Farmers and gardeners are among those who have been warned to take extreme care when using pesticides.

Irish Water has said that while notable progress has been made in reducing the impact of pesticide use on drinking water sources, scope for improvement remains.

In 2022, there were 48 pesticide breaches recorded in public drinking water supplies. These breaches were detected as part of Uisce Éireann’s public water supply monitoring programme from a total of over 35,000 samples.

Uisce Éireann’s drinking water compliance lead Dr Pat O’Sullivan said: “While our consultation with the HSE has concluded that the levels we are detecting do not represent a threat to public health, they are still 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.”

Priority areas

Four catchment areas have been prioritised for action by Uisce Éireann, because they have recorded recurring pesticide breaches. These are Belturbet, Co Cavan; Clonroche, Co Wexford; Newport, Co Mayo; and Foynes Shannon Estuary, Co Limerick.

Members of the National Pesticides and Drinking Water Action Group (NPDWAG) and local focus groups aim to co-ordinate targeted actions in these areas.

Uisce Éireann and the NPDWAG are asking the farming community and domestic users of pesticides to consider whether they need to use pesticides at all. Pesticides must only be used where strictly necessary.

Biodiversity

Leaving areas unsprayed can help native flowering plant species to grow and support a range of insects, including bees and other vital pollinators.

One third of Ireland’s bee species are threatened with extinction and by helping the bee population survive and thrive, we are also helping to protect our precious water sources.

Irish Water said that farmers should also bear in mind that the application of herbicides reduces sward species diversity and could negatively impact on payments through agri-environmental schemes.

Advice on how to control rushes using MCPA can be found here:

How to reduce risk

If pesticides have to be used, steps to reduce risks to drinking water sources and the aquatic environment are:

  • Choose the right pesticide product (products containing MCPA are NOT approved for use in weed-wipers and are not permitted to be used from the end of September until the beginning of March).
  • Read and follow the product label.
  • Do not use pesticides if rain is forecast in the next 48 hours.
  • Make sure you are aware of the location of all nearby water courses.
  • Comply with any buffer zone specified on the product label to protect the aquatic environment.
  • Avoid spills, stay well back from open drains and rinse empty containers three times into the sprayer.
  • Store and dispose of pesticides and their containers properly.
  • Never fill a sprayer directly from a water course or carry out mixing, loading or other handling operations beside a water course.