Despite a reduction of over 50% in the number of pesticide exceedances recorded since 2018, there were 52 pesticide exceedances recorded in public drinking water supplies last year.

These were detected as part of Uisce Éireann’s public water supply monitoring programme.

The National Pesticides and Drinking Water Action Group (NPDWAG) is reminding users of pesticide products, especially users of herbicides, to consider the vulnerability of their local drinking water supplies to pesticide contamination and the importance of these supplies to local homes and businesses in the community.

Continued vigilance is necessary, since inappropriate or careless use of pesticides could easily lead to a reversal of the good progress that has been made, it said.


Uisce Éireann acknowledged that great progress has been made by the farming community and other pesticide users, particularly in the priority catchment areas of Newport, Co Mayo, and Clonroche, Co Wexford, where pesticide exceedances have been eliminated.

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

Minimising use

Pesticides should only be used where necessary.

"Minimising pesticide use not only helps to protect water quality, but also has many wider environmental benefits, such as helping native flowering plant species to grow and support a range of insects including bees and other vital pollinators.

"The application of herbicides reduces sward species diversity and could negatively impact on payments through agri-environmental schemes," it added.

Dr Aidan Moody of the Department of Agriculture and chair of the group commented: “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.

"Users of pesticides must always carefully consider the possibilities for alternative control methods in the first instance and if the application of pesticides is considered essential, make sure that they follow best practice measures to protect water quality.”


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

  • Choose the right pesticide product.
  • 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, including drains, wells and springs.
  • 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 three times into the sprayer.
  • Store and dispose of pesticides and their containers properly.
  • Never fill a sprayer directly from a watercourse or carry out mixing, loading or other handling operations beside a watercourse.
  • Never fill or wash a sprayer on concrete or sealed surface areas, where spillage or runoff to drains and watercourses is possible.
  • Never leave a sprayer unattended during filling, mixing or agitating.
  • Further guidance

    A video on the best practice use and application of products containing MCPA can be viewed on Uisce Éireann’s YouTube channel.

    Information leaflets on pesticide use are also available to download from the Teagasc website.

    The Department of Agriculture provides a number of guidelines and advice services on its water protection webpage.