Section 319
              NONPOINT  SDURCF PROGRAM  SUGCESf  STORY
Land Treatment Practices Lower Atrazine Levels
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                              R°ut'ne monitoring conducted by the Nebraska Department of
                              Environmenta| Qua|ity (DEO) in 1997 identified high concentrations of
                              atrazine in southeast Nebraska's Swan 5A Reservoir, prompting DEQ to
add it to the state's 1998 Clean Water Act section 303(d) list of impaired waters for atrazine. In response,
stakeholders developed and implemented a watershed  management plan. The reservoir's atrazine levels
dropped, and DEQ removed Swan 5A Reservoir's atrazine impairment from Nebraska's 2006 303(d) list.
Problem
The 95-acre Swan 5A Reservoir was designed
and developed as a multipurpose, flood-con-
trol/public use area in Saline County, Nebraska,
and falls within the Big Blue River Basin.
Approximately 52 percent of the reservoir's
4,590-acre watershed is used for crop produc-
tion (2,399 acres). Monitoring data collected in
1997 showed that the reservoir had elevated
levels of the herbicide atrazine. This herbicide
is typically applied to crops such as corn and
sorghum—both of which are grown in the
watershed.

The Nebraska water quality standard for
chronic exposure to atrazine is 12 micrograms
per liter (ji/g/L), which is equivalent to 12 parts
per billion (ppb). Eight of the 24 samples col-
lected from the reservoir in 1997 exceeded the
chronic water quality standards with a median
concentration of 5.6 ppb and a maximum
concentration of 42.56 ppb. For the reservoir to
meet standards, regulations would allow only
4 exceedances of the standard in a sample size
of 24. Consequently, DEQ added the reservoir
to the state's 1998 303(d) list of impaired
waters  due to an impairment of the aquatic life
use from high atrazine concentrations.
Project Highlights
The majority of watershed landowners (35 of
43) participated in the project. Participants
implemented numerous pollution control mea-
sures, including placing an additional 65 percent
                            of the cropped ground (1,550 acres) under
                            no-till and nutrient and pesticide manage-
                            ment practices, installing 29,345 linear feet of
                            terraces on highly erosive crop ground, con-
                            structing or restoring 16 water quality basins
                            to original holding capacity, converting 237
                            acres of crop ground to grass, installing 2 new
                            waterways, planting 7 acres of trees, decom-
                            missioning 5 abandoned wells and bringing 6
                            septic systems into compliance with current
                            standards (Figures 1 and 2).
                                                               Figure 1.
                                                               Watershed
                                                               landowners and
                                                               operators attend-
                                                               ed water quality
                                                               workshops to learn
                                                               about the benefits
                                                               of no-till farming
                                                               and nutrient and
                                                               pesticide manage-
                                                               ment.
                            Figure 2.
                            Constructing a weir
                            has established a
                            wetland area directly
                            above the reservoir.
                            The wetland will
                            complement other
                            nonpoint source
                            controls in the
                            watershed aimed at
                            reducing sediment,
                            nutrient and pesti-
                            cide loads.

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In 2003 the Lower Big Blue Natural
Resources District partnered with sev-
eral local, state and federal agencies to
initiate a Community Based Planning
process. Through this locally led process,
the partners developed a Watershed
Management Plan that incorporated a
unique mix of cost share and incentives
to encourage farmers to implement a
host of agricultural management practic-
es. The plan also requires that landown-
ers upgrade septic systems and close
abandoned wells.
Results
           Atrazine Concentrations in Swan 5A Reservoir
    40-
    30-
  .Q
  Q.
  Q.
  •i 20-
  ro
    10-
    0-
                       NE Standard - 12.0
Water quality data collected between
2004 and 2006 showed that all 13 atra-
zine samples were below the standard
with a post-project median concentration
of 2.85 ppb, which led DEQ to remove
Swan 5A Reservoir from the state's
303(d) list in 2006 (Figure 3). Two samples
collected in 2007 exceeded the chronic stan-
dard; however, Swan  5A remained off the 2008
303(d) list because of a large sample size.

Loadings of other targeted pollutants such as
sediment and nutrients have also decreased.
To date, land treatment measures in the water-
shed have helped reduce sediment loading by
almost 69 percent and phosphorus loading by
58 percent—exceeding the 50 percent reduc-
tion goals established for both.
                                                   Pre-Project Atrazine
                                   Post-Project Atrazine
Partners and Funding
The project was made possible through a
strong partnership of the Lower Big Blue
Natural Resources District, U.S. Department
of Agriculture (USDA) Natural Resources
Conservation Service, Nebraska Environmental
Trust, Nebraska DEQ, U.S. Environmental
Figure 3. Boxplots indicate the interquartile range (25th-75th percen-
tile), median (represented by dots) and outliers (represented by aster-
isks) of the date in each of two periods: Pre-project data (years 1997
and 2003) and post-project data (2004-2007).
        Protection Agency, Saline County Cooperative
        Extension, Nebraska Game and Parks
        Commission, Swan Reservoir Watershed
        Council and watershed landowners and opera-
        tors. Section 319 funding supported efforts to
        conduct resource inventories ($7,500), engi-
        neering design ($100,000) and management
        practice cost-share and incentives ($300,000).
        Additional sources of cost share and  incentive
        funds include the USDA Environmental Quality
        Incentive Program ($215,000), Nebraska
        Environmental Trust ($275,000), Lower Big Blue
        Natural Resources District ($124,000) and land-
        owners ($175,000). This project to implement
        land treatment measures began in 2004  and
        will continue through fall 2008. Maintaining a
        high-quality reservoir will continue to be a pri-
        ority for the resource management agencies,
        so they will maintain and implement traditional
        and nontraditional practices as needed in the
        future.
     U.S. Environmental Protection Agency
     Office of Water
     Washington, DC


     EPA841-F-08-001S
     September 2008
       For additional information contact:
       Paul Brakhage
       Nebraska Department of Environmental Quality
       402-471-4224  •  paul.brakhage@ndeq.state.ne.us
       Scott Sobotka
       Lower Big Blue Natural Resources District
       402-228-3402  •  sobotka@lbbnrd.org

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