BWN following detection of cryptosporidium has been lifted

Following consultation with the Health Service Executive, Irish Water and Mayo County Council are pleased to confirm that the Boil Water Notice for the area supplied by the Knock Airport Public Water Supply (PWS) has been lifted. This also affects Cloonlyon Group Water Scheme along with Knock Airport, Cloonlyon National School and approximately 15 households. 

The Boil Water Notice was put in place on October 17 2019 following the detection of cryptosporidium in the Knock Airport Public Water Supply.

What was the problem?

Cryptosporidium is a tiny parasite found in human and animal waste. If it is swallowed (ingested), it can cause a disease called cryptosporidiosis. The symptoms of cryptosporidiosis include fever, stomach upset, weight loss and diarrhoea. Cryptosporidium may be found in water if it has been contaminated or if there has been a problem with water treatment.

The water treatment plant for this area did not have a cryptosporidium barrier in place which resulted in the issuing of the Boil Water Notice when detected. However Irish Water have been able to install a twin UV reactor and filtration system from the recently decommissioned Kilconnell Public Water Supply in Co Galway to the Knock Airport PWS. This has provided the cryptosporidium barrier for the Knock Airport PWS.

Commenting, Ger Greally, Irish Water’s Asset Operations Water Lead said “The great advantage of a national utility is that we can re-use decommissioned systems from water treatment plants all over the country. In this case a UV filtration system used in a plant in County Galway was relocated to where it was needed in Co Mayo. Typical flows and conditions at Knock Airport PWS are compatible with those at Kilconnell which allowed for the UV system to be installed at the Knock Airport treatment plant.”

Steps to ensure lifting of notice

A network and reservoir cleaning programme has also been completed with all samples taken last week proving compliant. An audit of the upgraded plant was completed earlier today by the EPA and the HSE and the recommendation to lift the Boil Water notice was made.

Irish Water would like to apologise for the inconvenience caused by this incident and thank customers for their patience in complying with this notice. Irish Water and Mayo County Council acknowledge the patience, cooperation and assistance of those affected during this period. Ger added “Our priority is to provide safe, clean, drinking water and safeguarding that water supply for the future is a vital focus.

More information

To view the drinking water quality in your area and to find out where your water comes from visit our Drinking Water Quality section. 


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