Uley South – Coffin Bay Observation Well Network Review

Deborah S Clarke, Volmer Berens and Kevin J Dennis

Resource Assessment Department of Water, Land and Biodiversity Conservation

January 2003

Report DWLBC 2003/4

Government of South Australia

Resource Assessment Division Department of Water, Land and Biodiversity Conservation 25 Grenfell Street, Adelaide GPO Box 2834, Adelaide SA 5001 Telephone National (08) (08) 8463 6946 International +61 8 8463 6946 Fax National (08) 8463 6999 International +61 8 8463 6999 Website www.dwlbc.sa.gov.au

Disclaimer Department of Water, Land and Biodiversity Conservation and its employees do not warrant or make any representation regarding the use, or results of the use, of the information contained herein as regards to its correctness, accuracy, reliability, currency or otherwise. The Department of Water, Land and Biodiversity Conservation and its employees expressly disclaims all liability or responsibility to any person using the information or advice.

© Department of Water, Land and Biodiversity Conservation 2003 This work is copyright. Apart from any use as permitted under the Copyright Act 1968 (Cwlth), no part may be reproduced by any process without prior written permission from the Department of Water, Land and Biodiversity Conservation. Requests and inquiries concerning reproduction and rights should be addressed to the Director, Resource Assessment Division, Department of Water, Land and Biodiversity Conservation, GPO Box 2834, Adelaide SA 5001.

Acknowledgements Thanks are forwarded to John Dinninson, David Cunningham, Peter Russ, Mark Sindicic, Natasha Hall, Jason Van Der Akker, for their assistance in the field.

Clarke, D.S., Berens, V., and Dennis, K.J., 2003. Uley South – Coffin Bay Observation Well Network Review. South Australia. Department of Water, Land and Biodiversity Conservation. Report, DWLBC 2003/4.

Foreword

South Australia’s natural resources are fundamental to the economic and social wellbeing of the State. One of the State’s most precious natural resources, water is a basic requirement of all living organisms and is one of the essential elements ensuring biological diversity of life at all levels. In pristine or undeveloped situations, the condition of water resources reflects the equilibrium between rainfall, vegetation and other physical parameters. Development of these resources changes the natural balance and may cause degradation. If degradation is small, and the resource retains its utility, the community may assess these changes as being acceptable. However, significant stress will impact on the ability of a resource to continue to meet the needs of users and the environment. Understanding the cause and effect relationship between the various stresses imposed on the natural resources is paramount to developing effective management strategies. Reports of investigations into the availability and quality of water supplies throughout the State aim to build upon the existing knowledge base enabling the community to make informed decisions concerning the future management of the natural resources thus ensuring conservation of biological diversity.

Bryan Harris Director, Resource Assessment Division Department of Water, Land and Biodiversity Conservation

South – Coffin Bay Observation Well Network Review I Report DWLBC 2003/4

CONTENTS

FOREWORD...... I

CONTENTS ...... II

EXECUTIVE SUMMARY...... 1

INTRODUCTION...... 5

GEOLOGY AND HYDROGEOLOGY ...... 9

AIM ...... 12 Project objectives...... 12 Project outcomes ...... 12 METHODOLOGY...... 13 Establishment of a more rigorous monitoring framework to facilitate the management of the resource...... 13 Identification of the scope of works to be undertaken to understand the hydrodynamic behaviour of these systems in response to recharge and pumping demands...... 13 Definition of current spatial variability of salinity within Southern Basins PWA...... 16 RESULTS ...... 17 Observation well rehabilitation and augmentation ...... 17 Salinity profiling...... 19 FINDINGS...... 20

Coffin Bay ...... 20

Uley South ...... 21 Surface geophysics...... 22 Water level and rainfall monitoring ...... 24 FINDINGS...... 24

Uley South Lens ...... 24

Coffin Bay Lens ...... 29 Water quality...... 29 FINDINGS...... 29

Uley South Lens ...... 29

Coffin Bay Lens ...... 35 DISCUSSION...... 36 Impact of extraction on the Quaternary Aquifer System...... 36 CHANGE IN WATER LEVEL BETWEEN 1997 AND 1999...... 36 CHANGE IN WATER LEVEL BETWEEN 1999 AND 2000...... 36 CHANGE IN WATER LEVEL BETWEEN 2000 AND 2002...... 38

South – Coffin Bay Observation Well Network Review II Report DWLBC 2003/4

TEM SURVEYS ...... 39 TEM inversions ...... 39 Survey details ...... 40 SLEAFORD SHEET (1:50 000)...... 40 Presentation of results ...... 40 Discussion of results ...... 42 ULEY 1000N...... 43 ULEY 2000N...... 45 ULEY 2500N...... 47 ULEY 3000N...... 48 Conclusions ...... 50 ULEY SOUTH AND COFFIN BAY AUTOMATED MONITORING EQUIPMENT...... 51 Uley South Lens...... 51 WATER LEVEL SENSORS...... 51 RAINGAUGES...... 51 Coffin Bay Lens...... 53 WATER LEVEL SENSORS...... 53 RAINGAUGE ...... 53 CONCLUSIONS...... 55

RECOMMENDATIONS...... 57

SHORTENED FORMS...... 59

REFERENCES ...... 60

List of Tables Table 1. Well location and instrument information...... 24 Table 2. Uley South automated monitoring equipment...... 52 Table 3. Coffin Bay automated monitoring equipment...... 54

List of Figures Figure 1. Location of Coffin Bay ‘A’ and Uley South Lens areas over Landsat imagery...... 6 Figure 2. Observation well locations and potentiometric surface contours — Uley South ...... 7 Figure 3. Observation well locations and potentiometric surface contours — Coffin Bay ...... 8 Figure 4. Extent and thickness of the Quaternary Aquifer System — Uley South...... 10 Figure 5. Example of solution feature — a point recharge site typical across Uley South Lens...... 11 Figure 6. Location of project activites — Uley South ...... 14

South – Coffin Bay Observation Well Network Review III Report DWLBC 2003/4

Figure 7. Location of project activites — Coffin Bay ...... 15 Figure 8. Original Uley South observation well, openhole with 65 mm steel piping ...... 18 Figure 9. A rehabilited monitored observation well; PVC casing, cement sealed, capped and tagged ...... 18 Figure 10. Well purging in Uley South — observation well ULE 139, May 2002...... 20 Figure 11. Geophysicists operating the SIROTEM unit at Coffin Bay, May 2002...... 23 Figure 12. Four-hourly water level and rainfall data, Uley South Lens...... 25 Figure 13. Hydrograph of the water level changes in observation well ULE 134 ...... 27 Figure 14. Hydrograph of the water level changes in observation well ULE 147 ...... 27 Figure 15. Hydrograph of the water level changes in observation well ULE 197 ...... 28 Figure 16. Hydrograph of the water level changes in observation well ULE 202 ...... 28 Figure 17. Four-hourly water level and rainfall data, Coffin Bay Lens...... 30 Figure 18. Uley South Lens: Quaternary Bridgewater Formation observation well salinity monitoring (ULE 77, 92, 99, 101, 102, 114, 126, 139, 145, 184, 186) ...... 31 Figure 19. Uley South Lens: Quaternary Bridgewater Formation observation well salinity monitoring (ULE 187–197) ...... 32 Figure 20. Uley South Lens: Tertiary Wanilla Formation observation well salinity monitoring...... 33 Figure 21. Coffin Bay ‘A’ Lens: observation bore salinity monitoring ...... 34 Figure 22. Change in water level in the Bridgewater Fromation ...... 37 Figure 23. Geophysical survey locations — Uley South...... 41 Figure 24. Geophysical interpretation of subsurface structure. Line 1000N, Uley South ...... 44 Figure 25. Geophysical interpretation of subsurface structure. Line 2000N, Uley South ...... 46 Figure 26. Geophysical interpretation of subsurface structure. Line 2500N and 3000N, Uley South ...... 49

List of Appendices APPENDIX A Fieldwork completed on observation wells and groundwater chemistry results...... 61 APPENDIX B Coffin Bay and Uley South observation well information sheets and sonding results...... 67 APPENDIX C Geophysical interpretation and resistivity values...... 108

South – Coffin Bay Observation Well Network Review IV Report DWLBC 2003/4

EXECUTIVE SUMMARY

South Australian Water Corporation (SA Water) and the Department of Water, Land and Biodiversity Conservation (DWLBC) have been working cooperatively on Eyre Peninsula to ensure that extractions of water from underground water supplies, particularly from the Southern Basin Prescribed Wells Area, are managed sustainably. At this time, the Uley South Lens appears to be utilised within its sustainable limits. However, with the expansion of the Uley South Public Water Supply wellfield in 1999– 2000, extraction pressures have changed within the lens. Future residential and irrigation demand on the water resources of the Peninsula will require effective management of the lens with reliance on accurate monitoring of storage and recent recharge history to assure sustainability. A review of the current monitoring networks to evaluate the condition of the Uley South and Coffin Bay observation wells was undertaken between May and July 2002. The adequacy of the information provided by the wells was investigated and positions within the basin where knowledge gaps exist were identified. In addition, surface geophysical surveys were undertaken to establish the position of the saline water interface, pressure transducers were installed in some wells and pluviometers were established in order to provide more accurate storage and recharge information. The aims of this review were: • increasing the information base required for effective management of the resource • augmentation of the network • rehabilitation of ineffective wells where required • installation and application of investigative equipment • carrying out geological surveys. These elements provide important information to enable efficient management, competent volume prediction, and effective recharge and extraction modelling of this complex groundwater system. The ultimate aim is to ensure current and future extraction will be within the available yield of the resource. The project outcomes are: • Establishment of a more rigorous monitoring framework to facilitate the management of the resource. • Identification of the scope of works to be undertaken to understand the hydrodynamic behaviour of these systems in response to recharge and pumping demands. • Definition of variability of salinity within the Uley South and Coffin Bay ‘A’ portions of the Southern Basins Prescribed Wells Area (PWA). Hydrogeological knowledge gaps have been identified at strategic positions within the basin. It is recommended that four historical observation wells are rehabilitated and three new wells drilled and included in the current monitoring network. It has also been identified that three wells within the current network have not been rehabilitated and therefore should be incorporated in the rehabilitation upgrade. There are ~55 openhole historical observation wells within the Uley South Lens. These wells are not currently monitored and not rehabilitated and therefore potentially allow surface runoff to enter and

South – Coffin Bay Observation Well Network Review 1 Report DWLBC 2003/4

mix with the aquifer formation water and also aquifer mixing through the open column. These wells may be used as future observation wells as information is required, however, the expense of rehabilition at this stage may not be warranted. It is recommended that SA Water and DWLBC review the future of these wells. Information from salinity profiling of purged wells can identify the presence of salinity stratification within the aquifer. Well purging, sampling and salinity profiling with sonde was performed on most observation wells. Sonding of all the purged wells indicated a consistant salinity profile with depth in the majority of wells. However, two wells showed stratification. One well is positioned near the lens boundary where no confining layer exists and the other near the swamp where complex recharge and discharge processes may be occurring. Results from transient electromagnetic (TEM) surface geophysics may assist in defining the extent of the groundwater lens and map the saline interface. The analysis of the results of the Uley South survey identified broad hydraulic zones beneath the surface indicative of changes in groundwater salinity. A possible saline interface has been identified in Uley South Lens about 700 m from the coast on transect 1000N at an approximate depth of 85 m. The interpretation is that the saline water body is within the Tertiary Wanilla Formation. However, as there is no clay aquitard beneath the Quaternary sequence in this area there is a potential risk to induce a saline intrusion by groundwater extraction from pump stations USPB 15, 16 and 17. The TEM survey results indicate that at present there is freshwater within the Quaternary Bridgewater Formation at this site and it is uncertain whether this interface is mobile. Future monitoring will determine the risk to the Quaternary Aquifer. It is recommended that an observation bore is drilled to groundtruth the geophysical results and define the geological, hydrogeological and geochemical profile to identify possible salinity stratification, and that a transducer is installed to monitor any water level changes. It is understood that the saline interface in coastal aquifers can be dynamic with movement caused by tidal fluctuations and changes in groundwater level. Monitoring will be necessary to identify the natural range of movement, setting a benchmark to identify any induced intrusion as a result of groundwater extraction. Access for geophysical surveying into the sand dunes south of the Coffin Bay borefield was unachievable by the impedance of the dense vegetation, but several geophysical transects were achieved at Coffin Bay . Unfortunately the data is of lower quality than that from Uley South. Preliminary results show an area of higher resistivity to a depth of ~50 m correlating with geological logs. It is difficult to define whether there is a saline interface present or this confined formation is naturally saline throughout from this data. Analysis is continuing. Ten pressure transducers recording water level changes have been installed in selected wells — two in Coffin Bay and eight in Uley South. Four pluviometers logging rainfall intensities have been also been installed — one in Coffin Bay and three in Uley South. All pluviometers are associated with nearby pressure transducers to enable rainfall recharge relationships to be further researched. This data will provide important long-term information on the aquifer response to rainfall intensity and subsequent recharge and pumping pressures. Groundwater samples show a salinity trend of no change, and in most wells it appears that the previous or current extraction regime is not influencing the salinity. However, a slight expansion of the higher salinity zone about the original wellfield in the Uley South

South – Coffin Bay Observation Well Network Review 2 Report DWLBC 2003/4

Lens is evident. The erratic salinity curve in several Coffin Bay wells is likely due to the bailed method of sampling. Bailed sampling has been shown to give unreliable representation of aquifer salinity. The recommendation is that water samples be collected using accepted sampling standards to give representative salinity measurements of the aquifer formation water. The predominant baseline trend indicates that aquifer salinity is likely to be not increasing. With the expansion of the Uley South Public Water Supply wellfield in 1999, re-distribution of extraction pressures has occurred within the lens. An analysis of the changes in water level from 1997 to 2002 was carried out by contouring the water level changes over this period. Current extraction does not appear to alter the regional water level trends apart from what is estimated to be a short-term adjustment period adjacent to the new production wells. At this time, the Uley South Lens appears to be utilised within its sustainable limits. The work completed in Uley South has shown that further work is required to address the following known knowledge gaps to: • Better define the aquifer and groundwater characteristics throughout the basin by rehabilitating strategic observation wells and constructing up to three new wells that will be geologically and geophysically logged and chemically analysed. • Better define basin geometry by undertaking strategic TEM geophysical surveys and monitor movement of the saline interface. • Establish the extent and thickness of the lens by completing a second series of salinity profiling of wells; comparison with existing salinity profiling results will determine any trend in groundwater salinity and lens size. • Relate aquifer extraction demands to enable salinity and water level trends to recharge events, and sound management decisions. Augmentation and rehabilitation of the monitoring network will provide a more comprehensive knowledge base to effectively observe changes in the basin over time. It is recommended that: • Current observation wells ULE 97, 134 and 147 be rehabilitated. • Historical observation wells SLE 10, ULE 133, ULE 98 and ULE 96 be rehabilitated and included in the current monitoring network. • Three new wells be drilled at strategic positions in the basin where hydrogeological knowledge gaps have been identified. It is further recommended that all drilled wells be geophysically logged. This standard procedure carried out at the completion of drilling provides a high degree of certainty to geological and hydrogeological interpretation. • SA Water and DWLBC review the future of openhole historical wells. • Monitoring frequency remains monthly due to the irregularity of timing and magnitude of recharge events. The assessment of the ongoing monitoring records of water level changes and chemical analyses from sites within the Uley South groundwater monitoring network will give confidence that the current management framework is appropriate for this lens. It is recommended that:

South – Coffin Bay Observation Well Network Review 3 Report DWLBC 2003/4

• The current observation wells, including the new and rehabilitated wells, undergo salinity profiling (with the exception of those wells without casing and completion details). This involves well purging followed by immediate salinity profiling and a repeat salinity profiling after one month residence time. The information from a second and third profiling coupled with the first should give clear indication on salinity stratification within the basin. • A second round of water samples be collected during well purging. If conducted during Autumn these will assist in determining any trend in lens salinity which will help to establish the extent and thickness of the lens and assist in defining the saline interface when compared with the July 2002 results. • SA Water review the groundwater sampling technique to ensure that samples are representative of the aquifer. A pumped sample, not bailed, is recommended. Other recommendations are: • The strategic placement of two additional transducers in either the new or rehabilitated wells to provide an effective coverage for water level monitoring. This will, over time, provide confidence that the current management framework is appropriate and assist with the determination of the extent and sustainability of the resources. • An investigation well is drilled to groundtruth the geophysical results and define the geological, hydrogeological and geochemical profile to identify possible salinity stratification. This well should be installed with one of the transducers to monitor any water level changes. It is understood that the saline interface in coastal aquifers can be dynamic with movement cased by tidal fluctuations and aquifer water level changes. Monitoring will be necessary to identify the natural range of movement setting a benchmark to identify a negative shift due to saline intrusion. • It is critical that geophysical surveys are repeated in future programs. By correlating the geophysical data with the geological borehole logs, and downhole salinity profiling of the proposed new and rehabilitated wells, a more precise position of any saline interface can be interpreted and monitored. This knowledge will greatly improve the ability to manage the groundwater resources to protect them from induced migration of saline water into the aquifer due to pumping pressures. • It is recommended that SA Water and DWLBC review other options of investigating the extent of the Coffin Bay Lens. Drilling wells is the only definitive method in identifying the extent of the lens, therefore it is recommended that a series of wells be drilled through the sand dunes into the Bridgewater Formation aquifer. If the saturated depth and the water quality are similar to that within the borefield it is proposed that another series of wells be drilled some distance south of the original series. Further suggestions may include a remote geophysical investigative method such as aerial surveys. In addition environmental tracer analysis may be useful to delineate recharge processes. • No interpretation is currently available from TEM surveys on the coast due to data collection difficulties. It may be necessary to conduct a survey and water quality testing of private wells situated in the township to establish any change in salinity with distance from the coastline in both aquifers.

South – Coffin Bay Observation Well Network Review 4 Report DWLBC 2003/4

INTRODUCTION

SA Water and DWLBC have been working cooperatively on Eyre Peninsula to ensure that extractions of water from underground water supplies, particularly from the Southern Basin PWA, are managed sustainably. SA Water relies on groundwater from the Southern Basins PWA for a major component of its public reticulated water supply for Eyre Peninsula. SA Water requires a sufficient allocation of water to satisfy the demands for the public water supply in the region. Approximately 10 000 ML/y is used across the Eyre Peninsula (ERWRPC, 2000). The ratio of groundwater to surface water resources (Tod Reservoir) used in the Eyre region varies each year. Over the period 1995 and 1996, 68% of supplied water was groundwater. The percentage increased to 96% for 2001 and 2002, and 100% groundwater is anticipated in this 2002–03 financial year (D Cliff, SA Water Corporation, Port Lincoln, per. comm., 22 January 2003). The potable groundwater resources occur as isolated shallow watertable lenses within the Quaternary limestone (Bridgewater Formation). These resources are delineated by geological structure and the 1000 mg/L isohaline, and occur on the southern and western parts of Eyre Peninsula. The principal lens, Uley South, has been developed for water supply extraction and is the prime source of groundwater for the Peninsula. The Coffin Bay ‘A’ Lens is utilised to supply reticulated public water supply to the Coffin Bay township (Fig. 1). At this time, the Uley South Lens appears to be utilised within its sustainable limits. However, with the expansion of the Uley South Public Water Supply wellfield in 1999– 2000, extraction pressures have changed within the lens. Future residential and irrigation demand on the water resources of the Peninsula will require effective management of the lens with reliance on accurate monitoring of storage and recent recharge history to assure sustainability. A review of the current monitoring networks to evaluate the condition of the Uley South (within the lens boundary and including ULE 89 and 141; Fig. 2) and Coffin Bay (within SA Water boundary; Fig. 3) observation wells was undertaken between May and July 2002. The adequacy of the information provided by the wells was investigated and positions within the basin where knowledge gaps exist were identified. In addition, surface geophysical surveys were undertaken to establish the position of the saline water interface, and pressure transducers were installed in some wells and pluviometers were established in order to provide more accurate storage and recharge information.

