News
Release

May 3, 2017

New Report Shows Some Private Wells in
Connecticut Test High for Naturally Occurring Arsenic, Uranium

A report published today by the U.S. Geological Survey, in
cooperation with the Connecticut Department of Public Health (DPH), reveals
that water from some private wells across the state has registered high levels
of Arsenic and Uranium.

As part of the joint research project, DPH, with the help of
local health officials, collected and analyzed water samples from 674 private
wells in Connecticut. The lab results indicated that seven percent of the private
well samples tested for Arsenic or Uranium at levels higher than Maximum
Contaminant Levels, which are regulated in public water supplies and newly
constructed private wells under Connecticut law.     

These results were then examined by USGS Scientists, who
compared the water sample collection sites in relation to geologic information
in those areas.

“During our research, we discovered there was more Arsenic
and Uranium in private wells than was previously known,” said Sarah Flanagan,
USGS Hydrologist.

While high levels of Arsenic and Uranium
were discovered across the state, the USGS found there were specific areas of
high concentrations in wells that correlated with certain types of bedrock.
This data indicated higher levels were associated with 81 different types of
bedrock in Connecticut; however, bedrock type alone was not always predictive
of higher or lower concentrations.

“For example, some major bedrock categories that had
generally low levels of contamination, also had a few isolated wells with high
concentrations of Arsenic or Uranium,” said Sarah Flanagan, USGS Hydrologist
and lead author of the study. 

The results of this study reaffirm
DPH’s previous recommendation that private well owners in Connecticut should
test their wells for naturally occurring Arsenic and Uranium.

“Our study shows that any private well in Connecticut has the
potential to have elevated Arsenic or Uranium,” said Ryan Tetreault, DPH
Private Well Program supervisor. “Private well owners should have their well
tested at least once for these contaminants.”

Arsenic and Uranium are metals that can be found naturally
in bedrock around the world. Sometimes, water from wells drilled into bedrock
aquifers can contain Arsenic or Uranium that has leached out of the bedrock.
Arsenic exposure has been related to many adverse health outcomes and can
increase the risk of certain cancers.  It
also may be a risk factor for a developing fetus, and can affect child
intellectual function.  Naturally
occurring Uranium can have adverse effects on the kidneys, but does not have
high levels of radioactivity and is not considered a significant cancer
risk.  

According
to DPH, routine testing required for private wells does not usually include
testing for Arsenic and Uranium. It is up to private well owners to have their well
tested for these contaminants. Potential homeowners may also ask for such
testing when purchasing a home with a private well. Local health departments
have the authority to require testing for arsenic and uranium for new wells if
they have reason to believe there is a problem in their jurisdiction.

To read the full study, click here.

More
information about private well testing in Connecticut can be obtained from the
Connecticut Department of Public Health, by clicking here.