34
Groundwater Management Plan Tanilba Northern Dune Lots 11-13 Extraction Zone Environmental Management December 2014
Groundwater Management Plan Tanilba Northern Dune Lots 11-13 Extraction Zone
Environmental Management
December 2014
Document Control Author: Ian Oppy Date: 15 December 2014 Status: Final Distribution: NSW Department of Planning and Infrastructure NSW Office of Water Hunter Water Corporation Sibelco Australia Limited Report No: 20130809ND
TABLE OF CONTENTS 1. INTRODUCTION ........................................................................................................................1
1.1 Background .......................................................................................................................1 1.2 Purpose and Scope ...........................................................................................................2 1.3 Report format ...................................................................................................................2
2. MONITORING PLAN ......................................................................................................................3 2.1 Monitoring Network ...............................................................................................................3 2.2 Groundwater Measurement and Sampling ............................................................................3 2.3 Baseline Groundwater Level Monitoring ...............................................................................3
2.3.1 Groundwater Level Monitoring Schedule .......................................................................3
2.3.2 Provisional Baseline Groundwater Level Results ............................................................3
2.4 Baseline Groundwater Quality Monitoring ............................................................................4 2.4.1 Groundwater Quality Monitoring Schedule and setting of Trigger Values .....................4
2.4.2 Provisional Baseline Groundwater Quality Results .........................................................5
2.4.3 Analysis of Provisional Baseline Groundwater Quality Results .......................................5
2.4.4 Provisional Trigger Values ...............................................................................................5
2.5 Operational Groundwater Level Monitoring ..........................................................................5 2.5.1 Groundwater Level Monitoring Schedule .......................................................................5
2.5.2 Exceedance Investigation ................................................................................................5
2.6 Operational Groundwater Quality Monitoring ......................................................................6 2.6.1 Groundwater Quality Monitoring Schedule ....................................................................6
2.6.2 Exceedance Investigation ................................................................................................6
2.6.3 Groundwater Assessment Plan .......................................................................................6
2.6.4 Groundwater Contamination Remediation Plan .............................................................6
3. OTHER REQUIREMENTS ................................................................................................................7 3.1 Predicted Maximum Groundwater Elevation .........................................................................7 3.2 Groundwater Dependent Ecosystems ....................................................................................7 3.3 Acid Sulphate Soil Contingency Plan ......................................................................................8
4 REPORTING AND REVIEW ..............................................................................................................9 4.1 Quarterly Reporting of Groundwater Level Monitoring ........................................................9 4.2 Six-Monthly Groundwater Quality Reporting ........................................................................9 4.3 Annual Environmental Management Report .........................................................................9
REFERENCES .................................................................................................................................. 10 Appendix 1: Location of Extraction Zones ..................................................................................... 11 Appendix 2: Northern Dune Groundwater Monitoring Network.................................................. 12 Appendix 3: SAL4 and SAL5 Groundwater Level ........................................................................... 13 Appendix 4: Lots 11-13 Baseline Groundwater Quality ................................................................ 15 Appendix 5: Statistical analysis of provisional results ................................................................... 28 Appendix 6: PMGE surface and piezometer PMGE ....................................................................... 29 Appendix 7: Piezometer PMGE ..................................................................................................... 30
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1
1. INTRODUCTION 1.1 Background Sibelco Australia Limited (Sibelco), formerly Unimin Australia Limited, currently operates a white silica sand extraction operation on the Tanilba Northern Dune near Oyster Cove on the Tilligerry Peninsula, NSW. See Figure 1.
