b'24Pesticide source risk identification - an evaluation of Decision Support Tools in Northern Irish catchmentsFarrow LG1, Cassidy R1, Krogshave Laursen R2 and Doody D11Agri-Food and Bioscience Institute, 18a, Newforge Lane, Malone Upper, Belfast, Northern Ireland. BT9 5PX2SEGES, Danish Agriculture & Food Council F.m.b.A, Agro Food Park 15, DK8200, Aarhus N.DenmarkThe FAIRWAY project (https://www.fairway-project.eu/) is a multi-national, EU Horizon 2020 funded project that is evaluating different approaches to drinking water source protection from contamination by pesticides and nitrate. Through analysis of 13 case study catchments across Europe the project seeks to identify and further develop innovative measures, and identifydecision support tools (DSTs) and governance approaches for more effective protection in the future. In Northern Ireland, the herbicide MCPA ((4-Chloro-2-methylphenoxy) acetic acid) is of particular concern for water quality as it is extensively used to control rushes (Juncus effuses) ingrassland. MCPA sorbs poorly to soil and concentrations in river water frequently exceed 0.1g/L. There are significant costs associated with treating contaminated water abstracted for drinking water purposes. DSTs are often developed for specific climatic and geographic conditions and theirtransferability to other regions may not be considered. Currently there are no pesticide lossDSTs designed for Northern Ireland and so the transferability of three established DSTs(Farmscoper and SCIMAP (English) and Phytopixal (French)) were evaluated. Farmscoper is an Excel-based model designed to encourage use by individuals with a wide variety of technical backgrounds and is pre-populated with a variety of datasets based on standard British farm practice, climate and soil types. SCIMAP (offline) and Phytopixal DSTs are both GIS-based models that require the operator to provide site-specific data and to follow an analysis protocol. Although the user interface of Farmscoper makes it more suitable for non-specialists to operate, we found that the pre-provided datasets translated poorly to Northern Ireland. The SCIMAP (offline) and Phytopixal DSTs both require a basic level of skill with GIS software, which would be a barrier to adoption at the farm-scale, but they both make use of catchment-specific datasets. In bothcases it was possible to generate spatial risk assessment maps at the catchment scale.68'