Appendix K – Groundwater Hydrology Report

467 Pages·2012·20.3 MB·English

Kintyre Joint Venture Project
Hydrogeological Investigations
Cameco Australia Pty Ltd

Hydrogeological Investigations

Kintyre Joint Venture Project

Page i 1122 Rev 6: August 2012
Kintyre Joint Venture Project
Hydrogeological Investigations

Cameco Australia Pty Ltd
Hydrogeological Investigations
Kintyre Joint Venture Project

1122 | Rev 6
August 2012 Pennington Scott ABN 76 747 052 070
Level 12 / 3 Hasler Road, Herdsman, WA
GPO Box A10, Perth, WA 6849

T [phone]
F [phone]
www.penningtonscott.com.au

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Kintyre Joint Venture Project
Hydrogeological Investigations

This report has been prepared on behalf of and for the exclusive use of Cameco Australia Pty Ltd,
and is subject to and issued with the agreement between Cameco Australia Pty Ltd and Pennington
Scott. Pennington Scott accepts no liability or responsibility whatsoever for it in respect of any use or
reliance upon this report by any third party.
Copying this report without permission of Cameco Australia Pty Ltd or Pennington Scott is not
permitted.

REVISION AUTHOR REVIEW ISSUED DESCRIPTION
Rev 0 RT, LB, NT DS 30 Mar 2012 Issued to Cameco and Tetra Tech for comment
Incorporated pit dewatering data and re-issued to Cameco
Rev 1 RT, LB, NT DS 23 May 2012
and Tetra Tech for comment
RT, LB, NT,
Rev 2 DS 31 May 2012 Re-issued to Cameco and Tetra Tech for comment
RB
RT, LB, NT, Incorporated model results and re-issued to Cameco and
Rev 3 SC, GR 12 July 2012
RB, DS Tetra Tech for comment
RT, LB, NT,
Rev 4 HM 18 July 2012 Issued to Cameco
RB, DS
RT, LB, NT,
Rev 5 SW 26 July 2012 Incorporated changes from Cameco
RB, DS
RT, LB, NT, Incorporated geochemistry summary; issued as a final
Rev 6 DS 13 Aug 2012
RB copy

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Kintyre Joint Venture Project
Hydrogeological Investigations

EXECUTIVE SUMMARY
The Kintyre Joint Venture (KJV), comprising Cameco Australia Pty Ltd (70%) and Mitsubishi
Development Pty Ltd (30%), is developing a 4.4 kTpa uranium project on the western edge of the
Great Sandy Desert in the East Pilbara region of Western Australia. Water supply will be sourced
from groundwater and is required for ore processing, plant construction and camp water supply.
Annualised demand for years 3 to 11 of the 13.5 year project life is estimated at 3,100 kL/day.
Hydrogeological analysis in this report draws on an extensive water exploration program undertaken
by the KVJ between 2009 and 2012, as well as information from other investigations undertaken over
several decades. The KJV investigations incorporated exploration drilling, construction and hydraulic
testing of eleven test production bores, and detailed numerical modeling.
The hydrogeology of the Project area is dominated by a Permian glacial valley that has been filled by
predominantly glaciofluvial and glaciolacustrine deposits of the Paterson Formation. The main aquifer
units are located in Permian sand, gravel and conglomerate deposits of the Paterson Formation and
the underlying Coolbro Sandstone, a Proterozoic fluvial-deltaic succession comprised mostly of fine to
coarse grained quartz sandstone.
The Paterson Formation occupies a broad flat glacial palaeovalley about 5 km wide through the
central and lower reaches, rapidly narrowing to under 2 km in its upper reaches. The formation is
divided into two broad units referred to as the upper Paterson and lower Paterson, each representing
episodes of glacial advance and retreat. The upper unit generally forms an extensive clayey sand
aquifer with a lower aquitard associated with the fine-grained glacio-lacustrine facies. However, sand
and gravel lenses, present within the unit, are capable of forming appreciable local aquifers. The
lower unit comprises beds of glacial tillite, glaciofluvial and glaciolacustrine deposits, which are
generally unsorted and held within a suspended matrix of mud or sand and sparse gravel. The unit is
typically thickest in the deepest parts of the palaeovalley, reaching a maximum of thickness of 105 m,
and increases northward forming a laterally continuous aquifer or series of aquifers along the length
of the palaeovalley. Both units are considered productive aquifers.
Numerical groundwater modelling of the aquifer system demonstrates that:
 The maximum design Project demand of 3,100 kL/day can be drawn from a proposed
borefield comprising 10 production bores (7 active water supply bores, plus 3 standby bores);
 With the proposed borefield, there will be more than sufficient borefield capacity and
contingency to sustain an overall abstraction 3,100 kL/day over the mine life without causing
unacceptable drawdown or loss of bore productivity;
An appraisal of the potential environmental and social issues arising from the borefield development
and operation indicates that:
 There are no other groundwater users within 80 kilometres of the KJV. Since borefield
depressurisation will not extend beyond 10 km from the borefield, the KJV will not adversely
impact other water users;
There should be no impact on waterholes and vegetation associated with Rudall River and Lake Dora
as they are far outside of the zone of drawdown related to the Project;

