Expert Witness Statement of Dr Tamie Weaver - Trustpower/media/files/dundonnell newsletters... ·...

Environmental Resources Management Australia Pty Ltd

Expert Witness Statement of Dr Tamie Weaver

September 2015

Environmental Resources Management Australia Level 3, Tower 3, World Trade Centre

18-38 Siddeley Street, Docklands Victoria 3005, Australia

Telephone +61 3 9696 8011 Facsimile +61 3 9696 8022

www.erm.com

Expert Witness Statement of Dr Tamie Weaver

September 2015

For and on behalf of Environmental Resources Management Australia

Approved by: Position: Technical Fellow and Partner Signed:

Date: 23 September 2015

This disclaimer, together with any limitations specified in the report, apply to use of this report. This report was prepared in accordance with the contracted scope of services for the specific purpose stated and subject to the applicable cost, time and other constraints. In preparing this report, ERM relied on: (a) client/third party information which was not verified by ERM except to the extent required by the scope of services, and ERM does not accept responsibility for omissions or inaccuracies in the client/third party information; and (b) information taken at or under the particular times and conditions specified, and ERM does not accept responsibility for any subsequent changes. This report is subject to copyright protection and the copyright owner reserves its rights. This report does not constitute legal advice.

Contents 1 INTRODUCTION 1 1.1 Guide to Expert Evidence 1 1.1.1 Name and address 1 1.1.2 Qualifications and experience 1 1.1.3 Area of expertise 1 1.1.4 Instructions 2 1.1.5 The documents and material relied upon for this report 2 1.1.6 Declaration 3 1.2 Submissions Received 3 1.3 Structure of this report 3 2 THE PROPOSAL 4 2.1 Site Locality and Hydrologic Setting 4 2.1.1 Topography and Geology 4 2.1.2 Springs and wetlands 4 2.2 Planned Windfarm Infrastructure 4 2.2.1 Roadways, WTG, laydown areas and permanent operations buildings 5 2.2.2 Quarry area 5 2.2.3 Concrete batching plants 5 2.2.4 Water requirements 5 3 HYDROGEOLOGICAL ASSESSMENT 6 3.1 Hydrogeological Assessment 6 3.2 Baseline Groundwater Conditions 6 3.2.1 Registered groundwater bores, registered uses and aquifer yield 7 3.2.2 Groundwater potential beneficial uses and groundwater chemistry 7 3.2.3 Rainfall and groundwater levels 7 3.3 On-Site Hydrogeological Works 8 3.3.1 Groundwater elevations 8 3.3.2 Preliminary assessment of aquifer yield and extent of drawdown 8 3.4 Conceptual Hydrogeological Model 9 3.5 Potential Impacts on Groundwater and Spring Discharges 10 3.5.1 Potential receptors 10 3.5.2 Construction and operations 10 3.5.3 Assessment of potential impacts 11 3.5.4 Groundwater impact assessment conclusions 11 4 WATER-RELATED ISSUES FROM SUBMISSIONS 13 4.1 Hydrogeological Assessment 13 4.2 Potential effects of turbine foundations and tracks 14 4.3 Potential effects of quarrying 14 4.4 Protection of spring discharge 15 4.5 Potential impacts to existing groundwater supply bores 15 4.6 Storage and use of hazardous chemicals 15 5 CONCLUSIONS 16 6 REFERENCES 17

Annex Tamie Weaver’s CV Annex A -

23 September 2015 Expert Witness Statement of Dr Tamie Weaver

Environmental Resources Management Australia Pty Ltd /September 2015

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1 INTRODUCTION

This expert witness report relates to hydrogeological aspects of the proposed construction and operation of the Dundonnell Wind Farm at the wind farm site located to the north-east of Mortlake and to the west of Derrinallum in Victoria. Groundwater assessment for the Environmental Effects Statement (EES) has focussed on the wind farm site rather than the transmission corridor because of the nature of the proposed construction and operational activities.

1.1 Guide to Expert Evidence

I acknowledge that I have read and complied with Planning Panels Victoria, Guide to Expert Evidence (PPV, 2015). In accordance with this guide, I provide the following information.

1.1.1 Name and address

Dr Tamie R Weaver Environmental Resources Management Australia Pty Ltd (ERM) Level 3, Tower 3, World Trade Centre 18-38 Siddeley Street, Docklands Victoria, 3005

1.1.2 Qualifications and experience

I am a hydrogeologist with over 30 years’ experience. I hold a PhD in Hydrogeology from the University of Waterloo (1994), a MS in Hydrogeology from the University of Wisconsin - Madison (1988) and a BA (Hons) in Geology from Cornell University (1984). I am a member of the National Ground Water Association (NGWA) and an Associate Editor of their scientific journal Ground Water. I am also a member of the Australasian Land and Groundwater Association (ALGA) and, through ERM, of the Australian Contaminated Land Consultants Association (ACLCA).

Prior to re-joining the environmental consulting industry, I was a Lecturer and Senior Lecturer of Hydrogeology in the School of Earth Sciences, The University of Melbourne from 1994 to 2007. During that time I coordinated postgraduate degrees and degree streams in hydrogeology, led hydrogeological research in Victoria, lectured in hydrogeology at undergraduate and postgraduate level, and supervised Honours, Masters, and PhD students in groundwater-related projects.

Since 2007 I have been employed in the environmental consulting industry as a hydrogeologist providing hydrogeological assessments of proposed, active and closed facilities. I am currently a Technical Fellow and Partner at ERM.

My CV is provided as Annex A of this report.

1.1.3 Area of expertise

As a hydrogeologist I have experience in the development of conceptual hydrogeological models for rural and urban environments, assessment of groundwater flow and quality conditions in Victorian aquifers and at proposed, operating and closed facilities, and evaluation of interactions between groundwater and surface water.

I have published on groundwater conditions in fractured rock and Victorian aquifers, including the mineral springs of Central Victoria, and have supervised and conducted groundwater-related projects in basalt environments in Victoria. I was a contributing author to Environment Protection Authority (EPA) Victoria’s Hydrogeological Assessment (Groundwater Quality) Guidelines (#668).



