Context of the Study

 Pesticide indicators allow to identify high risk sites as well as problematic substances  Highlight the necessity to optimize the susbtance monitoring : decreasing of the number of susbtances for monitoring ; increase the monitoring frequence monitoring from 6 to 12  More informative than the total pesticide concentration assessment  Useful for managers as allow reliable diagnostics and policy actions  Allows to overcome the data gaps and to define pesticide interpretation methodology issues : avoid to have wrong or incomplete assessments  In the Artois-Picardie water basin, final score range between -1 and 30 for substances (possible range from -5 to 70), and between 2 and 59 for sites (possible range from 0 to 88)  The substances final score can be negative in the case of decreasing concentration trends  Four quality classes according to the value of the final score ; no very good quality class (blue) as no site has been identified without pesticides Results