Adani
Appendix E2 – Groundwater Technical Report
Abbot Point Coal Terminal 0 EIS • Adani
Terminal 0 Environmental Impact Statement
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iii
Table of Contents
1.1 Introduction ......................................................................................................................................................... 1 1.2 Relevant Legislation ......................................................................................................................................... 1
1.2.1 Queensland Regulatory Process ........................................................................................................... 1 1.2.2 Assessing the Availability and Condition of Groundwater ....................................................... 1
1.3 Assessment Methods ........................................................................................................................................ 2 1.4 Site Description .................................................................................................................................................. 2
1.4.2 Topography .................................................................................................................................................... 3 1.4.3 Surface Water ................................................................................................................................................ 3 1.4.4 Geology............................................................................................................................................................. 3
1.5 Field Methodology ............................................................................................................................................. 5 1.5.1 Sample Collection ........................................................................................................................................ 6 1.5.2 Sample Handling and Preservation ..................................................................................................... 7 1.5.3 Equipment Calibration .............................................................................................................................. 7 1.5.4 Pump and Slug Tests .................................................................................................................................. 7
1.6 Groundwater Quality Assessment .............................................................................................................. 8 1.6.1 Groundwater Investigation Levels ...................................................................................................... 8 1.6.2 Field Parameter Results ........................................................................................................................... 9 1.6.3 Groundwater Analytical Results ........................................................................................................... 9 1.6.4 Graphical Representation of Analytical Results .......................................................................... 11
1.7 Groundwater Modelling ................................................................................................................................ 15 1.7.1 Objectives ...................................................................................................................................................... 15 1.7.2 Scope of Work ............................................................................................................................................. 15 1.7.3 Hydrogeological Conceptualisation .................................................................................................. 15 1.7.4 Numerical Model Development .......................................................................................................... 21 1.7.5 Boundary Conditions ............................................................................................................................... 23 1.7.6 Model Parameters ..................................................................................................................................... 24 1.7.7 Hydraulic Conductivity ........................................................................................................................... 24 1.7.1 Climate ........................................................................................................................................................... 25 1.7.2 Evapotranspiration................................................................................................................................... 26 1.7.3 Recharge ........................................................................................................................................................ 26 1.7.4 Model Setup ................................................................................................................................................. 27 1.7.5 Model Calibration ...................................................................................................................................... 28 1.7.6 Modelling Scenarios ................................................................................................................................. 30 1.7.7 Groundwater Level Scenarios .............................................................................................................. 31
1.8 Conclusions ........................................................................................................................................................ 32 1.9 Recommendations ........................................................................................................................................... 32
1.9.1 Mitigation Measures ................................................................................................................................. 32 1.9.2 Monitoring Measures ............................................................................................................................... 33
1.10 References ........................................................................................................................................................... 33
List of Figures
Figure 1-1: Geology of Abbot Point and Surrounding Regions ........................................................................... 4 Figure 1-2: Groundwater Bore Sampling Plan .................................................................................................... 6 Figure 1-3: Piper Diagram for Major Groundwater Ions ................................................................................... 13 Figure 1-4: Durov Diagram for Groundwater Quality Results ........................................................................... 14 Figure 1-5: Cross Section A ............................................................................................................................... 18
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Figure 1-6: Cross Section B ................................................................................................................................ 19 Figure 1-7: Cross Section C ................................................................................................................................ 20 Figure 1-8: Groundwater Level Contours (m AHD) ........................................................................................... 21 Figure 1-9: Original Abbot Point Model Domain .............................................................................................. 22 Figure 1-10: The Project Groundwater Model Domain .................................................................................... 23 Figure 1-11: Monthly average precipitation, temperature, and evaporation for the Abbot Point site
(148.05°E, 19.9°S, 187 m) based on synthetic weather record (1889-2012) .................................................... 26 Figure 1-12: Features included in the Model .................................................................................................... 27 Figure 1-13: Rainfall Data for the Project Area ................................................................................................. 28 Figure 1-14: Steady State Calculated vs. Observed Water Levels ..................................................................... 29 Figure 1-15: Steady State Groundwater Levels ................................................................................................. 30 Figure 1-16: Predicted Groundwater Levels ..................................................................................................... 31
List of Tables
Table 1-1: Sample handling and preservation .................................................................................................... 7 Table 1-2: Input Data in Groundwater Model .................................................................................................. 24 Table 1-3: Hydraulic Conductivities .................................................................................................................. 25
Appendices
Appendix A - QA/QC Assessment Appendix B - Laboratory Reports Appendix C - Aquifer Test Analyses
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Executive Summary
CDM Smith Australia Pty Ltd was engaged to undertake groundwater investigations as part of the
Environmental Impact Statement for the Project area at Abbot Point, Queensland.
The purpose of the groundwater investigations was to determine the likely effects of the proposed
developments on the groundwater environment.
The scope of works of this investigation included:
Undertaking a desktop hydrogeological conceptualisation;
Conducting detailed field investigations including sampling and pump/slug tests;
Modelling potential impacts to groundwater by the infrastructure plan; and
Providing mitigation and monitoring measures.
Two groundwater investigation programs were undertaken to assess the existing groundwater
conditions within the Project area. The first groundwater investigation program was conducted
between the 23rd and 28th April 2012, and the second one was undertaken between the 3rd and
8th June 2012.
A total of 7 bores (BH307, BH315, BH316, BH327, 125268, 125269 and 125272) were sampled.
Pump and slug tests were completed on 2 bores (BH316 and BH327), and automatic water level
loggers were installed in 3 bores (BH316, BH327, 125272) for ongoing water level monitoring
purposes.
Concentrations of total petroleum hydrocarbons, benzene, toluene, ethylbenzene, xylenes and
volatile organic compounds were below the laboratory detection limits and the ANZECC (2000)
groundwater criteria in all bores sampled.
Concentrations of arsenic, cadmium, chromium, lead, copper, mercury, nickel and zinc were below
the ANZECC (2000) groundwater criteria in the majority of bores sampled, with the exception of
the following:
Concentrations of arsenic were above the ANZECC (2000) freshwater criteria at two locations
(125269 and BH315 in both the April and June 2012 sampling rounds).
Concentrations of zinc were above the ANZECC (2000) freshwater criteria in three locations
(125268 in June 2012, 125269 and BH327 in April and June 2012).
Concentrations of zinc were above the ANZECC (2000) marine water criteria in two locations
(125272 in June 2012, and BH316 in April 2012)
Concentrations of ammonia and nitrate (as N) were below the adopted ANZECC (2000)
groundwater criteria in all bores sampled.
Salinity concentrations ranged from 120 mg/L (BH327 in April 2012) to 6,600 mg/L (BH307 in
April 2012) and TDS concentrations ranged from 170 mg/L (BH327 in June 2012) to 61000 mg/L
(BH307 in April 2012).
The hydrogeological conceptualisation indicates the presence of three bands of sandy clay which
are located within a predominantly sandy aquifer system. The first sandy clay layer is quite
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shallow, from approximately -2 m AHD to approximately -5 m AHD beneath the Wetland, and the
bottom sandy clay layer site generally overlying the weathered bedrock. In some cases, the layers
do not continue throughout the cross section transects and this is likely a result of sediment
deposition from the ocean. The whole systems sits on unfractured bedrock which has very low
(nearly impermeable) hydraulic conductivity (Freeze and Cherry, 1979) so, for modelling
purposes, this unit is considered a no-flow boundary. As indicated by Freeze and Cherry 1979,
the hydraulic conductivity in the sandy clay units is generally 3 - 6 orders of magnitude lower than
the sandy units (1 - 4 m/day as per pump and slug tests, Table 1-3). Therefore, the sandy clay units
are expected to act as leaky or confining units. Hydraulic conductivity values for these materials
can be summarised as follows;
a. Sand = 2 m/day;
b. Silty clay/sandy clay = 0.5 m/day;
c. Weathered bedrock = 5 m/day; and
d. Bedrock = no hydraulic conductivity, no flow boundary.
A numerical groundwater model for the Project area was developed in the Visual Modflow
software using the MODFLOW 2000 modelling code (Harbaugh et al, 2000). The model was
adapted from a model built previously for a related study, with appropriate authorisation. The
earlier Abbot Point model was constructed using 8 layers (i.e. representing 3 sandy layers, 3 sandy
clay layers, 1 weathered bedrock layer and 1 bedrock layer) and approximately 230,400 grid cells
in 480 rows and 480 columns, covering an aerial extent of 12,000 m (east-west) by 12,000 m
(north-south). The extents of the original model were constrained by aerial photography and
contour data and relevant hydrogeologic features in the vicinity of the Abbot Point area
The calibration process involved trial and error matching of potentiometric heads determined by
the model at observation bores within the site with observed water levels. Recharge in the model
was adjusted to better simulate the observed heads, and the resulting steady state model
predicted water levels at the bores within 0.098 m AHD of the observed levels.
Based on the baseline groundwater assessment and preliminary steady state model simulations,
the following conclusions are provided:
Time series data from across the perimeter of the T1 facility and the Project area indicate tidal
influences in groundwater elevations of up to approximately 1 m. Based on this it can be
assumed that there is likely a mixing zone extending from the sea to the Project area and
groundwater flow will be tidally impacted.
The highly variable measured electrical conductivities across the perimeter of the T1 facility
and the Project area indicate that a series of complex interactions are occurring. Surface
waters are too fresh and are unlikely to be significantly impacted by saline groundwater. In
addition, the low salinities observed in selected bores close to the coast, indicate that there is
likely some localised freshwater recharge taking place. The saline water recorded in other
bores indicates that a certain degree of confinement limiting the amount of fresh recharge to
these units.
