Development of an assessment methodology to evaluate agricultural use of plant protection products for drinking water production from surface waters : a proposal for the registration procedure in the Netherlands

Two tiers were developed to assess the drinking water standard of 0.1 μg/L at nine locations where surface water is abstracted to produce drinking water in the Netherlands. Two tiers were developed to assess the drinking water standard of 0.1 μg/L at nine locations where surface water is abstracted to produce drinking water in the Netherlands. In Tier I, concentrations at the abstraction points are calculated on the basis of edge-of field surface water concentrations for all crops in the intake area on which the pesticide can be used. The edge-of-field concentrations are corrected to estimate the concentration at the abstraction point by factors accounting for e.g. the relative cropped area of the intake area, degradation and difference in timing of applications