EPA bigwigs say water is safe to drink, but internal reports note methane and mineral pollution

Over the past year, officials at the Environmental Protection Agency have declared that drinking water in suspect wells is safe, despite being warned that "several wells had been contaminated with methane and substances such as manganese and arsenic, most likely because of local natural-gas production," and that further testing was needed, according to an internal EPA PowerPoint presentation obtained by Neela Banerjee of the Los Angeles Times. (Times photo by Caroline Cole: A natural gas well near Dimock, Pa.)

The presentation was based on data collected over four and a half years at 11 wells around Dimock, Pa., where the EPA closed an investigation into groundwater pollution, saying the level of contamination was below federal safety triggers. The presentation found that "methane and other gases released during drilling (including air from the drilling) apparently cause significant damage to the water quality," and "Methane is at significantly higher concentrations in the aquifers after gas drilling and perhaps as a result of fracking (hydraulic fracturing) and other gas-well work," Banerjee reports.

EPA spokeswoman Alisha Johnson told Banerjee, "This presentation represents one (on-scene coordinator's) thoughts regarding 12 samples and was not shared with the public because it was a preliminary evaluation that requires additional assessment in order to ascertain its quality and validity. The sampling and an evaluation of the particular circumstances at each home did not indicate levels of contaminants that would give EPA reason to take further action." The presentation isn't the only one to raise concerns about drilling in the Marcellus Shale formation; a Duke University study that looked at 141 private water wells near natural gas production found methane in 82 percent of the samples.

"The presentation provides charts for nine of the 11 Dimock-area wells, tracking natural-gas production work in the area and the concentration of methane and metals over a four- to five-year period, depending on the well," Banerjee reports. "Some wells underwent a 'short-term disruption,' or a rise in methane in the water six to eight months after nearby gas development activity. Over two or three years, the concentration of methane fell. Four other wells experienced long-term disruption to their water quality. In those instances, methane levels did not fall over time but remained high after an initial increase or began to climb after a period of decline. The presence of metals such as manganese and arsenic also rose over time in some of those wells."

Dimock isn't the only area where scientists have concerns. "In March 2012, the EPA closed an investigation of methane in drinking water in Parker County, Texas, although the geologist hired by the regulator confirmed that the methane was from gas production," Banerjee reports. "In late June, the EPA dropped a study of possible contamination of drinking water in Pavillion, Wyo., despite its earlier findings of carcinogens, hydrocarbons and other contaminants in the water."

Kate Sinding of the Natural Resources Defense Council, an environmental group, told Banerjee, "We don't know what's going on, but certainly the fact that there's been such a distinct withdrawal from three high-profile cases raises questions about whether the EPA is caving to pressure from industry or antagonistic members of Congress." Or, perhaps, looking over its shoulder at the White House, which looks favorably on the natural-gas boom. (Read more)