Bathing Water Sampling & Testing
Bathing water in dlr is tested at these locations:
• Blackrock Baths Shore
• Seapoint Beach
• Beach Gardens Dún Laoghaire
• Sandycove Beach
• The Forty Foot Bathing Area
• Colliemore Harbour
• Killiney Beach
• White Rock Beach
• Corbawn Strand
The five areas listed in bold above are identified bathing areas under the regulations. Water quality must be monitored at identified bathing areas. The remaining four areas are other popular bathing areas that we have chosen to monitor as well.
Water is sampled and tested twice per month outside of bathing season and once per week during the season. This is much more frequent than the minimum requirement of four tests per year. The bathing season runs from June 1st until Septmeber 15th each year.
A sample of at least 250ml is taken at each bathing area and all samples are brought to Dublin City Council’s central lab as soon as possible, usually on the same day. Taking samples at all locations and delivering them to the lab takes 3-5 hours adn requires 2 staff members. Due to the lab’s opening hours and the changing time of high tide each day, sometimes samples cannot be delivered to the lab on the same day as testing. Samples are always delivered to the lab within 24 hours.
To properly test the water, the lab uses a technique which requires the growth of bacteria, because of this, it usually takes 2-4 days for the lab to complete the tests and send the results back to us. For this reason, we prefer to test the water early in the week wherever possible to avoid delays over the weekend. On occasion we have to test on Thursdays or Fridays and in these cases the results may take 4-5 days to return.
Did you know? After a heavy rainfall event it is important to avoid contact with the water for at least 48 hours to prevent the risk of getting a recreational water illness. Click here for more information on the 48 hour rule.
Results & Actions
The lab tests for Escherichia Coli (E. coli) and Intestinal Enterococci (I.E.). Depending on the levels of either of these in the samples that were taken, we may be required to take certain actions in order to inform and manage health risks to bathers.
If the presence of either E. coli or I.E. is higher than certain levels, we may be required to carry out one of the following actions:
• Re-sample and monitor the situation
• Issue a Bathing Advisory Notice
• Issue a Bathing Prohibition Notice
We also have a process in place for notifying bathers of these outcomes which includes posting information on the noticeboards at each beach, posting information on our website and social media accounts and updating our digital screens as relevant at Seapoint, Sandycove, and Killiney beaches.
With current technology, it is not possible to provide daily or real-time information about water quality (for both E.coli and I.E.) in line with regulatory requirements.
The Dublin Bay Bathing Task Force (BWTF) are currently in the process of developing a Bathing Water Prediction System (BWPS) for Dublin Bay. The system will combine weather forecast information with water quality models to provide a daily indication of water quality, and will include the designated bathing areas of Seapoint, Sandycove, and the Forty Foot within our county.
We will continue to test and monitor bathing water quality in the County far above the minimum legal requirement as we recognise the popularity of sea swimming and other open-water based activities in the County.