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 The hydrology of the Yandagooge Creek and its catchment is dominated by seasonal rainfall
and is unlikely to be affected by groundwater drawdowns;
 There is unlikely to be groundwater dependent vegetation in the area of drawdown impact.
Two tree species that possibly could have some groundwater dependence are considered
robust to groundwater level changes and would likely be able to adapt to water level changes
of 0.5-1.0 m/year;
 Several ephemeral river pools along the Coolbro and Yandagooge creeks are likely to be
perched on clayey alluvial strata, fed by surface flows and therefore not affected by
groundwater abstraction for the Project. Further monitoring will take place to confirm these
findings in the next stage of the project, and develop triggers and contingencies if required;
and
 Of the stygofauna species which have been identified in the Project area all or most are likely
to occur elsewhere and are not likely to be threatened by development. Even if a species
were localised, only a small fraction of the potential habitat within the aquifers impacted by the
Project will be affected by drawdown.

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CONTENTS
1.  BACKGROUND ............................................................................................ 1 
1.1  Previous Work ............................................................................................................... 4 
1.2  Water Licensing ............................................................................................................. 5 
2.  ENVIRONMENTAL SETTING ....................................................................... 6 
2.1  Climate ........................................................................................................................... 6 
2.2  Geomorphology ............................................................................................................. 7 
2.3  Hydrology ....................................................................................................................... 9 
2.4  Potentially Groundwater Dependent Ecosystems ....................................................... 11 
2.4.1  Vegetation .................................................................................................... 11 
2.4.2  Subterranean Fauna .................................................................................... 12 
3.  GEOLOGICAL SETTING ............................................................................ 14 
3.1  Stratigraphy ................................................................................................................. 17 
3.1.1  Rudall Complex ............................................................................................ 17 
3.1.2  Coolbro Sandstone – Yeneena Supergroup ................................................ 17 
3.1.3  Broadhurst Formation and Isdell Formation – Yeneena Supergroup .......... 19 
3.1.4  Paterson Formation (Permian) ..................................................................... 20 
3.1.5  Cenozoic Deposits ....................................................................................... 30 
3.2  Structural geology in the Kintyre pit area .................................................................... 32 
4.  HYDROGEOLOGICAL SETTING ............................................................... 36 
4.1  Groundwater Occurrence ............................................................................................ 36 
4.1.1  Cenozoic Deposits ....................................................................................... 36 
4.1.2  Upper Paterson aquifer ................................................................................ 37 
4.1.3  Lower Paterson aquifer ................................................................................ 37 
4.1.4  Coolbro Sandstone aquifer .......................................................................... 38 
4.1.5  Rudall fractured rock aquifer ........................................................................ 38 
4.2  Hydraulic Parameters .................................................................................................. 38 
4.2.1  Paterson Formation aquifers ........................................................................ 41 
4.2.2  Coolbro Sandstone aquifer .......................................................................... 41 
4.2.3  Rudall fractured rock aquifer ........................................................................ 42 
4.3  Groundwater Dynamics ............................................................................................... 43 
4.3.1  Groundwater Recharge ................................................................................ 43 
4.3.2  Groundwater Levels and Flow ..................................................................... 46 
4.3.3  Groundwater Discharge ............................................................................... 50 
4.4  Groundwater Quality .................................................................................................... 50 
4.4.1  Upper Paterson aquifer ................................................................................ 54 
4.4.2  Lower Paterson aquifer ................................................................................ 54 