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1.1.4 Instructions

I have been requested by Herbert Smith Freehills (HSF) acting on behalf of Trustpower Australia Holdings Pty Ltd (Trustpower) to prepare an expert witness report for the Dundonnell Wind Farm Project Inquiry (DELWP, 2015). This report summarises the hydrogeological assessment presented in the Dundonnell Wind Farm Environmental Effects Statement (EES) and provides responses to submissions received that relate to hydrogeological issues.

1.1.5 The documents and material relied upon for this report

This report draws on the following:

• Hydrogeological Study, Dundonnell Wind Farm (ERM, 2015)

- prepared primarily by Mr David Walker (previously of ERM), Mr Mark Wakeman (ERM) and myself;

• Groundwater related sections of Dundonnell Wind Farm Environmental Effects Statement (Trustpower Ltd, 2015) which drew largely on information in the above-cited Hydrogeological Study (ERM 2015); and

• A site visit with Mark Wakeman (ERM) on 11 August 2015.

I was technical lead for development of the scope of works for the hydrogeological study, and was an author and final technical reviewer of the Hydrogeological Study and of groundwater-related aspects of the Dundonnell Wind Farm EES.

The Hydrogeology Study was based in part on field works completed by:

• Mr Mark Wakeman who supervised groundwater well installation and conducted groundwater gauging on site. Mark is a Senior Hydrogeologist at ERM with 14 years’ experience and holds a MSc Hydrogeology from the University of Birmingham, UK; and

• Ms Julia Noorda who supervised a pumping test and conducted groundwater gauging on site. Julia is a Hydrogeologist at ERM with 2.5 years’ experience and holds a BEng (Hons) Environmental Engineering from RMIT.

This Expert Witness Report also draws on information in the following documents (prepared by others) that is relevant to groundwater and springs conditions at and in the vicinity of the Dundonnell Wind Farm site:

• Work Plan for Work Authority 1540, Dundonnell Victoria, prepared by C.K. Prowse of C.K. Prowse & Associates Pty. Ltd., March 2015 (Prowse, 2015);

• Proposed Dundonnell Wind Farm Geoscience Features, Significance & Sensitivity Assessment, prepared by Neville Rosengren of Environmental GeoSurveys Pty. Ltd. (Environmental GeoSurveys, 2014);

• Dundonnell Wind Farm Surface Water Assessment, prepared by Water Technology (Water Technology, 2014); and

• Chapter 19, Traffic, Dundonnell Wind Farm Environmental Effects Statement (Trustpower Ltd, 2015).

Ms Sarah Sawyer, a Principal Consultant and hydrogeologist at ERM assisted in the preparation of this evidence.



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1.1.6 Declaration

I have made all the inquiries that I believe are desirable and appropriate and no matters of significance which I regard as relevant have to my knowledge been withheld from the Panel.

1.2 Submissions Received

Several submissions were received during and following exhibition of the EES. The submissions that relate to hydrogeology and groundwater and which were provided to me are summarised below.

• #1. Call for Submissions to Dundonnell Wind Farm Proposal EES;

• #6. Submission for Dundonnell Wind Farm;

• #7. Submission: Dundonnell Wind Turbine Installation, Environment Effects Statement;

• #22. Attention: Mr Richard Wynne;

• #32. Submission to Dundonnell Wind farm proposal EES;

• #61. Objection to Dundonnell Wind Farm Project;

• #66. Dundonnell Wind Farm Project EES Submission;

• #101. To Dundonnell Wind Farm Project EES Submissions;

• #102. Dundonnell Wind Farm Project EES Submission;

• #112. Submission to Planning Minister regarding Trustpower Dundonnell IWEF EES;

• #115. Dear Mr Richard Wynne;

• #127. Submission to Planning Panels Victoria about Trustpower Dundonnell Wind Farm and EES;

• #128. Submission regarding the Dundonnell Wind Farm EES Brolga Assessment (Vol. 2 Annex M DDWF Brolga report); and

• #135. Submission to the Minister for Planning on Planning Permit Applications 2015/23858, PL15/074, PL15/075 and the Environment Effects Statement associated with the Dundonnell Wind Energy Facility, transmission line and off-site substation.

Two submissions were received by the Moyne Shire Council prior to the Council Meeting held 11 August 2015 that related to hydrogeology and groundwater. These were provided to me and the issues raised are captured in the submissions to the Panel listed above and are addressed in this statement.

1.3 Structure of this report

Sections 2 and 3 of this expert witness report describe the proposed facility and hydrogeological conditions at the proposed Dundonnell wind farm facilities and assess potential impacts of the proposed activities on groundwater supply, groundwater- surface water interactions, and groundwater dependent ecosystems.

Themes raised in submissions during and following EES exhibition and received by Moyne Shire Council are presented and discussed in Section 4.

Conclusions are presented in Section 5, and references upon which this report draws in Section 6.



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2 THE PROPOSAL

2.1 Site Locality and Hydrologic Setting

The wind farm site (the site) is located at Dundonnell, Victoria on the volcanic plains of western Victoria. The site is used primarily for pasture and is adjacent to the Mt Fyan’s Wildlife Reserve. The Project Area includes the wind farm site, transmission line corridor and off-site substation. However, the construction and operation of the associated transmission line and off-site substation are considered unlikely to affect groundwater. Consequently, they are not discussed further in this evidence.

2.1.1 Topography and Geology

The site lies on the western Victorian volcanic plains and is characterised by flat to gently undulating terrain. Key topographic features in the area include Mt Hamilton (elevation of 317 mAHD) which is located approximately 6.5 km to the north and Mt Fyans (elevation of 275 mAHD) which is surrounded by the wind farm site.

The site is dominated by flows of basalt lava from Mt Fyans and is part of the ‘stony rise’ volcanic terrain unit. Away from Mt Fyans the site is characterised by mounds and broad ridges of broken basalt blocks. The basalt is underlain by Cambrian to Silurian marine sediments intruded by granites.

