.9.1). The 55 dBA contour will affect largest part of the residential properties, but the 60 dBA contour only those that are in close proximity to the highway;

During the night (see Figure 6.4..3) there will be a reduction in the extent of the contours. The amount of this reduction depends on the distance from the highway, i.e. the shorter the distance the less the reduction. The total resulting ambient noise levels in the entire Van Reenen area will exceed the SANS 10103 6 night-time guideline level of 45 dBA for an ‘urban district’ by a very significant margin; and

However, both during the day and night the increase in ambient noise levels over current conditions on both sides of the highway (see Figures 6.4.2 and 6.4.4) will be insignificant, i.e. less than 3 dB. This is due to the presently experienced high ambient noise caused by road traffic on the existing N3. Therefore the expected community reaction to these increases will mostly be ‘little’ with ‘sporadic complaints’.

Two possible mitigation measures were considered for Alternative C at Van Reenen:



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Erecting noise barriers along the boundary of the highway opposite inhabited areas (Figures 6.4.5 and 6.4.6). The assumed height of the barrier above ground level is 3.5 m; and

Using a porous texture for the paving of the highway on sections that are close to residential properties in addition to the barriers (Figures 6.4.7 and 6.4.8).

The results are illustrated for night-time conditions only since the maximum extent of

the contours describing the increase in ambient noise levels occur during this period.

Figure 6.4.5: Contours describing the mitigated total resulting ambient noise levels for Alternative C. The noise barriers are indicated by the green lines.



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Figure 6.4.6: Contours describing the mitigated increase in ambient noise levels for Alternative C. The noise barriers are indicated by the green lines.

Figure 6.4.7: Contours describing the mitigated total resulting ambient noise levels for Alternative C. The porous paving is indicated by the violet dashed line.



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Figure 6.4.8: Contours describing the mitigated increase in ambient noise levels for Alternative C. The noise barriers are indicated by the green lines and the porous textured paving by the violet dashed line.

Comparing the noise impacts mitigated by the erection of noise barriers alone (Figures 6.4.5 and 6.4.6) with the unmitigated situation (Figures 6.4.3 and 6.4.4) it is clear that:

The extents of the contours have been effectively reduced;

In the centre of Van Reenen and the south-eastern residential area the 60 dBA contour has been removed;

The increase in ambient noise levels in these areas has also been brought down considerably, i.e. below 1 dB which is entirely negligible;

The core areas of the village will in fact experience a slight reduction in ambient noise levels, compared to the present (2010) conditions; and

The total resulting ambient noise levels will, for the largest part of Van Reenen, still be in excess of 50 dBA and even 55 dBA in areas bordering on the highway. This clearly is far in excess of the guideline limit of 45 dBA recommended by SANS 10103 6 for ‘urban districts’ during the night.

Comparing the noise impacts mitigated by, in addition to the noise barriers, by paving

the indicated road sections with porous asphalt (Figures 6.4.7 and 6.4.8) with the unmitigated situation (Figures 6.4.3 and 6.4.4) it is clear that:



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The extents of the contours have been significantly further reduced;

In the centre of Van Reenen and the south-eastern residential area the 55 dBA contour has been removed;

The increase in ambient noise levels in these areas has also been brought down to such an extent that a large area surrounding Van Reenen will actually experience a reduction compared to present (2010) conditions;

The core areas of the village will in fact experience a significant reduction in ambient noise levels of more than 3 dB; and

The total resulting ambient noise levels will in some areas of Van Reenen still be in excess of 50 dBA, but for a significant part they will be below this level. This is then comparable to the guideline limit of 45 dBA recommended by SANS 10103 6 for ‘urban districts’ during the night.

The noise impacts for Alternative C are assessed in Tables 6.4.1to 6.4.3.



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TABLE 6.4.1 Assessment of the noise impact during Construction: Alternative C at Van Reenen

Noise






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Cumulative Impact


TABLE 6.4.2

Assessment of the noise impact during Operations (mitigated by noise barriers): Alternative C at Van Reenen

Noise



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TABLE 6.4.3 Assessment of the noise impact during Operations (mitigated by noise barriers and porous

asphalt): Alternative C at Van Reenen Noise



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Negative Low High Medium Low Low Low Medium Medium High

Cumulative Impact


7. RESULTS OF THE NOISE STUDY: SECTION 2: ALTERNATIVES A & C 7.1 THE NOISE IMPACT AT SWINBURNE: ALTERNATIVE A The impact caused by road traffic on Alternative A in Swinburne is illustrated in






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Figure 7.1.1: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A in Swinburne during the day.



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Figure 7.1.2: Contours describing the increase in ambient noise levels caused by traffic on Alternative A in Swinburne during the day, compared to present (2010) conditions.



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Figure 7.1.3: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A in Swinburne during the night.



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Figure 7.1.4: Contours describing the increase in ambient noise levels caused by traffic on Alternative A in Swinburne during the night, compared to present (2010) conditions.


During the day the contours of high noise impact, i.e. in excess of 55 dBA, follow the alignment of Alternative A and will affect one farmstead to the north (see Figure 7.1.1). Although this is far in excess of the 45 dBA recommended by SANS 10103 6 for ‘rural districts’ this is already the case at present;

During the night (see Figure 7.1.3) there is a considerable reduction in the extent of the contours representing the total resulting ambient noise levels on both sides of Alternative A. However, as for the case at present the noise levels will remain very high;

The extent of the noise impact expressed in terms of the increase in ambient noise levels expands dramatically with distance from the current trajectory of the N3, due to the low ambient noise levels in a rural environment (see Figures 7.1.2 and 7.1.4). Apart from the farmstead north of the highway some residential properties



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to the south will also experience a significant increase in ambient noise levels. According to Table 5 of SANS 10103 6 the community reaction will range between ‘little’ with ‘sporadic complaints’ to ‘medium’ with ‘widespread complaints’; and

It is clear that Alternative A will cause a very significant reduction in road traffic noise at Swinburne.

The noise impact for Alternative A is assessed in Tables 7.1.1 and 7.2.2.

TABLE 7.1.1 Assessment of the noise impact during Construction: Alternative A at Swinburne

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation

Negative Medium Low Low Low Low Medium High Medium High

With Mitigation


Cumulative Impact




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TABLE 7.1.2 Assessment of the noise impact during Operations: Alternative A at Swinburne

Noise


Mitigation Due to the low intensity of the unmitigated noise impact no mitigation measures were considered necessary.

Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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7.2 THE NOISE IMPACT AT SWINBURNE: ALTERNATIVE C The impact caused by road traffic on Alternative C in Swinburne is illustrated in

Figures 7.2.1 to 7.2.4. Over and above the present traffic noise emissions the ambient noise levels were assumed to be 45 dBA (day-time) and 35 dBA (night-time).

