People in several Dutchess County communities are being told to boil their water before using it following a problem at the Hyde Park water plant.
A boil water notice has been issued for areas including Hyde Park, Staatsburg and Pine Brook Estates.
County officials said equipment at the water plant stopped adding chlorine to the water.
The issue has since been corrected, officials said.
Testing is now underway to ensure the water is safe to use.
Residents in affected areas are being advised to use boiled or bottled water for drinking and cooking.
Officials said the boil water notice could remain in effect for the next two to four days.