Mobile Bay

Water Quality Model Intensive Surveys Report
July 2000/May 2001

US EPA - SESD

Project #01-0546/
Project #00-0704

US EPA - SESD
980 College Station Road
Athens, GA 30605


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Table of Contents

Page

Field Survey Personnel		i

List of Tables		ii

List of Figures		iii

Introduction		1

Study Objectives		2

Study Area		2

Survey Components/Results		4

DST Profiling		4

Tide-Phased WQ Sampling/DO Profiling		10

Continuous DO Monitoring		17

Production/Respiration		21

Diffusion/Reaeration		25

Hydrological/Meteorological Data		28

Sediment Oxygen Demand		40

Point Source Sampling		42

Conclusion		46


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Field Survey Personnel

July 2000

May 2001

EPA - SESD

EPA - SESD

Leslie Cagle
Tom Cavinder
John Deatrick
Candace Halbrook
Pete Kalla
Mark Koenig
Laura McGrath
Philip Murphy
Mel Parsons
Bob Quinn

Bill Bokey
Leslie Cagle
Tom Cavinder
John Deatrick
Candace Halbrook
Elizabeth Jones
Pete Kalla
Mark Koenig
John Marlar
Laura McGrath
Philip Murphy
Mel Parsons
Bob Quinn
Dan Thoman

EPA - WMD
Ed Decker
Bob Howard
Tom McGill

EPA - WMD
Ed Decker
Morris Flexner
Bob Howard

ADEM

Charles Reynolds - Montgomery Office
Heather Boche - Mobile Office
Nancy Shaneyfelt
Rob Turner
Eddie Wolfe

ADEM

Charles Reynolds - Montgomery Office
Heather Boche - Mobile Office
Nancy Shaneyfelt
Rob Turner
Eddie Wolfe

ESAT
Jerry Ackerman
Bruce Heinish
Roseanne Hutchison

EPA appreciates the extensive field support provided by the Alabama DEM in conducting
these surveys.

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List of Tables

No.	Description	Page

1.	Study Components	4

2.	Water Quality Sampling Stations	5

3.	WQ Sampling Results - July 12, 2000 - High Slack Tide	12

4.	WQ Sampling Results - July 14,2000 - Ebbing Tide	13

5.	WQ Sampling Results - May 15, 2001 - High Slack Tide	14

6.	WQ Sampling Results - May 16, 2001 - Low Slack Tide	15

7.	Continuous Dissolved Oxygen Monitoring Summary	17

8.	July 2000 Production/Respiration	21

9.	May 2001 Production/Respiration	22

10.	July 2000 Chlorophyll/AGPT	23

11.	May 2001 Chlorophyll/AGPT	24

12.	Solar Radiation	40

13.	Sediment Oxygen Demand Rates	41

14.	July 2000 Point Source Sampling Results	44

15.	May 2001 Point Source Sampling Results	45

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List of Figures

No.	Description	Page

1.	Mobile Bay Study Area	3

2.	Water Quality Sampling Stations	6

3.	July 2000 DST Profiling Locations	7

4.	May 2001 DST Profiling Locations	9

5.	MB3 Turbidity vs. Tide/Wind - 2001	19

6.	MB4 Turbidity vs. Tide/Wind - 2001	19

7.	Gas/Tracer Study Locations	26

8.	7/13/00 Reaeration Wind/Current Vectors	27

9.	7/15/00 Reaeration Wind/Current Vectors	27

10.	5/15/01 Reaeration Wind/Current Vectors	28

11.	July 2000 MB 1 Currents (Oyster/Time Series Plots)	30

12.	July 2000 MB3 Currents (Oyster/Time Series Plots)	31

13.	July 2000 MB4 Currents (Oyster/Time Series Plots)	32

14.	May 2001 MB1 Currents (Oyster/Time Series Plots)	33

15.	May 2001 MB3 Currents (Oyster/Time Series Plots)	34

16.	May 2001 MB4 Currents (Oyster/Time Series Plots)	35

17.	May 2001 MS0 Currents (Oyster/Time Series Plots)	36

18.	July 2000 Water Level - Dog River	37

19.	July 2000 Water Level - Fowl River	37

20.	May 2001 Water Level - Dog River	38

21.	May 2001 Water Level - Fowl River	38

22.	July 2000 Wind	39

23.	May 2001 Wind	39

24.	Point Source Locations	43

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Introduction

The Mobile River/Bay is a 303(d) listed water body with impairment resulting from
depressed dissolved oxygen (DO) levels. In addition, the State water quality criteria for DO for
the Mobile River, Chickasaw Creek, and Three Mile Creek has been disapproved by EPA. As
part of TMDL development being coordinated by EPA Region 4's Water Management Division
(WMD), the Science and Ecosystem Support Division (SESD) was requested to conduct water
quality studies of Mobile Bay designed specifically to provide instream data for use by WMD in
development and calibration/verification of a 3-dimensional time-variable water quality model.
To obtain adequate data for model calibration and verification, two intensive surveys were
conducted on Mobile Bay.

The first SESD Mobile Bay intensive water quality survey was conducted in July 2000,
followed by a second intensive survey in May 2001. By design, one survey dataset is intended to
serve as a model calibration dataset, while the other is intended for model verification. While the
2000 and 2001 intensive survey study plans are very similar with respect to the type of data
targetted, the surveys were conducted during different seasonal conditions in order to provide
comparable data across a range of conditions. In addition, dissolved oxygen, salinity and
temperature (DST) profiling during the 2001 survey was expanded to obtain more measurements
east-west along the bay. It should also be noted that WMD indicated at the outset of the project
that considerable hydrodynamic data exists for Mobile Bay and that SESD activities should be
more focussed on water quality measurements and kinetics. This report describes and
summarizes the results of the 2000 and 2001 calibration/verification surveys.

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Study Objectives

The purpose of the 2000 and 2001 intensive surveys was to provide the necessary water
quality data along with supplemental hydrodynamic information to enable calibration and
verification of a 3-dimensional, time-varying water quality model for Mobile Bay. The studies
were designed to provide water quality data, oxygen dynamics, and meteorologic data , and
limited hydrodynamic data throughout the study area including the modeled system boundaries
and several representative calibration points. In addition, the surveys were designed to provide
instream data over a range of seasonal and tidal conditions so that the calibrated model could be
applied in a predictive mode over a wide range of conditions.

Study Area

Mobile Bay is a very large bay stretching approximately 30 miles from top to bottom and
encompassing an area of approximately 400 square miles. The Mobile Bay study area includes
the entire bay from its mouth at the Mississippi Sound/Gulf northward into the Mobile River at its
confluence with Chickasaw Creek (Figure 1). The Mobile Bay study area also includes Three
Mile Creek, Chickasaw Creek, and Dog River. In addition, a headwater sampling station was
located in the Mobile River at a public boat ramp near Mt. Vernon, Alabama. Finally, in order to
aid in potential future model development or expansion, insitu water quality data was collected in
Oyster Bay, Weeks Bay, Magnolia River, and the Intracoastal Waterway.

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Figure 1 - Mobile Bay Study Area


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Survey Components/Results

The 2000 survey includes eight separate study components. For the 2001 survey,
dissolved oxygen/salinity/temperature (DST) profiling and water quality sampling were broken
into separate components (Table 1).

Table 1 - Study Components

Module

2000 Survey

2001 Survey

1

Tide-phased WQ Sampling/
DST Profiling

DST Profiling

2

Continuous DO Monitoring

Tide-phased WQ Sampling

3

Photosynthesis/Respiration

Continuous DO Monitoring

4

Diffusion

Photosynthesis/Respiration

5

Reaeration

Diffusion

6

Hy drol ogi c/Meteorol ogi c

Reaearation

7

SOD

Hy drol ogi c/Meteorol ogi c

8

Point Source Sampling

SOD

9

-

Point Source Sampling

DST Profiling

In 2000, DO, salinity, and temperature (DST) profiling was conducted throughout the bay
during a 6 day period from July 11 to July 16. On July 11, preliminary profiling was conducted at
several stations in association with the deployment of other instrumentation (e.g., current meters,
stage recorders) In addition, one crew profiled the upper tributaries (Chickasaw Creek and Three
Mile Creek) and upper Ship Channel near station SCI. On July 12 and 14, profiling was
conducted by several crews in association with water quality sample collection. Water quality

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sampling station locations/crews are shown in Table 2 and Figure 2. (Due to a storm, stations
SC4, MB3, and MSO were not profiled during the July 14 sample collection.) Profiling during
these events provided information on stratification necessary for proper sampling at each of the
water quality sampling stations. The July 12 event represents a high slack tide event while the
July 14 event occurred during an ebbing tide. Also during the July 14 effort, profiling was
conducted above and below three major effluent dischargers including International Paper,
Kimberly Clark, and Mobile WWTP. The remaining profiling efforts were designed to provide
significant coverage of bay salinity and DO for use in model setup and calibration. These events
included lower bay profiling on July 13, middle bay profiling on July 15, and profiling throughout
the Ship Channel on July 16. Figure 3 shows the areal extent of DST profiling conducted in July
2000.

