Total Maximum Daily Load for Second Creek

Final Second Creek TMDL Pathogens (fecal coliform)

AL06030002-1204-103

Final

Total Maximum Daily Load

for

Second Creek

Waterbody ID# AL06030002-1204-103

Pathogens (fecal coliform)

Alabama Department of Environmental Management

Water Quality Branch

Water Division

December 2006

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Figure 1: 303(d) Listed Segment of Second Creek

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Table of Contents Page

1.0 Executive Summary 4

2.0 Basis for §303(d) Listing 6

2.1 Introduction 6

2.2 Problem Definition 6

3.0 Technical Basis for TMDL 9

3.1 Water Quality Target Identification 9

3.2 Source Assessment 9

3.3 Landuse 9

3.4 Linkage Between Numeric Targets and Sources 12

3.5 Data Availability and Analysis 12

3.6 Critical Conditions 13

3.7 Margin of Safety 14

4.0 TMDL Development 14

4.1 Definition of a TMDL 14

4.2 Load Calculations 14

4.3 TMDL Summary 16

5.0 Follow Up Monitoring 17

6.0 Public Participation 17

Appendices

A. References 18

B. Water Quality Data 19

List of Figures

Figure 1: 303(d) Listed Segments of Second Creek 2

Figure 3.1: Landuse Map of the Second Creek Watershed 10

Figure 3.2: Sampling Stations in the Second Creek Watershed 13

List of Tables

Table 1.1: Current/Allowable Loads and Required Reductions 5

Table 1.2: TMDL for Second Creek 5

Table 2.1: Geometric Mean Fecal Coliform Violations 8

Table 3.1: Landuse in the Second Creek Watershed 11

Table 3.2: Sampling Station Location Descriptions 12

Table 4.1: Current vs. Allowable Pathogen Loadings for

Second Creek 15

Table 4.2: Current/Allowable Loads and Required Reductions 20

Table 4.3: TMDL Pathogen Loadings 20

Table 5.1: ADEM’s Major River Basin Schedule 21

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1.0 Executive Summary

Section 303(d) of the Clean Water Act and EPA’s Water Quality Planning and Management

Regulations (40 CFR Part 130) require states to identify waterbodies which are not meeting their

designated use(s) and to determine the Total Maximum Daily Load (TMDL) for pollutants

causing the use impairment. A TMDL is the sum of individual waste load allocations for point

sources (WLAs), load allocations (LAs) for nonpoint sources including natural background

levels, and a margin of safety (MOS).

Second Creek is on Alabama’s 303(d) list for pathogens (fecal coliform) from Lauderdale

County Road 76 to the Alabama/Tennessee state line. The listed portion of Second Creek has a

designated use classification of Fish and Wildlife (F&W) from US Highway 72 to the

Alabama/Tennessee state line. Second Creek is a part of the Upper Tennessee River Basin and

begins in Tennessee and flows into Alabama near the town of Lexington and continues on to

Wheeler Lake on the Tennessee River. The USGS hydrologic unit code (HUC) for Wheeler Lake

is 06030002. The Second Creek watershed is comprised of the upper and lower Second Creek

subwatersheds. The HUC numeric ID for the upper and lower Second Creek subwatershed is

06030002-1203 and 06030002-1204, respectively. The total drainage area of the Second Creek

watershed including the portion in the state of Tennessee is approximately 59.0 square miles.

Almost a third of the watershed (33.6%) lies within the state of Tennessee.

Second Creek was placed on the Alabama’s §303(d) list for pathogens in 1998 based on a study

conducted by TVA in 1997. The data used for the listing was gathered from TVA station 10118-

1 and can be found in Appendix B.

TVA collected data monthly at Station 10118-1 in 1997 from June through October. ADEM

collected data on Second Creek at Station SCDL-11 once in July 1998. More recently, ADEM

has collected data on Second Creek at Stations SCDL-11, SCDL-12, and SCDL-13 five times

during the month of June and five times during the month of August in 2003. In 2004, ADEM

has collected data on Second Creek at Stations SCDL-11, SCDL-12, and SCDL-13 five times

during the month of July and five times during the month of September. It should also be noted

that TVA station 10118-1 is the same as ADEM station SCDL-11.

