Russel, CK, Orr, PL, Berthelot, D & Ludgate, I 2011, 'Post decommissioning monitoring of eleven uranium mines – the development of an integrated and adaptive environmental monitoring programme to address multiple sites over time', in AB Fourie, M Tibbett & A Beersing (eds), Mine Closure 2011: Proceedings of the Sixth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 309-318, https://doi.org/10.36487/ACG_rep/1152_99_Russel (https://papers.acg.uwa.edu.au/p/1152_99_Russel/) Abstract: Rio Algom Ltd. and Denison Mines own and operated 11 uranium mines all within the Serpent River Watershed (Elliot Lake, ON). The mines operated from the late 1950s to the mid 1960s and again from the early 1970s to 1990s when the mines ceased operations. At the time of decommissioning, each mine had its own environmental monitoring programme which had evolved over the operating life of the mine and did not necessarily reflect the objectives associated with monitoring of decommissioned sites. In order to assess the effectiveness of the decommissioning plans to achieve predicted conditions and the cumulative effects within the watershed, a single watershed monitoring programme was developed in 1999: the Serpent River Watershed Monitoring Programme (SRWMP) which focused on water and sediment quality, and biological response over time. In order to integrate watershed conditions with source releases from the tailings management areas (TMAs) and the operations of the TMAs, two companion programmes were developed: 1) the Source Area Monitoring Programme (SAMP) and 2) the TMA Operational Monitoring Programme (TOMP). Through the development of programmes that were objective driven, more meaningful data have been provided to allow for informed decision making by the mines and the federal and provincial regulators which have jurisdiction at these sites. When the programme was developed, the removal of redundancies and inefficiencies in the existing monitoring programmes generated an initial cost savings of about 60 to 70% over operational monitoring costs. Through the incorporation of acceptability criteria and response triggers that allow the scope of the programme to retract in response to improvement in environmental conditions, the scope and cost of the programme has been further reduced by 30 to 40% while still generating relevant data for future decision making. Environmental conditions within the Serpent River Watershed have improved dramatically over the past ten years and through the effective implementation of the SRWMP, these improvements have been documented and accepted by regulators and the public.