The Susquehanna is America’s most endangered river, according to the national environmental group American Rivers. In a press conference Tuesday morning at the state capitol, the group said the Susquehanna is “a victim of natural gas drilling and the environmental hazards associated with hydraulic fracturing, also known as ‘fracking.’”

Drilling for natural gas in the

has proliferated within the Susquehanna River basin the past few years. The process of fracturing the shale by pumping millions of gallons of water mixed with sand and chemicals deep into the ground at high pressure has been criticized as hazardous to water supplies.

Although some water wells have been fouled by natural gas, there has been no evidence that is caused by

.

A study by Duke University released last week concluded faulty well casings were most likely to blame for the migrating gas, which DEP tests have shown did not come from the Marcellus, but rather from shallower deposits disturbed during the drilling process.

The Duke study also found no evidence of contamination by fracking fluids.

On Tuesday, the Sierra Club — a partner of American Rivers at the press conference — called on the Susquehanna River Basin Commission to immediately impose a moratorium on any new drilling; however, SRBC spokeswoman Susan Obleski said that’s not within the commission’s power.

The SRBC has a very limited authority, she said: it oversees and regulates water withdrawals only. If the commission were to attempt a moratorium, Obleski said, “We would be sued, and we would lose.”

Last year’s “most endangered river” was the Delaware — and for the same reasons — which highlights the political nature of the annual list: the first criteria for American Rivers' "endangered" designation is whether or not there's "a major decision that the public can help influence in the coming year."

Tuesday’s announcement called for passage of the federal FRAC Act, which would make gas drilling subject to the Safe Drinking Water Act and put the Environmental Protection Agency in charge of regulating hydraulic fracturing.