An interesting read:
http://www.cleanenergy.org/pdf/WoundedWaters.pdf"Water quality damage begins upstream...
The Case of the Big Sandy River
Water quality issues do not begin at the power plant.
In October, 2000, water and sludge broke through the
bottom of a mountaintop coal impoundment in Martin
County Kentucky, spilling 300 million gallons of coal
sludge into Coldwater and Wolf Creeks, and the Big
Sandy River. Fish populations were hard hit, and lawns
were buried under seven feet of sludge.52 In December,
2003, a Virginia mine impoundment overflowed, spilling
thousands of gallons of liquid coal waste into the
headwaters of the Big Sandy River.53
Of the 635 coal waste lagoons located nationwide,
about 240 have been constructed in areas (atop
abandoned underground mines) that carry a risk of
collapsing."