Conradie BLMEP, Thornton - Western Cape · PDF fileMackenzie Hoy Consulting Acoustics Engineers Fax: +27 (0) 21 531 3334 . 5 Coniston Way Cell: +27(0) 82 568 8924 . Pinelands ... This

Conradie BLMEP, Thornton

Traffic Noise Impact Assessment

Revision 1

machoy Tel: +27 (0) 21 531 4452 Mackenzie Hoy Consulting Acoustics Engineers Fax: +27 (0) 21 531 3334 5 Coniston Way Cell: +27(0) 82 568 8924 Pinelands email: [email protected] South Africa web: www.machoyrsa.com

T.E. Mackenzie-Hoy Pr. Eng. Bsc (Elec) M.S.A.I.E.E., M.S.P.E., IngP (Eur), AmASA (Director) Rachel Viljoen BEng (Mechatronics), T. Matora BSc (Mechatronics), M. Attwood (Adv Dip S.Eng)

Mackenzie Hoy Consulting Engineers Page 1 of 47

___________________________________________________________________________________

17th March 2017 - DRAFT.

31st March 2017 - Revision 1.

Conradie Better Living Model Exemplar Project, Thornton:

Noise Impact Assessment.

1. Introduction

This report was commissioned by Mr Alastair Rendall, the Managing

Director of ARG Design (tel: +27 21 448 2666, email:

[email protected].).

The report is a Noise impact Assessment for the proposed Conradie Better

Living Model Exemplar Project (BLMEP).

This report lists our recommendations for the proposed Conradie BLMEP

road network to comply with the Western Cape Noise Control Regulations,

2013.

The following was established from the noise model generated for the

proposed Conradie BLMEP:

a. Residents along the existing Forest Drive Extension are less likely to

be affected by traffic noise from the proposed road layout Alternatives

insofar as the residual noise for the applicable environment is barely

Mackenzie Hoy Consulting Acoustics Engineers if you have a problem that nobody else can solve....

5 Coniston Way, Pinelands, 7405 TEL: + 27 (0)21 424 5719 Cape Town, South Africa FAX: + 27 (0)21 531 3334 www.machoyrsa.com Email: [email protected]

T.E. Mackenzie-Hoy Pr. Eng. Bsc (Elec) M.S.A.I.E.E., M.S.P.E., IngP (Eur), AmASA (Director)

Rachel Viljoen BEng (Mechatronics), T. Matora BSc (Mechatronics), M. Attwood (Adv Dip S.Eng) Mackenzie Hoy Consulting Engineers Page 2 of 47

exceeded. Road layout Alternative 2 and road layout Alternative 3 will

therefore have less of a noise impact than road layout Alternative 1.

b. Road layout Alternative 1 will have a higher noise impact on residents

of Elm and Rooikrans Road than road layout Alternative 2 and road

layout Alternative 3. This noise impact is likely to be substantially

noticeable and may result in complaints.

c. Noise barriers for road layout Alternative 2 and Alternative 3 will be

most beneficial at the elevated junction and Forest Drive Extension

off-ramps.

d. The cost of noise mitigation measures such as noise barriers will be

higher for road layout Alternative 1 than for road layout Alternative 2

and road layout Alternative 3.

e. Despite mitigation measures such as noise barriers, residents of Elm

Road and Rooikrans Road are likely to be significantly affected by

road layout Alternative 1.

The road layout alternatives proposed for the Conradie BLMEP can

therefore be ranked as follows:

Table 1: Ranking table of the proposed road layout alternatives for Conradie BLMEP

Description Alternative 1 Alternative 2 Alternative 3

Noise impact High Low Low

Probability of complaints Definite Improbable Improbable

Relative cost of mitigation High Low Low

Level of significance after mitigation High Low Low



The summarised recommendation for Conradie BLMEP to comply with the

Western Cape Noise Control Regulations, 2013 is to install solid noise

barriers along sections of the proposed road alignment. The noise barrier

must be a continuous solid structure with constant element height extending

between the following areas:

a. Road Layout Alternative 1: Elevated T-junction to Conradie Access

BLMEP access road.

b. Road Layout Alternative 2: Forest Drive Extension West ramp road

chainage 150 to Maitland Cemetry road chainage 450 as referenced

from drawing 7293 Alternative 2 Layout.

c. Road Layout Alternative 3: Forest Drive Extension East Ramp road

chainage 150 to road chainage 450 and Forest Drive Extension West

Ramp road chainage 80 to road chainage 268 as referenced from

drawing 7293 Alternative 3 Layout.

