Inadequate treatment & infrastructure at drinking water plants put public health at risk from Cryptosporidium

Date released: September 09, 2019


The EPA Drinking Water Quality in Public Supplies Report 2018, released today, shows that the quality of drinking water in public supplies remains high with 99.9% compliance with microbiological parameters and 99.6% compliance with chemical parameters. However, the report highlights that the incidence of Cryptosporidium detections has increased in the past three years, posing a serious risk to human health.

The EPA has seen detections of Cryptosporidium in 25 public water supplies in 2018, up from 17 in 2017 and 12 in 2016. Of particular concern are supplies which have inadequate processes in place to treat or remove Cryptosporidium and those where there is no treatment in place at all.

Commenting on the report, Dr Tom Ryan, Director of the EPA’s Office of Environmental Enforcement said:

“We are seeing an upward trend in Cryptosporidium contamination in drinking water supplies. We know that Cryptosporidium can cause serious gastrointestinal illness, particularly in young children and the elderly, and the EPA has ensured that Irish Water has investigated each of these Cryptosporidium detections. 

“Irish Water must make certain that water treatment plants are properly and effectively operated to protect public health. Those plants without appropriate treatment for Cryptosporidium need to be prioritised for investment by Irish Water.” 
The EPA has added supplies to the EPA Remedial Action List, following its audits of drinking water plants. Irish Water has to prioritise sites on the EPA Remedial Action List and develop action plans for improvements to be completed, by set dates.

Andy Fanning, Programme Manager, EPA’s Office of Environmental Enforcement, commented: 

“At the end of 2018, the number of supplies on the EPA’s Remedial Action List had decreased. Unfortunately, that downward trend has been reversed in the first six months of 2019, when we added eight supplies to the Remedial Action List.

“These additions highlight that there are still significant problems at many of Ireland’s water treatment plants, with the potential to harm people’s health. The EPA is particularly concerned about supplies where we have seen poor operational practices at water treatment plants.  Consumers must have confidence that their water supply is not just safe to drink today but will also be safe in the long term.” 

The EPA has also identified priorities for Irish Water to address on a national level to protect and improve public water supplies.

The EPA Drinking Water Report 2018 and the complete list of public water supplies currently on the Remedial Action List - including details of the proposed remedial measures and associated timeframes - is available on the EPA website.


Further information: Niamh Hatchell, EPA Media Relations Office 053-9170770 (24 hours) or

Notes to Editor

Some key findings of the 2018 report on public water supplies:

  • 99.9% of samples comply with microbiological parameter limits.
  • 99.6% of samples comply with chemical parameter limits.
  • Nearly two-thirds of all boil water notices issued in 2018 were in place for less than 30 days.
  • 44 boil water notices and a further 15 water restrictions were in place in 2018, affecting more than 100,000 people in 16 counties.
  • E. coli bacteria was detected at least once in 12 supplies, compared to 20 supplies in 2017.
  • Trihalomethanes limits were exceeded in 54 supplies, compared to 73 in 2017.
  • Pesticides limits were exceeded in 34 supplies, compared to 48 in 2017.
  • 63 supplies were on the EPA’s Remedial Action List at the end of 2018 compared to 77 at the end of 2017.
  • The EPA conducted 58 audits of water treatment plants and three audits of Irish Water’s monitoring programmes in 2018.
  • The EPA issued six Directions (legally binding instructions) to Irish Water in 2018.

The EPA has identified the following priorities for Irish Water to address on a national level to protect and improve public water supplies:

  • Progressing action programmes for all Remedial Action List schemes;
  • Prevention of long-term boil water notices by providing robust disinfection systems;
  • Minimising harmful disinfection by-products such as Trihalomethanes (THM) by providing treatment that adequately removes organic matter in the water;
  • Eliminating lead from our drinking water networks;
  • Preventing pesticides from entering our drinking water sources;
  • Managing risks to our public water supplies by adopting Drinking Water Safety Plans for all supplies. 

List of the supplies currently on a Boil Water Notice

Name of SupplyCountyPopulation affected
Knockadoon  Cork 27
Kilconnell  Galway 198
Tallanstown  Louth  1,978
Baltrasna  Meath  9
Longwood  Meath  3
Slane  Meath  3
Lough Talt  Sligo  12,576
Clonmel Poulavanogue Tipperary  90
Glenary  Tipperary  24
Kilgobnet  Waterford  99
Robert’s Cross  Waterford  72
Scrothea  Waterford  3
Mullingar Regional  Westmeath  3
Ballinavarry  Wexford  10
Kilmyshall  Wexford  90
South Regional - Taylorstown Wexford  54
South Regional - Horeswood Wexford  12
Ballymorris  Wicklow  17
Johnstown South (Arklow) Wicklow  6