JEFFREY BROWN: Energy companies are increasingly scouring the country for natural gas. But, as they do so, one of the methods they're using, known as fracking, is coming under sharp scrutiny in many states.
NewsHour correspondent Tom Bearden reports from Colorado.
TOM BEARDEN: By now, you have likely seen the videos of people seemingly lighting their water on fire. The images were featured in a much-publicized documentary called "Gasland" and have generated government hearings and news coverage about whether the gas in the water was the result of drilling for natural gas.
All the attention has also popularized a word that was little known to the public just a few years ago: fracking.
MAN: Fracking is a form of natural gas drilling.
TOM BEARDEN: It's even inspired a YouTube video.
MAN: Water goes into the pipe, the pipe into the ground. The pressure creates fissures 7,000 feet down. The cracks release...
TOM BEARDEN: It's shorthand for hydraulic fracturing, the process used to get the gas out of the ground. Concerns about it have ignited a national debate about whether natural gas, long touted as a greener alternative, is indeed a clean technology.
The process begins with vertical and then horizontal drilling through thousands of feet of rock and soil. Once the gas-laden shale layer is reached, a pipe is inserted and encased in concrete to prevent leaks. Then, a fracking fluid is injected at extremely high pressure, causing the rock to crack.
Matt Abell works in Colorado for Encana, one of the largest gas companies in North America.
MATT ABELL, Encana: The whole purpose of that is to induce a series of additional fractures, a fracture network within the rock, which then allows gas to come into the well wall.
TOM BEARDEN: Abell says the fluid used to make those cracks is 90 percent water, nine percent sand, and less than one percent added chemicals to facilitate the process.
But it's those chemicals that have gotten much of the publicity in recent months. Despite years of reassurances from government agencies and the gas companies, a lot of ranchers here in Garfield County believe these operations are a serious threat to their health.
Carol and Orlyn Bell owned a 110-acre ranch just outside of Silt, Colo., for 27 years.
CAROL BELL, fracking critic: The corporations themselves consistently insist that fracking fluid is nothing but water and sand. And we know that's not true. It's laced with hydrocarbons that are extremely dangerous. And we had a neighbor who became very, very ill because her water well was -- the fracking fluids got into it.
TOM BEARDEN: In 2004, Encana drilled a well on their property, and the Bells say their lives changed forever. After three spills and what they say was constant exposure to fumes, the Bells sold out and moved away. But they say they still suffer from coughs, headaches, and even memory loss.
ORLYN BELL, fracking critic: You know, you can look at those things, and it gets you to wondering. Was breathing five, six, eight, 10, 20 shots of gas fumes during the day while you're out and about on your property messing with your brain, or is it messing with your body? You just don't know.
CAROL BELL: Or both.
ORLYN BELL: It's unexplained.
TOM BEARDEN: In fact, dozens of Garfield County residents have complained of headaches, nausea and nosebleeds they believe were caused by gas wells.
But any scientific link between fracking and health effects has been difficult to prove. The Environmental Protection Agency has just begun a two-year investigation into the safety of fracking.
In the meantime, some members of Congress are taking action of their own. Denver Congresswoman Diana DeGette recently released a congressional report which showed gas companies use some 750 different chemicals in fracking fluids. Twenty-nine are known or possible human carcinogens.
REP. DIANA DEGETTE, D-Colo.: Including benzene and other -- other cancer-causing substances. A couple of months ago, we found out that, despite their assurances that they were not putting diesel into the fracking fluid, that the industry was, in fact, putting diesel into the fluid, millions of gallons of diesel into the fracking fluid.
TOM BEARDEN: Her worry is that the chemicals can seep into wells through faulty concrete work in the wellbores or into surface water from spills and leaky containment structures.
DeGette has sponsored legislation to force companies to disclose the chemicals in fracking fluids.
Doug Hock, with Encana, explains why the industry has been hesitant.
DOUG HOCK, Encana: They have put a lot of money, a lot of capital into R&D, and so they're reluctant to talk about those formulas. However, because there has been so much concern, industry has taken steps, and where companies, including Encana, are now starting to post for each well the chemicals that are used, the quantities that are used, so that that's publicly available.
TOM BEARDEN: Hock says he's also concerned about passing new laws without the science to back it up.
DOUG HOCK: There's got to be some kind of a causal link. And we haven't seen that. We have heard a lot of anecdotes, but we can't make decisions and we shouldn't make public policy based on anecdotes.
TOM BEARDEN: Officials at Encana say they have taken steps to prevent water contamination, including an expensive closed-loop system which uses a treatment facility to clean and recycle water.
The state agency that regulates the industry is also confident that the fracking process is safe. The Colorado Oil and Gas Conservation Commission is responsible for issuing drilling permits, water testing, regulating the wells, and investigating complaints.
David Neslin is its director.
DAVID NESLIN, Colorado Oil and Gas Conservation Commission: We have typically received a couple of dozen complaints a year where people are complaining about impacts or they think there might be impacts to their water well from oil and gas development.
We investigate all of those very seriously. In no instance have we been able to verify, though, that there was an impact attributable to hydraulic fracking.
TOM BEARDEN: How many wells do you think they have done in the area?
LISA BRACKEN, resident of Garfield County, Colo.: You know, we're right at about 60 right now within a mile of where I live.
TOM BEARDEN: But Garfield County resident Lisa Bracken says the industry's safety claims are highly questionable. In 2004, her family found gas seeping up beneath a creek on their property and recorded a video of igniting it.
LISA BRACKEN: And that's what we saw was bubbling like a soda can all throughout the creek. And, so, we called the Department of Wildlife, the Health Department. We called the EPA. Really, no one has jurisdiction but the -- but the state agency that oversees oil and gas operations.
TOM BEARDEN: Ultimately, the agency fined Encana for a faulty concrete job they said caused the gas in the creek. But Bracken says the water is still contaminated and accuses state regulators of being too cozy with industry.
LISA BRACKEN: It's pretty frustrating to be dependent on the industry that creates the polluting effect to tell you the extent of pollution, and to have a regulatory body that they either deny what has happened or they ignore you.
DAVID NESLIN: We have not been afraid to disagree with the industry where it's warranted. We have assessed large six-figure penalties where it's warranted, where operators have violated our rule.
TOM BEARDEN: Still, some think it's time for the federal government to get more involved.
Another part of DeGette's fracking bill would remove the industry's 2005 exemption from the Safe Drinking Water Act.
REP. DIANA DEGETTE: Water tables don't just stop at state boundaries. That's why we have the Safe Drinking Water Act. Voluntary disclosure is good, but if there's no national standard, then it's difficult for people to find out exactly what's in that fluid, what the percentages are.
TOM BEARDEN: Industry says more federal oversight is unnecessary.
DOUG HOCK: The states have a much better understanding of the geology and hydrology in their area. And they're in a much better position to regulate and to really understand what we're doing.
The issues that we deal with here are different than the issues in Pennsylvania or even in Wyoming, for that matter. So, it's important that each state has their own rules that they can apply to that situation.
TOM BEARDEN: The U.S. Department of Energy has ordered a review of fracking practices and said it would issue guidelines for cleaner and safer gas procedures by the end of summer.