Fecal Indicator Bacteria Concentrations in Furman Lake and its Feeder Streams
Philip Hearn, TJ Melton, Emily Tripp, and Victoria Grimm-Oropesa
SUMMARY
One of the primary objectives of the Lake Restoration Project is to improve
the water quality of the lake by reducing the amount of fecal bacteria. The
Environmental Protection Agency (EPA) and South Carolina Department of Health
and Environmental Control (SCDHEC) set limits for fecal coliform, E. coli, and
Enterococcus concentrations in recreational waters at 126 cells/100mL (EPA),
fecal coliform at 200 cells/mL (Sc DHEC), and Enteroococcus at 33 cells/100mL
(EPA). In previous years, students enjoyed activities such as boating, swimming,
and fishing in Furman Lake. Nowadays, these practices are prohibited due to
elevated concentrations of total coliform, Escherichia coli, and Enterococcus
sp.
There are two tributary streams feeding Furman Lake (Fig. 1) . We analyzed water
chemistry and fecal indicator bacteria concentrations from the tributary passing
under Poinsett Highway and through North Village Apartments. The other tributary
passes through a forested area. Previous research has demonstrated that urbanization
leads to increased concentrations of fecal indicator bacteria; therefore, we
sampled five sites along the North Village Stream. We sampled upstream and downstream
of both Poinsett Highway and North Village Apartments in order to assess the
source of the elevated bacterial concentrations.
We found significantly elevated total coliform concentrations downstream of
North Village (FU0G, FU01) as compared to levels upstream of Poinsett Highway
(Fig. 2). There were no significant differences in E. coli or Enterococcus sp.
concentrations among the five sites, however, and levels of these E. coli and
Enterococcus were below EPA thresholds (Fig. 3,4). Additionally, water temperatures
were higher downstream of North Village which may be due to increased impervious
surface runoff. There is a significant correlation between dissolved oxygen
and E. coli concentration (r=0.631 p=0.0018, ). Total coliform and temperature
were positively correlated ( r=0.7533 p=0.0012).
Further research could assess the stream quality by means of fecal indicator
bacterial concentrations in both tributary streams feeding Furman Lake. More
sampling would improve the statistical strength and enable us to understand
trends in water chemistry and bacterial concentrations over time. Two streams
feed into the Furman Lake Stream, and another potential study involves testing
the water quality of these headwaters.
Figure 1. Map of collection sites of second order streams feeding Furman
Lake
in Greenville, SC. FU0G, FU01, FU00, FUDP, and FUUP were sampled three
times
on April 7, 2010 for chemical and bacterial data. Conductivity, pH,
dissolved
oxygen, temperature, and fecal indicator bacteria concentration were
quantified
at each of five sites. Previous fecal indicator bacteria quantification
has
been recorded from FU01, FU04, and FU05 between July 2006 and November
2009.
Black lines represent streams and dots represent sample collection
sites.
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Figure 2. Mean total coliform concentrations in a second order stream
feeding
Furman Lake in Greenville, SC. FU0G, FU01, FU00, FUDP, and FUUP were
sampled
three times on April 7, 2010. Total coliform concentrations were
statistically
different among the five collection site according to ANOVA (p=0.0298).
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Figure 3. E. coli concentrations in a second order stream feeding
Furman Lake
in Greenville, SC. FU0G, FU01, FU00, FUDP, and FUUP were sampled three
times
on April 7, 2010. E. coli concentrations were not significantly
different among
the five collection site according to Kruskal-Wallis analysis
(p=0.0705).
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Figure 4. Enterococcus sp. concentrations in a second order stream
feeding Furman
Lake in Greenville, SC. FU0G, FU01, FU00, FUDP, and FUUP were sampled
three
times on April 7, 2010. Enterococcus concentrations were not
significantly different
among the five collection site according to Kruskal-Wallis analysis
(p=0.3820).
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