Figure 1: Location of the Tanilba Northern Dune operation The operation is subject to the approval granted by the NSW Land and Environment Court (Application No. 10013 of 2000) and a Court approved Environmental Management Plan, which has been amended and updated as required since project commencement. In addition to the requirements of the conditions of consent relating to groundwater, the NSW Office of Water (NOW) in conjunction with Hunter Water Corporation (HWC) and the NSW Government Department of Planning and Infrastructure, have specified additional groundwater monitoring requirements. Sand is extracted at Northern Dune as a rolling west to east cycle in approved zones of clearing native vegetation, extracting sand, reforming a new surface and planting of native vegetation. Sand extraction commenced in 2003 at Zone 1 and 10 years later at Zone 4 in 2013. Following the completion of Zone 4 Sibelco plans to extend silica sand extraction to the Lots 11-13 area immediately north and adjacent to the existing approved extraction area. See Appendix 1.
2
1.2 Purpose and Scope This Groundwater Management Plan (GMP) has been developed to ensure compliance with the conditions of consent and licensing requirements stipulated by the relevant regulatory authorities, during development and operation of Lots 11-13 at Northern Dune. The broad primary objectives of the GMP are to develop an implementable approach to manage the potential impact of:
1. Sand extraction on groundwater level and quality
2. Contaminated groundwater on Groundwater Dependent Ecosystems
3. Acid sulphate and potentially acid sulphate soils
The GMP has been developed to provide a formal framework for ongoing monitoring of groundwater at the site. It is intended that this program will provide sufficient data of adequate quality to achieve the following specific objectives:
• Monitor groundwater levels and quality in the vicinity of the site, refine knowledge of the current depth to groundwater and natural fluctuations in groundwater level, and document baseline conditions;
• Demonstrate that sand extraction has not resulted in the release of contaminants that might impact upon groundwater resources
• Demonstrate that sand extraction does not significantly alter the groundwater flow regime within the aquifer
• Demonstrate that sand extraction does not impact on Groundwater Dependent Ecosystems
• Provide a contingency plan to manage any acid sulphate soils and potentially acid sulphate soils encountered during quarrying operations
1.3 Report format This report is structured as follows:
• Sections 2 outlines groundwater monitoring management arrangements
• Section 3 outlines other requirements eg. Groundwater Dependent Ecosystems
• Section 4 outlines reporting and review
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2. MONITORING PLAN 2.1 Monitoring Network Sand extraction commenced in Extraction Zone 1 at Northern Dune in 2003 following the initiation of groundwater monitoring in 2002. The monitoring network has expanded with the installation of new piezometers into planned zones and in 2011 the network consisted of nineteen piezometers (Sibelco, 2011). In 2012 the network was further expanded to twenty one piezometers with the installation of piezometers SAL4 and SAL5 at the Lots 11-13 planned extraction zone. See Appendix 2. Baseline groundwater level and quality monitoring is undertaken within a planned zone prior to commencing sand extraction. Baseline groundwater quality samples are collected to create Trigger Values for comparison against sample concentrations during extraction operations and post-extraction operations to assist in detecting any changes in groundwater level and quality at the site. Since the Groundwater Management Plan is approved prior to the commencement of operations baseline monitoring is incomplete and trigger values determined from the incomplete monitoring are provisional.
2.2 Groundwater Measurement and Sampling
Groundwater monitoring data can be collected in numerous ways by a range of people from suitably trained Sibelco personal to various consultants. Groundwater monitoring at Northern Dune is described in detail in the Sibelco Groundwater Monitoring Guidelines. These guidelines are regularly updated to reflect best practices.
2.3 Baseline Groundwater Level Monitoring 2.3.1 Groundwater Level Monitoring Schedule Baseline groundwater level monitoring within a new zone is initiated as soon as possible after the completion of the extension of the monitoring network. At Lots 11-13 the NOW requested that data loggers be installed into the two new piezometers, SAL4 and SAL5, to log groundwater levels every 6 hours for 3 months. After 3 months groundwater level data was analysed and further monitoring was undertaken until the NOW was satisfied that there was sufficient groundwater level data for understanding groundwater level behaviour. Baseline groundwater level monitoring ceases when sand extraction commences and the Operational Monitoring Plan is initiated. 2.3.2 Provisional Baseline Groundwater Level Results Groundwater level monitoring of SAL4 and SAL5 commenced on the 29 May 2012 with the installation of data loggers to record 6 hourly data. The SAL5 data logger subsequently failed in June 2012 as did a later installed replacement, because of elevated groundwater causing the equipment to malfunction, and manual readings were subsequently undertaken of SAL5 on a fortnightly basis. SAL4 and SAL5 groundwater levels are shown in Appendix 3. In July 2013 SAL4 was incorporated into the site wide routine monitoring program and SAL5 was removed from the Groundwater Monitoring Network.