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GEOLOGY AND HYDROGEOLOGY

Detailed geology and hydrogeology of the Southern Basins are described previously (Evans,1997; Martin and Clarke, 2000). In summary, the groundwater predominantly occurs in rocks and sediments of three different geological environments: Quaternary Bridgewater Formation limestone, Tertiary Uley Formation clay and Wanilla Formation sand sediments overlaying a volcano- metasedimentary basement sequence. The Bridgewater Formation unconfined aquifer has been primarily developed for reticulated public water supply. The aquifer occurs as isolated lenses with generally high yields and low salinity. The Bridgewater Formation aquifer overlies the Wanilla Formation aquifer. A clay sequence, the Uley Formation, exists at the top of the Wanila Formation and behaves as an aquitard between the Bridgwater Formation and the Wanilla Sands aquifer However, there are several areas to the SE and north (Fig. 4), where the confining layer is absent from the profile and there is potential for local hydraulic connection between the aquifers. Figure 4 illustrates the Bridgewater Formation saturated thickness within the Uley South Lens boundary. These unconfined groundwater resources receive recharge via direct infiltration of incident rainfall only. Dominant groundwater flow within the Uley South Lens SW toward the Southern Ocean and westward toward the Coffin Bay National Park (illustrated by the potentiometric surface contours Fig. 2). No groundwater investigations have been undertaken beneath the sand dunes of Coffin Bay National Park. The Coffin Bay Basin comprises three freshwater lenses, Coffin Bay A, B and C. The SA Water wellfield is within the Coffin Bay ‘A’ Lens. The principal direction of groundwater flow is NW towards Kellidie Bay (illustrated by the potentiometric surface contours, Fig. 3). Groundwater discharge is evident as surface springs along the southern shore line of Kellidie Bay. Water level behaviour within the Quaternary lenses reveals that recharge occurs after intense rainfall events, where short lived overland flow is directed to solution features (sinkholes; Fig. 5) and infiltrate to the watertable rapidly. The sinkholes are often characterised by washouts with no soil. Research of the Uley Basin system (Evans, 1997) indicates that these resources show an annual water level rise when they receive more than 10 days of >10 mm of rainfall between the months of May and October. It is estimated that up to 30% of the annual rainfall will infiltrate as recharge to these Quaternary lenses. It has been reported in the Southern Basins Prescibed Wells Area groundwater monitoring status report 2002 (Evans, 2003) that there has been a general groundwater level decline in all lenses in the Southern Basins irrespective of wellfield development. This highlights the dominance of effective rainfall on storage.

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South – Coffin Bay Observation Well Network Review 11 Report DWLBC 2003/4

AIM

The aims of this review were: • increasing the information base required for effective management of the resource • augmentation of the network • rehabilitation of wells which are declining in condition • installation and application of investigative equipment • carrying out geological surveys. These elements provide important information to enable efficient management, competent volume prediction, and effective recharge and extraction modelling of this complex groundwater system. The ultimate aim is to ensure current and future extraction will be within the available yield of the resource.

Project objectives The project objectives were to: • review spatial extent and adequacy of existing monitoring wells, and frequency of monitoring • purge, clean and survey wells to obtain true downhole salinity profiles using SONDE and collect pumped samples for electrical conductivity (EC) determinations • identification of sites to establish additional monitoring wells to enable an assessment of the potential threat from saline intrusion • identification of sites for the installation of automated monitoring devices.

Project outcomes The project outcomes are: • Establishment of a more rigorous monitoring framework to facilitate the management of the resource. • Identification of the scope of works to be undertaken to understand the hydrodynamic behaviour of these systems in response to recharge and pumping demands. • Definition of variability of salinity within the Uley South and Coffin Bay ‘A’ portions of the Southern Basins PWA.

South – Coffin Bay Observation Well Network Review 12 Report DWLBC 2003/4

METHODOLOGY

Fieldwork was completed in the Uley South and Coffin Bay Observation Well Networks in July 2002 and are summarised below, represented spatially in Figures 6 and 7 and presented in Tables A1 and A2 in Appendix A.

Establishment of a more rigorous monitoring framework to facilitate the management of the resource • The total well depth and water levels were recorded for all current observation bores within the total Southern Basins Observation Well Network and the database updated. Water levels will continue to be recorded monthly as part of the Observation Well Monitoring Program by SA Water personnel. • Maintenance was completed on all Uley South (within the lens boundary and including ULE 89 and 141) and Coffin Bay (within the SA Water Waterworks Reserve) observation wells. This included tagging, capping and general repairs. It is recommended that selected wells (three currently and four not currently monitored (historical) at this time) are rehabilitated and monitored to fill recognised spatial knowledge gaps. • A total of 23 of the 36 Uley South observation wells were purged and/or pumped. The remaining 13 were not purged for the following reasons: ° three wells were completed with 63 mm casing, which is too small a diameter to accommodate the pump (ULE 97, 134, 147) ° one well could not be located (ULE 204) ° two wells were dry (ULE 92, LKW 12) ° in two wells the sampling pump jammed (ULE 184, ULE 192) ° could not get access to one well (ULE 203) ° technical problems involving the pump resulted in four unpurged wells (ULE 77, 188, 190, 201). • The four Coffin Bay observation wells where not purged due to technical problems involving the pump (LKW 37, 38, 39, 40). It is recommended that these 17 unpurged wells be purged in further work.

Identification of the scope of works to be undertaken to understand the hydrodynamic behaviour of these systems in response to recharge and pumping demands • Ten pressure transducers were installed — two at Coffin Bay and eight at Uley South. They have been programmed to record water level readings every four hours and data is downloaded every two months. Results of the first collected data are presented in the results section. • Four pluviometers logging rainfall intensities have been installed — one in Coffin Bay and three in Uley South — all pluviometers are associated with nearby pressure transducers. The pluviometer at Coffin Bay and the one positioned at ULE 196/135 are triple channel instruments simultaneously recording rainfall intensities and water

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levels. In Coffin Bay the transducers are installed in LKW 38 and 39 both monitoring the Quaternary Aquifer. In Uley South both the Quaternary (ULE 196) and the Tertiary Aquifers (ULE 135) are montiored. The results of the first download (July–Nov. 2002) are presented in the results section. This data will provide important information on the aquifer response to rainfall intensity and subsequent recharge and pumping pressures. • TEM geophysical survey transects and several point penetrations were completed in Coffin Bay and Uley South. The location of these transects are illustrated in Figures 6 and 7. Analysis of the TEM data will clarify the lens extent (aquifer geometry), and assist in the identification and position of the saline interface and possible saline intrusion (a negative consequence of over-pumping on the resource) in both study areas. A detailed report of the results is presented in the ‘TEM surveys’ section.

Definition of current spatial variability of salinity within Southern Basins PWA • Water samples to analyse full chemistry and EC were collected from the 23 purged wells. Results are discussed in the Results section and detailed in Table A3, Appendix A. • A total of 32 Uley South and four Coffin Bay observation wells have been sonded to profile any salinity changes in the groundwater with depth. Of these wells 29 produced suitable data for analysis and are presented in the Observation Well Information sheets in Appendix B. Four were not sonded for the following reasons: ° one could not be located (ULE 204) ° two were dry (ULE 92, LKW 12) ° one was obstructed (ULE 192). The purpose of salinity profiling is to map the changes in groundwater salinity with increasing depth. The changes can identify a saline interface, setting a benchmark for future monitoring. The montioring of saline interfaces using this method may establish whether there is an induced migration of saline water into the aquifer due to the current groundwater extraction regime. The equipment installed within the basin is presented in the ‘Uley South and Coffin Bay automated monitroing equipment’ section.

South – Coffin Bay Observation Well Network Review 16 Report DWLBC 2003/4

RESULTS

Observation well rehabilitation and augmentation The earliest Uley South observation wells were drilled from the late 1950s for the then E&WS Department to investigate the hydrogeology of the groundwater resources and used to monitor water level behaviour. These wells were originally left as openholes. Later 65 mm steel pipes were place in the holes to assist with monitoring but were never completed or sealed to standard (Fig. 8). In the1990s the observation wells chosen for continued monitoring were rehabilitated. The process involved the removal of the metal casing, redrilling the hole, installing PVC casing, gravel packing, cement sealing and capping (Fig. 9). Rehabilitation of openhole wells is required for the following reasons: • The aquifer formation water in open wells is at risk of water quality changes as the well provides a point of entry for rainfall runoff and contamination. • The formation waters from aquifers will mix if the column is open across different aquifers. Aquifer mixing not only alters water quality, but it can also alter the hydraulics of the aquifer with a net negative effect. • The 65 mm steel pipes will not permit entry of pump equipment and therefore well purging or water sampling can not be achieved. The deeper holes penetrating the Tertiary sands and left with openhole completion have collapsed infilling the well to the base of the Quaternary sequence. Water level information from these holes is likely to reflect the Quaternary Aquifer behaviour. The field survey revealed that three wells within the current network (ULE 97, 134, 147) have not been rehabilitated (Fig. 2). It is recommended that these well be rehabilitated in further work. There are ~55 openhole historical observation wells within the Uley South Lens. These wells are not currently monitored and not rehabilitated and therefore potentially allow surface runoff to enter and mix with the aquifer formation water and also aquifer mixing through the open column. These wells may be used as observation wells in the future as information is required, however, the expense of rehabilition at this stage may not be warranted. It is recommended that SA Water and DWLBC review the future of these wells. Hydrogeological knowledge gaps have been identified at strategic positions within the basin. It is recommended that historical observation wells SLE 10, ULE 133, ULE 98 and ULE 96 are rehabilitated and three new wells drilled and included in the current monitoring network (Fig. 2). It is suggested that two new observation wells be drilled in close proximity to the coast (Fig. 2) to obtain geological logs that will: • provide essential hydrogeological information • assist the interpretation of surface and well logging geophysical data by correlating, validating and truthing the information from all techniques. This provides added certainty, resulting in more reliable analysis.

South – Coffin Bay Observation Well Network Review 17 Report DWLBC 2003/4

Figure 8. Original Uley South observation well, openhole with 65 mm steel piping. A potential site for aquifer water quality changes and aquifer mixing.

Figure 9. A rehabilited monitored observation well; PVC casing, cement sealed, capped and tagged

South – Coffin Bay Observation Well Network Review 18 Report DWLBC 2003/4

In addition the drilling of new wells and the rehabilitation of historical wells SLE 10 and ULE 133 will provide vital salinity profiling sites to establish a strong definition of the saline interface to benchmark for future monitoring. Another area where there is limited hydrogeological information is in the western region of the Uley South Lens, down hydraulic gradient from the wellfields (Fig. 2). The additional montoring data from a new well and two rehabilitated historical wells ULE 98 and ULE 96 in this vicinity will provide further understanding as to the extent of the lens and behaviour of the resource. It is further recommended that all drilled wells be geophysically logged. Geophysical well logging (downhole geophysics) involves lowering a series of logging probes down a borehole. The probes transmit signals to the recorder at the surface. Important information about the borehole and the geological formations encountered are achieved and are correlated with the geological log recorded during drilling. This standard procedure carried out at the completion of drilling provides a high degree of certainty to geological and hydrogeological interpretation.

Salinity profiling Information from salinity profiling of purged wells can identify the presence of salinity stratification within the aquifer. Successful well purging should remove all the stagnant groundwater in the casing or column (Fig. 10). This groundwater is removed by careful placement of the pump within the column, usually just above the production zone or screen, and pumping at suitable pumping rates for the aquifer type. The EC and pH of the extracted groundwater is monitored during pumping. The stabilisation of these parameters indicates that formation water is being pumped. The removed water is naturally replaced with formation water within the column. Sonding after pumping will how a constant salinity profile within the column. Re-equilibration of the water within the casing is achieved after an undisturbed period of several months. Sonding may show a salinity stratification within the production zone of the well with a deviation from the constant casing profile and can indicate: • recharge processes for different water bodies • the position of a saline interface or saline intrusion within coastal aquifers. This type of investigation was undertaken for the project to identify and map the position of a saline interface, thereby setting a benchmark for future monitoring. Once a saline interface has been identified, monitoring using salinity profiling may establish whether there is an induced migration of saline water, or saline intrusion, into the aquifer, caused by groundwater extraction. Well purging occurred in May and salinity profiling with sonde occurred in July 2002. The results of the salinity profiling are detailed in the Observation Well Information sheets, Appendix B. As stated earlier, only 23 of the 40 observation wells were purged. Of the 33 wells sonded, 22 had been purged. It is recommended that the remainder be purged in future work.

South – Coffin Bay Observation Well Network Review 19 Report DWLBC 2003/4

Figure 10. Well purging in Uley South — observation well ULE 139, May 2002

FINDINGS

Coffin Bay The Coffin Bay wells LKW 37, 38, 39 and 40 were not purged therefore the sonding and results show stratification that may not be representative of the aquifer. However the results do illustrate the unreliablility of the SA Water bailed sampling method. The sonding data for LKW 37 shows a constant salinity of 750 EC throughout the cased column which rapidly increases to >1200 EC in the production zone. The results indicate that the representative salinity of the Bridgewater Formation at this location is ~1300 EC. However the latest salinity recorded on 18 November 2002 was 721 EC. This indicates that the water sampling technique by SA Water is likely to be flawed. It is recommended that only pumped groundwater samples be collected where the pump is placed just above the production zone to sample groundwater representative of the aquifer monitored.

South – Coffin Bay Observation Well Network Review 20 Report DWLBC 2003/4

The representative salinity in LKW 38 is located within the production zone at ~900 EC. As identified in LKW 37 the sampling technique is not reflecting the formation water. The sudden reduction of salinity in the last three readings is representative of the sonde penetrating sediment at the base of the hole. This well has suffered some infill of sediment. The representative salinity of the Bridgewater Formation aquifer located within observation well LKW 39 may be >1800 EC which has been profiled in the production zone. However, the latest salinity record of 18 November 2002 is 687 EC. Additonally, LKW 40, monitoring the Wanilla Formation, shows a similar result. The representative salinity profiled in the production zone is >5000 EC, increasing to >25000 EC with depth, while the latest salinity reading by SA Water is 2760 EC. A review of SA Water’s sampling techniques is recommended to ensure that samples are representative of the aquifer.

Uley South The salinity profiling results of the Uley South observation well LKW 34 show a deviation at the last recorded point. The point is likely to be anomalous and should be compared to future sondings. It is considered that the first four readings in the profile represent the salinity of the formation. The ULE 89 salinity profile shows a deviation part way down the column. This position may be where the pump was placed and while the water below was successfully purged, the water above, in the column, remained. Therefore, the first readings profile the old unpurged water and those below signify the salinity of the formation. The last reading was possibly taken when the sonde penetrated the mud at the bottom of the hole. This type of reading can be seen in several of the profiles presented and is anomalous. Observation wells ULE 99, 101,102, 114, 139, 141, 145, 185, 186, 189, 191, 193, 196, 202 and 203 show constant salinity profiles indicative of successfully purged wells with no stratification. The salinity in some of the wells is slightly higher than that of the latest monitoring record. This may be a result of seasonal variation due to recharge in the zone of the well. The ULE 126 salinity profile shows stratification, although it is only slight. The salinity of the groundwater may be increasing with depth. This well is situated on the upgradient lens boundary where there is no confining layer between the Quaternary and Tertiary, and therefore may be mixing with minor lateral inflow groundwater. There are no casing and production zone details for ULE 127 and 134 and therefore it is difficult to analyse the results. It is recommended that these wells are not sonded until these details are established. It is possible that the salinity stratification of the ULE 135 profile indicates the mixing of the groundwater between the Wanilla Formation and the weathered basement. ULE 147 and 184 were not purged. The latest salinity record for ULE 147 was taken in 1964 when the well was drilled. It is recommended that these wells are purged, sampled and sonded in further work. The reduction in salinity in the last two readings in ULE 187 is representative of the sonde prentrating sediment at the base of the hole.

South – Coffin Bay Observation Well Network Review 21 Report DWLBC 2003/4

ULE 188, 190 and 201 were not purged. The salinity profiles within the production zones possibly represent formation water salinity. The salinity profile for ULE 194 increases with depth at a constant rate. This well is situated on the boundary of the swamps, a zone of potential discharge. Flow processes around the swamp may vary slightly to the understood regional processes causing stratification. ULE 197 may not have been purged successfully. The representative salinity profile is probably within the production zone about the 1200 EC range.

Surface geophysics TEM surface geophysics is used to indirectly determine the extent and nature of geologic and hydrogeological materials beneath the surface. This non-invasive technique uses electromagnetically induced eddy currents to establish the ground resistivity or conductivity as a function of depth. Current is more easily transmitted through fluids in pore spaces and at fluid-grain interfaces than through the mineral grains. Strong current transmission is analogous to conductive structure such as saline fluid, porous mediums and clays. The results identify boundaries shown by changes in conductivity that can be caused by formation changes or groundwater salinity changes. Results from TEM surface geophysics may assist in defining the extent of the groundwater lens and map the saline interface. Several transects were undertaken in Coffin Bay and Uley South (Figs 6, 7). A comprehensive report of the geophysical results can be found in the ‘TEM surveys’ section. The analysis of the results of the Uley South survey identified broad hydraulic zones beneath the surface indicative of changes in groundwater salinity. This geophysical method cannot identify the changes between dry and wet limestone therefore the boundaries do not necessarily identify different aquifers but different salinities within or across aquifers. A possible saline interface has been identified ~700 m from the coast on transect 1000N at an approximate depth of 85 m. The interpretation is that the saline water body is within the Tertiary Wanilla Formation. However as there is no clay aquitard beneath the Quaternary sequence in this area there is a potential risk to induce a saline intrusion by groundwater extraction from pump stations USPB 15,16 and 17 (Fig. 4). The TEM survey results indicate that at present there is freshwater within the Quaternary Bridgewater Formation at this site and it is uncertain whether this interface is mobile. Future monitoring will determine the risk to the Quaternay Aquifer. It is recommended that an observation bore (Fig. 2) is drilled to groundtruth the geophysical results and define the geological, hydrogeological and geochemical profile to identify possible salinity stratification, and a transducer if installed to monitor any water level changes. It is understood that the saline interface in coastal aquifers can be dynamic with movement caused by tidal fluctuations and changes in groundwater level. Monitoring will be necessary to identify the natural range of movement, setting a benchmark to identify any induced intrusion as a result of groundwater extraction. The analysis of the results also showed that there is some evidence of closure on the west side of the lens, identified by a resistive rise in the profile, possibly caused by a basement high. The transects 3000N and 2500N also indicate that groundwater salinity may be higher on the western side of the lens compared to the eastern side. Evans (1997)

South – Coffin Bay Observation Well Network Review 22 Report DWLBC 2003/4

observed this salinity anomaly and suggested that the Tertairy system was isolated from the eastern portion by a N–S basement ridge (see Fig. 23). A geophysical survey was conducted in Coffin Bay to investigate whether, and how far, the lens extends southward under the sand dunes, and to identify the presence of a saline interface and possible saline intrusion around the northern coast line. Unfortunately access for geophysical surveying into the sand dunes south of the Coffin Bay borefield was unachievable by the impedance of the dense vegetation. This area is unsuitable for this type of investigative method. It is recommended that SA Water and DWLBC review other options of investigating the extent of the Coffin Bay Lens. Drilling wells is the only definitive method in identifying the extent of the lens, therefore it is recommended that a series of wells be drilled through the sand dunes into the Bridgewater Formation aquifer. If the saturated depth and the water quality are similar to that within the borefield it is proposed that another series of wells be drilled some distance south of the original series. Further suggestions include a remote geophysical investigative method such as aerial surveys and environmental tracer analysis to delineate recharge processes.

