A Boil Water Notice has been issued for Castlerea Public Water Supply in Roscommon.
The notice will impact close to 4,000 people following disinfection issues at the Longford Springs Water Treatment plant.
The notice will affect Castlerea Town, Ballintober, Trien, Kilmurray, Castleplunkett and the surrounding areas.
Uisce Eirean is advising that water must be boiled for drinking, meal prep, brushing teeth and making ice.
The utility is also advising that caution be taken when bathing children to ensure they do not swallow the water.