| This research aims to begin filling the gap between the relatively advanced modeling expertise in groundwater contamination, and the emerging field of exposure assessment modeling. The objective of this research is to analyze the uncertainty on the magnitude of potential exposure and its variability in space, due to the uncertainty of different groundwater flow and contaminant transport parameters.; This study has developed a methodology for modeling the magnitude of exposure and its uncertainty, while accounting for both the temporal and spatial properties of exposure. This methodology is based on numerical stochastic modeling of flow and contaminant transport in a heterogeneous aquifer. Among the geostatistical and sampling technics that proved to be very useful in implementing this methodology were the Sequential Gaussian Simulations and Latin Hypercube Sampling.; This investigation has shown that the magnitude of potential exposure may vary by orders of magnitude, depending on the aquifer contamination history, the exposure duration, and the exposure location in space. Latin Hypercube sampling has made uncertainty analysis of exposure in a heterogeneous aquifer feasible. Stochastic modeling has shown that a deterministic estimate of the magnitude of exposure can be orders of magnitude different from the values corresponding to high percentiles (e.g. 95th) of its statistical distribution. |