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2.4 Baseline Groundwater Quality Monitoring 2.4.1 Groundwater Quality Monitoring Schedule and setting of Trigger Values Baseline groundwater quality monitoring is undertaken prior to conducting any sand extraction within a planned zone. This data is used to create Trigger Values for comparison against sample concentrations during extraction operations and post-extraction operations to assist in detecting any changes in groundwater quality within the zone. At Lots 11-13 the NOW requested that water quality sampling be undertaken for 3 months. After 3 months groundwater quality data was analysed and further monitoring was undertaken until the NOW was satisfied that there was sufficient groundwater quality data for understanding groundwater quality behaviour. Baseline groundwater quality monitoring ceases when sand extraction commences and the Operational Monitoring Plan is initiated. Groundwater Quality Parameters sampled for establishing baseline hydro-geochemical conditions and Trigger Values determined for specified parameters for SAL4 are displayed in Table 1.
Table 1: Groundwater Quality Parameters and SAL4 Trigger Values Note: 1. Provisional Trigger Values may be changed following review and statistical analysis of natural variability on completion of baseline monitoring 2. Trigger Values not determined for major ions (cations and anions)
Process SAL4 Provisional
Acidity/ Alkalinity 0.01 pH unit 5.08 - 6.63
Salinity 1 μS/cm 213 μS/cm Dissolved 0.01 mg/L 0.001 mg/L
Total 0.01 mg/L 0.002 mg/LDissolved 0.001 mg/L 0.093 mg/L
Total 0.001 mg/L 0.116 mg/LDissolved 0.1 mg/L 3.21 mg/L
Total 0.1 mg/L 3.64 mg/L 0.002 mg/L 0.02 mg/L 0.005 mg/L 0.05 mg/L
0.1 mg/L 1 mg/L 0.1 mg/L 1 mg/L 1 mg/L 1 mg/L 1 mg/L 1 mg/L 1 mg/L 1 mg/L 1 mg/L 1 mg/L
pH
Trigger ValuesDetection Limit Parameters Tested
Cations
Anions
Heavy Metals
TPH
EC
C6-C9
Bicarbonate (HCO3)
C29-C40 Magnesium (Mg)
Arsenic
Manganese
Iron
C10-C14 C15-C28
Carbonate (CO3)
Baseline monitoring
results
10x detection limit
N/A N/A
Calcium (Ca) Potassium (K) Sodium (Na) Chloride (Cl)
Sulphate (SO4)
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2.4.2 Provisional Baseline Groundwater Quality Results Groundwater quality monitoring of SAL4 and SAL5 commenced on the 5 July 2012 and results are provided in Appendix 4. In July 2013 SAL4 was incorporated into the site wide routine monitoring program and SAL5 was removed from the Groundwater Monitoring Network. 2.4.3 Analysis of Provisional Baseline Groundwater Quality Results Groundwater quality at Northern Dune is driven by the nature of rainfall and properties of the unsaturated zone. Rainfall entering the soil zone undergoes significant changes in chemical composition and pH by processes such as root respiration and decomposition of organic matter via chemical reactions such as sorption and redox. The chemical constituency of infiltrating water in turn modifies groundwater chemistry by processes such as dilution/concentration and dissolution/precipitation. The depth of groundwater can also influence groundwater quality by evaporative concentration although at Northern Dune licence conditions protect against exposing this effect as extraction is limited to one metre above predicted maximum groundwater elevation and also because capillary rise in sand is less than one metre. Groundwater salinity generally increases with increased residence time (with groundwater flow) and the salinity of SAL4 is generally lower than SAL5 except during high rainfall events when salinities are similarly relatively high due to leaching of salt stored in the unsaturated zone . A more detailed analysis of Lots 11-13 groundwater level and quality results was provided in a Response to Submissions report by Sibelco (2012). 2.4.4 Provisional Trigger Values The effect of multiple processes on groundwater quality parameters and therefore setting Trigger Values is that water quality data is often multiple-modal (non-normal distribution) and simple statistical analysis may not adequately represent processes leading to water quality change. The Provisional Baseline Trigger Values provided in Table 1 have been derived based on maximum and minimum rather than mean plus or minus two standard deviations as per the current GMP because maximum and minimum are observed results. The metals arsenic, manganese and iron demonstrate non-normal distribution because the mean plus two standard deviations exceeds the maximum. See Appendix 5. Baseline Groundwater Trigger Values will be finalised when sand extraction commences.