Figure 7.2.1: Contours describing the total resulting ambient noise levels caused by traffic on Alternative C in Swinburne during the day.



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Figure 7.2.2: Contours describing the increase in ambient noise levels caused by traffic on Alternative C in Swinburne during the day, compared to present (2010) conditions.



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Figure 7.2.3: Contours describing the total resulting ambient noise levels caused by traffic on Alternative C in Swinburne during the night.



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Figure 7.2.4: Contours describing the increase in ambient noise levels caused by traffic on Alternative C in Swinburne during the night, compared to present (2010) conditions.

The results presented in Figures 7.2.1 to 7.2.4 (Alternative C) indicate that:

During the day the contours of high noise impact, i.e. in excess of 55 dBA, follow the alignment of Alternative C and on the western side affect the commercial properties (see Figure 7.2.1). The total resulting ambient noise levels here will be in excess of 55 dBA and 60 dBA to a smaller extent. This is essentially in line with the guideline levels listed by SANS 10103 6 for ‘Urban districts with one or more of the following: workshops; business premises; and main roads’;

During the night (see Figure 7.2.3) there will be a very slight reduction in the extent of the noise impact contours. The result is that the total resulting ambient noise levels will significantly exceed the SANS 10103 6 corresponding night-time guideline levels of 45 dBA and 50 dBA. However, this should not affect the commercial activities at Swinburne;



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However, both during the day and the night the increase in ambient noise levels over current conditions on both sides of the highway (see Figures 7.2.2 and 7.2.4) will be insignificant, i.e. less than 3 dB. This is due to the present high ambient noise caused by road traffic on the existing N3. Therefore the expected community reaction to these increase will at most be ‘little’ with ‘sporadic complaints’;

The noise impacts for Alternative C are assessed in Tables 7.2.1 and 7.2.2.

TABLE 7.2.1 Assessment of the noise impact during Construction: Alternative C at Swinburne

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 7.2.2

Assessment of the noise impact during Operations: Alternative C at Swinburne Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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8. RESULTS OF THE NOISE STUDY: SECTION 3: ALTERNATIVES A & C

8.1 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE A (SOUTH) The impact caused by road traffic on Alternative A in Harrismith (south) is illustrated

in Figures 8.1.1 to 8.1.4. Over and above the present traffic noise emissions the ambient noise levels were assumed to be:


Everywhere else: 45 dBA (day-time) and 35 dBA (night-time). For modelling purposes a number of assumptions were made concerning the

locations, depths and elevations of cuttings and fillings.

Figure 8.1.1: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A (south) in Harrismith during the day. The green lines indicate the assumed locations of the cuts.



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Figure 8.1.2: Contours describing the increase in ambient noise levels caused by traffic on Alternative A (south) in Harrismith during the day, compared to present (2010) conditions. The green lines indicate the assumed locations of the cuts.



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Figure 8.1.3: Contours describing the total resulting ambient noise levels caused by traffic on Alternative A (south) in Harrismith during the night. The green lines indicate the assumed locations of the cuts.



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Figure 8.1.4: Contours describing the increase in ambient noise levels caused by traffic on Alternative A (south) in Harrismith during the night, compared to present (2010) conditions. The green lines indicate the assumed locations of cuts.

The results presented in Figures 8.1.1 to 8.1.4 indicate that:

The screening effect of the assumed cuts can be clearly seen both during the day and night (see Figures 8.1.1 and 8.1.3);

During the day the contours of high noise impact, i.e. above 55 dBA, follow the alignment of Alternative A and have no effect on the central and southern residential areas (see Figure 8.1.1). Here the total resulting ambient noise levels generally will be between 50 dBA and 55 dBA, determined by localised traffic and other sources of noise;

This is also true for conditions during the night (see Figure 8.1.3) and the total resulting ambient noise levels generally will be between 40 dBA and slightly in



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excess of 45 dBA, but which also is determined by localised traffic and other sources of noise;

Both during the day and the night the increase in ambient noise levels over current conditions (see Figures 8.1.2 and 8.1.4) will be below 0 dB, i.e. there will be an effective reduction in ambient noise levels;

The total resulting ambient noise levels at farmstead to the north of Alternative A will be slightly in excess of 45 dBA and 35 dBA during the day and night, respectively. This is still acceptable in terms of the guidelines provided by SANS 10103 6 for ‘rural districts’ during the day and night, i.e. 45 dBA and 35 dBA, respectively; and

The increase in ambient noise levels over current conditions at the farmstead will be insignificant (less than 3 dB) during the day, but significant (between 3 dB and 10 dB) at night. These excesses are due to the very low current ambient noise levels at this location. According to Table 5 of SANS 10103 6 the community reaction will range between ‘little’ with ‘sporadic complaints’ to ‘medium’ with ‘widespread complaints’.

The noise impact for this section of Alternative A is assessed in Tables 8.1.1 and

8.1.2.

TABLE 8.1.1 Assessment of the noise impact during Construction: Alternative A in Harrismith (south)

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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TABLE 8.1.2 Assessment of the noise impact during Operations: Alternative A in Harrismith (south)

Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation

Negative Low High Low Low Low Low High Low High

With Mitigation


Cumulative Impact


8.2 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE A (NORTH) The impact caused by road traffic on Alternative A in Harrismith (north) is illustrated



Everywhere else: 45 dBA (day-time) and 35 dBA (night-time). Furthermore, for modelling purposes a number of assumptions were made

concerning the locations, depths and elevations of cuttings and fillings. These were arrived at by slicing a digital elevation model of the area along the trace of the highway, and then aligning the road elevations to arrive at a smoothed vertical trace of the road. The locations of the cuts are indicated by green line on the images.



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Figure 8.2.1: Contours describing the total resulting ambient noise levels caused by

traffic on Alternative A (north) in Harrismith during the day. The green lines indicate the assumed locations of the cuts.



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Figure 5.5.2: Contours describing the increase in ambient noise levels caused by

traffic on Alternative A (north) in Harrismith during the day, compared to present (2010) conditions. The green lines indicate the assumed locations of the cuts.



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traffic on Alternative A (north) in Harrismith during the night. The green lines indicate the assumed locations of the cuts.



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traffic on Alternative A (north) in Harrismith during the night, compared to present (2010) conditions. The green lines indicate the assumed locations of cuts.