Visual mitigation design must be to Landscape Architect’s specification

and conceptual design drawings must be signed off by a registered

Professional Acoustics Engineer.

The above recommendations are valid provided the following:

i. The proposed road layout Alternatives as illustrated in this report are

not changed.

ii. The predicted future traffic volumes stated in this report, as provided

by the updated Traffic Impact Assessment (Revision 3) submitted by

HHO Africa in March 2017, are not exceeded.



iii. The road paving installed for the proposed road alignment complies

with the Friction Courses recommended by the Western Cape Province

as specified in this report.

iv. The assumptions stated in this report are accepted as true and correct.

2. Background and Present Situation

2.1 The Conradie Better Living Model Exemplar Project (BLMEP) is a

land development project proposed for Thornton, Cape Town.

2.2 The proposed Conradie BLMEP development framework comprises

residential units, schools, offices, retail and service facilities.

2.3 Based on the expected increase in traffic due to the Conradie BLMEP,

it was required that road networks be constructed linking Voortrekker

Road to Thornton.

2.4 Figure 1 to Figure 3 on the following pages show the three road layout

Alternatives proposed to link Conradie BLMEP to Voortrekker Road.

2.5 Mackenzie Hoy Consulting Engineers were commissioned by Mr

Alastair Rendall, the Managing Director of ARG Design, to provide

recommendations for traffic noise management along each of the

proposed road alignments.

2.6 This document lists our findings and provides recommendations for the

proposed road alignments link Conradie BLMEP to Voortrekker Road

to comply with the Western Cape Noise Control Regulations, 2013.



Figure 1: Overview of proposed road layout Alternative 1 for Conradie BLMEP.



Figure 2: Overview of proposed road layout Alternative 2 for Conradie BLMEP (drawing 7293 Alternative 2 Layout).



Figure 3: Overview of proposed road layout Alternative 3 for Conradie BLMEP (drawing 7293 Alternative 3 Layout).



3. Measurements

3.1 Instruments

3.1.1 The following equipment was used for measurements conducted

along the proposed Conradie BLMEP road alignment:

a. Norsonic Nor140 Type 1/Class 1 Precision Sound Analyser, Serial

No. 1405477,149467. Serial No. 1403729, 180327. Calibration by

M and N Acoustic Services cc in July 2016, SANAS Reg No 148

1302, Certificate Number 2016-1333.

Calibration certificates are available upon request.

3.2 Measurement Procedure

3.2.1 All noise measurements were conducted in accordance with the

methods referenced from the following standards which are stated in

the Western Cape Noise Control Regulations, 2013:

i. ‘‘SANS 10103’’which means the latest edition of South African

National Standard publication number 10103 titled ‘‘The

measurement and rating of environmental noise with respect to

annoyance and to speech communication’’, as amended from time

to time, or its corresponding replacement;

ii. ‘‘SANS 10210’’ which means the latest edition of South African

National Standard publication number 10210 titled ‘‘Calculating

and predicting road traffic noise’’, as amended from time to time,

or its corresponding replacement, as referred to in SANS 10328;



iii. ‘‘SANS 10328’’ which means the latest edition of South African

National Standard publication number 10328 titled ‘‘Methods for

environmental noise impact assessments’’, as amended from time

to time, or its corresponding replacement;

3.2.2 The measurements are LAeq, which is defined as the equivalent

average continuous A-weighted sound pressure level determined over

a time interval.

