AUSTRALIAN DOLOMITE COMPANY PTY LTD … mineral exploration pty ltd australian dolomite company pty ltd ‘wonga’ blast management plan for proposed granite quarry

RANGOTT MINERAL EXPLORATION PTY LTD

AUSTRALIAN DOLOMITE COMPANY PTY

LTD

‘Wonga’

Blast Management Plan

FOR PROPOSED GRANITE QUARRY

LOWES MOUNT ROAD, TARANA, NSW

Author: Paula Dell‐McCumstie Rangott Mineral Exploration Pty LtdPO Box 1141, Orange, NSW Tel: (02) 6362 5115 August 2015

TABLE OF CONTENTS………………………………………………………………………………….. Page

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

2.0 PROPOSED ACTIVITIES……………………………………………………………………… 3

3.0 LEGAL AND OTHER REQUIREMENTS…………………………………………………. 4

4.0 OBJECTIVES AND OUTCOMES………………………………………………………….. 7

5.0 COMPETENCE TRAINING AND AWARENESS……………………………………… 8

6.0 SURROUNDING RESIDENCES…………………………………………………………….. 8

7.0 ANTICIPATED BLAST‐RELATED IMPACTS…………………………………………… 9

7.1 POTENTIAL IMPACT………………………………………………..….…. 9

7.1.1 Introduction………………………………………………………..………. 9

7.1.2 Airblast Overpressure Structural Impacts……….…….……… 9

7.1.3 Ground Vibration Structural Impacts…………………….……… 9

7.1.4 Blasting Guidance…………………………………………………..…… 10

7.2 PREDICTED LEVELS OF BLAST EMISSIONS……………………….…….… 11

8.0 MANAGEMENT MEASURES……………………………………….…………………….. 12

8.1 BLASTING COMPLIANCE………………………………………………….……… 12

8.2 BLASTING HOURS AND FREQUENCY…………………………………..…… 12

8.3 OPERATION CONDITIONS………………………………………………..…….. 12

8.3.1 Blasting Operations………………………………………………..…… 12

8.3.2 Flyrock and Dust Management………………………………..….. 12

8.3.3 Ground Vibration…………………………………………………..……. 15

8.3.4 Management of Airblast Overpressure…………………..…… 17

8.3.5 Blasting Safety Management…………………………………..….. 19

8.4 TEMPORARY CLOSURE OF LOWES MOUNT ROAD………………..…. 20

8.5 PROPOERTY INSPECTIONS……………………………………………….……… 20

8.6 PROPERTY INVESTIGATION……………………………………………………... 20

9.0 BLAST MONITORING………………………………………………………………………… 22

9.1 BLAST MONITORING REPORT………………………………………………..… 22

10 CORRECTIVE AND PREVENTATIVE ACTIONS…………………...................... 23

11 COMPLAINT HANDLING AND RESPONSE………………………….................. 24

12 INCIDENT REPORTING ……………………………………………………………………… 25

13 PUBLICATION OF MONITORING INFORMATION……………….................. 25

FIGURES: Figure Number Figure Title Scale Size

Figure 1 Project Site Regional Location 1:200,000 A4

Figure 2 330m blast clearance radius around Wonga Quarry 1:5,000 A4

Figure 3 One kilometre radius around Wonga Quarry 1:12,500 A4

Figure 4 Position of blast monitor close to Wonga Main Residence

1: 2,000 A4

TABLES:

TABLES: Table Title Page

Table 1 Australian and New Zealand Environment Council (ANZEC) Technical basis for guidelines to minimise annoyance due to blasting overpressure and ground vibration Guidelines

5

Table 2 Objectives and Key Performance Outcomes 7

Table 3 Transient Vibration Guide for Cosmetic Damage (from BS 7385: Part 2: 1993

9

Table 4 Predicted Levels of Blast Emissions (Nitrotek Consulting). 11

Table 5 Blast design parameters used as the base case 14

Table 6 Range of particle shape factors with modelled value highlighted 14

Table 7 Estimated blast clearance distances 15

GRAPHS:

Graph Graph Title PageGraph 1 BS 7385: Part 2: 1993, Summary of Damage Thresholds for Transient Vibration

on Domestic Structure 10

Graph 2 Maximum probable vibration as a function of distance away from blasting activity

16

Graph 3 Maximum probable overpressure as a function of distance away from blasting activity

18

APPENDICES: APPENDIX I Fair Work Ombudsmen Best Practice Guide Effective Dispute Resolution

APPENDIX II Road Closure Plan for blasting at Wonga Quarry adjacent to Lowes Mount Road

APPENDIX III Example of Wonga Quarry Site Induction

APPENDIX IV Technical Report from Darren Francis, Principal Engineer, Nitrotek Consulting

1 Wonga EIS‐Blast Management Plan

1. INTRODUCTION

This Blast Management Plan has been prepared by Rangott Mineral Exploration Pty. Ltd. on behalf of

Australian Dolomite Company Pty. Ltd. (Australian Dolomite) for the proposed Wonga Quarry. The

quarry is located 18km north of Oberon, in the Central Tablelands region of New South Wales and

approximately 200km west of Sydney (Figure 1).

With reference to the Environmental Planning and Assessment Regulations 2000, Schedule 3, Part 21

(c) (viii) this application has triggered designated development due the location of a dwelling that is

not associated with the development, within 500m of the quarry where blasting will occur. An

Environmental Impact Statement was therefore necessary and Director General’s Requirements were

sought. The Secretary’s Environmental Assessment Requirements (EAR 888) were received on 12th

March 2015. Assessment of the potential impacts of Noise and Blasting is required, as stated in EAR

888: an assessment of the likely blasting and vibration impacts of the development, having regard to

the relevant ANZEC guidelines and paying particular attention to the impacts on people, livestock,

heritage items and infrastructure.

It is well established that the extraction and initial particle size reduction of hard rock deposits is most

efficiently undertaken with the use of explosives. However, as with most industrial processes, this is

not a completely efficient process when converting potential (chemical) energy into useful work.

Where energy is transmitted into the adjacent rock mass these losses are referred to as vibrations.

Vibrations are a series of elastic waves, the strength of which are related to the mass of the individual

charge detonated. Losses occurring into the atmosphere above the blast are referred to as

overpressure (noise).

Usually, a neighbour will perceive vibration as a shake of ground, perhaps with accompanied response

noise of stored items (eg china display cabinet), while overpressure commonly manifests as a rattle of

windows and in most situations a directly associated audible noise.

As a generalisation, an increase in distance away from a blast will result in a reduction of both

overpressure and vibration at a point of interest.

This report addresses the following:

The proposed blasting activities at Wonga Quarry

The legal requirements associated with management of blast emissions from the quarry

The objectives and key performance outcomes for this plan and the quarry

Roles and responsibilities

Bathurst

Oberon

O'ConnellTarana

WONGA QUARRY

Owner

Oval

Owner

Oval

Owner

Oval

Owner

Line


Competence training and awareness

Surrounding residences and potential blast‐related impacts

Blast management measures

Blast‐related monitoring that will be undertaken

Evaluation of compliance with blast criteria

Corrective and preventative actions that will be implemented should exceedance(s) of the

relevant criteria be identified

Complaints handling and response procedures that will be implemented

Incident reporting procedures

Publication of monitoring information

The proposed quarry is fully described in the Environmental Impact Assessment dated June 2015 and

associated technical reports prepared to support the application documents and therefore no

further background information is provided in this plan.


2 PROPOSED ACTIVITIES

The proposed activities at Wonga Quarry comprise the following:

Extracting approximately 500 tonnes of broken granite per year.

Transporting the broken granite from Wonga Quarry to Australian Dolomite’s crushing plant

at Wallerawang, using 30 tonne capacity semi‐trailer tipper trucks.

A drill and blast event once every six to ten years including the closure of Lowes Mount Road

due to a calculated blast clearance radius of 330m around the quarry (Figure 2).

The proposed quarry life is until 2065 and the intended hours of operation are as follows:

o Monday to Friday, between 7.00am to 6.00pm

o Saturday, between 8.00am to 2.00pm

o Sunday and Public Holiday‐ Nil

765,

750

mE

766,

000

mE

766,

250

mE

6,281,250 mN

6,280,500 mN

6,280,750 mN

6,281,000 mN

765,

500

mE

765,

000

mE

765,

250

mE

User

Callout

Wonga Quarry extension

User

Callout

330m radius around Wonga Quarry


3 LEGAL AND OTHER REQUIREMENTS

Australian Dolomite is applying to extract granite from Wonga Quarry to produce architectural

aggregate. The application includes the submission of a Development Application and Environmental

Impact Statement. As designated development, the application must comply with the requirements

in Clause 6 and 7 of Schedule 2 of the Environmental Planning and Assessment Regulations 2000 as

set out by the Director General’s Requirements. Assessment of the potential impacts of Noise and

Blasting is included, as stated: an assessment of the likely blasting and vibration impacts of the

development, having regard to the relevant ANZEC guidelines and paying particular attention to the

impacts on people, livestock, heritage items and infrastructure.

