This story was updated at 3:21 p.m. EST.

U.S. EPA decided not to move forward with a potential well-contamination case after the driller threatened not to cooperate with a national study into hydraulic fracturing, according to a confidential report.

A resident of a Fort Worth, Texas, suburb reported that his family's drinking water had begun to bubble like Champagne, leading EPA to issue an emergency order that said at least two homeowners could be in danger from flammable methane seeping into a well.

More than a year later, the agency rescinded its order against driller Range Resources, setting aside scientific evidence that said hydraulic fracturing could be the cause of the problem. The agency has not offered a public explanation for why it changed its order.

In a statement, EPA said resolving the matter would allow the agency to shift its "focus in this case away from litigation and toward a joint effort on the science and safety of energy extraction."

EPA's decision ignored the dangers of the situation, said Steve Lipsky, who lives in Weatherford, Texas, the Fort Worth suburb, and is a member of one of the families affected by the contaminated well.

"I just can't believe that an agency that knows the truth about something like that, or has evidence like this, wouldn't use it," Lipsky said (Ramit Plushnick-Masti, AP, Jan. 16).

Energy In Depth, a campaign created by the industry trade group Independent Petroleum Association of America, issued a rebuttal, denying claims that EPA changed its position because of Range. Instead, the campaign said, the scientific research EPA had intended to use had been called into question. -- JE