Groundwater levels are below the base of the Project stockyard platform levels. Therefore, the
construction of these structures is unlikely to impact upon the normal groundwater flow and
levels during the driest seasons of the year. Although seasonal groundwater level fluctuations
can be expected to rise up to 2 m bgs (i.e. 4 m AHD) no impacts on surface water can be
expected across the Project area during the wettest seasons. Due to the exceptional wet period
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experienced across the region in the last two years, groundwater level fluctuations are
currently at maximum historic levels and are unlikely to continue to increase, so will remain at
least 2 m below the base of the Project stockyard platform levels.
It is anticipated that that the general filling, and area drainage to sediment ponds, will reduce
rainfall (fresh) water recharge to groundwater This might increase the inland intrusion of
saline groundwater lenses.
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1.1 Introduction
The following chapter describes the existing groundwater regime within the Project area,
including aquifers and beneficial uses (environmental values). Predicted changes to the existing
groundwater regime and potential impacts to environmental values are discussed in detail.
Mitigation measures presented in this chapter have been developed in accordance with relevant
Department of Environmental Heritage and Protection (DEHP) guidelines.
1.2 Relevant Legislation
1.2.1 Queensland Regulatory Process
The majority of Queensland’s groundwater resources are administered by DEHP under the Water
Act 2000. A Water Resource Plan (WRP) is developed for each catchment which assesses the size
and nature of the resource to enable sustainable water allocation and management. WRPs include
both surface and groundwater systems. The Water Act 2000 also establishes a process by which
existing entitlements to water are converted to “water allocations” and are tradable. WRPs are
implemented through a corresponding Resource Operations Plan (ROP) which ensures that the
environmental and consumptive objectives detailed in the WRP are achieved through establishing
guidelines for water trading and water use.
Groundwater in Queensland is managed through the establishment of groundwater management
areas under a WRP or other regulation under the Water Act, with additional management
measures set out under the Wild Rivers declaration in some instances. Queensland has declared
Groundwater Management Units (GMUs) which have specific groundwater management plans
covering groundwater abstraction, allocation and use. GMU’s outside of a WRP are administered
via water licensing.
GMUs fall into either the sub-artesian or artesian category and may overlap. Sub-artesian GMUs
have been defined in accordance with current management practices applied by the DEHP.
Artesian GMUs have been defined into hydrologic zones in accordance with the guidelines set by
the Great Artesian Basin Water Resources Plan.
Other legislation which relate to groundwater resources in Queensland include:
The Environmental Protection (Water) Policy 2009 (EPP [Water]), which applies to all water
in Queensland and provides a framework for defining the environmental value of water and
guidelines for water quality. The policy aims to protect water to designated environmental
values; and
Sustainable Planning Act 2009, which promotes development based on the concept of
ecological sustainability.
1.2.2 Assessing the Availability and Condition of Groundwater
At the planning stage, DEHP requires that a proponent carry out a groundwater investigation to
assess the impacts of the project on groundwater. This includes collecting and assessing
groundwater data (usually at a local scale and specific to their proposed activities). In this
assessment process, DEHP considers these data in the context of the entire water resource system
and all potential impacts.
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Any direct or indirect (e.g. dewatering) take of groundwater from an aquifer in an area where
water is managed will require an authority to take water and the conditions or approvals of the
authority are dependent upon either the relevant WRP or declared groundwater area policy rules.
Approvals are issued with conditions that require monitoring, reporting, assessment and
mitigation of the effects of the take where appropriate.
1.3 Assessment Methods
For a comprehensive groundwater assessment to be undertaken, background groundwater quality
and groundwater levels need to be determined. Groundwater levels and quality parameters were
measured in registered bores located in the Project area during two separate monitoring rounds in
April and June 2012, respectively. Groundwater quality parameters and water level results are
provided in Section 1.6. In order to comprehensively assess the existing groundwater environment
and predict the likely impacts to groundwater from the development of this project, the following
tasks were undertaken:
Review of geological, stratigraphy, rainfall, borehole, water quality and water level data
relevant to the Project area;
Field investigations at the Project site to conduct aquifer hydraulic tests and groundwater
sampling in order to determine site-specific hydraulic conductivity and groundwater
characterisation;
Development of a three-dimensional finite difference (numerical) groundwater model for the
Project site using the MODFLOW 2000 modelling code;
Calibration of the groundwater model against water level data collected during groundwater
investigations at the Project site; and
Model simulations incorporating the proposed development plan to assess the impact and
influence of construction and operational activities on groundwater at the Project.
1.4 Site Description
1.4.1 Vegetative Cover
The majority of the area around the Project area is surrounded by thin, low lying vegetation,
particularly around where most groundwater monitoring bores are located. However a small
portion of the Project area is covered by thick undergrowth, which obscured the visibility of
monitoring bores. In some areas, creeks and thick, tall vegetation made access difficult for some
sites. The sites located within T1 were generally open, easily accessible and usually surrounded by
low lying grasses, at either the side of a road or along access points.
The flat country plains, including the Wetland area south of T1 and the Project consisted mainly of
large clearings with mature trees and low lying grasses. Some areas contained thick shrubs, tall
grasses, mature trees and medium sized bushes and other areas appeared to have been disturbed,
resulting in large patches of uprooted vegetation and bare rough ground, likely due to wild pigs
foraging.
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1.4.2 Topography
A digital elevation model with 1 m grid resolution over the Queensland's Whitsunday Regional
Council (Local Government Area) was generated from ground point LiDAR data obtained from
DEHP via North Queensland Bulk Ports (NQBP). The Airborne Laser Scanning (ALS) 1 m interval
point data has vertical and horizontal accuracies of 0.1 m and 0.3 m respectively at a ##%
confidence level. The survey was carried out between 10 June 2009 and 17 June 2009. Data
processing was undertaken using a ground algorithm to automatically classify and separate
ground points from non-ground points.
The topography of the Abbot Point region consists of coastal sand dunes and mud flats lying at
elevations below 5 m Australian Height Datum (AHD) and abrupt granitic hills - Mount Luce and
Mount Roundback have peak elevations of approximately 300 m AHD and 700 m AHD,
respectively.
1.4.3 Surface Water
The dominant hydrological feature of the area is the Caley Valley Wetland system (Wetland),
which has been listed as a Nationally Important Wetland under the Department of Sustainability,
Environment, Water, Population and Communities (SEWPaC) Directory of Important Wetlands.
The Wetland covers an area of approximately 51.50 km2 including its lowland catchments and is
located immediately south west of the Project area.
The total catchment draining into the Wetland is approximately 830 km2 (including Saltwater
Creek) and includes portions of Mount Roundback and Mount Little immediately to the south.
Spring, Splitters, Tabletop, Main and Mount Stuart Creeks drain into Curlewis Bay to the northeast,
whilst Six Mile, Goodbye and Saltwater Creeks drain into the Caley Valley Wetland area. The
Wetland retreats on a seasonal basis to to a small lake (Lake Caley) and can become completely
dry during drought; however when inundated, covers up to an area of 50 km2 (BHP, 2011).
No major and minor watercourses exist within the Project area. Surrounding water bodies are
described as ephemeral and generally only flow following intense or prolonged periods of rainfall.
However, Saltwater Creek contained water during winter fieldworks (refer Section XX-
Hydrology).
To the south west of the Project area, watercourses upstream of the Caley Valley Wetland are
described as lowland freshwater creeks (as per the ANZECC/ARMCANZ Guidelines). These are
generally small, shallow streams (<10 m in width) with sandy soils and sediments, and sparse
riparian areas dominated by wetland flora species. The water bodies within the Abbot Point area
are likely to provide drinking water for cattle and native fauna, and are too small to be used
recreationally by humans. Also, there is no surface water directly within the Project area.
1.4.4 Geology
The Australia 1:250,000 Geological Series – Ayr Sheet SE 55-15 (Bureau of Mineral Resources,
Geology and Geophysics, 1968) states that the geology in the Abbot Point and Wetland region is
comprised primarily of Quaternary coastal mud flats (Qm) with marginal coastal sand dunes (Qr)
and some minor deposits of outwash and talus. An excerpt of this geological sheet is shown below
in Figure 1-1.
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Figure 1-1: Geology of Abbot Point and Surrounding Regions
Intercepting the coastal sand dune formations at the tip of Abbot Point (Bald Hill) and winding
down the coast to Mt Luce, west of APSDA, are Upper Carboniferous to Late Permian aged deposits
of mafic intrusive igneous rocks (C-Pd). These units comprise diorite, quartz diorite, tonalite,
gabbro, norite and minor granodiorite, adamellite and granite. South of Mt Luce and throughout
the southern and south western parts of the Wetland region are the Quaternary coastal mud flats
(Qm) while the eastern coast line is comprised of the Quaternary aged coastal sand dunes (Qr).
Further south of the Wetland area is an area of Alluvial and deltaic deposits (Cza) and beyond this
region to the South and leading up to Mt Roundback are formations of adamellite, granite, some
granodiorite and minor fine-grained variants (C-Pg) which make up the Hectate Granite formation
which surrounds the area to the north of Bowen (Connell Hatch, 2009).
Based on a review of the borehole logs from previous investigations, particularly the Connell
Hatch report (2009), the following information on geological profiles was compiled.
