The Environmental Protection Agency (EPA) in Ireland has warned inadequate water treatment has put the public at risk from Cryptosporidium.
The EPA’s Drinking Water Quality in Public Supplies 2018 report reveals that while the quality of drinking water remains high, the incidence of Cryptosporidium detections has increased in the past three years, posing a “serious risk” to human health.
Cryptosporidium is a single celled parasite which, if ingested, can cause an illness called cryptosporidiosis.
The main symptom in humans is watery diarrhoea, which can range from mild to severe. It is often accompanied by stomach pain, nausea or vomiting, fever and sometimes dehydration and weight loss.
In its report, the EPA said it 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.
“We are seeing an upward trend in Cryptosporidium contamination in drinking water supplies,” said the director of the EPA’s Office of Environmental Enforcement, Dr Tom Ryan.
“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,” added Ryan.
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.
The report also found that 99.9% of water samples comply with microbiological parameter limits and a similar number (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, according to the report and E. coli bacteria was detected at least once in 12 supplies, compared to 20 supplies in 2017.
Andy Fanning, programme manager, EPA’s Office of Environmental Enforcement, added: “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,” said Fanning.
“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.”