U.S. Department of the Interior U.S. Geological Survey Assessing Watershed Scale Assessing Watershed Scale Responses to BMP Responses to BMP Implementation Implementation - - Fairfax County, VA - Fairfax County, VA - John Jastram John Jastram Hydrologist Hydrologist USGS Virginia Water Science Center USGS Virginia Water Science Center
U.S. Department of the Interior U.S. Geological Survey Assessing Watershed Scale Responses to BMP Implementation - Fairfax County, VA - John Jastram Hydrologist.
Dec 26, 2015
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U.S. Department of the InteriorU.S. Geological Survey
Assessing Watershed Scale Assessing Watershed Scale Responses to BMP ImplementationResponses to BMP Implementation
- - Fairfax County, VA -Fairfax County, VA -
John JastramJohn JastramHydrologistHydrologist
USGS Virginia Water Science CenterUSGS Virginia Water Science Center
Topics
Objectives and Introduction Study Approach Site Selection and Watershed Characteristics Instrumentation and Methods Anticipated Products Preliminary Data Additional Related Research
Study Objectives
1.1. Generate Generate long-termlong-term monitoring data to describe: monitoring data to describe: Current water-quality (sediment and nutrients) and quantity Current water-quality (sediment and nutrients) and quantity
conditions,conditions, Trends in water-quality and quantity,Trends in water-quality and quantity, Nutrient and Sediment Loads and Yields.Nutrient and Sediment Loads and Yields.
2.2. Evaluate relations between observed Evaluate relations between observed conditions/trends and BMP implementation.conditions/trends and BMP implementation.
3.3. Transfer the understanding gained to other less-Transfer the understanding gained to other less-intensively monitored watersheds.intensively monitored watersheds.
Introduction: The Challenge
BMP induced changes are difficult to quantify BMP induced changes are difficult to quantify at the watershed scale:at the watershed scale:
Environmental factors cause great variability Environmental factors cause great variability – need to separate signal from noise,– need to separate signal from noise,
Lag times may be considerable,Lag times may be considerable,
Numerous samples at multiple sites over Numerous samples at multiple sites over extended periods of time.extended periods of time.
Operate four intensive Operate four intensive monitoring stationsmonitoring stations
5 – 10 years of data collection5 – 10 years of data collection- - Continuous-record stream gage Continuous-record stream gage
- - Continuous water-quality monitor Continuous water-quality monitor (turbidity, pH, SC, water temp)(turbidity, pH, SC, water temp)
- Automated stream sampler (storm Automated stream sampler (storm samples)samples)- Nutrients & SedimentNutrients & Sediment
- Scheduled monthly samplingScheduled monthly sampling- Nutrients & SedimentNutrients & Sediment
- Annual benthic monitoringAnnual benthic monitoring
Evaluate trends and loads.Evaluate trends and loads.
Approach: Intensive Monitoring
Approach: BMP Evaluation
Assemble BMP implementation dataset for monitored watersheds.
Extent of BMP implementation. Types of BMPs installed.
Evaluate relations between water-quality conditions/trends and BMP activities.
All Fairfax County Watersheds
0
5
10
15
20
25
30
35
0 10 20 30 40 50
Percent Implementation Within Watershed
5-ye
ar i
mp
rove
men
t in
wat
er q
ual
ity
(%)
Operate 10 trend monitoring Operate 10 trend monitoring stations.stations.
Partial-record stream gage Partial-record stream gage Scheduled monthly sampling Scheduled monthly sampling
Nutrients & SedimentNutrients & Sediment
Annual benthic monitoringAnnual benthic monitoring
Evaluate trends in water-quality Evaluate trends in water-quality and quantity.and quantity.
Evaluate relations between trend- Evaluate relations between trend- and intensive monitoring sites.and intensive monitoring sites.
Approach: Knowledge Transfer
Status
Intensive SitesIntensive Sites Streamgages & Water-Quality Monitors installed Streamgages & Water-Quality Monitors installed
and fully operationaland fully operational Real-time data on web (Real-time data on web (http://va.water.usgs.govhttp://va.water.usgs.gov))
Sampling underwaySampling underway Surrogate regressions under developmentSurrogate regressions under development
Partial Record - Trend SitesPartial Record - Trend Sites Staff plates and Crest Stage Gages installedStaff plates and Crest Stage Gages installed Monthly sampling underwayMonthly sampling underway
Complete data were not available on all potential study Complete data were not available on all potential study basin characteristics, we used what was available.basin characteristics, we used what was available.
