Iron Valley Iron Ore Project - Department of Environment ... · Iron Valley is a below the water table (BWT) blast and hydraulic shovel open pit mine of 10 million tonnes of iron

Iron Valley Iron Ore Project

Licence L8859/2014/1 amendment application supporting attachments

FINAL

Prepared for Mineral Resources Limited by Strategen-JBS&G July 2019

Iron Valley Iron Ore Project

Licence L8859/2014/1 amendment application supporting attachments

FINAL

Strategen-JBS&G is a trading name of JBS&G Australia Pty Ltd Level 1, 50 Subiaco Square Road Subiaco WA 6008 ABN: 62 100 220 479 July 2019

Limitations

This report has been prepared for use by the client who has commissioned the works in accordance with the project brief only and has been based in part on information obtained from the client and other parties.

The advice herein relates only to this project and all results conclusions and recommendations made should be reviewed by a competent person with experience in environmental investigations, before being used for any other purpose.

Strategen-JBS&G accepts no liability for use or interpretation by any person or body other than the client who commissioned the works. This report should not be reproduced without prior approval by the client or amended in any way without prior approval by Strategen-JBS&G, and should not be relied upon by other parties, who should make their own enquires.

Client: Mineral Resources Limited

Report Version Revision No. Purpose Strategen-JBS&G

author/reviewer Submitted to Client

Form Date Preliminary Draft Report A Client review R Mason / L Whitley ; J

Bailes Electronic 15/7/19

Draft Report B Client review R Mason/ K Moyle Electronic 24/7/19 Final Report 0 Submission L Whitley Electronic 26/7/19

Filename: MRL19351_01 R002 Rev 0 - 26 July 2019

FINAL Iron Valley Iron Ore Project | Licence L8859/2014/1 Amendment Supporting Document

MRL19351_01 R002 Rev 0 26-Jul-19

Table of contents 1. Introduction 3

1.1 Background 3 1.2 Purpose and scope 3

2. Attachment 1C: Authorisation to act as a representative 5 3. Attachment 2: Premises maps 7 4. Attachment 3A: Proposed activities 10

4.1 Stockyard to E1 Drain 10 4.1.1 Scope, size and scale 10 4.1.2 Key infrastructure and equipment 10 4.1.3 Description of processes 15 4.1.4 Emission/discharge points 15 4.1.5 Waste storage/disposal locations 16 4.1.6 Construction, commissioning and operations activities 16

5. Attachment 5: Other approvals and consultation documentation 17 5.1 DWER Approvals 17 5.2 Environmental Protection Act 1986 17

5.2.1 Part IV referral and assessment 17 5.2.2 Existing Part IV approvals 17

5.3 Environment Protection and Biodiversity Conservation Act 1999 17 5.4 Mining Act 1978 17 5.5 Stakeholder consultation 17

6. Attachment 6A: Emissions and discharges 18 6.1 Sources 18

6.1.1 Dewatering 18 6.1.2 Stormwater 18 6.1.3 Dust Emissions 18

6.2 Impact to Ecological Receptors 18 6.2.1 Discharge of water 18 6.2.2 Dust 19

7. Risk Assessment 20 7.1 Risk Assessment Framework 20 7.2 Risk assessment results 22

8. Attachment 9: Application fee 25 9. References 26

List of tables Table 1: Location of information relevant to the Application Form 4 Table 2: Key infrastructure requirements 10 Table 3: CEMP Dewater water quality monthly analysis 16 Table 4: Monitoring to measure environmental outcome against trigger/threshold criteria (as outlined in CEMP

[Appendix 1]) 19 Table 5: Risk analysis matrix (DWER 2017) 20 Table 6: DWER consequence and likelihood criteria 20 Table 7: Risk treatment protocol 21 Table 8: Risk assessment 22

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List of figures Figure 1: Premises map 8 Figure 2: Proposed dewatering infrastructure layout 9 Figure 3: Cross section of drain design 11 Figure 4: Drain connecting to E1 pit void schematic 12 Figure 5: E1 outflow long section 13 Figure 6: E1 outflow design 13 Figure 7: E1 outflow design showing bund wall, funnel area and trench spillway to DDL4 14 Figure 8: Example of flow meter for trench spillway to measure discharge volume 14 Figure 9: Works Approval Application fee 25

List of Appendices Appendix 1 Condition Environmental Management Plan (CEMP)

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1. Introduction

1.1 Background Mineral Resources Limited (MRL) operates the Iron Valley Iron Ore Mine (Iron Valley) which is located on Mining Tenements held by BCI Minerals Limited (BCI), approximately 75 km north-west of Newman and 75 km south-south east of the Auski Tourist Village (Munjina) in the Central Pilbara region of Western Australia (Figure 1). Iron Valley is a below the water table (BWT) blast and hydraulic shovel open pit mine of 10 million tonnes of iron ore per annum. The ore is mined in a staged approach from multiple pits and sent to the Run of Mine (ROM) pad where it is blended. The ore is then rehandled and transported off site to the port of Port Hedland for export.

The site is operated under Environmental Protection Act 1986 (EP Act) Licence (L8859/2014/1) with the current prescribed premises being:

• Category 5 – processing or beneficiation of metallic or non-metallic ore • Category 6 – mine dewatering • Category 89 – putrescible landfill site.

Iron Valley is approved under Ministerial Statement No. 1044 (MS 1044). BCI applied under Section 45C (s 45C) of the EP Act in November 2018 to amend MS 1044. The proposed amendment was to increase the volume of mine dewatering, and the subsequent dewater discharge into a tributary of Weeli Wooli Creek (WWC). The proposed increase in dewater discharge volume was from 17 Gigalitres per year (GL/yr) to 42 GL/yr. The s 45C application is currently under assessment. Parallel to this assessment, MRL has submitted Licence Amendment applications for both Licence L8859/2014/1 and Groundwater Licence (GWL) 182884 (submitted 20 December 2018) to reflect the increased dewater volume.

This Licence Amendment application is to request a change to the design of the dewatering infrastructure to accommodate the anticipated increased capacity of discharge water volumes and reduce the total suspended soils (TSS) in the dewater caused from in pit sumps agitated by the BWT mining activity.

MRL proposes to upgrade and utilise the existing drain to divert surplus dewater to E1 pit for water retention and sediment settlement. Water will then be discharged into WWC through the existing dewatering discharge location (DDL4). Diverting in-pit sump water through this proposed drain to E1 pit allows for greater dewatering to meet the required rates for BWT mining.

No change will be made to the current dewatering pipeline infrastructure to DDL4. This line will continue to be used to transport production bore dewater to the discharge at DDL4. The new drain will be utilised for in-pit sump water (and storm water runoff) only.

To accommodate the required activities the Licence Amendment requires the: • change to the dewatering infrastructure requirements (Table 1.2.3 of L8859/2014/1) • removal of contingency stormwater discharge point (W1).

1.2 Purpose and scope This document supports an application for a Licence Amendment application for the change of dewatering regime infrastructure under Part V of the EP Act.

This document is structured to align with the Department of Water and Environmental Regulation’s (DWER) Application Form: Works Approval/Licence/ Renewal/ Amendment/ Registration (February 2019, v 11) (Application Form).

Table 1 provides an overview of the Application Form and the relevant sections of this document that addresses each of the information requirements.

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Table 1: Location of information relevant to the Application Form Section in Application Form Section in this document

Part 1. Application type Refer to Application Form

Part 2. Applicant details Refer to Application Form

Part 3. Premises details Section 3

Part 4. Proposed activities Section 4

Part 5. Index of Biodiversity Surveys for Assessments (IBSA) Refer to Application Form

Part 6. Other DWER approvals Section 5

Part 7. Other approvals and consultation Refer to Application Form

Part 8. Fit and competent operator Refer to Application Form

Part 9. Emissions, discharges, and waste Section 6

Part 10. Siting and location Refer to Application Form

Part 11. Submission of any other relevant information Refer to Application Form

Part 12. Proposed fee calculation Section 8

Part 13. Commercially sensitive or confidential information Refer to Application Form

Part 14. Submission of application Refer to Application Form

Part 15. Declaration and signature Refer to Application Form

Attachments Attachment 1A: Proof of Occupier Status Not required Attachment 1B: ASIC company extract Not required Attachment 1C: Authorisation to act as representative Section 2 Attachment 2: Premises maps Section 3 Attachment 3A: Proposed activities Section 4 Attachment 3B: Map of area proposed to be cleared Not required Attachment 3C: Additional information for clearing assessment Not required Attachment 4: Biodiversity surveys Not required Attachment 5: Other approvals and consultation documentation

Not required

Attachment 6A: Emissions and discharges Section 6 Attachment 6B: Waste acceptance Not required Attachment 7: Siting and location Not required Attachment 8: Additional information submitted Appendix 1 Attachment 9: Fee calculation Section 8 Attachment 10: Request for exemption from publication Not required



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2. Attachment 1C: Authorisation to act as a representative


Thursday, 21 May 2019 Department of Water and Environmental Regulation PO Box 836 KARRATHA, WA 6714

Dear Department RE: Tenement Authorisation BCI Minerals (BCI), formerly Iron Ore Holdings (IOH) has an Iron Ore Sale and Purchase Agreement (the Agreement) in regard to the Iron Valley Project (IVP) on tenement M47/1439 with Mineral Resource Limited (MRL). The general terms of this Agreement are as follows: 1. MRL agrees to develop the mine on IOHs behalf; 2. BCI agrees to sell and MRL agrees to purchase the iron ore product; and 3. MRL will seek approvals and licenses on BCI’s behalf to operate the Project. This letter formerly gives MRL and their officers the authority to access BCI tenure for the purpose of continued mining and to gain any necessary approvals required under the Environmental Protection Act 1986 and Rights in Water and Irrigation Act 1914. Yours sincerely,

Michael Klvac General Manager Corporate Affairs

T +61863113400 E [email protected] W www.bc1m1nerals.com.au

~ BCI MINERALS - LIMITED

GPO 8ox2811 West Perth WA 6872


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3. Attachment 2: Premises maps


Proposed new landfill facility Are to be cleared 2.3 ha

Current approved landfillfacility (4.32 ha)

New E1 Plan

E1 Drain DesignCulvert

Pipeline

Drain

E1 Outfall Design

SW MONITORING LOCATIONSDDL1

DDL4

W1

M471439 Boundary entities

Site Text

Legend

Figure 1: Premises Map Proposed Dewatering Infrastructure

L8859/2014/1

Iron Valley Project July 2019

0

0

0

500

~~ ,!!'!~~~~ ~ RESOURCES

1000 m

Proposed new landfill facility Are to be cleared 2.3 ha

Current approved landfillfacility (4.32 ha)

E1 Outfall Structure2 m High bund wall andgauging station trench

Proposed drain designutilising part ofexsisting drain

New E1 Plan

E1 Drain DesignCulvert

Pipeline

Drain

E1 Outfall Design

SW MONITORING LOCATIONSDDL4

W1

M471439 Boundary entities

Site Text

Legend

Figure 2: Proposed Dewatering Infrastructure L8859/2014/1

Iron Valley Project July 2019

Proposed drain designutilising part of exsisting

drain

E1 Outfall Structure2 m High bund wall andgauging station trench

0

0

200

~ RESOURCES' ""'--

~ 400m n


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4. Attachment 3A: Proposed activities

4.1 Stockyard to E1 Drain

4.1.1 Scope, size and scale

The proposed amendment is to change the dewatering infrastructure (Figure 2). Construction of a new drain will intersect the existing stormwater drain at approximately 468.2 RL and divert water through the eastern edge of Stockyard 5 and 9 where it will enter the E1 (at approximately 464.4 RL) pit for settlement. The E1 pit void volume capacity is up to 466.5RL. The discharge rate will be at 250L/s which allows approximately 21 days for the void to reach capacity (without considering evaporation and ground dissipation). Water will then flow into the outflow structure for discharge into WWC through the existing discharge point DDL4. Water volume will be captured via a gauging station flow meter.

4.1.2 Key infrastructure and equipment

The following changes to onsite infrastructure will include:

Table 2: Key infrastructure requirements Infrastructure Design/Construction requirements Site plan reference

Drain • depth of the drain starts from ~0.5mto 2m where it intersects the pit with 1:100 slope towards the pit • base will be 1m wide with a batterangle of 30° • rip rap will be rock pitched intostream training areas and keyed into place • further rip rap laid into place to slowand turn water flow to relieve sediment before out flow at each end • windrows of 1.5 m to be installedalong drain

Figure 3

Figure 5

E1 spillway structure to DDL4 • pit crest low point (approximately465.2RL) is below intended outflow (465.9RL). 2m high bund wall built to channel flow to outflow • E1 outflow to have funnel area withrip rap to prevent erosion • outflow funnelled into a trenchspillway to DDL4 (0.3% grade). May require geo-fabrication and windrow to increase volume. • flow meter gauging station installedin the trench spillway

Figure 5

Figure 6

Figure 7

Figure 8



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Figure 3: Cross section of drain design1

1 Cross section of 1.0m wide and a batter angle of 30° (orange line).

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Figure 4: Drain connecting to E1 pit void schematic

ept

l y

l... x /_~ ~466RL Spillway earth work

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Figure 5: E1 outflow long section2

2 E1 outflow to have funnel area (orange line) and a bund (green line) to be constructed to raise the RL of the ‘natural’ spill above the out flow RL.

463.5RL

465.88R 465.85R

466.1RL 466.0RL

464.0RL

Figure 6: E1 outflow design

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Figure 7: E1 outflow design showing bund wall, funnel area and trench spillway to DDL4

Figure 8: Example of flow meter for trench spillway to measure discharge volume

CREST LOW POINT 465.2RL

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4.1.3 Description of processes

Dewatering of the underlying aquifer is required for safe, dry pit excavation. During the Life-of-Mine (LOM), mine dewater will be used for dust suppression, domestic use at the offices, and excess disposed to WWC.

Dewatering currently occurs via production bores and in-pit sumps, with surplus dewater pumped to a pipeline and discharged to a tributary to WWC through an outfall structure (DDL4). The water from the tributary channel flows to the adjacent WWC line.

In the event of a significant flow event, contingency stormwater is diverted from the central mine pit via a drain to a sedimentation point prior to discharge at W1. This drain will be utilised to divert both surplus in-pit sump dewater and contingency stormwater into the E1 pit prior to discharge to DDL4. This method provides greater water capacity to accommodate the increased dewater supply and greater retention time for sediment in the water to settle.

Sump water pumping to E1 will be at approximately 250L/s.

No change will be made to the current dewatering pipeline infrastructure to DDL4. This line will continue to be used to transport production bore dewater to the discharge at DDL4. The new drain will be utilised for in-pit sump water (and storm water runoff) only.

4.1.4 Emission/discharge points

The inflow to E1 pit will be from the new drain (at approximately 464.4 RL). Outflow water from the E1 pit is to be funnelled into a trench spillway (Figure 7) to the existing approved discharge point DDL4 (Table 2.2.1 L8859/2014/1).

The discharge point W1, previously used to discharge contingency stormwater in the event of a significant flow event, will no longer be used. In the event of a significant rainfall, water will flow via the drain to E1 and then be discharge via DDL4.

Licence L8859/2014/1 sets a limit for mine dewatering at 17GL/year, stipulates the surface water emission points for the dewatering of the mine pits and requires a report on the cumulative volumes discharged during dewatering in the Annual Environmental Report. Impacts as a result of discharge will be managed under the required MS 1044 condition environmental management plan (CEMP; Appendix 1) and Licence L8859/2014/1. Discharge locations, monitoring and reporting will remain the same. Related monitoring includes discharge volume, annual aquatic fauna monitoring, annual groundwater dependant ecosystem monitoring and monthly monitoring of toxicants and physio-chemical stressors in water discharged to WWC, including the analytes detailed in Table 3:



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Table 3: CEMP Dewater water quality monthly analysis

4.1.5 Waste storage/disposal locations

There is no additional waste storage or disposal related to the Licence Amendment application. All waste storage and disposal will remain as per the existing approved operations (MS 1044 and L8859/2014/1).

4.1.6 Construction, commissioning and operations activities

Construction, commissioning and commencement of operations of the proposed dewatering infrastructure is planned to occur following approvals.

Construction shall consist of clearing and grading the drain channel, channel construction and bund development. Part of the drain already exists as part of the W1 drain structure and the remaining drain channel construction is to be situated within previously disturbed areas and no additional clearing of native vegetation will be undertaken. Existing site waste facilities shall be used with no significant change to waste management practises.

Commissioning shall consist of testing the drain and E1 outflow equipment and infrastructure, including stream flow gauge meters and drain and culvert inspections to ensure drain integrity.

Operational activities shall consist of discharge of dewater, and quarterly inspections of dewatering infrastructure and pit. Maintenance shall occur as required, and any incidents shall be reported as per the Iron Valley Incident Reporting Procedure.

