Section 319
NONPOINT SOURCE PROGRAM SUCCESS STORY
Local Group and Partners Implement Practices to Reduce Atrazine in
Higginsville South Lake
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HeavyherbicideaPP|icationon row crops and a golf course,
combjnec| with subsequent storm runoff, impaired water quality in
Missouri's Higginsville South Lake. The lake, a drinking water source for several nearby towns and
a three-county public water supply district, was placed on the 1998 Clean Water Act (CWA) section
303(d) list of impaired waters for high concentrations of atrazine. Through planning and outreach
programs, farmers were encouraged to measure and time herbicide applications more carefully and
implement best management practices (BMPs). The lake met water quality standards for atrazine in
2003 and was removed from the impaired waters list in 2004.
Problem
The 147-acre Higginsville South Lake provides drink-
ing water for several towns and a rural water district
in west-central Missouri (Figure 1). Located in
Lafayette County within the Blackwater River Basin,
the reservoir's subwatershed drains approximately
3,200 acres of primarily agricultural land.
State records indicate that elevated levels of
atrazine existed in the lake beginning in 1994.
Atrazine is commonly applied in Missouri on corn,
sorghum and pastures to control broadleaf weeds.
New atrazine label restrictions were added regard-
ing application rates and required setbacks in 1993;
however, atrazine continues to be used in Missouri.
Atrazine is considered a human carcinogen and
the state water quality standard for groundwater
and drinking water supply is set at the maximum
contaminant level (MCL) of 3 micrograms per liter
(jUg/L). Unlike many herbicides, atrazine is weakly
adsorbed (attached) to soil particles and nearly
all soils found in the Blackwater River watershed
have moderate to severe potential for pesticide
loss due to runoff or leaching. The local golf course
was an additional source of the herbicide, where it
was used to control broadleaf weeds. Runoff from
the golf course flowed to Higginsville South Lake,
increasing atrazine concentrations in the water-
body. According to Missouri Department of Natural
Resources (DNR) data, in 1997 the lake contained
atrazine concentrations of up to 6/jg/L. As a result,
DNR added the Higginsville Lake South (segment
(MO-7190-L) to the 1998 CWA section 303(d) list.
Figure 1. Higginsville South Lake is in Lafayette County in west-
central Missouri.
A total maximum daily load (TMDL) information
sheet was written by Missouri DNR in 2002 (and
revised in 2004) in preparation for developing a
TMDL to address the contaminated drinking water
supply and beneficial use impairment by atrazine.
The water was declared restored before a full TMDL
could be developed.
Projects and Highlights
Average atrazine concentrations exceeded the
MCL in Higginsville South Lake beginning in 1994.
In response, the city of Higginsville applied to the
Missouri DNR for an exemption to the atrazine MCL.
In August 1995, an exemption was provided to allow
up to 1 year for planning and implementing a perma-
nent solution for the high atrazine concentrations.
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As a result, in 1995 a watershed steering committee
was formed to develop the Higginsville City Lake
Watershed Management Plan to address atrazine
and other potential drinking water contaminants in
the lake.
A $214,000 CWA section 319 grant was provided
from 1996-2000 to the Missouri Corn Growers
Association, later associated with Syngenta
Corporation, for the Watershed Research and
Stewardship Project. The overall goal of the proj-
ect was to continue to provide leadership in the
water policy determination process and to assist
Missouri's corn growers in water resource steward-
ship. Production practices were evaluated for their
effect on water quality and economics. Practice
evaluation included tillage practices and herbi-
cide programs over a large area, which included
Higginsville South Lake. Special emphasis was
placed on increasing the effectiveness of buffer
strips. The project also assisted with water quality
monitoring and analyses.
The watershed steering committee worked with
the Higginsville Country Club golf course to ensure
the use of U.S. Environmental Protection Agency
(EPA)-certified applicators and to help establish
a policy for application, storage and handling of
all chemicals on-site. Shoreline stabilization and
clean-out of culverts and drainage ways were also
performed. The U.S. Department of Agriculture's
Natural Resource Conservation Service (NRCS)
and Lafayette Soil and Water Conservation District
(SWCD) worked extensively to install practices
to reduce atrazine runoff from other areas of the
watershed. Practices included grassed waterways,
vegetated buffers, two-pass application systems,
and increased use of no-till farming and alternative
herbicides.
In 1999 a $4,000 CWA section 319 grant supported
the Osage Valley Resource Conservation and
Development's program providing portable table-
sized watershed interactive models to help initiate
water quality-related discussions and educational
interactions at area schools and local civic group
events.
In 2009 the Higginsville South Lake watershed plan
was revised to address EPA's nine critical ele-
ments. These watershed efforts led to water quality
improvement in Higginsville South Lake. Watershed
information, outreach, planning, demonstration and
implementation efforts were all a result of collabo-
ration and partnership efforts.
Trend for Atrazine in Higginsville South Lake
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1990 1995 2000 2005 2010
Year
Figure 2. Atrazine levels in Higginsville South Lake
have declined since 2000 and became undetectable
after 2005.
Results
Monitoring results show that atrazine in the lake has
declined since 2000 (Figure 2). Higginsville South
Lake was determined to be attaining applicable
water quality standards in 2003 and now fully sup-
ports its public drinking water supply designated
use. In January 2004, the average in-lake concentra-
tion of atrazine was 2.09/jg/L. Quarterly samples
collected from 2005 through 2007 showed that
atrazine was no longer detected in the lake.
Partners and Funding
Monitoring of Higginsville South Lake began in
1992 through a partnership that included Novartis,
Monsanto, Syngenta and the Missouri DNR.
In February 1995 a public meeting was held to
address the levels of atrazine and other contami-
nants in Higginsville South Lake. The meeting was
hosted by the city of Higginsville, Lafayette County
SWCD, Missouri Farm Bureau, Ciba Corporation,
and DNR. Funding was provided by the NRCS, the
University of Missouri Outreach and Extension,
and the Missouri Department of Conservation. City
residents, elected officials, farm owners and pro-
ducers, representatives of agricultural businesses
and manufacturers, and government agencies were
recruited to participate in a steering committee. The
watershed steering committee directed activities
and developed a watershed management plan.
Two CWA section 319 grant-funded projects (a total
of $218,000 between 1996 and 2000) supported the
watershed partners' improvement efforts. Other
partners whose efforts contributed to this success
story include the Corn Growers Association and the
Higginsville Country Club.
s
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-001Q
February 2015
For additional information contact:
Colleen Meredith
Missouri Department of Natural Resources
Soil and Water Conservation Program
573-751-7143 • colleen.meredith@dnr.mo.gov
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