The recommended criteria for blasting is set out in the Australian and New Zealand Environment

Council (ANZEC) Technical basis for guidelines to minimise annoyance due to blasting overpressure

and ground vibration. All relevant recommendations within this ANZEC technical document will be

adhered to.


Recommended Criteria as stated in ANZEC: Technical basis for guidelines to minimise annoyance due to blasting overpressure and ground vibration.

Criteria Allowable exceedance Report Section

Airblast overpressure

Airblast overpressure maximum level is 115 dB (Lin Peak)

5% of the total number of blasts over a period of 12 months

8.3.4

Airblast overpressure maximum level is 120 dB (Lin Peak)

0% 8.3.4

Ground Vibration Impact

Ground Vibration maximum level is 5mm/sec peak particle velocity

5% of the total number of blasts in a 12 month period

8.3.3

Ground Vibration maximum level is 10mm/sec peak particle velocity

0% 8.3.3

Blasting hours and frequency

Blasting is permitted during the hours of 9.00am to 5.00pm Monday to Friday. No blasting shall occur on Saturdays, Sundays and Public Holidays

8.2

Blasting may occur once a day 8.2

Operating Conditions

During the quarry operations on site, the Drill and Blasting specialist contracted by Australian Dolomite shall implement best practice:

(a) conduct blasting operations in accordance with AS 2187.2‐2006 Explosives – Storage and use – Use of explosives;

8.3

(b) minimise fly‐rock and dust and fume emissions from blasting; 8.3.2

(c) protect travellers on Lowes Mount Road; Appendix

II

(d) protect the safety of people and livestock, the serviceability of private property and private infrastructure, to the satisfaction of the Director‐General.

Appendix II

Blast Management Plan

Australian Dolomite shall prepare and implement a Blast Management Plan for the project to the satisfaction of the Director‐General. This plan must:

(a) be submitted to the Director‐ General for approval prior to the commencement of blasting activities; and

(b) include:

proposed blasting programo site induction

proposed mitigation contingencieso road closure plan

8 and Appendix

II

Blast Monitoring

Australian Dolomite shall: (a) hire a blast monitoring instrument for each blasting campaign, to be placed

within close proximity to the Wonga Main Residence. An authorised and

9


competent person shall install and calibrate the instrument in accordance with AS 2187.2‐2006

b) evaluate blasting impacts on, and demonstrating compliance with, the blastingcriteria in this approval for privately‐owned residences and other structures.

9

Public Notice

Australian Dolomite shall: (a) notify the landowner/occupier of any residence within 1 kilometre of the site about the blasting schedule, at least three working days prior to blasting, to the satisfaction of the Director‐General

13

(b) erect temporary signs along Lowes Mount Road, close to Wonga Quarry on the day of blasting, to informing the passing traffic of the blasting activities

Appendix II

Property Inspections

At least two months prior to the commencement of blasting operations at the quarry, Australian Dolomite shall advise the Webb family who are the only owners of privately‐owned land within 1 kilometre of the proposed quarry, that they are entitled to a structural property inspection to establish the baseline condition of buildings and other structures on their property. If Australian Dolomite receives a written request for a structural property inspection from the Webb family, they shall:

within 2 months of receiving the request, commission a suitably qualified,experienced and independent person, whose appointment has been approved by the Director‐General, to inspect the conditions of any building or structure on the land, and recommend measures to mitigate any potential blasting impacts; and

8.5

give the landowner a copy of the property inspection report. 8.5

Property Investigations

If the Webb family, or any other landowner nominated by the Director‐General, claims that buildings and/or other structures on his/her land have been damaged as a result of blasting at the project site, Australian Dolomite shall within 2 months of receiving this claim:

(a) commission a suitably qualified, experienced and independent person, whose appointment has been approved by the Director‐General, to investigate the claim; and

8.6

(b) give the landowner a copy of the property investigation report. 8.6

If the independent property investigation confirms the landowner’s claim, and both parties agree with these findings, then Australian Dolomite shall repair the damage to the satisfaction of the Director‐General.

11

If Australian Dolomite or landowner disagrees with the findings of the independent property investigation, then either party may refer the matter to the Director‐General for resolution.

11

If the matter cannot be resolved in 21 days, the Director‐General shall refer the matter to an independent Dispute Resolution Process.

Appendix

I

Table 1: Australian and New Zealand Environment Council (ANZEC) Technical basis for guidelines to minimise annoyance due to blasting overpressure and ground vibration Guidelines


4. OBJECTIVES AND OUTCOMES

Table 2, below presents the objectives and key performance outcomes for this Plan and Wonga

Quarry.

OBJECTIVES KEY PERFORMANCE OUTCOMES

To take into consideration the relevant ANZEC guidelines

To follow all relevant guidelines and not exceed recommended limits

To implement blast management and mitigation measures during the Project

All identified blast management and mitigation measures will be implemented prior to the commencement of blasting

To implement an appropriate monitoring program to observe ground vibration and air overpressure results

All monitoring will be undertaken with reference to relevant ANZEC guidelines

Table 2: Objectives and Key Performance Outcomes


5. COMPETENCE TRAINING AND AWARENESS

Blasting at Wonga Quarry is likely to occur once every six to ten years, therefore a Drill and Blasting

Specialist will be contracted by Australian Dolomite to carry out blasting when required. The blasting

specialist will be fully competent in blast management awareness focussing on the following:

Awareness of the blast emissions enhancing effects of temperature inversion and the times

of day and meteorological conditions under which they may occur

Awareness of safety for travellers on Lowes Mount Road, surrounding residents and

livestock and implement the attached Road Closure Plan (Appendix II).

Awareness of explosive storage, transport and use in accordance with AS 2187.2‐2006

Explosive Storage, Transport and Use

Minimising flyrock and dust emissions from blasting

Awareness of restricted blast operating hours and frequency

Monitoring of blast emissions at required residences

Ensure all personnel adhere to the site induction

Australian Dolomite is responsible for ensuring that blast management plan is adhered to by the Site

Supervisor and Drill and Blasting Specialist.

6. SURROUNDING RESIDENCES

Figure 3 displays the locations of the residences within 1 kilometre of the Project site.

6,279,500 mN

6,280,000 mN

6,280,500 mN

6,281,500 mN

6,282,000 mN

6,282,500 mN

765,

500

mE

764,

500

mE

765,

000

mE

766,

000

mE

766,

500

mE

6,281,000 mN

User

Oval

User

Oval

User

Callout

1km radius around Wonga Quarry


7. ANTICIPATED BLAST‐RELATED IMPACTS

This section describes the predicted potential airblast overpressure and ground vibration structural

impacts of blasting and the blast emission levels.

7.1 POTENTIAL IMPACTS

7.1.1 Introduction

Airblast overpressure is a pressure wave that travels through the air following a blast, while ground

vibration is caused by energy from the blast travelling through the intervening rock strata

surrounding the blast location.

7.1.2 Airblast Overpressure Structural Impacts

Plaster that cracked within residences is the type of damage that is monitored in most airblast

overpressure complaints.

7.1.3 Ground Vibration Structural Impacts

British Standard BS 7385: Part 2 1993 ‘Evaluation and measurement for vibration in buildings Part 2:

Guide to damage levels from ground borne vibration’ gives guidance on the levels of vibration above

which the building structures could be damaged. It considers only the direct effect of the vibration

on a building, since the other mechanisms are different.

