Water quality in mining refers to the physical, chemical, and biological characteristics of water associated with mining operations — including pit dewatering effluent, process plant discharge, tailings storage facility seepage, stormwater runoff, and water bodies within or adjacent to the mine site — and their suitability for intended uses such as process water supply, aquatic ecosystem support, potable use, or agricultural irrigation. Mining activities can adversely affect water quality through the introduction of suspended sediments, heavy metals, acidic or alkaline drainage, process chemicals such as cyanide and flocculants, and elevated concentrations of naturally occurring elements including iron, manganese, sodium, and sulphate. In bauxite mining and alumina refining, water quality concerns focus on caustic soda contamination, elevated aluminium and sodium levels in runoff, and the management of alkaline seepage from red mud disposal facilities. Gold mining operations face water quality risks from acid mine drainage, cyanide breakthrough, and the mobilisation of arsenic and mercury associated with gold ore mineralogy. Iron ore mining affects water quality through the release of suspended iron and manganese particulates, and through the drawdown of regional aquifers that sustains biodiversity in arid zone spring systems. Diamond mine water quality issues include kimberlite fines turbidity, elevated sodium and magnesium concentrations in process water, and the control of marine sediment plumes in offshore alluvial operations. Water quality monitoring programs use a network of surface water and groundwater sampling points, continuous monitoring sensors, and regular laboratory analysis to detect and manage potential impacts.
