for the dargues reef gold project modification 1 · following public exhibition of the...
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BIG ISLAND MINING PTY LTD ABN 12 112 787 470
Response to Government Agency and Public Submissions
for the
Dargues Reef Gold Project
Modification 1
Project Approval 10_0054
June 2012
Prepared in conjunction with:
R.W. CORKERY & CO. PTY. LIMITED
R. W. CORKERY & CO. PTY. LIMITED
BIG ISLAND MINING PTY LTD ABN 12 112 787 470
Response to Government Agency and Public Submissions
for the
Dargues Reef Gold Project
Modification 1
Project Approval 10_0054
Prepared for:
Big Island Mining Pty Ltd
ABN: 12 112 787 470
Level 5, 72 Kings Park Road
WEST PERTH WA 6005
Telephone: (08) 9485 0577 Facsimile: (08) 9485 0706 Email: [email protected]
Prepared by:
R.W. Corkery & Co. Pty. Limited
Geological & Environmental Consultants
ABN: 31 002 033 712
Brooklyn Office: 1st Floor, 12 Dangar Road PO Box 239 BROOKLYN NSW 2083
Telephone: (02) 9985 8511 Facsimile: (02) 9985 8208 Email: [email protected]
Orange Office: 62 Hill Street ORANGE NSW 2800
Telephone: (02) 6362 5411 Facsimile: (02) 6361 3622 Email: [email protected]
Brisbane Office: Suite 5, Building 3 Pine Rivers Office Park 205 Leitchs Road BRENDALE QLD 4500
Telephone: (07) 3205 5400 Email: [email protected]
Ref No. 752/28
June 2012
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This Copyright is included for the protection of this document
COPYRIGHT
© R.W. Corkery & Co. Pty Limited 2012
and
© Big Island Mining Pty Ltd 2012
All intellectual property and copyright reserved.
Apart from any fair dealing for the purpose of private study, research, criticism or review, as permitted under the Copyright
Act, 1968, no part of this report may be reproduced, transmitted, stored in a retrieval system or adapted in any form or by any
means (electronic, mechanical, photocopying, recording or otherwise) without written permission. Enquiries should be
addressed to R.W. Corkery & Co. Pty Limited.
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
CONTENTS Page
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iii
1. INTRODUCTION .............................................................................................................................. 1
2. GOVERNMENT AGENCY SUBMISSIONS ..................................................................................... 1
2.1 INTRODUCTION ................................................................................................................... 1
2.2 ENVIRONMENT PROTECTION AUTHORITY ...................................................................... 1
2.3 DEPARTMENT OF PRIMARY INDUSTRIES ...................................................................... 11
2.3.1 NSW Office of Water ................................................................................................. 11
2.4 EUROBODALLA SHIRE COUNCIL ..................................................................................... 13
3. PUBLIC SUBMISSIONS ................................................................................................................ 23
3.1 INTRODUCTION ................................................................................................................. 23
3.2 ISSUE A – DARGUES REEF CONSULTATIVE COMMITTEE ........................................... 24
3.3 ISSUE B – ASSESSMENT OF XANTHATE USE AND RESIDUES ................................... 25
3.4 ISSUE C - GROUNDWATER QUALITY - METALS ............................................................ 26
3.5 ISSUE D – GROUNDWATER QUALITY – ALKALINITY .................................................... 27
3.6 ISSUE E – LONG TERM STABILITY OF PASTE FILL ....................................................... 29
3.7 ISSUE F – ASSESSMENT OF THE APPLICATION ........................................................... 30
3.8 ISSUE G – EUROBODALLA RESIDENTS AS STAKEHOLDERS ..................................... 30
3.9 ISSUE H – CONCLUDING COMMENTS ............................................................................ 31
4. ADDITIONAL COMMITMENTS ..................................................................................................... 35
5. REFERENCES ............................................................................................................................... 36
APPENDICES
Appendix 1 Dargues Reef Paste Fill Testwork and Design .................................................................A1-1
Appendix 2 Backfill Specialists Capability Statement ..........................................................................A2-1
Appendix 3 MSDS – Portland Cement .................................................................................................A3-1
TABLES
Table 1 Indicative Chemical Composition – Low Heat Cement .......................................................... 7
Table 2 Submissions and Issues Raised .......................................................................................... 24
Table 3 Additional Commitment for Inclusion in Statement of Commitments................................... 35
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1. I N T RO D U C TI ON
Following public exhibition of the Environmental Assessment for the proposed Dargues Reef
Gold Project Modification 1 to permit the use of Paste Fill (referred to hereafter as RWC,
2012), submissions were received by the Department of Planning and Infrastructure (DP&I)
from:
three government agencies; and
five individuals or non-government agencies.
All submissions received were forwarded by the DP&I to the Proponent, Big Island Mining Pty
Ltd, and R.W. Corkery & Co. Pty Limited (RWC) for the preparation of a response to the issues
raised. This document, presents a consolidated set of responses to each of the submissions
received and has been prepared by the Proponent in conjunction with RWC. This document
also presents in Section 4 additional commitments that the Proponent would be willing to
include in the Statement of Commitments included as Appendix 7 of the revised Project
approval, should it be granted.
2. G OV E R NM EN T AG E N C Y S U BM I SSI O N S
2.1 INTRODUCTION
Submissions were received from the following government agencies.
Environment Protection Authority (dated 7 June 2012).
NSW Department of Primary Industries (dated 12 June 2012).
Eurobodalla Shire Council (dated 30 May 2012).
In addition, the Department of Planning and Infrastructure advised that the following agencies
provided responses supporting the proposed modification or did not provide a submission.
Division of Resources and Energy.
Palerang Shire Council.
The following sub-sections present the submissions received from relevant government
agencies (in italics). A response to each issue raised is presented (in normal text).
2.2 ENVIRONMENT PROTECTION AUTHORITY
This sub-section provides a response to the submission by the Environment Protection
Authority (EPA). The response to each of the issues presented is provided under the same
heading and in the same general order as they appear in the submission.
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Tailings and Paste Characteristics
Regarding the leaching potential of paste fill, the provided EA appears to include a
number of claims that are based on a level of speculation or a number of assumptions.
The EPA considers cement stablisation to be acceptable in principle, however, submit
that the proponent should be required to conduct suitable trials to optimise the mix
design and provide a trial report for comment before conducting full scale treatment.
Any resulting trial data would provide an evidentiary basis for the EPA, as the
regulatory authority, to amend the EPL as required.
Response:
The Proponent notes that physical testing and confirmation of the paste fill mixture was
completed during the Feasibility Study completed for the Project. The testing methodolgy and
results are contained in a report prepared by Mr Mathew Revell of Revell Resources entitled
Dargues Reef Paste Fill Testwork and Design (P147-R01). That report is, hereafter referred to
as Revell (2010) and is presented in Appendix 1.
In summary, Revell (2010) states that ‘paste fill offers a sound technical solution for backfill at
Dargues Reef’. The testwork completed to confirm the paste fill mixture is described in detail in
Revell (2010) and may be summarised as follows.
Particle size distribution testing was completed to determine the suitability of the
tailings to be used for paste fill (Section 3.2.3, Revell (2010)). Generally to
produce paste fill, the tailings must have nominally 15% to 20% of the particles
smaller than 20µm to prevent segregation of the paste within the paste reticulation
system. Revell (2010) confirms that the tailings have the required particle size
distribution and noted that ‘the Dargues Reef tailings has an almost perfect
[particle size distribution] for paste production’.
Mineralogical analysis was completed on a sample of tailings material with the
primary minerals identified being plagioclase feldspar, quartz and muscovite. It is
noted that feldspars are likely to contribute to moderate paste strength but that
muscovite may adversely impact on the strength characteristics of paste fill. As a
result, strength characteristics would need to be managed during paste filling
operations.
Rheology testing to determine the rate at which the paste would flow or move
once emplaced was undertaken. This involved creation of a conical pile of
uncured paste and measuring how much deformation occurred within a specified
timeframe. Suitable rheology characteristics ensure that the paste, once emplaced
flows into all sections of the stope to be backfilled without being overly fluidised.
Ideal paste composition would result in a slump of 220mm. Revell (2010)
determined that at a solids content of 69.5% and 3% to 6% binder addition this
slump rate could be achieved.
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Unconfined Compressive Strength (UCS) tests were completed on various paste
mix designs (Section 3.4.1, Revell (2010)). The purpose of this test work is to
generate an understanding of the influence of binder addition, time and solids
content on the strength of the paste fill. The Results of these tests are contained in
Table 5 of Revell (2010) and indicate that with a slump of 220mm and binder
content of 6%, that a UCS of approximately 1000kpa can be achieved (Figure 7,
Revell (2010). Revell (2010) indicates that this is suitable for the proposed paste
filling operations.
Strength testing of the proposed paste fill mixture has been completed over 7, 28,
56, 112 and 260 days and that the strength of the paste fill continues to develop
over that time (Table 5 and Figure 8, Revell (2010)), with a suitable strength for
the majority of the proposed stopes being achieved after 28 days. In addition, the
curing characteristics of the paste fill are considered suitable for the operational
needs of the Project.
Based on the test work completed, the Proponent contends that the paste fill mixture presented
in Table 4 of RWC (2012) would meet the operational requirements of the Project and contends
that it is has been suitably optimised for the Project.