Based on the data from 2003 and 2004, Second Creek is not meeting the pathogen criteria

applicable to its use classification of Fish and Wildlife. Therefore, this TMDL is being developed

for Second Creek.

A mass balance approach was used to calculate this TMDL which utilizes the conservation of

mass principle. The pathogen loading to Second Creek was calculated using a geometric mean

exceedance concentration times the average flow for the 5 samples used to calculate the

geometric mean. The allowable loading was calculated using the same average flow value times

the fecal coliform geometric mean criterion target of 180 colonies/100 mL (200 colonies/100 mL

– 10% Margin of Safety). Reductions to meet the allowable loading were then calculated by

subtracting the allowable loading from the current loading. Table 1.1 is a summary of current

loads, allowable loads and required load reductions necessary to meet the applicable water

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quality pathogen geometric mean criterion for Second Creek. Table 1.2 lists the required TMDL

pathogen loadings under critical conditions for Second Creek.

Table 1.1 Current/Allowable Loads and Required Reductions

Source

Current

Load

(col/day)

Allowable

Load

(col/day)

Required

Reduction

(col/day)

Reduction

Final

Load

(col/day)

1.83E+11 1.08E+11 7.55E+10 41% 1.08E+11

WLA

0.00E+00 0.00E+00 0.00E+00 0% 0.00E+00

Table 1.2 TMDL for Second Creek

TMDL

(col/day)

WLA

(col/day)

MOS

(col/day)

1.20E+11 0.00E+00 1.08E+11 1.20E+10

The majority of the watershed is undeveloped and consists of agriculture and forest landuse. The

most likely sources of impairment to the stream come from agricultural landuse. This watershed

has an uncommonly high concentration of agricultural uses accounting for slightly over half of

the landuse (54.6%).

ADEM, in cooperation with other stakeholders, will need to verify the likely sources of fecal

coliform located within the watershed. The likely areas where mitigation efforts will need to

occur will be pastures that contain dense sources of livestock that have direct access to Second

Creek or pasture areas that lie adjacent to the streams that have little to no best management

practices (BMPs) in place. Following identification of these and other landuse issues within the

Alabama portion of the watershed, ADEM will need to coordinate with TDEC in order to

determine the possible pathogen sources in Tennessee. Based on results of these studies, the two

agencies will need to generate a plan that can produce the overall needed reduction in fecal

coliform using BMPs.

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2.0 Basis for §303(d) Listing

2.1 Introduction

Section 303(d) of the Clean Water Act and EPA’s Water Quality Planning and Management

Regulations (40 CFR Part 130) require states to identify waterbodies which are not meeting their

designated uses and to determine the total maximum daily load (TMDL) for pollutants causing

use impairment. The TMDL process establishes the allowable loading of pollutants for a

waterbody based on the relationship between pollution sources and instream water quality

conditions, so that states can establish water-quality based controls to reduce pollution and

restore and maintain the quality of their water resources (USEPA, 1991).

As previously mentioned, Second Creek was placed on the Alabama’s §303(d) list for pathogens

in 1998 based on a study done by TVA in 1997. In the TVA study, there were two out of the

five samples collected that exceeded the maximum single sample criterion of 2000 col/100 ml. It

should be noted that during the 1997 sampling did not provide enough data within the specified

timeframe to calculate a geometric mean. The data collected for the study mentioned above can

be found in Appendix B.

2.2 Problem Definition

Waterbody Impaired: Second Creek from Lauderdale County

Road 76 to the Alabama/Tennessee state line

Waterbody length: 13 miles

Waterbody drainage area: 59 square miles

Water Quality Criterion Violation: Pathogens (in the form of fecal coliform)

(single sample and geometric mean)

Pollutant of Concern: Pathogens (fecal coliform)

Water Use Classification: Fish & Wildlife (F&W)

Usage related to classification:

The impaired stream segments, Second Creek, are classified as F&W. Usage of waters in this

classification are described in ADEM Admin. Code R. 335-6-10-.09(5)(a), (b), (c), (d), and (e) as

follows:

(a) Best usage of waters: fishing, propagation of fish, aquatic life, and wildlife, and

any other usage except for swimming and water-contact sports or as a source of

water supply for drinking or food-processing purposes.