Analyte Notes ANZECC/ ARMCANZ

Trigger Criteria1 Threshold Criteria' (2000) 95% TV

Alkalinity (as CaCOa) np 300 386

Boron (B) T 0.37 0.37 1.3

Electrical Conductivity (µS/cm} 250-900 940 1930

Iron (Fe} T 0.3 0.3 1.0

Hardness (as CaCOa} np 360 470

Magnesium (Mg) np 54 70

Nitrate-nit rit e nitrogen (N-NOX} (eutrophication} 0,03 0.4 1.0

Nit rate (NO3) T, N 11 11 17

Nit rogen-total {eutrophication) 0.3 0.7 3.1

Phosphorus-t otal (eutrophicat ion) 0.01 0.02 0.1

pH-field (H'} 6.0-8.0 7.5-8.1 6.0-8.4

Sulphate (S-SO4) np 60 71

Strontium (Sr) T np 0.19 0.22

Total Dissolved Solids (TDS} - Surface Water SSTV np 520 1100

Total Dissolved Solids (TDS} - Groundwater SSTV np 5203 6223

Total Suspended Solids (TSS} np 5 17

Zinc {Zn) T, H 0.008 0.008 0.031

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5. Attachment 5: Other approvals and consultation documentation

5.1 DWER Approvals A Native Vegetation Clearing Permit is not required, as all activity will occur on previously disturbed areas.

5.2 Environmental Protection Act 1986

5.2.1 Part IV referral and assessment

The Proposal has not been referred to the EPA pursuant to Part IV of the Environmental Protection Act 1986 (EP Act), as it was concluded that the impact of clearing activities, construction and mining operations could be adequately managed under Part V of the EP Act.

5.2.2 Existing Part IV approvals

Iron Valley is approved under Ministerial Statement No. 1044 (MS 1044). BCI applied under Section 45C (s 45C) of the EP Act in November 2018 to amend MS 1044. The proposed amendment is to increase the volume of mine dewatering, and the subsequent dewater discharge into a tributary of Weeli Wooli Creek (WWC).

5.3 Environment Protection and Biodiversity Conservation Act 1999 The Project does not impact any Matters of National Environmental Significance, therefore referral to the Department of the Environment and Energy (DEE) is not required.

5.4 Mining Act 1978 Mining Proposal applications will be submitted for approval. The Project is operating under approved Mining Proposals.

5.5 Stakeholder consultation Consultation with relevant stakeholders will occur as part of this application.



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6. Attachment 6A: Emissions and discharges

6.1 Sources The main emission source from the proposed activities is the discharge of water and dust emissions.

6.1.1 Dewatering

Surplus mine dewater from operations is currently discharged into WWC at a six-monthly average rate of 16.3 GL/yr through DDL4 (approximately 96% of the amount approved under MS 1044 and L8859/2014) (Golder 2018). Abstraction and discharge volumes are proposed to increase. A full assessment of the potential environmental impacts of this increase in dewater was undertaken as part of the s 45C application which was submitted to the EPA in November 2018 (Preston Consulting 2018) and the Licence Amendment submitted to DWER in December 2018 (18111669-002-L-Rev0).

Groundwater quality in the region is considered to be fresh to marginal in terms of salinity and slightly alkaline. The salinity of groundwater may vary seasonally and is dependent on the overall water balance within the local catchment. The orebody is a major aquifer and is linked to WWC via a fault line, and with it, offering good water conductivity. As a result, the surface water quality is relatively similar in water chemistry to that of the groundwater. Dewatering currently occurs via production bores and in-pit sumps, with surplus dewater pumped to a pipeline and discharged to a tributary to WWC through the DDL4 outfall structure. The water from the tributary channel flows to the adjacent WWC line. To allow for the increased water production rate of 42GL for BWT mining, a combination of production bores and in-pit sumps will be utilised, in conjunction with the drain infrastructure to E1 and DDL4 outfall in addition to the existing pipeline which is at full capacity. This will allow for reduced sedimentation in the dewater to WWC.

6.1.2 Stormwater

The volume of stormwater that may enter each mine pit has been estimated for a range of 72- hour design storms, including the 1:1-yr, 1:50-yr, and 1:100-yr Average Recurrence Interval (ARI) storm events. The potential peak flow from a 1:100 ARI has been calculated as 306 m3/s from the Iron Valley Catchment. The peak flow for the Weeli Wooli Catchment is 5,684 m3/s. As stormwater run-off can be contaminated by heavy sediment loads, hydrocarbon and other chemicals it is currently diverted to sedimentation ponds prior to discharge at W1. This system will be replaced by the E1 pit drain and retention system to DDL4 to contain any stormwater containing higher sediment loads.

6.1.3 Dust Emissions

Minimal fugitive dust emissions are expected for the following activities: • construction involving clearing and vehicle movements • operations involving vehicle movements for material distribution, monitoring and any maintenance work

required.

6.2 Impact to Ecological Receptors

6.2.1 Discharge of water

Discharge via DDL4 to WWC will continue to occur under the conditions outlined in MS 1044 and Licence L8859/2014. This involves the discharge of up to 17 GL/yr of surplus dewater into WWC via three separate on-site dewater discharge locations (DDL1, DDL4, and DDL5). Based on current mine planning, discharge is only occurring at DDL4 and will remain at this location.

The volume of stormwater runoff that may enter each mine pit has been estimated for a range of 72-hr design storms, including the 1:1-yr, 1:50-yr, and 1:100-yr Average Recurrence Interval (ARI) storm event. Dewatering infrastructure has been designed to account for these significant stormwater events and therefore reduce the risk of inadvertent discharge due to spillage or overtopping. As detailed in the CEMP, impacts to ecological receptors as a result of discharge to WWC include:

• groundwater dependent riparian vegetation



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• aquatic fauna • surface water quality • groundwater quality.

Discharge of water will continue at DDL4. Potential impacts to ecological receptors within WWC will continue to be monitored in accordance with the conditions set out in the CEMP and L8859/2014.

The CEMP (Appendix 1) was developed to fulfil the requirements of MS 1044 Condition 5: Environmental Factor Guideline; Inland Waters and Flora and Vegetation - dewatering, discharge of surplus water, riparian and groundwater dependent vegetation. This CEMP outlines a monitoring regime, trigger criteria and threshold criteria to ensure the following environmental outcomes are met: 1. Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does

not cause long term impacts to the environmental values of WWC. 2. Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does

not cause long term impacts on the aboriginal heritage values linked to the physical and/or biological surroundings of WWC.

3. Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does not cause long term impacts on the health or cover of riparian and groundwater dependent vegetation within the Drainage Line Exclusion Zone and outside the approved Development Envelope

Table 4 summarises the monitoring parameters and regime outlined in the CEMP.

Table 4: Monitoring to measure environmental outcome against trigger/threshold criteria (as outlined in CEMP [Appendix 1])

Criterion Parameters Location Frequency

Criteria 1: guidelines for toxicants in water

Toxicants in water as outline in Appendix 1 of CEMP (Appendix 1)

1. Discharge outlet. 2. Compliance or

contingency site in the main channel of WWC.

3. Upstream control monitoring site.

Monthly for the life of the mine.

Criteria 2: guidelines for physico-chemical stressors

Physico-chemical stressors in water as outlined in Appendix 1 of CEMP (Appendix 1)

1. Discharge outlet. 2. Compliance or

contingency site in the main channel of WWC.


Monthly for the life of the mine.

Criteria 3: guidelines for aquatic fauna assemblage

Aquatic fauna assemblages include: Hyporheic fauna: • species richness • composition. Macroinvertebrates: • species richness • composition. Fish: • species richness

Three groups of sites: 1. Five replicate potential

exposed sites in WWC downstream of the Iron Valley dewatering discharge, but within the Iron Valley wetting front.

2. Five replicate control sites in WWC upstream of the Iron Valley dewatering discharge.

3. Three Suitable local and/or regional analogue reference sites.

Annual (wet season) for life of mine operations, commencing post-discharge wet season 2018. Targeted (if repeat water quality exceedance). One-off during closure / Post closure

Monitoring of volumetric flow rate (cumulative) will continue as per Condition 3.2.1 of Licence L8859/2014.

6.2.2 Dust

The drain channel will be located within a previously disturbed area, so minimal dust emissions are expected in association with clearing.

During construction and operations, dust suppression along unsealed roads and coarse reject operational areas will effectively minimise dust emissions. Existing roads will be used for all activities.



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7. Risk Assessment In accordance with DWER’s Guidance Statement: Environment Risk (February 2017) an assessment has been undertaken of the risk of emissions and discharges associated with the change in dewatering discharge infrastructure. Potential sources, pathways and impacts to receptors have been identified in this process.

7.1 Risk Assessment Framework Table 5 (risk analysis matrix), Table 6 (consequence and likelihood criteria) and Table 7 (risk treatment protocol) outline the risk assessment matrix and criteria used by DWER to evaluate the risk of adverse impacts to public health and the environment. The outcomes of the risk assessment are provided below in Table 8.

Table 5: Risk analysis matrix (DWER 2017)

LIKELIHOOD CONSEQUENCE

Slight Minor Moderate Major Severe Almost Certain Moderate High High Extreme Extreme Likely Moderate Moderate High High Extreme Possible Low Moderate Moderate High Extreme Unlikely Low Moderate Moderate Moderate High Rare Low Low Moderate Moderate High

Table 6: DWER consequence and likelihood criteria Likelihood Consequence

The following criteria will be used to determine the likelihood of the risk / opportunity occurring.

The following criteria will be used to determine the consequences of a risk occurring:

Environment Public Health* and Amenity (such as air and water quality, noise and odour)

Almost Certain

The event is expected to occur in most circumstances

Severe • on-site impacts: catastrophic • off-site impacts local scale:

high level or above • off-site impacts wider scale:

mid-level or above • mid to long term or permanent

impact to an area of high conservation value or special significance^.

Specific Consequence Criteria (for environment) are significantly exceeded.

• loss of life • adverse health effects: high

level or ongoing medical treatment

• Specific Consequence Criteria (for public health) are significantly exceeded.

local scale impacts: permanent loss of amenity.

Likely

The event will probably occur in most circumstances

Major • on-site impacts: high level • off-site impacts local scale:

mid-level • off-site impacts wider scale:

low level • Short term impact to an area of

high conservation value or special significance^.

Specific Consequence Criteria (for environment) are exceeded.

• adverse health effects: mid-level or frequent medical treatment

• Specific Consequence Criteria (for public health) are exceeded.

local scale impacts: high level impact to amenity.

Possible The event could occur at some time

Moderate • on-site impacts: mid-level • off-site impacts local scale:

low level • off-site impacts wider scale:

minimal. Specific Consequence Criteria (for environment) are at risk of not being met.

• adverse health effects: low level or occasional medical treatment

• Specific Consequence Criteria (for public health) are at risk of not being met.

local scale impacts: mid-level impact to amenity.

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Likelihood Consequence

Unlikely The event is unlikely to occur

Minor • on-site impacts: low level • off-site impacts local scale:

minimal • off-site impacts wider scale:

not detectable. Specific Consequence Criteria (for environment) likely to be met.

• on-site impacts: mid-level • off-site impacts local scale:

low level • off-site impacts wider

scale: minimal. Specific Consequence Criteria (for environment) are at risk of not being met.

Rare The event may only occur in exceptional circumstances

Slight • on-site impact: minimal. Specific Consequence Criteria (for environment) met.

• on-site impacts: low level off-site impacts local scale: minimal.

Table 7: Risk treatment protocol Risk Rating Acceptability Treatment

Extreme Unacceptable Risk event will not be tolerated. DWER may refuse application.

High May be acceptable. Subject to multiple regulatory controls

Risk event may be tolerated and may be subject to multiple regulatory controls. This may include both outcome-based and management conditions.

Moderate Acceptable, generally subject to regulatory controls

Risk event is tolerable and is likely to be subject to some regulatory controls. A preference for outcome-based conditions where practical and appropriate will be applied.

Low Acceptable, generally not controlled

Risk event is acceptable and will generally not be subject to regulatory controls.



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7.2 Risk assessment results

Table 8 shows the proposed controls and the residual risk after implementation of controls.

Table 8: Risk assessment Activity Emission Receptor Pathway Potential impact Controls Consequence Likelihood Risk

Discharge of E1 pit water to WWC via DDL4

Water emissions

Fauna Flora Surface water quality

Discharge at DDL4

Flora and fauna health Surface water quality

• Discharge of water will continue to be undertaken in accordance with current Part IV (MS 1044) and Part V approvals (L8859/2014) • Monitoring of WWC ecological receptors will continue to be undertaken in accordance with current Part IV (MS 1044) and Part V approvals (L8859/2014) • Dewatering infrastructure will increase water retention time and decrease sediment discharge • Groundwater from the Iron Valley mine site is similar to the surface water flow sampled in WWC. The disposal of the excess water to the Creek system is not expected to have a material impact on the water quality

Minor Unlikely Moderate

Discharge of dewater to E1 pit

Water emissions

Water quality Discharge into E1 pit

Change to surface water quality

• Continual monitoring of water quantity and quality discharged into E1 pit • Monitoring of seepage via monitoring bore MBK (located at the Southern end of E1 pit) • Rock armouring installed at various points along the drain and the slope design prevents scouring and erosion • Dewatering discharge is similar in composition to the surrounding aquifer

Slight Unlikely Low

Construction of drain and E1 earthworks

Air emissions – dust

Vegetational Dust emissions

Vegetation health

• The Dust Management Plan will be implemented • No clearing is required as all activities are within a previously disturbed area • Dust suppression techniques, including the application of water or appropriate suppressants to dry surfaces, as required • Vehicle speeds on unsealed roads will be controlled to minimise dust generation from road surfaces • Minimum separation distances or load heights between excavator and trucks may be incorporated into operations procedures

Slight Unlikely Low

{/I!\, strategcn .... -''JBS&G


MRL19351_01 R002 Rev 0

26-Jul-19 23

Activity Emission Receptor Pathway Potential impact Controls Consequence Likelihood Risk

Air emissions – dust

Soil and vegetation Fauna Surface water (WWC)

Wind blown dust

Contamination of vegetation, soil, fauna habitat or surface water

• Area is previously disturbed • Dust suppression techniques, including the application of water or appropriate suppressants to dry surfaces, as required • Vehicles and machinery will only use designated tracks/roads

Slight Unlikely Low

{/I!\, strategcn .... -''JBS&G


MRL19351_01 R002 Rev 0

26-Jul-19 25

8. Attachment 9: Application fee

Figure 9: Works Approval Application fee

I Instrument No.

Proposed Amendment application fee calculator 2018/19 Fee multiplier 6.80

Categories Units Fee 5 - Processing or beneficiation of metallic or non-metallic ore: More than 5 000 000 tonnes per year 450 $3,060.00

6 - Mine dewatering: More than 500 000 tonnes per year 100 $680.00

89 - Putrescible landfill site: Not applicable 24 $163.20

0 $0.00

0 $0.00

0 $0.00

0 $0.00

0 $0.00

0 $0.00

0 $0.00

Note.· Amendment fee is determined by the categoty with the largest fee units !Fee Payable I $3,oso.ool

{ ~ strate gcn ""--iiJBS&G


MRL19351_01 R002 Rev 0

26-Jul-19 26

9. ReferencesGolder (2018), Iron Valley Central Pit Numerical Groundwater Model Report, prepared for Mineral Resources Limited.

Preston Consulting Pty Ltd (2018), Iron Valley Project Application to Amend Ministerial Statement 1044 Under Section 45C of the Environmental Protection Act 1986, prepared for BCI Minerals Ltd by Preston Consulting Pty Ltd.

{~ strategcn ... .,-iJBS&G

Appendix 1 Condition Environmental Management Plan (CEMP)

REVISED IRON VALLEY IRON ORE PROJECT MS1044

CONDITION ENVIRONMENTAL MANGEMENT PLAN

MRL-IV-CEMP-001

MINERAL RESOURCES

Iron Valley CEMP – MS1044

Issue Date: 8/03/2017 MRL-IV-CEMP-001 Page 2 of 61

Printed copies of this document are not controlled. Please ensure that this is the latest available version before use.

