A bug that causes serious stomach illness was found 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 over the last three years.
In its latest report, it’s blaming the increase on inadequate treatment and infrastructure at some drinking water plants.
Boil notices are currently in place on two water supplies in the Clonmel area – 90 people are affected on the Poulavanogue supply in Clonmel with a further 24 on the Glenary supply.
57 people on the Crotty’s Lake supply for Carrick on Suir are also on a boil water notice as are 5 on the Commons supply.