More than half of surface water bodies in Europe are at less than good ecological status according to Water Framework Directive assessments, and diffuse pollution from agriculture remains a major, but not the only, cause of this poor performance. Agri-environmental policy and land management practices have, in many areas, reduced nutrient emissions to water. However, additional measures may be required in Ireland to further decouple the relationship between agricultural productivity and emissions to water, which is of vital importance given on-going agricultural intensification. The Source Load Apportionment Model (SLAM) framework characterises sources of phosphorus (P) and nitrogen (N) emissions to water at a range of scales from sub-catchment to national. The SLAM synthesises land use and physical characteristics to predict emissions from point (wastewater, industry discharges and septic tank systems) and diffuse sources (agriculture, forestry, etc.). The predicted annual nutrient emissions were assessed against monitoring data for 16 major river catchments covering 50% of the area of Ireland. At national scale, results indicate that total average annual emissions to surface water in Ireland are over 2700tyr of P and 82,000tyr of N. The proportional contributions from individual sources show that the main sources of P are from municipal wastewater treatment plants and agriculture, with wide variations across the country related to local anthropogenic pressures and the hydrogeological setting. Agriculture is the main source of N emissions to water across all regions of Ireland. These policy-relevant results synthesised large amounts of information in order to identify the dominant sources of nutrients at regional and local scales, contributing to the national nutrient risk assessment of Irish water bodies.

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Effective implementation of the integrated catchment management approach, catchment characterisation and suitable catchment management strategies and measures are the means of ensuring protection of satisfactory water resources and improvement of unsatisfactory water resources, and achievement of Water Framework Directive requirements. Lessons have been learned from the firstcycle River Basin Management Plans, particularly on the need for proper public and community engagement and involvement, improved governance and targeting of appropriate mitigation measures. However, challenges need to be overcome: there needs to be genuine integration of the work of discipline-or process-based sections in public bodies and better collaboration between these bodies; the environment must be at the core of sustainable intensification; appropriate mitigation measures for diffuse and small point sources will need to be analysed and targeted to the pressures; and there is a need to ensure the involvement, cooperation and co-ownership of water (and biodiversity) management by local people and communities. The approach currently being undertaken is laying a solid foundation for integrating science and people, and is a basis for optimism.

12Characterising catchment scale biogeochemical processes controlling nitrate fate in groundwater 13 constitutes a fundamental consideration when applying programmes of measures to reduce risks 14 posed by diffuse agricultural pollutants to water quality. Combining hydrochemical analyses with 15 nitrate isotopic data and physical hydrogeological measurements permitted characterisation of 16 biogeochemical processes influencing nitrogen fate and transport in the groundwater in two 17 fractured bedrock aquifers with contrasting hydrogeology but comparable nutrient loads. bedrock conditions need to be considered when implementing catchment management plans to 7 reduce the impact of agricultural practices on the quality of groundwater and baseflow in receiving 8 rivers. 9 10 Nitrate isotopic signatures in the groundwater of a freely draining catchment underlain by a 11 karstified aquifer and a poorly draining aquifer with a low transmissivity aquifer.