The basalt flows on the wind farm site have well-preserved features (Environmental GeoSurveys, 2014), often with rocky outcrops, steep-sided linear ridges and irregular, stony surfaces with relief of ± 10 m (stony rises) with little or no soil cover. A small cave is present in a basalt dyke at Mt Fyans. Although there are no known lava caves or open lava flow pathways within the wind farm site, there is the possibility that lava tubes that have not yet been identified may be present in the area.

2.1.2 Springs and wetlands

The wind farm site and transmission line corridor are located within the Glenelg Hopkins Catchment Management region. The local catchment is not within a designated water supply protection area and does not drain to a designated water supply catchment. There are numerous designated waterways within the wind farm site; however, they are not located within 20 m of wind turbine generators (WTG).

The site is surrounded by several wetlands. Runoff from the site predominantly flows towards two wetland areas to the north-west and south-east.

Springs are present at elevations of between 191 and 195.5 m AHD in the southern and eastern parts of the site and off site to the south and east. While some springs are located within the site boundary they are not co-located with wind farm infrastructure.

2.2 Planned Windfarm Infrastructure

The following elements that will be required during the construction phase of the Project are considered specifically with respect to groundwater in the EES:

• earthworks for access tracks, WTG, platforms and foundations;

• an on-site quarry;

• water supply for concrete batching and construction activities; and

• the use and storage of hazardous substances.



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2.2.1 Roadways, WTG, laydown areas and permanent operations buildings

Crane pads or handstand areas will be located adjacent to the base of the WTGs. Each crane pad will consist of crushed rock hardstand of approximately 50 m by 30 m; however final design will depend on the topography at each location. Additional construction laydown areas may be required at select locations within the wind farm site and will be approximately 75 m by 75 m. The area of land occupied by the permanent site operations and maintenance facility will be approximately 100 m by 75 m.

Approximately 75 km of private access tracks will also be constructed within the wind farm site. Should storm water run-off be collected from the internal road network and hardstand areas, water will be conveyed by channel and/or pipe systems to designated disposal locations (e.g. soak pits or discharges into the existing drainage channels on site).

2.2.2 Quarry area

Extraction of rock for construction purposes is proposed to be from up to two quarry pits and the basalt material processed into crushed rock products. The extraction area is confined to 19.2 ha and 17.8 ha for the north and south quarry pits respectively.

The base of the north quarry pit is proposed to be at 222 mAHD and the base of the south quarry pit is proposed to be at 204 mAHD. Extraction to design depth is unlikely to intersect the water table and drainage from disturbed areas will be captured internally and directed to quarry drainage lines and a retention pond.

2.2.3 Concrete batching plants

Two temporary concrete batching plants are proposed at the wind farm site, located at the site entrance and at the site facilities area. Typically the area required for each plant will be approximately 100 m by 100 m. The batching plants will be bunded to contain runoff and potential contaminants.

2.2.4 Water requirements

An on-site water supply for the concrete batching plants, dust suppression and other construction activities is proposed. It is anticipated that water for the concrete batching plant will be supplied by groundwater sourced from within the wind farm site, subject to an appropriate resource being available and appropriate approvals being obtained. In the unlikely event that the abstracted groundwater volume is insufficient for the wind farm requirements, water will be obtained from local sources, subject to approval.

During construction, dust suppression will be applied to the internal access roads and the quarry work area as needed, using water carts and other applicable measures. It is anticipated that the on-site groundwater supply would also be used for dust suppression.

Trustpower has advised that the total potential water volume required for the construction phase of the Project (estimated 24-36 months duration) is approximately 180 ML. Of this amount, 80% (144 ML) is expected to be sourced on site from groundwater. This is dependent on receiving relevant approvals and licenses from Southern Rural Water (SRW) following their application.



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3 HYDROGEOLOGICAL ASSESSMENT

3.1 Hydrogeological Assessment

The hydrogeological assessment completed for the wind farm site included the following:

• review of publically available information relating to groundwater resources in the area;

• collation and review of information from groundwater investigation programs completed on site between 16 and 26 February 2015; and

• review of information provided regarding proposed site infrastructure (e.g. WTGs, quarry pits, concrete batching plant) and the proposed transmission line corridor (including the off-site sub-station).

The assessment evaluated baseline groundwater quality and water table depth, locations of existing groundwater bores, and actual and potential beneficial uses of groundwater. Based on existing data and results from the drilling and aquifer testing program, it identified and assessed potential environmental impacts that may affect groundwater and/or linked surface water features during the construction and operational phases of the Project.

The activities associated with construction and operation of the transmission line corridor and off-site substation are not considered to pose a significant risk of impact to groundwater and were not considered further in the assessment.

3.2 Baseline Groundwater Conditions

Baseline groundwater data were acquired through desktop research and were supplemented by information collected during the on-site groundwater investigation, and drilling and testing programs conducted in February 2015. A map showing locations of groundwater supply bores, groundwater monitoring bores, and spring discharges on the wind farm site is provided as Figure 3-1.

Figure 3-1 Map showing location of groundwater bores and spring discharges, Dundonnell Wind Farm site



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3.2.1 Registered groundwater bores, registered uses and aquifer yield

The five registered groundwater bores within the wind farm site boundary ranged in depth from 15 metres below ground surface (mbgs) to 104 mbgs. Two of these bores are registered as observation wells, three are registered for stock watering use and one is registered for domestic use.

A total of 291 registered bores were identified in the entire Project area, including the transmission line corridor. Of these, 35 registered bores completed within the basalt aquifer and located within 4 km of the wind farm site had had some form of pumping or aquifer testing completed on them.

A summary of the data available from those bores indicated that yields ranged from 0.2 to 6 litres per second (L/sec) with an average of approximately 1 L/sec (which is equivalent to 86.4 m3/day). The yield data reviewed were wide ranging and are consistent with the characteristics of the Newer Volcanics basalt aquifer which is characterised by variably fractured and weathered zones.

The yields identified in the basalt aquifer from existing on-site bores ranged from 0.63 L/sec to 1.67 L/sec in the shallower basalt and 6 L/sec in the deeper basalt (based on one deeper bore).

3.2.2 Groundwater potential beneficial uses and groundwater chemistry

Based on groundwater chemistry data from the data base and samples collected from the south quarry pit monitoring well (BH02) and the water supply test well (TW01), groundwater beneath the site would be classified predominantly as Segment A1 to Segment A2 in accordance with the State Environment Protection Policy Groundwaters of Victoria (Groundwater SEPP).

