U.S. EPA has abandoned its investigation of groundwater contamination near oil and gas operations in Wyoming. The agency will not seek peer review and will not finalize its 2011 draft report that linked hydraulic fracturing to contaminated groundwater near the town of Pavillion. Instead, the state will carry on the investigation with the help of a $1.5 million grant from Encana Oil & Gas Inc. -- the company accused of contaminating the water.