Hydrogeological site characterization in an acid rock drainage management program

Surface and subsurface hydrological processes play important roles in the flushing and transport of acid rock drainage. A thorough understanding of the hydrogeologic regime at proposed mine sites and sites generating acid rock drainage is therefore necessary prior to the initiation of an ARD management program. The hydrogeological site characterization should establish the regional hydrogeological setting, local baseline groundwater quality, the local hydrogeologic regime geometry, hydrogeologic parameters of hydrostratigraphic units and site specific flow conditions. The site characterization involves a regional study, the site investigation and site groundwater flow assessment. Available hydrogeological data from the abandoned Mount Washington Mine located on Vancouver Island will be reviewed and the site will be used as an example to demonstrate the importance of groundwater in ARD flushing and transport. The mine was in operation through the mid-1960's. Acidic rock drainage and associated elevated copper concentrations generated in the North Pit of the site have been implicated in fishery losses in the Tsolum River. Strong hydrogeological controls on ARD flushing and transport have been identified but the hydrogeologic regime of the site is still not well understood.Applied Science, Faculty ofMining Engineering, Keevil Institute ofUnreviewedOthe