Story updated at 10:30 a.m. EST on Dec. 8 to include comment from U.S. EPA.

One of hydraulic fracturing's most vocal supporters in Congress says recent comments by U.S. EPA Administrator Lisa Jackson raise questions about a high-profile drinking water contamination incident in Wyoming.

Sen. James Inhofe (R-Okla.) sent a letter to Jackson today asking about her statement last month that fracturing might be linked to high levels of methane, benzene and other chemicals in wells in Pavillion, Wyo. (Greenwire, Nov. 18).

He said EPA staff had assured him previously that hydraulic fracturing was not a focus of the Pavillion investigation and that there were no significantly new data in an EPA announcement last month.

"Because of these contradictory statements, I am concerned that EPA has pre-determined that hydraulic fracturing is the cause of contamination in their Pavillion investigation and the agency is trying to make the data conform to that conclusion," Inhofe wrote.

An EPA spokeswoman did not immediately respond to a message seeking comment.

In a television interview last month, Jackson said, "It is possible that fracking in one bearing zone may have impacted nearby areas that may contain some groundwater."

It was the first time Jackson raised a possible link between the oil and gas industry practice of fracturing and the water pollution in Pavilion.

Encana Corp., which drills in the area's gas field, has denied the link between drilling and the contamination, saying EPA drilled its monitoring wells in a natural gas zone.

"We will review the Senator's letter and respond accordingly. Last month, EPA met with members of the Pavillion community to share our latest round of sampling results of drinking water wells and deep monitoring wells in an effort to ensure that the community is fully informed and engaged. We also shared the data with Encana, the tribes and the State for their preliminary review," said EPA spokeswoman Betsaida Alcantara in a statement.

"EPA scientists are continuing to complete their analysis of those data and we are working hard to complete a report interpreting the findings very soon," the statement said. "To ensure that we have the best quality data, we will also send the report to a panel of independent scientists for review and will have a period of public comment for people throughout the country, including the Pavillion community to provide their comments before we finalize the findings."

Click here to read the letter.