Sand
These sequences range in texture from fine to coarse grained sand with angular to sub-rounded
grains. The material was friable and varied from very moist to very stiff, with a loose to medium
density. The clay present in these units had high plasticity. When dry, the shallow clayey sands
were generally relatively stiff and competent materials, however once wetted, these materials
became extremely soft.
Sandy Clay
Three bands of sandy clay are present through a predominantly sandy aquifer system. The first
sandy clay layer is quite shallow from approximately 2 meters below ground surface (m bgs) to
approximately 5 m bgs, and the bottom sandy clay layer is generally overlying the weathered
bedrock.
Weathered Bedrock
These units were described as dark grey in colour, fine to coarse grained with an igneous fabric
texture. The units were extremely low strength with fine to medium angular gravel and were
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highly fractured. A generally clay/silty clay matrix-supported rock was observed at lower depths
to be clast-supported. This weathered rock is saturated and soft.
Bedrock
These units were described as dark grey, fine grained, massive structures of a very high strength
and are intensely to highly fractured on sub-horizontal and sub-vertical joints, irregular and
planar with iron stains.
1.5 Field Methodology
Two groundwater investigation programs were undertaken to assess the existing groundwater
conditions within the Abbot Point region. Both programs were conducted in accordance with
Appendix A and Appendix B. The first groundwater investigation program was conducted between
the 23rd and 28th April 2012, and the second one was undertaken between the 3rd and 8th June
2012. All field staff were trained and experienced in the collection of environmental samples.
Weather conditions were generally dry during both groundwater investigation programs (April
and June 2012). Site access to bore locations during both investigation programs was relatively
good and sometimes restricted by the presence of creeks and very long grass. Tidal conditions
during both investigation programs were low in the morning and high in afternoon.
The bore sampling plan is shown in Figure 1-2. A total of 7 bores (125268, 125269, BH307,
BH315, BH316, BH327 and 125272) were sampled. Pump and slug tests were completed on 2
bores (BH316 and BH327), and Level TROLL pressure transducer water level loggers were
installed permanently in these 2 bores, for ongoing water level monitoring purposes.
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Figure 1-2: Groundwater Bore Sampling Plan
1.5.1 Sample Collection
Wells were gauged using an electronic interface probe to measure and record the standing water
level (SWL). All groundwater wells selected for monitoring were purged until approximately three
well volumes of water was removed and until the water quality parameters stabilised.
Field parameters including temperature, electrical conductivity (EC), dissolved oxygen (DO), and
pH were measured and recorded during purging activity using a calibrated water quality meter.
Purging was continued until the field parameters stabilised as much as practicable. Sampling was
then completed using a peristaltic pump under low flow.
Field intra- and inter-laboratory duplicates were prepared by collecting discrete groundwater
samples at a rate of one per 10 primary samples and one per twenty primary samples respectively.
Samples for duplicate analyses were selected from monitoring well locations showing the highest
probability of containing contaminants of concern.
Legend
The
Project
Area
Caley Valley
Wetland
N
Groundwater Bore
Sampling Location
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1.5.2 Sample Handling and Preservation
During sampling, a new pair of disposable nitrile sampling gloves was worn at each of the sampled
wells. Samples were placed immediately into a laboratory prepared and supplied container.
Groundwater samples were placed in a chilled, insulated container with ice between sampling and
analysis. Samples were preserved for the various contaminants of concern in accordance with the
requirements of NEPC (1999) as detailed in the table below:
Table 1-1: Sample handling and preservation
Matrix Analyte Container Preservation
Groundwater Heavy Metals 100 mL plastic bottle HNO3 preserved, 40C
TPH (volatile), BTEX, VOCs 2 x 40 mL glass vials HCl preserved, 40C
SVOCs, TPH (C10-C36) 500 mL amber glass container Unpreserved, 40C
Anions, Cations, Inorganics 1 L plastic bottle Unpreserved, 40C
Ammonia 120 mL plastic bottle H2SO4 preserved, 40C
Sample numbers, preservation and analytical requirements were recorded on the chain-of-custody
documentation (signed copies provided with the laboratory reports), which accompanied the
samples to the laboratory.
1.5.3 Equipment Calibration
During the groundwater sampling, a water quality meter (WQM) was utilised for the measurement
of groundwater physico-chemical parameters. The WQM used onsite in April 2012 was a YSI
Quatro Pro Plus. This WQM was calibrated by Airmet Scientific prior to use and daily (prior to
sampling) with solutions of pH 4, pH 7 and 1,014 µS cm standard solutions. During the June
program, the WQM used was a 90 FLMV Meter which was calibrated by ThermoFisher Scientific
prior to use by CDM Smith.
1.5.4 Pump and Slug Tests
Pump and slug tests were completed on 2 bores (BH316 and BH327). At these selected locations, a
pump test and/or slug test were conducted in order to collect aquifer recharge properties and the
hydraulic conductivity at these two bores – selected to be representative of the Project area.
Pump tests were undertaken using the following general procedure:
1. Static water level in the bore was gauged using a water level interface probe (interface probe).
2. A Level TROLL pressure transducer data logger (data logger) was set up in WinSitu 5, a data
logging program, to record water levels and pressure within the bore every 2 seconds during
the test.
3. The data logger and peristaltic pump were installed down the bore, with the data logger set
approximately 0.5 m from the bottom of the bore, and the peristaltic pump approximately 0.5
m above the data logger, to allow for accurate readings without disturbing the data logger.
4. The water level in the bore was left to stabilise for approximately 5 minutes prior to turning
the peristaltic pump on.
5. The peristaltic pump was turned on and allowed to run for approximately 30 minutes, during
groundwater purping and sampling. Prior to switching the peristaltic pump off, the interface
probe was inserted into the well to measure the standing water level.
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6. The peristaltic pump was turned off and the water table was allowed to rebound for a
minimum of approximately 10 minutes. Every 5 seconds after the pumping was stopped, the
water levels were manually read using the interface probe until the water level had recovered
to within 10% of the original gauged level and the peristaltic pump was subsequently
removed.
Slug tests were undertaken using the following general procedure:
1. A "slug" (cylinder of known volume) was installed down the bore to displace the water inside
the bore and by measuring the recovering water level.
2. A slug measuring 1.5 m long and 40 mm diameter was used to ensure a suitable displacement
of water and leaving enough space between the minimum water level in order to avoid hitting
and disturbing the logger.
3. The slug was dropped quickly and gently into the well in order to raise the water level and was
then held steady. The interface probe was then inserted into the well to manually gauge the
standing water level.
4. As in the pump test, a reading was recorded every 5 seconds until the water level had
recovered to within 10% of the original gauged level.
At the completion of the pump and slug test, the logger data was downloaded to WinSitu 5 and
then imported into Aquifer Test 4.0 for statistical analysis (Appendix C). The results of this
analysis are presented in the hydraulic conductivity assessment in Section 1.7.7.
In addition to pump and slug tests, permanent water level loggers were installed in 2 bores
(BH316 and BH327) for ongoing water level monitoring purposes.
1.6 Groundwater Quality Assessment
1.6.1 Groundwater Investigation Levels
The ANZECC & ARMCANZ (2000) "Australia and New Zealand Guidelines for Fresh and Marine
Water Quality" provide guidance to assess water quality in aquatic ecosystems. These guidelines
stipulate that the identification of the receiving environment or the likely beneficial use of the
water is essential for selecting the most applicable criteria.
Groundwater across the region flows radially from the base of Mt Roundback towards Abbot Point,
with some discharge into the Wetland. The measured groundwater salinity (indicated by Electrical
Conductivity) at the site exhibited noteworthy variability, which suggests some
surface/groundwater interaction. The receiving waters for the Project are likely to be the Wetland,
which is an Estuarine Aquatic Ecosystem. In ANZECC & ARMCANZ (2000), the Estuarine Aquatic
Ecosystem is a sub-set of the Marine Aquatic Ecosystem. However, there are no Estuarine criteria
for the main parameters of concern so it is necessary to adopt the Marine values. In the absence of
Marine values it is common practice to refer to Fresh water criteria to at least provide some sort of
benchmark for comparison purposes. Consequently, results of the groundwater monitoring will be
compared with both the marine and freshwater trigger levels within the ANZECC & ARMCANZ
(2000) guidelines. Due to the likely ultimate receiving environment, trigger values with the
highest level of species protection 95%, have been adopted.
It is noted that that some of the trigger levels for various analytes for environments presented in
ANZECC & ARMCANZ (2000) are currently less than the laboratory detection limits. Consequently,
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it was considered that the laboratory detection limit is suitable for use as a screening value for
concentrations of analytes in groundwater where trigger values provided in ANZECC & ARMCANZ
(2000) cannot be applied. It is noted that the ANZECC & ARMCANZ (2000) criteria do not endorse
an accepted trigger value for Total Petroleum Hydrocarbons (TPHs), the majority of volatile
organic compounds (VOCs), and major anions and cations due to their large variability across
regions.
With respect to the use of groundwater for human consumption, the Project is located within an
area where groundwater is unlikely to be utilised for household purposes. Given this, it is
considered that the NHMRC & NRMMC (2011) Drinking Water guidelines are not generally
applicable to the Project area and, therefore, have not been included.
Therefore, the only applicable criteria for the Project area are the ANZECC (2000) fresh and
marine water 95% trigger levels.