In light of the above, the Proponent contends that the physical characteristic of the paste have
been adequately tested for, at this stage of the Project. However, the Proponent also notes that
following commissioning of the processing plant and prior to commencement of paste filling
operations, that further testing would be required to determine the physical characteristics of the
paste under operational conditions and confirm the bench-top test results presented in Revell
(2010)
The development of a cement grout is a highly specialised engineering field. It is
recommended that the proponent be required to engage the service of a suitably
qualified expert in the area, with good field experience in underground applications, to
develop any trial and evaluation regime
Response:
The Proponent notes that Mr Mathew Revell, as Principal Backfill Consultant with Revell
Resources has a Bachelor of Engineering (Minerals Processing) and has worked in both
operational and design roles as a metallurgist and project manager since 1997, including
establishing and operating Revell Resources, a specialist paste fill consultancy, in 2005. As a
result, Mr Revell may be considered to be a suitably qualified expert in the field of paste fill. A
Capability Statement is presented as Appendix 2.
It is the Proponent’s intention that Mr Revell would continue to provide consultancy services to
the Project during the commissioning and operational phases of the Project.
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Depending on the gold extraction process, the chemical residues present in the
tailings/residue can retard or otherwise accelerate the setting of cement. The EPA notes
that the hydrobiology consultant completed leachate testing (TCLP) on a tailings
sample rather than a sample of the paste. In addition, results are only presented for 3
tailings samples and two leachate samples.
Response:
The Environment Protection Agency’s submission raised two issues, namely whether the
chemical residues present in tailings can impact on the physical characteristics of the paste and
why Toxicity Characteristics Leaching Procedure (TCLP) testing was completed on a sample of
the tailings rather than a tailings/paste mixture.
In relation to the first issue, the Proponent notes that the test work described in Revell (2010)
was undertaken using tailing that would have, to the degree possible at the current stage of the
Project, the same chemical and physical characteristics as tailings that would be produced by
the processing plant, once operational. In addition, the Proponent has confirmed that further
test work would be undertaken to confirm the results of Revell (2010), following
commissioning of the processing plant. As a result, the Proponent does not anticipate that
chemical residues, the physical or mineralogical characteristics of the tilings would adversely
impact on paste curing or physical characteristics.
In relation to the use of tailings rather than paste for the characterisation of the leaching
potential of the material, the Proponent notes the following.
The paste, once cured, is a solid mass with permeability of approximately 1x10-
8m/s, which is the same permeability required of the lining for the Tailings
Storage Facility. This would effectively inhibit the ability of the leaching solution
to leach contaminates as only the surface and any cracks of the cured paste fill
would be subject to leaching. By contrast, the use of unbound tailings ensured
that the maximum surface area of the tailings was exposed to the leaching solution
during the test work to create a worst case leachate for assessment of the proposed
modification.
While cured paste could have been crushed and ground for use during the leach
test work, the tailings particles with the potential to leach metals would be
covered with a cement/carbonate matrix, restricting the ability of those particles to
liberate their metals, resulting in a lower concentration in leachate than leaching
of tailings alone.
Finally, while the leach test work could have been undertaken using an uncured
tailings and binder mix, the Proponent contends that this would have resulted in
the curing reaction occurring concurrently with the leaching reactions and would
have produced leach test results that were unrelated to the likely leaching
characteristics of the paste.
As a result, the Proponent contends that the use of unbound tailings to determine the leaching
characteristics of the material is appropriate as it would produce a worst case scenario leachate
for characterisation of the material.
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The Proponent accepts that there is some ‘speculation’ as to the levels of contaminants that
would be leached from the paste fill material once cured, however, contends that as the tailings
material tested was unbound, that the maximum amount of contaminants were leached from the
tailings. Hence, the speculation is only around the degree to which the binder would prevent
leaching of contaminants into ground water.
The Proponent notes that the contaminants contained in the leachate were all significantly
below the TCLP1 threshold (Tables 5 and 6 of RWC (2012)) and that the paste fill, once cured
has a permeability of 1x10-8
m/s and is expected to further reduce the leaching of contaminants
into groundwater.
In relation to the number of tailings samples tested, the Proponent notes that the issue of the
representativeness of the tailings samples was an issue tested in the Land and Environment
Court case. In particular, the affidavits of Aaron Green and David Morgan, which were
accepted by the Appellants in that case, stated the following.
Alteration and mineralisation within the Dargues Reef deposit is unusually
uniform and homogenous. As a result, the ore material used to produce the
tailings sample tested is representative of the ore body as a whole to the extent
possible considering the relative size of the sample available.
Mr Morgan noted that it is typical to test one sample of tailings per ore type to
determine the physical and geochemical properties of the tailings. As there is
only one ore type within the Dargues Reef ore body, then only one tailings sample
would normally be tested
As a result, the Proponent contends that the number of samples tested adequately represents the
tailings that will be produced during the life of the Project.
No information appears to have been included to provide a comparative analysis of the
differences between the tailings material and the paste material after the reactive
process (binding) has been completed. Although it could be assumed that the paste
would leach at concentrations less than the tailings, it may be appropriate to conduct
bench trials on the paste for confirmation and an appropriate level of due diligence.
Response:
The issue of the use of tailings material in the test work has been addressed previously. In
addition, the Proponent notes that curing of cement is a hydration reaction and does not
anticipate that the reaction would result in the production of contaminants with increased
solubility to groundwater. However, as previously discussed, the cement hydration process
would result in the binding of the tailings material, reducing the permeability and reducing the
leaching potential of the paste fill.
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In consideration of the total quantity of tailings to be processed, it is likely that the
concentrations of the tailings will vary and may not be a homogeneous material – the
concentrations shown in table 7 as part of the classification process vary to those
presented in Table 3 on the tailings composition. No justification of the number of
samples tested is presented.
Response:
The representativeness of the tailings material has been addressed previously.
The Proponent notes that an explanation regarding the data contained in Tables 3 and 7 of RWC
(2012) is provided in response to Item 5 in Section 2.4.
In addition to the above comments the EPA recommends the proponent be required to
provide the following information to confirm suitability of the paste fill process”
Identification of any chemical species in the tailing material which are capable
of interfering with the setting of cement and means to overcome this problem.
Details of proposed cement/binder type to be used-grade, characteristics,
including any additives to be used.
Details of any proposed surfactant/other chemical additives to be used.
Indication of the likely reaction products of the tailing waste and cement/lime
mixture.
Setting profile or curing strength over the following durations: 24hrs, 7 days, 14
days and 28 days.
Response:
A response to each issue identified by the EPA is provided below.
The Proponent notes that no chemical species have been identified that would
interfere with the curing of the paste fill. Strength testing using tailings material
indicates that the paste fill develops strength consistently over the 260 day test
period (Table 5, Revell (2010)) and that this increase in strength indicates that the
curing process is not being inhibited.
The Proponent has conducted all test work using Low Heat Cement produced by
BGC Cement, which is a blend of Portland Cement and ground granulated blast
furnace slag. An MSDS for BGC Low Heat Cement has been provided as
Appendix 3. The indicative chemical composition of Low Heat Cement is
presented in Table 1.
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Table 1 Indicative Chemical Composition – Low Heat Cement
Parameter CL Typical
SiO2 29.20%
Al2O3 11.10%
Fe2O3 1.20%
CaO 50.40%
MgO 4.60%
SO3 2.20%
LOI 0.70%
Chloride 0.01%
Na2O 0.40%
Source: Big Island Mining
The Proponent does not intend to use, at this stage, surfactants or other chemicals in
the production of paste fill. As indicated in RWC (2012), the constituents of the
paste fill are tailings, cement binder and water. If constituents other than those
identified are required in response to operational issues, identified during the life of
the Project, then the Proponent would consult with the EPA prior to their use.
The Proponent notes that curing of cement is a hydration reaction and does not
anticipate that the reaction would result in the production of contaminants with
increased solubility to groundwater.
The Proponent notes that strength testing of the paste fill has been completed over 7,
28, 56, 112 and 260 day time frames and that this information is included in Section
3.4, Table 5 and Figure 8 of Revell (2010).
Waste Sampling and Analysis
The provided EA suggests that the paste fill material will be classified as ‘General solid
waste (non-putrescible)’ in accordance with the EPA’s ‘Waste Classification
Guidelines’. In this regard the proponent will need to ensure paste fill continues to meet
that classification throughout the period the waste is to be applied to land.
The EPA recommends frequent testing of the waste for an initial period to establish that
the characteristics of the waste are consistent enough to give the waste generator
confidence to reduce the frequency of testing. It is the responsibility of the waste
generator (in this caste the proponent) to ensure that frequency of testing provides a
representative sample for all contaminants in that waste while the application of waste
continues.
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It is recommended that any consent include condition to implement an initial testing
regime with capacity for amendment based on an assessment of testing data.
Response:
The Proponent notes that best practice processing operations require regular sampling and
classification of the ore, concentrate and tailings during commissioning and operation of the
process plant and that this would include a period of time prior to the commencement of paste
fill operations. Analysis of these samples would be undertaken using on-site and off-site
laboratories and would be sufficient to comply with the Proponent’s obligations identified by
the Environment Protection Authority.
Noise
The EA does not provide adequate information for the EPA to determine whether the
proposed modification will cause noise impacts at sensitive receiver locations. The EA
does not identify sound power levels for plan and equipment associated with the
proposal (for example the operation of a concrete batching plant or delivery of cement
to the batching plant) and has not considered the cumulative noise impacts generated by
the proposed activities and currently licensed mining activities. In order for the EPA to
be able to determine whether the predicted noise impacts at sensitive receiver locations
are acceptable, it requires the information provided in Attachment A.
Response:
The Proponent notes that the proposed modification would result in the installation of a limited
amount of additional equipment, and considers that the proposed modification would have a
negligible additional impact. The Proponent further notes that the anticipated noise-related
impacts of the Project as approved are significantly below the relevant criteria.
