Chowan River TMDL Development

Blackwater Area

09/07/04

Impaired Waters in the Blackwater River Drainage

Rattlesnake Creek Swamp – Fecal Coliform Mill Swamp – Fecal Coliform Cypress Swamp – Fecal Coliform Spring Branch – General Standard (Benthic)

TMDL Development

Historical data analysis Source assessment

Physical Source Identification Bacterial source tracking

Modeling Allocation

Fecal Coliform ImpairmentsImpaired Stream Segments in the Blackwater River watershed

Water Quality Data AnalysisLocation of VADEQ water quality monitoring stations used for TMDL assessment in the Blackwater River watershed

Water Quality Data Analysis

Fecal Coliform Concentrations

Impairment Station Id Sampled Dates Count Minimum Maximum Mean Median

% Violations

1000

% Violations

400

Cypress Swamp 5ACPP003.20 9/90 - 3/04 55 18 9,200 592 100 7 11

Cypress Swamp 5ACPP006.04 5/01 - 6/03 12 100 800 242 100 0 17

Cypress Swamp 5ACPP007.84 7/03 - 3/04 9 25 2,000 383 75 11 22

Johnchecohunk S. 5AJCH002.27 7/03 - 3/04 9 25 1,300 366 250 11 22

Mill Swamp 5AMSW006.77 8/94 - 3/04 38 18 16,000 775 105 13 18

Rattlesnake Cr. 5ARKN006.40 8/94 - 3/04 102 13 4,800 312 100 8 16

Water Quality Data AnalysisLocation of BST water quality monitoring stations in the Blackwater River watershed

Water Quality Data Analysis

E. coli concentrations

Impairment Station Id Sampled Dates Count Minimum Maximum Mean Median

% Violations

235 Cypress Swamp 5ACPP003.20 12/03-3/04 4 12 44 28 28 0 Cypress Swamp 5ACPP007.84 7/03-3/04 9 20 800 163 60 11 Johnchecohunk S. 5AJCH002.27 7/03 - 3/04 9 30 300 132 100 11 Mill Swamp 5AMSW006.77 11/03-3/04 5 14 134 55 38 0 Rattlesnake Cr. 5ARKN006.40 10/03-3/04 7 28 142 67 60 4

Water Quality Data Analysis Statistical Analysis of Water Quality Measurements

versus Precipitation to determine the relationship between rainfall and water quality

Analyzed relationships for seasonal trends No seasonal trends found

Source Assessment Identification of Sources

DEQ/DCR/Locality records VPDES U.S. Census Ag Census Habitat Analysis Stakeholders, local knowledge – improve estimates BST

Delivery Mechanisms Direct Land-applied Exported Out of Watershed

Temporal Variation Migration Patterns/Resident Populations Import/Export of agricultural/STP waste?

Permitted Discharges

Permitted Discharges

Facility Name Permit No Design Flow (MGD)

Permitted For Fecal Control Data Availability

Spring Branch WWTF VA0061310 0.9 Yes 2/02 - 3/04

Human (2004)

Impairment Population

Housing Units (HU)

HU with Sewer

HU with Septic

HU with Other

Cypress Swamp 1,118 436 31 365 41Mill SwampRattlesnake Swamp

8431,147

338446

3413

271400

3333

Human

Sanitary sewer Overflows - reported to DEQ Exfiltration – rate from literature

Failing septic systems Rate based on age of house

Straight pipes U.S. Census and VDH consultation

Pets (2004)Impairment Dogs CatsCypress Swamp 233 261Mill Swamp 180 202Rattlesnake Swamp 238 267

Livestock - 1997

Impairment Beef Dairy Horse Sheep Poultry Swine

Cypress SwampMill SwampRattlesnake Swamp

202227180

1057

153819

171614

9,3354,7596,908

Wildlife PopulationImpairment Deer Turkey Goose Duck Muskrat Raccoo

n Beaver

Cypress SwampMill SwampRattlesnake Swamp

1352859974

356217255

14491122

367232309

19,9689,432

12,007

Bacterial Source TrackingLocation of BST stations in the Blackwater River watershed

