Viruses as Tracers: A tool to characterize fast groundwater flowpaths

Abstract:

Groundwater systems are often characterized by long travel times relative to human timeframes, and most established techniques for dating groundwater work at the decadal to millennial scale. Viruses are attractive tracers of short (<3 yr) travel times in aquifers because they have unique genetic signatures, are detectable in trace quantities, and are mobile in groundwater. Virus “snaphots” result from infection and disappearance in a human or animal population over time; therefore, the virus snapshot shed in the fecal wastes of an infected population at a specific point in time can serve as a marker for tracking virus and groundwater movement. Examples of virus tracing demonstrate their ability to characterize travel times in high groundwater velocity settings, but are less applicable to low velocity settings due to virus degradation. Because they can trace very short travel times and identify the presence of preferential flowpaths, virus approaches provide new insights about aquifers unavailable from standard hydrogeologic approaches.