Boundary Hill SoutH Project/media/Files/A/Anglo... · 2014-03-11 · Boundary Hill South Environmental Impact Statement 9B-1 9B. GROUNDWATER 9B.1 Introduction This chapter describes

Boundary Hill SoutH Project

Groundwater

9B.

Boundary Hill South Environmental Impact Statement

9B-1

9B. GROUNDWATER 9B.1 Introduction This chapter describes the existing groundwater Environmental Values (EVs) for the Project area, potential impacts to these EVs, as well as objectives and practical measures for protecting or enhancing groundwater EVs. Additionally, guidance is provided as to how quantitative standards and indicators can be determined, monitored and audited to achieve sustainable groundwater management. This chapter provides an assessment and considers following elements:

- Geology of the Project area and surrounds;

- Stratigraphy of the Project area; and

- Aquifer units potentially affected by the Project.

This chapter summarises the key findings of the groundwater assessment undertaken by Matrix+ Consulting (2007), and subsequently updated by GHD for the Project. The assessment by GHD (2013) (Appendix M) supplements the detailed assessment undertaken by Matrix+ Consulting to address the updated Project mine plan.

9B.2 Applicable Legislation and Policy

9B.2.1 Legislation

Water Act 2000

The Water Act 2000 administers the sustainable management and allocation of groundwater within Queensland to provide secure supplies for water users, whilst maintaining EVs. The Act advances sustainable management and efficient use of water and other resources by establishing a system for the planning, allocation and use of water.

The allocation and management of water resources in Queensland is underpinned by a planning framework to meet future water requirements. Under the Water Act 2000, allocation is regulated through a Water Resource Plan (WRP) with its administration under a Resource Operation Plan (ROP). For the Fitzroy Basin the following subordinate legislation exists:

- Water Resource (Fitzroy Basin) Plan 2011; and

- Fitzroy Basin Resource Operation Plan (DERM, 2011).

The WRP and ROP are discussed further in Chapter 9A Surface Water.

The Project is located within the Callide sub-artesian declared area. The taking of water within this area is regulated by the Water Act 2000 and Water Regulation 2002. The Queensland Department of Natural Resources and Mines (DNRM) administer water licensing of groundwater bores. A water license may be required to take or interfere with sub-artesian water in declared sub-artesian areas or in areas defined in a WRP. The requirement for a water license is based on a number of factors and is determined by DNRM on a case by case basis.

Environmental Protection Act 1994

The objectives of the Environmental Protection Act 1994 (EP Act) are to protect Queensland’s environment and allow for development that improves the total quality of life, both now and in the future, while maintaining ecological processes. Environmental protection is to be achieved by an integrated management program which is consistent with ecologically sustainable development (ESD) principles. The Environmental Protection (Water) Policy 2009 (EPP (Water)) is enacted under the EP Act.

Environmental Protection (Water) Policy 2009

The EPP (Water) is a framework to achieve the objectives of the EP Act in relation to Queensland waters. This framework is based on the following key processes:

- identifying EVs and management goals for Queensland waters;

- stating water quality guidelines and water quality objectives to enhance or protect EVs;

-

-

-

-

-

-

-

-

-

-

9B.3 Methodology of Assessment

9B.3.1 Scope of Assessment

-

-

-

-

-

9B.3.2 Previous Investigations

-

-


9B-3

- ‘Callide Coalfields Water Management – Groundwater Review’ (Australian Groundwater Consultants Pty Limited , 1987);

- ‘Groundwater Supply Investigation Drill Target Study – Dunn Creek, Trap Gully, The Hut’ (Boyd Mining Pty Ltd , 1990);

- ‘Callide Groundwater Monitoring Study’ (Coffey Partners International Pty Ltd, 1993);

- ‘Pump Test – Trap Gully, Callide’ (Golder Associates Pty Ltd , 1993);

- ‘Kilburnie Coal Project – Hydrogeological Assessment’ (Coffey Partners International Pty Ltd, 1999);

- ‘Oaky Creek Rural Water Supply Board Replacement Groundwater Supply Bores – Bore Construction and Testing’ (Australasian Groundwater & Environmental Consultants Pty Ltd , 2002); and

- ‘Kilburnie Coal Project Feasibility Assessment – Hydrogeological Assessment’ (Water Studies, 2002).

These assessments have been reviewed and summarised by Matrix+ Consulting (2007). This assessment relies on the review summary undertaken by Matrix+ Consulting, and subsequently updated by GHD (2013) (Appendix M).

Groundwater assessments undertaken in the Boundary Hill area have included a combination of field surveys and groundwater modelling. More specifically, the assessments involved:

- reviewing the available geological and stratigraphical information;

- surveying of bore locations

- drilling and installation of groundwater monitoring bores and water supply bores;

- monitoring of groundwater levels within the bores.

- pumping tests within water supply bores and aquifer testing bores;

- groundwater sample collection by pump or bailer for chemical analysis;

- collection of groundwater usage data on neighbouring properties using ‘Tiny Tag’ data logging systems and manual measurements;

- interpretation of groundwater level data and groundwater quality analyses ;

- assessing the potential of groundwater as a source of water supply for the Project;

- analytical and numerical modelling of potential pit groundwater inflow for the life of mine;

- assessing the impact of groundwater dewatering via mine pit void on surrounding aquifers; and

- evaluating groundwater monitoring requirements during mine operation.

In addition to the assessments undertaken by Matrix+ Consulting (2007) and GHD (2013), Callide Mine has implemented a dynamic groundwater monitoring program for the identified key groundwater users and bores close to the Project area. The monitoring program assesses the specific capacity of eight water supply bores using pumping tests and analyses of water quality from collected samples on a quarterly basis. Data from pump tests and water quality results have been used to statistically derive thresholds defining a significant change, triggering any further investigations. To protect the interests of businesses and landholders associated with the monitoring program, the specific monitoring data has not been publically included in this EIS, however has been provided to government departments as part of the EIS assessment process.

In addition to the aforementioned groundwater monitoring program, a comprehensive static groundwater monitoring program is undertaken to satisfy Callide Mine’s Environmental Authority conditions. Under this program, monitoring wells are sampled for Standing Water Levels (SWL), and bore water samples are collected for analysis at accredited laboratories.

9B.3.3 Current Investigation

Advice from the Commonwealth Minister for the Environment on 17 October, 2013 indicated that as the Project may have an impact on the hydrology and quality of water in the area, Water Resources (under ss. 24D and 24E of the Environment Protection and Biodiversity Conservation Act 1999) is a controlling provision for the Project. Given the timing of advice from the Commonwealth Minister for the Environment, a full assessment of water resources to satisfy the Department of the Environment’s (DoE’s) information requirements was unable to be made.


9B-4

At the time of assessment, the impacts to groundwater were considered at an appropriate scale given the nature of the Project. To satisfy DoE’s requirements, an assessment of the impacts to water resources at a regional scale, including an assessment of cumulative impacts, is currently being undertaken for the Project. Additional assessment of water resources in the Project area will be included as part of the Supplementary EIS or as an addendum.

9B.4 Existing Environment

9B.4.1 Regional Geology

The occurrence and flow of groundwater at any location is linked to the geology of that location. The Project is located within the Callide Basin, a fault bounded synclinal basin of Middle to Upper Triassic age. Callide Basin is approximately 22 kilometres long and eight kilometres wide, and is aligned generally along a north-west to south-east axis. The topography of the area is characterised by numerous steep sided gullies incised into the sandstone (Matrix+ Consulting Pty Ltd, 2007; GHD, 2013).

The geology of the Project area is primarily made up of the following strata:

- Callide Coal Measures;

- Triassic Muncon Volcanics;

- Precipice Sandstone;

- Biloela Formation; and

- Callide Creek Alluvium.

Figure 9B-1 illustrates the geology of the Project area and the locations of water supply, test pumping bores, monitoring bores, privately registered groundwater bores, and springs in the Project area. The following sections describe the stratigraphy, structure and geological units within the Project area.

