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ARS Home » Midwest Area » Bowling Green, Kentucky » Food Animal Environmental Systems Research » Research » Publications at this Location » Publication #328681

Title: Management Can Reduce Mobility of Escherichia coli compared to traditional groundwater tracers within karst terrains

item BANDY, ASHLEY - University Of Kentucky
item Cook, Kimberly - Kim
item GILFILLEN, REBECCA - University Of Kentucky
item POLK, JASON - Western Kentucky University
item MACKO, STEPHEN - University Of Kentucky

Submitted to: Karst Water Environment Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 1/27/2016
Publication Date: 1/27/2016
Citation: Bandy, A., Cook, K.L., Gilfillen, R., Polk, J., Macko, S. 2016. Management Can Reduce Mobility of Escherichia coli compared to traditional groundwater tracers within karst terrains. Karst Water Environment Symposium. January 27-20, 2016. San Juan, Puerto Rico.

Interpretive Summary:

Technical Abstract: An understanding of fundamental processes controlling pathogen movement is necessary to protect water resources across the globe. Limited filtration and turbulent flow make karst aquifers susceptible to microbial contamination. Groundwater tracers typically used in karst terrains include fluorescent dyes and latex microspheres. Not only can these tracers be cost-prohibitive, depending on the system being studied, but they may not accurately mimic the transport behaviors of bacteria and other potential pathogens, and thus may not be good proxies for risk assessment involving microorganisms. This study examines the movement and attenuation of two serotypes of Escherichia coli (E. coli) with differing attachment efficiencies compared to traditional tracers (rhodamine WT dye and 1-µm diameter fluorescent microspheres). E. coli is quantified by molecular methods (qPCR) and dual stable isotope analyses using enrichment levels of 13C and 15N. Transport of the tracers is being evaluated for vertical infiltration through epikarst (weathered bedrock) above Crumps Cave near Smiths Grove, KY following stormsand lateral flow within a karst conduit aquifer near Lexington, KY under baseflow conditions. Breakthrough curves show differential behavior among all of the tracers within the epikarst, with isolates containing the iha gene having later breakthrough curves than the isolate with the kps gene. Field data on survival and transport of agricultural isolates of E. coli can be applied to improve transport models and used by regulatory agencies for making decisions to prevent bacterial contamination of water resources in karst terrains.