Extracting fuel from shale formations requires pumping hundreds of thousands of gallons of water, sand and chemicals into the ground to break apart rock and free the gas. Some of that water, along with large quantities of existing underground water, returns to the surface, and it can contain high levels of salt, drilling chemicals, heavy metals and naturally occurring low-level radiation.
But some conventional oil and gas wells are still drilled, so the complaints about water contamination can come from them, too. Experts say the most common type of pollution involves methane, not chemicals from the drilling process.
Some people who rely on well water near drilling operations have complained about pollution, but there’s been considerable confusion over how widespread such problems are. For example, starting in 2011, the Pennsylvania Department of Environmental Protection aggressively fought efforts by the AP and other news organizations to obtain information about complaints related to drilling. The department has argued in court filings that it does not count how many contamination “determination letters” it issues or track where they are kept in its files.
Steve Forde, a spokesman for the Marcellus Shale Coalition, the leading industry group in Pennsylvania, said in a statement that “transparency and making data available to the public is critical to getting this historic opportunity right and maintaining the public’s trust.”
When the state Environmental Department determines natural gas development has caused problems, Forde said, “our member companies work collaboratively with the homeowner and regulators to find a speedy resolution.”
Among the findings in the AP’s review:
— Pennsylvania has confirmed at least 106 water-well contamination cases since 2005, out of more than 5,000 new wells. There were five confirmed cases of water-well contamination in the first nine months of 2012, 18 in all of 2011 and 29 in 2010. The Environmental Department said more complete data may be available in several months.