The Environmental Protection Agency (EPA) has released the report on Domestic Waste Water Treatment System Inspections 2024, which details the findings of septic tank inspections completed by local authorities in 2024.

Domestic waste water treatment systems, mostly septic tanks, are used by householders to treat sewage. There are nearly half a million systems in Ireland.

The EPA’s  National Inspection Plan 2022-2026requires local authorities to complete a minimum of 1,200 inspections annually, targeted near rivers and in areas where septic tanks are co-located with household drinking water wells.

A total of 1,390 septic tanks were inspected in 2024 with 56% (773) failing because they were not built or maintained properly. 

Advisory notices

When septic tanks fail inspection, local authorities issue advisory notices to householders setting out what is required to fix the problem. The EPA report found that 82% of septic tanks that failed during 2013-2024 were fixed, up from 75% at the end of 2021. The number of advisory notices open more than two years decreased for the first time, from 576 at the end of 2023 to 523 at the end of 2024.

Dr Micheál Lehane, director of the EPA’s Office of Radiation Protection and Environmental Monitoring said: “The reduction in the number of old advisory notices (over two years) is to be welcomed, however, the number not resolved remains unacceptably high, allowing risks to public health and the environment to continue.

"Greater and sustained enforcement effort is needed by local authorities during their annual septic tank inspections, checking that faulty septic tanks are fixed and taking legal action where necessary.”

The grant schemes for remediation of septic tanks were changed at the start of 2024 to increase the amount from €5,000 to €12,000 and remove the requirement to have registered the septic tank in 2013. There were 265 grants awarded in 2024, totalling nearly €2.5m, up from 194 grants in 2023.

'Real concern'

Noel Byrne, EPA programme manager, said: "More than half of septic tanks failed inspection, which is a real concern. Householders’ water supplies and local rivers may be exposed to contamination from faulty septic tanks, which can pose a serious health risk to individuals and the local environment. 

"By maintaining their septic tank and fixing any problems identified, householders will protect their health and the environment. Householders should take advantage of the enhanced grants where applicable.”

The National Inspection Plan for Domestic Waste Water Treatment Systems 2022 - 2026was published by the EPA in 2021.

The plan requires a minimum of 1,200 inspections from 2023 onwards. There was a shortfall in inspections by four local authorities (Limerick, Donegal, Wexford and Leitrim) in 2024 and these need to be completed in 2025. The EPA will continue to monitor local authorities that are required to make up these shortfalls in 2025.