Virus Survival and Transport in Groundwater

Almost half of all documented outbreaks of water-borne disease in the United States result from contaminated groundwater. Many of these outbreaks are known to be caused by viral agents. An understanding of factors that control virus migration through subsurface soil systems is necessary for the management of septic tank and wastewater land-treatment systems. The effectiveness of virus removal during land application of wastes is determined by their survival in the subsurface and their retention by soil particles. Both survival and retention are largely determined by (1) climate; (2) nature of the soil; and (3) nature of the microorganisms. Climate influences subsurface temperature which is probably the single most important factor in survival of viruses. Viruses are removed from groundwater by adsorption which is controlled by various characteristics of soil and the type and strain of virus. Both electrostatic and hydrophobic effects are now believed to be involved in virus adsorption.