CrowdersCreekFecalFinalTMDL2004

Total Maximum Daily Load for
Fecal Coliform for Crowders Creek
North Carolina and South Carolina

Final Report
June 2004
Approved July 1, 2004

Prepared by:
NC Department of Environment
and Natural Resources
Division of Water Quality
Water Quality Section
1617 Mail Service Center
Raleigh, NC 27699-1617
[phone]
Catawba River Basin
Crowders Creek TMDL Final Report

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Summary Sheet
Total Maximum Daily Load (TMDL)

1. 303(d) List Information

State: North Carolina, South Carolina
County: Gaston (NC), York (SC)
Major River Basin: Catawba River Basin
Watershed: Crowders Creek, HUC 3050101180010

303(d) Listed Waters (North Carolina)
Name of Stream Description Class Index # Subbasin Miles
Crowders Creek SR 1108 to NC 321 C 11-135e 30837 1.4
Crowders Creek US 321 to SR 2424 C 11-135f 30837 1.4
Crowders Creek SR 2424 to NC/SC line C 11-135g 30837 0.8

Constituent of Concern: Fecal Coliform
Designated NC Uses: Biological integrity, propagation of aquatic life, secondary recreation
Applicable Water Quality Standards for Class C Waters in NC: Fecal coliforms shall not exceed a
geometric mean of 200/100ml (membrane filter count) based upon at least five consecutive
samples examined during any 30 day period, nor exceed 400/100 ml in more than 20 percent of
the samples examined during such period.

303(d) Listed Waters (South Carolina)
Name of Stream Station Description Class Station Impaired
Use
Cause
Crowders Creek At S-46 564 NE Clover Freshwater CW-023 REC FC
Crowders Creek S-46-1104 Freshwater CW-024 REC FC
South Fork
Crowders Creek
At S-46-79 4.5 mi NW Clover Freshwater CW-192 REC FC
REC=recreation; FC=fecal coliform

Constituent of Concern: Fecal Coliform
Designated SC Uses: Primary and secondary contact recreation, a source for drinking water
supply after conventional treatment in accordance with the requirements of SC, fishing and the
survival and propagation of a balanced indigenous aquatic community of fauna and flora, and
industrial and agricultural uses.

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Applicable Water Quality Standards for Freshwater in SC: Not to exceed a geometric mean of
200/100 ml, based on five consecutive samples during any 30 day period; nor shall more than
10% of the total samples during any 30 day period exceed 400/100ml.

2. TMDL Development

Development tools: WARMF model
Critical condition: Exceedances of the fecal coliform occur during both wet and dry conditions,
and all seasons. The TMDL has been determined using a 5-year simulation (1998-2002) covering
a wide range of hydrologic conditions.
Seasonality: Seasonal variation in hydrology, climatic conditions, and watershed activities are
represented through the use of a continuous flow gage and the use of all readily available water
quality data collected in the watershed.

3. Allocation Watershed/Stream Reach

Crowders Creek Fecal Coliform TMDL
Units per day % Reduction
TMDL 2.21E+11

NC Continuous WLA1 8.27E+09 0%
NC MS4 WLA 7.45E+10 79%
NC LA 1.15E+11 79%

SC LA 2.36E+10 79%
Station CW-023 -- 79%
Station CW-024 -- 79%
Station CW-192 -- 79%
1 Continuous point sources must meet monthly geometric mean of 200 cfu/100ml and cannot exceed 400
cfu/100ml maximum.

Total maximum daily load (TMDL): 2.21E+11 units per day
Waste load allocation (WLA): 8.287E+10 units per day
Load allocation (LA): 1.384E+11 units per day
Margin of Safety (applied to the water quality criteria): This TMDL utilizes an explicit margin
of safety (MOS): the geometric mean target is set at 175 cfu/100ml (MOS = 25 cfu/100ml) and
the instantaneous limit is set to 360 cfu/100ml (MOS = 40 cfu/100ml).

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This TMDL is set at the confluence of Crowders Creek and Beaverdam Creek in SC. The TMDL
applies to all impaired segments identified in (1).

4. Public Notice Date: 5/23/2004

5. Submittal Date: 6/10/2004

6. Establishment Date: 7/1/2004

7. Endangered Species (yes or blank):

8. EPA Lead on TMDL (EPA or blank):

9. TMDL Considers Point Source, Nonpoint Source, or both: both
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TABLE OF CONTENTS
1 Introduction.............................................................................................................................1
1.1 Watershed Description....................................................................................................2
1.2 Water Quality Target......................................................................................................3
1.3 Water Quality Assessment..............................................................................................5
2 Source Assessment................................................................................................................11
2.1 Point Source Assessment..............................................................................................11
2.2 Non-Point Source Assessment......................................................................................12
2.2.1 Urban Development and Sewer Systems .................................................................12
2.2.2 Septic Systems..........................................................................................................13
2.2.3 Livestock..................................................................................................................14
2.2.4 Waste Application....................................................................................................15
2.2.5 Wildlife.....................................................................................................................15
3 Modeling Approach...............................................................................................................16
3.1.1 Model Framework....................................................................................................16
3.1.2 Model Setup .............................................................................................................16
3.1.2.1 Observed Data Input........................................................................................17
3.1.2.2 Fecal Loading Initial Inputs.............................................................................18
3.1.2.3 Fecal Coliform Decay......................................................................................19
3.1.3 Calibration................................................................................................................20
3.1.3.1 Flow and Temperature.....................................................................................20
3.1.3.2 Fecal Coliform.................................................................................................24
3.1.4 Model Output ...........................................................................................................27
4 Allocation..............................................................................................................................28
4.1 Total Maximum Daily Load (TMDL)..........................................................................28
4.2 Critical Conditions........................................................................................................29
4.3 Seasonal Variation........................................................................................................30
4.4 Model Uncertainty and Margin of Safety.....................................................................30
4.5 Allocation .....................................................................................................................31
5 Implementation Plan..............................................................................................................33
6 Stream Monitoring ................................................................................................................33
7 Future Efforts ........................................................................................................................33
8 Public Participation ...............................................................................................................34
9 Further Information...............................................................................................................34
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10 References.............................................................................................................................35
11 Appendix...............................................................................................................................37

Appendix I. Water quality data collected in the Crowders Creek watershed (1997-2002)...........38
Appendix II. Land use by WARMF subwatershed based on 1993-1996 landcover in the
Crowders Creek watershed....................................................................................................43
Appendix III. Calibrated soil layer parameters..............................................................................47
Appendix IV. Load allocation calculation for Kings Mountain....................................................49
Appendix V. Modeled fecal coliform loading scenarios...............................................................51
Appendix VI. Load allocation calculations for South Carolina portion of Crowders Creek........52
Appendix VII. Crowders Creek Fecal Coliform TMDL Allocation Worksheet...........................54
Appendix VIII. Septic system loading estimates for the Crowders Creek watershed. .................55
Appendix IX. Affidavits of Publication for Public Notices..........................................................56
Appendix X. Comments on the Crowders Creek TMDL 58
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TABLES
Table 1. Monitoring locations in the Crowders Creek watershed....................................................6
Table 2. Summary of fecal coliform monitoring in the Crowders Creek watershed (1997-2002)...6
Table 3. Potential sources of fecal coliform bacteria in watersheds. ............................................11
Table 4. Summary of septic usage in Crowder’s Creek watershed (NC portion) based on data
taken from Gordon (2003).....................................................................................................14
Table 5. Septic data used in the WARMF model for Crowders Creek..........................................19
Table 6. Livestock data used in the WARMF model for Crowders Creek. ...................................19
Table 7. Precipitation weighting factors and temperature lapse for the Crowders Creek watershed.
...............................................................................................................................................21
Table 8. Calibration statistics for temperature and flow in subwatershed 11. ..............................21
Table 9. Calibration statistics for fecal coliform (#/100ml) in subwatershed 11 (downstream
station)...................................................................................................................................24
Table 10. Existing fecal coliform loading (1998-2002) by source in the Crowders Creek
watershed...............................................................................................................................27
Table 11. Total maximum daily load allocation for the Crowders Creek watershed (detailed in
Appendix)..............................................................................................................................31
Table 12. Relative fecal coliform loading rates in the Crowders Creek watershed.......................32

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FIGURES

Figure 1. Location map for the Crowders Creek watershed.............................................................4
Figure 2. North Carolina monitoring stations within the Crowders Creek watershed. Numbered
stations correspond to sites in Table 1.....................................................................................7
Figure 3. Fecal coliform concentrations at the NCDWQ ambient station for the period 1997 –
2002. A value >2000 from 1/8/98 is not shown.....................................................................8
Figure 4. Geometric mean fecal coliform concentrations in the Crowders Creek watershed, 2001.
.................................................................................................................................................9
Figure 5. Load duration curve at the Crowders Creek NCDWQ ambient station for the period,
1998-2002..............................................................................................................................10
Figure 6. Load duration curve at the Crowders Creek station SR 2424 for the period, 2001-2002.
...............................................................................................................................................10
Figure 7. Crowders Creek watershed with subwatersheds (WS) as depicted in the WARMF
model. Primary stations used for calibration have been labeled. .........................................17
Figure 8. Observed vs. simulated temperature at the downstream calibration station in
subwatershed 11 (R2=0.86)....................................................................................................22
Figure 9. Observed versus simulated temperature at the upstream calibration station in
subwatershed 5 (R2=0.98)......................................................................................................22
Figure 10. Observed versus simulated flow at the downstream calibration station in subwatershed
11 (R2=0.50)..........................................................................................................................23
Figure 11. Observed versus simulated flow at the upstream calibration station in subwatershed 5
(R2=0.43)...............................................................................................................................23
Figure 12. Observed versus simulated fecal coliform at subwatershed 11. ..................................25
Figure 13. Observed versus simulated fecal coliform at SR 1131 in subwatershed 5. .................26
Figure 14. Rolling 30-day geometric means of observed fecal coliform at SR 2424 and simulated
fecal coliform at the subwatershed 11 outlet.........................................................................26
Figure 15. Results of TMDL simulation for a rolling 30-day geometric mean for fecal coliform in
the Crowders Creek watershed..............................................................................................29

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1 Introduction

Crowders Creek is currently on 303(d) lists of impaired waters in North Carolina (NC) and South Carolina
(SC). The NC Division of Water Quality (NCDWQ) has identified a 3.6-mile segment of Crowders Creek in
the Catawba River Basin as impaired by fecal coliform bacteria, stretching from state road (SR) 1108 to the
state line. The SC Department of Environmental Health and Control (SCDHEC) considers the South Fork
Crowders Creek and Crowders Creek impaired due to elevated levels of fecal coliform bacteria in South
Carolina.

Section 303(d) of the Clean Water Act (CWA) requires states to develop a list of waters not meeting water
quality standards or which have impaired uses. This list, referred to as the 303(d) list, is submitted biennially
to the U.S. Environmental Protection Agency (EPA) for review.

The 303(d) process requires that a Total Maximum Daily Load (TMDL) be developed for each of the waters
appearing on Part I of the 303(d) list. The objective of a TMDL is to estimate allowable pollutant loads and
allocate the loads to known sources so that actions may be taken to restore the water to its intended uses
(USEPA, 1991). Generally, the primary components of a TMDL, as identified by EPA (1991, 2000a) and
the Federal Advisory Committee (FACA, 1998) are as follows:

Target identification or selection of pollutant(s) and end-point(s) for consideration. The pollutant and end-
point are generally associated with measurable water quality related characteristics that indicate compliance
with water quality standards. North Carolina indicates known pollutants on the 303(d) list.

Source assessment. All sources that contribute to the impairment should be identified and loads quantified,
where sufficient data exist.

Reduction target. Estimation of the level of pollutant reduction needed to achieve water quality goal. The
level of pollution should be characterized for the waterbody, highlighting how current conditions deviate
from the target end-point. Generally, this component is identified through water quality modeling.

Allocation of pollutant loads. Allocating pollutant control responsibility to the sources of impairment. The
wasteload allocation portion of the TMDL accounts for the loads associated with existing and future point
Crowders Creek TMDL Final Report

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sources. Similarly, the load allocation portion of the TMDL accounts for the loads associated with existing
and future non-point sources, stormwater, and natural background.

Margin of Safety. The margin of safety addresses uncertainties associated with pollutant loads, modeling
techniques, and data collection. Per EPA (2000a), the margin of safety may be expressed explicitly as
unallocated assimilative capacity or implicitly due to conservative assumptions.

Seasonal variation. The TMDL should consider seasonal variation in the pollutant loads and end-point.
Variability can arise due to stream flows, temperatures, and exceptional events (e.g., droughts, hurricanes).

Critical Conditions. Critical conditions indicate the combination of environmental factors that result in just
meeting the water quality criterion and have an acceptably low frequency of occurrence.

