Who inspects

Inspections are carried out by council staff who are trained and appointed by the EPA. They carry a certificate of appointment and ID, and will show them if you ask.¹ Councils inspect over 1,200 systems a year nationally.¹

How many fail

59%

of the septic tanks inspected in 2025 failed.² Typically about half fail, and around a quarter of those pose a risk to health or the environment.¹

Many of the problems found come down to simple maintenance and desludging.¹

If yours fails

The council issues an Advisory Notice listing the works needed.³ A failed inspection can also open the door to a grant of up to €12,000 towards repairs or a replacement.³ See our grants guide.

How to be ready

Know where the lids are, and keep them reachable. They're needed for regular maintenance.¹
Keep your desludging receipts. Owners need records to show the tank has been emptied on schedule.⁴
Get it emptied if it's due: about every 3 years for a standard tank, never more than 5.⁴
Keep rainwater out. Downpipes and yard water shouldn't run into the tank.⁶
Keep the percolation area clear of vehicles, heavy animals and anything that breaks the sod.⁶

Is yours registered?

By law every domestic septic tank and treatment system has to be on the council register. You can register online at protectourwater.ie for €50.⁵ If you bought the house recently, check it was done.

Due an empty before an inspection? Ring Ryan on 085 195 6808.

Sources

Checked 19 October 2026. This is general information, not legal advice. Rules and grant terms change, so check with Donegal County Council or the relevant body before relying on them.

Septic tank inspections: what to expect