mine closure plan wonmunna iron ore project...mine closure plan wonmunna iron ore project m47/1423,...

Mine Closure Plan

Wonmunna Iron Ore Project

M47/1423, M47/1424, M47/1425 & L47/727

View of Weeli Wolli Creek

Revised - March 2015

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN March 2015

Address: Ascot Resources Limited 512 Hay Street, Subiaco WA 6008

Postal Address:

Ascot Resources Limited 512 Hay Street, Subiaco WA 6008

Report title: Mine Closure Plan for the Wonmunna Iron Ore Project M47/1423, M47/1424, M47/1425 & L47/727 Revised – March 2015

Project Name: Wonmunna Iron Ore Project

Tenements: M47/1423, M47/1424, M47/1425 & L47/727

Site contact: Andrew Caruso, Managing Director

Email: [email protected]

Phone: 08 93814534 Mobile: 0439981763

Prepared by: Piacentini & Son

Version: Version 1 Revision 3

Version date: 25 March 2015

Reviewed by: R Gerrard & F. Sibbel Date: 25 March 2015

Final approval: A Caruso Date: 25 March 2015

Submission Date: 26th March 2015

Distribution: Provided an electronic copy on DVD with spatial files to the DMP, as an appendix of the Wonmunna Mining Proposal.

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN i March 2015

Table of Contents

1.0 Mine Closure Plan Checklist .......................................................................................................... v

2.0 Scope and Purpose ......................................................................................................................... 1

3.0 Project Overview ............................................................................................................................. 1

3.1 Historical Disturbance ................................................................................................................... 8

4.0 Identification of Closure Obligations and Commitments ......................................................... 13

4.1 Summary of Closure Commitments ............................................................................................ 13

5.0 Collection and Analysis of Closure Data .................................................................................... 15

5.1 Climate ........................................................................................................................................ 15 5.1.1 Temperature ........................................................................................................................ 15 5.1.2 Rainfall and Evaporation ..................................................................................................... 15

5.2 Topography & Geology ............................................................................................................... 17 5.2.1 Topography ......................................................................................................................... 17 5.2.2 Regional Geology ................................................................................................................ 17 5.2.3 Local Geology...................................................................................................................... 19

5.3 Seismicity & Geotechnical Data ................................................................................................. 19 5.3.1 Seismicity ............................................................................................................................ 19 5.3.2 Geotechnical Data ............................................................................................................... 19

5.4 Hydrology .................................................................................................................................... 20 5.4.1 Hydrogeology ...................................................................................................................... 20 5.4.2 Groundwater ........................................................................................................................ 20 5.4.3 Surface Water...................................................................................................................... 21

5.5 Flora & Vegetation ...................................................................................................................... 33 5.5.1 Vegetation ........................................................................................................................... 33 5.5.2 Flora .................................................................................................................................... 35

5.6 Fauna & Habitats ........................................................................................................................ 36 5.6.1 Vertebrates .......................................................................................................................... 36 5.6.2 Short Range Endemics ....................................................................................................... 37 5.6.3 Troglofauna ......................................................................................................................... 38

5.7 Soils / Growth Medium ................................................................................................................ 39

5.8 Waste Materials .......................................................................................................................... 41

5.9 Design and Construction of Waste Dumps ................................................................................. 43 5.9.1 Waste scheduling & volumes .............................................................................................. 43 5.9.2 Sedimentation...................................................................................................................... 45 5.9.3 Surface Water Flow ............................................................................................................. 45 5.9.4 Dump Modelling .................................................................................................................. 46

5.10 Rehabilitation ............................................................................................................................ 53 5.10.1 Haul Roads & Access Roads ............................................................................................ 53 5.10.2 Infrastructure Sites ............................................................................................................ 54 5.10.3 Recontoured Waste Dump Landforms .............................................................................. 54 5.10.4 Seed Mixes ........................................................................................................................ 55 5.10.5 Growth Medium ................................................................................................................. 56

5.11 Information Gaps ...................................................................................................................... 56

5.12 Monitoring Regime & Feedback Loop ...................................................................................... 57

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN ii March 2015

6.0 Stakeholder Consultation............................................................................................................. 58

6.1 Summary of Stakeholder Consultation to Date .......................................................................... 58

6.2 Planned Stakeholder Consultation ............................................................................................. 58

6.3 Feedback Loop ........................................................................................................................... 59

7.0 Post-mining Land Use and Closure Objectives ......................................................................... 60

7.1 Post-mining Landuse .................................................................................................................. 60

7.2 Closure Objectives ...................................................................................................................... 61

8.0 Identification and Management of Closure Issues .................................................................... 62

9.0 Development of Completion Criteria & Monitoring Program ................................................... 65

9.1 Completion Criteria Development ............................................................................................... 65

9.2 Rehabilitation Objectives ............................................................................................................ 65

9.3 Monitoring Program .................................................................................................................... 68 9.3.1 Monitoring Site Parameters ................................................................................................. 69 9.3.2 Field Monitoring Procedures ............................................................................................... 72 9.3.3 Description and Definition of Measures and Data ............................................................... 73 9.3.4 Description of Data Analyses for Rehabilitation Assessment ............................................. 74 9.3.5 Analogue Community Selection .......................................................................................... 77

9.4 Proposed Monitoring Schedule .................................................................................................. 83 9.4.1 Analogue Communities ....................................................................................................... 83 9.4.2 Rehabilitated Areas ............................................................................................................. 83 9.4.3 Procedures to Assess Rehabilitation Process .................................................................... 84

10.0 Financial Provision for Closure ................................................................................................. 85

11.0 Closure Implementation ............................................................................................................. 95

12.0 Closure Monitoring and Maintenance ....................................................................................... 97

13.0 Management of Information and Data ....................................................................................... 97

14.0 References ................................................................................................................................... 98

15.0 Acronyms ................................................................................................................................... 100

16.0 Appendices .................................................................................................................................... 1

Appendix 16.1: Geotechnical Report ................................................................................................. 1

Appendix 16.2: Groundwater Report ................................................................................................. 2

Appendix 16.3: Surface Water Report ............................................................................................... 3

Appendix 16.4: Flora Report .............................................................................................................. 4

Appendix 16.5: Fauna Report - Vertebrates ...................................................................................... 5

Appendix 16.6: Fauna Report – Short Range Endemics .................................................................. 6

Appendix 16.7: Fauna Report – Subterranean .................................................................................. 7

Appendix 16.8: Soil and Waste Characterisation .............................................................................. 8

Appendix 16.9: Waste Dump Modelling ............................................................................................ 9

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN iii March 2015

List of Tables Table 1: Clearing requirements associated with the Wonmunna Iron Ore Project .................... 2 Table 2: Current disturbance on Wonmunna Iron Ore Project tenements ................................. 8 Table 3: Wonmunna Iron Ore Project Legal Obligations Register.......................................... 14 Table 4: Average monthly temperature for Newman .............................................................. 15 Table 5: Average monthly rainfall and evaporation for Newman ........................................... 16 Table 6: Average rainfall intensities for Newman ................................................................... 16 Table 7: Proportion of vegetation associations located in the disturbance area of the Wonmunna Project................................................................................................................... 34 Table 8: Conservation significant fauna species recorded at Wonmunna ............................... 36 Table 9: Texture of Wonmunna Topsoil Samples ................................................................... 40 Table 10: Volumes of topsoil and laterite to be salvaged ........................................................ 41 Table 11: Quantity of topsoil and laterite required to sheet waste dumps ............................... 41 Table 12: Preliminary Waste Scheduling for Wonmunna Project ........................................... 44 Table 13: WASTE Dump Volumes ......................................................................................... 44 Table 14: Waste Dump Surface Area ...................................................................................... 44 Table 15: Concave Profile Option for a 40m high Landform sheeted entirely with rock armour. ..................................................................................................................................... 47 Table 16: Progressive Rehabilitation Schedule ....................................................................... 53 Table 17: Potential Closure Issues in order of decreasing risk ................................................ 63 Table 18: Proposed completion criteria for Wonmunna Project ............................................. 67 Table 19: Monitoring Template .............................................................................................. 70 Table 20: Template for Seed Data for Monitoring Rehabilitation .......................................... 71 Table 21: Quantitative measures attained with the proposed monitoring system ................... 73 Table 22: Criteria used to assess the state of rehabilitated landforms ..................................... 76 Table 23: Vegetation Associations at Wonmunna Project site ................................................ 79 Table 24: Habitat matching vegetation associations at Wonmunna Project with proposed landforms ................................................................................................................................. 80 Table 25: Descriptions of potential analogue communities ..................................................... 81 Table 26: Summary of the disturbance and rehabilitation areas at the Wonmunna Project at Decommissioning .................................................................................................................... 86 Table 27: Mine Closure Planning and Cost Estimation ........................................................... 88

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN iv March 2015

List of Figures Figure 1: Tenement layout of Wonmunna Iron Ore Project ...................................................... 3 Figure 2: Proposed infrastructure layout for NMM-west area................................................... 4 Figure 3: Proposed infrastructure layout for NMM-east area .................................................... 5 Figure 4: Proposed infrastructure layout for CMM area ........................................................... 6 Figure 5: Proposed Infrastructure Layout for SMM Area ......................................................... 7 Figure 6: Current disturbance at M47/1424 ............................................................................. 10 Figure 7: Current disturbance at M47/1423 ............................................................................. 11 Figure 8: Current disturbance at M47/1425 ............................................................................. 12 Figure 9: Geological Map of the Wonmunna Iron Ore Project .............................................. 18 Figure 10: Location of Main Surface Drainage Pathways at Wonmunna ............................... 23 Figure 11: Surface water flow modifications and sediment traps for NMM-west .................. 29 Figure 12: Surface water flow modifications and sediment traps for NMM-east ................... 30 Figure 13: Surface water flow modifications and sediment traps for CMM ........................... 31 Figure 14: Surface water flow modifications and sediment traps for SMM............................ 32 Figure 15: Concave profile option for a 40m high landform sheeted entirely with rock armour.................................................................................................................................................. 47 Figure 16: Concave profile option for a 40m high landform sheeted with soil ....................... 48 Figure 17: Concave profile option for a 40m high landform sheeted with soils and with rock armour on the toe ..................................................................................................................... 48 Figure 18: Recontoured NMM-east waste dump with two cross section profiles ................... 49 Figure 19: Recontoured NMM-west waste dump with cross section profile .......................... 50 Figure 20: Recontoured CMM waste dump with cross section profile ................................... 51 Figure 21: Recontoured SMM-west and SMM-east waste dumps with cross section profiles.................................................................................................................................................. 52

List of Plates Plate 1: Historic costeans ........................................................................................................... 9 Plate 2: Recent drilling sump which lies within NMM-east pit boundary ................................ 9 Plate 3: Example of lateritic subsoil to be utilised to sheet waste dump profiles (average diameter of 3cm) ...................................................................................................................... 42 Plate 4: Most main drainage lines on site will not be affected ............................................... 45 Plate 5: An ant’s nest surrounded by seed at Wonmunna ........................................................ 55 Plate 6: View southeast from NMM-east area ......................................................................... 57 Plate 7: Wonmunna waterhole – east of the Great Northern Highway................................... 59 Plate 8: Recent vandalism at the Wonmunna water hole – not on Project tenements ............. 60 Plate 9: Examining drill core onsite at Wonmunna ................................................................. 62 Plate 10: At closure most access tracks, including historical disturbance, will be rehabilitated.................................................................................................................................................. 85 Plate 11: No corefarm will be present on site .......................................................................... 96

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN v March 2015

1.0 Mine Closure Plan Checklist

Q No Mine Closure Plan (MCP) checklist Y/N

NA Page No.

Comments

1 Has the Checklist been endorsed by a senior representative within the tenement holder/operating company? (See bottom of Checklist.)

Y vi

2 How many copies were submitted to DMP? (See Appendix C for requirements)

Hard copies = 2 Electronic =1

Public Availability

3 Are you aware that the Mine Closure Plan is publicly available?

Y N/A

4 Is there any information in this Mine Closure Plan that should not be publicly available?

N N/A

5 If “No” to Q4, do you have any problems with the information contained in this Mine Closure Plan being publicly available?

N N/A

6 If “Yes” to Q4, has confidential information been submitted in a separate document/section?

N/A N/A

Cover Page, Table of Contents

7

Does the cover page include; Project Title Company Name Contact Details (including telephone numbers and

email addresses) Document ID and version number Date of submission (needs to match the date of this

checklist)

Y

Page after front cover

Scope and Project Summary

8 State why is the MCP is submitted (as part of a Mining Proposal or a reviewed MCP or to fulfil other legal requirements)

N/A N/A

As Appendix 9 of the Mining Proposal for Wonmunna Iron Ore Project

9

Does the Project summary include; Land ownership details; Location of the Project; Comprehensive site plan(s); Background information on the history and status of

the Project.

Y

Pg1-2

Figs 2-5

Legal Obligations and Commitments

10 Has a consolidated summary or register of closure obligations and commitments been included?

Y Sect 4.0

Data Collection and Analysis

11 Has information relevant to mine closure been collected for each domain or feature (including pre-mining baseline studies, environmental and other data)?

Y Sect 5.0

12 Has a gap analysis been conducted to determine if further information is required in relation to closure of each domain or feature?

Y Sect 5.1

Stakeholder Consultation

13 Have all stakeholders involved in closure been identified? Y Sect 6.0

14 Has a summary or register of stakeholder consultation been provided, with details as to who has been consulted and the outcomes?

Y Mining Prop

Final land use(s) and Closure Objectives

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN vi March 2015

Q No Mine Closure Plan (MCP) checklist Y/N

NA Page No.

Comments

15 Does the MCP include agreed post-mining land use(s), closure objectives and conceptual landform design diagram?

Y Sect 9.1 & 5.8.4

16 Does the MCP identify all potential (or pre-existing) environmental legacies, which may restrict the post-mining land use (including contaminated sites)?

Y Sect 3.1

Identification and Management of Closure Issues

17 Does the MCP identify all key issues impacting mine closure objectives and outcomes?

Y Sect 8.0

18 Does the MCP include proposed management or mitigation options to deal with these issues? Y

Sect 8.0

19 Have the process, methodology, and rationale been provided to justify identification and management of the issues?

Y Sect 8.0

Closure Criteria

20 Does the MCP include an appropriate set of specific closure criteria and/ closure performance indicators?

Y Sect 9.0

Closure Financial Provisioning

21 Does the MCP include costing methodology, assumptions and financial provision to resource closure implementation and monitoring?

Y Sect 10.0

22 Does the MCP include a process for regular review of the financial provision?

Y Sect 10.0

Closure Implementation

23 Does the reviewed MCP include a summary of closure implementation strategies and activities for the proposed operations or for the whole site?

Y Sect 10.0

24 Does the MCP include a closure work program for each domain or feature?

Y Sect 10.0

25 Have site layout plans been provided to clearly show each type of disturbance?

Y Fig 2-5

26 Does the MCP contain a schedule of research and trial activities?

Y Table 8

27 Does the MCP contain a schedule of progressive rehabilitation activities?

Y Table 8

28 Does the MCP include details of how unexpected closure and care and maintenance) will be handled?

Y Sect 8.0

29 Does the MCP contain a schedule of decommissioning activities?

Y Sect 10.0

30

Does the MCP contain a schedule of closure performance monitoring and maintenance activities?

Y Sect 9.0

Closure Monitoring and Maintenance

31

Does the MCP contain a framework, including methodology, quality control and remedial strategy for closure performance monitoring including post-closure monitoring and maintenance?

Sect 9.0

Closure Information and Data Management

32 Does the Mine Closure Plan contain a description of management strategies including systems, and processes for the retention of mine records?

Pg 98

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN vii March 2015

Corporate Endorsement: “I hereby certify that to the best of my knowledge, the information within this Mine Closure Plan and checklist is true and correct and addresses all the requirements of the Guidelines for Preparing Mine Closure Plans approved by the Director General of Mines”.

Name: Mr Andrew Caruso Position: Managing Director

Signature:

Date: 25th March, 2015

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN 1 March 2015

2.0 Scope and Purpose This Mine Closure Plan (MCP) has been developed for the proposed Wonmunna Iron Ore Project (the Project) and was produced in general accordance with the Department of Minerals and Petroleum (DMP) online guidelines (DMP 2011) and the ANZMEC strategic framework (ANZMEC 1995) and in consultation with DMP, Main Roads Department (MRD), Department of Water (DoW), Department of Parks and Wildlife (DPaW) and other stakeholders. It is submitted as Appendix 9 of the Mining Proposal for the Project. This MCP is preliminary in form and will evolve throughout the life of the Project. This will occur with increased knowledge gain through further waste characterisation, rehabilitation trials, potential advances in technology and monitoring results. Changes to the MCP may also result as an outcome of ongoing stakeholder consultation.

The contact for any queries or further information for the Wonmunna Iron Ore Project Mining Proposal is:

Andrew Caruso Managing Director Ascot Resources Ltd Phone: 0893814534 Mobile: 0439981763 Email: [email protected]

3.0 Project Overview The Project is described in detail within the Mining Proposal. The Project is located approximately 70km west-northwest of Newman in the Pilbara region of Western Australia (Figure 1 of Mining Proposal).The Project is located within the Hamersley Ranges which has a long mining history. The Project is located within 25 kilometres of operating mines; Hope Downs (Rio Tinto/Hancock JV), Area C (BHPB) and West Angelas (Rio Tinto) (Figure 2 of Mining Proposal). The northern boundary of tenement M47/1425 abuts the Great Northern Highway (Figure 3 of Mining Proposal). Wonmunna Iron Ore Pty Ltd (WIO) is proposing to develop the Project on leases M47/1423, M47/1424, M47/1425 & L47/727(Figure One). The proponent is a 100% subsidiary of Ascot Resources Limited. A letter of authority for the submission of environmental approval documents is provided and is contained in Appendix 11.1 of the Mining Proposal. The Project will involve the extraction of high grade iron ore from the three Marra Mamba deposits, and will thus require the development of multiple open pits, commencing at the western end of the North Marra Mamba deposit. The mine plan and throughputs are based on an average grade of 57.5% Iron and production of


3Mtpa of ore in year one increasing to 5Mtpa from year three to end of mine life at year eight (Table 1 of the Mining Proposal). Further details on the Project are provided in the Mining Proposal. The planned layout of the mine is provided in Figures Two to Five. The areas and types of proposed disturbance are summarised below in Table 1.

Table 1: Clearing requirements associated with the Wonmunna Iron Ore Project

Mine Areas M47/1423 (ha) M47/1424 (ha) M47/1425 (ha) Total (ha) INFRASTRUCTURE Road Train Park Up / Workshop

7.21 7.21

Camp 7.46 7.46 Magazine 0.28 0.28 Offices/Workshop/Go-line 5.64 5.64 Crusher/Truck Load Out 43.23 43.23 Total 0.28 63.54 63.82 PITS NMM-west 26.66 26.66 NMM-east (pits combined) 85.26 85.26 CMM 48.43 48.43 SMM-east 21.52 21.52 SMM-west 21.76 21.76 Total 48.43 111.91 43.28 203.62 WASTE DUMPS NMM-west 21.47 21.47 NMM-east 67.48 67.48 CMM 66.55 66.55 SMM-east 26.87 26.87 SMM-west 34.68 34.68 Total 66.55 88.95 61.73 217.24 ROADS Camp to Offices 6.59 6.59 Magazine Road 1.06 1.06 NMM Haul Roads 37.27 37.27 CMM Haul Roads 14.26 14.26 SMM Haul Roads 1.68 1.68 Total 15.32 43.86 9.68 68.86 MISCELLANEOUS Borefields 0.2 0.2 0.2 0.6 Topsoil Stockpiles* 0 Total 0.2 0.2 0.2 0.6 Total area to be cleared 130.78 308.47 114.89 554.14 Total Purpose Permit area 669.14 1266.05 528.24 2463.61

(*included in pit and dump footprints)

The abbreviations for the pits and waste dumps are: - NMM refers to Northern Marra Mamba deposit - CMM refers to the Central Marra Mamba deposit and - SMM refers to the Southern Marra Mamba deposit.