Section 303(d) of the CWA and the Water Quality Planning and Management regulation (USEPA, 2000a)
require EPA to review all TMDLs for approval or disapproval. Once EPA approves a TMDL, then the
waterbody may be moved to Category 4a of the Integrated Report. Waterbodies remain in Category 4a until
compliance with water quality standards is achieved. Where conditions are not appropriate for the
development of a TMDL, management strategies may still result in the restoration of water quality.

The goal of the TMDL program is to restore designated uses to water bodies. Thus, the implementation of
source controls throughout the watershed will be necessary to restore uses in Crowders Creek. Although an
implementation plan is not included as part of this TMDL, reduction strategies for point and nonpoint
sources will be needed. The involvement of local governments and agencies will be critical in order to
develop implementation plans and reduction strategies.

1.1 Watershed Description

Crowders Creek, a tributary to Lake Wylie (NCDWQ subbasin 030837) in the Catawba River Basin, drains
92.9 mi2 at its confluence with Beaverdam Creek in South Carolina (Figure 1). Most of the NC portion of
Crowders Creek is located within Gaston County in the piedmont physiographic region. A small portion is
located in Cleveland County. Approximately 16% of the watershed area (excluding Beaverdam Creek) is
located within South Carolina (York County). The watershed includes the municipalities of Gastonia, Kings
Mountain and Bessemer City in NC, and Bowling Green in SC.
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The land use and land cover characteristics of the watershed were determined using 1996 land cover data that
were developed from 1993-94 LANDSAT satellite imagery (included within the WARMF model). Land use
was 57% forest, 9% pasture, 11% cultivated, and 13% developed (low and high intensity residential,
commercial/industrial).

As reported by the USGS, the average flow of the creek below SR 2424 is approximately 91 cubic feet per
second (cfs), with a summer 7Q10 of 6.7 cfs. The drainage area at this point is 79.4 mi2. The predominant
soils are Cecil-Appling-Pacolet and Nason-Tatum associations, underlain by gneiss/schist/slate and schistose
rocks, respectively.

Surface water classifications are designations applied to surface water bodies that define the best uses to be
protected within these waters (e.g., swimming, fishing, and drinking water supply) and carry with them an
associated set of water quality standards to protect those uses. Crowders Creek (and its tributaries) is
classified as a class C waterbody in NC. The waters are protected for secondary recreation, fishing, wildlife,
fish and aquatic life propagation and survival, agriculture and other uses suitable for Class C. Secondary
recreation includes wading, boating, and other uses involving human body contact with water where such
activities take place in an infrequent, unorganized, or incidental manner.

South Carolina classifies Crowders Creek and its tributaries as Freshwaters. Freshwaters are suitable for
primary and secondary contact recreation and as a source for drinking water supply after conventional
treatment in accordance with the requirements of SC. In addition, the waters are suitable for fishing, the
survival and propagation of a balanced indigenous aquatic community of fauna and flora, and industrial and
agricultural uses.

1.2 Water Quality Target

The North Carolina fresh water quality standard for fecal coliform in Class C waters (T15A:
02B.0211) states:

Organisms of the coliform group: fecal coliforms shall not exceed a geometric mean of 200/100ml (membrane filter
count) based upon at least five consecutive samples examined during any 30 day period, nor exceed 400/100 ml in more
than 20 percent of the samples examined during such period; violations of the fecal coliform standard are expected
during rainfall events and, in some cases, this violation is expected to be caused by uncontrollable nonpoint source
pollution; all coliform concentrations are to be analyzed using the membrane filter technique unless high turbidity or
Crowders Creek TMDL Final Report

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other adverse conditions necessitate the tube dilution method; in case of controversy over results, the MPN 5-tube
dilution technique will be used as the reference method.

South Carolina’s standard for fecal coliform in Freshwater is:

Not to exceed a geometric mean of 200/100 ml, based on five consecutive samples during any 30-day period; nor shall
more than 10% of the total samples during any 30-day period exceed 400/100ml.

Figure 1. Location map for the Crowders Creek watershed.

GastoniaKings Mtn
Bessemer City
CLEVELAND Co.
GASTON Co.
South Fork Crowders Creek BEAVERDAM CR
CROWDERS CR
CROWDERS CR
South Crowders Creek
McGill Branch
Abernethy Creek
NC
SC
NC-274
US-321
US-74
C8660000
2 0 2 4 Miles
N
EW
S
Bowling Green
Lake Wylie
YORK Co.
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The instream numeric target, or endpoint, is the restoration objective associated with implementing the
specified load reductions in the TMDL. The target allows for the evaluation of progress towards the goal of
reaching water quality standards for the impaired stream by comparing the instream data to the target. For
this TMDL the water quality target is South Carolina’s standard: it is more stringent based on the portion
relating to 10% of samples during 30 days versus a 20% allowance in NC. Both portions of the SC standard
will be evaluated for TMDL purposes. Note that the unit for fecal coliform bacteria is colony-forming units
(cfu), but may also be referred to as “counts” or “#” throughout this assessment.

1.3 Water Quality Assessment

NCDWQ collects samples monthly at a fixed ambient monitoring station (C8660000) on Crowders Creek at
Ridge Rd near Bowling Green, SC (Figure 2).1 In 2001, NCDWQ, the Gaston County Cooperative
Extension Service, and the City of Gastonia agreed to conduct intensive surveys of water quality in the
Crowders Creek watershed. Six locations were selected for intensive monitoring (Table 1). Samples were
collected weekly for six weeks in the spring and 10 weeks in the summer. As such, eight running geometric
means could be calculated using the data from this study.

During 2002, NCDWQ conducted additional sampling of Crowders Creek to supplement 2001 sampling.
Samples were collected at Blackwood Creek, Crowders Creek at SR 1108, and Crowders Creek at SR 2424.
A summary of all recent data is presented in Table 2.

Sampling at the ambient station near the base of the watershed indicates that fecal coliform concentrations
have been elevated for several years (Figure 3). Further sampling to evaluate the geometric mean fecal
coliform standard suggests elevated concentrations at a number of locations throughout the watershed
including the upper portion at SR 1131 and the southwest portion at SR 1109 (Figure 4). The geometric
means of 9/4/2001 include a significant storm event that appears to have contributed to high concentrations.
Blackwood Creek fecal coliform levels are consistently higher than other locations throughout the study.
This subwatershed contains primarily suburban development and many older south Gastonia neighborhoods.

1 SCDHEC also monitors fecal coliform bacteria in Crowders Creek at US 321 0.5 miles north of the NC/SC border
(CW- 152) and at S-91-79 4.5 miles northwest of Clover (CW-192). SC’s CW-024 is co-located with NC’s ambient
station.
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Table 1. Monitoring locations in the Crowders Creek watershed.

1 Crowders Creek at Linwood Road (SR1131)
2 Blackwood Creek at SR 1136
3 Crowders Creek at SR 1108
4 South Crowders Creek at Crowders Creek Rd
(SR1103)
5 South Fork Crowders Creek at Ferguson Ridge
Rd (SR1109)
6 Crowders Creek at SR 2424
7 DWQ Ambient Station

Table 2. Summary of fecal coliform monitoring in the Crowders Creek watershed (1997-2002).

Site Period Number of
Samples
Number greater than
400 cfu/100ml a
Number greater than
200cfu/100ml geometric
mean b
Crowders Creek at
Linwood Road (SR1131) 2001 16 3 5
Blackwood Creek at SR
1136 2001-2002 25 14 13
Crowders Creek at SR
1108 2001-2002 25 8 6
South Crowders Creek at
Crowders Creek Rd
(SR1103)
2001 16 3 3
South Fork Crowders
Creek at Ferguson Ridge
Rd (SR1109)
2001 16 4 5
Crowders Creek at SR
2424 2001-2002 25 6 6
Crowders Creek
NCDWQ Ambient 1997-2002 67 10 -- c
a Instantaneous fecal coliform measurements greater than 400cfu/100ml
b 30-day geometric mean of fecal coliform measurements greater than 200cfu/100ml based on at least 5 samples in 30
days.
C Data collected monthly; insufficient frequency to calculate a 30-day geometric mean.

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Figure 2. North Carolina monitoring stations within the Crowders Creek watershed. Numbered stations correspond to sites in Table 1.
1
2
34
5
6
7
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Figure 3. Fecal coliform concentrations at the NCDWQ ambient station for the period 1997 – 2002. A value
>2000 from 1/8/98 is not shown.

A load duration curve analysis (Stiles 2002, Cleland 2002) was used to evaluate flow conditions under which
the standard is violated and also help identify the sources contributing to impairment. Exceedances that
occur only during low-flow events are likely caused by continuous or point source discharges, which are
generally diluted during storm events. Livestock deposits directly to the stream may also be noticeable
during low flow events. Exceedances that occur during higher flow events are generally driven by storm-
event runoff. A mixture of point and nonpoint sources may cause exceedances during normal flows.

The load duration method plots observed data with flow. Data is available for only 2000 to present for a
gage on Crowders Creek (USGS 02145642). Since a long historical flow series is recommended for use in
flow and load duration analyses, data from nearby gage was used: USGS 02144000 on Long Creek near
Bessemer City. The Long Creek gage is in the neighboring watershed to the north of Crowders Creek and
has a drainage area of 31.8 mi2. Daily flow data for the period from 1/1953 through 9/2002 was used to
establish the historic flow regimes. Drainage area (DA) ratios were used to create flow series for the DWQ
ambient station on Crowders Creek (DA = 88.9 mi2) and the station at SR 2424 (DA = 79.4 mi2).
Crowders Creek NCDWQ Ambient Station
0
200
400
600
800
1000
1200
1400
1600
1800
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Figure 4. Geometric mean fecal coliform concentrations in the Crowders Creek watershed, 2001.

Observed flow is plotted based on the percent of time that historic flows exceed the value on the date
collected. Once the relative rankings were calculated for flow, monitoring data were matched by date to
compare observed water quality to the flow ranking. The curves approximate the allowable load that meets
the water quality standard for fecal coliform (flow * standard; see Figure 5).

In the Crowders Creek watershed, water quality violations of fecal coliform occur during both wet and dry
periods, and during most times of the year (Figures 5-6). All data points in Figures 5 and 6 are based on
instantaneous samples.2 A greater number of exceedances occurred during April – October and in mid-range
to drier flows.

2 The geometric mean line is provided only as an additional reference; geometric mean values have not been plotted.
Geometric Mean Fecal Coliform Levels, 2001
0 200 400 600 800 1000 1200 1400 1600
Crowders Creek at
SR1131
Blackwood Creek at
SR1136
Crowders Creek -
SR1108
South Crowders
Creek at SR1103
South Fork Crowders
Creek at SR1109
Crowders Creek at
SR2424
Fecal coliform level, cfu/100mL
3/26/2001
4/4/2001
7/31/2001
8/7/2001
8/14/2001
8/21/2001
8/28/2001
9/4/2001
Crowders Creek TMDL Final Report

Figure 5. Load duration curve at the Crowders Creek NCDWQ ambient station for the period, 1998-2002.

Figure 6. Load duration curve at the Crowders Creek station SR 2424 for the period, 2001-2002.

























































 






































































 











Crowders Creek TMDL Final Report

2 Source Assessment

Both point and nonpoint sources may contribute fecal coliform to waterbodies. In rural areas, stormwater
runoff can transport fecal coliform from livestock operations, septic systems, and wildlife deposits. Sewer
systems, pets, and wildlife are potential sources in urbanized areas (septic systems to a lesser extent).
Wastewater treatment plants (WWTP), both municipal and package plants, are another source of fecal
coliform.

Potential sources of fecal coliform loading in the watershed were identified based on an evaluation of land
use data, septic and sewer service areas, discharge monitoring data, and agricultural information. The source
assessment was used as the basis for development of the watershed model and ultimate analysis of the
TMDL allocations. Table 3 lists the potential human and animal sources of fecal coliform bacteria.

Table 3. Potential sources of fecal coliform bacteria in watersheds.

Source Origin Type Source
Human Sources Sewered watershed Combined sewer overflows; Sanitary sewer
overflows; leaking sanitary sewers
Wastewater treatment plants (POTWs)
Illegal sanitary connections to storm drains
Illegal disposal to storm drains
Non-sewered watershed Septic systems
Package WWTP plants
Non-human Sources Domestic animals and urban wildlife Dogs, cat, rats, raccoons, opossum,
squirrels, pigeons, waterfowl
Livestock and rural wildlife Beef and dairy cows, horses, poultry, swine,
beaver, deer, waterfowl

2.1 Point Source Assessment

Point sources are regulated under the National Pollutant Discharge Elimination System (NPDES) and include
continuous municipal and industrial sources and regulated stormwater (NPDES Phase I and II). The major
point source of fecal coliform in the Crowders Creek watershed is Gastonia’s Crowders Creek Wastewater
Treatment Plant (NC0074268), which is currently permitted to discharge 6 MGD (see Figure 2 for location).
Crowders Creek TMDL Final Report

There are no point sources, neither continuous or MS4 stormwater, within the South Carolina portion of the
watershed (Giffin, 2003).