Figure 11. Geophysicists operating the SIROTEM unit at Coffin Bay, May 2002 Several geophysical transects were achieved at Coffin Bay, but the data is of lower quality than that from Uley South. Successful analysis of information and models of subsurface trends are expected. The task, however, is rather more arduous and hence a delay with the Coffin Bay interpretation. Preliminary results show an area of higher resistivity to a depth of ~50 m correlating with the hydrogeology derived from geological logs. Salinity readings from the Coffin Bay Bridgewater Formation observation wells indicate an average TDS of 370 mg/L and from the Wanilla Formation observation wells of

South – Coffin Bay Observation Well Network Review 23 Report DWLBC 2003/4

~1500 mg/L. It is difficult to define whether there is a saline interface present or this confined formation is naturally saline throughout from this data; analysis is still continuing. It is unclear how competent the aquitard is between the Bridgewater and Wanilla Formation aquifers, thereby leaving the fresher Bridgewater Formation aquifer vulnerable to saline intrusion when under pumping stresses greater than the resource is currently subject to. No interpretation is available from TEM surveys on the coast due to data collection difficulties. It may be necessary to conduct a survey, and water quality testing of private wells situated in the township, to establish whether there is any change in salinity with distance from the coastline in both aquifers.

Water level and rainfall monitoring Ten pressure transducers automatically recording water level changes have been installed in selected wells — two in Coffin Bay and eight in Uley South. Four pluviometers automatically logging rainfall intensities have been also been installed — one in Coffin Bay and three in Uley South. All pluviometers are associated with nearby pressure transducers to enable understanding of rainfall recharge relationships. The spatial positioning of these remote recording instuments is detailed in Figures 6 and 7. Eight of the loggers were downloaded in November 2002. Table 1 details well location and instrument information.

Table 1. Well location and instrument information

Obs. well Fig. Instrument Aquifer monitored Lens number no. ULE 196 Pressure transducer and Bridgewater Formation 12 Uley South ULE 135 pluviometer Wanilla Formation ULE 134 13 ULE 147 14 Pressure transducer Bridgewater Formation Uley South ULE 197 15 ULE 202 16 LKW 38 Pressure Transducer 17 Bridgewater Formation Coffin Bay LKW 39 and pluviometer

This data will provide important long-term information on the aquifer response to rainfall intensity and subsequent recharge and pumping pressures.

FINDINGS

Uley South Lens In Uley South the Quaternary (ULE 196) and the Tertiary Aquifers (ULE 135) and rainfall intensities are recorded four hourly. The results of the first download for this logger is detailed are Figure 12.

South – Coffin Bay Observation Well Network Review 24 Report DWLBC 2003/4

4 Hourly Water Level and Rainfall Data Uley South Lens 5.8 14.4 Daily Rainfall (mm) ULE 135 Wanilla Formation ULE 196 Bridgewater Formation 5.7 12

5.6 9.6

5.5 7.2 Daily Rainfall (mm) Rainfall Daily 5.4 4.8 Water Level above Transducer (m)

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Figure 12. Four-hourly water level and rainfall data, Uley South Lens

South – Coffin Bay Observation Well Network Review 25 Report DWLBC 2003/4

The hyrodgraphs indicate the change in water level above the transducers while the bar graph represents the daily rainfall. The Bridgewater Formation hydrograph shows a recharge response to significant rainfall events (>5 mm/d) which occurred on the 3, 7 and 12 August 2002. After which the water level declines until the next set of significant rainfall events from 3 to 4 August 2002, where a recharge response is evident by the levelling trend in the hydrograph. Due to the distance of the observation wells from the extraction wellfield (~800 m), pumping pressure may influence the water level decline marginally. The influence of pumping can be better defined with the additional SA Water extraction information. The frequency of the peak and troughs are irregular and thus tend to exclude natural influences such as tidal changes. The Tertiary Aquifer hydrograph is reflecting the Quaternary water level changes with increased amplitude. The response is typical of a confined aquifer responding to load pressure changes from varying water level (storage volume) in the Quaternary Aquifer system. It is postualted, in the Evans (1997) study, that the variation in water levels exhibited by the Teritary sand aquifer may reflect the direct pressure loading of the variation in the level of saturation of the unconfined Quaternary system. The hydrographs for observation wells ULE 134, 147, 197 and 202 (Figs 13–16) are all situated within 700 m of pump stations and show similar water level trends. An increase in water level is evident until 12 August 2002 were it remains stable then declines near the end of October 2002 with ULE 197 declining much earlier at the end of September 2002. The water level increase is likely a result of recharge from recent rainfall events. The rainfall information from the pluviometers (not attained at this time) in the western and northern parts of the lens will assist in verifying this result. The water level decline is likely due to natural discharge exceeding recharge and, to a minor extent, the influence of pumping pressures. The amplitudes of the hydrographs are very similar indicating similar transmissitives, except observation well ULE 147 where the behavour indicates a site of lower transmissivity. The sudden dropoff of the reading after the 31 October 2002 indicates that the position of the transducer may have changed and will be investigated and readjusted. This initial logged data has added to the understanding of the aquifer response to rainfall and discharge events. The absolute information potential of the remote monitoring instruments coupled with SA Water extraction data will assist in the future management of the system. It is recommended that to broaden the knowledge base two addition transducers are installed in several of the wells proposed for rehabilitation. The assessment of the ongoing monitoring will give confidence that the current management framework is appropriate for the lens.

South – Coffin Bay Observation Well Network Review 26 Report DWLBC 2003/4

Two Hourly Water Level Changes - Observation Well ULE 134 Uley South Lens

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Figure 13. Hydrograph of the water level changes in observation well ULE 134

Two Hourly Water Level Changes - Observation Well ULE 147 Uley South Lens 1.6

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Reduced Standing Water Level (mAHD) 1.2

1.15

1.1 3/06/2002 8/06/2002 3/07/2002 8/07/2002 2/08/2002 7/08/2002 1/09/2002 6/09/2002 1/10/2002 6/10/2002 5/11/2002 29/05/2002 13/06/2002 18/06/2002 23/06/2002 28/06/2002 13/07/2002 18/07/2002 23/07/2002 28/07/2002 12/08/2002 17/08/2002 22/08/2002 27/08/2002 11/09/2002 16/09/2002 21/09/2002 26/09/2002 11/10/2002 16/10/2002 21/10/2002 26/10/2002 31/10/2002 10/11/2002 15/11/2002 20/11/2002 25/11/2002 Date

Figure 14. Hydrograph of the water level changes in observation well ULE 147

South – Coffin Bay Observation Well Network Review 27 Report DWLBC 2003/4

Two Hourly Changes in Water Level - Observation Well ULE 197 Uley South Lens 5.8

5.75

5.7

5.65

5.6

5.55

5.5

5.45

Reduced Standing Water Level (mAHD) 5.4

5.35

5.3 3/06/2002 8/06/2002 3/07/2002 8/07/2002 2/08/2002 7/08/2002 1/09/2002 6/09/2002 1/10/2002 6/10/2002 5/11/2002 29/05/2002 13/06/2002 18/06/2002 23/06/2002 28/06/2002 13/07/2002 18/07/2002 23/07/2002 28/07/2002 12/08/2002 17/08/2002 22/08/2002 27/08/2002 11/09/2002 16/09/2002 21/09/2002 26/09/2002 11/10/2002 16/10/2002 21/10/2002 26/10/2002 31/10/2002 10/11/2002 15/11/2002 20/11/2002 25/11/2002 Date

Figure 15. Hydrograph of the water level changes in observation well ULE 197

Two Hourly Water Level Changes - Observation Well ULE 202 Uley South Lens 1.700

1.650

1.600

1.550

1.500

1.450

1.400

1.350

Reduced Standing Water Level (mAHD) 1.300

1.250

1.200 3/06/2002 8/06/2002 3/07/2002 8/07/2002 2/08/2002 7/08/2002 1/09/2002 6/09/2002 1/10/2002 6/10/2002 5/11/2002 29/05/2002 13/06/2002 18/06/2002 23/06/2002 28/06/2002 13/07/2002 18/07/2002 23/07/2002 28/07/2002 12/08/2002 17/08/2002 22/08/2002 27/08/2002 11/09/2002 16/09/2002 21/09/2002 26/09/2002 11/10/2002 16/10/2002 21/10/2002 26/10/2002 31/10/2002 10/11/2002 15/11/2002 20/11/2002 25/11/2002 Date

Figure 16. Hydrograph of the water level changes in observation well ULE 202

South – Coffin Bay Observation Well Network Review 28 Report DWLBC 2003/4

Coffin Bay Lens In Coffin Bay rainfall intensities and Quaternary Aquifer water levels in LKW 38 and 39 are monitored four hourly. The results of the first download for this logger are detailed in Figure 17. LKW 38 is a shallower well with a production zone between 15 and 21.5 m while LKW 39 is a deeper well with a production zone between 27 and 36 m (although current depth is now 31.75 m). The two wells monitor different sections of the Bridgewater Formation. The hydrographs show a recharge response to rainfall events greater than ~3 mm between 3 and 12 August 2002, declining after the 17 August 2002 until the next recharge event on the 2 and 3 September 2002 where the hydrograph stablises then gradually declines after 1 October 2002. The hydrographs show two distinct patterns. The daily fluctuations indicate the influence of the adjacent extracton wellfield (50 m). The troughs coincide with nightly pumping. The broadscale trends indicate the aquifer response to recharge and discharge. The near full recovery of the daily drawdowns and the regional response to significant rainfall events indicates that the current extraction regime is not dominating water level behaviour in this aquifer.

Water quality Groundwater samples were collected during purging and sent to the Australian Water Quality Centre for analysis. The results of the full chemical analyses can be found in Table A3, Appendix A. The data and comprehensive report of the historical chemistry characteristics of Uley South Lens groundwater is detailed in Evans (1997). The report details TDS measurement from the initial drilling programs in the 1950s and early 1960s prior to the stresses of extraction. The average production well salinity shows seasonal variations between summer maxima and winter minima of up to 50mg/L. The observed long term behaviour for salinity is influenced by significant rainfall events and recharge causing up to 80mg/L variations in average TDS levels. The long term salinity trends for the Uley South Bridgewater Formation are illustrated in Figures 18 and 19 and Uley South Wanilla Formation Figure 20. The long-term salinity trend for both Coffin Bay aquifers are illustrated in Figure 21.

FINDINGS

Uley South Lens

Bridgewater Formation observation well salinity monitoring Figure 18 illustrates that in general the salinity levels in this selection of wells monitoring the Bridgewater Formation has been stable over time. ULE 187, 188 and197 have salinity values that range between 600 and 700 mg/L. These wells are located in the vicinity of the original wellfield where salinity has been historically above 500 mg/L (Evans, 1997). The increase in salinity between April 1993 and November 1996 in ULE 190 is probably related to a slight expansion of the higher salinity zone about the original wellfield.

South – Coffin Bay Observation Well Network Review 29 Report DWLBC 2003/4

4 Hourly Water Level and Rainfall Data Coffin Bay Lens 8.40 10 Daily Rainfall LKW 39 9 LKW 38 8.30 8

7 8.20

6 6/9/02 0:00 7/9/02 0:00 8/9/02 0:00 9/9/02 0:00 6/9/02 12:00 7/9/02 12:00 8/9/02 12:00 9/9/02 12:00 10/9/02 0:00 11/9/02 0:00 12/9/02 0:00 13/9/02 0:00 10/9/02 12:00 11/9/02 12:00 12/9/02 12:00 8.10 5

4 Daily Rainfall (mm) Rainfall Daily 8.00 3 Water Level above Transducer(m)

2 7.90

1

7.80 0 28/07/02 04/08/02 11/08/02 18/08/02 25/08/02 01/09/02 08/09/02 15/09/02 22/09/02 29/09/02 06/10/02 13/10/02 20/10/02 27/10/02 03/11/02 10/11/02 Date

Figure 17. Four-hourly water level and rainfall data, Coffin Bay Lens

South – Coffin Bay Observation Well Network Review 30 Report DWLBC 2003/4

Uley South Lens Bridgewater Formation Observation Well Salinity Monitoring (mg/L TDS) 800 ULE187 ULE188 750 ULE189 ULE190 700 ULE191 ULE192 650 ULE193 ULE194 600 ULE196 ULE197 550

TDS (mg/L) 500

450

400

350

300 11/06/1991 08/11/1991 06/04/1992 03/09/1992 31/01/1993 30/06/1993 27/11/1993 26/04/1994 23/09/1994 20/02/1995 20/07/1995 17/12/1995 15/05/1996 12/10/1996 11/03/1997 08/08/1997 05/01/1998 04/06/1998 01/11/1998 31/03/1999 28/08/1999 25/01/2000 23/06/2000 20/11/2000 19/04/2001 16/09/2001 13/02/2002 13/07/2002 10/12/2002 Date

Figure 18. Uley South Lens: Quaternary Bridgewater Formation observation well salinity monitoring

South – Coffin Bay Observation Well Network Review 31 Report DWLBC 2003/4

Uley South Lens Bridgewater Formation Observation Well Salinity Monitoring (mg/L TDS) 800 ULE77 750 ULE92 ULE99 700 ULE101 ULE102 650 ULE114 ULE126 600 ULE139 ULE145 550 ULE184 ULE186 TDS (mg/L) 500

450

400

350

300 11/06/1991 08/11/1991 06/04/1992 03/09/1992 31/01/1993 30/06/1993 27/11/1993 26/04/1994 23/09/1994 20/02/1995 20/07/1995 17/12/1995 15/05/1996 12/10/1996 11/03/1997 08/08/1997 05/01/1998 04/06/1998 01/11/1998 31/03/1999 28/08/1999 25/01/2000 23/06/2000 20/11/2000 19/04/2001 16/09/2001 13/02/2002 13/07/2002 10/12/2002 Date

Figure 19. Uley South Lens: Quaternary Bridgewater Formation observation well salinity monitoring

South – Coffin Bay Observation Well Network Review 32 Report DWLBC 2003/4

Uley South Lens Wanilla Formation Observation Well Salinity Monitoring (mg/L TDS)

1300 LKW12 LKW34 1200 ULE89 ULE109 1100 ULE127 ULE135 1000 ULE141 ULE185 900

800 TDS (mg/L)

700

600

500

400 11/06/1991 08/11/1991 06/04/1992 03/09/1992 31/01/1993 30/06/1993 27/11/1993 26/04/1994 23/09/1994 20/02/1995 20/07/1995 17/12/1995 15/05/1996 12/10/1996 11/03/1997 08/08/1997 05/01/1998 04/06/1998 01/11/1998 31/03/1999 28/08/1999 25/01/2000 23/06/2000 20/11/2000 19/04/2001 16/09/2001 13/02/2002 13/07/2002 10/12/2002 Date

Figure 20. Uley South Lens: Tertiary Wanilla Formation observation well salinity monitoring

South – Coffin Bay Observation Well Network Review 33 Report DWLBC 2003/4

Coffin Bay 'A' Lens Observation Bore Salinity Monitoring (mg/L TDS) 1800 LKW37 'Bridgewater Formation' LKW38 'Bridgewater Formation' 1600 LKW39 'Bridgewater Formation' LKW40 'Wanilla Formation' 1400

1200

1000

TDS (mg/L) All samples collected by bailed 800 method. Bailed sampling has been shown to give unreliable 600 representation of aquifer salinity.

400

200 11/06/1991 08/11/1991 06/04/1992 03/09/1992 31/01/1993 30/06/1993 27/11/1993 26/04/1994 23/09/1994 20/02/1995 20/07/1995 17/12/1995 15/05/1996 12/10/1996 11/03/1997 08/08/1997 05/01/1998 04/06/1998 01/11/1998 31/03/1999 28/08/1999 25/01/2000 23/06/2000 20/11/2000 19/04/2001 16/09/2001 13/02/2002 13/07/2002 10/12/2002 Date

Figure 21. Coffin Bay ‘A’ Lens: observation bore salinity monitoring

South – Coffin Bay Observation Well Network Review 34 Report DWLBC 2003/4

ULE 196, 189, 193, 192 and 191 range between 400 and 500 mg/L and level remain constant. ULE 194 has experienced a salinity increase from approximately 600 mg/L to >750 mg/L between April 1996 and July 1997. Salinity profiling of this well showed stratification. The close proximity well to the swamp area may have some influence. Sampling techniques may be the cause of this increase. Ongoing monitoring will further define salinity variation in this well. The proposed drilling of an observation well within that region will provide opportunity to further investigate and monitor this salinity increase. All the wells in Figure 19 show a constant salinity trend ranging between 400 and 650 mg/L and it appears that the previous or current extraction regime is not influencing the salinity.

Wanilla Formation observation well salinity monitoring All the wells in Figure 20 show a constant salinity trend. Observation wells LKW 12, 34, ULE 89, 127 and 141 range between 400 and 800 mg/L. These wells are all situated on the periphery of the Quaternary lens boundary. ULE 109 and 135, situated within the lens in the vicinity of the wellfields, both show a higher but level salinity trend ranging between 1100 and 1300 mg/L. It appears that the new extraction regime is not influencing changes in the salinity within the Tertiary Wanilla Formation.

Coffin Bay Lens

Coffin Bay ‘A’ Lens observation well salinity monitoring The salinity values in Figure 21 for the Quaternary Bridgewater Formation aquifer range between 300 and 900 mg/L in the Coffin Bay ‘A’ Lens. The erratic salinity curve in LKW 38 and 40 is likely due to the bailed method of sampling. Bailed sampling has been shown to give unreliable representation of aquifer salinity. The recommendation is that water samples be collected using accepted sampling standards to give representative salinity measurements of the aquifer formation water. The predominant baseline trend indicates that aquifer salinity is likely to be not increasing.

