Prior to the start of 2016, Cork county council inspectors had carried out 245 examinations of septic tanks, of which 137 (56%) were non-compliant.
This year, they have carried out 21 inspections, 15 of which did not meet the required standard, amounting to a non-compliance rate of 71%. Six inspections were carried out on septic tanks in West Cork and all were non-complaint.
Fine Gael Councillor Kevin Murphy said he was concerned at the increasing failure rate. In most cases, septic tanks fail because they are not regularly de-sludged, he said, while Independent Councillor Alan Coleman urged council officials to carry out a public awareness programme on the issue.
Officials said it was estimated there are upwards of 50,000 septic tanks in the county, a number of which are not registered.
If people have not registered their septic tanks, they will not get any government grant-aid should they develop a fault.
Five recent inspections identified major non-compliance issues, which will require significant work, or even the complete replacement of septic tanks, said council officials.
The county council has, on behalf of the Department of Environment, paid out 10 grants to householders who needed to carry out repairs to the tanks. The grants totaled €20,336.
A number of applications are currently being processed by the council.
Ted O’Leary, a senior official with the council’s environment directorate, said there was a significant level of non-compliance and he agreed with Mr Coleman that it would be a good idea if the local authority carried out an awareness programme on de-sludging.
The council is concentrating its inspections in areas where leaking septic tanks could pollute rivers and springs which are sources for public drinking water.