Noise and Blasting Impact Assessment Taronga Stage 1

Spectrum Acoustics Pty Limited

ABN: 40 106 435 554

1 Roath Street, Cardiff NSW 2285

Phone: (02) 4954 2276

Fax: (02) 4954 2257

Project No: 151073

Noise and Blasting Impact Assessment Taronga Stage 1 Project Emmaville, NSW Prepared for: Aus Tin Mining Limited GPO Box 5621 Brisbane QLD 4001 Author:

…………………………………… Neil Pennington B.Sc., B. Math.(Hons), MAAS, MASA

Principal / Director December 2016

Noise and Blasting Impact Assessment – Taronga Tin Project

Doc. No: 151073-5922

December 2016 Page i

TABLE OF CONTENTS

1.0 INTRODUCTION ............................................................................................................................................................ 1

1.1 The Proposal ...................................................................................................................................................... 1

1.2 Receiver Locations ............................................................................................................................................. 1

2.0 THE PROPOSAL ............................................................................................................................................................ 1

2.1 Stage 1 Mining .................................................................................................................................................... 1

2.2 Haul route ........................................................................................................................................................... 3

3.0 DESCRIPTION OF TERMS ............................................................................................................................................ 4

4.0 EXISTING ENVIRONMENT ............................................................................................................................................ 5

4.1 Meteorology ........................................................................................................................................................ 5

4.2 Existing Acoustic Environment ........................................................................................................................... 5

5.0 NOISE AND VIBRATION CRITERIA ............................................................................................................................. 5

5.1 Project Specific Noise Goals .............................................................................................................................. 5

5.2 Sleep Disturbance .............................................................................................................................................. 6

5.3 Vehicle Noise ...................................................................................................................................................... 6

5.4 Blasting ............................................................................................................................................................... 7

6.0 ASSESSMENT METHODOLOGY .................................................................................................................................. 7

5.1 Site Operations ................................................................................................................................................... 7

5.2 Modelled Scenarios ............................................................................................................................................ 8

5.3 Noise Sources ................................................................................................................................................... 8

5.3 Blasting ............................................................................................................................................................... 8

6.1.1 Blast Overpressure....................................................................................................... 9

6.1.2 Blast Vibration ............................................................................................................. 9

7.0 RESULTS AND DISCUSSION ....................................................................................................................................... 9

7.1 Predicted Operational Noise Levels ................................................................................................................... 9

7.2 Blasting ............................................................................................................................................................. 10

8.0 SUMMARY ................................................................................................................................................................... 10

TABLES

Table 1. Definition of Acoustical terms …………………………..…………………………………………………….……………….. 3

Table 2. Road Traffic Noise Criteria …………………………………………………………………………………………………….. 5

Table 3. Noise Sources and Sound Power Levels ..…………...……………………………………………………………………... 7

Table 4. Calculated Noise levels .………………..…………………………………………..…………………………………………. 8

Table 5. Calculated Blast Levels ……………………………………………………………..…………………………………………. 9

FIGURES

Figure 1. Project Site Map ……….................................................................................………….………………………………… 1

Figure 2. Project Site Layout …………………….…………………………………………………………….…………………………. 3

Noise Impact Assessment – Taronga Tin Mine

Doc. No: 151073-5922

December 2016 Page 1

1.0 INTRODUCTION

1.1 The Proposal

Aus Tin Mining Limited (ASX:ANW, the Proponent) is seeking to progress trial

mining and pilot processing at the Taronga Tin Project (Taronga) located 7.5 km

northwest of Emmaville, NSW (see Figure 1).

This noise impact assessment has been carried out in accordance with the NSW

Industrial Noise Policy (INP, 2000) and vibration guidelines to accompany a

Environmental Impact Statement (IES) for the proposal to be submitted as part of

a Development Application to the Glen Innes Severn Council (GISC).

1.2 Receiver Locations

There are five land owners around the Project Site as identified in Figure 1, with

permanent or non-permanent residences, denoted R1 to R5 respectively. R1 is a

permanent dwelling and R2 is a caravan used as a semi-permanent residence.

R3, R4 and R5 are understood to be permanent dwellings. Noise and vibration

impacts from the proposal are assessed for these five receivers. The

communications tower is also assessed for vibration impacts.

Figure 1. Local area and Project Site.