Figure 1: Tenement layout of Wonmunna Iron Ore Project


Figure 2: Proposed infrastructure layout for NMM-west area


Figure 3: Proposed infrastructure layout for NMM-east area


Figure 4: Proposed infrastructure layout for CMM area


Figure 5: Proposed Infrastructure Layout for SMM Area


3.1 Historical Disturbance The disturbance already present on the tenements (as provided in the 2014 Mining Rehabilitation Fund submission) is summarised in Table 2 and Figures 6-8. This exploration was carried out prior to the acquisition of the tenement rights by Ascot Resources Ltd.

Table 2: Current disturbance on Wonmunna Iron Ore Project tenements

Tenement Disturbance Type

Number Length Width Area (m2)

Hectares (ha)

M47-1423 Tracks 11524 4 46096 4.61 Hydrological

Drill Holes 4 0.099

M47-1424 Tracks 49042 4 196166.3 19.62 Hydrological

Drill Holes 13 1.24

Camp 8850 0.88 M47-1425 Tracks 19229 4 76916 7.69 Hydrological

Drill Holes 2 0.72

TOTAL 7.76 All areas of disturbance not already progressively rehabilitated or within the proposed disturbance footprint will be progressively rehabilitated after equipment is mobilised to site for the commencement of site preparation. The rehabilitation will be carried out according to DMP guidelines with drill holes being plugged to below the ground surface at 500mm and backfilled for water shedding. Drill spoils, if present, will be placed into existing sumps and backfilled. Stockpiled topsoil will be spread over the disturbed area, along with any stored cleared vegetation. The rehabilitation of any disturbance within the Exclusion Zone will receive extra supervision and special management.


Plate 1: Historic costeans

Plate 2: Recent drilling sump which lies within NMM-east pit boundary


Figure 6: Current disturbance at M47/1424


4.0 Identification of Closure Obligations and Commitments The list of legal obligations is currently limited as this Closure Plan is to be submitted with a Mining Proposal for a new mine site. The Legal Obligations Register is provided as Table 3. There are no other non-legally binding commitments or promises for the Project to date.

The decommissioning and rehabilitation of the Project will be conducted in accordance with the general provisions of key legislation, policy documents and related guidelines. These include:

Mining Act 1978 Environmental Protection Act 1986 Environmental Protection and Biodiversity Conservation Act 1999 Conservation and Land Management Act 1984 Mines Safety and Inspection Act 1994 Mines Safety and Inspection Regulations Contaminated Sites Act 2003 Wildlife Conservation Act 1950 Rights in Water and Irrigation Act 1914 Native Title Act 1993 Aboriginal Heritage Act 1972.

4.1 Summary of Closure Commitments The Wonmunna Iron Ore Project agrees to undertake the following closure commitments:

- Design waste landforms to effectively manage surface water flow to reduce erosion.

- Lateritic windrows will be constructed at the margins and edges of waste rock landforms whilst under construction.

- Culverts or floodways will be installed at road creek crossings to prevent disruption to large sheet water flow events.

- All current areas of disturbance not already progressively rehabilitated or within the proposed disturbance footprint will be progressively rehabilitated after equipment is mobilised to site for the commencement of site preparation.

- All progressive rehabilitation will be set up as rehabilitation trials to determine soil ameliorant type and rate, and seed mix type, proportions, treatments and rates.

- Once mining commences, access to larger quantities of waste will enable more detailed waste characterisation. Results will be used in rain simulation modelling, and final profiles may be changed accordingly. Similarly soil amelioration (to growth medium on waste dumps) may be modified.

- The groundwater monitoring regime will be continued to maintain the awareness of groundwater levels to ensure mining remains 5m or more above the water table.

- Areas to be disturbed will be surveyed for active Pebble Mound Mice mounds before vegetation clearance.

W o n m u n n a I r o n O r e P t y L t d

M I N E C L O S U R E P L A N 1 4 M a r c h 2 0 1 5

T a b l e 3 : W o n m u n n a I r o n O r e P r o j e c t L e g a l O b l i g a t i o n s R e g i s t e r

Source of Obligation

Tenement Number

End/Cond Number

Closure Condition

DMP Tenement Endorsement /

Conditions

M47/1423 M47/1424 M47/1425

E10 Measures such as effective drainage controls, sediment traps and stormwater retention facilities being implemented to minimise erosions and sedimentation or receiving catchments and adjacent areas.

E11 No mining/activities in respect to mining operations being carried out that may disrupt the natural flow of any waterway unless in accordance with current licence to take surface water or permit to obstruct or interfere with beds of banks issued by DoW.

E13 Measures such as effective drainage controls, sediment traps and stormwater retention facilities being implemented to minimise erosion and sedimentation of receiving catchments and adjacent areas.

C6 The lessee submitting a plan of proposed operations and measures to safeguard the environment to the Director, Environment, DMP for his assessment and written approval prior to commencing any developmental or productive mining or constructive activity.

L47/727 No conditions in relation to closure Ministerial Statement None to date

Works Approval None to date EP Act Licence None to date

NVC Purpose Permit 6261/1

M47/1423 M47/1424 M47/1425

3 The Permit Holder must not clear more than 555 hectares of native vegetation. All clearing must be within the area cross-hatched yellow on attached Plan 6216/1.

6 Weed control When undertaking any clearing or other activity authorised under this Permit, the Permit Holder must take the following steps to minimise the risk of the introduction and spread of weeds: (i) clean earth-moving machinery of soil and vegetation prior to entering and leaving the area to be cleared; (ii) ensure that no weed-affected soil, mulch, fill or other material is brought into the area to be cleared; and (iii) restrict the movement of machines and other vehicles to the limits of the areas to be cleared.

7 Watercourse management (a) Where practicable the Permit Holder shall avoid clearing riparian vegetation. (b) Where a watercourse or wetland is to be impacted by clearing, the Permit Holder shall maintain the existing surface flow.

8 In relation to the clearing of native vegetation authorised under this Permit, (i) the location where the clearing occurred, recorded using a Global Positioning System (GPS) unit set to Geocentric Datum Australia 1994 (GDA94), expressing the geographical coordinates in Eastings and Northings or decimal degrees; (ii) the date that the area was cleared; (iii) the size of the area cleared (in hectares); and (iv) purpose for which clearing was undertaken

Licence to Take Water

GWL No 179990

This condition does not affect mine closure: Water to be taken for exploration drilling purposes, and mining camp purposes for 12 month period from October 14 2014.

NOI/Mining Proposal

This MCP is to be submitted with Mining Proposal – thus none to date


5.0 Collection and Analysis of Closure Data As the development of the Wonmunna Project has been conducted over a number of years, it has allowed for the gathering of both baseline data, plus the completion of follow up studies to provide detailed knowledge of the ecosystems of the Project site. The baseline environmental data is provided in detail within the Mining Proposal. The following is therefore a summary of environmental information on the Wonmunna Project, with particular reference to mine closure.

5.1 Climate Western Australia has three broad climate divisions. The Pilbara is characterised by an arid-tropical climate receiving summer rainfall. Cyclones can occur during this period, bringing heavy rain. The south west corner has a Mediterranean climate, with long, hot summers and wet winters. The remainder is mostly arid land or desert climates.

5.1.1 Temperature

The Pilbara climate is arid and experiences hot summers and mild dry winters. Mean maximum summer temperatures average 36-37 Celsius (°C) from November to April, rising to 50°C. Temperatures over the May to October period are milder, with mean maximum temperatures averaging 28-29°C and cooler nights, particularly in inland desert regions, reflected in the mean minimum for this period of 15°C, down to around 6-9°C in July (dropping to around 0°C). The nearest current Bureau of Meteorology (BOM) climatic station to Wonmunna area is at Newman Aero (Site Number 007176). The average monthly temperatures at Newman range from 6 to 39°C (Table 4).

Table 4: Average monthly temperature for Newman

Average temperature

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Max (oC) 39 37 35 32 27 23 23 26 30 35 37 38 Min (oC) 25 24 22 17 12 7 6 8 12 18 21 24

5.1.2 Rainfall and Evaporation

Rainfall in the Pilbara is generally low (270-400mm) and variable throughout the year, but greatest during summer and autumn, resulting from summer storms bringing sporadic and drenching thunderstorms. Occasional tropical cyclones typically from January to March (on average, two cyclones) cross the Pilbara coastline each year, and are capable of producing very destructive winds. With the exception of these large events, rainfall can be erratic and localised due to thunderstorm activity. Rainfall from a single site may not be representative of the spatial variability of rainfall over a wider area. High summer temperatures and humidity seldom occur together, giving the Pilbara its very dry climate. During May and June, cold fronts move easterly across WA, sometimes reaching the Pilbara, producing light winter rains. Rainfall is at its lowest in August to November. The


annual average rainfall for Newman is 326mm (BOM, Newman Aero). Annual variability is high with recorded rainfall varying between 153mm (1976) and 619mm (1999). On average, the driest period is July to November, with September and October the driest months. January and February are the wettest months. Average monthly rainfall for Newman is shown in Table 5.

Table 5: Average monthly rainfall and evaporation for Newman

Average rainfall/evap

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Rainfall (mm)

67 75 39 19 17 15 15 7 4 6 12 39

Evaporation (mm)

461 369 343 290 174 173 199 193 264 377 424 466

The mean annual pan evaporation rate at Newman is above 3733mm (Department of Agriculture, 1987), exceeding mean annual rainfall by 3400mm. Average monthly pan evaporation rates for Newman are shown in Table 6 (varying between minimum 173mm in June and maximum 466mm in December. Design rainfall intensity data for the Wonmunna area for various rainfall durations and Average Recurrence Interval (ARI) are provided given in Table 3 (Institution of Engineers Australia, 1987). This data can be used for waterway designs.

Table 6: Average rainfall intensities for Newman

Rainfall Duration

5yr ARI 10yr ARI 20yr ARI 50yr ARI 100yr ARI

1hr 32.9 38.5 45.5 55.0 62.4 6hr 9.7 12.0 14.8 18.9 22.3 9hr 7.3 9.2 11.5 14.8 17.6 12hr 6.0 7.6 9.6 12.5 14.9 24hr 3.7 4.7 5.9 7.8 9.3 48hr 2.2 2.8 3.6 4.7 5.6 72hr 1.6 2.0 2.6 3.4 4.1


5.2 Topography & Geology

5.2.1 Topography

The Department of Agriculture and Food Western Australia (van Vreeswyk et al. 2004) has mapped the land systems of the Hamersley subregion from aerial photography. Land systems are grouped according to landform, soils, vegetation and drainage patterns (Payne & Leighton 2004; van Vreeswyk et al. 2004). The Project area intersects four land systems:

Egerton – dissected hardpan plains supporting Mulga shrublands and hard spinifex hummock grasslands (south west - 40%)

Newman – rugged jaspilite plateaus, ridges and mountains supporting hard spinifex grasslands (north & north east - 40%)

Rocklea – basalt hills, plateaus, lower slopes and minor stony plains supporting hard spinifex (and occasionally soft spinifex) grasslands (north east - 20%)

Platform – dissected slopes and raised plains supporting hard spinifex grasslands, represents a very minor portion of the study area.

5.2.2 Regional Geology

The geology in the tenement area consists of Precambrian rocks (bedrock) overlain by Cainozoic deposits. The Cainozoic deposits consist of Quaternary alluvium developed in major creeks, colluvium and Tertiary Channel Iron Deposits (CID), silcrete, ferricrete and calcrete (Figure 9). The thickness of the Cainozoic deposits within the tenements, proven by exploratory drilling in 2008, is up to 42m in the paleo-river valleys. The regolith is represented by thin, skeletal soils over weathered bedrock. Precambrian bedrock in the tenement area consists of the mafic volcanic dominated Fortescue Group and the banded iron formation (BIF) dominated Hamersley Group (Johnson S.L., Wright A.H. 2001). Late Archaean Jeerinah Formation is up to 2km thick and consists of grey to black carbonaceous shales with pyrite and pyrrhotite. The formation also contains numerous thin (<2m) beds of dolomite and chert, which become more abundant towards the top. In the weathered and oxidised part of the formation, dolomitic shale forms units up to several tens of metres thick. The Jeerinah Formation is intruded with mafic sills (dolerite) up to 200m thick, which makes up most of the exposed section in the tenement. Pillow basalts up to 100m thick, may also be present in the upper part of the formation. Proterozoic Marra Mamba Iron Formation of the Hamersley Group is present in the tenement area and comprises bedded BIF and shales which have become variably enriched in iron locally. The formation generally forms moderate topographic highs in the tenement area with a laterite capping usually developed. The lowest unit is the Nammuldi Member consisting of 70m of yellow weathering chert and cherty BIF with some shale bands. Towards the top of the unit podding of chert bands is common with the development of a marker band known as the “potatoes”. The middle unit is the MacLeod Member comprising 25m of interlayered shale and thin BIFs. The upper unit is the Mount Newman Member consisting of 50 m of BIF interbedded with 18 thin shale bands.


Figure 9: Geological Map of the Wonmunna Iron Ore Project


The three deposit areas, North Marra Mamba (NMM), Central Marra Mamba (CMM) and South Marra Mamba (SMM) occur where iron enrichment of the BIF units have occurred.

5.2.3 Local Geology

There is relatively poor outcrop in the Project area. In the east alluvial/CID cover forms a well preserved Hamersley Surface – i.e. laterite cover, and to the west more Marra Mamba Iron Formation (MMIF) outcrops. From examination of the present NMM drill and gamma logs - and with some confirmation during a ground examination during a site visit - the full sequence of MMIF appears to be present (i.e. Nammuldi Member to Mt Newman Member, together with some West Angela Member of the overlying Wittenoom Formation (Pearcey & Sergeev 2012, Slater & Kneeshaw 2012).. The high grade mineralisation typically occurs within the Mt Newman Member.

5.3 Seismicity & Geotechnical Data

5.3.1 Seismicity

The Wonmunna area is located within a region of Australia judged to be at low risk from future natural seismic events (earthquakes) taking place over the life of the mining operation. The estimated maximum earthquake acceleration in a 50 year period with a 10% chance of being exceeded is low at ~0.9m/s2 (0.09g)5. Earthquake-induced ground accelerations of this magnitude (if occurring) would be expected to have minor adverse influence on future overall pit wall stability performance (P O’Bryan 2014).

5.3.2 Geotechnical Data

Preliminary geotechnical work was completed to enable the initial designs for pit walls, which enable disturbance footprints to be calculated. Details of findings are presented in Appendix 16.1. Further geotechnical studies will continue for the life of the mine. The report also indicated that due to geotechnical considerations:

Haul roads should be located 30m or more beyond the pit crests due to the expected poor rock mass conditions and wall design parameters.

Final waste dumps should be 70m or more behind the pit crests to meet compliance with DMP pit abandonment guidelines (DoIR 1987).


5.4 Hydrology

5.4.1 Hydrogeology

Unconfined local aquifers are likely to be developed in the more recent Quaternary and Tertiary sediments. Generally, yields of up to 500kL/d are anticipated in bores intercepting sands and gravels and/or weathered basement materials. Groundwater potential is significantly increased where localised calcrete deposits exist and yields up to 750kL/d are possible. Bores are typically expected to be less than 100m deep with groundwater salinities ranging from 400 to 1,000mg/L Total Dissolved Solids (TDS). The Jeerinah Formation consists of basal quartz sandstone (Woodiana Member) and a sequence of interbedded carbonaceous pelite, chert and minor sandstone (GSWA 1997). Groundwater occurrence is generally associated with faults and fracture zones, where locally increased permeability occurs. Within the tenement area tectonic folding caused brittle deformation in the banded dolomites and highly siliceous lithologies such as cherts. The formation may be further fissured by thermal metamorphism on the contact with mafic sills. Bore yields are likely to be variable and range from minor flows to up to 400kL/d. Groundwater quality is expected to be fresh (less than 1,500mg/L TDS) to brackish (1,500–10,000mg/L TDS). The Marra Mamba Formation is a banded iron formation (BIF) aquifer with permeability associated mainly with fractures and ore mineralisation. Mineralised Marra Mamba is generally permeable and moderate (approx. 300 to 500kL/d) supplies of groundwater are expected. Weathered and fractured chert within BIF can also be a source of groundwater.

5.4.2 Groundwater

During a 15 month period, 10 groundwater monitoring rounds were completed on 20 bores. Data, including groundwater contours, is detailed in the report attached as Appendix 16.2. From the majority of the data, it can be seen that this is a “flashy” system with a quick response to rainfall events followed by a quick recession afterwards. It does not show a full recession however with water levels leveling out once the system has reached its draining point. The magnitude of water level change recorded in all bores was a maximum of 0.79m and a minimum of 0.19m. This is not considered significant considering that the deposit will be mined to 5m above the water table, giving a large buffer zone. The groundwater levels recorded during the monitoring period have been used to create groundwater elevation contours across the site and these contours have been plotted along with survey levels of the lowest points of the Weeli Wolli Creek bed Appendix 16.2). It was clearly seen that groundwater and surface water systems are not in direct hydraulic connection. Groundwater is shown to flow towards the north east and is well below the level of the Weeli Wolli Creek bed. At its highest point, in January 2012, groundwater levels are 14.53m below the Weeli Wolli Creek in the north eastern section of the site, 26.87m at CMM and 39.07m at SMM.


Based on current monitoring information, groundwater levels vary by between 0.19 and 0.8 metres. Therefore, under normal rainfall conditions, it is unlikely that groundwater will discharge into the Weeli Wolli Creek. Groundwater levels may rise significantly during the cyclone season due to large amounts of recharge however; flow within the creek would be dominated by surface water runoff. Therefore, in effect, both the Weeli Wolli Creek system and the associated indigenous riverine rock hole (Forgotten Pool) features are totally dependent on surface water flows. The water quality analyses indicated that water from beneath the Wonmunna site meets the Australian Drinking Water Guidelines (ADWG) standards for drinking water and is therefore potable. Although hardness is shown to exceed the aesthetic guideline value of 200mg/L, this is not cause for concern as there are no deleterious health effects associated with this. Water from MRD3 bore (for which a Groundwater Extraction Licence has been obtained) is of a calcium–magnesium–sulphate type and levels of sulphate are likely to be attributable to the igneous geology. There are exceedances if results are compared to the ADWG guidelines for aesthetic values for Total Dissolved Solids (TDS) and sulphate but again, these are not a major health concern (Appendix 16.2). Groundwater abstraction has the potential to affect Groundwater Dependent Ecosystems (GDEs) such as phreatophytic vegetation and stygofauna as well as other groundwater users. As the Project plans to mine to no closer than 5m from the water table, no dewatering for mining will be required. Therefore, the mining of the deposits on site will not impact the groundwater levels on site. The Department of Water have issued a 5C Licence (GWL179990) to take groundwater from the Main Roads Department bore MRD3. This licence allows for a maximum of 3,000kL/annum (0.1L/s) to be abstracted for mining camp purposes and exploratory drilling operations. There are no known areas of phreatophytic vegetation within close proximity to either bore which could be affected by this abstraction. Groundwater in the area is mostly associated with weathering features, ore mineralisation or fracturing/faulting of the bedrock, or with intrusive lithologies including quartz veins, pegmatites and dolerite dykes (particularly where structural deformation occurs along contact margins). Annual recharge will be through extreme rainfall events in the summer months. Consequently, due to the very low abstraction rates, absence of GDEs and other users in the area, the risk to the environment and to the aquifer as a water source is considered extremely low from the abstraction.

5.4.3 Surface Water

5.4.3.1 Stream Flow Streamflow in the Pilbara region is typically correlated with rainfall, with the majority of streamflow occurring during the summer months. Streamflow in the smaller flow channels is typically short in duration, and ceases soon after the rainfall passes. In the larger river channels and catchments, runoff can persist for some time following major rainfall events, such as those resulting from tropical cyclones. Available river gauging data (Fortescue River near Newman) indicates an average annual runoff volume of 5.4% of the Newman annual rainfall. However the variability of annual runoff is high, with annual runoff varying between 0-15% of the Newman average


rainfall (Appendix 16.3). Due to relative catchment sizes, streamflow data recorded at this station does not necessarily represent the runoff characteristics in the Wonmunna area.