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(b) Conditions related to best usage: the waters will be suitable for fish, aquatic life

and wildlife propagation. The quality of salt and estuarine waters to which this

classification is assigned will also be suitable for the propagation of shrimp and

crabs

water contact and recreation during June through September, except that water

contact is strongly discouraged in the vicinity of discharges or other conditions

beyond the control of the Department or the Alabama Department of Public

Health.

(d) Conditions related to other usage: the waters, under proper sanitary supervision

by the controlling health authorities, will meet accepted standards of water

quality for outdoor swimming places and will be considered satisfactory for

swimming and other whole body water-contact sports.

(e) Specific Criteria

Fecal Coliform Criteria:

Criteria for acceptable bacteria levels for the Fish and Wildlife use classification are described in

ADEM Admin. Code R. 335-6-10-.09(5)(e)7.(i) and (ii) as follows:

7. Bacteria:

(i) In non-coastal waters, bacteria of the fecal coliform group shall not exceed a

geometric mean of 1,000 colonies/100 mL; nor exceed a maximum of 2,000

colonies/100 mL in any sample. In coastal waters, bacteria of the enterococci

group shall not exceed a maximum of 275 colonies/100 mL in any sample. The

geometric mean shall be calculated from no less than five samples collected at a

given station over a 30-day period at intervals not less than 24 hours.

(ii) For incidental water contact and recreation during June through September, the

bacterial quality of water is acceptable when a sanitary survey by the controlling

health authorities reveals no source of dangerous pollution and when the

geometric mean fecal coliform organism density does not exceed 200

colonies/100 mL in non-coastal waters. In coastal waters, bacteria of the

enterococci group shall not exceed a geometric mean of 35 colonies/100 mL nor

exceed a maximum of 158 colonies/100 mL in any sample. The geometric mean

shall be calculated from no less than five samples collected at a given station over

a 30-day period at intervals not less than 24 hours. When the geometric bacterial

coliform organism density exceeds these levels, the bacterial water quality shall

be considered acceptable only if a second detailed sanitary survey and evaluation

discloses no significant public health risk in the use of the waters. Waters in the

immediate vicinity of discharges of sewage or other wastes likely to contain

bacteria harmful to humans, regardless of the degree of treatment afforded these

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wastes, are not acceptable for swimming or other whole body water-contact

sports.

Criteria Exceeded:

There have been no single sample violations, yet several geometric mean violations for fecal

coliform for the data collected from 2003 through 2004. More specifically, Second Creek had

three events where it exceeded the geometric mean criterion of 200 col/100 ml. Summary table

2.1 and 2.2 document all violations from ADEM’s 2003-2004 sampling event. The single sample

violations did not account for 10% or more of the samples collected, therefore, the TMDL

calculations will be based on the highest geometric mean violation.

Table 2.1 Geometric Mean Fecal Coliform Violations

Station_ID Date

Stream

Flow

(cfs)

Fecal

Coliform

(col/100ml)

Geometric Mean

Summer

Geometric Mean

Criterion of 200

col/100mL

SCDL-11 8/14/2003 34.5 144

8/18/2003 41.3 132

8/20/2003 46.4 124

8/25/2003 38 780

8/26/2003 14.5 610

257 EXCEEDANCE

SCDL-12 6/4/2003 -- 190

6/11/2003 21.8 220

6/18/2003 19.9 175

6/24/2003 25.9 270

6/26/2003 19.2 700

268 EXCEEDANCE

8/14/2003 27.3 212

8/18/2003 31.9 300

8/20/2003 320

8/25/2003 21.5 750

8/26/2003 17.3 176

306 EXCEEDANCE

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3.0 Technical Basis for TMDL

3.1 Water Quality Target Identification

For the purpose of this TMDL a geometric mean fecal coliform target of 180 colonies/100

mL will be used. This target was derived by using a 10% explicit margin of safety from

the geometric mean of 200 colonies/100 mL criterion. This target should not allow the

geometric mean of 200 colonies/100 mL or the single sample maximum of 2000

colonies/100 mL to be exceeded.

3.2 Source Assessment

Point Sources in the Second Creek Watershed:

There are no point sources in the Second Creek watershed. In addition, the Alabama

portion of the Second Creek watershed does not presently qualify as a municipal separate

stormwater sewer system (MS4) area as defined as an urban area serving 50,000 residents

or greater. Therefore, the WLA portion of the TMDL will be zero. Any new discharges to

this stream must meet a geometric mean discharge limit of 200 colonies/100 mL and an

instantaneous maximum limit of 2000 colonies/100 mL for fecal coliform.

