A risk assessment tool for contaminated sites in low-permeability fractured media

A risk assessment tool for contaminated sites in low-permeability fractured media is developed, based on simple transient and steady-state analytical solutions. The tool, which explicitly takes into account the transport along fractures, covers different source geometries and can be applied to a wide range of compounds (conservative, sorbing, degradable). The superiority of this risk assessment tool compared to an Equivalent Porous Media (EPM) model is clearly demonstrated on experimental data. The use of the model for risk assessment is illustrated for diffuse pesticide sources in a Danish catchment. The model simulates well the presence of pesticides in drinking water wells and predicts the contamination duration, however, the early breakthrough and long term tailing cannot be validated due to lack of long term monitoring data.