5.4.3.2 Peak Discharge Estimates Peak streamflow discharges from ungauged catchments in the Pilbara region can be estimated using empirical techniques, such as those recommended in “Australian Rainfall and Runoff” (ARR), which recommends the use of the Rational Method and Index Flood Method. Due to the relatively sparse and short stream gauging records in the Pilbara region (upon which the estimation methods were based); the ARR methods do not provide reliable flood peak discharge estimates and tend to overestimate flows. For these purposes, flood estimates were generic “upper limit” estimates for the Eastern Pilbara (based on catchment area). In this general vicinity, some large creeks flow north across the Great Northern Highway. Weeli Wolli Creek is the largest and has previously been estimated to have a 100 year ARI peak discharge downstream of 5923m³/s upstream of the Marillana Creek confluence (53km north of the Wonmunna deposit) and 8310m³/s downstream of Marillana Creek.

5.4.3.3 Local Surface Flows The Wonmunna Project area consists of low lying mesas with steep sides, cut by drainage paths. The main iron ore deposit (pits and dumps) is the Northern Marra Mamba (NMM), split into two by the Weeli Wolli Creek. The Central Marra Mamba (CMM) and the Southern Marra Mamba (SMM) deposits lie further south west. Overall surface water drainage in the area generally trends north towards the Fortescue Marsh, but is locally variable in dissected terrain (Figure 10). Associated mine infrastructure is located adjacent to the NMM operations. A proposed haul road links all the deposits to the mine infrastructure. The following discussion on the effect of infrastructure and pits on surface water flow is repeated from the Mining Proposal (Section 6.2.1). This is because the issues of surface water flow need to be considered during mining to prevent any issues for surface water at closure. ..


Figure 10: Location of Main Surface Drainage Pathways at Wonmunna


NMM-west

The NMM-west pit is about 750m long and located west of Weeli Wolli Creek in a shallow valley over the main drainage line in the valley (Figure 11). The pit is therefore potentially subject to minor sheet flow from three sides – north, south and west – with main drainage east down the valley and into Weeli Wolli Creek. The associated waste dump lies over the head of the same valley and will largely drain east towards the pit. Part of the dump will also drain west and north off the mesa. The mine infrastructure layouts are shown in Figure 2.

Crusher / Stockpile Area – this area (500m x 700m) is located on a mesa within a shallow westward draining valley. The site slopes in several directions but mainly west. Minor surface water diversions will protect against sheet flow.

Accommodation Camp - the camp site (250m x 250m) is located on a northward sloping site. Minor surface water diversion will be necessary along the southern side of the site to protect against sheet flow off the adjacent ridge.

Office Area - the offices are located on higher ground and will have no drainage issues.

Truck Park Bay – the site of the truck parking area (about 250m x 250m) is located nearer to the Great Northern Highway and slopes gently to the north. Minor surface water diversion will be necessary along the southern side to protect against sheet flow off the ridge behind.

NMM-east

The NMM-east pits span about 2.6km located on a low mesa 20-30m high, east of Weeli Wolli Creek. The mesa runs parallel to, and 600m south of Great Northern Highway, and generally drains both to the south and north sides. On the north side, drainage collects in watercourses (including Weeli Wolli Creek) that flow north and cross the highway. On the south side, runoff collects in a valley adjacent to the mesa, which drains to the east to join a join a large creek running north past the eastern end of the mesa. It then passes beneath the highway in a large culvert installation approximately 1.5km east of the Weeli Wolli Bridge (Figure 12). Located on the top of the mesa, only minor pit bunding is required to protect the pits from ingress of surface water. The associated NMM-east waste dump is about 1.5km long and overlies the valley immediately to the south of the pits (Figure 3). The impacting surface water catchment is about 2km² and would generate 100 year ARI flows of about 13m³/s. Subject to further investigation, it is proposed to divert the flow along the south edge of the dump (adjusted to suit the diversion design), and discharge it back into the valley downstream. The waste dump will be designed to ensure little ponding at the western end.


CMM

The CMM deposit is located about 4.5km south west of the proposed crusher/stockpile area (Figure 4). The waste dump is 1300m long and located north of the pit and cuts off southward surface flow off a ridgeline, up to 600m from the dump at the west end. There is a trapped low point part way along the north edge of the dump footprint. It is noted however that once ponded water levels built up, the pond would overflow over an adjacent low saddle and into the catchment immediately to the north. This saddle could be excavated to further reduce the size of the pond that could form against the dump. A second diversion is required at the north west end of the dump where water will be diverted through a shallow cut around the west end of the dump. This 300m diversion would similarly carry a nominal 100 year flow of 2.0-2.5m³/s. The pit is nominally 1500m long and is largely protected from surface water impacts by the proposed dump location. In this regard however it is noted that the northern edge of the pit forms a trapped low point that could require a significant diversion channel around the western end of the pit, about 1km long with cuts up to 7m deep. The sequencing of the pit excavation and placement of the resulting waste to form a bund at sufficient distance north of the pit edge will allow gravity drainage of most of the impacting surface water flows towards the west (Figure 12). This will be undertaken so that a diversion channel will not be required. In addition, a significant creek (branch of Weeli Wolli Creek, 8km²) runs along the south western side of the pit for 550m. The 100 year ARI flow at this point is about 35m³/s. This creek then turns south and away from the pit. The pit footprint could be adjusted to avoid the creek line or a diversion constructed over 550m (e.g. 4m wide base, 1.5m water depth). The haul road also passes just south of the pit, and is crossed by the same creek. An initial redesign has been done and this indicates that the redesign looks like the best option but it will be reexamined before the mining of this area is undertaken in year 3 of the Project.

SMM-east

The SMM-east deposit is located about 6.5km south west of the proposed stockpile area (Figure 5). The waste dump 700m long is located north of the pit and cuts off southward surface flow off a ridgeline about 500m to the north. A nominal diversion (pit bund with an associated low flow channel at the toe) is required to divert runoff around the west and east ends of the dump. The pit is nominally 600m long and is largely protected from surface water impacts by the proposed dump location. However the pit lies across a significant watercourse (3km²) at the north west end of the pit as currently proposed. Investigations will be carried out on possible surface water management options in the future. A water course diversion would be over about 750m around the south west side of the pit to rejoin the original channel (channel 5m wide base, 1.2m water depth, or a bund / channel combination) (Figure 14). Again the northern edge of the pit forms a trapped low point and requires consideration of the sequencing of the pit excavation and placement of the resulting waste to reduce the problem. . As this pit is the last pit to be mined toward the end of the Project, the sequencing and any diversions required will be considered in detail before pit excavation commences.


SMM-west

The SMM-west deposit is located about 8km south west of the proposed stockpile area and 1km west of the east deposit. The waste dump is 800m long and located north of the pit and is generally not impacted by surface water, except at the proposed north western edge. Storm water can be readily diverted around the dump at this location. A significant watercourse passes to the east of the dump (Figure 14). The pit is nominally 800m long and is largely protected from surface water impacts by the proposed dump. The pit is not impacted by any significant surface water drainage paths. A minor watercourse passes close to the proposed south west edge of the pit.

Haul Road

A haul road is to be constructed from the crusher / stockpile area to each of the proposed pits. The haul road crosses Weeli Wolli Creek to reach the NMM-east (Figure 3). The sections of the haul road are:

An 8.5km haul road is located along higher ground towards the west and then south to the CMM. It then drops off the mesa and crosses a large creek (tributary to Weeli Wolli Creek) before climbing over a small ridgeline to SMM-east, and then climbs again to the SMM-west.

A 5km haul road crosses Weeli Wolli Creek and then climbs towards NMM-east.

From the crusher / stockpile area, a 2.5km road passes around the west side of the NMM-west dump and then drops down to the truck park bay.

An access road runs down to the accommodation camp.

Drainage of unsealed roads is important to maintain the condition of the road. Conversely, in dry weather, it is necessary to apply water to the road surface for dust suppression.

Effective drainage of the pavement surface is determined by the pavement cross fall, the longitudinal grade and the nature of the pavement materials. Side drains collect runoff from the road surface and cut batters. There is limited scope to alter the slope of the table drain (which follows the slope of the road / natural surface), but the flow velocity may be constrained by varying the catchment area contributing to the drain (via spacing of turn-outs and cross drain outlets) to prevent scouring. Armouring of drains can be considered if required. Intervals between turn-outs should be shortened as terrain steepens.

The selected road route will cross two significant creeks, Weeli Wolli Creek with a 15m wide sandy drainage channel between the NMM pits, and a creek crossing near CMM. The other catchments crossing the haul road are relatively minor. Road crossings of watercourses will be low level floodways designed to resist submergence, or at least subsequent repair. Culverts may be installed to provide a better level of service, but have greater environmental impacts (more potential for erosion and scouring) than a floodway set at bed level. The floodway trafficable surface may range from the natural bed, interlocking rock armour, gravel materials, or a paved or sealed surface. The duration of the flow across a road can be used as a measure of consequence of failure / downtime in haulage and production.


5.4.3.5 Potential Surface Water Impacts Potential surface water impacts include:

• Interruption to existing surface water flow patterns, • Reduction of surface water runoff volume and quality in the downstream

environment, • Impact on downstream vegetation communities (that may be dependent on

this drainage), • Discharge of various chemicals, including hydrocarbons and sewage

treatment plant and • Haul roads and other infrastructure.

The general objectives in regard to surface water will be to manage the potential effects of mine operations on the integrity, functions and environmental values of watercourses downstream and ensure that existing and potential uses are protected. The management principles for effective erosion and sediment control for clearing areas will be based on the following:

• Minimise the extent of soil disturbance, especially near natural surface water flow paths (this has been done with location of infrastructure and waste dumps planned to minimise surface flow interruption).

• Avoid disturbance of riverine vegetation where possible (the 1km wide Exclusion Zone protects the majority of the Weeli Wolli Creek) (Figure 15).

• Salvage topsoil in dry conditions where practicable. • Progressive rehabilitation wherever possible. • Restrict access to undisturbed areas. • Integration of erosion and sediment control issues into site and construction

planning (already commenced with end waste dump landforms and sediment traps location plans).

• Road crossings of waterways constructed and designed to minimise bed and bank disturbance.

• Construction of surface drains to control and manage surface runoff, separation of clean water runoff (undisturbed catchments) from dirty (sediment laden) and contaminated runoff from disturbed catchments.

• Runoff from disturbed areas, waste dumps and stockpiles will typically be sediment laden and will require treatment in sediment traps prior to overflowing to the downstream environment.

• Waste Dumps will be designed to be water harvesting on top, and therefore not water shedding with no flow escaping from the top of the dump to the recontoured side profile as the water on top will dissipate either by seepage or evaporation.

• All vehicles will remain on established haul roads or access roads. No off road driving will be permitted (excluding emergencies).

• Haul roads will be located and designed to not disrupt major surface water flow and to keep road runoff local to the road.

• Sediment captured in basins will be allowed to settle out to achieve quality criteria before the treated runoff overflows into the natural system.

• The erosion and sediment control measures will all be maintained to ensure they are in proper working order at all times.


• Sediment basins will be constructed to a specified design criterion to contain runoff from disturbed areas, and to keep water quality in downstream watercourses and water bodies within acceptable limits.

• Potentially polluted runoff will be controlled to drain into ponds fitted with outflow baffles, to prevent the discharge of oil and grease products into natural waterways.

Sediment Basins

Sediment basins are located at low points and constructed by forming earth bunds. Storage volume consists of a permanent pool settling zone and a sediment storage zone. An outlet structure (i.e. ‘control’ outlet such as an overflow pit / pipe system) is preferred so that flows captured in the basin continue to discharge downstream. A spillway allows flow volumes that exceed the capacity of the basin to discharge downstream. The alternative is a spillway only (no ‘control’ outlet). In this case smaller flow events are fully contained within the trap and slowly infiltrate and evaporate until the trap is empty. Alternatively, water could be pumped from the trap. In both cases, larger events would pass through the trap and over the spillway. Flow events larger than the design event would still be treated by the trap prior to discharging downstream. During these large events, although the trap would have a lower trapping efficiency, a larger volume of water and the resultant effect of dilution is greater. Prior to the commencement of the wet season, sediment traps will be cleaned out if necessary. An access ramp into the trap would allow sediment removal. The sediments removed from the trap would be placed within an active waste dump so the sediments will not be washed back into the basin or to the downstream environment. Access to these sediment traps would be removed after final DMP inspection of closure rehabilitation. The sediment traps will remain in situ, but at this stage effective and successful rehabilitation of the waste dump will mean that ongoing sediment removal will not be required. The design of sedimentation basins is based on the size and percentage of particles to be removed, the removal of which is governed by the rate of inflow and top surface area of the basin, and varies with the duration and ARI of the storm considered. Water quality capture and treatment devices are never expected to treat all the flow, but rather focus on smaller more frequent runoff events. The trap size is calculated to match the settling velocity of the target sediment size with the design flow. Larger particle sizes such as sand (60um-2mm), gravel and cobbles (>2mm) all settle readily. Clay particles are <2um and cannot be settled under gravity alone. The target size is usually silt (2-60um) to maximise the amount of settleable particles captured - smaller particles are assumed to mostly stay in suspension and exit the pond with the flow. A surface water monitoring program will be established to monitor the impacts of operations on downstream watercourses during the construction and operation phases, with trigger levels and contingency actions developed and documented in the Environmental Management Plan. This monitoring will continue until tenement relinquishment.


Figure 11: Surface water flow modifications and sediment traps for NMM-west


Figure 12: Surface water flow modifications and sediment traps for NMM-east


Figure 13: Surface water flow modifications and sediment traps for CMM


Figure 14: Surface water flow modifications and sediment traps for SMM


5.5 Flora & Vegetation A Level 2 flora and vegetation survey was conducted by G&G Environmental within the Project tenements, with autumn and spring reconnaissance in May and September 2011 in accordance with the EPA Guidance Statement No 51 “Terrestrial Flora and Vegetation Surveys for Environmental Impact Assessment in WA” (EPA 2004a). This report was updated in 2014, with all name changes or Priority listing modifications in the interim incorporated into the report attached as Appendix 16.4 (G&G Environmental 2014). A more detailed summary is provided in the Mining Proposal.

5.5.1 Vegetation

The surveys identified 16 vegetation associations within the survey area. The associations represent six riparian (creek) communities, two spinifex (Triodia) steppe communities, one shrubland, two Acacia woodlands, one Eucalyptus woodland and four Eucalyptus mallee woodlands. Vegetation at Wonmunna was dominated by six of the associations recorded. The Eucalyptus woodland (EW1) and four Eucalyptus mallee woodlands (M1, M2, M3 and M4) comprised a combined 49.13% of the survey area. Spinifex steppe communities (SS1, SS2) covered 34.73% and two Acacia woodlands (AW1, AW2) covered 12.09% of the survey area. Riparian vegetation was dominated by a Eucalyptus camaldulensis woodland which accounted for 3.75% of the survey area and included some of the smallest associations ranging in area from 0.4 to 120ha. The S1 association covered 0.22% of the survey area at 10.7ha. None of the vegetation associations of the Wonmunna survey area resemble National or DEC listed TECs or PECs. Each of the associations defined for Wonmunna resemble vegetation described in prior surveys, the majority of which were considered to be of low conservation significance as they represent units believed to be widespread and common in the locality. It is therefore considered that none of the vegetation at Wonmunna has regional conservation significance. The following vegetation associations of the survey may be considered locally significant:

Eight of the associations occupy less than 1% of the survey area. In accordance with EPA Guidelines (EPA Guidance Statement No. 51) these communities may be considered locally significant due to their scarcity.

o Spinifex steppes - SS2 o Shrubland - S1 o Acacia woodland - AW2 o Mallee woodland - M1 o Creeks and drainage lines - C6, C5, C4, C2.

Vegetation Community C2 also represents habitat for Priority flora, as a Priority 3 species Gymnanthera cunninghamii was located there (but outside the mining tenements).

Shrubland Community S1 also represents a community where 30.1% of the species located there were not recorded anywhere else within the survey


area. For two species, Tephrosia sp. B Kimberley Flora and Corchorus trilocularis, this result represents an apparent moderate (~100km) range extension.

Creeks and Drainage Lines Community C1 was the most species rich community recorded with 40.6% of taxa recorded only within this habitat.

The mining tenements occupy 2713ha of the total area of the vegetation survey of 4840ha. The approved NVCP is 555ha. The vegetation clearing zone of the main infrastructure (pits, waste dumps, camp, truck areas, access and haul roads) covers 505ha. The proportion of vegetation associations located within the main infrastructure vegetation clearing zone was calculated in relation to the entire area of flora survey, 4840ha (Table 7, Appendix 16.4). The proportions range from zero (AW2, C2, D, SS2) to 82 % (C6). A high proportion (75%) of the S1 association occurs within the main infrastructure vegetation clearing zone. The S1 association resembled the BUTG site type of van Vreeswyk et al (2004) recorded on basaltic upland gilgaied stony plains considered a unique site type that frequently supports threatened flora and is preferentially grazed. In the current survey 30.1% of the species in the S1 association not recorded anywhere else within the survey area and included two species Tephrosia sp. B Kimberley Flora and Corchorus trilocularis, for which the survey area represents an apparent moderate habitat extension to the DEC recorded range.

Table 7: Proportion of vegetation associations located in the disturbance area of the Wonmunna Project.

% of Survey

Area % Association in

NVCP Zone % Association Outside

VCZ AW1 12.01 31.29 68.71 AW2 0.08 0.00 100.00 C1 2.48 0.56 99.44 C2 0.10 0.00 100.00 C3 1.00 15.35 84.65 C4 0.15 34.38 65.62 C5 0.01 21.93 78.07 C6 0.01 82.04 17.96 D 0.08 0.00 100.00 EW1 12.35 8.45 91.55 M1 0.88 40.77 59.23 M2 3.17 15.87 84.13 M3 10.90 6.10 93.90 M4 21.82 16.74 83.26 S1 0.22 76.19 23.81 SS1 34.73 0.18 99.82 SS2 0.01 0.00 100.00


5.5.2 Flora

A total of 226 taxa recorded in the quadrats during the May survey comprised 172 perennial and 54 annual species. The taxa represented 36 families and 111 genera. During the September survey 167 taxa were recorded comprising 139 perennial species and 28 annuals. These taxa represented 36 families and 78 genera. The September survey added 44 taxa (6 annuals, 38 perennials), 6 families and 13 genera not recorded in May. In total 270 taxa comprised of 210 perennial species and 60 annuals from 42 families and 124 genera were recorded for the Wonmunna survey area (Appendix 16.4). The most prominent families recorded at Wonmunna were the Fabaceae (54 taxa), Poaceae (40) and Malvaceae (31). The Amaranthaceae (17), Asteraceae (17), Goodeniaceae (15), Myrtaceae (14), Chenopodiaceae (12) and Scrophulariaceae (8) were also well represented. The dominant families recorded at Wonmunna were also dominant in flora surveys conducted previously in the Hamersley subregion bioregion. No threatened flora species were recorded within the Wonmunna survey area. A total of eight introduced (weed) species were recorded and all were recorded in the riparian vegetation of creeks. None of the species was a declared plant under the Biosecurity and Agricultural Management Act 2007. The Wonmunna Project area lies within the mapped distribution of each of the species (NatureMap and Florabase). All of the species have a broad distribution and have been recorded in several bioregions in Western Australia. The proposed mine will not impact on any known TEC, PEC or ESA and none of the vegetation at Wonmunna was considered regionally significant. A number of communities were considered potentially locally significant due to a limited distribution, scarcity, combination of novel species or habitat for Priority flora. To conserve these potentially locally significant associations the following recommendations will be included in site management plans.