The results presented in Figures 8.2.1 to 8.2.4 indicate that:

During the day the contours of high noise impact, i.e. above 55 dBA, follow the alignment of Alternative A and have little effect on 42nd Hill and the associated developments further east (see Figure 8.2.1). As can be expected the areas close to the present alignment of the N3 are now exposed to lower traffic noise levels. However, there are some farmsteads north of Alternative A that will experience significantly higher ambient noise levels;

The contours describing the increase in ambient noise levels extend considerably further in a northern direction than south (see Figure 8.2.2). This is due to the lower present ambient noise levels in the further north lying areas. As a result the



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farmsteads mentioned under the previous bullet will experience a significant increase in ambient noise levels. According to SANS 10103 6 the reaction in the affected farming community will still be ‘little’ with ‘sporadic complaints’;

As is the case during the day at night the contours of high noise impact also follow the alignment of Alternative A, but are slightly closer to the highway (see Figure 8.2.3). However, the identified farmsteads will still be exposed to ambient noise levels well in excess of the limits recommended by SANS 10103 6 and the WHO 7;

During the night the contours of the increase in ambient noise levels extend further north, while there is no change towards the south. This is due to the low pre-development ambient noise levels in the affected areas during the night. According to SANS 10103 6 the reaction in the affected farming community will change to ‘medium’ with ‘widespread complaints’; and

The mitigating effect of placing a noise barrier, either in the form of earth berms or

walls or a combination of both, on the northern side of the highway was further investigated. Since only a small number of individual farmsteads need to be protected the noise barriers were placed in close proximity to these. The barrier heights were assumed to be 3.5 m above ground level. The results are illustrated in Figures 8.2.5 and 8.2.6 for night-time only.



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Figure 8.2.5: Contours describing the mitigated total resulting ambient noise levels

caused by traffic on Alternative A (north) in Harrismith during the night. The green lines represent the cuts and noise barriers. The dashed lines indicate the locations of the unmitigated noise contours.



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Figure 8.2.6: Contours describing the mitigated increase in ambient noise levels caused by traffic on Alternative A (north) in Harrismith during the night, compared to present (2010) conditions. The green lines represent the assumed cuts and noise barriers. The dashed lines indicate the locations of the unmitigated noise contours.

The results in Figures 8.2.5 and 8.2.6 indicate that although the porous asphalt and

noise barriers do reduce the northward extent of the noise impact the beneficial effect on the farmsteads is moderate to very little.

The noise impact for this section of Alternative A is assessed in Tables 8.2.1 and

8.2.2.



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TABLE 8.2.1 Assessment of the Construction noise impact: Alternative A in Harrismith (north)

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 8.2.2

Assessment of the noise impact during Operations (mitigated by noise barriers): Alternative A in Harrismith (north)

Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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8.3 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE C (SOUTH) The impact caused by road traffic on Alternative C in Harrismith (south) is illustrated





traffic on Alternative C (south) in Harrismith during the day.



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traffic on Alternative C (south) in Harrismith during the day, compared to present (2010) conditions.



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traffic on Alternative C (south) in Harrismith during the night.



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traffic on Alternative C (south) in Harrismith during the night, compared to present (2010) conditions.

The results given in Figures 8.3.1 to 8.3.4 indicate that:

During the day there are large areas behind both the western and eastern boundaries of the highway where the ambient noise levels will be in excess of 55 dBA and in narrow bands even in excess of 60 dBA. Therefore, the recommended 55 dBA provided by SANS 10103 6 and the WHO 7 for ‘urban districts’ and residential areas, respectively, are largely exceeded (see Figure 8.3.1);

However, the corresponding increase in ambient noise levels (see Figure 8.3.2) will be less than 2 dB, i.e. insignificant. This is caused by the combined screening



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of the embankments and house façades. According to SANS 10103 6 the community reaction will be ‘little’ with ‘sporadic complaints’;

At night these residential areas will be exposed to ambient noise levels in excess of 50 dBA which is significantly in excess of the 45 dBA recommended by SANS 10103 6 the WHO 7; and

However, compared to the assumed existing conditions the increase in ambient noise levels during the night will be less than 2 dB, i.e. insignificant. According to SANS 10103 6 the community reaction will be ‘little’ with ‘sporadic complaints’.

The mitigating effect of placing a noise barrier, either in the form of earth berms or

walls or a combination of both, on the western and eastern boundaries of the highway was further investigated. The barrier heights were assumed to be 3.5 m above ground level. The results are illustrated in Figures 8.3.5 and 8.3.6 for night-time only.



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caused by traffic on Alternative C (south) in Harrismith during the night. The green lines represent the noise barriers. The dashed lines indicate the locations of the unmitigated noise contours.



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Figure 8.3.6: Contours describing the mitigated increase in ambient noise levels

caused by traffic on Alternative C (south) in Harrismith during the night, compared to present (2010) conditions. The green lines represent the assumed noise barriers. The dashed lines indicate the locations of the unmitigated noise contours.

The results in Figures 8.3.5 and 8.3.6 indicate that the noise barriers have a

moderate effect on the western side of the highway, although the increase in ambient noise levels has been significantly reduced. On the eastern side there is a marked reduction of the noise impact.

The noise impact for this section of Alternative C is assessed in Tables 8.3.1 and

8.3.2.



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TABLE 8.3.1 Assessment of the noise impact during Construction: Alternative C in Harrismith (south)

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 8.3.2

Assessment of the noise impact during Operations (mitigated by noise barriers): Alternative C in Harrismith (south)

Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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8.4 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE C (NORTH) The impact caused by road traffic on Alternative C in Harrismith (north) is illustrated





traffic on Alternative C (north) in Harrismith during the day.



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traffic on Alternative C (north) in Harrismith during the day, compared to present (2010) conditions.



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traffic on Alternative C (north) in Harrismith during the night, compared to present (2010) conditions.



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traffic on Alternative C (north) in Harrismith during the night, compared to present (2010) conditions.


During the day the ambient noise levels in the residential areas of 42nd Hill are well below 55 dBA, which conforms to the guideline limit of 55 dBA recommended by both SANS 10103 6 and the WHO 7 for ‘urban districts’ and residential areas, respectively;

At night the ambient noise levels are in excess of the recommended limit of 45 dBA over a large area of 42nd Hill; and

However, the difference between the trigger traffic flow and assumed current conditions is very small, i.e. less than 3 dB and, therefore, insignificant.

The noise impact for Alternative C in Harrismith (northern) is assessed in Tables

8.4.1 and 8.4.2.



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TABLE 8.4.1 Assessment of the noise impact during Construction: Alternative C in Harrismith (north)

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 8.4.2

Assessment of the noise impact during Operations: Alternative C in Harrismith (north) Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


No specific mitigation measures are recommended, although it must be stressed that

the calculations were performed assuming a smooth road surface texture.



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8.5 THE NOISE IMPACT AT HARRISMITH: ALTERNATIVE C/N3 (CENTRE) The impact caused by road traffic on Alternative C/N3 in Harrismith (centre) is

illustrated in Figures 8.5.1 to 8.5.4. Over and above the present traffic noise emissions the ambient noise levels were assumed to be:




traffic on Alternative C (centre) in Harrismith during the day.



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traffic on Alternative C (centre) in Harrismith during the day, compared to present (2010) conditions.



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traffic on Alternative C (centre) in Harrismith during the night.



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traffic on Alternative C (centre) in Harrismith during the night, compared to present (2010) conditions.


