Bathing Water Quality Monitoring FAQs

Identified bathing waters are bathing waters (sea, river or lake surface waters) which Fingal 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. Fingal County Council also monitor a number of other waters which are not formally identified.  We refer to these as ‘other monitored waters’.

Each year Fingal County Council is required for the upcoming bathing season 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. At present, Fingal County Council have identified 10 bathing waters.  The public consultation period for the identification of new bathing waters is open to submissions from 17th May to 17th June annually.  Please find further information on current public consultation here;

The bathing season in Ireland runs from 1st June to 15th September. All identified bathing waters are monitored, assessed and managed under the requirements of the Bathing Water Quality Regulations 2008 as amended during this period. All bathing water monitoring results are available on the national Beaches EPA website (, posted in hardcopy at the beach noticeboard during the bathing season.  The EPA-approved results can be sent directly to your phone by registering for Fingal Alerts service on our website.

Bathing waters are sampled on a regular basis from the end of May (22nd- 31st) to 15th September to assess the microbiological quality of the water and to minimise any public health risk. The minimum number of samples required to be taken during the bathing season is 4. Fingal County Council take samples approximately every two weeks across 11 bathing water locations.

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 as amended 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, occur in very large numbers in the gut of warm-blooded animal and human faeces.

E. coli and Intestinal Enterococci 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 Intestinal Enterococci are a better indicator of pollution as they survive for longer periods. E. coli and Intestinal Enterococci can survive for several days up to several weeks in waters.

We work to have results of analysis within the 48hour window following sample collection. Rapid tests/analysis for the determination of public health risk are being evaluated by 3rd Level institutions as well as industry specialists however the methodology and testing requirements are set out in the current legislation and we are required to follow that standard.  Such real-time approaches to sampling and testing of bathing waters needs to be considered with reference to the standard methodologies in use in order to demonstrate equivalence.

If there are microbiological exceedances (not visible to human eye) arising from bathing water quality tests this will inform if there is a potential risk of illness based on that sample result.  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.

‘Poor’ results can indicate a new pollution event affecting a bathing water or a past pollution event having occurred in the mobile environment.  Investigations begin if there are high microbiological exceedances or reports of visible pollution e.g. pipe discharging to water with foul smelling or discoloured water or visible sewage related waste floating in the water (including sanitary type waste).  In addition, wastewater infrastructure is monitored by telemetry and failures (mechanical/electrical) would be shown up on alarms and are acted on to protect bather health e.g. temporary prohibition (Do not swim) notices erected.  The lifting of notices requires a sample to be taken to confirm that the pollution event has ended and water quality levels must meet at least ‘sufficient’ status results.   If a resample is ‘poor’ the notice will not be lifted and the prohibition (Do not swim) period will be extended until results show a return to normal background water quality.  A red flag will be raised by lifeguards on duty while a Prohibition (Do not swim) notice is on display.

Samples are taken in the bathing waters where there is the greatest risk of pollution or where there are the most bathers, usually where the lifeguards are stationed. Samples are taken in water about 1 metre deep (if safe to do so). The location of the sampling point is shown in the bathing water profiles produced for each beach and available at

There are five major sources of pollution responsible for the faecal bacteria in our bathing waters. These sources increase when it rains, washing more pollution into rivers, lakes and seas and in times of very heavy rain can overwhelm sewage systems. The impacts of these events are generally very short-lived lasting 1-2 days.

  • Pollution from waste water treatment plants & sewage systems – bacteria from sewage can enter our waters as a result of system failures or storm overflows or directly from sewage works.
  • Water draining from urban areas - water draining from urban areas via street drains and culverts following heavy rain can contain pollution including animal and bird faeces from roads and other paved surfaces.
  • Water draining from agricultural areas – water run-off from agricultural land/ditches which are connected to rivers/streams or road drains can export faecal waste from land where animals have been feeding or grazing. 
  • Domestic sewage – misconnected drains and poorly located and maintained septic tanks and wastewater treatment systems can pollute surface and ground water systems.
  • Animals and birds on or near beaches - dog, bird, and other animal faeces can affect bathing water as they often contain high levels of bacteria (much higher than treated human waste).