What are the different warnings or notices that are used during the bathing season?

Prior Warning Notice – Bathers are advised of the possibility of an increase in the levels of bacteria in the bathing water over the coming days due, for example, a storm event.

Advisory Notice – Bathers are advised not to swim at a bathing area due to an increase in the levels of bacteria found in bathing water samples taken on a specific date.

Prohibition Notice, Warning Do Not Swim – Bathers are warned not to swim in a bathing area as swimming in the water may cause illness.

How do I know it is safe to swim and when is it not?

There are different ways you can use to find out what is the latest quality status of bathing waters and if there are any current warnings or advice against bathing:

  • This page on our website regularly publishes results of bathing water sampling carried out at all 9 locations including the 5 identified bathing areas, inside and outside the bathing season.  
  • Before going to the bathing water you can check the EPA national bathing water website here to see the latest water quality (excellent, good, sufficient or poor) and find out if there are any current warnings or advice against bathing notices in relation to water quality. Only applicable during the bathing season.
  • At the bathing area - lifeguards will fly the red flags when bathing waters are considered unsafe for bathing. You can check out the notice boards to see the latest water quality and if any warnings or advice against bathing notices have been posted by the local authorities.
  • Swimming after heavy rainfall carries an added risk of pollution from surface runoff and is best avoided for 48 hours. Further information can be found here.
  • You can follow the EPA Beaches Twitter account and for news and information on bathing waters and tweets of when bathing water incidents start and end.
Should I swim after heavy rain?

Heavy rain can wash pollution into rivers, lakes, and seas and in some instances overwhelm sewage systems. The impacts of these events are generally very short-lived lasting typically 1 - 2 days. Swimming after heavy rainfall is best avoided as it carries an added risk of pollution as well as a likely increase in the amount of sediment and turbidity in the water which would make it visually unappealing.

More information is available here.

What are Algal Blooms of Phaeocystis species and can I still go swimming?

Algal blooms of Phaeocystis species have occurred several times along the east coast of Ireland, over the summer months, in recent years.

Phaeocystis forms part of the natural cycle of phytoplankton in Irish waters and often occurs after the initial seasonal spring bloom. In the North Sea dense blooms of this species have been associated with nutrient enriched continental coastal waters but this is unlikely to be a factor in the low nutrient waters of the western Irish Sea.

The Phaeocystis species cause water discolouration and foaming along the shore in windy conditions. According to experts in the Marine Institute this species is not harmful to humans either through swimming or from consuming fish that have been exposed to the bloom. The beaches remain safe despite any discolouration of water.

In some cases, oxygen depletion can occur when the bloom decays and this can result in fish and shellfish mortalities, but this has not occurred with previous blooms of Phaeocystis in Irish waters.

Blooms of Phaeocystis species usually dissipate within a few weeks. The progress of any current blooms of Phaeocystis and other potentially harmful algal blooms can be viewed on the Marine Institute’s website here.

Should I swim if the lifeguard red flag flying?

Never swim where a sign says not to or when the red flag is flying. The red flag is flown when there is a water safety risk like the presence of dangerous under-currents. The red flag can also be flown when there is an increased risk of illness if you go into the water or where pollution has been identified.

Is there anything I can do to help?
  • Follow the instructions of lifeguards, they are there for your safety.
  • Report any missing or damaged lifebuoys to us or
  • Take all your litter home with you - several hundred beach users on a sunny weekend can generate a lot of rubbish.
  • Do a 2 Minute Beach Clean every time you go to the beach.
  • Keep your dog under control and always bag & bin your dog’s mess - don’t bury it in the sand!
  • Do not walk on the dunes - vegetation is a valuable filter of pollutants, prevents erosion, and reduces runoff.
  • Get involved in a local Coastcare group – check out this website for more info.
  • Don’t feed seabirds - one seagull poo contains millions of bacteria!
  • Don't bury soiled nappies or rubbish in the sand, your child could be the next one to dig it up!


What are identified bathing waters

Identified bathing waters are bathing waters (sea, river or lake surface waters) which Dún Laoghaire- Rathdown County Council consider to be widely suitable by the public for bathing. Identified bathing waters are monitored, managed and assessed under the requirements of the Bathing Water Quality Regulations 2008 as amended. Under the Bathing Water Quality Regulations 2008, Dún Laoghaire- Rathdown County Council has responsibilities in relation to the management of bathing areas in the dlr area. These responsibilities include the identification of bathing areas, the establishment of bathing water profiles for identified bathing areas, the monitoring of bathing water quality at identified bathing areas, and the management of short-term pollution incidents and communication of health risks to bathers.

