Friday, March 27, 2009
Regional water to be tested for arsenic and uranium
A Boston Globe article (“U.S. to test local wells for traces of uranium,” March 6) listing Carlisle as one of several towns located on an “arsenic belt” stretching from Maine through eastern Massachusetts should not be a cause for alarm, says geologist Tony Mariano of Page Brook Road. “We don’t have an arsenic belt,” he says, noting that stones containing arsenic are dotted around, but “they’re rare minerals.” Both uranium and arsenic can be naturally-occurring in granite and metamorphic rock, he continues, but are “quite stable chemically.” Typically they do not enter ground water at levels high enough to be of great concern.
A U.S. Geological Survey study this spring will be testing this theory. It will sample the water of 1,600 home wells in Massachusetts to determine if higher levels of arsenic and uranium are found with certain rock types, and whether those levels are associated with health risks. Some of those tested wells will be in Carlisle. According to USGS hydrologist John A. Colman, “We have sent kits to 11 households. Depending on response, we may send a few more.”
If elevated levels of arsenic are found, homeowners will be advised and may be asked to submit urine samples to the state Department of Public Health. Participation is voluntary and free, and the results of all testing, both water and medical, will be confidential. The state Department of Environmental Protection will also be involved.
Arsenic in Carlisle wells not a concern
Carlisle Board of Health (BOH) Agent Linda Fantasia reports that the last town-wide water test conducted in 2008 indicated 13% of wells contained arsenic levels above the ten parts per billion EPA recommendations. This contrasts with the 7.4% in 2004 or the 4.7% in 2006, probably the random result of sampling. In the past the town has not collected data for uranium. The Globe reports that about 4% of Massachusetts wells contain uranium, the EPA threshold for which is 30 parts per billion.
Asked if the 2008 arsenic results are cause for concern, Gretchen Caywood, administrative assistant for the BOH, said that the standards are very tight and the wells in question were at or only slightly above the recommendations. “These are not levels to be freaked out about,” she added. Mariano noted that high arsenic levels are often the result of herbicide application at farms and orchards. Sites with industrial arsenic pollution are easily identified because their water samples lack the minerals which would be present with natural arsenic.
Carlisle cancer rate below average
Health statistics do not indicate any cause for alarm. High arsenic levels carry an increased risk of developing bladder or lung cancer, neurological problems, and developmental delays in children, according to the Globe, and uranium concentrations can affect the kidneys. An Associated Press article of August 20, 2008 also notes a correlation between arsenic and Type II diabetes. But the Department of Health’s cancer registry (www.mass.gov) for 2001 to 2005 shows Carlisle’s incidence of bladder cancer at four diagnoses versus an expected six. In addition, six residents developed lung cancer versus an expectation of 16.4. Overall, Carlisle’s cancer rate is about 20% below the state average.
Although public water systems have to comply with strict standards for arsenic and uranium, private well water in Carlisle is required to be tested only when a house is sold or a new well is drilled. The testing information is advisory, and it is up to the homeowner to decide what to do about elevated levels. Arsenic and uranium can be removed by use of a water softener or reverse osmosis system, says Fantasia. Some owners elect to purchase drinking water and use well water for other purposes.
But Mariano says that in his 40-plus years in town, “I’ve really looked at the rocks here and I drink the water.” He notes that bottled water probably has no health advantages over what comes out of the tap. Most significant water pollution comes from past chemical use or storage, but Carlisle has long had an organic sensibility, says Mariano, noting that in 1845 Carlisle farmers refused to allow copper processing at a local mine for fear of the effect on their land and animals.
The town’s bi-annual water survey is next planned for May 2010. At that time the BOH will offer subsidies for homeowners who have their water tested and share the results with the board. Volunteers are usually solicited via Mosquito announcements, and typically about 40 to 50 homeowners take part.
Well owners are encouraged to have their water tested for bacteria annually, with comprehensive testing for metals every three years. For those who do not want to wait for the town testing and are not part of the Geological Survey, information on water testing is contained on the BOH website (www.carlislema.gov) along with facts about arsenic and uranium. Also available is a list of labs used for town water testing. The BOH has been advised that Thorstensen Laboratory of Westford has been removed from the state’s list of certified water testing labs.
Fantasia warns homeowners to compare the list of items tested for, as some labs include arsenic in the basic test while others do not. She also counsels residents to avoid companies selling filtration systems who offer free testing. ∆
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