The discovery has had a transformative effect on the American energy economy. It means the United States is becoming less reliant on foreign energy sources; some proponents say it will eventually mean energy independence. For struggling Midwest towns like Youngstown, Ohio, which saw its fortunes fall with the steel industry's decline, fracking represents an economic lifeline. Over the past five years or so, fracking projects have transformed communities in Pennsylvania, Ohio, and elsewhere in the country, sometimes turning residents who sell their land rights into millionaires - or "shaleionares."

Natural gas burns cleaner than the coal it has begun to replace as an energy source. But, environmentalists say, it also carries with it a host of as-yet-understood risks. They argue that the boom is outpacing the science - that states and local communities, desperate for the money and jobs that fracking can bring, have been ignoring the costs, both present and future. As the debate has raged, the industry has turned to academia to calm concerns. It got what appeared to be a piece of good news last February, when the University of Texas at Austin released a study that found there is no evidence that fracking contaminates groundwater.

Fracking involves pumping a mixture of water, sand and chemicals into shale rock formations deep underground at high pressure, which causes the rock to crack and release natural gas. Critics say chemicals from the fracking fluid used in drilling, as well as the natural gas and other chemicals released from the rocks, can enter aquifers; the Environmental Protection Agency said in a 2011 report, which has been contested by fracking advocates and remains in draft form, that chemicals from fracking were present in well water in Wyoming.

The lead author of the UT study, Dr. Charles Groat, said his aim was to "separate fact from fiction" in "what has become an emotional debate" over fracking. "There is at present little or no evidence of groundwater contamination from hydraulic fracturing of shales at normal depths," his report found. "No evidence of chemicals from hydraulic fracturing fluid has been found in aquifers as a result of fracturing operations."

A few months later, the Public Accountability Initiative released a report of its own. It found that two sections of the Groat study were marked as rough drafts and that numerous citations were missing from the "environmental impacts" section. It also found that paper had not been peer reviewed - despite claims to the contrary from the director of the UT Energy Institute, Roy Orbach - and that Groat had declined to reveal his connection to industry. That connection was not incidental: Groat earned $413,900 as a board member of the oil and gas company Plains Exploration and Production in 2011, according to the report - more than double his university salary.

In the wake of the revelations, the University of Texas at Austin named an outside panel of experts to review the study. It found "failures and inadequacies in several procedural areas," according to a December news release, including "the failure of the principal investigator to disclose a conflict of interest that could have had a bearing on the credibility a reader wished to assign to the resulting work." Groat retired from his faculty position amid the controversy, and Orbach resigned; the university removed the study from its website.