9B.4.1.1 Stratigraphy

The Callide Creek Alluvium within the Project area and its immediate surrounds consists of a north-easterly trending tongue of floodplain alluvium associated with Campbell (Gate) Creek, a tributary feeding Callide Creek (GHD, 2013). This tongue of alluvium ranges from 100 to 400 metres wide.

Tertiary Clays of the Biloela Basin overlie the central-western portion of the Callide Basin including a significant area surrounding the Project area. These clays are known as the Biloela Formation.

The Jurassic Precipice Sandstone crops out in the north-eastern segment of the Project area. This stratigraphic unit consists of a massive (uniform) cross-bedded and well-jointed quartzose sandstone, interlayed with siltstone and carbonaceous (black, organic rich) layers. The sandstone varies from fine to very coarse-grained and in places is almost conglomeratic (gravel-sized grains). The Precipice Sandstone underlies the Biloela Formation and extends south towards Callide Creek and overlies the Callide Coal Measures (GHD, 2013).

The Callide Coal Measures are of Middle to Upper Triassic age and comprise interbedded quartzose and lithic sandstone, siltstone, shale and coal. The Callide Coal Measures overlie the relatively impermeable rocks of the Triassic Muncon Volcanics over most of the area. For the purposes of this assessment, the Muncon Volcanics represent both the stratigraphic and hydrogeological basement (GHD, 2013).

Figure 9B-1 describes the stratigraphy of the Project area.

!(

!(!(

!(

!(!(!(!(

!(!(

!(

!(!(!(!(!(!(

!(!(!(!(!(

!(

!(

!(!(!(!(

!(

!(!(

!(!(!( !(

!( !(

!(

!(!(

!(

!(

!(

!(

!(

!(!(

!(

!(!(!(!(

!(

!(

!(

!(

!(

!(!(

!(

!(

!(

!(!( !(

!(!(!(!(!(

!(!(!(

!(!(

!(

!(

!(

!(!(!(

!(

!(

!(!(!(!(

!(

!(

!( !(

!(

!(!(

!(!(

!(

!( !(!(

!(

!(

!(

!(

!(!(

!(!(!(

!(

!(!(

!(!(!(

!(

!(

!(!(!(

!(

!(!(!(

!(!(!(

!(

!(!(

!(

!(!(!(

!(!(!(!(!(

!(

!(

!(!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(!( !(

!(

!(

!(!(

!(!( !(

!(

!5

!5

!5

!5

!(

!(

!(

!(

!(

!(

Jp

Badder House Bore

RN: 68798

RN: 68215

RN: 33576

RN: 68797

RN: 31818

R3084

RN: 34564

NR: 34565RN: 36238

RN: 47343

RN: 68683

RN: 57631

R3079

R3076TB1

R0507675

R3070

C0507663R3072

R3068

RN: 507659

RN: 34557

Saline GroundwaterSeep Area Near Dam

RN: 34556

C2903

R2940

Emergency Bore

Kilburnie Bore No.2Kilburnie Bore No.1

R3038

C0507659R0507674

R3061

R0507673

C0507655

R3044R0507672

R3046

C0507653

R3055

RN: 62933

C2017

C2903

C2951R2951

ENV01

R2938

ROAD

ROAD

FREE

MAN

S R

D E

RO

AD

ARGOON RD

JAMBIN DAKENBAH

RD

FREEMANS RD W

BLACKS RD

RO

AD

CALLIDE RD

FORESTRY RD

DUDARKOS RD

MALLINSONS RD

EARLSFIELD RD

GREVELLS RD

EARLSFIELD PIT RD

INVER

NESS R

D

CALLIDE KILBURNIE RD

JAMBIN DAKENBAH RD

ARGOON KILBURNIE RD

CALLIDE

ARGOON

KOONKOOL

Burnett Hwy

Daws

on H

wyQa

Ps

To

Qpa

Td

Qr>To

Jp

Rc

Pg/g

Pg/g

JpQhh

Pg/g

RcTbPg/g

To

Jp?

To

Rc

Rc

Td

Jp?

Qf Tb?

To

To

Td

Qf

Qr>To

CPy

Qa

CPy

PaPRg/g

Pa

Jp

Rc

Rc

Rc

Jp

Rv

Rv

RvRc

CPy

RcJp

Rc

To

CPyJp

Qf

Rv

JpRc

Jp

RvRc

Jp

TbTb

Td

Jp

Qa

Jp

Qf

Qa

Qr>To

Qr

To

JpQhh

Qhh

Qr>ToQf

Jp

Tb

Jp

RcRv Jp

JpJp

Jp

Qhh

JpTb

Tb

Qr>To Rc

¹0 1 20.5

Kilometers

AECOM does not w arrant the accuracy or completeness of information displayed in thismap and any person using it does so at their ow n risk . AECOM shall bear no responsibilityor liability for any errors, faults, defects, or omissions in the information.

PROJECT IDLAST MODIFIEDFILE NAME

60238883CFS 10-July-201360238883_ENV_112v2

Data sources:Geolog y – Geoscience Australia Detailed 2008DCDB – DERM 2012Boundary Hill Mine leases – DEEDI 2012Project Site - Ang lo Coal 2012Borehole Locations – AECOM 2012

BOUNDARY HILL SOUTH EISGeology

Figure 9B-1

1:55,000 (w hen printed at A3)Scale:

Legend!5 Locality

!( BHME Test Pumping Bore

!( BHME Monitoring Bore

!( Boundary Hill Mine Monitoring Bore

!( Registered Groundwater Bore

!( Spring

!( Water Supply Bore

Railway Lines

Main Road

Minor Road

Property Boundary

Project Site (MLA 80186)

Final Pit and Dump Extent

Mine Leases

Granted

Key/Code LithologyCPy Granule to boulder polymictic conglomerate commonly with abundant

granite and rhyolite clasts, felsic volcaniclastic sandstone, tuffaceous and carbonaceous siltstone and mudstone, dacitic to rhyolitic ignimbrite, breccia, minor coal

Jp White to brown, poorly sorted, thick-bedded, cross-bedded, fine to very coarse-grained, pebbly quartzose sandstone; minor white to yellowish brown, laminated siltstone (in upper part), carbonaceous shale, lithic sublabile sandstone, granule conglomerate

Pg/g Granite, granodioritePgcr Grey to pink medium-grained hornblende quartz monzodiorite,

hornblende-augite quartz diorite, biotite-hornblende quartz dioritePRg/b Grey, fine to coarse-grained, equigranular to porphyritic gabbro,

hornblende diorite and quartz diorite to biotite-hornblende quartz monzodiorite

PRg/g Granite, granodioritePa Sandstone, siltstone, limestone, chert, minor andesitePgcr Grey to pink medium-grained hornblende quartz monzodiorite,

hornblende-augite quartz diorite, biotite-hornblende quartz dioritePs Andesitic conglomerate and sandstone, mudstone, minor andesite lava

Pvi Dark grey trachyte to dacite, volcanic breccia; numerous small hornblende quartz monzodiorite intrusions

Qa Clay, silt, sand, gravel; floodplain alluviumQf Clay, silt, sand and clayey to sandy gravel; alluvial fans, sheetwash and

floodout sheetsQhh Gravel, sand, silt - man-made deposits generally associated with land-

fill or mining (tailings, dumps and rehabilitated areas)Qpa Clay, silt, sand, gravel; flood plain alluvium on high terracesQr Clay, silt, sand, gravel and soil; colluvial and residual depositsRc Poorly sorted polymictic pebble to boulder conglomerate, sandstone,

siltstone, coal seams, felsic tuffRv Polymictic, volcaniclastic, pebble to cobble conglomerate, volcaniclastic

sandstone; trachytic to andesitic, lithic and crystal tuff; quartz-lithic sandstone and siltstone; rare carbonaceous siltstone

Tb Poorly sorted polymictic pebble to boulder conglomerate, sandstone, siltstone, coal seams, felsic tuff

Td Duricrusted palaeosols at the top of deep weathering profiles, including ferricrete and silcrete; duricrusted old land surfaces

To Mudstone, siltstone, oil shale, carbonaceous mudstone and sandstone; minor lignite, coal and limestone


9B-6

Table 9B-1 Boundary Hill South – stratigraphic summary (GHD, 2013)

Age Stratigraphic Unit Lithology Occurrence

Quaternary Callide Creek Alluvium (Qa)

Silt, sand, clay soil Occurs on floodplains of major watercourses and as outwash fan deposits. Only minor occurrences in Callide Basin and Boundary Hill South area.