Table 2 - Water Quality Sampling Stations

Station

Sampling Crew

Description

Latitude

Longitude

MR1

1 - Headwater

Upstream Boundary - Mobile River

31° 05.27'

87° 58.60'

CC

2 - River/Tribs

Chickasaw Creek near mouth

30° 44.37'

88° 02.75'

TMC

2 - River/Tribs

Three Mile Creek near mouth

30° 43.62'

88° 02.92'

DR

3 - Middle Bay

Dog River near mouth

30° 34.2'

88° 05.7'

SCI

2 - River/Tribs

Mobile Ship Channel - Station 1

30° 43.0'

88° 02.5'

SC2

3 - Middle Bay

Mobile Ship Channel - Station 2

30° 36.0'

88° 02.0'

SC3

3 - Middle Bay

Mobile Ship Channel - Station 3

30° 28.8'

88° 01.0'

SC4

4 - Lower Bay

Mobile Ship Channel - Station 4

30° 22.8'

88° 01.3'

SC5

4 - Lower Bay

Mobile Ship Channel - Station 5

30° 15.5'

88° 02.3'

MB1

3 - Middle Bay

Upper Bay near Montrose

30° 36.0'

87° 58.0'

MB2

3 - Middle Bay

Middle Bay near Point Clear

30° 28.3'

87° 58.0'

MB3

4 - Lower Bay

West Bay below Fowl River

30° 22.0'

88° 04.0'

MB4

4 - Lower Bay

Bon Secour Bay

30° 19.0'

88° 53.0'

MSO

4 - Lower Bay

Mississippi Sound

30° 17.5'

88° 07.1'

GULF

4 - Lower Bay

Gulf of Mexico east of Bay inlet

30° 08.7'

88° 02.2'

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Figure 2 - Water Quality Sampling Stations
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Figure 3 - July 2000 DST Profiling Locations


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The three profiles conducted at the upstream boundary station MR1 support its suitability
as the upstream boundary sampling location. This location was consistently freshwater when
profiled with all measured DO levels greater than the 5 mg/1 EPA Fish & Wildlife DO criteria. In
general, data for all profiles showed DO above 5 mg/1 in the upper water column (depth < 3') with
significant reductions in DO with depth at many locations especially in the upper bay and
tributaries. With respect to calibration, it should be noted that the DO end check of the meter
used during the July 15 middle bay profiles indicated a DO reading above the Winkler titration
standard (+ 0.38 mg/1) slightly outside EAB tolerances for this parameter (+ 0.2 mg/1). Heating
of the DO chamber between Winkler titration and meter recording may have occurred resulting in
the difference. Since this meter was used throughout the rest of the survey period without
calibration problems and the error is relatively small versus the measured Bay DO range, SESD
believes the profiling data to be acceptable for the purposes of model development and
calibration.

In 2001, significant DST profiling was again conducted. On May 15 and 16, profiling was
again conducted in association with water quality sampling. In addition, on May 16 profiling was
conducted in Weeks Bay and the Magnolia River while Oyster Bay and the Intracoastal
Waterway were profiled on May 17. Finally, on May 17 and 18 a profiling crew conducted
profiles laterally across the bay to enhance the 3-dimensional water quality "picture" of the bay.
The locations of the May 2001 DST profiling stations are shown in Figure 4.

Again in 2001, DO at the headwater station MR1 was consistently well above 5 mg/1. DO
in the bay and tributaries again exceeded 5 mg/1 in the upper layers (3' - 6') with DO decreasing
with depth frequently below 5 mg/1. With the exception of the bottom reading at one Magnolia
River station, all DO measurements in profiles for Weeks Bay, Magnolia River, Oyster Bay, and

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Figure 4 - May 2001 DST Profiling Locations


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the Intracoastal Waterway exceeded 5 mg/1.

In addition to DO, salinity, and temperature profiling, the 2001 profiling included some
turbidity measurements. In general, the data show turbidity levels decreasing from the north end
of the bay to the bay outlet. The following calibration information should be considered during
any application of the data to a model. Specifically, the turbidity meter used by the
river/tributaries sampling team during the first water quality sampling run (5/15) read a 10.0 NTU
standard at only 8.3 NTU, while the same unit when used for the Weeks Bay/Magnolia River
profiling (5/16) read a 10.0 NTU standard as 12.6 NTU.

Tide-phased Water Quality Sampling

Water quality sampling locations for the both the 2000 and 2001 surveys are shown in
Figure 2 (p.6). Measured water quality parameters during these studies include ultimate
biological oxygen demand (BODu - 120 day test), carbonaceous 5-day biological oxygen demand
(CBOD5), dissolved phosphorus (Diss-P), total phosphorus (Tot P), total kjeldahl nitrogen
(TKN), ammonia nitrogen (NH3-N), nitrate/nitrite (N02/N03), and total organic carbon (TOC).
In addition, limited samples were collected for total suspended solids (TSS) analysis during the
2001 survey. Where pronounced stratification in either temperature, salinity, or dissolved oxygen
was observed during profiling, samples were collected in an upper layer of the water column and
a lower layer. Upper layer samples are denoted for the 2000 survey by the letter T while lower
layer samples are denoted by the letter B (eg, MB3-B). For 2001, the designators are A and B for
upper and lower layer samples, respectively. Where no stratification was observed amiddepth
sample was collected. Also, due to laboratory constraints, long-term BOD analysis was generally

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not conducted on lower layer samples. In July 2000, samples were collected for the suite of
parameters during a high slack tide period and an ebbing tide period at the stations in Table 2.
The selection of the sampling period was based in part on ensuring that holding times would not
be exceeded during transport from the Mobile area to the SESD laboratory in Athens, Georgia. In
2001, traditional slack tide sampling was employed with the first of two sampling efforts
occurring during a high slack tide and the second taking place on the following low slack tide.

The sampling results for the 2000 survey are shown in Tables 3 and 4 while results for the
2001 survey are provided in Tables 5 and 6. For both the 2000 and 2001 surveys, the BODu
values reported in Tables 3-6 represent total ultimate BOD reported by the laboratory. For the
2000 survey, CBOD5 concentrations were < 2 mg/1 for most of the stations during both events.
Slightly higher concentrations were observed in the ship channel (SC2 & SC4). For the 2001
survey, CBOD5 concentrations were again generally below 2 mg/1 with all stations below 3 mg/1.
In 2000, only limited TOC sampling was conducted and then only for the high slack event.

