Ringsend and Rush has failed EU tests for water quality.
The report from the Environmetal Protection Agency highlights the need for investment in the area.
The Urban Waste Water report from the EPA shows that the quality of water at Ringsend is not up to scratch.
It failed to meet the EU Directive water quality and sampling standards.
The report also found that with no treatment facility at Rush, raw sewage is being discharged into the sea resulting in poor bathing quality at South Beach.
In a statement, Irish water says the discharge of untreated sewage will end by 2021.
The company says it plans to invest another 2 billion euro in infrastructure over the next six years.
