There needs to be a significant increase in the scale and pace of implementation of measures to reduce nutrient losses from the agriculture sector into the country’s waterbodies, the Environmental Protection Agency (EPA) has said.

Speaking before the Joint Oireachtas Committee on Agriculture on Wednesday evening, the EPA’s director of the office of evidence and assessment Dr Eimear Cotter said that this should include full compliance with good agricultural practice (GAP) regulations.

She also said that there must be “significant improvements” in nitrogen use efficiencies to reduce the nitrogen surplus.

“We may also need to see an overall reduction in load in some catchments where nitrates levels are substantially in excess of the levels needed to support good water quality,” she said.

Dr Cotter noted that there is much action already under way in the sector to improve water quality.

“All farmers, and not just those in derogation, have a role to play in reducing nutrient losses to water. The science and knowledge are available to know what the problems with water quality are, where they are and how to solve them,” she added.

Lag times

She told the committee that reducing nitrogen losses to water requires a reduction in the amount of nitrogen leaching through freely draining soils.

“This requires a reduction in the nitrogen surplus through measures such as improving the nitrogen use efficiency, better nutrient management planning and reducing the overall nitrogen load.

“The lag time between nitrogen reduction measures and reduced nitrogen concentrations in water bodies can vary depending on the soil type and weather.

“However, if nitrogen reduction measures are implemented at scale and in the critical source areas where most leaching occurs, we would expect to see signs of improvements in nitrogen levels within six months to a year at a national level,” she said.


Specifically related to phosphorous, it is critical that the flow pathway between the land and the water body is broken, Dr Cotter said.

“This includes, for example, preventing soiled water or effluent running into a drain or watercourse, or by maintaining a buffer zone to intercept flow and nutrients at the area where the run-off occurs.

“Breaking the pathway, if implemented at scale by all farmers, should reduce phosphate levels and deliver improvements in water quality relatively quickly, particularly in our freshwater rivers and lakes,” she said.

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