Deficiencies in a large public water scheme in Cavan last year were not notified to the authorities which would have allowed them to assess the risk to public health, according to an environmental watchdog.
An audit by the Environmental Protection Agency on December 12 found “serious deficiencies regarding management and control” of the regional water supply scheme in Bailieborough, Co Cavan, including a lack of automatic plant shutdowns and callout alarms for turbidity in the water.
The audit team found the water was brown in colour while there was a lack of automated chemical dosing to respond to changes in raw water quality and deficiencies in the filter backwash process.
The scheme provides supplies of drinking water, sourced from Skeagh Lough, to almost 7,800 customers in Co Cavan including in Bailieborough, Mullagh, Virginia, and Killinkere.
As a result of the audit, the HSE issued a ‘Do Not Consume’ notice for drinking water from the Bailieborough on December 13 with Irish Water distributing water to consumers via tankers.
It was lifted 10 days later after the authorities were satisfied that water quality had been restored and adequate treatment plant systems and controls were in place.
The EPA said an upgrade to the plant was due to be completed by the end of March 2019 but the works had not progressed and no date for when they would take place could be provided.
The watchdog said it had not been notified of excessive levels of manganese in the water sourced for the scheme between October 9 and December 1 last year.
Although not toxic, high levels of the mineral in drinking water can result in bad tasting water and staining.
The maximum level of manganese recorded in the Bailieborough supply was approximately seven times the recommended limit.
“Cavan County Council did not report the plant deficiencies and water quality failures to Irish Water and the HSE when these occurred,” the EPA said.
It added: “This action prevented the HSE in determining the potential risk to human health posed to those consumers on the water supply in a timely manner.”
The EPA said the presence of manganese in drinking water supplies had implications for other metals of concern such as the release of lead, arsenic, nickel, chromium and iron.
The EPA said Irish Water had stated in writing in September 2018 that plant upgrade works at Bailieborough were at an advanced stage and due for completion by the first quarter of 2019.
“The auditors found that these proposed works had not commenced on site,” the EPA noted.
Irish Water said it had complied with a direction issued by the EPA under EU regulations to install an alarm for turbidity and chlorine in the supply which had been completed by January.