For the purposes of BS 7385, damage is classified as cosmetic (formation of hairline cracks), minor

(formation of large cracks) or major (damage to structural elements). Guide values given in the

Standard are associated with the threshold of cosmetic damage only, usually in wall and/or ceiling

lining materials. Since case‐history data, taken alone, has so far not provided an adequate basis for

identifying thresholds for vibration‐induced damage, data using controlled vibration sources within

buildings has been established to enable definition of vibration thresholds judged to give a minimal

risk of vibration‐induced damage. Limits for primarily transient vibration (from a train, for example)

above which cosmetic damage could occur are reported in tabular form and graphical form in the

Standard and reproduced exactly below:

Transient Vibration Guide for Cosmetic Damage (from BS 7385: Part 2: 1993)

Line Type of building Peak Component Particle Velocity in Frequency Range of Predominant Pulse

4 Hz to 15 Hz 15 Hz 15 Hz above

1 Reinforced or framed structures. Industrial and heavy commercial buildings

50 mm/s at 4 Hz and above

2 Unreinforced or light framed structures. Residential or light commercial type buildings

15 mm/s at 4 Hz increasing to 20 mm/s at 15 Hz

20 mm/s at 15Hz increasing to 50 mm/s at 40 Hz and above

Table 3: Transient Vibration Guide for Cosmetic Damage (from BS 7385: Part 2: 1993)


The origin of line 1 and 2 are found in graph 1, below: BS 7385: Part 2: 1993: Summary of Damage

Thresholds for Transient Vibration on Domestic Structure. The graph compares Frequency against

Peak Componentt Particle Velocity

Graph 1: BS 7385: Part 2: 1993, Summary of Damage Thresholds for Transient Vibration on Domestic Structure

7.1.4 Blasting Guidance

Secretary’s Environmental Assessment Requirements (EAR 888) state: an assessment of the likely

blasting and vibration impacts of the development, having regard to the relevant ANZEC guidelines

and paying particular attention to the impacts on people, livestock, heritage items and

infrastructure.

Table 1: Australian and New Zealand Environment Council (ANZEC) Technical basis for guidelines to minimise annoyance due to blasting overpressure and ground vibration Guidelines, above displays the required guidelines:

The maximum level for airblast overpressure maximum level is 115 dB (Lin Peak). The level

of 115 dB (Lin Peak) may be exceeded on up to 5% of the total number of blasts over a

period of 12 months. The level should not exceed 120dB (Lin Peak) at any time.

The maximum level for ground vibration is 5mm/sec peak particle velocity. The level of

5mm/sec may be exceeded on up to 5% of the total number of blasts over a period of 12

months. The level should not exceed 10mm/s at any time.


7.2 PREDICTED LEVELS OF BLAST EMISSIONS

During the environmental assessment, the predicted levels of airblast overpressure and ground

vibration were assessed at the two residences that fall within the one kilometre radius

Maximum Probable Blasting Impacts

Residence Distance from BlastingActivity (m)

Ground Vibration (mm/s)

Airblast Overpressure(dB (L))

Wonga Main Residence 240 0.19 117

Wonga Second Residence 370 * 112

1km radius 1000 * 102

*Below threshold level

Table 4: Predicted Levels of Blast Emissions (Nitrotek Consulting).

The key results of the assessment are as follows:

A blast clearance distance of 330m for all personnel is recommended to provide a factor of

safety of at least 2.0.

Blast induced ground vibration is likely to be below 1.0mm/s at the closest identified

residential structure ‐ well below public amenity limits identified in AS2187.2‐2006 (5.0mm/s)

and significantly below levels associated with the onset of cosmetic damage in lightly

constructed structures.

Maximum blast overpressure levels are likely to be below 117dB(L) at the closest identified

residential structure ‐ below public amenity limits identified in AS2187.2‐2006 (120dB(L) ) and

significantly below levels associated with the control of damage in lightly constructed

structures.


8. MANAGEMENT MEASURES

EAR 888 requires this plan to describe mitigation measures that will be adopted to ensure

compliance with ANZEC Technical basis for guidelines to minimise annoyance due to blasting

overpressure and ground vibration Guidelines, paying particular attention to the impacts on people,

livestock, heritage items and infrastructure. Oberon Council require that the close proximity to

Lowes Mount Road be investigated. This section has been prepared in satisfaction of those

guidelines.

8.1 BLASTING COMPLIANCE

Australian Standard 2187.2 Explosive Storage, Transport and Use states:

that blasting will only be undertaken by qualified personnel or contractors

blasting personnel or contractors operate under AS 2187.2

Australian Dolomite will be responsible to ensure blasting is carried out according to the relevant

standard.

8.2 BLASTING HOURS AND FREQUENCY

Australian Dolomite will ensure that the operating hours and conditions identified in ANZEC

Technical basis for guidelines to minimise annoyance due to blasting overpressure and ground

vibration Guidelines will be adhered to.

Australian Dolomite will be responsible for ensuring the operating hours are included in the site

induction and that no breaches of this condition will be tolerated.

Blasting is recommended only once a day.

8.3 OPERATING CONDITIONS

8.3.1 Blasting Operations

All blasting will adhere to the specific recommendations within AS2187.2 – 2006, such that the

project will observe all regulations for blasting where safe handling and use of explosives is

implemented at the Wonga Quarry Project through a defined Blast Management Plan (BMP).

8.3.2 Flyrock and Dust Management

The control of flyrock is a relatively complex interaction between blast design, diligent operational

application and local geology. However, the issue of maintaining personnel safety demands a strong

engineering basis to ensure safety under all blasting conditions at all times. Experience has shown


that flyrock projection distance estimations and subsequent selection of appropriate clearance

zones must be carefully assessed with as complete knowledge as possible of each individual blasting

application.

Best practice blasting incorporates a level of redundancy within the blast design to ensure an

acceptable factor of safety is maintained even in the event of unintended unknown deviations

during application of the design (such as shorter stemming lengths).

Various studies have sought to generate predictive equations for maximum flyrock range and are

generally based on consideration of:

Rock density

Blast hole diameter

Explosive density

Confinement levels

Particle size achieving maximum range

The equations developed, combined with other known equations of motion allow the determination

of practical limits for any charge configuration, blast hole size, rock type and shape factor (ratio of

surface area to volume). More recently, improved realistic particle motion has been achieved by

incorporating the additional influence of air resistance for estimated particle trajectories.

The calculation adopted for the Wonga Quarry site combines all of the points mentioned above into

a succinct form:

〖Range〗_max=11 ×〖SDB〗^(‐2.167) (∅/F_s )^0.667 (Equation 1)

where Φ is the hole diameter in mm, Fs is the shape factor, SDB is the scaled depth of burial

equation and Rangemax is the maximum probable flyrock projection. The scaled depth of burial

component provides a relationship to define the relative confinement of the explosive charge and is

defined as:

SDB= d_c/∛MJ (Equation 2)

where d_c is the depth from the collar of the blast hole to the cratering charge centroid (cratering

charge assumed to be equivalent to 8 times the blast hole diameter) and MJ is the explosive energy

contained in the cratering charge.

In order to progress the investigation, a base case blast design is required and has been completed.

Little historic blast design data and no geotechnical data is available at this time to guide the blast

design process. Operational parameters and initial rock mass data have been selected based on

experience of similar material. For the Wonga Quarry site the following criteria have been adopted:

• Individual blast to produce 5 years supply of material


• Intact rock strength in the order of 110MPa to 140Mpa

• Intact rock ‐ Young's Modulus = 62GPa

• Intact rock ‐ Poisson's Ratio = 0.32

• Working face height = 4.0m

• Blast hole diameter = 89mm

• Bulk explosive density = 1.10g/cc

The onset of fresh fracture in rock due to rapid strain rates (known as the critical vibration level ‐

PPVcritical) has been well documented and can be used to provide a first estimate of a productive

blast pattern design. Here, a multiple of 4 times the PPVcritical generally achieves good levels of

fragmentation and results in the following parameters for the base case blast design:

Blast design parameters used as the base case

Hole diameter

Burden Spacing Bench Height

Hole Length

Stem Length

Sub Drill Length

Explosive Product Density

Explosive Product Energy

Scaled Depth of burial (E)

B:S Ratio

Powder Factor

mm m m m m m m g/cc MJ/kg m/MJ^⅓ s/b Kg/bcm89 2.3 2.6 4.0 5.0 2.7 1.0 1.1 2.7 1.29 1.13 0.66

Table 5: Blast design parameters used as the base case

Selection of the particle shape factor described in Equation 1 is an important consideration.

Observations reported in literature indicate values ranging from 1.1 to 1.3 adequately describe the

range of flyrock particles likely to be encountered. Furthermore, values of this parameter can be

ranked according to the sensitivities of the project at hand and are shown below in Table 6. A value

of 1.2 has been selected as this represents the most probable value in the absence of actual

measured data to calibrate the flyrock model.

Table 6: Range of particle shape factors with modelled value highlighted

As mentioned above, it is appropriate that a layered approach to risk mitigation is implemented. To

that end, a factor of safety (FOS) for personnel clearance during blasting of 2.0 is desirable and

often specified. Table 7, below shows the maximum flyrock range likely to be encountered at Wonga

Quarry when using parameters noted in Table 5. The blast clearance zone is then calculated by

multiplying Rangemax by the minimum desired factor of safety ‐ in this case 2.