3.2.3 Baseline ambient noise measurements were conducted to establish the

existing noise levels due to current activities along the proposed

Conradie BLMEP road alignment.

3.2.4 Table 1 below provides a summary of the baseline noise levels

measured at each location:

Table 2: Baseline noise measurement results conducted along the proposed Conradie BLMEP road alignment.

Receiver Measurement Location Measurement

Time

Measured Equivalent

Continuous Sound

Pressure Level (Leq10)

R03 Elm Court G - Rooikrans

Road 14h48 - 14h58 46.1 dBA

R04

Corner Forest Drive

Extension & Rooikrans

Road

15h00 - 15h10 60.2 dBA

R05 Maitland Cemetery -

Circular Intersection 14h20 to 14h30 46.6 dBA

R06 Voortrekker Road

intersection point 14h32 to 14h42 68.7 dBA



Note: The measurements conducted are for design and evaluation purposes

only. While they are in accordance with the provisions of the Western Cape

Noise Control Regulations, 2013 these measurements may not be used by third

parties as the basis for legal action. If legal action is proposed, the parties

involved must arrange for Mackenzie Hoy Consulting Engineers to conduct

further measurements.



3.3 SoundPLAN Noise Propagation Model

3.3.1 Mackenzie Hoy Consulting Engineers use SoundPLAN noise

modeling software to create noise prediction models and consequent

noise contour maps.

3.3.2 SoundPLAN is a standards-based program with modeling algorithms

based on noise regulations. SoundPLAN is ISO9001:2008 certified.

3.3.3 The model takes into account source sound power levels, surface

reflection and absorption, accurate building models, geometric

divergence, meteorological conditions, terrain elevations, walls,

barriers, berms and roads.

3.3.4 The results of the traffic study undertaken by WSP in July 2016 as

part of the traffic study undertaken by GIBB (Pty) Ltd predict the

following future traffic volumes along the proposed road alignment

alternatives:

Table 3: Estimated future traffic volumes accessing Conradie BLMEP.

3.3.5 The trip generation predicted for each road layout Alternative were

modelled as per the updated Traffic Impact Assessment (Revision 3)

submitted by HHO Africa in March 2017.

3.3.6 Refer to Appendix A for the road paving material (Friction Courses)

specification recommended by the Western Cape Province.



4. Discussion

4.1 Noise Assessment and Evaluation

4.1.1 The Western Cape Noise Control Regulations, 2013 use the following

definitions and descriptions:

“disturbing noise” means a noise, excluding the unamplified human

voice, which;

a) exceeds the rating level by 7 dBA

b) exceeds the residual noise level where the residual noise level is

higher than the rating level; or

c) exceeds the residual noise level by 3 dBA where the residual noise

level is lower than the rating level.

“Rating level” means the applicable outdoor equivalent continuous

rating level indicated in Table 2 of SANS 10103:2008 “The

measurement and rating of environmental noise with respect to

annoyance and to speech communication”.

“Residual noise” means the all-encompassing sound in a given

situation at a given time, measured as the reading on an integrated

impulse sound level meter for a total period of at least 10 minutes,

excluding noise alleged to be causing a noise nuisance or disturbing

noise.

“Noise nuisance” means any sound which impairs or may impair the

convenience or peace of a reasonable person.



4.1.2 The proposed road alternatives will link Voortrekker Road to

Conradie BLMEP directly or through Forest Drive Extension.

4.1.3 With reference to SANS 10103:2008 “The measurement and rating of

environmental noise with respect to annoyance and to speech

communication”, the following outdoor rating levels apply for the

proposed road alternatives:

a. Day-time rating level (06h00 – 22h00) : 60 dBA

b. Night-time rating level (22h00 – 06h00) : 50 dBA

4.1.4 According to the Western Cape Noise Control Regulations, 2013 the

maximum allowable noise level along the proposed road alignment is

therefore as follows:

a. Day-time limit (60 dBA +7 dBA) : 67 dBA

b. Night-time limit (50 dBA +7 dBA): 57 dBA

4.1.5 Peak hour traffic in Cape Town generally occurs within the following

times:

a. Peak hour traffic in the morning: 06h30 to 09h30.

b. Peak hour traffic in the evening: 16h00 to 18h30.

