Compliance with discharge standards for the amount of sediment in runoff from mines demands a holistic approach to runoff control. Sediment dams are but one aspect of an overall approach to mine sediment control. This observation is nicely demonstrated by a paper from BiTech’s Geotechnical News as recently posted in the InfoMine library. The Paper is Rock Filter Dams, Sedimentation Ponds and Maintenance: Key to Solving Storm Water Challenge by James Wellington.
Although the paper deals with sediment control and discharge from a landfill, we post it and write about it here as the technical approaches described are equally applicable to most mining operations. The author describes the use of a series of rock filter dams along runoff stream courses in conjunction with borrow pit sediments ponds and clever use of natural vegetation and reduced flow velocities to bring erosion-laden runoff into compliance with sediment discharge criteria for total suspended solids. Regular maintenance is undertaken to remove sediment accumulating behind the rock filter dams and thus to ensure their continued efficiency in trapping and removing suspended solids before the water enters the sediment ponds for a “final polishing”.