South – Coffin Bay Observation Well Network Review 35 Report DWLBC 2003/4

DISCUSSION

Impact of extraction on the Quaternary Aquifer System With the expansion of the Uley South Public Water supply wellfield in 1999, re-distribution of extraction pressures has occurred within the lens. Figure 22 illustrates the changes in water level that have occurred from 1997 to 2002 • before the new wellfield went on line between 1997 and 1999, • during the change over between 1999 and 2000 and • after the new wellfield became fully functional between 2000 and 2002. The water level difference contours illustrate the broad scale water level response of pumping within the wellfield. The purpose of the difference maps is to monitor whether the impact of pumping causes water levels to vary at a rate different from the natural trends. A settling in period is expected where decline around the new wellfield will be greater than that of regional trends. This impact of the new wellfield should placate overtime providing extraction is within sustainable limits. Contouring the differences can identify the need for additional regional observation wells to better understand the regional changes and impact of the wellfield.

CHANGE IN WATER LEVEL BETWEEN 1997 AND 1999 The highest negative changes in water level are centred on the original wellfield with values – 0.67 to – 0.60 m. These high negative values are possibly recorded during pumping of adjacent production wells. The value in the northern area of the original wellfield of (– 0.24) is lower, possibly indicating that levels were read while the adjacent production well was off. There is a general negative trend throughout the area due to the regional decline in water levels from low recharge influence by low rainfall from 1993. The zone of influence of extraction induced drawdown extends downgradient from the wellfield in the direction of the regional hydraulic gradient.

CHANGE IN WATER LEVEL BETWEEN 1999 AND 2000 During the year 1999 – 2000 the new wellfield, which includes the southern and western branches, went online. The redistribution in extraction pressure caused a considerable impact on the system, illustrated by the change in water level contours. There has been a significant water level recovery in the region of the original wellfield with the reduction of extraction rate. The water level change in the region of the new wellfield is not significantly negative. However, there had been a moderately good recharge season during this period (2000) and it is likely that the impact of pumping was negated by the general rise in groundwater from recharge.

South – Coffin Bay Observation Well Network Review 36 Report DWLBC 2003/4 IQS°QH9 IQS°QS9 IQS°QH9 IQS°QS9 IQS°QH9 IQS°QS9 SRSHHH SSHHHH SSSHHH SRSHHH SSHHHH SSSHHH SRSHHH SSHHHH SSSHHH

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CHANGE IN WATER LEVEL BETWEEN 2000 AND 2002 Three values were disregarded from the contours as they are highly negative, indicating that pumping of adjacent production wells influenced the water levels in these observation wells during monitoring and are therefore not regionally representative. The contours indicate that the system is gradually reaching equilibrium, with a slight elongated depression in the vicinity of the new wellfield. It is expected that this water level difference contour distribution will even out as the changes in water level become less extreme. At this time, the Uley South Lens appears to be utilised within its sustainable limits.

South – Coffin Bay Observation Well Network Review 38 Report DWLBC 2003/4

TEM SURVEYS

The equipment used for the survey was the SIROTEM MK3. The instrumentation is sensitive to conductive material in the sub surface. It is well suited to the detection of conductors such as saline groundwater or groundwater in porous media. Strong conductors of large extent will tend to dominate TEM results, sometimes resulting in the concealment of more resistive layers. Electromagnetic geophysical methods make use of electromagnetic induction to measure the electrical resistivity of the ground. The system consists of a transmitter loop or coil through which a time-varying current is passed. This current produces a time-varying magnetic field, which induces current flow in nearby electrical conductors, such as clay rich or water saturated geologic materials. The induced currents, in turn, produce a secondary magnetic field, which is detected as a voltage in the receiver coil. The strength of this voltage is influenced by the electrical resistivity of the subsurface material. The amplitude and dissipation of signal are a function of the ground resistivity with signal dissipation greater through resistive ground. By transmitting electrical pulses through cable loops that are laid on the ground surface, the SIROTEM records transient voltage decay. The Transmitter loop doubles as the receiver and detects the strength of the induced secondary electromagnetic field. The induced voltage is measured at series of delay times after current cut-off. Since the eddy currents migrate and decay with time the representative depth is greater at later times. The delay time can be related qualitatively to depth for interpretation purposes. The voltages measured are very small, so stacking of multiple readings (256 common) is done to improve the signal to noise ratio. The measured voltages are a measure of the apparent resistivity of the ground (Dodds, 1991).

TEM inversions Raw data are retrieved from the SIROTEM internal memory and pre processed using Sirosoft software produced by Sandy Dodds (DWLBC). At this stage data is visually inspected for quality and the gain splicing operation produce resistivity calculation outputs for the line files. The line or station data can then be inverted and this is done so using GRENOCC or EMVISION (GRENDL) software. GRENDL is designed to operate on a single TEM sounding using either a forward or inverse approach. GRENDL assumes a one-dimensional earth and examines only the response of a single sounding at a time. In situations with rapidly changing lateral layering, GRENDL can be unreliable or inaccurate in its solutions. In the process called inversion, the model parameters (layer thickness and resistivity) are adjusted to reduce the average squared misfit error between the observed and computed responses. The philosophy used in inverting the data is to determine the model with the fewest layers whose response adequately fits the data. The inversion process is automated but requires the user to define a reasonable starting model from which a solution can converge. The numbers of layers that are selected are quite critical and need to reflect the raw data. If too many or too few layers are selected the resultant model is bound to be in error. If additional layers can be adequately resolved, they are retained; otherwise, the simpler model is used. The resulting models had three layers in this investigation.

South – Coffin Bay Observation Well Network Review 39 Report DWLBC 2003/4

The data are modelled using a layered Earth that comprises a series of horizontal, stratified layers each of definable thickness and electrical property. The extent of the layers is infinite laterally and defined by the thickness parameter vertically. The bottom layer is assumed to represent basement and so has resistivity properties but no thickness definition. While the data are modelled with sharp transitions between resistivity values, actual variations in pore water conductivity, geology, and formation resistivity, are likely to be transitional over a finite distance. This point should be kept in mind when using the TEM model results.

Survey details

SLEAFORD SHEET (1:50 000) Three lines were proposed for this area, Lines 1000N, 2000N and 3000N (Fig. 23). Satellite and air photos were initially inspected to determine best line access suitable to our needs. Lines 1000N and 2000N were completed as proposed but Line 3000N was hampered with access difficulties, due to dense vegetation. Line 1000N provided 2 line kilometres of data and gave access within 200 metres of the coastal cliff face. This coastal proximity was also desired for Line 2000N. A combination of access and instrument difficulties limited surveying to within 400 metres of the coastal cliffs. Interpretation has not been affected, as trends in the sub surface structure have been suitably determined. Access to the western (coastal) end of Line 3000N was not possible and the survey was begun from the eastern end. 1 line kilometre of survey was achieved before again being restricted by access difficulties. This section proved to be too short to interpret whether a suitable fresh to saline contrast was present. In light of the truncation of Line 3000N, Line 2500N was proposed. Starting at the coastal end, 400 metres of survey was completed. The line, restarted from the eastern end managed 700 metres before surveying was again restricted. The single loop configuration was used for this survey, both current transmission and response voltage measurements being done on a single loop of wire. The loop size for all reading was 100 metres square with a 100-metre spacing between readings (stations). The results are used to locate the extent of seawater intrusion in the Uley South aquifer systems and to map the base of the Wanilla and Bridgewater aquifers in regions where well coverage is sparse.

Presentation of results The data for each survey line are presented as three-layered resistivity model sections. Line locations are given (Fig. 23). The horizontal axis is the station location and vertical axis represents the depth as calculated by the software. The models are simplistically displayed for reader convenience. Layers are interpreted as representing geologic formation or combinations of formations. For each station and each layer there is a calculated value of resistivity. Profiles displaying these values (Ohm.metre) are given in Appendix C.

South – Coffin Bay Observation Well Network Review 40 Report DWLBC 2003/4 IQS°QH9 IQS°QP9 IQS°QR9 SRTHHH SRVHHH SSHHHH SSPHHH TISRHHH 5 5 5 5 5 5ƒ 5 5 5 5

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Topographic corrections have been applied to those profiles where actual topography has been variable enough to suffice a correction. Line 1000N, 2000N and 3000N have had a topographic correction applied, with the vertical axis then representing elevation (AHD) rather than depth. The resistivity depth sections resulting from measured surveys data represent a simple distribution of resistivity. Such inversions are not unique and the accuracy of the interpretation needs to be checked with geological logs before reliance can be placed on the results (Love et al., 1994). The drill logs are required before the geological cause of the geophysical parameter can be positively identified.

Discussion of results The profiles created indicate zones of differing resistivity. A variation in resistivity can be a result of varying geological structure or a change in saturation or saline content within the structure. Not all geological formations will be resolvable from one another and the solution is never unique. That is, there is likely to be more than one possible geological cause for the geophysical response and careful consideration need be applied in identifying the most probable scenario. Sections have been created using a 3-layer model. Analogies between structural geology and zones of resistivity can be made but are not always unique. An understanding of how geological and hydrogeological properties affect resistance is important. A less porous medium will generally be more resistive than a more porous medium. Saline water within a medium will cause the resistance of the medium to be lower. With an understanding of the formation geology in the region it has been possible to correlate formations or combinations of formations with zones of resistive continuity. The major geological units of concern in this interpretation are given. The Bridgewater formation: A Quaternary limestone aquifer that is dry above the watertable. The TEM survey has not been able to delineate between the unsaturated (vadose) and saturated (phreatic) zone. This can be explained by the fact that the fresh groundwater is resistive and the limestone in which it is contained is also resistive, thus bearing insufficient contrast. The Uley formation: A Tertiary clay aquitard; a discontinuous confining layer beneath the Quaternary Aquifer. The geophysical response is expected to be different to that of the Bridgewater formation. That is, it is expected that clay, due to immobile pore fluid and salt accumulation, is less resistive than the Bridgewater formation. The Wanilla formation: A semi confined to confined Tertiary sand aquifer. The salinity in this aquifer is variable and generally higher than the overlying unconfined aquifer. The resistivity of a sand aquifer would be lower than the limestone formation above or crystalline basement below. Further to this, the resistivity measured is strongly dependent on the salinity of the water contained within. Variation in the saline content of the groundwater may be resolvable if the contrast in actual salinity is large enough. This Tertiary sand aquifer, a conductor is not resolvable from the Tertiary clay aquitard, which is also a conductor. Weathered basement and basement: Weathered basement, although composed of resistive crystalline structure, is considered more conductive than crystalline basement on

South – Coffin Bay Observation Well Network Review 42 Report DWLBC 2003/4

its own. Weathered basement bears groundwater and provides sufficient conduits for electrical current transmission. For this reason weathered basement is not uniquely resolvable from the Wanilla formation above. Its presence is inferred but the distribution is not interpretable. True basement (crystalline) will produce a resistive response. Basement does not contain water evenly throughout its matrix but predominately in fractures. To TEM basement is highly resistive due to this apparent ‘no water’. It bears no water and will resist current unless there are conductors within the structure. The contrast in resistance between basement and weathered basement is sufficient to delineate the two. To summerise, the formation resistivities are such that the resistive Bridgewater formation can be resolved from the conductive Uley, Wanilla and weathered basement formations. The Uley, Wanilla and weathered basement are not resolvable from each other. The conductive zone that represents them, interprets as some combination of those formations. Below the conductors, the resistive basement is resolvable from the structure above.

ULEY 1000N The continuous 2 km transect displayed good subsurface contrast between the NE (inland) and SW (coastal) ends. A 3-layer model (Fig. 24, App. C) was used to invert the data with good quality fits throughout the profile. The major features are basement topography and the presence of saline groundwater (saline interface) extending inland from the coast. The three distinct layers are used to represent the profiles sub-structure. The top layer (yellow) describes the distribution of the Bridgewater formation, a Quaternary limestone aquifer. This formation is generally known to have low salinity with permeability ranges from low to very high. The combined signal of the fresher water and the structure of the Bridgewater formation have a signal distinct to that of the two formations lying beneath it, the Uley and Wanilla formations. The Uley formation aquitard is generally a confining layer beneath the Quaternary Bridgewater aquifer. This Tertiary clay aquitard is expected to produce a characteristic low resistivity (high conductivity) response. The model suggests, and it is reasonable to assume, that the signal retrieved from the lower Wanilla formation is not dissimilar to that of the Uley formation and hence a distinction cannot be made between the two. It is known that the Wanilla formation in this location bears water of a higher salinity than that of the Bridgewater formation. This will give rise to a lower resistance. It is also reasonable to assume that the fresh-water saturated Quaternary limestone aquifer will represent greater resistance than both the Tertiary clay aquitard and the saturated Tertiary sand aquifer of higher salinity. Therefore a strong to moderate amount of reliance can be placed on the conclusion that the bottom of the first layer represents the base of the Bridgewater formation and the top of the Uley formation where it is present. The third layer, of much higher resistivity, more than likely represents crystalline basement structure. A distinction can be made between weathered basement and basement. That is, the weathered basement, a conductor, is most likely represented within the second layer. The boundary between the second and third layers is interpreted as the top of crystalline basement. With this in mind, the interpretation gives a basement high at the SW end, peaking at ~ -50m AHD between stations 1100 and 1500. This feature correlates

South – Coffin Bay Observation Well Network Review 43 Report DWLBC 2003/4 SW ULEY1000 N NE

100 1000 1500 2000 2500 3000 100

Moderate resistance zone (Bridgewater Formation)

Approximate Watertable (Bridgewater Formation) 0 0

Strong conductor Low resistance zone (saline groundwater) – Uley Formation – Wanilla formation – Weathered Basement

-100 -100 Saline extent

Elevation (m) AHD

High resistance zone -200 (Basement) -200

-250 -250

1000 1500 20002500 3000

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well with a known basement high interpreted from geological logs. The extent of these highs are illustrated (Fig. 23). From the profile, additional undulations in basement topography can be observed with highs at stations 2200 and 2900. The critical feature in this profile is a zone of high conductivity within the interpreted Wanilla formation. The feature, which is only present from the coastal end, leads interpretation towards a saline ground water interface that extends to station 1500 (700 m from the coast). Another indicator that supports this interpretation is the gradual progression of values (App. C) within the saline zone from low to slightly higher resistivity as you move away from the coast. This gradation could arise from decreasing saline content in the direction away from the coast. Within the first layer (interpreted as Bridgewater formation) between stations 1100 to 1300, resistivity values (App. C) indicate lower resistance relative to the rest of the layer. It is not likely that this represents a saline interface within the Bridgewater Formation as the values themselves are too resistive and elevation of the formation above sea level too great. The cause could be explained as salt spray from the ocean that has penetrated the unsaturated part of the formation through rainfall infiltration. Alternatively, the lowered resistance could indicate a more porous region of the formation. Above the saline conductor (2nd layer, Stations 1100 – 1500) and below sea level, is a zone of interpreted Bridgewater Formation (1st layer). Current understanding of this formation gives the watertable in this location at 1 to 2 metres above sea level. The model has defined the zone as resistive, suggesting that saline water has not entered the formation. The presence of fresh water within this layer will not alter the resistance of the formation markedly. Drill logs and hydrostratigraphic logs are required to validate geophysical data. Near this profile one drillhole (6028 758) was suitable to aid interpretation. Further validation of the data may require that new holes be drilled. The hydrostratigraphic log for well 6028 758 defines the base of the Bridgewater Formation at 55 m, the base of the Wanilla at 87 m and crystalline basement below. Adjacent to the well, stations 2500 and 2600 compare well to the base of the Bridgewater (55 and 65 m). The model suggests that the depth to basement is somewhat deeper than the log suggests (130 m compared with 90 m). Comparisons here may be tricky, as the basement appears to rise sharply in this region. It is plausible that weathered basement is represented in the zone 90–130 m and that the log is somewhat incorrect without definition of a weathered zone.

ULEY 2000N The continuous 2 km transect produced good quality data with high confidence in interpretation. A 3-layer model was used to invert the data with good fits throughout. The major features are formation boundary trends and the absence of saline intrusion. As with 1000N it is reasonable to assume that the fresh, water saturated Quaternary limestone aquifer will bear greater resistance than the Tertiary clay aquitard, the saturated Tertiary sand aquifer and weathered basement. At stations 1400 to 2500 (Fig. 25), the 3-layered structure interprets as described in line 1000N. That is, the top layer is interpreted to represent the Bridgewater formation. The middle layer interprets as the Uley, Wanilla and weathered basement formations and the

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100 1000 1500 2000 2500 3000 100

Moderate resistance zone (Bridgewater Formation) Interpreted swamp region Approximate Watertable (BridgewaterFormation) 0 0

Low resistance zone – Uley Formation – Wanilla formation – Weathered Basement

-100 -100

Elevation (m) AHD Moderate resistance zone Moderate resistance (Basement) zone (Basement)

High resistance zone -200 (Basement) -200

1000 1500 20002500 3000

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bottom layer represents crystalline basement. The main differences are at stations 2600 to 3000 where the Wanilla is represented at the surface and given in the first layer. At these stations the model can be considered as two-layer. Also, between stations 1100 to 1300, the interpreted Wanilla Formation becomes non-resolvable or not present and the model can be considered as two layered. The noticeable difference between profiles 1000N and 2000N is distribution of the interpreted Wanilla formation. 1000N displays coastal connection. Importantly this is not the trend in line 2000N. From the model it is interpreted that the formation is pinched out at station 1300. This is due to the presence of a basement high that peaks between stations 1200 and 1300. An important result, it suggests there are no connections between the Wanilla aquifer and the sea at this point. Rather, there is a zone of resistance that may act as a barrier to saline intrusion and aquifer drainage At the eastern end of the line between stations 2600 and 3000 the data represents a known, low lying swamp region where conductive structure appears to rise towards ground surface. The presence of a basement high below this region, may have forced the formations above to pinch and become narrow. In this region the Bridgewater formation is not represented in the model. However, it is likely that the Bridgewater formation is still present but simply too thin to resolve until station 2500, where a resistor is modelled in the first layer. This is a plausible result, as thin resistors are not easily resolved by the TEM technique. The profile is bounded in the SW and NE by basement highs. These highs peak at stations 1300 and 2800 respectively. In between, a basement low is filled with deepening Tertiary sediment and weathered basement material. In the third layer, between stations 2300 to 2500 a zone of high resistance is displayed. The resistivity values are unique from the surrounding basement material (App. C) but only represent a zone of greater basement resistance. The nearest geological log for validation (well 6028 754) is some 500 metres from the survey line and is considered unsuitable for validation. Only general comparisons should be made as stratigraphy could vary considerably over this distance. Stations 2500 and 2600, nearest to borehole 754 suggest that the Bridgewater formation is thin. The bore log gives the thickness of the Bridgewater formation as 14 metres, which in comparison with the interpreted formation thickness towards the sea, is thin. Further comparisons should not be drawn. This is a region of basement rise and quick variations in formation thickness should be expected. It is recommended that new drillholes be logged for validation of the geophysical interpretation. New drillholes are recommended to validate geophysical interpretation.

