chowan river tmdl development blackwater area 09/07/04
DESCRIPTION
TMDL Development Historical data analysis Source assessment Physical Source Identification Bacterial source tracking Modeling AllocationTRANSCRIPT
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