Boil Water Notice

Learn about Boil Water Notices and what you should do if you are issued with one.

A Boil Water Notice is a formal notice issued to all properties in an area advising that drinking water from the public mains is not safe to drink unless it is boiled and cooled beforehand. Irish Water will only issue a Boil Water Notice after consulting with the Health Service Executive (HSE) , the statutory authority on public health matters. 

Why they are issued

The most common reason for issuing a Boil Water Notice would be where routine testing of the drinking water supply has shown the presence of harmful bacteria (such as E. coli), or pathogens such as Cryptosporidium. The public health of our customers is of the utmost importance to Irish Water – therefore if such results are confirmed, we consult with the HSE to ensure an appropriate advisory notice is issued immediately.

In some cases a Boil Water Notice may be imposed where there is a risk of contamination but where test results are yet to be confirmed. An example might include where the disinfection system has failed, or where a pollution event has occurred in the vicinity of the source water. In these cases it is prudent to protect public health by issuing a Boil Water Notice rather than wait for test results to confirm the risk.

In these cases boiling the drinking water and cooling it will kill any harmful bacteria that may be present making it safe to drink.

Using water in a boil water notice

How to boil and store water safely

Boil the drinking water by bringing it to a vigorous, rolling boil, for example with an electric kettle. This will kill any harmful bacteria and pathogens. Allow the water to cool before use. It is advisable to fill a container with the boiled water, cover and store in a refrigerator or cold place. Great care should be taken with boiled water to avoid burns and scalds. Accidents can easily happen, especially with children.

It is important to remember that water from the hot tap is not safe to drink. In addition, Irish Water cannot vouch for the ability of any domestic water filters to remove harmful bacteria. We advise you to boil water even if these are in place.

What you should use boiled and cooled water for

Drinking, drinks made with water and filtered water

Brushing your teeth or water for gargling

Making ice (discard existing ice cubes)

Preparing foods which aren't cooked before eating e.g. salads

You do not have to boil water for personal hygiene (e.g. showering and bathing) or flushing the toilet.

Water for children and infants

These tips should help to care for children and infants during a boil water notice.


If you are bathing children please ensure that they do not swallow the bath water.

Preparing feeds and baby bottles

Irish Water has received the following advice from the HSE on this matter:

Where a Boil Water Notice is in place, you can prepare infant feeds with water that has been brought to the boil once and cooled. Do not use water that has been re-boiled several times. If bottled water is used for the preparation of infant feeds it should be boiled once and cooled.

If you are using bottled water for preparing baby food, be aware that some natural mineral water may have high sodium content. The legal limit for sodium in drinking water is 200mg per litre. Check the label on the bottled water to make sure the sodium or `Na' is not greater than 200mg per litre. If it is, then it is advisable to use a different type of bottled water. If no other water is available, then use this water for as short a time as possible. It is important to keep babies hydrated.

Ready-to-use formula that does not need added water can also be used.

Water for animals


It is a good idea to boil drinking water and let it cool before giving to your pet.


A Boil Water Notice is imposed to protect human health. If you have concerns regarding your animals drinking water that is subject to a Boil Water Notice then you should consult your vet. Outdoor animals, such as cattle and horses, are exposed to bacteria on a daily basis that is vastly in excess of that experienced by humans.