2.0 THE PROPOSAL

2.1 Stage 1 Mining

The proposed trial mining at Taronga Tin Mine (Stage 1, see Figure 2) is

described by the Proponent as follows:

R1 (2.5km)

R2 (750m) R3 (2.3km)

Project site

R4 (2.6km) R5 (2.6km)

Telecommunications tower


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Mining of approximately 335,000 tonnes of ore and 75,000 tonnes of waste

rock

o Drill and blast – blast up to 30,000 tonnes at a time.

Pilot plant operation, crushing/screening, pre-concentrate and all activities

including tin dispatch during normal daytime hours Monday-Saturday

Between 12 and 18 month operation

Employment of 20 staff

Disturbance area no more than 10 Ha within the Proponent’s freehold land

Access via existing roads.

Hours of operations are summarised in Table 1.

TABLE 1

HOURS OF OPERATION

Activity Monday to Friday Saturday Sunday

Site Establishment 7am-6pm 8am – 1pm -

Stockpile and Waste Rock Management

7am-6pm - -

Mining Operations 7am-6pm - -

Drilling 7am-6pm - -

Blasting 9am to 5pm - -

Crushing and Screening Operations

7am-6pm 8am – 6pm

Ore Pre-concentration 7am-6pm 8am – 6pm

Concentrate Dressing 7am-6pm - -

Ore Comminution 7am-6pm - -

Concentrate Dressing 7am-6pm - -

Tin Concentrate Dispatch 7am-6pm - -

Pre-start checks and Maintenance

6am to 6pm

+ Other times+

8am to 6pm

+ Other times+

Anytime+

+ Maintenance would be undertaken at other times, Monday to Saturday and anytime Sunday, provided it is inaudible at any surrounding residence.


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Figure 2. Proposed site layout

2.2 Haul route

The haul route to and from the Project site would include an existing road on site,

linking to Grampians Road and the local road network to the New England

Highway.


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3.0 DESCRIPTION OF TERMS

Table 2 contains the definitions of commonly used acoustical terms and is

presented as an aid to understanding this report.

TABLE 2

DEFINITION OF ACOUSTICAL TERMS

Term Description

dB(A) The quantitative measure of sound heard by the human ear, measured by the A-

Scale Weighting Network of a sound level meter expressed in decibels (dB).

SPL Sound Pressure Level. The incremental variation of sound pressure above and

below atmospheric pressure and expressed in decibels. The human ear

responds to pressure fluctuations, resulting in sound being heard.

STL Sound Transmission Loss. The ability of a partition to attenuate sound, in dB.

Lw Sound Power Level radiated by a noise source per unit time re 1pW.

Leq Equivalent Continuous Noise Level - taking into account the fluctuations of noise

over time. The time-varying level is computed to give an equivalent dB(A) level

that is equal to the energy content and time period.

L1 Average Peak Noise Level - the level exceeded for 1% of the monitoring period.

L10 Average Maximum Noise Level - the level exceeded for 10% of the monitoring

period.

L90 Average Minimum Noise Level - the level exceeded for 90% of the monitoring

period and recognised as the Background Noise Level. In this instance, the L90

percentile level is representative of the noise level generated by the surrounds of

the residential area.


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4.0 EXISTING ENVIRONMENT

The existing meteorological and acoustical environments of the site have been

studied to determine prevailing conditions and to allow noise goals to be set.

4.1 Meteorology

The atmospheric conditions most relevant to noise assessments are temperature

inversions, gentle winds (indicative of possible wind shear) and relative humidity.

The NSW Industrial Noise Policy (INP) states that wind effects need to be

assessed where source to receiver winds (at 10m height) of 3m/s or below occur

for 30% or more of the time in any season in any assessment period.

Seasonal wind roses for Tenterfield were analysed for the assessment of

prevailing winds.

The analysis found that winds up to 3 m/s occurred less than 15% of the time

during all seasons, from all directions. Winds are generally aligned from the east

and west, with stronger winds in excess of 3 m/s dominating and consideration of

winds in the noise assessment is not required.

Consequently, noise modelling of proposed daytime activities was carried out

under the prevailing condition of neutral atmospheric conditions (20°C, no wind).

The INP also requires assessment of temperature inversions if the project is to

operate at night time during winter months. There are no major noise-generating

activities proposed for night time hours. Some maintenance works may occur at

night, as required, but the proponent would communicate with nearby landowners

to ensure these activities are not audible.

4.2 Existing Acoustic Environment

The area around the Project Site is rural in nature with some potential noise from

agricultural activities, but contains no significant industrial noise sources. Taking

a conservative approach, the INP default minimum background noise level of 30

dB(A),L90 will be adopted at all receivers.