During the day the calculated ambient noise levels mostly are lower than 55 dBA and, therefore, the recommendations provided by SANS 10103 6 the WHO 7 are largely met (see Figure 8.5.1). The exception occurs in the areas that are in close proximity to the highway. However, the ambient noise levels are well below 60 dBA. There is no 50 dBA contour south of the highway since it was assumed that the existing ambient noise level in the residential and commercial areas is 55 dBA;

During the day the increase over the current ambient noise levels (see Figure 8.5.2) are below 2 dB and, therefore, insignificant. According to SANS 10103 6 the community reaction will be ‘little’ with ‘sporadic complaints’;

At night the residential areas in proximity to the highway will be exposed to ambient noise levels in excess of 50 dBA which is significantly in excess of the 45 dBA recommended by SANS 10103 6 the WHO 7;



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However, compared to the assumed existing conditions the increase in ambient noise levels during the night will be less than 2 dB, i.e. insignificant. According to SANS 10103 6 the community reaction will be ‘little’ with ‘sporadic complaints’; and

The existing earth berms on the southern boundary of the servitude, clearly visible in the images, have a significant effect on the locations of the noise contours. Therefore, they are effective noise control measures for this section of the N3 highway.

The mitigating effect of extending the existing earth berms south- and northward was

investigated. The extended berms heights were assumed to be 3.5 m above ground level. The results are illustrated in Figures 8.5.5 and 8.5.6 for night-time only.


caused by traffic on Alternative C (centre) in Harrismith during the night. The blue and green lines represent the existing and extended earth berms, respectively. The dashed lines indicate the locations of the unmitigated noise contours.



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Figure 8.5.6: Contours describing the mitigated increase in ambient noise levels

caused by traffic on Alternative C/N3 (centre) in Harrismith during the night, compared to present (2010) conditions. The blue and green lines represent the existing and extended earth berms, respectively.

Although there will still be a narrow strip of the residential areas exposed to ambient

noise levels in excess of 50 dBA the mitigating measures reduce the increase to 1 dB or less. This is for all practical purposes negligible.

The noise impact for this section of Alternative C is assessed in Tables 8.5.1 and

8.5.2.



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TABLE 8.5.1 Assessment of the noise impact during Construction: Alternative C in Harrismith (centre) Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 8.3.2

Assessment of the noise impact during Operations (mitigated by noise barriers): Alternative C in Harrismith (centre)

Noise


Mitigation The implementation of noise barriers in Figures 8.3.7 and 8.3.8. Please note that these results are only intended for purposes of illustration and must not be used for the actual placement of barriers. These have to be custom designed and installed by the necessary experts.

Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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9. RESULTS OF THE NOISE STUDY: SECTION 1: DE BEERS PASS ROUTE AND ALTERNATIVES

9.1 GENERAL ASPECTS

As described in section 4.3 of this report the noise sensitive receptors along the De Beers Pass Route mostly are single homesteads or small groups of dwellings. Therefore, the noise impacts were calculated for the specific receptors that could be identified from satellite images and which were thought to be inhabited at the time when they were taken (mostly 2009).

The same modelling procedures as described in section 4.3 of this report were

applied.

The noise impacts at the identified noise sensitive receivers were calculated for unmitigated and mitigated conditions. The investigated mitigation measure was a combination of noise barriers and porous asphalt paving for sections of the N3 affecting the noise impacts at receivers. The symbols used in this section have the meaning as set out in Table 9.1.1.

TABLE 9.1.1 Explanation of symbols used in figures

Severity Total resulting ambient noise level Increase in ambient noise level

Criteria Symbol Criteria Symbol

LOW Day: ≤ 45 dBA

Night: ≤ 35 dBA ≤ 3 dBA

MEDIUM Day: > 45 dBA < 50 dBA

Night: > 35 < 40 dBA > 3 dBA < 5 dBA

HIGH Day: ≥ 50 dBA

Night: ≥ 40 dBA ≥ 5 dBA

Furthermore, the following procedure was followed:

The adjudication of a symbol to a sensitive receptor was calculated on the basis of the number of them falling into the three levels of impact severity;

For each section of the alternative routes and deviations the number of receptors per level, without and with mitigation measures applied, was analysed in order to estimate the overall intensity of the noise impact per section for each alternative and deviation option; and

Based on the overall intensities and the resulting significance ratings the different routes, alternatives and options were ranked.

9.2 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND THE KWAZULU -

NATAL BORDER: THE ORIGINAL DE BEERS PASS ROUTE

The results for the original De Beers Pass Route (DBPR) between Keeversfontein and the KwaZulu - Natal border are given in Figures 9.2.1 and 9.2.2.



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Figure 9.2.1: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR



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Figure 9.2.2: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR

The results given in Figure 9.2.1 and 9.2.2 show that:

The severity of the noise impacts is due to a combination of the proximity to the N3 and the screening provided by the topography of the area in which the sensitive receptor (sr) is located;



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In terms of the resulting total ambient noise levels during the day (Figure 9.2.1) the noise impacts at approximately half the number of sensitive receptors fall within the criterion level of 45 dBA (dot-symbols), i.e. the severity of the noise impact there is Low. The others will experience a Medium impact, the exception being at sr18 (severity High);

The same observation can be made for the noise impacts expressed as the increase in ambient noise levels. At two of the receptors, i.e. sr7 and sr18 (for the dwellings closest to the N3), the impact will be High, i.e. in excess of 5 dBA;

During the night (Figure 9.2.2) the noise impacts are significantly higher than during the day, as illustrated by the majority number of red dots which indicate a High severity.

The increases in ambient noise levels during the night are larger than during the day, even though the traffic flow is significantly less. This is due to the very low pre-development ambient noise levels in the area of Section 1.

The mitigation measures that were investigated for the DBPR in Section 1 were:

The placement of noise barriers along stretches of the N3 that affect the ambient noise levels at the sensitive receptors the most; and

Paving the same stretches with porous asphalt.

The results are given in Figures 9.2.3 and 9.2.4, where the bright green lines indicate the locations where the mitigation measures were applied.



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Figure 9.2.3: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR



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Figure 9.2.4: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR

The results given in Figures 9.2.3 and 9.2.4 show that:

The noise impact in terms of both the total resulting and the increase in ambient noise levels has been effectively reduced, both during the day and night;

During the day the severity of the noise impact has generally been reduced to a Low intensity; and



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During the night the severity in the general area has been reduced from High to Medium, although sr7 will still experience an impact of High severity in terms of the increase in ambient noise levels.

The noise impact for the DBPR is assessed in Tables 9.2.1 and 9.2.2.