Phase 1 WatershedsPhase 1 Watersheds
Applied cluster analysis to classify sites based on Applied cluster analysis to classify sites based on watershed characteristics. watershed characteristics.
Land use and age of development.Land use and age of development. Existing water-quality and benthic macro-invertebrate data.Existing water-quality and benthic macro-invertebrate data. Presence/amount of BMPs currently in watershed.Presence/amount of BMPs currently in watershed. Percent imperviousness.Percent imperviousness.
All basins < 6 miAll basins < 6 mi22..
Planned BMP implementation was considered in the final Planned BMP implementation was considered in the final site selection, but not the cluster analysis…site selection, but not the cluster analysis…
Site Selection Approach Avoid selection of sites based on best professional judgment…
Industrial
High/Medium Density Urban
Low Density Urban
Cluster Analysis for Site Selection
1
3
56
7
8
1011
12
14
15
16
18
2325
26
28
3133 3
4
353
6
37
38
394
2
43
44
45
46
48
49
50
51
53
54
55
56
57
58
59 6
16
2
63
64
65
66
676
8
69
70 71
05
10
15
He
igh
t
%_D
ET
0
5
10
15
20
25
30
1
Column 18
Variability Chart for %_DET
Variability Gauge
%_D
BM
P
0
10
20
30
40
50
60
1
Column 18
Variability Chart for %_DBMP
Variability Gauge
IBI_
aver
ag
0
10
20
30
40
50
60
70
1
Column 18
Variability Chart for IBI_averag
Variability Gauge
Pct
_IM
P
5
10
15
20
25
30
35
40
45
1
Column 18
Variability Chart for Pct_IMP
Variability Gauge
Pro
j_bm
p_m
0
5
10
15
1
Column 18
Variability Chart for Proj_bmp_m
Variability Gauge
Mea
n IB
I S
core
%_D
ET
0
5
10
15
20
25
30
1
Column 18
Variability Chart for %_DET
Variability Gauge
%_D
BM
P
0
10
20
30
40
50
60
1
Column 18
Variability Chart for %_DBMP
Variability Gauge
IBI_
aver
ag
0
10
20
30
40
50
60
70
1
Column 18
Variability Chart for IBI_averag
Variability Gauge
Pct
_IM
P
5
10
15
20
25
30
35
40
45
1
Column 18
Variability Chart for Pct_IMP
Variability Gauge
Pro
j_bm
p_m
0
5
10
15
1
Column 18
Variability Chart for Proj_bmp_m
Variability Gauge
% I
mpe
rvio
us
%_6
0
10
20
30
40
50
60
1
Column 18
Variability Chart for %_6
Variability Gauge
% M
ed D
ensi
ty R
esid
entia
l
Distribution of Basin Characteristics
Intensive SitesTrend Sites Sites Considered
Network
0 2.5 51.25 Miles ´
Frog BranchFlatlick Branch
SF Little Difficult Run
Little Difficult Run
Old Courthouse Spring Br
Captain Hickory Run
Dead Run
Popes Head Creek
Castle Creek
Indian Run
Turkeycock Run
Paul Spring Branch
Difficult Run
Upper Big Rocky Run
DIFFICULT RUN
ACCOTINK CREEK
CAMERON RUN
FOUR MILE RUN
CUB RUN
PO
PE
S H
EA
D C
RE
EK
POHICK CREEKS
UG
AR
LAN
D R
UN
DOGUE CREEK
LIT
TLE
HU
NT
ING
CR
EE
K
POND BRANCH
NIC
HO
L R
UN
PIMMIT RUN
BULL RUN
SC
OT
TS
RU
N
VA
MD
WV
Lab Analyses
Suspended Sediment USGS Sediment Lab – Louisville, KY
Suspended Sediment Concentration (SSC)
Nutrients – Fairfax County Environmental Services Lab
Nitrogen Total N Filtered TN Particulate TN Nitrate Ammonia
Phosphorus Total P Filtered TP Particulate TP Orthophosphorus
Instrumentation (Gage House)
•Sutron Accubar Bubbler SystemSutron Accubar Bubbler System
•Stage measurement systemStage measurement system
•Sutron 9210 w/ SATLINK2 Sutron 9210 w/ SATLINK2
•Datalogger/controllerDatalogger/controller
•Satellite TransmitterSatellite Transmitter
•ISCO 6712 FRISCO 6712 FR
•Refrigerated SamplerRefrigerated Sampler
•24 bottle configuration24 bottle configuration
•2 bottles per sample2 bottles per sample
Instrumentation (In-stream)
YSI 6920 Water-Quality Monitor 6136 Turbidity Sensor Temperature Specific Conductance pH
Bubbler Orifice Sampler Intake Staff Plate
Field Methods
Sampling National Field Manual for the Collection of Water Quality
Data (USGS TWRI Book 9)
Continuous Water-Quality Monitoring Guidelines and Standard Procedures for Continuous Water-
Quality Monitors: Station Operation, Record Computation, and Data Reporting: USGS TWRI 1-D3
Streamgaging USGS TWRI Book 3
Value of Continuous Water Quality Data
• Richness of continuous and real-time data allows broad application.
