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Terramin Australia 19 May 2011 Document No. 60151412 A11E01RP-01

Angas Zinc Mine Updated Environmental Noise Assessment

AECOM

Angas Zinc Mine

X:\Projects\AA Job Numbers\AA0704\10. Reporting\60151412 A11E01RP-01.docx Revision 1 - 19 May 2011

Angas Zinc Mine Updated Environmental Noise Assessment

Prepared for

Terramin Australia

Prepared by AECOM Australia Pty Ltd Level 28, 91 King William Street, Adelaide SA 5000, Australia T +61 8 7100 6400 F +61 8 7100 6499 www.aecom.com ABN 20 093 846 925

19 May 2011

60151412

AECOM in Australia and New Zealand is certified to the latest version of ISO9001 and ISO14001.

© AECOM Australia Pty Ltd (AECOM). All rights reserved.

AECOM has prepared this document for the sole use of the Client and for a specific purpose, each as expressly stated in the document. No other party should rely on this document without the prior written consent of AECOM. AECOM undertakes no duty, nor accepts any responsibility, to any third party who may rely upon or use this document. This document has been prepared based on the Client’s description of its requirements and AECOM’s experience, having regard to assumptions that AECOM can reasonably be expected to make in accordance with sound professional principles. AECOM may also have relied upon information provided by the Client and other third parties to prepare this document, some of which may not have been verified. Subject to the above conditions, this document may be transmitted, reproduced or disseminated only in its entirety.

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Quality Information Document Angas Zinc Mine

Ref 60151412

Date 19 May 2011

Prepared by Tom Evans

Reviewed by Jonathan Cooper

Revision History

Revision Revision Date Details

Authorised

Name/Position Signature

0 4-May-2011 For Issue Tom Evans Engineer - Acoustics

1 19-May-2011 Revised Issue Tom Evans

Engineer - Acoustics

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Angas Zinc Mine


Table of Contents Glossary i 1.0 Introduction 1 2.0 Noise criteria 2

2.1 General environmental duty 2 2.2 Environment Protection (Noise) Policy 2007 2 2.3 Mining and Rehabilitation Program 3 2.4 Summary of noise criteria 4

3.0 Measured noise levels 5 3.1 Ball mill gearbox 5 3.2 Swamp Road measurements 5

4.0 Environmental noise predictions 6 4.1 Environmental noise model 6 4.2 Predicted noise levels 6 4.3 Maximum permissible noise levels 6

5.0 Conclusion 8 Appendix A

Predicted noise contours – MARP noise targets A Appendix B

Predicted noise contours - Noise EPP limits B

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Glossary A-weighting The A-weighting scale is used to adjust the noise level to the subjective response of the

human ear to sound.

dB(A) A-weighted noise levels are expressed in units of dB(A).

Leq The equivalent (continuous) noise level is defined as the equivalent steady noise level which, in a given period of time, would contain the same noise energy as the time-varying noise during the same time period.

Leq,15min The equivalent (continuous) noise level over a 15 minute period. The Leq,15min noise level is used to assess compliance with environmental noise legislation in South Australia.

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1.0 Introduction AECOM has been engaged by Terramin to update the environmental noise assessment for the Angas Zinc Mine, following modifications to the mine site. The Angas Zinc Mine is situated 2.7 kilometres from the township of Strathalbyn, on the Callington – Strathalbyn Road.

Recent modifications have been made to the gearbox of the ball mill at the mine and an existing earth mound has been extended between the mine and the nearest residential locations to the west.

This updated environmental noise assessment has included:

- site measurements of the noise generated by the ball mill gearbox following the completion of modifications

- measurements of the noise generated by the mine at residential locations to the west

- updates to the existing environmental noise model of the site in order to predict noise emissions to residential locations around the mine

- assessment of the predicted noise levels against the relevant environmental noise criteria for the Angas Zinc Mine.

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2.0 Noise criteria

2.1 General environmental duty Under the Environment Protection Act 1993 (EP Act), Terramin have a duty of care for the environment during operation of the Angas Zinc Mine. The general environmental duty, which is defined in Section 25 of the EP Act, is:

A person must not undertake an activity that pollutes, or might pollute, the environment unless the person

takes all reasonable and practicable measures to prevent or minimise any resulting environmental harm.

In order to gauge environmental noise impacts from operations such as the Angas Zinc Mine against the general environmental duty, the Environment Protection Authority (EPA) has developed the Environment Protection

(Noise) Policy 2007 (Noise EPP).

