PRIOR’eau, a Tool for Spatializing the Detection of Plant Protection Products in Walloon Water Resources for Prevention Purposes

The PRIOR’eau tool exploits the Walloon Region’s databases of plant protection products (PPP) detection in groundwater (GW) and surface water (SW). It can be used to define priority areas, where awareness-raising actions by field advisors need to be targeted. This tool is developed in collaboration with the Public Service of Wallonia (PSW) to support the actions of the regional water resource protection operator PROTECT’eau. PSW’s database are used to highlight active substances or metabolites, which concentrations found in the various analysed catchments, are between 30 and 75% of the groundwater quality standard (100 ng l−1). Mostly herbicides are found in waterbodies. To monitor groundwater, the Water Framework Directive networks (WFD) and a “supplementary” network include almost 1000 sites spread across Wallonia. We define a list of molecules, based on the frequency of detections, their concentrations and the agronomic pertinence. Based on this list, GW priority areas are studied and proposed. These areas, in which worrying detections have been confirmed, will allow us to identify plots of land. Then, advisors from the regional operator can prioritize the farms on which they need to focus their efforts. Finally, operational summaries will be produced to transfer knowledge. These summaries will include GW priority areas, as well as any other information deemed relevant (agricultural land parcels, statistics, hydrogeological information). The objective is to act more accurately and rapidly to support farmers in their efforts to reduce induced pressure on water resources.