Diagnosis of a base metal mine tailings capping failure
thesisposted on 28.03.2022, 18:20 authored by Gyan Connor
Conrad, in northern NSW, is a derelict base metal mine that has undergone extensive rehabilitation. In 2002, the upper tailings (UT) was hydraulically isolated through clay capping; however this was unsuccessful as As, Pb, Cu, and Zn enriched water is exiting the containment structure into Borah and Maids creeks, then Copeton Reservoir, the local drinking water supply, 3 km downstream of the mine. This thesis identifies UT as the highest priority for further rehabilitation. The UT is characterised through elemental and mineralogical analysis of solid samples taken from 0-10 m depth, and leachate extraction from tailings. Metal(loid) concentrations of sediment and water exceed NEPM and ANZECC guidelines onsite and downstream of the mine. Aquatic macroinvertebrate edge sampling along the creeks shows decreased family richness and diversity onsite and downstream from the mine. These results show that capping of the UT has been ineffective, and improvements are suggested to properly rehabilitate the area to stop further offsite spread of contamination. These include a replacement capping design incorporating geofabric, and investigating the possibility that water is infiltrating through the fractured granite in the valley wall on which the UT rests.
Table of Contents1. Introduction -- 2. Regional setting -- 3. Current site condition -- 4. Methods -- 5. Results -- 6. Discussion -- 7. Recommendations -- 8. Conclusions -- 9. References -- Appendices.
NotesBibliography: pages 51-53 Empirical thesis.
Awarding InstitutionMacquarie University
Degree TypeThesis MRes
DegreeMRes, Macquarie University, Faculty of Science and Engineering, Department of Environmental Sciences
Department, Centre or SchoolDepartment of Environmental Sciences
Year of Award2018
Principal SupervisorDamien B. Gore
Additional Supervisor 1Scott Wilson
RightsCopyright Gyan Connor 2018. Copyright disclaimer: http://mq.edu.au/library/copyright
JurisdictionNew South Wales
Extent1 online resource (v, 61 pages) colour illustrations, colour maps
Former Identifiersmq:71005 http://hdl.handle.net/1959.14/1269891
ecotoxicologyXRFXRDMines and mineral resources -- Waste disposal -- Environmental aspects -- New South WalesremediationTailings (Metallurgy) -- Environmental aspects -- New South WalesHazardous wastes -- New South Wales -- ManagementtailingsrehabilitationgeochemistryTailings (Metallurgy)Hazardous wastesmine wasteMines and mineral resourcesmine