We currently have 5 identified Bathing Areas under these regulations - Seapoint, Sandycove, The Forty Foot Bathing Area, Killiney Beach and White Rock Beach. However, we do monitor water quality at a total of 9 locations which also include Blackrock Baths Shore, Beach Gardens Dún Laoghaire, Coliemore Harbour and Corbawn Strand.

How are identified bathing waters chosen?

Each year, Dún Laoghaire-Rathdown County Council is required to identify bathing waters (sea, river or lake surface waters) within their area which they consider to be widely used by the public for bathing for the upcoming bathing season.

At present, 18 local authorities have identified 148 bathing waters which is approximately 1 for every 40 km of coastline.

How can I suggest my favourite beach for identification?

Public participation is generally needed during May and June each year for the identification of identified bathing areas. The EPA has produced guidance for the public on what information is required to nominate bathing areas and how this should be assessed, both of which are available to download from the Resources page of the website here. If your particular beach is not identified by Dún Laoghaire-Rathdown County Council this could be for various reasons such as low numbers of bathers, accessibility issues, poor water quality or limited amenities.

How long is the bathing season?

The bathing season in Ireland runs from June 1st until September 15th of each year.


How is bathing water quality monitored?

To assess the microbiological quality of the water and to minimise any public health risk, bathing waters are sampled and testing is carried out approximately twice per month outside the bathing season and once per week during the bathing season. This is more frequent than is required under the regulations, which require only four samples per year.

 The location where the sample is taken at each bathing area is where most bathers are expected. Samples are taken 30cm below the water surface in water that is at least 1 metre deep.

Dún Laoghaire-Rathdown County Council take samples approximately every week during the bathing season and every fortnight outside of the bathing season across 9 bathing water locations along the coastline.

Samples are tested for two types of faecal indicator bacteria: Escherichia coli (also known as E. coli) and Intestinal Enterococci (I.E.). The Central Laboratory count the number of each these bacteria, which may indicate the presence of pollution e.g. found in sewage or animal waste.

The results of the analysis are assessed against the standards defined in the Bathing Water Quality Regulations 2008 and on a four-year data set using a statistical approach.

Why do we test for E.coli and I.E.?

All natural waters contain bacteria, usually as a result of contact with the soil. Most of these bacteria are quite harmless however, some types of bacteria which can be found in faeces, both animal and human, can cause illness. The two organisms, Escherichia coli (E. coli) and Intestinal Enterococci (I.E.), occur in very large numbers in the gut of warm-blooded animal and human faeces.

E. coli and I.E. are analysed in assessing bathing waters compliance because they are used as ‘indicator’ organisms where their presence in large numbers in bathing waters is a warning of a possible health risk from other harmful bacteria and viruses which might be present.

E. coli provide a good indicator of pollution in fresh waters while in seawater I.E. provide a better indicator of pollution as they survive for longer periods. E. coli and I.E. can survive for several days up to several weeks in waters.

How do you know when to do the bathing water testing?

When preparing the bathing water sampling calendar, effort is made to spread out the sampling days. However, due to tides and the requirement to sample during high tide, and factoring in the opening times of the central lab, there are only limited days when sampling can be completed and delivered on time to the lab.

Why is there no real-time bathing water quality results available?

Rapid tests and analysis for the determination of public health risk are currently being evaluated by 3rd Level institutions and industry specialists.

The existing methodology and testing requirements are set out in legislation and we are required to follow that standard.

We work to have results of analysis within the 48-hour window following sample collection.

What are the standards used in bathing water quality?

Our bathing water tests can tell us if there is a potential risk of illness if there are microbiological quanities above certain limits.

 The test results are explained by the standard terms: ‘excellent’, ‘good’, ‘sufficient’, or ‘poor’. 

In the case of 'excellent' water quality the risk of contracting gastro-intestinal illness is predicted to be circa 3%, in ‘good’ waters circa 5%, in ‘sufficient’ waters 8-9% and in ‘poor’ waters circa >10%.

Bathing water quality below the general background quality expected for that water is generally investigated.

What are the HSE Action Levels in Response to Microbiological Sample Results?

The thresholds of bathing water quality and the required responses can be found in this table.

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