Results of this limited sampling showed a maximum TOC of 6.2 mg/1 at the headwater station and
a minimum concentration of 1.8 mg/1 at the downstream boundary (GULF). The remaining ten
TOC values are in a narrow range from 2.7 to 3.6 mg/1. More extensive TOC sampling was
conducted during the 2001 survey. Due to instrument malfunctions during analysis,
holding times for a few TOC samples on the low slack tide event were missed and the analytical
results flagged as estimated (See Table 6). The reported TOC data for the 2001 survey again
show little variation throughout the bay during either sampling event with concentrations slightly
lower during the low slack tide period. Nearly all ammonia and nitrate/nitrite concentrations were

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Table 3 - Water Quality Sampling Results
July 12, 2000 - High Slack Tide

Station

T ime

BODu

(mg/1)

CBOD5

(mg/1)

TOC
(mg/1)

NH3-N
(mg/1)

N02/N03
(mg/1)

TKN
(mg/1)

Tot P

(mg/1)

Diss P

(mg/1)

Samp le
Depth

(ft)

MR1

1600

7.53

2.0 UJ

6.2

0.050 U

0.050 U

0.480

0.077

0.041

10

CC

1130

5.36

2.0 UJ

3.4

0.118

0.050 U

0.540

0.710

0.020 U

7

TMC

1200

8.46

2.0 UJ

3.6

0.253

0.323

1.46 J

0.191

0.125

7

TMC (d)

1200

9.02

2.0 UJ













7

SC1T

1015

5.18

2.0 UJ



0.154 A

0.050 U

0.489 J

0.084 A

0.084 A

8

SC1B

1030



2.0 UJ



0.272

0.050 U

0.494 J

0.096

0.061 A

28

SC2

1145

23.7

6.8 J



0.050 U

0.050 U

0.714

0.090



4

SC2 (d)

1145



3.1 J













4

SC3T

0950

6.24

2.0 UJ

2.8

0.050 U

0.050 U

0.417 A

0.072

0.020 U

3

SC3T (d)

0950

6.14















3

SC3B

1000



2.0 UJ



0.050 U

0.050 U

0.398 A

0.045 A

0.046

9

DR

1230

10.8

2.0 UJ

3.6

0.050 U

0.050 U

0.506

0.064

0.0 23 A J

12

MB1

1115

8.23

2.0 UJ

3.4

0.050 U

0.050 U

0.414

0.069



6

MB2

1030

5.97

2.0 UJ

2.9 AJ

0.050 U

0.050 U

0.502

0.059

0.02 U

6

SC4T

1450

12.4

5.8 J



0.050 U

0.050 U

0.590 J

0.044

0.038

5

SC4T (d)

1450

10.9















5

SC4B

1500

3.75

2.0 UJ



0.050 U

0.050 U

0.350 J

0.043

0.029

20

SC5T

1200

5.04

2.0 UJ

2.7 AJ

0.050 U

0.050 U

0.335 J

0.0 46 AJ

0.020

5

SC5T (d)

1200

4.56

2.0 UJ













5

SC5B

1210

3.68

2.0 UJ



0.050 U

0.050 U

0.292 J

0.058

0.020 U

26

MB3T

1430

9.42

2.2 J

3.2

0.050 U

0.050 U

0.580 J

0.066

0.041

3

MB3B

1420

5.05

2.0 UJ



0.050 U

0.050 U

0.394 J

0.084

0.020 A

11

MB4

1300

5.56

2.0 UJ

2.8

0.050 U

0.050 U

0.442 J

0.077

0.059

6

MSO

1400

8.90

2.0 UJ

3.0

0.050 U

0.050 U

0.562 J

0.040

0.020 U

6

MSO (d)

1400

8.81

2.0 UJ













6

GULFT

1110

2.71

2.0 UJ

1.8

0.050 U

0.050 U

0.292 A

0.020 U

0.020 U

5

GULFB

1100

1.41

2.0 UJ



0.050 U

0.050 U

0.107

0.020 U

0.020 U

26

GULFB (d)

1100

1.35















26

A - Ave rage Value; J - Estim ated Value; U - M aterial analyzed for but no t detected (number is minimum quantitation limit); (d) - QA duplicate sample

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Table 4 - Water Quality Sampling Results
July 14, 2000 - Ebbing Tide

Station

T ime

BODu

(mg/1)

CBOD5

(mg/1)

TOC
(mg/1)

NH3-N
(mg/1)

N02/N03
(mg/1)

TKN
(mg/1)

Tot P

(mg/1)

Diss P

(mg/1)

Samp le
Depth

(ft)

MR1

1635



2.0 UJ



0.050 U

0.050 U

0.392

0.044

0.036

11

CC

1335



2.0 UJ



0.120

0.050 U

0.465 J

0.036

0.038

9

TMC

1405



2.0 UJ



0.162

0.050 U

0.503 J

0.079

0.050

8

IPU

1215

5.69

2.0 UJ



0.173

0.050 U

0.499 A

0.105

0.045

8

IPD

1240

5.98

2.0 UJ



0.155

0.050 U

0.484 J

0.151

0.071

9

KCD

1305

6.23

2.0 UJ



0.133

0.050 U

0.466 J

0.054

0.022

8

MTPU

1515

5.22

2.0 UJ



0.166

0.050 U

0.443 J

0.088

0.046

11

MTPD

1600

14.7

2.3 J



0.103

0.050 U

0.432 J

0.049

0.0 49 A J

9

SC1T

1430

5.96

2.0 UJ



0.176 A

0.050 U

0.462 J

0.0 86 A J

0.043

10

SC1T (d)

1430

5.83















10

SC1B

1435



2.0 UJ



0.294

0.050 U

0.450 J

0.072

0.049

29

SC2

1130



6.9 LJ



0.050 U

0.050 U

0.737 J

0.098

0.078

3

SC2 (d)

1130



5.0 LJ













3

SC3T

0910

5.72

2.0 UJ



0.050 U

0.050 U

0.396 J

0.076

0.057

3

SC3B

0915



2.0 UJ



0.061

0.050 U

0.435 J

0.068

0.0 56 A J

10

DRT

1230



3.5 J



0.050 U

0.050 U

0.595 J

0.073

0.064

2

DRB

1235



2.0 UJ



0.050 U

0.050 U

0.592 J

0.078 A

0.068

15

MBIT

1050

9.54

2.2 J



0.050 U

0.050 U

0.455 J

0.077

0.067

4

MB1B

1055



2.0 UJ



0.050 U

0.050 U

0.465 J

0.115

0.080

10

MB2

0940

6.03

2.0 UJ



0.050 U

0.050 U

0.409 J

0.068

0.032

6

SC4T

1610



2.0 UJ



0.050 U

0.050 U

0.396

0.033

0.046

5

SC4B

1620



2.0 UJ



0.056

0.050 U

0.396J

0.037

0.417

30

SC5T

1340

9.42

2.0 UJ



0.050 U

0.050 U

0.337 J

0.055

0.029

5

SC5B

1330

3.71

2.0 UJ



0.050 U

0.050 U

0.301

0.020 U

0.025

30

MB3T

1630

7.55

2.0 UJ



0.050 U

0.050 U

0.433

0.039

0.033

3

MB3B

1640



2.0 UJ



0.050 U

0.050 U

0.418 A

0.028

0.033

11

MB4

1415

6.72

2.0 UJ



0.050 U

0.050 U

0.487

0.0 92 AJ

0.052

5

MB4 (d)

1415

6.93















5

GULF

1245

3.75

2.0 UJ



0.050 U

0.050 U

0.286 A

0.020 U

0.020 U

5

A - Average Value; J - Estimated Value; U - Material analyzed for but not delected (number is minimum quantitation limit); (d) - QA duplicate sample;
L - Actual value known to be higherthan value given.

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Table 5 - Water Quality Sampling Results
May 15, 2001 - High Slack Tide

Station

T ime

BODu

(mg/1)

CBOD5

(mg/1)

TOC
(mg/1)

NH3-N
(mg/1)

N02/N03
(mg/1)

TKN
(mg/1)

Tot P

(mg/1)

Diss P

(mg/1)

TSS

(mg/1)

D

(ft)

MR1

1530

5.01

1.0 U

6.6

0.050 U

0.050 U

0.36

0.039

0.027

5.5

< 1

CC-A

1645



1.0 u

3.9

0.090

0.050 U

0.49

0.036

0.021

5.0

6

CC-A (d)

1645



1.0 u

4.4

0.10

0.050 U

0.41

0.034

0.020 U



6

CC-B

1650



1.0 u

4.7

0.18

0.050 U

0.31

0.058

0.048

12

20

TMC-A

1730



2.4

5.3

0.050 U

0.48

0.68

0.097

0.068

10

3

TMC-B

1735



1.0 U

4.6

0.18

0.052

0.48

0.052

0.043

9.5

11

SC1-A

1755

4.34

1.0 U

3.3

0.13

0.098

0.48

0.051

0.033



3.5

SC1-B

1800



1.0 U

4.7

0.15

0.050 U

0.41

0.077

0.035



31

SC2-A

1910

4.49

1.0 U

4.0

0.050 U

0.050 U

0.38

0.033

0.023



2

SC2-B

1920



1.2

4.3

0.063

0.050 U

0.37

0.046

0.031



16

SC3-A

1540

6.70

1.4

3.9

0.050 U

0.050 U

0.40

0.028

0.020 U



4

SC3-B

1550



1.0 UJ

4.3

0.050 U

0.050 U

0.33

0.037

0.022



13

DR

2010



1.4

3.9

0.050 U

0.050 U

0.42

0.038

0.033



11

DR (d)

