Background Note from Water Advisory Unit (part of Department of Housing, Local Government and Heritage) on Domestic Septic Tanks

On 29 October 2009, the European Court of Justice ruled against Ireland in relation to the treatment of domestic waste waters from septic tanks and other on-site wastewater treatment systems. 

The Court ruled that, with the exception of bye-laws in County Cavan, Irish legislation did not transpose Articles 4 and 8 of Directive 75/442/EEC (the Waste Directive) insofar as domestic waste waters from such on-site treatment systems are concerned.

The Court ruled that the existing legislation only partially provided the protections required by the Directive in relation to on-site waste-water treatment systems. Specifically, the Court highlighted the absence of an appropriate system of inspection for such systems.

A response setting out Ireland’s proposed legislative response issued to the Commission in December 2009.  Following the ruling the Department worked closely with the Environmental Protection Agency and with officials from a number of local authorities on developing proposals to address the ruling and provide for a system of inspection.

The issues raised from the 2009 European Court of Justice ruling have since been addressed by various pieces of legislation. These include the Water Services (Amendment) Act 2012, Domestic Waste Water Treatment Systems Regulations (e.g. SI 220 of 2012 and SI 223 of 2012), and the introduction of the National Inspection Plan for Domestic Waste Water Treatment Systems to support these regulations.  Regulations can be found on the Irish Statute book website at

Current details regarding Domestic waste water treatment systems (septic tanks) can be found on the Rural Water section of the Department’s website at:

In terms of Ireland’s obligations, the EU Water Framework Directive, which was adopted in October 2000, is now the relevant piece of environmental legislation requiring implementation to protect our waters and it lays down very detailed requirements for the management and improvement of water quality.

These include the requirement that member states must put a programme of measures in place to protect and, where necessary, restore to at least good status all bodies of surface water and groundwater within prescribed timeframes.

To implement this requirement, member states are required to prepare “River Basin Management Plans” every 6 years. These plans must, amongst other requirements, set out the environmental improvements that will be delivered during the river basin planning cycle in question and describe the programme of measures that will be implemented to meet the objectives set out in the plan.

Details relating to the Water Framework Directive are available on the Water Advisory Units section on the Department’s website at

Details of the most recent plan can be found at: and details of public consultation on the draft River Basin Management Plan for Ireland 2022-2027 can be found at the following link:

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