"GasLand" is the most important and politically incendiary documentary we've seen since "Sicko". Kudos to HBO for showing this Sundance award winning film; do whatever you can to make sure you (and everyone you know) see it. (You'll never quite get over the shots of officials insisting there's nothing harmful in the drinking water, juxtaposed with a scene of fire coming out of someone's tap water. And of course, officials consistently decline to sample the water they keep insisting is "safe".)

The film focuses on damage to water supplies done by the high-powered natural gas mining process known as "fracking," and the shameless efforts by industry and politicians to cover it up. It's all too resonant with what just happened in the Gulf. (The energy industry has already issued a point by point rebuttal. Fox says he's putting together his own response.)

This story is of special interest to people like me who live in the NY-NJ-PA watershed that supplies clean drinking water to nine million people, because industry is now drilling in the Marcellus Shale in northern PA, thought to be the site of massive gas deposits.

Near the end of the film, Josh Fox interviews John Hanger, PA's secretary of environmental protection, who says look, you're on the other side of a camera, you're not the person who has to sit here and make these hard decisions. And he's right -- we as a nation have some hard choices to make about how we get our energy, and why. What price are we willing to pay?

(In a jarring epilogue, Fox notes that shortly after they spoke, the state's Department of Environmental Protection announced massive layoffs.)

Here's one review:

Narrating a first-person account, Fox relates how a natural gas company made him a lease offer for $100,000 from a natural gas company to explore on his land, which includes the house his parents built in Pennsylvania's Delaware River Basin abutting upstate New York.Fox begins to do his own research on drilling, and leaves countless unreturned messages with natural gas drillers like Halliburton.

Congress' 2005 Energy Policy Act, crafted by former vice president (and ex-Halliburton exec) Dick Cheney, exempts the hydraulic fracturing drilling process used by natural gas companies (known as "fracking") from long-held environmental regulations such as the Clean Air and Clean Water Acts. Freed from customary laws, natural gas companies have drilled like wildcatters in 34 states where huge shale fields contain gas deposits.

Once Fox learns that his beloved Delaware River watershed is being targeted by drillers as part of the massive Marcellus Shale field, he goes on the road to track down residents living near drilling sites. This is seat-of-pants investigating that yields astonishing and disturbing findings, not least of which is how the residents can customarily light a flame near their tap water outlet and set the polluted water on fire. As Fox ventures west, to Colorado, Wyoming and Texas, states riddled with natural gas drill sites, he documents horror story after horror story.

The primary cause is the cornucopia of toxic chemicals, blended with water, which must be used in fracking. Infrared-camera footage records venting of polluting gases coming off drill rigs, crushing the myth that natural gas is "clean" and a greenhouse solution. In vivid animation and graphics, Fox illustrates how the continent-wide explosion of fracking projects threatens watersheds and river basins, the source of drinking water.

For all of its engaging information, the film itself is a piece of beautiful cinema, rough-hewn and poetic, often musical in its rhythms and about as far from the "professional" doc that's the stock-and-trade of Sundance, where "GasLand" is vying in the U.S. competish. The marriage of sound and image (Fox joins Matthew Sanchez on lensing, and Brian Scibinico on sound) veers between nightmarish moods and lyrical reveries, even while the camera peers into the faces of government and corporate officials.

A combo of fest and grassroots exhibition, with viral networking, is part of the pic's goal to push for new federal controls on fracking (now being considered in Congress). But if a film can ever enact social change, which is rare, the potency of "GasLand" suggests that this may be that film.