Additional minor point sources discharging domestic waste include Berkley Oaks (NC0062278), CWS
Saddlewood WWTP (NC0060755), Ridge Community WWTP (NC0069175) and Pines Mobile Home Park
(NC007499), totaling approximately 0.07 MGD in permitted capacity. Facilities not listed are either inactive
or contain waste streams lacking significant fecal coliform (e.g., some industrial process water).

CBP Resources, a chicken processing plant, ceased its discharge to Crowders Creek in December 1998 by
connecting to the Gastonia Crowders Creek WWTP. The Bessemer City WWTP (1.5 MGD; NC0020826)
connected to the Crowders Creek WWTP in March 2002. Prior to this, the Bessemer City WWTP
discharged into Abernathy Creek, a tributary to Crowders Creek.


EPA requires that loads allocated to NPDES permitted stormwater be placed in the wasteload allocation
(WLA), which had previously been reserved for continuous point source loads (Wayland, 2002). The three
MS4 entities that are permitted through Phase II of the NPDES stormwater program in the Crowders Creek
watershed are Gastonia (NCS000429), Bessemer City (NCS000412), and Gaston County (NCS000411).
Their entire jurisdiction is covered under the permits. The NC Department of Transportation also has a
NPDES stormwater permit in this watershed (statewide_. Kings Mountain, with approximately 5.4 mi2 of
area in northwest corner of the watershed, is not currently regulated under the Phase II program.

2.2 Non-Point Source Assessment

Nonpoint sources of fecal coliform bacteria include those sources that cannot be identified as entering the
waterbody at a specific location such as a NPDES permitted pipe or stormwater outfall. Diffuse sources of
fecal coliform bacteria may originate from human and non-human sources (livestock, pets, wildlife).

2.2.1 Urban Development and Sewer Systems

Developed land typically generates greater areal pollutant loads relative to rural land uses. Mallin et al.
(2000) found a strong relationship between the percentage of watershed imperviousness and fecal coliform
density. Higher amounts of impervious surface result in less opportunity for infiltration, increasing high flow
Crowders Creek TMDL Final Report

volumes, peak flows and velocities. The resultant stormwater runoff carries with it waste from pets, wildlife,
and other sources.

Sewer systems for Gastonia (WQCS00017) and Bessemer City (WQCS00107) may also contribute fecal
coliform to waterways during overflows and as a result of other defects. Kings Mountain also has a
collection system (WQCS 00036) and sends a portion of its waste to the Crowders Creek WWTP. Sewer
pipes may become blocked, damaged, or flooded by stormwater. Sanitary sewer overflows (SSO) may occur
due to pump station failures caused by stormwater infiltration into the pipes through leaks. Sewer pipe leaks
may also contribute to elevated levels of fecal coliform during low flow periods via exfiltration. Between
1997 and 2002, there were six SSOs reported by Gastonia (collection system associated with the Crowders
Creek WWTP), twenty by Bessemer City and three by Kings Mountain. Not all the SSOs in Bessemer City
and Kings Mountain occurred within the Crowders Creek watershed.

Site-specific information for fecal coliform loading from urban runoff in the Crowders Creek watershed was
not available. However, studies from nearby Mecklenburg County can be used to provide initial estimates of
fecal loads. The USGS calculated build-up and wash-off rates for developed land uses based on stormwater
samples collected from 1993-1997 (Bales et al., 1999). Fecal coliform rates of accumulation for light
residential, heavy residential/industrial, and heavy commercial/industrial were 5.3 x 10^11 counts/ha/mo, 6.9
x10^11 counts/ha/mo, and 2.1 x 10^11 counts/ha/mo, respectively.

2.2.2 Septic Systems

Failing septic systems are a potential source of fecal coliform to water bodies. Lack of maintenance and
improper use can cause systems to fail, creating the potential for discharge to water bodies. A study by the
NC Office of Budget and Management suggested that 11% of systems surveyed had malfunctions or failures
(NC DEH, 2000). In Gaston County, the septic failure rate is thought to be near 4% (Gordon, 2003). Septic
usage in the Catawba River Basin portion of Gaston County was approximately 45% based on 1990 census
(NC DEH, 1999). The 2000 census did not collect information on sewage and septic. Since that time, the
percentage may have decreased as more areas are developed and sewer service expands.

Gordon (2003) analyzed septic usage in the Crowders Creek watershed using GIS layers of residential parcel
data, census data, and utility customers to determine the number of septic tanks by subwatershed. It was
assumed that all residential households that were not municipal utility customers relied on septic. Results of
Crowders Creek TMDL Final Report

the analysis indicated that nearly 5,000 septic systems were in use within the NC portion of the watershed
(Table 4). Resulting septic densities were extrapolated to SC by NCDWQ resulting in an estimated 18,710
people served by septic in the watershed.

Table 4. Summary of septic usage in Crowder’s Creek watershed (NC portion) based on data taken from
Gordon (2003)

Subwatershed
Description
Septic
Systems
Avg. #
persons/system Acres Population
served
Persons per
mi^2
North Crowders 857 2.78 13737 2363 110
Central Crowders 1115 2.95 9175 3290 229
Blackwood Creek 422 3.03 2202 1382 402
South Crowders 1119 2.79 10686 3023 181
Lower Crowders 1457 2.48 8792 3334 243

2.2.3 Livestock

According to the NC Department of Agriculture’s (2001) livestock population census, Gaston County has
approximately 9,100 head of cattle. However, only a small portion is located within the Crowders Creek
watershed. There were relatively small amounts of other animal agriculture. Within the Crowders Creek
watershed, there are no large concentrated animal operations. At NCDWQ’s request, a livestock survey of
the watershed was conducted by the Gaston County Cooperative Extension Service (Hudson, 2003).
Estimates from the survey were approximately 160 beef cattle and 280 dairy cattle, located mostly in the
southwest portion of the watershed. In addition, there are an estimated 150 horses.

Waste produced by cattle that is deposited on pasture or directly into streams can be a significant source of
fecal coliform. Beef cows, dairy cows and horses produce on average 1.06 x 10^11 counts/day, 1.04 x10^11
counts/day, and 4.2 x 10^8 counts/day, respectively (NCSU, 1994). A watershed survey in July 2003 by
NCDWQ indicated that some of the cattle had access to streams. The Gaston County Natural Resources
Department estimates 30 to 50% of livestock within the watershed are permanently fenced out of streams
based on its implementation of cost share program funding for livestock exclusion and alternate water
sources (Gordon, 2003).

Crowders Creek TMDL Final Report

2.2.4 Waste Application

Cattle and horses that graze on pasture land deposit waste directly onto the land. Runoff during storm events
can transport fecal coliform in the waste to water bodies, particularly when there is a lack of stream buffer or
cattle have access to the buffer and stream. Confined dairy operations must properly apply manure collected
in feedlots onto cropland or pastureland. Manure is applied to cropland in the Crowders Creek watershed,
primarily during March, April, September and October.

Biosolids application is permitted in the watershed for Gastonia (WQ0001793) and Bessemer City
(WQ0002264). Sludge byproducts of the wastewater treatment process, which may contain fecal coliform, is
applied to agricultural land at approved rates. Anaerobic digestion is used to reduce pathogens. NCDWQ
records for 2002 indicated that 1,300 acres were permitted for Gastonia. Only a portion of this acreage is
located within the watershed. The Crowders Creek WWTP plant produced approximately 804 dry tons of
biosolids during 2002, accounting for approximately 22% of the total tonnage applied by Gastonia. There
were no recent records of residuals application under the Bessemer City permit since it connected to
Gastonia.

2.2.5 Wildlife

Wildlife deposit fecal-containing waste throughout the landscape, but likely deposit more heavily in rural and
forested areas where populations are larger. Loadings from wildlife are a background source. Population
estimates for many types of wildlife are not available. The deer population is estimated to be 20 to 30
animals per square mile (NC DWQ, 2002). An upper limit of 30 was chosen to account for other wildlife.
Fecal loading rates for deer have been estimated at 5.0 x 10^8 #/animal/day (US EPA, 2000c).

Crowders Creek TMDL Final Report

3 Modeling Approach
3.1.1 Model Framework

Due to the watershed size and variable sources of fecal coliform, the watershed model Watershed Analysis
Risk Management Framework (WARMF) was selected to evaluate fecal coliform in the Crowders Creek
watershed. WARMF is a decision support system designed to support the watershed approach and TMDL
calculations. The model has been applied to watershed regions in the USA and Taiwan (Systech
Engineering, 2001).

WARMF contains several embedded models adapted from the ILWAS model, ANSWERS, SWMM, and
WASP. The model simulates hydrology and water quality for the landscape of a river basin. WARMF
divides a watershed into land catchments, river segments, and reservoirs and uses the continuously stirred
tank reactor (CSTR) model for flow routing and mass balance within a given soil layer or river segment.

Simulated parameters include flow, temperature, water depth and velocity, and constituent concentrations. In
the case of fecal coliform bacteria, the model simulates the deposition and transportation of the bacteria from
land surface loading and point source discharge. The model then computes the resulting water quality
response instream using first order kinetics. The model also includes a facility for calculating TMDLs for
non-point source loads under different control levels of point source loads and vice versa.

3.1.2 Model Setup

The Crowders Creek watershed is represented as eleven catchments within the model (Figure 7). The
Beaverdam Creek tributary to Crowders Creek located in South Carolina is not modeled in this project. The
confluence of these two creeks is located downstream of DWQ’s ambient station. A TMDL for fecal
coliform in the Beaverdam Creek watershed has been prepared and approved for South Carolina. Both point
and nonpoint sources are represented in the water quality model. The model was run for a continuous
simulation period of January 1, 1998 through December 31, 2002.

Crowders Creek TMDL Final Report

Figure 7. Crowders Creek watershed with subwatersheds (WS) as depicted in the WARMF model. Primary
stations used for calibration have been labeled.

3.1.2.1 Observed Data Input

Water quality data collected at the NCDWQ ambient station located in subwatershed (WS) 11 and the station
at SR 1131 in WS 5 were used as primary calibration points (Figure 7). Other data stations supplemented the
calibration process. Since there are no meteorological data stations located within the watershed,
meteorological data collected at nearby Long Creek, located immediately north of the Crowders Creek
watershed, were associated with WS 1-4. The other subwatersheds were associated with data collected at
Gastonia to the east (NCDC station 313356). Precipitation and temperature lapse factors were applied during
the calibration process.

Crowders Creek TMDL Final Report

Flow data from Long Creek, adjusted for drainage area and the Bessemer City WWTP, was associated with
the upper portion of the watershed. Data from a station on Crowders Creek (USGS 02145642) that is co-
located with the ambient station was used for the lower part of the watershed. Flow data at the Crowders
Creek USGS station was only available for October 2000 to present. Since flow data for a 5-year period
(1998 – 2002) was needed, a regression between Crowders Creek and Long Creek was used to fill in the
missing values (Crowders Flow = 2.4513*Long Creek Flow + 12.889; R2 = 0.88). Finally, a DA ratio was
used to adjust upward the Crowders Creek flow to represent the remaining portion of the watershed (to the
confluence with Beaverdam Creek).

3.1.2.2 Fecal Loading Initial Inputs

Initial values for fecal loading (kg/ha/mo) by land use and by subwatershed were input into the model. In
addition, fecal loading based on discharge monitoring data from the two primary point sources, the Crowders
Creek WWTP and Bessemer City WWTP, were input into the model.

The initial fecal coliform rates of accumulation for light residential, heavy residential/industrial, and heavy
commercial/industrial are from Bales et al. (1999). An initial background loading of 1.8x10^9 #/ha/mo was
applied to forested land uses to account for wildlife.

The population served by septic was input to the model according to Table 5. These figures were obtained
from some of the previous analysis discussed in Section 2.2.2. A failure rate of 4% based on Gaston County
data is used. Septic loading assumes 265 L/cap/day and a fecal coliform concentration of 10,000 cfu/100ml
for the load associated with failure (Horsley and Whitten, 1996).

Livestock loading of fecal coliform was input into the model using estimated livestock numbers (Table 6)
and fecal production based on NCSU (1994). Loading was generally associated with pasture. Additional
loading associated with dairy manure application to cultivated land was incorporated during March/April and
September/October in subwatersheds 4 and 6. Loading is also associated with direct deposit when livestock
have access to streams. Initially, the model assumed that 40% of livestock were excluded from streams
(increased to 70% during calibration).

Crowders Creek TMDL Final Report

Table 5. Septic data used in the WARMF model for Crowders Creek.

