The notice is expected to remain in place for at least another few days.
Heavy rainfall in the Slieve Bloom Mountains is the cause of a boil water notice in the midlands, according to Uisce Éireann.
The notice has been in place for eight days, and is expected to remain valid for at least another few days.
Residents in the Tullamore South area, with the exception of Colliers Brook Estate and Spollanstown Industrial Estate, are affected, as well as those in Clonaslee.
Customers are being advised to boil and cool their water before use.
John Gavin from Uisce Éireann explains what happened:
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