2010



1.3

4.2

0.050 U

0.050 U

0.33

0.035

0.026



11

MB1 -A

1800

6.59

1.6

4.0

0.050 U

0.050 U

0.32

0.032

0.020 U



3

MB1 -B

1810



2.7

4.8

0.065

0.050 U

0.52

0.084

0.054



9

MB2 -A

1640

7.20

1.9

3.5 AJ

0.050 U

0.050 U

0.37

0.034

0.030



3

MB2-B

1650



2.2

4.7

0.050 U

0.050 U

0.52

0.070

0.063



10

SC4-A

1710

4.60

1.1

3.2 AJ

0.050 U

0.050 U

0.51

0.029

0.020 U



7

SC4-A (d)

1710



1.2

3.8

0.050 U

0.050 U

0.52

0.026

0.020 U



7

SC4-B

1715



1.0 U

4.7

0.050 U

0.050 U

0.28

0.034

0.020 U



35

SC5-A

1505

3.83

1.2

3.7

0.050 U

0.050 U

0.28

0.024

0.020 U



5

SC5-B

1510



1.0 U

4.7

0.050 U

0.050 U

0.23

0.028

0.020 U



25

MB3

1625

4.87

1.5

3.9

0.050 U

0.050 U

0.36

0.020 U

0.020 U



5

MB4

1750



2.1

4.1

0.050 U

0.050 U

0.45

0.032

0.032



3

MSO

1555

6.09

1.9 AJ

4.2

0.050 U

0.050 U

0.40

0.042

0.020 U



3

GULF-A

1435

6.93 A

1.0 U

4.7

0.050 U

0.050 U

0.12

0.020 U

0.020 U



10

GULF-B

1430



1.0 U

4.7

0.050 U

0.091

0.10 U

0.028

0.020 U



40

A - Average Value; J - Estimated Value; U - Material analyzed for but not detected (number is minimum quantitation limit); (d) - QA duplicate sample;

-14-


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Table 6 - Water Quality Sampling Results
May 16, 2001 - Low Slack Tide

Station

T ime

BODu

(mg/1)

CBOD5

(mg/1)

TOC
(mg/1)

NH3-N
(mg/1)

N02/N03
(mg/1)

TKN
(mg/1)

Tot P

(mg/1)

Diss P

(mg/1)

TSS

(mg/1)

D

(ft)

MR1

0915

6.16

1.2

6.2

0.050 U

0.050 U

0.34

0.049

0.031

10

< 1

CC-A

1100

5.03 A

1.0 U

4.1

0.11

0.077

0.50

0.044

0.030

10

9

CC-B

1105



1.0 UJ

3.7

0.28

0.050 U

0.49

0.057

0.046

22

25

TMC-A

1015

7.98 A

1.3

2.8 J*

0.11

0.74

0.61

0.15

0.110

9.0

4.5

TMC-A (d)

1015



1.3

3.0 J*

0.11

0.72

0.61

0.14

0.091

12

4.5

TMC-B

1025



1.0 U

1.6 J*

0.51

0.25

0.72

0.12

0.080

8.0

11

SC1-A

0945

4.64

1.0 U

4.4

0.11

0.059

0.38

0.043

0.033



6.5

SC1-B

0800



1.0 U

2.8 AJ

0.24

0.050 U

0.36

0.054

0.038



35

SC2-A

0840

6.62

1.5

3.1

0.052

0.050 U

0.38

0.044

0.030



4

SC2-B

0850



1.0 UJ

3.4

0.13

0.050 U

0.29

0.033

0.030



19

SC3-A

1050

5.57

1.5

3.3

0.050 U

0.050 U

0.30

0.024

0.021



4

SC3-B

1100



1.0 U

3.1

0.053

0.095

0.18

0.023

0.020 U



20

DR

1140

6.11

1.7

3.9

0.45 J

0.050 U

0.38

0.037

0.023



9

MB1 -A

0920

8.32

2.9

3.9

0.075 J

0.050 U

0.38

0.032

0.020



4

MB1-A (d)

0920

7.48

2.2

3.8

0.050 U

0.050 U

0.41

0.031

0.029 J



4

MB1 -B

0930



1.9

3.6

0.075

0.050 U

0.56

0.054

0.048



9

MB2

1010

8.05

2.5

3.3

0.050 U

0.050 U

0.45

0.038

0.027



5

SC4-A

1145

6.21

2.0

2.9

0.050 U

0.050 U

0.30

0.021

0.020 U



5

SC4-B

1150



1.0 U

2.9

0.050 U

0.050 U

0.19

0.020 U

0.020 U



30

SC5-A

1010

4.69

1.0

2.9

0.050 U

0.050 U

0.23

0.020 U

0.020 U



5

SC5-B

1015



1.0 U

1.0 UJ*

0.050 U

0.050 U

0.17

0.020 U

0.020 U



25

MB3 -A

1105

4.95

1.1

3.2

0.050 U

0.050 U

0.27

0.020 U

0.020 U



3

MB3-B

1110



1.5

3.0

0.050 U

0.050 U

0.29

0.020

0.020



8

MB4

0750

7.95

1.8

3.2

0.050 U

0.050 U

0.52

0.093

0.033



4

MB4 (d)

0750

8.17

1.8

3.1

0.050 U

0.050 U

0.47

0.092

0.054



4

MSO

1035

5.49

1.2

3.3

0.050 U

0.050 U

0.36

0.088

0.060



3

GULF

0920

2.48

1.0

3.2

0.091 J

0.050 U

0.28

0.020 U

0.020 U



20

Pres. Blank







1.0 U

0.050 U

0.050 U

0.10 U

0.020 U



4.0 U



A - Average Value; J - Estimated Value; U - Material analyzed for but not detected (number is minimum quantitation limit); (d) - QA duplicate sample;
* - holding time exceeded due to instrument malfunction

-15-


-------
less than detection (0.05 mg/1) in 2000 except near point sources where concentrations were still
less than 0.2 mg/1. Again in 2001, ammonia and nitrate/nitrite concentrations were generally less
than detection except in the tributaries (CC, TMC, and DR) and in the upper ship channel (SCI,
SC2, and SC3). Higher 2001 ammonia concentrations in tributaries and the upper ship channel
may be due to greater freshwater discharge into the Bay during May than July resulting in more
nitrogen loading from upstream swamps. TKN concentrations were somewhat higher during the
ebb tide sampling in 2000 than during the high slack tide possibly due to TKN input to the bay
from Chickasaw Creek and Three Mile Creek. It should be noted that some of the reported 2000
TKN concentrations are flagged as estimated due to recovery problems encountered during
analysis. With a few exceptions, TKN concentrations in 2001 were higher in the upper layer of
the water column than in the lower layer at the same station. Total phosphorus concentrations in

2000	and 2001 generally varied throughout the bay from less than detection (0.020 mg/1) to less
than 0.1 mg/1. In 2000, only stations TMC and CC exceeded 0.1 mg/1 total phosphorus during the
slack tide sampling while total phosphorus exceeded 0.1 mg/1 only at MB1 and above and below
International Paper during ebb tide sampling. In 2001, 0.1 mg/1 total phosphorus was exceeded
only at station TMC during the low slack tide sampling. Finally, TSS samples were collected in

2001	at the headwater station (MR1), Chickasaw Creek (CC), and Three Mile Creek (TMC)
during both slack tide events. With the exception of the lower layer sample in Chickasaw Creek
(22 mg/1), the remaining TSS concentrations were in a fairly narrow range from 5-12 mg/1.

-16-


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Continuous DO Monitoring

In both 2000 and 2001, continuous recording DO meters were deployed at ten locations in
the bay and tributaries. Each meter was deployed from a floating buoy to maintain a probe depth
of approximately five feet (5') and recorded dissolved oxygen, salinity, pH, and temperature in 30
minute intervals throughout the deployment period. In addition, turbidity measurements were
recorded during the 2001 deployments at stations MR1, CC, DR, MB1, MB3, and MB4. Table 7
summarizes the continuous DO monitoring data for the two surveys.

