Bathing has been banned at dozens of beaches across the country after massive rainfall overwhelmed sewage systems.
From coast to coast, swimmers are being told to stay out of the water for several days, in the case of Dublin's Killiney, or over a week, for Lahinch in Co Clare.
The official Government site, Beaches.ie, has listed 53 popular spots which are deemed to be unfit for bathing.
Spanish Point and Kilkee in Co Clare carry a three-day warning "due to possible pollution", as does White Strand at Doonbeg.
Swimmers are advised to stay out of the water in Oysterhaven in Co Cork for six days, as they are at Youghal Strand, the scene of Sunday's tragic deaths in the Ironman event.
The six-day bathing ban is also in effect at the Forty Foot, Seapoint and Sandycove in south Dublin.
Find out if your beach is affected here.