Tertiary

Undifferentiated Alluvium (Qf)

Clay, silty sand, clayey to sandy gravel

Alluvial fans, sheetwash deposits and floodout sheets. Present as isolated outcrops to the south and west of the Boundary Hill South area.

Biloela Formation (To)

Mudstone, claystone, siltstone, sandstone, minor coal

Extensively exposed at surface, forms flat to moderately rolling plains.

Jurassic

Precipice Sandstone (Jp)

Fine to very coarse-grained pebbly quartzose sandstone, and laminated siltstone in upper part

Remnant sandstone ridges of moderate relief. Outcrops in the northern segment of the Boundary Hill area and present below surface over the Project area and surrounds.

Triassic

Callide Coal Measures (Rc)

Poorly sorted conglomerate, sandstone, siltstone, coal seams and tuff

Only present in the subsurface at the Boundary Hill South area.

Muncon Volcanics (Tb?)

Basalt to andesite, volcaniclastic pebble conglomerate, sandstone, siltstone, volcanic breccia, tuff

Forms the basement of the Callide Basin. Only present in the subsurface at the Boundary Hill South area.

Table 9B-2 describes the stratigraphic sequence interpreted from the lithological log of exploration bore 507655.

Table 9B-2 Stratigraphic interpretation of log of bore 507655 (Rob Lait & Associates, 2013)

Depth from (m) Depth to (m) Interpreted Stratigraphic Unit

0.0 34.5 Biloela Formation

34.5 57.7 Precipice Sandstone

57.7 85.0 Callide Coal Measures

85.0 92.3 Muncon Volcanics

Similar stratigraphic interpretations are possible where the lithological logs of bores are detailed enough. The level of detail shown in Table 9B-2 does not exist for the majority of the privately owned water bores in the area as there was no requirement for registration or licensing of those bores during installation (Rob Lait & Associates, 2013).

9B.4.1.2 Geological Structure

The Callide Basin was formed due to down-warping and subsidence of Palaeozoic sediments during periods of regional extension and normal faulting associated with the Hunter Bowen Orogeny. The Callide Basin sequence was tilted to the south-west during the Tertiary, exposing and eroding the eastern margins of the Callide Basin and subsequently burying the western, possibly fault-bounded, margins under Tertiary sediments of the Biloela Basin (GHD, 2013).

Much of the south-western edge of the basin was folded up as the basin was tilted in a narrow zone with dips of 55 to 75 degrees. Dips decrease more typically to five to ten degrees within approximately 50 to 100 metres of the basin margin. The Project area appears to be affected by folding along the western edge of the deposit. No significant faulting has been observed in the Project area (GHD, 2013).

9B.4.1.3 Geological Units

The geological formations of primary interest for the groundwater assessment are as follows:

- Callide Creek Alluvium;

- Biloela Formation;

- Precipice Sandstone; and

- Callide Coal Measures.


9B-7

These geological formations can be regarded as the primary hydrostratigraphic units for the Project, as described in the following sections.

Callide Creek Alluvium

Within the Project area, the alluvium is restricted to very thin, narrow deposits along major creek lines, including Campbell (Gate) Creek. Although some portions of the Project area are situated within the designated Callide Alluvium Groundwater Management Area, it is on the northern clayey fringe of the alluvium associated with the management area (GHD, 2013).

There is very limited subsurface information on the thickness and nature of the alluvium within the Project area. Only one water bore (Registered Number [RN] 345590) is drilled into this alluvium, and there is no lithological log for the bore. Based on previous experience with narrow alluvial sequences of this nature, it is considered likely to be thin (GHD, 2013).

Matrix+ Consulting (2007) reported that the thickness of the alluvium is generally less than 20 metres and that the Callide Creek Alluvium does not constitute a regionally significant aquifer in the Project area.

Biloela Formation

Accurate data exists for only one privately owned water bore (RN 57659) located approximately two kilometres south-west of the Project area. This bore was drilled 114 metres deep and is reported to be dry or damaged. The only groundwater intercept in this bore was reported as a soak in the Biloela Formation from 14.6 to 15.6 metres deep in sandy clay (GHD, 2013). This bore is about 300 metres north of a saline spring, as illustrated on Figure 9B-1.

Matrix+ Consulting (2007) reported that the Biloela Formation ranges from approximately 60 metres thick in the west of the Project area to 20 metres in the east. Landholders adjacent to the Project area reported there were several abandoned shallow bores in the Biloela Formation. Water in the Biloela Formation is reported to be salty and of low yield (Rob Lait & Associates, 2013).

Matrix+ Consulting (2007) considered that the low permeability within the varying proportions of fine-grained siltstone and mudstone within the Biloela Formation results in low yield and high salinity. The Biloela Formation is not considered to be a significant aquifer for the purposes of this assessment. It does, however, form a confining layer 'cap rock' for the underlying Precipice Sandstone, restricting the flow of water in (recharge) or out (discharge) of the underlying aquifers.

Precipice Sandstone

The Precipice Sandstone is the principal aquifer unit in the Project area. Based on exploration borehole data, the Precipice Sandstone ranges from 20 metres in the western edge of the proposed mine pit shell to 50 metres in thickness along the eastern edge. The unit pinches out approximately one kilometre to the west of the Project and reaches a maximum thickness of 70 metres at a distance of 500 metres to the east (GHD, 2013).

There are several small areas where the Precipice Sandstone crops out through the Biloela Formation clays to the west and south of the Project area, in which RN 57631 is situated. The drilling log for this bore shows that aquifers were encountered in coarse-grained sandstone from 15 to 21 metres deep and in fine-grained sandstone from 30 to 40 metres deep. As the water level in the bore is above ground level (artesian), water from this bore flows naturally to the surface. Like many privately owned bores, this bore was only drilled to a depth at which presumably the landholder or driller was satisfied that an adequate supply for its intended purpose was obtained (GHD, 2013).

Water-bearing layers are generally discrete and are separated by either non-groundwater producing or low groundwater yielding layers within the same bore. An analysis of the data available from privately owned bores for the Precipice Sandstone shows that water-bearing layers within the Precipice Sandstone occur within the depth range 10.4 to 54.3 metres and a thickness range of 0.3 to 21.9 metres (GHD, 2013).

Matrix+ Consulting (2007) reported that the groundwater resources of the Precipice Sandstone are difficult to define as the higher yields tend to be restricted to structural features and irregularly distributed porous zones, although as noted in section 9B.4.3.3, aquifer thickness also has a significant effect on yields, with higher yields associated with the thicker zones of Precipice Sandstone (GHD, 2013). Air-lifted discharge rates from exploration boreholes throughout the Basin were up to 20 litres per second or greater, with the highest flow rates in area of the thickest saturated Precipice Sandstone. Yields within the footprint of the Project were, however, generally less than 5 litres per second (GHD, 2013).


9B-8

Callide Coal Measures

Water bearing aquifers are known to exist within the Callide Coal Measures, however there is little accurate data available to quantify the extent. In general, coal measures are composed of fine-grained lithologies (siltstone, mudstone and coal), hence they have very little primary (or inter-granular) porosity or permeability with low yields.

Matrix+ Consulting (2007) reported that the average thickness of the Callide Coal Measures in the Project area is about 75 metres and that groundwater inflows from the coal measures (at other mines within the Callide Basin) appear to be primarily from the upper sandstone horizons with minor contributions from the lower coal seams and siltstone members. Due to low porosity, any useable groundwater in coal measure aquifers occurs within fractures within the siltstone, mudstone and coal.

There are very few records of groundwater intercepts within the coal exploration bores, and the privately owned bores rarely extend to the Callide Coal Measures. As such, it is not possible to quantify the depth to and thickness of water bearing aquifers within the Callide Coal Measures.

Muncon Volcanics

All exploration boreholes within the Project area and its surrounds are terminated as soon as the Muncon Volcanics are encountered. There are no reports of aquifers being associated with the Muncon Volcanics. This unit is regarded as the hydrogeological basement for the Project area (Rob Lait & Associates, 2013).

