Submitted to: Journal Of Water Air And Soil Pollution
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/21/2005
Publication Date: 1/6/2006
Citation: Corapcioglu, M.Y., Vogel, J.R., Munster, C.L., Pillai, S.D., Dowd, S., Wang, S. 2006. Virus transport experiments in a sandy aquifer. Journal of Water, Air, and Soil Pollution. 169:47-65. Interpretive Summary: Viruses are very small microorganisms that cause a wide range of serious and even deadly diseases in humans. It has been discovered that viruses, upon contamination of soil, can survive and migrate long distances where they may contaminate drinking wells. This can pose a significant health risk to humans. Experiments were conducted to determine how far viruses can migrate through sandy aquifers in order to evaluate the risk of well-head contamination if an aquifer actually became infected with virus. To do this, a sandy aquifer research site was artificially contaminated with virus, and wells downward of the aquifer flow were sampled over time. Virus particles were able to migrate 34 meters, indicating a high potential for well-head contamination if sandy aquifers become contaminated. This study provides valuable data that allows for better virus transport modeling, risk assessment, and control of well-heads if aquifers become contaminated or if they exist near potential contamination sources, thereby improving the safety of water supplies.
Technical Abstract: The occurrence of human enteric viruses in ground water has been well documented in the literature. Bacteriophages, such as MS-2 and PRD1, have properties similar to pathogenic human viruses, suggesting that bacteriophages can be used as proxies for virus transport. The objective of this study is to investigate a "worst case scenario" for virus transport in a ground water aquifer, i.e., sand and gravel aquifer under a forced-gradient, by using bacteriophages. Field studies have been conducted to trace large-scale (34 m) and small-scale (10 m) virus transport under natural and forced gradients through a sand and gravel aquifer at a ground water research site at the Texas A&M University. Virus transport was monitored under natural and forced gradient conditions using MS-2 and PRD-1 as virus tracers and bromide as a conservative tracer. Results indicate virus and bromide transport to down-gradient monitoring wells in both the large and small scale field tests. During the tests conducted, MS-2 transport appears to exhibit little longitudinal dispersion, showing a narrow peak at the well nest 34 m down-gradient in 13 days, which is 20 days before the bromide breakthroughs, indicating that bacteriophage transport through the aquifer was mainly by advective flow. Differences in tracer transport can be attributed to the heterogeneity of the sand and gravel aquifer at the site, different injection methods, different sampling methods, and different tracer properties. Heterogeneity of the aquifer would cause virus transport through preferential flow paths.