• Typically, few discrete samples (20 per year) are collected and used to develop water quality interpretations.• Detailed understanding of the system is almost never developed if discrete
sampling is used.
• Delay between sample collection and lab analysis may be critical.
• Time and costs associated with manual sampling are significant.
• Sampling designs for loading studies conflict with sampling designs for trend analysis.
• Estimating non-monitored constituents typically involves regressions to discharge.
• - Use water-quality data to estimate water-quality data!
Surrogate MethodsSurrogate Methods
• Continuously measure (15 min. interval) parameters related to constituent of interest (Turbidity, SC, etc.)
• Manually collect discrete samples of constituent to be estimated (sediment, dissolved solids, nutrients, etc.)
• Develop regression to estimate constituent concentrations/loads during non-sampled periods
This approach provides the ability to generate a time-series of constituent concentrations – improving
load estimations.
Methods: Surrogate Approaches
Multivariate RegressionTransformed Variables
Logarithmic Square Root
Best Subsets Regression Mallows CP, PRESS, Adj. R2
Partial Residual PlotsDuan Smearing Correction
0
100
200
300
400
500
600
700
0 100 200 300 400 500 600 700
Observed SSC (mg/L)
Es
tim
ate
d S
SC
(m
g/L
)
ε])f(xβ)...f(xβy)f(turbiditββ[fSSC kkjj ˆˆˆˆ10
1
Discontinuous Nature of Sediment TransportDiscontinuous Nature of Sediment TransportWhy not just use streamflow?Why not just use streamflow?
300 fnu450 mg/L
235 fnu350 mg/l
22,000 cfs
0
200
400
600
800
1000
0 100 200 300 400 500 600
Observed SSC
Est
imat
ed S
SC
ESTIMATOR (Study Period)
Turbidity
1:1 Line
Flow-based SSC Estimation
Turbidity-based SSC Est.
Integrate continuous water-quality monitor with autosampler to optimize sample collection
Algorithm for triggering autosampler (storm samples):- Turbidity threshold (50 FNU)
- Stage Threshold (site specific)
- Stage Rate of Change (0.1 ft in 15 min)
- Time threshold (1 sample per 30 min period)
Algorithm will be refined as needed to optimize sample collection at each site.