2.2 Environment Protection (Noise) Policy 2007 Under the Noise EPP, the general environmental duty is satisfied in relation to noise from a noise source if measurements taken in relation to the noise source and the noise-affected premise show that:

- the Leq,15min source noise level does not exceed the indicative noise level for the noise source, or

- the Leq,15min source noise level does not exceed the background noise level (L90) plus 5 dB(A) where the background noise level plus 5 dB(A) is higher than the indicative noise level.

Due to the relatively quiet background noise environment surrounding the Angas Zinc Mine, the relevant noise criteria would be controlled by the indicative noise level.

The indicative noise level is based on the land use of the area as “principally promoted by the relevant Development Plan provisions” for the noise source and noise-affected premises. The Noise EPP defines indicative noise levels for particular land usages as shown in Table 1. Table 1 Environmental noise criteria applicable to different land usages, in dB(A)

Land use category Indicative noise factor, Leq dB(A)

7 am – 10 pm 10 pm – 7 am

Rural Living 47 40

Residential 52 45

Rural Industry 57 50

Light Industry 57 50

Commercial 62 55

General Industry 65 55

Special Industry 70 60

The Angas Zinc Mine and the nearest sensitive receivers are located within the Alexandrina Council Area. The

Alexandrina Council Development Plan (Alexandrina DP) defines the zoning of the Angas Zinc Mine and nearest sensitive receivers as:

- Angas Zinc Mine – Grazing Zone

- nearest sensitive receivers located on Swamp Road and east of mine – Grazing Zone

- nearest sensitive receivers located on Callington Road and west of mine – Landscape (Strathalbyn District) Zone.

Objective 1 of the Grazing Zone in the Alexandrina DP is:

Objective 1: Retention of land in primary production.

Based on this, the Grazing Zone represents a locality that principally promotes “Rural Industry” land use.

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Objective 1 of the Landscape (Strathalbyn District) Zone in the Alexandrina DP is:

Objective 1: A zone comprising land which has significant landscape qualities and which is to be retained

in use primarily for farming purposes and for natural open space.

Based on this, the Landscape (Strathalbyn District) Zone also represents a locality that principally promotes “Rural Industry” land use.

As both the noise source and the nearest receivers are located in Rural Industry land uses under the Noise EPP, the following noise criteria would be applicable:

- day time Leq,15min of 57 dB(A) from 7 am to 10 pm

- night time Leq,15min of 50 dB(A) from 10 pm to 7 am.

Noise character penalties are applied to the measured or predicted noise levels under the Noise EPP for each of the characteristics of tonal, impulsive, low frequency or modulating noise. If the noise emission from the noise source contains these characteristics, and the characteristics are a dominant feature of the noise at the receiver, then the source noise level must be adjusted in the following way:

- if noise from the source contains one characteristic, 5 dB(A) must be added to the Leq,15min source noise level

- if noise from the source contains two characteristics, 8 dB(A) must be added to the Leq,15min source noise level

if the noise from the source contains three or four characteristics, 10 dB(A) must be added to the Leq,15min source noise level.

2.3 Mining and Rehabilitation Program The Mining and Rehabilitation Program (MARP) for the Angas Zinc Mine, dated January 2007, specified noise criteria for the mine to be achieved at the nearest residential locations. The noise criteria specified by the MARP were developed in accordance with the Environment Protection (Industrial Noise) Policy 1994 (INP), which was the environmental noise policy in place at that time.

The following criteria were adopted:

- day time Leq,15min of 47 dB(A) from 7 am to 10 pm

- night time Leq,15min of 40 dB(A) from 10 pm to 7 am.

Under the MARP, noise emissions from the Angas Zinc Mine should be at or lower than these limits.

In response to the MARP, Primary Industries and Resources SA (PIRSA) granted Mineral Lease ML6229 to Terramin with the following conditions related to noise:

The Lessee must, in constructing and operating the least ensure that there are no public nuisance impacts

from noise emanating from the operating site.

Noise must at all times comply with the relevant environment protection policy under the Environment Protection Act 1993.

However, following acceptance of the MARP, the EPA released the Noise EPP which represents the relevant environment protection policy since 2007, with the noise criteria developed under that policy presented in Section 2.2.

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2.4 Summary of noise criteria As outlined in the previous sections, the applicable environmental noise criteria for the Angas Zinc Mine have increased by 10 dB(A) since the introduction of the Noise EPP. This represents a significant increase of the noise limit relative to that was applied as part of the MARP and is due to:

- a clearer definition of noise levels for rural industry land uses in the new Noise EPP

- the 5 dB(A) reduction applied during the assessment of new noise sources does not apply to existing noise sources undergoing assessment

- original noise criteria determined under the INP assumed a 5 dB(A) noise character penalty would be applied but no noise character penalty has been noted based on monitoring results.

