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1 NONPOINT SOURCE SUCCESS STURY
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Community Partnerships Restore the Water Quality of Mill Creek
Watprhnrh/ lmnrn\/pH 'n ^006, the Alabama Department of Environmental Management
(ADEM) added Mill Creek to the Clean Water Act (CWA) section
303(d) list due to a poor macroinvertebrate assessment rating. In 2010, the listing was updated
based on additional data that indicated Mill Creek did not fully support its use classification of
fish and wildlife with respect to organic enrichment, low dissolved oxygen, and compromised
macroinvertebrate community as a result of urban development and runoff. Partners implemented
targeted best management practices (BMPs) to reduce nonpoint source (NPS) pollution using a
watershed management plan (WMP) developed with stakeholder contributions. Water quality
improved thanks to a series of CWA section 319(h) implementation grants and community support
in the watershed, and ADEM removed the segment from the CWA section 303(d) list in 2018.
Problem
The headwaters for Mill Creek are In the city of Smiths
Station in Lee County, Alabama. The stream flows for
9.93 miles through Lee County into Russell County
and eventually discharges into the Chattahoochee
River in Phenix City, Alabama (Figure 1). The basin is
in the Southeastern Plains, Fail Line Hills Ecoregion
(Ecoregion 65i), which is characterized by loamy and
sandy sediments, in 2011 the watershed was com-
prised of approximately 60% urban development and
31% forested iand. The Recovery Potential Screening
Tool estimated that a 7.7% increase in urban develop-
ment occurred between 2001 and 2011. This land use
change contributed additional stress that threatened
Mill Creek's water quality.
An NPS screening assessment of the Chattahoochee
and Chipola river basins revealed the macroinverte-
brate community was impaired. In 2006, ADEM listed
Mill Creek on the CWA section 303(d) list with the
cause and source of impairment both as unknown. In
2010, after further sampling, the CWA section 303(d)
list was updated to signify the stream did not fully
support its use classification of fish and wildlife. This
impairment was attributed to a dissolved oxygen level
of less than 5.0 milligrams per liter (mg/L) and organic
enrichment that was elevated over the least-impaired
reference reach data collected elsewhere in Ecoregion
65i. (When assessing impairment, ADEM's reference
condition approach considers ambient water quality
data from reference streams in the same ecoregion
Figure 1. Monitoring stations along Mill Creek.
and having characteristically similar watersheds.)
Riparian buffer loss combined with increased impervi-
ous surfaces and urban development/runoff in the
watershed have been identified as a source of the
excessive nutrients and sedimentation that resulted
in decreased water quality and increased stormwater
volume entering Mill Creek.
Story Highlights
In 2010, Alabama Cooperative Extension System
(ACES), ADEM, and other local, private and public
entities collaborated to assemble information for the
Mill Creek WMP. The goal of the plan was to identify
scientifically supported and economically effective
restoration activities to improve the health and habitat
• Mill Cr Stns 2013
• Mill Cr Stns 2014
— AL 03130003-
0101-100
Mill Creek
Watershed

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of Mill Creek. The objective of this plan was to address
impairments to the creek with on-the-ground BMPs
and education for the communities in the watershed.
Beginning in 2011, the first phase of the project
involved installing bioretention cells, rain gardens,
vegetated swales, constructed stormwater wetiands,
stream restoration, sediment and erosion control prac-
tices, and a septic tank pump-out program. In addition,
education/outreach activities included presentations
at local schools and public meetings for landowners.
A second phase (2013-2016) focused on accelerating
the removal of the waterbody from the CWA section
303(d) list and reducing excessive NPS pollutant
loadings to the waterbody. The project targeted
high-yielding pollution sites, partnering with local
landowners to install BMPs to control NPS runoff, and
providing education and outreach to the surrounding
community. BMPs implemented included three stream
restorations, a constructed stormwater wetland, a rain
garden with cisterns, and streambank stabilization.
The low impact development practices such as
bioretention cells, rain gardens, swales, and wetlands
created during these projects allow for detention and
infiltration of stormwater to reduce the volume of
urban runoff. Nutrient uptake has been enhanced with
the installation of additional vegetation with these
practices, which reduces the abundance of organic
enrichment entering the stream. The stream restora-
tion regenerated habitat complexity with riffles, pools,
runs, and woody/natural materials, which increased
the abundance and diversity of macroinvertebrates in
the stream. The structures placed in stream redirect
the flow of water to the middle of the stream channel,
which reduces stream bank erosion. Improved aera-
tion occurs when air is drawn into the water as it flows
over structures in the stream (Figure 2).
Results
In 2014, ADEM sampled station MICR-1 for indicators
of excessive organic enrichment and dissolved oxygen.
Water quality in parameters for organic enrichment
were within the ecoreference level concentrations.
Dissolved oxygen concentrations remained within
normal levels during the sampling events and
ranged between 5 and 10.5 mg/L. In 2014, eight
EPT (Ephemeroptera, Plecoptera, and Trichoptera)
^tD	y.s. Environmental Protection Agency
0**	Office of Water
\	Washington, DC
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pRol^	January 2020
Figure 2. A boulder cross-vane redirects erosive flows.
taxa were also collected, an increase from samples
collected In 1999 (one EPT) and 2008 (four EPT); the
Improved macroinvertebrate assessment rating is
designated as fair. The ADEM assessment of water
quality data collected following the implementation of
numerous restoration activities in the watershed from
2011-2016, determined that Miii Creek fuily supports
its use classification and removed the segment from
the 2018 CWA section 303(d) list.
Partners and Funding
ACES and Auburn University coordinated the Mill
Creek watershed projects. Partnerships that developed
and strengthened through the years contributed to the
project success. Three CWA section 319(h) watershed
implementation grants from fiscal years 2009, 2011,
and 2012, which totaled $534,963 in federal fund-
ing, was the principal funding source for restoration
activities. Watershed partners provided $433,092
in nonfederal match. The National Fish and Wildlife
Foundation's Five Star Grant leveraged $49,964 for
the stream project and an outdoor classroom. Other
partners include Smiths Station; Lee and Russell
counties; Phenix City; Lee County Board of Education;
University of Georgia Extension Services; Columbus
Water Works; North State Environmental, LLC;
Jennings Environmental, LLC; Zink Environmental, LLC;
Alabama Water Watch; Chattahoochee River Warden;
Phenix City Beautiful; Consolidated Resources; Phenix
City Public Schools; Motz Enterprises, Inc; Erosion Pros;
Alabama Power; Alabama Clean Water Partnership;
and others.
For additional information contact:
Alabama Nonpoint Source Management Program
Alabama Department of Environmental Management
334-260-4501 • ADEM.NPS.Program@adem.alabama.gov
Eve Brantley
Alabama Cooperative Extension System
334-844-3927 • brantlef@auburn.edu

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