Beaches and Bathing Water Quality

Bathing Water Quality

Dublin City Council is responsible for monitoring bathing water quality at its two designated bathing waters namely; Dollymount and Sandymount. Merrion Strand was declassified as a designated bathing water from the 1st June 2020.  

The bathing season is from 1st June to September 15th each year, with pre-season sampling commencing in mid-May.

In addition, Dublin City Council also undertakes water quality monitoring at undesignated bathing areas, namely; Merrion Strand, Shelley Banks beach, the South Bull Wall at the Half Moon Swimming Club, as well as the North Bull Wall. At least twenty samples are taken from each location during the bathing season.  Furthermore, Dublin City Council continue to monitor water quality throughout the year, outside of the bathing season on a fortnightly basis.

Assessment of water quality involves analysis of two types of bacteria (E coli and Intestinal Enterococci) which may be present in the water. These bacteria are indicators of water quality. The results are categorised in accordance with Bathing Water Regulations, 2008. Bathing water quality is classified as ‘excellent’, ‘good’, ‘sufficient’ or ‘poor’ and these classifications are based on the concentrations of the two bacteria species detected in samples of bathing water.

Temporary Bathing Prohibitions, Advisory and Prior Warning Notices

To protect bather health, it may be necessary to advise against or prohibit bathing at Dublin City Council’s bathing areas. Bathing water quality is particularly impacted by weather conditions, with factors such as rainfall amount and intensity, temperature, sunlight and tidal conditions being the main influences. Faecal matter from dogs and birds on a beach can significantly impact on water quality as can temporary overflows from urban drainage infrastructure.

Additionally, if Dublin City Council receives information which indicates a risk of deterioration in bathing water quality, a precautionary advisory or prohibition notice may be issued. Examples of such include a prediction of an extreme weather event or an exceedance/non-compliance from the Wastewater Treatment Works (i.e. effluent quality fails to meet the conditions of discharge as set out in the Wastewater Discharge Licence issued by the EPA for the Works).

The Environmental Protection Agency (EPA) and Health Service Executive (HSE) have established a protocol outlining various recommended actions to be taken by local authorities where, levels of bacteria in the bathing water exceed the satisfactory standard. In such circumstances, the local authority consults with the HSE in the first instance before proceeding with an agreed action. The public are informed of the short term pollution event through social media, web notifications and by erecting temporary signage at the locations affected. The website www.beaches.ie shares the latest information on national bathing water quality. Swim restrictions and annual water quality ratings can be found here. In addition, Dublin City Council operates a series of electronic signs on Dollymount and Sandymount Strands which notify the public when it is unsafe to swim. Once the event has passed and water quality returned to a satisfactory standard, the public are immediately informed.

Further information on real time water temperature, wave height and wind direction can be find on the following external website: https://cilpublic.cil.ie/metocean/