A boil water notice was issued by Irish Water on Tuesday evening affecting more than half a million people in parts of Dublin, Co Kildare and Co Meath.
Roughly 600,000 live in the areas of Fingal, Dublin City Council, South Dublin County Council; parts of Kildare and in Dunboyne, Co Meath which are affected by the notice.
The warning follows issues with a water treatment plant in Leixlip, Co Kildare, which may have compromised the disinfection process which makes the water safe to drink.
Irish Water said the notice was issued to protect the health of customers on a precautionary measure and came into immediate effect.
It said the issues have now been resolved, but affected water is still travelling through the system.
A spokeswoman said the notice is likely to be in place for a number of days and that updates will be available on its website and on social media.
The spokeswoman added that Irish Water will be continually testing the the supply and liaising with the HSE throughout the process. Once the HSE is satisfied with the water quality, the notice will be lifted.
Irish Water's website had crashed on Tuesday evening, shortly after the company issued the notice. An interactive map of the areas affected has been posted online.
Boil water
Irish Water has advised that water must be boiled for drinking; drinks made with water; preparation of salads and similar foods, which are not cooked prior to eating; brushing of teeth and making ice cubes.
The company acknowledged the impact and inconvenience caused by the notice to homes and businesses.
“We would like to reassure our customers that Irish Water’s drinking water and operational experts are working with our colleagues in Fingal County Council to resolve this issue as quickly as possible,” the company said, in a statement.
“Irish Water is contacting all registered vulnerable customers who are affected by this boil water notice to advise them.”
It has asked anyone with queries to contact Irish Water directly on its customer care helpline (1850 278 278) and or check its website (water.ie) for updates.
The company has advised that water can be used for personal hygiene, bathing and flushing of toilets but not for brushing teeth or gargling.
It says users should boil water by bringing to a vigorous, rolling boil and allow to cool. This water should be covered and stored in a refrigerator or cold place. Domestic water filters will not render water safe to drink, it says.
Bottled water
It adds that caution should be taken when bathing children to ensure that they do not swallow the bathing water.
For the preparation of infant feeds with water, it advises the use of water that has been brought to the boil once and cooled. Water that has been re-boiled several times should not be used.
It has advised caution if using bottled water for preparing baby food as some natural mineral water may have high sodium content. The legal limit for sodium in drinking water is 200mg per litre.