4.1.6 The estimated future traffic along the proposed road alternatives was

modelled in SoundPLAN to determine the noise impact of peak hour

traffic from Conradie BLMEP to Voortrekker Road.



4.2 SoundPLAN Noise Prediction Calculations

4.2.1 The traffic volume projections incorporated in the noise model

illustrate the worst-case scenario during peak hour traffic.

4.2.2 The following assumptions were made for each noise model

generated for the proposed road alignment:

a. Vehicle traffic noise was modelled between 06h00 and 22h00

when average daily traffic is anticipated to be at its peak.

b. The general speed limit applicable does not exceed 60 km/h for

both light vehicles and heavy vehicles.

4.2.3 Noise measurement receivers were included in the noise model at key

baseline noise measurement locations to predict the potential noise

impact of the proposed road layout Alternatives.

4.2.4 Computer aided drawings supplied by the client were used to generate

the terrain, existing surroundings and import the proposed road

profile in the noise model.



4.3 Proposed Road Layout Alternatives - Without Noise Mitigation

4.3.1 Table 3 lists the predicted noise contribution of the proposed road

layout Alternative 1 during peak hour traffic conditions predicted

using SoundPLAN:

Table 4: Predicted noise contribution of road layout Alternative 1 during peak hour traffic conditions without noise mitigation.

Location Description

Predicted sound pressure level

during peak hour traffic (dBA)

R03 Elm Court G - Rooikrans Road 65.3

R04 Corner Forest Drive Extension &

Rooikrans Road 61.3

R05 Maitland Cemetery - Circular

Intersection 71.7

R06 Voortrekker Road intersection

point 66.0

Refer to Figure 5 in Appendix B for the grid noise map generated for

road layout Alternative 1as summarised in Table 3.

4.3.2 The overall noise contribution predicted for road layout Alternative 1

without noise mitigation installed established that traffic noise

exceeded the maximum allowable limit of 67 dBA at Maitland

Cemetery Circular Intersection (R05) by 4.7 dBA.





using SoundPLAN:

Table 5: Predicted noise contribution of road layout Alternative 2 during peak hour traffic conditions without noise mitigation.






Rooikrans Road 61.3


Intersection 71.7


point 66.0


road layout Alternative 2 as summarised in Table 4.


without noise mitigation installed established traffic noise exceeded

the maximum allowable limit of 67 dBA at Maitland Cemetery

Circular Intersection (R05) by 4.7 dBA.





using SoundPLAN: Table 6: Predicted noise contribution of road layout Alternative 3 during peak hour traffic conditions without noise mitigation.






Rooikrans Road 62.5


Intersection 71.6


point 66.0


road layout Alternative 3 as summarised in Table 5.


without noise mitigation installed established that traffic noise

exceeded the maximum allowable limit of 67 dBA at Maitland

Cemetery Circular Intersection (R05) by 4.6 dBA.

4.3.7 Additional noise mitigation is necessary for each road layout

Alternative to comply with the Western Cape Noise Control

Regulations, 2013.

4.3.8 The most suitable noise mitigation measure that can be applied for the

proposed Conradie BLMEP road layout Alternatives are solid barriers



built between the proposed road alignment and noise sensitive

receptors.

4.4 Proposed Road Layout Alternatives - With Noise Mitigation Installed

4.4.1 According to SANS10103, it is probable that the predicted traffic

noise is annoying or otherwise intrusive to the community or to a

group of persons if the rating level of the ambient noise under

investigation exceeds the applicable of the following:

a. The rating level of the residual noise (determined in the absence of

the specific noise under investigation);

b. The maximum rating level for the ambient noise; or

c. The typical rating level for the ambient noise for the applicable

environment.

