Two months after the BP oil spill, it may be easy to hear the words "water contamination" and "drilling" and immediately think "Gulf Coast."
But one filmmaker says there's another water source at risk -- and this one is in our own backyards.
In his new film, "Gasland," filmmaker Josh Fox spotlights the practice of hydraulic fracturing, or hydrofracking, a process that extracts natural gas from rock formations.
He started his film after a gas company offered him nearly $100,000 for the rights to drill for natural gas on his property in the Delaware River Basin, along the New York-Pennsylvania border.
Instead of accepting, Fox began investigating.
His documentary premiered on HBO on Monday night and highlighted what Fox claims are the direct results of hydraulic fracturing: water contamination, well failures and health problems for people living near the wells.
HBO will be replaying the documentary later this month and next month.
The film explains hydraulic fracturing as a "mini earthquake." Gas companies insert a horizontal pipe several thousand feet below the ground and blast a "fracking fluid" to break up the rock and release natural gas.
To tell the story, Fox -- whose property sits on the Marcellus Shale Field, a rock formation often called the Saudi Arabia of natural gas -- dubbed himself a "natural gas drilling detective." He traveled across the country with a camera, interviewing landowners who have entered into contracts with natural gas companies.
The film has generated both acclaim and controversy. "Gasland" won the Special Jury Prize at the 2010 Sundance Film Festival. Variety called it "one of the most effective and expressive environmental films of recent years."
The New York Times was more critical: "Mr. Fox shows a general preference for vivid images ... over the more mundane crossing the t's and dotting the i's of investigative journalism," wrote the reviewer.
Cabot Oil & Gas is one of the companies featured in "Gasland." In response to questions from ABCNews.com, spokesman George Stark wrote, "'Gasland' is long on rhetoric and emotion, yet short on accurate facts and information."
Other companies also have spoken out against the film's claims, specifically regarding the characterization that the chemicals in the fracking fluid are a secret.
Fox narrates, "Because of the exemptions, fracking chemicals are considered proprietary, like the special sauce for a Big Mac or the secret formula for Coca-Cola."
Range Resources, an oil and gas company, called that claim "100 percent false," Matt Pitzarella, spokesman for Range, told ABCNews.com. He added that gas companies are required to submit a material safety data sheet to the Department of Environmental Protection every time they frack a new well.
The Pennsylvania Department of Environmental Protection lists the chemicals, such as hydrochloric acid, methanol and glutaraldehyde, on its Web site.
A spokesperson from Energy In Depth, a nonprofit group created by the Independent Petroleum Association of America, drafted a response called "'Gasland' Debunked": "The entire universe of additives used in the fracturing process is known to the public ... The Occupational Safety and Health Administration mandates this information be kept at every wellsite."
Fox responded, "The actual chemical names are available to the public, but we only know the actual chemical composition of about 50 percent of the products. And the ones we do know are nasty."
Though a fossil fuel, natural gas is a form of alternative energy. The United States Environmental Protection Agency reported on its Web site in 2007 that natural gas produces half as much carbon dioxide emissions as coal, and fewer nitrogen oxides than burning oil.
After the BP oil spill in the Gulf of Mexico, President Obama called for the nation to decrease its dependence on foreign oil. Hailing the future of American energy as clean energy, Obama is pushing for investments in alternative energy industries.
So is Range Resources.
"I think we need to look no further than the Gulf of Mexico," Pitzarella said. "If we don't want to see that, then we need to develop our own energy resources. [Natural gas] is a much safer, cleaner energy."
The industry is attempting to expand hydrofracking beyond the 34 states where wells are operating. "Gasland," not surprisingly, cautions against such a widespread expansion.
"When [the gas companies] first started this process, they advertised it as a safe thing, as clean energy in the United States," Fox told ABCNews.com. "But what's actually going on at the ground level is this enormous problem of water contamination, air pollution and people getting sick."
Traveling to 25 states, Fox interviewed landowners who said their water and health were fine until the hydrofracking started. In "Gasland," Fox argues the chemicals in the fracking fluid entered aquifers, or ground water supplies. When people drink the contaminated water, Fox said, it can cause health problems.
For example, Fox spoke with a woman who said drinking her water caused her to suffer brain damage. In Pennsylvania, a woman said her cats and horses were losing their hair because of the gas-laced water. And in Wyoming a man said his water smelled like turpentine. One family in Fort Lupton, Colo., could even light its tap water on fire, according to the film.
"Any time you engage in an activity, like driving a car, there's a potential for an accident," said Dennis Holbrook, executive vice president of Norse Energy, a Norwegian company that operates in the United States. "But you have to look at the results over time. The science behind hydraulic fracturing has been developing over the last 50 years, and these examples [in "Gasland"] are very rare."
