Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Arts and Sciences


Earth and Environmental Sciences (Geology)

First Advisor

Dr. Alan E. Fryar


Bacterial contamination of karst aquifers is a concern as water quality across the globe deteriorates in the face of decreasing water security. This study examined the transport and attenuation of two non-virulent isolates of Escherichia coli in relation to traditional groundwater tracers such as rhodamine WT dye and latex microspheres in two karst regions in Kentucky. Differential movement between the four tracers was observed in both epikarst and karst aquifer traces, with differences in behavior dependent on flow conditions. Attenuation was greater for the bacterial isolate containing the iha gene, compared to the isolate containing the kps gene. Microspheres of comparable size (1 µm diameter) were more easily remobilized during increases in discharge during the observed periods for both study sites. Bacteria were remobilized during storm events over 1 month after injection. Recoveries of tracers that were < 100% combined with observed remobilization during storm events illustrate the storage capacity of epikarst and karst aquifers with regard to potential contaminants.

Digital Object Identifier (DOI)