Around 1,400 homes have been affected by the disruption.
Dublin City Council said this evening it has made significant progress in tackling the problem and has eased the restrictions for the residents.
The initial advice was not to use the tap water for drinking or cooking, but this evening officials have said the water is safe to used if boiled.
The council has also said it has made considerable progress in flushing the bacteria out.
Officials said they expect normal service to resume in the coming days.
The council has ruled out the presence of E Coli or metals such as lead in any of the samples.
A map of the affected area is available on the council’s website.