Quantifying point source entries of pesticides in surface waters. International Advances in Pesticide Application

Measurements of the water boards have shown that pesticide concentrations in surface water have decreased less than was expected based on model calculations. Possibly, the implementation of spray drift reducing techniques is overestimated in the model calculation. The impact of point sources is probably underestimated. A project was initiated for the quantification and qualification of possible point sources in Dutch agriculture. Several point source entries were identified: e.g. internal and external cleaning of sprayers, filling stations and discharge of transport water from fruit sorting installations. A method was developed to discriminate the contamination of the pesticide activities in their possible impact on surface waters; the POint Source SUrface waters Model (POSSUM).