Comment & Debate
I love mountains.org: “PROCESSING — The coal is washed and treated before it is loaded on trains. The excess water left over from this process is called coal slurry or sludge and is stored in open coal impoundments. Coal sludge is a mix of water, coal dust, clay and toxic chemicals such as arsenic mercury, lead, copper, and chromium. Impoundments are held in place by mining debris, making them very unstable.”