Nonpoint Sources in the Second Creek Watershed:

The landuse in the Second Creek watershed is predominately forest and agriculture. On a

site visit on February 18, 2004 to the watershed there were many livestock and horses

observed. The following are examples of how different landuses can contribute to fecal

coliform bacterial loading:

• Agricultural land is commonly a large source of fecal coliform bacteria. Pasture land

runoff, animal operations, improper land application of animal waste, and animals

with access to streams are all contributing factors of fecal coliform bacteria to water

bodies. Agricultural land accounts for half of the landuse in the Second Creek

watershed.

• Fecal coliform bacteria can also originate from forested areas due to the presence of

wild animals such as deer, raccoons, turkeys, waterfowl, etc.

• Leaking septic systems can be another source of fecal coliform bacteria.

The nature and extent of fecal coliform bacterial sources in the watershed will be better

identified during the implementation phase of the TMDL.

3.3 Landuse

Table 3.1 on the next page provides the various landuses (and their associated

percentages) for the Second Creek watershed. Figure 3.1 is a map of landuse within the

Second Creek watershed. The Tennessee portion of the watershed is 33.6% of the total

area and comprises 20.6% of the total agricultural landuse of the entire Second Creek

watershed. Land use for the Second Creek watershed was determined using ArcView with

land use datasets from 2001. Land use information for this assessment was derived from

the 2001 National Land Cover Dataset (NLCD).

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Figure 3.1 Landuse Map of the Second Creek Watershed

Final Second Cree

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Table 3.1 Landuse in the Second Creek Watershed

acres

% acres

Open Water 621.1 1.0 2.5 2.0 0.0 0.0 623.1 1.0 1.6

Developed, Open Space 1257.0 2.0 5.0 715.4 1.1 5.6 1972.4 3.1 5.2

Developed, Low Intensity 96.5 0.2 0.4 27.8 0.0 0.2 124.3 0.2 0.3

Developed, Medium Intensity 8.0 0.0 0.0 1.3 0.0 0.0 9.3 0.0 0.0

Barren Land (Rock/Sand/Clay

)

0.0 0.0 0.0 2.7 0.0 0.0 2.7 0.0 0.0

Deciduous Forest 6565.5 10.3 26.2 2487.0 3.9 19.6 9052.5 14.1 24.0

Evergreen Forest 603.4 0.9 2.4 362.9 0.6 2.9 966.3 1.5 2.6

Mixed Forest 1261.6 2.0 5.0 498.8 0.8 3.9 1760.5 2.8 4.7

Shrub/Scrub 1044.4 1.6 4.2 672.7 1.1 5.3 1717.1 2.7 4.5

Grassland/Herbaceous 195.3 0.3 0.8 62.7 0.1 0.5 258.0 0.4 0.7

Pasture/Hay 11033.0 17.2 44.0 6908.7 10.8 54.3 17941.6 28.0 47.5

Cultivated Crops 1816.1 2.8 7.2 874.9 1.4 6.9 2691.0 4.2 7.1

Woody Wetlands 569.8 0.9 2.3 95.2 0.1 0.7 665.0 1.0 1.8

Total 25071.6 39.2 100.0 12712.3 19.9 100.0 37783.8 59.0 100.0

Agriculture 12849.0 20.1 51.2 7783.6 12.2 61.2 20632.6 32.2 54.6

Forest 9000.3 14.1 35.9 3444.0 5.4 27.1 12444.3 19.4 32.9

Developed 1361.5 2.1 5.4 744.6 1.2 5.9 2106.1 3.3 5.6

Other 1860.8 2.9 7.4 740.1 1.2 5.8 2600.9 4.1 6.9

Total 25071.6 39.2 100.0 12712.3 19.9 100.0 37783.8 59.0 100.0

Combined Watersheds

Second Creek Watershed

Land Cover

Alabama Tennessee

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3.4 Linkage between Numeric Targets and Sources

It is envisioned that sources will be better defined during actual implementation. As can

be seen from viewing the above table, Second Creek has two major landuses – forest and

agriculture. Pollutant loadings from forested areas tend to be low due to their filtering

capabilities. Observation of the landuses within the Second Creek watershed indicates

agricultural areas as being the likely sources of fecal coliform bacteria. However, since

the impaired segment consists of such a large drainage area, (59.0 square miles) with

diverse land cover/uses, it was not considered practicable to determine individual

components of nonpoint source (NPS) loading. As such, individual loads or reductions for

various sources such as forest, agriculture, and septic systems will not be specified.