4.4.2 The probable community or group response to the excess as given in

Table 5 of SANS 10103 is as follows:

Figure 4: Categories of community or group response according to SANS 10103, Table 5.

4.4.3 The nearest noise sensitive community to the proposed road layout

Alternatives are residents of Thornton along Forest Drive Extension,

Elm Road and Rooikrans Road.



4.4.4 According to results predicted for each road layout Alternative

without noise mitigation installed:

a. Residents along Forest Drive Extension will experience traffic

noise ranging from 61.3 dBA to 62.5 dBA. This does not exceed

the existing residual noise by more than 3 dBA, which is barely

perceptible by the human ear.

b. According to the Land Use Application to City of Cape Town for

the Conradie BLMEP, Forest Drive Extension has an 18m wide

road reserve. The noise levels experienced at the cadastral

boundary of properties extending from the proposed Conradie

BLMEP development to Rooikrans Road will barely exceed the

maximum applicable limit of 67 dBA.

c. Residents in Elm Road and Rooikrans Road will experience traffic

noise ranging from 56.1 dBA to 65.3 dBA. This exceeds the

existing residual noise level by 10 dBA or more.

4.4.5 The following can be established from the predicted community

response:

a. Residents along the existing Forest Drive Extension are less likely

to be affected by traffic noise from the proposed road layout

Alternatives insofar as the residual noise for the applicable

environment is barely exceeded.

b. Road layout Alternative 1 will likely result in widespread

complaints and probable group action. Residents along the

existing Elm Road and Rooikrans Road are likely to be marginally

affected by road layout Alternative 2 and road layout Alternative

3.



4.4.6 Solid noise barriers were simulated using SoundPLAN along the

proposed road layout Alternatives where noise sensitive receivers are

located.

4.4.7 A suitable noise barrier that ensures that noise contribution during

peak hour traffic conditions will not exceed the maximum allowable

limit of 67 dBA must have a height of 2 m above road surface level.

4.4.8 The noise barrier must be a continuous solid structure with constant

element height.

4.4.9 The following tables list the noise contribution predicted using

SoundPLAN of the proposed road layout Alternatives for Conradie

BLMEP traffic during peak hour conditions with the recommended

noise mitigation installed: Table 7: Predicted noise contribution of Conradie BLMEP road layout Alternative 1 during peak hour traffic conditions with noise mitigation installed.


Predicted Sound Pressure Level




Rooikrans Road 60.1


Intersection 61.8


point 56.7



Table 8: Predicted noise contribution of Conradie BLMEP road layout Alternative 2 during peak hour traffic conditions with noise mitigation installed.






Rooikrans Road 57.7


Intersection 61.7


point 56.5

Table 9: Predicted noise contribution of Conradie BLMEP road layout Alternative 3 during peak hour traffic conditions with noise mitigation installed.






Rooikrans Road 57.7


Intersection 61.7


point 56.5



4.4.10 According to results predicted for each road layout Alternative with

the recommended noise mitigation installed:

a. Residents along the existing Elm Road and Rooikrans Road are

likely to be significantly affected by road layout Alternative 1 due

to elevated noise levels despite the installation of noise barriers.

Road layout Alternative 1 will therefore require extensive noise

barriers along the proposed alignment to be feasible.

b. Noise barriers for road layout Alternative 2 and Alternative 3 will

be most beneficial at the elevated junction and Forest Drive

Extension off-ramps.

4.4.11 Refer to Figure 8 to Figure 10 in Appendix B for the predicted noise

propagation with the recommended noise mitigation installed.

4.4.12 Refer to Figure 11 to Figure 13 in Appendix C for the recommended

barrier profile for each road layout Alternative.



5. Conclusions and Recommendations 5.1 Residents along the existing Forest Drive Extension are less likely to

be affected by traffic noise from the proposed road layout Alternatives

insofar as the residual noise for the applicable environment is barely

exceeded. Road layout Alternative 2 and road layout Alternative 3 will

therefore have less of a noise impact than road layout Alternative 1.