1.6.2 Field Parameter Results
Field parameters for groundwater were measured spatially and temporally over two periods; 23-
28 of April 2012 and 3-8 of June 2012. The field parameters were collected after purging
approximately three bore volumes. Three readings were collected unless the parameters did not
stabilise in which case further parameter readings were collected. Field parameters measured
included Dissolved Oxygen (DO), Electrical Conductivity (EC), pH, Redox potential and
temperature. These parameters are presented in Table T2. A summary of the parameters is as
follows:
EC of the groundwater ranged from 200 µS/cm (BH327 – June 2012) to 9,964 µS/cm (BH307 –
April 2012) indicating fresh to saline water environments. In general, there is a difference in
EC between bores but, within individual bores, results indicate consistent EC in April 2012 and
in June 2012;
The redox potential (Eh) of groundwater ranged from -209 mV (BH307 – June 2012) to 101
mV (BH327 – June 2012), indicating both oxidising and reducing conditions. The results
indicate a large amount of variability between the April 2012 and the June 2012 sampling
rounds;
The DO content of the groundwater ranged from 0.7 mg/L (BH327 – April 2012) to 1.80 mg/L
(BH315 – June 2012), indicating anaerobic conditions. The results indicate that generally the
DO levels were higher in June 2012 than April 2012; and
The pH of groundwater ranged from 5.34 (bore 125272 – June 2012) to 7.26 (bore 125269 –
April 2012), indicating slightly acidic to neutral conditions.
1.6.3 Groundwater Analytical Results
A summary for the chemical parameters tested is provided below and in Table T3.
Total Petroleum Hydrocarbon (TPH)
All concentrations of TPHs were reported below the laboratory detection limits and therefore
below the ANZECC (2000) criteria.
Benzene, Toluene, Ethylbenzene and Xylenes (BTEX)
Groundwater Adani
T0 EIS - Groundwater 10
All concentrations of BTEX were below the laboratory detection limits and the ANZECC (2000)
criteria.
Heavy Metals
Concentrations of arsenic were above the ANZECC (2000) freshwater criteria at two locations
(125269 and BH315) in both the April and June 2012 sampling rounds.
Concentrations of zinc were above laboratory detection limits in all locations sampled for both
April and June 2012. Of these:
Three locations (125268 in June, 125269 and BH327 in April and June) had
concentrations greater than the ANZECC (2000) freshwater criteria; and
Two locations (BH316 in April and 125272 in June 2012) had concentrations greater
than the ANZECC (2000) marine water criteria.
Concentrations of cadmium, chromium, lead, nickel and mercury were below the laboratory
detection limits for all locations for April and June 2012.
Volatile Organic Compounds (VOCs)
All concentrations of VOCs were below the laboratory detection limits and the ANZECC (2000)
criteria.
Major Anions
There are no applicable ANZECC (2000) freshwater or marine water guidelines applicable to
major anions.
Chloride concentrations ranged from 12 mg/L (BH316 in April 2012) to 3,000 mg/L (BH307
in both April and June 2012);
Sulphate concentrations ranged from 8 mg/L (BH316 in both April and June 2012 and BH327
in April 2012) to 300 mg/L (BH307 in both April and June 2012);
Total alkalinity concentrations ranged from 19 mg/L (125272 in June 2012) to 360 mg/L
(BH307 in April 2012); and
Concentrations of carbonate as CaCO3 ranged from 19 mg/L CaCO3 (125272 in June 2012) to
230 mg/L CaCO3 (BH315 in June 2012) and concentrations for bicarbonate as CaCO3 ranged
from 30 mg/L CaCO3 (125272 in April 2012) to 360 mg/L CaCO3 (BH307 in April 2012).
Major Cations
There are no applicable ANZECC (2000) freshwater or marine water guidelines applicable to
major cations.
Calcium concentrations ranged from 0.5 mg/L (125269 in April and June 2012) to 51 mg/L
(BH307 in April 2012);
Magnesium concentrations ranged from 1 mg/L (125269 in June 2012) to 120 mg/L (BH307
in April 2012);
Potassium concentrations ranged from 1.5 mg/L (BH327 in April and June 2012) to 45 mg/L
(BH307 in June 2012); and
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T0 EIS - Groundwater 11
Sodium concentrations ranged from 33 mg/L (BH327 in April 2012) to 2,200 mg/L (BH307 in
June 2012).
Miscellaneous Inorganic Compounds
Concentrations of ammonia ranged from 0.008 mg/L (QC202 – intra laboratory duplicate of
BH315 in April 2012) to 0.076 mg/L (125272 in June 2012 and BH307 in both April and June
2012). All concentrations were below the adopted ANZECC (2000) groundwater criteria;
Concentrations of nitrate (as N) ranged from 0.017 mg/L (BH327 in June 2012) and 0.44 mg/L
(BH327 in April 2012). Of these, three locations (QC302 – inter-laboratory duplicate of BH315
and BH327 in April 2012 and BH316 in both April and June 2012) had concentrations greater
than ANZECC (2000) freshwater guidelines;
Concentrations of nitrogen (total) ranged from 100 µg/L to 1,500 µg/L (BH327 in April 2012).
The adopted groundwater criteria is not applicable for nitrogen (total); and
Concentrations of Total Kjehldahl Nitrogen (TKN) ranged from 0.1 mg/L to 1.1 mg/L (BH327
in April 2012).
Salinity
Salinity concentrations ranged from 120 mg/L (BH327 in April 2012) to 6,600 mg/L (BH307
in April 2012). The adopted groundwater criteria is not applicable to salinity; and
TDS concentrations ranged from 170 mg/L (BH327 in June 2012) to 61,000 mg/L (BH307 in
April 2012). The adopted groundwater criteria is not applicable to TDS.
1.6.4 Graphical Representation of Analytical Results To further understand the quality of the groundwater at Abbot Point, a graphical representation of
the major ions is shown in Figures 1-3 and 1-4.
Figure 1-3 depicts a Piper Diagram of the major ions in groundwater samples collected at the
Abbot Point site. The data points shown on these figures correspond to both sampling events
(April and June 2012). The diagram illustrates that the major cations present in groundwater
samples are Na and K, while the major anions are HCO3- and Cl (sometimes), thus samples are of
the Na-HCO3 or Na-HCO3-Cl type. This indicates that the waters range from a chemistry impacted
by interaction with the surface sediments and shallow geology (HCO3 type) to a chemistry
impacted by salinity (Cl type). Specifically, the HCO3 influenced locations comprise predominantly
inland boreholes, confirming the likely domination of a mineralogical influence from surrounding
geologies. Conversely the samples indicating the strongest Na+K & Cl chemistry are located
proximal to the coast, indicating that the saline influence is likely to be sea water. The sample from
bore 125272 appears to be an anomalous result being predominantly of the SO4 water type. SO4 is
commonly associated with oxidation of pyrite which could be present naturally in the soils around
bore 125272
Figure 1-4 is a Durov Diagram. The majority of the data in this diagram is directly comparable to
the data within Figure 1-3, and the only difference is that the Durov Diagram contains data on
Total Dissolved Solids (TDS) and pH. The majority of the pH results fall between 5 and 7 across
both saline and freshwater sites. Measured TDS ranging between 300 to 1,000 mg/L suggests
freshwater, whereas 5,000 to 10,000 mg/L suggests influences from the sea water. Between 1,000
and 3,000 mg/L, the water type becomes difficult to distinguish, having been influenced possibly
with minerals by geology or sea. From the Durov Diagram the majority of the sites fall between
approximately 200 to 4,000 mg/L concluding that the water is influenced by both mineral geology
Groundwater Adani
T0 EIS - Groundwater 12
and the sea. Only one site, BH307 is definitively placed between 5,000 to 10,000 mg/L, being
influenced to a significant degree by the sea.
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-3: P
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1.7 Groundwater Modelling
1.7.1 Objectives
The objectives of the baseline groundwater modelling work were to:
Define the commencement date, duration, anticipated quantity and frequency of development
activities;
Carry out a baseline assessment of the receiving environment (before development), including
seasonal variability of water flow, if applicable;
Determine via scientific modelling the radius of influence and profile of the proposed
development; and
Identify further groundwater investigations that might be required to refine this baseline
groundwater model.
1.7.2 Scope of Work
In order to achieve the objectives for the groundwater modelling work outlined above, the
following were undertaken:
Review of previous environmental investigation and groundwater reports relevant to the local
area;
Field investigations at the site to conduct aquifer pump/slug tests in order to determine site-
specific hydraulic conductivity;
Development of a three-dimensional finite difference (numerical) groundwater model for the
site using the MODFLOW 2000 modelling code;
Calibration of the groundwater model against water level data collected during historical field
investigations; and
Model simulations incorporating the proposed infrastructure plan to assess the impact and
influence of infrastructure activities on groundwater.
1.7.3 Hydrogeological Conceptualisation
A conceptual hydrogeological model was developed by taking into account previous
conceptualisations (GHD, 2012), new data, and field information. This model was subsequently
used to develop a numerical groundwater model depicting baseline conditions and development
scenarios. The following information was reviewed to better understand the relationship and
interaction between groundwater and hydrogeologic features in the local area:
Connell Hatch, 2009: Geotechnical Investigation Report, Abbot Point Bulk Coal Terminal
X80/X110 Expansion. Report H6000-80-GEO-GT06-002/01 prepared for the Ports Corporation
of Queensland; and
EHA Pty Ltd, 2005: Abbot Point Expansion. Baseline Groundwater Monitoring Investigation
Report. Report GW-05-16-REP-002 Rev 0 prepared for WBM Oceanics Pty Ltd.
Groundwater Adani
T0 EIS - Groundwater 16
Where data was available from the field investigations completed in April and June 2012, these
data were utilised as much as practicable. The next most reliable data that was utilised was the
Connell Hatch (2009) report as this included borehole logs and geotechnical logs that gave insight
into the subsurface across the Project area. Third to be utilised was the EHA (2005) reports which
provided borehole and monitoring bore installation information for several of the boreholes
around the Project area.
