Cork southside area had over eight times permitted levels of manganese in water

Seven months after the HSE castigated Uisce Éireann for not informing the public of high levels of manganese in drinking water in Cork city, one southside area had more than eight times the maximum allowed in EU law.

Across the city, in one northside area, two-thirds of the tests carried out on drinking water this year showed manganese levels exceeding EU maximums.

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

The EU Drinking Water (2023) Regulations allow a maximum of 50 microgrammes per litre (µg/L).

During the week beginning September 22, manganese levels of 428µg/L were recorded at Friars Walk, more than eight times the EU maximum, according to data released under a Freedom of Information request from Thomas Gould, Sinn Féin TD for Cork North Central.

In the first nine months of this year, two-thirds of all tests carried out in the Ballyhooley Rd 'B' area showed manganese levels above EU maximums.

Half of those carried out in the Ballyhooley Rd ‘A’ area also failed to comply with regulations. In February, the HSE expressed alarm at high levels of manganese in drinking water on the northside and in parts of the southside, saying that if such exposure was ongoing, its immediate recommendation would be a ‘Do Not Consume’ notice.

Above the levels of 50µg/L, water can appear discoloured, giving a metallic taste and staining laundry, but the HSE cautioned Uisce Éireann on its claims that clear water was safe to consume from a manganese perspective.

Uisce Éireann “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.

On March 3, manganese levels of 193µg/L were recorded at Richmond Tce, off Gardiner’s Hill, almost four times the EU maximum, and when The Echo published those figures in September, Taoiseach Micheál Martin described the situation as “very serious”.

“It’s quite shocking that the levels would be that high, and if known about, the public should be made aware of it, of course,” he said.

A week after Mr Martin’s comments, on Friday, September 26, Brian McCarthy, Uisce Éireann’s regional operations manager, told this newspaper the reason the public was not made aware was because other, contemporaneous, samples might have been lower.

“On any given week, we sample 25 locations around the city, and on the week of the 193(µg/L), there might have been 23, 24 samples taken, all of which are compliant, so where do you stop?” Mr McCarthy asked. 

“What about the other 24 samples that were fully compliant? Are you going to tell all those people that their water is unsafe?”

He said that “up to 94, 95%” of samples were in compliance on manganese limits.

According to data subsequently released to Mr Gould, 82% of tests carried out across the city that week by Uisce Éireann were compliant.

That week, manganese levels of 100µg/L were recorded at Capwell, twice the EU limit; 108µg/L at Deerpark; 271µg/L on College Rd, more than five times the EU limit; and 428µg/L at Friars Walk, more than eight times the EU limit.

Mr Gould said that the high levels of manganese in Cork city drinking water had not gone away. “This is a public health crisis and it is clear that Uisce Éireann do not have a handle on it,” the northside TD said.

“Uisce Éireann have tried to dismiss this as water discolouration and a nuisance for people — there are multiple occurrences in areas like Blarney St and the Boreenmana Rd, where manganese levels were above the limit, but the water was not discoloured. 

"This is not about the water looking dirty, this is about the danger posed to newborn babies, pregnant women, and vulnerable people,” Mr Gould said.

A spokesperson for Uisce Éireann said: “In 2025, the vast majority of samples taken across the network are compliant: 94% for manganese, 96% for iron, and 94% for colour. Following all exceedances at customer properties, including those in September referred to in your query, an investigation is carried out, reactive flushing is typically undertaken, and follow-up sampling arranged. For the locations referenced, multiple compliant sample results have been returned since the reactive flushing work was carried out.”