Technology: Turbidity Threshold Sampling
Turbidity Threshold SamplingDead Run
9/27 00:00, 2109/27 00:30, 220
9/27 01:15, 160
9/27 04:30, 90
9/27 05:00, 570
9/27 05:30, 520
9/27 06:00, 310
9/27 06:30, 250
9/27 07:00, 180
9/27 07:30, 120
9/27 15:30, 62
9/27 16:15, 180
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
9/26
12:
00
9/26
18:
00
9/27
0:0
0
9/27
6:0
0
9/27
12:
00
9/27
18:
00
9/28
0:0
0
9/28
6:0
0
9/28
12:
00
Sta
ge
(ft)
0
100
200
300
400
500
600
Tu
rbid
ity
(FN
U)
Stage
Turbidity
Sample
Google Map Data Portal (under construction)
Realtime Data
Methods
Continuous
Stage/
Q
Perio
dic S
tage/
Q
Continuous
Wat
er Q
uality
Storm
flow N
utrien
t Sam
pling
Month
ly N
utrien
t Sam
pling
Storm
flow S
uspen
ded S
edim
ent
Month
ly S
uspen
ded S
edim
ent
Annual B
enth
ic M
acro
inve
rtebra
tes
Annual F
ish
Inte
nsive
Site
s(4)
Trend
Site
s (10
)
Continuous Stage/QPeriodic Stage/QContinuous Water QualityStormflow Nutrient SamplingMonthly Nutrient SamplingStormflow Suspended SedimentMonthly Suspended SedimentAnnual Benthic MacroinvertebratesAnnual Fish
Summary of Measurements
Realtime Data Products
We have realtime water-quality data,
We are generating regressions for sediment and nutrient estimations,
We will be able to generate realtime estimates of constituent concentrations and loads!
Examples from USGS Kansas WSC…
Realtime Estimated Concentrations and Loadshttp://ks.water.usgs.gov/rtqw/
Monthly Sampling Results April through September 2008
OP
fil
0.00
0.05
0.10
0.15
0.20
BIG
RO
CK
Y R
UN
CA
PTA
IN H
ICK
OR
Y R
UN
CA
ST
LE C
RE
EK
DE
AD
RU
N
DIF
FIC
ULT
RU
N
FLA
TLI
CK
BR
AN
CH
FR
OG
BR
AN
CH
IND
IAN
RU
N
LIT
TLE
DIF
FIC
ULT
RU
N
OLD
CO
UR
TH
OU
SE
SP
R B
R
PA
UL
SP
RIN
G B
R
PO
PE
S H
EA
D C
RE
EK
TR
IB
SF
LIT
TLE
DIF
FIC
ULT
RU
N
TU
RK
EY
CO
CK
RU
N
SNAME
Variability Chart for OP fil
Variability Gauge
Ort
ho P
(m
g/L)
TP
unf
0.00
0.05
0.10
0.15
0.20
0.25
1001
purpose
Variability Chart for TP unf
Variability Gauge
OP
fil
0.00
0.05
0.10
0.15
0.20
1001
purpose
Variability Chart for OP fil
Variability Gauge
All Sites
OrthoP (mg/L)
TN
unf
0
1
2
3
4
5
6
7
BIG
RO
CK
Y R
UN
CA
PTA
IN H
ICK
OR
Y R
UN
CA
ST
LE C
RE
EK
DE
AD
RU
N
DIF
FIC
ULT
RU
N
FLA
TLI
CK
BR
AN
CH
FR
OG
BR
AN
CH
IND
IAN
RU
N
LIT
TLE
DIF
FIC
ULT
RU
N
OLD
CO
UR
TH
OU
SE
SP
R B
R
PA
UL
SP
RIN
G B
R
PO
PE
S H
EA
D C
RE
EK
TR
IB
SF
LIT
TLE
DIF
FIC
ULT
RU
N
TU
RK
EY
CO
CK
RU
N
SNAME
Variability Chart for TN unf
Variability Gauge
Tot
al N
(m
g/L)
TN
unf
0
1
2
3
4
5
6
7
1001
purpose
Variability Chart for TN unf
Variability Gauge
All Sites
Total Nitrogen (mg/L)
NO
30
1
2
3
4
5
6
7
BIG
RO
CK
Y R
UN
CA
PTA
IN H
ICK
OR
Y R
UN
CA
ST
LE C
RE
EK
DE
AD
RU
N
DIF
FIC
ULT
RU
N
FLA
TLI
CK
BR
AN
CH
FR
OG
BR
AN
CH
IND
IAN
RU
N
LIT
TLE
DIF
FIC
ULT
RU
N
OLD
CO
UR
TH
OU
SE
SP
R B
R
PA
UL
SP
RIN
G B
R
PO
PE
S H
EA
D C
RE
EK
TR
IB
SF
LIT
TLE
DIF
FIC
ULT
RU
N
TU
RK
