|GOTKOWITZ, MADELINE - Wisconsin Geological And Natural History Survey|
|BRADBURY, KENNETH - Wisconsin Geological And Natural History Survey|
|KRAUSE, JACOB - Wisconsin Geological And Natural History Survey|
Submitted to: American Water Resources Association Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/3/2014
Publication Date: 3/13/2014
Citation: Gotkowitz, M.B., Bradbury, K.R., Borchardt, M.A., Spencer, S.K., Krause, J.J. 2014. Effects of precipitation events on virus presence in groundwater. American Water Resources Association Conference Proceedings. March 13-14, 2014.
Technical Abstract: Previous studies by our group have demonstrated the presence of human enteric viruses in groundwater, and that leakage from sanitary sewers is a likely source of such contamination in urban areas. This work showed high rates of virus detection, and that virus detection was positively correlated with precipitation events. In a recent study, we developed a network of 24 wells at seven field sites in Dane County, Wisconsin. A total of 455 groundwater samples were collected over a twelve month period and analyzed for viruses and coliform bacteria. In contrast to our initial study, rates of virus detection in the more recent work were low. Viruses were detected in 13 of the 24 wells, but of the virus positive wells, 9 were positive only once and four were positive twice. The presence of viruses did not correlate to the presence of coliform bacteria. The over-all virus detection rate of 3.7 percent (17 of 455) was much lower than the 43 percent positive rate observed earlier at a subset of these wells. Our data analysis focuses on causes of the low detection rate. Climatic conditions during the study varied from an extended period of drought to conditions favorable for spring recharge, which induced over six feet of water table rise in the study area. However, in contrast to previous studies, these data do not show an association between precipitation events and virus levels in wells. Understanding all factors, abiotic and biotic, contributing to well vulnerability to virus contamination is an ongoing research priority.