Revision

Number Issue Date Prepared By Approved By Signature

01 8/03/2017 K.Allan P.Currie

02 24/08/2017 K.Allan P.George

03 22/10/2018 L. Purves T. Berryman

I I




TABLE OF CONTENTS

1. SUMMARY .................................................................................................................................................. 5

2. CONTEXT, SCOPE AND RATIONALE ............................................................................................................ 8

2.1 Project Description .......................................................................................................................... 8

2.2 Key Environmental Factors addressed in this CEMP ....................................................................... 8

2.3 Requirements of the condition ..................................................................................................... 10

2.4 Rationale and approach in meeting the Environmental Objective ............................................... 13

2.4.1 Heritage ................................................................................................................................... 13

2.4.2 Inland Waters .......................................................................................................................... 13

Results of (baseline surveys/modelling/scientific studies/tests) conducted ................... 13

Key assumptions and uncertainties .................................................................................. 19

Management approach .................................................................................................... 20

Rationale for deriving SSTVs for protection of aquatic ecosystems ................................. 22

Rationale for choice of trigger level actions and threshold contingency actions ............ 23

2.4.3 Flora and Vegetation ............................................................................................................... 24

Results of (baseline surveys/modelling/scientific studies/tests) conducted ................... 24

Key assumptions and uncertainties .................................................................................. 29

Management approach .................................................................................................... 29

Rationale for choice of environmental criteria................................................................. 30

Rationale for choice of trigger level actions and threshold contingency actions ............ 31

3. CEMP PROVISIONS ................................................................................................................................... 32

3.1 Monitoring ..................................................................................................................................... 35

3.1.1 Inland Waters .......................................................................................................................... 35

Monitoring sites ................................................................................................................ 35

Sampling frequency .......................................................................................................... 36

Target bioindicators of ecosystem health ........................................................................ 36

Reviewing and Interpreting Monitoring Data ................................................................... 37

3.1.2 Riparian and groundwater dependent vegetation monitoring program ................................ 42

3.2 Actions ........................................................................................................................................... 47

3.2.1 Inland Waters .......................................................................................................................... 47

Implementation of Trigger Level Actions ......................................................................... 47

Implementation of Threshold Contingency Actions ......................................................... 48

3.2.2 Flora and Vegetation ............................................................................................................... 49

Implementation of Trigger Level Actions ......................................................................... 49

2.4.2.1

2.4.2.2

2.4.2.3

2.4.2.4

2.4.2.5

2.4.3.1

2.4.3.2

2.4.3.3

2.4.3.4

2.4.3.5

3.1.1.1

3.1.1.2

3.1.1.3

3.1.1.4

3.2.1.1

3.2.1.2

3.2.2.1

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Implementation of Threshold Contingency Actions ......................................................... 52

4. Reporting provisions ................................................................................................................................ 55

4.1.1 Reporting on exceedance of trigger criteria and threshold criteria ........................................ 55

5. ADAPTIVE MANAGEMENT AND REVIEW OF THE CEMP .......................................................................... 56

6. Stakeholder Consultation ........................................................................................................................ 57

7. References ............................................................................................................................................... 58

8. APPENDICES ............................................................................................................................................. 59

LIST OF TABLES

TABLE 1-1: PROJECT DETAILS ............................................................................................................................. 6

TABLE 2-1: INLAND WATERS ASPECTS AND IMPACTS ....................................................................................... 9

TABLE 2-2: FLORA AND VEGETATION ASPECTS AND IMPACTS ....................................................................... 10

TABLE 2-3: MS1044 CONDITIONS RELATING TO THE DEVELOPMENT OF THE CEMP ..................................... 11

TABLE 2-4: SUMMARY OF BASELINE SURFACE WATER AND GROUNDWATER QUALITY DATASETS USED TO

DERIVE THE REVISED SSTVS AND OPERATIONAL WATER QUALITY GUIDELINES FOR IRON VALLEY

DEWATERING DISCHARGE. .............................................................................................................................. 17

TABLE 3-1: INLAND WATERS TRIGGER AND THRESHOLD CRITERIA ................................................................ 33

TABLE 3-2: FLORA AND VEGETATION TRIGGER AND THRESHOLD CRITERIA ................................................... 34

TABLE 3-3: MONITORING TO MEASURE THE ENVIRONMENTAL OUTCOME AGAINST TRIGGER/THRESHOLD

CRITERIA OUTLINED IN TABLE 3-1. .................................................................................................................. 37

TABLE 3-4: MONITORING METHODS IN THE RIPARIAN AND GROUNDWATER DEPENDANT VEGETATION

MONITORING PROGRAM ................................................................................................................................ 46

TABLE 3-5: MONITORING TO MEASURE THE EFFICIENCY OF ENVIRONMENTAL OUTCOMES FOR RIPARIAN

AND GROUNDWATER VEGETATION AGAINST TRIGGER CRITERIA .................................................................. 50

TABLE 3-6: MONITORING TO MEASURE THE ENVIRONMENTAL OUTCOMES FOR RIPARIAN AND

GROUNDWATER DEPENDANT VEGETATION AGAINST THRESHOLD CRITERIA ................................................ 53

LIST OF FIGURES

FIGURE 1: LOCATION OF THE DOLERITE DYKE................................................................................................. 15

FIGURE 2: MINOR WATERCOURSES TRAVERSING THROUGH THE PROJECT ................................................... 16

FIGURE 3: PROCEDURES FOR DERIVING TRIGGER VALUES FOR PROTECTION OF AQUATIC ECOSYSTEMS

(REPRODUCED FROM ANZECC/ARMCANZ (2000) AUSTRALIAN WATER QUALITY GUIDELINES) .................... 18

FIGURE 4: DECISION SUPPORT FLOW CHART FOR ASSESSING AND RESPONDING TO EXCEEDANCE OF

OPERATIONAL GUIDELINES (SSTVS) FOR DEWATERING DISCHARGE FROM IRON VALLEY ............................. 21

FIGURE 5: DECISION SUPPORT FLOW CHART FOR MANAGEMENT RESPONSE TO ACTION TRIGGER FOR THE

IRON VALLEY PROJECT ..................................................................................................................................... 22

FIGURE 6: IRON VALLEY MINE GROUNDWATER ABSTRACTION AND DISCHARGE RISK MODEL ..................... 26

FIGURE 7: IRON VALLEY AND CUMULATIVE IMPACTS GROUNDWATER ABSTRACTION AND DISCHARGE RISK

MODEL ............................................................................................................................................................. 27

FIGURE 8: LOCATION OF COMPLIANCE, CONTINGENCY AND DISCHARGE MONITORING LOCATIONS IN

RELATION TO THE PRELIMINARY MODELLED WETTING FRONT EXTENT ........................................................ 39

3.2.2.2

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FIGURE 9. MAP SHOWING SPATIAL SAMPLING EXTENT UPSTREAM AND DOWNSTREAM OF THE IV

DISCHARGE OUTLET. EXACT SITE LOCATIONS WILL VARY DEPENDING ON EXTENT OF SURFACE FLOWS AT

THE TIME OF SAMPLING .................................................................................................................................. 40

FIGURE 10. MAP SHOWING NOMINAL SITE LOCATIONS FOR REGIONAL REFERENCE SITES SAMPLED AS PART

OF THE AQUATIC FAUNA MONITORING PROGRAM. EXACT SITE LOCATIONS WILL VARY DEPENDING ON SITE

ACCESS / CONDITIONS EACH YEAR. ................................................................................................................. 41

FIGURE 11: MONITORING TREES AND WEED MONITORING PLOTS AT THE DRAINAGE EXCLUSION ZONE

MONITORING SITE WITHIN THE RIPARIAN AND GROUNDWATER DEPENDANT VEGETATION MONITORING

PROGRAM ........................................................................................................................................................ 43

FIGURE 12: MONITORING SITES IN THE MARILLANA/WEELI WOLLI SYSTEM WITHIN THE RIPARIAN AND

GROUNDWATER DEPENDANT VEGETATION MONITORING PROGRAM.......................................................... 44

1. SUMMARY This Condition Environmental Management Plan (CEMP) is prepared and implemented for the Revised Iron Valley Below Water Table (BWT) Iron Ore Project (the Project) in accordance with Ministerial Statement No.1044, Condition 5.

Table 1-1 below presents the environmental criteria to measure achievement of the conditioned environmental outcome that must be met through implementation of this CEMP.

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Table 1-1: Project Details

Title of Project Revised Iron Valley Iron Ore Project

Proponent BC Pilbara Iron Ore Pty Ltd

Ministerial Statement No 1044

Purpose of this CEMP To fulfil the requirements of MS1044 Condition 5: Environmental Factor Guideline;

Inland Waters and Flora and Vegetation - dewatering, discharge of surplus water,

riparian and groundwater dependent vegetation

EPA’s environmental objective

for the key environmental

factor/s

Inland Waters

To maintain the hydrological regimes and quality of groundwater and surface water

so that environmental values are protected

Flora and Vegetation

To protect flora and vegetation so that biological diversity and ecological integrity are

maintained

Condition environmental

outcomes

1. Groundwater abstraction and/or surplus dewater discharge from the

implementation of the Proposal does not cause long term impacts to the

environmental values of Weeli Wolli Creek


implementation of the Proposal does not cause long term impacts on the aboriginal

heritage values linked to the physical and/or biological surroundings of Weeli Wolli

Creek


implementation of the Proposal does not cause long term impacts on the health or

cover of riparian and groundwater dependent vegetation within the Drainage Line

Exclusion Zone and outside the approved Development Envelope

Environmental Criteria –Inland Waters

Trigger Criteria

Trigger criterion 1: Ensure water discharged to WWC does not exceed specified

surface water quality trigger values for toxicants outlined in Appendices Table A1.

Monitoring actions for management in relation to Trigger Criterion 1 are outlined in

Table 3-3.

Trigger Criterion 2: Ensure water discharged to WWC does not result in a statistically

significant repeat exceedance (12-month rolling median) of the specified water

quality trigger values for physico-chemical stressors outlined in Appendices Table A1.

Monitoring actions for management in relation to Trigger Criterion 2 are outlined in

Table 3-4.

Trigger Criteria 3: Ensure aquatic fauna overall impact rating does not exceed

specified trigger value (i.e. Low Impact) outlined in Appendices Table A2. Monitoring

actions for management in relation to Trigger Criterion 3 are outlined in the Aquatic

Fauna Management Plan.

Threshold criteria Threshold Criterion 1: Ensure water discharged to WWC does not exceed specified

surface water quality threshold values for toxicants outlined in Appendices Table A1.

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Threshold Criterion 2: Ensure water discharged to WWC does not result in a

statistically significant repeat exceedance (12-month rolling median) of the specified

water quality threshold values for physico-chemical stressors outlined in Appendices

Table A1.

Threshold Criterion 3: Ensure aquatic fauna overall impact rating does not exceed

specified threshold value (i.e. High Impact) outlined in Appendices Table A2

Environmental Criteria – Flora and Vegetation

Trigger Criteria

Trigger criterion 1: Significant decrease in riparian tree health rating measured on-

ground at one or more drawdown/discharge sites when compared to reference sites

and decrease greater than 2 standard deviations of baseline rating

Trigger criterion 2: Decrease beyond 2 standard deviations of baseline for remote

sensing vegetation condition index of riparian trees across the drawdown/discharge

zone and the decrease is greater than across the reference zone

Trigger criterion 3: Significant increase in distribution or cover of weeds measured on-

ground at one or more drawdown/discharge sites when compared to reference sites

AND

increase greater than a 25% increment in distribution (frequency) or cover from

baseline at any one site

Trigger criterion 4: New weed species recorded at any drawdown/discharge site

Threshold criteria

Threshold criterion 1: Significant decrease in riparian tree health rating measured on-

ground across the drawdown/discharge sites when compared to reference sites and

decrease greater than 3 standard deviations of baseline rating

Threshold criterion 2: Significant increase in cover or distribution of weeds measured

on-ground across the drawdown/discharge sites when compared to reference sites.

AND

Increase greater than a 10% increment in cover or distribution (frequency) from

baseline across the drawdown/discharge sites

Threshold criterion 3: A new weed species increases in frequency of occurrence to

exceed 25% at any drawdown/discharge site

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2. CONTEXT, SCOPE AND RATIONALE

2.1 Project Description

The Project is located approximately 90 km north-west of Newman in the east Pilbara region of Western Australia. The Minister for the Environment issued Ministerial Statement No.1044 (MS1044) on the 8th December 2016 (revision of MS 933 dated 1st February 2013) allowing implementation of the IV IOP. Schedule 1 of MS1044 currently allows for groundwater abstraction of up to 23 GL/a and dewater discharge of up to 17 GL/a into Weeli Wolli Creek (WWC). A revised proposal to the existing MS1044 has been submitted to Department of Water and Environmental Regulation (DWER) (under section 45c of the Environmental Protection Act 1986 (EP Act 1986)) to allow for modifications to enable the following changes:

1. Increase water abstraction of groundwater from 23 GL/a up to 42 GL/a.

2. Increase surface discharge of surplus dewatering water to WWC from 17 GL/a to 42 GL/a.

The development envelope of the Project is located within the Nyiyaparli Native Title Claim, who continues to be consulted regarding the Project.

2.2 Key Environmental Factors addressed in this CEMP

As determined by the EPA, Flora and Vegetation, and Inland Waters were considered Key Environmental Factors for the Project for the reasons stated below.

Inland Waters

The Project will result in changes to the hydrogeology and water quality of the aquifer in the area, and the hydrological regime and the water quality of WWC from mine site dewatering, the discharge of up to 42 GL/a of surplus dewater, and run-off and/or seepage from waste rock landforms, and other disturbed areas. Aspects and impacts of inland waters are shown in Table 2-1.

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Table 2-1: Inland waters aspects and impacts

Environmental

Factor

Project Aspect Environmental Aspect Impact

Inland Waters

Mine Pit

Dewatering of aquifer Depletion of aquifer potentially assisting the

intrusion of a saline wedge and subsequent

degradation of groundwater quality from north of

the tenement boundary

Prolonged depletion of aquifer, resulting in

depleted water supplies for existing terrestrial and

aquatic ecosystems and end users

Discharge of pit

dewatering to WWC

Potential change of inland water quality in WWC

from the discharge of mine water from Iron Valley

operations likely to be noticeable within the

wetting front

Increase in quantity of water within WWC

resulting in wetting front extending 5.8km

downstream

Discharge resulting in increased localised

groundwater mounding from sole outlet (DDL4)

Altered aquatic fauna and flora communities due

to changes in hydrological regime and potential for

altered water quality.

Potential impacts on heritage values associated

with WWC

Mine

Infrastructure

Interception of surface

water flows across the

tenement to WWC

Potential for changes to hydrological regime and

subsequent changes in water quantity to

downstream environments

Potential for increased sediment loads in

stormwater runoff generated from site

Flora and Vegetation

Direct impacts from the additional clearing of 314 ha of flora and vegetation and indirect impacts to riparian and groundwater dependent vegetation from changes to the hydrological regime from mine site dewatering and the discharge of surplus dewater into WWC.

Groundwater drawdown due to dewatering and groundwater mounding and the extension of the permanent wetting front in WWC due to the discharge of surplus dewater have the potential to impact on riparian and groundwater dependent vegetation (Table 2-2).

A flora and vegetation survey undertaken in 2012 for the Iron Valley Above Water Table (AWT) Project concluded that there were no Threatened Ecological Communities (TECs), Priority Ecological Communities (PECs), or conservation significant species present within the survey area.

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Table 2-2: Flora and vegetation aspects and impacts

Environmental Factor

Project Aspect Environmental

Aspect

Impact

Flora and

Vegetation

Mine Pit and

Infrastructure

Direct clearance of

vegetation

Clearance of an additional 314 ha, all of which is

considered to be in good to excellent condition

Mine Pit

Dewatering of

aquifer

Change in groundwater availability for

groundwater dependant vegetation

Mine pit water

discharge

Discharge of water to

WWC

Potential changes to riparian vegetation from

periods of inundation

Flourishing of vegetation in some areas due to

increased water permanency within WWC system

Introduction, spread or increase in the

prevalence of weed species.

Potential impacts on heritage values associated

with WWC.

2.3 Requirements of the condition

Specifically, this CEMP is submitted in accordance with Ministerial Statement 1044, Condition 5. The relevant conditions are outlined in Table 2-3 below.

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Table 2-3: MS1044 Conditions relating to the development of the CEMP

5-1

Within 3 months of issue of this Statement or as otherwise agreed in writing by the CEO, the Proponent shall

prepare and submit a Condition Environmental Management Plan/s to the satisfaction of the CEO. These

plan/s shall demonstrate that the following environmental outcomes will be met:

(1) groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal

does not cause long term impacts to the environmental values of Weeli Wolli Creek.


does not cause long term impacts on the aboriginal heritage values linked to the physical and/or biological

surroundings of Weeli Wolli Creek.


does not cause long term impacts on the health or cover of riparian and groundwater dependent vegetation

within the Drainage Line Exclusion Zone and outside the approved Development Envelope as shown in Figure

1.

5-2

The Condition Environmental Management Plan/s shall:

(1) specify the environmental outcomes to be achieved, as specified in condition 5-1;

(2) specify trigger criteria that must provide an early warning that the threshold criteria identified in

condition 5-2(3) may not be met;

(3) specify threshold criteria to demonstrate compliance with the environmental outcomes specified in

condition 5-1. Exceedance of the threshold criteria represents non-compliance with these conditions;

(4) specify monitoring to determine if trigger criteria and threshold criteria are exceeded;

(5) specify trigger level actions to be implemented in the event that trigger criteria have been exceeded;

(6) specify threshold contingency actions to be implemented in the event that threshold criteria are

exceeded;

(7) provide the format and timing for the reporting of monitoring results against trigger criteria and threshold

criteria to demonstrate that condition 5-1 has been met over the reporting period in the Compliance

Assessment Report required by condition 3-6.

5-3

The plan/s required by condition 5-1 shall include provisions required by condition 5-2 to address impacts on

riparian and groundwater dependent vegetation including from, but not limited to: changes to groundwater

levels and groundwater quality; changes to surface water flows (including the location of the wetting front as

depicted in Figure 2 as a trigger criterion) and surface water quality; and weeds.

