EPA investigating sewage discharge into Dublin Bay

Irish Water confirmed discharge followed a storage tank failure and apologised

An aerial photograph taken using a drone shows the large discharge. Photograph: Eoin O’Shaughnessy

An aerial photograph taken using a drone shows the large discharge. Photograph: Eoin O’Shaughnessy


The Environmental Protection Agency is investigating the circumstances of a discharge of sewage effluent into Dublin Bay from the country’s largest waste water treatment plant located in Ringsend.

EPA inspectors took water samples from the mouth of the river Liffey on Tuesday following the release of effluent on Saturday morning from a nearby outfall in Poolbeg following a storage tank failure.

It was informed on Monday by Irish Water about the release of waste water sludge from the plant into the Lower Liffey Estuary, a spokeswoman confirmed. The incident happened at 9am but an aerial photograph taken some eight hours later confirmed effluent was continuing to seep out into the bay.

“The EPA is investigating this incident and inspectors are carrying out a site inspection to determine the cause of the incident and to monitor the discharge. Our priority is to ensure that Irish Water completes the corrective actions needed to bring the discharge under control and to protect the Lower Liffey Estuary,” she added.

Details of the sewage discharge were reported in Tuesday’s Irish Times.

The Green Party criticised the discharge – the second major pollution incident in the vicinity within the past two years – as “totally unacceptable”, while swimmers who swam in the area over the weekend claimed they should have been warned promptly after it occurred.

“We want Irish Water to come clean on what is happening in the Poolbeg Waste water treatment plant. Two days after a major pollution incident, the company seems to have no clear detail on the failure of their plant,” said Green Party Cllr Claire Byrne. “The company is constantly reassuring local representatives that the plant is working well when the reality is clearly different.”

Party leader Eamon Ryan said the discharge happened in the same area where another major pollution incident took place in October 2017. “That occurred during Storm Brian but last weekend the weather conditions were relatively benign.”


He added: “The unexplained failure led to a massive volume of raw sewage being released into the bay. That bay has been recognised by UNESCO as an internationally important biosphere but we are not providing the protection it deserves. Seeing the lower reaches of the Liffey full of our own excrement is a sickening disgrace.’’

On the swimming issue, Clontarf resident Donna Cooney said: “Even in early Spring there are a lot of people swimming in the bay but there seems to have been no public warning from Irish Water as to what had happened and no advice to stay out of the sea. The company needs to also explain why this communications failure has taken place.”

Irish Water has to notify various authorities, including Dublin City Council, when there is an incident at the facility and have to issue a public warning when there is a proven risk to public bathing. It is understood the company believes it was not necessary in this case because it is not an official public bathing area.

In a statement on Tuesday, Irish Water said “the discharge occurred for approximately 20 minutes and it is estimated that 100 cubic metres of activated sludge was discharged”.

It added: “It should be noted that this discharge was not raw sewage and does not pose the same risk to public health or the environment as a raw sewage discharge would. The tank was isolated and repairs are now progressing. Irish Water would like to apologise for the discharge which we acknowledge was unsightly and which is not to the standards we set ourselves.”

Irish Water has standard protocols in place when incidents of this nature occur and incidents are escalated on the basis of the potential impact to human health and the environment. “Statutory stakeholders are notified in line with protocols and we can confirm that the EPA carried out an audit of the site today,” it said.

Due to ongoing overloading of the wastewater treatment plant, “the discharge from the treatment plant does not comply with the Urban Wastewater Treatment requirements as the treated effluent discharging from the plant has higher amount of solids than is optimal and this could give rise to a coloured plume in the water”, it said.

The plant is in continuous breach of waste water regulations because it has been operating at 20 per cent over capacity in recent years. It is due to be upgraded at a cost of €400 million to cater for a population of 1.9 million people based in the greater Dublin region.