To address this, Terramin propose that a noise target and noise limit will be adopted as outlined in Table 2. Table 2 Summary of noise criteria

Leq,15min noise level in dB(A)

Day time, 7 am to 10 pm Night time, 10 pm to 7 am

Noise target 47 40

Noise limit 57 50

The measured / predicted noise levels from the Angas Zinc Mine will be adjusted for any applicable noise character penalties in accordance with the Noise EPP (refer Section 2.2).

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3.0 Measured noise levels

3.1 Ball mill gearbox Noise levels immediately adjacent to the ball mill gearbox were measured on 7 April 2011 in order to determine an updated sound power level for the gearbox to be included in the environmental noise model.

The measurements indicated that the sound power level of the gearbox was approximately 2 dB(A) higher than the sound power level of the previous gearbox measured as part of the post-construction measurements conducted in May 2009. It should be noted that a difference of 2 dB(A) is within typical variability during noise measurements but the environmental noise model has been updated to increase the sound power level from the gearbox by 2 dB(A).

During the measurements immediately adjacent to the gearbox, it was noted that the gearbox noise included a clearly audible tone at a frequency of approximately 500 Hz. However, as noted in Section 3.2, tonal noise from the gearbox was not a dominant characteristic of the noise at the residential locations on Swamp Road.

3.2 Swamp Road measurements The noise level at the eastern property boundary of the nearest residential location on Swamp Road was measured at the following times:

- 11:15 am on Thursday 7 April 2011

- 8:45 pm on Wednesday 13 April 2011.

Table 3 presents the measured noise levels at the nearest residential location on Swamp Road. Note that extraneous noise sources such as Callington Road traffic and bird noise were excluded from the measurements. Table 3 Measured noise levels at nearest residential location on Swamp Road

Time Measured Leq, dB(A) Notes

11:15 am 40 Noise from mine faintly audible during lulls in traffic

8:45 pm 31

Noise from mine audible during lulls in traffic.

Overcast, still conditions (no wind) during measurements. These conditions are typical of CONCAWE Weather Category 4 (neutral weather conditions).

During the measurements, it was noted that noise from the mine was typically broadband in nature and no noise character penalty was considered applicable. Tonal noise from the gearbox was not audible at the residential location.

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4.0 Environmental noise predictions

4.1 Environmental noise model The previously developed environmental noise model for the site has been updated based on the ball mill gearbox measurements outlined in Section 3.1. The model has also been updated to include the extended earth mound on the western side of the site entrance road.

The noise model was developed in SoundPLAN Version 6.5 noise propagation software1 and uses CONCAWE2 algorithms, implemented in the software, to predict noise levels at the nearest residences under weather conditions conducive to the propagation of sound from source to receiver.

4.2 Predicted noise levels The updated environmental noise model was used to predict environmental noise levels from the mine assuming worst case weather conditions, i.e. CONCAWE Weather Category 6, which are conducive for the propagation of sound from source to receiver.

The predicted levels indicated that noise from the ball mill gearbox was expected to be more than 10 dB(A) below the overall mine noise level at each of the nearest residences. Based on this and the observations made on site during the evening measurements on Swamp Road, no character penalty is considered applicable to noise from the Angas Zinc Mine under the Noise EPP.

Environmental noise contours for typical day and night time activities under these worst case weather conditions are included in Appendix A for comparison with the MARP noise targets. The contours indicate that the noise targets defined in the MARP are expected to be achieved at all residential locations to the west of the site. Under worst case weather conditions, the night time noise levels at three residences to the east of the site are predicted to exceed the MARP noise target by between 1 to 2 dB(A). However, compliance with the MARP noise target is expected at all locations under all weather conditions other than worst case conditions (i.e. CONCAWE Weather Categories 1 to 5).

Appendix B includes noise contours for comparison against the Noise EPP noise limits. Predicted noise levels at all residential locations are well below the applicable noise criteria determined in accordance with the Noise EPP.

4.3 Maximum permissible noise levels The predictions were also used to determine maximum permissible noise levels at the two alternative noise monitoring locations on the eastern and western sides of the site. These monitoring locations have previously been selected in order to minimise the influence of extraneous noise sources on measured noise levels.