Fs Rangemax

1.0 Conservative

1.1

1.2 Realistic

1.3

1.4 Aggresive


Table 7: Estimated blast clearance distances.

The data also demonstrates that if a maximum unknown deviation of 0.5m in the stemming length is

inadvertently applied, a clearance distance of 328m is required to maintain a FOS=2. However, it

should be noted that an over charged hole is significant as this is likely to be detected and remedied

during charging activities prior to stemming being applied.

On the basis of the modelling calculations and consideration of a worst case scenario, a minimum blast

clearance distance of 330m from the actual blast boundary is recommended².

8.3.3 Ground Vibration

Many factors specific to an individual site will affect the transmission of vibration through the

ground. Indeed, the most accurate estimates of future blasting impacts are generated from analysis

of multiple vibrations recorded at that location. Given the nature and history of the site, it is not

unexpected that no blast vibration data is available for the Wonga Quarry. AS2187.2‐2006 does

however provide guidance in the absence of such site data where it indicates that the following

equation may be used to estimate maximum likely ground vibration levels in average conditions

where blasting to a free face is carried out:

PPV=1140(R/√(2andQ))^(‐1.6) (Equation 3)

where:

PPV ‐ ground vibration as vector peak particle velocity, in millimetres per second

R ‐ distance between charge and point of measurement, in metres

Q ‐ maximum instantaneous charge (ie effective charge mass per delay), in kilograms

1.6 ‐ vibration decay factor

1140 ‐ site constant

Particle Shape Factor = 1.2Stemming

LengthRangemax

Blast Clearance Radius

# (m) (m) (m)

Base Case 2.7 111 222

Stemming Error (-0.1m) 2.6 119 239





Flyrock Rangemax SummaryFactor of Safety = 2


Published data relating specifically to granite formations indicate that the actual decay factor, a

measure of how rapidly elastic strain waves (ie vibration) attenuate over distance, is greater with

values ranging from 2.1 to 2.4. Site constants are similarly noted to vary from that provided in

Equation 3 with values ranging from 500 to 1300. It is appropriate in this case to modify the

AS2187.2 estimates for decay factor and site constant values based on these published values

combined with operational experience in similar materials to the following values:

vibration decay factor = 2.1

site constant = 1050

The selected values retain a level of conservatism appropriate to the planned operational nature of

the site. For Wonga Quarry, the following equation may be used with a high degree of confidence to

estimate maximum likely ground vibration levels at any point of interest:

PPV=1050(R/√(2andQ))^(‐2.1) (Equation 4)

Applying the above blast vibration model to the base case blast design yields:

Graph 2: Maximum probable vibration as a function of distance away from blasting activity.

The results presented in graph 2 clearly show that blast induced vibration levels at ranges beyond

180m will be difficult to detect without the aid of sensitive monitoring equipment. This is directly

related to the relatively small charge quantities (16kg per blast hole) employed in the initial design.

Distance to closest residential structure= 240m


The closest identified residential structure is located at a range of approximately 240m. Estimated

vibration levels at this distance are in the order of 10 times lower than the public amenity level of

5.0mm/s recommended in AS2187.2‐2006 for blasting operations. Likewise, this is many times lower

than any of the commonly accepted limits for the onset of cosmetic damage to residential and

similar lightly fabricated structures.

8.3.4 Management Airblast Overpressure

Overpressure is a measurement of the pressure levels transmitted into the atmosphere radiating

outwards from the source. It has been documented that well confined blasts generate pressure

waves at frequencies predominantly below 20Hz, with relatively small amounts of energy contained

in frequencies greater than this level. It is important to note that the human ear does not respond to

noise with frequencies below the 20Hz level. However, it is equally important to note that buildings

tend to respond to frequencies in the range of 2 to 20Hz. It is on this basis that most monitoring for

human response to noise utilises a filtered sound level where frequencies below 20Hz are removed.

This is known as the decibel (A) scale ‐ or dB(A) scale. As blasting generally produces frequencies

predominantly below 20Hz, atmospheric overpressure levels are recorded using the decibel (Linear)

scale ‐ or dB(L).

Again, as with the case for blast vibration estimation, the most accurate estimations of overpressure

rely on calibrating site specific models using actual recorded data. These models tend to rely on

established scaling methods which seek to establish the relationship between explosive charge mass

detonated per delay period, the range to the point of interest and the overpressure level. The

following cube root scaling formula is commonly utilised:

P=K(D/∛W)^a (Equation 5)

where

P ‐ sound pressure level (kPa)

D ‐ distance from charge (m)

W ‐ explosive charge mass per delay (kg)

K ‐ site constant

a ‐ site exponent

Without the assistance of actual historic data, published data has been accessed. For average

confinement levels in typical quarry blasting applications, values of the site constant K commonly

range between 3.15 (good confinement) to 31.5 (extremely poor confinement) for a site exponent

(a) of ‐1.2. Appropriate initial values for Wonga Quarry Project have been selected:


K = 3.3

a = ‐1.2

For Wonga Quarry, the following equation may be used with a high degree of confidence to estimate

maximum likely air overpressure levels at any point of interest:

P=3.3(D/∛W)^(‐1.2) (Equation 6)

Graph 3: Maximum probable overpressure as a function of distance away from blasting activity.

The results presented in graph 3 show that the maximum probable blast induced overpressure levels

at the closest nearby residential structure will be below 117dB(L). The inference here is that actual

recordings will form a statistical distribution with the average value positioned much below this

level. For all existing nearby residential structures, overpressure levels can be expected to be below

the sensitive site amenity level of 120dB(L) recommended in AS2187.2‐2006 for blasting operations

where less than 20 blasting events are conducted annually. Similarly, the expected maximum

overpressure levels are significantly below AS2187.2‐2006 recommended air blast limits for damage

control in typical residential and similar lightly fabricated structures.

Distance to closest residential structure= 240m


As indicated in Table 4, airblast overpressure at Wonga main property will have a maximum of 117

dB (L). As identified in ANZEC Technical basis for guidelines to minimise annoyance due to blasting

overpressure and ground vibration Guidelines, the relevant criteria for airblast overpressure is 115

dB Linear, with exceedances of this level permitted during no more than 5% of blasts in any 12

months period. In order to achieve compliance with this requirement, Australian Dolomite will

implement the following when blasting within the section of the Extraction Area closest to Wonga

main property,

Maximum instantaneous charges will be adjusted to ensure compliance with the

115 dB Linear criteria

Blasts will not be initiated, where practicable, during temperature inversion, when

low cloud is present or when the wind is blowing from the southeast

8.3.5 BLASTING SAFETY MEASURE

Oberon Council’s request of 9th July 2015 and EAR 888 require the protection of travellers on Lowes

Mount Road, people, livestock, heritage items and infrastructure.

As no heritage items were identified in the project area during the Environmental Assessment, this

does not need to be mitigated. The requirement for safety measures for Lowes Mount Road, people,

Wonga properties and livestock still apply. The following will be implemented:

Review location of blast and its proximity to Lowes Mount Road, the presence of

landowners, property and livestock and determine the appropriate exclusion zone

Where required, blasts should be orientated such that flyrock will be directed away from

Lowes Mount Road, Wonga properties, people or livestock

Advise surrounding landholders within 2km of the blast three days prior to blasting of the

date and times of the blast.

Temporarily close Lowes Mount Road. A Road Closure Plan is attached in Appendix II

Inspect blasts to determine if flyrock has propelled outside the blast envelope and

investigate where appropriate

Design blasts to minimise uncontrolled flyrock by the Principal Blast Engineer, Nitrotek

Consulting

Ensure blasting personnel are competent by employing Specialist Drill and Blasting

Contractors

Australian Dolomite will be responsible for ensuring that the relevant safety measures have been

implemented prior to blasting within the Quarry.


8.4 TEMPORARY CLOSURE OF LOWES MOUNT ROAD

Due to the close proximity of Wonga Quarry to Lowes Mount Road, it is recommended that the road

be closed for a period of time prior to blasting, during the blast and immediately after blasting.

A Road Closure Plan is attached in Appendix II.

8.5 PROPERTY INSPECTIONS

EAR 888 requirements state that regard to ANZEC Technical basis for guidelines to minimise

annoyance due to blasting overpressure and ground vibration Guidelines must be made, paying

particular attention to impacts on infrastructure. Australian Dolomite will advise Mr and Mrs Webb,

the owner of Wonga Main property and second property two months prior to the commencement

of blasting operations at the quarry. To ensure that this requirement is met, the following will be

implemented:

Advise the Webb family of their entitlement to a structural property inspection at least two

months prior to blasting.