Modeling

Hydrologic model Runoff model HSPF

Water Quality model HSPF

Model Calibration and Validation Based on data availability, period of

interest

Modeling

$

Determination of Critical Conditions: Observed Fecal Coliform Versus Stream Flow

Cypress Swamp: VADEQ Station 5ACPP006.04 and USGS Station #02047500

1

10

100

1,000

10,000

100,000

0 10 20 30 40 50 60 70 80 90 100

Flow Duration Interval (%)

Feca

l Col

iform

(cfu

/100

ml)

Listing Standard New Instantaneous Standard Observed FC

High Flow Moist Conditions Mid-Range Flow Dry Conditions Low Flow

Determination of Critical Conditions: Observed Fecal Coliform Versus Stream Flow , cont.

Cypress Swamp: VADEQ Station 5ACPP003.20 and USGS Station #02047500

1

10

100

1,000

10,000

100,000

0 10 20 30 40 50 60 70 80 90 100

Flow Duration Interval (%)

Feca

l Col

iform

(cfu

/100

ml)

Listing Standard New Instantaneous Standard Observed FC

High Flow Moist Conditions Mid-Range Flow Dry Conditions Low Flow

Determination of Critical Conditions: Observed Fecal Coliform Versus Stream Flow, cont.

1

10

100

1,000

10,000

100,000

0 10 20 30 40 50 60 70 80 90 100

Flow Duration Interval (%)

Feca

l Col

iform

(cfu

/100

ml)

Listing Standard New Instantaneous Standard Observed FC

High Flow Moist Conditions Mid-Range Flow Dry Conditions Low Flow

Rattlesnake Creek Swamp: VADEQ Station 5ARKN006.40 and USGS Station #02047500

Determination of Critical Conditions: Observed Fecal Coliform Versus Stream Flow , cont.

1

10

100

1,000

10,000

100,000

0 10 20 30 40 50 60 70 80 90 100

Flow Duration Interval (%)

Feca

l Col

iform

(cfu

/100

ml)

Listing Standard New Instantaneous Standard Observed FC

High Flow Moist Conditions Mid-Range Flow Dry Conditions Low Flow

Mill Swamp: VADEQ Station 5AMSW006.77 and USGS Station #02047500

Hydrologic Calibration

$

Observed vs. Modeled (10/1/1990-9/30/1995)

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

10/0

1/19

90

11/1

3/19

90

12/2

6/19

90

02/0

7/19

91

03/2

2/19

91

05/0

4/19

91

06/1

6/19

91

07/2

9/19

91

09/1

0/19

91

10/2

3/19

91

12/0

5/19

91

01/1

7/19

92

02/2

9/19

92

04/1

2/19

92

05/2

5/19

92

07/0

7/19

92

08/1

9/19

92

10/0

1/19

92

11/1

3/19

92

12/2

6/19

92

02/0

7/19

93

03/2

2/19

93

05/0

4/19

93

06/1

6/19

93

07/2

9/19

93

09/1

0/19

93

10/2

3/19

93

12/0

5/19

93

01/1

7/19

94

03/0

1/19

94

04/1

3/19

94

05/2

6/19

94

07/0

8/19

94

08/2

0/19

94

10/0

2/19

94

11/1

4/19

94

12/2

7/19

94

02/0

8/19

95

03/2

3/19

95

05/0

5/19

95

06/1

7/19

95

07/3

0/19

95

09/1

1/19

95

Date

Flow

(cfs

)

0

1

2

3

4

5

6

7

8

9

10

Prec

ipita

tion

(in.)

