^tosrx
a
I NONPOINT SOURCE SUCCESS STURY
- -
ArkMnsM
Reducing Agricultural Runoff Improves Water Quality in the Cache River
Waterbody Improved
High lead levels in sediment running off from row crop areas impaired
Arkansas' Cache River. As a result, the Arkansas Department of
Environmental Quality (ADEQ) added two segments of the stream (47.6 miles total) to the state's 2004 Clean Water
Act (CWA) section 303(d) list of impaired waters and three segments (47.9 miles total) to the state's 2006 CWA
section 303(d) list for lead impairment. Watershed partners initiated watershed assessments and implemented
best management practices (BMPs) to abate sediment runoff from row crops in the watershed. Along with
sediment reductions from the BMPs, lead levels in the Cache River also declined and fell below the water quality
standard (WQS). Although the stream remains impaired for turbidity, ADEQ removed five segments from the 2016
CWA section 303(d) list for lead impairment.
Problem
The Cache River (Waterbody AR-4B-08020302) is a
long, narrow watershed that includes parts of Greene,
Craighead. Poinsett,, Jackson. Woodruff, Monroe,
Prairie, Lawrence and Clay counties (Figure 1). The
Cache River begins in southern Missouri, flows 203
miles south through northeastern Arkansas, and emp-
ties into the White River near Clarendon, Arkansas.
Bayou DeView is a major tributary to the Cache River.
Runoff from agricultural row crop fieids was contribut-
ing excess lead to the Cache River as the sediments
from these fields also contained high ievels of lead
from iegacy agricultural practices. An October 1998-
September 2003 ADEQ assessment (for the 2004 CWA
section 303(d) list) found that reach 018 (25 miies
long) and reach 020 (22.6 miies long) did not meet
the state's WQS for lead. The next ADEQ assess-
ment, conducted October 2000-September 2005
(for the 2006 CWA 303(d) list), found that reaches
017 (15.8 miles long), 019 (13.7 miles long), and 021
(18.4 miles long) also did not meet the state's WQS for
lead, in Arkansas, the WQS for lead in a given stream
reach is derived from the hardness index; therefore, it
varies by region, in the Cache River, the WQS for lead
is 2 micrograms per liter (|ig/L). ADEQ found exceed-
ances of the WQS when sampling during high-flow
events. The samples were evaluated, and the five
reaches were added to the state's 2004 and 2006
CWA section 303(d) lists of impaired waters for lead
impairment. ADEQ subsequently completed draft total Figure L The Cache River is in northeast Arkansas,
maximum daily loads for lead and total dissolved solids Lead impairment has been removed from stream
for the Cache River in 2012.	reaches 017, 018, 019, 020 and 021.
1 Impaired Reaches
—	Streams
—	Cities
Major
Highway
Missouri
Arkansas

-------
Surface inlet with trash guard.
Surrounded with riprap underlaid with
non-woven geotextile
Grassed berm
Outlet drainage
channel or stream
Anti-seepage collar
Corrugated steel outlet pipe
(or equivalent) with hinged rodent gate
Riprap or other protection flush with drainage
channel surface underlaid with non-woven geotextile
Figure 2. An illustration of a type of drainage water
management system BMP implemented in the watershed.
Project Highlights
in 2001 the Jackson County Conservation District
(JCCD) and The Nature Conservancy (TNC), using CWA
section 319 funds provided by the Arkansas Natural
Resources Commission (ANRC), began providing
financial and technical assistance to help landown-
ers implement drainage water management systems
in runoff-prone agricultural fields (Figure 2). Many
landowners took advantage of this opportunity; they
installed 430 water control structures, preventing
approximately 36,980 tons per year of soil from erod-
ing and entering the Cache River. By controlling the
rate, velocity and volume of field runoff, these BMPs
help prevent sediment (which carries lead) from leav-
ing agricultural fields and entering the stream.
In 2004, TNC used CWA section 319 funding from
ANRC to propose a work plan for a series of integrated
sediment, hydrological, geomorphological and biologi-
cal monitoring surveys. The surveys culminated in a
report and spatial relational database containing a
priority ranking of the Cache River's tributary streams.
Because of the short length of the study (one year),
however, no flow regime or water quality trends could
be established for statistical predictions.
From 2006 until 2009, TNC began a second phase of
the project with funding assistance from ANRC through
CWA section 319. This phase built upon the first TNC
project by honing in on specific areas of concern in
high-priority subwatersheds that were identified in
phase L Upon completion of the project, critical stream
bank erosion areas were identified, ranked and priori-
tized based on the sediment contribution to the Cache
River main stem. This information was used for future
implementation projects that Installed BMPs designed
to reduce the sediment and lead contributions in
the watershed; it also allowed for a system of ranking
streams in the priority watershed. As a result, ANRC
was able to make data-driven management decisions
concerning funding allocation in the watershed.
The Cross County Conservation District (CCCD) installed
water conveyance and control structures in the water-
shed from 2009 to 2011. A total of 13 water control
structures were installed in the Cache River Watershed,
which wiii prevent 3,805 tons of soii erosion per year.
Moving forward, this project wili continue to reduce the
amount of lead and sediment entering the Cache River.
Results
ANRC and its partners successfully addressed erosion
and excess lead from agricultural row crop sources
through cost-effective targeting of CWA section 319
funds. As a result of the practices implemented in
the watershed, both lead and sediment levels have
decreased. The 2016 ADEQ water quality assessment
showed that Cache River reaches 017, 018, 019, 020
and 021 now meet the state's WQS for lead. Therefore,
ADEQ has removed these five reaches from Arkansas'
2016 CWA section 303(d) list for lead impairment. The
stream remains listed as impaired for turbidity.
Partners and Funding
The following partners helped to restore the five reaches
of the Cache River: local landowners in the watershed,
JCCD, CCCD, TNC, ANRC, ADEQ, the U.S. Department of
Agriculture's Natural Resources Conservation Service,
and the U.S. Environmental Protection Agency (EPA).
ANRC provided $994,751 of EPA CWA section 319 funds
to watershed partners to support several projects. JCCD
and TNC used $250,000 in CWA section 319 funds to help
local landowners identify problem areas and purchase
materials for implementing BMPs. JCCD and TNC also
provided $200,400 in cash and in-kind match to purchase
and install materials. CCCD used $450,000 in CWA section
319 funds to purchase BMP materials. CCCD also provided
$450,000 in cash and in-kind match to purchase and
install materials.
TNC used $294,751 In CWA section 319 funds to iden-
tify, quantify and rank stream segments for restoration.
These data helped pinpoint projects where targeted
BMPs could reduce sediment inputs in the watershed.
TNC also provided $247,220 in cash and in-kind match
to identify priority stream segments in the watershed
and install monitoring stations.
* ^ '
%
\
*1 PROt*°
2
0
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-16-001W
October 2016
For additional information contact:
Kevin McGaughey
Arkansas Natural Resources Commission
501-682-3908 • Kevin.mcgaughey@arkansas.gov

-------