The hydrogeological conceptualisation is summarised as follows:
Three hydrogeological cross sections (A, B and C) were developed and are presented in
Figures 1-5, 1-6 and 1-7, respectively. The cross sections show the presence of three bands of
sandy clay which are located through a predominantly sandy aquifer system.
The region of Abbot Point which includes the Project area is shaped like an alluvial fan at the
base of Mount Roundback, located to the south of the Caley Valley Wetland. From the base of
Mount Roundback the alluvial fan is formed from interbedded sands and sandy clays. This
alluvial material is highly variable ranging from clean sands though silty sands to clayey sands
and sandy clays. The clean sands appear relatively massive, and are indicative of aeolian
deposition processes, while it is probable that the sandy clay deposition occurred through
riverine and wetland depositional events and as such these layers are variable on a small scale,
resulting in lenses of silty clays and sandy clays within a broader high silt / clay content sandy
deposition. The deposition of silty clay and sandy clay materials through riverine and wetland
depositional events is considered to be typical of marine transgressional environments, where
clays originated from the weathered bedrock tend to deposit in small layers or lenses over
long periods of time, as the marine depositional environment regresses back into the sea.
The first sandy clay layer is quite shallow, from approximately -2 m AHD to approximately -5
m AHD beneath the Wetland, and the bottom sandy clay layer site generally overlying the
weathered bedrock. In some cases, the layers do not continue throughout the cross section
transects and this is likely a result of sediment deposition from the ocean. The whole system
sits on unfractured bedrock which has very low (nearly impermeable) hydraulic conductivity
(Freeze and Cherry, 1979) so, for modelling purposes, this unit is considered a no-flow
boundary.
As indicated by Freeze and Cherry 1979, the hydraulic conductivity in the sandy clay units is
generally 3 - 6 orders of magnitude lower than the sandy units (1 - 4 m/day as per pump and
slug tests, Table 1-3). Therefore, the sandy clay units are expected to act as leaky or confining
units. An assessment of the actual hydraulic properties of the materials present in the Project
area is provided in Section 1.7.6 including Table 1-2. Hydraulic conductivity values for these
materials can be summarised as follows;
a. Sand = 2 m/day;
b. Silty clay/sandy clay = 0.5 m/day;
c. Weathered bedrock = 5 m/day; and
d. Bedrock = no hydraulic conductivity, no-flow boundary.
Groundwater levels around the Project area have been measured at between 0 m AHD and 2 m
AHD (Figure 1-8), and therefore sit slightly higher than the wetland water levels. Time series
data from the coastal side of the Wetland indicates tidal fluctuation in groundwater elevations
of up to approximately 1 m. This indicates that groundwater flow is tidally influenced and
there is likely a mixing zone extending inland to some degree.
Groundwater Adani
T0 EIS - Groundwater 17
It is expected that groundwater levels would be at the highest (shallowest) during the wet
season when groundwater recharge is greatest. With the changes in groundwater levels
between the wet and dry seasons, the interaction of groundwater and surface water systems
may have temporal variability. For example, groundwater levels may rise to provide a
baseflow component to waterways and fresher recharge may result in a seaward shift in the
coastal saline groundwater interface (GHD 2012).
Groundwater recharge occurs in the Quaternary alluvium across the area located at the foot of
Mount Roundback. The nature of the depositional system in this area rapidly mineralises the
recharged groundwaters to a freshwater/brackish water characteristic. Groundwater flows
radially away from Mount Roundback towards the ocean as identified in the model which was
based on historic groundwater levels throughout the region.
The highly variable measured electrical conductivities across the coastal perimeter of the
Project area indicates that a series of complex interactions are occurring. Freshwater flows
within the surface waters are too low to be significantly impacted by the groundwater
characterised by a brackish environment, i.e. groundwater originally recharged in proximity to
Mount Roundback. However, the low salinities observed in selected bores close to the coast
indicate that there is likely some localised freshwater recharge directly to the shallow aquifer
systems impacting on measured concentrations in bores. Conversely, the saline water
recorded in other bores indicates a direct recharge to the shallow aquifer from the more
brackish/saline surface waters.
The measured electrical conductivity of groundwater and surface waters shows the following
trends:
- Inland of the Wetland, measured electrical conductivity in groundwater ranges from
approximately 1,500 to 4,000 S/cm, indicative of a brackish environment;
- On the coastal side of the Wetland, measured electrical conductivity in groundwater
is highly variable, with reported electrical conductivity in some bores as low as 200
S/cm, indicative of freshwater, and others as high as 8,900 S/cm, indicative of
saline water, though still substantially below seawater concentrations; and
- Measured electrical conductivities of surface waters within the Wetland and
associated creek systems range from 300 S/cm to 5,200 S/cm, indicating the
surface waters range from freshwater to saline, though again substantially below
seawater concentrations.
The Piper Plots shown in section 1.6.6 indicate that the groundwater is largely of the Na+K
type, and varies from HCO3 to Cl type. The groundwater becomes increasingly dominated by
Na+K, and particularly the sodium component, with proximity to the coast, which correlates
with the above statement that brackish/saline waters, sourced from the Wetland and
consequently the sea, increasingly impact on groundwater quality with proximity to the ocean.
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: Cro
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Groundwater Adani
T0 EIS - Groundwater 21
Figure 1-8: Groundwater Level Contours (m AHD)
1.7.4 Numerical Model Development
A numerical groundwater model for the Project area was developed in the Visual Modflow
software using the MODFLOW 2000 modelling code (Harbaugh et al, 2000). The model was
adapted from a model built previously for a related study, with appropriate authorisation. The
earlier Abbot Point model was constructed using 8 layers (i.e. representing 3 sandy layers, 3 sandy
clay layers, 1 weathered bedrock layer and 1 bedrock layer) and approximately 230,400 grid cells
in 480 rows and 480 columns, covering an aerial extent of 12,000 m (east-west) by 12,000 m
(north-south).
The extents of the original model were constrained by aerial photography and contour data and
relevant hydrogeologic features in the vicinity of the Abbot Point area. Figure 1-9 shows the
original Abbot Point model and shows the approximate location of the Project within the model
domain.
The
Project
Area
Caley Valley
Wetland
N
Groundwater Adani
T0 EIS - Groundwater 22
Figure 1-9: Original Abbot Point Model Domain
The Project groundwater model domain was defined by focusing the original Abbot Point model
on the immediate region of the Project. The model grid and extent are shown in Figure 1-10.
The
Project
Area
Caley Valley
Wetland
Mt Roundback
Mt Luce
N
Inactive
Cells
Constant
Head
Boundary
Groundwater Adani
T0 EIS - Groundwater 23
Figure 1-10: The Project Groundwater Model Domain
1.7.5 Boundary Conditions
Boundary conditions for the model were defined by the groundwater head results from the
current groundwater monitoring event. The boundary conditions for the model were defined by
assigning constant head cells at the coastline of the northern area of the model extent to be 0 m
AHD, and all cells to the north of the coastline were made inactive as they do not take part in the
groundwater flow regime for the site. Also, constant head cells were assigned at the eastern,
southern and western boundaries of the model domain, with head values defined by the results of
the current groundwater monitoring event under steady state conditions. The values were
determined by assigning the hydraulic head results under steady state conditions to the
corresponding boundaries of the model domain. It is noted that hydraulic head results from June
2012 used as constant heads were representative of the lowest groundwater levels during the
driest season of the year. Therefore, the constant head conditions were based on worst case
scenarios of specific groundwater modelling events, which can increase up to 2 m over the wettest
seasons of the year.
N
Inactive
Cells
The
Project
Area
Constant
Head
Boundary
Caley Valley
Wetland
Groundwater Adani
T0 EIS - Groundwater 24
1.7.6 Model Parameters
Site specific values for hydraulic conductivity were calculated from field tests undertaken around
the Project area (refer Section 1.5.4). Table 1-2 summarises the aquifer properties used in the
model.
Table 1-2: Input Data in Groundwater Model
Parameter Value Source
Sand Hydraulic Conductivity, Kx = Ky = Kz
Sandy Clay Hydraulic Conductivity, Kx = Ky = Kz
Weathered Bedrock (Siltstone-Granite) Hydraulic Conductivity, Kx = Ky = Kz
2 m/day 0.5 m/day 5 m/day
CDM Smith Field data Model Calibration Model Calibration
Sand Specific Storage, Ss
Sandy Clay Specific Storage, Ss
Weathered Bedrock (Siltstone-Granite) Specific Storage, Ss
0.5 m-1
0.005 m-1
1 m-1
CDM Smith Field data Model Calibration Model Calibration
Sand Specific Yield, Sy
Sandy Clay Specific Yield, Sy
Weathered Bedrock (Siltstone-Granite) Specific Yield, Sy
0.5 0.15 1
CDM Smith Field data Model Calibration Model Calibration
Sand Total Porosity Sandy Clay Total Porosity Weathered Bedrock (Siltstone-Granite) Total Porosity
0.3 0.1 0.5
Todd (1980) Model Calibration Model Calibration
Sand Effective Porosity Sandy Clay Total Porosity Weathered Bedrock (Siltstone-Granite) Effective Porosity
0.3 0.1 0.5
Model Calibration
1.7.7 Hydraulic Conductivity Hydraulic conductivity values imported into the model were determined from aquifer pump and
slug test data collected from bores BH316 and BH327 during April and June 2012. Pump and slug
tests were undertaken using the general procedures described in Section 1.5.4.
