Front Strand Balbriggan Do Not Swim Notice Lifted September 15th, bathing season results listed

The Prohibition Do Not Swim Notice that had been in place at Front Strand Balbriggan was removed and replaced with the All Season Advisory on September 15th. This followed results from samples collected on Tuesday the 13th of September which met the result for “excellent” water quality.

The following table gives full details of results of sampling from the beginning of the bathing season and is followed by some background information to give context to the decision making regarding the Prohibition Notice in place from July 26th to September 15th.

Do Not Swim Prohibition Notice July 26th and the investigation which followed

On 26th July Fingal received the first ‘poor’ bathing water sample of the 2022 season. Following consultation with the HSE a prohibition ‘do not swim’ notice was erected, replacing the All-Season Advisory Notice. An investigation was started aided by information from an increase to the river monitoring programme on the lower section of the River Bracken and accompanied by additional investigative bathing water sampling to determine the cause of the elevated results.   No issues were reported by Irish Water or evident during initial visual inspections from the riverbank.  An in-channel river walk found a visible source of pollution on 3rd August.  A surface water pipe with foul effluent discharging into the river within the town was then inspected by Environment/Drainage teams.

Following these detailed investigations involving dye testing and tracing of the surface water line the pipe was traced back to a source. This involved investigating a complicated pipe network connecting several buildings which had to be investigated and eliminated as potential sources. On the 23rd of August the misconnected pipe was rectified. 

Bathing water results from 25th August met the standard for ‘good’ water quality (as shown in table above) however following consultation with the HSE the prohibition ‘do not swim’ notice remained in place.  On 25th August a cleaning of that surface water pipe was completed (jetted).  Results returned to “excellent” from 31st August.  Irish Water are conducting a CCTV survey of the integrity of the foul sewer line (started during this incident) and while a small leak was found and repaired (2nd September) no other issues have been reported to date.

Yellow rainfall warnings raised by Met Éireann  September 3rd and 11th 

Results of testing on August 31st and September 2nd met the quality of Excellent but Yellow weather rain warnings were issued by Met Éireann for the following periods;

Expected Onset: Saturday 3/9/2022 21:00 Expires: Sunday 4/9/2022 12:00

and

Expected Onset: Sunday 11/9/2022 09:13 Expires: Monday 12/9/2022 03:00

Such periods of intense heavy rainfall (Thunderstorms) can affect water quality for 48 hours following such events and the prolonged heatwave prior to the first rainfall event meant ground conditions were very dry and run-off effects extensive from the land to the water.  Therefore following a precautionary approach to a decision on whether to lift the notice and discussion with the HSE on 2nd September, the notice was extended rather than lifted.  A return to the normal background levels followed these rainfall events (sample taken 13th September) and the notice was agreed to be lifted following discussions with the HSE on receipt of those results (15/9/22).