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One of the problems associated
with the use of ambient water quality standards for surface water regulatory
compliance is the difficulty of identifying nonpoint source pollution at the
local level. To this end,
practitioners in the real world need credible information to make informed
decisions on improving local surface water quality.
Our research attempts to address the practitioner’s needs by using
alternative (less expensive) nutrient and bacteria measurement and a targeted
sampling strategy to locate nutrient and bacterial sources in a complex
watershed.
At present all, our fieldwork is
conducted in the rural Bush River watershed located in the South Carolina
Piedmont. The Bush River watershed
is located in the South Carolina Piedmont and is some 297 km2 (116
sq. miles) in area and is on the South Carolina Department of Health and
Environmental Control’s (SCDHEC) 303(d) (or impaired water body) listing for
the fecal coliform indicator bacteria based on the designated recreational use. In
addition, the watershed is impaired for total phosphorus at its outlet into Lake
Murray at SCDHEC site S-309.
We divided the watershed into 24
manageable reaches and sampled each reach repeatedly, analyzing for total
nitrogen (TN) total phosphorus (TP) and Escherichia
Coli bacteria. The most
polluted stream reaches are located in riparian grazing operations, and one was
located in a downtown area. We have
found that these traditional “nonpoint sources” behave like point sources in
the sense that we were able to detect significant pollution, even under base
flow conditions. We found that this
sampling strategy gives practitioners the real-world information they needed to
communicate with their respective stakeholders and that the information provides
them with reasonable justification to take concrete management actions in the
watershed.
Our ongoing monitoring efforts
are focused on targeted sampling for E.
coli of in two of the most polluted reaches where the specific sources are
not identified. In addition, we are
sampling the whole watershed regularly to measure the effects of newly installed
best management practices
Questions? e-mail Buz Kloot at rwkloot@esri.sc.edu
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