There are almost half a million registered domestic wastewater treatment systems in Ireland, according to new figures released by the CSO.
There were 5,481 new systems set up last year, a one per cent increase compared to 2020. Overall, there are 481,694 systems in the country.
These systems are usually septic tanks which collect, treat and discharge wastewater from households that are not connected to public sewer systems.
Six coastal counties accounted for 45 per cent of registrations last year.
Cork has 55,034 domestic wastewater treatment systems, the highest proportion in the whole country. It accounted for 11 per cent of all systems, and 12 per cent of new registrations from last year.
Galway had 42,577 and Kerry had 33,890 systems, accounting for nine and seven per cent respectively.
Next were Donegal, Mayo and Tipperary, who each accounted for six per cent of all systems and Wexford at five per cent. These seven counties accounted for roughly half of all individual wastewater treatment systems.
Household owners accounted for 97 per cent of all systems registered last year.
The registration and inspection system for domestic wastewater treatment systems was introduced under the Water Services (Amendment) Act 2012.
The Act was in response to a European Court of Justice ruling against Ireland in October 2009. The purpose of the Act is to protect ground and surface water from pollution from malfunctioning systems.
Each water services authority is required to establish and maintain a register of domestic waste water treatment systems situated within its functional area.
In a statement, Irish Water said they were responsible for public water and wastewater services and have no remit in relation to the registration or operation of domestic wastewater treatment systems. “Similarly, the issue of planning for one-off rural houses is also a matter for the planning authorities.”
They said they were committed to playing their part in the national drive to provide homes, by developing and prioritising the delivery of key water service infrastructure.
“We have a dedicated team in place to support the delivery of Government housing targets. In 2021 we issued connections offers for 32,404 housing units, while just 170 connection applications did not meet the criteria for approval.”
Cork City Council and Cork County Council were contacted for comment.