Table 7 - Continuous DO Monitoring Summary

Station

July 2000
Min.-Max Ave

Number
of Hours
Deployed

May 2001
Min.-Max. Ave

Number
of Hours
Deployed

MR1

7.50 - 10.29 8.43

67.1

8.33 - 12.10 9.29

53.2

CC

3.91 -23.52 12.51

74.0

5.75 -7.38 6.43

69.9

TMC

2.47- 13.02 6.97

74.2

5.59 -9.24 7.06

69.5

DR

0.73 -9.13 5.22

69.8

3.45 -7.88 6.07

69.8

SCI

No Data - Meter Lost

-

4.98 -7.33 5.99

64.7

MB1

5.46-7.89 6.13

72.1

No Data - Probe
Malfunction

72.3

MB2

5.38 -7.10 6.06

70.3

5.68 -7.73 6.71

66.8

MB3

No Data - Meter Lost

-

2.55 - 8.14 5.96

71.8

MB4

5.15 -6.74 5.79

69.2

6.15 - 8.52 6.98

66.1

GULF

No Data - Meter Lost

-

No Data - Meter Lost

-

Upper West
Bay (UWB)

1.70-7.14 4.62

72.9

4.47 - 8.07 6.28

62.4

As shown in Table 7, there is tremendous daily variability in DO in the bay tributaries

-17-


-------
(Dog River, Three Mile Creek, and Chickasaw Creek). During portions of the day in 2000,
individual DO measurements at these stations fell well below 5 mg/1, while the overall average
DO levels at these stations during both surveys was above 5 mg/1; however, this average is
significantly affected by the supersaturated conditions also experienced during portions of the
deployment. Only the Upper West Bay station during the 2000 survey exhibited an average DO
for the monitoring period less than 5 mg/1 (4.62 mg/1). With the exception of MB3, the ship
channel (SCI) and Mobile Bay stations (MB1, MB2, and MB4) exhibited a relatively narrow
range of DO over the monitoring period from about 5 mg/1 to 8.5 mg/1. Observed DO was as
low as 2.55 mg/1 at MB3.

During the 2001 deployment, turbidity concentrations at MR1 ranged from 10 to 32 NTU
with an average of 20 NTU. Turbidity at CC and DR was in a slightly more narrow range of 11 -
20 NTU (16 NTU average) and 5-13 NTU (8 NTU average), respectively. Turbidity in the
middle bay was around the same level as in the tributaries. Specifically, at MB1 turbidity ranged
from 5-25 NTU with an average of 11 mg/1 while MB3 ranged from 4-17 NTU with a 7 NTU
average. Turbidity in the lower bay (MB4) was significantly higher ranging from 6-64 NTU
with an average of 31 NTU. Turbidity data for stations MB3 and MB4 were also plotted against
water level (tidal stage) at Fowl River and wind speed to determine if turbidity levels in the bay
are related to either tides or wind. As shown in Figures 5 and 6, higher turbidity levels occur
during lower tide stage. While it was expected that higher wind speed would correlate with
higher turbidity levels due to potential resuspension of bottom sediments, the effects of tide stage
on turbidity masks any influence by wind.

-18-


-------
Turbidity vs. Tide/Wind

Station MB3- May 2001

— Wind (fps)

~	Turbidity
(NTU)

*	Relative
Tidal
Stage [ft)

Figure 5 - MBS Turbidity vs. Tide/Wind

Turbidity vs. Tide/Wind

Station MB4- May 2001

— Wind
(fps)
•* Tuibidity
(NTU)

* Relative
Tidal
Stage

(ft)

Figure 6 - MB4 Turbidity vs. Tide/Wind

Overall, calibration of continuous recording instruments was successful for both surveys;
however, difficulties for specific parameters on a few instruments were encountered. Following
the 2001 survey deployment, the instrument at MR1 read 7.90 mg/1 for a 7.45 mg/1 Winkler

-19-


-------
titration standard. The difference, 0.45 mg/1, exceeds the EAB tolerance for dissolved oxygen
calibration of 0.2 mg/1. Comparisons between DO reading from this meter and DST profiling DO
data at MR1 at approximately the same time and depth show the continuous meter also reading
approximately 0.25 mg/1 - 0.45 mg/1 higher than the profiling meter. Similarly, the instrument at
Three Mile Creek read the same Winkler standard (7.45 mg/1) at 7.15 mg/1 resulting in a
difference of 0.3 mg/1 versus EAB tolerance of 0.2 mg/1. Comparisons with DST profile data
confirm this slight underreading by the continuous meter. Also following the 2001 deployment,
the turbidity probes at stations DR and MB 1 read a 100 NTU turibidity standard as 69.6 NTU
and 84.9 NTU, respectively. Though of less importance to model development, it should be noted
that the pH probes at stations MB2 and MB4 following the 2001 deployment read a 7 pH
standard as 8.04 and 7.68 SU, respectively.

Following the 2000 deployment, several meters failed to measure the Winkler DO titration
standard within the EAB tolerance possibly due to growth on the instrument DO membrane.
Specifically, the instrument at MR1 was off by +1.48 mg/1. There is fairly close agreement
between the final continuous DO reading at MR1 and a profiling measurement taken a short time
later (difference of 0.22 mg/1); however, for model development and calibration, the modeling
team is recommended to rely on the DST profiling data for dissolved oxygen information for the
2000 survey at station MR1. Similarly, the meters at stations CC, TMC, DR, and MB1 deviated
from the Winkler standard by +0.60 mg/1, +0.39 mg/1, +0.45 mg/1, and -0.58 mg/1, respectively.
While the continuous DO data for these stations may be useful for evaluating the variation in DO
throughout a diurnal period, the DST profiling data is the recommended source of field data for
model setup and calibration.

-20-


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Due to tidal effects and stratification, the Diel Curve Method was not applied to the
Mobile Bay continuous DO data.

Production/Respiration

In order to determine production and respiration rates, light and dark bottle deployments
were conducted in both 2000 and 2001 at six stations including two bay stations (MB2 and MB3),
two ship channel stations (SC2 and SC5) and two tributary stations (CC and TMC). Tables 8 and
9 show the result gross primary production and respiration measurement results for 2000 and
2001, respectively.

Table 8 - July 2000 Production/Respiration

Station

Date

Incubation
Period

Gross Primary
Production (GPP)
(g 02/m2/day)

Respiration

(R)

(g 02/m2/mday)

GPP:R
Ratio

SC2

7/13/00

0900-1300

2.77

1.77

1.56

SC5

7/12/00

1415-1715

5.14

5.64

0.91

MB 2

7/13/00

1140-1520

1.12

1.04

1.08

MB 3

7/14/00

0915-1315

2.05

1.28

1.60

CC

7/15/00

1100-1500

0.62

0.73

0.85

TMC

7/15/00

1240-1600

3.96

2.50

1.59

During the 2000 and 2001 light/dark bottle experiments, samples were collected at
multiple depths (3-4 depths in the euphotic zone based on marine photometer light profiles) for
chlorophyll analysis for the purpose of providing instream chlorophyll data for model calibration
In 2001, chlorophyll samples were also collected at MB4. Tables 10 and 11 show the results of
chlorophyll a sampling for the 2000 and 2001 surveys, respectively.

-21-


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Table 9 - May 2001 Production/Respiration

Station

Date

Incubation
Period

Gross Primary
Production (GPP)
(g 02/m2/day)

Respiration

(R)

(g 02/m2/mday)

GPP:R
Ratio

MB 2

5/16/01

0840 - 1250

4.23

7.42

0.57

SC2

5/16/01

1000 - 1400

6.80

5.93

1.15

MB 3

5/17/01

0920 - 1330

3.73

3.97

0.94

SC5

5/17/01

1105 - 1510

5.64

5.94

0.95

MB 4

5/17/01

1225 - 1640

4.74

4.80

0.99

TMC

5/18/01

0900 - 1330

5.04

1.55

3.25

cc

5/18/01

1035 - 1435

5.54

2.40

2.31

In general, chlorophyll concentrations were much higher in 2000 than in 2001, presumably
because the 2000 study, conducted in July, took place in the middle of the growing season
whereas the growing season was just beginning in 2001. While concentrations for all stations
except Three Mile Creek were generally below 12 ug/1 in 2001, only station MB2 exhibited
concentrations below 12 u/gl at depths less than five feet in 2000. For both survey periods, Three
Mile Creek exhibited some of the highest chlorophyll concentrations ranging from 12.1 to 14.6
ug/1 in 2000 and from 13-40 ug/1 in 2001. Concentrations at station SC-2, well downstream of
Three Mile Creek, were as high in 2000 as in Three Mile Creek with a range of 37 - 43 ug/1 above
five feet. Concentrations in the high teens and twenties were observed as far down in the bay as
MB3.

