"We stand behind everything in the movie," Fox said in a telephone interview from Los Angeles.
The tart exchange between the gas industry and its nemesis is the latest salvo in a public relations war over hydraulic fracturing, a controversial extraction process that has opened up vast reserves of natural gas and oil, but has raised fears about environmental damage.
Fox, who is making a sequel to Gasland, basked in the glory Tuesday of getting an Oscar nomination for his first documentary effort.
"It's kind of amazing, isn't it?" he said. He said the nomination was a tribute to the families featured in the film who have suffered from gas drilling.
Fox has practically become a full-time activist since the movie was released last year, and he now spends much time organizing anti-drilling groups, which use the film for fund-raising.
Even critics of Gasland, including mainstream environmentalists such as Penn Future president Jan Jarrett, acknowledge that Fox's powerful movie has framed the public debate about gas drilling.
Industry trade groups, which last year set up websites to conduct a point-by-point rebuttal of the film's allegations, on Tuesday renewed their denunciations.
"While it's unfortunate there isn't an Oscar category for propaganda, this nomination is fitting, as the Oscars are aimed at praising pure entertainment among Hollywood's elite," Lee Fuller, executive director of Energy in Depth, said in a statement.
America's Natural Gas Alliance, an association of large producers, said the nomination was "deeply disappointing" because state and federal regulators have disproved many of the allegations in Gasland.
"The stakes are too high to allow our energy choices to be influenced by the gross and deliberate misrepresentations by this filmmaker who knew the facts and chose to ignore them," said Tom Amontree, the alliance's executive vice president.
Fox blames numerous incidents of water contamination on hydraulic fracturing; the industry says the contamination was either naturally occurring or caused by other drilling activity, but not "fracking."
In the movie's signature moment, a Colorado resident ignites the gas seeping from his faucet. The industry, in its rebuttal, said that official reports traced the gas in the man's well to natural decomposition of organic material near the earth's surface, rather than gas seeping in from drilling operations.
In another fleeting episode, the movie blames a 2009 fish kill in Dunkard Creek in southwestern Pennsylvania on hydraulic fracturing; federal and state regulators have conclusively linked the discharge to drainage from a coal-mining operation.
John Hanger, the Pennsylvania secretary of environmental protection who becomes Fox's foil in the movie, last year dismissed Gasland in an Inquirer interview as "fundamentally dishonest" and "a deliberately false presentation for dramatic effect."
The movie also has come under attack on right-wing websites for its anticapitalist tilt.
Fox, whose previous experience was as a director of avant-garde theater, said he shot the movie on a shoestring. He said he received a $20,000 grant from the Sundance Institute in 2009 that paid for the film's final production. Sundance then gave the film a special jury prize at its 2010 film festival, which helped catapult the movie onto HBO.
"It's not as if there's some hidden left-wing agenda to the film," he said. "It's an honest film.
"I knew if we got this big, the natural gas industry would go after us," he said.
See the movie website, plus websites set up by the gas industry at go.philly.com/gasland
Contact staff writer Andrew Maykuth at 215-854-2947 or firstname.lastname@example.org.