5-4

After receiving notice in writing from the CEO that the Condition Environmental Management Plan/s satisfy

the requirements of condition 5-2 the Proponent shall:

(1) implement the provisions of the Condition Environmental Management Plan/s; and

(2) continue to implement the Condition Environmental Management Plan/s until the CEO has confirmed by

notice in writing that the Proponent has demonstrated the outcomes specified in condition 5-1 have been

met.

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5-5

In the event that monitoring indicates exceedance of threshold criteria specified in the Condition

Environmental Management Plan/s, the Proponent shall:

(1) report the exceedance in writing to the CEO within 7 days of the exceedance being identified;

(2) implement the threshold contingency actions specified in the Condition Environmental Management

Plan/s within 24 hours and continue implementation of those actions until the CEO has confirmed by notice

in writing that it has been demonstrated that the threshold criteria are being met and the implementation of

the threshold contingency actions is no longer required;

(3) investigate to determine the cause of the threshold criteria being exceeded;

(4) investigate to provide information for the CEO to determine potential environmental harm or alteration

of the environment that occurred due to threshold criteria being exceeded; and

(5) provide a report to the CEO within 21 days of the exceedance being reported as required by condition 5-

5(1). The report shall include: (a) details of threshold contingency actions implemented;

(b) the effectiveness of the threshold contingency actions implemented, against the threshold criteria;

(c) the findings of the investigations required by condition 5-5(3) and 5-5(4);

(d) measures to prevent the threshold criteria being exceeded in the future;

(e) measures to prevent, control or abate the environmental harm which may have occurred; and

(f) justification of the threshold remaining, or being adjusted based on better understanding, demonstrating

that outcomes would continue to be met.

5-6

The Proponent:

(1) may review and revise the Condition Environmental Management Plan/s, or

(2) shall review and revise the Condition Environmental Management Plan/s as and when directed by the

CEO.

5-7

The Proponent shall implement the latest revision of the Condition Environmental Management Plan/s,

which the CEO has confirmed by notice in writing, satisfies the requirements of conditions 5-2 and 5-3.

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2.4 Rationale and approach in meeting the Environmental Objective

Results of baseline surveys and a number of assumptions and uncertainties inform the management approach for meeting the environmental outcomes stated in Section 1. The identified trigger criteria, threshold criteria, trigger level actions and threshold contingency actions are aligned with the overall management approach.

2.4.1 Heritage

The WWC is particularly important and significant to the Nyiyaparli people. The creek supports an ecologically diverse community of floral and faunal species (van Leeuwen 2009) which, in turn, has provided food and medicine for the Nyiyaparli. As a result, the creek has supported life for generations and has played a vital role in the continued survival of the Nyiyaparli people and their continued occupation of the area. The sources of food (fauna and flora) are well distributed along the entire length of the creek and are not limited to specific locations in the creek. The Iron Valley operations will impact the fauna and flora of the creek by adding water to this environment. This will increase the abundance of flora and fauna in some areas and reduce abundance in others due to groundwater drawdown. The dewatering and water disposal will have competing positive and negative impacts which will partly balance each other out. The impacts likely from the Project will be temporary and within ten years of the completion of mining, groundwater and surface water regimes are predicted to be restored to pre-mining status.

Spiritually, the WWC is a central feature of the Dreamtime Yurduba Rainbow Serpent story and song line, which details the path of the serpent as it travelled underground and emerged in the Fortescue Marsh. The underground pathway of Yurduba will not be impacted by the proposal as there is no ground disturbance of the WWC, nor is any impact predicted from the proposal on the Fortescue Marsh.

MRL have not included any trigger or threshold values specifically relating to heritage within this CEMP, but rather will use the monitoring of Ground Dependant Vegetation (GDV), weeds, water quality and aquatic fauna to determine if any impacts have been caused as a result of the Project. If any threshold values stated in the below sections are exceeded, MRL will consult the Nyiyaparli traditional owners.

2.4.2 Inland Waters

Results of (baseline surveys/modelling/scientific studies/tests) conducted

Hydrogeological Investigations

Mineral Resources Limited (MRL) has undertaken field drilling, permeability tests and aquifer tests to define the hydrogeology of the Project area (AQ2, 2016). Regionally, the direction of groundwater flow in the Project area is from south to north.

The following are the key features of the Iron Valley hydrogeology:

• A transmissive, mineralised orebody aquifer

• Saturated, leaky alluvium above the orebody

• Orebody aquifer is surrounded to the east and west by low permeability shales and BIFs

• An east/west dolerite dyke that traverses the northern section of the orebody limiting groundwater flow to the north

• Connection of the orebody to the WWC via the East Fault

• Northern extension of the orebody aquifer connected to the WWC

2.4.2.1

I I




• Prevailing groundwater conditions have been altered by historical and ongoing excess water disposal from upstream mines (RTIO and BHPB)

• Static water levels have been measured ranging from 26 to 43 metres below ground level (mbgl) in the north of the dolerite dyke to 6 to 18 mbgl south of the dyke. The location of the dyke is shown in Figure 1.

• The major surface water feature in the vicinity of the Project area is the WWC. The WWC flows directly north from this point, away from the eastern tenement boundary. WWC is a major Pilbara drainage line which flows into the Fortescue Marsh, which in turn is a nationally designated wetland system and the final receptor of all surface water flows generated in the Upper Fortescue Basin.

Natural perennial flows in the WWC only occur at Weeli Wolli Spring (located approximately 25 km upstream). Artificial perennial flows occur at various locations within the Marillana and Weeli Wolli Catchments as a result of excess groundwater disposal from mine dewatering operations. A number of minor water courses traverse the site with flow in a west to east direction toward the WWC (Figure 2). Stream flow in these tributaries is typically ephemeral, being directly related to intense rainfall events usually associated with cyclonic activity or localised thunderstorms. Surface water flow rates decay rapidly once rainfall has ceased.

I I

Figure 1: Location of the dolerite dyke

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MINING PROPOSAL

IRON VALLEY BELOW WATER TABLE MINING PROJECT

Figure

1

Figure 2: Minor watercourses traversing through the Project

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Prescribed Premise Boundary Tenements - Live Tenement• - Pending Wate<course - Major Watercourse - Minor

Disturbance legend CJ Open Pit ~ Infrastructure Area c;;;;J Was1e Rock Lanc:florms

PROJECT LAYOUT

Author: J. Hesford Date: December 2015




Surface Water and Groundwater Quality

Baseline sampling of background surface water quality has been taken from ephemeral and perennial reaches along WWC during the wet and dry season between 2014-2017 (Table 2-4). The baseline data included values for toxicants (e.g. metals) and stressors (e.g. conductivity, pH, dissolved oxygen, nutrients) for comparison of these concentrations with default ANZECC/ARMCANZ (2000) Australian Water Quality Guidelines for the protection of aquatic ecosystems.

Discharge water quality from the dewatering discharge location, DDL4 has also been taken since dewatering commenced in December 2016 to present.

Table 2-4: Summary of baseline surface water and groundwater quality datasets used to derive the revised SSTVs and operational water quality guidelines for Iron Valley dewatering discharge.

WWC Sampling Program

Location Sampling Period

Sampling Frequency No. of samples

Polaris Metals Spot Sample

Polaris Metals site IV SW North (ephemeral pool)

Feb 2014 One-off 1

WRM Aquatic Fauna Baseline Survey

WRM sites WWC3 to WWC9 (seasonal and/or ephemeral pools)

March 2015 One-off 7

WRM sites WC1 and WWC2 (long-term pools)

March 2015 One-off 2

MRL Baseline Surface Water Quality Sampling

WRM sites WW4-1 and WW4-4 (long-term pools)

June 2016- Oct 2016

One-off 24

MRL Additional Baseline Surface Water Quality Sampling

WRM site WW4-4 (reference long-term pool, upstream)

Jan 2017-Apr 2017

Periodic 5

Dewatering Discharge Sampling Program

Dewatering discharge location 4 (DDL4)

Jan 2017 - Present

Fortnightly for first 3 months, thereafter Monthly

27

Local conditions vary from the conservative default ANZECC/ARMCANZ (2000) guidelines, or trigger values (TVs), as current baseline represents ‘altered’ water quality from cumulative dewater and discharge operations upstream of the Project. Baseline sampling has shown that surface waters upstream of the IV Project Area are elevated in some parameters (electrical conductivity, pH, and nitrogen and phosphorus nutrients). Background values for these parameters often exceed default TVs for protection of 95% of aquatic species. For this reason, site specific trigger levels (SSTVs) are preferable to the default TVs, as depicted in the ANZECC/ARMCANZ (2000) preferred hierarchy for deriving TVs shown in Figure 3.

A site-specific threshold value has been developed separately for the TDS of groundwater that is discharged from active dewatering locations as this is generally fresher than surface water. There are currently 10 dewatering production bores on site, with an average TDS of 480g/L.

I I




Figure 3: Procedures for deriving trigger values for protection of aquatic ecosystems (reproduced from ANZECC/ARMCANZ (2000) Australian Water Quality Guidelines)

As local biological effects data were not available for WWC in vicinity of the Project area, MRL commissioned a preliminary risk assessment that informed the development of interim operational water quality guidelines in November 2016 (WRM 2016). The interim operational guidelines were based on site-specific trigger values (SSTVs) derived in accordance with protocols recommended under the Australian Water Quality Guidelines for Fresh and Marine Waters (ANZECC/ARMCANZ 2000). The SSTVs were developed using baseline data from spot-measurements of water quality in ephemeral and perennial reaches of WWC. These data were collected by Polaris Metals in 2014, WRM in 2015 (as part of baseline aquatic fauna surveys; WRM 2015a), and site MRL environmental staff between June and October 2016.

A hazard analysis (HA) was undertaken following collection of monitoring data post-commencement of discharge, to ascertain actual concentrations in dewatering discharge water and in the downstream receiving environment of WWC. Additional baseline and reference data were collected between August 2016 and April 2017 from two production bores (PB1 and PB2) for revision of the SSTVs as part of the HA. The HA compares post-discharge monitoring data against the SSTVs derived from the 80th percentile value (and 20th percentile for pH and dissolved oxygen) of the baseline and reference water quality data. Water quality analytes in dewatering discharge that were identified in the HA as being of no or negligible risk, with no apparent source from which to become elevated, were omitted from further monitoring. Appendix 1 (Table A1; WRM 2017) presents updated operational water quality guidelines based on this new suite of analytes. For detailed methodology of the HA process and SSTV derivation please see WRM, 2016 and 2017.

More recently, additional groundwater quality monitoring data obtained from ten production bores (September 2016 to August 2018) were provided by IV to provide a better understanding of the ecological risks and hazards associated with discharge of groundwater from the Project to WWC. These data were used to update trigger and threshold criteria accordingly, with revised operational water quality guidelines outlined in Appendix Table A1.

PrPf Prr~d hiPrarcby for dPri ,dng trig·g·er v.afues

Local or site-specifiic infon.mtion

Local b iological effects dab

je-.9. eoo'!llxi~ly 1esls, inclulfllg mlfliple species toxicity tests, 11llE!50CCISllll!">)

Mast preferred

Least preferred

I

Lo cal ,refer ence d'ara

(mainly FD}!Sical and chemical StresSiOGS; for toxicalill:s a nd sedimems, aPfE:es ooly fur !he case li'fflErE!· ba~i:,oond data exceed defallt

YalJes from lhe box inme!futely below)

Default approach

Regional refereoce data

!Physical ;.111d memical slressm; only-see Tailes

3.22 1!o 3.3.11)

Generic effects-based guidelines

(Toxicaris - Table3.4.1 Sediments - Table 3.!d l

I




Aquatic Fauna

Aquatic fauna and faunal habitats likely to be affected by changes in water quality and/or flow were identified from WRM desktop and baseline field surveys of fish and invertebrates (zooplankton, hyporheic & benthic macroinvertebrates) within the project area (see WRM 2015a,b).

The 2015 baseline survey recorded a total of three fish species (Leiopotherapon unicolor, Melanotaenia australis, Neosilurus sp.), 72 microinvertebrate species, 74 hyporheic species (only 4 of which were obligate groundwater species) and 172 macroinvertebrate species. All fish and most of the invertebrate species recorded are common and widespread throughout the Pilbara. No aquatic fauna communities or species listed under the national Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) or state Wildlife Conservation Act 1950 (WC Act) were recorded from the IV project area. However, there were a number of invertebrate species of conservation and/or scientific value:

• Three stygal paramelitid amphipods of conservation significance as short-range endemics (SREs) or possible SREs; Chydaekata sp., Paramelitidae sp. B and sp. D;

• Six species of scientific interest as Pilbara endemics; the copepods Australoeucyclops karaytugi and Mesocyclops holynskae, and the aquatic beetles Haliplus fortescueensis, Laccobius billi, Limbodessus occidentalis and Tiporus tambreyi;

One potentially new cladoceran species, cf. Anthalona sp. (family Chydoridae), of scientific interest, as no species of this recently-erected genus have been described from Australia.

With the exception of Paramelitidae sp. B and sp. D and cf. Anthalona sp., the above species have known local and/or regional distributions outside the influence of dewatering discharge and/or groundwater drawdown from the IV project area and other current and proposed mines. As such, any potential impact to local populations of these species as a result of cumulative dewatering discharge or drawdown is unlikely to affect their regional populations. Paramelitidae sp. B and sp. D and the cladoceran cf. Anthalona sp. occur outside the zone of influence of the Project, however they are known only from locations potentially affected by cumulative dewatering discharge and/or groundwater drawdown from other current and proposed mines.

The first round of wet season post-discharge monitoring was undertaken in May 2018 to assess any change in surface water quality and/or aquatic fauna assemblages from baseline condition, within the receiving environments of dewatering discharge. Results from this study confirm current discharge operations show no evidence of any adverse effects to macroinvertebrates or fish in the receiving environment (see WRM 2018).

Water Quality Trigger Values

Key assumptions and uncertainties

Surface Water and Groundwater Quality

ANZECC/ARMCANZ (2000) state SSTVs are not intended as compliance levels, but, as the name implies, they are a trigger for further investigation (e.g. re-sample) to determine:

i. if the exceedance is still within the historic range, or

ii. if the exceedance represents a short-term event with likely low risk to the environment, requiring no management intervention, or

iii. if the exceedance represents a longer-term trend with moderate to high risk to the environment, requiring management intervention.

2.4.2.2

I I




Operational water quality guidelines based on the SSTVs should therefore not be used as 'pass/fail' compliance criteria. Exceedance of the operational guideline or SSTV does not automatically imply increased toxicity and increased risk to the ecosystem. It does however, warrant investigation into the bioavailability of the analyte and/or the duration and frequency of elevated concentration. Biota may be unaffected by infrequent events that are of short duration, though this may need to be confirmed by supporting field ecological studies.

Additional uncertainties are the extent to which concentrations in discharge waters from the IV mine may be diluted by wet season rainfall, or alternatively, increased by evapoconcentration in remnant pools over the dry season, under an intermittent discharge regime.

As the trigger and threshold values set for TDS of groundwater need to be related to potential impacts on WWC, the water quality of discharge entering the creek from the active dewatering discharge locations is more relevant than the TDS at individual production bores.

Aquatic fauna

The key uncertainties in assessing risk associated with dewatering discharge to WWC are, i) the tolerance of local freshwater species to consistently elevated levels of potential contaminants of concern above SSTVs, and ii) the longitudinal extent and persistence of any bed armouring, should this occur.

Management approach

Threshold actions (see Section 3.2.1.2) will be initiated in the event that environmental targets (water quality & aquatic fauna assemblages) for water discharge are not being achieved. Three trigger levels are used to prompt management responses to protect environmental values. The levels and generic actions are:

Trigger 1: Focus - establish a watching brief. Determine the cause of the trigger level exceedance. Determine whether the trigger event is the effect of mining activities or caused by changes in the natural environment. The focus trigger ensures that appropriate monitoring and management attention is given to the event or issue. No significant or irreversible environmental impacts are foreseen.

Trigger 2: Investigate - detailed investigation required. Causal investigations to be undertaken with increased monitoring focus. The investigate trigger ensures that the event or issue is understood, and appropriate response measures are developed. No significant or irreversible environmental impacts are foreseen.

Trigger 3: Action - highest investigation level with advisory notification of event or issue to regulatory agencies, the Nyiyaparli traditional owners and other appropriate stakeholders. Active intervention/management measures required. The action trigger is to ensure appropriate countermeasures are deployed.

Surface Water Quality

The proposed decision support framework for applying operational SSTVs for toxicants and chemical stressors is shown in Figure 4 & 5.

2.4.2.3

I I




Figure 4: Decision support flow chart for assessing and responding to exceedance of operational guidelines (SSTVs) for dewatering discharge from Iron Valley

Note, for the first three months following commencement of dewatering discharge into the rivers, fortnightly monitoring was undertaken, where possible. Following this, the frequency of monitoring reduced to monthly sampling

Is a single value ≥95%ile of baseline data or

≥ANZECC default 90% species protection

level TV (w hichever is higher)?

No Low

risk

CHECK STATISTICAL SIGNIFICANCE

Is the median statistically higher than the SSTV (i.e. test using a one-tailed non-parametric ‘t-test’, w ith signif icance level p = 0.1)?

