A recent audit of Millstreet’s water supply by the Environmental Protection Agency revealed that cryptosporidium — a parasite that causes gastroenteritis — had been detected on two dates in September.
The HSE said there had been no reported cases in the area of anyone suffering any illness associated with drinking infected water.
The EPA found there was no treatment facility in place to prevent against cryptosporidium during the inspection, despite the fact that an assessment of the Millstreet water supply in 2015 rated the risk of cryptosporidium as “very high”.
It has recommended that Irish Water should install an adequate barrier against the parasite to ensure the town’s water supply is adequately disinfected at all times.
“Irish Water needs to prioritise the installation of a cryptosporidium barrier in order to ensure the safety and security of Millstreet public water supply,” said the EPA.
It has added the town’s supply to its remedial action list because of the inadequate treatment for cryptosporidium.
The audit was carried out after the parasite was detected in the Millstreet water supply on September 20 and 28.
Three further reports of cryptosporidium were detected on dates in October since the EPA audit. Irish Water said an investigation into the cause of the infection was ongoing. It confirmed no unusual activities were found in the catchment area of the spring prior to the detection of cryptosporidium.
The EPA has instructed Irish Water to liaise with Cork County Council to ensure farm and septic tank inspections are carried out on houses near the spring.
It has also advised Irish Water to ensure the source is made secure and fenced off to prevent animal access and ensure that the gates are kept closed at all times.
The supply provides 2,200 cubic metres of water on a daily basis to a population of 3,800 in the Millstreet area.
It is mostly sourced from the Tubrid spring which is an uncovered spring source.
Although located on privately-owned land, it is accessed by members of the public who regard it as a holy well. The source is also potentially accessible to birds and other animals.
The EPA said visitors to the holy well would not realise it is the main source of drinking water for Millstreeet. Drinking water supplies for Millstreet are disinfected by chlorination and fluoridation.
Irish Water installed an ultra-violet transmittance monitor in May to collect background data but the company said a year’s monitoring was generally required to design a barrier for cryptosporidium. The company admitted the monitor had been offline periodically since it was installed.