Avoid disturbance to the communities wherever possible. Keep vegetation clearance to a minimum. Progressive rehabilitate wherever possible. Establish trials for species establishment during progressive rehabilitation. Use seed collected from local populations to preserve provenance. Restrict off road driving. Salvage topsoil, and use in progressive rehabilitation if possible. Salvage 10cm depth topsoil to avoid dilution of seed store. Restrict height of topsoil stockpiles to two metres and construct in a dome

shape to maximise long term viability.


5.6 Fauna & Habitats Intensive Level 2 and targeted surveys were undertaken on vertebrates, short range endemics and troglofauna at the Wonmunna site. These are summarised in the Mining Proposal, and reports are attached as Appendix 16.5, 16.6 & 16.7.

5.6.1 Vertebrates

The field surveys recorded 170 vertebrate species representing five orders of vertebrate taxa. Five conservation significant fauna were recorded during the survey (Table 8).

Table 8: Conservation significant fauna species recorded at Wonmunna

Scientific Name Common Name EPBC Act Category

WA Wildlife

Cons. Act 1950

DPaW Priority

Category

Located during Survey

MAMMALS Pseudomys chapmani

Western Pebble mound Mouse

Priority 4 Yes

BIRDS

Ardeotis australis Australian Bustard

Priority 4 Yes

Burhinus grallarius Bush Stone-curlew

Priority 4 Yes

Merops ornatus Rainbow Bee-eater

Migratory S3 Yes

Neochimia ruficauda subclarescens

Star Finch (western subspecies)

Priority 4 Yes

The Level 2 survey in 2011 recorded a large population of Western Pebble mound Mouse (Pseudomys chapmani) with several active mounds located in the proposed NMM pits and areas of associated infrastructure. The targeted survey recorded additional active mounds south and west of the previous findings. The Western Pebble mound Mouse is often identified by the ‘pebble mounds’ which are made up of up of thousands of evenly sized pebbles. The estimated home range of the Western Pebble Mound Mouse is up to 14.4ha for males and 4.67ha for females. The two main effects of vegetation clearance and minesite activity in the Project area will be habitat loss and mortality or displacement of individual animals. Infrastructure connecting pits and waste dumps across the mining zone may also create a physical barrier for some species, leading to habitat fragmentation. Based on the faunal survey results, the most important habitat for vertebrate fauna in the proposed vegetation clearing zone is the Weeli Wolli Creek and the associated riparian habitat of the major drainage line. This area provides suitable habitat for the Neochmia ruficauda subclarescens (Star Finch), Merops ornatus (Rainbow Bee-eater) and several additional potential conservation significant species. The one kilometre wide Exclusion Zone centred on the Weeli Wolli Gorge to be established during the clearing operations, and during the operation of the proposed Project will


protect this important habitat as it provides a buffer between it and the proposed areas of disturbance. This Exclusion Zone will therefore substantially reduce the loss of the most significant fauna habitat from the Project. It will also provide a corridor for species and will remain in situ at the end of mining. The successful progressive rehabilitation of the disturbed areas will ensure the return of habitat. ‘Tree trash’ will be spread on the lower slopes of the recontoured waste dumps to provide an initial habitat for fauna on these sites.

5.6.2 Short Range Endemics

A total of 1,049 individual specimens in the short range endemic (SRE) target groups were identified from the study area, representing 49 individually recognised taxa from ten orders, 25 families and at least 37 genera Appendix 16.6). A total of 12 taxa in at least ten genera from ten families and six orders, comprising 118 individuals (11.2% of total catch), are considered to include species from the three SRE categories. One taxon is considered a confirmed SRE:

• the millipede Antichiropus ‘wonmunna’ (Paradoxosomatidae). Two species represent likely SREs:

• the mouse spider Missulena langlandsi (Actinopodidae) • the isopod cf. Spherillo ‘wonmunna’ (Armadillidae).

A further ten taxa include potential SREs: • the trapdoor spider Teyl ‘MYG027’ (family Nemesiidae) • the trapdoor spider Yilgarnia sp. indet. (Nemesiidae) • the pseudoscorpion Synsphyronus ‘PSE014’ (Garypidae) • the centipede Sepedonophilus sp. indet. (Geophilidae) • the centipede Mecistocephalidae sp. indet. • all other geophilomorphan centipedes, Geophilomorpha sp. indet. • the centipedes Cryptops sp. indet. (Cryptopidae) • the land snail Bothriembryon (Bulimulidae) • the land snail Succinea sp. indet. (Succineidae) • the isopod Laevophiloscia sp. B (Philosciidae).

The millipede Antichiropus ‘wonmunna’ was found in Mulga woodlands both in impact area and non-impact areas (in the south of the Project area). The two isopod species, cf. Spherillo ‘wonmunna’ and Laevophiloscia sp. B., are considered potential and likely SREs respectively. In addition to the Antichiropus millipede, these are also the only SREs which have not been reported from outside the study area. This is not surprising as the knowledge of slaters in the Pilbara region is poor. Both isopod species are mainly known from the deep gorge of Weeli Wolli Creek in the northern parts of the study located in the proposed exclusions. None of the other likely or potential SREs appear to be restricted to the study area, or their taxonomy is too poorly known to assess their distribution patterns. A management plan will be developed to protect the Antichiropus during operation. There will be no closure impacts to consider for this species.


5.6.3 Troglofauna

A total of 511 samples were taken from 198 sample sites (including 192 survey bores and six Karaman-Chappuis sites). A total of 68 sites were surveyed in the NMM deposit, 53 sites in the SMM deposit and 46 and 31 sites in the CMM and EMM (Eastern Marra Mamba) deposits respectively. In total, 45 sites were sampled in the direct impact area for troglofauna (mining pits) and 153 sites were reference bores. The survey resulted in a total of 252 individuals representing 35 putative troglobitic species, and eight higher taxonomic ranks (sp. indet.). Overall, the survey was highly biased towards records of species from single boreholes. Twenty-two species were collected from one bore only, nineteen of these as single specimen. Nine SRE species were only recorded from impact bores:

the micro-whipscorpions Palpigradi ‘w2’ and ‘w3’ the centipede Cryptops ‘w1’ the pincushion millipede Polyxenidae ‘w1’ the glasshouse millipedes Symphyla ‘w1’ and ‘w3’ the dipluran Japygidae ‘w1’ and Projapygidae ‘w1’ the slater Isopoda ‘w1’ (Phoenix 2014c).

This multiple number of species collected only once represents the low abundance pattern of assemblance, and are proportionate both within and outside the proposed zones of disturbance. In contrast nine SRE species were sampled from more than one bore and five of these occurred in more than one deposit indicating some level of subterranean habitat connectivity between deposits. Surface geology data indicate that NMM CMM and SMM are part of the same formation. Whilst EMM is in the same type of geology as the other three deposits, the absence of specimen records makes it difficult to comment on the connectivity of EMM with the other deposits (Appendix 16.7). As the troglobitic species were recorded from bores intersecting the Czr surface geology, this geology appears to represent the matrix for their habitats. The proposed mining footprints occupy approximately 204ha of Czr surface geology, which represents only 2.9% of the continuous Czr extent (6,934ha) that intersects the study area. Given the extent of the habitat comprising the Czr geology, and the relatively small proportion proposed for disturbance, it is unlikely that the Project would cause any significant impact on the resident troglofauna community. There are no environmental impacts to be considered for troglofauna at closure.


5.7 Soils / Growth Medium The topsoils on the uplands of the mesa formations, which dominate the Project area, vary from shallow rocky topsoil layers where spinifex dominates towards the mesa rocky breakaways to deeper topsoil layers with higher clay and loam content where Acacia and Eucalyptus communities are abundant. Soils are skeletal and poorly developed. On the mesas and hill tops the soils are stony, ferruginous mostly stony soils, red shallow loams, and some red shallow sands. Profile development is negligible. On lower slopes in the Project area soil development is the same. Both situations are mantled with pebbles to cobbles lateritic materials. Alluvial deposits are restricted to the larger creeks, including Weeli Wolli Creek which traverses the Project area from southwest to northeast. The topsoils on the uplands of the mesa formations, which dominate the Project area, vary from shallow rocky topsoil layers where spinifex dominates towards the mesa rocky breakaways to deeper topsoil layers with higher clay and loam content where Acacia and Eucalyptus communities are abundant. The dissected lowlands are dominated on the slopes by stony shallow soils largely vegetated by spinifex and sparse Acacia and Eucalyptus species. The soils associated with ephemeral drainage systems and riparian vegetation communities are largely high in sand and clay content, variable in depth and distribution, resulting from deposition during rainfall events. Soil characterisation has indicated that the Wonmunna soils are generally:

Neutral pH Low salinity High sodicity 25-35% clay, 0.5% silt & 6-70% sand.

The pH values of the topsoil assessed are typical of those for the Pilbara. Neither the pH nor the salinity of the topsoil is likely to reduce plant growth potential (Appendix 16.8). Being mainly lateritic, the salvaged topsoil will be an excellent coarse medium for growth. Early characterisation has shown:

Soils appear suitable for plant growth, though their typically sandy texture and low fertility will require management (Table 9).

The sandy soils will hold low amounts of water that is available to plants, have low fertility potential, and be erodible.

The higher clay soils, found principally in lower lying areas, will be able to hold more water and nutrients but will likely remain erodible.

The risk of tunnel erosion of the soils appears minor. Characterisation of soils will continue once operations commence onsite to provide a more comprehensive analysis.


Table 9: Texture of Wonmunna Topsoil Samples

SAMPLE ID TEXTURE N-AW1 Sandy Clay Loam N-AW2 Sandy Clay Loam N-AW3 Sandy Clay Loam N-C1 Sandy Clay Loam N-C2 Clay N-EW1 Clay N-EW2 Clay N-M1 Clay – Clay Loam N-M2 Clay Loam N-M3 Sandy Clay Loam E-AW3 Sandy Clay Loam RSS1 Sandy Clay Loam RSS2 Loam

The soils samples were typically low in total nitrogen. Total phosphorous appeared adequate for growth (Appendix 16.8). All soil samples are shown to be deficient in available sulphur. Some samples have low manganese values. The low nitrogen and sulphur levels could be addressed through application of sulphate of ammonia at a rate of 250kg/ha. Addition of trace amounts of manganese will also be considered. The actual response to fertiliser will be determined through field-based trials that include consideration of rates, type of fertiliser, and modes and timing of application. Gypsum application may be applied to topsoil (or waste if it represents a likely rooting zone) once respread onto contoured rehabilitation slopes if it has been assessed to be potentially dispersive. The estimated application rate required to reduce ESP1 to 4% is 2 tonne/ha. This rate is calculated assuming:

70% effectiveness of gypsum a depth of 0.3m will be treated (approximate depth of the active plant root

zone in the WA arid zone) bulk density is 1.4 g/cm³ and the gypsum is thoroughly incorporated into the soil profile.

1 Exchangeable Sodium Percentage


5.8 Waste Materials The waste characterisation indicated that the waste will generally be:

Acidic pH Low salinity High sodicity 25-35% clay, 0.5% silt and 60-70% sands (Appendix 16.8).

Wastes of high sodicity are potentially dispersive and will require management to prevent tunnel erosion, a hard setting surface that will limit plant growth and reduced water holding capacity. Wastes of this nature are therefore not to be placed near or at the surface of final waste dump designs, and need to be sheeted with sufficient non-dispersive wastes to prevent the risk of tunnel erosion.

Table 10: Volumes of topsoil and laterite to be salvaged

AREA OF DISTURBANCE

PIT WASTE DUMPS TOTAL AREA TO BE DISTURBED

203.62ha 217.24ha 555.0ha Topsoil to be salvaged at 10cm depth

203 620m3 217 240m3 *555 000m3

Laterite to be salvaged at 0.5m depth

1 018 100m3 1 086 200m3 *2 104 300m3

*Potential resource volume Lateritic subsoil will be collected at a depth of up to 1.0m to provide 0.5m depth of rock armouring on contoured waste dumps slopes, with excess in dump toe bunding (Plate 3). Geology has indicated that the SMM area might not have this depth of lateritic topsoil available, but this will be compensated by the extra depth collected elsewhere. Table 10 demonstrates that there will be adequate topsoil and subsoil volumes harvested to adequately sheet the recontoured waste dumps to recommended depths.

Table 11: Quantity of topsoil and laterite required to sheet waste dumps

DUMP DUMP SURFACE AREA (m2)

Laterite required for 0.5m depth (m3)

Topsoil required for 0.1m depth (m3)

NMM-west

214 000 107 000 21 400

NMM-east 647 000 323 500 64 700 CMM 653 000 326 500 65 300 SMM-west 333 000 166 500 33 300 SMM-east 222 000 110 000 22 200 TOTAL 2 069 000 1 033 500 206 900 Laterite will be salvaged in excess of waste dump sheeting requirements (Table11) as stockpiles will be utilised to provide a bund around the base of waste dumps to prevent any sediment runoff as dumps are being constructed. Dispersive waste is most likely to be encountered at the commencement of mining each pit, and will be


placed at the centre of the waste dump circumference. Laterite bunds will prevent any runoff from the waste caused by rain to escape the dump area. Extra laterite in these bunds will enable effective salvaging to not require scraping down to non-laterite levels during retrieval for rehabilitation. It will also enable laterite to be available for progressive rehabilitation without destroying the integrity of the bund. Clearing and the salvaging of topsoil will occur on an as needed basis within the 5 year time frame of the NVCP permit. This will reduce the total amount of disturbance at any one time, reducing environmental impacts such as dust generation and habitat fragmentation. Progressive rehabilitation will occur as soon as areas become available, and will provide the same benefits from reducing the total area of disturbance onsite. Areas of progressive rehabilitation will be utilised to trial rehabilitation techniques including depth of topsoil, depth of laterite, fertiliser type and rate, seed mixes, seeding rates, application of gypsum, rate of gypsum and so on. Modifications will made to methodology, where required, to continually improve rehabilitation results.

Plate 3: Example of lateritic subsoil to be utilised to sheet waste dump profiles (average diameter of 3cm)


5.9 Design and Construction of Waste Dumps Preliminary final waste dump designs were designed utilising all data known to date on the site specific conditions and requirements at Wonmunna:

- Climate - Topography - Surface water - Waste characterisation - Topsoil Characterisation - Approved NVCP disturbance footprint - Exclusion Zone - Geotechnical analyses - Aesthetics - Heritage site locations - End land use & stakeholder input - Resource definition - Costing - Waste volumes - Height limitations - Availability of topsoil and subsoil resource.

The first dump designs were made according to the general site information and the location of the resource and economics of haulage. These were then modified for:

- Avoidance of heritage sites where possible - Minimisation of the disruption to surface water flow and requirements for

diversion - Avoidance of the Exclusion Zone.

Final preliminary designs were completed utilising specialist advice (see Appendix 16.9) and engineering software (Orelogy and Landloch) to provide plans that match desired long term stability goals with aesthetics. As there is no acid generating potential of the waste, nor heavy metal contaminants, the main issues for the dump construction are:

- Sediment escaping into waterways - Disruption to surface water flow, and reduction of flow - Aesthetics - Construction of a stable landform - Preparation of a suitable growing medium to achieve vegetative growth to

achieve the long term end land use of a self-sustaining ecosystem.

5.9.1 Waste Scheduling & Volumes

The initial waste volumes and scheduling is provided in Table 11 and 12. Geologists will complete block modelling for the waste once prior to the commencement of operations, and this will provide greater detail on when dispersive wastes are expected, such that specific scheduling for dump placement can be made. Currently, it is predicted that clays will be encountered beneath the lateritic subsoil in most areas when pits are first developed. This waste will therefore be easily placed at the centre of the dumps to be encapsulated by less dispersive and more competent


rock. There is the possibility of encountering dispersive dolerite at the base of some of the pits. This will again be placed within the centre of the dump, although higher in the dump profile.

Table 12: Preliminary Waste Scheduling for Wonmunna Project

Table 13: WASTE Dump Volumes

DUMP

QUANTITY OF WASTE Weight (million tonnes)

Specific Gravity

Swelling Factor

Volume (million BCM*)

Volume (million LCM**)

NMM-west 7.00 2.5 1.25 2.80 3.50 NMM-east 18.51 2.5 1.25 7.40 9.26 CMM 16.06 2.5 1.25 6.43 8.03 SMM-east 4.31 2.5 1.25 1.72 2.16 SMM-west 7.76 2.5 1.25 3.10 3.88 *BCM=bank cubic metres **LCM=loose cubic metres Five landforms are to be constructed, with maximum heights varying from 22 to 40m Table 14). The contoured dump designs, with cross-sections, are provided in Figures 15-21.

Table 14: Waste Dump Surface Area

DUMP HEIGHT (m) **MAXIMUM DISTURBANCE FOOTPRINT (ha)

NMM-west 22 21.47 NMM-east 36 85.26 CMM 39 66.55 SMM-west 40 34.68 SMM-east 30 26.87 **As per approved NVCP


5.9.2 Sedimentation

To avoid any of the fine sediment escaping into waterways adjacent to the dumps during heavy rainfall events, a bund of lateritic subsoil is to be placed around the toe of the dump before any dispersive waste is unloaded. Haul roads entering the waste dump area will be suitably bunded with sediment traps strategically placed, so these will not constitute a sediment release site from the dump. After the construction of the dump and rehabilitation earthworks of contouring and lateritic sheeting, topsoil and tree trash spreading are completed, sediment traps, both open and closed, will be installed at the dump toe. The probable locations of these traps are included in the designs in Figure 11-14. Construction details are provided in the Section 5.2.3.4. With these precautions, plus the design of the waste dumps for the long term, there should be minimal sediment released off site to any adjacent waterways.

5.9.3 Surface Water Flow

There were some requirements to modify the surface flow of water at the Project site, although these were minimised as much as possible by dump and haul route relocations (Plate 4). This topic is described above in Section 5.2.3.4.

Plate 4: Most main drainage lines on site will not be affected


5.9.4 Dump Modelling

Climate parameters from nearby West Angelas, including 100 year sequence of event data, and a range of storm events, were available and suitable to be utilised in the Water Erosion Prediction Project (WEPP) Runoff and Erosion Model developed by Landloch (2014). Similarly, data from soil from the Juna Downs region matched the early characterisation data from Wonmunna soil samples. This soil had the following base properties:

- Neutral pH - Low salinity - Low sodicity - 25% clay, 3% silt and 72% sand - Mean rock size of 40mm.

Erodibility parameters have been calculated on this soil by both field and laboratory based testing and were:

- Effective hydraulic conductivity = 13mm/hr - Inter-rill Erodibility = 140 000kg.s/m4 - Rill erodibility = 0.0050s/m - Critical shear for rill initiation = 30Pa.

Once mining commences, greater volumes of waste, from difference depths and different pits, will be similarly tested to ensure than onsite waste performs in a similar manner. Dump designs will be modified accordingly if there is significant variation. On advice from Landloch (2014), various landscape design scenarios were calculated with threshold erosion values were predicted to be less than 5 tonne per hectare per year, with the maximum erosion rates predicted for the design to be less than 10 tonne per hectare per year, above which the landform batter would erode at an unacceptable rate, The design scenarios were therefore constant in soil type, dump height (40m) and threshold erodibility values, but varied the gradient of the slope according to the presence, part presence or absence of rock armouring (detailed in Appendix 16.9). The best current scenario for the Wonmunna site was full rock armouring which enabled the dump disturbance footprint to be reduced to 250m (with a maximum height of 40m) (Figure 15 & Table 15). Two other scenarios shown in Figures 16 & 17 demonstrate the need for shallower angles and longer slopes to meet erodibility criteria if the dump were not entirely rock armoured. The 3-D images of the dump designs are provided in Figures 18-21. Cross-sections demonstrate the aesthetic blending to the contours of the surrounding landscape. Calculations have been made and there is more than adequate volumes of the lateritic subsoil to utilise as rock armouring (Table 10 & 11) (refer to Section 6.6 in Mining Proposal for more details on waste rock management during mine life). With this scenario, the disturbance footprint of each dump is less than that allowed for in the NVCP. The rehabilitation of these slopes, and the construction of a suitable growing medium, is discussed in Section 5.9.