2.5 Operational Groundwater Level Monitoring 2.5.1 Groundwater Level Monitoring Schedule The NOW and HWC require that groundwater levels in monitoring wells be measured monthly, but that this frequency be increased to weekly for a period of four weeks following any period when rainfall at Williamtown equals or exceeds 100 millimetres over a seven day rolling period, or when water levels are within 100 millimetres of the maximum predicted groundwater levels. Monitoring will continue for the duration of mining, and until the release of the obligation by the NOW and HWC. General (visual) observation of currently mined and progressively rehabilitated areas will be carried out regularly to check for the occurrence of surface water ponding or the presence of groundwater windows. 2.5.2 Exceedance Investigation If analysis of groundwater level monitoring sample shows anomalous levels above the Predicted Maximum Groundwater Elevation (PMGE) which is outlined in Section 3.1 then groundwater in the effected monitoring well will be retested again as soon as possible and in any case within fourteen days to
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confirm the results. If retesting confirms the anomaly, NOW and HWC will be notified immediately, by telephone and in writing, and within fourteen days of confirmation and an investigation will be initiated.
2.6 Operational Groundwater Quality Monitoring 2.6.1 Groundwater Quality Monitoring Schedule Operational groundwater quality monitoring will be carried out six monthly once mining commences in a zone, and will continue at a lower frequency for four years after mining ceases or as otherwise determined by the NOW and HWC. The monitoring frequency is subject to review in consultation with the NOW and HWC. 2.6.2 Exceedance Investigation If analysis of water quality monitoring sample shows anomalous concentrations of any analyte above Trigger Values, then groundwater in the effected monitoring well will be resampled and tested again as soon as possible and in any case within fourteen days to confirm the results. If resampling confirms the anomaly, NOW and HWC will be notified immediately, by telephone and in writing, and a Groundwater Assessment Plan will be prepared within twenty eight days of confirmation. Note: Hydrocarbons pose the greatest potential threat to groundwater. The hydrocarbon risk is reduced by the implemented control measure that no refuelling or mechanical work is undertaken at Northern Dune. 2.6.3 Groundwater Assessment Plan The Groundwater Assessment Plan will:
• Identify the specific groundwater quality parameters
• Establish the spatial and temporal variability of the water quality parameters
• Determine whether the anomaly is natural variability (background) or potentially related to a site activity
• Provide an assessment of the potential impact upon the groundwater resource
If the exceedance is determined to be potentially related to a site activity then the Groundwater Assessment Plan will outline a proposed sampling plan to obtain sufficient information to prepare a Groundwater Contamination Remediation Plan if and as required. Note: The procedure described above will only be implemented if investigation monitoring confirms the presence of contaminants in groundwater at concentrations above provisional limits. 2.6.4 Groundwater Contamination Remediation Plan A Groundwater Contamination Remediation Plan will be prepared based on the results of the Groundwater Assessment Plan. The plan will describe the process to protect groundwater resources from further pollution and, if necessary, nominate a method to remediate impacted groundwater. This plan will be submitted to the NOW and HWC for approval prior to implementation. Note: The procedure described above will only be implemented following development of a Groundwater Assessment Plan.