Commission a suitably qualified, experienced and independent person, approved by the

Director‐General of the Department of Planning and Infrastructure to inspect the condition

of any building or structure within two months of receiving a request from The Webb family

Implement relevant recommendations by the independent person to mitigate any potential

blasting impacts

Make available a copy of the report to the Webb family

Australian Dolomite will be responsible for advising the Webb family of their entitlement for

structural property inspection and the potential provision of mitigation measures prior to blasting on

site.

8.6 PROPERTY INVESTIGATIONS

Australian Dolomite will investigate, within two months, any claims regarding blast‐related damage

to buildings or structures. To ensure that this requirement is met, the following will be implemented:

On receipt of a written complaint, Australian Dolomite will commission a suitably qualified,

experienced and independent person, approved by the Director‐General of the Department

of Planning and Infrastructure to inspect and investigate the alleged blast‐related damage to

privately‐owned buildings or structures to determine the likely cause of the damage and

prepare a report outlining the findings of the investigation

Make available a copy of the report to the Webb family


Repair damage if it is confirmed by the report and both parties have agreed to the findings

to the satisfaction of the Director‐General

Refer the matter to the Director‐General if both parties do not agree with the findings for

resolution Appendix I

Implement an Independent Resolution Process if directed by the Director‐General if the

matter cannot be resolved with 21 days

Australian Dolomite will be responsible for ensuring that claims of damage are managed

according to the relevant requirements


9 BLAST MONITORING

To ensure blast criteria is not exceeded within the one kilometre radius around Wonga Quarry, a blast

monitor will be placed at the only inhabited dwelling; Wonga Main Residence. The monitor will be

situated within close proximity to the house, as shown on Figure 4. As blasting will occur so

infrequently at Wonga Quarry a blast monitoring instrument will be hired for each blasting campaign,

installed and calibrated in accordance with AS 2187.2‐2006 by an authorised and competent person.

Australian Dolomite will be responsible for blast monitoring.

9.1 BLAST MONITORING REPORT

A blast monitoring report will be prepared within 7 days of each blasting campaign. This report will

include an assessment of the monitoring results against the guidance in ANZEC Technical basis for

guidelines to minimise annoyance due to blasting overpressure and ground vibration Guidelines.

The monitoring report will be reviewed by Australian Dolomite and a copy included within the Annual

Review.

765,

700

mE

765,

500

mE

765,

600

mE

6,280,800 mN

6,280,900 mN

6,281,000 mN

6,281,100 mN

765,

200

mE

765,

300

mE

765,

400

mE

AutogridQuarry_extensionQuarry_boundary_330m_blast_zoneGc122_132_88301n_tarana

User

Callout

Extension to Wonga Quarry

User

Callout

Approximate position of blast monitor, close to Wonga Main Residence


10 CORRECTIVE AND PROVENTATVE ACTION

In the event that blast monitoring identifies an exceedance of the blast criteria identified in ANZEC

Technical basis for guidelines to minimise annoyance due to blasting overpressure and ground

vibration Guidelines, the exceedance will be investigated to determine the likely cause.

The investigation will seek to determine:

the date and time of the exceedance;

whether the exceedance of the criteria was directly related to a blast source associated with

the Quarry or if any other factors contributed to the exceedance;

the primary cause of the incident;

any contributing factors which led to the incident;

whether appropriate controls were implemented to prevent the incident; and

corrective and preventative measures that may be implemented to prevent a recurrence of

the incident.

If it has been identified that the criteria have been exceeded, Australian Dolomite will report and

investigate the exceedance.

Corrective and/or preventative actions will be assigned to relevant personnel.


11 COMPLAINTS HANDLING AND RESPONSE

A complaints management procedure will be implemented on receipt of a blast‐related complaint.

Blast‐related complaints may be received via one of the following methods:

directly via Australian Dolomite’s main office number (02) 9604 3100 from Monday to Friday

9.00am to 5.00pm

directly via Australian Dolomite’s main office email: [email protected]

indirectly via the relevant government agencies

Following the receipt of any blast‐related complaint, Australian Dolomite will implement the

following procedure:

1. The complaint will be reviewed by the Manager of Australian Dolomite or their delegate

to determine the nature, date and time of the blast emission

2. Should the blast monitoring report indicate that an exceedance of the criteria identified

in ANZEC Technical basis for guidelines to minimise annoyance due to blasting

overpressure and ground vibration Guidelines, the Manager of Australian Dolomite will

continue to consult with the complainant in relation to managing blast emissions within

the quarry

3. Should the blast monitoring report indicate that an exceedance of the criteria identified

in ANZEC Technical basis for guidelines to minimise annoyance due to blasting

overpressure and ground vibration Guidelines, the Manager of Australian Dolomite will

notify the Department of Planning and Infrastructure and Environment Protection

Authority and will implement the procedures identified in this section. In addition, the

Manager of Australian Dolomite will continue to consult with the complainant in relation

to the complaint.

All complaints will be recorded using a proforma complaints record sheet.


12 INCIDENT REPORTING

In the event that an initial investigation concludes that an exceedance of an environmental criterion

was directly attributed to activities associated with Wonga Quarry, as described in Section 10, the

event will be reported to NSW Department of Planning and Infratructure, EPA and the relevant

landholder (s) within 24 hours of confirming the exceedance.

Within 7 days of identifying the exceedance, Australian Dolomite will submit a written report with

regular updates on the status of the additional mitigation actions to the Director‐General, EPA and,

where relevant, the landholder(s). In addition, a copy of all reports will be made publicly available on

Australian Dolomite’s website: http://www.pebblecrete.com.au and be included in the Annual

Review.

Australian Dolomite will be responsible for incident reporting.

13 PUBLICATION OF MONITORING INFORMATION

All blast monitoring reports will be made publicly available on Australian Dolomite’s website

http://www.pebblecrete.com.au and will be included in the Annual Review.

All blast exceedance investigation reports will be made publicly available on Australian Dolomite’s

website http://www.pebblecrete.com.au

Australian Dolomite will be responsible for all reporting.

APPENDIX I

Fair Work Ombudsmen Best Practice Guide

Effective Dispute Resolution

01 Work & family

02 Consultation & cooperation in the workplace

03 Use of individual flexibility arrangements

04 A guide for young workers

05 An employer’s guide to employing young workers

06 Gender pay equity

07 Small business & the Fair Work Act

08 Workplace privacy

09 Managing underperformance

10 Effective dispute resolution

11 Improving workplace productivity in bargaining

12 Parental leave

Fair Work Ombudsman 1

Best Practice Guide

Effective dispute resolution

Working at best practice

Disputes can arise at any workplace. A dispute exists when one or more people disagree about something and matters remain unresolved. A fair and balanced dispute resolution process is important for the effective operation of any business.

This Best Practice Guide explains the:

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irement for a dispute resolution clause in ern awards and enterprise agreements, and the regarding overlap between these instruments

fits of a dispute resolution clause even where oyees are not covered by awards or enterprise

ements

res of a good dispute resolution clause, and

regarding the powers of the Fair Work mission or other independent persons in ving a dispute.

Included also is a checklist on best practice dispute resolution.

This guide illustrates best practice when it comes to effective dispute resolution. For specific information regarding your minimum legal obligations and entitlements, contact the organisations listed under the ‘For more information’ section at the end of this guide.

Why work at best practice?

Effective dispute resolution can help employers to maintain good relationships with their employees by dealing with workplace issues at an early stage. Employees will likely be more cooperative and productive if they know that their grievances will be taken seriously by the employer and there is the opportunity for an independent party to assist in resolving the dispute if it cannot be resolved at the workplace.

A good dispute resolution process with a focus on effective resolution at the workplace level may help to avoid the costs of resolving a claim externally; for instance, via arbitration before the Fair Work Commission, or through litigation in the Federal Court of Australia.

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Best Practice Guide


What is dispute resolution?

Dispute resolution refers to the processes by which disputes are brought to an end. This can occur through:

a s

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ain

negotiated outcome, where the parties concerned ort out things themselves

mediated outcome, where the parties use the ervices of an independent mediator to help them rive at their own agreement, or

n arbitrated or adjudicated outcome, where an dependent arbitrator or court determines how

the dispute is to be resolved and makes a binding decision or order to this effect.