9B.4.2 Groundwater

9B.4.2.1 Aquifer Units

The aquifer types within the Project area and its surrounds are as follows:

- Callide Creek Alluvium – unconfined with limited extent in Project area proximal to Campbell (Gate) Creek;

- Biloela Formation – unconfined, fine grained, low yield and higher salinity;

- Precipice Sandstone – unconfined in outcrop area and confined below the Biloela Formation; and

- Callide Coal Measures – unconfined in outcrop area and confined below the Precipice Sandstone.

For the purposes of this assessment, these are the primary aquifers of interest for understanding the hydrogeology of the Project area. Specifically, the Precipice Sandstone formation is the key hydrogeological formation of interest due to interaction with other users, hence a comprehensive groundwater monitoring program exists for this aquifer.

Callide Creek Alluvium

The Callide Creek Alluvium, located approximately eight kilometres to the south-east of the Project area, is of high regional significance and is a major source of groundwater for irrigation along the broader Callide Valley. However, as the alluvium is only present as isolated clayey deposits within the Project area, it is not considered a significant aquifer for the purpose of this assessment (GHD, 2013).

Biloela Formation

Due to low aquifer yields and generally saline groundwater, the Biloela Formation is not considered to be either locally or regionally significant as an aquifer unit. It also provides a hydrogeological barrier between the Precipice Sandstone / Callide Coal Measures and the Callide Creek Alluvium (GHD, 2013).

Precipice Sandstone

Matrix+ Consulting (2007) reported that groundwater resources of the Precipice Sandstone aquifer are used in the pastoral industry, for mine water supply and domestic uses. Subsequently, the Precipice Sandstone aquifer is considered as a locally and regionally significant aquifer unit. The groundwater from the Precipice Sandstone is not generally suitable for irrigation of salt-sensitive crops. Due to the yields and cultural uses of water from the Precipice Sandstone it is the aquifer of interest for the Project. As such, this aquifer is the main focus of the ongoing pump testing and quality monitoring program executed at quarterly intervals by Callide Mine.


Although groundwater within the Callide Coal Measures is a source of groundwater seepage to mines, the sequence is not used as a primary source of water for the pastoral industry or other users in the Callide Basin, due to the low yields, elevated salinity and availability of alternative water supplies. The Callide Coal Measures are not considered a regionally significant aquifer unit (Matrix+ Consulting Pty Ltd, 2007).


9B-9

9B.4.3 Hydraulic Properties

9B.4.3.1 Groundwater Levels

In addition to the eight pump tested water supply bores, Table 9B-3 shows details of the locations of seven groundwater monitoring bores that are monitored at Callide Mine to observe groundwater levels within the Precipice Sandstone.

Table 9B-3 Location details of Boundary Hill long term groundwater level monitoring bores

Bore identification Easting MGA94 Northing MGA94

C2017 245943.20 7320024.18

C2903 246071.78 7318865.94

C2951 246146.72 7319319.49

ENV01 246432.00 7318752.00

R2940 244449.25 7320231.60

R2938 245086.50 7319734.66

R2951 246146.72 7319319.49 Bore position recorded using a GPS (MGA 94, UTM)

Of these seven bores, the most comprehensive long term data exist for R2940, C2903 and ENV01 (Rob Lait & Associates, 2013). R2940 is located approximately two kilometres to the west of the existing Boundary Hill pit. C2903 and ENV01 are both located about one kilometre to the south of the existing Boundary Hill pit. Figure 9B-2 shows the depth to groundwater in these three bores.

Figure 9B-2 Chart of depth to groundwater level in selected Boundary Hill South monitoring bores

As illustrated on Figure 9B-3, R2940 shows that the depth to groundwater in this bore has been essentially static over a period of almost 20 years, varying by less than 1.5 metres. The measured bore data indicates little response to major rainfall events, with a gradual increase of less than one metre following heavy rainfall in 2010 and 2011. This suggests that groundwater levels are more significantly impacted by long period (one year or more) rainfall averages, but only to a limited extent.

Therefore, it can be concluded that, where there are no anthropogenic effects on the aquifer (for example, nearby groundwater pumping), the seasonal groundwater level in response to rainfall events is only of the order of about 1.2 metres. Consequently, it is unlikely that an individual rainfall event would have a significant impact on groundwater flows (GHD, 2013).

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

Dep

th to

Gro

undw

ater

(m b

elow

m

easu

rem

ent r

efer

ence

poi

nt)

R2940C2903Env01


9B-10

Figure 9B-3 Standing water level (SWL) (mAHD) in monitoring bore R2940

The groundwater levels in C2903 and ENV01 show the impact of groundwater pumping; predominantly assumed as dewatering in the existing Boundary Hill pit, given they are located within one kilometre of the pit (see Figure 9B-1). ENV01 shows a decline of approximately 14 metres from the commencement of measurements until 2012. C2903 shows a groundwater level decline of about 10 metres between 2005 and 2008 followed by a recovery response beyond 2008 (Rob Lait & Associates, 2013).

The varying groundwater level responses between ENV01, and C2903 and ENV01 as shown in Figure 9B-2 indicate that, although the aquifer units are always regarded as continuous hydraulic entities, they should not be considered homogeneous. The data demonstrates limited hydraulic connectivity between each of these bores. The data suggests that secondary (fracture) porosity rather than primary (intergranular) porosity is a major control on groundwater level behaviour in the Project area (Rob Lait & Associates, 2013).

Further reinforcement of the role of secondary porosity affecting connectivity within the Precipice Sandstone can be seen within pump testing and monitoring data collected as part of Callide Mine’s existing operations indicating that, based on available data, there is no indication that the mine has any impact on the regional groundwater levels near the bores tested (Waste Solutions Pty Ltd, 2013).

9B.4.3.2 Groundwater Flow

Contours of groundwater levels from late 2012 (GHD, 2013) show a general trend of flow from the recharge areas in the north-east and east to the mines in the west, with localised flow towards the Project area. Groundwater flow in the Project area is described and illustrated in Appendix M.

9B.4.3.3 Groundwater Yield

Matrix+ Consulting (2007) reported that landholder stock and domestic bores are equipped with submersible pumps to extract groundwater at rates of less than five litres per second but more likely closer to one litre per second for only a few hours per day. Two mine water supply bores (Kilburnie Nos. 1 and 2) each extract groundwater at about three litres per second.

As noted in Water Studies (2002), yields from exploration boreholes in the Precipice Sandstone average around four litres per second with maximum flows of over 20 litres per second. Yields within the Callide Coal Measures averaged around one litre per second. Groundwater yields appear to be related to the thickness of the Precipice Sandstone, with the highest yields occurring in areas with the greatest thickness of saturated Precipice Sandstone (GHD, 2013). However, there are some high-yielding boreholes along the western margin of the

0

20

40

60

80

100

120

140

160

180

200

190.0

192.0

194.0

196.0

198.0

200.0

202.0

204.0

206.0

208.0

210.0

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

Dai

ly R

ainf

all (

mm

)

SWL

(mA

HD

)R2940 SWL (mAHD)


9B-11

Precipice Sandstone (approximately one kilometre south-west of Project area where the sandstone starts to thin out) where yields may have been enhanced by local fracturing.

Based on the dispersed location of the bores and relatively low extraction rates, the impact to the regional groundwater resource by current landholder pumping is likely to be negligible, in both the Precipice Sandstone and the Callide Coal Measures.

9B.4.3.4 Hydraulic Conductivity and Storage Coefficients

Hydraulic conductivity is measured by undertaking falling head permeability tests within and around the Project site.

Water Studies (2002) carried out a series of falling head tests in holes drilled in the Precipice Sandstone. Six tests gave a minimum of 0.023 metres per day, a median of 0.155 metres per day and a maximum of 0.69 metres per day. Pumping tests carried out in two test bores (T1 and T2), however, gave hydraulic conductivities in the order of 2.5 metres per day. Given the wider area of influence of long-term pumping tests, they may be more representative than localised and short-term falling head tests, which can be influenced by skin effects due to drilling. The higher permeability is supported by the high yields discussed in Section 9B.4.3.3. Radke (2012) summarised permeability and porosity data for the Precipice Sandstone throughout the Great Artesian Basin (GAB) and calculated a modal permeability of 1,000 mD (approximately equivalent to one metre per day) with a modal porosity of 20 percent.

