Uranium has contaminated water in 16 well systems in Connecticut in the past year, according to state public health records reviewed by the Hartford Courant.
There have not been any health problems linked to the contamination, health officials said, and they don't expect any at the levels found.
All water systems serving 25 or more people must be tested quarterly. At the end of September, nine systems were out of compliance. Seven other systems had violated the standard earlier in the year but were found in compliance in the latest round of tests.
Federal health regulations allow 30 parts per billion of uranium in well water. The water supply at Johnson Memorial Hospital contained an average of 38 to 42 parts per billion.
The hospital has proposed a $500,000 plan to address the problem through filtration.
"I am aware of our levels and the limits set by the (EPA), and I am very comfortable drinking the water," Peter J. Betts, the hospital's interim chief executive officer, told the newspaper.
Some areas are more susceptible because the underlying bedrock may contain uranium.
Brookfield's First Selectman, Bob Silvaggi, said his town has been dealing with the issue for two decades. Parts of town have been plagued by excessive radon and radium, both of which are byproducts of uranium decay.