Groundwater in the area is used for stock watering and domestic use which are recognised beneficial uses of A1-A2 Segment groundwater.

The low Total Dissolved Solids (TDS) content and major ion composition of groundwater from the site are considered to be consistent with rainfall recharge that is likely to occur in the stony rise areas of the Newer Volcanics basalt aquifer.

3.2.3 Rainfall and groundwater levels

Rainfall data were used to assess trends between rainfall amounts and groundwater elevations on the wind farm site. Rainfall was lower during the drought period of the late 1990s through 2010; groundwater elevations were also lower during this period.

Groundwater elevation data from two bores located on site north-east of Mt Fyans Reserve indicated a downward vertical hydraulic gradient between the shallow (basalt) aquifer and the deeper aquifer underlying the basalt, which is consistent with their occurrence in a recharge area. The more pronounced fluctuations in groundwater levels recorded in the shallower bore were attributed to variations in rainfall, consistent with the bore’s shallower installation depth.



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3.3 On-Site Hydrogeological Works

3.3.1 Groundwater elevations

Three bores (BH01, BH02 and TW01) were drilled by D.K. & E.M. Murray Water Boring between 18 and 20 February 2015. Each bore was completed in the basalt aquifer.

Bore BH01 located near the north quarry pit was drilled to a depth of 30.5 mbgs and remained dry during the field program. This indicated that the groundwater elevation in the vicinity of this bore was below the final depth of the bore (i.e. less than 212.4 mAHD). This bore was backfilled and grout plugged at the end of the field program.

Bores BH02 and TW01 were constructed at and below the water table in the basalt aquifer and were airlift developed. TW01 was located to the west of the north quarry pit and was drilled to 69 mbgs. BH02, near the south quarry pit, was drilled to 25.5 mbgs.

Groundwater elevation data at BH02, TW01 and a number of existing bores within the wind farm site indicated that the slope of the water table was very flat. The exception to this was at Bore A (Figure 3-1) where the estimated groundwater elevation was approximately 2 m higher than elsewhere south of Mt Fyans. It is unclear if this was due to the condition of the bore or represented the elevation of the regional water table in this location.

Notwithstanding the potentially anomalous groundwater elevation at Bore A, the general groundwater flow direction is considered to be to the south, consistent with regional data and topography. This is based on recorded groundwater elevations from the shallow bore to the north-east of Mt Fyans, inferred recharge in the vicinity of the Mount Fyans topographic high, measured water table elevations and the elevation of spring issues to the south. The water table may vary seasonally, potentially responding to periods of higher recharge and controlled to some extent by the springs to the south.

3.3.2 Preliminary assessment of aquifer yield and extent of drawdown

In order to provide a preliminary assessment of the capacity of the aquifer to produce sufficient water for use during the construction period of the Project, and to assess the potential extent of drawdown in response to pumping, two types of aquifer tests were completed at the test well (TW01). These tests were completed between 24 and 26 February 2015 and comprised:

• a step test, results of which were used to indicate a suitable pumping rate for the subsequent constant rate pumping test; and

• a 24-hour constant rate pumping test to assess the transmissivity of the aquifer.

The transmissivity results from the constant rate pumping test were combined with estimated aquifer parameters to provide initial indications of the drawdown in water level that may be associated with pumping groundwater for water supply.

Step Test Results The results of the step test were used to estimate a pumping rate that could be used for the constant rate pumping test. Based on the results of the step test a pumping rate of 1.8 L/sec was selected for the second test.

The yield of 1.8 L/sec was similar to the higher value reported for existing wells in the shallower basalt (0.63 L/sec to 1.67 L/sec). Based on this preliminary assessment and the water supply requirement of approximately 5 L/s during the construction period, groundwater abstraction from several bores on site should be able to provide the estimated water supply requirements during construction.



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24-hour Constant Rate Pumping Test

The drawdown that occurred in the well (TW01) in response to pumping over 24 hours was analysed, and indicated bulk aquifer transmissivity values of between 420 m2/day and 480 m2/day. Based on a pumping rate of 1.8 L/s for the construction period, the aquifer transmissivity values from the test, and a range of assumed storage parameters, estimated drawdown impacts of greater than 0.5 m were not predicted to extend beyond 500 m from test well TW01. Therefore for that pumping rate and duration, and at a distance of more than 500 m from the nominated location of the pumping well, it is unlikely that pumping-related impacts would produce an increase in the depth to groundwater (i.e. a decreased in the water table) of more than 0.5 m.

3.4 Conceptual Hydrogeological Model

A conceptual hydrogeological model (CHM) combines groundwater and aquifer information to provide a working framework of groundwater flow and quality characteristics. It is a valuable tool for assessing and understanding groundwater conditions at a site.

In this case, a CHM was developed for the site and was used to inform the drilling locations of BH01, BH02 and the test well TW01. Together with the results from the drilling and preliminary aquifer testing program the CHM was used as the basis from which to assess potential impacts to groundwater on site from the Project.

The regional1 groundwater flow direction beneath much of the site is considered to be from north to south, generally following topography from Mt Fyans towards the springs and wetlands to the south and south-east. Locally2, groundwater flow towards wetlands in the west and south-west of the site may also occur.

The stony rise geological terrain acts as a recharge zone, and the slope of the water table measured in February 2015 may increase with increased recharge such as is likely to occur over the winter months. Groundwater discharge from the basalt aquifer occurs in the form of springs and wetlands, mainly located towards and beyond the southern and eastern boundaries of the proposed wind farm site. The Surface Water Assessment (Water Technology, 2014) identified small wetlands to the south and north-east of the wind farm site and larger wetlands in the west of the site.

The springs issue at basalt flow boundaries and their elevations are approximately 5-10 m below the elevation of the water table measured in groundwater bores on the wind farm site (February 2015). The springs are in hydraulic continuity with regional groundwater beneath the site, and are likely supplied by groundwater derived from the stony rise recharge area located on site as well as potentially by a component of groundwater flow from deeper in the basalt.

