NONPOINT SOIRCf SICCESS STOIY
Upgrading Wastewater Treatment and Installing Best Management
Practices Improves Crowders Creek
WaterbodieS Improved Agricultural practices failing septic systems, and
urban development led to high fecal cohform and
degraded biological conditions in Crowders Creek. As a result, multiple segments of
the creek were added to the Clean Water Act (CWA) section 303(d) impaired waters
list for fecal coliform and biological impairment in 2002 and 2008, respectively.
Watershed partners implemented numerous agricultural and stormwater best
management practices (BMPs) and improved wastewater infrastructure from 2005
to 2013. These efforts have led to the improvement in water quality of four stream
segments, which were removed from the state's list of impaired waters in 2014.
Problem
Crowders Creek runs through the cities of Kings
Mountain and Gastonia, approximately 23 miles
west of Charlotte, North Carolina. The 26,524-acre
Crowders Creek watershed (HUC 030501011501),
within the Catawba River Basin, flows 12.5 miles
before crossing the South Carolina border (Figure 1).
The watershed comprises a mixture of forested, agri-
cultural, residential, commercial and industrial land
cover. The majority of residential, commercial and
industrial development occurs within the city limits of
Kings Mountain and Gastonia (combined population
of approximately 83,000 residents).
Monitoring conducted by the North Carolina Division
of Water Resources (DWR) in 1989, 1992 and
2002 found fair biological integrity ratings in the
macroivertebrate EPT (short for the order names
Ephemeroptera, Plecoptrea and Trichoptera) index
in two Crowder Creek segments—assessment unit
(AU) 11-135c and AU 11-135d. In addition, fish commu-
nity sampling conducted in 2002 in these segments
indicated decreased diversity and numbers of species
when compared to sampling conducted in 1989. As
a result of these data, North Carolina added these
waterbodies to the CWA section 303(d) list in 2002.
DWR monitoring also showed that Crowders Creek
segments AU 11-135eand AU 11-135f had high
fecal coliform (FC) bacteria counts, prompting the
state to add these two segments to the 2008 CWA
Crowders Creek Watershed
Source: NC Department of Environment and Natural Resources.
2004 Total Maximum Daily Load for Fecal Coliform for Crowders Creek.
Figure 1. The 26,524-acre Crowder Creek watershed is on
the North Carolina/South Carolina border.
section 303(d) list of impaired waters for bacteria.
The state's FC water quality standard requires that
fecal coliform: (1) not exceed a geometric mean of
200 colonies (col) per 100 milliliters (ml), based on at
least five consecutive samples examined during any
30-day period; and (2) not exceed 400 col/100 ml
in more than 20 percent of the samples examined
during that period.
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Total maximum daily load (TMDL) reports generated
for Crowders Creek (in 1996 and 2004) indicated that
low dissolved oxygen, a leaking sanitary sewer and
failing septic tanks were to blame for water quality
impairments in the stream. The 2010 Catawba River
Basin Plan, prepared by DWR, outlined recommen-
dations for restoring Crowders Creek, including:
(1) decommission a failing septic sand-filtration
package treatment system and providing sanitary
sewer extension to three communities of concern,
(2) survey stormwater outfalls to identify dry weather
flows due to illicit discharges, groundwater seep-
age and exfiltration, (3) assess FC input from stream
sediments and in-line sewer deposits as a second-
ary cause of bacteria loads following runoff events,
and (4) develop a spatial decision support system
with field and GIS data to support a comprehensive
watershed and infrastructure improvement program
throughout the watershed.
Project Highlights
Using the Crowders Creek Watershed Plan and
existing TMDL for FC, the city of Gastonia, in part-
nership with the Gaston County Natural Resources
Department and the Gaston Soil and Water
Conservation District (SWCD), planned a complete
overhaul of the existing sewer system. Gastonia and
Gaston County installed a wastewater collection sys-
tem connecting homes to
sanitary sewer, eliminating
straight pipes and decom-
missioning and demolish-
ing failing on-site sand
filter systems (Figure 2).
Over 6,470 linear feet of
sewer line was laid during
phase I of the process,
connecting 93 homes to
sanitary sewer systems
and eliminating 16 straight
pipes to the creek.
Additional work in phase II
added 8,630 linear feet of
sewer line and decommis-
sioned and demolished an
outdated failing sand filter
system fed by a mobile
home community.
Figure 2. Partners installed
sanitary sewer line to
replace failing onsite
systems.
The SWCD and Gaston Natural Resources
Department implemented BMPs on county-owned
properties to address stormwater runoff. Over 100
acres of land are now treated by bioretention areas
that allow infiltration of rainwater and prevent sheet
flow runoff. A stream protection system was installed
to prevent 30 beef cattle from entering the stream,
102 acres of agricultural land were put under long-
term no-till management, 71 acres of land were
planted for critical area buffers and an additional
20 acres of land were converted to grassland.
From 2005 to 2013, Gaston County worked to incor-
porate a stormwater ordinance to protect and restore
the watershed. Sand filters treating 6 acres were
installed, 2 acres of land were installed with bioreten-
tion systems, and an underground inline stormwater
treatment system was installed.
Results
After years of fair benthic data, water quality in AUs
11-135c and 11-135d began to improve (Table 1). On
the basis of these data, AUs 11-135c and 11-135d
were rated as good for aquatic life on the 2014
integrated report.
Table 1. Crowders Creek benthic data (1989-2013)
Waterbody
Crowders Creek
Crowders Creek
Crowders Creek
Crowders Creek
Crowders Creek
Crowders Creek
Crowders Creek
AU
1-135d
1-135d
1-135d
1-135d
1-135c
1-135c
1-135c
Date
10/09/2013
7/10/2007
5/20/2002
08/20/1997
01/7/2014
05/21/2002
09/21/1989
Rating
Good*
Good-Fair
Fair
Fair
Good*
Good-Fair
Fair
*Fully support designated uses
FC numbers also declined. Data collected from 2011
to 2013 in AU 11-135eand AU 11-135f showed FC lev-
els of 200 cfu/100ml_, indicating that these segments
are safe for recreation. As a result, these AUs were
delisted fortheir FC impairment in 2014.
Partners and Funding
The water quality improvement in Crowders Creek
can be attributed to many stakeholders active in the
restoration effort throughout the watershed, includ-
ing the U.S. Environmental Protection Agency (EPA),
North Carolina DWR, the city of Gastonia, Gaston
County, University of North Carolina-Charlotte and
the Gaston County Natural Resources Department/
SWCD. A combined total of $2,415,338 has been
invested in the watershed since 2003, with a small
portion of EPA CWA section 319 funding ($181,133)
directed towards plan development and failing
septic tanks.
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O
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA#841-F-15-001SS
November 2015
For additional information contact:
Heather Jennings
NC Division of Water Resources
919-807-6437 • heather.b.jennings@ncdenr.gov
Dr. Jy S Wu
UNC Charlotte Civil Engineering
704-687-1240 • jwu@uncc.edu
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