Investigation ongoing as turbidity issues hit North Cork village's water supply 

Turbidity, or cloudiness of water, is caused by the presence of suspended solids and inspection found turbidity levels had risen rapidly at a treatment plant borehole — one of two sources of drinking water for the village of Killavullan

An EPA report noted there had been another spike in turbidity at the plant on May 7, when it was over nine times the recommended level.

An audit of the drinking water supply for a North Cork village which has experienced two extended boil water notices this year said an investigation into the cause of the problem is ongoing.

The public water supply for Killavullen, Co Cork, which serves a population of over 830, still has a boil water notice in place which was introduced on May 2 due to turbidity issues.

An earlier boil water notice was also instigated on February 28 and remained in place for three and a half weeks due to a similar problem.

Turbidity, or cloudiness of water, is caused by the presence of suspended solids and it is recommended that turbidity levels should not be above 1.0 NTU — a measure of the opaqueness of the water.

Following an inspection of the plant last month, the Environmental Protection Agency (EPA) has called on Irish Water to complete its investigations into the cause of the high turbidity in the Killavullen supply and undertake any necessary remedial actions.

The audit said turbidity levels had risen rapidly at the treatment plant borehole — one of two sources of drinking water for the village — on both occasions, which meant disinfection would be compromised.

Irish Water said the exact geological reasons for the spikes in turbidity were not known but were not linked directly to heavy rainfall.

The audit found the abstraction source of the supply was not adequately protected against contamination.

Faecal coliform bacteria found 

It observed that faecal coliform bacteria had been found on six occasions in the raw water at the treatment plant since last November.

The EPA said it indicated there is a source and pathway for contamination into the borehole at the water treatment plant, which is located in a housing estate with adjoining agricultural land.

Irish Water said it had written to local landowners in May to remind them of the requirements under law to observe good agricultural practice for the protection of waters.

The EPA said the time delay fixed at 20 minutes for a shutdown of the plant when triggered by an alarm was “considered to be too long to prevent inadequately treated water entering the network”. 

It also called for increased monitoring of the Killavullen supply for cryptosporidium — a parasite that can cause a variety of illnesses in people who consume infected water.

Officials from Irish Water and Cork County Council told the EPA that the pumping rate at the plant needs to be as steady as possible as they believed some spiking was caused by the turning on and off of pumps.

The report noted there had been another spike in turbidity at the plant on May 7, when it was over nine times the recommended level.

Irish Water said a number of possible corrective actions to address the turbidity issues with the Killavullen supply were being examined.

The company said the boil water notice remained in place as public health remained its number one priority.

Irish Water said the measure had been introduced to protect its customers and it thanked the public for their patience.