HSE slams Uisce Éireann's response to water issues in Cork city 

The HSE has castigated Uisce Éireann for not informing consumers that drinking water in Cork city contained high levels of manganese, on one occasion almost four times the maximum allowed under EU legislation.

Correspondence released to Thomas Gould, Sinn Féin TD for Cork North Central, shows the HSE expressed serious concern at high levels of exposure to manganese in drinking water on the northside and parts of the southside, and emphasised that if such exposure was ongoing, its immediate recommendation was a ‘Do Not Consume notice’ for the affected area.

Manganese is a naturally occurring mineral which is essential in small doses, but which can be extremely harmful at high levels, possibly affecting brain development in infants and children, and it can also cause symptoms similar to Parkinson’s disease in adults.

The EU Drinking Water (2023) Regulations allow a maximum of 50 microgrammes per litre (µg/L), but on March 3, manganese levels of 193µg/L were recorded in a sample taken at Richmond Terrace, off Gardiner’s Hill, from a water supply potentially affecting 86,738 people.

Water quality has been a major issue in Cork city since the summer of 2022, when Irish Water opened its €40m Lee Rd water treatment plant.

In late 2022, Irish Water (now Uisce Éireann) told The Echo that an adjustment of chemicals used in water preparation at the Lee Rd plant had caused rusty sediment to be stripped from the inside of the city’s ageing cast-iron water mains, resulting in discoloured water in homes across Cork city.

The correspondence released to Mr Gould under freedom of information legislation shows that the HSE expressed serious concern at the lack of communication to the public regarding manganese exceedances from Uisce Éireann.

LETTER

A letter from the HSE to Brian McCarthy, Uisce Éireann’s regional operations manager, dated February 14, said that in a meeting the previous day, the water utility had clarified that it had not relayed to the public the HSE’s health advice on manganese.

“The HSE had understood otherwise prior to yesterday’s meeting … that consumers had got this advice,” the letter said.

 “The HSE emphasises that consumers on affected parts of the supply — when manganese levels exceeding the regulatory limit have been reported by UÉ [Uisce Éireann] to the HSE — need to be given this advice by UÉ,” the letter stated.

While EU legislation allows a maximum manganese level of 50µg/L, the World Health Organization suggests a maximum of 80µg/L. The HSE said it had repeatedly sought reassurance from Uisce Éireann that consumers in affected areas were not being exposed to drinking water with manganese levels above 80µg/L on a continuing basis.

“[We] are unsure if we can be reassured by UÉ that consumers in affected areas are not being exposed to drinking water with manganese levels above 80µg/l on an ongoing basis,” the HSE stated.

Above the levels of 50µg/L, water can appear discoloured and blackish, giving a metallic taste to the water and staining laundry, but the HSE sounded a note of caution on Uisce Éireann’s advice that consumers should not drink discoloured water and its claims that clear water was safe to consume from a manganese perspective.

“However, UÉ must understand that the HSE’s health advice is not based on the subjectivity of whether water is discoloured or not, but on evidence-based manganese concentration levels in drinking water in relation to health,” the HSE said.

“The HSE emphasises that, if consumers in affected areas are being exposed to drinking water with manganese levels above 80µg/l on an ongoing basis, then our immediate recommendation would be a ‘Do Not Consume’ notice.”

Mr Gould said he was “disgusted” by what he had read in the documents released to him.

“For over three years, I, along with our community, have been raising serious concerns at the quality of water on the northside,” he said.

“I am now calling for an independent review into Uisce Éireann’s handling of this situation. This must be escalated to the highest level — the EU drinking water regulations have been breached, and this should now be referred for independent investigation to the EU Commission,” Mr Gould said.

“I believe that trust in Uisce Éireann is now at an all-time low, and will be fully eroded with these revelations.

“They must provide an alternative drinking supply now. Manganese cannot be boiled out of water, and for many people, the cost-of-living crisis means they cannot afford to buy bottled water or they are having to sacrifice other necessities to supply their home with clean, dependable water.”

A spokesperson for Uisce Éireann said it wanted to reassure the public that it was taking comprehensive action to address the issue.

“We’ve had a dedicated task force of experts in place for the past 19 months — working on targeted solutions and long-term improvements,” the utility stated.

Among those measures, it listed an extensive sampling and testing programme; continued rehabilitation of the city’s water mains; and investment in advanced treatment processes at the Lee Rd water treatment plant to reduce instances of manganese and iron in the network.

“Early indications point to these steps as having a positive impact at both the plant and on the network, resulting in a significant decrease of 42% on reports of discolouration year to date, when compared to the same period in 2024,” the spokesperson stated.

“In 2025, the vast majority of samples taken across the network are compliant: with 94% of the test results compliant for manganese, 96% compliant for iron, and 94% compliant for colour.

“Where exceedances have occurred, they have been addressed through remedial measures, including targeted flushing and follow-up sampling, until a compliant result is achieved.”

The spokesperson said Uisce Éireann continues to advise customers not to drink discoloured water.