RISK BASED ASSESSMENTS OF PHYSICAL MINE HAZARDS AT ABANDONED MINES LOCATED NEAR URANIUM CITY
Mr Robert McCauley ( - Golder Associates Ltd.), Mr Paul Palmer ( - Golder Associates Ltd.), Mrs Patty Ogilvie-Evans ( - Saskatchewan Research Council)
Since 2012 Golder Associates Ltd. (Golder) and The Saskatchewan Research Council (SRC) have completed several risk-based assessments of physical hazards (shafts, raises, adits, crown pillars etc.) for abandoned mining properties located near Uranium City in Northern Saskatchewan. The purpose of these assessments is to define and reduce the risk to the public and environment. This is carried out by reviewing the current stability conditions, defining data gaps, and recommending additional investigation and remediation measures required for long term closure. The completed assessments have follow a phased approach beginning with a thorough review of all known historical documentation relating to the operations and geological settings associated with the site (Phase 1). This data is then verified and compared to observations and surveyed features collected during site visits (Phase 2). The information compiled in Phases 1 and 2 are used to assess, when possible, the stability conditions of the physical hazards. Following the assessment each hazard is assigned a risk-ranking and reviewed to determine if additional data is required, the current remediation measure is sufficient, or if additional remediation is required. Since these assessments are based almost entirely on historical data conservative assumptions are commonly made to fill in data gaps and compensate for potential inaccuracies. This poses a challenge in determining the cost-effectiveness of completing site investigations (excavation, drilling etc.) to obtain more accurate data or establishing final remediation measures based on the conservative desktop results.