Table 15: Concave Profile Option for a 40m high Landform sheeted entirely with rock armour.

VERTICAL DISTANCE

FROM BASE

HORIZONTAL DISTANCE

FROM CREST (m)

GRADIENT (degrees)

GRADIENT (%)

SURFACE MATERIAL

40-33 0-19.2 20 36.4 Rock Armour 33-23 19.2-66.2 12 21.2 Rock Armour 23-0 66.2-250.0 7.1 12.5 Rock Armour

Figure 15: Concave profile option for a 40m high landform sheeted entirely with rock armour


Figure 16: Concave profile option for a 40m high landform sheeted with soil

Figure 17: Concave profile option for a 40m high landform sheeted with soils and with rock armour on the toe



F i g u r e 1 8 : R e c o n t o u r e d N M M - e a s t w a s t e d u m p w i t h t w o c r o s s s e c t i o n p r o f i l e s



F i g u r e 1 9 : R e c o n t o u r e d N M M - w e s t w a s t e d u m p w i t h c r o s s s e c t i o n p r o f i l e



F i g u r e 2 0 : R e c o n t o u r e d C M M w a s t e d u m p w i t h c r o s s s e c t i o n p r o f i l e



F i g u r e 2 1 : R e c o n t o u r e d S M M - w e s t a n d S M M - e a s t w a s t e d u m p s w i t h c r o s s s e c t i o n p r o f i l e s


5.10 Rehabilitation (This section is largely a repeat from Section 8.2 of the Mining Proposal because the principles utilsed are the same). All disturbed sites will be progressively rehabilitated during mine life, where possible (Table 16). The clearing for CMM will commence in 2015 for the installation of the magazine, and access. Clearing for infrastructure placement will occur at the commencement of mine development, and will be unable to be rehabilitated until after decommissioning when infrastructure will be removed.

Table 16: Progressive Rehabilitation Schedule

SITE

YEAR

2015 2016 2017 2018 2019 2020 2021 2022 2023

Clearing for roads, pits & dumps

NMM-west

100%

NMM-east

100%

CMM 50% 50%

SMM 100%

Progressive rehabilitation of dumps

NMM-west

** ** **

NMM-east

** ** **

CMM ** ** **

SMM ** **

Once all infrastructure, services and waste are removed, areas will be recontoured ready for topsoil replacement (see Table 25 for itemised schedule of closure tasks).

5.10.1 Haul Roads & Access Roads

Light vehicle access to the site is to remain until rehabilitation monitoring is complete and DMP have completed the final inspection. Rehabilitation of the haul roads will generally follow the following process.

All power sources, power cables, water pumps, water pipes and stands will be removed from site.

Where necessary, a rockbreaker will dismantle concrete culverts, and waste will to be removed from site.

Windrow material will to be graded back across the road surface. Gypsum may be used, dependent upon further specific site location

characterisation at a probable rate of 14 tonne/ha, dependent on site trials. Roads will be deep ripped using a single tyne from a large bulldozer at full

depth ground penetration to break up compaction. Topsoil will be respread at 10cm depth and contour ripped at a depth of 30cm.


Larger salvaged vegetation, if not spread with topsoil, can be spread over road.

Seeding and fertilising will occur at a rate determined by field trials (likely 8kg/ha seed if using topsoil that has been stockpiled for more than a year and likely 100kg/ha DAP fertiliser).

5.10.2 Infrastructure Sites

In general, the process for rehabilitation of infrastructure sites such as the offices, camp and contractor yard will be as follows:

All utilities such as the power source, powerlines and water pipes will to be disconnected and removed from site.

All transportables, or similar (such as water tanks) will be transported offsite. All concrete slabs, fencing, signage, delineators, liners and other manmade

items to be collected and removed from site. Septic tanks will be emptied, decommissioned and backfilled. Biotreatment septic unit from camp will be removed from site. Any exposed underground services to be excavated and removed offsite. All windrows, other than salvaged topsoil, will be pushed and leveled to the

natural surface level. Topsoil will be spread to 10cm depth, and contour ripping will occur to 30cm

depth to prevent lifting underground services. Seeding and fertilising will occur at a rate determined by field trials (likely

8kg/ha seed if using topsoil that has been stockpiled for more than a year and likely 100kg/ha DAP fertiliser).

5.10.3 Recontoured Waste Dump Landforms

Description of the profiling of the waste dumps is provided in Section 5.8.4. The rehabilitation of these recontoured profiles will be according to the following process.

Dependent upon further waste characterisation carried out during mine life, gypsum may be used, at a probable rate of 14 tonne/ha. If gypsum is applied, the waste will then be ripped to mix in the gypsum to a depth of 60cm with a triple tyne.

Lateritic subsoil will be spread to a depth of 0.5m over the entire sloped profile to encapsulate any dispersive waste.

Topsoil will be spread to a depth of 10cm. The site will be seeded and fertilised at a predetermined rate, with a

predetermined mix of seed and type of fertiliser. Contour ripping will occur simultaneously at this stage with a winged tyne to a depth of 60cm at 0.5m contours. It will be very important that ripping occurs on the contour to promote water infiltration, and to prevent runoff.

The top of the recontoured waste dump will be treated similarly, after a 2m high crest is constructed around the perimeter of the top. One hectare cells will be constructed on the tops of the dumps (refer to Wattle Dam Closure Plan 2012 & Bond Release Application 2013 for photographs of construction) to further encourage water


penetration and to prevent over topping, and the associated erosion problems that can occur with increased water flow down slopes. Any larger salvaged vegetation that was not spread with the topsoil, will be spread on lower slopes to provide habitat refuges and microclimates for seed germination. This ‘tree trash’ will be placed in clumps, and not spread thinly and evenly over the entire lower slope.

5.10.4 Seed Mixes

Seed mixes will be comprised of identified site species collected locally to maintain provenance. Seed will be purchased from licensed collectors. Progressive onsite rehabilitation will be utilised to determine the optimal;

species within the mix, treatment of seeds, composition of the seed mix and rate of seeding to continually improve on rehabilitation outcomes.

All seed will be tested, or be received already tested, for purity, viability and germinability for quality assurance. If topsoil can be utilised ‘fresh’ (within 12 months of collection) seeding rates will be able to be reduced from potentially 8kg/ha to 3kg/ha.

Plate 5: An ant’s nest surrounded by seed at Wonmunna


5.10.5 Growth Medium

Vegetation will be stripped using dozers with a clearing rake blade attached. The cleared vegetation will be stockpiled in wind rows adjacent to topsoil stockpiles. All stockpiles will be placed strategically adjacent to designated waste dump areas. Vegetation will be utilised in the rehabilitation of disturbed areas. Topsoil will be salvaged from all areas to be disturbed, at a rate of 10cm depth. This topsoil is to be stockpiled separately to minimise the dilution of the soil seed bank. Beneath this topsoil layer, most sites will also offer a lateritic subsoil that will provide an excellent growth medium. This will be collected at 1m depth, and slightly more in some areas to compensate where this type of subsoil is not available in some areas at SMM. The quantity of subsoil to be collected has been calculated to provide 0.5m depth of cover to rock armour contoured waste dumps, before the 10cm depth of topsoil is spread. For more details on volume calculations, and justification for rock armouring depth, refer to Section 5.8. The volumes of topsoil and subsoil required to be collected to satisfy rehabilitation requirements are detailed in Table 10 &11. Topsoil and subsoil salvaging operations will not occur in high wind or rainy conditions to prevent resource compaction, and dust issues. Topsoil and subsoil will be stockpiled separately beyond the final toe of the waste dumps, strategically placed in the area indicated in the Figures 2-5. Stockpiles will be located away from designed drainage pathways, and will be a maximum 2m in height to maintain maximum viability of the resource. If topsoil stockpiles are required to be left in situ for some time, and if stockpiles have not vegetated, ripping and seeding will occur to maintain the quality of the resource. Stockpiles will be monitored for erosion losses, and weed growth.

5.11 Information Gaps After review of the environmental data and analysis, the following areas will require further investigation during mine life to ensure the best possible outcome for closure rehabilitation.

Geotechnical investigations will be ongoing throughout the life of the mine, essentially for pit wall integrity. Any variations in data may alter the required final location of the abandonment bund, or the final toe of the waste dump.

Once mining commences, access to larger quantities of waste will enable more detailed waste characterisation. Results will be used in rain simulation modelling, and final profiles may be changed accordingly. Similarly, soil amelioration for use as an effective growth medium may be modified.

All progressive rehabilitation will be set up as rehabilitation trials to determine soil ameliorant type and rate, and seed mix type, proportions, treatments and rates.

The groundwater monitoring regime will be continued to maintain the awareness of groundwater levels to ensure mining remains at least 5m above the water table.

Areas to be disturbed will be surveyed for active Pebble Mound Mice mounds before vegetation clearance.


5.12 Monitoring Regime & Feedback Loop Monitoring progressive rehabilitation will be integral in achieving the best practical result at closure as it will enable rehabilitation procedures to incorporate new data obtained both onsite, locally and industry wide throughout the life of the mine. Monitoring post-decommissioning rehabilitation will ensure that completion criteria have been met. The monitoring program has been developed to comply with the requirements Department of Mines and Petroleum Guidelines for preparing mine closure plans (DMP 2011) and the Environmental Protection Agency (EPA) Guidance Statement No. 6 for the rehabilitation of terrestrial ecosystems (EPA 2006). The proposed monitoring program was designed for post-mine land use of reinstatement of a ‘natural, ecosystem as similar as possible to the original ecosystem (DMP 2011) Main components of the program include:

selection of appropriate analogue sites with justification of their selection; description of field monitoring procedures; description of floristic data provided by the monitoring method; procedures for assessment of rehabilitation success; provision of closure criteria in accordance with DMP and EPA guidelines; procedures to evaluate the success of rehabilitation processes; and time-line of rehabilitation monitoring (i.e. frequency and period of monitoring)

based on the outcomes and recommendations from successive assessments. Further discussion on monitoring is incorporated into Section 9 with completion criteria. Similarly, the feedback loop for monitoring results into the rehabilitation program will be discussed in Section 9.

Plate 6: View southeast from NMM-east area


6.0 Stakeholder Consultation

6.1 Summary of Stakeholder Consultation to Date Previous tenement holders, Talisman Mining and Ochre Resources (previously known as Rico Resources), had numerous stakeholder meetings on the Wonmunna Iron Ore Project but, as records for this time period are not complete, details are not provided in this document. Ochre Group Holdings Ltd (formerly Rico Resources Ltd) had extensive consultation with the Ngarlawangga group which culminated in the signing of a Native Title Mining Agreement (NTMA) on 23 April 2012. Since acquiring the tenements, Ascot Resources has also consulted with a wide range of stakeholders and discussed the details of the Project, and issues pertinent to the particular stakeholders. These have included:

- DMP - MRD - East Pilbara Shire - Native Title Claimants - Ngarlawangga and Nyiyaparli people - Port Hedland Port Authority (now Pilbara Port Authority) - Department of Transport - Department of State Development - Newman community - Department for Regional Development.

Details of stakeholder meetings to date are provided in the Mining Proposal in Section 7.2 & Appendix 11.7. Discussions on recent vandalism at the Wonmunna Waterhole were recently held with a Nyiyaparli elder (Plates 4 & 5). Although the site does not occur on Wonmunna tenements, WIOP will assist the group by supporting initiatives to install appropriate signage to discourage such activity in the future.

6.2 Planned Stakeholder Consultation Stakeholder consultation will be an ongoing process throughout the life of the mine, as discussed in the Mining Proposal (Section 7.2). It will continue with liaison with relevant stakeholders during the decommissioning of the site, before final closure. Discussions will be continue to be held with regulators to determine such issues as:

the long term use of any borefield established (DoW) the rehabilitation of the haul roads and the access point to the Great Northern

Highway (MRD) the final rehabilitation preparation (DMP).


Community update information sessions will continue to be held, and could include annual tours of the mine. Local and Perth businesses will be involved in the removal and recycling of infrastructure onsite (local and Perth businesses). Discussions with Ngarlawangga and Nyiyaparli representatives will be ongoing throughout the life of the mine, and discussions will include the event of closure of the mine, and such issues as the access to the Forgotten Pool and other heritage sites. Internal stakeholders, represented by WIO personnel and onsite contractors, need to also be continually reminded of the long term goals for closure to ensure that planning for closure is integrated into the life of mine strategies for the Project.

6.3 Feedback Loop The Mine Closure Plan is presented as the initial plan of intent. As more information is obtained, rehabilitation plans will be modified as required to enable the best possible outcome for the closure of the site. This information will includes feedback from stakeholders that will aid in improving achievement of end goals (discussed in Section 7).

Plate 7: Wonmunna waterhole – east of the Great Northern Highway


7.0 Post-mining Land Use and Closure Objectives

7.1 Post-mining Landuse The goal for the closure works and rehabilitation is to:

Rehabilitate the land to achieve ecosystems that are self-sustaining and/or capable of being sustainably managed without unwarranted additional expense. This requires the rehabilitated ecosystems to be resilient, to aid in stabilisation of landforms, soils and hydrology and provide animals with shelter, food and nesting sites (EPA 2006). A further objective of rehabilitation is to return sufficient representation of species to allow vegetation to be identified as belonging to a nominated plant community type (floristic community, or vegetation complex).

Ongoing discussions with the native title working groups of the Ngarlawangga and Nyiyaparli will include the event of closure of the mine, and such issues as the access to the Forgotten Pool and other heritage sites. There is no pastoral lease on the tenements, and so upon fulfillment of completion criteria and other closure commitments, the tenements will be relinquished subject to the agreement of the DMP.

Plate 8: Recent vandalism at the Wonmunna water hole – not on Project tenements


7.2 Closure Objectives The over-riding closure objective is provided above as the post-mining landuse goal. To achieve this, a number of closure objectives must be met.

Compliance – all legal obligations and commitments are to be met. Therefore an obligations register must be maintained throughout mine life to ensure it is current at decommissioning. All commitments within this Closure Plan, when accepted by the DMP, will become part of that register.

These commitments are summarised in Section 4.0 and include:

Landforms – to be designed to be aesthetically pleasing (integrate with natural landscape), safe (geotechnical data) and stable & non-eroding (waste characterisation and dump modelling & design).

Revegetation – effective rehabilitation procedures of reconstituting a growth medium (topsoil management and amelioration and subsoil encapsulation of dispersive soils) and seeding with the derived seed mix (species / treatment / rate) to achieve a self-sustaining resilient ecosystem similar to analogue sites in the region.

Fauna – Effective management plan enforcement to ensure few casualties due to vehicles or otherwise, and to eradicate any feral animal number increases, where possible.

Surface Water – No surface water drainage systems are inadvertently affected by mining (All ‘dirty’ water treated onsite, and any other water is diverted around and back into natural drainage paths. The design of dumps and roadways are effective at minimising generated sediment, and sediment basins design are effective are preventing any downstream decreased water quality).

Waste – All wastes will be recycled or removed according to relevant

legislations and will not be evident onsite at closure.

Cultural Heritage – Ongoing discussion with the Ngarlawangga and Nyiyaparli working groups, and the formulation of Cultural Heritage Management Plans to be implemented throughout mine life and decommissioning will ensure that cultural heritage values of the Project area will be maintained as much as practicable.


8.0 Identification and Management of Closure Issues The closure issues, and the mitigation measures to remove or minimise the risks of these environmental hazards, have been discussed throughout the text of this document. These issues, in order of risk, are discussed below (Table 17) and are relatively minor, and all are manageable, because of the following:

It is known from waste characterisation studies that there will be no acid mine drainage likely to occur.

There will be no radioactivity to consider. There will be no mine lakes as mining will occur above the water table. The habitat for the troglofauna extends well beyond the planned mine pits. There will be no tailings storage facilities or process or treatment plants. There will be no saline water issues. There will be adequate volumes of topsoil and subsoil for an effective growth

medium. Erosion minimising concave waste dump designs fit within the approved

disturbance footprints. An Exclusion Zone protects the valuable habitat and vegetation communities

of the Weeli Wolli Creek and gorge, as well as the heritage site of the Forgotten Pool.

There are no TECs, PECs or conservation areas in the vicinity of the Project. No rare or endangered species or flora or fauna were recorded during

detailed site surveys. No vegetation communities of regional significance will be disturbed. Minimal potential contaminants will be used onsite. Comprehensive baselines studies have been completed so there should be

no unexpected issues arising through mine life. Ongoing monitoring will detect any unexpected outcome or event enabling a

rapid response to mitigate effects.

Plate 9: Examining drill core onsite at Wonmunna



T a b l e 1 7 : P o t e n t i a l C l o s u r e I s s u e s i n o r d e r o f d e c r e a s i n g r i s k

ISSUE EVIDENCE MITIGATION MEASURES Erosion and associated sedimentation of waterways

Waste characterisation indicates that some wastes from pits will be dispersive.

Dispersive wastes placed in centre of waste dumps

Concave waste dump design modelled with 1m of lateritic subsoil sheeting all waste

Sediment basins designed for 1:100 year rainfall events

Ongoing monitoring of downstream water quality until tenement relinquishment.

Modification to surface drainage patterns of region.

Examination of surface contours of site indicated some effects will occur due to mine infrastructure.

Planning has designed waste dumps in locations to minimise effect on drainage flow, and to prevent pooling.

Catchments to the areas of drainage modification are small.

Diversions will be put in place to ensure pits and waste dumps do not interfere with surface drainage flows.

Culverts and creek crossings designed to minimise effect.

Dust affecting aesthetics, plant health and creating human health issues

Dry climate, unsealed roads and vehicular traffic will create dust.

Construct and maintain roads to high quality to reduce dust lift off from wheels

Wet down roads in dry conditions to prevent dust

Enable drainage from roads in wet conditions to reduce mud

Ore will be wetted down to 8% before transport in trucks offsite

Trucks hauling ore offsite will have covers.

Dust control equipment will be fitted at the crusher

Dust monitoring will determine if mitigation efforts are adequate

SRE Antichiropus ‘wonmunna’ is located in the vicinity of areas to be cleared.

Surveys identified it in habitat both within and outside of disturbance areas.

The habitat outside of the disturbance area will be protected from interference

The species will be included in environmental awareness sections of the site induction

Further targeted surveys will improve the knowledge on distribution of the species.

Reduction in cultural value of heritage sites.

Heritage surveys have located a number of sites of significance.

The Forgotten Pool site is within the Exclusion Zone and protected from disturbance as minesite personnel will not be allowed access to the site.

Where possible, minesite infrastructure locations such as the camp and access track were moved to avoid sites.

Section 18 forms will be lodged with the DAA to include the 3 (currently unregistered) sites



that could not be avoided.

A Cultural Heritage Management Plan will detail protocols for any further sites discovered during operations, especially clearing.

Reduction in visual amenity of the Project site.

The construction of the waste dumps and pits will modify the local landscape.

Waste dumps are designed for minimal impact on the surrounding landscape and once vegetated should not be immediately obvious from a distance.

The waste dumps will not be visible from the Great Northern Highway.

Loss of 550ha of vegetation and habitat.

Vegetation will be cleared to enable establishment of infrastructure and haul routes, and open pit mining.

This impact will not affect any PEC, TEC or ESA areas, or any vegetation types of regional significance.

Clearing of vegetation will be limited to that determined to be necessary for infrastructure construction. Clearing limits will be marked on all design drawings and pegged in the field prior to any disturbance.

Progressive rehabilitation is to occur wherever possible.

Local seed will be collected to ensure provenance is retained.

Topsoil will be harvested and used as soon as is possible.

Survey before clearing for active Pebble Mound Mouse mounds.

Unexpected closure. Falling commodity prices may cause an unexpected shut down of operations.

A care and maintenance period followed by potential closure will be accounted for in the closure funding calculations.

The care and maintenance protocol is presented in Section 8.0.

Hydrocarbon Contamination.