Dispute resolution in modern awards and enterprise agreements

Modern Awards

The Fair Work Act 2009 (FW Act) requires that all modern awards include a term which sets out a procedure for resolving disputes between employers and employees about any matter arising under the modern award and the National Employment Standards (NES).

Every modern award contains a dispute resolution clause. Generally, the clause will provide for a process with the following stages:

oyee/s meet with their direct supervisor to ss the grievance

g resolution, the matter is discussed further more senior management

g resolution of the matter, the employer refers ispute to a more senior level of management or senior national officer within the organisation

e the dispute remains unresolved, the parties may y or individually refer the matter to the Fair Work mission, and

mployer or employee may appoint another on, organisation or association to represent during this process.

Employers should be aware of, and familiarise themselves with, any dispute resolution procedure that applies to their workplace.

Enterprise agreements

When making an enterprise agreement, the FW Act requires the parties to include a dispute resolution clause. Enterprise agreements lodged with the Fair Work Commission without such a clause will not be approved. The dispute resolution clauses in enterprise agreements m

Then

ust provide a process to resolve any disputes.

arising under the agreement, or

relating to the NES.

e FW Act requires that a dispute resolution clause in an terprise agreement must:

set out a procedure that requires or allows either the Fair Work Commission or some other independent person to settle the dispute, and

allow for the representation of employees covered by the agreement when there is a dispute (for example by another employee or a union).

A ‘model dispute resolution clause’ is available in the Fair Work Regulations 2009 and can be used to develop a dispute resolution term in an enterprise agreement. A link to the clause is available at the ‘For more information’ section at the end of this guide.

Which dispute resolution procedure applies to me or my business?

If a dispute involves employees covered by an enterprise agreement and relates to the NES or an enterprise agreement, the dispute resolution procedure in the enterprise agreement will apply and should be followed.

If there is no enterprise agreement in the workplace or an enterprise agreement does not cover the employees involved in the dispute, the procedure outlined in the modern award that applies to the employer and employee should be followed.

When neither an enterprise agreement nor a modern award applies to the employer and employee in relation to the dispute, the procedure in a contract of employment (if any) applies.


What if the employees are not covered by an award or enterprise agreement?

There are significant benefits to having a fair and transparent dispute resolution process in place.

Accordingly, even where no modern awards, enterprise agreements or other industrial instruments apply at a particular workplace, best practice employers will implement dispute resolution procedures in employees’ contracts of employment or in company policy documents.

What are the features of a good dispute resolution process?

A best practice dispute resolution process should:

be

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ow appropriate stages so that matters can, herever possible, be resolved at the workplace

courage parties to agree on a process that its them if the dispute reaches the Fair Work mmission, and

ovide the Fair Work Commission with the necessary scretion and power to ensure settlement of the spute if the dispute remains unresolved after the rly stages of the dispute resolution procedure have en attempted.

actice dispute resolution outcomes should be:

ick – the issues should be resolved quickly rather an allowing them to escalate through inaction

r – all relevant parties should be consulted so that sides of the story are taken into account

ndled sensitively – disputes should, where ssible and appropriate, be resolved in a nfidential context in order to minimise impact on

mployees not affected by the dispute, and

nsparent – the procedure should be made known every employee.

Dispute resolution procedures should not interfere with the continued operation of the business where possible. Any dispute resolution clause in an agreement, contract

or policy should require that work is to continue normally during the dispute resolution process subject to any reasonable concerns about health and safety.

Generally, the FW Act does not authorise employees to stop performing work while a dispute is being resolved.

Can the Fair Work Commission help with a dispute?

Where a provision in an award, an enterprise agreement, a contract of employment or other written agreement refers a dispute to the Fair Work Commission:

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the Fair parties, da bindin

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an whethgrounds flexible

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Unless provid

ng on the terms of the clause, the Fair Work ion may settle a dispute via mediation, on, or by making a recommendation or g an opinion, except in the circumstances

e parties have agreed to limit the powers of Work Commission, and

Work Commission may, where agreed by the eal with the matter by arbitration and make

g decision regarding the dispute.

Commission may only deal with disputes on has been made to the Fair Work y a party to the dispute.

Fair Work Commission must not deal with a about:

er an employer had reasonable business to refuse a request by an employee for

working arrangements, or

sion of unpaid parental leave beyond 12

ed for in a contract of employment, enterprise agreement or some other kind of written agreement that allows the Fair Work Commission to deal with the dispute.

The typical process explained

Employee(s) and/or any employee representative meet(s) with the employee’s direct supervisor to discuss a problem

The supervisor listens carefully to the employee(s) (and/or their representative) and together they try to resolve the dispute. If the supervisor and employee are unable to resolve the dispute or it is not appropriate that the supervisor deal with it, the matter should be referred to senior management

Senior management listens to the employee’s concerns and either resolves the dispute or refers the matter to more senior management

More senior/national officers listen to the employee (and/or their representative) and attempt to resolve the dispute. It is either resolved or referred to an independent body

An independent conciliator or mediator (for example the Fair Work Commission) assists to resolve the dispute

Resolution: Problems are solved and healthy working relationships are maintained

4

Best Practice Guide



Can independent persons help with a dispute?

Where a term in an award, an enterprise agreement or a contract of employment or other written agreement refers a dispute to an independent person (other than the Fair Work Commission):

the perswith the decision

the perswhether grounds flexible of unpaiprovideagreemethat allo

generallthe partiwith the relevant written a

on may, where agreed to by the parties, deal dispute via arbitration and make a binding about the dispute

on must not deal with a dispute if it is about an employer had reasonable business to refuse a request by an employee for

working arrangements or for an extension d parental leave beyond 12 months unless d for in a contract of employment, enterprise

nt or some other kind of written agreement ws them to deal with the dispute, and

y, an independent third party can only assist es to resolve their dispute in accordance powers that are expressly conferred by the clause of the award, agreement, or other greement.

Checklist for dispute resolution best practice

Where a dispute has arisen, employers working at best practice will:

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hey have a simple, quick, fair, confidential nsparent dispute resolution procedure in

hether it be included as part of a modern enterprise agreement, company policy, ment contract, or other industrial instrument

employees are made aware of the applicable resolution procedures.

pute has arisen:

wards solving the problem and maintaining working relationships

ne which dispute resolution procedure applies

with the correct procedure quickly and fairly

t efforts to resolve the dispute at the ce, and

his is not possible, refer the dispute to an ndent mediator or arbitrator such as the Fair ommission with the power to deal with the

Fair Work Ombudsman 13 13 94 www.fairwork.gov.au

For more information

Disclaimer

The Fair Work Ombudsman is committed to providing you with advice that you can rely on.

The information contained in this Best Practice Guide is general in nature. If you are unsure about how it applies to your situation you can call our Infoline on 13 13 94 or speak with a union, industry association or a workplace relations professional.

Produced December 2013. FWOBPG10a.02.

© Commonwealth of Australia 2013

Fair Work Ombudsman13 13 94 www.fairwork.gov.au

Fair Work Commission1300 799 675 www.fwc.gov.au

Model term for dealing with disputes for enterprise agreementsFair Work Regulations, Regulation 6.01

For more information

Acronyms used in this guide

FW Act Fair Work Act 2009

NES National Employment Standards

APPENDIX II

Road Closure Plan for blasting at Wonga Quarry

adjacent to Lowes Mount Road

Road Closure Plan for blasting at Wonga Quarry adjacent to Lowes Mount Road

Purpose

To provide a Management Plan and Operating Procedure for the temporary closure of Lowes Mount

Road, whenever blasting occurs at Wonga Quarry.

Procedure

This document provides a Road Closure Management plan, and Operating Procedure, which has

been advised by an external consulting Principal Blast Engineer, Darren Francis. The key aspects of

the document include:

the notification of affected parties

a protocol for the passage of emergency vehicles

Note 1: Blasting is permissible between 7.00am to 6.00pm Monday to Friday and between 8.00am

to 2.00pm on Saturday. The road traffic study indicates that the quietest traffic time on Lowes

Mount Road adjacent to the quarry is between 9.00am and 1.00pm and therefore it is advisable that

blasting take place between these times.

Notification

o Landholders within a 2km radius of Wonga Quarry shall be notified three days prior to

blasting

Traffic Management

o An authorised and competent traffic management company will be contracted to carry out

all traffic management in accordance with Roads and Maritime Services (RMS); Section 3

General Procedures‐Traffic Control at Worksites, including:

The correct placement of signage on the day of the blast

Certified controllers will be used for all road closures and must be familiar with the

road closure procedures, be accredited by RMS, wear reflective vests and carry an

operable hand held radio on the same frequency as Blast Co‐ordinator

Traffic controllers must be set up and in position thirty minutes prior to the

anticipated firing time, and able to make radio contact with the Blast Co‐ordinator

until the blast has been cleared. All traffic controllers must be at least 300m from the

boundary of the blast and public road traffic halted 500m from the blast zone.