Subwatershed Septic population/mi^2 Area (mi^2) Septic population
1 110 9.6 1056
2 110 6.3 693
3 181 11.5 2082
4 181 12.5 2263
5 247 * 21.3 5261
6 229 3.2 733
7 181 4.4 796
8 229 1.2 275
9 243 7.3 1774
10 229 0.9 206
11 243 14.7 3572
* Average of North and Central Crowders, and Blackwood Creek subwatersheds in
Gordon (2003).

Table 6. Livestock data used in the WARMF model for Crowders Creek.

Subwatershed Pasture
Area (ha)
Estimated Number of Animals
dairy beef horses
1 168.35 0 0 0
2 88.06 0 0 0
3 155.4 0 50 50
4 577.57 200 50 50
5 235.69 0 0 0
6 41.44 80 0 0
7 238.28 0 40 50
8 25.9 0 0 0
9 248.64 0 20 0
10 69.93 0 0 0
11 367.78 0 0 0

3.1.2.3 Fecal Coliform Decay

Fecal coliform bacteria produced in a watershed are subject to die-off in the soil and water environment.
Factors that influence their survival include sunlight, temperature, moisture conditions, salinity, soil
conditions, waterbody conditions, settling, and association with particles (USEPA, 2001). For example,
bacteria survival decreases as temperature increases.

Crowders Creek TMDL Final Report

Decomposition of fecal coliform in the soil was initially set at 0.27 day-1 based on the median value for the
soil environment in Crane and Moore (1986). The initial value of coliform decay in stream was set at 1.0
day-1 based on the median value of the data in Bowie et al. (1985).

3.1.3 Calibration

Calibration of a dynamic loading model involves both hydrologic and water quality components. First, the
model must be calibrated to represent flow and temperature in the watershed. Next, water quality
simulations and calibration can be performed. The hydrologic calibration involves comparison of simulated
streamflows to observed streamflow data. Simulated streamflows are generated from input and adjustment
of model parameters, including meteorological, physical and hydrologic response. Parameters are adjusted
within defensible ranges until an acceptable agreement is achieved between simulated and observed results.
The ambient station, located in WS 11, and the station at SR 1131 in WS 5 were used as primary calibration
points. Qualitative (seasonal trends, magnitude and timing of peaks) and quantitative (calibration statistics)
measures were used to evaluate calibration.

3.1.3.1 Flow and Temperature

Precipitation weighting factors and temperature lapse were applied by subwatershed during the calibration
process to improve the relationship between observed and simulated values (Table 7). Precipitation
weighting factors are multipliers applied to the precipitation in the meteorological file to account for local
variations in precipitation amount from orographic effects (varies from 1, unitless). Average temperature
lapse is the average amount subtracted from the temperature in the meteorological file to account for regional
variations in temperature from orographic effects. A positive value indicates that the catchment is cooler
than its meteorological station (varies from 0, degrees C).

The parameters associated with soil layers were also adjusted to represent hydrologic response. Four soil
layers are simulated in WARMF with saturated lower layers generally providing baseflow and the upper
layers providing stormflow. Thicker soil layers with lower horizontal conductivity tended to provide greater
baseflow, while thinner layers with higher conductivity often resulted in sharper peaks. The final calibrated
parameters are presented in Appendix III.

Crowders Creek TMDL Final Report

Table 7. Precipitation weighting factors and temperature lapse for the Crowders Creek watershed.

Subwatershed Meteorological
Station
Average
Temperature
Lapse
Precipitation
Weighting
Factor

1 Long Creek 1.4 1.05
2 Long Creek 1.4 1.05
3 Long Creek 1.4 1.15
4 Long Creek 1.4 1.20
5 Gastonia 1.25 1.10
6 Gastonia 1.25 1.10
7 Gastonia 1.25 1.15
8 Gastonia 1.25 1.10
9 Gastonia 1.25 1.10
10 Gastonia 1.25 1.10
11 Gastonia 1.25 1.10

The time series of simulated versus observed temperature and flow are presented in Figures 8 through 11.
There were only 16 observed temperature values for the upstream station (Figure 9). Calibration statistics for
the downstream station, which is located upstream of the outlet, are presented in Table 8. R2 is the square of
the correlation coefficient between simulated results and observed data over all time steps for which both
exist. A perfect correlation has a value of 1. Relative Error is the average of all errors (difference between
simulated and observed values) over all time steps for which it can be calculated. It is a measure of model
accuracy. Absolute Error, a measure of model precision, is the average of the absolute value of all errors
over all time steps for which it can be calculated. Unlike relative error, overpredictions and underpredictions
do not cancel each other out with absolute error. RMS Error is the root-mean-square error, which is the
square root of the average of the squares of all errors over all time steps for which it can be calculated. This
magnifies the effect of larger than average errors.

Table 8. Calibration statistics for temperature and flow in subwatershed 11.

Flow (cms) Temperature (°C)
Simulated Mean 1.78 15.92
Observed Mean 1.76 15.71
Simulated Range 0.38 to 26.87 2.06 to 27.72
Observed Range 0.12 to 43.30 4.00 to 25.00
Relative Error 0.02 0.49
Absolute Error 0.76 2.15
RMS Error 2.07 2.65
R2 0.50 0.86

Crowders Creek TMDL Final Report

Figure 8. Observed vs. simulated temperature at the downstream calibration station in subwatershed 11
(R2=0.86).

Figure 9. Observed versus simulated temperature at the upstream calibration station in subwatershed 5
(R2=0.98).
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Crowders Creek TMDL Final Report

Figure 10. Observed versus simulated flow at the downstream calibration station in subwatershed 11
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Figure 11. Observed versus simulated flow at the upstream calibration station in subwatershed 5 (R2=0.43).
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Crowders Creek TMDL Final Report

3.1.3.2 Fecal Coliform

Fecal coliform loading rates by land use adjusted during calibration are associated with “land application” in
the WARMF model. Forested land uses were reduced to 500 E6 #/ha. Pasture rates ranged from 10,000 to
30,000 E6 #/ha for the populated subwatersheds (WS) in Table 6. In WS 4 and 6, cultivated land received
1800 and 2000 E6 #/ha, respectively during March, April, October, and September due to dairy manure
application. Finally, low intensity, high intensity, and commercial/industrial development received 25,000,
30,000, and 15,000 E6 #/ha, respectively. The fraction of impervious surface associated with each of these
land uses was 0.3, 0.65, and 0.75, respectively. Final calibrated decay rates for fecal coliform were 0.35 day-
1 in the soil environment and 0.9 day-1 in the stream.

Calibration statistics for instream fecal coliform are presented in Table 9. While R2 is a measure of the
model's ability to predict trends in the data, is often not very useful when there is a large amount of scatter in
observed data. For example, the overall R2 for the complete fecal coliform time series is 0.02. However,
individual statistics by year may be more insightful with values of 0.16, 0.86, 0.08, 0.56, and 0.55 for 1998
through 2002, indicating improvement in prediction in the last two years.

The time series of observed versus simulated fecal coliform at subwatershed 11 is presented in Figure 12.
The capture of patterns is reasonable, although not all values are predicted well. At SR 1131 in
subwatershed 5, fecal coliform data was only available for 2001, which limits the comparison (Figure 13).

Table 9. Calibration statistics for fecal coliform (#/100ml) in subwatershed 11 (downstream station).

Simulated Observed
Mean 376.1 515.9
Minimum 45.44 18
Maximum 3695 4200

# of pts to compare 67
Relative Error -156.8
Absolute Error 459.9
RMS Error 967.8

A rolling 30-day geometric mean of observed fecal coliform at SR 2424 and simulated fecal coliform at the
subwatershed 11 outlet also suggests that the pattern is tracked, but with a few discrepancies (Figure 14).
Crowders Creek TMDL Final Report

This observed station is near the state line, upstream from the point where simulated results are provided
(Figure 7). A 30-day geometric mean is determined by calculating the geometric mean of an individual
day’s fecal concentration and the daily predictions for the 29 days that precede it. The rolling aspect is
achieved by moving to the next day and performing the same calculation.

It is important to note that in addition to the inherent difficulty in predicting fecal coliform, both sets of
observed data are from points upstream of the WS outlet where the simulated results are given.
This may account for some of the differences in modeled and observed values. Land based inputs as well as
instream decay are expected between the station and the watershed outlet.

Figure 12. Observed versus simulated fecal coliform at subwatershed 11.

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Crowders Creek TMDL Final Report

Figure 13. Observed versus simulated fecal coliform at SR 1131 in subwatershed 5.

Figure 14. Rolling 30-day geometric means of observed fecal coliform at SR 2424 and simulated fecal
coliform at the subwatershed 11 outlet.

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Crowders Creek TMDL Final Report

3.1.4 Model Output

Existing fecal coliform loading (1998-2002) predicted by the calibrated model is given in Table 10. Urban
land uses contributed 62% of the fecal loading and had the highest loading per unit area. Livestock
agriculture generated the second most fecal loading. Background loading associated with wildlife in forested
land uses was greater than both septic and point sources.

Table 10. Existing fecal coliform loading (1998-2002) by source in the Crowders Creek watershed.

Simulated Land-
based Load (1E6/d)
Percent Loading per
unit area
1E6/ha/yr
Deciduous Forest 29,100 3 1,260
Evergreen Forest 18,100 2 1,720
Mixed Forest 12,400 1 1,890
Pasture 284,000 28 46,700
Cultivated 14,300 1 1,760
Recr. Grasses 817 0 1,000
Water 270 0 1,400
Barren 300 0 678
Low Int. Develop. 304,000 30 54,700
High Int. Develop. 155,000 15 121,000
Comm / Industrial 179,000 17 66,600
Wetlands 0 0 0
Type 1 Septic System 1 6,670 1 --
Type 2 Septic System 0 0 --
Type 3 Septic System 2,780 0 --
General Point Sources 25,300 2 --
TOTAL 1,030,000 100 --
1 WARMF accepts inputs for 3 types of septic systems: standard, advanced, and failing.

Crowders Creek TMDL Final Report

4 Allocation
4.1 Total Maximum Daily Load (TMDL)

A Total Maximum Daily Load is the maximum amount of a pollutant that a water body can receive and still
meet water quality standards, partitioned among point and nonpoint sources. A TMDL is comprised of the
sum of wasteload allocations (WLA) for point sources, load allocations (LA) for nonpoint sources, and a
margin of safety (MOS), expressed by the equation:












The objectives of the TMDL are to estimate allowable pollutant loads, and to allocate them among the
general pollutant sources in the watershed. 40 CFR §130.2 (i) states that TMDLs can be expressed in terms
of mass per time (e.g. pounds per day), toxicity, or other appropriate measures. This TMDL will be
expressed in terms of % load reduction and allowable load of fecal coliform. It will be set at the outlet of the
modeled watershed, the confluence of Crowders Creek and Beaverdam Creek in South Carolina.

Two separate model runs were performed to evaluate the fecal coliform standards: a geometric mean
standard (200 cfu/100ml) and South Carolina’s instantaneous standard discussed in Section 1.2. The
WARMF model provides a facility in the TMDL module to evaluate each of these directly with a margin of
safety.

Initially, since total existing loading for the point sources was below their allowable load would indicate, the
model was run with existing point source loading and reductions were applied to nonpoint sources only.
However, these initial runs indicated that a TMDL could not be calculated because the fecal standard could
not be met even at zero nonpoint loading. This was due to several observed values in the point source data
file above 400 cfu/100ml. Therefore, the file was adjusted so that all values fell below 400. Simulations
were then run for the two standard evaluations. In order to meet SC’s instantaneous standard, a 61%
reduction would be needed in total loading versus a 79% reduction needed to meet the geometric mean
standard (Figure 15). The higher percentage was chosen since both standards must be met.

Crowders Creek TMDL Final Report

The fecal coliform geometric mean reductions were used to develop the TMDL loading. Further analysis
was required to determine the breakdown between point source (WLA) and nonpoint source (LA) loadings
that meet the TMDL objectives.

Figure 15. Results of TMDL simulation for a rolling 30-day geometric mean for fecal coliform in the
Crowders Creek watershed.

4.2 Critical Conditions

Critical conditions can be considered a subset of seasonality: the most stringent of the seasons. In the
Crowders Creek watershed, water quality violations of fecal coliform appear to occur during both wet and
dry periods (Figure 5 and 6). Recent ambient data collected in the Crowders Creek watershed indicate
observed exceedances may occur during all times of the year, with the four highest values in
August/September and December/January (Figure 3). The three highest simulated geometric means occurred
in January (Figure 15). However, a greater number of observed exceedances occurred during April –
October and in mid-range to drier flows (Figures 5 and 6). The TMDL has been set such that the standard is
met during all times of the modeled period (1998-2002).
Crowder’s Creek Watershed
Rolling 30-Day Geometric Mean Fecal Coliform Concentration (1998-2002)
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TMDL
Crowders Creek TMDL Final Report

4.3 Seasonal Variation

Seasonal variation is considered in the development of the TMDL because the allocation applies to all
seasons. Seasonal variation in hydrology, climatic conditions, and watershed activities are represented
through the use of a continuous flow gage and the use of all readily available water quality data collected in
the watershed. A wide range of flow conditions is modeled for this TMDL, demonstrated by the interannual
variation in hydrology seen in Figure 5.

