A non-profit health and environmental agency in Connecticut is urging all people on well water to get their wells tested for the presence of chlordane and dieldrin, two pesticides commonly used for termite control.
Those pesticides have been found in wells in Stamford and the Connecticut Department of Health is saying that all of those on well water should consider having their wells tested, said Nancy Alderman, president of Environment and Human Health, Inc.
"It's something people all over the state should do," she said.
"This ... pertains to all people in Connecticut on well water," Alderman said in a prepared release. "The two pesticides that have been found in Stamford, chlordane and dieldrin, are two pesticides that were heavily used in termite control in many many houses all over Connecticut and they are long-lasting. The Connecticut Department of Health is recommending that all those on well water have their wells tested for those two chemicals or that they put a filter on the water coming into their homes."
Alderman said that many people on well water have a filter that deals with hardness in the water, but that filter is not sufficient to deal with chemicals like chlordane and dieldrin. To filter out the chemicals, a charcoal or osmosis filter is needed, she said.
Alderman cited a recent article in the Connecticut Post, Well Contamination May Go Far Beyond Stamford.
Health officials are urging all Connecticut residents with private wells to test their water for contamination after 31 percent of 628 wells in Stamford tested positive for the banned pesticides chlordane and dieldrin. What was thought three years ago to be an environmental issue related to the polluted Scofieldtown landfill has sparked a statewide effort to examine whether pesticides used for farming and pest control decades ago have leached into private well water. Testing has proven the contamination is not limited to North Stamford, and health officials say the problem likely exists in other communities across the state.
The Connecticut Post article quotes Sharee Rusnak, an epidemiologist for the Connecticut Department of Health:
We believe that this problem in Stamford could reach much further than Stamford itself and it could exist even beyond Fairfield County. In the past year or so we've been sort of getting the word out to other health departments throughout the state to let them know that this exists and to let residents know they should test their wells.
Alderman said that homeowners are sometimes worried about getting their wells tested because they wonder if a finding of contamination will have an adverse impact on their property values. But she said testing can sometimes be done anonymously and that the negative impact can be alleviated by addressing the issue by installing the appropriate whole-house filter. She said local health departments can sometimes help homeowners address such issues.
Chlordane and dieldrin are carcinogenic organochlorine pesticides, but a recent study by the Bennett Cancer Center at Stamford Hospital did not establish a definitive link between the presence of the chemical in wells and increased cancer rates.
High levels of the carcinogenic organochlorine pesticides chlordane and dieldrin have been reported in the well water of homes in North Stamford. It is unclear if the contamination is associated with an increase in the cancer rate in North Stamford. We reviewed the demographics of the towns surrounding North Stamford and chose New Canaan, Wilton, Weston, and Darien as towns with sufficiently similar demographics that would permit comparison of cancer incidence with North Stamford. Data were obtained from the Connecticut Tumor Registry regarding the number of different cancers diagnosed per year from 1998 to 2007 in North Stamford and the four nearby towns. ... There was no statistically significant difference in the average annual cancer incidence from 1998 to 2007 between North Stamford and the four other communities. There was also no statistically significant difference seen in the incidence of the various cancer types.
Chlordane and dieldrin contamination of the well water of homes in North Stamford may not be associated with a higher incidence of cancer.
Chlordane was widely used for termite control until the mid-1980s, but scientists say that they can remain in the groundwater for long periods of time. "The treatment was supposed to last for at least 25 years, so it is long-lasting," Alderman said.