Section 319
NONPOINT SOURCE PROGRAM SUCCESS STORY
Implementing Best Management Practices Restores Water Quality in the
Keya Paha River
A/ t h H I H Agricultural nonpoint source pollution contributed to elevated
VVaterDOay imprOVea sedimentand bacteria levels in South Dakota's Keya Paha River. As
a result, the river was placed on South Dakota's 1998 Clean Water Act (CWA) section 303(d) list of
impaired waters due to these pollutants. Through the Lewis and Clark Lake Implementation Project,
the Randall Resource Conservation and Development (RC&D) Council worked with landowners to
voluntarily implement best management practices (BMPs) to reduce sediment and bacteria levels in
runoff. The river now meets the sediment standards and attains its warmwater semipermanent fish life
designated use. As a result, South Dakota removed the Keya Paha River's sediment impairment from
the state's list of impaired waters in 2014.
Problem
The Keya Paha River drains 1,092,300 acres in
southern South Dakota before entering Nebraska
and emptying into the Niobrara River (Figure 1). The
watershed is comprised of 57 percent rangeland
and 42 percent cropland. The Keya Paha River
begins at the confluence of Antelope and Rock
creeks near the Rosebud Indian reservation and
flows 68 miles to the Nebraska border.
The Keya River contributes sediment and bacteria to
the Niobrara River, which in turn discharges these
pollutants to Lewis and Clark Lake, a reservoir on
the Missouri River near Yankton, South Dakota. The
reservoir provides recreational opportunities and pro-
vides drinking water to South Dakota and Nebraska
residents. Sediment and bacteria loading from the
Keya Paha River threaten these beneficial uses.
To meet water quality standards for sediment, the
30-day average total suspended sediment (TSS)
concentration must be less than or equal to 90 mil-
ligrams per liter (mg/L) and the daily maximum must
not exceed 158 mg/L more than 10 percent of the
time. To meet standards for bacteria, fecal coliform
must not exceed a geometric mean of 1,000 colony-
forming units per 100 mL of water (cfu/100 mL) and
no single sample may exceed 2,000 cfu/100 mL
more than 10 percent of the time. In addition,
Escherichia coli must not exceed a geometric
mean of 630 cfu/100 mL and no single sample may
exceed 1178 cfu/100 mL more than 10 percent of
the time.
Best Management Practices
I KevaPalia«aleBlied • agwasesjswn
• urwnpared segment or Keya pana O cruca1 Mea Flaming
hlpafedGegTHlttf Kefa p*u A Grazing Management
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Figure 1. The Keya Paha River watershed is in
south-central South Dakota. Partners installed
numerous best management practices throughout
the watershed.
Monitoring data indicated that the Keya Paha
River failed to meet these water quality standards
for TSS and bacteria (fecal coliform and £ coli}.
Therefore, the South Dakota Department of
Environment and Natural Resources (DENR) placed
the 68-mile-long Keya Paha River (segment SD-NI-
R-KEYA _ PAHA _ 01) on the CWA section 303(d) list
of impaired waters for TSS in 1998, fecal coliform in
2008, and £ coli'm 2010. By failing to attain these
water quality standards, the river was unable to
support its beneficial uses for limited immersion
recreation and warm water semipermanent fish life.
DENR completed a TSS total maximum daily load
for the Keya Paha River in 2009.
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pre-1
(2004-
BMP
-2008)
BMP/post-BMP
(2009-2013)
pre-BMP
(2004-2008)
BMP/post-BMP
(2009-2013)
pre-BMP
(2004-2008)
BMP/post-BMP
(2009-2013)
nTSSmg/L waterqualitystandard
-•— %exceedance of standard
| mean£c0//cfu/100mL waterqualitystandard
—•— %exceedanceofstandard
I mean fecal coliform cfu/100 ml. - -. waterqualitystandard
—•— %exceedanceofstandard
Figure 2. Pollution parameter means (left axes) and percent exceedances of beneficial use standards (right
axes) before and during/after restoration. Error bars represent one standard deviation of the data. Percent
exceedances of maximum allowable pollutant concentrations below 10 percent meet the standards.
Project Highlights
After a watershed assessment was conducted from
2003 to 2005, the Randall RC&D Council and its
watershed partners launched the Lewis and Clark
Watershed Implementation Project. The project's
initial goal was to reduce the loads of sediment,
nutrients and bacteria entering Lewis and Clark
Lake by reducing loads in its tributaries, including
the Keya Paha River. BMPs were installed from late
2008 to 2013, and additional BMPs will be installed
in future years. BMPs installed in the Keya Paha
watershed include agricultural waste systems,
winter feeding areas, re-vegetation of critical areas,
riparian restoration and protection projects, and
implementation of grazing management plans that
included fencing to keep cattle out of tributary
creeks.
Results
After restoration, bacteria and sediment levels
decreased. TSS values in the Keya Paha River are
meeting water quality standards. This improve-
ment can be seen in Figure 2, which shows the
decreases in the percent exceedances of the daily
maximum pollutant levels for TSS (from 35 percent
in 2004-2008 down to 5 percent in 2009-2013),
which meets the water quality standard. As a result,
DENR removed TSS from the Keya Paha River's list
of impairments in 2014.
As seen in Figure 2, data show that E. coli bacteria
measurements are borderline, with two out of
10 samples (20 percent) exceeding the standard.
Fecal coliform bacteria measurements just meet
the standard (one out of 10 exceeding, or 10 per-
cent). The Keya Paha will continue to be monitored
for E. coli and fecal coliform to document improve-
ments so that it can be fully evaluated for com-
plete removal from the list of impaired waters.
Partners and Funding
Restoring the Keya Paha River was the result
of hard work from committed landowners and
local, state and federal agencies. The Randall
RC&D Council administered the Lewis and Clark
Watershed Implementation Project. Partners install-
ing BMPs in the Keya Paha watershed included
the Gregory County Conservation District (CD),
Clearfield/Keya Paha CD and the Todd County CD.
South Dakota DENR provided project oversight. The
U.S. Department of Agriculture's Natural Resources
Conservation Service, the U.S. Fish and Wildlife
Service and the U.S. Environmental Protection
Agency contributed funds and expertise. The
Rosebud Cattlemen's Association, South Dakota
Grassland Coalition, the South Dakota Association
of Conservation Districts, South Dakota Pheasants
Forever, and South Dakota Game, Fish and Parks
assisted with BMP design and construction.
BMP installation and monitoring in the Keya Paha
watershed was funded through the Lewis and
Clark Implementation Project from 2006 to 2014.
Partners spent $1,154,457 on six agricultural waste
systems, 16 critical areas, 48 grazing management
plans, and three riparian restoration projects. BMP
funding sources included CWA section 319 funds
($323,247), other federal funds ($247,087), and
state, local and in-kind sources ($584,123).
S
(9
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-001N
February 2015
For additional information contact:
Barry McLaury, South Dakota Department
of Environment and Natural Resources
605-773-5859 • barry.mclaury@state.sd.us
Al Basile, USEPA
303-312-6551 • basile.alfred@epa.gov
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