Crews are continuing to repair pumps that have broken down at the Ringsend wastewater treatment plant.
Irish Water says it could mean overflows from the facility during the next couple of days.
Crews are on site to carry out essential repairs as quickly possible in order to allow the plant to return to its full treatment capacity.
Irish Water said they have notified the Environmental Protection Agency, Dublin City council and Dun Laoighre-Rathdown County Council of the incident.
A series of discharges from the over-worked plant led to a number of beach closures this year.
Damien Cassidy, who lives in the area and is part of the local Environment Group, says residents have to deal with foul smells and sewage on their beaches.
"This plant has broken down several times and it is affecting the north side of the city as well as the south," said Mr Cassidy.
"The existing residents down there have had to put up with this situation of not being able to open their windows at certain times because of the prevailing winds."
Mr Cassidy said residents have been putting up with it for the last ten years.
"It has been a constant fight with the Environmental Protection Agency and the corporation to get our point across."
The plant treats approximately 40% of the country's sewage.