The traffic controllers shall close the road prior to blasting, when advised by the Blast

Co‐ordinator. All traffic and personnel must then be cleared from the affected area by

a competent person and the Blast Co‐ordinator advised when this has been

completed. Physical barriers should then be placed across the road to prevent access

as per the Traffic Control Plan.

All traffic must be halted for the duration of the blast. In the case of emergency traffic

refer below: Emergency Vehicle Passage

The traffic controllers shall not re‐open the road until advised by the Blast Co‐

ordinator that it is safe to do so. Prior to re‐opening, the road shall be inspected to

ensure it is in a safe and trafficable condition. Any damage, fly‐rock or other traffic

hazards shall be rectified, with personnel and ancillary equipment available on

standby for immediate road clearing purposes when deemed necessary. When the

blast has been cleared and the road inspected, normal traffic can be resumed and

signage removed.

Shot Firing Procedure

This procedure shall apply to all blasting at Wonga Quarry where fly‐rock is considered to

present a potential risk to traffic on Lowes Mount Road or when it is otherwise

considered necessary to close that road. The approximate area of affected blasting shall

be illustrated on the blast sentry plan and include a 330 metre exclusion zone. The Shot

Firer shall fire the blast according to Australian Standard’s and in accordance with other

applicable blasting and environmental procedures, with the following exceptions:

If passage of emergency vehicle is necessary

Blasting will not take place at times when adverse conditions (or other prevailing

conditions) make road closure hazardous.

All blasts will require the closure of Lowes Mount Road and will be tied up on the

day of firing and must not be left tied up overnight.

All blasts will require the closure of Lowes Mount Road and will not be tied up if

weather conditions are expected to prevent blasting within the required time

frame.

Misfires identified while Lowes Mount Road is closed will be treated as separate

blasts in order to prevent lengthy road closures.

After firing, the Blast Co‐ordinator shall advise the traffic controllers and sentries when it is

safe to check the road for damage/fly‐rock and if traffic flow can be permitted (under

supervision) prior to final clearance. Radio silence must be maintained and traffic controllers

remain in position until the blast has been cleared and the road inspected

Emergency Vehicle Passage

If traffic controllers or sentries encounter emergency vehicles (Police, Ambulance or Fire)

requiring immediate access along Lowes Mount Road, it may be necessary to abort the blast.

Traffic controllers and/or sentries must break radio silence and inform the Blast Co‐ordinator

if access is required (or has occurred) once the shot firing is in progress. If the blast can be

halted, emergency vehicles can be allowed to pass and the shot firing procedure

recommenced once the road is clear and secured.

Role Accountabilities for this document

Site supervisor Oversee the review of process and procedure Review and approve procedure Ensure a process for training of relevant personnel Complete the road closure checklist and submit required notifications Review procedure Ensure a process for training of relevant personnel

Drill and Blast Supervisor Complete the road closure checklist and submit required notifications To assist in the procedure development where required Supervise and document the provision of procedure training Ensure procedure is communicated, understood and followed by all personnel

Traffic Controller Position and remove required signage according to RTA guidelines and approved traffic control plan. Prevent access to the closed area while blasting in progress and until notified by the Blast Co‐ordinator

Sentries Prevent access to the closed area while blasting in progress and until the blast has been cleared

Blast Co‐ordinator To assist in the procedure development where required Ensure procedure is followed and blasting is carried out in accordance with shot firing and road closure procedures. Remain in contact with the traffic controllers and sentries during the shot firing process Report any deficiencies with the procedure

Road Closure Plan

An example of road signage

for road closure due to blasting

APPENDIX III

Example of Site Induction Form

Example of Wonga Quarry Site Induction for Blasting

Action Details Tick to comply

Blasting hours Blasting is permitted during the hours of 9.00am to 5.00pm Monday to Friday. No blasting shall occur on Saturdays, Sundays and Public Holidays

Competence All personnel using explosives must be fully qualified, competent and trained

Fitness for work All personnel entering the quarry must be fit for work. If anyone is affected by lack of sleep, fatigue, stress or other factors causing a person to be unfit for work they must inform the Site Supervisor

PPE (personal protective equipment

All personnel entering the quarry must wear steel toe capped boots, long pants, long sleeved collared Hi‐Vis shirt, safety glasses and hard hat

Emergency Evacuation

All personnel entering the quarry must be aware of the emergency evacuation muster points and exits

Mobile Phones All personnel entering the quarry must have their mobile phone turned off

Smoking Smoking is not permitted by personnel entering the quarry and within the 330m blast exclusion zone.

Drugs and alcohol

All personnel entering the quarry must have a blood alcohol and drug limit of zero. Random drug and alcohol testing may occur.

APPENDIX IV

Technical report from

Darren Francis, Principal Engineer

Nitrotek Consulting

Nitrotek Consulting Page 1 of 9

NITROTEK CONSULTINGBlasting Specialists

Mining ‐Civil ‐Agriculture

To Max Rangott – Rangott Mineral Exploration Pty/Ltd

cc Paula Dell-McCumstie

From Darren Francis – Principal Engineer, Nitrotek Consulting

Date Friday, 07 August 2015

Subject WONGA QUARRY DEVELOPMENT APPLICATION

Flyrock, Blast Vibration & Blast Overpressure

Purpose

To provide specific recommendations such that the project meets the requirements of

AS2187.2 - 2006 where safe handling and use of explosives is implemented at the Wonga

Quarry Project through a defined Blast Management Plan (BMP). To provide a robust

foundation to the BMP, detailed blast engineering input is required to:

1. Model & evaluate likely flyrock projection distances.

2. Recommend a blasting exclusion zone distance for personnel.

3. Evaluate potential blast induced ground vibration & overpressure (noise) levels at

adjacent residences.

4. Provide guidance of likely impacts of vibration & overpressure with respect to

AS2187.2-2006 recommended limits.

Summary:

The key results of this investigation are:

1. A blast clearance distance of 330m for all personnel is recommended to provide a factor of

safety of at least 2.0.

2. Blast induced ground vibration is likely to be below 1.0mm/s at the closest identified

residential structure ‐ well below public amenity limits identified in AS2187.2‐2006

(5.0mm/s) & significantly below levels associated with the onset of cosmetic damage in

lightly constructed structures.


3. Maximum blast overpressure levels are likely to be below 117dB(L) at the closest identified

residential structure ‐ below public amenity limits identified in AS2187.2‐2006 (120dB(L) ) &

significantly below levels associated with the control of damage in lightly constructed

structures.

Table 1 Summary of probable blasting impacts on nearby residences at the Wonga Quarry Project.

REVIEW DETAIL:

It is well established that the extraction & initial particle size reduction of hard rock deposits is most

efficiently undertaken with the use of explosives. However, as with most industrial processes, this is

not a completely efficient process when converting potential (chemical) energy into useful work.

Where energy is transmitted into the adjacent rock mass these losses are refer to as vibrations.

Vibrations are a series of elastic waves, the strength of which are related to the mass of the

individual charge detonated. Losses occurring into the atmosphere above the blast are referred to as

overpressure (noise).

Usually, a neighbour will perceive vibration as a shake of ground, perhaps with accompanied

response noise of stored items (eg china display cabinet), while overpressure commonly manifests

as a rattle of windows and in most situations a directly associated audible noise.

As a generalisation, an increase in distance away from a blast will result in a reduction of both

overpressure and vibration at a point of interest.

1. Flyrock

Flyrock & it's control is a relatively complex interaction between blast design, diligent operational

application & local geology. However, the issue of maintaining personnel safety demands a strong

LocationDistance from Blasting

ActivityVibration Overpressure

( m ) ( mm/s ) ( dB(L) )

Residence 1 240 0.19 117

Residence 2 370 * 112

1km Radius 1000 * 102

Maximum Probable Blasting Impacts

*Below threshold level


engineering basis to ensure safety under all blasting conditions at all times. Experience has shown

that flyrock projection distance estimations & subsequent selection of appropriate clearance zones

must be carefully assessed with as complete knowledge as possible of each individual blasting

application.

Best practice blasting incorporates a level of redundancy within the blast design to ensure an

acceptable factor of safety is maintained even in the event of unintended unknown deviations

during application of the design (such as shorter stemming lengths).

