Dog faeces the most ‘potent’ polluter of Dublin’s coastal bathing water

‘One dog foul can contaminate a water body the size of a tennis court,’ says expert

Dublin dog owners are set to face stricter controls on their use of beaches this summer due to overwhelming evidence connecting bathing water contamination to dog faeces.

Laboratory analysis of the bacteria found in seawater samples at Dublin beaches over the course of last year found dog faeces was "the most frequently detected and quantified faeces marker and at times reached very high levels", said Emma Finlay, senior executive engineer with Dublin City Council's environmental protection division.

“Dog faeces is a lot more potent than any other type and it can really have a big impact in a small area,” Ms Finlay wrote in a report to city councillors. “One dog foul can contaminate a water body the size of a tennis court.”

Tests had been carried out on water samples to detect genetic markers for human, bird and dog waste. Dog waste was not only the most prevalent but also the one for which there was a clear remedy, she said.


“While we knew the pressures of humans, dogs and gulls we didn’t know the true extent of each. Dog fouling has been highlighted as the major issue and has led the steer of our ship this bathing season to challenge that,” she said. “Unlike other bathing water challenges and pressures, dog fouling can be easily remediated by simply picking up after the dog.”

Smoking gun

The environmental protection section was, she said, “looking to increase dog warden patrols at the beaches”. Although this posed challenges as it required the “smoking gun” of catching the dog owner in the act of failing to pick up after their animal.

“The beach is a place where people let dogs off the lead and might not necessarily be aware their dog has gone to the bathroom,” she said.

The section was examining the council’s bylaws to see if there was a way of “improving dog restrictions on beaches”.

Improved signage and an educational campaign would also be implemented ahead of the bathing season, which begins on June 1st, she said. “It is a behavioural change we need to address with dog owners.”

An Taisce earlier this year warned local authorities they needed to keep dogs off “blue flag” beaches during the bathing season if they wanted to retain that EU designation.

The blue flag scheme applies to just 2 per cent of the coastline. The flag and associated restrictions may govern an entire beach, or just part of the beach, and may also apply to certain parts of the day only.

Olivia Kelly

Olivia Kelly

Olivia Kelly is Dublin Editor of The Irish Times