The National Pesticides and Drinking Water Action Group (NPDWAG) is reminding users of any pesticide products, to consider their local drinking water supplies to pesticide contamination and the importance of these supplies. 

“Significant progress” has been made in recent years in reducing the impact of pesticide use on drinking water sources.

There has been a reduction of over 50% in the number of pesticide exceedances recorded since 2018.

Progress continued in 2023, but there were still 52 pesticide exceedances in public drinking water supplies in Ireland last year. 

These exceedances were detected as part of Uisce Éireann’s public water supply monitoring programme from a total of over 33,000 samples.

The NPDWAG stated that vigilance is necessary since inappropriate or careless use of pesticides could easily lead to a reversal of the good progress that has been made.

Uisce Éireann’s Drinking Water Compliance senior manager, Dr. Pat O’Sullivan said:

“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.

“It is imperative that users of pesticides are mindful of best practice when using herbicides or pesticides and seek out alternatives.”

The NPDWAG added that there has been great progress made by the farming community and other pesticide users, particularly in Newport, and Clonroche, where pesticide exceedances have been eliminated.

However, there are other areas prioritised for action where Uisce Éireann has detected pesticide exceedances from the monitoring programmes, including Belturbet in Co. Cavan and Foynes Shannon Estuary, Co Limerick.

Uisce Éireann and the NPDWAG are asking the farming community, greenkeepers, grounds keepers, and also domestic users of pesticides, to consider in each case whether they need to use them at all.

Where pesticide use is considered necessary, the NPDWAG continues to work with local communities to ensure that best practice measures to protect drinking water sources and biodiversity are always followed. 

According to Uisce Éireann and the NPDWAG, the basic steps to reduce risks to drinking water sources 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);
  • Always 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 watercourses;
  • Comply with either a minimum 3m no-spray buffer zone, for any watercourse subject to CAP conditionality, or a larger product-specific aquatic buffer zone specified on a product label, if one has been set;
  • Avoid spills, stay well back from open drains and rinse empty containers 3 times into the sprayer;
  • Store and dispose of pesticides and their containers properly;
  • Never fill a sprayer directly from a watercourse;
  • Never fill/wash a sprayer where runoff can go to drains/watercourses.

Uisce Éireann and the NPDWAG stated that minimising pesticide use not only helps to protect water quality but also has many wider environmental benefits. 
 
E.g., leaving areas unsprayed can help native flowering plant species to grow and support a range of insects including bees and other vital pollinators. 

Tractor pesticides Source: NPDWAG

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.

Farmers and other landholders dealing with the challenge of rushes should note the Department of Agriculture, Food and the Marine (DAFM) guidance on the sustainable management of rushes.

Head of the Pesticides Registration Division DAFM and chair of NPDWAG, Dr. Aidan Moody said:

“I want to acknowledge the good work done by farmers and other users of pesticides to protect water quality. There needs to be a sustained effort by all stakeholders to make further progress.”

He added that users of pesticides must always consider alternative control methods, but if the application of pesticides is neccessary, make sure to follow the “best practice measures” to protect water quality.