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3. OTHER REQUIREMENTS At the request of the Department of Planning this section of the GMP outlines the Predicted Maximum Groundwater Elevation at Northern Dune; demonstrates that sand extraction does not impact on Groundwater dependent Ecosystems, and provides a contingency plan to manage acid-sulphate soils.
3.1 Predicted Maximum Groundwater Elevation Planned sand extraction is based on a predicted maximum groundwater elevation (PMGE) in order to protect the groundwater resource from the surface environment and also the surface environment from groundwater. A PMGE surface was created for Lots 11-13 in September 2013. The PMGE surface was constructed from the predicted maximum groundwater elevations of piezometers, which at Northern Dune are the observed maximum groundwater elevations. The PMGE surface was created in Mapinfo using an Inverse Distance Weighting method with a 3rd Power weight model, 50m cell size and the maximum calculated value of coincident points. The PMGE surface does not represent an actual surface that occurred in the past and cannot be correlated to the seasonally varying groundwater divide, but rather it is an artificial surface created from groundwater levels at different dates. The prediction is therefore cautionary because it overstates actual maximum groundwater elevation which occurred from other sample points at the time of peak measurement. In 2014 the September 2013 PMGE was reviewed by NOW and HWC. HWC requested that a new PMGE surface be constructed because HWC considered the groundwater divide to be unrealistic. A saddle in the groundwater divide was caused by the creation of a PMGE surface which honoured the previously unrecognised incorrect PMGE of piezometer ACI-12 (being 9.28mAHD but should have been 8.93mAHD).. Auger testing of groundwater was undertaken on the 9th October 2014 confirmed the spurious nature of the ACI-12 PMGE and also provided data from which additional groundwater level points were determined and were used in the construction of a new PMGE. The October 2014 PMGE surface is provided as Appendix 6.
3.2 Groundwater Dependent Ecosystems
Groundwater Dependent Ecosystems (GDE) are “any system that uses groundwater at any time for any duration in order to maintain its composition and condition” (SKM, 2012). Non-dependent ecosystems occur mostly in recharge areas and have no connection to groundwater. The risk of impacting on a GDE at Lots 11-13 is low because:
• Planned sand extraction is of a sand dune where depth to groundwater may be in excess of 10 metres and it is unlikely that vegetation is dependent on groundwater and instead rely on soil moisture (ie. no connection)
• The sand dune is a recharge area
• A study by SKM in 2012 for the NOW on NSW Coastal GDE’s did not identify a GDE at the site (NOW, 2012) and the site is not listed in the National Atlas of GDE’s
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3.3 Acid Sulphate Soil Contingency Plan Acid sulphate soils are naturally occurring soils, sediments or organic substrates that are formed under waterlogged conditions. These soils contain iron sulphide minerals which are benign in groundwater (saturated zone) but react with oxygen to form sulphuric acid in the unsaturated zone. The risk of encountering an acid sulphate soil at Lots 1-13 is low because:
• Sand extraction is of a clean white sand which has no potential for forming acid sulphate soils
• The underlying Coffee rock has potential for forming acid sulphate soils but because sand extraction is limited to 1 metre above the predicted maximum groundwater elevation of groundwater in this sand aquifer sand extraction will be at least 1 metre above the Coffee rock
If an acid-sulphate soil was unearthed, work will immeadiately cease and an Acid Sulphate Soil Contingency Plan be prepared to the satisfaction of Hunter Water and the NSW Office of Water which appropriately outlines how groundwater resources will be protected, and if required, will outline a method to remeadiate impacted groundwater.
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4 REPORTING AND REVIEW 4.1 Quarterly Reporting of Groundwater Level Monitoring The results of the groundwater levels measured in all monitoring bores will be submitted to the NOW and HWC on a quarterly basis.
4.2 Six-Monthly Groundwater Quality Reporting The results of the groundwater quality monitoring will be compiled in a summary report which will be submitted to the NOW and HWC on a six-monthly basis.