Aquifers are known to exist within the Callide Coal Measures, however there is little accurate data available to confirm this. As the coal measures comprise fine-grained lithologies (siltstone, mudstone and coal), they have little intergranular permeability, with most flow through fractures and joints, and hence they are significantly less permeable than the overlying Precipice Sandstones. The median hydraulic conductivity value for the Callide Coal Measures from the falling head tests (Water Studies, 2002) was 0.0072 metres per day, which is approximately an order of magnitude lower than that for the falling head results for the Precipice Sandstone. As noted previously with the comparison of pumping test and falling head test results done on the Precipice Sandstone, the falling head tests may underestimate the overall hydraulic conductivity of the Callide Coal Measures. The maximum value was 0.32 metres per day.

Water Studies (2002) determined a storage coefficient from the pumping tests of 0.00006. Given the thickness of the aquifer, this value is approximately equivalent to the typical specific storage of 0.0000005 (GHD, 2013).

9B.4.3.5 Interaction with Surface Water

The Project area sits within the Callide Creek catchment, a sub-catchment of the broader Fitzroy Basin. Watercourses associated with the Project include Campbell (Gate) Creek and another unnamed gully, both of which are tributaries of Callide Creek. No palustrine or lacustrine wetlands are identified within the Project area.

Creeks within the Project area are ephemeral and there are no perennial natural water holes present. Under natural conditions, groundwater does not contribute to surface water flow within these creeks and streams. Similarly, the short term nature of surface water flow suggests they are unlikely to provide significant recharge to the aquifers. Drawdown of the potentiometric surface associated with mining is, therefore, unlikely to have an impact on the discharge from perched alluvial aquifers. This is due to the fact that these perched alluvial aquifers sit above, and are likely to be poorly connected to, the aquifers below (Matrix+ Consulting Pty Ltd, 2007).

Recharge and Discharge Areas

Recharge to the aquifers in the region occurs via infiltration of a proportion of incidental rainfall predominately in the topographically higher areas in the north-east of the Project area where the Precipice Sandstone and the Callide Coal Measures crop out at the surface. Where the Biloela Formation overlies these formations recharge is limited due to the relatively low permeability of the fine-grained rocks and clays of the Biloela Formation.

Recharge estimates derived from Geoscience Australia’s ‘Method of Last Resort’ (MOLR) have a very wide range from 0.2 to 53 millimetres per year, with a best estimate of 3.26 millimetres per year, or approximately 0.4 percent of rainfall (Bradshaw, 2009). Water Studies (2002) used a simple estimate of one percent of rainfall (seven millimetres per year or 0.000019 metres per day) for modelling.

Matrix+ Consulting (2007) reported that some recharge to the Callide Coal Measures may occur via downward leakage from the Precipice Sandstone. This would only occur if the hydraulic pressure in the Precipice Sandstone exceeded the hydraulic pressure in the coal measures and suitable groundwater flow pathways existed. No groundwater discharge to watercourses is likely for the reasons outlined.


9B-12

9B.4.3.6 Interaction with Saline Water

Saline water in perched aquifers potentially associated with the Biloela Formation is poorly connected to the aquifers below, including the aquifer units through which open pit mining will occur. As such, exchange of saline groundwater from the Biloela Formation with the pit water is not expected to occur (Rob Lait & Associates, 2013).

Artesian heads are naturally present in the deeper Precipice Sandstone aquifers over the areas to the south of the Project area. If connected to the surface, long term discharge of even slightly saline groundwater would have resulted in widespread soil salinisation. Salinisation is not evident in the area (GHD, 2013).

Ponded water in the open cut pits in the Callide Basin, including the existing Boundary Hill pit show elevated salinity and sulfate due to evaporative concentration of naturally occurring salts within inflowing groundwater (GHD, 2013).

9B.4.3.7 Vulnerability to Pollution

The limited cover of alluvium that exists within the Project area is the most vulnerable to pollution from surface activities as it is close to the surface, unconsolidated and unconfined. The Biloela Formation is the least vulnerable to pollution from the surface due to its low permeability.

The Precipice Sandstone may be vulnerable to surface water interactions in its outcrop areas (in the north-east of the Project area), as it is composed primarily of porous sandstone with only a skeletal sandy soil cover. During mining, as flow is towards the pit, contamination of groundwater by pit water (that may contain elevated salinity, sulfate and possibly some metals), is not considered likely, even in the unlikely event that the final pit water level rises above the level of surrounding groundwater.

It is considered that, outside the excavated areas, the aquifers within the Callide Coal Measures have only minor vulnerability to surface water interactions as the formations:

- do not outcrop within the Project area;

- are covered by up to 60 metres of overlying stratigraphic units; and

- are composed mainly of fine-grained rocks with presumed secondary (fracture) porosity as the main mechanism for groundwater storage and flow.

9B.4.4 Water Quality

Matrix+ Consulting (2007) undertook a statistical evaluation of the groundwater from the two primary aquifer units in the Boundary Hill South area. They considered data from approximately 120 samples. Table 9B-4 summarises the results of that statistical evaluation.

Table 9B-4 Statistical comparison of water quality parameters (Matrix+ Consulting, 2007)

Parameter Units

Guideline Values

Median Groundwater Values

Aquatic Ecosystems (ANZECC)

Precipice Sandstone


Boundary Hill Pit Water

pH pH units 6.0-7.5 6.8 7.3 6.9

Electrical conductivity µS/cm 250 1,089 1,198 1,910

Sulphate mg/L - 14 14 460

Total dissolved solids (TDS)

mg/L 150 729 812 1,143

The data from Table 9B-4 show that the groundwater from both the Precipice Sandstone and the Callide Coal Measures is pH neutral, has slightly elevated salinity (but still potable in the case of the Precipice Sandstone and marginal in the Callide Coal Measures) and has a low sulphate content. The water from the existing Boundary Hill pit shows the effects of concentration by evaporation (higher electrical conductivity and TDS) and probable oxidation of sulphides from exposed coal.

The existing Boundary Hill pit void is a groundwater sink, as the water level within the pit is below the regional water table (the evidence for which is the localised groundwater drawdown of C2903 and ENV01 shown in Figure 9B-2). As pit dewatering rates and evaporation exceed inflow rates from groundwater and rainfall, the pit water level is always be below the regional water table; therefore, pit water does not flow into the surrounding


9B-13

aquifers from the pit. Support for this statement is presented in Table 9B-5 which shows the results of water analyses taken from RN 34557, RN 57631 and RN 68797 in April 2010, representing groundwater quality in the Precipice Sandstone.

The results show that the groundwater from these bores is similar in pH, electrical conductivity and TDS to the results of groundwater from the Precipice Sandstone shown in Table 9B-5. These results are from samples taken after mining commenced at the existing Boundary Hill pit, and there is no evidence of deterioration in the groundwater quality in any of these bores. Therefore, it is concluded that all of these bores draw water from the Precipice Sandstone, and not from the existing pit.

Table 9B-5 Groundwater analysis results from neighbouring privately owned bores (Rob Lait & Associates, 2013)

Sample Identification RN 34557 RN 57631 RN 68797

Date sampled Units 13/04/10 15/04/10 16/04/10

pH - 5.1 5 6.4

Conductivity µS/cm 1250 1100 1030

Total dissolved solids mg/L 830 650 680

Calcium mg/L 4.5 3.4 22.4

Magnesium mg/L 20 15.2 42.5

Potassium mg/L 206 5.1 146

Sodium mg/L 5 171 4.5

Sulphate mg/L 56 46 34

Chloride mg/L 310 240 210

Alkalinity mg/L 24 22 156

Total Phosphorus mg/L <0.1 <0.1 <0.1

Nitrate as N mg/L <0.5 <0.5 <0.5

Total Nitrogen (N03 + NO2) mg/L <0.5 <0.5 <0.5

Ammonia mg/L <1 <1 <1

Hardness as CaCO mg/L 94 71 231

Bicarbonate as CaCO mg/L 24 22 156

9B.4.5 Groundwater Use and Monitoring

9B.4.5.1 Private Groundwater Bores

Matrix+ Consulting (2007) compiled a list of 17 registered landholder bores within a five kilometre radius of the original Boundary Hill Project area, located approximately one kilometre south of the Project area. No new or replacement bores have been drilled since the 2007 survey. Based on discussions with landholders, there are no known unregistered bores within the search area (Rob Lait & Associates, 2013).

