Discolouration is due to the presence of Manganese

Irish Water, working in partnership with Kilkenny County Council, is actively working to address issues with discolouration of the water supply in the Clogh/Castlecomer area due to the presence of the mineral, Manganese.

The presence of this naturally-occurring mineral in the raw water, while posing no health risk, causes discolouration of the water. This has been a problem in Clogh/Castlecomer for many decades due to the geological and hydrological conditions in the area but the issue has been particularly pronounced in recent weeks due to depleted levels of water in the reservoirs as a result of the warm, dry weather. This has caused manganese deposits to become more concentrated in parts of the network.

Improvement works proposed to tackle the issue in the short to medium term

Irish Water and Kilkenny County Council recognise that this issue is causing severe inconvenience for customers in the area and we are proposing improvement works aimed at tackling the issue in the short to medium term. Works will be challenging as manganese is a particularly difficult parameter to remove from the raw water but Irish Water will make every reasonable effort to reduce levels in the drinking water supply. These works will involve refurbishing key elements of the Clogh Water Treatment Plant; implementing a reservoir cleaning programme in the area; and carrying out ice-pigging to remove manganese deposits that have built up over many years in the pipe.

Assessment and testing is currently underway

Assessment and testing of the Clogh Water Treatment plant infrastructure is currently underway and based on this it is proposed to carry out an interim refurbishment of the existing chemical dosing and filtration systems in the coming months with the aim of reducing manganese in the treated water. 

Reservoir assessment is currently ongoing

A reservoir assessment and cleaning programme is currently ongoing and includes a number of reservoirs in the Kilkenny area. The four reservoirs supplying the Clogh/Castlecomer area (Kiltown, Aughamucky, Moyhora and Gorteen) are included in the scope of this programme and will be prioritised for cleaning in July and August 2018.

It is confirmed that the full extents of the network are to be cleaned using a technique called ‘ice-pigging’. Ice-Pigging is a pipeline cleaning process in which an ice slurry solution is pumped into a pipeline under pressure to remove built-up sediment and deposits and is a very effective solution for the removal Manganese deposits. It is proposed that Ice-Pigging will be carried on the network following the treatment plant refurbishment works and reservoir cleaning works in August. 

Longer term solution

We are continuing to examine solutions to address this problem in the longer term, including the option of identifying a new source of raw water. However this is a long-term investment requiring significant forward planning, design and lead-in time. It is hoped that the actions outlined above will help address the discolouration issue in the interim.

James O’Toole, operations lead for Kilkenny, commented “We are fully aware of the inconvenience and concern this issue is causing for the people of Clogh/Castlecomer and are committed to resolving it. This is a legacy issue associated with the aging water supply infrastructure and the natural conditions of the area. We have now committed significant investment to improving water quality in the area and while we acknowledge that the naturally occurring manganese is very difficult to remove from the raw water we would like to reassure customers that we will take all reasonable steps to work through the constraints facing us to minimise the manganese in the drinking water supply.

We would like to thank our customers and elected representatives in Clogh and Castlecomer for their patience, engagement and support while we carry out this essential work. We would also like to remind them of the importance of conserving water where possible, particularly during the present dry spell. This will help us maintain adequate levels of water in the network while this remedial work is being carried out.”

Irish Water and Kilkenny County Council will continue to monitor the water supply and consider any additional actions required to address issues as they arise.

For updates on your supply, visit our Water Supply Updates section.


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