In November 1985, a Maximum Contaminant Level Goal of zero viruses in drinking water was published. By 1991, the U.S. Environmental Protection Agency Office of Drinking Water expects to promulgate regulations requiring that all ground water used for potable purposes be disinfected prior to distribution instead of requiring monitoring for viruses. The document discusses the possibility of using a virus transport model for granting variances from this requirement. The current state of knowledge in the area of virus transport is reviewed, and the information needed to model virus transport is critically examined. Two different approaches to modeling virus transport are described, including data requirements, model outputs, and limitations of the model. Finally, several areas in which research needs to be performed in order to use models of virus transport for granting variances from the disinfection requirement are presented.