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4.4.3  Coolbro Sandstone aquifer .......................................................................... 54 
4.4.4  Rudall Fractured Rock aquifer ..................................................................... 55 
5.  WATER DEVELOPMENT PLAN ................................................................. 56 
5.1  Pit Dewatering Strategy ............................................................................................... 56 
5.1.1  Basis of dewatering design .......................................................................... 57 
5.1.2  Dewatering development plan ...................................................................... 57 
5.2  Process Water Borefield Development Strategy ......................................................... 60 
5.2.1  Basis of borefield design .............................................................................. 60 
5.2.2  Borefield development plan .......................................................................... 60 
5.3  Mine Closure ................................................................................................................ 61 
6.  NUMERICAL MODELLING ......................................................................... 63 
6.1  Model Design and Calibration ..................................................................................... 63 
6.2  Process water supply simulations ............................................................................... 64 
6.3  Pit dewatering simulations ........................................................................................... 64 
6.4  Pit lake water balance ................................................................................................. 64 
7.  IMPACT ASSESSMENT ............................................................................. 66 
7.1  Impacts During Mining ................................................................................................. 67 
7.1.1  Environmental Impacts ................................................................................. 67 
7.1.2  Social Impacts .............................................................................................. 70 
7.2  Impacts Following Mine Closure .................................................................................. 72 
7.2.1  Water Quality after closure ........................................................................... 73 
7.2.2  Water Levels after closure ........................................................................... 74 
8.  CONCLUSIONS .......................................................................................... 75 
9.  REFERENCES ............................................................................................ 77 

ATTACHMENTS
Attachment A Kintyre ERMP Bore Completion Summary Report
Attachment B Kintyre ERMP Groundwater Modelling Report

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LIST OF FIGURES
Figure 1-1: Kintyre area location ............................................................................................................. 3 
Figure 2-1: Monthly rainfall distribution and maximum temperature at Telfer over the years 1974 to
2012, 90 km to the north of the Project area ................................................................................... 6 
Figure 2-2: Project geomorphology ......................................................................................................... 8 
Figure 2-3: Surface hydrology ............................................................................................................... 10 
Figure 2-4: The site at Pinpi Rockpool in a) March 2012 and b) July 2012 during both inundated and
dry conditions respectively. ............................................................................................................ 11 
Figure 2-5: Potentially groundwater dependent vegetation .................................................................. 13 
Figure 3-1: Regional geologic setting of the Project area (reproduced from Ferguson et al., 2005) .... 14 
Figure 3-2: Simplified surface geology in the Project area (from Western Australia Geological Survey
1:100 000 geological mapping). ..................................................................................................... 16 
Figure 3-3: Generalised stratigraphy of the Yeneena Supergroup (after Hickman and Clarke, 1994) . 18 
Figure 3-4: Fluvial sedimentary structures in outcropping Coolbro Sandstone; and exposed contact
between the Permian Paterson Formation basal conglomerate (a) and Coolbro Sandstone (b)
with inferred unconformity (dashed) .............................................................................................. 19 
Figure 3-5: Project Area prior to deposition of the Paterson Formation, showing extent of glaciation
and glacier movement. ................................................................................................................... 21 
Figure 3-6: Paterson Formation - extent and basal elevation in the Project area ................................ 22 
Figure 3-7: Moraine till deposition ......................................................................................................... 23 
Figure 3-8: Deposition of the fluvial braided sand of the Paterson Formation ...................................... 23 
Figure 3-9: Deposition of the lacustrine silt/mud of the Paterson Formation ........................................ 24 
Figure 3-10: Outcropping Paterson Formation 7 km north of Kintyre, and polymictic paraconglomerate
intersected in hole CWB17 at 28–42 m. ........................................................................................ 24 
Figure 3-11: Example of siltstone intersected during drilling at CWB17 over 50-106 m depth ............ 25 
Figure 3-12: Paterson Formation facies present in bores in the Project Area ...................................... 27 
Figure 3-13 Geological cross-section; north-south ............................................................................... 28 
Figure 3-14 Geological cross-section; east-west .................................................................................. 29 
Figure 3-15: Typical saprolite profile observed in the Project area ...................................................... 31 
Figure 3-16: Geology about Kintyre ...................................................................................................... 34 
Figure 3-17 Generalised and interpreted composite-litho-stratigraphic rock succession at Kintyre –
view is to the east with northerly dipping strata. (From Cameco 2010, unpublished.) .................. 35 
Figure 4-1: Interpretive watertable contours for the Yandagooge Creek valley ................................... 48 

