THE Endless Mountains, in northeastern Pennsylvania, are, geologically speaking, not mountains at all.

In summer, the dissected shale and sandstone plateau, eroded by rivers and rain, can resemble the English countryside, veined with winding roads, lined with trees: oak, ash, maple, beech, hemlock and pine. There are hay bales in the fields below shingle built farmhouses, some with American flags draped over the porch.

The region’s economy has traditionally been based on agriculture, lumber, quarrying and tourism, but there are signs going up speaking of a new industry, down freshly paved and dirt roads, in forest clearings, blocked by bright yellow gates: “Gas well drilling ahead. No open flames or lights beyond this point.”

Depending on who you listen to, this is the scene of an energy revolution with the potential to dramatically reduce the US’s dependence on foreign oil, or an unfolding environmental catastrophe.

Professor Terry Engelder, whose department at Pennsylvania State University is substantially funded by energy companies, has estimated the Marcellus shale, which stretches under New York state, through Pennsylvania, Ohio and Maryland to West Virginia, contains at least 363 trillion cubic feet (TCF) of recoverable gas: enough to meet US electricity needs for 14 years.

To unlock this resource, wells in the Marcellus are completed using hydraulic fracturing, or fracking, which involves pumping huge volumes of fluid into wells to break up rock formations more than a mile deep, releasing the gas inside. This practice was pioneered by Halliburton in 1949, but has become widespread in the past two decades, since engineers exploring the Barnett shale, in Texas, combined it with horizontal drilling.

Fracking is on its way to Scotland, with firms jockeying to drill exploratory wells, and the controversies now raging in the US offer a glimpse of the shape of things to come.

In the spring of 2008, shortly after moving to Dimock, in the Susquehanna County corner of the Endless Mountains, Craig and Julie Sautner signed a lease with Cabot Oil & Gas, granting the company mineral rights to their three-and-a-half acres of land, for a one-off payment of a little under $10,000 plus royalties on any gas produced by wells under their property.

Drilling began in the autumn, a quarter of a mile from their front door. Within weeks, the water from their taps was grey-brown. Cabot installed a filtration system, but tests commissioned by the Pennsylvania Department of Environmental Protection (DEP) showed dangerously high levels of methane, iron and aluminium. For a year, the family drank bottled water, but washed, cooked and cleaned in filtered water from their well. Julie suffered constant headaches, son Cody got sores and daughter Kelly often had to lie down after having a shower to avoid passing out. When their Pomeranians and German Shepherd drank tap water, all three dogs threw up straight away.

“I don’t even hunt deer around here anymore, because I don’t want to shoot one and eat it,” Craig Saunter says. “I love my bow hunting. When this is done, I’ll get back to it. I can’t spend the rest of my life doing this.”

The Sautners are lifelong Republicans and born-again Christians. In their living room, every other item is starred and striped. They make unlikely activists, but this is what they have become, in three years spent fighting, unsuccessfully, to get Cabot to accept liability for their ruined water supply. A DEP handout stuck to their fridge offers some ironic reassurance: “This water is most likely safe. If you have any questions or concerns about contamination due to hydraulic fracturing, expose water to flame.”

This is the anti-fracking movement’s defining image: water from the tap, lit with a match. In the Oscar-nominated documentary, Gasland, director Josh Fox travelled from Pennsylvania to Wyoming, Ohio, Colorado and Texas to meet people living near drill sites, some with enough methane in their water to set the kitchen sink on fire. On the Sautners’ street, a well belonging to retired nurse Norma Fiorentino blew up in 2009, blasting chunks of concrete onto her lawn.

All summer, Craig Sautner is working seven days a week, fixing telephone lines, to build up his final year’s salary, so he can retire. Julie runs the home and the campaign, setting up speaking engagements and interviews. In April 2010, the DEP called a halt to drilling in a nine square-mile area around Carter Road. The New York law firm Napoli, Bern & Ripka, is representing 63 Dimock residents in a no-win, no-fee lawsuit, seeking damages from Cabot for breach of contract.

On August 3, a group of the plaintiffs unveiled a billboard in the nearby town of South Montrose, listing chemicals in the Sautners’ water supply, including uranium, arsenic and butylbenzyl phthalate, a toxic precursor to plastic. Cabot’s press agent was on hand to call it a distortion, with supporters backing him up. The advert was pulled.

In the Energy Policy Act of 2005, gas firms are granted exemptions from the Clean Water Act, the Clean Air Act and other legislation designed to protect the environment. Written at the decree of then vice-president Dick Cheney, these provisions are known as the Halliburton Loophole, after the energy services company he used to run. There is no legal requirement to disclose the ingredients of fracking fluid, which generally contains solvents, surfactants, biocides and acids, plus tonnes of sand to prop open the fissures.