ULEY 2500N This line segment is broken into two separate segments (Fig. 23). The western (coastal) segment represents 400m of line data and the eastern (inland) segment represents 700 m of line data. Discussion on the western segment is limited and a profile is not provided. Both modelling programs (Grenocc and Grendl) had difficulty fitting the data. Inspection of the apparent resistivity section (App. C) indicates that there is little conductivity within the structure and what there is, does not fit a one-dimensional model. The data suggests high resistive values increasing with depth that correlate with current knowledge of a basement high in

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that region. If there were saline groundwater present here, it would be expected that the apparent resistivities recorded would be noticeably different. It is therefore concluded that no intrusion of saline water is present at this location. For the eastern Line segment (Fig. 26), interpretation provides distinction between the major units only. This profile has not needed corrections for surface topography, as the terrain was relatively flat throughout the survey section. The major features presented are formation boundary trends. The model is similarly interpreted as the previously presented line profiles. The interpretation presented is simple with model layers continuous throughout the profile. The model layers are interpreted as; the Bridgewater Formation (1st layer), the Uley, Wanilla and weathered basement formations (2nd layer) and crystalline basement (3rd layer). Variations in layer thickness represent variations in formation thickness. Interpretation of the model gives the Bridgewater Formation for the transect as continuous and ranging in thickness from 40 metres at station 800 (east) to 5 metres at station 500 (west). At stations 900 to 1100 (NE end) the model interprets the existence of a thick second layer overlying a basement trough (layer 3). At stations 500 to 800 the model interprets a basement ridge with corresponding thinning of the second layer sequence. At station 800, the model (App. C) displays a thin conductive second layer. The models presented are not unique and a conductive layer such as this may be a result of a ‘conductivity thickness product’. That is, a thin more conductive layer can produce the same geophysical response as a thicker less conductive layer. It is possible that the second layer at this location (station 800) is thicker and less conductive than presented in the model. Correlation with drillhole 602800755 to the bottom of the Bridgewater Formation at station 500 is good (15m compared with 17m). Correlation with depth to crystalline basement cannot be drawn as the drillhole penetrates only to weathered basement. Further drillholes are required to validate the geophysical model.

ULEY 3000N The model displays 1.1 km of line data (Fig. 26) and produced good quality fits to the data. The major features are formation boundary trends. Interpretation is based on the identification of the formations in the region. That is, interpretation provides distinction between some of the major units only. For consistency, a 3-layer model is used. The first layer is given as the Bridgewater Formation, the second layers as the Uley, Wanilla and weathered basement formations and the third layer as crystalline basement. Such is the case for most stations along this profile. With the exception of stations 200 to 400, where the presence of a basement high appears to pinch out the conductive sequence modelled as the second layer. At this location (stations 200 to 400) the transition of structure from the surface is interpreted as Quaternary limestone overlying a thin weathered basement zone then crystalline basement. At station 600 a thin, conductor is modelled in the second layer. The thickness of the layer appears to disjoint the structure to either side. The resistivity value (App. C) is also noticeably different. It is likely the result of a ‘conductivity thickness product’ problem. That is, the presented solution, and an alternate solution (with twice the thickness but half the conductivity) will fit the source data equally well. With consideration of the neighboring structure it could be reasonable to assume that the second (thicker less conductive) solution is the most likely scenario.

South – Coffin Bay Observation Well Network Review 48 Report DWLBC 2003/4 (a) (b) SW ULEY2500 N NE SW ULEY3000 N NE

0 500 600 700 800 900 1000 1100 50 0 250 500 750 1000 Moderate resistance zone (Bridgewater Formation)

Moderate resistance zone -50 0 (Bridgewater Formation)

-100 -50 Low resistance zone Low resistance zone – Uley Formation – Uley Formation – Wanilla formation – Wanilla formation

Elevation (m) AHD Elevation (m) AHD – Weathered Basement – Weathered Basement

-150 -100 Moderate resistance High zone resistance High resistance zone High resistance zone (Basement) zone -175 (Basement) -125 (Basement)

500 600 700 800 900 1000 1100 0 250 500 750 1000

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Interesting features (App. C) are the low resistivity values in the conductive second layer, some part of which represents the Tertiary Wanilla sands aquifer. The values are noticeably lower in comparison to the values of similar structure given in the other profiles. This is interpreted as either groundwater of higher salinity, or an aquifer medium of higher porosity. The former is more probable with salinity near this location known to be higher. Correlation with borehole 6028 657 at station 800 gives the thickness of the Bridgewater formation as 26 metres compared with 32 metres produced by the model. This result is reasonable. New drillholes will assist in model validation.

Conclusions The use of the TEM technique in the search for saline intrusion and definition of formation boundaries in this environment has proved successful. The survey has not been able to discriminate all geological formations, only those where suitable resistive contrast exists between adjacent sequences. The survey results have been successful in delineation of the Quaternary limestone over the conductive sequence below, where it is present. The conductive Tertiary clay, Tertiary sands and weathered basement are not resolvable from one another, but distinction between this combined sequence and the resistive limestone above and the crystalline basement below has been achieved. Where it is present high salinity groundwater yields sufficient resistive contrast and allows interpretation to be placed on its extent. The inversions have been able to discriminate between regions of saline water, fresher water and dry or crystalline rock. Identification of a saline intrusion at the SW end of line 1000N gives the extent 700 m NE from the coast. Interpretation of line 2000N suggests a basement high at the coastal end that prevents connectivity between the aquifer systems and a potential saline intrusion. Results from lines 2500N and 3000N have provided no evidence of a saline intrusion at those locations. All lines have been useful in defining the configuration of the basement and Quaternary limestone. The veracity of these interpretations must be checked by drilling before reliance can be placed on the results. The correlations between the resistivity and geology are not unique, so other evidence such as drilling is required.

South – Coffin Bay Observation Well Network Review 50 Report DWLBC 2003/4

ULEY SOUTH AND COFFIN BAY AUTOMATED MONITORING EQUIPMENT

Uley South Lens In conjunction with the survey work carried out during the Uley South – Coffin Bay Observation Well Network Review, eight (8) monitoring wells were fitted with water level sensors and adjacent to three of these wells tipping bucket rainfall gauges were also installed in Uley South Lens. All monitoring equipment is fitted with data logging devices to store the data collected.

WATER LEVEL SENSORS Six (6) of the eight (8) level sensors (transducers) were Innovonics MD4W (Water Level Recorder) stand alone sensor/logging units and the remaining two (2) were Greenspan PS100, 4-20 Ma output sensors linked to a GreenspanSL300 three (3) channel data logger.

RAINGAUGES Of the three tipping bucket rain gauges (pluviometers) two were linked to Cherryville single channel data loggers but these have since been changed out and replaced with Greenspan SL300 data loggers for reliability and ease of downloading. The remaining rain gauge is linked to a Greenspan SL300 data logger in conjunction with the two PS100 level sensors mentioned above. The rational for choosing a particular observation well for remote monitoring equipping with water level sensing and rainfall gauging equipment (Fig. 6) was based on the following • distribution of the existing production wellfields • effects of pumping on individual aquifers • areas most likely to react quickly to recharge events • where existing monitoring infrastructure could be utilized most effectively without modification. The selected observation wells, ULE147, 196, 134, 139, 197, 202 and 194, are all completed in the Bridgewater Formation, the main producing aquifer. Two adjacent wells ULE 135 and 196 are completed in the Wanilla and Bridgewater Formations respectively. An automatic rainfall gauge adjacent to the site is also linked to the same data logger enabling the capture of both rainfall and water level data simultaneously. The automatic monitoring provides an opportunity to research the rainfall recharge relationship and to some extent the effects that pumping within the basin has on both aquifers. Details of the selected observation wells, automated equipment installed, logging interval and relative position to the wellfield is detailed in Table 2.

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Table 2. Uley South automated monitoring equipment

Unit number 6028 711 6028 759 6028 660 6028 1747 6028 744 6028 1751 6028 1750 6028 745 Formation Bridgewater Bridgewater Bridgewater Bridgewater Bridgewater Bridgewater Bridgewater Wanilla Easting 553492 552035 548779 547859 550991 552511 551618 551618 Northing 6151286 6147708 6154502 6151029 6148603 6152937 6149131 6149131 Obs Well Number ULE 139 ULE 147 ULE 202 ULE 194 ULE 134 ULE 197 ULE 196 ULE 135 Transducer Sensor type MD4W MD4W MD4W MD4W MD4W MD4W PS100 PS100 Data logger MD4W MD4W MD4W MD4W MD4W MD4W SL300 SL300 Serial number 46692 48773 45002 46772 48771 45001 17698 17700 Span (m) 0-10 0-20 0-10 0-20 0-20 0-10 0-10 0-10 Logging Interval (hrs) 2 2 2 2 2 2 Background 4 hourly, Background 4 hourly, significant events significant events every 10 mins every 10 mins Set to start 8/06/2002 8/06/2002 8/06/2002 8/06/2002 8/06/2002 8/06/2002 28/07/2002 18:00 28/07/2002 18:00 2:00 2:00 2:00 2:00 2:00 2:00 Installed 7/06/2002 7/06/2002 7/06/2002 8/06/2002 7/06/2002 7/06/2002 27/07/2002 27/07/2002 Depth set (m) 21 72 23 13 22.3 13 8 8 Water Level Response Regional Local Local Regional Local Regional Regional Regional to pumping pressure Position in Reference Upgradient Central Central Downgradient Cental Upgradient Upgradient Upgradient to Wellfields Rain Gauge Adj yes yes yes Rain Gge Data logger SL300 SL300 SL300

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Coffin Bay Lens Two (2) Coffin Bay monitoring wells were fitted with water level sensors and a tipping bucket rainfall gauge. The water level sensors and automatic rainfall gauge adjacent to the site are linked to the same data logger enabling the capture of both rainfall and water level data simultaneously.

WATER LEVEL SENSORS The two wells adjacent to each other were fitted with Greenspan PS100, 4-20 mA output sensors linked to a Greenspan SL300 three (3) channel data logger.

RAINGAUGE The rain gauge is linked to a Greenspan SL300 data logger and cumulative rainfall is recorded on a four hourly interval in conjunction with the water level change. The Bridgewater Formation monitoring wells are within the wellfield and monitor the aquifer response to recharge and pumping. Wells LKW 38 and 39 are completed in the upper and lower portions of the Bridgewater Formations respectively. These portions appear to be separated by a clay layer which may act as partially confining. The wells, adjacent to each other, provide an opportunity to monitor the effects that pumping within the basin, has on the different sections of the Bridgewater Formation. Details of the selected observation wells, automated equipment installed, logging interval and relative position to the wellfield is detailed in Table 3. Down loading and calibrating of the monitoring equipment will occur every two (2) months and data will be stored in the DWLBC groundwater monitoring data base. Water samples collected from the rain gauges will be analysised for chloride. The comparison of chloride concentration in groundwater with local rainwater will assist in determining recharge values within the region.

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Table 3. Coffin Bay automated monitoring equipment

Unit number 5928 303 5928 304 Formation Bridgewater Bridgewater Easting 544305 544304 Northing 6167359 6167359 Obs Well Number LKW 38 LKW 39

Transducer Sensor type PS100 PS100

Data logger SL300 SL300 Background 4hourly, significant Background 4hourly, significant Logging Interval (hrs) events every 10 mins events every 10 mins Set to start 28/07/2002 13:30 28/07/2002 13:30 Installed 27/07/2002 27/07/2002

Water Level Response Local Local to pumping pressure

Position in Reference Central Central to Wellfields Rain Gauge Adj yes Rain Gge Data logger SL300

South – Coffin Bay Observation Well Network Review 54 Report DWLBC 2003/4

CONCLUSIONS

Hydrogeological knowledge gaps have been identified at strategic positions within the basin. It is recommended that four historical observation wells are rehabilitated and three new wells drilled and included in the current monitoring network. It has also be identified that three wells within the current network have not been rehabilitated and therefore should be incorporated in the rehabilitation upgrade. There are approximately 55 openhole historical observation wells within the Uley South Lens. These wells are not currently monitored and not rehabilitated and therefore potentially allow surface runoff to enter and mix with the aquifer formation water and also aquifer mixing through the open column. These wells may be used as future observation wells as information is required, however, the expense of rehabilition at this stage may not be warranted. It is recommended that SA Water and DWLBC review the future of these wells. Sonding of all the purged wells indicated a consistant salinity profile with depth in the majority of wells. However two wells showed stratification. One well is positioned near the lens boundary where no confining layer exists and the other near the swamp where complex recharge and discharge processes may be occurring. Further salinity profiling will provide a better understanding of the reasons for stratification. The analysis of the TEM surface geophysics results of the Uley South survey identified broad hydraulic zones beneath the surface indicative of changes in groundwater salinity. A possible saline interface has been identified in Uley South Lens about 700m from the coast on transect 1000N at an approximate depth of 85 m. The interpretation is that the saline water body is within the Tertiary Wanilla Formation. However as there is no clay aquitard beneath the Quaternary sequence in this area there is a potential risk to induce a saline intrusion by groundwater extraction from pump stations USPB 15,16 and 17. The TEM survey results indicate that at present there is freshwater within the Quaternary Bridgewater Formation at this site and it is uncertain whether this interface is mobile. Future monitoring will determine the risk to the Quaternary Aquifer. It is recommended that an observation bore is drilled to groundtruth the geophysical results and define the geological, hydrogeological and geochemical profile to identify possible salinity stratification and install a transducer to monitor any water level changes. It is understood that the saline interface in coastal aquifers can be dynamic with movement caused by tidal fluctuations and changes in groundwater level. Monitoring will be necessary to identify the natural range of movement, setting a benchmark to identify any induced intrusion as a result of groundwater extraction. Unfortunately access for geophysical surveying into the sand dunes south of the Coffin Bay borefield was unachievable by the impedance of the dense vegetation. Nevertheless several geophysical transects were achieved at Coffin Bay. Unfortunately the data is of lower quality than that from Uley South. Preliminary results show an area of higher resistivity to a depth of about 50 metres correlating with geological logs. It is difficult to define whether there is a saline interface present or this confined formation is naturally saline throughout from this data. Analysis is continuing. Ten pressure transducers recording water level changes have been installed in selected wells - two in Coffin Bay and eight in Uley South. Four pluviometers logging rainfall intensities have been also been installed - one in Coffin Bay and three in Uley South. All pluviometers are associated with nearby pressure transducers to enable rainfall recharge relationships to be further researched. This data will provide important long term

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information on the aquifer response to rainfall intensity and subsequent recharge and pumping pressures. Groundwater samples show a salinity trend of no change, and in most wells it appears that the previous or current extraction regime is not influencing the salinity. However a slight expansion of the higher salinity zone about the original wellfield in the Uley South Lens is evident. The erratic salinity curve several Coffin Bay wells is likely due to the bailed method of sampling. Bailed sampling has been shown to give unreliable representation of aquifer salinity. The recommendation is that water samples be collected using accepted sampling standards to give representative salinity measurements of the aquifer formation water. The predominant baseline trend indicates that aquifer salinity is likely to be not increasing. With the expansion of the Uley South Public Water supply wellfield in 1999, re-distribution of extraction pressures has occurred within the lens. An analysis of the changes in water level from 1997 to 2002 was carried by contouring the water level changes over this period. Current extraction appears not be alter the regional water level trends apart from what is estimated to be a short-term adjustment period adjacent to the new production wells. At this time, the Uley South Lens appears to be utilised within its sustainable limits.

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RECOMMENDATIONS

The work completed in Uley South has shown that further work is required to address the following: • better define the aquifer and groundwater characteristics throughout the basin by rehabilitating strategic observation wells and constructing up to three new wells that will be geologically and geophysical logged and analysed chemically • better define basin geometry by undertaking strategic transient electromagnetic (TEM) geophysical surveys and monitor movement of the saline interface • establish the extent and thickness of the lens by completing a second series of salinity profiling of wells and compare with existing salinity profiling results to determine any trend in groundwater salinity and lens size • relate aquifer extraction demands, salinity and water level trends to recharge events to enable sound management decisions to be made. Augmentation and rehabilitation of the monitoring network will provide a more comprehensive knowledge base to effectively observe changes in the basin over time. It is recommended that: • current observation wells ULE 97, 134 and 147 be rehabilitated (Fig. 2) • historical observation wells SLE 10, ULE 133, ULE 98 and ULE 96 be rehabilitated and included in the current monitoring network (Fig. 2) • three new wells be drilled at strategic positions in the basin where hydrogeological knowledge gaps have been identified (Fig. 2). It is further recommended that all drilled wells be geophysically logged. This standard procedure carried out at the completion of drilling provides a high degree of certainty to geological and hydrogeological interpretation. • SA Water and DWLBC review the future of openhole historical wells • Monitoring frequency remains monthly due to the irregularity of timing and magnitude of recharge events. The assessment of the ongoing monitoring records of water level changes and chemical analyses from monitoring sites within the Uley South groundwater monitoring network will give confidence that the current management framework is appropriate for this lens. It is recommended that: • The current observation wells, including the new and rehabilitated wells, undergo salinity profiling (with the exception of those wells without casing and completion details). This involves well purging followed by immediate salinity profiling and a repeat salinity profiling after one-month residence time. The information from a second and third profiling coupled with the first should give clear indication on salinity stratification within the basin. • A second round of water samples be collected during well purging. If this is conducted during Autumn, the results will assist in determining any trend in lens salinity, aid in establishing the extent and thickness of the lens, and assist in defining the saline interface when compared to the July 2002 results.

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• SA Water review the groundwater sampling technique to ensure that samples are representative of the aquifer. A pumped sample, not bailed, is recommended. The strategic placement of two additional transducers in either the new or rehabilitated wells will provide an effective coverage for water level monitoring. This will provide confidence that the current management framework is appropriate, and assist with determination of the extent and sustainability of the resources. It is recommended that an investigation well be drilled to groundtruth the geophysical results and define the geological, hydrogeological and geochemical profile to identify possible salinity stratification. This well should be installed with one of the transducers to monitor any water level changes. It is understood that the saline interface in coastal aquifers can be dynamic with movement caused by tidal fluctuations and aquifer water level changes. Monitoring will be necessary to identify the natural range of movement and set a benchmark to identify any negative shift due to saline intrusion. It is critical that geophysical surveys be repeated in future programs. Correlating the geophysical data with the geological borehole logs, and downhole salinity profiling of the proposed new and rehabilitated wells, will enable a more precise position of any saline interface to be interpreted and monitored. This knowledge will greatly improve the ability to manage the groundwater resources to protect them it from induced migration of saline water into the aquifer due to pumping pressures. It is recommended that SA Water and DWLBC review other options of investigating the extent of the Coffin Bay Lens. Drilling wells is the only definitive method in identifying the extent of the lens therefore it is recommended that a series of wells be drilled through the sand dunes into the Bridgewater Formation aquifer. If the saturated depth and water quality are similar to that within the borefield, it is proposed that another series of wells be drilled some distance south of the original series. Further suggestions may include a remote geophysical investigative method such as aerial surveys. In addition, environmental tracer analysis may be useful to delineate recharge processes. No interpretation is currently available from TEM surveys on the coast due to data collection difficulties. It may be necessary to conduct a survey and water quality testing of private wells situated in the township to establish any change in salinity with distance from the coastline in both aquifers.

