The Government has been fined €2m by the European Commission for failing to regulate the installation and use of almost 500,000 septic tanks.
In addition, the EU is imposing a daily fine of €12,000 per day as and from today for breach of a 2009 ruling until the issue is properly addressed.
Babara Nolan, head of representation at the EU Commission Office in Dublin, says the Irish taxpayer is about to take a costly hit because of Governmental delay on this matter.
"Hopefully the authorities will move quickly to correct the situation," she said.
These are the first judgments of this kind against Ireland.
"Today's judgments also remind the Member States of their duty to implement the judgments of the Court in a timely manner and that the failure to do so carries the risk of financial sanctions," said a European Commission statement.
"This also illustrates that poor implementation of environmental law has costs. It is estimated that failure to implement environment legislation costs the EU economy around economy around €50bn every year in health costs and direct costs to the environment."