TABLE 9.2.1 Assessment of the noise impact during Construction: DBPR in Section 1

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 9.2.2

Assessment of the noise impact during Operations: DBPR in Section 1 Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation

Negative Medium High Medium Low Low Medium Medium Medium High

With Mitigation


Cumulative Impact




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9.3 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND THE KWAZULU - NATAL BORDER: DBPR + KLIPRIVIER DEVIATION

The results for the original De Beers Pass route (DBPR) between Keeversfontein and the KwaZulu - Natal border which includes the Kliprivier deviation are given in Figures 9.3.1 and 9.3.2.

Figure 9.3.1: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR & Klip River deviation.



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Figure 9.3.2: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR & Klip River deviation.

The results given in Figure 9.3.1 and 9.3.2 show that the noise impacts for the DRP with the Klip River deviation are very similar to those of the DRP as originally proposed, both during the day and night. This could be expected since the road alignments are very much the same.

The same mitigation measures that were investigated for the DBPRin Section 1, i.e. a combination of noise barriers and the application of porous asphalt, were also



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considered for the DBPRwith the Klip River deviation. The results are given in Figures 9.3.3 and 9.3.4. The bright green lines again indicate the locations where the mitigation measures were applied.

Figure 9.3.3: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR & Klip River deviation



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Figure 9.3.4: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR & Klip River deviation

The results given in Figures 9.3.3 and 9.3.4 show that the noise impact in terms of both the total resulting and the increase in ambient noise levels has been effectively reduced to a Low and Medium severity during the day and night, respectively.

The noise impact for the DBPR with the Klip River deviation is assessed in Tables 9.3.1 and 9.3.2.



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TABLE 9.3.1 Assessment of the noise impact during Construction: DBPR & Klip River deviation in

Section 1 Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 9.3.2

Assessment of the noise impact during the mitigated Operations: DBPR & Klip River deviation in Section 1

Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation

Negative Medium High High Low Low High High Medium High

With Mitigation

Negative Medium High Low Low Low Low Medium Low High

Cumulative Impact




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9.4 THE NOISE IMPACT BETWEEN KEEVERSFONTEIN AND THE KWAZULU - NATAL BORDER: DBPR + GORGE DEVIATION – OPTION A3

The results for the original De Beers Pass route (DBPR) between Keeversfontein and the KwaZulu - Natal border which includes the Gorge deviation option A3 are given in Figures 9.5.1 and 9.5.2.

Figure 9.5.1: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR & Gorge Deviation Opt A3



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Figure 9.5.2: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR & Gorge Deviation Opt A3

The results given in Figure 9.4.1 and 9.4.2 show that:

As for Option A, Option A3 shifts the N3 further west from the original DBPR. As a result the western noise sensitive receptors will be more affected, both during the day and night; and



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During the day the general severity will be Medium, but at night it will be High. The same mitigation measures that were investigated in sections 9.2, 9.3 and 9.4, i.e. a combination of noise barriers and the application of porous asphalt, were also considered for Option A3 of Deviation 4. The results are given in Figures 9.5.3 and 9.5.4. The bright green lines again indicate the locations where the mitigation measures were applied.

Figure 9.5.3: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR & Gorge Deviation Opt A3.



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Figure 9.5.4: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR & Gorge Deviation Opt A3

The results given in Figures 9.5.3 and 9.5.4 show that the severity of noise impact in terms of both the total resulting and the increase in ambient noise levels has been effectively reduced to Low and Medium during the day and night, respectively. The exception is at sr17 where the mitigated noise impacts will still be High.

The noise impact for the DBPR with the Gorge Deviation Opt A3 is assessed in Tables 9.5.1 and 9.5.2.



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TABLE 9.5.1 Assessment of the noise impact during Construction: DBPR & Gorge Deviation Opt A3 in

Section 1 Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 9.5.2

Assessment of the noise impact during Operations: DBPR & Gorge Deviation Opt A3 in Section 1

Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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10. RESULTS OF THE NOISE STUDY: SECTION 2: DE BEERS PASS ROUTE AND

DEVIATIONS 10.1 THE NOISE IMPACT BETWEEN THE KWAZULU - NATAL BORDER AND

TANDJIESBERG: THE ORIGINAL DE BEERS PASS ROUTE

The results for the original De Beers Pass route (DBPR) between the KwaZulu - Natal border and Tandjiesberg are given in Figures 10.1.1 and 10.1.2.




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The results given in Figures 10.1.1 and 10.1.2 show that, as can be expected, the noise sensitive receptors nearest to the N3 will experience the most severe noise impacts. During the day sr2 and sr6 are the most seriously affected, but at night the whole area will experience a noise impact of Medium to High intensity.

The mitigation measures that were investigated for the DBPR in Section 1 were noise

barriers located along stretches of the N3 that affected the ambient noise levels at the sensitive receptors the most in combination with the application of porous asphalt. The results are given in Figures 10.1.3 and 10.1.4, where the bright green lines indicate the locations where the mitigation measures were applied.



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The results in Figures 10.1.3 and 10.1.4 indicate that the mitigation measures have

reduced the noise impact, although at night at sr2 and sr6 the intensity remains High. The noise impacts for the DBPR are assessed in Tables 10.1.1 and 10.1.2.



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Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 10.1.2




Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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10.2 THE NOISE IMPACT BETWEEN THE KWAZULU - NATAL BORDER AND TANDJIESBERG: DBPR + WILGE DEVIATION

The results for the original De Beers Pass route (DBPR) and Wilge Deviation between the KwaZulu - Natal border and Tandjiesberg are given in Figures 10.2.1 and 10.2.2.

Figure 10.2.1: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR + Wilge Deviation



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Figure 10.1.2: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR + Wilge Deviation

The results given in Figures 10.1.1 and 10.1.2 show that, as can be expected, the noise sensitive receptors nearest to the N3 will experience the most severe noise impacts, i.e. sr1, sr2 and sr6.

The mitigation measures that were investigated for the DBPR route was a

combination of noise barriers and the application of porous asphalt paving along stretches of the N3 that affected the ambient noise levels. The results are given in Figures 10.1.3 and 10.1.4, where the bright green lines indicate the locations where the mitigation measures were applied.



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Figure 10.2.3: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR + Option A



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Figure 10.2.4: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR + Option A

The results in Figures 10.2.3 and 10.2.4 indicate that, although somewhat reduced,

the noise impacts on sr2 and sr6 remain between Medium and High. The noise impacts for the DBPR including Option A are assessed in Tables 10.2.1

and 10.2.2.



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TABLE 10.1.1 Assessment of the noise impact during Construction: DBPR + Op A in Section 2

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 10.1.2

Assessment of the noise impact during Operations: DBPR + Op A in Section 2 Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation

Negative Medium High Low Low Low Medium High Low High

Cumulative Impact




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11. RESULTS OF THE NOISE STUDY: SECTION 3: DE BEERS PASS ROUTE AND ALTERNATIVES

11.1 THE NOISE IMPACT BETWEEN TANDJIESBERG AND THE LINCOLN

INTERCHANGE: DBPR

The results for the proclaimed De Beers Pass Route (DBPR) between Tandjiesberg and the Lincoln Interchange are given in Figures 11.1.1 and 11.1.2.

