The commission says Ireland was warned twice
The European Commission is taking Ireland to court over failures to upgrade our waste water treatment infrastructure.
Under EU law, towns and cities are required to collect and treat their urban waste water, as untreated waste water can put human health at risk and pollute lakes.
In a statement, the commission says 38 towns, cities and settlements have inadequate wastewater infrastructure.
It says: "The referral decision also raises additional concerns about the failure to ensure that a correct operating licence has been issued for the treatment plants serving the agglomerations of Arklow and Castlebridge.
EU member states had until the end of 2000 to ensure appropriate treatment of wastewater from large towns of more than 15,000 people
The commission says it initiated "the infringement against Ireland in September 2013, followed by warnings in September 2015 and September 2016."
According to a recent commission report on the implementation of EU environmental policy and law, one of the main challenges Ireland faces is maintaining the important investments required for water services, given the urgent need to invest in water infrastructure.
Speaking in response to the announcement, Green Party leader Eamon Ryan claimed the Government's failure to invest was harming the environment, tourism, jobs, and the economy.
"Once again the Government has failed to meet their environmental obligations under EU law.
"We welcome the commission's decision to take action against the State, and hope that this serves to inject some urgency into an unacceptable situation that has gone on for far too long.
"Whenever we experience heavy rain, we end up with raw sewage overflowing into our rivers, lakes and seas, thanks to the lack of wastewater processing facilities.
"Raw sewage is still being discharged into the environment in 43 locations around the country. The negative effects this has on the environment, tourism, jobs and the economy is shocking."
Mr Ryan also says the State is facing fines "in the hundreds of millions" for failing to meet their commitments in this area.