Groundwater Adani
T0 EIS - Groundwater 25
Water level data recorded on the data logger for the falling and rising head slug tests was analysed
using Theis, Neuman, Theis with Jacob Correction and Hvorslev methods to determine hydraulic
conductivity. Copies of the analysis sheets are included in Appendix B, and hydraulic conductivity
values determined for each pump and slug test are summarised in Table 1-3. A minimum of two
falling head and two rising head tests were conducted at each bore.
The hydraulic conductivity values determined for each borehole and for each slug test were
consistent, and the average value of 2 m/d was used as input for hydraulic conductivity in the
groundwater model.
Table 1-3: Hydraulic Conductivities
Groundwater Monitoring Bores Screened in Sand
bore Number
Pump Test (m/day) Slug Test (m/day)
Drawdown Recovery Falling Head Test Rising Head Test
Theis Neuman Theis with Jacob
Correction Thies
Recovery Hvorslev C-B-P Hvorslev
Bouwer & Rise
BH316 2.06 4.09 2.08 2.23 Unreliable Data Set 1.49 1.07
BH327 1.40 2.08 1.41 1.23 1.09 2.51 3.86 2.97
Average 2.19 1.73 1.80 2.35
Adopted Average Hydraulic Conductivity for Sandy Layer: 2 m/day
1.7.1 Climate Specific climate data at the Abbot Point Site is relatively scarce. There is only one weather station
(Abbot Point Bulkcoal Station, 148.07°E, 19.88°S) at the site with only 6 months of precipitation
data (1991). Towards the West, the closest weather station (Wattlevale Station, 147.85°E, 19.91°S)
with complete daily precipitation records (1971-2012) is about 25 km from the Abbot Point Site.
Towards the South East, the closest weather station with a complete precipitation, temperature,
and solar radiation record (1990-2012) is the Bowen Airport Station (148.22°E, 20.02°S) located
about 20 km from the Abbot Point site. There are other weather stations in the vicinity of this last
station, but their records are not as complete as the ones for the Bowen Airport Station.
In order to provide a comprehensive description of climate conditions at the Abbot Point Site,
synthetic weather data (1889-2012) for this location (148.05°E, 19.9°S, 187 m) was extracted
from SILO (Queensland Government, 2012). The data extracted includes synthetically generated
records for daily precipitation, temperature, and evaporation and is based on actual weather data
from nearby stations. Based on these data, the average annual precipitation at the Abbot Point site
is about 1037 mm/year. The wet season is from December to March with average monthly
precipitation values of almost 250 mm/year, and the dry season is from April to November with
average monthly precipitation less than 100 mm/year. Daily temperature at the Abbot Point Site
fluctuates between 7.9°C and 34.5°C. However, monthly average temperature fluctuates between
18°C (July) and 27°C (December - February). Evaporation at the site stays relatively high
throughout the year ranging from 99 mm/month to 210 mm/month. Figure 1-11 summarises
these results.
Groundwater Adani
T0 EIS - Groundwater 26
Figure 1-11: Monthly average precipitation, temperature, and evaporation for the Abbot Point site
(148.05°E, 19.9°S, 187 m) based on synthetic weather record (1889-2012)
1.7.2 Evapotranspiration From site visits and local knowledge, it has been noted that there are no forests but there is
significant wetland vegetation in the eastern half of the wetland. In addition, the land is covered by
grass and perennial vegetation (Jolly I et al., 2011). The Potential Evapotranspiration (PET) has
been previously estimated using a variety of methods and intermediary datasets (Jolly I et al.,
2011). Consequently, at the Abbot Point Site, Average Annual Evaporation is about 1891 mm/year
whereas PET has been estimated at around 2050 mm/year (8% difference) Therefore, water
consumption as a consequence of plant transpiration is not a significant process and
evapotranspiration can be estimated by using open surface evaporation methods.
In MODFLOW 2000, evapotranspiration is defined as a discharge from groundwater that is
inversely proportional to the depth from ground surface to the water table. The inputs required to
define evapotranspiration in the model are the maximum evapotranspiration rate, which is based
on the evaporation rate for the area, and an extinction depth. The rate of evapotranspiration in a
given cell at a given time is then calculated by linear interpolation between the maximum
evapotranspiration rate when the water table is at the ground surface, to an evapotranspiration
rate of zero when the water table is at (or below) the extinction depth.
Evapotranspiration data was derived from SILO rainfall data which has been recorded as daily
data for the Abbot Point area from January 1889 to June 2012. A maximum evapotranspiration
rate of 1890 mm/year was entered into the model, which corresponds to approximately 95% of
the average yearly evaporation rate derived from SILO. An extinction depth of 2 m was also used in
the model.
1.7.3 Recharge Based on the review of rainfall data derived from SILO, it is considered that evaporation tends to exceed precipitation throughout the year except for the months of January and February. These two months are likely the most important months for aquifer recharge. Aquifer recharge may occur as a combination of diffuse recharge (infiltration and percolation of rainfall) and from stream interactions with the groundwater system. Diffuse recharge is often estimated as a percentage of precipitation (Waterloo Hydrogeologic, 2005). This percentage typically ranges
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0.0
50.0
100.0
150.0
200.0
250.0
300.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Te
mp
era
ture
(°C
)
mil
lim
etr
es
Precipitation (mm/month) Evaporation (mm/month) Temperature (°C)
Groundwater Adani
T0 EIS - Groundwater 27
from 5% to 40% depending on many different factors including land use, vegetation type, surface topography (slope), and soil cover material. There are no detailed recharge studies at the Abbot Point site so this crude approach (e.g. recharge as a percentage of precipitation) is being used to provide an initial estimate to use in the groundwater model. Therefore, diffuse recharge at the site can range from about 52 mm/year (5% of precipitation) to about 415 mm/year (40% of precipitation). This analysis is complemented with an estimate of recharge for a small area (<1.6 Ha) about 8 km
south of Abbot Point calculated using the Method of Last Resort (Jolly I et al., 2011). This estimate
resulted in maximum recharge value of about 14% of precipitation. The most conservative
estimate is considered to be 20% of precipitation because recharge estimates at similar sites near
the coast of Queensland are usually in the 14%-26% range. According to this, the aquifer system
would receive approximately 208 mm/year as diffuse recharge from the surface. Consequently, this
recharge was used during calibration of the steady state model (refer section 1.7.11) to effectively
simulate hydraulic heads observed at the site.
1.7.4 Model Setup
Specific features included in the groundwater model for the Project include Mount Roundback to
the south, the Caley Valley Wetland in the centre, Mount Luce to the north west and the Project to
T3 to the north east. The Caley Valley Wetland was nominated as MODFLOW RIVER cells to allow
these areas to interact with groundwater in surrounding cells. Water levels in the wetland area
were set at 0 m AHD, based on the contour map provided. Hydrogeologic features included in the
groundwater model include the shallow sandy aquifer and weathered bedrock aquifer within the
Abbot Point region. Figure 1-12 shows the hydrogeologic features represented in the model.
Figure 1-12: Features included in the Model
The model adjusts hydraulic heads in surrounding cells to meet the bedrock no-flow boundary
condition. It is important to note that in using this model setup, the hydraulic conductivity in the
weathered bedrock is constant and influences groundwater flow in the surrounding cells, rather
than the opposite. Despite this, simulating the weathered bedrock with distinctive hydraulic
conductivities is considered appropriate due to the non-natural inputs and outputs for the
weathered bedrock.
It is important to note that using river cells for the Wetland imposes a boundary condition of the
specified head (in this case 0 m AHD) for those particular cells in the model. The model adjusts
Weathered
Bedrock
K = 5 m/day
Bedrock
(No hydraulic
conductivity,
No-flow
boundary)
Sandy Clay
K = 0.5 m/day
Sand
K = 2 m/day
Caley Valley Wetland
The
Project
Area
North
South
Mount Roundback
Groundwater Adani
T0 EIS - Groundwater 28
hydraulic heads in surrounding cells to meet this boundary condition. Topography and water level
data suggest the Wetland is likely to be partly fed by groundwater, and as a result water levels in
the Wetland are likely to be subject to groundwater levels in the surrounding area. These
additional inputs and outputs serve to artificially control the groundwater flow in the weathered
bedrock, making the use of distinctive hydraulic conductivities in the model appropriate for
simulating actual conditions.
1.7.5 Model Calibration
Due to the limited amount of site specific data available, the model was calibrated only in steady
state mode. Steady state model calibration involved the matching of hydraulic heads under steady
state conditions to water levels observed at the site.
Water level data available for the site exhibited considerable fluctuations between gauging events,
with water levels changing by as much as 2 m for bore 125269 between events (Figure 1-13).
These fluctuations likely reflect the influence of rainfall on water levels at the Project area. In
order to calibrate the steady state model to conditions less likely to be influenced by high rainfall
events, the date of each monitoring event was compared to rainfall data and water level data
provided by Adani and collected by CDM Smith to better establish groundwater levels under
‘normal’ conditions.
Figure 1-13: Rainfall Data for the Project Area
The calibration process involved adjusting variables such as recharge to match potentiometric
heads determined by the model at observation bores within the site to observed water levels.
Recharge in the model was used as a calibration parameter to better simulate the observed heads,
and the resulting steady state model predicted water levels at the bores within 0.098 m AHD of the
observed levels (Figure 1-14).
