Residents in five separate areas in the west and north-west are being told to boil all tap water before using it.
Gort in Co Galway, Carrickmacross in Co Monaghan, Sligo town and two areas in Co Limerick were all issued with boil notices following the torrential weather earlier in the week.
A spokesman for the Galway County Council said the contamination in Gort was not related in any way to last year's Cryptosporidium outbreak.
He said it was more likely to have resulted from the recent heavy rainfall bringing contaminated matter into the town supply.
Meanwhile, in Co Monaghan, householders in two housing estates in the Woodvale and Foxfield areas of Carrickmacross were also issued with a boil notice on a private water supply after tests revealed the presence of contaminants.
A boil notice remains in place in parts of Sligo town served by the Kilsellagh resevoir which was affected by landslides in the area.
As a result the water supplied to parts of the north of Sligo town is discoloured and people have to boil it before use.
Sligo County Council say all tests on the water to date have come back negative for microbiological contamination.
To minimise inconvenience to them the Council has been organising daily water drops since last Monday.
Sligo Fire Brigade have been bringing tankers full of clean water to various locations and housing estates where people have been filling up bottles, buckets and pots.
A Second 'boil water warning' has been issued by Limerick County Council. This latest one has been issued to customers in parts of Pallasgreen village.
100 households are affected by the new public water notice.
Earlier this week, the council issued a similar public alert to over 153 customers of the Rockhill Public Water Supply.