Loadings and reductions will only be viewed as a total NPS load.

3.5 Data Availability and Analysis

There have been three main studies in this watershed for relevant chemical data. The first

study was performed by TVA in 1997. Of the five stations in this study, station 10118-1

recorded two samples that exceeded the single sample criterion and placed Second Creek

on the §303(d) list in 1998 for fecal coliform. The second study was performed by ADEM

in which only one sample was collected on Second Creek at Station SCDL-11 in July

1998 which was below the single sample criterion of 2000 col/100 ml.

The third study was performed by ADEM in 2003 and 2004 in which §303(d) sampling

occurred at three stations on Second Creek at stations SCDL-11, SCDL-12, and SCDL-13.

The stations collectively produced 59 samples that were adequate for geometric mean

calculations and single sample analysis. Station SCDL-11 had one violation and SCDL-

12 had two violations exceeding the geometric mean water quality criterion of 200 col/100

ml for fecal coliform. When comparing the data to the single sample criterion of 2000

col/100 ml, there were no violations. The data for the stations mentioned above can be

found in Appendix B. Sample locations are shown in Figure 3.2. Location descriptions

for all stations can be found in Table 3.2. It should also be noted that TVA station 10118-

1 is the same as ADEM station SCDL-11.

Table 3.2 Sampling Station Location Descriptions

Year

Station

ID Data Source Station Location Latitude Longitude

1997

10118-1

TVA

1998 ADEM - NPS

2003 &

2004

SCDL-11

ADEM -

303(d)

Second Creek @ Lauderdale

County Road 76

34.8854 -87.3734

2003 &

2004

SCDL-12

ADEM -

303(d)

Second Creek @ Lauderdale

County Road 88

34.9395 -87.3368

2003 &

2004

SCDL-13

ADEM -

303(d)

Second Creek @ Lauderdale

County Road 489

34.9939 -87.3509

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Figure 3.2 Sampling Stations in the Second Creek Watershed

3.6 Critical Conditions

The summer months are generally considered critical conditions. In the summer, periods

of dry weather interspersed with thunderstorms allow for the accumulation and washing

off of fecal coliform bacteria into streams. These summer trends result in spikes of fecal

coliform bacteria counts. Winter trends show frequent low intensity rain events that do

not allow for the build-up of fecal coliform bacteria on the land surface, resulting in a

more uniform loading rate. The summer fecal coliform criterion is more stringent than the

winter criterion.

The Second Creek watershed follows both the trends described above for the summer

months and winter months. Table 2.1 and 2.2 show that the higher concentrations of fecal

coliform occur at high flows and low flows. The maximum geometric mean concentration

of 306 colonies/100 mL with an average flow of 24.5 cfs at SCDL-12 will be used to

estimate the TMDL pathogen loadings to Second Creek under critical conditions.

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3.7 Margin of Safety (MOS)

There are two methods for incorporating a MOS in the analysis: 1) implicitly incorporate

the MOS using conservative model assumptions to develop allocations, or 2) by explicitly

specifying a portion of the TMDL as the MOS. An explicit MOS was incorporated in this

TMDL and was applied by reducing the target criterion concentration by ten percent.

Thus, the geometric mean criterion was reduced by ten percent to achieve a target

concentration of 180 colonies/100 ml, which yields a MOS equal to 20 colonies/100 ml.

4.0 TMDL Development

4.1 Definition of a TMDL

A total maximum daily load (TMDL) is the sum of individual waste load allocations for

point sources (WLAs), load allocations (LAs) for nonpoint sources including natural

background levels, and a margin of safety (MOS). The margin of safety can be included

either explicitly or implicitly and accounts for the uncertainty in the relationship between

pollutant loads and the quality of the receiving waterbody. As discussed earlier, the MOS

is explicit in this TMDL. A TMDL can be denoted by the equation:

TMDL = Σ WLAs + Σ LAs + MOS

The TMDL is the total amount of pollutant that can be assimilated by the receiving

waterbody while achieving water quality standards under critical conditions.

