PITTSBURGH: At least two gas wells near a community thatís complained of sudden drinking water pollution had casing failures during the drilling process. A well casing is meant to prevent gas or other fluids from leaking into nearby aquifers.

Last week Rex Energy of State College and the Pennsylvania Department of Environmental Protection suggested there was no evidence that recent gas drilling contaminated water wells in the Woodlands community, 30 miles north of Pittsburgh. People in at least 10 households have complained of suddenly discolored and smelly water and unexplained illnesses.

But the Associated Press has learned that Rex acknowledged the well problems in a 2010 financial report.

A spokesman for DEP did not immediately respond to a question on whether the agency knew of the structural problems with the wells.