NoLow

risk

Yes

No Low risk

MO

NIT

OR

FO

CU

SA

CT

ION

INV

ES

TIG

AT

E

Yes

NoLow

risk

Seek expert advice. Is there increased risk

to biota?

No

No

Yes

ROUTINE WATER QUALITY MONITORING

Monthly sampling at Compliance Sites

CHECK VALUES AGAINST SSTVs

Analyse monitoring data each month

TOXICANTS (e.g. NO3, N-NH3, metals, pesticides)

Does the rolling 12 month median exceed

the SSTV?(use hardness modif ied TV for metals Cd, Pb, Ni, & Zn)

Yes

Yes

RESAMPLE TO CONFIRM EXCEEDANCE

Does the value still exceed the SSTV, local baseline and reference sites? Consider seasonal variation.

STRESSORS(e.g. nutrients (N-NOx, N-NH4, N-total, P-total, P-SR), pH, EC,

TDS, temp.)Does the rolling 12

month median exceed the SSTV?

Yes

CHECK STATISTICAL SIGNIFICANCE

Is the median statistically higher than the SSTV (i.e. test using a one-tailed non-parametric ‘t-test’, w ith signif icance level p = 0.05)?

INSTIGATE INTERNAL REPORTINGASSESS RISK

Yes

Yes

No

NoLow

risk

Low

risk

NoLow

risk

NoLow

risk

METALS & OTHER TOXICANTSSeek expert advice on biota

sensitivities versus concentrations, metal speciation,

labile concentrations etc?

NON-COMPLIANCEINSTIGATE EXTERNAL REPORTING

INVESTIGATE RISK

Yes

Is discharge water likely to be the cause of exceedance?

STRESSORSIs there a significant

upward trend? (e.g. plot of data and/or Spearman rank test show s upward trend)

Yes

--_ _____.I~

__ ! __

l ---~-- ___ + __

I I




Figure 5: Decision support flow chart for management response to action trigger for the Iron Valley Project

Rationale for deriving SSTVs for protection of aquatic ecosystems

Background concentrations of some water quality parameters, particularly metals and nutrients, may exceed default ANZECC/ARMCANZ (2000) guideline trigger values, as a result of natural mineralisation from the catchment substrate, ecosystem processes, and/or from other anthropogenic sources. In such cases, it would be unreasonable to insist on a guideline value below the background concentration. Depending on the background concentration of select parameters, and duration of time parameters have been elevated, it is possible local fauna may have adapted to these conditions. Therefore, in accordance with ANZECC/ARMCANZ (2000) the preferred approach is to establish local conditions where baseline data are sufficient to adequately describe the natural or existing seasonal or annual fluctuations in water quality.

SSTVs are provided for all analytes for which ANZECC/ARMCANZ (2000) provide default TVs and which are considered of potential issue for dewatering discharge. In addition, water hardness and alkalinity will be routinely analysed, as they can have an ameliorating effect on metal toxicity, and as such are important to monitor.

Application of SSTVs is typically outlined in Proponents Ministerial Conditions, where key factors Inland Waters are considered, and is the accepted regulatory measure with Department of Biodiversity, Conservation and Attractions (DBCA) and DWER. Use of SSTVs for the Project is consistent with monitoring programs implemented by Proponents upstream.

Investigate risk to environment in consultation

with external experts

No

LOW RISK Review operational TVs

based on results of aquatic biota monitoring

2.4.2.4

I

Undertake field studies to determine if a significant response in biota can be demonstrably linked to

the contaminant(s)

Continue routine water quality monitoring at Compliance Site

Yes

2. Determine if management response is needed to prevent further WQ deterioration

3. Inv i te r m di I ctio s

4. Co f ue ta g te o ito i g o aquatic bio a

I




Rationale for choice of trigger level actions and threshold contingency actions


Trigger criteria for each analyte are set separately, as are threshold criteria from trigger criteria.

To provide sufficient early warning of threshold criteria being approached, trigger criterion applicable to IV discharge operations are based on site-specific trigger values (SSTVs) derived from the 80%ile values (and 20%ile values for pH) of local baseline datasets, or the default trigger value (see ANZECC & ARMCANZ 2000) for protection of 95% of species in freshwater aquatic ecosystems, whichever value is greatest.

Threshold criterion are based on the maximum baseline value recorded, or the default trigger value for protection of 80% of species, whichever value is greatest. The method of setting threshold criteria is consistent with the condition environmental outcome in condition 5-1, which requires that the proposal not cause long term impacts to the environmental and aboriginal heritage values linked to the physical and/or biological surroundings of WWC.

It must be emphasised that SSTVs should not be used as 'pass/fail' compliance criteria. Exceedance of the operational guideline or SSTV does not automatically imply increased toxicity and increased risk to the ecosystem. A conservative approach will be to respond to single exceedances by follow-up sampling to determine if the high-test result was a singleton (one-off) or part of a consistent trend. Single values above the SSTVs are not unexpected, given that the guideline is derived from 80%ile values of baseline data. A subsequent exceedance (i.e. repeat exceedance), warrants further investigation into the bioavailability of the analyte and/or the duration and frequency of elevated concentration. Biota may be unaffected by infrequent events that are of short duration, however, this needs to be confirmed by supporting field ecological studies (i.e. threshold contingency action) to determine if a significant response in the biota can be demonstrably linked to the elevated levels of analytes.

Groundwater Quality

The trigger values set for TDS for the groundwater need to be related to potential impacts on the WWC (as per Items Environmental Outcomes 1 and 2). As a result, the water quality of the water being discharged to the Creek from mine dewatering is more relevant than the water quality at individual production bores. It is suggested that the trigger value for the dewatering discharge should be set relative to the water quality in the creek, as groundwater discharge to the stream will only impact on the creek quality if the quality is worse than the stream.

Since January 2017, the TDS of the water being discharged at Dewatering Discharge Location #4 (DDL4) has varied between 470 – 622 mg/L TDS, with the last three readings in June/August being just below the average from all the individual bores.

To provide sufficient early warning of threshold criteria being approached, the trigger value applicable to groundwater TDS is based on site-specific trigger values (SSTVs) derived from the 80%ile values) of local baseline datasets, or the default trigger value (see ANZECC & ARMCANZ 2000) for protection of 95% of species in freshwater aquatic ecosystems, whichever value is greatest.

The threshold value for groundwater TDS is based on the past monitored site chemistry. The highest water quality measured to date from the production bores utilized over the last 3 years has been 622 mg/L. This has been set as the threshold criteria for TDS in groundwater.

This threshold trigger value is far lower than the threshold trigger value of 1100 mg/L TDS set for surface water in the WWC (Appendices Table A1. A single test result exceeding the trigger value should not result in a compliance response, rather a response should only occur if a twelve-month running average remains above the trigger level.

2.4.2.5

I I




Aquatic Fauna

ANZECC/ARMCANZ (2000) recommends the use of field studies to compare results of laboratory toxicity testing to the observed response of aquatic fauna to known water quality. As such, post-discharge wet season aquatic fauna (i.e. hyporheic fauna, macroinvertebrates and fish) sampling will be undertaken annually throughout the life of mine (i.e. late wet season) to determine if dewater discharge operations can be demonstrably linked to any change in aquatic fauna of the downstream receiving environment. The objective of this approach is to quantitatively monitor any changes in invertebrate and fish species richness and composition as bioindicators of potential impacts, and measures of ecosystem health. Targeted sampling will be undertaken in response to repeat water quality exceedances, as required.

A multi-metric system for analysis and assessment of aquatic fauna has been adopted to show sensitivity to mine dewater discharge operations, rather than a single metric approach. These metrics include a combination of univariate structural and functional diversity measures and multivariate assemblage composition. These metrics will be used to determine an overall impact rating for the downstream receiving environment of WWC, relative to the upstream condition (i.e. control) and/or reference condition (i.e. local reference sites), by applying a weight of evidence approach based on the outputs of all metrics. This approach provides a more holistic ecosystem impact rating as opposed to a single metric approach for individual fauna, which can be problematic, particularly where one or two single metrics, but not all metrics, exceed trigger or threshold levels. Overall Impact Rating Bands include No Impact, Low Impact, Medium Impact, and High Impact.

The trigger and threshold criterion are based on the degree of change observed between the potential impact reach of creekline and the relevant control/reference condition. The trigger level is set as Low Impact and indicative of a minor adverse impact, whilst the threshold trigger level is set as High Impact and indicative of a major adverse impact (see Table A2).

2.4.3 Flora and Vegetation

Results of (baseline surveys/modelling/scientific studies/tests) conducted

Conservation significant flora and communities

The Level 2 AWT flora survey was conducted across the entire Iron Valley tenement in 2012 (Astron 2012). It concluded that there were no conservation significant flora species, threatened ecological communities or protected ecological communities present.

Vegetation

Vegetation formations identified across the Project area in the 2012 survey include:

• Eucalyptus scattered low trees over Acacia scattered shrubs over Triodia hummock grasslands on rocky hillcrests and slopes.

• Acacia shrublands over Triodia hummocks and scattered tussock grasses in creeklines/drainage.

• Mixed open shrublands (Acacia, Corchorus, Grevillea and Senna) over Triodia hummock grasslands and scattered tussock grasses on plains.

Riparian and Groundwater dependent vegetation

Riparian vegetation occurs in association with the drainage lines within the Project area and surrounds. Riparian vegetation is reliant on periodic inundation, permanent pools and/or groundwater; the component reliant of groundwater being groundwater dependent vegetation (GDV). GDV within the potential drawdown/discharge zone associated with the Project is dominated

2.4.3.1

I I




by GDV tree species comprising the facultative phreatophytes Eucalyptus victrix and Eucalyptus camaldulensis (Astron 2016a). Potential GDV associated with the Project has been identified and mapped utilising visual inspection of aerial imagery, analysis of multispectral satellite data including Landsat imagery in time series, high resolution (1.2 m) Worldview imagery, and on-ground reconnaissance (Astron 2016a). Upstream of discharge point DDL4, dense stands of saplings and small trees of other GDV species appear to have proliferated around permanent pools on Marillana and Weeli Wolli Creeks fed by discharge from upstream. Thus, significant portions of the riparian ecosystem that occurs along Marilina and WWC’s adjacent and upstream to the Project can be considered as modified by mine dewatering discharge (Astron 2016a).

The only GDV in potential drawdown zones associated with the Project are along a drainage that runs through the mining tenement and into WWC where scattered E. victrix are present. This species is known to vary in its groundwater dependence depending on setting and can even persist on unsaturated stores of subsoil moisture: i.e. as a vadophyte (Pfautsch et al. 2014). The E. victrix along this drainage are likely to have a relatively low groundwater requirement based on the stature of the individuals (Astron 2013a). A modelling study has drawn similar conclusions (Soil Water Consultants 2015).

A comprehensive risk assessment of potential impacts to riparian vegetation from discharge and drawdown was completed in 2016 (Astron 2016a) and then revised in 2018 (Astron 2018). The assessment used data developed from remote sensing and on ground survey, hydrological modelling and ecohydrological knowledge from available literature to estimate the risk of biologically significant decline in tree health. The assessment mapped this risk according to level (high, moderate, low and negligible) under dewatering and discharge regimes applicable to the Project in isolation (Figure 7), and regimes applicable to a cumulative impact scenario where additional discharge originates from upstream projects as they are developed (Figure 8). This risk assessment provides a solid foundation for testing assumptions relating to the predicted severity and location of impacts, and a framework for the location of management zones and monitoring sites. As monitoring data accumulates, the model will be updated, and management and monitoring activities adapted accordingly.

I I




Figure 6: Iron Valley mine groundwater abstraction and discharge risk model

BC Ir.,.; Lid

Iran I/ Grnund,.-,,1., Oependorrt [co>yst= lrTY,..tlptlon • 20111 ~ astron Figure 2: Base Case - Groundwater abstraction and discharge risk model •.. -._,,__T. !ifet>r N -er. .... c. °""'"

I I




Figure 7: Iron Valley and cumulative impacts groundwater abstraction and discharge risk model

BC Iron Ltd Iron Y Groundw;atu Ot!pendent [ cosystem lnvostlg;atlon • 2019

Figure 3: RT10 Case• Groundwater abstraction and diKharge risk model

AI.IN><. T. llllob~ Do1tU 1l> 21l!S

On."tt. C.,0¥dt

I I

wtloolpolnis

• conn .... pc1n,

--W,Dll'aturw Olfl.t.refffrle.

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The baseline condition of riparian trees have been monitored within and adjacent to the Project area. Monitoring of E. victrix has occurred annually since 2013 within the drainage that extends through the mining tenement (coincides with the Drainage Exclusion Zone listed in Ministerial Statement 1044) (Astron 2013a; Astron 2016b; ecologia Environment 2018). Monitoring focuses on rating tree health with data also collected for tree height and general site observations (encompassing recruitment, understorey condition and fire, weeds and other disturbances). Sample trees in the program include a mix of the three GDV species and samples of the three species are included at the site level whenever present. This monitoring occurred throughout the above-watertable mining period where groundwater was drawn down from production bores. No decline in health was observed despite predictions of groundwater drawdown of up to 6 m below a portion of the sample trees during the monitoring period (Astron 2016b). Baseline monitoring of tree health and site condition commenced across the broader potential impact area and reference areas in 2016 (Astron 2016c) with the layout of on-ground monitoring sites was informed by the risk assessment (Astron 2016a). Monitoring in 2017, the commencement of the potential impact period for the Marillana and Welli Wolli Creek section of the Project area, did not detect any impact to GDV, including within the Drainage Exclusion Zone (ecologia Environment 2018). Further detail on this monitoring program is outlined in Section 3.1.2.

Weeds

A weed baseline survey was conducted in 2013 (Astron 2013b) that identified nine commonly occurring Pilbara weed species within and adjacent to the Project area and include:

• Rumex vesicaria (ruby dock)

• Aerva javanica (kapok)

• Argemone ochroleuca (Mexican poppy)

• Cenchrus ciliaris (buffel grass)

• Cenchrus setiger (birdwood grass)

• Malvastrum americanum (spiked malvastrum)

• Setaria verticillata (whorled pigeon grass)

• Tribulus terrestris (caltrop)

• Vachellia farnesiana (mimosa bush)

None of these weed species are classified as Weeds of National Significance, however Cenchrus ciliaris and Cenchrus setiger are the most frequently recorded and have the highest cover values and therefore pose the greatest risk to biodiversity values for the Project.

Since 2013, weed monitoring has continued annually with monitoring results in 2016 indicating no significant increase since baseline (Astron 2016d).

Photographic and observational data relating to weeds has been collected across riparian tree monitoring sites in 2015 (Astron 2016b, c). In 2017, quantitative data on weed species presence and extent was measured across the sites to enable assessment against criteria in Table 1-1 (Astron 2017). Species recorded in this survey that were not recorded in the Astron (2013b) survey were the following additional common Pilbara species:

• Citrullus colocynthis (colocynthis)

• Datura leichhardtii (native thornapple)

• Flaveria trinervia (speedy weed)

I I




• Lactuca serriola (prickly lettuce)

• Solanum nigrum (blackberry nightshade)

• Sonchus asper (rough sowthistle)

Key assumptions and uncertainties

The following assumptions and uncertainties apply:

• The location, quantity and duration of drawdown and enhanced surface flows. Estimated risks of impact to GDV and other riparian vegetation are dependent on hydrological models of drawdown and surface flows associated with dewatering and discharge, respectively. These models have inherent assumptions and uncertainties.

• Rates of dewatering and discharge. Hydrological models underpinning the riparian vegetation risk assessments assume particular operational scenarios for the Project and other projects upstream that are currently operating or are proposed for development.

• Response of riparian vegetation to discharge and drawdown. Differences in tolerance to drawdown and inundation exist between species and between individuals within a species (Astron 2016a; Pfautsch et al. 2014).

• Interactions between altered hydrological regimes and other disturbances including extreme weather. Disturbance such as fire and grazing have the potential to negatively affect riparian vegetation health and even compound the impacts of altered hydrological regimes. In contrast, above-average wet or dry seasons may compound or negate the impacts of altered hydrological regimes depending on location within the riparian zone (i.e. depending on whether the location is under the influence of drawdown or discharge, or both).

The assumptions and uncertainties have been addressed in the following ways:

• Undertaking a risk assessment study which modelled alternative scenarios (Project impacts only and cumulative impacts), parameterisation informed by initial monitoring data, literature and other studies (e.g. known rates of root extension to determine impacts from different rates of watertable recession) and by a conservative approach (e.g. disregarding the potential for discharge to counteract dewatering and assuming all occurrences of GDV tree species indicate GDV (Astron 2016a; Astron 2018).

• Annual monitoring and data analysis that will trigger adaptive management responses as required. In particular, the inclusion of remote sensing to achieve whole of landscape data on vegetation condition will provide a powerful tool for testing and refining assumptions. Periodic review and update of the riparian vegetation risk assessment will provide a framework for adapting the monitoring program as required.

• An early warning indicator that prompts investigation and/or management responses well in advance of the exceedance of thresholds.

Management approach

The management approach for riparian vegetation includes the items below.

• Assessment of risk and periodic review and refinement as required.

• Application of statistically-based early warning indicator for changes in vegetation health across the entire potential impact area and adjacent reference areas using high resolution remote sensing data.

