A simple approach for ranking the leaching of pesticides from surface soil presented and tentatively calibrated with field data from an agricultural a The approach is based on the calculation of a leaching index indicating the proportion of active ingredient, with respect to the quantity applied, leac from a soil model in a given time interval (one year). In the selected area wells tapping an unconfined aquifer were sampled for groundwater pesticide residue analysis, in order to explore the index region between leachers and nonleachers.

The treatment of hazardous sites in Baden-Wuerttemberg is based on three legal documents: the state waste disposal act (LAbfG, 1990), the assessment committee directive (Kommissions VO, 1990), and the guide values directive (UM and SM B-W, 1993). The guide values directive was commonly issued by the Ministry of Labor, Health and Social Affairs and the Ministry of the Environment of the state of Baden-Wuerttemberg (UM and SM B-W, 1993) and contains a three-level hierarchy of numerical criteria and rules which serve as both screening levels during the investigation and as remediation objectives. The decision for the appropriate level of remediation is based on feasibility and environmental balance considerations. The levels are ordered as follows: - 1. (Background-Values) On principle, all remediations have to be based first on background levels. In the case of lack of feasibility or negative environmental balance for level-1 objectives use-specific requirements are considered next. - 2. (Assessment-Values for Worst Case Exposure Conditions) The generic requirements underlying level 2 afford appropriate protection for humans regarding the most sensitive uses of the environment. At least four resources are considered on this level: Groundwater as such and its use, the health of humans on contaminated sites, and soil with respect to growth and quality of plants. Barriers against migration of the contaminants, the effect of dilution, and abandonment of certain uses, etc., are not taken into consideration on level 2. - 3. (Site-Specific Requirements) Lack of feasibility or a negative environmental balance of level-2 objectives lead to consideration of site-specific circumstances which may alleviate the requirements.