THE European Commission has launched an investigation which could cost the fledgling Irish Water millions of euro in legal fees, the Irish Independent has learned.
Campaigners have included Irish Water in a complaint which has now been accepted by the commission. It centres on the country's longest-running planning dispute.
Donegal County Council has already spent an estimated €5m trying to install a sewage-treatment plant in the north of the county.
It has won an An Bord Pleanala ruling and a High Court case against residents of the towns of Greencastle and Moville on the Inishowen peninsula.
But Campaign for a Clean Estuary spokesman Enda Craig alleges that EU laws have been breached in terms of how the council -- and now Irish Water -- have handled the dispute.
The argument has been raging since 1989, with residents wanting an outflow pipe into the Atlantic and the council insisting that it should be built 5km inside the Lough Foyle estuary.
Silvija Aile, an environmental lawyer at the European Commission's Directorate General for the Environment, confirmed that the residents' complaint had been accepted and an investigation launched.
"With water treatment now in the hands of Irish Water, our dispute is now with them," said Mr Craig.
He added: "We have been in dispute with the council since 1989 and, as of now, Irish Water is the organisation we are in dispute with."