New Applications of the Geostatistical Procedure in the Recovering of Pollutant Release History in Aquifers with Highly Heterogeneous Flow Field, Abstract H34A-0468

The interest in environmental issues has led great attention to the quality of groundwater. Since '90 increasing attention has been paid to the problem of recovering the release history of a pollutant because the knowledge of the pollution injection function gives information about the future pollution spread, allows a better planning of remediation actions and it can be a useful tool for sharing the costs of remediation among the actors. The present work contains the last results obtained through an inverse procedure (Snodgrass and Kitanidis, 1997) which allows the recovering of the pollutant release history from a few concentration measurements; it is applied to very severe cases of non-uniform flow conditions. The application of the inverse procedure is possible if one knows the transfer function, which describes the transport process. This function can be analytically determined if the problem has a simple geometry and regular boundary conditions. The inverse procedure in hand, initially developed for a 1-D homogeneous isotropic aquifer, has been extended by the writers (see Butera et al., 2004) to multidimensional aquifers using the numerical modeling. In complex cases, such as non-uniform flow field, reactive transport and unsaturated aquifers, the transfer function can be numerically inferred using the methodology. The applications showed in this meeting concern with very complicate flow conditions that allow to evaluate the power of the methodology. Three cases are presented: - The first analyzed case consists in a fully saturated aquifer with highly heterogeneity conductivity field and a pumping well. - The second case describes a fully saturated aquifer, highly heterogeneous, contaminated by a reactive pollutant. - The last and most tricky case studies the diffusion of a pollutant, due to the leakage from a tank, through an unsaturated aquifer. The pollutant release history is satisfactory recovered in all of the studied cases.