Some 45% of septic tanks failed inspection by local authorities in 2023, according to a new report from the Environmental Protection Agency (EPA).

The report on Domestic Waste Water Treatment System Inspections 2023 outlined that 1,189 septic tank inspections were carried out, of which 532 failed.

The EPA said a “significant number” of failed septic tanks were identified as posing a risk to human health and the environment.

The inspections were targeted near rivers and household drinking water wells, which are most at risk of contamination by faulty septic tanks.

Where septic tanks fail inspection, local authorities issue advisory notices to householders detailing what is required to fix the problem.

The EPA report found there were 576 cases where issues notified to householders over two years previously had not been addressed. EPA programme manager Noel Byrne said greater enforcement is needed by local authorities to ensure failed systems are fixed.

“It is unacceptable that the number of septic tanks left unfixed for more than two years continues to rise.

“Where faulty septic tanks are not being fixed, particularly given the availability of the enhanced grant scheme, local authorities need to use their enforcement powers to protect the environment and public health,” he added.

Waterford, Roscommon and Kilkenny had the lowest rates of septic tank failures resolved.


The EPA stated that enforcement of advisory notices by local authorities is inconsistent.

Some 95% of legal actions were taken by just four local authorities - Wexford, Kerry, Mayo and Limerick.

“Local authorities need to increase enforcement, including prosecution where warranted, to resolve faulty domestic waste water treatment systems so that the environment and public health is protected,” it said.

Grants for fixing domestic waste water treatment systems increased from €5,000 to €12,000 at the start of 2024.

There are nearly half a million domestic waste water treatment systems in Ireland.