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SHORTENED FORMS

SI Units commonly used within text Name of unit Symbol Definition in terms of other metric units Millimetre mm 10-3 m length Metre m length Kilometre km 103 m length Hectare ha 104 m2 area Microlitre µL 10-9 m3 volume Millilitre mL 10-6 m3 volume Litre L 10-3 m3 volume Kilolitre kL 1 m3 volume Megalitre ML 103 m3 volume Gigalitres GL 106 m3 volume Microgram µg 10-6 g mass Milligram mg 10-3 g mass Gram g mass Kilogram kg 103 g mass

Abbreviations commonly used within text Abbreviation Name Units of measure TDS = Total Dissolved Solids (milligrams per litre) mg/L EC = Electrical Conductivity (micro Siemens per µS/cm centimetre at 25oC) pH = Acidity

o δD = Hydrogen isotope composition /oo CFC = Chlorofluorocarbon (parts per trillion volume) pptv 18 o δ O = Oxygen isotope composition /oo 14C = Carbon-14 isotope (percent modern Carbon) pmC

ppm = Parts per million ppb = Parts per billion mAHD = Metres above Australian Height Datum m

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REFERENCES Dodds, A.R., 1991. Sirotem survey for freshwater lenses, Penong, South Australia. South Australia. Department of Mines and Energy. Report Book, 91/100. Eyre Region Water Resources Planning Committee (ERWRPC), 2000. Water Allocation Plan for the Southern Basins Prescribed Wells Area. Department for Water Resources, Adelaide. Evans, S.L., 1997. Estimating long term recharge to thin, unconfined carbonate aquifers using conventional and environmental isotope techniques: Eyre Peninsula, South Australia. Finders University (South Australia). M.Sc. thesis (unpublished). Evans, S.L., 2003. Southern Basins Prescribed Wells Area groundwater monitoring status report 2002. South Australia. Department of Water, Land and Biodiversity Conservation. Report, DWLBC 2003/13. Love, A.J., Dowie, J., Smith, P.C., Dodds, S. and Dennis, K., 1994. Musgraves Proclaimed Wells Area groundwater assessment. South Australia. Department of Mines and Energy. Report Book, 96/10. Martin, R. and Clarke, D., 2000 Southern Eyre Peninsula Basins: Uley Basin review. South Australia. Department of Primary industries and Resources. Report Book, 2000/008. Morton,W. and Steel, T.M., 1968. Eyre Peninsula Groundwater Study, Uley South Basin, Progress Report No. 1 — aquifer evaluation. South Australia. Department of Mines. Report Book, 66/45.

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APPENDIX A Fieldwork completed on observation wells and groundwater chemistry results

Table A1. Fieldwork completed July 2002 on the Coffin Bay observation wells Observation Well unit Well Aquifer Monitored Purged Sonded Raingauge Transducer Rehabilitation site number. number. BRIDGEWATER 592800301 LKW 37 Not Done Yes No No No Coffin Bay FORMATION BRIDGEWATER 592800303 LKW 38 Not Done Yes Yes Yes Yes Coffin Bay FORMATION BRIDGEWATER 592800304 LKW 39 Not Done Yes No Yes No Coffin Bay FORMATION

592800306 LKW 40 WANILLA FORMATION Not Done Yes No No No Coffin Bay

South – Coffin Bay Observation Well Network Review 61 Report DWLBC 2003/4

Table A2. Fieldwork completed July 2002 on the Uley South observation wells Observation Well unit Well Aquifer Monitored Purged Sonded Raingauge Transducer Rehabilitation site number. number.

602801068 LKW 12 WANILLA FORMATION Dry Dry No No No Uley South

602801072 LKW 34 WANILLA FORMATION Yes Yes No No No Uley South

BRIDGEWATER 602800910 ULE 77 Pump Seized No data No No No Uley South FORMATION

602800666 ULE 89 WANILLA FORMATION Yes Yes No No No Uley South

BRIDGEWATER 602800876 ULE 92 Dry Dry No No No Uley South FORMATION BRIDGEWATER 602800755 ULE 97 Too Narrow No data No No Yes Uley South FORMATION BRIDGEWATER 602800752 ULE 99 Yes Yes No No No Uley South FORMATION BRIDGEWATER 602800773 ULE 101 Yes Yes No No No Uley South FORMATION BRIDGEWATER 602800743 ULE 102 Yes Yes No No No Uley South FORMATION

602800706 ULE 109 WANILLA FORMATION Yes no data No No No Uley South

BRIDGEWATER 602800775 ULE 114 Yes Yes No No No Uley South FORMATION BRIDGEWATER 602800894 ULE 126 Yes Yes No No No Uley South FORMATION

South – Coffin Bay Observation Well Network Review 62 Report DWLBC 2003/4

Observation Well unit Well Aquifer Monitored Purged Sonded Raingauge Transducer Rehabilitation site number. number.

602800895 ULE 127 WANILLA FORMATION Yes Yes No No No Uley South

BRIDGEWATER 602800744 ULE 134 Too Narrow Yes No Yes Yes Uley South FORMATION

602800745 ULE 135 WANILLA FORMATION Yes Yes No Yes No Uley South

BRIDGEWATER 602800711 ULE 139 Yes Yes No Yes No Uley South FORMATION

602800715 ULE 141 WANILLA FORMATION Yes Yes No No No Uley South

BRIDGEWATER 602800746 ULE 145 Yes Yes No No No Uley South FORMATION BRIDGEWATER 602800759 ULE 147 Too Narrow Yes No Yes Yes Uley South FORMATION BRIDGEWATER 602800767 ULE 184 Jammed Yes No No No Uley South FORMATION

602800766 ULE 185 WANILLA FORMATION Yes Yes No No No Uley South

BRIDGEWATER 602800735 ULE 186 Yes Yes No No No Uley South FORMATION BRIDGEWATER 602800734 ULE 187 Yes Yes No No No Uley South FORMATION BRIDGEWATER 602800792 ULE 188 Pump Seized Yes No No No Uley South FORMATION BRIDGEWATER 602800721 ULE 189 Yes Yes No No No Uley South FORMATION

South – Coffin Bay Observation Well Network Review 63 Report DWLBC 2003/4

Observation Well unit Well Aquifer Monitored Purged Sonded Raingauge Transducer Rehabilitation site number. number. BRIDGEWATER 602800793 ULE 190 Pump Seized Yes No No No Uley South FORMATION BRIDGEWATER 602800733 ULE 191 Yes Yes No No No Uley South FORMATION BRIDGEWATER Pump 602800794 ULE 192 Blockage No No No Uley South FORMATION Jammed BRIDGEWATER 602800795 ULE 193 Yes Yes No No No Uley South FORMATION BRIDGEWATER 602801747 ULE 194 Yes Yes Yes Yes No Uley South FORMATION BRIDGEWATER 602801750 ULE 196 Yes Yes Yes Yes No Uley South FORMATION BRIDGEWATER 602801751 ULE 197 Yes Yes No Yes No Uley South FORMATION BRIDGEWATER 602802295 ULE 201 Pump Seized Yes No No No Uley South FORMATION BRIDGEWATER 602800660 ULE 202 Yes Yes Yes Yes No Uley South FORMATION BRIDGEWATER 602802157 ULE 203 No Access Yes No No No Uley South FORMATION BRIDGEWATER 602802165 ULE 204 Not Located Not Located No No No Uley South FORMATION

South – Coffin Bay Observation Well Network Review 64 Report DWLBC 2003/4

Table A3 Groundwater chemistry analysis Observation Well Number LKW034 ULE202 ULE089 ULE099 ULE101 ULE102 ULE109 ULE114 ULE126 ULE127 ULE135 Sampling date 6/06/2002 6/06/2002 4/06/2002 6/06/2002 5/06/2002 5/06/2002 3/06/2002 4/06/2002 3/06/2002 4/06/2002 5/06/2002

Wanilla Bridgewater Wanilla Bridgewater Bridgewater Bridgewater Wanilla Bridgewater Bridgewater Wanilla Wanilla Formation Formation Formation Formation Formation Formation Formation Formation Formation Formation Formation pH 7.8 7.6 7.6 7.7 7.6 7.7 7.2 7.6 7.3 7.8 7.4 TDS (by EC) (mg/L) 440 510 520 520 430 420 650 490 640 510 1100 Conductivity (uS/cm) 792 923 937 940 783 768 1180 895 1160 921 1970 Dissolved Solids by Calculation 440 218 506 516 423 414 652 477 612 507 1100 (mg/L) Calcium (mg/L) 49.6 73.6 51 72.7 66.9 67.7 72.3 73.9 91.5 70.4 86.1 Magnesium (mg/L) 17.5 24.9 32.2 20.4 16.6 14.2 25.1 17.7 27.2 28.6 43.7 Potassium (mg/L) 2.4 2.5 3.1 2.7 2.2 2.1 3 2.3 2.7 2.1 6.4 Sodium (mg/L) 97.6 96.2 104 101 82.1 78 143 93.5 121 94.1 262 Bicarbonate (mg/L) 212 302 260 247 244 223 308 248 333 319 256 Chloride (mg/L) 136 147 156 173 112 115 219 145 177 129 524 Fluoride (mg/L) 0.13 0.43 0.78 0.44 0.43 0.45 0.43 0.38 0.46 0.6 0.46 Sulphide (mg/L) 33.1 25.7 30.9 24.6 23.2 27.7 37.8 22.5 28.7 25.5 55.1 Nitrate + Nitrite as N (mg/L) 2.52 4.38 3.22 3.97 5.01 4.98 0.018 3.9 3.86 3.95 0.019 Nitrate + Nitrite as NO3 (mglL) 11.2 19.4 14.3 17.6 22.2 22.1 0.08 17.3 17.1 17.5 0.09 Iron - total (mg/L) 1.01 0.351 1.22 <0.030 0.093 2.03 1.75 0.26 1.32 1.96 0.952 Alkalinity as CaCO3 (mg/L) 174 247 213 202 200 183 252 203 273 261 210 Langelier Index 0.18 0.31 0.06 0.27 0.22 0.23 -0.1 0.19 0.18 0.51 0.05 Sodium Absorption Ration 3.04 2.47 2.82 2.7 2.33 2.25 3.7 2.54 2.86 2.39 5.73 Total hardness as CaCO3 (mg/L) 196 286.2 260.3 265.4 235.7 227.6 283.9 257.5 340.6 293.6 395.1 Ion balance (%) 0.22 -0.01 1.27 0.15 1.92 0.9 -0.23 1.91 3.39 1.53 -1.79

South – Coffin Bay Observation Well Network Review 65 Report DWLBC 2003/4

Observation Well Number ULE139 ULE141 ULE145 ULE185 ULE186 ULE187 ULE189 ULE191 ULE193 ULE194 ULE196 ULE197 Sample date 5/06/2002 5/06/2002 5/06/2002 3/06/2002 4/06/2002 4/06/2002 5/06/2002 4/06/2002 5/06/2002 5/06/2002 5/06/2002 3/062002

Bridgewater Wanilla Bridgewater Wanilla Bridgewater Bridgewater Bridgewater Bridgewater Bridgewater Bridgewater Bridgewater Bridgewater Formation Formation Formation Formation Formation Formation Formation Formation Formation Formation Formation Formation pH 7.5 7.5 7.6 7.1 7.4 7.4 7.5 7.5 7.5 7.4 7.6 7.3 TDS (by EC) (mg/L) 450 450 420 700 510 600 440 450 430 740 430 650 Conductivity (uS/cm) 817 815 756 1270 934 1090 800 817 782 1340 786 1180 Dissolved Solids by 430 442 398 697 511 589 443 445 417 768 415 634 Calculation (mg/L) Calcium (mg/L) 74.7 73.8 62.8 75.6 75.7 78.3 77.3 78.5 71.4 87.4 68.6 83.3 Magnesium (mg/L) 15.7 15.1 14.9 29.1 28.4 25.6 15.4 16.6 15.4 28.8 14.9 27.9 Potassium (mg/L) 2 2.4 2.1 4 2 2.8 2 2.2 2.2 4.2 2 3.1 Sodium (mg/L) 78.8 79.3 79.3 152 90.3 118 75.8 79.2 76.9 159 79.2 133 Bicarbonate (mg/L) 244 239 206 323 327 303 257 261 232 306 217 306 Chloride (mg/L) 118 123 114 242 127 187 114 120 116 238 120 206 Fluoride (mg/L) 0.34 0.43 0.43 0.46 0.68 0.45 0.33 0.33 0.35 0.53 0.4 0.42 Sulphide (mg/L) 21.3 18.1 23.9 35.3 26.2 28.2 20.2 20.7 21 99.7 23.7 29.8 Nitrate + Nitrite as N (mg/L) 4.24 4.78 5.88 <0.005 4.42 3.69 3.95 4.05 4.32 0.134 4.7 3.7 Nitrate + Nitrite as NO3 (mg/L) 18.8 21.2 26 0.02 19.6 16.3 17.5 18 19.2 0.6 20.8 16.4 Iron - total (mg/L) <0.03 0.192 <0.030 15.4 <0.030 0.117 <0.03 0.381 5.79 0.506 0.036 <0.030 Alkalinity as CaCO3 (mg/L) 200 196 169 265 268 248 211 214 190 251 178 251 Langelier Index 0.17 0.09 0.11 -0.14 0.16 0.09 0.14 0.14 0.07 0.13 0.12 0.08 Sodium Absorption Ration 2.16 2.2 2.34 3.76 2.25 2.97 2.06 2.12 2.15 3.78 2.26 3.23 Total hardness as CaCO3 251.5 246.5 218.2 308.5 305.8 300.8 256.5 264.4 241.6 336.7 232.7 322.8 (mg/L) Ion balance (%) 2.48 1.85 2.13 -0.04 1.26 0.53 1.96 2.21 2.43 -0.27 2.23 2.44

South – Coffin Bay Observation Well Network Review 66 Report DWLBC 2003/4

APPENDIX B Coffin Bay and Uley South observation well information sheets and sonding results

South – Coffin Bay Observation Well Network Review 67 Report DWLBC 2003/4 COFFIN BAY LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: LKW 37 MONITORING STATUS WELL UNIT NUMBER: 592800301 SWL: Current COORDINATES EASTING: 544182 FREQUENCY: 1 monthly NORTHING: 6167580 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 12.41 GROUND: 12.17 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 11.54 DATE READ: 18/11/2002 LATEST SALINITY: EC(uS/cm) 721 TDS(mg/L) 397 DATE READ: 18/11/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 42 DATE: 3/05/1985 CURRENT DEPTH (m): 36.2 DATE: 31/05/2002 CASED FROM (m): 0 CASED TO (m): 36 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 36 PRODUCTION ZONE TO (m): 37 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Not Done SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonding Data Coffin Bay - LKW 37 Aquifer Monitored: Bridgewater Formation - Quaternary Aquifer 19/07/2002 EC (uS/cm) 0 200 400 600 800 1000 1200 1400 20.0 -7.59

22.0 -9.59

24.0 -11.59

26.0 -13.59

28.0 Bridgewater -15.59 Formation

30.0 -17.59 Depth (m) 32.0 -19.59 Elevation (m AHD) AHD) (m Elevation

34.0 -21.59

36.0 -23.59 36.20 Current depth 37.00 38.0 -25.59

40.0 -27.59

COFFIN BAY LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: LKW 38 MONITORING STATUS WELL UNIT NUMBER: 592800303 SWL: Current COORDINATES EASTING: 544127 FREQUENCY: 1 monthly NORTHING: 6167401 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 2.76 GROUND: 2.74 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 2.07 DATE READ: 18/11/2002 LATEST SALINITY: EC(uS/cm) 716 TDS(mg/L) 394 DATE READ: 18/11/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 49 DATE: 16/03/1985 CURRENT DEPTH (m): 19.1 DATE: 31/05/2002 CASED FROM (m): 0 CASED TO (m): 21 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 15 PRODUCTION ZONE TO (m): 21.5 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Not Done SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: Yes REQUIRES REHABILITATION: Yes

SALINITY PROFILING DATA

Sonde Data Coffin Bay - LKW 38 Aquifer Monitored: Bridgewater Formation - Quaternary Aquifer 19/07/2002 EC (uS/cm) 0 200 400 600 800 1000 1200 1400 10.00 -7.26

12.00 -9.26

14.00 -11.26 Bridgewater 16.00 Formation -13.26

18.00 -15.26 19.1 Current depth 20.00 -17.26 21.5 Depth (m) 22.00 -19.26 Elevation (m AHD) (m Elevation 24.00 -21.26

sum 26.00 -23.26

28.00 -25.26

30.00 -27.26

COFFIN BAY LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: LKW 39 MONITORING STATUS WELL UNIT NUMBER: 592800304 SWL: Current COORDINATES EASTING: 544122 FREQUENCY: 1 monthly NORTHING: 6167400 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 3.01 GROUND: 2.67 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 1.71 DATE READ: 18/11/2002 LATEST SALINITY: EC(uS/cm) 687 TDS(mg/L) 378 DATE READ: 18/11/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 36 DATE: 19/03/1985 CURRENT DEPTH (m): 31.75 DATE: 31/05/2002 CASED FROM (m): 0 CASED TO (m): 27 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 27 PRODUCTION ZONE TO (m): 36 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Not Done SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Coffin Bay - LKW 39 Aquifer Monitored : Bridgewater Formation - Quaternary Aquifer 19/07/2002 EC (uS/cm) 600 800 1000 1200 1400 1600 1800 2000 20.0 -17.0

22.0 -19.0

24.0 -21.0

26.0 -23.0 27.00 28.0 -25.0

30.0 -27.0

Depth (m) Depth 31.75 Current Depth 32.0 -29.0 Elevation (m AHD) (m Elevation

34.0 -31.0 Bridgewater Formation 36.0 -33.0

38.0 -35.0

40.0 -37.0

COFFIN BAY LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: LKW 40 MONITORING STATUS WELL UNIT NUMBER: 592800306 SWL: Current COORDINATES EASTING: 544310 FREQUENCY: 1 monthly NORTHING: 6167286 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 4.65 GROUND: 4.33 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 3.3 DATE READ: 18/11/2002 LATEST SALINITY: EC(uS/cm) 2760 TDS(mg/L) 1530 DATE READ: 18/11/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 60 DATE: 2/04/1985 CURRENT DEPTH (m): 53.5 DATE: 31/05/2002 CASED FROM (m): 0 CASED TO (m): 48 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 48 PRODUCTION ZONE TO (m): 54 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Not Done SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Coffin Bay - LKW 40 Aquifer Monitored: Wanilla Formation - Tertiary Aquifer 19/07/2002 EC (uS/cm) 0 5000 10000 15000 20000 25000 30000 35000 40.0 -39.0

42.0 -41.0 Uley Formation

44.0 -43.0

46.0 -45.0

48.0 48.0 -47.0 0

50.0 -49.0 Depth (m) Depth 52.0 -51.0 Elevations (m AHD) Elevations Current depth 54.0 -53.0 Wanilla Formation 56.0 -55.0

58.0 -57.0

60.0 -59.0

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: LKW 12 MONITORING STATUS WELL UNIT NUMBER: 602801068 SWL: Current COORDINATES EASTING: 549182.57 FREQUENCY: 1 monthly NORTHING: 6160076.97 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 32.67 GROUND: 32.65 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): Dry DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 830 TDS(mg/L) 457 DATE READ: 10/07/1997

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 61.87 DATE: 4/11/1960 CURRENT DEPTH (m): 25 DATE: 01/06/2002 CASED FROM (m): 0 CASED TO (m): 36 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 36 PRODUCTION ZONE TO (m): 39 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Dry SALINITY PROFILING: Dry TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: LKW 34 MONITORING STATUS WELL UNIT NUMBER: 602801072 SWL: Current COORDINATES EASTING: 549381 FREQUENCY: 1 monthly NORTHING: 6158040 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 28.41 GROUND: 28.448 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 26.89 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 810 TDS(mg/L) 446 DATE READ: 6/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 64.01 DATE: 2/12/1960 CURRENT DEPTH (m): 33.7 DATE: 01/06/2002 CASED FROM (m): 0 CASED TO (m): 27 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 27 PRODUCTION ZONE TO (m): 39 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonding Data Uley South - LKW 34 Aquifer Monitored : Wanilla Formation - Tertary Aquifer 21/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 20.0 8.41

