A boil water notice affecting 615,000 people across Dublin, Kildare and Meath remains in place following an inspection of the Leixlip Treatment Plant.
The notice was issued on Monday evening after an issue arose following a period of heavy rain.
The tap water ban could not be lifted this evening as issues remain at the old plant in Leixlip, which produces 20% of the water supplied to the Greater Dublin Area.
Irish Water says it will be monitoring the status yellow rainfall warning issued for Kildare this evening.
However, it cannot say how the rain will impact the water produced in the Kildare treatment plant.