Well water problems have become a sticking point for those who argue over the safety of natural gas drilling. But Friday we talked to people in Bradford County who say they've never seen anything like this.

Investigators from the Department of Environmental Protection were in Bradford County, trying to find answers to the bubbles rising out of the ground along the banks of the West Branch of the Susquehanna River near Wyalusing. Neighbors are concerned it may be caused by methane gas coming from nearby natural gas drilling.

"We don't know the ramifications of this. All we know is that gas coming out of the river is explosive," said Don Palmer, who lives along the river in Sugar Run.

D.E.P. would only say that gas samples were being taken from both the river as well as nearby gas drilling sites to try and see if the samples match up. A man who described himself to Newswatch 16 as an initial responder from Chesapeake Energy was also there alongside the D.E.P.

In the past few weeks, nearby homeowners have had to start replacing the filters on their water wells more often.

"You might change it once every few months. Every now and then I'd look at it and say maybe I'll do it, but now I have to change it all the time," said Donny Pickett as he showed us the dirty filter from his well.

Pickett is so concerned with the water that he and about a dozen of his neighbors paid to get their water tested privately. Those samples were taken from his faucet Friday, and the he'll get the results in about a month. DEP officials say the samples from the river must be sent out to determine if the bubbles may be naturally occuring.

Still some residents aren't convinced. "I'm an engineer by trade and I believe it cause and effect relationships," said Palmer. "We didn't have this problem until they started the drilling about a mile up river and I find it hard to believe that it's not related."

Chesapeake Energy told us there have been no complaints filed, and that their natural gas drilling wells are all several miles from the bubbling occuring along the river. They also added that no fracking has begun at those drill sites.