22.0 6.41

24.0 4.41 Bridgewater Formation 26.0 2.41 27.00 28.0 0.41 AHD)

30.0 -1.59 Depth (m) 32.0 -3.59 Elevation (m (m Elevation 33.70 open depth 34.0 -5.59

Wanilla 36.0 Formation -7.59

38.0 -9.59 39.00 40.0 -11.59

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 77 MONITORING STATUS WELL UNIT NUMBER: 602800910 SWL: Current COORDINATES EASTING: 550671.64 FREQUENCY: 1 monthly NORTHING: 6161942.74 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 46.29 GROUND: 45.27 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 26.89 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1030 TDS(mg/L) 567 DATE READ: 10/07/1997

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 42.67 DATE: 8/11/1960 CURRENT DEPTH (m): 32.12 DATE: 01/06/2002 CASED FROM (m): 0 CASED TO (m): 26 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 26 PRODUCTION ZONE TO (m): 29 SCREEN TYPE: Unknown SCREEN DIAMETER (mm): Unknown

WORK COMPLETED 2002

PUMPED AND PURGED: Pump Seized SALINITY PROFILING: Not done TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 89 MONITORING STATUS WELL UNIT NUMBER: 602800666 SWL: Current COORDINATES EASTING: 557114 FREQUENCY: 1 monthly NORTHING: 6154243 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 42.82 GROUND: 42.43 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 27.02 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 960 TDS(mg/L) 528 DATE READ: 4/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 57 DATE: 26/05/1961 CURRENT DEPTH (m): 42.45 DATE: 03/06/2002 CASED FROM (m): 0 CASED TO (m): 39 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 39 PRODUCTION ZONE TO (m): 42 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 89 Aquifer Monitored - Wanilla Formation - Tertiary Aquifer 0EC (uS/cm) 200 400 600 800 1000 1200 1400 25.0 17.820 Bridgewater Formation

27.0 15.820

29.0 13.820

31.0 11.820

33.0 9.820 Wanilla Formation

35.0 7.820 Depth (m) Depth 37.0 5.820 Elevation (m AHD) (m Elevation

39.0 3.820

41.0 1.820 42.00 Current depth 43.0 -0.180 Basement

45.0 -2.180

P ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 92 MONITORING STATUS WELL UNIT NUMBER: 602800876 SWL: Current COORDINATES EASTING: 550371 FREQUENCY: 1 monthly NORTHING: 6156026 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 25.53 GROUND: 25.491 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 24.34 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1070 TDS(mg/L) 589 DATE READ: 10/07/1997

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 38.1 DATE: 28/11/1960 CURRENT DEPTH (m): 24.8 DATE: 01/06/2002 CASED FROM (m): 0 CASED TO (m): 21 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 21 PRODUCTION ZONE TO (m): 27 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Dry SALINITY PROFILING: Dry TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 97 MONITORING STATUS WELL UNIT NUMBER: 602800755 SWL: Current COORDINATES EASTING: 548789 FREQUENCY: 1 monthly NORTHING: 6152876 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 5.42 GROUND: 5.42 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 4.2 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 4334 TDS(mg/L) 2416 DATE READ: 13/02/1961

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 47.85 DATE: 14/02/1961 CURRENT DEPTH (m): 47.85 DATE: 14/02/1961 CASED FROM (m): 0 CASED TO (m): 6.4 TYPE: Steel MINIMUM CASING DIAMETER (mm): 63 PRODUCTION ZONE FROM (m): 6.4 PRODUCTION ZONE TO (m): 47.85 SCREEN TYPE: Unknown SCREEN DIAMETER (mm):

WORK COMPLETED 2002

PUMPED AND PURGED: Too Narrow SALINITY PROFILING: Not done TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: Yes

SALINITY PROFILING DATA

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 99 MONITORING STATUS WELL UNIT NUMBER: 602800752 SWL: Current COORDINATES EASTING: 549244 FREQUENCY: 1 monthly NORTHING: 6151805 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 6.23 GROUND: 5.65 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 4.07 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 980 TDS(mg/L) 539 DATE READ: 06/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 34.75 DATE: 16/02/1961 CURRENT DEPTH (m): 6.8 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 0.5 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 0.5 PRODUCTION ZONE TO (m): 11.5 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 99 Aquifer Monitored - Bridgewater Formation - Quaternary aquifer 20/07/2002

0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.000 6.230 0.50

2.000 4.230 Bridgewater Formation

4.000 2.230

6.000 0.230

6.80 Current depth 8.000 -1.770 AHD)

10.000 -3.770

Depth (m) 11.50 12.000 -5.770 Elevation (m

14.000 -7.770 Uley Formation

16.000 -9.770

18.000 -11.770

20.000 -13.770

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 101 MONITORING STATUS WELL UNIT NUMBER: 602800773 SWL: Current COORDINATES EASTING: 549565 FREQUENCY: 1 monthly NORTHING: 6150500 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 5.91 GROUND: 5.46 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 3.64 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 800 TDS(mg/L) 440 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 19.81 DATE: 1/10/1965 CURRENT DEPTH (m): 17 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 5 TYPE: PVC MINIMUM CASING DIAMETER (mm): 75 PRODUCTION ZONE FROM (m): 5 PRODUCTION ZONE TO (m): 17 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 75

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 101 Aquifer Monitored: Bridgewater Formation - Quaternary Aquifer 21/07/2002 EC (uS/cm) 0 200 400 600 800 1000 1200 1400 0.0 6.0

2.0 4.0

4.0 2.0 5.00 6.0 0.0 Bridgewater Formation 8.0 -2.0 AHD)

10.0 -4.0 Depth (m) 12.0 -6.0 Elevation (m

14.0 -8.0

16.0 -10.0 Uley Formation 17.00 Current depth 18.0 -12.0 19.81

20.0 -14.0

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 102 MONITORING STATUS WELL UNIT NUMBER: 602800743 SWL: Current COORDINATES EASTING: 549893 FREQUENCY: 1 monthly NORTHING: 6149686 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 11.18 GROUND: 10.57 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 9.08 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 790 TDS(mg/L) 435 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 42.67 DATE: 17/03/1961 CURRENT DEPTH (m): 18 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 9 TYPE: PVC MINIMUM CASING DIAMETER (mm): 76 PRODUCTION ZONE FROM (m): 9 PRODUCTION ZONE TO (m): 21 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 76

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde data Uley South - ULE 102 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer - 21/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 2.0 9.2

4.0 7.2

6.0 5.2 Bridgewater Formation 8.0 3.2 9.00 10.0 1.2

12.0 -0.8 Depth (m) 14.0 -2.8 Elevation (m AHD) Elevation (m

16.0 -4.8

Uley Formation 18.0 -6.8

19.25 Current Depth 20.0 -8.8

21.00 22.0 -10.8

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 109 MONITORING STATUS WELL UNIT NUMBER: 602800706 SWL: Current COORDINATES EASTING: 552511 FREQUENCY: 1 monthly NORTHING: 6152937 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 11.96 GROUND: 11.8 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 6.57 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1190 TDS(mg/L) 655 DATE READ: 3/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 51.82 DATE: 21/02/1961 CURRENT DEPTH (m): 40.75 DATE: 03/06/2002 CASED FROM (m): 0 CASED TO (m): 38 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 38 PRODUCTION ZONE TO (m): 41 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: no data TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 114 MONITORING STATUS WELL UNIT NUMBER: 602800775 SWL: Current COORDINATES EASTING: 550945 FREQUENCY: 1 monthly NORTHING: 6151573 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 10.53 GROUND: 9.97 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 6.48 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 880 TDS(mg/L) 484 DATE READ: 4/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 12.19 DATE: 21/10/1965 CURRENT DEPTH (m): 10.1 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 4 TYPE: PVC MINIMUM CASING DIAMETER (mm): 75 PRODUCTION ZONE FROM (m): 4 PRODUCTION ZONE TO (m): 10 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 75

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 114 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 22/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 10.5

2.0 8.5

4.0 6.5

6.0 4.5 Bridgewater Formation 8.0 2.5 AHD)

10.0 0.5 Depth (m) 12.0 12.19 -1.5 Elevation (m

14.0 -3.5

16.0 -5.5

18.0 -7.5

20.0 -9.5

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 126 MONITORING STATUS WELL UNIT NUMBER: 602800894 SWL: Current COORDINATES EASTING: 554070 FREQUENCY: 1 monthly NORTHING: 6154700 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 26.39 GROUND: 25.9 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 14.81 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1160 TDS(mg/L) 639 DATE READ: 4/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 50.29 DATE: 2/05/1961 CURRENT DEPTH (m): 19.9 DATE: 03/06/2002 CASED FROM (m): 0 CASED TO (m): 14 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 14 PRODUCTION ZONE TO (m): 20 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 126 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 21/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 5.0 21.4

7.0 19.4

9.0 17.4

11.0 15.4

Bridgewater Formation 13.0 13.4

14.00 15.0 11.4 Depth (m) Depth 17.0 9.4 Elevation (m AHD) (m Elevation

19.0 7.4

20.00 Current depth 21.0 5.4

23.0 3.4

25.0 1.4

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 127 MONITORING STATUS WELL UNIT NUMBER: 602800895 SWL: Current COORDINATES EASTING: 552582 FREQUENCY: 1 monthly NORTHING: 6154685 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 21.22 GROUND: 21.46 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 15.84 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 970 TDS(mg/L) 534 DATE READ: 4/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 74.68 DATE: 12/04/1961 CURRENT DEPTH (m): 45.2 DATE: 04/06/2002 CASED FROM (m): Unknown CASED TO (m): Unknown TYPE: Steel MINIMUM CASING DIAMETER (mm): 100 PRODUCTION ZONE FROM (m): Unknown PRODUCTION ZONE TO (m): Unknown SCREEN TYPE: Unknown SCREEN DIAMETER (mm): Unknown

WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 127 Aquifer Monitored - Wanilla Formation - Tertiary Aquifer 21/07/2002 0 200 400 600 800 1000 1200 1400 EC (uS/cm) 25.0 20.2

25.91 Uley Formation 27.0 18.2

29.0 16.2

31.0 14.2

33.0 12.2 Wanilla Formation

35.0 10.2 Depth (m) Depth 37.0 8.2 Elevation (m AHD) (m Elevation

39.0 6.2

41.0 4.2

43.0 2.2

44.30 Current depth 45.0 0.2

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 134 MONITORING STATUS WELL UNIT NUMBER: 602800744 SWL: Current COORDINATES EASTING: 550991 FREQUENCY: 1 monthly NORTHING: 6148603 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 20.13 GROUND: 20.13 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 18.75 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 850 TDS(mg/L) 468 DATE READ: 4/04/1996

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 76.2 DATE: 3/02/1961 CURRENT DEPTH (m): 25.3 DATE: 05/06/2002 CASED FROM (m): Unknown CASED TO (m): Unknown TYPE: Steel MINIMUM CASING DIAMETER (mm): 63 PRODUCTION ZONE FROM (m): Unknown PRODUCTION ZONE TO (m): Unknown SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 63

WORK COMPLETED 2002

PUMPED AND PURGED: Too Narrow SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: Yes

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 134 Aqufier Monitored - Bridgewater Formation -Quaternary Aquifer 20/07/2002 EC (uS/cm) 0 200 400 600 800 1000 1200 1400 5.0 15.1

7.0 13.1

9.0 11.1

11.0 9.1

13.0 7.1 Bridgewater Formation 15.0 5.1 Depth (m) Depth 17.0 3.1 Elevation (m AHD)

19.0 1.1

21.0 -0.9

22.86 23.0 -2.9 Uley Formation

25.30 Current depth 25.0 -4.9

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 135 MONITORING STATUS WELL UNIT NUMBER: 602800745 SWL: Current COORDINATES EASTING: 551618 FREQUENCY: 1 monthly NORTHING: 6149131 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 7.32 GROUND: 6.73 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 4.84 DATE READ: 04/07/2002 LATEST SALINITY: EC(uS/cm) 2050 TDS(mg/L) 1132 DATE READ: 7/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 83.82 DATE: 3/02/1961 CURRENT DEPTH (m): 58.85 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 55 TYPE: PVC MINIMUM CASING DIAMETER (mm): 75 PRODUCTION ZONE FROM (m): 55 PRODUCTION ZONE TO (m): 58 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 75 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 135 Aquifer Monitored - Wanilla Formation - Tertiary Aquifer 20/07/2002 1000EC (uS/cm) 1200 1400 1600 1800 2000 2200 2400 40.0 18.9

42.0 16.9

44.0 14.9

46.0 12.9

48.0 10.9 AHD) Wanilla Formation

50.0 8.9 Depth (m) Depth Elevation (m (m Elevation 52.0 6.9

54.0 4.9

55.00 56.0 2.9

58.0 0.9 58.85 Current depth Weathered Basement 60.0 -1.2

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 139 MONITORING STATUS WELL UNIT NUMBER: 602800711 SWL: Current COORDINATES EASTING: 553492 FREQUENCY: 1 monthly NORTHING: 6151286 SALINITY: Historical ZONE 53 FREQUENCY 6 monthly ELEVATION (mAHD) REFERENCE : 21.96 GROUND: 21.49 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 15.59 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 830 TDS(mg/L) 457 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 60.96 DATE: 12/07/1961 CURRENT DEPTH (m): 23.8 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 13 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 13 PRODUCTION ZONE TO (m): 23.5 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 139 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 21/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 10.0 12.0

12.0 10.0 13.00

14.0 8.0

16.0 6.0 Bridgewater Formation

18.0 4.0 AHD)

20.0 2.0 Depth (m)

22.0 0.0 (m Elevation

23.50 24.0 23.80 Current depth -2.0 (cement plug)

26.0 -4.0

28.0 -6.0 Uley Formation

30.0 -8.0

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 141 MONITORING STATUS WELL UNIT NUMBER: 602800715 SWL: Current COORDINATES EASTING: 556430 FREQUENCY: 1 monthly NORTHING: 6151537 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 27.9 GROUND: 27.09 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 15.06 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 850 TDS(mg/L) 468 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 47.24 DATE: 21/04/1961 CURRENT DEPTH (m): 27.55 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 24.7 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 24.7 PRODUCTION ZONE TO (m): 27.5 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 141 Aquifer Monitored - Wanilla Formation - Tertiary Aquifer 21/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 10.0 17.9

12.0 15.9

14.0 13.9 Bridgewater Formation

16.0 11.9

18.0 9.9

20.0 7.9 Depth (m) Depth 22.0 5.9 Elevation (m AHD) (m Elevation

Uley Formation 24.0 3.9 24.70 26.0 1.9

27.50 Current depth 28.0 -0.1

Wanilla Formation 30.0 -2.1

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 145 MONITORING STATUS WELL UNIT NUMBER: 602800746 SWL: Current COORDINATES EASTING: 552601 FREQUENCY: 1 monthly NORTHING: 6149494 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 12.29 GROUND: 11.75 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 6.86 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 790 TDS(mg/L) 435 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 45.72 DATE: 24/01/1961 CURRENT DEPTH (m): 12.1 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 10 TYPE: PVC MINIMUM CASING DIAMETER (mm): 75 PRODUCTION ZONE FROM (m): 10 PRODUCTION ZONE TO (m): 12 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 75 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 145 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 25/07/2002

0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 12.3

2.0 10.3

4.0 8.3

6.0 6.3

8.0 4.3 AHD) AHD)

10.0 Bridgewater Formation 2.3 Depth (m) 12.0 0.3 Elevation (m Cement Plug 14.0 -1.7 Uley Formation

16.0 -3.7

18.0 -5.7

20.0 -7.7

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 147 MONITORING STATUS WELL UNIT NUMBER: 602800759 SWL: Current COORDINATES EASTING: 552035 FREQUENCY: 1 monthly NORTHING: 6147708 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 66.72 GROUND: 66.72 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 65.44 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 958 TDS(mg/L) 527 DATE READ: 9/04/1962

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 83.21 DATE: 10/04/1962 CURRENT DEPTH (m): 73.1 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 78.64 TYPE: Steel MINIMUM CASING DIAMETER (mm): 63 PRODUCTION ZONE FROM (m): Unknown PRODUCTION ZONE TO (m): Unknown SCREEN TYPE: Unknown SCREEN DIAMETER (mm): Unknown WORK COMPLETED 2002

PUMPED AND PURGED: Too Narrow SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: Yes

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 147 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 20/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 60.0 6.7

62.0 4.7

64.0 2.7

66.0 0.7

68.0 -1.3 Bridgewater Formation

70.0 -3.3 Depth (m) Depth 72.0 -5.3 Elevation (m AHD) AHD) (m Elevation

74.0 -7.3

73.10 Current depth 76.0 -9.3

78.0 -11.3 Wanilla Formation 80.0 -13.3

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 184 MONITORING STATUS WELL UNIT NUMBER: 602800767 SWL: Current COORDINATES EASTING: 551157 FREQUENCY: 1 monthly NORTHING: 6153167 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 8.13 GROUND: 8.09 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 4.33 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 980 TDS(mg/L) 539 DATE READ: 7/07/1997

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 45.11 DATE: 20/05/1964 CURRENT DEPTH (m): 12.7 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 7 TYPE: PVC MINIMUM CASING DIAMETER (mm): 75 PRODUCTION ZONE FROM (m): 7 PRODUCTION ZONE TO (m): 13 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): WORK COMPLETED 2002

PUMPED AND PURGED: Jammed SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 184 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 25/07/2002

0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 8.1

2.0 6.1

4.0 4.1

6.0 2.1 7.00 8.0 0.1

Bridgewater Formation AHD)

10.0 -1.9 Depth (m) 12.0 -3.9

12.70 Current depth Elevation (m 13.00 14.0 -5.9

16.0 -7.9 Uley Formation

18.0 -9.9

20.0 -11.9

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 185 MONITORING STATUS WELL UNIT NUMBER: 602800766 SWL: Current COORDINATES EASTING: 551131.78 FREQUENCY: 1 monthly NORTHING: 6153174.85 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 8.00 GROUND: 8.029 AQUIFER MONITORED: WANILLA FORMATION LATEST STANDING WATER LEVEL (m): 4.12 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1250 TDS(mg/L) 688 DATE READ: 3/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 40 DATE: 5/04/1990 CURRENT DEPTH (m): 38.7 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 35 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 35 PRODUCTION ZONE TO (m): 38 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): Unknown WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 185 Aquifer Monitored - Wanilla Formation - Tertiary Aquifer 25/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 20.0 -12.0 Uley Formation 21.00 22.0 -14.0

24.0 -16.0

26.0 -18.0

28.0 -20.0 Wanilla Formation

30.0 -22.0 Depth (m) 32.0 -24.0 Elevation (mElevation AHD)

