Chief medical officer alerted to Cork City drinking water crisis

The utility company confirmed on Friday that it will pay out another €1.6m on top of the €40m it already spent on the Lee Road water treatment plant in a bid to tackle discoloured drinking water.

The new spend will be on a water-conditioning process, but Uisce Éireann has said it will not be in place until the middle of the year, and has admitted it will take some time before it can even say if it has worked.

The drinking water crisis has now been referred to the chief medical officer, Professor Mary Horgan, who has passed it on to the HSE, after campaigners told her their water “looks like Tanora”.

Sinn Féin TD for Cork North Central, Thomas Gould, said people’s health is at risk because of the issue.

“People are drinking dirty, contaminated water unknowingly. Sometimes the water looks like sludge or Tanora but sometimes it is only a slight discolouration and people don’t notice it,” he said.

The Department of Health said the HSE will respond on the public health advice.

Uisce Éireann insisted on Friday that the water being produced at the plant is fully compliant with drinking water standards and is safe to drink once it runs clear.

The plant, which opened in summer 2022, produces about 30m litres of water a day for thousands of homes and businesses across the northside, in parts of the city centre, and in pockets of the southside.

But Uisce Eireann, which was getting an average of seven discolouration complaints a day before the plant was built, has been plagued by discolouration complaints since it opened.

There was a spike of complaints between August and September 2022, with more than 40 complaints on some days, between November 2022 and February 2023, between September and October 2023, and again between August 28, 2024, and September 3, 2024, when complaints peaked at around 80 a day on one day during that period.

The complaints have been trending downwards in recent months but are still well above the level they were at before the new plant was built.

Intermittent discolouration is an issue on every water network with cast-iron pipes when sediment built up inside the pipes is dislodged.

But Uisce Éireann has blamed the discolouration in Cork city on a combination of factors, including major rehabilitation works on the network, changes to the chemical treatment process at the new plant, and a higher velocity of water being pumped through the ageing network of cast-iron pipes.

It has tweaked the chemical treatment process and the pumping operation, and has established a taskforce to tackle the problem, with targeted pipe flushing ongoing, but the problem persists.

A manganese reduction step has been installed at the plant following the detection last year of elevated levels of manganese in the source water coming from the River Lee but another new process is being installed over the coming months to increase the alkalinity of the treated water.

Engineers hope this will deposit a thin lining on the inside of the pipes, minimising the risk of sediment being dislodged.

Uisce Éireann defended its decision not to issue a ‘do not consume’ advisory in the affected areas and insisted the water coming from the plant is safe to drink “when running clear”.

More than €100m has been invested in water infrastructure in Cork City in recent years, including the €40m Lee Road plant.

But Uisce Éireann it could take at least €500m and 50-years to replace the city's cast-iron pipes.