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.