Members of the scientific community are split on the hydrofracking issue.
"Gasland" features Dr. Theo Colborn, a former U.S. EPA advisor, who described the risk in hydraulic fracturing.
"Every environmental law we wrote to protect public health is ignored," Colborn said in the film. "The neurological effects are very insidious."
Syracuse University professor Donald Siegel disagreed. Siegel is a hydrogeologist with a specialization in water chemistry and water supplies.
With funding by the U.S. Geological Survey, he has researched how liquids enter aquifers, and his work has been published in the Journal of Ecology.
Siegel does not consider hydrofracking to be inherently dangerous because he has not found evidence that the fracking chemicals have entered aquifers.
"I have not heard of any problem, anywhere in the United States, where the actual process itself has caused any environmental harm," Siegel told ABCNews.com. "I think in the context of prudence and risk, it makes sense to pursue [the natural gas] industry."
Siegel stands behind the most recent EPA study on hydrofracking, which concluded in 2004 that "the injection of hydraulic fracturing fluids into coal bed methane wells poses little to no threat ... and does not justify additional study at this time."
"I read the EPA report, and to me, it was scientifically sound," Siegel said.
Critics, such as the Citizens Campaign for the Environment, said the 2004 study was too narrow, as it focused primarily on coal, and needed to include shale bed methane wells.
After watching the documentary, Siegel said the accidents shown in "Gasland" are not directly related to hydraulic fracturing, but rather to human and mechanical error.
Fox began his journey in Dimock, Pa., where residents alleged that Cabot contaminated their water supply after hydrofracking their wells. After residents filed a lawsuit, the company posted on its Web site, "We see no merit in these claims."
Fox thinks they do have merit.
"The industry keeps saying there's no health risk," he said. "It's incredible they're saying this with a straight face."
Cabot said there are no new developments in the lawsuit.
Methane was present in the water supplies "long before Cabot began its operations," the company wrote in an April press release. The natural gas in Dimock, the release continued, had naturally migrated there.
Siegel said the Dimock failure occurred after Cabot improperly installed a vertical pipe, and not because of the fracking fluid itself.
In response to ABCNews.com, Stark wrote, "Cabot's operations have complied with Pennsylvania Department of Environmental Protection regulations. Cabot is working with the PaDEP to address concerns of the PaDEP and residents of Dimock Township."
Siegel criticized the film for relying heavily on anecdotal evidence rather than scientific evidence or comments from the gas industry.
"Gasland" shows Fox calling gas companies and attempting to set up interviews.
"I was trying really hard to get them on the record in the film, and none of them would agree to sit down with us for an interview," Fox told ABC News.
"I've been asking the industry, 'Look, if you've got a perfect town with where you've got more than 100 gas wells and everybody's happy and rich, take me there. I want to go. I want a guided tour," he said. "So far, no response to that either."
Cabot, Range Resources and Norse Energy all said Fox did not contact them for a comment.
"That's really not true," Fox said. "We spoke to Cabot, and we asked them to go on the record and they wouldn't. We have records of the e-mails and the phone conversations."
Cabot said Fox contacted a Cabot lawyer, not an employee.
"If [Fox] contacted us, I can assure you that the call would have been returned," said Holbrook of Norse Energy.
Fox said he'd be happy to talk them, as long as it was on camera, on the record.
Instead of continuing to ask gas companies for interviews, Fox has turned his attention to alerting the public about what he considers the dangers of hydraulic fracturing.
In the weeks before the HBO premiere, Fox traveled to several cities in the New York and Pennsylvania area. He chose locations based on proximity to the Marcellus Shale, which spans from upstate New York to West Virginia. According to scientific and industrial estimations, the shale contains enough energy to supply the U.S. for two years, a value of about $1 trillion.
Natural gas companies have already started to hydrofrack in some areas of the Marcellus Shale. But in New York state, pending legislation could halt the process.
State Sen. Joseph P. Addabbo Jr., D-Howard Beach, is sponsoring a bill that calls for a moratorium upon hydraulic fracturing until 120 days after the EPA releases a new study regarding water quality and public health.
The next EPA study is expected to come out in December 2012.
"It's only common sense to stop it for awhile and really do a thorough investigation," said Fox, who backs the bill. "There's just too many people suffering."
After his screenings, Fox asked audiences to contact lawmakers and urge them to support the Addabbo Bill.
"You have to realize that New York can actually lead this charge and be this force of sanity," Fox told crowd in Syracuse, N.Y., to applause.
One audience member, Judith Fancher, left the "Gasland" screening feeling informed, yet afraid.
"I was aware of [hydrofracking] going on," she said, "but I had no idea about the extent of it. It really shook me all the way down my spine."
ABCNews.com contributor Danielle Waugh is a member of the Syracuse University ABC News on Campus bureau.