In recognition of the Environment Protection Authority’s request for additional information, the
Proponent provides the following.
Identify all noise sources from the development including associated sound power
levels. Detail all potentially noisy activities including ancillary activities such as
transport of goods and raw materials.
Additional noise sources would include the following.
A twin shaft horizontal pug mixer or similar with twin 11kW electric motors
(Photograph 3 of Revell (2010)). Anticipated sound power levels from this
equipment would be approximately 90dB.
A binder screw feeder, an example of which can be seen as the pipe coming from
the base of the silo shown in Photograph 2 of Revell (2010). The Proponent notes
that detailed design of this section of the paste fill plant is unavailable, however,
anticipates that the motor would be less than 10kW and that negligible noise
would be generated by the screw feeder itself.
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The location of these additional noise sources would be within the footprint of the approved
processing plant and would be both lower and further away from the closest residences than
other more significant noise sources, including operation of the front-end loader on the ROM
pad and the crushing circuit.
Delivery of bulk cement would be undertaken using semi-trailer trucks or similar, the operation
of which has already been considered in RWC (2010a).
There would be no other significant sources of noise associated with the proposed modification.
The Proponent contends that given that noise generated from the additional noise sources,
required as part of this modification, are significantly below that already approved, that no
further assessment of noise impacts is required.
Identify any noise sensitive locations likely to be affected by activities at the site,
such as residential properties, schools, churches, and hospitals.
Noise-sensitive receivers would remain as identified in Section 4.5.1 of RWC (2010a) and
Section 3.2 of RWC (2010b).
Identify the land use zoning of the site and the immediate vicinity and the
potentially affected areas.
The land use zoning remains as identified in Section 1.3.2 of RWC (2010a).
Determine expected noise level and noise character (e.g. tonality, impulsiveness,
vibration, etc) likely to be generated from noise sources during operation.
The anticipated additional noise level is not expected to be tonal or implusive in character, nor
is it likely to result in additional vibration.
Determine the noise levels likely to be received at the most sensitive locations
(these may vary for different activities at each phase of the development).
Noise levels at surrounding residences are not expected to change as a result of the proposed
modification. However, even if a small increase in noise was to result, given that the
anticipated noise impacts associated with the approved Project are significantly below the
relevant criteria, the impacts would still be non-significant.
For developments where a significant level of noise impact is likely to occur,
noise contours for both daytime (7am-10pm) and night time (10pm-7am) periods
should be derived. Particular attention will need to be paid to any potential
impulsive noise characteristics which may occur during some site activities (e.g.
maintenance, heavy vehicle).
Significant noise levels are unlikely to occur.
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Consider the influence of existing meteorological conditions such as winds and
temperature inversions in the prediction model so as to provide a true
representation of actual noise levels.
Existing meteorological conditions are identified in Sections 4.1.3 and 4.2.4.1 of RWC (2010a)
and have been taken into consideration in the noise assessment prepared for that application.
Assess the effect of noise mitigation measures incorporated into the predictive
modelling.
Noise mitigation measures are identified in Section 4.2.5 of RWC (2010a) and were taken into
consideration in the noise assessment prepared for that application.
Compare the predicted noise levels with the appropriate noise criteria for the
phase of development or activity being considered (determine the appropriate
noise criteria for the surrounding area using the appropriate guideline using the
Industrial Noise Policy).
Predicted noise levels and a comparison with the relevant criteria are presented in Section 4.2.6
of RWC (2010a) and remain valid.
Discuss the findings from the predictive modelling and, where relevant noise
criteria have not been met, recommend additional mitigation measures.
The results of the predicitive modelling is discussed in Section 4.2.6 of RWC (2010a) and that
discussion remains valid
Where relevant noise/vibration criteria cannot be met after application of all
feasible and cost effective mitigation measures the residual level of noise impact
needs to be quantified by identifying:
- locations where the noise level exceeds the criteria and extent of exceedence
- numbers of people (or areas) affected
- times when criteria will be exceeded;
- likely impact on activities (speech, sleep, relaxation, listening, etc)
- change on ambient conditions.
All noise and vibration criteria are expected to be achieved.
Determine the most appropriate noise mitigation measures including both noise
controls and management of impacts for both construction and operational noise.
This will include selecting quiet equipment and construction methods, noise
barriers or acoustic screens, location of stockpiles, temporary offices, compounds
and vehicle routes, scheduling of activities, etc.
The noise mitigation measures identified in Section 4.2.5 of RWC (2010a) and the final
Statement of Commitments remain valid for the modified Project.
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Variation to Environment Protection Licence
The EPA considers that the proposed medication will be classified as a Scheduled
Activity under the provisions of ‘Schedule 1’ of the ‘Protection of the Environment
Operations Act 1997’ (POEO Act), specifically subsection ’39 Waste Disposal
(application to land)’.
Because the medication will result in the inclusion of an additional scheduled activity,
the proponent will need to make separate application to the EPA for variation to
Environment Protection Licence 20095 prior to undertaking the activity. The required
variation application form can be accessed at the following internet address:
http://www.environment.nsw.gov.au/resources/licensing/20120243varpremises.doc
Response:
The Proponent acknowledges that a variation to Environment Protection Licence 20095 would
be required. The Proponent would submit the variation application to the Environment
Protection Authority as soon as practicable following receipt of project approval, assuming that
it is granted.
2.3 DEPARTMENT OF PRIMARY INDUSTRIES
2.3.1 NSW Office of Water
The Office of Water has identified considerable uncertainty in assessing the impacts of
this proposal. It is recommended this concern be acknowledged and the key issues in
this submission be addressed through amendments to the Water Management Plan
(WMP).
Response:
The Proponent disagrees with the assertion that there is considerable uncertainty in relation to
the impacts of the proposed modification. In particular, the Proponent notes the following.
Paste fill is a widely used technique and the behaviour of paste, both physical and
chemical, is a well understood field. In addition, significant test work has been
undertaken and is documented in Revell (2010)
As indicated in Section 1.6 of RWC (2012), the assessment of the proposed
modification has been prepared with the assistance of Mr Matt Revell, Dr Reinier
Mann and Mr Errol Briese, all recognised experts in the fields of paste fill
engineering, ecotoxicology and groundwater impact assessment respectively.
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The assessment of potential impacts from pastefill leachate in the EA is limited to
theories with uncertainty in regards to long term impacts. Whilst the general theories on
paste backfill characteristics and geochemical reactivity appear reasonable, it is
difficult to validate some of the key parameters at the scale of this proposal. This
therefore raises concern over the long term stability of the pastefill and potential
impacts to groundwater quality.
Response:
The Proponent notes that it has undertaken an assessment based on the drill samples that it has
available and that larger scale test work will not be possible until the ore body is exposed and
processing operation commence. However, as noted previously, it was accepted by the
Appellants to the Land and Environment Court action that the Dargues Reef ore body is
unusually homogeneous and uniform and that the tailings samples that exist are likely to closely
reflect the actual tailings characteristics once the Project becomes operational.
It is further noted that project-specific assessments were undertaken in relation to the physical
and leaching characteristics of the material. As a result, the Proponent contends that it has
adequately validated the appropriate key parameters to the extent possible based on the samples
available at this stage.
Finally, given the composition of the paste, namely cement, tailings and water, and the
environment in which it would be emplaced, namely underground in a stable granodiorite rock
mass, there is no reasons to suspect that the paste would degrade or become less stable.
However, in the event that the paste did degrade, the Proponent notes that leach testing was
conducted on unbound samples of the tailings material, which would be representative of a
complete degradation of the paste fill structure. It is also reasonable to assume, that should the
paste fill degrade, that it would occur over a significant period of time and therefore any
leachate from the degrading paste fill would not exceed the contaminant levels presented in
RWC (2012). As a result, the Proponent contends that the leach testing completed adequately
assess the risk from any degradation of the paste fill over time.
The understanding of groundwater quality in the EA is limited to the depth of the
current deepest monitoring bore which is 216 metres. As the proposed mine and
pastefill placement is to a depth of 500 metres, the Office of Water requests
characterisation of groundwater quality to this maximum depth. This characterisation
will need to represent background conditions to the satisfaction of the Office of Water
and will need to be completed prior to commencement of pastefill operations.
Response:
The Proponent notes that the aquifer that hosts the Dargues Reef deposit is a fractured rock
granodiorite aquifer associated with the Braidwood Granodiorite, a massive intrusion with an
aerial extent of approximately 1 000km2 and a depth of at least several kilometres. As a result,
with the exception of a reduction in the transmisivity of water bearing structures with depth, the
Proponent contends that there is no reason to expect that the aquifer properties or groundwater
quality below 216m would be different from above that depth.
In addition, the Proponent further notes that although it is feasible to drill, case and sample a
bore to a depth of 500m below surface, that it would require specialist equipment and
substantial cost to the Proponent with limited benefit.
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While mining operations will progress to an eventual depth of 500m below surface, they will
not reach this depth until Year 4 of the Project, well after the proposed commencement of paste
filling operations. As a result, the Proponent contends that direct characterisation of the
fracture-hosted granodiorite aquifer between 216m and 500m below surface is not required.
Notwithstanding the above and as noted below, the Proponent would monitor the quality of
groundwater within the underground workings during the life of the Project and following
completion of mining operations until all relevant agencies are satisfied that the proposed paste
fill operations does not pose a threat to groundwater quality.