It takes around five million gallons of fluid to frack a well in the Marcellus, at pressures of up to 15,000 pounds per square inch. Roughly half this liquid is driven back up the well by escaping gas, together with benzene, toluene and other contaminants, and must be disposed of above ground. The other half remains in the earth.

THERE have been comparatively few studies of hydraulic fracturing’s environmental impact. When the Environmental Protection Agency’s (EPA) lead regulator, Lisa Jackson, told Congress she is “not aware of any proven case where the fracking process has affected water”, she was paraphrasing a standard industry line that notes there have been more than a million wells fracked without a single documented instance of ground water contamination.

When chemicals do show up in water aquifers close to drill sites (officials in New Mexico released a report detailing 700 incidents) the industry blames human error, such as faulty well casings or a poorly finished cement job. In addition, compensation payouts come with a non-disclosure clause, ensuring in the few cases where gas companies admit liability, details of how the pollution occurred remain secret.

A recent study by scientists at Duke University found water wells within a kilometre of natural gas drilling in the Marcellus and Utica shale formations contained vastly increased quantities of methane, suggesting the gas may be reaching the surface through cracks and abandoned wells. They did not, however, find frack fluid had made the same journey, giving credence to the industry-approved consensus that it is physically impossible for it to migrate through a mile of rock.

Cornell University engineering professor, Anthony Ingraffea, is the most prominent dissenter. He argues fracking opens up new fissures and widens existing faults, meaning on rare occasions the pressure will drive frack fluid up into the water supply. He says: “The probability of this happening is very low, but I’m not prepared to accept the industry’s statement it has never happened and can never happen. A number of things have to line up at just the right space and just the right time, but when you try it a couple of hundred thousand times, it’s a certainty. When such incidents do occur, the industry locks them up from public view.

“But of all the things that can go wrong, hydraulic fracturing is the least of my worries. Every day in Pennsylvania there is a spill. Every day in Pennsylvania there is a leak. Every day there is a valve that wasn’t closed properly or a connection that failed. Some of that methane will get into the ground water. That which does not get into the ground water gets into the atmosphere, where it becomes a very potent greenhouse gas.”

Signs posted by Cabot at a well off Carter Road announce “peak day consumptive use 3.575 million gallons [of water] per day”. Trucks rumbled past the Sautners’ house at all hours: more than 1200 loads of water per frack, plus half as many again to dispose of waste. Nationally, the EPA estimates fracking consumed between 70 and 140 billion gallons of water last year. Because of high levels of salts, heavy metals and the carcinogen benzene, the waste water cannot be filtered at standard treatment plants.

At first glance, this might seem to be something communities would unite to oppose, but the reality in Dimock is different. Even on Carter Road, half the residents are happy to trade a water supply for gas royalties. “Most people in Dimock are against us,” Craig Sautner says. “They want the money. I’ve heard people say: ‘Put a well right through my living room and I’ll move out.’ ” Some have signed agreements with Cabot, absolving the company of responsibility and agreeing to keep quiet in return for twice the taxable value of their house plus a water filtration system.

DAN Whitten, vice-president for strategic communications at America’s Natural Gas Alliance, says when shale gas reserves are tapped, regions benefit: “Numerous states generated tens of thousands of jobs as a result of this industry last year, so the appeal for jobs in rural parts of the country where the country has been staggering is great.”

Investment analysts, however, question whether the gas boom is sustainable. Art Berman, a contributing editor at World Oil magazine, was forced out after writing natural gas companies are over-estimating the recoverable reserves in shale formations. His thesis is that the companies are using an optimistic theoretical model to predict the long-term performance of wells, when actual data from the Barnett and Fayetteville shales shows that production falls off inexorably.

The industry estimates that for a Barnett well to recoup its costs, it must produce 1.5 billion cubic feet of gas. So far only one in 20 of the Barnett shale’s 10,000 gas wells has reached that break even point.

In May the Sunday Herald reported that Australian firm Dart Energy was planning to sink a test bore at Airth, near Falkirk, to explore the potential for shale gas extraction. Spokesman for the company, Peter Reilly, called that story “alarmist”, but confirmed it is looking into the possibility of expanding activities at the site beyond coal-bed methane extraction. Cuadrilla Resources suspended fracking operations in Lancashire after two small earthquakes occurred.

The Sautners, meanwhile, unable to sell their home, are stuck in Dimock. Craig worries drilling will expand across the Marcellus. He says: “The problem here is they ruined some water wells, but what happens if you get into the Delaware watershed and contaminate that. We’re talking millions and millions of people. How do you correct that? It’s way too high risk.”