IRISH Water has contacted up to 140,000 of its customers to inform them that their water supply is likely to have excess chemical in it.
The homes and businesses affected are on the Environmental Protection Agency’s Remedial Action List, marked as ‘at risk’.
They are located in 16 counties on 55 water supply schemes.
The water supply issues vary from elevated THM’s, inadequate barriers for cryptosporidium, poor turbidity removal, or the presence of low levels of pesticides.
Trihalomethanes are a group of four chemicals—chloroform, bromodichloromethane, dibromochloromethane, and bromoform—formed, along with other disinfection by-products, when chlorine or other disinfectants used to control microbial contaminants in drinking water react with naturally occurring organic and inorganic matter in water.
At elevated levels, THMs have been associated with negative health effects such as cancer and adverse reproductive outcomes.
In other words, these are areas where drinking water quality isn’t as good as it could be.
Approximately 366,000 people could be affected overall.
Up until now, Irish Water only contacted homes and businesses if there was a drinking water supply problem that posed an immediate risk to health.
Environmentalists have welcomed the decision to warn customers directly.
Friends of the Irish Environment said it submitted a formal complaint to the European Commission of the utility’s failure to inform consumers of excessive chemicals in water supplies in the country.
Analysis conducted at that time showed 598,951 consumers were being supplied with drinking water over the recommended World Health Organisation and European Commission’s recommended limits for trihalomethanes (THMs).
Over the coming weeks, each home and business will receive a letter and booklet from Irish Water with information on their specific water supply.