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
0.0
50.0
100.0
150.0
200.0
250.0
300.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Wate
r L
ev
el (m
AH
D)
Millim
etr
es
Precipitation (mm/month) Water Level Bore 125269
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T0 EIS - Groundwater 29
Figure 1-14: Steady State Calculated vs. Observed Water Levels
The recharge value determined during model calibration (208 mm/yr) fell within 10% of the
average recharge determined for the Project area. Figure 1-15 shows the groundwater levels
under steady state conditions determined by the calibrated model.
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T0 EIS - Groundwater 30
Figure 1-15: Steady State Groundwater Levels
1.7.6 Modelling Scenarios
The Project involves the expansion of the existing T1 coal export terminal to create an additional
capacity of 35 Mtpa on top of the 50 Mtpa presently at T1. The Project will include:
Rail loops and train unloading facilities;
Coal stockpile bunds and associated infrastructure. The Project stockyard platform levels will
be approximately 4.7 m AHD;
Conveyors from the coal terminal tranche to port facilities;
Berthing and ship loading facilities that expand existing T1 facilities;
Laydown areas and support activities;
Site and common user infrastructure including, but not limited to:
- Roads;
- Communications;
- Electricity;
- Water supply; and
- Sewage treatment.
-
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T0 EIS - Groundwater 31
1.7.7 Groundwater Level Scenarios Following calibration of the model under steady state conditions, steady state simulations were
run to preliminarily investigate the likely effects the Project will have on the groundwater
environment.
The groundwater head results determined by the steady state model simulations were used as
initial heads for the steady state simulations. The relationship between rainfall data for the local
area and recharge values used in the model was based on the long term average annual rainfall for
Abbot Point and the recharge value determined during the steady state model calibration.
The platform levels were assumed based on concept specifications provided for the Project (i.e. 4.7
m AHD).
Based on the high variability in the shallow geology including highly permeable units and the
highly variable groundwater quality (from fresh through to saline) it is possible that there is local
connectivity between surface water and groundwater.
Results
The model indicates that groundwater levels across the Wetland are similar to surface water levels
(Figure 1-16). Therefore, any adverse impact on surface water quality will rapidly impact on
groundwater quality, conversely any adverse impact on groundwater quality will rapidly impact
on surface water quality.
Figure 1-16: Predicted Groundwater Levels
Although hydraulic head results from June 2012 used as constant heads were representative of the
lowest groundwater levels during the driest season of the year. These were also representative
within a period of wet weather across Australia, including a very wet March at Abbot Point.
Therefore, groundwater fluctuations were at the maximum levels during the driest season. These
groundwater levels are below the base of the Project stockyard platform levels. Therefore, these
are unlikely to impact upon the normal groundwater flow and levels. However, groundwater level
rises of up to 2 m bgs (i.e. 4 m AHD) can be expected across the Project area during the wettest
seasons.
Bedrock
Caley Valley Wetland
The
Project
Area
North
South
Mount Roundback
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T0 EIS - Groundwater 32
1.8 Conclusions
Based on the above baseline groundwater assessment and preliminary steady state model
simulations, there are a number of potential impacts on groundwater conditions associated with
the Project.
Time series data from across the perimeter of the T1 facility and the Project area indicate tidal
influences in groundwater elevations of up to approximately 1 m. Based on this it can be
assumed that there is likely a mixing zone extending from the sea to the Project area and
groundwater flow will be tidally impacted.
The highly variable measured electrical conductivities across the perimeter of the T1 facility
and the Project area indicate that a series of complex interactions are occurring. Surface
waters are too fresh and are unlikely to be significantly impacted by saline groundwater. In
addition, the low salinities observed in selected bores close to the coast, indicate that there is
likely some localised freshwater recharge taking place. The saline water recorded in other
bores indicates that a certain degree of confinement limiting the amount of fresh recharge to
these units.
Groundwater levels are below the base of the Project stockyard platform levels. Therefore, the
construction of these structures is unlikely to impact upon the normal groundwater flow and
levels during the driest seasons of the year. Although seasonal groundwater level fluctuations
can be expected to rise up to 2 m bgs (i.e. 4 m AHD) no impacts on surface water can be
expected across the Project area during the wettest seasons. Due to the exceptional wet period
experienced across the region in the last two years, groundwater level fluctuations are
currently at maximum historic levels and are unlikely to continue to increase, so will remain at
least 2 m below the base of the Project stockyard platform levels.
It is anticipated that that the general filling, and area drainage to sediment ponds, will reduce
rainfall (fresh) water recharge to groundwater This might increase the inland intrusion of
saline groundwater lenses.
1.9 Recommendations
1.9.1 Mitigation Measures
The following mitigation and monitoring measures are proposed to ensure that potential impacts
to groundwater are minimised and in order to prevent or minimise environmental and human
health impacts.
Establish baseline groundwater conditions and mitigation measures through:
Hydrogeological conceptualisation and prediction of groundwater conditions using
numerical modelling;
Preparation and implementation of a construction groundwater management plan (CGMP)
to outline environmental management practices and procedures to be followed during
construction of the project, including dewatering activities that are likely to be required
during excavations for infrastructure plan;
Manage construction activities that have a potential to impact groundwater quality, as
follows:
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T0 EIS - Groundwater 33
Control surface water flows, drainage and erosion by the implementation of a surface
water management plan. The proposed stormwater retention dams will avoid runoff
to environmental receptors (waterways) and will minimise any likely impacts on
groundwater quality
Fuels and chemicals are stored adequately (e.g. bunds and shelter) and MSDS for each
chemical is maintained onsite
Develop and implement construction and operational management plans for the
Project coal stockyard
1.9.2 Monitoring Measures
The following monitoring measures are designed to monitor groundwater quality conditions
before, during and after construction and to ensure potential impacts to groundwater quality are
addressed effectively. The monitoring measures include:
1. At least one groundwater monitoring event before, during and after construction; and
2. Monitoring groundwater quality and implementing a suitable groundwater monitoring
network. This would include the use of existing bores, as shown in Figure 1-2 (Section 1.5).
1.10 References
Australian and New Zealand Environment and Conservation Council/Agriculture and Resource
Management Council of Australia and New Zealand (ANZECC/ARMCANZ), 2000. ‘Australian
and New Zealand Guidelines for Freshwater and Marine Water Quality.’
Best, D (DERM), 2007. ‘Bowen Water Management Policy 2007’, WAM/2007/3184 – Version 1.
Queensland Department of Environment and Resource Management.
BMT WBM, 2009. ‘Baseline Profile for the Kaili Valley Wetlands’.
Connell Hatch, 2009. ‘Geotechnical Investigation Report. Abbot Point Bulk Coal Terminal
X80/X110 Expansion.’ Report H6000-80-GEO-GT06-002/01 prepared for the Ports Corporation
of Queensland.
Department of Environment and Resource Management (DERM), 2009. Queensland Water
Quality Guidelines. Version 3 September 2009.
Department of Land and Water Conservation (DLWC), 2002. The NSW State Groundwater
Dependent Ecosystems Policy. NSW Government, Sydney. 40 pp.
Department of Natural Waters and Resources (DNRW), 2007. Far North Queensland Draft
Regional Water Supply Strategy Technical Document No. 6: Far North Queensland water strategy
groundwater aspects, Brisbane.
Environment Australia (2001). A Directory of Important Wetlands in Australia, Third Edition. Environment Australia, Canberra.
Eamus, D., Froendm R., Loomes, R., Hose, G. and Murray, B., 2006. A functional methodology for
determining the groundwater regime needed to maintain the health of groundwater dependent
vegetation. Australian Journal of Botany 54, 97-114.
EHA Pty Ltd., 2005. ‘Abbot Point Expansion. Baseline Groundwater Monitoring Investigation
Report’. Report prepared for WBM Oceanics Pty Ltd. Report GW-05-16-REP-002 Rev 0.
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T0 EIS - Groundwater 34
EHA Pty Ltd., 2005: ‘Abbot Point Expansion. Preliminary Hydrogeological Review of Splitters
Creek Borefield Performance Report’. Report prepared for WBM Oceanics Pty Ltd. Report GW-
05-16-REP-001 Rev 0.
Evans, R. and Clifton, C., 2001. ‘Environmental water requirements to maintain groundwater
dependent ecosystems’. National Heritage Trust. Canberra, 93 pp.
Fensham, R.J., Fairfax, R.J., and Sharpe, P.R., 2004. ‘Spring wetlands in seasonally arid
Queensland: floristics, environmental relations, classification and conservation values’.
Australian Journal of Botany 52, 583-595.
Fensham, R.J., and Price, R.J., 2004. ‘Ranking spring wetlands in the Great Artesian Basin of
Australia using endemicity and isolation of plant species’. Biological Conservation 119, 41-50.
Freeze, R.A. and Cherry, J.A. 1979. ‘Groundwater’, Prentice-Hall, Englewood Cliffs, N.J.
Gallardo, A.H. and Marui, A., 2006. ‘Submarine groundwater discharge: an outlook of recent
advances and current knowledge’. Geo-Marine Letters 26, 102-113.
GHD Pty Ltd, 2012. ‘Abbot Point Cumulative Environmental Impact Assessment. Technical
Report. Groundwater Assessment’. Report prepared for Hancock Coal Infrastructure Pty Ltd.
GHD Pty Ltd, 2012. ‘Abbot Point Cumulative Environmental Impact Assessment. Caley Valley
Wetlands Surface Water Quality’. Report prepared for Adani Pty Ltd.
Gregory, C.M., Malone, E.J., Jensen, A.R., Paine, A.G.L., Olgers, F., Clarke, D.E., and Forbes, V.R.