2.4.3.2

2.4.3.3

I I




• Management decisions based on a before-after-control-impact (BACI) monitoring program (“control” being the equivalent of “reference”, the latter being the preferred term in this plan). This type of program enables regional impacts to be distinguished from Project-specific impacts. The ability to distinguish regional from Project impacts is critical for formulating suitable management responses.

• Drawing on the local body of knowledge and experience in managing riparian vegetation under the influence of mining related discharge and dewatering operations. Several other iron ore mines having operated in the region for over a decade or more; the accumulated knowledge resides across individuals in the mining industry, consulting and academia, and an important body of information is available in publications (e.g. Pfautsch et a. 2014; CSIRO 2015).

Rationale for choice of environmental criteria

The criteria outlined below are set against benchmarks for both baseline and reference areas. Statistical differences between reference and drawdown/discharge zones since baseline (BACI approach) are used to determine whether an impact has occurred. This enables changes to be evaluated against pre-existing conditions and natural variation in an objective and transparent way. It is noted however, that statistical differences are not used for criteria based on remote sensing because data comprise a complete census rather than a sample; as such, any difference is to be considered an actual difference and the focus is then on the spatial extent and severity of change.

In addition to statistical differences, magnitude of change is included in the criteria. In the case of thresholds, the percentage change components of the criteria are used to distinguish impacts that could be considered ecologically significant and long term. In the case of triggers and early warning indicators, the percentages or number of standard deviations represent the point at which the risks of a threshold impact occurring become unacceptably high. It is acknowledged that there is an arbitrary element to formulating the magnitude of acceptable change in the criteria. However, consideration was given to assigning percentage values and number of standard deviations chosen that are conservative and consistent with values used in other Pilbara riparian vegetation management plans that have been approved. The suitability of these criteria will be regularly assessed throughout the Project.

Threshold criteria in this section of the CEMP focus on:

• the outcome identified under Section 5-1 (3) of MS 1044 that states” the Proposal does not cause long term impacts on the health and cover of riparian and groundwater dependent vegetation”, and

• condition 5-3 of MS 1044 stating that impacts on riparian and groundwater dependent vegetation from weeds are to be addressed in the plan.

The criteria for a) have been formulated to apply to the keystone species within the riparian community: i.e. the groundwater dependent tree species. Collectively, these trees can be considered keystone by nature of their dominance, this defining the structure of the riparian vegetation and influencing the plant and animal species that co-occur, and their ecological functions, particularly in relation to groundwater use and potentially the redistribution within the soil profile (hydraulic redistribution; see Dawson 1993), modification of surface flows, cycling of nutrients, and influence over microclimate, including within creek pools.

The criteria specify that of the mean health of the pre-existing population of groundwater dependent trees should not fall below three standard deviations of the baseline mean. This recognises that GDV tree cover may decline in some sections of the Project with recovery expected to occur in 1 to 2 decades following the cessation of discharge/drawdown. The justification for this expectation is that the tree species in question have the ability to regenerate rapidly; evidence for this is clearly seen

2.4.3.4

I I




along WWC adjacent and upstream from the Project where regeneration of saplings and small trees has become prolific in some sections (Astron 2016a). Further, it recognises that discharge from this Project will also accelerate the regeneration of these tree species in additional areas. Thus, the threshold criteria set is consistent with no long-term impact to riparian vegetation, recognising that some short-term impact is inevitable, particularly with respect to discharge.

The criteria for b) weeds, consider both spread and composition. A limit on spread is set to 10% or less based on frequency of occurrence within sampling plots at monitoring sites and no new species to be introduced which spreads to a frequency of occurrence of 25% at any sampling site. These thresholds are considered consistent with no long-term impact and the expectation that weed growth has the potential to flourish under discharge. They also account for scale of impact, with a higher threshold set at the local (site) scale and lower threshold set for the ecosystem unit.

Trigger criteria in this section of the CEMP apply conservative values/conditions to select indicators, which if not exceeded, suggest that there is no imminent or unacceptably high risk that thresholds will be exceeded. The indicators selected mirror those for thresholds, with acceptable limits set at lower values or higher values but focused on a local (site) scale. However, for riparian trees, two additional indicators that enable the detection of changes in advance of mortality are included: visual tree health ratings and change in remotely sensed metrics of tree health. The use of the remotely sensed trigger also extends capability in monitoring and management response across the whole of the potential impact zone, not just in the immediate vicinity of the monitoring sites.

As with threshold criteria for weeds, trigger criteria also encompass local and landscape scales. Attention to the local scale and the detection of any new species acknowledges the principle that the containment of weeds and any potential impacts is most effective early when numbers are few.

Early warning indicators will be represented by statistically significant changes in vegetation health across the entire potential impact area using high resolution remote sensing data. Areas of statistically significant temporal and spatial change (significant clusters) in a vegetation condition index will be identified from the image layers for 1) riparian tree canopy and 2) all other areas excluding the tree canopy. The significant clusters in 1) may indicate tree decline or death if associated with negative change; in 2), they may indicate vegetation flourishing and therefore, sites where weed growth or spread is more likely to be occurring. Significant clusters will then be ranked in prominence (based on severity and extent) and ground-based investigation prioritised to determine the nature and cause of the changes. If changes indicate an unacceptably high risk of a threshold exceedance, a management response will be initiated.

.

Rationale for choice of trigger level actions and threshold contingency actions

Threshold and trigger level actions and contingencies were selected based on:

• baseline information on riparian vegetation composition and condition

• accepted ecological principles

• local experience in the management of drawdown, discharge and weeds

• planned mine operations, specifically opportunities for the management of discharge rates by location, including the redirection of discharge or irrigation to drawdown zones where GDV occurs

• other existing and potential projects within the catchment (cumulative impacts)

• timing, recognising that actions may be most effective at the cessation of operations; this is particularly the case with discharge where remedial actions may not be feasible or

2.4.3.5

I I




effective until operations of the Project, and possibly also the other projects upstream, cease.

3. CEMP PROVISIONS This section of the CEMP identifies the legal provisions that MRL proposes to implement the following environmental outcomes:

1. Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does not cause long term impacts to the environmental values of Weeli Wolli Creek.

2. Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does not cause long term impacts on the aboriginal heritage values linked to the physical and/or biological surroundings of Weeli Wolli Creek.

3. Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does not cause long term impacts on the health or cover of riparian and groundwater dependent vegetation within the Drainage Line Exclusion Zone and outside the approved Development Envelope.

This section also identifies the environmental criteria that MRL will use to measure performance and monitoring that will be undertaken in relation to these environmental criteria. Finally, it defines the trigger level actions and threshold contingency actions that MRL will undertake if the environmental criteria are exceeded (Table 3-1). These CEMP provisions aim to fulfil the requirements of condition 5-2 of MS1044.

Two levels of criteria were considered during development of this CEMP. They are trigger criteria and threshold criteria, which will vary in function. The trigger criteria were set at a conservative level to ensure trigger level actions are implemented well in advance of the environmental outcome being compromised. The threshold criteria were framed to measure achievement of the environmental outcome. A failure to meet threshold criteria signals the environmental outcome is not being met and implies non-compliance.

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Table 3-1: Inland Waters Trigger and Threshold Criteria

Condition Environmental Outcome Criteria Trigger Criteria Threshold Criteria

CEO 1: Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does not cause long term impacts to the environmental values of Weeli Wolli Creek. CEO 2: Groundwater abstraction and/or surplus dewater discharge from the implementation of the Proposal does not cause long term impacts on the aboriginal heritage values linked to the physical and/or biological surroundings of Weeli Wolli Creek.

Criterion 1: guidelines for toxicants in water

Ensure water discharged to WWC does not exceed specified surface water quality trigger values for toxicants outlined in Appendices Table A1. Monitoring actions for management in relation to Trigger Criterion 1 are outlined in Table 3-3.

Ensure water discharged to WWC does not exceed specified surface water quality threshold values for toxicants outlined in Appendices Table A1.

Criterion 2: guidelines for physico-chemical stressors

Ensure water discharged to WWC does not result in a statistically significant repeat exceedance (12-month rolling median) of the specified water quality trigger values for physico-chemical stressors outlined in Appendices Table A1. Monitoring actions for management in relation to Trigger Criterion 2 are outlined in Table 3-3.

Ensure water discharged to WWC does not result in a statistically significant repeat exceedance (12-month rolling median) of the specified water quality threshold values for physico-chemical stressors outlined in Appendices Table A1.

Criterion 3: guidelines for aquatic fauna assemblage

Ensure aquatic fauna overall impact rating does not exceed specified trigger value (i.e. Low Impact) outlined in Appendices Table A2.

Ensure aquatic fauna overall impact rating does not exceed specified threshold value (i.e. High Impact) outlined in Appendices Table A2.

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Table 3-2: Flora and Vegetation Trigger and Threshold Criteria

Environmental Criteria – Flora and Vegetation

Conditional Environmental Outcomes

3: Groundwater abstraction and/or surplus

dewater discharge from the implementation of

the Proposal does not cause long term impacts

on the health or cover of riparian and

groundwater dependent vegetation within the

Drainage Line Exclusion Zone and outside the

approved Development Envelope

Trigger criteria Trigger criterion 1: Significant decrease in riparian tree health rating measured on-ground at one or more

drawdown/discharge sites when compared to reference sites and decrease greater than 2 standard deviations of

baseline rating

Trigger criterion 2: Decrease beyond 2 standard deviations of baseline for remote sensing vegetation condition index

of riparian trees across the drawdown/discharge zone and the decrease is greater than across the reference zone

Trigger criterion 3: Significant increase in distribution or cover of weeds measured on-ground at one or more

drawdown/discharge sites when compared to reference sites

AND

increase greater than a 25% increment in distribution (frequency) or cover from baseline at any one site


Threshold criteria

Threshold criterion 1: Significant decrease in riparian tree health rating measured on-ground across the

drawdown/discharge sites when compared to reference sites and decrease greater than 3 standard deviations of

baseline rating

Threshold criterion 2: Significant increase in cover or distribution of weeds measured on-ground across the

drawdown/discharge sites when compared to reference sites.

AND

Increase greater than a 10% increment in cover or distribution (frequency) from baseline across the

drawdown/discharge sites

Threshold criterion 3: A new weed species increases in frequency of occurrence to exceed 25% at any

drawdown/discharge site

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3.1 Monitoring

The purpose of monitoring is to inform, through the environmental criteria, if the condition environmental outcome is being achieved and when trigger level actions or threshold contingency actions will be implemented. This section describes how MRL will undertake monitoring of surface water quality, aquatic fauna and riparian and groundwater dependant vegetation to measure performance against the environmental criteria.

3.1.1 Inland Waters

Monitoring sites


The surface water monitoring program of surface water will focus on the quality of surface flows in WWC downstream of the discharge point (Figure 8). In accordance with ANZECC/ARMCANZ (2000) guidelines, the compliance monitoring site location (738749E,7488662 N) is located as close to the discharge outlet to protect as much of the downstream receiving water environment as possible, but far enough downstream to allow for a ‘mixing zone’ and dilution of any contaminants. In the event the compliance monitoring site is dry, sampling will be undertaken at the nominated contingency location (740241 E,7485625 N), where practicable. A control monitoring site will be added to the surface water monitoring program (Figure 9). The control site will be located upstream of the Iron Valley dewatering discharge point to WWC, within the reach of creekline receiving perennial flows as a result of cumulative upstream dewatering discharge activities (see Figure 9, GPS UTM 50K 737679 7479074).

Discharge Water Quality

As groundwater total dissolved solids (TDS) is generally fresher and less variable than surface water quality, MRL will monitor TDS concentrations at the discharge outlet/location (DDL4, Figure 8).

Aquatic Fauna

The aquatic fauna (hyporheic fauna, macroinvertebrates, and fish) monitoring program will target replicate potential exposed sites in WWC downstream of the IV dewatering discharge (i.e. within the IV wetting front), together with replicate control sites in WWC upstream of the dewatering discharge, and suitable local and/or regional analogue reference sites during life-of-mine operations.

Exact site locations along WWC (upstream and downstream of the IV discharge point) will vary year-to-year, depending on surface water extent at the time of sampling (see Figure 9). Spatial / longitudinal representation of sites will capture the entire IV wetting front each wet season, which may vary as a result of discharge rates and volume, preceding rainfall events, and upstream mine dewatering operations. Reference sites will comprise local and/or regional permanent springs, where possible (see Figure 10).

Statistical analyses rely on adequate replication to characterise variability within and between groups in a given parameter (e.g. species richness, assemblage composition). Adequate replication provides the necessary statistical power to test for differences between groups (e.g. reference vs. potential exposed sites), and thereby detect statistically significant differences should they exist. Therefore, to obtain adequate statistical robustness, a minimum of five replicate sites (n = 5) will be sampled within each group of sites, where possible.12

1 The sampling design will establish suitable control and reference sites, against which any changes in WWC can be measured, to determine if they are project-attributable, result from upstream cumulative dewatering operations or represent temporal variation, thereby providing a level of confidence any observable impacts are within the limits of ecosystem resilience. 2 It may not always be feasible and/or practicable to sample five replicate local and/or regional analogue reference sites. At a minimum, three replicate local and/or regional analogue reference sites will be sampled to assess any natural temporal change within the region.

3.1.1.1

I I




Sampling frequency

Surface Water and Discharge Water Quality

For the first three months following commencement of dewatering discharge, fortnightly sampling will be conducted at the compliance site (or contingency site) in the main channel of WWC, the control site and any active dewatering discharge locations. Fortnightly sampling is required to generate an adequate number of samples to characterise discharge water quality. After this period, sampling will be conducted on a monthly frequency for life-of-mine operations.

Aquatic Fauna

Annual wet season aquatic fauna monitoring for the WWC System commenced post-discharge in 2018 and will continue for Life of Mine (LOM) operations. Historically, this reach of WWC was considered ephemeral, and only flowed seasonally. As such, biannual monitoring (dry and wet season survey) was not considered necessary for the Project, with a hydrological switch to permanent flows, and loss of seasonal/ephemeral signature of fauna likely.

Timelines and monitoring frequency provided will be subject to changes based on the outcomes of monitoring. Targeted sampling may be required in response to repeat water quality exceedances. One off sampling will be undertaken during closure / post closure.

Target bioindicators of ecosystem health

Surface Water and Discharge Water Quality

The surface water and dewatering discharge monitoring program will include all analytes recommended for ongoing monitoring, listed in Appendix 1, Table A1, for comparison to the operational SSTVs.

Aquatic Fauna

Macroinvertebrate, hyporheic fauna and fish will be targeted as bioindicators of ecosystem health as part of the multi-metric system approach to determining an overall impact score (as described above in Section 2.4.2.5). In-situ water quality (i.e. dissolved oxygen saturation, pH, temperature) and laboratory derived data (i.e. dissolved metals, nutrients) will be collected concomitant with aquatic fauna, additional to the surface water monitoring program.

The formation of precipitate from dewater discharge is cause for concern as it reduces the available habitat for the Macroinvertebrate community, which may in turn alter species composition and can result in a decrease in taxa richness. Field ecological studies will employ in-stream habitat assessment and visual grades of armouring. This approach to address the risk of armouring is best practice and in-line with ongoing studies along WWC upstream of the Project Area.

3.1.1.2

3.1.1.3

I I




Table 3-3: Monitoring to measure the environmental outcome against Trigger/Threshold Criteria outlined in Table 3-1.

Criterion Parameters Location Frequency

Criteria 1: guidelines for toxicants in water

Toxicants in water as outlined in Table A1-1.

Locations illustrated in figure 6, and include:

1. Dewatering Discharge outlet.

2. Compliance or contingency site in the main channel of WWC.


Fortnightly for first 3 months

from start of discharge. Thereafter monthly for life of mine operations.

Criteria 2: guidelines for physico-chemical stressors

Physico-chemical stressors in water as outlined in Table A1-1.

Locations illustrated in figure 6, and include:

1. Discharge outlet.

2. Compliance or contingency site in the main channel of WWC.


Fortnightly for first 3 months

from start of discharge. Thereafter monthly for life of mine operations.

Criteria 3: guidelines for aquatic fauna assemblage

Aquatic fauna assemblages include:

Hyporheic fauna:

- species richness

- composition.

Macroinvertebrates:

- species richness

- composition.

Fish:

- species richness

Three groups of sites:

1. Five replicate potential exposed sites in WWC downstream of the IV dewatering discharge, but within the IV wetting front.

2. Five replicate control sites in WWC upstream of the IV dewatering discharge.

3. Three Suitable local and/or regional analogue reference sites.

Annual (wet season) for life of mine operations, commencing post-discharge wet season 2018.

Targeted (if repeat water quality exceedance).

One-off during closure / Post closure.

Reviewing and Interpreting Monitoring Data

Surface Water and Discharge Location Monitoring Program

Practically, two approaches are recommended for monitoring and assessment:

i) monitoring incrementally by a decision control chart process, as the water quality data are collected, and comparing against the operational guideline, and

ii) an annual assessment at the end of the year, whereby the entire years’ monitoring data set is compared against the operational guideline.