Although the wetlands discussed in Water Technology (2014) were not described as groundwater discharge areas, based on their elevations it is likely that, similar to the springs, they also receive groundwater discharge. As such, in the EES both wetlands and springs on site and near the site boundaries have been considered to host groundwater dependent ecosystems.

Groundwater that does not discharge at the springs and wetlands on and surrounding the site would continue to flow down hydraulic gradient to discharge areas (e.g. wetlands and creeks/rivers) lower in the catchment.

1 “regional” indicates a scale of several kilometres to > 10 km 2 “local” indicates a scale of several 100s metres to 1-2 km



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A conceptualised cross section from the centre of the site to the south is shown in Figures 3-2a and 2b. Figure 3-2a presents the cross section without vertical exaggeration indicating in “real scale” the relationship between topography and the basalt aquifer from north to south across the site. Figure 3-2b presents the cross section with vertical exaggeration to more clearly indicate relationships between quarry depths, the water table, and elevations of spring discharges. The section without vertical exaggeration is reproduced in this figure.

Figure 3-2a Cross-section (A-A’) showing the terrain without vertical exaggeration

Figure 3-3b Conceptualised hydrogeological cross section (A-A’)

3.5 Potential Impacts on Groundwater and Spring Discharges

3.5.1 Potential receptors

The following receptors were identified and assessed as part of the impact assessment in the EES:

• groundwater supplies (including spring flows) exploited for irrigation, stock watering, potable, commercial or industrial uses (groundwater supply, GS);

• groundwater dependant ecosystems (GDEs); and

• where surface water flows are dependent on groundwater baseflow and endangered, endemic or migratory aquatic species exist, or there are other dependent commercial or cultural issues (groundwater-surface water interactions, GW-SW).

3.5.2 Construction and operations

Proposed operations associated with the wind farm site construction and operational phases, and the magnitude of the potential impact have been assessed.

The primary construction activities considered to potentially impact the identified receptors are:

• construction of the concrete batching plants;

• earthworks and WTG foundation design;



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• use of roads and access tracks;

• leaks, spills and losses of construction fluids, chemicals and / or fuels;

• quarrying and groundwater management; and.

• a groundwater supply of approximately 150 ML during the construction phase of the project.

The primary operational activities considered to potentially impact the identified receptors are:

• leaks, spills and losses of fluids, chemicals and fuels stored on site;

• ongoing surface water management and runoff control; and

• potential for the quarry base to wet should it intersect the regional water table.

3.5.3 Assessment of potential impacts

Impacts associated with these site activities during wind farm construction and/or operation primarily related to:

• potential changes to groundwater flow conditions, including discharges to springs, by altering recharge rates and locations and abstracting groundwater during construction;

• potential interruption / decline in availability of groundwater as a water supply from existing pumping wells due to declining water levels, primarily during construction; and

• potential contamination of groundwater from site activities (e.g. chemical and/or fuel spills.

Specific activities that could lead to potential impacts to the groundwater receptors are provided in the EES (Trustpower Ltd., 2015). The magnitudes of these impacts were assessed, overall, as being either minor or negligible. In the event of a spill, the magnitude of impact was considered to be moderate to major; however, this would become a minor impact based on the use of bunds. Mitigation measures recommended to manage groundwater-related activities are presented in the EES and are summarised in Section 3.5.4 below

Further assessment and regulatory approval (Southern Rural Water) would be required prior to abstraction of groundwater from the site for use during construction. Should groundwater be intercepted during quarrying activities, approvals would also be required.

3.5.4 Groundwater impact assessment conclusions

Based on the proposed WTG layout, foundation design and overall extent, the WTGs are considered unlikely to impact significantly on groundwater at the site and so from an operational perspective the residual impacts are expected to be minor or negligible.

Construction activities and infrastructure including potential leaks and spillages of chemicals and/or fuels are identified as having the potential to impact on groundwater supply as well as groundwater-surface water interactions or groundwater dependent ecosystems. With the adoption of general best practice in the storage and use of chemicals and fuels, including implementation of an approved clean-up plan in the case of a spill, the residual impact from these activities is expected to be minor.

The design depth of the north and south quarry pits is above the water table measured in BH02. Consequently, interception of the water table by quarrying is considered unlikely and the impact associated with this activity is expected to be negligible.



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Groundwater pumping to provide on-site water supply during construction has the potential to impact on other groundwater users, groundwater discharge to the springs, and groundwater dependent ecosystems. Mitigation measures would be put in place to limit potential impacts. These include but are not limited to:

• locating groundwater abstraction wells away from existing groundwater supply bores, springs and site boundaries where possible; and

• management of groundwater pumping rates and pumping cycles to reduce the radius of influence associated with groundwater abstraction.

Details regarding the rate and volume of groundwater abstraction required to support the concrete batching plant on site will be confirmed during the detailed design phase of the Project. Prior to groundwater abstraction for construction, necessary licenses and approvals would be obtained by Trustpower and a detailed assessment of potential impacts for review by Southern Rural Water would take place as part of that process. However, based on the assessment undertaken to date, the residual impacts as a result of groundwater abstraction are expected to be minor, subject to the implementation of appropriate mitigation measures.



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4 WATER-RELATED ISSUES FROM SUBMISSIONS

Submissions received following exhibition of the EES and by Moyne Shire Council that related to groundwater and hydrogeology are listed in Section 1.2. Several key themes were raised as part of these submissions as indicated in the following table. These themes are discussed below.

Submission No.

Impact on Aquifer /Water Table by Blasting or Crushing (Quarry / Foundations)

Quarry Impact by Creation of Surface Water Feature

Contamination Impact to Groundwater (Quarry and Operational Phase)

Surface Water Impact (Wetlands/ Aquatic Species and Brolga)

Spring Flow Impact / Fragile Water Systems

Water Source from Spring Flow

Impact to Bores in Surround-ing Areas

Use and Storage of Hazardous Chemicals

1

6

7

22

32

61

66

101

102

112

115

127

128

135

4.1 Hydrogeological Assessment

Point 2 - submission to Moyne Shire Council; Item 5 - submission to Moyne Shire Council; Submissions #1, #32, and #66 to PPV.