EY
CO
CK
RU
N
SNAME
Variability Chart for NO3
Variability GaugeN
O3
0
1
2
3
4
5
6
1001
purpose
Variability Chart for NO3
Variability Gauge
All Sites
Nitrate (mg/L)
TP
unf
0.00
0.05
0.10
0.15
0.20
0.25
BIG
RO
CK
Y R
UN
CA
PTA
IN H
ICK
OR
Y R
UN
CA
ST
LE C
RE
EK
DE
AD
RU
N
DIF
FIC
ULT
RU
N
FLA
TLI
CK
BR
AN
CH
FR
OG
BR
AN
CH
IND
IAN
RU
N
LIT
TLE
DIF
FIC
ULT
RU
N
OLD
CO
UR
TH
OU
SE
SP
R B
R
PA
UL
SP
RIN
G B
R
PO
PE
S H
EA
D C
RE
EK
TR
IB
SF
LIT
TLE
DIF
FIC
ULT
RU
N
TU
RK
EY
CO
CK
RU
N
SNAME
Variability Chart for TP unf
Variability Gauge
Tot
al P
(m
g/L)
TP
unf
0.00
0.05
0.10
0.15
0.20
0.25
1001
purpose
Variability Chart for TP unf
Variability Gauge
OP
fil
0.00
0.05
0.10
0.15
0.20
1001
purpose
Variability Chart for OP fil
Variability Gauge
All Sites
Total P (mg/L)
Preliminary Data
SC
100
150
200
250
300
350
400
450
500
550
BIG
RO
CK
Y R
UN
CA
PTA
IN H
ICK
OR
Y R
UN
CA
ST
LE C
RE
EK
DE
AD
RU
N
DIF
FIC
ULT
RU
N
FLA
TLI
CK
BR
AN
CH
FR
OG
BR
AN
CH
IND
IAN
RU
N
LIT
TLE
DIF
FIC
ULT
RU
N
OLD
CO
UR
TH
OU
SE
SP
R B
R
PA
UL
SP
RIN
G B
R
PO
PE
S H
EA
D C
RE
EK
TR
IB
SF
LIT
TLE
DIF
FIC
ULT
RU
N
TU
RK
EY
CO
CK
RU
N
SNAME
Variability Chart for SC
Variability Gauge
SC
100
150
200
250
300
350
400
450
500
550
1001
purpose
Variability Chart for SC
Variability Gauge
All Sites
Specific Conductance (us/cm)
DO
2
3
4
5
6
7
8
9
10
11
BIG
RO
CK
Y R
UN
CA
PTA
IN H
ICK
OR
Y R
UN
CA
ST
LE C
RE
EK
DE
AD
RU
N
DIF
FIC
ULT
RU
N
FLA
TLI
CK
BR
AN
CH
FR
OG
BR
AN
CH
IND
IAN
RU
N
LIT
TLE
DIF
FIC
ULT
RU
N
OLD
CO
UR
TH
OU
SE
SP
R B
R
PA
UL
SP
RIN
G B
R
PO
PE
S H
EA
D C
RE
EK
TR
IB
SF
LIT
TLE
DIF
FIC
ULT
RU
N
TU
RK
EY
CO
CK
RU
N
SNAME
Variability Chart for DO
Variability Gauge
DO
2
3
4
5
6
7
8
9
10
11
1001
purpose
Variability Chart for DO
Variability Gauge
All Sites
Dissolved Oxygen (mg/L)
Challenges!!!
$$$ Access/Permission Electricity Sample collection –500+ per year Very flashy streams and dynamic channels
Additional Research in Difficult Run - USGS National Research Program
Goal: Characterize sediment and nutrient retention functions of floodplains in a developed watershed.
Floodplain sediment deposition and erosion, Floodplain topographic change, Floodplain nutrient deposition and processes, Floodplain and stream sediment geochemistry, Floodplain and suspended sediment source tracking, Streambank erosion, …
In Summary…
Fairfax County and USGS have initiated a long-term study of watershed-scale water-quality responses to BMP implementation.
Multiple technologies are being used to generate dense datasets in 14 watersheds.
Process level research on sediment/nutrient transport has been added in Difficult Run.
U.S. Department of the InteriorU.S. Geological Survey
John JastramJohn Jastram804-261-2648
Shannon CurtisShannon Curtis703-324-5211
http://va.water.usgs.gov/projects/ffx_co_monitoring.htm
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