The first approach is recommended for internal reporting of stressors (e.g. DO, EC, TDS, N-NO3, N-NH4, P-SR, P-total, pH, TSS) and toxicants (e.g. NO3, N-NH3, metals, pesticides), and external reporting of toxicants. The second approach is recommended for annual compliance reporting for all stressors and toxicants. There is value in reviewing the data for stressors and toxicants at the end of each sampling period (i.e. fortnightly) to provide an early warning of any impending trends. Since the management goal is ‘no change’ in ecological condition, the monitoring and assessment for compliance reporting is based upon a hypothesis of ‘no change’ between the operational TV and median of the monitoring dataset. i

3.1.1.4

I I




As part of the review process, a ‘rolling’ annual median of the monitoring data should be calculated and plotted (see plot at left). To begin, the median of the preceding 12 months monitoring data should be calculated (even if there are only a limited number of data points). This median will form the first data point on a plot of rolling (moving) medians. Each new data point on the plot is then calculated by adding each new value from the fortnightly sampling to the preceding data and recalculating the median. After data has been collected for 12 months, each new value is added, and the oldest data point dropped from the median calculation, resulting in a sliding 12-month median.

For stressors (e.g. pH, temperature, EC, TDS, ions, alkalinity, hardness and nutrients), a single test result exceeding the operational guideline will not constitute a ‘compliance failure’ but will require the median of 12 months’ data to be statistically above the SSTV. For toxicants (e.g. NO3, N-NH3, metals, and particularly metals that bioaccumulate), a more stringent approach may be required, as discussed under reporting provisions (Section 3.5). However, it should be remembered that the SSTVs are not intended as compliance levels, but, as the name implies, they are a trigger for further investigation (e.g. re-sample) to determine:

i) if the exceedance is still within the historic range, or

ii) if the exceedance represents a short-term event with likely low risk to the environment, requiring no management intervention, or

iii) if the exceedance represents a longer-term trend with moderate to high risk to the environment, requiring management intervention.

Exceedance of the operational guideline or SSTV does not automatically imply increased toxicity and increased risk to the ecosystem. It does however, warrant investigation into the bioavailability of the analyte and/or the duration and frequency of elevated concentration. Biota may be unaffected by infrequent events that are of short duration, though this needs to be confirmed by supporting field

ecological studies.

Inherent in the use of 80%ile (or 20%ile) of baseline data to derive SSTVs, is the fact that monitoring (and baseline) data may exceed the SSTV at least 20% of the time. Therefore, a statistical test is required to determine if the exceedance is statistically significant. A non-parametric one-tailed test equivalent to a t-test (e.g. Wilcoxon’s signed rank test) is appropriate for this purpose.

A number of other environmental parameters will also be measured to support the interpretation of monitoring results, these include:

• Monthly rainfall via on-site weather station.

• In-situ groundwater quality parameters in accordance with DWER Groundwater Licence

To protect against prolonged exposure to high concentrations of toxicants such as metals, we recommend that single values also be checked against ANZECC/ARMCANZ (2000) default TVs for toxicants for protection of 90% of species (as opposed to default 95% species level TVs that form the basis of the operational guidelines). If a single value exceeds either the 95%ile of baseline data or the default 90% species level TV, then further investigation is warranted, and the actual impact to aquatic fauna should be ‘ground-trothed’ through field ecological monitoring.

Historic range

-5

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12

Met

al c

once

ntra

tion

(mg/

L)

Month

TV

HMTV

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Figure 8: Location of compliance, contingency and discharge monitoring locations in relation to the preliminary modelled wetting front extent

Legend

e Control Monitoring Site

e Compliance Monitoring Location

e MRL Contingency Monitoring Location

• Discharge Outtet

---Major Creeks

. .,..-:ePort Hedland " .fiKarratha

Onslow✓ Study Aru

{/ Tom Price • t=J • Newman

BCI IV IOP Surface Water Monitoring Sites

Map Created: 09 · 10 • 2018 Cartographic Scale: 1 : 80,000

Wetland Research and Management Coordinate system: GOA 1994 MGA Zone 50 File Name: BCI IV IOP Surface Water Monitoring Sites.jpg kilometers

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Figure 9. Map showing spatial sampling extent upstream and downstream of the IV discharge outlet. Exact site locations will vary depending on extent of surface flows at the time of sampling

Legend Weeli Woll, Creek Upstream Control Sampling Extent

---- Weeh Wolh Creek Potential Exposed Sampling Extent

---- 2018 Wetting Front

• Iron Valley Wetting Front Extent

.& Discharge Outlet

- - - Hydrology

c:J BC Iron Tenement

J . ~Port Hedland

/.Karratha

Onl/ Study Aru

•ram Price

Wetland Research & Management

SECTION 1 : BCI IV IOP LOM Aquatic Fauna Monitoring Design Map Created· OS-10-2018

Cc1rtograph1c Scale· 1 :•8.000

F1lp Name-: SECTION 2 _BC! IV IOP LOM Aquatic huna Monitonng De-s1gn.JPC

COord,nat~ system GOA 1994 MGA Zone- 50

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Figure 10. Map showing nominal site locations for regional reference sites sampled as part of the aquatic fauna monitoring program. Exact site locations will vary depending on site access / conditions each year.

Legend

• Regional Reference S ites

Hydrology

[::::J BC Iron Tenement

SECTION 2 : BCI IV IOP LOM Aquatic Fauna Monitoring Design Map Created: 0S-10-2018 File Name: SECTION l_BCI IV IOP LOM Aquatic Fauna Monitoring Design.jpg 0

Wetland Research & Management Cartographic Scale : 1 : SS0,000 Coordinate system: GDA 1994 MGA Zone SO

I I

Newmain

kilometers




3.1.2 Riparian and groundwater dependent vegetation monitoring program

The program is based on a BACI design. The potential impact area (drawdown, discharge and drawdown and discharge) comprises moderate and high-risk areas of riparian vegetation along the WWC system for the worst-case scenario of cumulative impacts as outlined in Astron (2018). The reference area (control) comprises the low and negligible risk areas of riparian vegetation along WWC for cumulative impacts scenario as outlined in Astron (2018).

Baseline GDV monitoring occurred in 2013 for the drainage line supporting E. victrix that flows through the Iron Valley mining tenement (Astron 2013a), the Drainage Exclusion Zone Program, and in 2016 for the potential impact zone along WWC. Baseline weed monitoring occurred at the WWC sites in 2017 with baseline weed information for the Drainage Exclusion Zone capture in 2013 (Astron 2013b).

The Drainage Exclusion Zone Program comprises 43 permanent sample trees of E. victrix along the extent of the occurrence of this species along this drainage line (Figure 8). Sample trees are all larger than 5 cm diameter at breast height (DBH).

The WWC program comprises sites with 20 permanent sample trees (all larger than 5 cm DBH) comprising the two GDV tree species E. victrix and E. camaldulensis. The composition of sample trees by species at each site is dependent on the presence/absence and abundance of the species at each site. Further description on the layout of the sites is outlined below:

• Four sites distributed across the Creek system to provide even coverage of potential impact (two sites) and reference areas (two sites) from north to south (Figure 9).

• Two reference sites located in areas of low to negligible risk of impact from groundwater drawdown, groundwater mounding or surface water effects: one downstream of the wetting front for discharge impacts from Iron Valley only (site 3) and one downstream of the wetting front for cumulative discharge impacts (site 22).

l l




Figure 11: Monitoring trees and weed monitoring plots at the drainage exclusion zone monitoring site within the riparian and groundwater dependant vegetation monitoring program

• Weed monltormc kKatlons

0 Su rfaat Flow Monltortna: Sites

-- Tracks

-- Watercourse

C:=J Su rface: Flow Monitoring Shes • SOm Boundary

c:::::J Prqect All•

GOE monitor-In& sites

c.. GOE Tree s

.& Su rf•c.e Ftow Trees

<> Monitoring Bon!:

+ Production Bore

Mineral Resources Limited Iron Valley GOE Monitoring

Figure 2: Location of Eucalyptus vic trix sample trees and surface flow monit oring sit es. Author: T. Bl~ Drawn: C. Dyde

I

Dawm..GDA 199& l"n:lfllCt4n. MGAZoneSO .. ..,.,. 0 100 .200 300 «JO 500

N

A ~ astron Date. 24- 10-.2016

I




Figure 12: Monitoring sites in the Marillana/Weeli Wolli system within the riparian and groundwater dependant vegetation monitoring program.

8 § ~

8 8 ~

'140000

I BC I ron Limited

Iro n Valley G DV M ooita r1ns

;Figure 1 : Location of Monitoring Sites

a .. te: 1s-10-2.ou1

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• "''"" M.NXAWCNCA

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Legend

0 Monlmr Sites.

Iron Valley- Q..,..n,, lllsd,~ IDc.itlm

A,_ R:lo Tinta Dtsctia,,--e l.oca,1,1::,n

~ l'm)ec1m """ v.i1.,., Wetting Frant

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- - - 'Tri l l

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A




Variables and measurement methods in the monitoring program are summarised in Table 3-4. Where possible, the GDV species will be treated separately in analyses. Note that tree height and crown condition trajectory were measured during baseline monitoring however these variables will not be routinely measured during the impact period. These measures may be repeated should any trigger exceedance occur, and additional information is required to evaluate impacts.

A key feature of the monitoring program is the multi-scale approach. Repeat on-ground monitoring sites are well distributed across the potential impact area and available reference area at permanent sites. This is complimented by remote sensing across the entire potential impact area and reference area that is capable of distinguishing and monitoring trees and other vegetation separately. Remote sensing analyses will also guide targeted on ground investigative survey of vegetation condition at locations away from the permanent monitoring sites in response to early warning indicator data or trigger exceedances.

I I




Table 3-4: Monitoring methods in the riparian and groundwater dependant vegetation monitoring program

Variable (Timing) Method Notes

1. Tree visual

health (annually,

end of dry

season)

Rating of tree health

using a published

ratings systems for

Australian riparian

trees

Measured on 20 permanently marked E. victrix and/or E.

camaldulensis sample trees at all sites (Weeli Wolli Program).

Measured on 43 permanently marked E. victrix sample trees (E.

victrix drainage Program).

Foliar extent and density (ongoing monitoring), and crown

condition trajectory (baseline only) are rated by a trained

observer using the ratings system (Souter et al. 2009; 2010).

Crown condition trajectory is determined from an assessment

of a range of scores for variables such as new growth,

reproduction and tip dieback as outlined in Souter et al. (2009).

The assessment provides an indication as to whether tree

health is improving, declining or stable.

2. Tree height

(baseline only,

repeated as

required)

Measurement of tree

height using a

clinometer

Measured on the same trees as for variable 1.

Height of tallest green foliage measured at a distance of at least

10 m from the tree.

3. General site

condition

(annually, end of

dry season)

Rapid visual

assessment of site

condition and

vegetation condition

using simple ratings

systems, and

accompanying digital

photographs

Site condition variables including recruitment of target species

(seedlings and saplings), recent tree death, understorey

dieback, grazing, weeds, surface water, recent fire and erosion

rated as either 0 (absent), 1 (scarce), 2 (common) or 3

(abundant).

Vegetation condition rated using the vegetation condition

classification scale of Trudgen (1988).

Ratings based on visual assessment of whole site.

Includes observations of any other non-mining related

biotic/abiotic impacts on site condition.

Site photographs taken from permanent photo point, from four

cardinal directions.

The purpose of this data is to provide supporting information,

particularly if investigations are prompted following

exceedance of triggers.

4. Remotely

sensed index of

vegetation

condition

(annually, end of

dry season)

Calculation of change

in a suitable

vegetation condition

index

Annual capture of digital multispectral imagery at 2 m

resolution or finer and that includes the near infrared band

Analysis to determine annual changes in vegetation condition

index for the tree canopy layer and other vegetation

separately.

Targeted ground truthing as required for investigation of

significant changes detected in remote sensing imagery

5. Weeds

(annually, end of

wet season)

Measurements of

weed species

presence/absence

and cover within

quadrats

Two 250 m long transects are established within a

250 m by 250 m quadrat centered on the site. Transects are

then further divided into 10 contiguous 25 m by 25 m quadrats.

One such quadrat is established at each of the Weeli Wolli

Program sites and two quadrats are dispersed across the E.

I I




Variable (Timing) Method Notes

victrix drainage Program site

Monitoring for weed cover and species presence/ absence

occurs within each quadrat.

Design is consistent with previous weed monitoring program

that has occurred on the Iron Valley tenement.

Monitoring is repeated within the same sampling frame each

year.

7. Groundwater

level (measured

quarterly,

reported

annually)

Monitoring bores Bore sampling

Data used to aid interpretation of vegetation monitoring data

post baseline.

8. Climate and

weather

(measured daily,

reported

annually)

Weather station Data acquired from nearest on-site weather station or nearest

official weather station.

Key variables include rainfall and temperature.

Data used to aid interpretation of vegetation monitoring data

post baseline.

3.2 Actions

The below section outlines the actions MRL will take if trigger or threshold values are exceeded for hydrological processes and inland water quality and riparian and groundwater dependant vegetation.

3.2.1 Inland Waters

Implementation of Trigger Level Actions

MRL has developed trigger level actions that would be implemented if the trigger criterion for water quality (toxicants and chemical stressors) and / or aquatic fauna signals the need for increased mitigation or protection. Trigger level actions will be implemented immediately if the trigger criteria are exceeded. Trigger level actions aim to prevent an exceedance of threshold criteria so that the threshold criteria are safeguarded. Trigger level actions will engage expert specialist opinion and/or field investigations into the nature/cause of exceedances to determine if a project-attributable trend is establishing. Trigger level actions will continue to be implemented until trigger criteria are met or the CEO of the DWER confirms in writing that the environmental outcome is being met and that trigger level actions are no longer required to be implemented.

Trigger level actions proposed include:

• Notify the CEO in writing within 7 days of becoming aware of the trigger level exceedance (see Section 4.1.1).

• Review results from upstream WWC monitoring location to determine if exceedance is project-attributable, or in response to cumulative upstream dewatering discharge activities.

• For a project-attributable exceedances in surface water quality,

3.2.1.1

I I




o resample monitoring/contingency site location and upstream control location as soon as practicable (i.e. within 7 days for surface water, within wet season for aquatic fauna).

o if both rounds of surface water monitoring show trigger levels have been exceeded, increase frequency of surface water quality monitoring (i.e. weekly surface water quality monitoring) in order to further assess changes.

o if both rounds of aquatic fauna monitoring show trigger levels have been exceeded, undertake investigations into the potential effect(s) of adverse water quality (i.e. measuring freshwater ecotoxicological impacts).

o identify and implement any operational actions to mitigate any impact (i.e. reduce/halt dewatering discharge, use alternative abstraction points, remediate where necessary etc.).

• For exceedances in ground water TDS at dewatering discharge locations

o resample dewatering discharge location as soon as practicable (within 7 days).

o if both rounds of surface water monitoring show trigger levels have been exceeded, increase frequency of dewatering discharge quality monitoring in order to further assess changes in TDS levels.

• Identify additional measures required to prevent the trigger level being exceeded in the future (i.e. update and revise trigger criteria levels with additional monitoring data).

• Provide a report on the trigger exceedance to the CEO within 21 days from the date of awareness of the exceedance.

• Document the threshold exceedance for later inclusion in the annual Compliance Assessment Report due to DWER on 1st May each calendar year (see Section 4).

Implementation of Threshold Contingency Actions

MRL has developed a number of threshold contingency actions that would be implemented if the threshold criterion for water quality (toxicants and chemical stressors) and / or aquatic fauna are exceeded (Table A1 and A2). Threshold level actions will be decisive actions that will prevent further damage to the environment, ascertain the extent of impact and remediate or rectify damage, where required. The threshold contingency actions will be implemented to manage aspects of the proposal, achieve the condition environmental outcome and manage the impact to below threshold and trigger criteria again, and hence bring MRL back into compliance.

Threshold level actions proposed include:

• Notify the CEO in writing within 7 days of becoming aware of the threshold level exceedance (see Section 4.1.1).

• Review results from upstream WWC monitoring location to determine if exceedance is project-attributable, or in response to cumulative upstream dewatering discharge activities.

• Confirm validity of project-attributable threshold level exceedance as soon as practicable (i.e. resample surface water quality within 7 days, undertake targeted aquatic fauna monitoring program).

• For a repeat project-attributable exceedances in surface water or groundwater quality,

3.2.1.2

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o implement operational actions to mitigate any impact (i.e. reduce/halt dewatering discharge, use alternative abstraction points, remediate where necessary etc.).

o Implement ongoing monitoring of aquatic fauna to determine level of adverse impact or alteration of the downstream receiving environment, and also the effectiveness of operational actions to mitigate any impacts.

o Initiate investigations (i.e. potential contamination sources) into the potential cause(s).

• Identify additional measures required to prevent the threshold level being exceeded in the future (i.e. update and revise threshold criteria levels with additional monitoring data)

• Provide a report on the threshold exceedance to the CEO within 21 days from the date of awareness of the exceedance.

• Document the threshold exceedance for later inclusion in the annual Compliance Assessment Report due to DWER on 1st May each calendar year (see Section 4).