Algal Growth Potential Tests (AGPT) were also run on samples collected at the P/R
stations in the Mobile Bay study area in order to determine the potential for algal enrichment of
the system. AGPT results for each survey are included in Tables 10 and 11. In general, a dry

-22-


-------
Table 10 - July 2000 Chlorophyll/AGPT

Date

Station
(AGPT, Dry Weight mg/1))
(Limiting Nutrient)

Depth (ft)

Chi a (ug/1)

7/12/00

SC5

0.5

12



(2.4)

0.5 (Duplicate)

12



(Nitrogen)

2.0

12





5.0

13





11.0

13

7/13/00

SC2

0.5

37



(3.9)

1.0

43



(Nitrogen)

2.5

39





5.5

8

7/13/00

MB2

0.5

7.5



(2.4)

1.5

8.2



(Nitrogen)

3.0

8.4





7.0

8.3





7.0 (Duplicate)

8.2

7/14/00

MB3

0.5

24



(6.0)

1.5

26



(Nitrogen)

3.0

18





3.0 (Duplicate)

16





7.5

19

7/15/00

TMC

0.5

29



(10.3)

1.5

37



(Nitrogen)

3.0

40





7.0

13

7/15/00

CC

0.5

14



(2.5)

1.5

15



(Nitrogen)

3.5

23





9.0

5.6





9.0 (Duplicate)

5.3

-23-


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Table 11 - May 2001 Chlorophyll/AGPT

Date

Station
(AGPT, mg/1)
(Lim. Nut.)

Depth (ft)

Chi a (ug/1)

Date

Station
(AGPT, mg/1)
(Lim. Nutrient)

Depth (ft)

Chi a (ug/1)

5/16/01

MB2

0.5

8.7

5/17/01

SC5 -Continued-

3

3.7



(2.4)

1

5.8



(1.5)

6.5

6.1



(Nitrogen)

3

8.0



(Nitrogen)

13

8.7





8

11.9

5/17/01

MB4

0.5

5.4

5/16/01

SC2

0.5

7.1



(1.4)

1.5

6.8



(i.i)

0.5 (Duplicate)

7.1



(Nitrogen)

1.5

(Duplicate)

7.0



(Nitrogen)

1.5

5.9





2.5

8.3





4

7.8





6

9.0





8

4.8

5/18/01

TMC

0.5

12.1





8 (Duplicate)

5.0



(25.0)

1

13.1

5/17/01

MB3

0.5

4.4



(Nitrogen)

2

14.6



(1.5)

1.5

4.2





4

12.4



(Not
determined)

1.5 (Duplicate)

4.2





4

(Duplicate)

13.4





2.5

4.6

5/18/01

CC

1

12.8





5.5

10.1



(8.2)

0.5

9.1





5.5 (Duplicate)

9.4



(Nitrogen)

1

9.3





10.5

11.6





3

8.4





10.5
(Duplicate)

11.1





6.5

7.6

5/17/01

SC5

0.5

2.8





6.5
(Duplicate)

7.7

weight AGPT greater than 10 mg/1 is considered an indication of enrichment in marine waters.
For both the 2000 and 2001 surveys, AGPT exceeded 10 mg/1 only at the Three Mile Creek
station (TMC) with the remaining stations all below 10 mg/1 indicating little enrichment in the
Mobile Ship Channel or Bay. For all stations, nitrogen was determined to be the limiting
nutrient.

-24-


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Diffusion/Reaeration

As part of the July 2000 survey, diffusion measurements were made at two locations in
order to determine an equivalent reaeration rate. Diffusion measurements for the Mobile surveys
utilized SESD/EAB's floating dome technique. The first measurement was made on July 14,
2000 in Dog River about two miles upstream of its mouth with a resulting reaeration rate of 0.15
1/day. The second measurement took place on July 16, 2000 in Chickasaw Creek about 1.25
miles upstream from its mouth. Using a depth of 7 meters based on observed stratification, the
resulting reaeration rate is 3.5 1/day; however, if a calculation is made using the entire water
depth at the measurement location of 10 meters, the resulting rate is 2.5 1/day.

In addition to dome method diffusion measurements, two gas/tracer reaeration studies
were conducted in Mobile Bay on July 13 south of SC-2 and on July 15, 2000 at MB1 (See
Figure 7). Utilizing krypton gas and Rhodamine WT dye, water samples were collected for
krypton analysis from the observed peak of the dye cloud over a period in excess of 4 hours. The
resulting gas reaeration rates were 1.82 1/day at 20° C on July 13 and 5.74 1/day at 20° C on July
15. Figures 8 and 9 show the prevailing currents and winds during the July 2000 gas/tracer
reaeration measurements.

During the May 2001 survey, a gas/tracer reaeration measurement was again made in
Mobile Bay southwest of SC-2 (See Figure 7). The resulting reaeration rate was found to be 2.37
1/day at 20° C. Prevailing wind/current vectors during this effort are shown in Figure 10. Also,
concurrent with the gas reaeration measurement, a floating dome diffusion measurement was
made in the same portion of the bay. The resulting rate of 3.86 1/day (at ambient temperature)
was in good agreement with the calculated reaeration rate at ambient temperature (3.20 1/day at
32.7° C).

-25-


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magna

tUcj-

May 16,2001 - Dye/Gas injection

July 13,2000 - Dye/Gas Injection

Figure 7 - Gas/Tracer Study Locations

-26-


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Wl
MO

NDV
BILE

**

ECTC
AIR!

re.:

7RSC
>OR7

4E1

KNO

Ml

is;

io

NT

_ ba	



7/13/2O0O *

*





-





I

\



X



\



\







V









1

















CUR,
MB-l

S l

Q W \

TORS (CA

VSEC

5



0800	0900	1000	1100	1200	1300	1400	1500	1600	1700

TIME

Figure 8 - 7/13/00 Reaeration Wind/Current Vectors





fe a

w v

BILE.

**RR

ECTORS
AIRPOR1

4ERA1

WOTS)

7a

£	

>



• 7115/2 o h o *

y\\y

*

!



-





f



I



i













1









1



/



/



/





CUR
MB-l

IENT VECTORS (Ch

USEC

)



0800 0900	1000 1100 1200 1300	1400 1500 1600 1700

TIME

Figure 9 - 7/15/00 Reaeration Wind/Current Vectors

-27-


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	Figure 10 - 5/16/01 Reaeration Wind/Current Vectors

Hvdrological/Meteorological Data

At the planning stage for this project, the Water Management Division indicated that
sufficient data existed for the development of a hydrodynamic model of the bay and only limited
hydrodynamic data would be needed to link the water quality datasets to a hydrodynamic model.
In addition, NOAA provides tide stage and current data for several locations in Mobile Bay which
could provide supplemental information for hydrodynamic modeling. As a result, only limited
hydrological data was collected during the 2000 and 2001 surveys. Hydrological data collected
during these surveys includes current direction/velocity and stage (water level). Meteorological
data includes wind speed/direction, and solar radiation collected in association with
production/respiration measurements.

In 2000, bay current speed and direction was measured at 10 minute intervals over a 3 day

-28-


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period at stations MB3 and MB4 and over a 5 day period at station MB1. At each station, the
current meter was deployed at middepth in the water column. In 2001, current meters were again
deployed at these stations at middepth over a 3 day period with a 10 minute measurement
interval. Also in 2001, a meter was located at middepth at station MS0. Figures 11-17 provide
oyster plots of current speed and direction as well as time series plots including temperature and
salinity for each station.

For both the 2000 and 2001 surveys, water level recorders were deployed at the Dog River
and Fowl River Marinas for the duration of the studies. Graphs of the water level data are
provided in Figures 18-21. Water level elevations atthe Fowl River Marina are referenced to
National Geodetic Vertical Datum (NGVD) through a NOAA tidal benchmark located at the
marina. No benchmark was available at the Dog River location, therefore these elevations are
reported relative to the mean water level for the record period.

In 2000 and 2001, wind speed and direction was measured at ten minute intervals at the
USS Alabama park located in the north portion of the Bay. Wind data are shown graphically in
Figures 22 and 23.

Problems were encountered with the EPA rain gage during the 2000 survey; however,
data obtained from the Mobile airport indicates 0.59" of rain fell on the afternoon of July 11
followed by 0.82" on the afternoon of July 16, 2000. No rainfall occurred at the SESD rain gage
during the 2001 survey.