It is recommended amendments to the WMP demonstrate an ability to monitor and
report on any impacts to groundwater quality associated with the paste backfill to the
full depth of operations, both during operation and following completion of the mine. It
is to also include a trigger response plan and mitigating options.
Response:
The Proponent notes that the dewatering operations would be required to be undertaken from
the deepest section of the underground workings and that this water would be available for
testing as soon as groundwater is intersected in the decline. In addition, potential exists for
infrastructure to remain in place to test groundwater within the deepest sections of the mine
following cessation of dewatering operations at the end of the life of the Project.
The Proponent anticipates that should the approval for modification be granted, that the Water
Management Plan would require updating in consultation with NSW Office of Water to reflect
the revised mining operations.
2.4 EUROBODALLA SHIRE COUNCIL
Eurobodalla Shire Council provided a submission supported by a letter report prepared by Dr
Peter Beck. The text of Dr Beck’s report provided an overview and background to his
comments, with his detailed comments included in a table. The following provides a response
to the tabulated issues identified in Dr Beck’s report.
1. While changes to mining operations are not unusual, it may be useful to obtain an
explanation and discussion that given the benefits highlighted in the BIM 2012
report why the use of paste backfill was not considered in the original proposal, as
more comprehensive and detailed assessment of potential impacts to the
environment could have been undertaken in the context of the overall project. This
modification only touches on some of the relevant issues that will have potential
knock on effects such as changes to the tailing storage facilities and waste rock
dumps.
Response:
The potential use of paste fill at the Project Site was first highlighted in Section 2.7.5 of the
Environmental Assessment prepared to support the original application for development consent
(hereafter referred to as RWC, 2010a). However, as indicated in Section 1.4.5 of RWC (2012),
approval for its use was neither sought nor granted at that time because the relevant studies had
yet to be completed at the time of finalisation of RWC (2010a).
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The following provides an indicative list of the studies that have been completed into the use of
paste fill since the submission of RWC (2010a).
Mining method trade off study – this assessed the most viable mining method for
the Project and provided for the highest safety, minimisation of environmental
impact and greatest economic return.
Paste fill design and assessment (Revell, 2010) – this study determined the
suitability of the tailings material for use as paste fill and the quantities of water
and cement required.
Rheology and strength testing (Revell, 2010) – this study examined a range of
different mixtures of paste fill to determine their suitability for use in the mine.
Specific Contaminant Concentration testing and Toxicity Characteristics Leaching
Procedure testing of the tailings material – this study assessed the impact on the
environment of emplacement of tailings material underground.
Groundwater studies – these assessments sought to determine the impact of paste
fill on groundwater levels, recharge rates and quality and are included as
Appendices 2 and 3 in RWC (2012).
In relation to the comment that this ‘modification only touches on some of the relevant issues’,
the Proponent notes that it has, in its opinion, addressed all matters relevant to the modification.
In relation to the matters expressly identified by Dr Beck, the Proponent notes the following.
There are no changes to the approved Tailings Storage Facility, with the exception
of the fact that Stage 3 of the facility may not need to be constructed.
The volume of waste rock that would be stored within the temporary waste rock
emplacement/ROM Pad would be increased by approximately 22 290m3, or
approximately 11%, as a result of the proposed modification. This increase would
not significantly change the design or size of the emplacement and that any
increase in size would be into areas already approved for disturbance. In addition,
the expert report of Clayton Rumble prepared for the Land and Environment
Court action and accepted by the Appellants to that action indicated that the waste
rock to be placed within the emplacement would be “naturally slightly alkaline,
non-saline and [non-acid forming].” As a result, there would be no additional
impacts associated with placement of waste rock as a result of the proposed
modification.
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2. The BIM 2012 report states “Transportation of sulphide concentrate from the
Project Site to the proponent’s customers via public roads surrounding the Project
Site using covered semitrailers”. This appears inconsistent with what my
understanding was. During the meetings it was stated that the sulphate concentrate
would be taken to the ore processing facility in Parks for processing.
Response:
The identified text is a quote directly from RWC (2010a), at which time the Parkes site was not
confirmed as the treatment site. The Proponent notes that the intention at the time of
finalisation of this document is to further process the concentrate at Parkes. However, as other
opportunities may become available in the future the Proponent does not wish to limit the
destination for concentrate from the Project.
3. The BIM 2012 report states “The completed stopes to be backfilled with paste would
be appropriately sealed to prevent leakage of paste during backfilling operations.”
But, no details on how this is to be achieved and verified appear to be provided.
Response:
The Proponent notes that the quote referred to by Dr Beck relates to sealing of the lower
entrances to the stopes (open voids) to prevent paste from flowing out of the stope and down
the decline into the remainder of the workings. The statement is not intended to indicate that
stopes would be fully lined or sealed.
In the interests of clarity, the Proponent notes the following in relation to placement of paste
and the nature of the stopes into which it would be placed..
The tailings would be mixed with cement binder and the precise amount of water
required to cure the mixture and ensure that no or very limited bleed water is
produced.
The paste fill would be a high density product with a consistency similar to
toothpaste.
The paste fill would be emplaced into a granodiorite aquifer where the principal
porosity is fracture-controlled.
The paste fill is expected to be largely cured within hours of emplacement and
fully cured within seven days.
As a result, past is not expected to “leak” from the stopes and not adverse environmental
impacts are anticipated.
4. The BIM 2012 report states that “Approximately, 84% of stopes by volume would be
backfilled with paste, with a further 7% by volume being backfilled with waste rock
as described in Section 2.5.4 of RWC (2010a). The remaining 9% by volume would
not be backfilled.” GHD understood that the original proposal included the
backfilling of all the stopes
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Considering that backfilling of 84% of the stope volume is now proposed to be
accomplished by paste fill how would this affect the management and placement of
waste rock that was to occupy this volume? Will this increase the size and or
duration of the surface waste storage facilities?
Response:
Dr Beck’s understanding is not consistent with Section 2.4.5 of RWC (2010a) which identified
that, as part of that application, waste rock would be used to stabilise “sections of the proposed
underground mine”, not all stopes created. The Proponent further notes that to completely
backfill all stopes with waste rock would be unachievable using the approved mining method.
As noted previously and in Section 2.4 of RWC (2012), the proposed modification would result
in an increase in waste rock being transported to the surface of approximately 11%. This
increase would not significantly change the design or size of the emplacement and any increase
in size of the emplacement would be into areas already approved for disturbance. The
additional waste rock would be used to backfill the box cut or used in rehabilitation of the
Project Site following the completion of mining operations.
5. Table 3 indicates average crustal abundance for various elements in the crust and
refers to an earlier Bankable feasibility study. Therefore, the source for this data is
unclear.
Response:
The data contained in Table 3 of RWC (2012) is based on data obtained during the Bankable
Feasibility Study prepared for the Project and was also included in RWC (2010a). The source
of the average crustal abundance used in that table was Table 4.15 of Independent
Metallurgical Operations, Dargues Reef Gold Project Bankable Feasibility Study Tailings
Management.
6. The BIM 2012 report states “Waste Classification Guidelines issued by the then
Department of Environment, Climate Change, and Water (now the Office of
Environment and Heritage) in April 2008”. A revised version of these guidelines
was published in December 2009.
The BIM 2012 report should be prepared with reference to the most up to date
version of the guidelines to ensure compliance with up to date requirements.
Otherwise there is a risk that the impact assessment could miss an issue of
relevance.
Response:
The Proponent notes that RWC (2012) incorrectly referred to the April 2008 version of the
Waste Classification Guidelines and that the December 2009 version was in fact used. The
Proponent apologises for this error and notes that no changes to the outcome of the assessment
would have resulted from the use of either version of the guidelines.
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7. The NSW EPA, Protection Of Environmental Operations (POEO) Act, 1999 defines
waste and waste facilities as follows: “waste includes:
(a) any substance (whether solid, liquid or gaseous) that is discharged, emitted
or deposited in the environment in such volume, constituency or manner as to
cause an alteration in the environment, or
(b) any discarded, rejected, unwanted, surplus or abandoned substance, or
(c) any otherwise discarded, rejected, unwanted, surplus or abandoned
substance intended for sale or for recycling, processing, recovery or purification
by a separate operation from that which produced the substance, or
(d) any processed, recycled, re-used or recovered substance produced wholly or
partly from waste that is applied to land, or used as fuel, but only in the
circumstances prescribed by the regulations, or
(e) any substance prescribed by the regulations to be waste. A substance is not
precluded from being waste for the purposes of this Act merely because it is or
may be processed, recycled, re-used or recovered.
waste facility means:
any premises used for the storage, treatment, processing, sorting or disposal of waste
(except as provided by the regulations).”
Therefore by definition the paste fill is a waste, as noted with respect to (a), (b) and
(e), that must be managed and placed in accordance with relevant guidance and
documents as outlined in the POEO Act and any documents issued under that act.
Response:
The Proponent acknowledges the above and notes that the material has been classified as
General Solid Waste (non-putrescible) in recognition of this fact. The Proponent further notes
the response to the EPA provide in Section 2.2 in regards to the Environment Protection
Licence.
8. This section [Section 2.2.3.4 - Step 2: Is the waste ‘liquid waste] and information
presented appears contradictory to the basic description provided in the earlier sections
of the BIM 2012 report. The paste fill mixing and emplacement process described
appears to suggest that the material would be in a liquid or sludge type state. The BIM
2012 report does not appear to reference any testing to support the statement made and
as such it is unclear as to whether the assentation that the paste fill is not a liquid waste
can be supported with the information presented in the BIM 2012 report.
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The key point that needs to be considered is the state of the “waste” when being placed
into the storage facility and as such the material is unlikely to pass this criteria.
