According to the consent agreement signed on Monday, the DEP investigated at least seven instances of methane migration that contaminated 16 residential water wells in Bradford County last year.
The DEP blamed improper cement casings of Chesapeake gas wells for allowing the natural gas to seep into drinking water supplies. .
http://www.philly.com/philly/business/20110517_Marcellus_driller_fined_record__1_1M.html