BIRDSALL-DREISS DISTINGUISHED LECTURE: PREDICTING AND PREVENTING ACIDIC DRAINAGE FROM SULFIDE BEARING MINE WASTES

The generation of acid mine drainage and the accompanying release of high concentrations of dissolved metals plague mining districts throughout the world. Without adequate control acidic, metal-laden drainage devastates river courses and contaminates aquifers. Acidic drainage results from the biologically mediated oxidation of sulfide minerals in mine workings and mine wastes, and the transport of the reaction products along groundwater and surface water flowpaths. Over the past two decades our understanding of the complex interactions between hydrogeology, microbiology, geochemistry and mineralogy has advanced significantly. At the same time, reactive transport models have evolved rapidly to a high level of sophistication, providing a framework for integrating these highly coupled processes. Our improved understanding of the causes of acidic drainage has led to the development of new approaches to mine-waste disposal, and to new and often passive approaches for remediating contaminated surface water and groundwater.