BREAKING NEWS: EPA concludes Dimock water probe Agency says treatment systems solve problem in 5 homes.

A seven-month investigation by the federal EPA into the safety of water in Dimock Pa. found elevated levels of hazardous substances in five of 64 homes. The agency concluded that, overall, the results do not suggest health risks from the water supply that has been at the center of controversy over the safety of shale gas development. That's partly because some homes, located amid Marcellus Shale drilling operations, showed no signs of contamination, and partly because filters are addressing problems in homes where high levels arsenic, barium, and manganese might otherwise create risks. All three contaminants occur naturally in the ground. They are also associated with drilling operations, which can exacerbate existing problems or introduce new ones. Based on the results, the agency found no need for continuing the investigation.

The 725 pages of testing results were summarized in a statement released this afternoon that read, in part:

Overall during the sampling in Dimock, EPA found hazardous substances, specifically arsenic, barium or manganese, all of which are also naturally occurring substances, in well water at five homes at levels that could present a health concern. In all cases the residents have now or will have their own treatment systems that can reduce concentrations of those hazardous substances to acceptable levels at the tap. EPA has provided the residents with all of their sampling results and has no further plans to conduct additional drinking water sampling in Dimock.

Dimock has been at the center of a national controversy over the impacts from shale gas development and high volume hydraulic fracturing in particular. The process, know as fracking, involves injecting bedrock with millions of gallons of chemical solution to stimulate the flow of natural gas. Residents in the small town in Susquehanna County sued Cabot Oil and Gas after tests in 2009 and 2010 showed signs ground water contaminated with various substances associated with drilling operations.

The investigated was conducted by EPA technicians and scientists from the agency's Region 3 office, which covers Pennsylvania, and Mid-Atlantic states. Finding a cause for the pollution was not part of the plan, according to Terri –A White, spokeswoman for the agency’s Region 3 Press Office who responded to my follow up questions through written statements.

Question: Given that water systems are dynamic and changing, and drilling operations move around, is there any chance that other water supplies might be affected in the future? Does the possibility of this make it necessary to isolate a cause?

Answer: “EPA’s goal was to provide the Dimock community with complete, reliable information about the presence of contaminants in their drinking water and determine whether further action was warranted to protect public health. At this time, EPA is not looking to identify potential trends regarding drinking water quality in Dimock.”

The federal agency’s reluctance to delve deeper into the source of contamination affecting 8-percent of the homes in its Dimock sample will raise complaints among those seeking more assurances that shale gas development is safe. On the other hand, it will likely meet with approval from industry proponents and regulators, including Michael Krancer, head of the Pennsylvania Department of Environmental Protection, who have charged that the federal agency is overzealous in butting into regulatory matters that have always been handled by the states.

While the process of fracking has driven much of the debate, it should be noted that fracking is technically different than drilling. Drilling (apart from fracking) can create pathways for naturally occurring elements in the ground such as methane, brine, and heavy metals to migrate into ground water supplies.

In January, EPA began providing alternative supplies of fresh water to four homes where records suggested pollution might be causing health risks. Between January and June the agency sampled water wells serving 64 homes, including two rounds of tests at the four suspect wells. According to the EPA statement, the investigation was “a precautionary step in response to prior data indicating the well water contained levels of contaminants that pose a health concern. At one of those wells EPA did find an elevated level of manganese in untreated well water. The two residences serviced by the well each have water treatment systems that can reduce manganese to levels that do not present a health concern.”

Today, the agency announced it is unnecessary to provide residents with alternative water, and it “is working with residents on the schedule to disconnect the alternate water sources provided by EPA,“ according to the agency statement.

In addition to collecting water samples to assess immediate health risks, EPA technicians collected samples from 12 Dimock homes for isotopic methane analysis, according to information provided by White. The goal is to determine whether methane found in Dimock wells migrated from deeper formations. The results will be included in a broader EPA study, with an update due at the end of the year, on the impact of hydraulic fracturing on groundwater. The pending report is especially relevant to a controversy over the so-called “Halliburton Loophole,” which exempts hydraulic fracturing from federal regulation under the Safe Drinking Water Act. The exemption was folded into a clause in the 2005 Energy Act after an earlier EPA study of coal bed methane (CPM) wells concluded that fracking was not a significant threat to groundwater.

The question over methane in Dimock wells and the broader consequences and implications is not new, and it gained national attention after Norma’s Fiorentino’s water well exploded on Jan. 1, 2009. A subsequent analysis of samples collected by the Pa. DEP under Gov. Rendell administration found that methane polluting the aquifer was thermogenic, from deeper producing formations, rather than biogenic gas that collects in shallow seeps.