5.0 NOISE AND VIBRATION CRITERIA

5.1 Project Specific Noise Goals

Industrial noise is assessed against the requirements of the INP. In relation to

residential receivers, the INP specifies two noise criteria: intrusiveness and

amenity criteria.

The Intrusiveness Criterion limits Leq noise levels from the industrial source to a

value of ‘background plus 5dB’. That is, the Rating Background Level (RBL) for


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the time period, plus 5 dB(A). The RBL (L90) is defined as the overall single

figure background level representing each assessment period.

The Amenity Criterion aims to protect against excessive noise levels where an

area is becoming increasingly developed. Amenity criteria are dependent upon

the nature of the receiver area and the existing level of industrial noise. There is

very little existing industrial noise in the area and the residential area that is

potentially affected by noise emissions from the proposal is best described

acoustically as rural.

The project specific noise level for all receivers will therefore be the intrusiveness

criterion of 35 dB(A) Leq(15 min) for daytime and night time activities.

This criterion applies to all emissions from the site including heavy vehicles on

private sections of the haul route.

5.2 Sleep Disturbance

To help protect against people waking from their sleep, the EPA recommends

that 1-minute (LA1) noise levels (effectively, the maximum noise level from

impacts) should not exceed the background level by more than 15 dB when

measured/computed at a point 1 m from a bedroom window. The “sleep

disturbance” criterion is only applicable to night-time noise emissions and is equal

to 45 dB(A),L1(1min).

5.3 Vehicle Noise

In NSW, noise from vehicle movements associated with an industrial source is

assessed in terms of the INP if the vehicles are not on a public road. If the

vehicles are on a public road, the NSW Road Noise Policy (RNP) applies. Noise

from the proposal must, therefore, be assessed against the project specific noise

goals of the INP and also the criteria in the RNP.

The RNP recommends various criteria based on the functional categories of

roads applied by the Roads and Traffic Authority (RTA). The RTA differentiates

roads based on a number of factors including traffic volume, heavy vehicle use,

through or local traffic, vehicle speeds and applicable traffic management options.

Vehicles accessing the site will do so via a local road network.

Table 3 below shows the noise criteria relevant to traffic on various road types

extracted from Table 1 of the RNP. For the assessment of traffic noise, the day

time period is from 7am to 10pm, whilst night is from 10pm to 7am.


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TABLE 2

ROAD TRAFFIC NOISE CRITERIA

Situation

Recommended Criteria

Day

(7am to 10pm)

Night*

(10pm to 7am)

6. Existing residences affected by additional

traffic on existing local roads generated by land

use developments

Leq (1hr) 55

(external)

Leq (1hr) 50

(external)

* It is not proposed to haul product at night, so only the daytime criteria are applicable.

The project would produce a relatively small amount of concentrate and would

generate no more than a few truck movements per day. Assessment of previous

projects of this magnitude suggest traffic noise levels at least 20 dB below the

criteria for receivers as close as 20m to the road. Due to such a small number of

traffic movements and resultant noise, off-site traffic noise will not be considered

further.

5.4 Blasting

Overpressure and vibration levels from blasting are assessable against criteria

proposed by the Australian and New Zealand Environment and Conservation

Council (ANZECC) in their publication “Technical Basis for Guidelines to Minimise

Annoyance due to Blasting Overpressure and Ground Vibration – September

1990”. These criteria are summarised as follows.

The recommended maximum overpressure level for blasting is 115dB.

The level of 115dB may be exceeded for up to 5% of the total number of

blasts over a 12-month period, but should not exceed 120dB at any time.

The recommended maximum vibration velocity for blasting is 5mm/s Peak

Vector Sum (PVS).

The PVS level of 5mm/s may be exceeded for up to 5% of the total number of

blasts over a 12-month period, but should not exceed 10mm/s at any time.

Blasting should generally only be permitted during the hours of 9am to 5pm

Monday to Saturday, and should not take place on Sundays and Public

Holidays.

Blasting should generally take place no more than once per day.

A blast vibration limit of 20mm/s is typically applied to infrastructure such as the

communications tower 250m from the proposed extraction area.

6.0 ASSESSMENT METHODOLOGY

5.1 Site Operations

The proponent is planning to conduct all activities on site during daytime hours

with maintenance works, as needed, outside these hours.


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5.2 Modelled Scenarios

A single scenario was modelled using the ENM point-calculation mode to

represent the potential worst case typical noise emissions during the daytime with

all activities operating at the same time.

