A swimming ban has been put in place for the Warren Beach near Rosscarbery due to high E. coli readings in water samples.
Cork County Council, on the advice of the HSE, have put a swim prohibition notice in place at the beach.
The Council will carry out further sampling today and full results will be available on Friday.
"Following advice from the HSE, the Prohibition Notice will remain on display at The Warren Beach until several rounds of compliant samples have been achieved and water quality is deemed satisfactory," the council said.
A similar swim ban was put in place at Coolmaine Beach in Kilbrittain last Friday.
Separately, swim warnings were in place at six other Cork beaches
Fountainstown, Garryvoe, Cadogan's Beach, Tragumna, Youghal’s Front Strand, and Claycastle beaches were all issued with prior warning notices by Cork County Council on Friday.
Swimming is still allowed at the beaches but bathers are urged to take precautions.
“Bathers are advised of the possibility of an increase in the levels of bacteria in the bathing water over the coming days due to the possibility of localised heavy rainfall,” said the warnings.
The council warned bathers to reduce the risk of illness by taking the following precautions; avoid swallowing or splashing water; wash your hands before handling food; avoid swimming with an open cut or wound; and avoid swimming if you are pregnant or have a weakened immune system.
Further water samples were taken on Monday and the warnings may be lifted today depending on the results.
The public can stay updated on the water quality at the website beaches.ie.