The highest reading for the bacteria, which is normally found in excrement, was at Youghal’s Front Strand.
It’s not safe to bathe where the level of faecal coliforms, such as E.coli, exceed 2,000 in 100ml of water. At the Front Strand a reading taken on Aug 14 was 7,701.
The strand, along with the town’s Claycastle beach, lost its Blue Flag status for high-quality bathing water last year.
The faecal coliform reading at Claycastle was 3,964, while Youghal’s only remaining Blue Flag beach at Redbarn had a reading of 2,481.
The second highest reading of 6,488 was recorded at Coolmaine beach, near Kilbrittain. At 4,106, the Blue Flag beach at Garryvoe had a reading more than double the EU limit, while Garretstown, also a Blue Flag beach, registered 2,909.
No reading was available for Oysterhaven, which was also closed by Cork County Council officials last Friday due to a breach of E.coli levels.
Under EU legislation which came into effect last year, council officials are obliged to put up warning signs at the beaches, while lifeguards operating there told the public it was not safe to swim.
It is believed the high reading at Front Strand was in part due to the fact that Youghal has not got a proper sewerage treatment system and continues to release raw effluent into the bay.
Normally such effluent washes out to sea, but the prevailing weather conditions prevented that last week.
A combination of spring tides and south-easterly winds prevented the sewage from flowing out of the bay. Torrential rain in many areas also caused a significant run-off of slurry from the land.
This would have affected Youghal as effluent would run into the bay from the Blackwater estuary.
In July, Clare County Council lifted a ban on swimming at three beaches after tests showed the amount of bacteria in the water had fallen.
The restrictions were implemented at the Kilkee, Lahinch, and Spanish Point beaches amid concern over E.coli pollution in the sea.
Tony Lowes, a director of Friends of the Irish Environment, pointed out that a report issued last year by the European Centre for Disease Prevention and Control stated that Ireland had a far higher than average EU rate for E.coli infections.
According to the HSE, the number of potentially fatal E.coli–related infections rose 200% in the first six months of the year. Heavy rainfall is believed to have contributed to the increase.
Mr Lowes said: “There are supposed to be regulations that slurry shouldn’t be spread when heavy rain is forecast. So in theory there should have been no spreading for weeks. If the climate is changing then contamination [of river and sea water] will become more frequent.”
A council spokesman said further water quality tests were being carried out yesterday at all the affected beaches.
“The samples will be tested at the Inniscarra laboratory and it will take two full days to get the results. We may know on Wednesday evening. If the results are OK then we will be likely to re-open the beaches on Thursday,” he said.
News: E.coli sparks calls for sewage plant