1971. ‘Australia 1:250,000 Geological Series, Bowen, Queensland , Sheet SF55-3, First Edition,
1971’, Bureau of Mineral Resources, Geology & Geophysics.
Great Barrier Reef Marine Park Authority, 2010. ‘Great Barrier Reef Marine Park Water Quality
Guidelines’. Revised Edition, 2010.
Hatton, T., and Evans, R, 1998: ‘Dependence of Ecosystems on Groundwater and its significance
to Australia’, LWRRDC Occasional Paper No.12/98.
Jolly, I., McEwan, K., Cox, J., Walker, G., and Holland, K. 2002. Managing groundwater and
surface water for native terrestrial vegetation health in saline areas. 20-25 October, 20-25
October, Albany.
Jolly I, Gow L, Davies P, O'Grady A, Leaney F, Crosbie R, Wilford J & Kilgour P. 2011. ‘Recharge
and discharge estimation in data poor areas: recharge and discharge estimation spreadsheets
and MapConnect’.
Kay, H., 2006. ‘Protection and Management of Groundwater-Dependent Ecosystems: Emerging
Challenges and Potential Approaches for Policy and Management’. Australian Journal of Botany
54, 231–237.
Land, Water and Biodiversity Committee, 2003. ‘Minimum Construction Requirements for
Water Bores in Australia, 2nd Edition’ (ARMCANZ Guidelines).
Paine, A.G.L, Gregory, C.M. and, Clarke, D.E. 1968. ‘Australia 1:250,000 Geological Series, Ayr,
Queensland, Sheet SE55-15, First Edition, 1968’, Bureau of Mineral Resources, Geology &
Geophysics.
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1
Appendix A - QA/QC Assessment
The following sections describe the components of the Quality Assurance and Quality Control
(QA/QC) assessment of the Data Quality Objectives by consideration of the data quality indicators
– DQIs (precision, accuracy, reproducibility, completeness and comparability).
Data Quality Indicators
The project DQIs have been established to set acceptance limits on field and laboratory data
collected as part of these works. For both field and laboratory procedures, acceptance limits are
set at different levels for different projects and by the laboratories.
Non-compliances with acceptance limits are to be documented and discussed in the report. The
DQIs are as follows:
Data Quality Indicators
DQI Field Laboratory Acceptability Limits
Pre
cisi
on
Sampling methodologies appropriate and complied with.
Collection of intra-laboratory duplicate and inter-laboratory duplicate samples
Analysis of:
Field intra-laboratory duplicate samples (1 in 10 samples)
Field inter-laboratory duplicate samples (1 in 20 samples)
Laboratory duplicate samples
Organics
RPD of < 50% Inorganics
RPD of < 30%
RPD of < 50%
Acc
ura
cy
Sampling methodologies appropriate and complied with.
Collection of rinsate blanks
Analysis of:
Rinsate blanks (1/day/equipment)
Method blanks
Matrix spikes
Matrix spike duplicates
Laboratory control samples
Surrogate spikes
Reference Materials
Non-detect for CoC
Non-detect for CoC
70 to 130%
RPD of <50%
70 to 130 %
70 to 130%
Varies
Rep
rese
nta
tive
ne
ss
Appropriate media sampled according to the SAQP
All media identified in the SAQP sampled.
All samples analysed according to the SAQP
All samples analysed according to the SAQP
Co
mp
arab
ility
Same sampling methodologies used on each day of sampling
Experienced sampler
Climatic conditions
Same types of samples collected
Same analytical methods used (including clean-up)
Sample laboratory detection limits (justify/quantify if different)
Same laboratories (NATA accredited)
Same units
As per NEPC (1999c)
< nominated criteria where applicable
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DQI Field Laboratory Acceptability Limits C
om
ple
ten
ess
All critical locations and media sampled
All samples collected
Sampling methodologies appropriate and complied with
Experienced sampler
Documentation correct
All critical samples analysed and all analytes analysed according to the Technical Specification
Appropriate methods
Appropriate laboratory detection limits
Sample documentation complete
Sample holding times complied with
As per NEPC (1999c)
< nominated criteria where applicable
As per NEPC (1999b)
Intra-laboratory and Inter-laboratory Duplicate
Samples
The purpose of field duplicate samples is to estimate the variability of a given characteristic or
contaminant associated with a population. Intra-laboratory duplicate samples were collected and
analysed at a rate of at least one in ten primary samples. Inter-laboratory duplicate samples were
collected and analysed at a rate of at least one in twenty primary samples.
During the sampling program in April, the duplicate and triplicate samples were obtained from
BH315 which was located within T1. Within 200m of the well, some workshops and a petrol
bowser were observed. In order to account for the possibility of groundwater contamination
within this area, the duplicates were collected from this location. During the June sampling
program, only a duplicate sample was collected.
Duplicated groundwater samples were collected from the same well after the primary sample was
collected. All duplicate samples were labelled to conceal their relationship to the primary sample
from the laboratory and the key to the duplicate samples was recorded in the field note book.
It is common that significant variation in duplicate results is often observed (particularly for solid
matrix samples) due to sample heterogeneity or low reported concentrations near the EQL. The
overall precision of field duplicates, laboratory split samples and laboratory duplicates is generally
assessed by their Relative Percent Difference (RPD), given by:
where D1 is the primary sample measurement
D2 is the duplicate sample measurement
It is expected that RPD’s would be less than 50%, and if not, liaison with the laboratory will be
undertaken and samples will be reanalysed, if required.
A summary of the calculations for soil RPDs is presented in Table 5-2 and a summary of the
exceedances is presented in the table below.
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Groundwater Duplicates
Sample Pair Duplicate
Type
Analytes Exceedances
BH315 and QC302 Inter Major Anions Carbonate as CaCO3 = 195%
Bicarbonate as CaCO3 = 199%
The RPD exceedances summarised above show exceedances of selected major anions within
groundwater. Given that this is between a primary and an inter-laboratory duplicate, it is possible
that different methodologies or different laboratory detection limits may have affected the
concentration levels. In addition, given that the lower result in both analytes is below detection
limits these exceedances would not affect the reliability that can be placed on the results of the
investigation.
The actual intra-laboratory duplicate sample frequency was as follows:
April Samples - 1 duplicate sample per 10 primary samples (10%);
June Samples - 1 duplicate sample per 11 primary samples (9%);
The actual inter-laboratory duplicate sample frequency was as follows:
April Samples - 1 duplicate sample per 10 primary samples (10%);
June Samples - 0 duplicate sample per 11 primary samples (0%);
Therefore the frequency of all duplicate samples from the April groundwater sampling met or was
beneath the criteria outlined in the SAQP and DQIs however the frequency for the June
groundwater sampling did not meet the criteria. Given the low concentrations across the region
from the April results, this is not expected to affect the reliance that can be placed on the
investigation.
Decontamination and Rinsate Blanks
Groundwater wells were purged and sampled using disposable dedicated ‘medical grade’ tubing
for the peristaltic pump. New disposable tubing was used at each sampling location.
In addition, silicon tubing is used for sampling however this was reusable tubing. Between each
monitoring well, clean water and Decon 90 (a phosphate-free detergent) was run through the
tubing to decontaminate it.
Also during the groundwater sampling, an interface probe was reused. This was decontaminated
between each well sampling location by scrubbing with a solution of Decon 90 (a phosphate-free
detergent) followed by a rinse in potable water.
During the groundwater sampling program, the following rinsate blanks were collected on each
day and analysed:
ERB24 (24th April 2012);
ERB25 (25th April 2012);
ERB26 (26th April 2012);
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T0 EIS - Groundwater 4
ERB27 (27th April 2012);
ERB28 (28th April 2012);
ERB5 (5th June 2012);
ERB6 (6th June 2012); and
ERB7 (7th June 2012).
Rinsate blanks were collected by running laboratory prepared deionised water over the interface
probe and directly into laboratory prepared sampling containers for analysis. Samples for analysis
of heavy metals were first filtered through 0.45 micron stericups.
Concentrations of analytes in the April sampling round were less than the laboratory detection
limits in each rinsate blank with the exception of ERB24 which had concentrations of Total
Dissolved Solids (TDS) slightly above the detection limits. This could be due to some dust or small
particulates in the water or in the sample bottle prior to sampling. Due to the small concentration,
this would not affect the reliance that can be placed on the decontamination procedures and as
such it is considered that the decontamination procedures undertaken during the works were
sufficient to prevent cross contamination between locations.
Each piece of reusable equipment was properly cleaned with Decon 90 and water between each
sampling location
Laboratory QA/QC
Samples were submitted to the following laboratories:
Envirolab in Chatswood, NSW (primary laboratory):
- 72608 – April 2012 Groundwater Analysis;
- 74661 and 74661A – June Groundwater Analysis;
- 74663 and 74663A – June Groundwater Analysis; and
- 74664 and 74664A – June Groundwater Analysis.
ALS in Smithfield, NSW (secondary laboratory):
- ES1210949 – April Inter-Laboratory Groundwater Analysis.
The Envirolab accreditation number is 2901, and its analytical procedures are based on
established internationally-recognised procedures such as those published by the US EPA, APHA,
AS and NEPM (1999).
ALS NATA accreditation number is 825, and its analytical procedures are based on methods
referenced from NEPC, ASTM, modified USEPA / APHA as well as some in house documented
methods that are detailed below and in the laboratories reports if utilised.
Based on the assessment of field and laboratory QA/QC data, given the discrepancies outlined
above, the reported field and analytical results are considered to be of a quality that can be relied
upon for the purposes of this environmental investigation works.