Date post: | 26-Dec-2015 |
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Data Needs
• Land Use/Land Cover map in GIS• Watershed model
– Internal model in SUSTAIN– External model (Examples: HSPF, SWMM)
• BMP types, design configurations, costs• Instream targets
$0.0 $10.0 $20.0 $30.0 $40.0 $50.0 $60.0 $70.0 $80.0 $90.0
-10%
0%
10%
20%
30%
40%
50%
60%
All Solutions
Cost-Effectiveness Curve
Selected Solution
Cost ($ Million)
Effe
ctiv
en
ess
(%
Re
du
ctio
n)
Cost-Effectiveness Optimization
Cost in Millions of Dollars
Effec
tiven
ess
(%Re
ducti
on)
0
0.0
24
81
61
8
0.0
85
47
79
4
0.0
85
47
79
4
0.1
95
77
20
6
0.2
06
80
14
7
0.2
44
48
52
9
0.2
45
40
44
1
0.3
29
96
32
4
0.3
29
96
32
4
0.3
67
64
70
6
0.3
67
64
70
6
0.3
98
89
...
0.4
12
68
38
2
0.4
25
55
14
7
0.4
36
58
...
0.4
39
33
82
4
0.4
66
91
...
0.4
88
97
...
0.5
10
11
...
0.5
38
60
29
4
0.5
46
87
...
0.5
47
79
41
2
0.5
48
71
32
4
0.5
48
71
32
4
0.5
49
63
...
0.5
49
63
...
0.5
50
55
14
7
$0.0
$5.0
$10.0
$15.0
$20.0
$25.0POROUSPAVEMENTBIORETENTIONRAINBARRELWETPONDCISTERNSeries6
Effectiveness (% Reduction)
Co
st (
$ M
illio
n)
Cost-Effectiveness Optimization
Effectiveness (%Reduction)
Cost
in M
illio
ns o
f Dol
lars
30%
63%
7%
SUSTAIN Aggregate BMPs• On-site interception
– Rain barrel– Cistern– Green roof
• On-site treatment– Bioretention– Porous pavement– Infiltration trench
• Routing attenuation– Vegetative swale– Conduit
• Regional storage/treatment– Wet Pond– Dry Pond
50 gallon rain barrel$220 unit cost including construction$ 85.40 per yr I&E O&M assumed negligible
Total Present Value unit cost = $1,533
~3,000 gallon cistern$1,600 unit cost including construction$ 85.40 per yr I&E O&M assumed negligible
Total Present Value unit cost = $2,913
Residential On-site Detention Facilities
30-yr lifecycle cost assuming 5% discount rate
Bioretention Facilities
1 Unit is 100 ft2
$20/ft2 Design, permitting, and construction
Rain Garden$ 1.10/ft2-yr O&M$213.50 per yr I&ETPV cost = $69.73/ft2
Roadside Bioretention$ 1.10/ft2-yr O&M$170 per yr I&ETPV cost = $63.04/ft2 30-yr lifecycle cost assuming 5% discount rate
Porous Parking Areas
1 Unit is 100 ft2
$ 20/ft2 design, permitting, andconstruction$ 0.02/ft2 O&M$427.00 per yr I&E
TPV = $85.95/ft2
30-yr lifecycle cost assuming 5% discount rate
Detention Pond
1 Unit is ~13,000 ft3
$ 3.43/ft3 construction cost$ 1.20/ft3 design and permitting$ 0.01/ft3 O&M
TPV Cost = $ 25.81/ft2
or $ 4.78/ft3
Land cost = $18.25 ft230-yr lifecycle cost assuming 5% discount rate
Objectives
• Documentation– BMPs to be considered and associated treatment trains– BMP designs used in SUSTAIN– Cost assumptions used in model– Methods used to estimate road, rooftop and parking areas– Application of hydrologic target used in model– Extrapolation methods to biological and water quality
improvements• Describe general approach for expanding modeling
effort beyond pilot catchment
Pilot Catchment Scale Study
Green-Duwamish River Watershed Quality Assessmenthttp://www.kingcounty.gov/environment/watersheds/green-river/watershed-quality-assessment.aspx
SUSTAIN Aquifers
Effective Impervious HRUs Pervious HRUs
