On June 5, I was among the hundreds at the Byham Theater for a preview screening of Josh Fox's smart, scary and impassioned new documentary about Marcellus Shale gas-drilling in Pennsylvania.

Gasland -- which goes national via HBO at 9 p.m. Mon., June 21 -- does something relatively few commentators about such drilling have done: It frames the race to exploit natural-gas deposits deep beneath Pennsylvania with what's already happening in deep-shale gas fields in some of the 33 other states where it goes on.

The results are ugly. Most of the concern about Marcellus drilling involves water quality. Already in Pennsylvania, with drilling efforts still ramping up, people and animals have been sickened when wells and other fresh water were contaminated with methane or other toxins after drilling took place.

The Pittsburgh area is a hotbed of current and projected Marcellus activity, in places like Washington County, but with efforts to drill near or even in the city itself advancing.

Meanwhile, out West, drilling is further along. From the air, some of the plains of Colorado, for instance, are revealed to be dotted with hundreds of well sites, regularly spaced as the dimples on a cracker.

One memorable sequence in Gasland finds Fox visiting a series of about ten homes in Wyoming … and setting fire to the water that comes out of their faucets. 

And in a riposte to those who cite landowners who've made big bucks by leasing to drillers, Fox interviews people who deeply regret what drilling has done to the land.

Fox himself turned down a $100,000 "signing bonus" from a gas company who wanted to drill on his family land in Mylanville, in Northeastern Pennsylvania. Mylanville is a short drive from Dimock, Pa., another town where residents say drilling has poisoned well water -- and hand Fox the jars of sickly yellow liquid to prove it.

This is heavy stuff, but Fox's approach is cogent, disarmingly low-key, and even humorous. (One scene finds him playing "This Land Is Your Land" on banjo at a drill site on federal land, while wearing a gas mask.)

Another point that's hammered home is that the avalanche of deep-shale drilling was unleashed by the so-called "Halliburton loophole" in national energy policy as crafted by former Vice President Dick Cheney. The loophole exempts oil and gas drilling from most of the federal rules to protect air and water.

Indeed, Fox was refused almost all interview requests to government officials. A notable exception is John Hanger, who heads Pennsylvania's Department of Environmental Protection.

Hanger doesn't come off looking so great. But even Fox, who attended the June 5 Byham screening and took part in a lively panel discussion afterward, agreed that Hanger has lately taken a tougher line.

Still, Fox is among those who argue that the risks are such that better regulation simply isn't enough. He says we need a moratorium on shale-gas drilling as part of a strategy to get off fossil fuels altogether.

Many in the audience agreed -- in part, no doubt, not only because of BP's Gulf disaster, but also because of the June 3 accident at a Marcellus gas well-site in Clearfield County that spewed gas and toxic wastewater into the air for 16 hours.

Learn more at www.gaslandthemovie.com/wp.