There is a huge variation in the inspection failure rates for septic tanks around the State, with some local authorities reporting that up to 79 per cent of tanks failed inspections.
However, many local authorities with high failure rates said minor maintenance issues such as desludging were the reason for the high rates.
The national inspection plan was announced by Minister for the Environment Phil Hogan last July, following the news that homeowners must register septic tanks and other domestic waste water systems under EU waste regulations.
A grant scheme for remedial work is available when septic tanks fail inspections, but only if the tanks have been registered.
Limerick County Council recorded the highest fail rate, at 79 per cent, but it pointed out that many of the failures were for issues such as desludging or crossed connections.
“When the minor fails are excluded, the figures are 56 per cent [fail] and 44 per cent [pass],” a spokeswoman said.
Similarly, Cavan County Council reported a failure rate of 70 per cent, but pointed out that most of these cases related to desludging the system.
Sligo County Council also reported a 70 per cent failure rate.
The highest inspection rate was reported by Dún Laoghaire Rathdown County Council, but this referred to just one septic tank inspection. Because there are only about 1,300 septic tanks in this area, just 10 inspections will be conducted.
Galway County Council had the second-highest pass rates, at 84 per cent. It has about 40,000 septic tanks in its area and under the national inspection plan, it must inspect at least 98 systems. It has inspected 36 of those.
The minimum number of inspections required in each area is determined by the Environmental Protection Agency, which is co-ordinating the national programme.
The required number of inspections varies widely, with Cork County Council, for example, having a quota of 99 inspections systems before the end of June, while Waterford County Council must inspect 16.
The agency said inspections should concentrate on areas that are at risk of waste water discharges.
At least eight local authorities have not started inspections yet, with many saying they were due to start this month.
Information was not available from five local authorities.
Leitrim County Council said no waste water treatment systems had been inspected “due to resource issues”.
It said the programme would begin later this month or early next month.
The Environmental Protection Agency is planning to publish an update on progress later this month.