Response:
The paste fill may be classified as a non-Newtonian fluid, with a consistency and behaviour
very similar to toothpaste and would not be free flowing. As identified in Table 4 of RWC
(2012), the paste fill has a slump of 220mm and that this slump rate would not classify it as a
liquid. Further information regarding the rheology of the paste fill is provided in Section 3.3 of
Revell (2010).
9. The data in Table 5 of the BIM 2012 report appears to contradict the data presented
in Table 3. Table 3 presents results for Multi Element analysis while Table 5
presents 95% UCL data. So it appears that Table 3 shows average data while 5
shows 95% UCL data. In general it would be expected that that 95% UCL would be
greater than average concentrations, yet the concentrations in Table 3 are routinely
higher than the concentrations in Table 5. Using the data in Table 3 at least nickel
concentrations exceed the General Solid Waste Criteria.
Based on the information included in Appendix 3 the UCL calculation is based on a
triplicate analysis of a single sample. In general a minimum of 5 samples is required
for calculation of UCL (NSW EPA Sampling Design Guidelines 1995, AS4482.1-
2005).
Also the testing of a single sample in triplicate is not considered sufficient to take
into account the potential heterogeneity of the material.
Response:
The Proponent notes that the data presented in Table 3 was reproduced from Table 4.15 of the
Bankable Feasibility Study and was included to ensure consistency with that document.
However, during preparation of RWC (2012), it was recognised that during the preparation of
the sample used to generate the data presented in Table 3 of RWC (2012), that stainless steel
grinding media was used to prepare the sample, contaminating it with small amounts of nickel,
chromium and molybdenum. As correctly identified by Dr Beck, this caused the nickel
concentration of the sample, presented in Table 3 RWC (2012) to exceed the SCC criteria
outlined in the Waste Classification Guidelines dated December 2009. To better replicate actual
paste characteristics, the Proponent prepared further samples of tailings for Specific
Contaminant Concentration testing with mild steel grinding media. The results from these
samples are provided in Table 5 of RWC (2012).
In relation to the number of samples tested, the Proponent notes that as identified in the expert
reports of Aaron Green and David Morgan prepared for the Land and Environment Court and
accepted by the Appellants in that case, the tailings material tested is a composite sample which
was considered to be representative of the Project’s tailings material as a whole and that testing
of multiple samples is not required. This position was accepted by the Appellants in that case.
As a result, the Proponent contends that the samples tested are representative of the tailings
material that would be produced by the Project. Further, the Proponent notes that as the ore
material is largely homogenous, that the variance in the samples tested is small and that as a
result, three samples are adequate to characterise the tailings material and the leachate.
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10. The BIM 2012 report indicates that TCLP testing was undertaken in accordance
with AS4439.3 using a pH 5 Buffer. Based on the information provided the leach
testing performed would be in accordance with the test designed for a Class 2
Monofilled putrescible landfill where a Acetate buffer st pH 5 is used.
The material tested (tailings) and testing regime (putrescible Class 2 monofilled
landfill scenario) is clearly significantly different from that actually experienced
(tailings and cement mix placed within a groundwater regime). Therefor the testing
conducted is considered to have little value in terms of assessing risks to the
environment due to the proposed pastefill placement.
Given that the addition of cement to the tailings will significantly alter the
geochemistry of the material to potential mobilisation of contaminants needs to be
understood in the context of the environment into which the material is to be placed.
Response:
The Proponent notes that the TCLP was completed in accordance with the Waste Classification
Guidelines dated December 2009 and that based on the SCC testing, the Proponent was not
required to undertake TCLP testing of the tailings material. The Proponent contends that the
TCLP method prescribed in the Waste Classification Guidelines dated December 2009 is
adequate for determining the potential mobility of metals from the tailings material. The
Proponent acknowledges that the paste fill environment will be slightly alkaline, however, that
the acidic buffer (pH 5) that the tailings material has been leached with provides a worst case
leachate for determination of metal mobility.
The Proponent further notes that all testing of the tailings material has been completed on an
unbound, ground up sample, which has maximised the surface area of particles exposed to the
leaching fluid during sampling, thus maximising the concentration of contaminates present in
the leachate. as noted previously, the permeability of the paste fill material, once cured, is
expected to be approximately 1x10-8
m/s. This would severely restrict the ability of the paste to
be leached by groundwater. As a result, the Proponent contends that the leach testing presents
an absolutely worst case leachate scenario, with significantly lower concentrations of
contaminates being available in reality to be leached into groundwater.
11. The testing procedure outlined in this section [Section 2.2.3.5] indicates the use of
distilled water as leaching medium but does not provide an indication of the pH of
the leaching medium. In general this type of test utilises leaching medium of pH
around 7 (ie. Neutral) the report contends that this would be indicative of a worst
case scenario. Clearly as can be seen in the figure shown for Item 10 that if cement
is addend and the pH becomes alkaline then metal solubility increases in
comparison to neutral conditions.
Response:
The issue of metal mobility has been previously addressed in the response to item 10 above.
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12. Table 7 in the report refers to Hydrobiology 2012 and Hogan 2003 but the
references are not included in the list at the back of the report and no context is
provided for them. In the table reference is made to median groundwater
concentrations based on Hydrobiology 2012. The context of these numbers is not
provided and no methodology on how samples were collected and analysed is
included. The report indicates median Al in groundwater is 2.25mg/L but does not
indicate whether this is total or dissolved Al. Review of the ALS laboratory
certificates suggests that results are total not dissolved which can have a significant
influence on the metal concentrations measured. Also as noted in Item 11, there is a
risk that leach testing was not representative of worst case due to the potentially
higher pH caused by pastefill
Response:
The Proponent acknowledges that these references were not included in the Reference section
of RWC (2012), however that “Hydrobiology (2012)” was identified in Section 4.2.3.1 as being
reproduced in Appendix 3 of that document and Dr Beck has made reference to that document
in his submission.
The Proponent notes that the results referred to in Table 3 of Hydrobiology (2012) are mean
results from Table 2 of that report which indicates that the analyses are of a “1:20 extract
following filtration (45µm)”. As a result, Aluminium results presented in Table 3 of
Hydrobiology (2012) are dissolved.
The issue of metal mobility has been previously addressed in the response to item 10 above.
13. The report discusses aluminium mobility and risk in the context of the leach testing
results and analysis by Hydrobiology. There are a number of issues with the
discussion and consequent conclusions on risk that would warrant further
consideration as the full risk profile may not have been appropriately assessed.
Response:
The discussion of Aluminium mobility in RWC (2012) was based on work prepared by Dr
Rainier Mann of Hydrobiology, an expert in aquatic ecotoxicology whose work was accepted
by the Appellants in the Land and Environment Court action. That discussion was not intended
to be comprehensive and interested readers such as Dr Beck were referred to the report of Dr
Mann which was included as an appendix.
In light of the specific criticisms of Dr Mann’s work, the Proponent notes the following.
Dr Mann is now no longer employed by Hydrobiology and cannot be contacted to
provide a rebuttal of Dr Becks criticisms.
In the unlikely event that minor levels of elevated Aluminium were to be leached
from the paste, that the risk of adverse environmental consequences would be
very small because the elevated Aluminium levels would be reduced through
buffering with the surrounding host rock prior to discharge to surface waters
As a result, the Proponent contends that no further response is warranted.
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14. The report indicates that the [Mercury] concentrations measured in the leachate
would attenuate as sulphide species in the groundwater and hence not pose a risk to
the groundwater quality. It is unclear in the report what evidence was used to
support this conclusions.
Dr Mann suggests that any soluble Mercury in leachate would form stable, insoluble complexes
with sulphide minerals within the host granodiorite. In light of the specific criticisms of Dr
Mann’s work, the Proponent notes the following.
The worst case leachate concentrations analysed by Dr Mann were very close to
the ANZECC and ARMCANZ trigger values and that real-life concentrations are
likely to be significantly less than those analysed.
That any leachate produced by the paste would be released into a groundwater
environment where it would be:
– buffered by the surrounding granodiorite aquifer
– subject to adsorption of dissolved metal onto clays and other minerals;
– subject to dilution by groundwater from up gradient of the workings; and
– any leachate would not be released into sensitive surface water environments
in the short term, permitting time for the above reactions and dilution to occur.
As a result, the risk of adverse consequences associated with Mercury in leachate is considered
to be negligible and the Proponent contends that that no further response is warranted.
15. The report fails to include sufficient information to allow independent review of the
data used in the assessment. No information on the number of samples utilised for
the data provided in some tables, the calculation of UCL methods or how many
leachate tests were performed was included. The report fails to include the
laboratory analysis certificates or chain of custody information for all analysis work
relied on. Also not included is information on what laboratory performed some of
the testing and whether they were NATA accredited to perform the tests.
Response:
The Proponent contends that this is not standard practice to include this information in an
Environmental Assessment. However, the Proponent is happy to provide any additional
information that the assessment authority requests.
16. This section [Section 4.2.3] of the report needs revision in light of the comments
above.
Response:
The Proponent contends that the issues raised have been appropriately addressed and that no
further revision is required.
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17. The report suggests no further groundwater monitoring is required with respect to
the proposed change in mining operations. This recommendation is difficult to
support given some of the key data gaps identified, particularly related to the
anticipated changes to the hydrogeochemical environment as a result of the propose
pastefill placement (eg increased pH and temperature in the mine workings
backfilled and surrounding groundwater regime.
Response:
The Proponent notes that an extensive groundwater and surface water monitoring program has
been established for the Project as part of the Water Management Plan and that this plan is
likely to be updated should approval for the proposed modification be received.
