A fatal November 30, 2012, collapse of part of a coal-slurry impoundment served as a reminder of safety issues that may not be adequately regulated in some states and localities. You can locate local coal-slurry impoundments and information on their status with an online public database.
The collapse at Consol Energy's Robinson Run mine slurry pond near Lumberport, WV, killed a bulldozer operator. There are about 596 similar impoundments in 21 states.
The Coal Impoundment Location and Information System offers location and emergency information about coal impoundments in a searchable online database. It is operated by a partnership of government agencies and industry groups. You can find it here. 
- "Man Still Inside Bulldozer in Coal Slurry Pond,"  Associated Press, December 10, 2012.