In this part of the study it concerns pumping stations which extract groundwater from so-called phreatic aquifers. These stations are characterized as the most vulnerable extractions. For a pumping site the recharge area and the development of the concentration were calculated. There has been a sensitivity which was adapted to the values of measurements. The half life is the most important factor affecting a spread in groundwater quality. A ban of the use of pesticides will not lead in all considered scenarios to a reduction of the concentration at a short time. Several limitations and uncertainties are attached. The effect of the neglects and simplifications implies an indicative result.

Abstract not available