Average nitrogen concentrations at representative monitoring points on 20 major Irish rivers were 4.3% higher in the first six months of 2026 than in the same period of 2025, Ireland's Environmental Protection Agency (EPA) said on September 16 as it published its Early Insights Nitrogen Indicator Report. The rise follows an increase between 2024 and 2025.

The agency acknowledged that the result would be "disappointing" for many, given how much work farmers have put into cutting nitrate losses to water. Too much nitrogen in rivers, lakes, estuaries and coastal waters feeds algal growth that strips oxygen and damages habitat for other species.

The greatest nitrogen pressures remain concentrated in the south-eastern half of the country and are driven largely by agriculture, the EPA said. Reducing them will need targeted action in the most vulnerable catchments, particularly where farming is intensive and free-draining soils let nitrogen move readily into watercourses.

Nitrogen levels fluctuate from year to year with source loading, land management and weather, the agency explained. Source loading — the nitrogen put into the environment — comes overwhelmingly from the chemical and organic fertilisers used in farming; rainfall and river flow then govern how it reaches the water, with wet periods able either to increase losses through leaching or to reduce concentrations through dilution, depending on soil and geology.

"These results will be disappointing for many, given the greater focus in recent years on reducing nitrogen losses to water and the work being undertaken by farmers, industry and other stakeholders to address the issue," said Roni Hawe, director of the EPA's office of evidence and assessment. "While there has been growing engagement and a stronger emphasis on targeted measures, these findings highlight that more work is needed to translate actions on the ground into improvements in water quality." He also called for policy and practice to be joined up more strongly, noting that water-quality measures can deliver wider benefits for agriculture, biodiversity and climate.

Joe Griffin reported the findings for Agriland.

Source: Agriland