The creation of large volumes of waste, including solids, liquid effluents, and air emissions, is a fact of life for mining and mineral processing operations. Depending on the minerals’ natural geology and how they are processed these wastes can often be hazardous to the environment and human health. Solid wastes including waste rock and tailings are, by volume, the most significant waste generated by mining and mineral processing. Solid wastes are typically in the tens to hundreds of millions of tons of waste for a single mine. A rough estimate of Canadian production is 2 million tonnes a day. Based on information available from the U.S., it is safe to assume that mining in Canada generates a greater volume of toxic waste than any other industry in the country.MiningWatch is grateful for the financial suport of the Walter and Duncan Gordon Foundation which helped make the research and writing of this publication possible.