Groundwater is limited to the subsurface except where it intersects topography or other pathways to the surface, where it can discharge as surface water. Consequently, multiple lines of evidence are used to develop and challenge our understanding of groundwater conditions. These include information on water levels, water quality and yields from groundwater wells, geological information from bores and mapping, and surface conditions including topography, springs and wetlands, and runoff. This information is consolidated into a conceptual hydrogeological model which is progressively tested and updated as more investigation and analysis is conducted.

We have applied this approach to the conceptual hydrogeological model for the wind farm site, starting with desktop information and augmenting and updating the conceptual hydrogeological model following drilling, aquifer testing, and site inspections.



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4.2 Potential effects of turbine foundations and tracks

Point 2 - submission to Moyne Shire Council; Item 5 - submission to Moyne Shire Council; Submissions #1, #32, and #66 to PPV.

Concerns regarding the impact of heavy machinery, development of roads and tracks, and blasting associated with quarrying and turbine foundations on stony rises, springs and, if present, caves and lava tubes, associated with the Newer Volcanics basalt at the site have been raised by several community members. Most of the wind farm site is characterised by stony rise terrain; of the land surface, <10% is proposed to be taken up by WTGs, access tracks, lay down and operations areas, and the concrete batching plants. Mitigation measures to reduce potential impacts to groundwater recharge and/or discharge are presented in the hydrogeological chapter of the EES and include location of access tracks where possible away from stony rises and that WTGs be located away from springs. Measures in the surface water chapter of the EES provide an exclusion zone of 20 m from designated waterways.

With the mitigation measures in place and given the relatively small percentage of land affected, the effect of reducing recharge associated with constructed, quarried and hard stand features on groundwater or flow to the springs is considered to be minor.

4.3 Potential effects of quarrying

Point 2 - submission to Moyne Shire Council; Item 5 - submission to Moyne Shire Council; Submissions #1, #32, #66, #101, #102, #112, #115, #127, and #135 to PPV.

Features in the unsaturated zone will, by definition, be removed by quarrying; however, the quarries represent less than ~5% of the land area at the wind farm site. Following construction, recharge in the area would be unlikely to decline as, within the quarries, the thickness of the unsaturated zone, and consequently the depth to the water table would be reduced.

The groundwater investigation included drilling of bores adjacent to each of the proposed quarry pit locations. At the north quarry pit, groundwater was not intercepted even though the bore (BH01) was drilled to approximately 10 m below the proposed base of the pit. BH01 was left open for several days; however, water did not enter the bore, consistent with the water table in other bores in the area being located below the final depth of this bore. Consequently, the design base of the north quarry pit is considered to be well above the water table and will not intercept groundwater.

The proposed base of the final stage of the south quarry pit is the lowest of the proposed quarrying. Groundwater monitoring bore BH02 was drilled adjacent to the proposed south quarry pit location to assess water table conditions in that area. The groundwater level in this bore was 2 m below the design depth of the base of the south quarry pit. Consequently, the base of the south quarry pit would also be above the water table.

Under these conditions, neither quarry pit would become permanent water features.

The proposed surface water storage, if required, would be operational during the construction phase of the project while groundwater abstraction is occurring.



15

4.4 Protection of spring discharge Point 2 - Submission 1 to Moyne Shire Council; Item 5 - Submission 2 to Moyne Shire Council; Item 5, Submissions #1, #6, #7, #22, #32, #61, #66, #101, #112, #115, #128, #135 to PPV.

The spring discharges on and surrounding the wind farm site are a recognised water resource and contributor to groundwater dependent ecosystems. As such the assessment of potential impacts of groundwater supply for the wind farm has explicitly considered the springs. As discussed in Section 4.2, WTGs and access tracks are to be located away from the springs to reduce potential impacts to recharge in the vicinity of the springs.

The continued flow of springs over summers and during drought indicates that they are fed by groundwater from the basalt aquifer; this is consistent with their elevations which are typically below the water table on site (as indicated by groundwater bores at the wind farm site). The occurrence of springs in the vicinity of stony rises in the south and south-east of the site indicates that recharge through those features is likely to be an important contributor to spring discharge. The wetlands surrounding the wind farm site are also likely to be fed by groundwater.

Because of the role of groundwater in contributing to springs and wetlands surrounding the site, the potential impacts of groundwater abstraction as a water supply for wind farm construction on these features were considered. Results of the initial on-site groundwater drilling and testing program indicate that there is the potential for groundwater to provide the proposed on site water supply while maintaining groundwater discharge to the springs. Based on the preliminary field program, the zone of influence of pumping for this supply can be managed so that it does not approach spring areas. A key part of this management is the location of proposed groundwater pumping wells away from the site boundaries and away from on-site springs.

Prior to development of an on-site water supply, further assessment would be required to support:

• approvals and license applications to take and use groundwater; and

• the design and location of the on-site groundwater supply system if a licence were granted.

4.5 Potential impacts to existing groundwater supply bores

Submission #32 to PPV.

Groundwater abstraction to provide on-site water supply during construction has the potential to impact on users of existing groundwater supply bores by lowering the water table in the near vicinity of the abstraction bores. Where possible, groundwater abstraction bores for the Project should be located away from existing groundwater supply bores so that effects of groundwater abstraction on groundwater levels in existing bores would be limited. In the case where existing supply bores are located in the near vicinity of the Project abstraction bores and water levels decline below the current levels at which pumps are set, mitigation measures such as an alternate water supply (e.g. Project abstracted groundwater) would be implemented to offset these effects. Based on the preliminary field program, the zone of influence of groundwater abstraction for this supply during construction can be managed so that it does not affect existing groundwater supply bores located off site.

4.6 Storage and use of hazardous chemicals

Submission #135 to Minister for Planning. Construction activities and infrastructure have the potential, through leaks and spillages of chemicals and/or fuels, to impact on groundwater quality. This has been considered in the EES and is to be managed through the adoption of general best practice in the storage and use of chemicals and fuels, and through implementation of an approved clean-up plan in the case of a spill.