Various studies have sought to generate predictive equations for maximum flyrock range & generally

are based on consideration of:

Rock density

Blast hole diameter

Explosive density

Confinement levels

Particle size achieving maximum range

The equations developed combined with other known equations of motion allow the determination

of practical limits for any charge configuration, blast hole size, rock type & shape factor (ratio of

surface area to volume). More recently, improved realistic particle motion has been achieved by

incorporating the additional influence of air resistance for estimated particle trajectories.

The calculation adopted for the Wonga Quarry site combines all of the points mentioned above into

a succinct form:

11 . ∅ . (Equation 1)

where Φ is the hole diameter in mm, Fs is the shape factor, SDB is the scaled depth of burial equation

& Rangemax is the maximum probable flyrock projection. The scaled depth of burial component

provides a relationship to define the relative confinement of the explosive charge & is defined as:

√

(Equation 2)

where is the depth from the collar of the blast hole to the cratering charge centroid (cratering

charge assumed to be equivalent to 8 times the blast hole diameter) & MJ is the explosive energy

contained in the cratering charge.

In


Individual blast to produce 5 years supply of material

Intact rock strength in the order of 110MPa to 140Mpa

Intact rock ‐ Young's Modulus = 62GPa

Intact rock ‐ Poisson's Ratio = 0.32

Working face height = 4.0m

Blast hole diameter = 89mm

Bulk explosive density = 1.10g/cc

The

Table 2 Blast design parameters used as the base case.

Selection of the particle shape factor described in 11 . ∅ .

(Equation 1 is an important consideration. Observations reported in

literature indicate values ranging from 1.1 to 1.3 adequately describe the range of flyrock particles

likely to be encountered. Furthermore, values of this parameter can be ranked according the

sensitivities of the project at hand and are shown below in Table 3. A value of 1.2 has been selected

as this represents the most probable value in the absence of actual measured data to calibrate the

flyrock model.

Table 3 Range of particle shape factors with modelled value highlighted.

Hole Diameter

Burden SpacingBench Height

Hole Length

Stem Length

Sub Drill

Length

Explosive Product Density

Explosive Product Energy

Scaled Depth of Burial (E)

B:S RatioPowder Factor

mm m m m m m m g/cc MJ/kg m/MJ^1/3 s/b kg/bcm

BASE CASE

1st Pass Design 89 2.3 2.6 4.0 5.0 2.7 1.0 1.10 2.70 1.29 1.13 0.66

WongaQuarryProposal

Fs Rangemax

1.0 Conservative

1.1

1.2 Realistic

1.3

1.4 Aggresive


As mentioned above, it is appropriate that a layered approach to risk mitigation is implemented. To

that end, a factor of safety (FOS) 1 for personnel clearance during blasting of 2.0 is desirable & often

specified. Error! Reference source not found. shows the maximum flyrock range likely to be

encountered at Wonga Quarry when using parameters noted in Table 2. The blast clearance zone is

then calculated by multiplying Rangemax by the minimum desired factor of safety ‐ in this case 2.

Table 4 Estimated blast clearance distances.

The data also demonstrates that if a maximum unknown deviation of 0.5m in the stemming length is

inadvertently applied, a clearance distance of 328m is required to maintain a FOS=2. However, it

should be noted that an over charged hole as significant as this is likely to be detected & remedied

during charging activities prior to stemming being applied.

On the basis of the modelling calculations & consideration of a worst case scenario, a minimum blast

clearance distance of 330m from the actual blast boundary is recommended2.

2. Ground Vibration

Many factors specific to an individual site will affect the transmission of vibration through the

ground. Indeed, the most accurate estimates of future blasting impacts are generated from analysis

of multiple vibrations recorded at that location. Given the nature & history of the site, it is not

1 The factor of safety (FOS) is based on the distance between the blasting location & the closest residential structure. The FOS can be increased by implementing greater clearance distances for personnel during blasting. 2 This recommendation is made on the basis of the available & assumed data presented. Any modification of blast design parameters require re‐assessment to confirm suitability for use at this site.

Particle Shape Factor = 1.2Stemming

LengthRangemax

Blast Clearance Radius

# (m) (m) (m)

Base Case 2.7 111 222






Flyrock Rangemax SummaryFactor of Safety = 2


unexpected that no blast vibration data is available for the Wonga Quarry. AS2187.2‐2006 does

however provide guidance in the absence of such site data where it indicates that the following

equation may be used to estimate maximum likely ground vibration levels in average conditions

where blasting to a free face is carried out:

1140.

(Equation 3)

where:

PPV

R

Q

1.6

1140

Published data relating specifically to granite formations indicate that the actual decay factor, a

measure of how rapidly elastic strain waves (ie vibration) attenuates over distance, is greater with

values ranging from 2.1 to 2.4. Site constants are similarly noted to vary from that provided

2 −1.6 (Equation 3 with values ranging

from 500 to 1300. It is appropriate in this case to modify the AS2187.2 estimates for decay factor &

site constant values based on these published values combined with operational experience in

similar materials to the following values:

vibration decay factor = 2.1

site constant = 1050

The selected values retain a level of conservatism appropriate to the planned operational nature of

the site. For Wonga Quarry, the following equation may be used with a high degree of confidence to

estimate maximum likely ground vibration levels at any point of interest:

1050.

(Equation 4)

Applying the above blast vibration model to the base case blast design3 yields:

3 Given the volumes of material to be blasted in any individual event, blast holes are able to be fired as discrete elements sequenced within the firing.


Figure 1 Maximum probable vibration as a function of distance away from blasting activity.

The results presented in Figure 1 clearly show that blast induced vibration levels at ranges beyond

180m will be difficult to detect without the aid of sensitive monitoring equipment. This is directly

related to the relatively small charge quantities (16kg per blast hole) employed in the initial design.

The closest identified residential structure is located at a range of approximately 240m. Estimated

vibration levels at this distance are in the order of 10 times lower than the public amenity level of

5.0mm/s recommended in AS2187.2‐2006 for blasting operations. Likewise, this is many times lower

than any of the commonly accepted limits for the onset of cosmetic damage to residential & similar

lightly fabricated structures.

3. Blast Overpressure

Overpressure is a measurement of the pressure levels transmitted into the atmosphere radiating

outwards from the source. It has been documented that well confined blasts generate pressure

waves at frequencies predominantly below 20Hz, with relatively small amounts of energy contained

in frequencies greater than this level. It is important to note that the human ear does not respond to

Distance to closest residential structure = 240m


noise with frequencies below the 20Hz level. However, it is equally important to note that buildings

tend to respond to frequencies in the range of 2 to 20Hz. It is on this basis that most monitoring for

human response to noise utilises a filtered sound level where frequencies below 20Hz are removed.

This is known as the decibel (A) scale ‐ or dB(A) scale. As blasting generally produces frequencies

predominantly below 20Hz, atmospheric overpressure levels are recorded using the decibel (Linear)

scale ‐ or dB(L).

Again, as with the case for blast vibration estimation, the most accurate estimations of overpressure

rely on calibrating site specific models using actual recorded data. These models tend to rely on

established scaling methods which seek to establish the relationship between explosive charge mass

detonated per delay period, the range to the point of interest & the overpressure level. The

following cube root scaling formula is commonly utilised:

√

(Equation 5)

where

P ‐ sound pressure level (kPa)

D ‐ distance from charge (m)

W ‐ explosive charge mass per delay (kg)

K ‐ site constant

a ‐ site exponent

Without the assistance of actual historic data, published data has been accessed. For average

confinement levels in typical quarry blasting applications, values of the site constant K commonly

range between 3.15 (good confinement) to 31.5 (extremely poor confinement) for a site exponent

(a) of ‐1.2. Appropriate initial values for Wonga Quarry Project have been selected:

K = 3.3

a = ‐1.2

For Wonga Quarry, the following equation may be used with a high degree of confidence to estimate

maximum likely air overpressure levels at any point of interest:

3.3√

. (Equation 6)


Figure 2 Maximum probable overpressure as a function of distance away from blasting activity.

The results presented in Figure 2 show that the maximum probable blast induced overpressure

levels at the closest nearby residential structure will be below 117dB(L). The inference here is that

actual recordings will form a statistical distribution with the average value positioned much below

this level. For all existing nearby residential structures, overpressure levels can be expected to be

below the sensitive site amenity level of 120dB(L) recommended in AS2187.2‐2006 for blasting

operations where less than 20 blasting events are conducted annually. Similarly, the expected

maximum overpressure levels are significantly below AS2187.2‐2006 recommended air blast limits

for damage control in typical residential & similar lightly fabricated structures.

Distance to closest residential structure = 240m

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