Almost half of Ireland’s rivers (47%) and a quarter of groundwater have nitrogen levels that are too high and rising, the Environmental Protection Agency (EPA) has warned.

Around one-fifth (21%) of estuarine and coastal water bodies also have nitrogen levels that are too high and result in algal blooms in estuaries.

The high nitrogen levels are primarily due to agricultural activities and the EPA has called for “urgent and targeted action” to reduce the amount of nitrogen entering waters.

“Our water quality is currently under threat, with nitrogen pollution from agriculture causing particular pressure in parts of the south, southeast and east of the country,” EPA director of evidence and assessment Dr Eimear Cotter said.

“Rivers such as the Bandon, Lee, Blackwater, Suir, Nore, Barrow and Slaney have nitrogen levels that are too high, with significant implications for the marine environments they flow into,” she said.

“We urgently need to address nitrogen pollution so that we can protect and restore the water quality in these areas. If we do not substantially reduce nitrogen inputs to our rivers, and ultimately our marine environment, we are in danger of further deteriorations in water quality and losing our excellent coastal water quality.”


The EPA found that in 2019 and 2020, 345 rivers showed improvements in quality, including an increase in the number of high-quality river sites.

On the flip side, however, 230 rivers declined in quality.

Just over half of Ireland’s rivers and lakes are in a satisfactory condition, which means that a large number are unable to sustain healthy ecosystems for fish, insects and plants.

Mary Gurrie, programme manager, said: “The scale of declines is offsetting the improvements and hampering progress towards improving water quality. It is essential that action is taken in both the next River Basin Management Plan and the Nitrates Action Programme to continue improvements, while also preventing further deterioration.”

Nitrates Action Programme

The report warned that the next Nitrates Action Programme must deliver reductions in nitrogen losses to water, as well as full implementation of the existing regulations by local authorities and the Department of Agriculture.

It added that the climate measures identified in the AgClimatise Roadmap and the agri food 2030 strategy would benefit both water quality and biodiversity.