5.2 Road layout Alternative 1 will have a higher noise impact on residents

of Elm and Rooikrans Road than road layout Alternative 2 and road

layout Alternative 3. This noise impact is likely to be substantially

noticeable and may result in complaints.

5.3 Noise barriers for road layout Alternative 2 and Alternative 3 will be

most beneficial at the elevated junction and Forest Drive Extension off-

ramps.

5.4 The cost of noise mitigation measures such as noise barriers will be

higher for road layout Alternative 1 than road layout Alternative 2 and


5.5 Despite mitigation measures such as noise barriers, residents of Elm

Road and Rooikrans Road are likely to be significantly affected by




5.6 The road layout alternatives proposed for the Conradie BLMEP can

therefore be ranked as follows:

Table 10: Ranking table of the proposed road layout alternatives for Conradie BLMEP.

Description Alternative 1 Alternative 2 Alternative 3

Noise impact High Low Low

Probability of complaints Definite Improbable Improbable

Relative cost of mitigation High Low Low

Level of significance after mitigation High Low Low

5.7 The summarised recommendation for Conradie BLMEP to comply

with the Western Cape Noise Control Regulations, 2013 is to install

solid noise barriers along sections of the proposed road alignment. The

noise barrier must be a continuous solid structure with constant

element height extending between the following areas:

a. Road Layout Alternative 1: Elevated T-junction to Conradie Access

BLMEP access road.

b. Road Layout Alternative 2: Forest Drive Extension West ramp road

chainage 150 to Maitland Cemetry road chainage 450 as referenced


c. Road Layout Alternative 3: Forest Drive Extension East Ramp road

chainage 150 to road Chainage 450 and Forest Drive Extension

West Ramp road chainage 80 to road chainage 268 as referenced




5.8 Visual mitigation design must be to Landscape Architect’s

specification and conceptual design drawings must be signed off by a

registered Professional Acoustics Engineer.

5.9 The above recommendations are valid provided the following:

i. The proposed road layout Alternatives as illustrated in this report

are not changed.

ii. The predicted future traffic volumes stated in this report, as

provided by the updated Traffic Impact Assessment (Revision 3)

submitted by HHO Africa in March 2017, are not exceeded.

iii. The road paving installed for the proposed road alignment complies

with the Friction Courses recommended by the Western Cape

Province as specified in this report.

iv. The assumptions stated in this report are accepted as true and

correct.

Eng. T.E. Mackenzie Hoy Pr. Eng Bsc (Elec) Registered professional engineer number 840428

for: Mackenzie Hoy Consulting Acoustics Engineers


Appendix A: Road Paving Material Specification












Appendix B: SoundPLAN Grid Noise Map Results Note: The following grid noise maps indicate the noise levels predicted for traffic noise

along the proposed Conradie BLMEP during peak hour traffic. For purposes of

illustration, a thick red line is shown representing the maximum allowable limit of 67

dBA for the day-time (06h00 to 22h00). The colour scale at the right hand side of each

map shows the corresponding range of sound pressure levels for each contour.


Figure 5: Predicted noise propagation of peak hour traffic along proposed Alternative 1 without noise mitigation.






Figure 8: Predicted noise propagation of peak hour traffic along proposed Alternative 1 with noise mitigation installed.


Figure 9: Predicted noise propagation of peak hour traffic along proposed Alternative 2 with noise mitigation installed.


Figure 10: Predicted noise propagation of peak hour traffic along proposed Alternative 3with noise mitigation installed.


Appendix C: Recommended Solid Noise Barrier Profiles


Figure 11: Solid noise barrier profile (highlighted as orange colour lines) recommended for the proposed road layout Alternative 1.





Documents

Conradie BLMEP, Thornton - Western Cape · PDF fileMackenzie Hoy Consulting Acoustics Engineers Fax: +27 (0) 21 531 3334 . 5 Coniston Way Cell: +27(0) 82 568 8924 . Pinelands ... This