Cavan County Council is lifting the warning notice issued to all water users served by Mountainlodge Group Water Scheme with immediate effect.
The decision was made following consultation with the Health Service Executive.
According to advice issued by Cavan County Council, the water is now "safe for use" and can be used for drinking and food preparation.
Members of the public who used their domestic water system for general use throughout the period of the notice can now access use their water supply as normal.
However, if water systems have not been in use for the duration of the notice, consumers should ensure that they flush out their systems by running their hot and cold taps for a period of at least thirty minutes before resuming normal use of the water supply.