Finally, solar radiation was measured on each day of production/respiration measurement
by recording pyroheliometer. A planimeter was then used to determine the amount of incident
solar radiation recorded on chart paper for each day of deployment. Table 12 provides the daily
solar radiation inLangleys for each production/respiration measurement.

-29-


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STATION MB-1 30

36.04N 87 57.91W



Speed Class Interval = 4.00









\

\

/

/



315

\



45

/

-



-

270 — <2^1



	 90

A



-

M



-

/



\ ®



225



135 3



/

u J X









8



/



2



180

Si







aj



OYSTEH PLOT OF SPEED AND DIRECTION

T







o



From 11-JUL-

0 To 16-JUL- 0

No. of Obs.

ENDECO Type 174SSM Solid

State Memory Current

Meter

Figure 11a - July 2000 - MBl Oyster Plot

Figure lib - July 2000 - MBl Time Series Plots

-30-


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STATION MB-3 30 22.015N B8 03.942W

Speed Class Interval = 4.00
0

180

OYSTER PLOT OF SPEED AND DIRECTION

From 11-JUL- 0 To 14-JUL- 0
ENOECO Type 174SSM Solid State Memory Current Meter

Figure 12a - July 2000 - MBS Oyster Plot

Figure 12b - July 2000 - MBS Time Series Plot

-31-


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STATION MB-4 30 19.00BN 87 52.961W
Speed Class Interval =4.00

OYSTER PLOT OF SPEED AND DIRECTION

From 11-JUL- 0 To 14-JUL- 0
ENDECO Type 174SSM Solid State Memory Current Meter

Figure 13a - July 2000 - MB4 Oyster Plot

Sin



STATION

MB — A

30 19.006N 8 ~7 52.961W

IS

13 194



195



196 197 196

IS

-S tu s
~ s| S-

13 19-4

T-J

|-1

195

V~~|

196 197 196

IS

& S

13 194 195 196 197 196

vVv^tA/Vv/x./

u

33 194
JULIAN DAYS

Endeco

195 196 197 196
11—JUL— O to 14—JUL— O

Type 174SSM Current Meter

Figure 13b - July 2000 - MB4 Time Series Plot

-32-


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STATION MB-1 N30 35.989 W087 SB.000

Spaed Class Interval - 16.00
0

/

OYSTER PLOT OF SPEED AND DIRECTION

From 15-MAY- 1 To 18-MAY- 1
ENDECO Type 174SSM Solid State Memory Current Meter

Figure 14a - May 2001 - MB1 Oyster Plot

o	STATION MB—1	N30 35.9B9 W087 5Q.OOO

135 136

Sr

m

137 1

		r	r

36 133 140 :

135 136 131

"1

1

Ml

38 139 140

Itth

135 136 137 136 139 1-40

=H	™—¦—2—	1-"	¦	*	f	"	1	1—

135	136	137	138	139	1-40

JULIAN PAYS	15—MAY— 1 to 18-MAY- 1

Endeco Type 174SSM Current Meter

Figure 14b - May 2001 - MB1 Time Series Plot

-33-


-------
Figure 15a - May 2001 - MB3 Oyster Plot

Figure 15b - May 2001 - MBS Time Series Plot

-34-


-------
MB 4 N30 19.046 W08B 59.972

Speed Claaa Interval "2.00
0

OYSTER PLOT OF SPEED AND DIRECTION

From 15-MAY- 1 To IB-MAY- 1
ENDECO Type 174SSM Solid State Memory Current Meter

Figure 16a - May 2001 - MB4 Oyster Plot

1 E

MB A N30 ±9.046 WOSS 59.972

i:

1" ~ «=,

35 136 137 138 139 140

12

§ g s

15 136 137 138 139 140

^nrriifH

s is

15 136 137 138 139 140

A M /*\

135 136 137 138 139 140
JULIAN DAYS ±5—MAY— 1 to IB—MAY— 1

Endec o Type 174SSM Current Meter

Figure 16b - May 2001 - MB4 Time Series Plot

-35-


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Figure 17a - May 2001 - MSO Oyster Plot

1 i £

STATION MSO N30 17.648 W08S 07.2

12
S&1

n« ^

ft 0

15 136 137 13B 139 1-40

12

1 I a

15 136 137 138 139 140

jTjyni'ii iiri

i:

» I

15 136 137 138 139 140

135 136 137 138 139 1-40
JULIAN DAYS 15—MAY— 1 to IB—MAY- 1

Endeco Type 174SSM Current Meter

Figure 17b - May 2001 - MSO Time Series Plot

-36-


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Water Level Record - Dog River
JULY 11-16, 2000

DATE -TINE

Figure 18 - July 2000 Water Level - Dog River

Water Level Record - Fowl River I

July 11 -16, 2000

DATE -TINE

Figure 19 - July 2000 Water Level - Fowl River

-37-


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Water Level - Dog River
May 15-18,2001

Time

Figure 20 - May 2001 Water Level - Dog River

Water Level - Fowl River
May 15-18, 2001

Time

Figure 21 - May 2001 Water Level - Fowl River

-38-


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Wind Data - Mobile Bay Survey - July 2000

Figure 22 - July 2000 Wind

Wind Data - Mobile Bay Survey - May 2001

— Speed — Direction

Figure 23 - May 2001 Wind

-39-


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Table 12 - Solar Radiation

Date

Radiation
(Langleys)

7/12/00

489

7/13/00

526

7/14/00

399

7/1500

609

5/16/01

567

5/17/01

579

5/18/01

366

Sediment Oxygen Demand

During the July 2000 survey, sediment oxygen demand (SOD) measurements were made
at five locations in the Mobile Bay study area. In 2001, SOD rates were measured at seven
locations. SOD measurements were made using four replicate chambers at each station and an
average SOD was determined for each station. Table 13 provides the resulting SOD rate for each
station. These rates are corrected for water column respiration, which is also measured using two
replicate chambers, and are reported at ambient temperature.

As shown in Table 13, SOD rates were measured at the four Mobile Bay water quality
sampling stations and in the bay near the entrance to Dog River in 2000. SOD rates for the bay
water quality stations were in a fairly narrow range from approximately 1.5 to 3.0 g02/m2/day
with rates slightly higher in the lower bay (MB3 and MB4) than in the upper bay (MB1 and
MB2). The station near Dog River also fell in this range with a rate of 1.7 g02/m2/day. In
addition to these stations, stations were added in Mobile Bay near the entrance to Fowl River and

-40-


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Table 13 - SOD Rates

Station

Date

SOD
(g02/m2/day)

Temperature
(°C)

Diver
Observations

Mobile Bay near
Dog River entrance

7/11/2000

1.70

31.5

11' Deep
Fine Sandy Muck

MB1

7/12/2000

1.84

30.8

13' Deep
Fine Sandy Muck

MB2

7/12/2000

1.53

30.6

13' Deep
Fine Sandy Muck

MB 3

7/13/2000

3.00

30.4

15' Deep
Mucky Fine Sediment

MB 4

7/13/2000

2.66

31.1

13' Deep
Mucky Fine Sediment

Mobile Bay near
Dog River entrance

5/18/2001

1.27

27.3

12' Deep
Silty Clay w/ Shell
Fragments

Mobile Bay near
Fowl River entrance

5/17/2001

1.31

25.6

14' Deep
Brown Silt

Mobile Bay near
Mobile River mouth

5/16/2001

3.15

27.7

8' Deep
Sandy Silt

MB1

5/18/2001

1.47

26.2

13' Deep
Brown Silty Clay

MB2

5/17/2001

1.97

25.7

13' Deep
Brown Silt

MB 3

5/16/2001

1.35

25.6

14' Deep
Grey Mucky Fine
Sediment

MB 4

5/15/2001

1.83

25.2

12' Deep
Brown Flock over
Grey Mucky F ine
Sediment

below the mouth of the Mobile River for the 2001 survey. A planned measurement in the Mobile
River above Chickasaw Creek could not be completed due to conditions at the time. Overall,
SOD rates were lower in 2001 than in 2000. As in 2000, the bay water quality stations as well as
the station near Fowl River fell in a narrow, though slightly lower, range from 1.3 to 2.0

-41-


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g02/m2/day. The bay station near Dog River was near this range at just below 1.3 g02/m2/day.
The station below the Mobile River, however, was somewhat higher than the other stations
measured in 2001.

