OVER HALF OF septic tanks inspected last year by local authorities last year failed inspection.

The Environmental Protection Agency (EPA) also noted that a “significant number” of tanks which failed inspection were also “identified as a risk to human health and the environment”.

The EPA today released its figures on Domestic Waste Water Treatment System Inspections 2024, which details the findings of septic tank inspections completed by local authorities last year.

Some 1,390 septic tank inspections took place last year, targeted near rivers and household drinking water wells which are most at risk of contamination by faulty septic tanks.

However, 56% failed inspection because they were not properly built or maintained.

The annual failure rate has varied between 44% and 57% since the National Inspection Plan started in 2013.

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 also decreased for the first time, from 576 at the end of 2023 to 523 at the end of 2024.

Local authorities issue advisory notices requiring householders to fix septic that fail inspection but the EPA cautioned that there are significant differences across local authorities and enforcement remains inconsistent.

The number of legal cases since inspections commenced in 2013 increased from 62 at the end of 2023 to 66 at the end 2024.

However, 95% of those cases were taken by four local authorities: Kerry, Limerick, Mayo and Wexford.

The EPA meanwhile said that faulty septic tanks pose a risk to human health because they can contaminate household drinking water wells with harmful bacteria and viruses.

People may also be exposed to waste water if it surfaces in gardens or runs off into ditches and streams.

They also post a risk to the environment because excessive releases of nitrogen and phosphorus from faulty septic tanks can cause pollution in receiving waters.

Domestic waste water is identified as a significant pressure on water quality in 148 (9%) of at-risk water bodies in Ireland.

Meanwhile, the National Inspection Plan requires that local authorities complete a minimum of 1,200 inspections.

Donegal, Leitrim, Limerick, and Wexford local authorities did not complete their full 2024 allocations and are required to make these up in 2025.

The EPA warned that it may issue a legal direction to local authorities in the event inspection shortfalls are not addressed.

Dr Micheál Lehane, Director of the EPA’s Office of Radiation Protection and Environmental Monitoring said “greater and sustained enforcement effort is needed by local authorities during their annual septic tank inspections”.

He added that local authorities should do more to ensure faulty septic tanks are fixed and take legal action where necessary.

Elsewhere, Noel Byrne, EPA Programme Manager, said that the number of failed inspections is a “real concern”.

“By maintaining their septic tank and fixing any problems identified, householders will protect their health and the environment, said Byrne.

He added that “householders should take advantage of the enhanced grants where applicable”.

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 €2.5 million, up from 194 grants in 2023.