PESTICIDES IN-GROUND WATER IN THE UNITED-STATES - MONITORING, MODELING, AND RISKS FROM THE US PERSPECTIVE

Scientific and regulatory interest in ground water contamination by pe sticides increased significantly in 1979. This was prompted by finding s of the nematicide 1,2-dibromo-3-chloropropane (DBCP) and the nematic ide/insecticide aldicarb (Temik(R)) in ground water in several states. Since that time, at least 130 pesticides and pesticide metabolites ha ve been detected in ground water in over 150 studies, but detection fr equencies are 4-10% nationally. Detection frequencies of pesticides ov er Health Advisory Levels are generally lower. Screening-level models and detailed computer simulation models are useful for risk assessment s and regulatory decisions. Attenuation Factor, CMLS, PRZM2 GLEAMS, an d LEACHM are all useful models.