4.3 Annual Environmental Management Report The results of the measured groundwater levels and quality analysis will also be summarised in tables and presented as both timeline plots and contour levels, and will be submitted to the NOW and HWC as part of the Annual Environmental Management Report (AEMR). This AEMR will also include rainfall data from Williamtown and descriptions of any environmental incidents, any ponding events, and any implementations of the Emergency Response Plan. Immediate reports to NSW Office of Water and HWC will be made if: 1. Any recorded water table level exceeds the benchmark highest predicted water levels; and
2. Any observations are made of water ponded on the surface for more than seven (7) consecutive days.
Data will be validated against monitoring program QA objectives, and interpreted with reference to the overall monitoring program objectives. The monitoring program and annual reporting will be used to establish a record of groundwater quality. Data will be reviewed and any trends identified and possible causes investigated. The Groundwater Management and Monitoring Plan will be reviewed prior to commencement of operations in each new zone. If this review indicates the desirability of change to programs or procedures, then a submission outlining the proposed changes and the need for them will be made to the NOW and HWC.
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REFERENCES AECOM (2009) Literature Review on Groundwater Conditions Underlying the Northern Dune and the Potential Impacts of the White Sand Mining Operation. Unpublished report AECOM (2010) Development of New Trigger Levels and a Data Analysis Protocol. Unpublished Report NSW Office of Water (2012) Risk Assessment guidelines for groundwater dependent ecosystems. Volume 2 – Worked examples for seven pilot coastal aquifers in NSW. Published by the Department of Primary Industries. SIBELCO (2011a) Tanilba Northern Dune Groundwater Management Plan. Unpublished report SIBELCO (2011b) Maximum groundwater elevation prediction at Tanilba Northern Dune operation. Unpublished report SIBELCO (2013) Groundwater Monitoring Guidelines SKM (2012) Summary Report for NWC NSW Coastal Groundwater Dependent Ecosystem and Groundwater Quality Project Unpublished Report
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Appendix 1: Location of Extraction Zones
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Appendix 2: Northern Dune Groundwater Monitoring Network
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Appendix 3: SAL4 and SAL5 Groundwater Level
0
5
10
15
20
25
30
35
40
45
50
6.00
6.50
7.00
7.50
8.00
8.50
9.0001
-May
-12
15-M
ay-1
2
29-M
ay-1
2
12-Ju
n -12
26-Ju
n-12
10-Ju
l-12
24-Ju
l-12
07-A
ug-1
2
21-A
ug-1
2
04-S
ep-1
2
18-S
ep-1
2
02-O
ct-1
2
16-O
ct-1
2
30-O
ct-1
2
13-N
ov-1
2
27-N
ov-1
2
11-D
ec-1
2
25-D
ec-1
2
08-Ja
n-13
22-Ja
n-13
05-F
eb-1
3
Rain
fall
(mm
)
RWL (
m)
Date
