Over 30 towns and villages are still releasing raw sewage into the environment every day because they don't have treatment plants.
A report from the Environmental Protection Agency has found just half of Ireland's sewage is being treated to EU standards to protect the environment, well below the EU average of 90 per cent.
It said Ringsend, Ireland's largest treatment plant, is overloaded, with a major upgrade to the facility not due to be complete until 2025.
Works to eliminate raw sewage flowing into seas and rivers from 32 towns and villages have commenced or are due to start by 2024.
Dr Tom Ryan, EPA Director, says Irish Water needs to fix the issues;
"Irish Water has failed to produce action plans to improve treatment at one-third of the priority areas identified by EPA where waste water is harming our rivers, lakes and coastal waters. It is essential that Irish Water provides clear, site specific action plans and time frames to improve treatment in these areas."
