Pesticide levels in public drinking water supplies breached regulations 81 times last year

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Caroline O'Doherty

March 17 2021 06:28 AM

Pesticides levels in public drinking water supplies breached regulations on 81 occasions last year.

The number is an increase of five on the previous year and has prompted Irish Water to call on farmers, gardeners and grounds keepers to take better care when blitzing weeds and insects.

The most regularly detected pesticide was MCPA which is found in products commonly used to kill thistles, dock and rushes.

Glyphosate, the main ingredient in Roundup, was also found along with bentazone and other chemicals used in large scale food crop production as well as those applied to ornamental plants.

Irish Water said even where exceedances were detected, they were not high enough to pose any “immediate risk” to health.

But John Leamy, the utility’s head of drinking water compliance, said they were still “undesirable” to have in drinking water.

“It is therefore imperative that users of pesticides are mindful of best practices when using herbicides and pesticides and seek out alternatives,” he said.

Six catchment areas are of particular concern with frequent pesticide breaches detected.

They are at Longford; Newcastlewest, Co Limerick; Belturbet, Co Cavan; Clonroche, Co Wexford; Newport, Co Mayo and Foynes in the Shannon Estuary.

All have been prioritised for action by the National Pesticides and Drinking Water Action Group (NPDWAG) which is made up of Government departments and State agencies, farming groups, group water schemes, golfing bodies and pesticide suppliers. Irish Water is also a member.

NPDWAG is concerned not only to ensure public health is not compromised but also about the impact of pesticides on plant and animal life in rivers and other waterways, and on the damage to bees and other pollinators.

Dr Aidan Moody, the group’s chair, said buy-in across society was needed to tackle the issue.

“Users of pesticides should always consider alternatives in the first instance and if the application of pesticides are considered essential, make sure that they are aware of the best practice measures that should be followed to protect water quality,” he said.

Irish Water said it consulted with the HSE on determining the safe thresholds for pesticide levels in drinking water.

It said where exceedances were detected, these were notified to the statutory authorities who have responsibility for protecting the water catchment in the area, such as the local council and Environmental Protection Agency, for investigation.