34.0 -26.0 35.00 36.0 -28.0

38.0 -30.0 38.70 Current Depth

40.0 -32.0

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 186 MONITORING STATUS WELL UNIT NUMBER: 602800735 SWL: Current COORDINATES EASTING: 551763 FREQUENCY: 1 monthly NORTHING: 6153404 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 10.87 GROUND: 10.22 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 5.82 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 970 TDS(mg/L) 534 DATE READ: 4/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 12.5 DATE: 18/03/1975 CURRENT DEPTH (m): 11.07 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 6.5 TYPE: PVC MINIMUM CASING DIAMETER (mm): 76 PRODUCTION ZONE FROM (m): 6.5 PRODUCTION ZONE TO (m): 12.5 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 76 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 186 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 22/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.000 10.867

2.000 8.867 Bridgewater Formation

4.000 6.867

6.000 4.867 6.50

8.000 2.867

10.000 0.867

Depth (m) Depth 11.06 Current depth 12.000 -1.133 12.50 AHD) (m Elevation

14.000 -3.133 Uley Formation

16.000 -5.133

18.000 -7.133

20.000 -9.133

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 187 MONITORING STATUS WELL UNIT NUMBER: 602800734 SWL: Current COORDINATES EASTING: 551844 FREQUENCY: 1 monthly NORTHING: 6152819 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 12.09 GROUND: 11.32 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 6.62 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1120 TDS(mg/L) 617 DATE READ: 4/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 22 DATE: 5/03/1975 CURRENT DEPTH (m): 19.1 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 13 TYPE: PVC MINIMUM CASING DIAMETER (mm): 75 PRODUCTION ZONE FROM (m): 13 PRODUCTION ZONE TO (m): 19 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 76 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 187 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 22/07/2002 200EC (uS/cm) 400 600 800 1000 1200 1400 1600 0.0 12.1

2.0 10.1 Bridgewater Formation

4.0 8.1

6.0 6.1

8.0 4.1 AHD)

10.0 2.1 Depth (m) Depth 12.0 0.1

13.00 Sonde Elevation (m 14.0 -1.9

16.0 -3.9

18.0 -5.9 19.00 Uley Formation 20.0 -7.9

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 188 MONITORING STATUS WELL UNIT NUMBER: 602800792 SWL: Current COORDINATES EASTING: 551133.72 FREQUENCY: 1 monthly NORTHING: 6152573.71 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 10.64 GROUND: 10.63 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 6.53 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1210 TDS(mg/L) 666 DATE READ: 7/07/1997

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 15.6 DATE: 16/11/1974 CURRENT DEPTH (m): 14.14 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 8.2 TYPE: PVC MINIMUM CASING DIAMETER (mm): 76 PRODUCTION ZONE FROM (m): 8.2 PRODUCTION ZONE TO (m): 14.25 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 76 WORK COMPLETED 2002

PUMPED AND PURGED: Pump Seized SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 188 Aquifer Monitored - Quaternary Aquifer (Qpcb) 0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 10.6

2.0 8.6

4.0 6.6 Bridgewater Formation

6.0 4.6

8.0 2.6 8.20

10.0 0.6 Depth (m) 12.0 -1.4 Elevaton (m AHD)

14.0 14.14 Current depth -3.4 14.25

16.0 -5.4

18.0 -7.4

20.0 -9.4

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 189 MONITORING STATUS WELL UNIT NUMBER: 602800721 SWL: Current COORDINATES EASTING: 553516 FREQUENCY: 1 monthly NORTHING: 6152207 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 15.19 GROUND: 14.23 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 8.17 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 830 TDS(mg/L) 457 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 13.72 DATE: 13/02/1969 CURRENT DEPTH (m): 14.27 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 5 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 5 PRODUCTION ZONE TO (m): 13 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 189 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 22/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 15.2

2.0 13.2 Bridgewater Formation

4.0 11.2 5.00 6.0 9.2

8.0 7.2

10.0 5.2 Depth (m) Depth 12.0 3.2 13.00 AHD) (m Elevation Uley Formation 14.0 1.2 14.27 Current depth

16.0 -0.8

18.0 -2.8

20.0 -4.8

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 190 MONITORING STATUS WELL UNIT NUMBER: 602800793 SWL: Current COORDINATES EASTING: 551334.75 FREQUENCY: 1 monthly NORTHING: 6152060.91 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 9.75 GROUND: 9.65 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 5.8 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1110 TDS(mg/L) 611 DATE READ: 9/07/1997

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 14.85 DATE: 23/11/1974 CURRENT DEPTH (m): 14.1 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 8.5 TYPE: PVC MINIMUM CASING DIAMETER (mm): 76 PRODUCTION ZONE FROM (m): 8.5 PRODUCTION ZONE TO (m): 14.85 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 75 WORK COMPLETED 2002

PUMPED AND PURGED: Pump Ceased SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA Sonde Data Uley South - ULE 190 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 25/07/2002

0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 9.8

2.0 7.8

4.0 5.8

6.0 3.8

8.0 1.8 8.5

10.0 -0.2 Bridgewater Formation Depth (m) Depth 12.0 -2.2 Elevation (m AHD) (m Elevation

14.0 14.10 Current depth -4.2 14.85 16.0 -6.2

18.0 -8.2

20.0 -10.2

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 191 MONITORING STATUS WELL UNIT NUMBER: 602800733 SWL: Current COORDINATES EASTING: 551982 FREQUENCY: 1 monthly NORTHING: 6152061 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 10.47 GROUND: 9.83 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 5.77 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 850 TDS(mg/L) 468 DATE READ: 4/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 14.30 DATE: 17/02/1975 CURRENT DEPTH (m): 14.3 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 8 TYPE: PVC MINIMUM CASING DIAMETER (mm): 76 PRODUCTION ZONE FROM (m): 8 PRODUCTION ZONE TO (m): 14 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 76 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 191 Aquifer Monitored - Bridgewater Formation - Quatenary Aquifer 20/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 10.6

2.0 8.6

4.0 6.6 Bridgewater Formation

6.0 4.6

8.0 2.6

10.0 0.6 Depth (m) Depth 12.0 -1.4 Elevation (m AHD) AHD) (m Elevation

14.0 -3.4 14.30 Uley Formation

16.0 -5.4

18.0 -7.4

20.0 -9.4

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 192 MONITORING STATUS WELL UNIT NUMBER: 602800794 SWL: Current COORDINATES EASTING: 551672 FREQUENCY: 1 monthly NORTHING: 6151480 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 10.55 GROUND: 10.6 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 7.18 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 800 TDS(mg/L) 440 DATE READ: 9/07/1997

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 15.5 DATE: 12/12/1974 CURRENT DEPTH (m): 14.64 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 15.5 TYPE: Unknown MINIMUM CASING DIAMETER (mm): 76 PRODUCTION ZONE FROM (m): 9.5 PRODUCTION ZONE TO (m): 15.50 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): Unknown WORK COMPLETED 2002

PUMPED AND PURGED: Pump Jammed SALINITY PROFILING: Blockage TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 193 MONITORING STATUS WELL UNIT NUMBER: 602800795 SWL: Current COORDINATES EASTING: 551891 FREQUENCY: 1 monthly NORTHING: 6150894 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 10.13 GROUND: 9.19 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 5.07 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 820 TDS(mg/L) 451 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 15.5 DATE: 4/02/1975 CURRENT DEPTH (m): 15.21 DATE: 05/06/2002 CASED FROM (m): 0 CASED TO (m): 8.5 TYPE: PVC MINIMUM CASING DIAMETER (mm): 76 PRODUCTION ZONE FROM (m): 8.5 PRODUCTION ZONE TO (m): 14.5 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 75 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 193 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 22/07/2002

0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 10.131

2.0 8.131

4.0 6.131 Bridgewater Formation

6.0 4.131

8.0 2.131 8.50

10.0 0.131 Depth (m) 12.0 -1.869 Elevation (m AHD)

14.0 -3.869 14.50 15.21 Current depth Uley Formation 16.0 -5.869

18.0 -7.869

20.0 -9.869

P:\ ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 194 MONITORING STATUS WELL UNIT NUMBER: 602801747 SWL: Current COORDINATES EASTING: 547859 FREQUENCY: 1 monthly NORTHING: 6151029 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 8.62 GROUND: 7.88 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 6.53 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1390 TDS(mg/L) 766 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 57 DATE: 2/05/1990 CURRENT DEPTH (m): 13.3 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 7 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 7 PRODUCTION ZONE TO (m): 12 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: Yes REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 194 Aquifer Monitored - Bridgewater Formaton - Quaternary Aquifer 21/07/2002 400 600 800 1000 1200 1400 1600 1800 2000 EC (uS/cm) 0.0 8.62

2.0 6.62

4.0 4.62

6.0 2.62 7. 8.0 0.62 Bridgewater Formation

10.0 -1.38 Depth (m) 12.0 -3.38 Elevation (m AHD)

13.30 Current depth 14.0 -5.38

Backfilled 16.0 -7.38

18.0 -9.38

Uley Formation 20.0 -11.38

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 196 MONITORING STATUS WELL UNIT NUMBER: 602801750 SWL: Current COORDINATES EASTING: 551618 FREQUENCY: 1 monthly NORTHING: 6149131 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 7.32 GROUND: 6.73 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 5.07 DATE READ: 04/07/2002 LATEST SALINITY: EC(uS/cm) 810 TDS(mg/L) 446 DATE READ: 5/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 11.36 DATE: 8/09/1992 CURRENT DEPTH (m): 11.2 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 3 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 3 PRODUCTION ZONE TO (m): 9 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: Yes REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 196 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer

0EC (uS/cm) 200 400 600 800 1000 1200 1400 0.0 7.317

2.0 5.317 3.00 4.0 3.317 Bridgewater Formation

6.0 1.317

8.0 -0.683 9.00 Uley Formation 10.0 -2.683

Depth (m) Depth 11.20 Current depth 12.0 -4.683 Elevation (m AHD)

14.0 -6.683

16.0 -8.683

18.0 -10.683

20.0 -12.683

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 197 MONITORING STATUS WELL UNIT NUMBER: 602801751 SWL: Current COORDINATES EASTING: 552511 FREQUENCY: 1 monthly NORTHING: 6152937 SALINITY: Historical ZONE 53 FREQUENCY: 6 monthly ELEVATION (mAHD) REFERENCE : 11.96 GROUND: 11.79 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 6.54 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 1200 TDS(mg/L) 661 DATE READ: 3/06/2002

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 15 DATE: 7/05/1990 CURRENT DEPTH (m): 17.1 DATE: 03/06/2002 CASED FROM (m): 0 CASED TO (m): 7 TYPE: PVC MINIMUM CASING DIAMETER (mm): 80 PRODUCTION ZONE FROM (m): 7 PRODUCTION ZONE TO (m): 13 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 80 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 197 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 22/07/2002 200EC (uS/cm) 400 600 800 1000 1200 1400 1600 0.0 12.0

2.0 10.0

4.0 8.0

6.0 6.0 7.00 8.0 4.0 Bridgewater Formation

10.0 2.0 Depth (m) 12.0 0.0 Elevation (m AHD) 13.00 14.0 -2.0 Sump 15.00 16.0 -4.0

18.0 -6.0

20.0 -8.0

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 201 MONITORING STATUS WELL UNIT NUMBER: 602802295 SWL: Current COORDINATES EASTING: 550321.97 FREQUENCY: 1 monthly NORTHING: 6150073.98 SALINITY: Non ZONE 53 FREQUENCY once: Non ELEVATION (mAHD) REFERENCE : 6.44 GROUND: UKN AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 5.05 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) Unknown TDS(mg/L) Unknown DATE READ: Unknown

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 22 DATE: 22/03/1999 CURRENT DEPTH (m): 22 DATE: 22/03/1999 CASED FROM (m): 0 CASED TO (m): 16 TYPE: PVC MINIMUM CASING DIAMETER (mm): 100 PRODUCTION ZONE FROM (m): 16 PRODUCTION ZONE TO (m): 22 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 100 WORK COMPLETED 2002

PUMPED AND PURGED: Pump Seized SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 201 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 20/07/2002 0 200 400 600 800 1000 1200 1400 EC (uS/cm) 5.00

7.00

9.00

11.00

13.00 Bridgewater Formation

15.00

Depth (m) Depth 16.00 17.00

19.00

21.00 Uley Formation 22.00 Current depth 23.00

25.00

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 202 MONITORING STATUS WELL UNIT NUMBER: 602800660 SWL: Current COORDINATES EASTING: 548778.63 FREQUENCY: 1 monthly NORTHING: 6154501.98 SALINITY: Non ZONE 53 FREQUENCY once: Non ELEVATION (mAHD) REFERENCE : 16.73 GROUND: 16.07 AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 14.78 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) 923 TDS(mg/L) 518 DATE READ: 6/06/2002

CONSTRUCTION DETAILS TOTAL DEPTH DRILLED (m): 31.39 DATE: 21/02/1969 CURRENT DEPTH (m): 29.5 DATE: 04/06/2002 CASED FROM (m): 0 CASED TO (m): 12.2 TYPE: Steel MINIMUM CASING DIAMETER (mm): 254 PRODUCTION ZONE FROM (m): 12.2 PRODUCTION ZONE TO (m): 29.59 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 254 WORK COMPLETED 2002

PUMPED AND PURGED: Yes SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: Yes RAINGAUGE ADJACENT: Yes REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 202 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 20/07/2002 0EC (uS/cm) 200 400 600 800 1000 1200 1400 10.0 6.4

12.0 4.4 12.20

14.0 2.4

16.0 0.4

18.0 -1.6

20.0 -3.6 Bridgewater Formation Depth (m) 22.0 -5.6 Elevation (m AHD)

24.0 -7.6

26.0 -9.6

28.0 -11.6

29.50 Current depth 30.0 29.59 -13.6

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 203 MONITORING STATUS WELL UNIT NUMBER: 602802157 SWL: Current COORDINATES EASTING: 548628.65 FREQUENCY: 1 monthly NORTHING: 6155260.77 SALINITY: Non ZONE 53 FREQUENCY once: Non ELEVATION (mAHD) REFERENCE : Unknown GROUND: Unknown AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 27.72 DATE READ: 14/11/2002 LATEST SALINITY: EC(uS/cm) Unknown TDS(mg/L) Unknown DATE READ: Unknown

CONSTRUCTION DETAILS TOTAL DEPTH DRILLED (m): 38 DATE: 19/08/1999 CURRENT DEPTH (m): 33 DATE: 19/08/1999 CASED FROM (m): 0 CASED TO (m): 27.8 TYPE: PVC MINIMUM CASING DIAMETER (mm): 78 PRODUCTION ZONE FROM (m): 27.8 PRODUCTION ZONE TO (m): 32.9 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 78

WORK COMPLETED 2002 PUMPED AND PURGED: No Access SALINITY PROFILING: Yes TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

Sonde Data Uley South - ULE 203 Aquifer Monitored - Bridgewater Formation - Quaternary Aquifer 20/07/2002

0EC (uS/cm) 200 400 600 800 1000 1200 1400 15.0

17.0

19.0

21.0

23.0 Bridgewater Formation

25.0 Depth (m) Depth 27.0 27.80

29.0

31.0

33.0 32.90 Current depth

35.0

ULEY SOUTH LENS OBSERVATION WELL INFORMATION SHEET

OBERVATION WELL NUMBER: ULE 204 MONITORING STATUS WELL UNIT NUMBER: 602802165 SWL: Current COORDINATES EASTING: 551858.7 FREQUENCY: 1 monthly NORTHING: 6148060.86 SALINITY: Non ZONE 53 FREQUENCY: Non ELEVATION (mAHD) REFERENCE : 58.81 GROUND: Unknown AQUIFER MONITORED: BRIDGEWATER FORMATION LATEST STANDING WATER LEVEL (m): 58.5 DATE READ: 17/04/1999 LATEST SALINITY: EC(uS/cm) Unknown TDS(mg/L) Unknown DATE READ: Unknown

CONSTRUCTION DETAILS

TOTAL DEPTH DRILLED (m): 72.5 DATE: 17/04/1999 CURRENT DEPTH (m): 72.5 DATE: 17/04/1999 CASED FROM (m): 0 CASED TO (m): 66.3 TYPE: PVC MINIMUM CASING DIAMETER (mm): 66 PRODUCTION ZONE FROM (m): 66.3 PRODUCTION ZONE TO (m): 72.3 SCREEN TYPE: Slotted Casing SCREEN DIAMETER (mm): 66 WORK COMPLETED 2002

PUMPED AND PURGED: Not Located SALINITY PROFILING: Not Located TRANSDUCER INSTALLATION: No RAINGAUGE ADJACENT: No REQUIRES REHABILITATION: No

SALINITY PROFILING DATA

APPENDIX C Geophysical interpretation and resistivity values

South – Coffin Bay Observation Well Network Review 108 Report DWLBC 2003/4 SW ULEY1000 N NE

100 1000 1500 2000 2500 3000 100 Moderate resistance zone (Bridgewater Formation)

186 180 196 365 72 70 251 429 599 424 75 98 113 203 296 180 126 200 150 0 50 0 100

1.4 3.8 1.6 2.1 2.7 9.4 34 33 17 25 19 19 31 23 21 19 Strong conductor 27 24 25 10 (saline groundwater) 24 -100 -100

Low resistance zone Elevation (m) AHD – Uley Formation – Wanilla formation 989 990 996 1006 1024 – Weathered Basement 862 453 229 -200 700 378 443 1655 1000 -200 486 746 841 862 1167 430 695 847 High resistance zone -250 (Basement) -250

1000 1500 20002500 3000 Apparent Resistivity Units (Ohm.Metres)

201750-010 SW ULEY2000 N NE

100 1000 1500 2000 2500 3000 100

Moderate resistance zone (Bridgewater Formation) 109 166

109 309 128 55 68 Interpreted swamp region 44 0 51 51 87 11 0 45 74 50 101 21 21 26 47 49 11 11 10 9.0 6.7 11 91 16 15 139

12 181 Low resistance zone 12 12 13 -100 – Uley Formation 8.9 -100 – Wanilla formation Moderate resistance Elevation (m) AHD – Weathered Basement zone (Basement) 55 89 100 150 1231 786 51 246 735 209 67 142 81 High 118 193 -200 188 resistance -200 Moderate resistance zone 194 191 189 zone (Basement) (Basement)

1000 1500 20002500 3000 Apparent Resistivity Units (Ohm.Metres)

201750-012 (a) (b) SW ULEY2500 N NE SW ULEY3000 N NE

0 500 600 700 800 900 1000 1100 50 0 250 500 750 1000 74 90 77 87 109 100 131 16 9.3 6.9 122 13 3.4 251 153 -50 11 0 157 123 210 70 111 17 106 111 7.9 24 3.8 1.0 3.9 -100 -50 6.1 7.0 7.6 85

1211 1130 1069 570

Elevation (m) AHD

Elevation (m) AHD 963 1134 291 84 62 94 1041 -150 -100 574 1232 552 56 442 459 -175 -125 62

500 600 700 800 900 1000 1100 0 250 500 750 1000 Apparent Resistivity Units (Ohm.Metres) Apparent Resistivity Units (Ohm.Metres)

201750-014 ULEY2500 N (WEST)

NE 2700 2800 2900 3000 SW

4 4

9 9

14 14

19 19

24 24

Instrument channel number 29 29

34 34

Apparent Resistivity Units (Ohm.Metres) 39 39

2700 2800 2900 3000 Station number 201750-015