Point Source Sampling

For purposes of the model calibration/verification surveys, the Water Management Division
identified three point sources of interest. Specifically, WMD requested sampling data for
International Paper, Kimberly Clark, and Mobile/Clifton Williams WWTP. International Paper
discharges to the Mobile River approximately 1.25 miles upstream of Chickasaw Creek while
Kimberly Clark discharges to the Mobile River roughly 3/4 mile upstream of Chickasaw Creek.
The Mobile WWTP outfall is located at the north end of Mcduffie Island and discharges to the
Mobile River very near its mouth. Figure 24 shows these locations within the study area.

In addition to the facilities of interest to the Water Management Division, sampling was
conducted at the Mobile/Three Mile Creek (W. Smith) WWTP and the Prichard WWTP to allow
these facilities to be easily integrated into the water quality model if they were later determined to
be of significance to wasteload allocation or total maximum daily load determinations. Sample
collection and insitu measurements were performed by survey participants from the Alabama
Department of Environmental Management's Mobile office. Tables 14 and 15 provide the results
of the effluent sampling and insitu measurements for the 2000 and 2001 surveys, respectively.

Effluent samples collected were 24 hour composite samples. Flows reported in Tables 14
and 15 represent the flow from each facility over the 24 hour compositing period. According to
ADEM, in December 2000 International Paper shut down its Mobile facility thus resulting in a
decrease in flow between the 2000 and 2001 studies from 27.5 MGD to 0.69 MGD. Also, in

-42-


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OakleighjEst
Beach Estate's,!*

International Paper|

.Chickasaw

Kimberly Clark |

(Blakeley

Orchard

^Overlook Enates

Toulminville

Crichton





Country Club Estates

Mobile/Williams WWTP

Ft'MsQejTnott.

ackson Heights | I
•*Eau Claire Estates!

Oakuiood Estates

Famell

Moiult

| Skyland.Park^ Estates

Village. Point/



Daphne

1 Dog River Point

f[7AB

flagged1

Rabbit Creek Estates^
JtlSAB



Theodore

'-DELORME

Figure 24 - Point Source Locations

-43-


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Table 14 - July 2000 Point Source Sampling Results



International
Paper

Kimb erly
Clark

Mobile/
Williams
WWTP

Mobile/
Smith WWTP

Prichard
WWTP

NPDES#

AL0002780

AL0002801

AL0023086

AL0023094

AL0023205

Date

7/12/00

7/12/00

7/12/00

7/12/00

7/12/00

Time

1140

1325

1235

1130

1145

Flow (MGD)

27.5

34.4

20.6

10.2

1.0

DO (mg/1)

0.2

8.84

7.22

6.0

7.8

Temp. (°C)

36.1

33

30.5

29.6

28.7

pH (SU)

7.7

8.4

6.6

6.7

7.4

Conductivity (uMho)

1960

735

12180

50700

52200

Total BODU (mg/1)

192.3

42.1

105.8

56.9

22.9

CBOD5 (mg/1)

25 J

4.7 J

2.0 UJ

6.8 J

2.0 UJ

NH3-N (mg/1)

0.566

3.20

15.6

2.82

1.36

N02/N03 (mg/1)

0.050 U

0.293

0.484

12.1

0.074

TKN (mg/1)

9.3

5.99

17.0

6.48

2.76 J

Tot. Phosphorus
(mg/1)

3.09

1.42

2.62

3.28

1.60

Diss. Phosphorus
(mg/1)

0.28

1.24

2.08

2.80

1.45

A - Average Value; J - Estimated Value; U - material analyzed forbut not detected; BODU is corrected for dilution.

Table 15 two values are shown for ultimate BOD and CBOD5 results. The first number of each
pair represents the analytical result corrected for dilution for a sample comprised of 10% effluent
sample and 90% laboratory dilution water. The second value in the pair is the analytical result
corrected for dilution for a 25% effluent sample. The time reported in each table is the end time
for sample compositing and the time at which insitu measurements were made.

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Table 15 - May 2001 Point Source Sampling Results



International
Paper

Kimb erly
Clark

Mobile/
Williams
WWTP

Mobile/
Smith WWTP

Prichard
WWTP

NPDES #

AL0002780

AL0002801

AL0023086

AL0023094

AL0023205

Date

5/16/01

5/16/01

5/16/01

5/16/01

5/16/01

Time

0840

0750

0740

0900

0800

Flow (MGD)

0.69

34.1

20.2

9.38

1.41

DO (m g/1)

6.9

10.6

7.5

7.7

8.2

Temp. (°C)

26

28

25

25

23

pH (SU)

7.8

8.5

6.6

6.7

7.5

TOC (mg/1)

47

14

29

17 J*

12

Total BODU (mg/1)
(10%/25%)

22.1/26.0

42.3/39.8

135.1/1 34.5

24.4/36.1

20.4/19.0

CBOD5 (mg/1)
(10 %/2 5 %)

12/6.3

12/8.6

19/18

15/11

8.8/7.6

NH3-N (mg/1)

0.47

2.20

20

1.3

0.46

N02/N03 (mg/1)

0.50

4.8

0.050 U

16

0.052

TKN (mg/1)

4.9

5.2

23

3.4

2.1

Tot. Phosphorus
(mg/1)

1.3

0.92

3.0

2.3

0.96

Diss. Phosphorus
(mg/1)

1.3

0.90

2.9

2.3

0.80

A - Average Value; J - Estimated Value; U - material analyzed forbut not detected; * - Holding time exceeded due to instrument malfunction.
BODU results reported by th e laboratory are correcte d for dilution (% sampl e shown in paranthese).

According to EPA's Envirofacts Warehouse website, International Paper and Kimberly
Clark have National Pollutant Discharge Elimination System (NPDES) permit limits for only two
water quality parameters measured by EPA during the two intensive surveys. Both facilities must
maintain a pH between 5 and 9 standard units while International Paper has an effluent
temperature limit of 95 °F (35 °C) and Kimberly Clark has an effluent temperature limit of 100 °F

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(37.8 °C). International Paper slightly exceeded the temperature limit in 2000; otherwise, the
remaining measured temperatures and pH for these facilities were in compliance with NPDES
limits. Of the parameters measured during these surveys, the Envirofacts site indicates that the
Mobile/Williams WWTP is required to maintain a pH between 6 and 9 standard units and a BOD5
less than 30 mg/1. Both these limits were met during both surveys. Finally, the Envirofacts site
shows effluent limitations on the Mobile/Smith WWTP and Prichard WWTP for BOD5 (15 mg/1),
ammonia-nitrogen (5 mg/1), dissolved oxygen (5 mg/1), and pH (6 - 9 SU). These effluent
limitations were met during both intensive surveys at both facilities.

Conclusion

The Mobile Bay water quality surveys conducted in July 2000 and May 2001 successfully
obtained the necessary water quality data and information to enable the Water Management
Division to calibrate and verify a 3-dimensional, dynamic water quality model of the bay.
Significant profiling both longitudinally and laterally in the bay and tributaries coupled with
extensive continuous meter coverage provides a comprehensive picture of dissolved oxygen,
salinity, and temperature within the bay and tributaries. Comprehensive water quality sampling of
ambient water and point sources along with specialized studies of bay oxygen dynamics including
reaeration, production/respiration, and sediment oxygen demand provide a vast amount of data
and information in support of model calibration and verification. In addition, appropriate
hydrodynamic data collected to characterize tidal conditions (currents, tide heights) allows the
modeling team to tie this water quality data to an existing hydrodynamic model. The surveys also
met the objective of providing data over a range of conditions as demonstrated by the differences
in chlorophyll concentrations and ambient water temperatures between the surveys. Finally,

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supplemental information collected during the 2001 survey including DST profiling in Oyster Bay,
Weeks Bay, Magnolia River, and the Intracoastal Waterway and water quality sampling of two
additional point sources (collected both on both surveys) provides information to allow these
systems to be added to the modeling framework, if necessary, while total suspended solids
analyses of bay tributaries including Dog River, Three Mile Creek, and the Mobile River, and
turbidity measurement at several continuous measurement stations provide a better understanding
of solids concentrations within the study area.

It is recommended that the modeling team pay special attention to the discussions related
to calibration of the continuous and profiling meters since some of the these meters fell out of
calibration during deployment.

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