For some pollutants, TMDLs are expressed on a mass loading basis (e.g. pounds per day).

However, for pathogens, TMDL loads are typically expressed in terms of organism counts

per day (col/day), in accordance with 40 CFR 130.2(i).

4.2 Load Calculations

A mass balance approach was used to calculate the TMDL for Second Creek which

utilizes the conservation of mass principle. The pathogen loading to Second Creek was

calculated using a geometric mean exceedance concentration times the average flow for

the 5 samples used to calculate the geometric mean.

Two loads were calculated in this analysis. The first was to estimate current pathogen

loads to the watershed during a violation event. It was done by multiplying a geometric

mean exceedance concentration of 306 col/100 ml times the average measured flow. This

concentration was measured at SCDL-12 in August of 2003 and can be found in Appendix

B. The average measured flow for this event was 24.5 cfs. The product of these two

values and a conversion factor gives the loading to the watershed under exceedance

conditions. The second load represents the allowable value to the watershed under the

same physical conditions as the first. This is done by taking the product of the same flow

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times the conversion factor times the allowable fecal concentration of 180 col/100 mL.

The difference between these two loads, converted to a percent reduction, represents the

loading reduction necessary to achieve the water quality criterion for fecal coliform under

critical conditions. Calculations for these two loads can be found below in Table 4.1.

Table 4.1 Current vs. Allowable Pathogen Loadings for Second Creek

Average Flow measured at SCDL-12 for Geometric Mean Samples: 24.5 cfs

Geometric Mean Fecal coliform concentration measured: 306 col/100 mL

Allowable fecal coliform maximum concentration minus MOS: 180 col/100mL = 200 - 10%

Margin of saftey for the maximum criteria 20 col/100mL = 10% of criteria

Load Calculations:

Load = Fecal Coliform Conc * Measured Flow * Conversion Factor

Load = colonies of Fecal Coliform/day Measured Flow = cfs

Fecal Coliform Conc = colonies/100 mL Conversion Factor = 24468984 (ml-s/ft3-day)

Current Load:

Nonpoint source load (LA) 1.83E+11 colonies/day

Point source load (WLA) 0.00E+00 colonies/day There are no point sources in this watershed

Current load = 1.83E+11 colonies/day

Allowable Load:

Nonpoint source load (LA) 1.08E+11 colonies/day

Point source load (WLA) 0.00E+00 colonies/day There are no point sources in this watershed

Allowable load = 1.08E+11 colonies/day

Margin of Saftey:

MOS load = 1.20E+10 colonies/day

Source

Current Load

(col/day)

Allowable

Load

(col/day)

Required

Reduction

(col/day) Reduction %

Final Load

(col/day)

LA 1.83E+11 1.08E+11 7.55E+10 41% 1.08E+11

WLA 0.00E+00 0.00E+00 0.00E+00 0% 0.00E+00

Total 1.83E+11 1.08E+11 7.55E+10 41% 1.08E+11

Total Maximum Daily Load (TMDL):

TMDL = WLA + LA + MOS

TMDL WLA LA MOS

1.20E+11 0.00E+00 1.08E+11 1.20E+10

Percent Reduction to Achieve the Fecal Coliform Criterion:

Total reduction: 41% = (current load - allowable load) / current load

The following assumptions are made for calculating the allowable load.

The water quality criterion for fecal coliform for summer geomtric means is 200 col/100 mL.

To account for an explicit Margin of Safety (MOS) a target concentration of 180 col/100 ml was

used to calculate the allowable load compared to the maximum criterion which = 200 – 10%

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4.3 TMDL Summary

Regulations require states to identify waterbodies which are not meeting their designated

use and to determine the Total Maximum Daily Load (TMDL) for pollutants causing the

use impairment. A TMDL is the sum of individual waste load allocations for point sources

(WLAs), load allocations (LAs) for nonpoint sources including natural background levels,

and a margin of safety (MOS).