The essential data from the Matrix+ Consulting private groundwater facility survey is shown in Table 9B-6. The locations of the private groundwater facilities are shown on Figure 9B-1.

Table 9B-6 Summarised data on privately owned groundwater facilities

Registered Bore Aquifer in which screened Status Type and Comments

NA Precipice Sandstone Active Sub-artesian

31779 Precipice Sandstone Unknown Sub-artesian, Low yield, potable

31818 Not available Unknown Sub-artesian, Limited data availability

33576 Precipice Sandstone Unknown Sub-artesian, Limited data availability

34556 Biloela Formation Not active Sub-artesian, Bore salty. Property watered by tanks

34557 Precipice Sandstone Active Flowing bore.


9B-14

Registered Bore

Aquifer in which screened Status Type and Comments

34564 Not available Unknown License cancelled by DNRM

34565 Not available Unknown License cancelled by DNRM

36238 Oaky Creek Alluvium Unknown License cancelled by DNRM

47343 Biloela Formation Unknown License cancelled by DNRM

57631 Precipice Sandstone Active Flowing bore

57659 Biloela Formation Not active Sub-artesian, Dry/damaged

62933 Precipice Sandstone/Callide Coal Measures

Unknown Sub-artesian, Limited data availability

68215 Precipice Sandstone Unknown Sub-artesian, Unused exploration bore

68683 Not available Unknown Sub-artesian, Information not available

68797 Precipice Sandstone/Callide Coal Measures

Unknown Sub-artesian

68798 Precipice Sandstone Unknown Sub-artesian

Each of the artesian bores is equipped with electric submersible pumps to assist in groundwater extraction. A number of these landholder bores are also monitored as part of Callide Mine’s existing monitoring program (see Section 9B.6.2). The bores shown in Table 9B-6 as in use are primarily used for stock watering. Some bores may also be used for domestic purposes and a number are production bores in continuous use providing water supply for both stock consumption and domestic purposes. Some bores in the Project area are also used regularly to supply water to properties that are part of the Oaky Creek Water Board. Observation bores are also located on neighbouring properties and are monitored as part of Callide Mine’s existing operations (Waste Solutions Pty Ltd, 2013).

9B.4.5.2 Pumping Parameters, Drawdown and Recovery

A series of pumping tests were conducted on a number of domestic bores (34557, 57631, 68798, 68797 and 68683) throughout 2009 and 2010. Table 9B-7 shows the data from the April 2010 tests.

Table 9B-7 Pumping parameters, drawdown and recovery data (Rob Lait & Associates, 2013)

Registered Bore 34557 57631 68798 68797 68683

Measured Parameter Units 13/04/10 14/04/10 Apr-10 Apr-10 Apr-10

Static water level m 2.14 mBGL* 2.092 mAGL** 27.30 27.91 24.545

Pumping depth m 32.00 28.00 40.20 50.47 43.70

Available drawdown m 29.86 30.09 12.90 22.56 19.15

Pumping duration mins 480 480 362 360 45

Total recorded drawdown m 4.68 9.23 8.35 11.95 -

Available drawdown used percent 15.67 30.67 64.73 52.97 -

Recorded recovery m 4.20 9.23 - - -

Total duration of recovery mins 84 24 - - -

Purge volume kL 38.0 37.9 - - -

Average pumping rate L/s 5.23 5.22 3.20 4.67 -

* below ground level ** above ground level

It can be seen from Table 9B-7 that the pumping discharge rates of all tested bores are between three and five litres per second. Drawdown at these pumping rates varies from about four to 12 metres.

In each case the proportion of drawdown used was less than 70 percent of the available drawdown. The bores therefore have some spare capacity at the pumping discharge rates that were used for the tests. It is assumed


9B-15

that the test pumping rates would be similar to the pumping rates used by the landholders in their normal operations.

The water level recovery data for bores 34557 and 57631 show that recovery is relatively rapid (24-84 minutes). From these tests it would appear that the aquifer units tested are not under stress.

9B.4.5.3 Seasonal Groundwater Level Variations

There are insufficient groundwater level measurements from any of the private groundwater facilities in the DNRM groundwater database with which to assess seasonal groundwater level variation.

9B.4.5.4 Groundwater Quality

Groundwater analyses from privately owned bores adjacent to the Boundary Hill South Project area are shown in Table 9B-5. The results show that the groundwater from these bores is similar in pH, electrical conductivity and TDS to the results of groundwater from the Precipice Sandstone from Callide Mine’s groundwater monitoring bores.

9B.4.6 Groundwater Monitoring Bore Network

Callide Mine has established 20 groundwater monitoring bores to assess the hydrogeological regime within the mine lease and immediate surroundings. Ten of these bores are screened in the Precipice Sandstone and 10 are screened in the Callide Coal Measures. Table 9B-8 shows the location and screened aquifer data for the groundwater monitoring bores. The locations of the Callide Mine monitoring bores are shown on Figure 9B-1. Existing monitoring bores and monitored farm bores are located in the vicinity of the Project.

The data from the groundwater monitoring bore network enables the identification of the major ionic species, pH, electrical conductivity, total dissolved solids and the likely potentially toxic or harmful substances.

Table 9B-8 Location and screened aquifer units – Callide Mine groundwater monitoring bores (Rob Lait & Associates, 2013)

Bore Number

Bore Name Easting Northing Screened Aquifer Unit

Length of Monitoring Record

R3038 J1 245658 7317105 Precipice Sandstone June 1999 - ongoing

R3046 J2 247025 7318447 Precipice Sandstone June 1999 – ongoing

C3061 J3 248195 7317676 Precipice Sandstone June 1999 - ongoing




R0507672 - 246410 7318296 Precipice Sandstone August 2002 - ongoing




R3044 C1 246210 7318072 Callide Coal Measures June 1999 - ongoing



R3070 C4 246469 7316455 Callide Coal Measures June 1999- ongoing



C0507653 - 247225 7318413 Callide Coal Measures August 2002 - ongoing




Bore position recorded using a GPS (MGA 94, UTM)


9B-16

9B.5 Potential Impacts

9B.5.1 Groundwater

Matrix+ Consulting (2007) undertook an evaluation of drawdown and groundwater quality impacts on the hydrogeological regime. Supplementary assessment of impacts has been made using numerical groundwater flow modelling carried out by GHD (2013) (Appendix M). The potential impacts are detailed in the following sections.

In addition to the steady state groundwater modelling undertaken for the Project, Callide Mine’s groundwater monitoring regime uses pump testing of water supply bores to assess bore-specific capacity and water quality, as well as draw down conditions, on a quarterly basis.

9B.5.1.1 Groundwater Quality and Drawdown

During mining operations, water quality within aquifers surrounding the mining activities is expected to remain the same as for pre-mining. No change in water quality during mining (as compared to pre-mining) is expected.

Simple radius of influence calculations (Matrix+ Consulting Pty Ltd, 2007) of the originally proposed Project indicated neighbouring registered bores (within approximately five kilometres of the pit) may experience up to 10 metres of drawdown (as compared to pre-mining) close to the Project (MLA 80186) boundary, reducing to less than one metre drawdown at a distance of approximately five kilometres from the mining activities. These calculations, however, were based on highly simplified and uniform conditions and did not take surrounding mining operations into account.

To provide a more detailed assessment of impacts, taking into account the variability in aquifer thickness and recharge, GHD (2013) has prepared a steady state numerical groundwater flow model. The model has been prepared using the MODFLOW suite of groundwater flow modelling packages and was calibrated against historical groundwater level data and mine inflow estimates (refer Figure 9B-4) using the assumption that the aquifer was in equilibrium (known as steady-state modelling).

