Galway City Council has extended the 'Do Not Swim' notices for Ballyloughane and Grattan Road Beaches.
It's described as a precautionary measure due to a storm overflow incident at Mutton Island Wastewater Treatment Plant.
The bathing water may have an increase in levels of bacteria over the coming days due to forecast heavy rainfall.
The City Council is asking swimmers to heed poster warnings, and says an update is expected tomorrow upon receipt of sample results.
