Dr. Eimear Cotter:

I thank the committee for inviting us to discuss the EPA's latest water quality monitoring report on nitrogen and phosphorous concentrations. As the Cathaoirleach indicated, I am joined by Ms Gurrie and Dr. Deakin, both of whom deal with water quality monitoring and assessment at the EPA.

One of the most significant stressors on the ecological health of our waterways is high levels of nitrate and phosphorus. In drinking water, high nitrogen levels, above the drinking water standard, can pose a risk to human health. Agricultural activity is one of the main sources of nutrient losses to water in Ireland and is a significant pressure on approximately 1,000 water bodies. These impacts are seen throughout the country and are associated with all types of agricultural activities. High nitrate levels are a particular problem in the south and south east, where they are associated with freely draining soils and more intensive agricultural activity.

As well as being too high, nitrogen levels in groundwaters, rivers and estuaries have increased over the past ten years since their lowest point in 2012-13. A short-term peak arose in 2018 to 2019 as a result of the drought conditions in 2018, together with increased application of fertiliser that year. While still too high, nitrate levels have come down somewhat from that peak. There has been a slight increase again in 2022, when average nitrate concentrations in rivers and groundwaters were higher than in 2021.

Rivers with high phosphorus levels are associated with areas that have poorly draining soils. Phosphorous concentrations are too high in many areas but have generally stabilised in recent years.

In 2023, the EPA was asked to provide an additional assessment of water quality, known as the interim review. That review was carried out using the criteria and monitoring network specified in the European Commission's implementing decision. The aim of the Commission's assessment is to identify where water quality is polluted, at risk of pollution or showing stable or worsening trends with respect to both nitrate conditions and eutrophication. The EPA was required to assess changes in water quality between 2021 and 2022. Where waters meet the Commission's water quality criteria, the lands draining to those waters must be identified. These lands are shown in map 1, the red map, on page 28 of the report.

All the data underpinning our water quality monitoring report on nitrogen and phosphorus concentrations and our interim review come from the EPA's national water quality monitoring programme. Nutrients are analysed using standard methods in the EPA's accredited laboratories. The biological elements are assessed using methods that have been intercalibrated and approved at European level. In terms of frequency, nutrients are monitored up to 12 times per year at each monitoring station. The biological elements are monitored at a minimum of once every three years in each water body. All EPA water monitoring data are publicly available on catchments.ieand on our data and mapping portal.

The European Commission's implementing decision specifies that the data used for the assessment must be based on the nitrates directive monitoring network, which is the network used for reporting under that directive since 1991. The network is a subset of our full national water quality monitoring network, which is used for all other EPA reports. This means some areas with high numbers of derogation farms, and which may need to reduce nitrogen losses in waters, are not included on the red map because they do not have a monitoring station in the nitrates directive monitoring network.

The red map also includes areas that do not have many derogation farms. This is because the Commission criteria include an assessment of eutrophication.

In Ireland, both phosphorus and nitrogen play a role in eutrophication. Areas with excess nitrate and-or excess phosphorous levels leading to eutrophication are therefore included in the red map. This brings in water bodies that are impacted by agricultural run-off from all farming types, not just derogation farms.

To allow for the targeting of measures, we included an additional map, map 9 on page 21. This provides a more refined assessment insight into water quality in Ireland. In particular, it highlights where targeted measures to address nitrate, phosphorus and sediment losses are required as well as potential farm point source issues. This map is based on the full national monitoring network and includes the impact of all types of farming activity.

In summary, clean water is essential for our health and well-being, our economy and wildlife. The agricultural sector has an essential role to play in improving water quality. Targeted and substantial measures are required as a matter of urgency to reduce nutrient losses to water using the full suite of tools, from advice and incentives to a strengthened inspection regime.