There are over 62,000 people in Killarney and Tralee and almost 20,000 people in Portlaoise that are under threat of contracting the illness from the parasite.
However, the report says that, overall, the quality of water in Ireland remains high and the incidence of microbiological contamination continues to fall.
“We have 58 of those supplies – serving over 400,000 people – that are in need of improvement”.
Pesticide products should not be present in drinking water and the Drinking Water Regulations set specific standards.
The most commonly found pesticide is MCPA, which is used for rush control in grassland.
He said it was “absolutely crucial that Irish Water has an ongoing secure and sustainable source of funding” so it has the funding in place to complete these projects.
Mr Page said the biggest concern was the 25 supplies around the country that do not have adequate treatment for cryptosporidium. “Very small amounts of these – if an empty container is thrown in or rinsed out at a river – that’s enough to contaminate a water supply”. They serve around 161,000 people.
25 drinking water supplies around the country are at risk of being infected with cryptosporidium.
As of September there are still 87 supplies of water on the remedial action list for work to be carried out to protect tap water standards.
Four thousand fewer people were on boil water notices at the end of 2016 compared with 2015.