4.4 Model Uncertainty and Margin of Safety

The lack of agreement between modeled and observed fecal coliform concentrations is due in part to the high
degree of uncertainty associated with predicting fecal coliform bacteria. The inability to accurately predict
specific observed fecal coliform concentrations can be attributed to many sources: model error, lack of
sufficient information in source assessment, gaps in our scientific knowledge, natural variability in instream
fecal coliform concentrations, field and laboratory measurement error, and lack of current site specific model
input parameters including decay rate, flow, rainfall data, and land use information. The watershed model
used in this project estimates daily average fecal coliform concentrations based on land use information.
Because of certain lack of site-specific information, professional judgment and literature values were
sometimes used to calculate the fecal coliform loading from the various land uses. In sum, the model results
should be interpreted in light of the model limitations and prediction uncertainty.

The margin of safety is an additional factor of the TMDL that accounts for some of the uncertainty in the
relationship between pollutant loads and receiving water quality. This margin of safety can be provided
implicitly through conservative analytical assumptions and/or explicitly by reserving a portion of the load
capacity. This TMDL utilizes an explicit margin of safety (MOS): the geometric mean target is set at 175
cfu/100ml (MOS = 25 cfu/100ml) and the instantaneous limit is set to 360 cfu/100ml (MOS = 40 cfu/100ml).

Crowders Creek TMDL Final Report

4.5 Allocation

The continuous waste load allocation (Table 11) is based on the maximum permitted loading, calculated as
permitted flow for the Crowders Creek WWTP plus the minor point sources (6.07 MGD times the 200
cfu/100mL fecal coliform standard). The Crowders Creek WWTP must also must meet monthly geometric
mean of 200 cfu/100ml and cannot exceed 400 cfu/100ml maximum.

Table 11. Total maximum daily load allocation for the Crowders Creek watershed (detailed in Appendix).

Units per day % Reduction % of TMDL
TMDL 1 2.21E+11
NC Continuous WLA 8.27E+09 0% 3.7%
NC MS4 WLA plus LA 2 2.13E+11 79%
NC MS4 WLA 7.45E+10 79% 33.7%
NC LA 1.15E+11 79% 51.8%
SC LA 2.36E+10 79% 10.7%
Station CW-023 -- 79%
Station CW-024 -- 79%
Station CW-192 -- 79%

1 Equivalent to a 79% reduction in existing loading (1998-2002).
2 TMDL minus continuous WLA

NPDES permitted stormwater including that associated with MS4s (small municipal separate storm sewer
systems) must also be included in the wasteload allocation.3 Kings Mountain is not an MS4 town, therefore,
their jurisdiction within Crowders Creek must be broken out to calculate this portion of the WLA. Kings
Mountain covers 34.1% of the area in WS 1 and 2. The nonpoint source load from these two subwatersheds
is 19.5% of the total watershed nonpoint loading. Accordingly, a ratio of 6.65% (34.1%*19.5%) is used to
separate the Kings Mountain LA (1.4E+10 units/d) from the nonpoint source loading in the remainder of the
watershed (Appendix IV).

3 According to the Phase II rules, MS4 permittees are responsible for reducing the loads associated with stormwater
outfalls for which it owns or otherwise has responsible control.
Crowders Creek TMDL Final Report

Except for Kings Mountain, the entire NC portion of the Crowders Creek watershed falls within Phase II
boundaries. Therefore, all fecal loadings from urban land uses within this area were assigned to the WLA
component. Loadings from land uses such as agricultural and forested areas are considered nonpoint sources
and are reported as LAs. A loading ratio based on relative land use and loading rate is used to apportion the
load between WLA and LA (Table 12). The distribution of the urban (developed land uses) and non-urban
land uses, 14.5 % and 86.5%, respectively, was determined from the landuse coverage within WARMF. In
addition, the relative loading rates between the urban and rural landuse types were determined based
modeled unit-loading rates (Table 10).

A load is allocated to SC based on land use and unit loading rates in the border subwatersheds.
Subwatersheds 4, 7, and 11 are split between SC and NC. The land uses are relatively homogenous within
each subwatershed. These watersheds are predominately rural in character. WS 4 and 11 are approximately
one half in SC and WS 7 is approximately one quarter in SC. The TMDL loading per unit area was multiply
by the land use area to generate fecal loading in each of these subwatersheds. As a result, SC is
approximately 16% of the watershed and will receive a load allocation that is 10.7% of the total nonpoint
source load (see Appendix VI for detail).

Table 12. Relative fecal coliform loading rates in the Crowders Creek watershed.

Relative Land Use Relative Loading Rate Loading Ratio
Urban Land 14.5% 81.3% 42.6%
Non-Urban Land 85.5% 18.6% 57.4%

Crowders Creek TMDL Final Report

5 Implementation Plan

The TMDL analysis was performed using the best data available to specify the fecal coliform reductions
necessary to achieve water quality criteria. The intent of meeting the criteria is to support the designated use
classifications in the watershed. A detailed implementation plan is not included in this TMDL. The
involvement of local governments and agencies in both NC and SC will be needed in order to develop the
implementation plan. An implementation plan will be developed under a NC 319 grant to Dr. Jy Wu with
the University of North Carolina at Charlotte (refer to section 7).

6 Stream Monitoring

Fecal coliform monitoring will continue on a monthly interval at the ambient monitoring sites on Crowders
Creek. Monitoring of fecal coliform concentrations will allow evaluation of progress towards the goal of
achieving water quality standards and intended best uses.

7 Future Efforts

This TMDL represents an early phase of a long-term restoration project to reduce fecal coliform loading to
acceptable levels in the Crowders Creek watershed. NCDWQ in cooperation with SC and local governments
should evaluate the progress of implementation strategies and refine the TMDL as necessary, in the next
phase based on NC’s five-year basin management cycle. This will include recommending specific
implementation plans for reduction of fecal coliform loading.

The NC 319 Grant program has recently funded a project entitled, Restoring and Assessing Fecal Coliform
Impairment of Crowders Creek. The principal investigator is Dr. Jy S. Wu with the Department of Civil
Engineering, University of North Carolina at Charlotte. The project, an extension of work associated with
the TMDL, aims to begin restoring the impaired section of the Crowder Creek due to fecal coliform.

Components of the project include installation of new and/or retrofit of existing structural best management
practices (BMPs) and/or low impact design (LIDs) at strategic locations of the Crowders Creek watershed or
at its Blackwood Creek sub-watershed. In addition, a watershed restoration plan for long-term fecal coliform
Crowders Creek TMDL Final Report

mitigation for the Crowders Creek watershed will be developed. The plan will integrate the efforts of TMDL
modeling, a bacterial source tracking (BST) study by NCDWQ (scheduled for summer 2004), and additional
monitoring and analyses to be performed by the investigators.

8 Public Participation

A draft of the Crowders Creek TMDL was publicly noticed through various means, including notification in
the local newspapers of NC and SC. Copies of the affidavits of publication are provided in Appendix IX.
The draft TMDL and public comment information was distributed electronically to known interested parties.
The TMDL was also available from the Division of Water Quality’s website at
http://h2o.enr.state.nc.us/tmdl/ during the comment period. The comment period occurred from March 23,
2004 through May 6, 2004. A public meeting was held on April 28 at the Gaston Citizen’s Resource Center
in Dallas, NC to present the TMDL and answer questions. Nine citizens attended the public meeting. One
comment was received from Mr. Alton C. Boozer, Chief of the South Carolina Bureau of Water. A copy of
the letter is located in Appendix X. The comments were positive and no response is needed.

9 Further Information

Further information concerning North Carolina’s TMDL program can be found on the Internet at the
Division of Water Quality website: http://h2o.enr.state.nc.us/tmdl/.

Technical questions regarding this TMDL should be directed to the following members of the DWQ
Modeling/TMDL Unit:

J. Todd Kennedy, Modeler ([e-mail]),
Michelle Woolfolk, Supervisor ([e-mail]).
Crowders Creek TMDL Final Report

10 References
Bowie, G.L, W.B. Mills, D.B. Porcella, C.L. Campbell, J.R. Pagenkopf, G.L. Rupp, K.M. Johnson, P.W.H.
Chan, and S.A. Gherini. 1985. Rates, constants, and kinetic formulations in surface water quality modeling.
2nd edition. EPA/600/3-85/040. Environmental Research Laboratory, Athens, GA.

Canale, R. P., M.T. Auer, E.M. Owens, T.M. Heidtke, S.W. Effler. 1993. Modeling Fecal Coliform Bacteria
–II. Model Development and Application. Water Research, 27(4):703-714.

Crane, S.R. and J. A. Moore. 1986. Modeling enteric bacterial die-off: A review. Water, Air, and Soil
Pollution 27:411-439.

Cleland, B.R. 2002. TMDL Development from the “Bottom Up” – Part II: Using load duration curves to
connect the pieces. Proceedings from the WEF National TMDL Science and Policy 2002 Conference.

Giese, G.L. and R.R. Mason, Jr. 1993. Low-flow characteristics of streams in North Carolina. U.S.
Geological Survey water-supply paper 2403.

Giffin, Mark. 2003. South Carolina DEHC. Personal Communication.

Gordon, R.D. 2003. A fecal coliform source assessment for the Crowders Creek watershed. Gaston County,
North Carolina. Civil Engineering Independent Study. Final Project. UNC Charlotte.

Hudson, Craven. 2002. Gaston County Cooperative Extension. Personal communication.

Mallin, M.A., K.E. Williams, E.C. Esham, and R.P. Lowe. 2000. Effect of human development on
bacteriological water quality in coastal watersheds. Ecological Applications, 10(4):1047-1056.

North Carolina Department of Agriculture. 2001. Agricultural Statistics Division-County Statistics.
www.ncagr.com/stats/cntysumm/ and http://govinfo.library.orst.edu/cgi-bin/agstate?North+Carolina.

North Carolina Cooperative Extension Service, North Carolina State University (NCSU), College of
Agriculture and Life Sciences, Raleigh, Livestock Manure Production and Characterization in North
Carolina. January 1994.

North Carolina Division of Environmental Health (NCDEH). NCDENR. 1999. North Carolina On-Site
Wastewater Non-Point Source (NPS) Pollution Program. www.deh.enr.state.nc.us/oww/nonpointsource/
NPS.htm June 24, 1999.

North Carolina Division of Environmental Health (NCDEH). NCDENR. 2000. Report on the Proper
Maintenance of Septic Tank Systems in Accordance with Section 13.5 of HB 1160 (Clean Water Act of
1999). http://www.deh.enr.state.nc.us/oww/Maintenance.PDF. March 15, 2000.

North Carolina Equine Survey. 1996. North Carolina Agricultural Statistics. NC Department of Agriculture
and Consumer Services, Raleigh, NC – 27611. http://www.agr.state.nc.us/stats.

North Carolina Division of Water Quality. February 2002. Fecal Coliform Total Maximum Daily Load for
the Irwin, McAlpine, Little Sugar and Sugar Creek Watersheds, Mecklenburg County. Catawba River Basin.
Final report submitted to EPA.
Crowders Creek TMDL Final Report

North Carolina Division of Water Quality. August 2002. Fecal Coliform Total Maximum Daily Load for the
Clark Creek Watershed, Catawba and Lincoln County. Catawba River Basin. Final Report.

Office of Water. 1997. Guidelines for preparation of the comprehensive state water quality assessments.
EPA-841-B-97-00. U.S. Environmental Protection Agency, Washington D.C.

Stiles, T.C. 2002. Incorporating hydrology in determining TMDL endpoints and allocations. Proceedings
from the WEF National TMDL Science and Policy 2002 Conference.

Systech Engineering. October 2001. Watershed Analysis Risk Management Frame Work (WARMF): Update
One: A Decision Support System for Watershed Analysis and Total Maximum Daily Load Calculation,
Allocation and Implementation. EPRI, Palo Alto, CA:1005181.

Thomann, R.V. and Mueller, J.A. 1987. Principles of Surface Water Quality Modeling and Control. Harper
and Row, New York, NY.

U.S. Environmental Protection Agency (USEPA) 1985. Rates, constants, and kinetics formulations in surface
water quality modeling (II ed.). Athens, GA: EPA-600-3-85-040.

