Windsor and two nearby Nova Scotia communities are under a boil water order after an apparent contamination of the Three Mile Plains Water Utility.
The order affects residents who get their water from the Town of Windsor Water Utility, Three Mile Plains Water Utility and the Wentworth Road Water Utility.
Residents are asked to boil their water for at least one minute before drinking, making ice cubes, washing foods, brushing teeth, or consuming the water in any way.
The utility said Thursday that this must be done until further notice.
Falmouth residents are not affected.
The utility says it is trying to determine the cause of the contamination, but it has not said what the contaminant is.
The Nova Scotia Department of Environment and the Medical Officer of Health have been called in to help determine the cause.