A bug that results in serious stomach illness was discovered in 25 public water supplies around the country last year.
The Environmental Protection Agency says while the quality of supplies remains high, cases of cryptosporidium have risen considerably over the last three years.
In its latest report, it is blaming the increase on inadequate treatment and infrastructure at some drinking water plants.
According to Breaking News, a senior inspector at the EPA, Dr Michelle Minihan, says the parasite can pose a serious health risk.
"It can be quite a nasty bug, particularly when it affects younger children, the elderly or those with an underlying health condition," said Dr Minihan.
"It can cause nasty diarrhoea which can last for a few days. The consequences of that are dehydration and generally feeling unwell."
Dr Minihan said they "want to ensure that our drinking water supplies are safe and that the risk of cryptosporidium is addressed" and that the water "is properly treated."
Source: Irish Examiner
