EPA says water supplies overdosed with disinfectant in Kerry water treatment plant

The EPA says water supplies were overdosed with disinfectant in a West Kerry water treatment plant.

An audit has found Kerry County Council failed to manage an incident in order to maintain water quality and protect public health in the Dingle Water Treatment Plant in January of this year.

The EPA has since made a number of recommendations.

The Environmental Protection Agency undertook an announced site visit on the 24th January of this year to the Dingle Water Treatment Plant.

The plant produces over 1.8 million litres per day and serves a population of 1,700 people.

On the morning of January 12th, plant staff manually dosed sodium hypochlorite directly into one of the reservoirs – this was done to increase chlorine levels.

However, an error lead to overdosing of the disinfectant, which in turn increased levels of residual chlorine in the supply.

Twelve complaints related to taste and odour issues were received by Irish Water and Kerry County Council the following morning and the local authority took immediate corrective actions.

It scoured the network, emptied the town reservoir and flushed the mains.

Kerry County Council estimated that the error resulted in a level of 20-25 milligrams per litre of residual chlorine in the water in the reservoir versus the normal chlorine dosing target rate of less than 1 milligram per litre.

No water restriction was issued following consultation with the HSE.

In its audit, the EPA found the council failed to notify Irish Water promptly following the incident as required.

This meant Irish Water was not included in the risk assessment of water quality prior to consultation with the HSE.

The EPA made a number of recommendations, including Irish Water and Kerry County Council develop procedures for responding to all alarms generated at the water treatment plant.