The Applications of Chemical Analyses of Sediments and Soils in ...

mobile through chelation with humic materials (Pauli, 1975).The presence of sulphate reducing bacteria at and just below the interface,leading to the precipitation of sulphide, was noted earlier (Cappenberg, 1974).SOME PROBLEM AREASI. MININGMINING AND THE ENVIRONMENTIt has been estimated that in Ontario, 80 million short tons of waste mill tailingsmust be disposed of annually, preferably in engineered impoundment basins (Capliceand Shikaze, 1970). Tailings banks have to be stabilized, preferably by aself-sustaining vegetated cover, such as at INCO in Sudbury (Peters, 1968) and at theHollinger gold mine in Timmins (Gordon, 1969).Mine water and tailings overflows can also cause problems. Much of it can berecycled as at INCO, Sudbury. Cyanide from gold mining can be oxidized and arsenic,associated with silver ores, precipitated by liming. In uranium mining radium removalcan be effected by co-precipitation with sulphate by addition of barium chloride, as atDennison and Rio Algom Mines.Serious problems can arise following abandonment of a mining operation. TheOntario Ministry of Environment is monitoring arsenic leaching into the Moira Riverthrough the ground water from calcium arsenite settling ponds at the Deloro Mineabandoned in 1963 (Ministry of Environment, 1973).23