Half of almost 1,200 septic tanks failed an inspection last year, while more than a quarter of failed inspections in the past seven years are still not fixed.
That is according to the Environmental Protection Agency (EPA), which said in its National Inspection Plan a lack of maintenance and desludging were the main reasons for half of the 1,160 tanks failing their examinations.
Desludging involves removing sediments by draining and cleaning a tank.
The EPA is responsible for the development of a national inspection plan for domestic wastewater treatment systems, with local authorities required to undertake a minimum of 1,000 inspections each year.
The agency said local authorities had identified more serious issues with nearly 300 systems “where they were found to be a risk to human health or the environment”. It said 27% of systems that failed inspections during the period of 2013 to 2019 are still not fixed, and local authorities had to get a grip on the problem.
Cork county saw 60 inspections carried out in 2019, with a failure rate of 52%. Some 320 systems have failed an inspection in Cork since 2013, but 93% of those failures have now been rectified, the EPA said.
Co Kerry saw a failure rate of 65% on 52 inspections in 2019, with 82% of 207 issues now fixed since 2013.
Co Clare saw a 59% failure rate from 41 inspections in 2019, Co Tipperary a 54% failure rate from 46 inspections, while half of Co Limerick’s 34 inspections failed, the EPA said. Just 15% of Co Waterford’s 20 inspections failed in 2019.
Only Co Louth had a clean slate in 2019, with all eight inspections passing.
Co Mayo saw 85% of 67 inspections fail last year, while Co Wexford saw 70% of 156 inspections fall short.
In addition to desludging and maintenance issues, structural defects causing illegal discharges to ditches and streams, leaks, ponding and rainwater ingress were also factors. Householders with private wells are particularly vulnerable to pollution from faulty septic tanks, the EPA said.
There are half a million septic tanks and other domestic wastewater treatment systems in the country, according to the EPA’s estimates.
Director of the EPA’s office of environmental enforcement, Tom Ryan, said, “if you do not maintain your septic tank, it can contaminate your own or your neighbour’s well, putting your health at risk and that of your family and neighbours.
“It may also pollute your local stream or river. You can take simple steps to maintain your septic tank by cleaning it out regularly and by making sure it is not leaking, ponding or discharging to ditches.”
He said that the Government’s expanded septic tank grant scheme broadens the availability of grants and increases the maximum grant available to €5,000 for faulty systems that fail under the national inspection plan.
The EPA reported the grant scheme for septic tanks has been expanded to cover specific areas where work is being focused to improve water quality under the national River Basin Management Plan.
Local authorities need to take action to make sure householders fix systems that fail, EPA senior inspector Noel Byrne said.
“While there has been an improvement in the number of systems fixed, there are still many systems where faults are not addressed over a number of years. This requires increased engagement and enforcement by local authorities to address remaining failures,” he said.