Based on ADEM’s 2003 & 2004 sampling events, the violations of geometric mean

criterion at two of the three stations in the watershed make it evident that Second Creek is

impaired for fecal coliform. The fecal coliform violations in this watershed were relatively

moderate in number and concentration with the highest geometric mean concentrations at

306 col/100 ml which is approximately one and a half times the geometric mean fecal

coliform criterion of 200 col/100 ml.

A mass balance approach was used to calculate the TMDL. Table 4.1 is a summary of

current loads, allowable loads and required load reductions necessary to meet the

applicable water quality pathogen geometric mean criterion for Second Creek. Table 4.2

lists the required TMDL pathogen loadings under critical conditions for Second Creek.

Table 4.2 Current/Allowable Loads and Required Reductions

Source

Current

Load

(col/day)

Allowable

Load

(col/day)

Required

Reduction

(col/day)

Reduction

Final

Load

(col/day)

1.83E+11 1.08E+11 7.55E+10 41% 1.08E+11

WLA

0.00E+00 0.00E+00 0.00E+00 0% 0.00E+00

Table 4.3 TMDL for Second Creek

TMDL

(col/day)

WLA

(col/day)

MOS

(col/day)

1.20E+11 0.00E+00 1.08E+11 1.20E+10

The most likely source of fecal coliform in this watershed is activities associated with

agricultural landuse (i.e. pasture/hay). Of the 59 square miles of watershed, 32.2 square

miles are designated as agricultural lands, which is just over half of the entire watershed.

High agricultural use is common in the Tennessee basin. Based on USGS’s 2001 NLCD,

the portion of the Second Creek watershed in the state of Tennessee has an agricultural

land cover equal to 61.2% and the portion of the Second Creek watershed in the state of

Alabama, specifically Lauderdale County, is 51.2% agriculture. Combined, the total

landuse for the Second Creek watershed is more than half (54.6%) agriculture.

ADEM, in cooperation with other stakeholders, will need to verify the likely sources of

fecal coliform located within the watershed. The likely areas where mitigation efforts will

need to occur will be pastures that contain dense sources of livestock that have direct

access to Second Creek or pasture areas that lie adjacent to the streams that have little to

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no best management practices (BMPs) in place. Following identification of these and

other landuse issues within the Alabama portion of the watershed, ADEM will need to

coordinate with TDEC in order to determine the possible pathogen sources in Tennessee.

Based on results of these studies, the two agencies will need to generate a plan that can

produce the overall needed reduction in fecal coliform using BMPs.

5.0 Follow Up Monitoring

ADEM has adopted a basin approach to water quality management; an approach that

divides Alabama’s fourteen major river basins into five groups. Each year, the ADEM

water quality resources are concentrated in one of the five basin groups. One goal is to

continue to routinely monitor §303(d) listed waters until such waters are meeting their

designated uses. Monitoring will help further characterize water quality conditions

resulting from the implementation of best management practices in the watershed. This

monitoring will occur in each basin according to the schedule shown in Table 5-1.

Table 5.1 ADEM’s Major River Basin Monitoring Schedule

River Basin Group Year to be Monitored

Escatawpa / Mobile / Lower Tombigbee / Upper Tombigbee 2006

Black Warrior / Cahaba 2007

Tennessee 2008

Chattahoochee / Chipola / Choctawhatchee / Perdido-Escambia 2009

Alabama / Coosa / Tallapoosa 2010

6.0 Public Participation

As part of the public participation process, this TMDL was placed on public notice and

made available for review and comment. The public notice was prepared and published in

the four major daily newspapers in Montgomery, Huntsville, Birmingham, and Mobile, as

well as submitted to persons who have requested to be on ADEM’s postal and electronic

mailing distributions. In addition, the public notice and subject TMDL was made

available on ADEM’s Website: www.adem.state.al.us. The public can also request paper

or electronic copies of the TMDL by contacting Mr. Chris Johnson at 334-271-7827 or

[email protected]. The public was given an opportunity to review the TMDL and

submit comments to the Department in writing. At the end of the public review period, all

written comments received during the public notice period became part of the

administrative record. ADEM considered all comments received by the public prior to

finalization of this TMDL and subsequent submission to EPA Region 4 for final review

and approval.

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Appendix A

References

Alabama Department of Environmental Management (ADEM), Alabama’s Water Quality

Assessment and Listing Methodology, December 2005.

Alabama Department of Environmental Management’s 303(d) Monitoring Program. 2001-

2002.