Risk is low as hydrocarbon management plan will be detailed and enforced.

Hydrocarbon Management Plan will incorporate initiatives such as bunding to prevent potential leaks, training, spill kits and collection of washdown water (Section 6.7).

Any hydrocarbon contamination of soil at closure will be removed from site.


9.0 Development of Completion Criteria & Monitoring Program

9.1 Completion Criteria Development The closure objectives for the Wonmunna site are discussed in Section 7.2 and can be summarised as: - regulatory compliance; - stable and aesthetically appropriate landforms; - sustainable ecosystem rehabilitation; - surface water & groundwater levels and quality to reflect background levels as far as practicable; and - prevention of loss of cultural value of heritage sites. Rehabilitation objectives and monitoring requirements are described in detail in Section 9.2 – 9.4. Qualitative completion criteria are supplied in Table 18. Through the life of the mine, these will be reviewed and developed into quantitative criteria as more site specific information is obtained and trial rehabilitation is completed.

9.2 Rehabilitation Objectives The assessment of rehabilitated areas is achieved by developing key performance indicators and completion criteria to compare rehabilitation sites with analogue natural communities (Parker 1997; Parkes et al. 2003). The abundance and distribution of organisms in nature is the basic standard for completion criteria (Krebs 1985). Individual examples of communities may be subject to varying disturbance histories and/or natural resource availability resulting in considerable variance in ecological measures (Clewell & Rieger 1997; White & Walker 1997). Therefore, adopting a range of values (key performance indicators) that reflect natural, temporal and spatial variation of communities for completion criteria is preferred to set numerical targets (Ehrenfeld & Toth 1997; White & Walker 1997). EPA (2006) and DMP (2011) require that information from baseline studies from suitable analogue sites are used to establish achievable closure outcomes (completion criteria) and provide baseline data for closure monitoring programs. Permanent quadrants and/or transects are used to measure biodiversity targets and permanent photographic-monitoring points should also be established (EPA 2006). The following suggestions for completion criteria for specific measures are provided (EPA 2006):

for plant species diversity and richness specified targets are typically set at 60-80% of the natural community;

for plant cover and density, in most instances, completion criteria based on the relative cover (% of area) are most effective and efficient, this is the % of area occupied by plants and bare ground;

for weed species that the relative cover of minor weeds be low and either declining or stable, that major weeds capable of dominating the community are absent and that declared weeds be controlled as required by regulations; and


for dominant plant species that specific targets be set for plants from different strata, that cover and abundance targets be set for dominant plant species and that dominant plants be present at appropriate relative densities with evidence that sufficient relative cover of these species will be established.

Plant diversity is established as the most common completion criteria used and is often assumed to be an effective surrogate for all other types of organisms. The number of stems of native plants in a given area is often used as a completion criterion for plant cover. However, it may be difficult to set meaningful values for these targets, because plants growing in rehabilitated areas are unlikely to be the same average size as those in reference systems. These targets are also relatively time-consuming to measure. Therefore in most cases, completion criteria based on relative cover (% of area) will be most effective and efficient. This is the relative area occupied by native plants, weeds and bare ground measured in permanent plots or transects. Examples of completion criteria provided in the guidelines for mine closure (DMP & EPA 2011) are:

vegetation composition on the rehabilitated site is representative of the target ecosystem in species diversity/richness and vegetation structure,

species richness is greater than the percent of the mean value recorded in all reference plots in analogue sites in the target ecosystem,

foliar cover is within the range of values from analogue sites in the target ecosystem and

minimal evidence of weed species, including both declared agricultural weeds and environmental weeds.

The principle objective for rehabilitation is to minimise environmental impacts resulting from permanent change to ecosystems (EPA 2006). This requires rehabilitation plans to be based on clear objectives and targets which can be effectively monitored and audited to confirm objectives are achieved. A key objective of rehabilitation is that ecosystems must be self-sustaining and/or capable of being sustainably managed without unwarranted additional expense. This requires rehabilitated ecosystems to be resilient, which is unlikely to be the case if keystone species are lacking. Keystone species that provide essential ecosystem functions include vegetation required to stabilise landforms, soils and hydrology and provide animals with shelter, food and nesting sites (EPA 2006). A further objective of rehabilitation is to return sufficient representation of species to allow vegetation to be identified as belonging to a nominated plant community type (floristic community, or vegetation complex). This requires (1) the majority of local native species to be returned, (2) the relative abundance of key species, especially dominants such as trees to be similar to reference plots and (3) the absence of substantial cover of non-local species and weeds.



T a b l e 1 8 : P r o p o s e d c o m p l e t i o n c r i t e r i a f o r W o n m u n n a P r o j e c t

CLOSURE OBJECTIVE COMPLETION CRITERIA TYPE OF MONITORING PERFORMANCE INDICATORS

Regulatory compliance All regulatory conditions & commitments are met.

Auditing All commitments and conditions are met.

Landforms are stable and aesthetically compatible with surrounding landscape

Post-mining landforms are designed to minimise surface erosion and sediment loss as far as is practicable.

- Landform construction monitored against design criteria

- Erosion monitoring.

Landforms designed to criteria based on waste characterization, and erosion limited to minimal acceptable levels with vegetative cover increasing.

Sustainable ecosystem establishment

Rehabilitation of areas disturbed as a result of mining operations to a functional ecosystem.

Annual ecosystem function and vegetation monitoring

Described in Table 22, including species richness and plant density.

Surface & groundwater levels and quality to reflect background levels as far as practicable

- Surface drainage to downstream environments retained or reinstated where possible

- Groundwater levels to reflect background levels as far as practicable

- Quality of surface and groundwater to reflect background levels.

- Downstream water quality monitoring until tenement relinquishment.

- Groundwater monitoring to occur until tenement relinquishment.

Groundwater and surface water quality, and levels, are comparable to baseline conditions.

Prevention of loss of cultural value of heritage sites

No culturally significant sites are impacted without approval and stakeholder consultation.

Annual review of Cultural Heritage Management Plan, and compliance.

Compliance with the mining agreement and Cultural Heritage Management Plan.


9.3 Monitoring Program The site specific monitoring program for the Wonmunna Project described in the following sections is based on a rehabilitation program developed by G&G Environmental in collaboration with Minara Resources, Landloch and Rally Environmental and in consultation with government regulators (by conducting annual environmental workshops) for the Murrin Nickel-Cobalt Operation. The collaboration culminated with a presentation of a framework for rehabilitation success at the international Mine Closure Conference in 2006 and a Golden Gecko award for environmental excellence in 2008. The Golden Gecko Award was presented by the Western Australian Department of Mines and Petroleum (then Department of Industry and Resources), in recognition for excellence, leading practice and innovation in environmental management. The collaboration enabled the development of a monitoring program with completion criteria for the assessment of vegetation establishment in rehabilitated areas based on detailed analysis of benchmark data obtained from natural analogue communities. The program developed increased the potential of success for key stages of rehabilitation, improving the user’s ability to self-regulate and remove any subjectivity from assessing rehabilitation performance. A number of rehabilitation areas were subsequently approved for full bond return, emphasizing the effectiveness of the rehabilitation framework devised. The awarded rehabilitation program has since been employed at a number of mine sites, including Kalgoorlie Consolidated Gold Mines (KCGM), Crescent Gold Laverton operations, St Barbara Leonora and Southern Cross operations and the Range River Indee Gold Mine in the Pilbara bioregion. Derivation of completion criteria for vegetation community structure prior to the commencement of rehabilitation provides specific targets at which rehabilitation processes may be targeted. For example, identification of dominant species in local communities provides the desirable species composition for seed mixes to apply to rehabilitated areas. Quantification of species richness in analogues dictates the number of different species to include in seed mixes and/or plantings. In accordance with government guidelines (EPA 2006, DMP 2011) the monitoring program provides cost effective quantitative data pertaining to:

quantitative identification of keystone (dominant) plant species present in vegetation associations,

quantitative measures for keystone species, quantitative measures of weed species and plant density, diversity and foliage cover measures including relative values

for all species recorded in monitoring transects. The data provided by the monitoring program is applicable to:

providing clear quantitative completion criteria for rehabilitation assessment, identification of keystone and other native species to target for rehabilitation

and quantitative evaluation of rehabilitation process success, e.g. success of

seeding programs.


The planned monitoring program is outlined in four sections:

records of rehabilitation processes, installation of field monitoring sites and field monitoring procedures, description and definition of measures and data provided and description of data analyses for rehabilitation assessment.

9.3.1 Monitoring Site Parameters

The following monitoring template (Table 19) is an example of one used to record all the site variables required for the analysis of rehabilitation success, and the review of rehabilitation procedures. The type of site rehabilitated e.g. waste dump versus haul road, and the characterisation of the rooting zone below the topsoil (e.g. waste versus compacted in situ subsoil) is also important data for effective interpretation of monitoring results. The data provide the opportunity to evaluate the efficacy of key rehabilitation processes including the contribution to the established community from seeding and topsoil return. The following template (Table 20) is an example of one to be used to record all rehabilitation job seed data for use in analysis of revegetation monitoring results.


Table 19: Monitoring Template

TOPSOIL Source (include GPS co-ords): Vegetation description: Date(s) of stripping: Method/Machinery: Depth of collection: Location of stockpile: Date(s) of respreading: Method/Machinery: Age of stockpile: Depth of topsoil on rehab: Depth of ripping VEGETATIVE / ROCK MULCH Source (include GPS co-ords): Vegetation description: Date of harvest: Location of stockpile: Date(s) of respreading: Method/Machinery: Age of stockpile: Depth of mulch on rehab: FERTILISER Brand: Constituents (& %) N (%) P (%) K (%) Mo (%) Zn (%) Cu (%) Supplier: Cost: Date(s) of Application: Rate of Application: Method of Application: GYPSUM Supplier: Cost: Date(s) of Application: Rate of Application: Method of Application:



T a b l e 2 0 : T e m p l a t e f o r S e e d D a t a f o r M o n i t o r i n g R e h a b i l i t a t i o n

BROADCAST SEED

Family Species Cohort Code

Treatment Mass Sown (kg)

Seed/g Viability Germinability Total Seed Sown (#)

Area Sown (ha)

Seed/m2 Price ($/kg)

Proportion in seed mix (%)

T o t a l S e e d C o s t :

D a t e ( s ) o f B r o a d c a s t i n g

M e t h o d o f S o w i n g


9.3.2 Field Monitoring Procedures

Field monitoring involves the installation of permanent monitoring transects (for repeat measures of collection of quantitative data), permanently marked photo-points and recording of general observations in unbounded plots. Vegetation transects and photo-points are placed on the top/crest and sides/batters of each rehabilitated landform in areas representative of the establishing communities.

9.3.2.1 Permanent Monitoring Transects The number of monitoring transects installed is dependent on the characteristics of the site to be assessed. In accordance to EPA guidelines a minimum of two transects (replicates) are installed for any given area. For analogue communities two transects are installed and monitored. For rehabilitated areas the number of transects is influenced by the size, structure and rehabilitation history of the site. Where possible transects should be installed to represent each face (e.g. different face/lift and top of waste rock dumps) and on each area rehabilitated at a different time or utilising different methods to accurately portray an overall picture of the entire rehabilitated area. Transects (25 x 1m) are measured out and marked at all corners with posts2 and GPS coordinates for the start of each transect is recorded. At the time of installation, the monitoring post to which the tape measure is attached is clearly labelled with the site name or code and the number of the transect replicate. During subsequent monitoring periods the measuring tape should always be attached to this ‘marker’ post to ensure data is collected sequentially in different monitoring periods. At the completion of installation of the transect, a photograph is taken from the marker post along the length of the transect whilst the measuring tape is in place. Quantitative floristic data are then collected in sequential 1 x 1m quadrats along the 25m transect. The following data are recorded for each quadrat:

the name of all species present in the quadrat3, the density of each species present, a visual estimate of the projected foliage cover of each species present and a visual estimate of the total litter cover.

9.3.2.2 Photo-points Permanent photo-points are installed in order to provide a pictorial record of the establishment and development of the plant community over time. As a general rule photo-points are established within the vicinity of monitoring transects to provide a broader view of the area being monitored than is provided by the photograph of the

2 Metal fence droppers are preferred as they are light-weight facilitating haulage over

rehabilitated landforms, are reasonably easily driven into the ground with a hammer, are

resistant to fire and maybe clearly labelled with the use of a paint-marker pen.

3 Where the species is unknown to the person conducting the survey a voucher specimen

should be collected, pressed and dried to be used to identify the species.


transect itself. As an example, for a monitoring transect placed mid-slope of a waste dump batter a photo-point would be placed at the base or top of the batter such that the subsequent photographs capture as large an area of the batter being assessed as possible. Each photo-point is marked with three posts set in a triangular formation. The photographs are taken standing at the apex of the triangle (or central post). The remaining ‘marker’ posts are positioned to the left and right of the central post. Two photographs are taken such that the top of each of the marker post lies centrally positioned at the base of the view finder. A GPS co-ordinate is taken of the central post which is also labelled with the site name or code and the photo-point number.

9.3.2.3 General Observation in Unbounded Plots The following general observations of the state of the rehabilitated area are recorded:

a description of the vegetation community according to the height and structural classes of National Vegetation Inventory System (NVIS 2003),

notes on the reproductive state of species present, presence of seedlings and/or different age classes of the dominant vegetation, presence of dead plants and the potential sustainability of the community based on plant death and/or presence of seedlings and

notes in relation to the presence of erosion.

9.3.3 Description and Definition of Measures and Data

There are a multitude of information gathered during each transect survey, and this is summarised in Table 21.

Table 21: Quantitative measures attained with the proposed monitoring system

Community Measures Species Measures

Species richness.

Mean diversity (species m-2) per site.

Mean diversity (species m-2) per transect.

Mean plant/foliage cover per site.

Mean plant/foliage cover per transect.

Mean litter cover per site.

Mean litter cover per transect.

Mean density (plants m-2) per site.

Mean density (plants m-2) per transect.

Proportion (%) bare quadrats per site.

Proportion of community floristics (cover, density, diversity and frequency attributable to dominant species).

Mean cover of each species per site.

Mean density of each species per site.

Range of mean cover values between different communities.

Range of mean density values between different communities.

Relative density of each species.

Relative frequency of each species.

Relative cover of each species.

Importance value index for each species.

Range of importance values for the species between different communities.


Litter cover is the proportion (%) of the ground surface covered by vegetation litter. The terms ‘richness’ and ‘species richness’ refer to the total number of species recorded for a site or transect. Diversity is the mean number of species recorded per square metre (quadrat) for a site or transect. Foliage cover is the proportion (%) of the quadrat encompassed by the perimeter of the canopy of all plants of the species either rooted within or outside of the quadrat, i.e. any foliage of plants that are rooted outside of the quadrat projected into the quadrat is included in the cover value for the species. Density is the number of plants of the species that are rooted within the quadrat, density for the transect or site is the mean number of plants of the species per square meter (quadrat). Frequency is the number of quadrats in which the species is recorded. Dominant species in communities are identified utilising values from the importance value index (IVI, Krebs 1985): IVI = Relative Frequency + Relative Cover + Relative Density

where: Relative Frequency = (species frequency/total frequency of the community) x 100 Relative Cover = (total cover of species/total plant cover of the community) x 100 Relative Density = (total density of species/total plant density of the community) x100 The IVI provides a strong indicator of a species importance in the community because it considers not only the number of plants present (density)and the size of the plant (cover) but also how often it occurs in the landscape (frequency). Species with the highest IVI values are dominant in the community. By assigning an arbitrary value for dominance, the proportion of the community structure attributable to the dominant species may be determined. For example, a species may be considered ‘dominant’ if it attains any relative value (cover, density or frequency) of 5% or higher. By listing the assigned species and summing their relative values the proportion of plant density, foliage cover and plant frequency in the community attributable to the species may be determined.

9.3.4 Description of Data Analyses for Rehabilitation Assessment

9.3.4.1 Climatic Data Long term monthly rainfall and temperature averages collected at the township of Newman and total monthly precipitation and mean monthly minimum and maximum temperatures for the 12 months preceding the monitoring of the vegetation are obtained from the Bureau of Meteorology. The data is graphed and comparisons conducted to identify any extremes in rainfall and temperature that may have impacted on vegetation establishment and condition in the rehabilitated areas.


9.2.4.2 Transect/Site Data Mean values for the community floristics in rehabilitated landforms are compared directly with values established for analogue communities. Column graphs for each of the measures are used to compare the rehabilitated area to analogue communities. Rehabilitation is assessed utilising the criteria summarised in Table 22. The criteria consider the natural variation (or the range of values) of the analogue communities. Rehabilitation is considered excellent if measures exceed the mean value for all analogue communities as this indicates that the vegetation is representative of the ‘better’ analogue communities. Rehabilitation is considered satisfactory if the values are equivalent to at least one analogue community as this indicates that the community has attained a natural level. If the values are below all analogues then the rehabilitation does not fall in the natural range and is considered unsatisfactory.

Annual versus Perennial Species

Data are collected for both annual and perennial species however the criteria provided in Table 22 will utilise data from perennial species only. When data from annual and perennial species are combined seasonal fluctuations in the numbers and prominence of annual species may create too much ‘noise’ in the data set making it difficult to establish the trajectory of indices, e.g. increasing plant cover. Fluctuations in annual species may be used to determine whether site conditions in the rehabilitated areas are conducive to native species completing the short term life cycle whilst the trajectory of data from perennial species identifies whether the community progresses toward completion criteria.

9.3.4.3 Species Composition The species composition of the rehabilitation is compared to analogues by cluster analysis (PATN™) using UPGMA (Unweighted Pair-Group Method of Arithmetic Averages). The analysis provides a dendrogram that shows relatedness between the communities. Analysis is weighted by the IVI value derived for each species. If the rehabilitated community is ‘clustered’ in amongst the analogue communities then it is considered that the community resembles analogues and the rehabilitation is considered satisfactory.

9.3.4.4 Weed Species The monitoring program provides density, frequency and cover values for all species, these values for weed species may be compared between rehabilitated and analogue communities to ascertain whether weed species are more prominent (or not) in the rehabilitation. These data may also be used to monitor temporal fluctuations between monitoring periods to ascertain whether the species are growing or declining in prominence. Monitoring temporal fluctuations may also be used to determine whether any management actions undertaken are having the desired result. The EPA (2006) recommend that completion criteria for weeds be based on the relative cover of weeds in analogues, i.e. that the relative cover of weeds in the rehabilitated community does not exceed the relative abundance in analogue communities. The monitoring method applied provides relative cover for all species recorded in the transects. Comparison of relative cover of weed species between the rehabilitated community and analogues is used to assess the success of the rehabilitation referencing the criteria in Table 22.


Table 22: Criteria used to assess the state of rehabilitated landforms

Community/Site Measure

Completion Criteria Rehabilitation Assessment

Plant Density Value in rehabilitated area is equivalent to or exceeds the mean for all analogue communities.

Excellent

Value in rehabilitated area is equivalent to at least one analogue community.

Satisfactory

Value in rehabilitated area is lower than all analogue communities. Unsatisfactory

Species Diversity

Value in rehabilitated area is equivalent to or exceeds the mean for all analogue communities.

Excellent


Satisfactory


Species Richness

Value in rehabilitated area is equivalent to or exceeds the mean for all analogue communities.

Excellent


Satisfactory


Foliage Cover Value in rehabilitated area is equivalent to or exceeds the mean for all analogue communities.

Excellent


Satisfactory


Litter Cover Value in rehabilitated area is equivalent to or exceeds the mean for all analogue communities.

Excellent


Satisfactory


% Bare Quadrats

Value in rehabilitated area is equivalent to or lower than the mean for all analogue communities.

Excellent


Satisfactory

Value in rehabilitated area is higher than all analogue communities. Unsatisfactory

Dominant Species

All dominant species in rehabilitated area are also dominant or have been recorded in an analogue community.

Excellent

The majority of dominant species in rehabilitated area are also dominant or have been recorded in an analogue community.

