More bathing bans are likely for Dublin bays.
It follows swimming restriction for four beaches across the city earlier this week.
Heavy rain last weekend caused an overspill of the storm tank at the Ringsend wastewater facility.
Test results on the water at Dollymount Strand, Sandycove, Sea Point and The Forty Foot are due back today.
Upgrade works at the Ringsend plant aren't due to be completed until the mid 2020's.
Until then, more sewage is expected to flood into Dublin bays as the plant struggles to cope with the amount of waste it has to treat.
Currently, the plant treats sewage the equivalent of the Dodder river from source to sea every single day.
A spokesperson for Irish Water says they hope the upgrade works will be completed by 2022.