PADDY THOMPSON EXITS the changing area of the Half Moon Swimming Club on the Great South Wall, drops his towel at the granite bathing area and dives into the waters below. 

Up ahead, in the distance, sits the Ringsend Wastewater Treatment Plant. Three times last month untreated wastewater was discharged from the plant into Dublin Bay, forcing beaches to close and politicians to demand answers. 

“Beautiful,” says Thompson, coming for air as the sun beats down on the blue and white foam, tinged today with green and brown. 

Sewage seeping into Dublin Bay won’t deter 83-year-old Thompson from taking his daily swim at the Half Moon, first founded in 1898. He has cycled down here six days a week for the past 18 years.

For others, recent spillages from the plant have led to closed off bathing areas and  cancelled swimming races. And until the plant is upgraded, the Environmental Protection Agency (EPA) has said more discharges are inevitable. 

For Thompson, though, “everybody’s gone hygienic mad.”

‘See the algae’

The Ringsend plant treats approximately 40% of the country’s sewage.

Irish Water is currently investing hundreds of millions of Euro as part of a staged upgrade of the facility to allow the wastewater of an additional 400,000 people to be treated.

Further improvements to bring the treatment capacity up to serve 2.4 million people are expected to be completed by 2023.

In February, 100 cubic metres of sludge entered the River Liffey’s estuary near Dublin Bay after 300 tonnes of waste entered the plant and a tank at the plant failed. 

In early June, eight Dublin bathing spots were closed after a storm water overflow at the plant. 

And twice in the last fortnight more bathing restrictions were imposed after further discharges into Dublin Bay. 

Unlocking the blue door of the Half Moon club house, Thompson explains that people swimming near the Poolbeg Lighthouse at the end of the Great South Wall are often put off by the algae floating in the water. 

“A lot of people see the algae and think it’s something else,” Thompson says, pointing to a photograph of a swimming team hanging on the clubhouse’s whitewashed wall. 

The algae isn’t raw sewage – instead it is down to the build up of a micro-alga called noctiluca scintillans and it’s been described as “non-toxic”. 

Last week, at the 40 Foot in Sandycove, locals were put off by a brown substance in the water which later turned out to be an algal bloom.

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“There’s the upgrade there,” says Thompson, pointing to a construction site near the Ringsend plant.

‘Continue To Breach’

Outside, dressed in his trunks, Thompson walks to the wall’s edge, dives headfirst into the sea and spends ten minutes in the water. 

Locals around Ringsend have been inconvenienced by the persistent discharges into the bay, according to Thompson. ”We don’t like it but they’re okay,” he says. 

The water is relatively clean for swimming at Ringsend this morning. 

The EPA conducted an inspection at the facility earlier this week after it received a report that a brown plume discharged into Dublin Bay from the plant.

The agency has said that these plumes of sewage will continue to be visible in water near the plant until upgrade works are finished.

“Waste water discharged from the plant is breaching, and will continue to breach, the quality standards until the upgrade works are complete,” it said.

Video by Andy Roberts