Irish Water take action on Portlaoise's crypto drinking water pollution risk

Conor Ganly


Conor Ganly


crypto water portlaoise irish water

Portlaoise water supply no longer at risk of crypto contamination.

People in Portlaoise are no longer facing the risk of drinking water being polluted by cryptosporidium with confirmation that the supply has been removed from the Environmental Protection Agency's (EPA) latest Remedial Action List (RAL).

Irish Water says the move is the result of an analysis on the water supply it commissioned the water supply that serves 19,869 customers. It has taken nearly three and half years for Portlaoise the risk to be tackled.

The water supply was placed on the RAL in September 2014 due to a risk for cryptosporidium which is a threat to the water supply if the proper barriers are not in place. 

Irish Water says it carried out measures to review the risk for cryptosporidium in the supply. A consultant hydrogeologist was appointed, risk assessments were carried out on all boreholes in the supply area to indicate that they are not at risk of cryptosporidium. This work facilitated the removal of the Portlaoise Water Supply from the EPA RAL.

The company says work was carried out to upgrade the treatment and disinfection processes at the water treatment plant. Following the hydrogeology report Irish Water said it was established that UV systems were not needed as current equipment in place at the plant ensures the water treated at the plant meets all drinking water regulations.

The EPA said it is satisfied that the detailed hydrogeological investigations carried out by Irish Water confirms the Cryptosporidium risk is actually ‘low’ to ‘moderate’ rather than the ‘very high’ risk identified originally by the Cryptosporidium risk screening tool in 2014. 

It said that these investigation are supported by the results of the raw water sampling programme which found no evidence of contamination by Cryptosporidium, E.coli or Enterococci in monthly samples taken from the 9 borehole sources from March 2016 to August 2017. 

On this basis, the EPA said it was satisfied that no additional treatment for Cryptosporidium would be required at Kilminchy water treatment plant.  It added that the existing filtration and disinfection (chlorination) processes are sufficient to ensure the water supply meets the requirements of the Drinking Water Regulations.   

Irish Water’s Regional Compliance Specialist Andrew Boylan welcoming the removal of the Portlaoise supply from the RAL 

“The removal of the Portlaoise supply from the Environmental Protection Agencies (EPA) latest Remedial Action List (RAL) is a confirmation of the focus and collaboration between Irish Water and Laois County Council to establish that the water supply was not at risk for cryptosporidium.

"The assessments and surveys carried out and reviewed by the Geological Survey of Ireland (GSI) have confirmed that Irish Water is delivering a safe water supply to our customers in Portlaoise. The work carried at the plant means that the water supply is meeting all drinking water standards. As a single utility Irish Water can take a comprehensive look at the overall performance of Ireland’s drinking water production plants so that when the most serious problems are identified like the issues in Portlaoise projects and budgets can be prioritised,”  he said. 

The RAL is updated quarterly by the EPA for those water supplies where investment in treatment processes is required because of the risk to contamination of supply.