In 2010, the Environmental Protection Agency (EPA) issued an emergency order against Range Resources, stating that the company's drilling activities in Parker County, Texas had contaminated at least two residential drinking water wells. The company denied the allegations, and said the presence of methane was a result of naturally occurring migration, and had shown up in nearby water wells long before Range drilled its gas wells. However, after a January 2011 Texas Railroad Commission (TRRC) hearing, TRRC staff concluded that, based on chemical composition, the gas in the water wells came from the shallow Strawn Formation, rather than the deeper Barnett Shale, in which the Range wells were completed. They also concluded that pressure tests by Range showed mechanical integrity of the casing. EPA and the two homeowners were invited to present evidence at the TRRC hearing, but did not. In March 2012, the EPA dropped its order against Range.