Other water impacts include acid rock drainage refers to metal-rich acidic waters that are generated through the exposure of sulfidic minerals in mine wastes to water, oxygen, and microorganisms from coal a combustible black or dark brown rock consisting chiefly of carbonized plant matter, found mainly in underground seams and used as fuel mines, the obliteration of mountain streams and valleys by mountain top removal mining and the energy-water collisions that occur when coal a combustible black or dark brown rock consisting chiefly of carbonized plant matter, found mainly in underground seams and used as fuel plants rely too heavily on local water supplies.