Council officials claim the failure of owners to clean up after their dogs at popular seafront locations meant dog fouling events were “a significant pressure and root cause of many bathing water failures and prohibitions” during the 2021 bathing season.
“Dog fouling is unlike other water quality pressures. It is easily remediated and wholly preventable,” the council said.
A new report shows all four notices issued by the local authority last year which temporarily banned swimming at Sandymount Strand and one of two notices related to Dollymount Strand were linked to dog fouling events.
Dublin City Council monitors water quality at six locations in Dublin Bay – Dollymount Strand, Sandymount Strand, the North Bull Wall, Half Moon, Shelly Banks and Merrion Strand.
The report shows “poor” water quality was recorded in five out of 20 samples taken at Sandymount Strand last year during the bathing season which runs between June 1 and September 15.
The “poor” classification means the samples exceeded the recommended limits of Ecoli and intestinal enterococci which are indicators of faecal material in the water.
Two samples at Merrion Strand and two at North Bull Wall also failed to meet the required standards as well as one at Dollymount Strand.
However, five out of every six samples were classified as “excellent”.
Overall, the classification of the two EU designated bathing areas under the council’s control – Dollymount Strand and Sandymount Strand – are “good” and “sufficient” respectively.
The council said it has carried out novel testing methods in collaboration with UCD’s School of Biomolecular and Biomedical Science in the past two years as part of its investigative monitoring programme to differentiate between faecal contamination of human and animal origin such as dogs and birds.
It said such information had been particularly useful in identifying possible sources of pollution that were not attributable to the drainage infrastructure system which can cause problems following periods of heavy rainfall.
Council officials said UCD researchers using PCR testing were able to use gut bacteria distinctive to each species to identify and quantify the source of faecal contamination.
“A review of 2021 PCR analysis carried out by University College Dublin indicated that dog faeces market was the most frequently detected and quantified faeces market and at times reached very high levels,” the council stated.
While dog fouling was known to be a pressure on water quality, the council said the latest tests showed the true extent of its proliferation and damage.
Results showed faecal matter from dogs was 10 times the level from humans in water samples taken from Sandymount Strand on September 15 last year.
Almost 200,000 gene copies of dog faeces per 100ml of water were detected compared to less than 20,000 gene copies of human matter.
While overall levels were much lower in other tests, dog fouling remained the predominant type of faecal matter in most other samples.
The council said it would encourage all dog walkers to pick up after their pet, especially on beaches.
“We need wardens to be on the spot to tackle problems where they arise and it is a role that could easily pay for itself"
Separate figures show only two fines have been issued by council dog wardens for dog fouling across the city in the past three years, with none issued last year.
The council also said it was unable to designate the North Bull Wall as an EU identified bathing area due to consistent issues of poor water quality at the location.
Labour councillor, Dermot Lacey, said confirmation of dog fouling being the main source of pollution on Sandymount Strand would come as no surprise to people living in the area as it was an issue that gets raised regularly by constituents.
Mr Lacey believed there was a need for a new type of community warden with responsibility for traffic, litter and dogs around the city to help tackle issues like dog fouling.
“We need wardens to be on the spot to tackle problems where they arise and it is a role that could easily pay for itself,” said Mr Lacey.