Interpretation of monitoring data on pesticide contamination of surface water by a hydro-ecoregion approach

Abstract

The study of the state of surface water contamination by pesticides at a monitoring station is necessary to meet the requirements of the European Water Framework Directive. Faced with the results of millions of point analyses of the presence of pesticides in surface waters, we have developed an interpretation method based on the grouping of data by a hydro-ecoregion approach. This method was developed based on herbicides because data and measurements on these substances are more readily available than on fungicides or insecticides. We first present the available data and their limitations in terms of analysis and interpretation, we describe the method developed, the results it provides and then conclude with a critical analysis of the method and possible perspectives. The method for assessing the state of contamination could be used to study the links between pressure and contamination and between contamination and impact on aquatic organisms.