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5 CONCLUSIONS

Desktop assessments and field-based hydrogeological investigations at the wind farm site have allowed a conceptual hydrogeological model to be developed. This conceptual model indicates that the water table occurs in the basalt aquifer, which forms the shallowest aquifer at the site. The basalt aquifer is underlain by Cambrian to Silurian sediments. Recharge to the groundwater flow system occurs across the stony-rise dominated landscape, consistent with the terrain type and groundwater quality at the site. Locally, discharge of groundwater from the water table aquifer occurs at springs in the lower part of the stony rise terrain, with additional discharge of groundwater to wetlands around the site. Groundwater that is discharged to these features would continue to flow down catchment.

The major receptors of groundwater from the wind farm site are:

• groundwater users, pumping groundwater from existing wells to provide stock and domestic supply;

• groundwater discharge to surface water such as occurs at spring discharges and which provides water supply to properties on and surrounding the site; and

• groundwater dependent ecosystems such as those present at spring discharges and wetlands.

Activities that have the potential to impact on these receptors were considered in the assessment and include:

• construction of roads, WTG foundations and site operations facilities;

• excavation of the north and south quarry pits; and

• abstraction of groundwater from the site for its use as a water supply during construction of the wind farm.

The construction of roads, WTG foundations and site operations facilities is considered unlikely to reduce recharge substantially. Locating these features, where possible, away from stony rises and on-site water bodies would further reduce the effect on recharge and their construction is considered unlikely to cause more than minor impact to groundwater or spring discharges.

The hydrogeological assessment indicates that the design depths of the quarry pits would be unlikely to intersect the water table. If groundwater were intersected during excavation of the quarry pits, approval would be required from Southern Rural Water prior to ongoing interception of groundwater as a result of quarrying.

Preliminary assessments of aquifer parameters, yield and drawdown indicate that the nominated water supply required during the construction period is likely to be able to be provided by groundwater from the basalt aquifer on site. Prior to groundwater being pumped for water supply on site, further assessments would be undertaken to support an application to take and use groundwater. These assessments would further evaluate both the capacity of the aquifer to provide the required yield and the potential effects of pumping on groundwater levels, local groundwater users, and discharges to springs. The application to take and use groundwater would require approval by Southern Rural Water before groundwater abstraction to support site construction activities could occur.

Based on the hydrogeological assessment to date, and contingent on the groundwater-related mitigation measures and further assessments discussed in the EES, I am of the opinion that potential impacts of the wind farm on groundwater and spring discharges would be negligible to minor.



17

6 REFERENCES

Department of Environment, Land, Water & Planning (DELWP), State Government of Victoria, 2015. Terms of Reference, Dundonnell Wind Farm - Inquiry, July 2015. http://www.dtpli.vic.gov.au/__data/assets/pdf_file/0019/282241/Dundonnell-Wind-Farm-EES-Inquiry-signed-Terms-of-Reference.pdf, accessed 14 August 2015.

Environmental GeoSurveys Pty. Ltd., 2014. Proposed Dundonnell Wind Farm Geoscience Features, Significance & Sensitivity Assessment, prepared for Trustpower Australia Holdings Pty. Ltd, Revision 10, August 2014.

ERM, 2015. Dundonnell Wind Farm Hydrogeological Study, prepared for Trustpower, Version 3, April 2015.

EPA Victoria (1997). State Environmental Protection Policy, Groundwaters of Victoria (1997).

Planning Panels Victoria (PPV), 2015. Department of Transport, Planning and Local Infrastructure, State Government of Victoria, 2015. Guide to Expert Evidence. http://www.dtpli.vic.gov.au/planning/panels-and-committees/planning-panel-guides-and-faqs, accessed 14 August 2015.

C.K. Prowse & Associates Pty. Ltd. (Prowse), 2015. Work Plan for Work Authority 1540, Dundonnell Victoria, prepared for Dundonnell Wind Farm Pty. Ltd., Draft, March 2015.

Trustpower Australia, 2015. Dundonnell Wind Farm Environmental Effects Statement, June 2015.

Water Technology, 2014. Dundonnell Wind Farm Surface Water Assessment, prepared for Trustpower, August 2014.

http://www.dtpli.vic.gov.au/__data/assets/pdf_file/0019/282241/Dundonnell-Wind-Farm-EES-Inquiry-signed-Terms-of-Reference.pdf

http://www.dtpli.vic.gov.au/__data/assets/pdf_file/0019/282241/Dundonnell-Wind-Farm-EES-Inquiry-signed-Terms-of-Reference.pdf

http://www.dtpli.vic.gov.au/planning/panels-and-committees/planning-panel-guides-and-faqs

http://www.dtpli.vic.gov.au/planning/panels-and-committees/planning-panel-guides-and-faqs


TAMIE WEAVER’S CV Annex A -

Tamie Weaver Technical Fellow and Partner

The world’s leading sustainability consultancy

Dr Tamie Weaver is a Technical Fellow and Partner within ERM based in Melbourne, Victoria. She has 30 years’ experience as a hydrogeologist with over 20 years experience in Victoria. Her work has focussed on understanding groundwater flow and chemistry and the movement of solutes and contaminants in complex systems and over long timeframes: critical issues for groundwater and environmental management.

Tamie has provided hydrogeological advice and technical leadership in site investigations and impact assessments involving the fate and transport of; hydrocarbons, metals, radionuclides and salinity in groundwater at proposed, current, and closed upstream and downstream oil and gas facilities, mine sites, landfills and industrial sites. Throughout her career she has worked on projects that involve communication of technical outcomes with community stakeholders. She has developed and presented workshops to members of the community and regulators that distill key outcomes of technical reviews and translate them to plain English and accessible concepts.

As a lecturer and senior lecturer at The University of Melbourne, she taught undergraduate, postgraduate and professional short courses in hydrogeology, hydrogeochemistry, and contaminant behaviour for over a decade, and was coordinator of a Masters hydrogeology program for over 5 years. Tamie has also supervised over 60 honours and postgraduate students in hydrogeology, hydrogeochemistry and contaminant transport.

