Authorities in charge of public water supplies have been warned to carry out checks for a dangerous parasite that can be fatal to the very young and very old.
In its annual report of drinking water, the Environmental Protection Agency (EPA) said Cryptosporidium tests had been carried out in supplies to 59 per cent of those served by public water systems.
However, the remaining 41 per cent served by public water systems have not had their supplies checked.
The parasite can cause cryptosporidiosis, a disease that can cause fever, stomach upsets, weight loss and diarrhoea. It can be fatal in the young and old and those with weak immune systems.
New drinking water regulations came into force on January 1st, 2004. Since then, cryptosporidiosis has been made a notifiable disease. This means that where a case of the disease is detected it must be reported to the Health Protection Surveillance Unit.
The unit reported that there were three outbreaks of the disease, whose transmission route was suspected to be waterborne, in 2004.
Of 371 risk assessments carried out on public water supplies to determine their vulnerability to the parasite, 21 per cent were identified as being in the high-risk or very high-risk categories.
The EPA report found the overall rate of compliance with drinking water standards in 2004 was 96.4 per cent. It said drinking water quality was improving and the quality of drinking water supplied by sanitary authorities (serving 84 per cent of the population) was satisfactory.
The quality of drinking water supplied by private group water schemes (serving less than 7 per cent of the population) remains unsatisfactory, the report added.
The compliance rate for E.Coli, the most important indicator of drinking water quality, improved in both public water supplies and group water schemes.
