ROLE OF SUSPENDED SEDIMENT
IN FACILITATING PATHOGEN TRANSPORT
IN INNER BLUEGRASS KARST AQUIFERS
Principal Investigator:
Alan Fryar, Geological Sciences
Co-Principal Investigators:
Gail Brion, Civil Engineering
Mark S. Coyne, Department of Agronomy
Joe Taraba, Biosystems and Agricultural Engineering
Alex Fogle, Kentucky Geological Survey
Tom Reed, Geological Sciences
Keywords:
karst environment,
suspended sediment,
pathogens,
coliform
Brief Project Summary
Almost 40%
of Kentucky is underlain by limestone, which is prone to dissolution (karstification).
Because karstification results in the development of preferential flow
paths through sinkholes and subsurface conduits, karst aquifers are
especially vulnerable to nonpoint-source pollution from urban and
agricultural runoff. Suspended sediment, which can be carried into the
subsurface or remobilized within karst conduits following storms, can
adsorb pathogens and other pollutants. However, there have been few
studies of the association between pathogens and sediment in karst
aquifers in Kentucky, and none in the Inner Bluegrass region.
The objectives of this study were to characterize the relationship
between suspended sediment and pathogen indicators at two springs
draining karst basins with contrasting land uses (urban and
agricultural) in Woodford County, Kentucky. Blue Hole Spring is located
in Versailles; spring SP-2 is at the University of Kentucky (UK) Animal
Research Center (ARC). At each site, specific conductance (SC), pH, and
temperature (T) were manually measured weekly from fall 2002 to spring
2004. Concentrations of fecal coliform bacteria (FC), total coliforms (TC),
atypical coliforms (AC), male-specific coliphage (MSP, an indicator of
viruses in waste water), and major ions were measured biweekly.
Discharge at SP-2, stream stage at Blue Hole (which has been correlated
to discharge), SC, pH, T, and turbidity were monitored continuously by
sensors linked to digital data loggers. Bed sediments at SP-2 and the
sinkhole feeding it were analyzed for mineralogy, petrology, particle
size, total organic carbon (TOC), and total inorganic carbon (TIC).
During two storms, SC, T, FC, TC, AC, MSP, and total suspended solids (TSS)
were measured at both springs, and suspended sediment samples were
collected at SP-2 for the same analyses previously performed on bed
sediments. |