Aggregate BMP
BMP Aquifer (Aquifer 1)
Pervious Aquifer(Aquifer 2)
AssessmentPoint
Surface Runoff
Pervious Subsurface FlowBMP Infiltration
BMP Outlet FlowRelease from BMP Aquifer
Release from Pervious Aquifer
Evaporation Loss
Till Scenarios
Treatment TrainOn-site
Detention Pervious TreatmentAquifer Recession Coefficient (/hr)
Green Rain Barrel 0 0Green Rain Barrel 0 0.1Green Rain Barrel 80 0Green Rain Barrel 80 0.1Green Cistern 0 0Green Cistern 0 0.1Green Cistern 80 0Green Cistern 80 0.1
Green + Gray Rain Barrel 0 0Green + Gray Rain Barrel 0 0.1Green + Gray Rain Barrel 80 0Green + Gray Rain Barrel 80 0.1Green + Gray Cistern 0 0Green + Gray Cistern 0 0.1Green + Gray Cistern 80 0Green + Gray Cistern 80 0.1
0%10%20%30%40%50%60%
%Effectiveness
0%10%20%30%40%50%60%
%Effectiveness
Rain Barrels Cisterns
EIA only +80% P EIA only +80% P EIA only +80% P EIA only +80% P
Rain Barrels Cisterns
$0.0
$5.0
$10.0
$15.0
$20.0
TPV Cost in $M
$0.00
$5.00
$10.00
$15.00
$20.00
TPV Cost in $M
Green + Gray on Till Scenarios
$0
$5
$10
$15
$20Detention Pond
Roadside Bioretention
Porous Parking
Rain Garden
Onsite Detention
BMP Cost BreakdownGreen+Gray Treatment Train on Till
Rain Barrels Cisterns
EIA only +80% P EIA only +80% P
$0
$5
$10
$15
$20
Private Capital
Public Capital
O&M
I&E
Green+Gray on Till Cost Breakdown
Rain Barrels Cisterns
EIA only +80% P EIA only +80% P
$0.0 $10.0 $20.0 $30.0 $40.0 $50.0 $60.0 $70.0 $80.0 $90.00
2
4
6
8
10
12
14
16
18
All Solutions
Cost-Effectiveness Curve
Selected Solution
Cost ($ Million)
Hig
h P
uls
e C
ou
nt
In terms of High Pulse Count
$0.0 $10.0 $20.0 $30.0 $40.0 $50.0 $60.0 $70.0 $80.0 $90.015%
20%
25%
30%
35%
40%
45%
50%
55%
All Solutions
Cost-Effectiveness Curve
Selected Solution
Cost ($ Million)
%M
axi
mu
m B
-IB
IIn terms of Log-Linear Regression Model
relating HPC to B-IBI
$0.0 $2.0 $4.0 $6.0 $8.0 $10.0 $12.0 $14.0 $16.0 $18.0 $20.015%
25%
35%
45%
55%
65%
75%
All SolutionsCost-Effectiveness CurveSelected Solution80% UCL80% LCL
Cost ($ Million)
%M
axi
mu
m B
-IB
IIn terms of %ofMaximum B-IBI including
uncertainty bounds (80% CL)
Water Quality Extrapolation
• SUSTAIN model includes TSS• Extrapolate to turbidity, Cu and Zn using 95%
Upper CL regression equations• Calculate TSS, Total Cu and Total Zn load
reductions• Calculate frequency of exceedance of
turbidity, Dissolved Cu and Dissolved Zn standards
Water Quality ExtrapolationSelected “Best” of Best Scenarios
• Up to ~80% reduction in TSS loads• Copper and Zinc loads reduced 30-40%• Frequency of exceedance of turbidity standard
reduced ~85%• Copper was not predicted to exceed standards
under current conditions• A low frequency of exceedance of the Zn
standard was effectively eliminated
Conclusions
• A variety of BMP treatment systems can meet similar targets at a variety of costs
• Generally, Green+Gray treatment trains performed better than Green only
• Effectiveness is highly dependent on assumptions regarding the fate of BMP infiltration
Recommendation
• Extend catchment modeling approach to a number of other catchments with relatively homogeneous land use/land cover