Septic tank and wastewater treatment system inspections

In the past year, Environmental Services Inspectors from Cavan County Council have completed extensive inspections of septic tanks/domestic wastewater treatment systems in specified risk areas as part of the National Inspection Plan.

These areas are linked to risks associated with the environment as well as risks to human health such as drinking water supply source catchments. A properly functioning system presents a lower risk to ground waters and surface waters such as rivers and lakes.

During 2025, 34 inspections were completed by Environmental Services Inspectors. Twenty-seven of these inspections are now closed with certificates of compliance issued to the relevant homeowners. The remaining homeowners are working on carrying out the necessary work to ensure their systems are functioning properly.

Desludging or regular emptying/maintenance was the dominant cause of a system not functioning properly from the inspections undertaken during 2025.

Emptying/desludging the system is an important responsibility as it helps to keep it working properly. If too much sludge builds up, it can affect how the system works. It can also block the system. You might then need to repair it or replace it, which can be expensive.

You must use an authorised collector to empty (de-sludge) your septic tank. If you are a farmer, you can empty your own septic tank. However, you cannot empty a septic tank for anyone else.

For advice on how you can complete a septic tank system check, desludging your system and on domestic wastewater treatment systems/septic tanks, visit www.cavancoco.ie/dwwts for information nd guidance.

For further information on water quality or any other queries you may have regarding protecting water quality, please contact the Environment Section of Cavan County Council on 049 437 8486 or alternatively at environ@cavancoco.ie