A total of 69 pesticide breaches in public water supplies recorded countrywide

There were 69 cases of pesticide levels exceeding statutory limits within drinking water regulations across 24 public water supplies in 2025

The majority of exceedances were linked to the commonly used herbicide substance MCPA, a popular herbicide to control broad-leaved weeds, which accounted for 49 non-compliant findings.

Pesticide breaches were recorded in public water supplies last year despite overall improvements, with 69 exceedances detected countrywide.

In 2025, the 69 cases of pesticides exceeding statutory limits within drinking water regulations were detected across 24 public water supplies. These non-compliance cases were drawn from more than 45,000 analyses carried out countrywide by Uisce Éireann’s monitoring programme, reflecting an overall high rate of compliance.

The majority of exceedances were linked to the commonly used herbicide substance MCPA, a popular herbicide to control broad-leaved weeds, which accounted for 49 non-compliant findings.

Several supplies have been prioritised for action in 2026 due to recurring exceedances, including Greenmount in Louth, Longford Central in Longford and the Foynes/Shannon Estuary supply in Limerick.

Uisce Éireann, in partnership with the National Pesticides and Drinking Water Action Group, is urging all pesticide users to exercise extra care as the 2026 spraying season begins, reminding communities it only takes one drop to impact a drinking water source.

Over the past nine years, since the action group was established, pesticide exceedances have reduced by more than 50%. The small number of exceedances that continue to occur underscores the group’s push for responsible use, adherence to best practice, and continued vigilance across both rural and urban settings.

Despite the breaches, there have been several other supplies which have shown notable improvement in 2025 following targeted engagement, local collaboration and consistent best-practice implementation.

Uisce Éireann and the National Pesticides and Drinking Water Action Group highlighted that across the country, farmers, landowners, local authorities and amenity partners continue to demonstrate meaningful improvements are possible when local knowledge and best practice come together.

The Hacketstown water supply in Carlow, the Belturbet water supply in Cavan, and the Newcastle West water supply in Limerick all recorded strong improvements in 2025, each showing a clear turnaround compared to previous years.

Chair of the National Pesticides and Drinking Water Action Group Aidan Moody said: “While we continue to see strong progress since the NPDWAG was established, the 2025 results highlight there are still some instances of pesticides entering water sources. Even very small quantities can affect drinking water quality.

We also want to acknowledge the continued commitment of the farming community, who have played a vital role in reducing exceedances in recent years. Their willingness to adapt, follow best practice and work proactively with local partners is making a real and measurable difference to protecting our drinking water. 

Patrick O’Sullivan of Uisce Éireann noted: “Our monitoring programme carried out more than 45,000 analyses last year, and while the vast majority show full compliance, we are still seeing preventable exceedances within a small number of supplies. Local action is delivering real improvements, and we are encouraging all pesticide users to keep up this positive momentum as we enter the 2026 spraying season.” 

As the 2026 campaign begins, the National Pesticides and Drinking Water Action Group, chaired by the Department of Agriculture and involving stakeholders from various Government agencies, water sector organisations, local authorities, industry representative bodies, farming organisations and amenity sector organisations, will continue national and regional awareness activities, tailored engagement within prioritised catchments, and ongoing collaboration with local catchment focus groups to support long-term improvements.