The currently approved program has been designed to detect changes in water quality within
and surrounding the Project Site. The Proponent contends that this monitoring program would
detect all relevant changes in water quality as a result of the approved Project and the Project as
modified.
18. As with Item 17. Given the key data gaps identified and considering the comments
and issues raised in relation to the hydrogeochemical analysis the conclusion
reached in this section [Sections 4.3.3 and 4.3.4] may require revision and
modification once the issues raised are addressed.
Response:
The Proponent contends that the issues raised have been appropriately addressed and that no
further revisions are required.
19. As noted in Item 17 and 18 given the issues raised and data gaps identified this
conclusion needs further consideration once the issues are addressed.
Response: The Proponent contends that the issues raised have been appropriately addressed
and that no further revisions are required.
20. Given that this section [Section 5] is heavily dependent on the outcomes and results
of how the items above are addressed revision and medication of the relevant
sections may be required.
Response:
The Proponent contends that the issues raised have been appropriately addressed and that no
further revisions are required.
21. Aluminium mobility could significantly increase as a consequence of the increased
pH resulting from the addition of cement.
Response:
The issue of metal mobility has been previously discussed in the response to item 10.
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22. Potential oxidation of chromium in the tailings to the hexavalent state (CrVI) as a
result of cement addition.
Response:
The issue of metal mobility has been previously discussed in the response to item 10.
23. Most mineral solubility increases with temperature and hence enhanced
mobilisation of metals and other inorganic compounds in the area around the mine
workings could occur as a result of the proposed use of paste fill
As indicated in Section 2.2, low heat cement will be used in the paste fill to reduce the
generation of heat during the curing process. In addition, the relatively small volumes of paste
that would be generated and placed within completed stopes when compared to the massive
volume of granodiorite host rock surrounding the Dargues Reef deposit indicate that any heat
generated by the paste would be insignificant
24. The BIM 2012 report does not include some of the backing information presented
such as laboratory certificates and other information sources.
Response:
The Proponent notes that this item has been previously addressed at item 15.
3. P U B LI C S U BM I SSI ON S
3.1 INTRODUCTION
This section provides a response to the public submissions presented in Table 2. In order to
limit repetition and allow the matters raised to be adequately and efficiently addressed in the
following sub-sections, each submission was reviewed and the matters raised were categorised
as follows.
Issue A – Dargues Reef Consultative Committee
Issue B – Additional Conditions
Issue C – Xanthate Testing
Issue D – Water – Impacts on Groundwater Quality
Issue E – Water – Alkaline Concrete Leaching
Issue F – Long Term Stability of Paste Fill
Issue G – Assessment of the Modification
Issue H – Eurobodalla Residents as Stakeholders
Table 2 identifies the issues raised in each submission.
Finally, in order to provide a ‘flavour’ of the issues raised by the various submissions, selected
sections of each submission are provided in italics in the following subsections.
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Table 2 Submissions and Issues Raised
Submission No
Respondent Issue
A B C D E F G H
001 Araluen Valley Producers and Protectors of the Ecosystem Coalition (AVPPEC)
X X X X X
002 Peter Cormick X X
X X
003 Coastwatchers X X X
004 Jackie French X X X
005 Brian Sullivan X X
3.2 ISSUE A – DARGUES REEF CONSULTATIVE COMMITTEE
1. The use of a Community Consultation Committee to approve such an amendment
without independent advice
The use of the Community Consultation Committee to “approve’/”support” such an
amendment would appear flawed in terms of capacity to make such a technical decision
without independent advice and/or access to research concerning the environmental
and other issues associated with paste fill operations.
It is apparent that a Consultation Committee can quickly lose both its legitimacy and
value once the broader community gains an understanding that the community people
involved have no independent advice and have only their own (limited we would
suggest) resources to fall back on. This approach is de-valuing of the processes
whereby the community could derive some comfort that the Committee was keeping a
watchful eye upon the operation.
It is respectfully suggested that the Committee be afforded access to independent advice
as matters like this come before it. For example the Water Management Plan currently
released is a dense and technical document and the Committee should have capacity to
source outside advice and information that will assist it consider such technical matters.
To provide only proponent advice to the Committee is to ensure the Committee will
gradually become irrelevant and appears disrespectful to the community participants.
Submission No. 001 – AVPPEC
Response:
The Proponent contends that the role of the DRCCC in this application is not a matter that is
relevant to the determination of the application for modification of PA 10_0054. However, in
acknowledgement of the concerns raised by the submission and as stated in Section 3.2.2 of the
EA, the committee was requested to express support or otherwise for the following statement.
Based on the information presented and relying on Cortona’s assertion as to its accuracy, the DRCCC broadly supports the application to modify Project Approval 10_0054 to permit the use of Pastefill.
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The committee was not asked to ‘approve’ the application. It was merely asked in its advisory
and non-technical capacity whether, based on the information provided by the Proponent, the
members of the committee broadly supported the proposed modification. The Proponent
contends that this information, and the manner in which information was presented and
feedback sought, is appropriate as significantly more consultation and community engagement
would have been required to be undertaken if the committee was not comfortable with the
proposed modification.
Finally, the Proponent acknowledges that some issues presented to the committee can be
complex and technical in nature. Where issues of this nature are presented, the Proponent has
endeavoured to provide significant support from within the company. However, the Proponent
contends that access to external independent advice is not required or appropriate given the role
of the committee.
3.3 ISSUE B – ASSESSMENT OF XANTHATE USE AND RESIDUES
It is also of note and concern that no test for Xanthate residues has been approved in
NSW and all approvals thus should remain provisional
The waste it makes contains heavy metals. Xanthates bind with heavy metals and pulls
them out of solution. It is difficult to see this material as general waste, because of the
heavy metals. The non-reacted Xanthate is still a reactive chemical. It could react with
heavy metals or wildlife and given the range of unknowns concerning the aquifers and
Araluen Valley it is our contention it absolutely should not be a general waste, it should
be a pollutant. It is a chemical waste and should be treated as such.
Submission No. 001 – AVPPEC
Why do the “Tailings Characteristics”, shown in Table 3 at section 2.2.3.2 of the
proposal, not list amyl xanthate? What will its ppm presence be? Also, Table 6 at
section 2.2.3.5 sets out “Toxicity Characteristics Leaching Procedure Test Results” but,
again, amyl xanthate is not included in the list. And yet again, at Table 7, “Paste fill
Leachate Characteristics”, there is no mention of amyl xanthate. Why is that?
Submission No. 002 – Cormick
The Tailings Characteristics table shown at section 2.2.3.2 of the proposal does not list
amyl xanthate, although presumably these tailings, like those destined for the tailings
dam, will be treated. Cortona claim that the Xanthates will bind to the ore sent to the
proposed Parkes Processing plant. They do not, however, supply adequate
substantiation of that, given that expert consensus on the issue is that paste fill is a
relatively new process, and that the many variables mean that both the cement content
and the leachate vary, even on a single site.
Submission No. 004 – French
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Response:
The Proponent notes that this issue was raised by the DRCCC and that it has been
comprehensively addressed in Appendix 1 of RWC (2012). In summary, however, the
following was agreed by both the Appellant’s and Respondent’s experts during the Land and
Environment Court.
Xanthate binds strongly to sulphide minerals, and to a lesser extent other minerals,
and the vast majority will be removed with the sulphide concentrate.
There is no commonly accepted methodology for directly testing xanthate
concentration in tailings because the xanthate would be destroyed during the
extraction process prior to testing occurring.
The negligible amount of xanthate would be bound to the solidified paste fill and
would not be mobilised in groundwater.
In addition, xanthate is a commonly used chemical, including as a component of commonly
used herbicides and other horticultural and agricultural products, and the Proponent is not aware
of any significant adverse impacts associated with its use as a reagent in mining operations in
Australia.
Further, the Proponent notes that testing for xanthates is not a requirement of the Waste
Classification Guidelines dated December 2009 and that no approved method for the testing of
xanthates exists in NSW.
3.4 ISSUE C - GROUNDWATER QUALITY - METALS
in relation to “Groundwater”, we are told that “Test work results on leachate
chemistry were analysed by Hydrobiology (2012) who confirm that the anticipated
worst-case chemical composition of the leachate that would be leached from the paste
fill would comply with the ANZECC and ARMCANZ (2000) trigger values for the
protection of 95% of aquatic species for all relevant elements except aluminium,
mercury and silver.” What of these levels of Al, Hg and Ag – how far above the trigger
values are they expected to be - and what are there estimated impacts? And, again, what
of the xanthate presence and its impact? To continue: “The levels of those three
elements are sufficiently low that the leachate is unlikely to result in significant adverse
groundwater quality-related impacts.” And, further, we are told that “In light of the
above, the Proponent contends that the proposed modification would not result in
significant adverse impacts to threatened species, Endangered Ecological Communities
or groundwater dependent ecosystems.” (emphases added) In meaningful statistical
terms, what is meant by “significant” and “unlikely”, in the quoted passages?
Submission No. 002 – Cormick
Response:
Table 15 of the Environmental Assessment provides the relevant concentrations of Aluminium,
Silver and Mercury and the relevant trigger levels.
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In relation to the use of the terms “unlikely” and “significant adverse impacts”, reference is
made to the ANZEC and ARMCANZ trigger values and the fact that anticipated concentration
of the above elements were determined by Hydrobiology, taking into account the natural
physical and chemical properties of the paste, aquifer and groundwater, to not pose a risk of
environmental harm. The terms are used in a manner that is consistent with Section 5A of the
Environmental Planning and Assessment Act 1979.