Precip Observed Modeled

Hydrologic Calibration

$

Observed Modeled Error Target

Total In-stream Flow: 48.57 47.29 -2.62% 10.00%

Upper 10% Flow Values: 22.02 21.42 -2.73% 15.00%

Lower 50% Flow Values: 6.85 6.37 -6.89% 10.00%

Winter Flow Volume 24.90 24.45 -1.78% 30.00%

Spring Flow Volume 12.68 13.91 9.65% 30.00%

Summer Flow Volume 4.48 3.50 -21.86% 30.00%

Fall Flow Volume 6.50 5.43 -16.51% 30.00%

Total Storm Volume 45.46 46.35 1.94% 20.00%

Winter Storm Volume 24.13 24.22 0.38% 30.00%

Spring Storm Volume 11.90 13.67 14.81% 30.00%

Summer Storm Volume 3.71 3.28 -11.75% 30.00%

Fall Storm Volume 5.72 5.19 -9.32% 30.00%

Modeling Source Loads

Source Characterization Fecal production / densities / distribution

Delivery Mechanisms Direct Land-applied Exported Out of Watershed

Temporal Variation

Load CharacteristicsAnimal Waste Load

(lb/an-day) Fecal Coliform Density

(cfu/lb) # Dairy Cow Equivalents

Dairy 120.4 1.23E+08 1 Beef 46.4 4.58E+07 7

Horse 51.0 4.26E+07 7 Swine 11.3 1.81E+08 7 Sheep 2.4 1.95E+07 316 Goat 5.7 6.80E+06 382

Broiler 0.2 2.66E+08 328 Layer 0.3 2.66E+08 214

Human 0.9 2.91E+08 58 Dog 1.0 2.18E+08 69 Cat 0.0 4.08E+03 84,765,882

Raccoon 1.0 9.53E+08 16 Muskrat 0.2 8.62E+08 78 Beaver 0.4 4.54E+05 74,001 Deer 1.7 1.72E+08 50

Turkey 0.7 6.04E+05 34,723 Goose 0.5 1.13E+08 263

Mallard 0.3 1.59E+06 28,191

Model Load Characterization “Direct to Stream” Loads

Point Sources: Design Flow/Fecal Discharge Overflows: Reported overflow volume Characterize Volume and Duration Animal/Human: direct deposition, straight pipes

“Land Applied” Loads Wildlife, Livestock, Pets Transported to stream during runoff producing event Use measured waste characteristics Compute die-off in between events

Application timing

Wildlife

Animal Type Portion of Day in Stream Access Areas

Direct Deposition

Time of Day Loads Produced

(%) (%) (hr) Deer 5 1 6PM – 6AM Raccoon 5 5 6PM – 6AM Muskrat 90 5 6AM – 6PM Beaver 100 100 6AM – 6PM Turkey 5 1 6AM – 6PM Goose 50 5 6AM – 6PM Duck 75 5 6AM – 6PM

Livestock

Month Applied % of Total Land use Dairy Beef Swine Poultry January 1.50 8.33 0.00 0.00 Cropland February 1.75 8.33 0.00 5.00 Cropland March 17.00 8.34 20.00 25.00 Cropland April 17.00 8.34 20.00 20.00 Cropland May 17.00 8.33 20.00 5.00 Cropland June 1.75 8.33 0.00 5.00 Pasture July 1.75 8.33 0.00 5.00 Pasture August 1.75 8.33 0.00 5.00 Pasture September 5.00 8.34 0.00 10.00 Cropland October 17.00 8.34 20.00 10.00 Cropland November 17.00 8.33 20.00 10.00 Cropland December 1.50 8.33 0.00 0.00 Cropland

Average percentage of collected livestock waste applied throughout year

Livestock

Average time dairy milking cows spend in different areas per day

LivestockAverage time dry cows and replacement heifers spend in different areas per day

LivestockAverage time beef cows not confined in feedlots spend in areas per day

Allocation

Quantify Current Source Conditions Run model with present-day sources

Develop reduction scenarios that will meet water quality standards 100% reduction in straight pipes, 25%

reduction in failed septic systems 100% reduction in straight pipes, 50%

reduction in livestock direct deposition Allocate loads to each source

Livestock - 2002

Impairment Beef Dairy Horse Sheep Swine

Cypress Swamp 162 2 51 1 9,117Mill Swamp 329 6 77 14 2,957Rattlesnake Swamp 183 2 51 4 6,236

* Must get information regarding import/export of poultry litter in watershed.

Allocation

Time, (days)

FC C

onc.

, (cf

u/10

0ml)

Historical Data

TMDL