Section 319
NONPOINT SOORCE PROGRAM SUCCESS STORY
Implementing Best Management Practices Improves Water Quality
ImnrnwoH "' 'eve's °^- co// bacteria and low dissolved oxygen due in part
improved to runoff from agricu|tura| areas impaired Oklahoma's Little Elk
Creek, preventing the waterbody from attaining its primary body contact recreation and fish and wild-
life propagation designated uses. In addition, the stream was impaired from the presence of oil and
grease, which prevented it from attaining its aesthetics designated use. In response, Oklahoma added
a 16-mile-long segment of Little Elk Creek to the state's 2002 Clean Water Act (CWA) section 303(d)
list of impaired waters. Implementing best management practices (BMPs) that promoted conservation
tillage and proper nutrient management led to decreased bacteria and nutrient levels in the creek. As
a result, a segment of Little Elk Creek was removed from Oklahoma's 2008 CWA section 303(d) list for
E. co// and dissolved oxygen. The creek was also delisted for oil and grease. The creek now partially
attains its primary body contact recreation designated use and fully attains its fish and wildlife propaga-
tion and aesthetics uses.
Problem
Little Elk Creek is in Washita and Kiowa counties in
west-central Oklahoma (Figure 1). Land use in the
watershed is primarily cow/calf and wheat produc-
tion. The most likely nonpoint source pollution
problems in the watershed are improperly managed
cattle waste and sediment from eroding crop and
grazing lands. Excess nutrients from agricultural
runoff contributed to the overgrowth of nuisance
algae, and the subsequent breakdown of the algae
caused dissolved oxygen levels to decrease in Little
Elk Creek.
A 2002 water quality assessment found that 16 per-
cent of Little Elk Creek's dissolved oxygen values
fell below the dissolved oxygen criterion of 2.0
milligrams per liter (mg/L). In addition, the runoff of
manure from grazing lands has contributed to high
levels of bacteria in the creek. To meet standards,
levels of E. coli in the stream must not exceed
406 colonies/100 milliliters (ml), and the geometric
mean must be less than 126 colonies/100 ml.
In the 2002 assessment, Little Elk Creek's geo-
metric mean for £ coli bacteria was 177.6 colo-
nies/100 ml, which violated the standard.
Because elevated bacteria levels (E. coli,
Enterococcus, and fecal coliform) and low dissolved
oxygen prevented Little Elk Creek from meeting
its primary body contact recreation and fish and
wildlife propagation designated uses, respectively,
Oklahoma added a 16-mile segment of the creek
to the 2002 CWA section 303(d) list of impaired
waters. Additionally, in 2004 Oklahoma added an
impairment for oil and grease to the CWA section
303(d) list for Little Elk Creek.
Little Elk Creek Watershed
Figure 1. The Little Elk Creek Watershed is in west-
central Oklahoma.
Project Highlights
Landowners implemented numerous BMPs with
support from Oklahoma's locally led cost-share
program; Natural Resources Conservation Service
(NRCS) general technical assistance funds; and
NRCS programs such as the Environmental Quality
Incentives Program (EQIP) and the Conservation
Reserve Program. The Little Elk Creek watershed
was part of the EQIP Cheyenne-Arapahoe Local
Emphasis Area project, which began in 2002 and
focused on reducing erosion by improving cropland
and grazing land. From 2003 to 2007, landowners
implemented conservation tillage (mulch till, no
till, strip till) on 1,452 acres and conservation/cover
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ed Oxyg
Little Elk Creek
2002 2008
Assessment Year
Figure 2. Little Elk Creek met standards by 2008. A
stream is impaired for dissolved oxygen if two or
more samples per year are below 2 mg/L (red line) or
if more than 10 percent are below 5 mg/L (black line)
[or 4 mg/L from June 16-Oct. 15 (dashed black line)].
Little Elk Creek
2 500-
126
0-
Geometric Mean = 177.6
Geometric Mean = 103.5
2002 2008
Assessment Year
Figure 3. Bacteria levels in Little Elk Creek met
bacteria water quality standards by 2008. Boxplots
indicate the interquartile range (25th-75th percentile)
and median of the data for assessment years 2002
and 2008.
crop rotations on more than 1,000 acres. They
established contour farming on 237 acres, which
included adding 51,549 feet of terraces, 1,842 feet
of diversions, five grade-stabilization structures,
three ponds, and 58 acres of grassed waterways.
Landowners also improved grazing lands by plant-
ing 516 acres of pasture and 151 acres of range,
adopting nutrient management on 1,565 acres, and
initiating pest (weed) management on 1,455 acres.
BMP implementation continued during 2008 and
2009. Farmers converted another 1,647 acres of crop-
land to conservation tillage and added conservation
crops in rotation on 184 acres. Other BMPs consisted
of adding another 184 acres of contour farming, plant-
ing 8 acres of grassed waterways, adding almost
64,000 feet of terraces, adopting nutrient manage-
ment on 456 acres, implementing weed management
on 340 acres, conducting prescribed grazing on
152 acres, and planting 51 acres of pasture.
Results
The Oklahoma Conservation Commission's (OCC's)
statewide nonpoint source ambient monitoring
program, known as the Rotating Basin Monitoring
Program, documented water quality improvements
in Little Elk Creek. The installed cropland and graz-
ing land BMPs decreased the amount of erosion,
which in turn reduced nutrient loading to streams
because phosphorus typically binds to soil particles.
Reductions in nutrients reduced algal growth and
resulted in increased levels of dissolved oxygen
observed in Little Elk Creek. No samples fell below
state dissolved oxygen criteria in the 2008 assess-
ment (Figure 2).
In addition, implementing pasture and range land
BMPs increased the density of vegetation, which
helped to reduce the volume of runoff and the
transport of soil, nutrients and bacteria into water-
bodies. The geometric mean for £ coli bacteria was
reduced from 177.6 colonies/100 mL in the 2002
assessment to 103.5 colonies/100 mL in 2008, indi-
cating that the BMPs had been effective (Figure 3).
Additionally, OCC did not observe any oil and grease
in Little Elk Creek from April 2002 to February 2007.
On the basis of those results, Oklahoma removed
the 16-mile segment of Little Elk Creek from the
2008 CWA section 303(d) list of impaired waters for
bacteria, dissolved oxygen, and oil and grease.
Partners and Funding
OCC's Rotating Basin Monitoring Program is funded
using U.S. Environmental Protection Agency (EPA)
CWA section 319 funds at an average annual cost
of $1 million. Monitoring costs fund personnel,
supplies and lab analysis for 19 parameters from
samples collected every 5 weeks at about 100 sites
for a total of 20 episodes per 5-year cycle. In-stream
habitat, fish and macroinvertebrate samples are
also collected. Approximately $600,000 in EPA
section 319 funds supports statewide education,
outreach and monitoring efforts through the Blue
Thumb program.
The Oklahoma cost-share program provided $8,627
in state funding for BMPs in the watershed, and land-
owners contributed $10,976. NRCS invested approxi-
mately $183,493 to implement BMPs in the area
from 2003 to 2007 and had committed $264,075 for
expanding the scope of BMPs in 2008 and 2009.
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-10-001F
March 2010
For additional information contact:
Shanon Phillips
Water Quality Division
Oklahoma Conservation Commission
shanon.phillips@conservation.ok.gov
405-522-4500
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