RENEE MONTAGNE, host:
Drive through rural Pennsylvania and you'll see barns, fields, cows and drilling rigs perched on big concrete pads. That's because the northern part of the state is at the center of a natural gas boom. New technology is pushing gas out of huge shale deposits underground, which has created jobs and wealth and may also be contaminating drinking water.
NPR's Christopher Joyce recently traveled to Pennsylvania with a scientist who's leading the search for an answer.
CHRISTOPHER JOYCE: When you frack, as hydraulic fracturing is called, you pump fluids underground. That cracks the shale a mile deep and drives natural gas up to the surface - gas that otherwise could never be tapped. But some people fracking also ruins their water.
Mr. MIKE BASTION: What gives the gas industry the right to take your clean water away?
JOYCE: Mike Bastion lives near Alba, in northern Pennsylvania. He says fracking ruined his well water.
Anxiety about fracking runs high here. Bastion's brother Steve says some of his neighbors can't drink their well water anymore. Today, Steve has invited a team of scientists from Duke University into his home to test the water from his kitchen sink.
Mr. STEVE BASTION: You take for granted doing this, all right? Do this when it doesn't work, or you can't drink it - everything changes. That's a good sound right there.
JOYCE: Bastion says drilling has brought wealth, but at a high price.
Has this pitted neighbor against...
Mr. S. BASTION: Oh, you betcha. The haves and the haves-not. You know what I'm saying? The have-nots should count because we got to drink water too.
JOYCE: The thing about these tainted water stories is they're hard to prove. So Duke University's Rob Jackson, a chemical engineer and ecologist, is trying to figure out if they're true.
Mr. ROB JACKSON (Chemical Engineer): Homeowners will come to tears when you talk to them. There's fear about water; there's something visceral about water.
JOYCE: Jackson has tested about 125 water wells in Pennsylvania and New York. He is looking for potentially dangerous drilling fluids or radioactive material from deep underground. He hasn't found any of that.
Mr. JACKSON: What we found was that people living near a natural gas well had a much greater chance of having high methane concentrations in their water.
JOYCE: Dangerously high, in some cases. And it's methane that appears to come from the same deep gas deposits that gas companies are drilling. Deep methane has its own chemical signature - a unique mix of isotopes accompanied by other gases like ethane and propane. Methane from the surface, where microbes make it in the soil, looks different.
Jackson used the same technique that's common in the gas industry. When Jackson published his findings, it caused a big stir. Critics said he focused on methane trouble spots and should have sampled randomly. They said the methane could be just natural seepage that was there before fracking. Jackson agrees he needs more baseline data on water wells before drillers move in, and from more places.
That's why he's visiting Carl Young's house to test his water. There's no fracking yet near Young's water well.
(Soundbite of machinery)
Mr. JACKSON: We'll run the water for five or 10 minutes just to flush it out. The bucket is for sampling methane, and then we'll grab samples for lots of chemical analyses - salt concentration...
JOYCE: Jackson is broad-shouldered and wears a camouflage ball cap. He and Young, a retired truck inspector, swap deer-hunting stories. Young says the gas boom has been good here for the local economy, but not easy for everyone.
Mr. CARL YOUNG: This is a small rural community with very few people, and now you've got a lot of people. So you need everything you know, motels, food -you need all of that. You know, there has to be change.
JOYCE: Young says there's a dairy farmer nearby who wants a water test as well. We drive past drilling pads and big trucks that haul fracking water and equipment down narrow country roads.
(Soundbite of dog barking)
JOYCE: Inside the farmer's barn, a couple dozen cows stand listlessly in stalls.
(Soundbite of water splashing)
JOYCE: Duke researcher Stephen Osborne draws water from a sink to test. He says dairy farmers have been especially worried about their water.
Mr. STEPHEN OSBORNE (Researcher, Duke University): If there's any contamination from something, it makes it difficult, almost impossible, in fact, to sell their milk, so their business is done, essentially, if that occurs.
JOYCE: Then down the road a bit we visit Steve Miller. His house sits less than 500 yards from an active drilling pad. He wants a water test too. He says the big drilling trucks have ruined the roads, but he says the companies do fix them. There are more strangers in town too nowadays. But he says in balance the gas business has helped the local economy.
Mr. STEVE MILLER: The people who own the land are going to be able to keep the farm, pay their taxes. And farmers are selling their cows and are going to have an easier life because of the wells.
JOYCE: Yet more people are reporting bad water. Many say it wasn't that way before fracking.
One way to get a fix on what's natural and what's caused by fracking is to look at an old methane seep.
(Soundbite of bubbling)
JOYCE: We find one at Salt Springs State Park, near the New York-Pennsylvania border. At the center of a shallow pond, there's a hole in the rock. Methane bubbles up, as if there's a giant champagne bottle under there. It's been doing that as long as anyone remembers.
Mr. JACKSON: One of the questions is, is that methane the same as the methane that we're finding in people's drinking water?
JOYCE: So far, Jackson's results are consistent: What's in peoples' wells is deep gas, created in high heat with its own chemical signature. It's not like the methane in this old seep.
So if water wells are contaminated with deep methane from a mile down, how is it getting there? It might be seeping up through underground cracks opened up by fracking. Or, says Jackson, it could be the cement casing around gas wells that sometimes leaks. That's happened before.
Mr. JACKSON: Think of a garden hose with a pinhole leak. That water spurts out, and if you don't fix that leak, over time it gets bigger.
JOYCE: Jackson says there actually are data about water wells and methane taken before fracking. The gas industry has them. The state has some of that data too. Jackson says they aren't sharing that data with him. He says he understands why the industry might be defensive.
Mr. JACKSON: My first job out of college, I was an engineer - I worked for the Dow Chemical Company - so I understand what it's like to be accused of things that a company didn't do.
JOYCE: Jackson says he's offered to work with industry and the state. So far, though, no one's taken him up.
But more people are paying attention now. A special commission set up by Pennsylvania's governor now says environmental protections should be tougher. The U.S. Environmental Protection Agency is planning a water study. And the U.S. Department of Energy has asked experts to weigh in on the environmental effects of fracking. Penn State University is testing wells too.
Meanwhile, Jackson continues his survey work across the state. He says there's no time to waste. The industry is expected to drill as many as 10,000 new wells in Pennsylvania in the next few years.
Christopher Joyce, NPR News.