9725086 Welty The objective of the proposed work is to develop a three-dimensional stochastic model of virus transport in aquifers and to evaluate the usefulness of the model by comparing it to available field observations. The hypothesis to be tested is that the stochastic spectral approach provides an improved representation of field-scale virus transport compared to other currently available models. The motivation for the proposed work arises from: (1) the public health need to predict virus transport in shallow drinking water aquifers due to evidence that many waterborne disease outbreaks can be attributed to contamination of water supply wells by nonindigenous viral pathogens emanating from land-disposed wasters, and (2) the lack of appropriate existing models to represent virus transport at large scales (tens to hundreds of meters) in heterogeneous settings. A stochastic approach is needed over a deterministic computation because defining a heterogeneous aquifer structure deterministically for large scales is difficult and impractical. The model will be derived by using spectral perturbation analysis to evaluate the effect of coupling of local-scale virus transport phenomena with a three-dimensional, correlated-random-field model of aquifer permeability. The result will be a set of mean differential equations representing the transport of free viruses and conservation of mass of attached viruses at the field scale. It is expected that the mean equations will include mathematical expressions for field-scale advection, dispersion, detachment, filtration and adsorption coefficients that are dependent on aquifer statistical properties and local-scale virus transport parameters. The theory will predict the interaction between local-scale processes and field-scale heterogeneities and the importance of this interaction on large-scale virus transport. The resulting model could be simplified and applied also to the movement of abiotic colloids in groundwater.
