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.
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 Beaches.ie 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.
The bathing season in Ireland runs from June 1st until September 15th of each year.
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.
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.
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.
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.
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.
The thresholds of bathing water quality and the required responses can be found in this table.
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.
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:
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.
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.
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.
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.
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 Beaches.ie 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.
The bathing season in Ireland runs from June 1st until September 15th of each year.
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.
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.
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.
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.
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.
The thresholds of bathing water quality and the required responses can be found in this table.
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.
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:
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.
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.
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.