Raw sewage is discharged into rivers, lakes and the sea in 42 towns and villages around the State, according to the Environmental Protection Agency.
The material is being discharged despite a European Union directive issued 23 years ago stating that untreated sewage should not be discharged into the water system.
According to the report 94 per cent of urban waste water is subject to secondary treatment, the minimum level required.
The Report has found even thought there is a Secondary treatment plant. That even 30 % of the secondary treatment plants do not meet the required standards.