SAL4
SAL4Rainfall
14
0
5
10
15
20
25
30
35
40
45
50
6.00
6.50
7.00
7.50
8.00
8.50
9.00
01-M
ay-1
2
15-M
ay-1
2
29-M
ay-1
2
12-Ju
n -12
26-Ju
n-12
10-Ju
l-12
24-Ju
l-12
07-A
ug-1
2
21-A
ug-1
2
04-S
ep-1
2
18-S
ep-1
2
02-O
ct-1
2
16-O
ct-1
2
30-O
ct-1
2
13-N
ov-1
2
27-N
ov-1
2
11-D
ec-1
2
25-D
ec-1
2
08-Ja
n-13
22-Ja
n-13
05-F
eb-1
3
Rain
fall
(mm
)
RWL (
m)
Date
SAL5
SAL5
Rainfall
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Appendix 4: Lots 11-13 Baseline Groundwater Quality
0
10
20
30
40
50
60
70
80
90
100
3.0
4.0
5.0
6.0
7.0
8.0
9.0Ap
ril 2
012
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
pH
Date
pH
SAL4 pH SAL5 pH
ACI-13 pH ACI-14 pH
ACI-11 pH ACI-16 pH
ACI-2 pH ACI-5 pH
Rainfall
16
0
10
20
30
40
50
60
70
80
90
100
0
50
100
150
200
250
300
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
EC
Date
EC
SAL4 EC SAL5 ECACI-13 EC ACI-14 ECACI-11 EC ACI-16 ECACI-2 EC ACI-5 ECRainfall
17
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Na
Date
Na
SAL4 Na SAL5 Na
ACI-13 Na ACI-14 Na
ACI-11 Na ACI-16 Na
ACI-2 Na ACI-5 Na
Rainfall
18
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
HCO
3
Date
HCO3
SAL4 HCO3SAL5 HCO3ACI-13 HCO3ACI-14 HCO3ACI-11 HCO3ACI-16 HCO3ACI-2 HCO3
19
0
10
20
30
40
50
60
70
80
90
100
0
5
10
15
20
25
30
35
40
45
50
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
SO4
Date
SO4
SAL4 SO4 SAL5 SO4
ACI-13 SO4 ACI-14 SO4
ACI-11 SO4 ACI-16 SO4
ACI-2 SO4 ACI-5 SO4
Rainfall
20
0
10
20
30
40
50
60
70
80
90
100
0
5
10
15
20
25
30
35
40
45
50
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Cl
Date
Cl
SAL4 Cl SAL5 ClACI-13 Cl ACI-14 ClACI-11 Cl ACI-16 ClACI-2 Cl ACI-5 ClRainfall
21
0
10
20
30
40
50
60
70
80
90
100
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Diss
olve
d Fe
Date
Dissolved Fe
SAL4 D FeSAL5 D FeACI-13 D FeACI-14 D FeACI-11 D FeACI-16 D FeACI-16 D Fe
22
0
10
20
30
40
50
60
70
80
90
100
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Tota
l Fe
Date
Total Fe
SAL4 T FeSAL5 T FeACI-13 T FeACI-14 T FeACI-11 T FeACI-16 T FeACI-2 T Fe
23
0
10
20
30
40
50
60
70
80
90
100
0.000
0.005
0.010
0.015
0.020
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Diss
olve
d As
Date
Dissolved As
SAL4 D As SAL5 D AsACI-13 D As ACI-14 D AsACI-11 D As ACI-16 D AsACI-2 D As ACI-5 D AsRainfall
24
0
50
100
150
200
250
0.000
0.005
0.010
0.015
0.020
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Tota
l As
Date
Total As
SAL4 T As SAL5 T As
ACI-13 T As ACI-14 T As
ACI-11 T As ACI-16 T As
ACI-2 T As ACI-5 T As
Rainfall
25
0
50
100
150
200
250
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.160
0.180
0.200
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Diss
olve
d M
n
Date
Dissolved Mn
SAL4 D Mn SAL5 D Mn
ACI-13 D Mn ACI-14 D Mn
ACI-11 D Mn ACI-16 D Mn
ACI-2 D Mn ACI-5 D Mn
Rainfall
26
0
50
100
150
200
250
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.160
0.180
0.200
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Tota
