Four Irish beaches failed to meet basic bathing water quality standards last year, according to a new report by the European Commission writes Liam Reid.
The Commission's annual report on bathing water quality also found that another 15 Irish beaches reached only basic water quality standards.
The report found that, while bathing water quality tended to be very good in Ireland, the overall number of sites meeting high levels of cleanliness had declined.
It also criticised Ireland for the limited number of designated bathing areas which are subject to water quality monitoring.
Local authorities are only required to monitor water quality in sites they have designated as bathing areas.
A total of 122 beaches are currently designated.
The Commission has already launched infringement proceedings against Ireland to designate one site, Tramore Pier, as a bathing site.
Waterford County Council had refused to designate the pier, which has had very poor water quality in the past but which continues to be a popular swimming area.
According to the report, the designated beaches which failed to meet the basic standards were Balbriggan in north Dublin, Bray in Co Wicklow, Spiddal beach in Co Galway and Keem beach in Achill, Co Mayo.
The water pollution in Balbriggan and Bray was caused by untreated sewage, while agricultural pollution was the primary factor in Achill and Spiddal.
While meeting basic standards, another 15 sites did not achieve water quality levels required before they could be considered for blue flag status.
Galway County Council had one of the worst records for bathing water quality.
Of only seven beaches designated as bathing areas on its coast, one failed to meet the basic standards, while two others did not meet the higher standards.
Waterford had an equally poor record, with three of its six designated beaches meeting only basic standards.
In Mayo, one of the 11 designated beaches failed to make the basic standards and a further three meeting basic standards.
Donegal, which has designated the most beaches, 19, had only one beach where water quality had failed to meet the highest standard.
Only two of the 28 beaches in Cork and Kerry do not meet the highest standards, while all of Louth's four designated beaches meet the blue flag quality status.
Yesterday the EPA, which collated the data for the European Commission, acknowledged the low number of designated bathing areas in the country and said it was hoped that the number would increase over the next few years.
"It is up to each local authority to designate sites," said Mr Ger O'Leary of the EPA.
"From our point of view, we'd like to see more areas being designated, and we believe [a designated clean beach] can be a huge tourism boost for an area.
"The general public certainly have an understanding of these designations."