Louth pesticide users urged to protect local drinking water as spraying season ends

Uisce Éireann and the National Pesticides and Drinking Water Action Group (NPDWAG) are urging pesticide users in Louth to help protect local drinking water sources as the spraying season draws to a close.

Since 2017, the number of pesticide exceedances detected in public drinking water supplies has dropped by more than 50%. They say that his improvement reflects the commitment of farmers, landowners, and amenity managers to reducing pesticide use and following best practice. However, recent monitoring shows there is still work to be done. 

Given the current good weather, some users might be considering if there could be a suitable opportunity to spray grassland or amenity areas to manage rushes and weeds such as docks, thistles, and nettles. The NPDWAG reminds users that application of chemical pesticide products should only be considered for situations where their use is strictly necessary and following a full consideration of the potential to use non-chemical control methods. In cases where the use of chemical products has been deemed necessary, great care must be taken to protect surface water and groundwater bodies, and product label directions and best-practice guidelines for responsible use must be followed. 

Dr Pat O’Sullivan, Uisce Éireann’s Drinking Water Compliance Senior Manager, warns: “Last year, we saw a worrying number of pesticide detections occurring outside the main spraying season for MCPA. While this has not yet happened in 2025, the risk of it repeating itself remains high. We are urging all pesticide users to be mindful of their use as the spraying season comes to a close, so that we can avoid late-season exceedances again this year. Even one drop of pesticide can travel up to 30km in a watercourse, so every action counts.” 

Dr Aidan Moody, Department of Agriculture, Food, and the Marine (DAFM) and Chair of NPDWAG, adds: “We have seen excellent work by farmers and land managers in recent years to reduce pesticide use and to follow correct application methods. We urge everyone to continue the great work and always consider whether a pesticide is needed at all, and where it is, to make sure that best practices are followed. This approach not only protects our drinking water but also supports biodiversity and healthy ecosystems.” 

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They say that pesticide users should also note that a closed spray period is specified on the label of some products, during which product use is not allowed. For example, herbicide products containing MCPA must not be used between the end of September (or the end of October depending on the specific product) and the beginning of March. 

This is because late season applications, combined with wetter autumn and winter conditions, increase the risk of pesticides reaching drinking water sources. 

More information can be obtained from your local farm advisor or at www.pcs.agriculture.gov.ie/sud/waterprotection