The most common reason for issuing a BWN 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 BWN 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 BWN 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.
Boiling the drinking water by bringing it to a vigorous, rolling boil (e.g. with an automatic kettle) and allowing it to cool will kill any harmful bacteria and pathogens. 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.
N.B. Water from the hot tap is not safe to drink. Also, Irish Water cannot vouch for the ability of any domestic water filters to remove harmful bacteria – therefore it is advisable that water should be boiled even if these are in place.
If you are bathing children please ensure that they do not swallow the bath water.
Irish Water has received the following advice from the HSE on this matter:
Bottled water can be used to make up infant formula. All bottled water, with the exception of natural mineral water, is regulated to the same standard as drinking water. It is best not to use bottled water labelled as ‘Natural Mineral Water’ as it can have high levels of sodium (salt) and other minerals, although it rarely does. ‘Natural Mineral Water’ can be used if no other water is available, for as short a time as possible, as it is important to keep babies hydrated.
If bottled water is used to make up infant formula it should be boiled once (rolling boil for 1 minute), and cooled in the normal way.
Ready-to-use formula that does not need added water can also be used.
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.