Data reveals high manganese levels in Cork drinking water supplies

Freedom of Information (FOI) documentation from Uisce Éireann shows that high levels of manganese in drinking water continue to be detected in parts of Cork city, with a recent test in May showing levels nearly four times higher than they should be.

In Ireland, the regulatory level for manganese in drinking water is 50 micrograms per litre, but the HSE advises that there is currently no scientific evidence suggesting any adverse health effects at levels of up to 80.

Documentation from Uisce Éireann provided to Sinn Féin TD for Cork North Central Thomas Gould shows that levels of 193 and 51 were detected in Richmond Terrace, Gardiners Hill, on March 3 and January 13 this year.

Additionally, levels of 121 and 54 were detected in Blarney St on January 15 and 8, while Uisce Éireann also reported levels of 51 in Brian Dillon Park on January 13 and 124 in Thomas Davis Bridge on January 27.

Stark

Mr Gould described the information provided in the FOI by Uisce Éireann as “stark”.

“When tests show dangerous levels of manganese, Uisce Éireann only inform the householder themselves. What about other residents served by the same water line? Every single resident there should be informed,” he said.

The records sent by Uisce Éireann include correspondence sent to residents of homes where high levels of manganese were detected, including a letter dated February 21 telling one customer that on January 8 and January 15 tests showed exceedances of manganese.

Mr Gould said: “One of these tests was 51% higher than the level of manganese the WHO considers a risk to public health. That is a scandal. It took them more than a month to warn this person.”

For one of the six exceedances, the Uisce Éireann reports show that the water was not discoloured.

Discoloration

“Uisce Éireann have repeatedly told us that exceedances of manganese would show up as discolouration in the water,” Mr Gould said.

“However, on January 13 in Dillon’s Cross, an exceedance of manganese did not as discolouration. This means that not only were people at risk but they didn’t even know they were at risk. They have been told to drink the water when it is clear, but there is now evidence that even this may not be safe.”

An Uisce Éireann spokesperson told The Echo that public health “remains our top priority, and the treatment process used by Uisce Éireann at the Lee Road Water Treatment Plant is fully in line with water treatment standards used nationally and globally”.

“Both the HSE and EPA are regularly updated regarding the water quality issues affecting customers in Cork city. Each non-compliance is risk assessed.

“Taking this risk assessment into it is agreed in consultation with the HSE whether consumers are required to be issued with additional specific health advice," the spokesperson added.