Wednesday, May 2, 2007

Poolesville’s water receives a clean bill of health

Additional testing of some wells needed to confirm results

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It’s safe to drink the water in Poolesville, town commissioners heard at a meeting last month.

The town, which is connected to a well system, has been testing its water since the Maryland Department of the Environment detected elevated alpha emitting radionuclide levels in three of Poolesville’s nine wells in November 2005, reported Poolesville resident Kathy Mihm, a geologist with S.S. Papadopoulos & Associates.

The testing, conducted after Mihm raised concerns about flaws in MDE’s laboratory procedures, has so far shown that all is clear with Poolesville’s water.

The town has an open-ended contract with S.S. Papadopoulos, an environmental and water resource consulting firm based in Bethesda, for about $5,000, with most of the costs incurred by laboratory testing, Town Manager Wade Yost said last week. The contract did not go out to bid, he said.

Alpha emitting radionuclides are naturally occurring compounds that emit alpha radiation when they decay, Mihm said. Some alpha emitters include plutonium, uranium, radium, radon and polonium.

Alpha radiation is not radioactive, although those who drink water with high levels of alpha emitters over an extended period of time may develop an increased risk of cancer, according to the Environmental Protection Agency.

The wells were tested after the EPA established new monitoring requirements for gross alpha particle radioactivity in community water systems. The agency began phasing in the new standard in December 2003, and all community water systems must be in compliance by this December.

In November 2005, MDE notified the town of elevated alpha emitting radionuclide levels in wells 4, 7 and 9⁄10. Wells 9 and 10 were considered one well because they shared a point of entry, although the two have since been separated, Yost said last month.

Although Poolesville was in compliance with the regulations, the department decided that additional testing was needed to avoid future problems, Yost said.

Shortly after receiving the results, the town contracted with S.S. Papadopoulos to conduct independent testing after Mihm voiced her concern that the length of MDE’s holding period for the samples could produce false readings, Yost said.

The department has since modified its procedures, Mihm said.

The EPA’s maximum concentration limit (MCL) for alpha radiation is 15 pico Curies per Liter (pCi⁄L), and compliance is based on an average of four quarterly water samples since testing results can be highly variable.

According to a compliance evaluation letter sent to the town by MDE last month, well 7 had an average MCL of 11.3 pCi⁄L based on two samples, and well 9⁄10 averaged 14 pCi⁄L based on three samples, Mihm said.

Well 7 needs to be tested twice more to determine compliance, and wells 9 and 10 must be tested individually — instead of as a single unit — four more times, Yost said. Well 4 was found to be compliant based on four quarterly samples in 2006.

The averages included data collected by both the town and MDE, Mihm said.

At the meeting, Mihm emphasized that the town is in compliance with the EPA regulations.

‘‘This is not a violation at all,” she said. ‘‘...It’s perfectly safe.”

However, Mihm advised the commissioners to be prepared for the MDE to determine non-compliance at any time, although she did not anticipate such an event based on the data collected thus far.

‘‘I don’t think it is likely, but I can’t guarantee it,” she said. ‘‘I think it’s unlikely, actually.”

Should the MDE determine non-compliance, the town has allocated $650,000 for any potential remediation efforts in its fiscal year 2008 budget, Yost said.