There is a do not swim advisory in effect at the pier in Enniscrone.
Irish Water has confirmed that a sewage discharge occurred at the location when a pump failed yesterday morning.
However, the beach at Enniscrone remains open to the public at this time.
Sligo County Council have been advised by the HSE to keep the notice in place until tests prove the water is no risk to bathers.
It is hoped that the advisory can be removed on Thursday.