Authors: Knight, K
Editors: Fourie, AB; Tibbett, M
Conference: Mine Closure 2016, 15–17 March, Perth
Published: Australian Centre for Geomechanics, Proceedings of the 11th International Conference on Mine Closure, pp.121-130, Perth
URS Australia Pty Ltd (now AECOM Australia Pty Ltd) was commissioned to prepare technical specifications and oversee remediation works to construct a containment cell for the encapsulation of lead tailings at the Northampton State Lead Battery site in Western Australia. The design and construction works were conducted between September 2009 and January 2010 with the objective to reduce residual risks and long term liabilities associated with a safe, stable and non-polluting site. Design of the containment cell was to encapsulate an approximate volume of 20,000 m³ lead tailings. As the onsite work progressed, 14,000m³ of additional buried tailings materials were identified and, due to a lack of other suitable options, it was determined by the client and other relevant stakeholders that the additional volume of tailings had to be encapsulated within the same footprint. This altered the design of the cell significantly, which subsequently affected the desired rehabilitation outcomes. The scope did not allow for an alteration of rehabilitation methodology and consequently, three years post construction works, the landform showed signs of instability and the landform surface would not sustain vegetation. In 2013 a refocussed effort was made to promote achievable rehabilitation outcomes. Despite various technical challenges such as steep batters, lack of growth medium, and challenging climatic conditions, these rehabilitation efforts have been successful; the landform is currently safe, stable, non-polluting, and is on a path towards hosting self sustaining vegetation. As a result, a collaborative technical approach, inclusive of engineers, hydrologists, geotechnical and rehabilitation specialists has become an important component of all URS remediation projects.
Keywords: landform design, rehabilitation decision making and outcomes, collaborative technical approach
Knight, K 2016, 'The importance of revisiting landform design after key decision-making events', in AB Fourie & M Tibbett (eds), Proceedings of the 11th International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 121-130.
Beard, JS 1990, Plant Life of Western Australia, Kangaroo Press, Kenthurst, New South Wales.
BOM (Bureau of Meteorology) 2015c, Nokanena Site No: 008267, Commonwealth of Australia, viewed 1 April 2015.
Demody & Cramer 2015, A townwide study into the presence and remediation of lead tailings – Northampton, Western Australia.
Gold Corporation 1998, Environmental Assessment of the Northampton State Battery Site, unpublished report.
NEPC (The National Environment Protection Council) 2013, Schedule 1. Investigation Levels for Soil and Groundwater. The National Environment Protection (Assessment of Site Contamination) Measure 2013, Federal Register of Legislative Instruments F2013C00288.
Tille, P 2006, ‘Soil-Landscapes of Western Australia’s Rangelands and Arid Interior’, Resource Management Technical Report 313, Department of Agriculture and Food, WA.
URS 2004, Volume I, Environmental Site Assessment – Northampton Lead Battery, Ref No. 52175- 001, unpublished report.
URS (URS Australia) 2011, Northampton State Battery Remediation Completion Report, 42906959-662-F9346_1, 2 March 2011, unpublished report.
URS (URS Australia) 2015, Northampton State Battery LFA 12 Month Monitoring Report, 42908520/TESG0483/A, October 2015, unpublished report.
Water and Rivers Commission 2001, Preliminary Investigation of Heavy Metal Contamination of Nokanena Brook, Northampton, Western Australia, unpublished report.