The water quality at some beaches have dropped, according to an environmental report.
Water quality at Ireland's swimming spots remains among the best in Europe, and an Environmental Protection Agency (EPA) report for 2002 found that 128 of the 131 bathing areas, 97.7 per cent, complied with the minimum standards laid down by Irish law under European Union legislation.
However, three beaches failed to comply with these mandatory standards - Ardmore, Co Waterford, Brittas Bay south and Brittas Bay north, Co Wicklow.
Ardmore and Brittas Bay south failed the mandatory value for both total and faecal coliforms. Brittas Bay north failed on surface- active substances (detergents).
Also, 111 of the 131, only 84.7 per cent of bathing areas, complied with the much stricter guideline standards specified by the EU. This represents a decline from the 2001 figure of 87.7 per cent.
Mr Micheál Lehane, senior scientist at EPA, said the bathing season started this weekend and local authorities should display the results of their monitoring tests at or near the beach.
His advice to swimmers was: "Be vigilant, look for the information and if anybody has any concerns about the safety of swimming then contact the local authority."
In the case of Ardmore and Brittas Bay north, both failed on one occasion last year, he said. "When they fail to reach the standards, it is not considered suitable for swimming. The type of problem there would give gastro-enteritis," Mr Lehane said.
Tests for salmonella were carried out in 13 or 10.7 per cent of the sea water bathing areas and the test was positive at Merrion Strand, Dublin.
Mr Lehane said Brittas Bay north was more unusual as there were indications of detergents. This gave less concern as that was a visual test. "The 17 beaches that failed to comply with the stricter EU standards are acceptable for swimming," Mr Lehane stated.
He said that the Irish standard was the minimum standard laid down by EU directive and was law. The stricter EU standard was more aspirational.
The inland bathing areas achieved a high standard for the first time in recent years, achieving a 100 per cent compliance rate with both the mandatory and guide standards.
An assessment of the water quality with respect to the additional national standards prescribed under Irish legislation indicated that all of the 131 bathing areas, 100 per cent, complied with the prescribed national standards for total and faecal coliforms.
Of the bathing areas sampled, 79.3 per cent complied with the specified values for dissolved oxygen (53 sites were tested) and 90.6 per cent of the bathing points complied with the national limit value for faecal streptococci.
Bathing areas that did not attain the higher standards
Lady's Bay, Co Donegal;
Port Arthur, Co Donegal;
Dollymount Strand, Dublin;
Merrion Strand, Dublin;
Sandymount Strand, Dublin;
Balbriggan, Dublin;
Malahide, Dublin;
Portmarnock, Dublin;
Rush (South Beach), Dublin;
Skerries, Dublin;
Burrow Beach, Dublin;
Clifden, Co Galway;
Na Forbacha, Co Galway;
Inny Waterville, Co Kerry;
Laytown/Bettystown, Co Meath;
Enniscrone, Co Sligo;
Clogga Beach, Co Wicklow.
(Ardmore Beach in Waterford and Brittas Bay in Wicklow failed to meet minimum EU standards.)