University of Wollongong Research Online Faculty of Science, Medicine & Health - Honours Theses University of Wollongong Thesis Collections 2014 Analysis of water level and water quality trends within shallow groundwater systems of monitoring sites within the Southern Sydney Basin’s Camden Gas Project. Erik Bartrop UnivFollowersity this of and Wollongong additional works at: https://ro.uow.edu.au/thsci University of Wollongong Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorise you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. You are reminded of the following: This work is copyright. Apart from any use permitted under the Copyright Act 1968, no part of this work may be reproduced by any process, nor may any other exclusive right be exercised, without the permission of the author. 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Recommended Citation Bartrop, Erik, Analysis of water level and water quality trends within shallow groundwater systems of monitoring sites within the Southern Sydney Basin’s Camden Gas Project., Bachelor of Science (Honours), School of Earth & Environmental Sciences, University of Wollongong, 2014. https://ro.uow.edu.au/thsci/84 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] Analysis of water level and water quality trends within shallow groundwater systems of monitoring sites within the Southern Sydney Basin’s Camden Gas Project. Abstract AGL Energy Pty Ltd owns and operates the Camden Gas Project in the Southern Sydney Macarthur region and are currently extracting water and methane from the underlying Illawarra Coal Measures. Within the Macarthur region are two groundwater monitoring sites located at Menangle Park and Denham Court. At each site has four monitoring bores established to monitor the groundwater levels and allow water quality testing. These monitoring bores enable the characterisation of the local groundwater system and an assessment of impacts from coal seam gas extraction on the groundwater system. The Menangle Park monitoring bores are within 100 metres of active production bores whereas Denham Court is ~15km outside the current Camden Gas Project. Both Menangle Park and Denham Court monitoring bores record the groundwater levels of the geological units such as alluvium, the Wianamatta Group and the Hawkesbury Sandstone. Groundwater level hydrographs assess and compare the recharge/drawdown characteristics. In addition, water samples were taken from the Menangle Park monitoring bores (MPMB01, MPMB02, MPMB03 and MPMB04), the nearby production bore (MP17) and the Nepean River. The samples were measured for major ions, elements, radioisotopes and stable isotopes. The techniques involved AMS, CRDS, EA-IRMS, IC and ICPMS. The results characterised the Hawkesbury Sandstone at Menangle Park into an ‘upper’ and ‘lower’ level separated hydrogeologically by a 12 metre thick shale layer. The ‘upper’ level was dated at 600BP whereas the ‘lower’ level was dated between 14,500-16,000BP. The hydrogeochemistry of the coal seam water was significantly different to the Hawkesbury Sandstone however, the age calculations were unrepresentative and unreliable. The water quality was assessed in the Hawkesbury Sandstone and was found to be relatively fresh whereas the Bulli Coal Seam was saline. Interpretation of these results suggests no or negligible hydraulic connection between beneficial aquifers and the coal seam aquifer. Based on this the author concluded that there is negligible impact from coal seam gas extraction on the Hawkesbury Sandstone. However, the data available did not enable the author to make an assessment for the likelihood of long term impacts from coal seam gas extraction. Degree Type Thesis Degree Name Bachelor of Science (Honours) Department School of Earth & Environmental Sciences Advisor(s) Brian Jones Keywords Isotopic geochemistry, hydrogeology This thesis is available at Research Online: https://ro.uow.edu.au/thsci/84 Analysis of water level and water quality trends within shallow groundwater systems of monitoring sites within the Southern Sydney Basin’s Camden Gas Project. Erik Bartrop Thesis submitted in part fulfilment of the requirements of the Honours degree of Bachelor of Science in the School of Earth and Environmental Sciences, University of Wollongong 2014 i The information provided in this thesis is entirely the result of investigations conducted by the author, unless otherwise acknowledged, and has not been submitted in part, or otherwise, for any other degree or qualification. Erik Bartrop Date: 14/10/2014 ii Acknowledgements I have a multitude of appreciative thanks and gratitude to several people whom supported, guided and encouraged me throughout this project. I want to give my first thank you to AGL Energy for the opportunity to conduct an independent Honours research project within the Camden Gas Project. I would like to thank Dr Helen Price for her instructions and patience in the ion chromatography laboratory. I thank Dr Lily Yu for her contributions to my ICPMS results. Professor Allan Chivas, for his openness to give feedback, as well as guidance with isotopes and hydrogeochemistry, thank you. Dr Sam Marx gave important feedback and critique early on in the project on the fundamentals, thank you. Dr Marijka Batterham, for her help with hydrograph analysis which I could not have done alone, thank you. Heidi brown and Alexandra Ulrich always gave more than enough help which made this project so much easier and clearer, thank you. Supervisor Professor Brian Jones offered his critic, knowledge, guidance and experience which were used to establish project goals, thank you. Nicola Fry of AGL was invaluable to this project, her kind logical feedback and devotion to ensuring I understand concepts was exemplary, thank you. Dr Dioni Cendon of ANSTO gave many hours out of his own working time to explain difficult concepts and ensure my commitment to critical thinking, thank you. Supervisor Dr John Bradd opened up the world of hydrogeology and isotopic analysis to me. His attitude was to work with me towards success and open my mind; he courageously endured many emails a day from me and responded immediately, thank you. Finally I would like to thank Keira Webb for her support, encouragement and those early morning coffees which ensured success, thank you. iii Abstract AGL Energy Pty Ltd owns and operates the Camden Gas Project in the Southern Sydney Macarthur region and are currently extracting water and methane from the underlying Illawarra Coal Measures. Within the Macarthur region are two groundwater monitoring sites located at Menangle Park and Denham Court. At each site has four monitoring bores established to monitor the groundwater levels and allow water quality testing. These monitoring bores enable the characterisation of the local groundwater system and an assessment of impacts from coal seam gas extraction on the groundwater system. The Menangle Park monitoring bores are within 100 metres of active production bores whereas Denham Court is ~15km outside the current Camden Gas Project. Both Menangle Park and Denham Court monitoring bores record the groundwater levels of the geological units such as alluvium, the Wianamatta Group and the Hawkesbury Sandstone. Groundwater level hydrographs assess and compare the recharge/drawdown characteristics. In addition, water samples were taken from the Menangle Park monitoring bores (MPMB01, MPMB02, MPMB03 and MPMB04), the nearby production bore (MP17) and the Nepean River. The samples were measured for major ions, elements, radioisotopes and stable isotopes. The techniques involved AMS, CRDS, EA-IRMS, IC and ICPMS. The results characterised the Hawkesbury Sandstone at Menangle Park into an ‘upper’ and ‘lower’ level separated hydrogeologically by a 12 metre thick shale layer. The ‘upper’ level was dated at 600BP whereas the ‘lower’ level was dated between 14,500-16,000BP. The hydrogeochemistry of the coal seam water was significantly different to the Hawkesbury Sandstone however, the age calculations were unrepresentative and unreliable. The water quality was assessed in the Hawkesbury Sandstone and was found to be relatively fresh whereas the Bulli Coal Seam was saline. Interpretation of these results suggests no or negligible hydraulic connection between beneficial aquifers and the coal seam aquifer. Based on this the author concluded that there is negligible impact from coal seam gas extraction on the Hawkesbury Sandstone. However, the data available did not enable the author to make an assessment for the likelihood of long term impacts from coal seam gas extraction. iv Contents Chapter 1 - Introduction .........................................................................................................................