More than 500 septic tanks that were judged to be a threat to human health have not been repaired though the owners were notified two years ago, according to the Environmental Protection Agency.
It warned on Thursday that these faulty septic tanks were leading to sewage ponding in gardens and discharges into ditches and streams.
The septic tanks in question failed local authority inspections and advisory notices were issued, but nothing was subsequently done despite there being grants of up to €5,000 to assist in addressing malfunctioning systems, it added.
EPA programme manager Noel Byrne said local authorities must do more to enforce inspections. “The need to fix failing septic tanks has been repeatedly highlighted by the EPA as a concern,” he added.
Only seven local authorities have taken legal actions for failure to fix faulty septic tanks since 2013, amounting to 36 actions in total.
There were 1,147 inspections of septic tanks and other domestic waste water treatment systems in 2021 and more than half (604) failed inspections because they were not built or maintained properly. Twenty nine per cent (337) of the facilities inspected were considered a risk to human health or the environment, because faulty systems can contaminate household drinking water wells and pollute rivers.
The most common faults were either poorly maintained sewage tanks or structural defects which led to sewage discharging into ditches or streams.
Domestic waste water treatment systems (DWWTS) are used by householders to treat sewage. There are nearly half a million systems in Ireland, mostly septic tanks.
Bacteria and viruses
DWWTS can contaminate household wells with harmful bacteria and viruses if not built and operated properly. Excessive releases of nitrogen and phosphorus can cause pollution in rivers and other waters.
The EPA’s national inspection plan has set targets for local authorities to inspect more than 1,000 waste-water systems every year but there has been a consistent failure rate of between 44 and 57 per cent since the inspections were brought in nine years ago.
The highest failure rates last year were in the counties of Leitrim (89 per cent of inspected DWWTS failed) and Roscommon (79 per cent).
Clare, Offaly, Kilkenny and Kerry County Councils did not complete their full 2021 allocation and have reported that they will make this up in 2022.
The EPA’s national inspection plan 2022-2026 requires increased enforcement by local authorities to resolve failed systems.
