Nitrates levels in Irish rivers reduced in 2024, according to a report published by the Environmental Protection Agency (EPA).

The EPA's early insights nitrogen indicator for 2024, published this Wednesday, shows that nitrogen levels in rivers have reduced in 2024 compared with 2023.

The report looks at data from 20 river monitoring sites up to the end of December 2024.

Location of the early insights nitrogen indicator monitoring stations and their contributing catchment area

It follows on from the EPA's first report in this series, which was published in late 2024 and covered the first six months of 2024.

The EPA said that this reduction across the board in 2024 is consistent with the suggestion of overall lower nitrates concentrations indicated in the 2024 January to June data.

However, despite the reduction, nitrogen remains too high in the southeastern half of the country and further reductions will be needed to bring them to satisfactory levels, the EPA has said.

Commenting on the report, director of the EPA’s office of evidence and assessment Dr Eimear Cotter said: “The EPA continually strives to produce timely information and evidence on Ireland’s environment. Specifically, this publication responds to a need for early insights into trends in nitrogen levels.

"Agriculture is the primary source of nitrogen in Irish rivers and there is significant action under way within the sector to improve water quality. It is therefore very welcome to see these early signs of improvement.

Early insight nitrogen concentrations for Jan-Dec (blue) periods of each year from 2016 to 2024 at 20 representative sites located around the country. The annual nitrate concentrations for the whole monitoring network (grey), and the levels to maintain good water quality in rivers (black dash) and in marine waters (orange dash) are also shown. Source: EPA

"It is important that the sector builds on this momentum and continues to implement actions to reduce nutrient losses in a targeted way," Dr Cotter said.

EPA programme manager Jenny Deakin added that it is very positive to see this improvement in nitrogen levels in 2024, following a

period of little positive change in recent years.

"However, nitrogen levels remain too high in the southeastern half of the country. Further actions will be necessary to reduce nitrogen and phosphorus losses to levels which will support good ecological health in our water bodies.

"The ecology will not improve until nutrient levels are reduced in the areas where they are elevated. The EPA will be reporting on the

ecological health of our waters later in 2025," she said.

Next assessment

The EPA will publish its three-yearly assessment of water quality in Ireland, for the period 2019 to 2024, later in 2025.

This future report will combine data on nitrogen and phosphorus concentrations in waterbodies, with the biological quality monitoring data on fish, aquatic insects and plants, to give a comprehensive assessment of the ecological health of all waters.