Figure 11.1.1: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): Section 3 - DBPR



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Figure 11.1.2: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): Section 3 - DBPR


The noise sensitive receptors nearest to the N3 will experience the most severe noise impacts;

This applies to conditions during both the day and night, especially at sr1, sr5 and sr9 where the intensity will be high in terms of the total resulting and increase in ambient noise levels; and

During the day the general intensity of the noise impact is Medium, and at night High.

The mitigation measures that were considered for the DBPR in Section 2, i.e. the

combination of noise barriers and application of porous asphalt paving along affected stretches of the N3, were also applied here. The results are given in Figures 11.1.3 and 11.1.4, where the bright green lines indicate the locations where the mitigation measures were applied.



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Figure 11.1.3: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): Section 3 - DBPR



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Figure 11.1.4: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): Section 3 - DBPR

The results in Figures 11.1.3 and 11.1.4 indicate that:

During the day the mitigation measures will effectively reduce the noise impacts to a mostly Low intensity. However, at nigh the intensity is mainly Medium;

At sr1, sr5 and sr9 the noise impacts in terms of the increase in ambient noise levels will remain High; and

The noise impacts for the DBPR are assessed in Tables 11.1.1 and 11.1.2.



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Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 11.1.2




Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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11.2 THE NOISE IMPACT BETWEEN TANDJIESBERG AND THE LINCOLN INTERCHANGE: DBPR + ALEXANDER PAN DEVIATION OPTION 2

The results for the original De Beers Pass route (DBPR) with Option 2 of the Alexander Pan Deviation between Tandjiesberg and the Lincoln Interchange are given in Figures 11.2.1 and 11.2.2.

Figure 11.2.1: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR + Alex Pan Opt 2



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Figure 11.2.2: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR + Alex Pan Opt 2


The sensitive receivers within a significant distance from the N3 will be the most affected;

During the day the general intensity will be Medium, but at night it will be High;

The overall intensity is rated Medium; The mitigation measures that were considered for the DBPR in Section 2, i.e. the




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Figure 11.2.3: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR + Alex Pan Opt 2



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Figure 11.2.4: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR + Alex Pan Opt 2


The mitigation measures generally reduce the noise impacts to a Low intensity during the day and Medium at night; and

The overall intensity is rated as Low. The noise impacts for the DBPR with Option 2 of the Alexander Pan Deviation are

assessed in Tables 11.2.1 and 11.2.2.



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TABLE 11.2.1 Assessment of the noise impact during Construction: DBPR+ Option 2 in Section 3

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 11.2.2

Assessment of the noise impact during Operations: DBPR + Option 2 in Section 3 Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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11.3 THE NOISE IMPACT BETWEEN TANDJIESBERG AND THE LINCOLN INTERCHANGE: DBPR + ALEXANDER PAN DEVIATION OPTION 1

The results for the original De Beers Pass route (DBPR) with Option 1 of the Alexander Pan Deviation between Tandjiesberg and the Lincoln Interchange are given in Figures 11.3.1 and 11.3.2.

Figure 11.3.1: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR + Alex Pan Opt 1



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Figure 11.3.2: Image illustrating the unmitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR + Alex Pan Opt 1


The noise impacts are for all purposes the same as for Option 2; and

The general intensity will be Medium; The mitigation measures that were considered for the DBPR in Section 2, i.e. the




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Figure 11.3.3: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the day (06:00 to 22:00): DBPR + Alex Pan Opt 1



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Figure 11.3.4: Image illustrating the mitigated noise impact at identified noise sensitive receptors during the night (22:00 to 06:00): DBPR + Alex Pan Opt 1

The results in Figures 11.3.3 and 11.3.4 are the same as for Option 1. Therefore, the

mitigation measures also reduce the noise impacts to a Low intensity. The noise impacts for the DBPR with Option 2 of the Alexander Pan Deviation are

assessed in Tables 11.3.1 and 11.3.2.



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TABLE 11.3.1 Assessment of the noise impact during Construction: DBPR + Option 1in Section 3

Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 11.3.2

Assessment of the noise impact during Operations: DBPR + Option 1 in Section 3 Noise



Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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12. RESULTS OF THE NOISE STUDY: SECTION 4: DE BEERS PASS ROUTE AND MITIGATION DEVIATIONS

12.1 EFFECT OF THE BUCKLAND DOWNS AND LINCOLN PAN ADJUSTMENT In Section 4 of the De Beers Pass Route there are only minor adjustments in the alignment of the proclaimed route, i.e. the Buckland Downs and Lincoln Pan adjustments. In terms of the noise impact caused by road traffic on the N3 at various sensitive receptors in the area the difference these adjustments cause will be negligible.



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12.2 THE NOISE IMPACT BETWEEN THE LINCOLN INTERCHANGE AND WARDEN: DBPR

The results for the proclaimed De Beers Pass Route (DBPR) between the Lincoln Interchange and Warden are given in Figures 12.2.1 and 12.2.2.




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The noise impacts of Medium and High intensity are located in close proximity to the N3, depending on the screening provided by the topography. This is evident during both the day and night;



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During the day the general intensity ranges between Low and Medium, whereas at night it is between Medium and High; and

The overall intensity rating for the area under investigation is Medium. The mitigation measures that were considered for the DBPR in Section 3, i.e. the




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During the day the mitigation measures will reduce the overall intensity of the noise impacts from Medium to Low. At night the intensity of the mitigated noise impact generally is Medium; and



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The overall rating of the noise impact intensity for Section 4 is Low.

The noise impacts for the DBPR are assessed in Tables 12.2.1 and 12.2.2.


Noise






Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact


TABLE 12.2.2




Natu

re

Exte

nt

Dura

tion

Inte

nsity

Revers

ibili

ty

Impact

on

Irre

pla

ce

able

Resourc

es

Conseq

uence

Pro

ba

bili

ty

Sig

nific

ance

Confide

nce

Without Mitigation


With Mitigation


Cumulative Impact




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13. CONCLUSIONS OF THE NOISE IMPACT STUDY 13.1 THE EFFECT OF THE ENVIRONMENT ON THE NOISE IMPACT SIGNIFICANCE

There will be a very marked difference in the significance rating of the noise impact depending on the type of environment through which the highway will pass:

In areas where the present ambient noise levels are already determined by the noise emissions from localised road traffic or the existing N3, the noise impact caused by the additional noise intrusion due to an increased traffic flow will be relatively low benign and only affect a small area;

However, ambient noise levels generally are very low in an environment previously undisturbed by the intrusion of major noise sources and the introduction of a new major source of noise will result in a very significant increase in ambient noise levels covering a large area;

Another factor to consider is that in an environment with a high population density, such as in and around Warden and Harrismith, considerably more people will be affected by a less significant noise impact than by a very significant noise impact in a rural area with a very low population density.

