Gas wells into the Marcellus and Utica shale formations drive thousands of feet below the water table. That means drinking water supplies should not be affected by the wells if their casings are intact.
That is a very big "if," however. It is one reason why new West Virginia regulations on gas and oil wells emphasize drillers' responsibility to place and maintain casings properly.
About 10 families in another drilling area about 30 miles north of Pittsburgh have complained about contaminated water wells. Both the Pennsylvania Department of Environmental Protection and the company with wells nearby, Rex Energy, say there is no evidence wells affected water supplies.
But it was revealed Monday that Rex Energy admitted casings at two of the wells had failed.
That still may not link the wells to contamination of drinking water. Clearly, however, the Pennsylvania DEP should be investigating the casing failures to determine what, if any, effects they had on the environment.
West Virginia and Ohio officials should seek the results of those investigations. They may indicate our two states need even stronger requirements on well casings. In the meantime, both states should be enforcing existing rules to the letter.