The model was then modified to represent post-mining conditions and iterated to simulate steady-state conditions that would be expected with the final Boundary Hill South pit fully drained of water (Figure 9B-5). The model assumes that pits at Callide Mine’s Southern operations were being mined, and would not be filled with water to a level above the water table and provides recharge to the aquifers (GHD, 2013).

Modelling of the proposed mining operation estimated a drawdown of 15 metres up to approximately one kilometre from the centre of the Boundary Hill South pit, decreasing to 10 metres approximately two kilometres to the west, east and south of the pit (Figure 9B-6). Following cessation of dewatering at existing Boundary Hill operations, water levels at locations greater than 500 metres to the north of the Project are predicted to increase from 2012 levels (GHD, 2013). These model results highlight the limitations of steady state modeling processes, having limited alignment with data obtained by both the pumping tests and groundwater monitoring programs currently undertaken by Callide Mine. It is proposed to upgrade the groundwater model to a transient calibration to obtain greater simulation of observed processes.

MLA 80186

ML80151Boundary Hill

ML6993

ML6994

ML5655

Trap Gully

ML80115

Dunn Creek

The Hut

ML80107

Mallinsons

Rd

Grevells Rd

Callide Kilb

urnie Rd

Argoon Kilburnie Rd

Daws

onHw

y

345

320310300290280270260250235

180

245235

225

220

215

210195

175

350

340335325

315305

295285

295

280

275

270

265260

250

245

240

410

400

390380

370360

245240235230225

220215

210

205

415

405395

385

375

190

350345

340

335

330

325

320

315

310

305

300

295

290

290

280

275

265

260

255

250

330

315305

300

29528

5

400395

380

370

365

360

355

245

240

235

230

225

220

215

200

405

395

390

385

380

175

195

200

205

210

180

185

190

270

365

360

355

350

345

345

340

340

335

335

330

330

325

325

325

320

320

315

315

315

315

310

310

310

310

305

305

305

305

300

300

300

300

295

295

290

290

290

290

285

285

285

285

285

285

280

280

280

280

280

280

280

275275

275

275

275

275

275

270

270

270

270

270

270

265

265

265

265

265

265

260

260

260

260

260

255

255

255

255

255

255

250

250

250

250

250

250

245

245

245

245

245

245

245

240240

240

240

240

240

235

235

235

235

230

230

230

230

230

230

225

225

225

225

225

220

220

220

220

215

215

215

215

290

220

210

210

210

210210

205

205205

205

205

200

200

200

200

200

195

195

195

190

190

210

185

Badder House Bore

RN: 68798

RN: 68215

RN: 33576RN: 68797

RN: 31818

RN: 34564

NR: 34565RN: 36238

RN: 47343RN: 68683

RN: 57631

RN: 507659

RN: 34557

RN: 34556

RN: 62933

¹0 1 20.5

Kilometers

AECOM does not warrant the accuracy or completeness of information displayed in thismap and any person using it does so at their own risk. AECOM shall bear no responsibilityor liability for any errors, faults, defects, or omissions in the information.


60238883CFS 02-Nov-201360238883_ENV_171

Cadastre - © 2010 The State of Queensland.Image supplied by Callide Mine (date unknown).StreetPro © 2010 Pitney Bowes Software Pty Ltd.Roads, Rivers - © 2010 PSMA Australia Pty Ltd.infrastructure in the project area - Callide Mine

BOUNDARY HILL SOUTH EISModelled Steady-State

Groundwater Levels (m AHD) June 2012 Pit Water Level

Figure 9B-4

1:60,000 (when printed at A3)Scale:

Legend!( Registered Groundwater Bore

Highway

Local Road

Project Site(MLA 80186)

Extent of Groundwater Levels

Mine Leases

Granted

Groundwater Levels (mAHD)

180 - 200m

201 - 225m

226 - 250m

251 - 275m

276 - 300m

301 - 325m

326 - 350m

351 - 375m

376 - 400m

401 - 415m

!(

!(

!(

!(!(

!(

!(!(!(!( !(

!(

!(

!(

!(

!(

MLA 80186

ML80151Boundary Hill

ML6993

ML6994

ML5655

Trap Gully

ML80115

Dunn Creek

The Hut

ML80107

Mallinsons

Rd

Grevells Rd

Callide Kilb

urnie Rd

Argoon Kilburnie Rd

Daws

onHw

y

435

430

425

420

415410

405

400

395

390385

205

345340335330325315305295285275265255245235225215210205200195190

380

375

370

365

360

355

350

345

340

335

330320310

300

295290

285

280

275

270265260

255

250

370

365360355350345335325315305295

310300290280

230

225220

215

210

205

200

315

305

275

195

195

185

320300290280270260250240230

285

245

330

325

320

315

310

305

300

295

240

245

250

255 260265

270275

280 290

240

235

230225

220

215

210

205

200

285

200

415

405

400

395390

390

385

380

380

375

375

375

370

370

365

365

365

360

360

355355

355

350

350

345

345

340

340

340

340

335

335

335

335

330

330

330

330

325

325

325

325

325

320

320

320320

320

315

315

315

315

315

310

310

310

310

310

305

305

305

305

305

305

300

300

300

300

300

300

300

295

295

295

295

295

290

290

290

290

290

285

285

285

285

285

285

285

280

280

280

280

280

275

275

275

275

275

275

275

270

270

270

270

270

270

265

265

265

265

265

265

265

260

260

260

260

260

255

255

255

255

255

255

250

250

250

250

250

250

245

245

245

245

245

245

245

240

240

240

240

240240

235

235

235

235

235

235

235

235

230

230

230

230

230

230

225

225

225

225

225

225

220

220

220220

220

220

220

215

215

215

215

215

215

215

210

210

210

210210

210

210

245

240

230

215

210

205

205

205

205

200

200

200

340

210

Badder House Bore

RN: 68798

RN: 68215

RN: 33576RN: 68797

RN: 31818

RN: 34564

NR: 34565RN: 36238

RN: 47343RN: 68683

RN: 57631

RN: 507659

RN: 34557

RN: 34556

RN: 62933

¹0 1 20.5

Kilometers



60238883CFS 02-Nov-201360238883_ENV_170


BOUNDARY HILL SOUTH EISPredicted Steady-State Groundwater

Levels (m AHD) End of Mine Pit LevelsFigure 9B-5



Highway

Local Road


Extent of Groundwater Levels

Mine Leases

Granted

Groundwater Levels (mAHD)

180 - 200

201 - 225

226 - 250

251 - 275

276 - 300

301 - 325

326 - 350

351 - 375

376 - 400

>401

!(

!(

!(

!(!(

!(

!(!(!(!( !(

!(

!(

!(

!(

!(

MLA 80186

ML80151

Boundary Hill

ML6993

ML6994

ML5655

Trap Gully

ML80115

Dunn Creek

The Hut

ML80107

Mallinsons

Rd

Grevells Rd

Callide Kilb

urnie Rd

Argoon Kilburnie Rd

Daws

onHw

y

5

-30

-10

45

40

35

3025

0-5

-25

15

10

0

15

10

5

10

5

-25

-20

-15

-10

40

35

30

25

25

20

15

20

50

5

25

15

0

10

5

5

10

-15

-10

10

10

10

10

10

10

10

1010

10

10

10

10

5

5

5

5

5

5

5

5

5

5

5

5

0

0-5

-5

35

35

30

30

30

25

25

25

25

25

15

20

20

20

20

20

20

15

15

15

15

-20

20

Badder House Bore

RN: 68798

RN: 68215

RN: 33576RN: 68797

RN: 31818

RN: 34564

NR: 34565RN: 36238

RN: 47343RN: 68683

RN: 57631

RN: 507659

RN: 34557

RN: 34556

RN: 62933

¹0 1 20.5

Kilometers



60238883CFS 16-Oct-201360238883_ENV_169


BOUNDARY HILL SOUTH EISPredicted Steady-State Drawdown (m)

Final Boundary Hill South Pit ShellFigure 9B-6



Highway

Local Road


Extent of Drawdown

Mine Leases

Granted

Drawdown (m)

50

45

40

35

30

25

20

15

10

5

0

-5

-10

-15

-20

-25

-30

-35


9B-20

9B.6 Mitigation Measures

Matrix+ Consulting (2007) identified measures for mitigation and monitoring of impacts, based on their investigation. These measures are detailed, along with some additional measures in the following sections as a result of subsequent assessment by GHD (2013).

