There were 81 breaches of pesticide limits detected in public drinking water supplies in Ireland in 2020, Irish Water has said. Irish Water is asking farmers, greens keepers, grounds keepers and domestic users, to consider whether they need to use pesticides at all.

This in an increase of five from 2019 and the exceedances were detected as part of Irish Water’s public water supply monitoring programme.

It found that MCPA, used in the control of thistles, docks and rushes, is still the most commonly detected pesticide in drinking water sources.

Counties Cavan and Mayo were the worst offenders, with 15 exceedances in Cavan and 15 in Mayo. MCPA was detected in Cavan while both MCPA and glyphosate, used in Roundup, were detected in Mayo. There were 11 exceedances in Monaghan, 10 exceedances in Donegal and nine in Galway.

“Minimising pesticide use not only helps to protect water quality but also has wider environmental benefits,” Irish Water said.

John Leamy, Irish Water’s drinking water compliance lead, said that the HSE has concluded that the levels being detected do not represent a threat to public health.

“They are, however, undesirable in drinking water and it is therefore imperative that users of pesticides are mindful of best practice when using herbicides or pesticides and seek out alternatives,” he said.

Drinking water

Recent drinking water monitoring results for Ireland show that a number of active substances contained in herbicide products used in agriculture, amenity and gardens, such as 2,4-D, Fluroxypyr, Glyphosate, MCPA, Mecoprop and Triclopyr, are being regularly detected.