Finally, the Proponent acknowledges the expert report of Dr Grant Hose, provided with
Submission No. 001 states.
To the best of my knowledge the leaching tests done on the paste fill sample seem appropriate and the interpretation of those data seem adequate, such that environmental harm from metals in the paste fill is unlikely, as it was for the mine waste rock in the absence of the paste.
3.5 ISSUE D – GROUNDWATER QUALITY – ALKALINITY
There appears to be no study to substantiate the presumption that there will be no risk
of alkaline concrete leaching leading to long term changes in the naturally acidic water
table. Any such change could be devastating to local flora, and persist for decades or
even longer after the facility is decommissioned.
Submission No. 001 - AVPPEC
My concern is that the pH of the leachate (~9) is above the background pH of most of
the groundwater (~7). The significance of this difference is not discussed in the EA or
supplementary report in appendix 3 despite the consultant concluding that the pH of the
groundwater will influence the concentrations of metals. Recent research has suggested
that even limited contact with concrete channels can influence the pH of stream water
(Wright et al 2011) so the dismissal of this issue in the letter from Cortona to the DRCC
seems to me premature. With longer residence times in groundwater compared to
surface streams, it seems likely to me that contact between groundwater and the paste
fill concrete will result in an increase in groundwater pH. As suggested in the
Hydrobiology report, increasing pH will likely reduce the availability of some metals in
the leachate, but it will also have it's own potential affects on biota in the groundwater
and receiving waters. It may be that the buffeting capacity of the groundwater is
sufficient to cope with the change in pH but this should be considered in the report.
Submission No. 001 – AVPPEC (Expert Report – Hose)
Concrete itself is not a stable substance and can present major alkaline leaching. The
EA for the Modification states that the pH of the leachate (~9) is above the background
pH of most of the groundwater (~7). The significance of this difference is not discussed
in the EA or supplementary report in appendix 3 even though the consultant concludes
that the pH of the groundwater will influence the concentrations of metals. The pH of
the groundwater will also have potential effects on biota in the groundwater and
receiving waters. Recent research has suggested that even limited contact with concrete
channels can influence the pH of stream water (Wright et al 2011) and dismissal of this
issue by Cortona is premature. With longer residence times in groundwater compared
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to surface streams, it is likely that contact between groundwater and paste fill concrete
will result in an increase in groundwater pH. The increased pH of the groundwater will
also have potential affects on biota in the groundwater and receiving waters.
Submission No. 003 – Coastwatchers
There also appears to be no study to substantiate the presumption that there will be no
risk of alkaline concrete leaching leading to long term changes in the naturally acidic
the water table. Any such change could be devastating to local flora, and persist for
decades or even longer after the facility is decommissioned.
Submission No. 004 – French
My concern is that the pH of the leachate (~9) is above the background pH of most of
the groundwater (~7). The significance of this difference is not discussed in the EA or
supplementary report in appendix 3 despite the consultant concluding that the pH of the
groundwater will influence the concentrations of metals. Recent research has suggested
that even limited contact with concrete channels can influence the pH of stream water
(Wright et al 2011) so the dismissal of this issue in the letter from Cortona to the DRCC
seems to me premature. With longer residence times in groundwater compared to
surface streams, it seems likely to me that contact between groundwater and the paste
fill concrete will result in an increase in groundwater pH. As suggested in the
Hydrobiology report, increasing pH will likely reduce the availability of some metals in
the leachate, but it will also have its own potential affects on biota in the groundwater
and receiving waters. It may be that the buffeting capacity of the groundwater is
sufficient to cope with the change in pH but this should be considered in the report.
Submission No. 005 – Sullivan
Response:
The matter of changes to groundwater pH was addressed in Appendix 1 of RWC (2012) and the
Proponent contends that the information provided in that document adequately addresses the
issues raised by the respondents. However, in recognition of the detailed nature of the
submission by Dr Hose, this sub-section specifically addresses the issues raised.
Firstly, the Proponent notes that Dr Hose is incorrect in stating that the pH of groundwater is
approximately 7. Table 4.19 of RWC (2010a) identifies that the pH of groundwater within the
Project Site varies from 7.0 to 8.2, with a single outlier with a pH of 12.2.
Secondly, the Proponent notes that the permeability of the paste fill, once cured, will be
approximately 1 x 10-8
m/s, the same permeability required for the lining of the Tailings Storage
Facility to minimise leaching of water from that facility. As a result, while Dr Hose is correct
in stating that following recovery of the groundwater levels within the Project Site, once mining
operations are complete, the rate at which water could seep out of the cured mass of paste fill is
extremely low. As a result, any water that did seep from the paste fill would very quickly be
diluted by surrounding groundwater. In addition, as the wider properties of the aquifer would
not be modified, any water that did leach from the paste fill with an elevated pH would be
buffered back to a mildly alkaline pH by the surrounding rock mass.
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3.6 ISSUE E – LONG TERM STABILITY OF PASTE FILL
Further, there is no mention in the EA regarding the longevity and stability of the
concrete paste fill. How long do the proponents expect that the concrete paste fill will
remain in tact as a solid mass. What is the half life (or similar) of concrete masses such
as they will be creating? I am no concrete engineer but if the concrete deteriorates over
time then the infiltration of groundwater to the paste fill will increase as will the
dissolution of metals and carbonates in the concrete etc. The long term stability of the
paste fill should be considered.
Submission No. 001 – AVPPEC (Expert Report – Hose)
4. What regard has been given to the consequences of the paste fill decomposing over
time?
Submission No. 002 – Cormick
Of critical importance in determining the likely environmental impacts associated with
the proposed operations is the long term stability of the pastefill. There is no mention of
this in the EA.
How long do the proponents expect that the concrete pastefill will remain intact as a
solid mass? If the concrete deteriorates over time then the infiltration of groundwater to
the pastefill will increase along with the dissolution of metals and carbonates in the
concrete. The Mine Environmental Neutral Damage (MEND) Program Report 10.2
(April 2006) investigates the quality of research on Paste Backfill Geochemistry and the
Environmental Effects of Leaching and Weathering. The report concludes that the
general theories associated with paste backfill characteristics and geochemical
reactivity appear sound, but there is not much field validation on the actual influence of
key parameters. There was little information on the influence of paste backfill on mine
water quality. The report recognised the fact that any backfill has the potential to
generate contaminant plumes in the long term, and potentially influence ground and/or
surface water.
Submission No. 003 – Coastwatchers
The long term stability and leaching potential of the paste fill should be considered, as
suggested by Dr Hose. As there have been no long term studies of the integrity of
pastefill, this would necessitate monitoring of both pastefill stability and effect on the
pH of the water table beyond the projected lifespan of the project, with a bond in place
to fund on going monitoring and any mitigation measures, if necessary.
Submission No. 004 – French
The long term stability and leaching potential of the paste fill should be considered, as
suggested by Dr Hose. As there have been no long term studies of the integrity of
pastefill, this would necessitate monitoring beyond the projected lifespan of the project,
with a bond in place to fund on going monitoring and any mitigation measures, if
necessary.
Submission No. 005 – Sullivan
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Response
The above submissions raise two issues, namely the long-term integrity of the paste fill and the
impact on groundwater quality in the event that the paste degrades.
In relation to the first issue, namely the long-term integrity of the paste fill, the Proponent
contends that there would be no reason why the paste fill would degrade with time as it would
not be subject to weathering, attack by acidic chemicals or natural degradation of the cement
binder. In addition, paste itself is primarily composed of ground granodiorite that is more than
400 million years old and is unlikely degrade. As a result, the stability of the filled voids would
not be adversely impacted even in the highly unlikely event of partial degradation of the cement
binder.
In relation to the second issue, namely the impact on groundwater quality in the unlikely event
that the paste fill does degrade, the Proponent notes that leachate testing of the tailings material
was completed on unbound material. This allowed the leaching solution to access the largest
possible surface area of the tailings material and presents a worst case scenario for leaching of
contaminants. As a result, the Proponent contends that the results presented in RWC (2012)
present the worst-case leachate quality that would result from the complete degradation of the
paste.
3.7 ISSUE F – ASSESSMENT OF THE APPLICATION
Will the Department itself be scrutinizing the claims made in the proposed modification
and involve itself directly in addressing and responding to the questions and concerns
expressed in the submissions it receives or will it be relying on the assessment and
responses of the proponent?
Submission No. 002 - Cormick
Response:
This is a matter for the Department of Planning and Infrastructure. However, the Proponent
anticipates that the Department’s standard assessment procedures will be implemented.
3.8 ISSUE G – EUROBODALLA RESIDENTS AS STAKEHOLDERS
The Moruya Catchment is a major source of Eurobodalla’s water supply, as evidenced
by proceedings initiated in the Land and Environment Court by Eurobodalla Shire
Council against the original DA. The EA for the Project DA acknowledges that the
southern section of the project site occurs within the Moruya catchment. This is why the
Coastwatchers Association recently requested (by email to Sarah Wilson at Planning)
advertisement of this modification for comment in the Eurobodalla newspapers. There
are many Eurobodalla residents who are interested in how this project might affect their
water supply, especially those who live along the Deua and Araluen rivers. As this
request was refused, only a small fraction of stakeholders would have seen the advert in
the Braidwood Times.
Submission No. 003 – Coastwatchers
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Response:
This is a matter for the Department of Planning and Infrastructure. However, the Proponent
notes that advertising of the proposed modification was undertaken in a manner that was
consistent with that implemented for the original application. In addition, advertising in
Eurobodalla, located approximately 80km downstream of the Project Site, would, in the
absence of a likely environmental impact, be highly unusual.