13.2 THE EFFECT OF MITIGATION MEASURES ON THE NOISE IMPACT The effect of three possible noise mitigation measures was investigated:

The erection of noise barriers: Noise barriers can provide effective reduction of intruding noise, but their effectiveness largely depends on numerous environmental factors, e.g. the relative heights of the noise source and receiver, meteorological and other atmospheric conditions. Although proper design can account for topographical and structural factors the final reduction achieved in practice in most cases has an upper limit, sometimes considerably less than the design value. A realistic upper limit typically falls in the interval from 6 dB to 10 dB. There also are situations where the erection of noise barriers simply is not a viable option. For this noise study a noise barrier height of 3.5 m above ground level was assumed since this should provide sufficient line-of-view screening for heavy vehicles fitted with a raised exhaust system. However, it must be noted that in order to be effective noise barriers must be specifically designed for a given locations.

Applying porous paving: The key mechanism responsible for the generation of road traffic noise on highways is the interaction of tyres and the road surface. Road surface texture is a determining factor and compared to a ‘smooth’ surface texture, depending on a number of parameters, a ‘rough’ texture can cause an increase of in excess of 4 dB. In contrast a porous surface texture can cause a reduction of around 3.5 dB. In many cases the application of a porous paving is a more effective noise control measure than noise barriers, since it controls the actual noise emissions at the source. An important factor to consider is that this mitigation measure affects both sides of the highway, whereas noise barriers only



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the side on which they are installed and, due to reflections, may actually have a negative effect there.

Applying a combination of the mitigation measures: Obviously a combination of the mitigation measures described above can bring about further reductions in the noise impact, depending on the influence of environmental factors.

The calculation results for sections where mitigation measures were investigated

clearly indicate that the application of porous paving gives the best results, although the combined measure of barriers and porous paving can bring about further improvements.

13.3 SPECIFIC ISSUES CONCERNING THE EFFECTIVENESS OF NOISE BARRIERS

The following aspects that influence the effectiveness of noise barriers must be noted:

The attenuation due to soft ground conditions between the road and the observer can be decreased by the presence of a noise barrier. This is due to the fact that the top edge of the barrier presents a new line source to the observer and, depending on the relative height of this source to the observer the ground effect is reduced;

The length and height of a barrier must be in excess of what is required to prevent line of sight onto the road section that needs to be screened. The effectiveness of a noise barrier can also be nullified by gaps in the continuity of the barrier;

Theoretically there is no difference between the effectiveness of an earth berm or wall serving as a noise barrier, provided that the mass per square meter of the latter exceeds a certain minimum value (typically 40 kg/m2). It is the height of the diffracting edge of the barrier that essentially determines the insertion loss. However, in order to optimise this insertion loss the diffracting edge should either be as close as practically possible to the noise source or the receiver. Depending on the design height the base width of an earth berm can be substantial, thereby increasing the distance from the noise source compared to that of a wall of equal height. Furthermore, there simply may not be sufficient space to construct an earth berm with the required height alongside a given section of the road.



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14. IMPACT ASSESSMENT PER SECTION FOR EACH ROUTE ALTERNATIVE 14.1 IMPACT AND MITIGATION DESCRIPTION: DBPR ALTERNATIVE A

The impact and mitigation description for DBPR Alternative A are provided in Tables 14.1.1 and 14.1.2.

TABLE 14.1.1

Impact and mitigation description for DBPR Alternative A: Construction

Phase: CONSTRUCTION

Route: Alt A IMPACT description The impact manifests itself as an increase in ambient noise levels caused by, in this case construction activities and equipment, the large majority of which are diesel

powered.

MITIGATION description Effective mitigating measures are:




Section 1 Significance: Medium Significance: Low

2 Significance: Medium Significance: Low

3 Significance: Low Significance: Low


TABLE 14.1.2

Impact and mitigation description for DBPR Alternative A: Operation

Phase: OPERATION

Route: Alt A IMPACT description The impact manifests itself as an increase in ambient noise levels caused, in this case, road traffic. The impact on people is the annoyance it may cause. However, there are secondary physiological that can become serious, e.g. sleep disturbance.

MITIGATION description The mitigation measures considered in this study are:

The erection of noise barriers along stretches of the N3 that provide the major contribution to the noise impacts.

Paving these same stretches with porous asphalt.

Section 1 Significance: High Significance: Medium


3 Significance: Medium Significance: Medium




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14.2 IMPACT AND MITIGATION DESCRIPTION: DBPR ALTERNATIVE C

The impact and mitigation description for DBPR Alternative C are provided in Tables 14.2.1 and 14.2.2.

TABLE 14.2.1 Impact and mitigation description for DBPR Alternative C: Construction

Phase: CONSTRUCTION

Route: Alt C IMPACT description The impact manifests itself as an increase in ambient noise levels caused by, in this case construction activities and equipment, the large majority of which are diesel

powered.





Section 1 Significance: Low Significance: Low




TABLE 14.2.2

Impact and mitigation description for DBPR Alternative C: Operation

Phase: OPERATION

Route: Alt C IMPACT description The impact manifests itself as an increase in ambient noise levels caused, in this case, road traffic. The impact on people is the annoyance it may cause. However, there are secondary physiological that can become serious, e.g. sleep disturbance.




Section 1 Significance: High Significance: Medium


3 Significance: High Significance: Medium




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14.3 IMPACT AND MITIGATION DESCRIPTION: DBPR

The impact and mitigation description for DBPR are provided in Tables 14.3.1 and 14.3.2.

TABLE 14.3.1

Impact and mitigation description for DBPR: Construction

Phase: CONSTRUCTION

Route: DBPR IMPACT description The impact manifests itself as an increase in ambient noise levels caused by, in this case construction activities and equipment, the large majority of which are diesel powered.





Section 1 Significance: Medium Significance: Medium




TABLE 14.3.2

Impact and mitigation description for DBPR: Operation

Phase: OPERATION

Route: DBPR IMPACT description The impact manifests itself as an increase in ambient noise levels caused, in this case, road traffic. The impact on people is the annoyance it may cause. However, there are secondary physiological that can become serious, e.g. sleep disturbance.




Section 1 Significance: Medium Significance: Low






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14.4 IMPACT AND MITIGATION DESCRIPTION: DBPR + DEVIATIONS

The impact and mitigation description for DBPR are provided in Tables 14.3.1 and 14.3.2.

TABLE 14.3.1 Impact and mitigation description for DBPR + Deviations: Construction

Phase: CONSTRUCTION

Route: DBPR + Deviations

IMPACT description The impact manifests itself as an increase in ambient noise levels caused by, in this case construction activities and equipment, the large majority of which are diesel powered.





