1MODELING OF CHLORINATED SOLVENTS TRANSPORT AND NATURAL ATTENUATION IN GROUNDWATER

The objective of this study is to test differents modeling approaches and the reliability of the codes used in water risk assessment for a site contaminated with chlorinated solvents. The final goal is to elaborate, within the framework of the TRANSPOL research program, a guideline that could be used as a scientist support for contaminated aquifers management. The models performed by 4 teams (ANTEA, ENSMP, ENVIROS and INERIS) to simulate a contamination of groundwater by perchloroethene were compared. The total amount of perchloroethene discharged into the aquifer was unknown and a simplified conceptual model was considered. A first synthesis of the results obtained shows two principal difficulties: evaluate source concentration and simulate natural attenuation phenomenon (sorption/degradation). More accurate diagnosis is needed in order to reduce the uncertainties of model parameters. 1. Context and Object When applying a risk assessment approach to contamined sites, of primary importance is the evaluation of the fate of pollutants in groundwaters and soils. This knowledge is based on the result of extensive investigations, available data from monitoring of pollutants in time and space and numerical modeling of the pollutants transport in the environment. In practice, results may vary greatly amon