Scenario 1: Daytime - Extraction activities and waste dump in locations indicated

in Figure 2. Use of ball mill dressing plant and crusher/screen. Transport of ore

using road-going trucks at a conservative rate of one truck movement per hour.

5.3 Noise Sources

Equipment proposed for use for extraction and processing is listed in Table 3.

TABLE 3

NOISE SOURCES AND SOUND POWER LEVELS, Lw dB(A)

Equipment Indicative

Number

Use Lw

dB(A)

# = sources that will be used at night.

D8 Bulldozer 1 Trimming waste dump 110

Atlas Copco T35 1 Drilling of ore for blasting. 110

18t Explosives truck 1 Explosives for blasting 103

WA470-1 Loader# 1

Stockpile management loading blasted rock.

103

320D Cat Excavator 1 Loading of blasted rock to crusher 105

Cat 769 30t Haul Truck

2 Transportation of products to stockpiles.

104

80kW Ball Mill 1 Ore comminution (grinding) 98

HOWCAM Dressing Plant#

1 Concentrate Dressing 90

HOWCAM Feeder /Trommell / Jig#

1 Ore Pre-concentration

98

Cat 140H Grader 1 Maintenance of internal haul road. Ancillary activities.

97

McCloskey J50 crusher 1 Primary crushing 112

McCloskey C44 cone crusher/ S190-2D screen

1 Secondary rushing/screening 110

10 000L Water truck 1 Dust suppression. 108

5 000L Mini tanker 1 Refuelling of mobile and fixed plant. 108

The modelling was undertaken for the atmospheric conditions described in

Section 4.1.

5.3 Blasting

The following sections provide standard equations for predicting blast

overpressure and ground vibration levels, sourced from the United States Bureau

of Mines.


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6.1.1 Blast Overpressure

Unweighted airblast overpressure levels (OP) are predicted from Equation 1

below.

OP = 165 – 24(log10(D) – 0.3 log10(Q)), dB (1)

where D is distance from the blast to the assessment point (m) and

Q is the weight of explosive per delay (kg).

6.1.2 Blast Vibration

The basic equations for calculation of peak particle vibration (PPV) levels from

blasting are as follows:

6.1

5.01140PPV

Q

D , mm/s (for average ground type) (2)

6.1

5.0500PPV

Q

D , mm/s (for hard rock) (3)

where D and Q are defined as in Equation 2. Given the hard geology of the area,

equation 3 will be adopted.

7.0 RESULTS AND DISCUSSION

7.1 Predicted Operational Noise Levels

Noise levels were modelled using ENM for the daytime and night time scenarios

described in Section 5.2. Point calculations were performed for Receivers 1 to 5

in Figure 1.

Predicted noise levels for the modelled scenarios are summarised in Table 4.

TABLE 4

CALCULATED NOISE LEVELS dB(A),Leq (15 min)

Receiver Scenario 1: Daytime (neutral) Criterion

R1 <20 35

R2 33 35

R3 <20 35

R4 25 35

R5 27 35

The above results show that there are no predicted exceedances of the noise

criterion at any receiver for either the extraction or processing activities.


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7.2 Blasting

The client has advised that blasting within the quarry would only be required

occasionally and that the typical maximum instantaneous charge weight (MIC) for

production blasts would be 100 kg.

Calculated blast overpressure and ground vibration levels at the five nearest

receivers based on this worst case MIC are summarised in Table 5.

TABLE 5

CALCULATED BLAST OVERPRESSURE AND VIBRATION LEVELS

Location

Distance, m

Overpressure,

dB

Criterion Vibration,

mm/s

Criterion

Comms tower 250m -- -- 2.7 20

R1 2500 99 115 0.1 5.0

R2 750 112 115 0.5 5.0

R3 2300 100 115 0.1 5.0

R4 2600 98 115 0.1 5.0

R5 2600 98 115 0.1 5.0

The above results show worst case blast impact levels below the overpressure

and ground vibration criteria at both assessed receivers and the nearby

communications tower.

8.0 SUMMARY

A noise impact assessment of the proposed Taronga Tin Mine trial mining project

has been conducted. The study has found the following:

No noise criterion exceedances at residential receivers;

No blasting criterion exceedances at residential receivers or nearby

communications tower; and

No exceedance of off-site traffic noise criteria at any receiver.

On the basis of these results, we advise that the project could operate within any

reasonable noise and vibration criteria as may be included in a project approval.

Documents

Noise and Blasting Impact Assessment Taronga Stage 1