3.9 ISSUE H – CONCLUDING COMMENTS
A number of the submissions provided a range of concluding or summary comments. This sub-
section provides brief responses to each of those comments, where relevant.
Approval dependent upon the monitoring and testing arrangement in place for the
tailings material be directly applied to the pastefill material.
Submission No. 001 – AVPPEC
Response:
The Proponent anticipates that the Water Management Plan will be required to be revised
should approval for the proposed modification be granted.
Recognition that the pastefill has the potential to generate contaminant plumes in the
long term, and potentially influence ground and/or surface water thus the rehabilitation
and long term monitoring be adjusted to reflect this.
Submission No. 001 – AVPPEC
Response:
RWC (2012) examined this issue in detail and concluded that the proposed modification would
be unlikely to result in adverse impacts on groundwater or surface water. However, in
recognition of the modified nature of the Project, the Proponent anticipates that the Water
Management Plan will be required to be revised should approval for the proposed modification
be granted.
and the Proponent contends that the existing monitoring regime would be largely capable of
detecting any adverse impacts should they occur.
3. Any alteration to the pastefill recipe to meet altered stope requirements be subject to
independent testing prior to alteration.
Submission No. 001 – AVPPEC
Response:
The Paste fill “recipe” comprises ground rock, cement and water. This is unlikely to change.
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Inclusion, by the Department of Planning, of Eurobodalla residents as regional
stakeholders. This should be through adverts in the Eurobodalla local newspapers that
inform of the opportunity to comment on proposed changes to the approved Major
Project Application.
Submission No. 003 – Coastwatchers
Response:
This is a matter for the Department of Planning and Infrastructure, however, the Proponent
contends that the inclusion of Eurobodalla Shire Council on the DRCCC already acknowledges
the residents of the Shire as stakeholders.
Inclusion of data on the expected long term stability of the pastefill in the EA.
Submission No. 003 – Coastwatchers
Response:
The Proponent contends that there is no reason why the paste fill would degrade with time.
Continuous testing for possible contaminant leaching over time
Submission No. 003 – Coastwatchers
Response:
The Proponent contends that this is a matter more appropriately dealt with via the relevant
management plans. However, continuous monitoring is unlikely to be required or provide
benefits over periodic monitoring at suitable intervals.
Inclusion of consideration of the buffering capacity of the groundwater to cope with the
predicted change in pH in the EA
Submission No. 003 – Coastwatchers
Response:
This issue has been discussed in Section 2.4.
Continuous sampling and assessment of the pastefill material as it is produced so that
there is little risk of leaching of toxics into groundwater. Details about how this will
happen need to be specified .
Submission No. 003 – Coastwatchers
Response:
This is an operational matter, however, continuous monitoring of a homogenous material is
unlikely to provide any benefits over periodic monitoring. The Proponent would, however,
undertake periodic testing of paste produced for its own internal management purposes.
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Results from testing in points 3 and 5 be made available to the community on the
Company web site within 28 days.
Submission No. 003 – Coastwatchers
Response:
The Proponent notes that making monitoring data available on the Project website is already a
requirement of PA 10_0054.
That the pastefill contain no more than 1% Xanthate, or its breakdown products.
Submission No. 004 – French
Response:
This issue has been addressed previously. In addition, imposition of such a requirement
without evidence related to how the figure was determined and the seriousness of any impacts if
it were would not be standard practice.
That the xanthate and breakdown content of the paste fill be tested weekly, and the
results made public on the Cortona web site, as well as the register of concerned public
downstream (which has yet to be put into place by Cortona), within 28 days of such
testing.
Submission No. 004 – French
Response:
This issue has been addressed previously. In addition, the Proponent contends that this is a
matter more appropriately dealt with via the relevant management plans.
That any spillage of paste fill, or it’s components, must be reported to downstream
residents as soon as possible, and no later than within six hours for residents who use
the water directly downstream for drinking and household use and irrigation.
Submission No. 004 – French
Response:
As the paste plant would be within the larger processing plant and measures are already
identified to prevent and manage spills of hydrocarbons, reagents or tailings, there is no need
for further measures.
Autopsies of dead fish or amphibians within 10 km downstream of the Project, or where
more than one animal that drinks water from up to 10 km downstream has died from no
apparent cause. These autopsies must be conducted within one week of samples being
provided.
Submission No. 004 – French
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Response:
The Proponent has already committed to regular stream health assessments using the
AusRIVAS methodology and contends that further assessment is not required.
A specified testing regime be put into place to determine any increased alkalinity of the
ground or surface water, with remediation to take place within 28 days if a rise in
alkalinity is detected. These results should also be made available on the website and
register. This must be combined with specified remediation measures to be put into
place within 28 days of any rise in the pH.
Submission No. 004 – French
Response:
The existing Water Management Plan includes a requirement to test the pH of both
groundwater and surface water within and surrounding the Project Site and make those results
available on the Project’s website. In addition, the Proponent anticipates that the Water
Management Plan will be required to be revised should approval for the proposed modification
be granted.
The long term stability and leaching potential of the paste fill should be considered, as
suggested by Dr Hose. As there have been no long term studies of the integrity of
pastefill, this would necessitate monitoring of both pastefill stability and effect on the
pH of the watertable beyond the projected lifespan of the project, with a bond in place
to fund on going monitoring and any mitigation measures, if necessary.
Submission No. 004 – French
Response:
This issue has been addressed in Section 2.6.
That the pastefill contain no more than 1% Xanthate, or its breakdown products.
That the xanthate and breakdown content of the paste fill be tested weekly, and the
results made public on the Cortona web site, as well as the register of concerned public
downstream (which has yet to be put into place by Cortona), within 28 days of such
testing.
That any spillage of paste fill, or it’s components, must be reported to downstream
residents as soon as possible, and no later than within six hours for residents who use
the water directly downstream for drinking and household use and irrigation.
Autopsies of dead fish or amphibians within 10 km downstream of the Project, or where
more than one animal that drinks water from up to 10 km downstream has died from no
apparent cause. These autopsies must be conducted within one week of samples being
provided. Preferably, an independent body would take such samples and collect the
subject for autopsy, but as in all recent incidents government authorities have no
responded within three weeks in this area to reported spillages, it is unlikely that they
would respond quickly enough for valid samples to be taken.
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A specified testing regime be put into place to determine any increased alkalinity of the
ground or surface water, with remediation to take place within 28 days if a rise in
alkalinity is detected. These results should also be made available on the website and
register. This must be combined with specified remediation measures to be put into
place within 28 days of any rise in the pH.
The long term stability and leaching potential of the paste fill should be considered, as
suggested by Dr Hose. As there have been no long term studies of the integrity of
pastefill, this would necessitate monitoring beyond the projected lifespan of the project,
with a bond in place to fund on going monitoring and any mitigation measures, if
necessary.
Submission No. 005 – Sullivan
Response:
Each of these issues has been addressed in the response to Submission No. 004 – French.
4. AD D I T I O N AL C OM M I TM EN TS
Table 3 presents an additional commitment that the Proponent would be willing to insert into
the Statement of Commitments presented in Appendix 7 of the revised Project approval, should
it be granted.
Table 3 Additional Commitment for Inclusion in Statement of Commitments
Desired Outcome Commitment Timing
Groundwater
Ensure that the properties of the paste are appropriately understood and managed
6.13 Undertake further testing of the tailings material to confirm the results of test work undertaken prior to the commencement of mining operations and the proposed paste fill operational, management and mitigation measures
Following commencement of processing operations and prior to the commencement of paste fill operations.
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5. R E F E RE N C ES
Revell (2010). Dargues Reef Paste Fill Testwork and Design (P147-R01), Report prepared for
Big Island Mining Pty Ltd dated October 2010.
R.W. Corkery & Co. Pty Limited (2010a). Environmental Assessment for the Dargues Reef
Gold Project, Major Project Application No. PA10_0054. Report prepared for Big
Island Mining Pty Ltd. September 2010.
R.W. Corkery & Co. Pty Limited (2010b) – Response to Government Agency and Public
Submissions for the Dargues Reef Gold Project, Major Project Application No.
PA10_0054. Report prepared for Big Island Mining Pty Ltd. December 2010.
R.W. Corkery & Co. Pty Limited (2012). Modification Environmental Assessment for the
Dargues Reef Gold Project, Major Project Application No. PA10_0054. Report
prepared for Big Island Mining Pty Ltd.
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(Total No. of pages including blank pages = 88)
Appendix 1 Dargues Reef Paste Fill Testwork and Design
Appendix 2 Backfill Specialists Capability Statement
Appendix 3 MSDS – Portland Cement
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Appendix 1
Dargues Reef Paste Fill Testwork and Design
Dated October 2010 and updated June 2012
(Total No. of pages including blank pages = 50)
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
Dargues Reef Gold Project Report No. 752/28
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
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Appendix 2
Backfill Specialists Capability Statement
(Total No. of pages including blank pages = 30)
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RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
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Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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R. W. CORKERY & CO. PTY. LIMITED
RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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BIG ISLAND MINING PTY LTD RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS
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Report No. 752/28 Dargues Reef Gold Project
R. W. CORKERY & CO. PTY. LIMITED
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RESPONSE TO GOVERNMENT AGENCY AND PUBLIC SUBMISISONS BIG ISLAND MINING PTY LTD
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R. W. CORKERY & CO. PTY. LIMITED
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Appendix 3
MSDS – Portland Cement
(Total No. of pages including blank pages = 6)
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