Section 319
NQNPOINT SOIHCE PROGRAM SUCCESS STORY
LSi
Implementing a Total Maximum Daily Load Reduces Bacteria
A/ K r\ I r\ Data from four monitoring sites within South Carolina's Rocky Creek
VBtGrDOOy irnprOVGQ watershed showed that the creek was impaired by fecal coliform bacte-
ria from agricultural practices, failing septic systems, forest runoff and other sources. As a result, the South
Carolina Department of Health and Environmental Control (SCDHEC) added four sites to the 2000 Clean
Water Act (CWA) section 303(d) list of impaired waters. Landowners implemented agricultural best man-
agement practices (BMPs) and upgraded septic systems, significantly reducing fecal coliform levels. The
four impaired Rocky Creek sites are showing progress toward attaining water quality criteria.
Problem
The Rocky Creek watershed covers an area of
approximately 127,872 acres in Chester and Fairfield
counties in northern South Carolina. SCDHEC
identified four sites within the watershed (CW-002,
CW-174, CW-175, and CW-236) as impaired by fecal
coliform bacteria and consequently added them to
the 2000 CWA section 303(d) list of impaired waters.
South Carolina derived its standards for primary
contact recreation from public health data used
in estimating humans' potential risks of contract-
ing waterborne illnesses after swimming due to
exposure to sewage-related pathogens. The degree
to which Rocky Creek supports its recreational use
is based on how often fecal coliform bacteria levels
exceed standards (number of excursions). For fecal
coliform bacteria, an excursion is an occurrence of
a concentration greater than 400 colony-forming
units (cfu) per 100 milliliters (ml) for all classes. If
10 percent or less of the samples are greater than
400 cfu/100 ml, recreational uses are said to be
fully supported; a 10 to 25 percent excursion is
considered partial support of the criterion unless
exceedances are due to natural conditions; and a
25 percent excursion rate or more indicates that the
standard is not supported.
Although the watershed is primarily forested, a
significant amount of land is in agricultural use,
particularly cattle pasture (Figure 1). Other fecal
coliform sources include runoff from wildlife in
forested areas, land application of manure, failing
septic systems, urban runoff, and leaking or over-
flowing sewer systems. To address these sources,
the SCDHEC used water quality data collected at
the monitoring sites to develop a total maximum
daily load (TMDL) for the watershed and begin the
restoration process. As the TMDL was developed,
preliminary studies identified sources of fecal
Figure 1. A site in the Rocky Creek watershed
before (top) and after (bottom) the landowner
installed livestock exclusion fencing.
coliform in the watershed and developed appropri-
ate BMPs for mitigating the sources.
Project Highlights
In 2004 South Carolina initiated a three-year proj-
ect to improve water quality in the Rocky Creek
watershed by reducing fecal coliform concentra-
tions and implementing a TMDL. The project was
developed in cooperation with landowners to design
appropriate site-specific BMPs that would benefit
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both water quality and farm operations. The project
targeted seven farms for participation on the basis
of affordability and the greatest potential for benefit
to the SCDHEC's water quality program. The BMPs
implemented included building fences along streams
and creeks to exclude livestock; installing cross-
fencing to reduce pasture size and better control
grazing; using no-till planting to reduce erosion;
adding vegetation buffers and filter strips; installing
water well/watering systems (Figure 2); establishing
stream crossings; and building manure sheds and
covered composters. Each
participating landowner
implemented at least four
and as many as six BMPs.
In addition to implement-
ing BMPs on the seven
selected farms to control
agricultural fecal coliform
sources, the project
addressed residential fecal
coliform sources. The
project partners identified
homeowners in the Rocky
Creek watershed who
had failing septic systems
Figure 2. This alternative watering
source, underlain by geotextile pad
and crushed gravel to prevent
erosion, serves two cattle pastures.
and then designed and implemented septic system
improvements for those willing to participate.
Results
The data collected indicate water quality improve-
ment at three of the four monitoring sites in the
Rocky Creek watershed after placing BMPs on par-
ticipating farms and repairing homeowners' septic
tanks. A comparison of data from 2004 and 2006
indicates that the three sites have all improved from
not supporting to partially supporting the creek's
recreational use. Table 1 shows the improvement at
each station.
In addition, fecal coliform levels have dropped
since the installation of BMPs. Table 2 shows the
geometric mean of fecal coliform values at the four
monitoring sites before and after BMP installation.
TMDL implementation efforts have continued in the
watershed. The state's goal is to improve water qual-
ity until data from all four stations fully meet water
quality standards for fecal coliform. Water quality
improvements to date were accomplished thanks
to farmers installing nearly 50,000 feet of animal
exclusion fencing and more than 65 other individual
Table 1. Exceedance Percentages for Fecal Coliform
Standard and Use Support Classification (Based on
2004 and 2006 Data Assessments)
Site ID
CW-002
CW-175
CW-236
CW-174
2004 FC Levels
26.09% exceedance
(Not supporting)
28.57% exceedance
(Not supporting)
31.04% exceedance
(Not supporting)
10.71% exceedance
(Partial support)
2006 FC Levels
19.44% exceedance
(Partial support)
20.69% exceedance
(Partial support)
23.91% exceedance
(Partial support)
11.77% exceedance
(Partial support)
Table 2. Fecal Coliform Geometric Mean Values Before
and After BMP Installation
Site ID
CW-002
CW-175
CW-236
CW-174
FC Levels Before (cfu/lOOmL)
343.66
248.59
281.15
60.03
FC Levels After (cfu/lOOmL)
296.22
37.02
216.67
16.50
BMPs, including alternative watering systems,
heavy-use areas, septic system repairs, and veg-
etated buffer zones with the secondary benefit of
providing habitat for wildlife.
Participating landowners expressed satisfaction
with the benefits received from the CWA section
319 program, noting improved health of their cattle,
increased property values, and improved water
quality in local creeks and streams. Implementing
selected BMPs has reduced fecal coliform bacteria
levels and increased participation in nonpoint source
control measures by watershed landowners. The
waterbody is showing progress toward attainment
of water quality criteria, and monitoring will continue
in order to measure success.
Partners and Funding
The project partners were SCDHEC; Research
Planning, Inc. (RPI), a science technology firm;
the City of Columbia; and the Clemson University
Cooperative Extension Service. The project was
funded by $243,427 in CWA section 319 grant funds
and a nonfederal match of $173,454. The nonfederal
component consisted of financial and labor contri-
butions by the landowners, as well as other select-
ed expenses covered by RPI and its associates.
UJ
O
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-09-001GG
October 2009
For additional information contact:
Meredith Murphy
NPS Coordinator, SC Department of Health
and Environmental Control
803-898-4222 • murphymb@dhec.sc.gov
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