Satisfactory

Less than half of the dominant species in rehabilitated area are also dominant or have been recorded in an analogue community.

Unsatisfactory

Species Composition

Rehabilitated community is embedded in a cluster of analogue communities in the dendogram.

Satisfactory

Rehabilitated community is not embedded in a cluster of analogue communities in the dendogram.

Unsatisfactory

Relative Cover of Weeds

Value in rehabilitated area is equivalent to or lower than the mean for all analogue communities.

Excellent


Satisfactory

Value in rehabilitated area is higher than all analogue communities. Unsatisfactory


9.3.4.5 Qualitative Measures from Photographs Photographs from rehabilitated areas are compared to those from analogue communities to provide pictorial evidence of whether the establishing community resembles the surrounding natural vegetation and will therefore be aesthetically pleasing and blend in with the natural landscape. Qualitative comparisons of rehabilitation to analogues include:

aesthetics (does the community resemble analogues and does the species composition look similar?),

canopy (are all canopy levels in the analogue appearing in the rehabilitation?) and

plant density and foliage (does plant density and foliage cover appear similar?).

Temporal comparison of the photographs between monitoring periods is also undertaken to identify:

vegetation establishment and growth (has plant density and foliage cover increased since last assessment?),

vegetation health (, are plants surviving and do they appear healthy? e.g. foliage is green and lack of bare limbs) and

evidence of self-sustainability (are plants flowering or with fruit/seed pods?). Utilising photographs in this fashion provides an immediate indication of the quality of the revegetation and provides confidence that the assessment procedure is transparent and directed at providing a true account of the state of the rehabilitation. Providing photographs of several locations on the landform also identifies how uniform (or not) the vegetation establishment is.

9.2.4.6 General Observations from Unbounded Plots Comparison of the general observations is typically restricted to discussion of the number of species reproducing, the number of different age classes of dominant or notable species. Photographic evidence of plant reproduction maybe used to complement recorded observations. These observations are utilised to identify whether the established community is progressing toward self-perpetuance and indicate when it may be appropriate to conduct community resilience monitoring.

9.3.5 Analogue Community Selection

A review of vegetation associations defined previously for Wonmunna (G&G Environmental 2011, 2014) was used to identify appropriate analogue communities to be included in the rehabilitation assessment. From the proposed disturbance area, vegetation associations to be impacted in excess of 30% were included in selection of species for revegetation. In addition, natural communities were selected as analogues by habitat matching as they occur on landforms representative of waste landforms.


Communities selected consider all areas in the proposed disturbance area and final rehabilitation landforms including:

waste rock landforms rehabilitated haul roads and rehabilitated plant and camp areas.

The Wonmunna NVCP Purpose Permit approved the clearing of 555ha of a total purpose permit area of 2464ha on leases M47/1423, M47/1424 & M47/1425. This area excludes the Exclusion Zone. Of 15 different vegetation associations defined for the purpose permit area, the four most common include: Mallee Woodland (M4), Acacia Woodland (AW1), Eucalyptus Woodland (EW1) and Spinifex steppe (SS1) (Table 23). However, SS1 occupy only 0.18 % of the currently proposed vegetation clearing zone and may be omitted from the rehabilitation program at this stage. The proposed vegetation clearing zone included five vegetation associations (AW1, C4, C6, M1 and S1) of which in excess of 30% may be cleared and therefore these associations may be considered for rehabilitation. However, the C4, C6 and M1 associations occupy small areas and collection of propagules may restrict the capacity to rehabilitate these communities. The shrubland, S1 community was considered to be potentially locally significant as it was scarce and comprised a novel combination of species including Tephrosia sp. B Kimberley Flora and Corchorus trilocularis, for which the survey area represents an apparent moderate range extension (G&G Environmental 2011). S1 should be included in rehabilitation to minimise the impacts to flora and habitat loss to fauna. To consider final rehabilitation landforms including: waste rock landforms, rehabilitated haul roads and rehabilitated plant and camp areas, specific communities are to be targeted for habitat matching (Table 24). Mallee, Eucalyptus and Acacia woodlands (M4, AW1, EW1) should be targeted as analogues for waste landforms, whilst M4, AW1, and S1 should be targeted as analogues for haul roads, plant and camp areas. The descriptions of potential analogue sites are summarised in Table 25. In summary, vegetation associations: M4, AW1, EW1 and S1 should be targeted for revegetation in order to match the pattern of rehabilitation with the surrounding landscape and minimise the impacts to flora and habitat loss to fauna. Two transects should be established in each vegetation community to satisfy government requirements (DMP 2011). Other reasons for the selection of these communities were:

they are representative of the natural vegetation communities which surround the mine dominated by Eucalyptus and Acacia woodlands over spinifex shrublands.

numerous examples of the type of analogue communities can be found in close proximity to the proposed mine and rehabilitated areas showing them to be common local communities and therefore provide an opportunity for the rehabilitated areas to integrate both aesthetically and biologically with the adjacent natural vegetation.


Table 23: Vegetation Associations at Wonmunna Project site

Association Vegetation Group Total of Area

in Purpose Permit (Ha)

% of purpose

permit area

% Association

outside VCZ

% Association in VCZ

AW1 Acacia Woodland, flat plain on plateau

496.5 20.15 68.71 31.29

AW2 Acacia Woodland, flat plain on plateau close to

the edge/breakaway

3.7 0.15 100.00 0.00

C1 Creek or Drainage line 34.25 1.39 99.44 0.56





EW1 Eucalyptus Woodland on hills, slopes and in

Drainage lines close to slopes and close to the

gorge

350.13 1.89 91.55 8.45

M1 Mallee Woodland on rolling hills and slopes

42.38 1.72 59.23 40.77


126.65 5.14 84.13 15.87


335.35 13.61 93.90 6.10


746.84 30.31 83.26 16.74

S1 Shrubland in brown clay in wet areas

7.39 0.3 23.81 76.19

SS1 Spinifex steppe on undulating planes

265.62 10.78 99.82 0.18

SS2 Spinifex steppe on undulating planes

0.49 0.02 100.00 0.00

Note: VCZ = vegetation clearing zone Highlight = Associations potentially to be cleared more than 30% of the total within the Purpose Permit Area


Table 24: Habitat matching vegetation associations at Wonmunna Project with proposed landforms

Landform Association Reasons for selection

waste rock M4, AW1, EW1

M4 was found throughout the tenements on rolling hills as the most widely distributed habitat and is suitable for upper and lower slopes of waste dumps. It occupies areas of current mine layout (e.g. NMM-west pit and waste dump, NMM-east waste dump).

AW1 typically occurred on flat plains and plateaus, and therefore is suitable for top of waste dumps. It occupies areas of Pit 6, 7 and 2, and CMM dump, ROM pad, Pit 3 waste dump). This vegetation may also be cleared in excess of 30 % and should be represented in the rehabilitated areas.

EW1 occurred on the hills and ridges and is suitable for upper steep slopes. In addition it occupies an area currently marked for establishment of a camp and truck park bay.

haul roads AW1, S1, M4 Acacia woodland (AW1) and shrubland S1 are suitable for flat plains and occurred in areas currently selected for haul roads in the mine layout. These associations may be cleared in excess of 30 % and should be targeted for revegetation to minimise impact to flora and preserve habitat for fauna.

M4 is most common association occurring on low rolling hills and also intercepts haul roads in the current mine plan layout.

plant and camp areas AW1, S1, M4 AW1 and S1 are suitable for flat plains, may be cleared in excess of 30 % and should be targeted for revegetation to minimise impact to flora and preserve habitat for fauna.

M4 is most common association occurring on low rolling hills and present close to plant areas.

Plate 7: Example of EW1 – Snappy Gum (Eucalyptus leucophloia)


Table 25: Descriptions of potential analogue communities

Vegetation Description Frequently Recorded Species

Photograph

Mallee woodland M4 - Isolated low Eucalyptus leucophloia trees and E. gamophylla mallee over isolated tall mixed Acacia spp. and Petalostylis labicheoides shrubs to open shrubland over isolated low mixed shrubs over a Triodia pungens and T. wiseana hummock grassland with pockets of a low Acacia distans and Eucalyptus leucophloia woodland over isolated tall mixed shrubs and isolated clumps of Triodia pungens hummocks on steep rocky slopes near the crest of plateaus and isolated mid-Eucalyptus leucophloia trees over a low E. repullulans mallee and tall Petalostylis labicheoides shrubland over Triodia longiceps and T. pungens mid-hummock grassland in drainage lines.

Trees– Eucalyptus leucophloia, E. gamophylla, E. repullulans, E. socialis, E. xerothermica, Hakea lorea

Mid/Tall Shrubs - Petalostylis labicheoides, Acacia ancistrocarpa, A. distans, A. atkinsiana

Low Shrubs – Gompholobium polyzygum, Dampiera candicans, Mirbelia viminalis, Keraudrenia velutina, Goodenia scaevolina

Grasses – Triodia pungens, T. wiseana, T. longiceps, T. brizoides, Amphipogon caricinus var. caricinus

Acacia woodland AW1 - A low to mid-Acacia aptaneura, A. distans and A. pruinocarpa woodland over isolated mid to tall Eremophila forrestii subsp. forrestii, E. fraseri and Anthobolus leptomerioides shrubs to open shrubland over a low mixed Triodia melvillei, T. pungens and T. wiseana open grassland to grassland with T. melvillei frequently dominant.

Trees– Acacia aptaneura, A. distans, A. pruinocarpa and Grevillea berryana

Mid/Tall Shrubs - Eremophila forrestii subsp. forrestii, E. fraseri, Anthobolus leptomerioides, Acacia kempeana

Low Shrubs – Eremophila platycalyx, Enchylaena tomentosa, Hibiscus burtonii, Senna glaucifolia

Grasses – Triodia melvillei, T. pungens, T. wiseana, T. brizoides

Eucalyptus woodland EW1 - Isolated low to mid-Eucalyptus leucophloia and Acacia aptaneura trees to low open woodland over isolated low Eucalyptus repullulans mallee to open mallee woodland frequently with E. socialis low mallee woodland in drainage foci over a variable low to mid-shrub layer with Acacia spp. and Melaleuca eleuterostachya common over a low to mid-Triodia brizoides grassland often with patches of T. angusta and T. pungens

Trees– Eucalyptus leucophloia, E. repullulans, E. socialis, E. gamophylla, Acacia aptaneura,

Mid/Tall Shrubs - Melaleuca eleuterostachya

Low Shrubs – Scaevola acacioides, Dodonaea viscosa subsp. angustissima, Senna glutinosa, S. glutinosa subsp. pruinosa, Maireana triptera

Grasses – Triodia brizoides, T. pungens, T. angusta


Vegetation Description Frequently Recorded Species

Photograph

S1 shrubland - Isolated low Acacia aptaneura trees over isolated mid to tall Acacia tetragonophylla shrubs to open shrubland over isolated low to mid-Eremophila lachnocalyx shrubs to mid-shrubland over a low to mid-mixed tussock grassland, frequently with Aristida latifolia, Eragrostis xerophila and Astrebla pectinata

Trees– Acacia aptaneura

Mid/Tall Shrubs - Acacia tetragonophylla

Low Shrubs – Eremophila lachnocalyx

Grasses – Aristida latifolia, Eragrostis xerophila, Iseilema vaginiflorum, Astrebla pectinata

Plate 8: Example of EW1 – gentle slope – at Wonmunna


9.4 Proposed Monitoring Schedule

9.4.1 Analogue Communities

Initial monitoring of analogue communities will be undertaken prior to the commencement of rehabilitation activities to facilitate the derivation of completion criteria. Derivation of completion criteria prior to the commencement of rehabilitation provides specific targets for rehabilitation processes. For example:

identification of dominant species in local communities provides the desirable species composition for seed mixes to apply to rehabilitated areas;

quantification of species richness in analogues dictates the number of different species to include in seed mixes and/or plantings; and

quantification of species densities in analogue communities may be used to calculate seed application rates for broadcast seeding programs.

Monitoring of analogue communities will be continued over mine life to expand the number of communities and provide a more accurate account of the variability of natural communities and ecosystems. Typically communities selected as analogues represent mature ‘climax’ vegetation as this is the desired outcome for rehabilitated areas, a mature self-sustaining vegetation community. As such frequent monitoring of a small number of mature communities provides little benefit to the monitoring program as (in the absence of a stochastic event) there is likely to be little change in floristics of a mature community. In the proposed monitoring program different analogue sites will be monitored in different years to provide a greater number of analogue communities for comparisons with rehabilitated areas for progress towards completion criteria. With broader range of analogue communities there is higher likelihood of similarity. In addition, new analogues can be selected to match developing rehabilitation communities. For example, rather than monitor five analogue communities on an annual basis for ten years, five analogue communities may be monitored every year on a five year rotation. With the latter system, at the end of ten years there is a much broader data set (25 analogues) than utilising the same five analogues every year.

9.4.2 Rehabilitated Areas

The monitoring schedule proposed for the Wonmunna Project is interpretive as the required frequency of monitoring is dependent on ‘triggers’ from the assessments undertaken. Frequency of monitoring is dependent on two factors:

age of the rehabilitation; and state of the rehabilitation.

Quantitative monitoring of rehabilitated areas will commence within six months of the end of the first wet season (December – March) following the completion of rehabilitation. Annual monitoring will then be conducted for the next three years as this facilitates early identification of undesirable outcomes, e.g. poor vegetation establishment or erosion. Early identification of problems allows for early intervention. Monitoring in the early stages of community establishment also provides the data necessary to evaluate the efficacy of rehabilitation processes, e.g. number of germinants from sown seed.


During each successive monitoring period the trajectory of the various floristic measures will be assessed to determine whether the establishing community is ‘on-track’ to attain completion criteria, e.g. plant density values are equivalent to analogue communities or are increasing toward analogue communities. If annual quantitative monitoring over the first three years indicates that the rehabilitation is progressing satisfactorily, changing to qualitative monitoring of the site, e.g. photographs at permanent monitoring points, on a bi-annual basis may be conducted. Assessment of the photographs is conducted to ensure any deterioration in rehabilitation quality is detected, or in the advent that the site progresses satisfactorily to identify when the site appears to have attained completion criteria. Quantitative assessment may then be conducted to provide empirical evidence for sign off. If at any stage of the monitoring program it is apparent that the vegetation is unlikely to attain completion criteria, e.g. after three years plant density is well below all analogue communities and/or site is disturbed by severe erosion, monitoring of the site should cease until remediation is completed and then annual assessment may proceed again as for a newly rehabilitated area.

9.4.3 Procedures to Assess Rehabilitation Process

At the completion of each monitoring period data recorded of the rehabilitation processes, i.e. topsoil return, seeding rates and planting rates are utilised to assess the efficacy of these processes. For example, species lists and densities in the rehabilitated areas may be compared to species lists and seeding rates of seed mixes:

% Seeding Success = Species Density/Species Sowing Rate x 100 Assessments of this nature will be used to re-assess the composition of future seed/plant mixes. If a particular species is continually absent in rehabilitation it may be prudent to include an alternative species, or remove the species form the program to conserve crucial propagule reserves and undertake research trials to establish methods to enhance establishment of the species. Correspondingly, evaluation will also identify those species that frequently successfully establish and therefore the frequency or quantity of its seed may be adjusted for future rehabilitation. Recruitment from topsoil and mulch propagules, e.g. soil-stored seed or bulbs, may also be determined by comparing the species composition of planting and seeding programs against the list of species recorded in the monitoring program. Determining the identity and plant numbers (density) of species recruiting from these propagule sources may be used in rehabilitation trials to determine optimum management of these propagule sources (such as the length of time topsoil is stockpiled). Annual assessment of rehabilitation processes in this fashion will determine what areas require trials/ research to produce a system for continuous improvement to rehabilitation outcomes.


10.0 Financial Provision for Closure A summary of the process of rehabilitation at decommissioning is provided in the section of this report on rehabilitation (Section 5.9). The areas that will be disturbed at the end of mine life are provided in Table 26. This includes the reduction in area of waste dumps to be rehabilitated due to the progressive rehabilitation during mine life. It is important to note that concave designed waste dumps can only be rehabilitated when the dump itself is complete, or at least one side is at full height. The estimation spreadsheet of the costing of closure is provided in Table 27. Actual number estimates are available on request. This can only be an estimate due to the probable change in pricing over time, and unforeseen events during mine life and changes in closure strategy due to improved knowledge or changed industry practice. Any changes will be reported in the Mine Closure Strategy updates, where any changes will be reflected in the costing estimates. This cost estimation can also be considered a schedule, as each task in listed in order of probable action. Costs are based on;

- Reshaping and topsoil spreading is cost at $1.80/m3, including D9 dozer and fuel.

- Seed cost is $1000/kg and rate is 5kg/ha, or 3kg/ha on lay down area and roads.

- Seeding and ripping is cost at $850/ha and includes D9, seeder, operator and vehicles.

- Rehabilitation of waste dumps, inclusive of contouring, rock armouring, topsoil spreading and seed and fertiliser application is approximately $35,000/ha.

Plate 10: At closure most access tracks, including historical disturbance, will be rehabilitated



T a b l e 2 6 : S u m m a r y o f t h e d i s t u r b a n c e a n d r e h a b i l i t a t i o n a r e a s a t t h e W o n m u n n a P r o j e c t a t D e c o m m i s s i o n i n g

Mine Area M47/1423 (ha) M47/1424 (ha) M47/1425 (ha)

Total (ha) Total Disturbance

Rehab to do at decommissioning

Total Disturbance


Total Disturbance


INFRASTRUCTURE Road train park up / Workshop 0 0 7.21 7.21 0 0 7.21

Camp 0 0 7.46 7.46 0 0 7.46 Magazine 0.28 0.28 0 0 0 0 0.28 Offices/Workshop/Go-line 0 0 5.64 0 0 0 5.64

Crusher/Truck Load Out 0 0 43.23 0 0 0 43.23

Total 0.28 0.28 63.54 63.54 0 0 64.00 PITS NMM-west 0 0 26.66 N/A 0 0 0 NMM-east (pits combined) 0 0 85.26 N/A 0 0 0

CMM 48.43 N/A 0 0 0 0 0 SMM-east 0 0 0 0 21.52 N/A 0 SMM-west 0 0 0 0 21.76 N/A 0 Total 48.43 0 111.91 0 43.28 0 0 WASTE DUMPS NMM-west 0 0 21.47 0 0 0 0 NMM-east 0 0 67.48 5 0 0 5.0 CMM 66.55 0 0 0 0 0 0 SMM-east 0 0 0 0 26.87 20 20.00 SMM-west 0 0 0 0 34.68 30 30.00 Total 66.55 0 88.95 5.0 61.73 5 0 55.00 ROADS Camp to Offices 00 0 6.59 6.59 0 0 6.59 Magazine Road 1.06 1.06 0 0 0 0 1.06 NMM Haul Roads 0 0 37.27 30 0 0 30.00 CMM Haul Roads 14.26 12.0 0 0 0 0 12.00 SMM Haul Roads 0 0 0 0 1.68 1.68 1.68 Total 15.32 13.06 43.86 36.59 1.68 1.68 51.33



MISCELLANEOUS Borefields 0.2 0.2 0.2 0.20 0.2 0.2 0.6 Topsoil Stockpiles* 0 Total 0.2 0.2 0.2 T O T A L 1 3 0 . 7 8 3 0 8 . 4 7 1 1 4 . 8 9 554.14

*included with dump areas



T a b l e 2 7 : M i n e C l o s u r e P l a n n i n g a n d C o s t E s t i m a t i o n

T a s k # C l o s u r e T a s k T i m i n g / N o t e E s t i m a t e d C o s t

P L A N N I N G

- Produce a Mine Closure and Rehabilitation Plan for approval by DMP. Develop a Task Register as part of the closure and rehabilitation process to manage all requisite activities

At beginning of mine life n/a

- Notify the District Inspector of Mines of abandonment in accordance with Sections 42 and 88 of the Mines Safety and Inspection Act 1994.

n/a

- Cap any open bores or drill holes. Recheck exploration logs for any outlying drill holes.