U.S. Environmental Protection Agency (USEPA). 1991. Guidance for Water Quality-Based Decisions: The
TMDL Process. Assessment and Watershed Protection Division, Washington, DC.

U.S. Environmental Protection Agency, Federal Advisory Committee (FACA). Draft final TMDL Federal
Advisory Committee Report. 4/28/98.

U.S. Environmental Protection Agency (USEPA) 2000a. Revisions to the Water Quality Planning and
Management Regulation and Revisions to the National Pollutant Discharge Elimination System Program in
Support of Revisions to the Water Quality Planning and management Regulation; Final Rule. Fed. Reg.
65:43586-43670 (July 13, 2000).

U.S.Environmental Protection Agency (USEPA) 2000b. Implementation Guidance for Ambient Water
Quality Criteria for Bacteria – 1986. DRAFT. Office of Water. EPA-823- D-00-001.

U.S. Environmental Protection Agency (USEPA) 2000c. Bacterial Indicator Tool. User’s Guide. Office of
Water. EPA-823-B-01-003. March 2000.

U.S.Environmental Protection Agency (USEPA). January 2001. Protocol for Developing Pathogen TMDLs:
First Edition. http://www.epa.gov/owow/tmdl/techsupp.html.

Crowders Creek TMDL Final Report

11 Appendix

Appendix I. Water quality data collected in the Crowders Creek watershed (1997-2002).

Station # Station Description Date Fecal Coliform Temp
BWC Blackwood Creek at SR 1136 2/28/2001 280 11.7
BWC Blackwood Creek at SR 1136 3/5/2001 320 10.8
BWC Blackwood Creek at SR 1136 3/12/2001 270 10.7
BWC Blackwood Creek at SR 1136 3/19/2001 400 10.1
BWC Blackwood Creek at SR 1136 3/26/2001 1285 10.0
BWC Blackwood Creek at SR 1136 4/5/2001 400 13.8
BWC Blackwood Creek at SR 1136 7/5/2001 4700 22.5
BWC Blackwood Creek at SR 1136 7/10/2001 265 22.4
BWC Blackwood Creek at SR 1136 7/17/2001 395 23.0
BWC Blackwood Creek at SR 1136 7/24/2001 2900 23.0
BWC Blackwood Creek at SR 1136 7/31/2001 2000 22.1
BWC Blackwood Creek at SR 1136 8/7/2001 132 23.2
BWC Blackwood Creek at SR 1136 8/14/2001 5600 23.7
BWC Blackwood Creek at SR 1136 8/21/2001 245 22.5
BWC Blackwood Creek at SR 1136 8/28/2001 375 21.9
BWC Blackwood Creek at SR 1136 9/4/2001 97000 20.7
BWC Blackwood Creek at SR 1136 9/10/2002 410
BWC Blackwood Creek at SR 1136 9/12/2002 240
BWC Blackwood Creek at SR 1136 9/17/2002 2800
BWC Blackwood Creek at SR 1136 9/19/2002 1200
BWC Blackwood Creek at SR 1136 9/24/2002 900
BWC Blackwood Creek at SR 1136 10/1/2002 520
BWC Blackwood Creek at SR 1136 10/8/2002 3000
BWC Blackwood Creek at SR 1136 10/15/2002 2400
BWC Blackwood Creek at SR 1136 10/22/2002 5900
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 2/28/2001 41 11.2
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 3/5/2001 210 10.8
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 3/12/2001 76 10.6
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 3/19/2001 66 8.6
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 3/26/2001 315 10.1
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 4/5/2001 115 13.5
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 7/5/2001 265 21.9
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 7/10/2001 84 22.7
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 7/17/2001 50 22.1
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 7/24/2001 330 22.7
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 7/31/2001 50 22.4
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 8/7/2001 41 23.6
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 8/14/2001 3600 24.1
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 8/21/2001 60 23.3
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 8/28/2001 83 23.0
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 9/4/2001 36000 20.7
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 9/10/2002 2600
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CC2 Crowders Creek at SR 1108 (Upstream WWTP) 9/12/2002 130
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 9/17/2002 1000
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 9/19/2002 2200
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 9/24/2002 370
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 10/1/2002 520
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 10/8/2002 670
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 10/15/2002 400
CC2 Crowders Creek at SR 1108 (Upstream WWTP) 10/22/2002 5800
CC3 Crowders Crk at SR 2424 at NC/SC state line 2/28/2001 120 11.2
CC3 Crowders Crk at SR 2424 at NC/SC state line 3/5/2001 550 11.3
CC3 Crowders Crk at SR 2424 at NC/SC state line 3/12/2001 250 11.2
CC3 Crowders Crk at SR 2424 at NC/SC state line 3/19/2001 74 10.3
CC3 Crowders Crk at SR 2424 at NC/SC state line 3/26/2001 174 11.1
CC3 Crowders Crk at SR 2424 at NC/SC state line 4/5/2001 114 13.8
CC3 Crowders Crk at SR 2424 at NC/SC state line 7/5/2001 3000 22.1
CC3 Crowders Crk at SR 2424 at NC/SC state line 7/10/2001 120 24.2
CC3 Crowders Crk at SR 2424 at NC/SC state line 7/17/2001 29 23.5
CC3 Crowders Crk at SR 2424 at NC/SC state line 7/24/2001 305 24.4
CC3 Crowders Crk at SR 2424 at NC/SC state line 7/31/2001 78 23.5
CC3 Crowders Crk at SR 2424 at NC/SC state line 8/7/2001 55 25.0
CC3 Crowders Crk at SR 2424 at NC/SC state line 8/14/2001 122 24.6
CC3 Crowders Crk at SR 2424 at NC/SC state line 8/21/2001 120 24.2
CC3 Crowders Crk at SR 2424 at NC/SC state line 8/28/2001 375 24.4
CC3 Crowders Crk at SR 2424 at NC/SC state line 9/4/2001 107000 20.4
CC3 Crowders Crk at SR 2424 at NC/SC state line 9/10/2002 250
CC3 Crowders Crk at SR 2424 at NC/SC state line 9/12/2002 400
CC3 Crowders Crk at SR 2424 at NC/SC state line 9/17/2002 1100
CC3 Crowders Crk at SR 2424 at NC/SC state line 9/19/2002 770
CC3 Crowders Crk at SR 2424 at NC/SC state line 9/24/2002 380
CC3 Crowders Crk at SR 2424 at NC/SC state line 10/1/2002 270
CC3 Crowders Crk at SR 2424 at NC/SC state line 10/8/2002 220
CC3 Crowders Crk at SR 2424 at NC/SC state line 10/15/2002 400
CC3 Crowders Crk at SR 2424 at NC/SC state line 10/22/2002 4300
CC1 Crowders Creek at SR 1131 2/28/2001 18 11.7
CC1 Crowders Creek at SR 1131 3/5/2001 220 10.1
CC1 Crowders Creek at SR 1131 3/12/2001 80 9.9
CC1 Crowders Creek at SR 1131 3/19/2001 37 9.9
CC1 Crowders Creek at SR 1131 3/26/2001 200 9.5
CC1 Crowders Creek at SR 1131 4/5/2001 230 10.7
CC1 Crowders Creek at SR 1131 7/5/2001 3300 23.1
CC1 Crowders Creek at SR 1131 7/10/2001 83 24.0
CC1 Crowders Creek at SR 1131 7/17/2001 260 23.9
CC1 Crowders Creek at SR 1131 7/24/2001 140 24.1
CC1 Crowders Creek at SR 1131 7/31/2001 380 23.5
CC1 Crowders Creek at SR 1131 8/7/2001 235 25.1
CC1 Crowders Creek at SR 1131 8/14/2001 5000 25.0
CC1 Crowders Creek at SR 1131 8/21/2001 60 25.4
CC1 Crowders Creek at SR 1131 8/28/2001 365 22.8
CC1 Crowders Creek at SR 1131 9/4/2001 6000 20.9
Crowders Creek TMDL Final Report

CCE Crowders Creek WWTP effluent 2/28/2001 106 11.3
CCE Crowders Creek WWTP effluent 3/5/2001 370 11.2
CCE Crowders Creek WWTP effluent 3/12/2001 90 11.5
CCE Crowders Creek WWTP effluent 3/19/2001 72 10.4
CCE Crowders Creek WWTP effluent 3/26/2001 145 10.7
CCE Crowders Creek WWTP effluent 4/5/2001 92 13.9
CCE Crowders Creek WWTP effluent 7/5/2001 1603 21.4
CCE Crowders Creek WWTP effluent 7/10/2001 33 26.3
CCE Crowders Creek WWTP effluent 7/17/2001 9 27.0
CCE Crowders Creek WWTP effluent 7/24/2001 36 27.5
CCE Crowders Creek WWTP effluent 7/31/2001 6 27.2
CCE Crowders Creek WWTP effluent 8/7/2001 12 28.2
CCE Crowders Creek WWTP effluent 8/14/2001 152 26.9
CCE Crowders Creek WWTP effluent 8/21/2001 23 27.8
CCE Crowders Creek WWTP effluent 8/28/2001 20 27.9
CCE Crowders Creek WWTP effluent 9/4/2001 21500 21.3
SCC South Crowders Creek at SR 1103 2/28/2001 270 11.2
SCC South Crowders Creek at SR 1103 3/5/2001 300 10.8
SCC South Crowders Creek at SR 1103 3/12/2001 220 10.6
SCC South Crowders Creek at SR 1103 3/19/2001 76 8.6
SCC South Crowders Creek at SR 1103 3/26/2001 1125 10.1
SCC South Crowders Creek at SR 1103 4/5/2001 630 13.5
SCC South Crowders Creek at SR 1103 7/5/2001 44 21.9
SCC South Crowders Creek at SR 1103 7/10/2001 48 22.7
SCC South Crowders Creek at SR 1103 7/17/2001 35 22.1
SCC South Crowders Creek at SR 1103 7/24/2001 86 22.7
SCC South Crowders Creek at SR 1103 7/31/2001 58 22.4
SCC South Crowders Creek at SR 1103 8/7/2001 20 23.6
SCC South Crowders Creek at SR 1103 8/14/2001 385 24.1
SCC South Crowders Creek at SR 1103 8/21/2001 530 23.3
SCC South Crowders Creek at SR 1103 8/28/2001 108 23.0
SCC South Crowders Creek at SR 1103 9/4/2001 28000 20.7
SFCC South Fork Crowders Creek at SR 1109 2/28/2001 94 11.3
SFCC South Fork Crowders Creek at SR 1109 3/5/2001 330 11.1
SFCC South Fork Crowders Creek at SR 1109 3/12/2001 240 10.7
SFCC South Fork Crowders Creek at SR 1109 3/19/2001 60 10.0
SFCC South Fork Crowders Creek at SR 1109 3/26/2001 106 10.6
SFCC South Fork Crowders Creek at SR 1109 4/5/2001 215 13.6
SFCC South Fork Crowders Creek at SR 1109 7/5/2001 4000 22.7
SFCC South Fork Crowders Creek at SR 1109 7/10/2001 465 23.0
SFCC South Fork Crowders Creek at SR 1109 7/17/2001 35 22.4
SFCC South Fork Crowders Creek at SR 1109 7/24/2001 365 22.6
SFCC South Fork Crowders Creek at SR 1109 7/31/2001 320 22.5
SFCC South Fork Crowders Creek at SR 1109 8/7/2001 335 23.7
SFCC South Fork Crowders Creek at SR 1109 8/14/2001 555 24.0
SFCC South Fork Crowders Creek at SR 1109 8/21/2001 50 23.2
SFCC South Fork Crowders Creek at SR 1109 8/28/2001 27 22.7
SFCC South Fork Crowders Creek at SR 1109 9/4/2001 46000 20.6
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 1/8/1998 42000 15
Crowders Creek TMDL Final Report

CC4 CROWDERS CRK AT SC 564 (NC Ambient) 2/16/1998 230 8
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 3/11/1998 220 8
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 4/28/1998 400 15
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 5/20/1998 420 21
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 6/23/1998 350 23
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 7/22/1998 610 26
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 8/10/1998 1100 23
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 9/21/1998 1600 23
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 10/29/1998 82 16
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 11/23/1998 64 10
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 12/30/1998 400 7
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 1/27/1999 220 9
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 2/23/1999 73 5
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 3/18/1999 180 12
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 4/27/1999 120 17
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 5/24/1999 100 22
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 6/22/1999 230 19
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 8/3/1999 110 25
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 8/23/1999 210 23
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 9/13/1999 170 21
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 10/19/1999 240 16
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 11/4/1999 420 11
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 12/6/1999 800 13
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 1/5/2000 710 9
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 2/21/2000 100 8
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 3/22/2000 440 12
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 4/18/2000 210 16
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 5/17/2000 130 17
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 6/20/2000 260 22
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 7/27/2000 220 22
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 9/13/2000 230 22
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 10/19/2000 82 16
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 11/29/2000 190 8
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 12/28/2000 54 4
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 1/29/2001 18 6
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 2/13/2001 230 8
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 4/23/2001 240 18
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 5/29/2001 580 19
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 6/14/2001 190 24
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 7/23/2001 66 23
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 8/22/2001 110 23
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 9/18/2001 81 18
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 10/22/2001 200 17
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 11/29/2001 260 15
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 12/17/2001 360 12
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 1/16/2002 200 6
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 2/14/2002 100 8
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 3/18/2002 700 12
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 4/25/2002 320 18
Crowders Creek TMDL Final Report

CC4 CROWDERS CRK AT SC 564 (NC Ambient) 5/22/2002 280 14
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 6/13/2002 210 23
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 7/1/2002 260 25
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 8/13/2002 87 24
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 9/9/2002 190 22
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 10/24/2002 320 15.3
CC4 CROWDERS CRK AT SC 564 (NC Ambient) 11/20/2002 160 9.6

Crowders Creek TMDL Final Report

Appendix II. Land use by WARMF subwatershed based on 1993-1996 landcover in the Crowders Creek
watershed.