Section 1 Significance: Medium Significance: Medium




TABLE 14.3.2

Impact and mitigation description for DBPR + Deviations: Operation

Phase: OPERATION

Route: DBPR + Deviations

IMPACT description The impact manifests itself as an increase in ambient noise levels caused, in this case, road traffic. The impact on people is the annoyance it may cause. However, there are secondary physiological that can become serious, e.g. sleep disturbance.




Section 1 Significance: Kliprivier: Medium Dev4OpA3: High

Significance: Kliprivier: Low Dev4OpA3: Low

2 Option A: Medium Option A: Low

3 Option 1: Medium Option 2: Medium

Option 1: Low Option 2: Low

4 Buckland: Medium Buckland: Low



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15. SUMMARY OF THE NOISE IMPACT RATINGS

A summary of the noise impact ratings is provided in Tables 15.1and 15.2.

TABLE 15.1 Summary of the noise impact ratings: Unmitigated

Section Description

No

DBPR DBPR +

Deviations Section

Description

No Alt A

Alt C


1 Medium High* Keeversfontein –

Van Reenen 1 High High


2 Medium Medium Van Reenen –

Swinburne S922 2 Low Low


3 Medium Medium Swinburne –

42nd

Hill R722 3 Medium High

Lincoln – Warden

4 Medium Medium 42nd

Hill to Warden 4 Medium Medium

Overall route ranking relative to

each other 1 2 3 4

*Note: The ‘High’ rating is given due to the most severe rating given for Section 1 in

Table 14.3.2.

TABLE 15.2 Summary of the noise impact ratings: Mitigated

Section Description

No

DBPR DBPR +

Deviations Section

Description

No Alt A

Alt C


1 Low Low Keeversfontein –

Van Reenen 1 Medium Medium


2 Low Low Van Reenen –

Swinburne S922 2 Low Low


3 Low Low Swinburne –

42nd

Hill R722 3 Medium Medium

Lincoln – Warden

4 Low Low 42nd

Hill to Warden 4 Low Low

Overall route ranking relative to

each other 1 1 3 4

16. REFERENCES In this report reference was made to the following documentation: (1) Environment Conservation Act (Act No. 73 of 1989) (2) Constitution of the Republic of South Africa, Act 108 of 1996 (3) Model noise regulations published under the Environment Conservation Act, Act

73 of 1989, by the Minister of the Environment in 1997.



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(4) Model air quality management by-law for easy adoption and adaptation by municipalities, 2010, published under the National Environment Management Air Quality Act, Act 39 of 2004, Government Gazette No. 33342, 2 July 2010.

(5) National Environment Management Air Quality Act, Act 39, 2004, Government

Gazette No. 27318, 24 February 2005. (6) SANS 10103:2008 ‘The measurement and rating of environmental noise with

respect to annoyance and to speech communication’, Edition 6. (7) Guidelines for Community Noise, World Health Organisation, Geneva, 1999. (8) ISO 1996-1, Acoustics – Description, measurement and assessment of

environmental noise – Part 1: Basic quantities and assessment. (9) ISO 1996-2, Acoustics – Description, measurement and assessment of

environmental noise – Part 2: Determination of environmental noise levels. (10) SANS 10210:2004 ‘Calculating and predicting road traffic noise’, Edition 2.2.

F le R Malherbe Pr Eng



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APPENDIX A

Measurement Instrumentation



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17. APPENDIX A: MEASUREMENT INSTRUMENTATION

The measurement instrumentation that was used in this noise study is summarised in Table A-1. The measurement instrumentation complies with the accuracy requirements specified for a Type 1 instrument in:

SANS 61672-1/IEC 61672-1, Electro acoustics – Sound level meters – Part 1: Specifications. Amdt 1

SANS 60942/IEC 60942 (SABS IEC 60942), Electro acoustics – Sound calibrators.

TABLE A-1

Measurement instrumentation

Instrument Type Serial

Number Date

calibrated Calibration Certificate

Sound Analyser Svan 955 11188 2008/10/21 2008-1064

Microphone ACO 7052S 2008/10/21 2008-1064

Sound level calibrator Rion NC-74 34283657 2009/11/22 2009-1069

The calibration status of the instrumentation was checked before and after each set

of measurements against a calibrated signal with a level of 94,0 dB at 1 kHz. In each case the instrument displayed a reading of within 1 dB of the calibrated value. A windshield supplied by the manufacturer of the instrument was used during all the measurements.



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APPENDIX B

The CKA assessment methodology



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18. APPENDIX B: THE CKA ASSESSMENT METHODOLOGY Table B-1: Impact Criteria Assessment and Rating Scales

Criteria Rating Scales Notes

Nature

Positive This is an evaluation of the type of effect the construction, operation and management of the proposed NPS development would have on the affected environment.

Negative

Neutral

Extent

Low Site-specific, affects only the development footprint.

Medium Local (limited to the site and its immediate surroundings, including the surrounding towns and settlements within a 10 km radius);

High Regional (beyond a 10 km radius) to national.

Duration

Low 0-4 years (i.e. duration of construction phase).

Medium 5-10 years.

High More than 10 years to permanent.

Intensity

Low Where the impact affects the environment in such a way that natural, cultural and social functions and processes are minimally affected.

Medium

Where the affected environment is altered but natural, cultural and social functions and processes continue albeit in a modified way; and valued, important, sensitive or vulnerable systems or communities are negatively affected.

High

Where natural, cultural or social functions and processes are altered to the extent that the impact will temporarily or permanently cease; and valued, important, sensitive or vulnerable systems or communities are substantially affected.

Potential for impact on irreplaceable resources

Low No irreplaceable resources will be impacted.

Medium Resources that will be impacted can be replaced, with effort.

High There is no potential for replacing a particular vulnerable resource that will be impacted.

Consequence (a combination of extent, duration, intensity and the potential for impact on irreplaceable resources).

Low

A combination of any of the following: - Intensity, duration, extent and impact on irreplaceable resources are all rated low. - Intensity is low and up to two of the other criteria are rated medium. - Intensity is medium and all three other criteria are rated low.

Medium Intensity is medium and at least two of the other criteria are rated medium.

High

Intensity and impact on irreplaceable resources are rated high, with any combination of extent and duration. Intensity is rated high, with all of the other criteria being rated medium or higher.

Probability (the likelihood of the impact occurring)

Low It is highly unlikely or less than 50 % likely that an impact will occur.

Medium It is between 50 and 70 % certain that the impact will occur.



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Criteria Rating Scales Notes

High It is more than 75 % certain that the impact will occur or it is definite that the impact will occur.

Significance (all impacts including potential cumulative impacts)

Low Low consequence and low probability. Low consequence and medium probability. Low consequence and high probability.

Medium

Medium consequence and low probability. Medium consequence and medium probability. Medium consequence and high probability. High consequence and low probability.

High High consequence and medium probability. High consequence and high probability.

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