If you love the outdoors, this might put a damper on your next hike.

Natural gas drilling has scarred Pennsylvania’s pastoral landscape, divided communities and neighbors, and raised serious questions about public health

The defining natural feature of northern Pennsylvania is its woodlands, which make up one of the largest expanses of publicly accessible forest remaining in the eastern United States. Though decimated by logging in the late nineteenth and early twentieth centuries, this region has been recovering for nearly 100 years, and now attracts hundreds of thousands of hunters and trout fishers, hikers and canoers, bird-watchers, campers, skiers, and stargazers. (The so-called Pennsylvania Wilds are renowned for their exceptionally dark skies.)

But these plateaus of hardwoods and conifers, whose biological diversity and ecological integrity send scientists into reveries, are coming under increasing pressure from the rapidly expanding energy industry. Most of Pennsylvania lies atop the gas-rich Marcellus Shale, where industry may develop as many as 60,000 wells over the next two decades -- two-thirds of them within forest areas. The opening photograph by Martha Rial, taken over Tiadaghton State Forest in Lycoming County, hints at what’s at stake.

The Marcellus Shale Documentary Project is a nearly yearlong reconnaissance by six veteran photographers of the impact of shale gas in Pennsylvania. Taken together, the work depicts both winners and losers, the good and the bad, the awesome and the appalling. At times it’s difficult to say which is which: the issues are that complicated, the social and economic terrain ever shifting, and the dividing lines surprisingly fluid.

By any measure, extracting natural gas from deep shale formations is an ugly process. Three-and-a-half-acre drill pads are scraped from the earth, then connected with roads, pipelines, and million-gallon ponds that hold fresh and contaminated water. Clearings are crammed with condensate tanks, separators, compressors, generators, chemical-filled storage containers the size of freight cars, office trailers, and Porta-Potties. Drill rigs, like the one pictured above, project like rocket gantries from the rolling terrain.

What happens underground is no less violent for going unobserved. After reaching the shale formation, in places more than a mile deep, operators turn their drill bits 90 degrees and proceed for another thousand feet or more. They blast small holes in the lateral borehole, then inject millions of gallons of highly pressurized water laced with chemicals and sand. The shale fractures, releasing pockets of natural gas along with water now contaminated with volatile organic compounds, radioactive materials, and heavy metals. (Many of these chemicals are linked with cancer, genetic mutations, and endocrine disruption.)

The development of a drilling site involves roughly 1,000 vehicle trips back and forth each day, generating plumes of dust and diesel exhaust and straining local roadways. Engines rev, steel clanks, trucks beep, and the earth shakes as pipes are pounded into wells. At night, methane flares lend forests and cornfields a Hadean glow. During drilling and fracking, high-intensity lights shine around the clock. Noxious fumes from vehicles, tanks, flares, and wellheads drift on the wind.

Nobody likes these intrusions, but industry reminds us that most of the assaults are temporary: drilling a single well can take months, but fracking rarely lasts longer than a few days. Still, opponents say, degradation of groundwater and soil (to say nothing of forest fragmentation and increased runoff of pollutants into streams) will last far longer. Then there are the social impacts: depressed home and business values, increased traffic and crime (as transient workers move in), rental units priced beyond the reach of non-gas-field workers, and fractured relations with neighbors, especially when drilling rigs rise just over the property line of a homeowner who will receive no financial benefit.

On the flip side, energy booms have also boosted local economies, manufacturing, and tax revenues. Oil and gas royalties have allowed livestock owners to expand herds, parents to send children to college, and debtors to pay off loans. And let us not forget that natural gas is abundant, cheap (for the moment), and domestically sourced. Burning it generates fewer greenhouse gases than does burning coal, but producing it -- a process during which up to 9 percent of total gas output may be lost through venting and leaks -- may negate those advantages.

To read the complete story, please visit OnEarth.