BHP : Underground Water Impact Report (PDF 19.9 MB)

Saraji Open Cut Extension Project

Underground Water Impact Report

Contents

	Introduction and background	1
1.1	Introduction	1
1.2	Purpose of the report	1
1.3	Legislative requirements	3
	1.3.1 Bore trigger thresholds	5
1.4	Report structure	5

	Report consultation day	6
	Part A: Underground water extractions	7
3.1	Quantity of water already produced	7
3.2	Quantity of water to be produced in the next three years	7
	Part B: Aquifer information and underground water flow	8
4.1	Aquifer descriptions	8
4.2	Underground water flow and aquifer interactions	8
4.3	Underground water level trend analysis	9
	Part C: Predicted water level declines for affected aquifers	10
5.1	Maps of affected area	10
	5.1.1	Yearly predictions	13
	5.1.2	Model classification	13
5.2	Methods and techniques used	13
5.3	Water bores within the immediately affected area	13
5.4	Review of maps produced	15
	Part D: Impacts on environmental values	16
6.1	Identifying and describing environmental values	16
6.2	Nature and extent of the impacts on the environmental values	16
	6.2.1	Mitigation measures	17
6.3	Impacts to formation integrity and surface subsidence	17
	Part E: Water monitoring strategy	18
7.1	Rationale	18
7.2	Monitoring strategy	18
7.3	Timetable	19
7.4	Reporting program	19
	Part F: Spring impact management strategy	20
8.1	Spring inventory	20
8.2	Connectivity between the spring and aquifer	22
8.3	Spring values	22
8.4	Management of impacts	22
8.5	Timetable for strategy	22
8.6	Reporting program	22
8.7	Connectivity between the spring and aquifer	22

BHP

8.8	Spring values	22
8.9	Management of impacts	22
8.10	Timetable for strategy	22
8.11	Reporting program	22

BHP

Introduction and background

1.1 Introduction

The BHP Mitsubishi Alliance (BMA1) operates the Saraji Open Cut Coal Mine (Saraji Mine) under Environmental Authority (EA) Permit number EPML00862313.

In 2016, BMA submitted an Environmental Authority (EA) amendment application under the Environmental Protection Act 1994(EP Act) to authorise the extension of Grevillea Pit to access further coal resources. A mining lease (ML) application for ML 700021 was submitted in conjunction with the EA amendment application in accordance with requirements under the Mineral Resources Act 1989.

In order to meet its requirements under the Water Act 2000(QLD) (Water Act), BMA has engaged AECOM to prepare and publically notify an Underground Water Impact Report (UWIR). Pursuant to section 271A of the Mineral Resources Act 1989, ML 700021 was granted on 16 October 2018.

The area to which this report relates is ML 700021. ML 700021 is shown in Figure 1 as the Project Site.

1.2 Purpose of the report

The purpose of this report is to fulfil the legislative requirements of a UWIR in accordance with Chapter 3 of the Water Act.

This UWIR has been prepared as an addendum to the pre-existing Groundwater Technical Report which was prepared for the approved Saraji Open Cut Extension Project EA Amendment application by AECOM (2016). For this purpose, this UWIR is not intended to be read as a standalone report and instead should be read in conjunction with the Groundwater Technical Report (AECOM, 2016) and the approved EA conditions.

This UWIR includes a cross-reference to the relevant UWIR required data presented in the Groundwater Technical Report. Where the Groundwater Technical Report does not address UWIR requirements, additional evaluation of the groundwater is provided in this report. Where any information differs between the Groundwater Technical Report and this report, the approved EA conditions are to be consulted. The groundwater monitoring requirements are provided within the approved EA conditions.

• BMA is an unincorporated joint venture also known as the Central Queensland Coal Associates Joint Venture which comprises seven companies including BHP Coal Pty Ltd and which has BM Alliance Coal Operations Pty Ltd ABN 69096412752 as a duly authorised representative.

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Saraji Open Cut Extension Project

Underground Water Impact Report

Contents

	Introduction and background	1
1.1	Introduction	1
1.2	Purpose of the report	1
1.3	Legislative requirements	3
	1.3.1 Bore trigger thresholds	5
1.4	Report structure	5

	Report consultation day	6
	Part A: Underground water extractions	7
3.1	Quantity of water already produced	7
3.2	Quantity of water to be produced in the next three years	7
	Part B: Aquifer information and underground water flow	8
4.1	Aquifer descriptions	8
4.2	Underground water flow and aquifer interactions	8
4.3	Underground water level trend analysis	9
	Part C: Predicted water level declines for affected aquifers	10
5.1	Maps of affected area	10
	5.1.1	Yearly predictions	13
	5.1.2	Model classification	13
5.2	Methods and techniques used	13
5.3	Water bores within the immediately affected area	13
5.4	Review of maps produced	15
	Part D: Impacts on environmental values	16
6.1	Identifying and describing environmental values	16
6.2	Nature and extent of the impacts on the environmental values	16
	6.2.1	Mitigation measures	17
6.3	Impacts to formation integrity and surface subsidence	17
	Part E: Water monitoring strategy	18
7.1	Rationale	18
7.2	Monitoring strategy	18
7.3	Timetable	19
7.4	Reporting program	19
	Part F: Spring impact management strategy	20
8.1	Spring inventory	20
8.2	Connectivity between the spring and aquifer	22
8.3	Spring values	22
8.4	Management of impacts	22
8.5	Timetable for strategy	22
8.6	Reporting program	22
8.7	Connectivity between the spring and aquifer	22

BHP

8.8	Spring values	22
8.9	Management of impacts	22
8.10	Timetable for strategy	22
8.11	Reporting program	22

BHP

Introduction and background

1.1 Introduction

The BHP Mitsubishi Alliance (BMA1) operates the Saraji Open Cut Coal Mine (Saraji Mine) under Environmental Authority (EA) Permit number EPML00862313.

In 2016, BMA submitted an Environmental Authority (EA) amendment application under the Environmental Protection Act 1994(EP Act) to authorise the extension of Grevillea Pit to access further coal resources. A mining lease (ML) application for ML 700021 was submitted in conjunction with the EA amendment application in accordance with requirements under the Mineral Resources Act 1989.

In order to meet its requirements under the Water Act 2000(QLD) (Water Act), BMA has engaged AECOM to prepare and publically notify an Underground Water Impact Report (UWIR). Pursuant to section 271A of the Mineral Resources Act 1989, ML 700021 was granted on 16 October 2018.

The area to which this report relates is ML 700021. ML 700021 is shown in Figure 1 as the Project Site.

1.2 Purpose of the report

The purpose of this report is to fulfil the legislative requirements of a UWIR in accordance with Chapter 3 of the Water Act.

This UWIR has been prepared as an addendum to the pre-existing Groundwater Technical Report which was prepared for the approved Saraji Open Cut Extension Project EA Amendment application by AECOM (2016). For this purpose, this UWIR is not intended to be read as a standalone report and instead should be read in conjunction with the Groundwater Technical Report (AECOM, 2016) and the approved EA conditions.

This UWIR includes a cross-reference to the relevant UWIR required data presented in the Groundwater Technical Report. Where the Groundwater Technical Report does not address UWIR requirements, additional evaluation of the groundwater is provided in this report. Where any information differs between the Groundwater Technical Report and this report, the approved EA conditions are to be consulted. The groundwater monitoring requirements are provided within the approved EA conditions.

• BMA is an unincorporated joint venture also known as the Central Queensland Coal Associates Joint Venture which comprises seven companies including BHP Coal Pty Ltd and which has BM Alliance Coal Operations Pty Ltd ABN 69096412752 as a duly authorised representative.

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