3.2.2 Flora and Vegetation

Implementation of Trigger Level Actions

Further detail is provided here with respect to the trigger level contingency action that may follow from a potential discharge impact being detected and then confirmed. Firstly, a review of current discharge management practices will be initiated and completed within 21 days of the conclusion of the investigation as outlined in Table 3-5. Following the review, one or more of the following, or any another appropriate intervention, may be implemented, if feasible:

•

• Reallocation of discharge rates following the addition of new discharge points and/or the decommissioning of existing points. Addition of new discharge points to consider opportunities for mitigating any current or future drawdown impacts on GDV.

• Reduce discharge volumes through increasing on site use or supplying an off-site demand.

• Reinjection

• Staging the reduction of discharge towards the end of mining.

Feasibility will consider upstream discharge activities in other Projects. In particular, the effectiveness of any discharge management interventions by BCI Minerals Limited (BCI) will need to be evaluated with respect to this upstream discharge. A feasible option for altering the discharge regime to achieve an improved outcome for riparian vegetation condition may not exist under circumstances where discharge from upstream projects increases.

3.2.2.1

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Table 3-5: Monitoring to measure the efficiency of environmental outcomes for riparian and groundwater vegetation against trigger criteria

Trigger criterion 1: Significant decrease in riparian tree health rating measured on-ground at one or more drawdown/discharge sites when compared to reference sites and decrease greater than 2 standard deviations of baseline rating

Indicator Method Location Frequency Trigger Level Actions and timing to implement

Visual Tree health

rating.

Rate visual tree health

using Souter et al (2009)

on permanent sample

trees at each site.

Monitoring sites are

shown in Figure 7 and

Figure 8.

Annual – end of

dry season.

• Investigate the cause of the exceedance within 21 days. The investigation should include an evaluation of the risk that the threshold will be exceeded within 12 months. If the cause is due to BC Iron water management practices (discharge or drawdown), increase the frequency of on-ground monitoring at affected sites and applicable reference sites; re-investigate if an exceedance recurs.

• Outcome of investigation and/or ongoing monitoring may necessitate one or more of the following interventions depending on whether the exceedance relates to drawdown or discharge:

If drawdown-related, implement a watering program within three months to enable patches of mature trees to survive within the affected area until dewatering ceases.

If discharge-related, undertake a review of current discharge management practices and implement one or more changes, if feasible (see Section 3.1.2) within three months.

• Documentation of trigger exceedances and response actions

taken.

• Records of relevant notification / consultation with stake holders.

Trigger criterion 2: Decrease beyond 2 standard deviations of baseline for remote sensing vegetation condition index of riparian trees across the drawdown/discharge zone and the decrease is greater than across the reference zone

Tree canopy condition change from remote sensing.

Calculation of change in

suitable vegetation

condition index derived

from high resolution (2

m or less) multispectral

imagery (inclusive of

Complete coverage of

potential

drawdown/discharge

zone and adjacent

reference areas.

Annual – end of

dry season.

As above.




near infrared band).

Trigger criterion 3: Significant increase in distribution or cover of weeds measured on-ground at one or more drawdown/discharge sites when compared to reference sites

AND

increase greater than a 25% increment in distribution (frequency) or cover from baseline at any one site

Distribution (frequency of occurrence) and cover of weeds.

Presence/absence and

estimated cover of

weeds in 2 transects of

10, 25m x 25 m

contiguous quadrats at

each site.



Figure 8.

Annual – end of

wet season.

Undertake targeted weed control (focused on affected sites and

accessible areas between or approximately halfway to the nearest

unaffected site) using herbicide applications and/or other suitable

methods. To be commenced within three months of detection.

Records of relevant notification / consultation with stake holders.


Presence/absence of weed species

Presence/absence of

weed species in 2

transects of 10, 25m x 25

m contiguous quadrats

at each site.

As above for Trigger

criterion 3.

Annual – end of

wet season.

As above for Trigger criterion 3.

"""'"""

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Implementation of Threshold Contingency Actions

MRL has developed a number of threshold contingency actions that would be implemented if the associated threshold criterion for riparian and groundwater dependant vegetation and weeds signals that the environmental outcome is exceeded (Table 3–6). The threshold contingency actions will be implemented to manage aspects of the proposal and achieve the condition environmental outcome and manage the impact to below threshold and trigger criteria again and hence bring MRL back into compliance.

3.2.2.2

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Table 3-6: Monitoring to measure the environmental outcomes for riparian and groundwater dependant vegetation against threshold criteria

Threshold criterion 1: Significant increase in tree mortality within drawdown/discharge zone when compared to reference sites.

AND

more than 25% of sample trees dead compared to baseline across the drawdown/discharge zone

Indicator Method Location Frequency Threshold Contingency Actions and timing to implement

Visual tree health

rating.

Rate visual tree health

using Souter et al (2009)

on permanent sample

trees at each site.



Figure 8.

Annual – end of

dry season.

• If the threshold exceedance is in the drawdown zone (no discharge present), within 24 hours, reduce dewatering rates at one or more locations and/or implement a plan that expands and/or improves the tree watering program and that includes measures to promote the regeneration of GDV tree species.

• If the threshold exceedance is in the discharge zone, implement suitable modifications to the discharge regime and/or prepare a plan for the post-discharge period to recover riparian vegetation in areas significant impact.

• Follow condition 5-5 in Ministerial Statement 1044 which outlines procedures for reporting, investigation and implementation of contingency actions.

• Consult with government agencies, the Nyiyaparli traditional owners and other appropriate stakeholders

Threshold criterion 2: Significant increase in cover or distribution of weeds measured on-ground across the drawdown/discharge sites when compared to reference sites.

AND

Increase greater than a 10% increment in cover or distribution (frequency) from baseline across the drawdown/discharge sites

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Distribution (frequency

of occurrence) and

cover of weeds

Presence/absence and

estimated cover of

weeds in 2 transects of

10, 25m x 25 m

contiguous quadrats at

each site.


shown Figure 7 and

Figure 8.

Annual – end of

wet season.

• Implement a program of weed control across the discharge zone within 24 hours or as soon as weather conditions are suitable for weed control.

• Follow condition 5-5 in Ministerial Statement 1044 which outlines procedures for reporting, investigation and implementation of contingency actions.

• Consult with government agencies, the Nyiyaparli traditional owners and other appropriate stakeholders.

Indicator Method Location Frequency Threshold Contingency Actions and timing to implement

• Threshold criterion 3: A new weed species increases in frequency of occurrence to exceed 25% at any drawdown/discharge site

Presence/absence of

weed species

Presence/absence of

weed species in 2

transects of 10, 25m x 25

m contiguous quadrats

at each site.

As above for Threshold

criterion 2.

Annual – end of

wet season

• Undertake targeted weed control (focused on affected sites and accessible areas between or approximately halfway to the nearest unaffected site) using herbicide applications and/or other suitable methods. To be commenced within 24 hours or as soon as weather conditions are suitable for weed control.

• Consult with government agencies, the Nyiyaparli traditional owners and other appropriate stakeholders

"""'"""

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4. Reporting provisions MRL will report each environmental outcome against trigger and threshold criteria in the annual compliance report, due to DWER on 1 May.

In the event that trigger criteria or trigger and threshold criteria were exceeded during the reporting period, the annual report will include a description of the effectiveness of trigger level actions, and threshold contingency actions that have been implemented to manage the impact, as well as an analysis of trends and any stakeholder consultation.

4.1.1 Reporting on exceedance of trigger criteria and threshold criteria

In the event of exceedance of any trigger or threshold criteria, MRL will notify the DWER in writing within 7 business day.

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5. ADAPTIVE MANAGEMENT AND REVIEW OF THE CEMP MRL will also implement adaptive management to learn from the implementation of mitigation measures, monitoring and evaluation against trigger and threshold criteria, to more effectively meet the condition environmental outcome.

Monitoring data for GDV’s, weeds, groundwater discharge quality and aquatic fauna will be systematically evaluated and compared to baseline and reference site data after each monitoring round in a process of adaptive management to verify whether hydrological responses to the impact are the same or similar to predictions. The monitoring data will also be used to determine the impacts of the Project on the heritage values of WWC.

The HA, updated SSTVs and dewatering discharge monitoring program outlined within this plan is designed to maintain the existing aquatic ecosystems at a low level of risk. The trigger criterion is applicable to IV discharge operations, and is based on site-specific trigger values (SSTVs) derived from the 80%ile values (and 20%ile values for pH and DO) of local baseline datasets. The HA should be viewed as a dynamic process, and progressively reviewed as mining operations develop, and/or as new ecological effects data (laboratory ecotoxicity or field ecological survey data) become available. For example, data from on-going surface water monitoring upstream and downstream of the discharge outlet should be used to refine the operational guidelines, particularly as new dewater discharge operations commence at other BWT mines upstream of the Project.

For the monitoring of GDV and weeds, the assumptions and uncertainties have been addressed in the following ways:

• In the risk assessment study by modelling alternative scenarios (Project impacts only and cumulative impacts), parameterisation informed by literature and other studies (e.g. known rates of root extension to determine impacts from different rates of watertable recession) and by a conservative approach (e.g. disregarding the potential for discharge to counteract dewatering and assuming all occurrences of GDV tree species indicate GDV) (Astron 2016).

• Annual monitoring and data analysis that will trigger adaptive management responses as required. In particular, the inclusion of remote sensing to achieve whole of landscape data on vegetation condition will provide a powerful tool for testing and refining assumptions. Periodic review and update of the riparian vegetation risk assessment will provide a framework for adapting the monitoring program as required.

• An early warning indicator that prompts investigation and/or management responses well in advance of the exceedance of thresholds: see Section 2.4.3.

MRL will review this CEMP following any changes to CEMP provisions.

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6. Stakeholder Consultation BCI met with the Nyiyaparli People at the Project in August 2016 to discuss the proposed BWT project and the impacts to the environment and aboriginal places identified across the site. The Nyiyaparli People were given all approval documents and raised no issues associated with the discharge of water into WWC. The Nyiyaparli welcomed the increase volume of water into the WWC for the duration of the Project as it will allow the group and its members greater enjoyment.

BCI will continue to meet with the Nyiyaparli every six months to discuss the project and ongoing heritage management and any issues the Nyiyaparli may have with the project.

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7. References Astron Environmental Services (Astron) 2012, ‘Iron Valley Project – Flora and Vegetation Survey’, unpublished report to URS Australia Pty Ltd.

Astron 2013a, 'Iron Valley GDE Survey, August 2013', unpublished report to URS Pty Ltd.

Astron 2013b, ‘Iron Valley Mining Tenement – Weed Mapping Survey’, unpublished report to URS Australia Pty Ltd.

Astron 2016a, 'Iron Valley Groundwater Dependent Ecosystem Investigation, December 2015', unpublished report to BC Iron Limited.

Astron 2016b, 'Iron Valley Groundwater Dependent Ecosystem Monitoring Program, November 2016', unpublished report to Mineral Resources Limited.

Astron 2016c, ‘Iron Valley Mining Tenement – Weed Monitoring’, August 2016, unpublished report to Mineral Resources.

Astron 2017, ‘Iron Valley Mining Tenement Baseline Weed Monitoring August 2017’, November 2017, unpublished report to Mineral Resources Limited.

Astron 2018, ‘BCI Minerals Iron Valley Flora Veg and GDE – Risk Assessment Update’, October 2018, unpublished report to BCI Minerals.

CSIRO 2015, ‘Pilbara Water Resource Assessment: Upper Fortescue region, A report to the government of Western Australia and industry partners from the CSIRO Pilbara Water Resource Assessment’, CSIRO Land and Water, 7 October 2015.

ecologia Environment 2018, ‘Iron Valley GDV Monitoring Programs 2017 – Drainage Line Exclusion Zone and Marillana/Weeli Wolli Creek’, April 2018, unpublished report to Mineral Resources Limited.

Pfautsch, S, Dodson, W, Madden, S & Adams, MA 2014, 'Assessing the impact of large-scale water table modifications on riparian trees: a case study from Australia', Ecohydrology, vol. 8, no. 4, pp. 642-51.

Soilwater Consultants 2015, ‘Increase in Groundwater Abstraction at Iron Valley – Impact Assessment’, unpublished report to Mineral Resources Limited.

Souter, N, Watts, R, White, M, George, A and McNicol, K 2009, Method manual for the visual assessment of lower River Murray floodplain trees river red gum (Eucalyptus camaldulensis), DWLBC Report 2009/25, Department of Water Land and Biodiversity Conservation, Adelaide.

Trudgen, ME 1988, A Report of the Flora and Vegetation of the Port Kennedy Area, unpublished report to Bowman Bishaw and Associates.

WRM 2017, Iron Valley Project: Hazard Analysis and Revised Operational Water Quality Guidelines for Dewatering Discharge to WWC to Mineral Resources Pty Ltd by Wetland Research & Management. Draft v1, 8 August 2017.

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Issue Date: 8/03/2017 MRL-IV-CEMP-001 Appendices


8. APPENDICES Table A1. Revised operational water quality guidelines (i.e. trigger and threshold criteria) for Iron Valley dewatering discharge from WWC baseline (i.e. current background condition) datasets, together with ANZECC/ARMCANZ default 95% TVs. All values are mg/L unless otherwise indicated (WRM 2017).

Analyte Notes ANZECC/ ARMCANZ (2000) 95% TV

Trigger Criteria1 Threshold Criteria2

Alkalinity (as CaCO3) np 300 386

Boron (B) T 0.37 0.37 1.3

Electrical Conductivity (µS/cm) 250-900 940 1930

Iron (Fe) T 0.3 0.3 1.0

Hardness (as CaCO3) np 360 470

Magnesium (Mg) np 54 70

Nitrate-nitrite nitrogen (N-NOX) (eutrophication) 0.03 0.4 1.0

Nitrate (NO3) T, N 11 11 17

Nitrogen-total (eutrophication) 0.3 0.7 3.1

Phosphorus-total (eutrophication) 0.01 0.02 0.1

pH-field (H+) 6.0-8.0 7.5-8.1 6.0-8.4

Sulphate (S-SO4) np 60 71

Strontium (Sr) T np 0.19 0.22

Total Dissolved Solids (TDS) – Surface Water SSTV np 520 1100

Total Dissolved Solids (TDS) – Groundwater SSTV np 5203 6223

Total Suspended Solids (TSS) np 5 17

Zinc (Zn) T, H 0.008 0.008 0.031

Notes:

1 = Trigger criteria for each analyte are set based on site-specific trigger values (SSTVs) derived from the 80%ile values (and 20%ile values for pH) of local baseline datasets, or the default trigger value (see ANZECC & ARMCANZ 2000) for protection of 95% of species in freshwater aquatic ecosystems, whichever value is greatest.

2 = Threshold criteria for each analyte are set based on the maximum baseline value recorded, or the default trigger value for protection of 80% of species in freshwater aquatic ecosystems, whichever value is greatest.

3= The Trigger and Threshold criteria for Total Dissolved Solids in groundwater has been developed by AQ2 as groundwater is generally fresher and less variable than surface water quality. Threshold criteria has been updated to represent the peak concentration recorded from production bores during routine monitoring.

H = TV should be modified for water hardness at the time of sampling

g= using the default algorithms in Tables 3.4.3 and 3.4.4 of ANZECC/ARMCANZ (2000).

N= Default TV for NO3 as a toxicant is soon to be revised to around 11 mg/L NO3 (i.e. 2 - .5 mg/L N-NO3); to convert nitrate-nitrogen (N-NO3) to nitrate (NO3), multiply by 4.43. Therefore, the interim operational guideline is based on the revised value rather than the current ANZECC/ARMCANZ (2000) default TV of 0.7 mg/L NO3 or the 80%ile of baseline data (1.6 mg/L).

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NP= Not provided.

T= Toxicant.

Table A2. Aquatic fauna impact ratings (i.e. trigger and threshold criteria) for Weeli Wolli Creek.

Performance Indicator Trigger Criteria Threshold Criteria

Aquatic Fauna Impact Rating Low High

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Table A2. Current SSTV analytes applicable to Iron Valley dewatering operations.

Parameter class Water Quality Parameters Monitoring sites Frequency

General

Electrical conductivity (EC), pH, temperature, dissolved oxygen,

alkalinity (CaCO3), total suspended solids (TSS), turbidity, total dissolved

solids (TDS) Compliance monitoring

location downstream of the

discharge point and

designated contingency

monitoring location

Fortnightly monitoring

for the first 3 months

following the

commencement of

dewater discharge.

After this period,

sampling will be

conducted on a

monthly frequency for

life-of-mine

operations.

Major ions Ca, Cl, Na, K, SO4_S, Mg, CO3, HCO3

Nutrients TN, TP, N_NH3, NO3, N_NH4

Metals and metalloids Al, As total, B, Ba, Cd, Co, Cr_total, Cu, Fe, Hg, Mn, Mo, Ni, P_SR, Pb, S,

Se, U, V, Zn

General - TDS TDS dewatering discharge

location (DDL4) Monthly

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Documents

Iron Valley Iron Ore Project - Department of Environment ... · Iron Valley is a below the water table (BWT) blast and hydraulic shovel open pit mine of 10 million tonnes of iron