Dog faeces left on beaches and washed into the sea is the biggest contributor to Dublin bathing spots having poor water quality, a new report has said.
The report, prepared by a task force set up to improve bathing water quality in Dublin, said a bigger focus should be put on encouraging dog owners to pick up after their pets on the beach.
The group was set up in response to deteriorating bathing water quality at Merrion Strand, south Dublin, which was judged as poor in 2018 and later lost its status as a designated bathing area.
Recent years
Water quality at Sandymount Strand improved from poor in 2018 to “sufficient” in recent years, according to the Environmental Protection Agency (EPA).
Meanwhile, Dollymount Strand, north Dublin, was judged as having good water quality, with Killiney and the Forty Foot in south Co Dublin deemed to have excellent quality bathing water.
The report said water samples had shown bathing water at Merrion Strand had “not deteriorated further”, with early signs of some “incremental” improvement.
One “significant learning” was the impact dog faeces had on bathing water quality, it said.
A detailed microbial analysis of water samples found in around half of cases where bathing water was deemed to be poor, dog faeces was a contributing factor.
Capacity issues in the sewage infrastructure was another factor, with human faecal matter contributing to a quarter of poor water quality findings. Gull faeces was a factor in a fifth of cases, the report added.
Drainage infrastructure
The report said faecal matter from dogs and birds on beaches could “significantly impact on water quality”, as well as “temporary overflows from urban drainage infrastructure”.
The group recommended that people should not swim in bathing spots for at least two days after significant rainfall, due to the risk of diluted sewage overflowing into the sea.
The task force included representatives from Dublin City Council (DCC), Dún Laoghaire Rathdown County Council, Fingal County Council, Uisce Éireann and academics from University College Dublin (UCD).
The report said in response to its findings local councils had been targeting dog owners and encouraging them to pick up after their pets on the beach.
It noted that UCD research last year examined the impact of dog fouling on bathing water quality, which found one dog poo had the potential “to pollute a volume of water the size of a tennis court”.
Preventing contamination
The report said “while dog fouling is not the only pressure on bathing water quality, it is a significant contributor. Unlike other sources of pollution, dog foul can be easily removed by the pet owner to prevent contamination of a nearby waterbody.”
Roy O’Connor, a senior engineer at DCC who chairs the task force, said the group had expected dog faeces washed into the sea to be “a bit” of a problem. The group were surprised to learn it was “the leading cause” of poor water quality, ahead of diluted sewage overflowing into waters, he said.
Mr O’Connor said while councils could look at dog wardens issuing more fines to dog owners who failed to clean up after their pets, the group was “leaning towards” focusing on education over enforcement.