WARMF LU % m^2 mi^2
1 1119
Deciduous Forest 27.59 6.85E+06 2.64
Evergreen Forest 12.9 3.20E+06 1.24
Mixed Forest 7.19 1.79E+06 0.69
Pasture 6.77 1.68E+06 0.65
Cultivated 14.55 3.61E+06 1.39
Recr. Grasses 2.46 6.11E+05 0.24
Water 0.24 5.96E+04 0.02
Barren 1.21 3.00E+05 0.12
Low Int. Develop. 12.63 3.14E+06 1.21
High Int. Develop. 3.49 8.67E+05 0.33
Comm / Industrial 10.24 2.54E+06 0.98
Wetlands 0.74 1.84E+05 0.07
TOTAL 100 9.59
2.48E+07
2 1118 %
Deciduous Forest 56.8 9.27E+06 3.58
Evergreen Forest 11.41 1.86E+06 0.72
Mixed Forest 5.8 9.47E+05 0.37
Pasture 5.4 8.81E+05 0.34
Cultivated 7.72 1.26E+06 0.49
Recr. Grasses 2.35 3.84E+05 0.15
Water 0.13 2.12E+04 0.01
Barren 0.32 5.22E+04 0.02
Low Int. Develop. 4.74 7.74E+05 0.30
High Int. Develop. 1.6 2.61E+05 0.10
Comm / Industrial 2.78 4.54E+05 0.18
Wetlands 0.92 1.50E+05 0.06
TOTAL 100 6.30
1.63E+07
3 1102 %
Deciduous Forest 65.61 1.95E+07 7.53
Evergreen Forest 11.01 3.27E+06 1.26
Mixed Forest 7.8 2.32E+06 0.89
Pasture 5.22 1.55E+06 0.60
Cultivated 7 2.08E+06 0.80
Recr. Grasses 0.08 2.38E+04 0.01
Water 0.37 1.10E+05 0.04
Barren 0.16 4.75E+04 0.02
Low Int. Develop. 1.71 5.08E+05 0.20
High Int. Develop. 0 0.00E+00 0.00
Comm / Industrial 0.48 1.43E+05 0.06
Wetlands 0.54 1.60E+05 0.06
TOTAL 100
Crowders Creek TMDL Final Report

2.97E+07
4 1106 %
Deciduous Forest 15.05 4.89E+06 1.89
Evergreen Forest 23.78 7.73E+06 2.98
Mixed Forest 14.75 4.79E+06 1.85
Pasture 17.74 5.77E+06 2.23
Cultivated 22.79 7.41E+06 2.86
Recr. Grasses 0.23 7.48E+04 0.03
Water 0.28 9.10E+04 0.04
Barren 2.17 7.05E+05 0.27
Low Int. Develop. 1.65 5.36E+05 0.21
High Int. Develop. 0 0.00E+00 0.00
Comm / Industrial 0.36 1.17E+05 0.05
Wetlands 1.21 3.93E+05 0.15
TOTAL 100
3.25E+07
5 1111 %
Deciduous Forest 34.16 1.89E+07 7.28
Evergreen Forest 13.76 7.60E+06 2.93
Mixed Forest 8.18 4.52E+06 1.74
Pasture 4.29 2.37E+06 0.91
Cultivated 5.94 3.28E+06 1.27
Recr. Grasses 1.85 1.02E+06 0.39
Water 0.3 1.66E+05 0.06
Barren 0.38 2.10E+05 0.08
Low Int. Develop. 16.86 9.31E+06 3.59
High Int. Develop. 5.45 3.01E+06 1.16
Comm / Industrial 8.35 4.61E+06 1.78
Wetlands 0.47 2.59E+05 0.10
TOTAL 100
5.52E+07
6 1110 %
Deciduous Forest 43.52 3.64E+06 1.40
Evergreen Forest 15.63 1.31E+06 0.50
Mixed Forest 8.34 6.97E+05 0.27
Pasture 4.85 4.05E+05 0.16
Cultivated 8.1 6.77E+05 0.26
Recr. Grasses 0.85 7.10E+04 0.03
Water 0.1 8.35E+03 0.00
Barren 0.17 1.42E+04 0.01
Low Int. Develop. 14.58 1.22E+06 0.47
High Int. Develop. 1.61 1.35E+05 0.05
Comm / Industrial 1.69 1.41E+05 0.05
Wetlands 0.56 4.68E+04 0.02
TOTAL 100
8.35E+06
7 1101 %
Deciduous Forest 0 0.00E+00 0.00
Crowders Creek TMDL Final Report

Evergreen Forest 24.13 2.78E+06 1.07
Mixed Forest 20.68 2.38E+06 0.92
Pasture 20.74 2.39E+06 0.92
Cultivated 27.08 3.12E+06 1.20
Recr. Grasses 0 0.00E+00 0.00
Water 0.29 3.34E+04 0.01
Barren 0.18 2.07E+04 0.01
Low Int. Develop. 4 4.60E+05 0.18
High Int. Develop. 0.02 2.30E+03 0.00
Comm / Industrial 0.51 5.87E+04 0.02
Wetlands 2.36 2.72E+05 0.10
TOTAL 100
1.15E+07
8 1108 %
Deciduous Forest 53.53 1.64E+06 0.63
Evergreen Forest 11.97 3.66E+05 0.14
Mixed Forest 12.69 3.88E+05 0.15
Pasture 8.6 2.63E+05 0.10
Cultivated 7.75 2.37E+05 0.09
Recr. Grasses 0.21 6.42E+03 0.00
Water 0 0.00E+00 0.00
Barren 0.21 6.42E+03 0.00
Low Int. Develop. 1.92 5.87E+04 0.02
High Int. Develop. 0 0.00E+00 0.00
Comm / Industrial 1.58 4.83E+04 0.02
Wetlands 1.53 4.68E+04 0.02
TOTAL 100
3.06E+06
9 1099 %
Deciduous Forest 19.96 3.75E+06 1.45
Evergreen Forest 18.82 3.53E+06 1.36
Mixed Forest 9.15 1.72E+06 0.66
Pasture 13.28 2.49E+06 0.96
Cultivated 16.27 3.06E+06 1.18
Recr. Grasses 2.12 3.98E+05 0.15
Water 0.27 5.07E+04 0.02
Barren 0.75 1.41E+05 0.05
Low Int. Develop. 11.28 2.12E+06 0.82
High Int. Develop. 1.2 2.25E+05 0.09
Comm / Industrial 6.54 1.23E+06 0.47
Wetlands 0.36 6.76E+04 0.03
TOTAL 100
1.88E+07
10 1100 %
Deciduous Forest 6.32 1.46E+05 0.06
Evergreen Forest 12.28 2.84E+05 0.11
Mixed Forest 18.38 4.26E+05 0.16
Pasture 30.22 7.00E+05 0.27
Crowders Creek TMDL Final Report

Cultivated 20.81 4.82E+05 0.19
Recr. Grasses 0.74 1.71E+04 0.01
Water 0.59 1.37E+04 0.01
Barren 1.69 3.91E+04 0.02
Low Int. Develop. 4.63 1.07E+05 0.04
High Int. Develop. 0 0.00E+00 0.00
Comm / Industrial 1.25 2.89E+04 0.01
Wetlands 3.09 7.16E+04 0.03
TOTAL 100
2.32E+06
11 1095 %
Deciduous Forest 41.83 1.59E+07 6.15
Evergreen Forest 17.08 6.50E+06 2.51
Mixed Forest 10.39 3.96E+06 1.53
Pasture 9.68 3.68E+06 1.42
Cultivated 11.88 4.52E+06 1.75
Recr. Grasses 0.97 3.69E+05 0.14
Water 0.4 1.52E+05 0.06
Barren 0.2 7.61E+04 0.03
Low Int. Develop. 5.45 2.07E+06 0.80
High Int. Develop. 0.5 1.90E+05 0.07
Comm / Industrial 1.11 4.23E+05 0.16
Wetlands 0.5 1.90E+05 0.07
TOTAL 100
3.81E+07 2.41E+08 108.79

Crowders Creek TMDL Final Report

Appendix III. Calibrated soil layer parameters.

Subwatershed Soil Layer Area Thickness Initial Field Sat. Horizontal Vertical Root Density Soil
m2 cm Moisture Capacity Moisture Cond. cm/d Cond. cm/d Distr. g/cm3 Tortuosity
1 1 24829000 25 0.20 0.15 0.20 9800 3 0.75 0.2 10
2 24829000 60 0.28 0.20 0.30 3000 40 0.1 1.3 10
3 24829000 50 0.30 0.25 0.30 2500 80 0.1 1.3 10
4 23180000 100 0.37 0.28 0.37 1500 60 0.05 1.5 10

2 1 16321000 25 0.20 0.15 0.20 9800 3 0.75 0.2 10
2 16321000 60 0.30 0.20 0.30 3000 40 0.1 1.3 10
3 16321000 50 0.35 0.25 0.30 2500 80 0.1 1.3 10
4 15239000 100 0.37 0.28 0.37 1500 60 0.05 1.5 10
15239000 100 0.37 0.28 0.37 1500 60 0.05 1.5 10

3 1 29711000 25 0.22 0.15 0.20 9800 3 0.75 0.2 10
2 29711000 60 0.30 0.20 0.30 3000 40 0.1 1.3 10
3 29711000 75 0.35 0.25 0.30 1000 80 0.1 1.3 10
4 27737000 150 0.37 0.28 0.37 300 60 0.05 1.5 10

4 1 32506000 25 0.22 0.15 0.20 9800 3 0.75 0.2 10
2 32506000 60 0.30 0.20 0.30 3000 40 0.1 1.3 10
3 32506000 75 0.35 0.25 0.30 1000 80 0.1 1.3 10
4 30343000 150 0.37 0.28 0.37 300 60 0.05 1.5 10

5 1 55196000 40 0.24 0.15 0.20 9700 25 0.75 0.2 10
2 55196000 80 0.32 0.20 0.35 2000 40 0.1 1.3 10
3 55196000 50 0.38 0.28 0.35 2000 60 0.1 1.3 10
4 51529000 150 0.38 0.22 0.36 300 60 0.05 1.5 10

6 1 8354000 40 0.22 0.15 0.20 9700 25 0.75 0.2 10
2 8354000 80 0.30 0.20 0.35 2000 40 0.1 1.3 10
3 8354000 75 0.38 0.28 0.35 2000 60 0.1 1.3 10
4 7798700 150 0.38 0.22 0.36 300 60 0.05 1.5 10

7 1 11509000 40 0.22 0.15 0.20 9700 25 0.75 0.2 10
Crowders Creek TMDL Final Report

2 11509000 80 0.30 0.20 0.35 2000 40 0.1 1.3 10
3 11509000 75 0.38 0.28 0.35 2000 60 0.1 1.3 10
4 10743000 150 0.38 0.22 0.36 300 60 0.05 1.5 10

8 1 3056600 40 0.22 0.15 0.20 9700 25 0.75 0.2 10
2 3056600 80 0.30 0.20 0.35 2000 40 0.1 1.3 10
3 3056600 75 0.38 0.28 0.35 2000 60 0.1 1.3 10
4 2853600 150 0.38 0.22 0.36 300 60 0.05 1.5 10

9 1 18777000 40 0.22 0.15 0.20 9700 25 0.75 0.2 10
2 18777000 80 0.30 0.20 0.35 2000 40 0.1 1.3 10
3 18777000 75 0.38 0.28 0.35 2000 60 0.1 1.3 10
4 17530000 150 0.38 0.22 0.36 300 60 0.05 1.5 10

10 1 2315900 40 0.20 0.15 0.20 9700 25 0.75 0.2 10
2 2315900 80 0.30 0.20 0.35 2000 40 0.1 1.3 10
3 2315900 75 0.38 0.28 0.35 2000 60 0.1 1.3 10
4 2161800 150 0.38 0.22 0.36 300 60 0.05 1.5 10

11 1 38067000 40 0.22 0.15 0.20 9700 25 0.75 0.2 10
2 38067000 80 0.30 0.20 0.35 2000 40 0.1 1.3 10
3 38067000 75 0.38 0.28 0.35 2000 60 0.1 1.3 10
4 35537000 150 0.38 0.22 0.36 300 60 0.05 1.5 10

Crowders Creek TMDL Final Report

Appendix IV. Load allocation calculation for Kings Mountain.

