THE State has been ordered to pay a €2m lump-sum fine plus daily penalties of €12,000 because it failed to introduce a registration system for septic tanks.
The European Court of Justice has ruled that Ireland failed to do enough to protect groundwater and had "not yet" adopted the measures necessary to comply with a 2009 ruling.
The fines, which were not unexpected, put further pressure on Environment Minister Phil Hogan to ensure that the bulk of the 500,000 septic tanks across the State are registered for inspection by next February.
And in a separate judgment, the State was ordered to pay €1.5m after failing to protect the environment from damage caused by large-scale projects.
However, the court decided to reduce the level of fines because the State's ability to pay "has been diminished in the context of the economic crisis".
Septic tank inspections will begin next summer, and local authorities will carry out checks, particularly in areas where water sources are under threat of pollution from tanks.