Table 4 presents the maximum permissible noise levels at the two monitoring locations in order for predicted noise levels to comply with the MARP targets and the Noise EPP limits under worst case weather conditions. Table 4 Maximum permissible noise levels at alternative monitoring locations

Location Maximum permissible Leq,15min noise levels to comply with MARP targets

Maximum permissible Leq,15min noise levels to comply with Noise EPP limits

Day time (7 am to 10 pm)

Night time (10 pm to 7 am)

Day time (7 am to 10 pm)

Night time (10 pm to 7 am)

East monitoring location 62 56 72 66

West monitoring location 64 57 74 67

1 SoundPLAN is a suite of noise propagation software accepted by the EPA. 2 CONCAWE Report 4/81, The propagation of noise from petroleum and petrochemical complexes to neighbouring communities. This is a noise propagation model for the prediction of industrial noise.

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Note that the maximum permissible levels at both of these monitoring locations have been determined on the basis of worst case weather conditions, conducive to the propagation of sound from source to receiver. A higher noise level at these monitoring locations would be acceptable under all other weather conditions as the difference in noise level between the alternative location and residences is greater under other weather conditions.

Worst case weather conditions (CONCAWE Weather Category 6) for a particular residence typically occur for:

- night time clear or partially cloudy skies with slight breeze from the mine to the residence

- strong winds towards the residence during overcast conditions, after sunrise or before sunset.

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5.0 Conclusion An updated environmental noise assessment for the Angas Zinc Mine has been undertaken following modifications to the ball mill gearbox on the site.

The measured noise level from the gearbox was found to be marginally higher than that measured during the original assessment conducted in 2009. The measurements were used to update the environmental noise model for the site and to predict noise levels to the nearest residential locations. The predictions indicated no change to the environmental noise levels at the nearest residential locations due to the modifications to the ball mill gearbox.

Under worst case weather conditions conducive for the propagation of sound from source to receiver, it is predicted that noise levels from the Angas Zinc Mine comply with the MARP noise level target at all residences to the west of the site. A relatively small 1 to 2 dB(A) exceedance of the target is predicted at three residences to the east of the site under worst case weather conditions, although compliance with the target is expected to be achieved at these locations under all other weather conditions.

The predicted noise levels are significantly below the applicable noise criteria derived from the Noise EPP at all times.

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Appendix A

Predicted noise contours – MARP noise targets

A3 size

ANGAS ZINC MINEPredicted worst case day timenoise contoursMay 2011

Data sources:

Base Data (c) 2010, NearMap

PROJECT ID

LAST MODIFIED

CREATED BY

60151412

TRE

TRE - 19 May 2011

LEGEND

Point sourcesLine sourcesMine buildingsReceiver

Day Leq,15min noise levelAbove 72 dB(A)67 to 72 dB(A)62 to 67 dB(A)

57 to 62 dB(A)52 to 57 dB(A)47 to 52 dB(A)

A1Map0 150 30075

Metres

´1:6,000 (when printed at A3)

DATUM GDA 1994, PROJECTION MGA ZONE 54

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A3 size

ANGAS ZINC MINEPredicted worst case night timenoise contoursMay 2011

Data sources:


PROJECT ID

LAST MODIFIED

CREATED BY

60151412

TRE

TRE - 19 May 2011

LEGEND

! Point sourcesLine sourcesMine buildingsReceiver

Night Leq,15min noise levelAbove 70 dB(A)65 to 70 dB(A)60 to 65 dB(A)

55 to 60 dB(A)50 to 55 dB(A)45 to 50 dB(A)40 to 45 dB(A)

A2Map0 150 30075

Metres



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Angas Zinc Mine


Appendix B

Predicted noise contours - Noise EPP limits

A3 size

ANGAS ZINC MINEPredicted worst case day timenoise contoursMay 2011

Data sources:


PROJECT ID

LAST MODIFIED

CREATED BY

60151412

TRE

TRE - 19 May 2011

LEGEND

Point sourcesLine sourcesMine buildingsReceiver

Day Leq,15min noise level> 72 dB(A)67 to 72 dB(A)62 to 67 dB(A)57 to 62 dB(A)

B1Map0 150 30075

Metres



!

! !

!!!!!

!

!!!

!

!

!

!!

A3 size

ANGAS ZINC MINEPredicted worst case night timenoise contoursMay 2011

Data sources:


PROJECT ID

LAST MODIFIED

CREATED BY

60151412

TRE

TRE - 19 May 2011

LEGEND

! Point sourcesLine sourcesMine buildingsReceiver

Night Leq,15min noise levelAbove 70 dB(A)65 to 70 dB(A)60 to 65 dB(A)55 to 60 dB(A)50 to 55 dB(A) B2

Map0 150 30075

Metres



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