Environmental Protection Agency Administrator Lisa Jackson on Wednesday sought to tamp down concerns raised by Republican senators that the Obama administration will try to curtail shale gas and oil development through its studies of hydraulic fracturing.

At a hearing before a Senate Appropriations Committee panel on EPA’s $8.3 billion 2013 budget request, Jackson said a request for $8 million for additional hydraulic fracturing research was not intended to put new roadblocks in the way of domestic drilling.

The additional money would pay for EPA’s portion of new fracking studies to be done with other federal agencies. The agency has also asked for more than $4 million to continue work on the congressionally-mandated study of potential impacts to drinking water supplies.

“I guess I’m a little concerned about the scope of the study that we’re seeing come out,” said Sen. Lisa Murkowski, R-Alaska, the top Republican on the Interior, Environment and Related Agencies Subcommittee.

Sen. Roy Blunt, R-Mo., asked, “Does that study stop us from moving forward with hydraulic fracturing?”

Jackson said the drinking water study would inform EPA of any unexpected threats to public health, but not to stop fracturing, which has led to a boom in gas development in Pennsylvania and West Virginia and oil drilling in the Plains states.

“What I’ve said about the drinking water study is that if we learn things that teach us better ways to protect drinking water, certainly we’re going to share that with all the people out there, as our partners, trying to protect drinking water,” Jackson said.

She noted that the planned new studies are part of a coordinated effort with the U.S. Geological Survey and the Energy Department to examine impacts to air quality, water quality and ecosystems. The White House announced the effort last month.

“There is on the part of the administration, from the president, from the White House, a desire to do additional science around hydraulic fracturing . . . because the public’s trust in that technology we believe is also based on the belief that we are looking to bring the very best science to bear, to ensure that it remains safe,” she said.

She said EPA is on track to complete the drinking water study in 2014, with initial results to come out at the end of 2012.

The chairman of the subcommittee, Sen. Jack Reed, D-R.I., said later he did not expect opposition to the request for additional money outside the drinking water study, but could not predict whether the funds would be approved given the difficult budget environment.

“I think it’s promising, because everyone wants to ensure there are no consequences. That includes industry,” Reed said. “Part of the enthusiasm of this new technique is establishing the confidence in the American people that it has no adverse environmental effects. This is money that could be well spent,” he added.

Murkowski’s spokesman, Robert Dillon, did not say whether she would oppose the spending, but noted that with the department already looking at a reduced budget for 2013 as proposed by Obama, any large spending boost is going to get increased scrutiny from the Alaska senator.