As part of the West Virginia Natural Gas Horizontal Well Control Act passed and signed into law in December 2011, the state legislature directed the WV Dept. of Environment Protection to conduct several studies. One of those studies, due by Dec. 31, 2012, was the Impoundment and Pit Safety Study. The study was done on Dec. 17, but only recently released to the public (February 15, 2013).
Details are now emerging from the study (full copy of the study is embedded below), including a warning there may be problems with the way oil and gas drillers are building waste pits for shale drilling, and with how state inspectors are checking them: