Manganese has been found in higher than state advisory levels in water samples collected in mid-June in town wells and at 182 Plain St. and 250 East Main St., water officials said.
Manganese is necessary for normal immune system function, digestion and bone strength.
At elevated levels, manganese could produce neurological effects with some variation in sensitivity between individuals, according to the state Department of Environmental Protection.
Residents are advised that infant formula should be prepared with bottled water or made with water from an alternate source with manganese levels below 0.3 mg/L.
Residents are reminded the town has a free water dispenser outside town hall that filters out manganese and is safe to use for baby formula.
If water customers have health-related concerns about manganese, they are advised to contact their health care provider.
"People are going to expect clean water" when the plant goes on line, Selectman Robert Salvo said.
"People are very frustrated.
Selectmen are asking water officials, including the water and sewer commission members, to come before their board to discuss the issues.
Selectmen also remind residents there is an opening on the water and sewer commission that needs to be filled.