Methodology for the implementation of monitoring plans with different spatial and temporal scales of plant protection products residues in water bodies based on site-specific environmental pressures assessments

The awareness of plant protection products residues causing problems in water bodies is increasing more and more. A lot of effort is being made by countries in investigating the situation of diffuse pesticide pollution. This article illustrates a new methodology developed for the implementation of monitoring plans for plant protection products residues in rivers, lakes and groundwater, at river basin scale, based on an operational workflow which, by integrating different databases, let to evaluate site-specific environmental pressures affecting the definition of the related monitoring networks. It follows that sampling and analytical activities, carried out in the monitoring network nodes, not only are functional to water bodies ecological and chemical quality status assessment but are able to highlight possible compromises of environmental balance in agro-ecosystems, deriving from plant protection products use, through the application of environmental modeling able to bring out evolutive trends. This information would allow the Administrators to take increasingly effective initiatives both in the field of controls and authorizations for particular substances, in the light of the negative effects shown, and in the field of spatial planning, being able to dispose of the necessary knowledge in order to take safeguard measures before a certain evolutionary process of degradation becomes irreversible.