Abstract: Pollution by mine drainage is a major problem in many parts of the world. The most frequent contaminants are Fe, Mn, Al and SO (sub 4) with locally important contributions by other metals/metalloids including (in order of decreasing frequency) Zn, Cu, As, Ni, Cd and Pb. Remedial options for such polluted drainage include monitored natural attenuation, physical intervention to minimise pollutant release, and active and passive water treatment technologies. Based on the assessment of the key hydrological and geochemical attributes of mine water discharges, a rational decision-making framework has now been developed for deciding which (or which combinations) of these options to implement in a specific case. Five case studies illustrate the application of this decision-making process in practice: Wheal Jane and South Crofty (Cornwall), Quaking Houses (Co Durham), Hlobane Colliery (South Africa) and Milluni Tin Mine (Bolivia). In many cases, particularly where the socio-environmental stakes are particularly high, the economic, political and ecological issues will prove even more challenging than the technical difficulties involved in implementing remedial interventions which will be robust in the long term. Hence truly “holistic” mine water remediation is a multi-dimensional business, involving teamwork by a range of geoscientific, hydroecological and socio-economic specialists.

Abstract: Acidic spoil-heap drainage, containing elevated concentrations of iron, aluminium and manganese, has been polluting the Stanley Burn in County Durham for nearly two decades. Following the success of a pilot-scale wetland (the first application of its kind in Europe), a full-scale wetland was installed. Waste manures and composts have been used as the main substrate which is contained within embankments constructed from compacted pulverized fuel ash. The constructed wetland, which cost less than £20,000 to build, has consistently reduced iron and aluminium concentrations and has markedly lowered the acidity of the drainage. A third phase of activities at the site aims to identify and eliminate pollutant-release 'hot spots' within the spoil.