Courses Tamie has developed and taught include Solute Transport in Groundwater, Hydrogeology and Environmental Management, Managing Groundwater Environments, and Hydrogeology at the University of Melbourne. She has also taught groundwater chemistry and contaminated site assessment, contaminant hydrogeology and fractured rock systems in multiple short courses.

Tamie is an Associate Editor of the international journal Ground Water. She has been a long-standing member and is now Chair of the Nuclear Safety Committee for the Australian Radiation Protection and Nuclear Safety Agency and provides technical advice to state and federal governments on groundwater and waste management issues. Her work for government agencies includes:

Professional Affiliations and Registrations

Member of the Technical Advisory Group for the SA Government providing advice on the rehabilitation of the former Brukunga mine site, 2011 on.

Member (2003-current) and Chair (current) of the Nuclear Safety Committee for the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), providing advice on nuclear related safety issues to the CEO of ARPANSA.

Chair of the Hydrogeology Working Group (2004), Nuclear Safety Committee (ARPANSA), providing a review of the hydrogeological aspects of the application for the Proposed National Radioactive Waste Repository.

Development of Hydrogeological Assessment (Groundwater Quality) Guidelines (Contaminated Sites, EPA668) for EPA Victoria.

Contribution to the Groundwater Sampling Guidelines (EPA669), EPA Victoria.

Technical review of Groundwater Management Plans as a member of the Technical Audit Panel, Dept Sustainability and Environment, Victoria, 2005-2006.

Evaluating metal transport into the King River and King River Delta from mine tailings as part of the Office of the Supervising Scientist and Dept Environment & Heritage Tasmania, 1995.

Education

PhD Hydrogeology, University of Waterloo, Canada

MS Hydrogeology, University of Wisconsin – Madison, USA

BA (Hons) Geology, cum laude, Cornell University, USA

23.09.15 TAMIE WEAVER

Professional History

2015, Technical Fellow and Partner, ERM, Melbourne

2011-2015, Technical Director - Hydrogeology, ERM, Melbourne

2007-2012, Senior Fellow, School of Earth Sciences, University of Melbourne

2008-2011 Senior Principal Hydrogeologist, URS Australia, Melbourne

2006-2007 Principal Hydrogeologist, URS Australia, Melbourne

1994-2007 Senior Lecturer and Lecturer in Hydrogeology, University of Melbourne

2000-2007 Hydrogeology Stream Coordinator, Graduate Environmental Program, University of Melbourne

1994-2000 Co-coordinator, MSc and MEnvSc Hydrogeology Program, University of Melbourne

1991-1994 (part time) Hydrogeologist, Golder Associates, Melbourne and Lecturer, Monash University

1989-1994 PhD Candidate and Demonstrator (field techniques and groundwater chemistry), University of Waterloo

1986-1988 MSc Candidate, University of Wisconsin

1984-1986 Hydrogeologist, New Jersey Dept Environmental Protection.

Key Projects

Member of Technical Advisory Group for

Rehabilitation of the Former Brukunga Pyrite Mine,

South Australia (2011-2015): As a member of both the

geochemical and geotechnical subgroups of the Technical

Advisory Group (TAG), Tamie provides hydrogeological

advice to the SA Government regarding hydrogeological

conditions, modeling requirements and field programs

for a proposed rehabilitated landform. She acts as a

liaison between the engineers and geochemists on the

TAG, linking engineering design with hydrogeological

performance and water quality objectives.

Third Party Review - Impacts to Groundwater and

Surface Water for a Proposed Mine Site (2012):

Conducted a third party review of groundwater-related

aspects of an impact assessment statement for a proposed

mine in North America. Areas of particular focus

included potential changes in the amount, quality and

timing of groundwater discharge to surface water and

groundwater dependent ecosystems as a result of mining

activities. Confidential client.

Assessment of Mercury Mobility in Groundwater,

Sydney (2008-2010): Evaluated groundwater flow and

geochemistry data to assess the potential migration and

mobility of mercury in groundwater. Conducted

geochemical modelling to evaluate current and potential

forms of mercury in groundwater and the potential for

those forms to migrate. This work provided the basis for a

species-specific approach to risk assessment at the site.

Independent Review of Hydrogeology of the Tailings Dam at Ranger Uranium Mine, Kakadu, Northern

Territory (2009-2011): Provided a sole-sourced, independent technical review of over 20 years of groundwater monitoring data surrounding the tailings dam. The review assessed major ion, metal and radionuclide fate and transport in groundwater and potential interactions with the surface water environment. Throughout the project participated in a working group comprising representatives from the mine and its consultants, local traditional owners and the community to consider multiple stakeholders’ perspectives during the review. Provided recommendations regarding further assessment and monitoring of groundwater and surface water to inform site performance.

Assistant to Auditor - Assessment and Remediation of

Hydrocarbons in Coastal Environments, Former

Adelaide Refinery, South Australia (2009 - current):

Providing technical hydrogeological assistance to the

Auditor (Contaminated Land) in the assessment of the

occurrence, fate and transport of separate phase and

dissolved phase hydrocarbons and dissolved metals at the

former Adelaide Refinery, Port Stanvac, South Australia.

Design and Review of Groundwater – Surface Water

Interaction Assessment, Intertidal Zone, Corio Bay,

Shell (2007-2008): Developed project design and scope

and provided technical review of installation and data

assessment for study evaluating groundwater and

contaminant discharge to an intertidal and subtidal area.

The design included use of mini-piezometers, seepage

meters and both inorganic and organic groundwater

chemistry.

Fate and transport assessment and modelling of

leaching processes in ash ponds from coal mining and

electricity generation (2004). Supervision of PhD into

leaching rates of sulfate and metals from ash ponds to the

shallow groundwater environment. Related published

paper has multiple citations.

23.09.15 TAMIE WEAVER

Discharge of metals and acid from groundwater to the

King River, Office of the Supervising Scientist and

Dept Env Tasmania (1995-1996): Designed and

implemented a groundwater and pore water monitoring

program to assess the fate and transport of metals and

acid from mine tailings along the river bank and delta into

the King River and Macquarie Harbour, Tasmania.

Conducted solute transport modelling to assess discharge

of metals from groundwater to surface water.

Publications

References available upon request.


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