9B.6.1 Mitigation

Callide Mine already has established and documented mitigation agreements with potentially affected groundwater users as part of existing mine operations. Groundwater monitoring is already undertaken on a regular basis, as outlined in section 9B.6.2, to enable groundwater yield and quality impacts to be detected prior to any detrimental impacts on surrounding landholder bores. Landholders can access alternative water supplies without demonstrated impacts to existing landholder bores, and beneficial reuse agreements are currently used to supply water to landholders where agreed.

Due to the progressive nature of drawdown within aquifers and groundwater system, the provision of alternative supplies would be staged during the life of the Project if localised impacts were identified through the monitoring program. Options for alternate supplies may include:

- installation of new pumps capable of extracting groundwater from greater depth within existing bores;

- deepening of existing bores;

- installation of a new bore at another location on the property; and

- provision of piped water sourced from the mine as is currently undertaken.

Additional arrangements for affected landholders would be negotiated with the relevant parties, similarly to the existing, successfully implemented agreements that have been in place with various landowners for many years.

In addition to mitigation of impacts on specific bores, additional broader drawdown mitigation measures should be investigated, such as:

- recharging of mine water with suitable quality, via surface infiltration or discharge to mine voids; and

- substitution of current groundwater extraction with surface water or mine water supplies, subject to water quality constraints.

9B.6.2 Monitoring

Two groundwater monitoring programs are currently undertaken at Callide Mine’s existing operations. One program incorporates a dynamic groundwater monitoring regime for the identified key groundwater users and bores close to the Project area and active mine. The program assesses the specific capacity of eight bores using pumping tests and analyses water quality from collected samples on a quarterly basis; data collected from this program has been used to validate modelling undertaken for the Project. To protect the interests of businesses and landholders associated with the monitoring program, specific monitoring data has not been publically included in this EIS however has been provided to government departments as part of the EIS assessment process.

In addition to the aforementioned groundwater monitoring program, a comprehensive static groundwater monitoring program is undertaken to satisfy Callide Mine’s Environmental Authority (EA) conditions. Under this program, monitoring wells are sampled for Standing Water Levels (SWL), and bore water samples are collected for analysis at accredited laboratories.

The monitoring program provides a quantitative method for identifying any significant variations in the groundwater system, enabling the timely implementation of management measures to minimise impacts on nearby groundwater users. Monitoring undertaken as part of Callide Mine’s existing operations shows that, based on available data, there is no indication that the mine has any impact on the regional groundwater levels near the bores tested (Waste Solutions Pty Ltd, 2013). In the course of mining operations at Callide Mine a number of bores monitored to satisfy the mine’s EA conditions have been destroyed or are no longer accessible. Subsequently, a review and rationalisation of groundwater monitoring bores has been undertaken across the site, including the Project area.

It is proposed that up to 14 additional monitoring bores may be required to supplement the existing static monitoring network over the life of the Project due to destruction and optimisation of observation to compliment modelling processes. The number of new bores that may be installed is variable due to a number of factors including presence of aquifers, depth to groundwater, geology, how many bore monitoring agreements can be


9B-21

developed with neighbouring properties and modelling requirements. Separate monitoring bores may be required within the Precipice Sandstone, Callide Coal Measures and any other local aquifers identified.

At each monitoring bore, groundwater level and water chemistry should be monitored to detect any fluctuations in the water depth, flow and quality. As detailed in Matrix+ Consulting (2007), the proposed operational phase groundwater monitoring program is as follows:

- Near field monitoring from observation bores:

Water levels would be monitored on a periodic basis at monitoring locations. It is anticipated that some existing monitoring bores would be progressively destroyed by the mining activities. Near field monitoring is expected to detect a decline in water levels within the first few years of mining operations; and

Groundwater samples should be collected on an annual basis from selected monitoring bores. Groundwater samples would undergo laboratory analysis for pH, electrical conductivity, TDS, major cations, major anions, nutrients (total nitrogen, ammonia, total phosphorus and reactive phosphorus) and selected metals (aluminium, arsenic, cadmium, copper, lead, mercury, selenium and zinc).

If existing or future water analysis shows no presence or variation of minor analytes, these would be removed from the analysis suite.

The existing dynamic groundwater sampling program actively pump testing bores for specific capacity and water quality data will be maintained and reviewed quarterly, as per current Callide Mine practice.

9B.7 References

Australasian Groundwater & Environmental Consultants Pty Ltd . (2002). Oaky Creek Rural Water Supply Board Replacement Groundwater Supply Bores - Bore Constructing and Testing. n.s: Australasian Groundwater & Environmental Consultants Pty Ltd, for Water Solutions Pty Ltd.

Australian Groundwater Consultants Pty Limited . (1987). Callide Coalfields Water Management - Groundwater Review. n.s: Australian Groundwater Consultants Pty Limited , Report prepared for Callide Coalfields Pty Ltd.

Boyd Mining Pty Ltd . (1990). Groundwater Supply Investigations Drill Target Study - Dunn Creek-Trap Creek-The Hut. n.s: Boyd Mining Pty Ltd, report prepared for Blain Johnson Pty Ltd.

Bradshaw, B. S. (2009). Queensland carbon dioxide geological storage atlas. Geoscience Australia.

Coffey Partners International Pty Ltd. (1993). Callide Groundwater Monitoring Study. n.s: Coffey Partners International Pty Ltd, report prepared for Callide Coalfields Pty Ltd.

Coffey Partners International Pty Ltd. (1999). Kilburnie Coal Project - Hydrogeological Assessment. n.s: Coffey Partners International Pty Ltd, prepared for Callide Coalfields Pty Ltd.

DERM. (2011). Fitzroy Basin Resource Operations Plan. Brisbane: State of Queensland (Department of Environment and Resource Managment).

GHD. (2013). Callide Basin Groundwater Flow Model - Boundary Hill South Lease Extension Project Impact Model.

GHD. (2013). Callide Basin Groundwater Flow Model - Model Development and Calibration.

Golder Associates Pty Ltd . (1979). Geotechnical Investigations for Open Cut Mining - Boundary Hilt Block, Callide Basin. n.s: Golder Associates Pty Ltd , report prepared for Thiess Bros Pty Ltd Mining Division. Report 29035.

Golder Associates Pty Ltd . (1993). Pump Test - Trap Gully - Callide, QLD. n.s: Golder Associates Pty Ltd, Prepared for Callide Coalfields Pty Ltd. Report 93638246(A).

Matrix+ Consulting Pty Ltd. (2007). Boundary Hill Mine Extension Project, Hydrogeological Assessment. n.s: Matrix+ Consulting Pty Ltd , internal report prepared for Anglo Coal.

Radke, B. K. (2012). Lexicon of the lithostratigraphic and hydrogeological units of the Great Artesian basin and its Conozoic cover. CSIRO.


9B-22

Rob Lait & Associates. (2013). Boundary Hill South Lease Extension Project Environmental Impact Assessment – Groundwater Aspects. n.s: n.s.

Thiess Bros Pty Limited. (1983). AP188C Callide - Groundwater Conditions in and around Mining Lease No. 377 (Mount Morgan) Trap Gully. n.s: Thiess Bros Pty Limited.

Waste Solutions Pty Ltd. (2013). Callide Mine Fourth Annual Review Report.

Water Studies. (2002). Kilburnie Coal Project Feasibility Assessment - Hydrogeological Assessment. n.s: Water Studies Pty Ltd , Prepared for Callide Coalfields Pty Ltd.

Documents

Boundary Hill SoutH Project/media/Files/A/Anglo... · 2014-03-11 · Boundary Hill South Environmental Impact Statement 9B-1 9B. GROUNDWATER 9B.1 Introduction This chapter describes