Can be progressively completed. n/a

1 Implement the approved Mine Closure and Rehabilitation Plan – requiring onsite supervisor

At decommissioning

M I N E O P E N I N G S

2 The entrance to the open pit workings will be closed with a waste rock bund across the entry to the pit access ramp.

Price included in open pit – task #22.

N/A

3 Complete the construction of abandonment bunds when haul roads are removed. Refer to the DMP guidelines ‘Safety bund walls around abandoned open pit mines’ (DMP 1997). Competent rock will need to be selectively stockpiled during mine life.

After use of haul roads within bunding perimeter are no longer

required – note mostly constructed during life of mine

O P E N P I T

22 Install waste rock safety bund at top of ramp access All disposal of concrete to sump at bottom of pit needs to be complete before access removed

M A G A Z I N E A R E A

4 Remove fence and salvage

5 Contour soil bund

6 Deep rip to break compaction

7 Spread topsoil at 10cm depth and contour rip & seed/fertilise

TOTAL




W A S H D O W N W A T E R D A M

8 Remove poly-liner and encapsulate in WRL

9 Contour external bunding


11 Spread topsoil at 10cm depth and contour rip

O F F I C E S / W O R K S H O P / G O - L I N E

12 Disconnect utility services including electricity, plumbing, septic

13 Demobilise all buildings including: main office, crib room, toilet block, change room, training room, first aid room:

Costs included in camp costs N/A

14 Demobilise office Genset

15 Demobilise office fuel tank

16 Remove security poles and camera system

17 Remove office pad and encapsulate in WRL

18 Rip only to 30cm to break compaction but not to lift too many service cables

19 Spread topsoil at 10cm depth and contour rip & seed/fertilise

TOTAL

C O N T R A C T O R O F F I C E S & W O R K S H O P

20 Demobilise all buildings including: main office, muster room, toilet block, change room, workshop dome, sea containers & stores

21 Demobilise fuel tank

22 Dismantle and remove wash down pad facility

23 Use rockbreaker to remove concrete pads and bury in pit sump. Concrete to be buried under one metre of fill.



TOTAL

R O A D T R A I N P A R K U P

26 Demobilise fuel tank




27 Dismantle and remove wash down pad facility

28 Use rockbreaker to remove concrete pads and bury in pit sump. Concrete to be buried under one metre of fill.




TOTAL

M O D U L A R C R U S H E R & R O M P A D

32 All utilities such as power source, powerlines, water pipes to be disconnected and removed from site

33 Breakdown Crusher and transport to Perth:

- 4 weeks supervision/planning 2 persons

- 4 weeks electrical work 5 persons

- 5 weeks labour 8 persons

- 4 weeks Franna crane hire 1 operator & 1 rigger

- 4 weeks x2 100t cranes 2 operators & 2 riggers

- 4 weeks 4x access equipment

- 3 weeks x2 belt slicers

- 5 weeks x 6 light vehicles

- Transportation including floats, pilot escorts & permits

- Unloading in Perth

- T O T A L (excluding meals, accommodation, earthworks including removal of containers, removal concrete pads or admin area)

+GST

34 All transportable buildings moved from site

35 All concrete slabs, fencing, signage, delineators and other manmade items to be collected and removed from site

36 Any exposed underground services to be excavated and removed from site

37 All windrows and any stockpiled material, other than topsoil, will be pushed




and leveled to natural surface level

38 Spread topsoil at 10cm depth and contour rip to 30cm to prevent lifting underground services & seed/fertilise

T O T A L

C A M P

39 Disconnect utility services including electricity, plumbing and remove from site

40 All underground services to be excavated and removed from site

41

Lift all transportables with a 50 tonne Franna mobile crane and placed onto prime mover and sent to Perth

105 x 4 person staff quarters 1 x 2 person disabled quarter

2 x linen/cleaners store 1 x kitchen & dining facility

1 x M/F/disabled ablution block & ice room

1 x wet mess 1 x recreation/TV room

1 x gymnasium 1 x gym equipment

1 x Administration office & shop 6 x laundry units

42 All manmade structures such as concrete paths to be excavated and removed from site or disposed of in final land fill (e.g. dump) before rehabilitation

43 Septic systems & bioremediation system to be decommissioned and backfilled, or removed from site

44 All windrows and any stockpiled material, other than topsoil, will be pushed and leveled to natural surface level

45 Spread topsoil at 10cm depth and contour rip to 30cm to prevent lifting underground services & seed/fertilise

TOTAL

W A S T E D U M P S




46 Complete design for ramp closure, with concave design and top of dump with 1 hectare cell construction requirements

Require photographs throughout process for utilisation in DMP

report for tenement relinquishment

47 Reshape with dozer & encapsulate landfill and bioremediation areas

48 Spread gypsum at rate 14 tonnes/ha

49 Spread topsoil at depth of approximately 10cm

50 Contour rip & seed/fertlise

51 Remaining salvaged tree trash to be spread across lower ramp to 80% cover

TOTAL

55ha only due to progressive rehab

H A U L R O A D S & A C C E S S R O A D S

52 Light vehicle access to site is to remain until rehabilitation monitoring is complete with DMP inspection and sign off

53 All power sources, power cables, water pumps, water pipes and stands are to be removed from site

54 All other roadways within the mine fence are to be deep ripped using a single tyne from a large bulldozer at full depth ground penetration to break up compaction.

55 Windrow material is to be graded back across the road surface.

56 Where necessary, a rockbreaker will dismantle concrete culverts, and waste is to be buried in pit sump or removed offsite

57 Large tyres utilised in signage on roads and poly pole markers are also to be buried at the top of the waste dump.

58 Topsoil will then be spread at 10cm depth, and contour ripped. & seeded /fertilised

59 Prevent access onto rehabilitated areas by blocking potential entry points with large boulders, logs or earth bunds.

TOTAL 52 ha

M I S C E L L A N E O U S A R E A S




60 All windrows and any stockpiled material, other than topsoil, will be pushed and leveled to natural surface level

M O B I L E E Q U I P M E N T

61

All equipment is to be demobilised.

D9 dozer, 16G grader, 4 x dump trucks water cart, 988 loader, 3 light vehicles, service truck and fuel truck will remain onsite until

all rehabilitation earthworks complete.

G E N E R A L S I T E

62 All scrap metal is to be collected and recycled by contractor.

Should already be offsite Included in mobilisation of

equipment costs

63 All fencing is to be collected and recycled.

Not onsite as site is not on a pastoralist lease

64 Conduct a final ‘emu parade’ to search for any remaining rubbish on site. 2 days loader & 3 men.

65 Examine ground for hydrocarbon staining. Excavate any hydrocarbon stained soil and transport to approved bioremediation area offsite.

66 Remove all polypipe to be collected for recycling/salvaging. Included in #77 N/A

67 Remove all cables to salvage for recycling.

TOTAL

W E E D S

68 Eradicate any introduced plants from areas to be rehabilitated. Use herbicides as required. Check that any rootstock material is treated with herbicide or physically removed.

69 Wash down all machinery used for rehabilitation prior to entry onto site to prevent weed contamination.

Equipment already onsite. N/A

70 Topsoil to be checked for weeds. Weed infested soil will be excluded from rehabilitation use.

TOTAL




P O S T R E H A B I L I T A T I O N

71 Appropriate sign-posting.

72 Notify the DMP Environmental Inspector of the completion of rehabilitation earthworks.

n/a

M O N I T O R I N G

73 Monitoring of rehabilitation sites will be undertaken annually after closure until sign off by DMP. It is expected that monitoring will continue for approximately 5 years.- include specialist fees

$50 000.00/yr – assume x5 years

74 Monitor for weed outbreaks and implement weed spraying campaigns as necessary.

75 If revegetation is unsuccessful or patchy then re-seed using locally collected native plant species. Use only using seed collected within the provenance area under a commercial seed picker’s licence. Seed to be checked for weeds prior to use and discarded if weed contaminated.

Not included here

76 If rehabilitation requires remedial work for erosion etc., require remobilise dozer

Not included here

77 Ongoing stakeholder consultation

78 Legal requirements/administration

T O T A L E S T I M A T E D C L O S U R E C O S T


11.0 Closure Implementation The implementation of closure at decommissioning has been discussed in various earlier sections.

The closure works program is incorporated into Table 27. All progressive rehabilitation will be set up as rehabilitation trials to determine

soil ameliorant type and rate, and seed mix type, proportions, treatments and rates.

The schedule for progressive rehabilitation, and therefore the timing of trials, is provided in Table 15.

Availability of topsoil and subsoil rock armouring is discussed in Section 5.6. The detailed nature of all information supplied within this document ensures that closure will be planned for at the commencement of mine life, and throughout mine life. Such planning is based on all information collected to date. With ongoing monitoring, further waste characterisation and analysis of data throughout mine life, final waste dump designs and rehabilitation procedures will be developed to ensure best practice for the establishment of the end landuse goal specific for the region and the site. The end landuse goal is to:

Rehabilitate the land to achieve ecosystems that are self-sustaining and/or capable of being sustainably managed without unwarranted additional expense. This requires the rehabilitated ecosystems to be resilient, to aid in stabilisation of landforms, soils and hydrology and provide animals with shelter, food and nesting sites (EPA 2006). A further objective of rehabilitation is to return sufficient representation of species to allow vegetation to be identified as belonging to a nominated plant community type (floristic community, or vegetation complex).

If the mine should unexpected close, the closure costing allows for a care and maintenance period of three years before closure commences. Closure can, however, commence if it is so directed by mine management. A caretaker will be appointed to be on site in a full time capacity during care and maintenance. The role of the caretaker will be to manage all risks of the mine during that period.

The sewage treatment plant will need to be maintained. Make daily inspections of the bellum cage over the landfill (either near to the

camp, or on the active waste dump). All waste hydrocarbons should be collected and removed offsite by a

registered contractor. Any unused hydrocarbons will be stored onsite in bunded facilities. Dust should not be a major concern due to the limited vehicular use. Dust

monitors will be maintained and inspected weekly to ensure that dust levels do not increase above acceptable standards.


Dangerous goods not needed onsite during care and maintenance will be removed. Any remaining onsite will be on a MSDS register and stored in the correct manner.

The main risk associated with wasted dumps during a care and maintenance period is sediment discharge during rainfall events. As part of the Mining Proposal, WIO has committed to building windrows with laterite material around the circumference of each waste dump prior to dumping waste. These laterite windrows will stop sediment discharge entering natural vegetation during Pilbara rainfall events.

All vehicles entering site during care and maintenance will be inspected by the care taker for weeds and seeds prior to entering site. If any vehicles are found to be infested with soils or weed seeds they will not be permitted to site.

A comprehensive Caretaker Procedural Plan will be incorporated into mine management plans for the event of sudden mine closure.

Plate 11: No corefarm will be present on site


12.0 Closure Monitoring and Maintenance Monitoring strategies for closure will continue with the monitoring programs established throughout mine life, described in Section 9.3. If, for any reason, monitoring indicates that rehabilitation is not progressing toward end goals, then remedial earthworks will be carried out. Monitoring will then commence on this new rehabilitation site until agreed completion criteria have been met. The monitoring (& maintenance where required) program will include the monitoring of:

Groundwater for level and quality Permanent surface water diversions & sediment basins Surface water quality of downstream environments Erosion on waste dumps (remedial works if required) Revegetation on waste dumps Photographic assessment of rehabilitation areas Weed location and eradication Feral animal control if required.

The specific criteria for each parameter monitored, and the timing for each monitoring operation will be determined in the Environmental Management Plan to be written before mining commences. If the operation should be unexpectedly placed under care and maintenance, the monitoring will continue. The care and maintenance regime is described in Section 11.0.

13.0 Management of Information and Data An Environmental Management Plan will be written for the Wonmunna Project before work commences. It will include a document control policy. Copies of this document, both hard and electronic copies, will be stored appropriately in the WIO document management system, both in the main Perth office and onsite. This Mine Closure Plan will be reviewed every three years, or as requested by regulators. This will enable new monitoring information to be incorporated into plans, along with new legislation, standards, guidelines and best practice techniques. All site practices, including progressive rehabilitation, trials and monitoring are required to be stored in the WIO document control system as this data is invaluable in the longterm planning for closure.


14.0 References ANZMEC (1995) ANZMEC and Mineral Council Strategic Framework for Mine Closure BOM (2014) www.bom.gov/au Department of Agriculture (1987) Luke G.J., Burke K.L. & O’Brien T.M. Evaporation Data for Western Australia. Resource Management technical Report No. 65. DoIR (1987) Safety Bund Walls Around Abandoned Open Pits Guideline DMP (2011) Guidelines for Preparing Mine Closure Plans EPA (2002). Terrestrial Biological Surveys as an Element of Biodiversity Protection. Position Statement No. 3. EPA (2004a). Guidance for the Assessment of Environmental Factors: Terrestrial Flora and Vegetation Surveys for Environmental Impact Assessment in Western Australia. No. 51. EPA (2004b). Guidance for the Assessment of Environmental Factors: Terrestrial Fauna Surveys for Environmental Impact Assessment in Western Australia. No. 56. EPA & DEC (2010) Technical Guide – Terrestrial Vertebrate Fauna Surveys for Environmental Impact Assessment Florabase (2014) Names and descriptions of plant species, available at: http://florabase.dpaw.wa.gov.au/ G & G Environmental (2014) Flora and Vegetation Survey of the Wonmunna Area – Level 2 GSWA (1997) THORNE, A.M. and TYLER, I.M., 1997, Roy Hill, W.A. (2nd Edition): 1:250 000 Geological Series Explanatory Notes, Geological Survey of Western Australia, Perth Western Australia. Institute of Engineers Australia (1987) Australian Rainfall and Runoff. ARI table Keighery, B.J. (1994). Bushland Plant Survey: A Guide to Plant Community Survey for the Community. Wildflower Society of WA (Inc.), Nedlands, Western Australia. Kendrick P. (2001) Pilbara 3 (PIL3 – Hamersley subregion). In: A Biodiversity Audit of Western Australia’s 53 Biogeographical Subregions pp. 568-580. Department of Conservation and Land Management. October 2001.

http://www.bom.gov/au


Johnson & Wright (2001) Central Pilbara Groundwater Study. Hydrological Record Series, Report HG 8, 102p. Water and Rivers Commission, Western Australia. NatureMap (2014) Available at: http://naturemap.dec.wa.gov.au/default.aspx Payne, A. L. & Leighton, K. A. 2004. Land systems. In: van Vreeswyk, A. M. E., Payne, A. L., Leighton, K. A. &Hennig, P. (eds) Technical Bulletin 9. An inventory and condition survey of the Pilbara region, Western Australia. Department of Agriculture, Government of Western Australia, South Perth, WA, pp. 175–384. Pearcey, D. and Sergeev, N (2012). Exploration activity report, Wonmunna Project 2011 Western Australia. CSA Report to Rico Resources, R265.2012. 81pp. Slater, D. and Kneeshaw, M. (2012). NMM and CMM Resource Estimates, Rico Resources Wonmunna Project. Coffey Mining Confidential Report MINEWPER953AA. 55pp RPS Aquaterra (2012) Wonmunna Project Groundwater and Surface Water Scoping Study. Report prepared for: Rico Resources. Tille P. (2006) Soil landscapes of Western Australia’s Rangelands and Arid Interior Resource Management Technical Report 313 Department of Agriculture and Food. Trendall, A.F., (1990) Hamersley Basin. In: Geology and Mineral Resources of Western Australia; West. Australian Geological Survey, Memoir 3, pp.163-191. Van Leeuwen S. (2009). Biodiversity values of Weeli Wolli Spring: a Priority ecological community. Available at: http://www.dpaw.wa.gov.au/about-us/science-and-research/publications-resources/111-science-division-information-sheets 3/2009, 2 p Van Vreeswyk, A.M.E., Payne, A.L., Leighton, K.A. and Hennig, P. (2004) An inventory and condition survey of the Pilbara Region, Western Australia. Technical Bulletin No. 92. Department of Agriculture, Perth, Western Australia


15.0 Acronyms ABN Australian Business Number ACN Australian Company Number ADWG Australian Drinking Water Guidelines ANZMEC Australian & New Zealand Minerals and Energy Council ARI Average Recurrence Interval BIF Banded iron formation BOM Bureau of Meteorology CID Channel Iron Deposits CMM Central Marra Mamba DAA Department of Aboriginal Affairs DAP Di-Ammonium Phosphate DEC Department of Environment and Conservation DMP Department of Mines and Petroleum DoW Department of Water DPaW Department of Parks and Wildlife EPA Environmental Protection Agency EPBC Environment Protection and Biodiversity Conservation ESA Environmentally Sensitive Area ESP Exchangeable Sodium Percentage GDE Groundwater Dependant Ecosystems GPS Global Positioning System IBRA Interim Biogeographical Regionalisation of Australia KCGM Kalgoorlie Consolidated Gold Mines MCP Mine Closure Plan MMIF Marra Mamba Iron Formation MNES Matters of National Environmental Significance MRD Main Roads Department MSDS Material Safety Data Sheet NMM North Marra Mamba NTMA Native Title Mining Agreement NVCP Native Vegetation Clearing Permit PEC Priority Ecological Communities PSD Particle Size Distribution SMM South Marra Mamba SRE Short range endemic TDS Total Dissolved Solids TEC Threatened Ecological Community UPGMA Unweighted Pair-Group Method of arithmetic Averages WA Western Australia WEPP Water Erosion Prediction Project

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN A March 2015

16.0 Appendices

Wonmunna Iron Ore Pty Ltd MINE CLOSURE PLAN A1 March 2015

Appendix 16.1: Geotechnical Report

WONMUNNA PROJECT PRELIMINARY GEOTECHNICAL ASSESSMENT NMM & CMM OPEN PITS Peter O’Bryan & Associates November 2014 Refer to Appendix 11.7 in Wonmunna Mining Proposal


Appendix 16.2: Groundwater Report

WONMUNNA GROUNDWATER MONITORING REPORT RPS Aquaterra October 2014 Refer to Appendix 11.5.1 in Wonmunna Mining Proposal


Appendix 16.3: Surface Water Report

WONMUNNA SURFACE WATER ASSESSMENT STUDY RPS Aquaterra October 2014 Refer to Appendix 11.5.2 in Wonmunna Mining Proposal


Appendix 16.4: Flora Report

FLORA AND VEGETATION SURVEY OF THE WONMUNNA AREA LEVEL 2 G&G Environmental July 2014 Refer to Appendix 11.3 in Wonmunna Mining Proposal


Appendix 16.5: Fauna Report - Vertebrates

LEVEL 2 VERTEBRATE FAUNA SURVEY FOR THE WONMUNNA IRON ORE PROJECT Phoenix Environmental Sciences July 2014 Refer to Appendix 11.4.1 in Wonmunna Mining Proposal


Appendix 16.6: Fauna Report – Short Range Endemics

LEVEL 2 SHORT RANGE ENDEMIC INVERTEBRATE FAUNA SURVEY FOR THE WONMUNNA IRON ORE PROJECT Phoenix Environmental Sciences October 2014 Refer to Appendix 11.4.2 in Wonmunna Mining Proposal


Appendix 16.7: Fauna Report – Subterranean

TROGLOFAUNA SURVEY FOR THE WONMUNNA IRON ORE PROJECT Phoenix Environmental Sciences October 2014 Refer to Appendix 11.4.3 in Wonmunna Mining Proposal


Appendix 16.8: Soil and Waste Characterisation

CHARACTERISATION OF TOPSOIL AND RC DRILLING WASTE SAMPLES WONMUNNA IRON ORE PROJECT Landloch February 2012 Refer to Appendix 11.2 in Wonmunna Mining Proposal


Appendix 16.9: Waste Dump Modelling LANDFORM ADVICE FOR WONMUNNA IRON ORE PROJECT (memo) Landloch October 2014

mine closure plan wonmunna iron ore project...mine closure plan wonmunna iron ore project m47/1423,...

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