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Figure 4-2: Interpretive potentiometric heads in the Paterson Formation ............................................ 49 
Figure 4-3: Piper diagram showing variation in water quality speciation .............................................. 51 
Figure 4-4: Groundwater class distribution ........................................................................................... 52 
Figure 4-5: Chloride, Sulphate, and Bicarbonate ion concentration in groundwater ............................ 53 
Figure 5-1: Schematic of dewatering operations .................................................................................. 57 
Figure 5-2: Potential layout of dewatering bores (see Figure 3-16 for geologic legend). ..................... 59 
Figure 5-3: Proposed production drill sites ........................................................................................... 62 
Figure 7-1: Modelled water table in the centre of the vegetation area, 6 km north of the pit ............... 67 
Figure 7-2 Modelled water table drawdown at end of mining (Project area) ........................................ 68 
Figure 7-3 Modelled water table drawdown at end of mining (broader region) .................................... 71 
Figure 7-4 Modelled water balance and water levels for northeast pit lake .......................................... 72 

LIST OF TABLES
Table 1-1: Project water demand ............................................................................................................ 1 
Table 1-2 Scope of the hydrogeological investigation ............................................................................ 2 
Table 1-3: Summary of existing water permits and licences .................................................................. 5 
Table 1-4: Details of 5C water licence application .................................................................................. 5 
Table 3-1: Geologic summary of the Kintyre area ................................................................................ 15 
Table 4-1: Summary of Aquifer types in the Kintyre area ..................................................................... 36 
Table 4-2: Summary of hydraulic parameters (bulk for the whole unit) derived from pumping tests and
estimated values ............................................................................................................................ 40 
Table 4-3: Recharge rates calculated using Chloride Mass Balance (CMB) method........................... 45 
Table 4-4: Carbon-14 isotope age dates from the Paterson aquifer near Kintyre (after Lewis, 2011) . 47 
Table 6-1: Calibrated model parameters .............................................................................................. 64

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1. BACKGROUND
The Kintyre Joint Venture (KJV), comprising Cameco Australia Pty Ltd (70%) and Mitsubishi
Development Pty Ltd (30%), is developing a 4.4 kTpa uranium project on the western edge of the
Great Sandy Desert in the East Pilbara region of Western Australia, referred to as the ‘Project' (Figure
1-1). The Project lies 90 km south of Telfer and 270 km northeast of Newman and encompasses five
mineralisation bodies; the Kintyre, Kintyre East, Whale, Whale East and Pioneer deposits. The Project
is expected to have a minimum life of 13.5 years and involves the development of open cut pits;
waste landforms, evaporation ponds, an acid leach processing facility and tailings storage facility
(TSF) within the operational area.
Water requirements for the Project include water for ore processing purposes as well as plant
construction and camp water supply. Table 1-1 summarises the project water demands over the 13.5
year mine life. The project will have a peak total demand of up to 3,100 kL/day in years 3 to 11, the
production years.

Table 1-1: Project water demand
Construction Potable Process Dust Total Project
Year
water Camp Water water suppression demand
(Inclusive)
kL/day kL/day kL/day kL/day kL/day
1 500 300 0 0 800
2 500 300 200 800 1,800
3-11 0 200 1,500 1,400 3,100
11-13 0 200 0 800 1,000

Water demand for the Project will be met by the following sources, in order of precedence:
 mine dewatering from bores and sumps;
 opportunistic capture of stormwater runoff; and
 make-up water from the process water supply borefield.
The proposed make-up water borefield is in a Permian glacial aquifer located 2 to 10 km north of the
project area, covered under pending miscellaneous license for groundwater exploration, L45/314.
The KJV partners engaged Pennington Scott (hydrogeological consultants), Tetra Tech (Geotechnical
and hydrogeological consultants) and MWH to undertake the necessary hydrogeological
investigations of the pit dewatering and water supply borefields to support an Environmental Risk
Management Plan (ERMP). The KJV partners, together with all their contractors and consultants are
hereinafter referred to collectively as ‘Cameco’.
This report is the Hydrogeological Appendix to the Environmental Review and Management
Programme (ERMP) for the Kintyre Uranium Project. The report represents the feasibility and
impacts assessments for the Project dewatering and makeup water supply in support of a
1,400,000 kL/year 5C water licence application to the WA Department of Water from the
sedimentary aquifer in the East Pilbara Groundwater Management Area.
Table 1-2 summarises the scope of the hydrogeological investigations. The report draws on the
knowledge gathered from previous investigations undertaken over several decades plus studies

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