l Mn
Date
Total Mn
SAL4 T Mn SAL5 T Mn
ACI-13 T Mn ACI-14 T Mn
ACI-11 T Mn ACI-16 T Mn
ACI-2 T Mn ACI-5 T Mn
Rainfall
27
0
10
20
30
40
50
60
70
80
90
100
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
April
201
2
May
201
2
June
201
2
July
201
2
Augu
st 2
012
Sept
embe
r 201
2
Oct
ober
201
2
Nov
embe
r 201
2
Dece
mbe
r 201
2
Janu
ary
2013
Febr
uary
201
3
Mar
ch 2
013
April
201
3
May
201
3
June
201
3
Rain
fall
(mm
)
Diss
olve
d Fe
Date
Dissolved and Total Fe
SAL4 D Fe
SAL5 D Fe
SAL4 T Fe
SAL5 T Fe
Rainfall
28
Appendix 5: Statistical analysis of provisional results
Minimum Mean - 2SD Minimum Mean - 2SD5.08 4.80 5.00 5.19
Maximum Mean + 2SD Maximum Mean + 2SD6.63 6.41 6.69 6.72213 198 203 192
Dissolved 3.21 3.30 1.38 1.43Total 3.64 3.79 1.88 1.67
Dissolved 0.001 0.001 0.002 0.002Total 0.002 0.003 0.003 0.004
Dissolved 0.093 0.111 0.038 0.039Total 0.116 0.123 0.052 0.049
Iron
Arsenic
EC
pH
Manganese
PARAMETER SAL4 SAL5
pH
29
Appendix 6: PMGE surface and piezometer PMGE
October 2014 PMGE contours (blue) and September 2013 PMGE contours (pink) Piezometers and auger points, notated A1-5 (red dots) NOW endorsed PMGE of piezometers (black), Calculated PMGE for new surface (blue), 9th October 2014 mAHD (green) Groundwater divide (blue) and current surface contours (black) and Groundwater discharge zone (cross-hatched red)
30
Appendix 7: Piezometer PMGE
Bore Easting NorthingDate of first
reading DBNS
Max groundwater
elevationDate of max groundwater PMGE PDBNS
ACI-1 402034 6376815 24-Jan-05 0.23 8.82 18-Jun-08 8.82 0.23ACI-2 402539 6376805 24-Jan-05 0.00 8.44 18-Jun-08 8.44 0.00ACI-3 402509 6377083 24-Jan-05 0.27 9.47 18-Jun-08 9.47 0.27ACI-4 402468 6377169 24-Jan-05 3.30 9.31 18-Jun-08 9.31 3.30ACI-5 403077 6376892 24-Jan-05 0.00 8.16 21-Jun-07 8.16 0.00ACI-6 403501 6377039 26-May-05 0.00 8.29 29-May-09 8.29 0.00ACI-7 403908 6377763 24-Jan-05 0.04 8.92 18-Nov-10 8.92 0.04ACI-8 404512 6377344 26-May-05 0.20 8.66 26-Jun-09 8.86 0.00ACI-9 402702 6377010 24-Jan-05 5.82 9.31 28-Apr-08 9.31 5.82
ACI-10 404433 6377589 24-Jan-05 4.16 9.49 02-Jul-08 9.49 4.16ACI-11 404948 6377746 26-May-05 1.15 9.54 18-Jun-08 9.54 1.15ACI-12 402872 6377281 24-Jan-05 3.19 9.28 26-Jun-09 9.28 3.19ACI-13 402269 6376892 24-Jan-05 1.47 9.20 28-Apr-08 9.20 1.47ACI-14 403300 6377206 24-Jan-05 0.39 9.02 18-Jun-08 9.02 0.39ACI-15 403756 6377328 24-Jan-05 0.76 9.26 28-Apr-08 9.26 0.76ACI-16 403963 6377456 24-Jan-05 14.91 9.26 05-May-08 9.26 14.91ACI-17 404292 6377608 24-Jan-05 5.85 9.47 28-Apr-08 9.47 5.85ACI-18 404591 6377671 26-May-05 0.00 9.12 10-Jun-08 9.12 0.00ACI-19 404483 6377940 24-Jan-05 7.15 9.06 18-Jun-08 9.06 7.15SAL4 402639 6377413 29-May-12 0.26 8.44 11-Jun-12 8.65 0.00SAL5 402886 6377487 29-May-12 0.06 6.64 05-Jul-12 7.20 0.00SK284 402695 6376662 07-Apr-76 0.24 8.49 17-Apr-00 8.49 0.24
SK3525 404096 6377795 16-Dec-76 0.00 9.55 14-Jul-08 9.55 0.00SK3530 401533 6377031 24-Jan-05 0.00 9.25 10-Jun-08 9.25 0.00