ADEM Administrative Code, 2002. Water Quality Program, Chapter 335-6-10, Water

Quality Criteria, and Chapter 335-6-11 Use Classifications for Interstate and Intrastate

Waters.

United States Environmental Protection Agency. 1991. Guidance for Water Quality-Based

Decisions: The TMDL Process, Office of Water, EPA 440/4-91-001.

USEPA. 2001. Protocol for Developing Pathogen TMDLs. EPA 841-R-00-001. U.S.

Environmental Protection Agency, Office of Water, Washington DC.

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Appendix B

Water Quality Data

Table B.1 Pathogen & Flow Data Collected by TVA on Second Creek (1997)

Station #

Stream

Name

Date

(yymmdd)

Time

(24 hr)

Stream

Flow

(cfs)

Fecal Coliform

(col/100ml)

10118-1 Second Cr 970609 1100 457 3200

10118-1 Second Cr 970708 1100 63.2 55

10118-1 Second Cr 970812 1100 23.3 1820

10118-1 Second Cr 970909 1045 20.1 1940

10118-1 Second Cr 971014 1030 39.3 2860

Table B.2 Pathogen & Flow Data Collected by ADEM on Second Creek (1998)

Station #

Date

(yymmdd)

Time

(24 hr)

Stream

Flow

(cfs)

Fecal Coliform

(col/100ml)

SCDL-011 980722 0955 28.5 350

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Table B.3 Pathogen & Flow Data Collected by ADEM on Second Creek at Station

SCDL-11 (2003 & 2004)

Station

ID Date

Stream

Flow (cfs)

Fecal Coliform

(col/100ml)

Geometric Mean

(col/100ml)

6/4/2003 77.8 67

6/11/2003 20.9 212

6/18/2003 23.8 220

6/24/2003 35.8 260

6/26/2003 15.1 390

200

8/14/2003 34.5 144

8/18/2003 41.3 132

8/20/2003 46.4 124

8/25/2003 38 780

8/26/2003 14.5 610

257

7/12/2004 43.4 73

7/13/2004 64.1 112

7/14/2004 62 76

7/19/2004 8.8 100

7/20/2004 36.5 57

9/14/2004 27.9 200

9/20/2004 42.3 60

9/23/2004 49.7 88

9/27/2004 28.7 124

SCDL-11

9/29/2004 24.3 78

100

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Table B.4 Pathogen & Flow Data Collected by ADEM on Second Creek at Station

SCDL-12 (2003 & 2004)

Station ID Date

Stream

Flow (cfs)

Fecal Coliform

(col/100ml)

Geometric Mean

(col/100ml)

6/4/2003 -- 190

6/11/2003 21.8 220

6/18/2003 19.9 175

6/24/2003 25.9 270

6/26/2003 19.2 700

268

8/14/2003 27.3 212

8/18/2003 31.9 300

8/20/2003 -- 320

8/25/2003 21.5 750

8/26/2003 17.3 176

306

7/12/2004 -- 120

7/13/2004 -- 232

7/14/2004 -- 92

7/19/2004 26.6 132

7/20/2004 27.1 232

151

9/14/2004 15.8 140

9/20/2004 49.4 135

9/23/2004 30.9 160

9/27/2004 18.6 148

SCDL-12

9/29/2004 19.7 270

165

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Table B.5 Pathogen & Flow Data Collected by ADEM on Second Creek at Station

SCDL-13 (2003 & 2004)

Station ID Date

Stream

Flow

(cfs)

Fecal Coliform

(col/100ml)

Geometric

Mean

(col/100ml)

6/4/2003 7.6 67

6/11/2003 10.7 152

6/18/2003 8.3 94

6/24/2003 8.1 116

6/26/2003 6.1 152

111

8/14/2003 10.7 --

8/18/2003 15.6 180

8/20/2003 13.5 132

8/25/2003 9.3 104

8/26/2003 8.7 490

n/a

7/12/2004 17.3 120

7/13/2004 15.6 220

7/14/2004 14 88

7/19/2004 36 37

7/20/2004 11.3 49

9/14/2004 4.9 116

9/20/2004 17.8 105

9/23/2004 10.8 156

9/27/2004 7.6 100

SCDL-13

9/29/2004 9.2 160

125

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