Optimal Groundwater
Remediation Design and
Redevelopment
Teresa B. Culver
Associate Professor
Bin Zhang
Research Assistant
Dept. of Civil Engineering
University Of Virginia
Contents:
„ Introduction
„ Case Study
„ Methodology
„ Results
„ Conclusion
„ Suggestion
Objectives of study
Combine an Optimal Groundwater
Remediation Design Model with
Consideration of Reuse Benefits
„ Evaluate Optimal Remediation and
Redevelopment System using a
Field Scale Case Study
„
Overall Methodology
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Optimal Groundwater Remediation
Design
Genetic Algorithm Optimization
Simulation of Groundwater Remediation
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Integration of Reuse Costs and Benefits
Evaluation of Overall Best Net Benefits
Methodology—Remediation
Objective Function for GA:
RC = remediation cost ($);
a1:fixed capital cost per well in terms of dollars ($),
yi binary variable equal to 1 if parameter i is active
or 0 if parameter i is inactive;
N: total number of parameters to be optimized;
a2: pumping & mass removal cost ($/ft3);
Qi pumping rate of well i (ft3/d);
∆ti duration of pumping associated with parameter i (d);
P: penalty function.
Objective Function for GA
Minimize the groundwater remediation cost ($)
Well Installation Costs ($)
P= Penalty for violations ($)
Operating Costs ($)
Constraints
Maximum number of wells
Bounds on pumping rates
Concentration goal for remediation
Case Study-Emmell’s Septic Landfill
„
Location
– Galloway township, Atlantic County, NJ
Site History
„ Primary Contaminants
„
– Vinyl Chloride
– TCE
– DCE
Case Study: Emmell’s Septic Landfill,
Atlantic County, New Jersey
Groundwater Model – Grids
Row:114, Column:75
Groundwater Model -- Layers
Groundwater Model -- Parameters
Simulation Model -- Flow
Simulation Model -- Plume
Remediation Scenarios
– Long-term remediation (3000 days)
» Endpoint 10ug/L
» Endpoint 5ug/L
– Short-term remediation (1500 days)
» Endpoint 10ug/L
» Endpoint 5ug/L
Remediation Results : Short-term
Remediation Results : Short-term
Results -- Remediation
Results -- Remediation
Results -- Remediation
Methodology—Reuse
Commercial (shopping center)
„ Ecological (Pineland, grassland, wildlife)
„ Residential
„ Government
„ Agriculture
„ Recreation
„
Ecological Reuse
Costs:
Benefits
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Land acquisition
Vegetative cover
Maintenance of
vegetation
Carbon Sequestration
Wildlife habitat
Aesthetic value
Property value
Methodology—Ecological
„
Benefits
– Carbon sequestration
» Amount of C sequestered by the pine trees*
the cost of carbon dioxide pollution control
– Wildlife habitat
» Hunting
» Non-consumptive wildlife uses
– Aesthetic value
» Value of “recreational” scenery
– Property value
» Increased property value * number of properties
Commercial Reuse
Costs:
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Land acquisition
Construction
Operation &
Maintenance
Benefits
ƒ Public benefits
» Infrastructure
» Taxes
» Property values
ƒ Private benefits
» Rent and other fees
charged to vendors
based on area used
Methodology—Commercial
„ Cost
– Construction costs
» 1 year for construction
– Land acquisition
– Site improvement
– Operating costs
Methodology—Commercial
„ Benefits
– Public benefits
» Infrastructure
» Taxes
» Property values
– Private benefits
» Rent and other fees charged to vendors based
on area used
Methodology – Remediation+ Reuse
„
Remediation Cost
– Equipment and operations (included in ob.)
» Extraction, air stripping, carbon adsorption
» Media disposal, monitoring and reporting
– External cost (not included)
» Increased medical costs to the exposed human
population due to contamination
Redevelopment Cost
„ Reuse Benefits
„
Methodology – Remediation+ Reuse
Long-term remediation
Methodology – Remediation+ Reuse
Short-term remediation
Results – External Cost
Medical costs due to VOCs exposure per
person per year: 192$
„ Distance weighted Population: 5060
„ Total external cost
„
192*5060=$971,520/year
* Applied to the first 4 years form the time
remediation has started.
Total: $3.89 million
Cost and Benefit Timeline
Benefits
Year 0
20
O&M
O&M Reuse
Capital
Costs
Land Acquisition
& Construction
Medical
Costs
Total Costs
Medical Cost
Results – Reuse (Ecological)
Results – Reuse (Commercial)
Results – Remediation+Reuse
Endpoint 10ug/L
Ecological Use
Total Benefits (million $)
Commercial Use
18.000
16.000
14.000
12.000
10.000
8.000
6.000
4.000
2.000
0.000
1500days
3000days
Simulation Time (days)
Results – Remediation+Reuse
Total Benefits (million $)
Ecological
3.000
2.500
2.000
1.500
1.000
0.500
0.000
10ug/L, 1500days
5ug/L, 1500days
10ug/L, 3000days
5ug/L, 3000days
10ug/L, 3000days
5ug/L, 3000days
Total Benefits (million $)
Commercial
20.000
15.000
10.000
5.000
0.000
10ug/L, 1500days
5ug/L, 1500days
Total Benefits (million $)
Results – Remediation+Reuse
18.000
16.000
14.000
12.000
10.000
Ecological
Commercial
8.000
6.000
4.000
2.000
0.000
10ug/L, 1500days
5ug/L, 1500days
10ug/L, 3000days
5ug/L, 3000days
Conclusion
Incorporating reuse benefits when doing
remediation design is useful:
– Long-term remediation dominants short-term
remediation when redevelopment is not
considered
– Net Benefits of Short-term remediation best
– The net benefits of the high and low endpoints
are similar in this case.
– Commercial development dominants ecological
Suggestion
More research are needed to examine reuse
benefits in more detail
„ Other reuse options could be included
„ Use robust GA instead of deterministic GA
to increase the reliability of the design.
„ Improve computational efficiency of
optimal design algorithm
„