PESTICIDES IN SURFACE-WATER - ANALYTICAL RESULTS FOR DRINKING-WATER RESERVOIRS AND BANK FILTRATE WATERS

The results of a series of a investigations are presented, performed by the governmental chemical laboratory Karlsruhe (CLUA) in order to determine pesticides in drinking water for purposes of food monitoring. 231 samples of 8 municipal water supplies (groundwater wells/no bank filtrate) and 34 private water supplies close to the bank of the river Rhine (groundwater wells/partly bank filtrate) were analysed. The sampling sites were located between Mannheim and Greffern, Germany. In 1986 high amounts of atrazine and simazine were determined in the drinking water wells of several private water supplies, especially at the sampling sites in the south. The likewise high chloride content of the samples was taken as a proof of bank filtrate contributing to the water. The decrease of atrazine load in the river water of the Rhine since 1987 has its parallel in the analytical results for the concerned drinking water wells. Obviously the pesticide contamination of water from bank filtrate pumping wells is mainly depending on the pesticide load of the river water. The application of fertilizers and pesticides in the fields seems not to be a significant source of the pesticide contamination of dringing waters derived from bank filtrate water. For reasons of public health a monitoring of pesticide content in bank filtrate pumping wells of private water supplies is recommended.