Acid and Metalliferous Drainage (AMD) is, and has been, a very signifi cant issue, and therefore represents both a long-term risk and cost, for many sectors of the global mining industry. Acid and Metalliferous Drainage, sometimes referred to as ‘acid mine drainage’ (AMD) or ‘acid rock drainage’ (ARD), frequently occurs in the mining of base metals, coal, and uranium, and may also become a signifi cant issue for the quarrying industry and the land development industry, where acid sulphate soils are exposed to oxygen and water.