TMDL Loading
Loading per unit area Fecal Loading
WARMF LU % m^2 mi^2 ha 1E6/ha/yr 1E6/yr
1 1119
Deciduous Forest 27.59 6850404 2.644941 685.0397 Deciduous Forest 282 193181.196
Evergreen Forest 12.9 3202980 1.23667 320.2976 Evergreen Forest 380 121713.1069
Mixed Forest 7.19 1785227 0.689276 178.5225 Mixed Forest 415 74086.83272
Pasture 6.77 1680944 0.649012 168.0942 Pasture 9910 1665813.452
Cultivated 14.55 3612663 1.394849 361.266 Cultivated 388 140171.19
Recr. Grasses 2.46 610800.8 0.23583 61.08002 Recr. Grasses 217 13254.36367
Water 0.24 59590.32 0.023008 5.959026 Water 312 1859.216125
Barren 1.21 300434.5 0.115998 30.04342 Barren 166 4987.208211
Low Int. Develop. 12.63 3135941 1.210787 313.5937 Low Int. Develop. 11600 3637687.447
High Int. Develop.3.49 866542.6 0.334572 86.65417 High Int. Develop. 25600 2218346.761
Comm / Industrial 10.24 2542520 0.981667 254.2518 Comm / Industrial 14100 3584950.066
Wetlands 0.74 183736.8 0.070941 18.37366 Wetlands 0 0
Sum 11656050.84

2 1118 %
Deciduous Forest 56.8 9270442 3.579318 927.0432 Deciduous Forest 282 261426.1917
Evergreen Forest 11.41 1862249 0.719014 186.2247 Evergreen Forest 380 70765.38819
Mixed Forest 5.8 946629.6 0.365494 94.66287 Mixed Forest 415 39285.08911
Pasture 5.4 881344.8 0.340287 88.13439 Pasture 9910 873411.8234
Cultivated 7.72 1259997 0.486485 125.9995 Cultivated 388 48887.82074
Recr. Grasses 2.35 383548.2 0.148088 38.35478 Recr. Grasses 217 8322.987617
Water 0.13 21217.56 0.008192 2.121754 Water 312 661.98721
Barren 0.32 52227.84 0.020165 5.222779 Barren 166 866.981277
Low Int. Develop. 4.74 773624.9 0.298697 77.36241 Low Int. Develop. 11600 897403.9634
High Int. Develop.1.6 261139.2 0.100826 26.11389 High Int. Develop. 25600 668515.6835
Comm / Industrial 2.78 453729.4 0.175185 45.37289 Comm / Industrial 14100 639757.7578
Wetlands 0.92 150155 0.057975 15.01549 Wetlands 0 0
Sum 3509305.674

in units/d
Crowders Creek TMDL Final Report

Grand Sum for entire Crowders= 2.13E+11 Grand Sum 15165357 4.15E+10
Grand Sum for WS 1 and 2 4.15E+10 19.51% 34.10%
Kings Mtn LA 5171387
212980.7
19.51% 34.10% 6.65% 5.17E+12 1.42E+10

Crowders Creek TMDL Final Report

Appendix V. Modeled fecal coliform loading scenarios.

Simulated Fecal Coliform Loading Current Conditions Geometric Mean SC Instantaneous SC Instantaneous
1E6/d w/ modified point source w/ modified point source
crowd_calibfin crowd_tmdl crowd_tmdl_2 crowd_tmdl_3
Managed Flow 0 0 0 0
Groundwater Pumping 0 0 0 0
Deciduous Forest 29100 6510 10900 11900
Evergreen Forest 18100 3990 6680 7290
Mixed Forest 12400 2720 4550 4970
Pasture 284000 60200 101000 110000
Cultivated 14300 3160 5280 5770
Recr. Grasses 817 177 296 323
Water 270 60 101 110
Barren 300 74 122 133
Low Int. Develop. 304000 64400 108000 118000
High Int. Develop. 155000 32800 54900 59900
Comm / Industrial 179000 37900 63400 69200
Wetlands 0 0 0 0
General Nonpoint Sources 0 0 0 0
Direct Precipitation 0 0 0 0
Direct Dry Deposition 0 0 0 0
Type 1 Septic System 6670 699 1200 1310
Type 2 Septic System 0 0 0 0
Type 3 Septic System 2780 291 498 547
Unpermitted Surface Mines 0 0 0 0
Unpermitted Deep Mines 0 0 0 0
Permitted Surface Mines 0 0 0 0
Permitted Deep Mines 0 0 0 0
General Point Sources 25300 8220 25300 8220
Nonpoint Total 1006737 212981 356927 389453
TOTAL 1030000 221000 382000 397000
Reduction Required 79% 63% 61%

Crowders Creek TMDL Final Report

Appendix VI. Load allocation calculations for South Carolina portion of Crowders Creek.

Subwatersheds 4,7, and 11 are split between SC and NC.
The landuses are relatively homogenous within each subwatershed. These watersheds are predominately rural in character.
4 and 11 are 1/2 in SC and 7 is 1/4 in SC.
TMDL Loading
WARMF LU % m^2 mi^2 ha Loading per unit area Fecal
Loading
NC SC
Subwatershed 4 1E6/ha/yr 1E6/yr
1106
Deciduous Forest 15.05 4892273.40 1.89 489.23 Deciduous Forest 282 137961.97
Evergreen Forest 23.78 7730117.04 2.98 773.01 Evergreen Forest 380 293744.15
Mixed Forest 14.75 4794753.00 1.85 479.47 Mixed Forest 415 198982.05
Pasture 17.74 5766706.32 2.23 576.67 Pasture 9910 5714800.2
Cultivated 22.79 7408299.72 2.86 740.83 Cultivated 388 287441.74
Recr. Grasses 0.23 74765.64 0.03 7.48 Recr. Grasses 217 1622.4128
Water 0.28 91019.04 0.04 9.10 Water 312 2839.7912
Barren 2.17 705397.56 0.27 70.54 Barren 166 11709.588
Low Int. Develop. 1.65 536362.20 0.21 53.64 Low Int. Develop. 11600 622179.53
High Int. Develop. 0.00 0.00 0.00 0.00 High Int. Develop. 25600 0
Comm / Industrial 0.36 117024.48 0.05 11.70 Comm / Industrial 14100 165004.35
Wetlands 1.21 393332.28 0.15 39.33 Wetlands 0 0
12.55 Sum 7436285.8 3718143 3718143

Subwatershed 7
1101
Deciduous Forest 0.00 0.00 0.00 0.00 Deciduous Forest 282 0
Evergreen Forest 24.13 2777218.22 1.07 277.72 Evergreen Forest 380 105534.19
Mixed Forest 20.68 2380143.92 0.92 238.01 Mixed Forest 415 98775.874
Pasture 20.74 2387049.56 0.92 238.70 Pasture 9910 2365563.7
Cultivated 27.08 3116745.52 1.20 311.67 Cultivated 388 120929.61
Recr. Grasses 0.00 0.00 0.00 0.00 Recr. Grasses 217 0
Water 0.29 33377.26 0.01 3.34 Water 312 1041.3695
Barren 0.18 20716.92 0.01 2.07 Barren 166 343.90053
Low Int. Develop. 4.00 460376.00 0.18 46.04 Low Int. Develop. 11600 534035.63
High Int. Develop. 0.02 2301.88 0.00 0.23 High Int. Develop. 25600 5892.8069
Crowders Creek TMDL Final Report

Comm / Industrial 0.51 58697.94 0.02 5.87 Comm / Industrial 14100 82764.013
Wetlands 2.36 271621.84 0.10 27.16 Wetlands 0 0
4.44 Sum 3314881.1 2486161 828720

Subwatershed 11
1095
Deciduous Forest 41.83 15923802.57 6.15 1592.38 Deciduous Forest 282 449050.78
Evergreen Forest 17.08 6501997.32 2.51 650.20 Evergreen Forest 380 247075.65
Mixed Forest 10.39 3955254.81 1.53 395.53 Mixed Forest 415 164142.91
Pasture 9.68 3684972.72 1.42 368.50 Pasture 9910 3651804.3
Cultivated 11.88 4522466.52 1.75 452.25 Cultivated 388 175471.53
Recr. Grasses 0.97 369258.63 0.14 36.93 Recr. Grasses 217 8012.9043
Water 0.40 152271.60 0.06 15.23 Water 312 4750.8692
Barren 0.20 76135.80 0.03 7.61 Barren 166 1263.853
Low Int. Develop. 5.45 2074700.55 0.80 207.47 Low Int. Develop. 11600 2406650.2
High Int. Develop. 0.50 190339.50 0.07 19.03 High Int. Develop. 25600 487268.63
Comm / Industrial 1.11 422553.69 0.16 42.26 Comm / Industrial 14100 595800.11
Wetlands 0.50 190339.50 0.07 19.03 Wetlands 0 0
14.70 Sum 8191291.8 4095646 4095646

Units are 1E6/yr
Grand
Total
31.69 Grand Sum 18942459 10299950 8642509
SC 14.7352 15.9% 54.37% 45.63%
Total Crowder 92.9 Total Nonpoint Crowder Loading 77737956
4,7,11 percent of total 24.37% 13.25% 11.12%

Crowders Creek TMDL Final Report

Appendix VII. Crowders Creek Fecal Coliform TMDL Allocation Worksheet

Crowder’s Creek Watershed
Fecal Coliform Allocation Worksheet

units/d % of TMDL
TMDL 2.21E+11
Continuos WLA * 8.27E+09 3.7%
Background LA ** 1.30E+10
MS4 WLA plus LA *** 2.13E+11
SC LA **** 2.36E+10 10.7%
Kings Mtn LA 1.41E+10
MS4 WLA plus NC LA 1.89E+11
MS4 WLA 7.45E+10 33.7%
NC LA 1.15E+11 51.8%
100%

* Based on maximum permitted loading, calculated as permitted flow (wwtp plus small pt. Sources = 6.07 mgd) times 200 cfu/mL standard.
Crowders Creek WWTP will need to reduce loading to also meet the 400 cfu/100ml instantaneous standard.
** Background is based on 5.9% loading derived from this landuse(forested/wetland/greenspace.
***TMDL minus continous WLA minus Background LA.
**** Based on landuse and unit load rates in border watersheds.

Crowders Creek TMDL Final Report

Appendix VIII. Septic system loading estimates for the Crowders Creek watershed.

acres population served pop/acre pop/sqmi
North Crowders Subwatershed
Census Tract Septic Systems Density 13737
(number) (people/system)
316* 259 2.78 720
318 88 2.89 254
331 107 2.78 296
317.02 167 2.77 463
317.01* 237 2.66 629
2363 0.17 110
Central Crowders Subwatershed
Census Tract Septic Systems Density 9175
(number) (people/system)
332.01 181 3.41 616
317.02 229 2.77 633
317.01 127 2.66 339
334 579 2.94 1702
3290 0.36 229

Blackwood Creek Subwatershed
Census Tract Septic Systems Density 2202
(number) (people/system)
318 20 2.89 58
331 73 2.78 204
332.01 328 3.41 1119
1382 0.63 402
South Crowders Subwatershed
Census Tract Septic Systems Density 10686
(number) (people/system)
317.02 13 2.77 36
334 163 2.94 480
317.01 942 2.66 2507
3023 0.28 181
Lower Crowders Subwatershed
Census Tract Septic Systems Density 8792
(number) (people/system)
332.02 409 2.71 1108
333.02 744 1.79 1331
334 304 2.94 894
3334 0.38 243

Grand Total 13391 0.36 233
Notes: Data from Gordon (2003). Per Gordon (2003), because tract boundaries do not exactly follow watershed
boundaries, tract % and acreages may not add correctly. For tracts that lie significantly outside of watershed
boundaries, population estimates were adjusted accordingly. Calculations in italics are by NC DWQ.
Crowders Creek TMDL Final Report

Appendix IX. Affidavits of Publication for Public Notices

Crowders Creek TMDL Final Report

Crowders Creek TMDL Final Report

Appendix X. Comments on the Crowders Creek TMDL