Irish Water is reminding farmers and other users to use best practice when spraying pesticides,particularly if using products for grassland weed control containing substances such as MCPA, fluroxypyr and 2,4-D.

The water company has issued the reminder in the face of ongoing instances where these substances and others have been detected in drinking water supplies across Ireland. The detected levels sometimes exceed the legally permitted limit for pesticides in drinking water, which is set at an extremely low value.

Irish Water, working in partnership with a range of organisations involved in the National Pesticides and Drinking Water Action Group (NPDWAG) is providing advice and guidance to all users of pesticides including the farming community, greens keepers and grounds keepers and domestic users, to ensure that best practice measures to protect drinking waters are always followed.

Irish Water said there are currently six priority catchment areas of particular concern where exceedances of pesticides are persistent - are Longford Central (MCPA), Newcastlewest (MCPA), Belturbet (MCPA), Cavan RWSS (MCPA), Clonroche (Bentazone), and Newport (Glyphosate/MCPA). All of the areas are being prioritised for action by members of the NPDWAG.

In addition,is a separate watch list, currently comprising over 20 supplies, is also a focus for targeted actions, since the pattern of detections in these areas indicates a risk of persistent pesticide exceedances.

Efforts to reduce the incidence of detections are being coordinated by the NPDWAG which is chaired by the DAFM. All of the key stakeholders are represented in this group and include other Government departments and agencies; local authorities; industry representative bodies; farming organisations; water sector organisations; and amenity sector organisations.

Commenting, Andrew Boylan, Irish Water’s Regional Drinking Water Compliance Specialist said:

“At a time of significant challenges for farmers and other essential workers managing land we are asking everyone to continue to be mindful to protect the water bodies.

“While MCPA accounted for the majority (63 per cent) of pesticide exceedances detected nationally in public water supplies during 2019, Irish Water routinely tests for a wide range of pesticides and is closely monitoring the situation for pesticides other than MCPA. Irish Water is continuing its extensive investment programme to safeguard the water supply for homes, farms and businesses in Ireland.

“Providing safe, clean drinking water for all is our first priority. In Ireland, the majority (82 per cent) of drinking water supplies come from surface water sources such as rivers, lakes and streams. Such supplies are vulnerable to contamination from land and animal run-off. Irish Water asks users of pesticide products to consider the vulnerability of the drinking water supply to pesticide contamination and the importance of this supply to the local community.”

Dr Aidan Moody, Chair of the NPDWAG added that while a lot of good work had been done and progress had been made, the continued engagement of all stakeholders, working in partnership, was needed to make further progress.

Improper application means any pesticides can end up in drinking water

MCPA, which is commonly used to kill rushes on wet land, is the main offender, however, other pesticides such as 2,4-D, fluroxypyr and MCPP (also known as mecoprop) are being detected more frequently than in previous years. Careless storage, handling or improper application of any pesticide product can easily result in traces ending up in drinking water, leading to breaches of the drinking water regulations. Users of pesticides are being asked to carefully consider how these products may access water courses via rainwater drains, drainage channels or other means before application.

The regulations are so stringent that a single drop of pesticide is enough to breach the drinking water limit in a small stream for up to 30 kilometres.