Nov 27, 2004 - OK. â Manufacturing of telephone switching equipment. ⢠Electroplating ... Currently Oklahoma Department of ... with Cost Cap Insurance ...
Design and Implementation of a Full-Scale Enhanced Reductive Dechlorination System Matthew J. Zenker (ENSR Corporation, Raleigh, NC) Nanjun V. Shetty (ENSR Corporation, Raleigh, NC) Blair Burgess (ENSR Corporation, Florence, AL)
Presentation Outline – Background – Treatability Study – Modeling and Design – System Implementation – Results
2
Background
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Background – 292 acre property in Oklahoma City, OK – Manufacturing of telephone switching equipment
•
Electroplating operations
– One million square foot manufacturing facility – Remediation Program
• •
Formerly RCRA Currently Oklahoma Department of Environmental Quality Corrective Action Strategy pilot project
– Guaranteed Remediation Program with Cost Cap Insurance 4
– Upper alluvium – silt with clay stringers – Lower alluvium – sand – Major aquitard – shale – Groundwater velocity
•
K = 210 ft/day
1 foot/day
– Flow south/southeast
•
Sand alluvium
35 ft
Coarsening downward
Discharge into North Canadian River
Hennessey Group Shale K = 0.01 ft/day
300 ft
•
Silt alluvium K = 21 ft/day
20 ft
Geology and Hydrogeology
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Source Areas – Multiple source areas – Chlorinated ethenes
• •
PCE/TCE Daughter products
SWMU 4 SWMU 14
SWMU 3 AOC 4
Source Area 5
6
Groundwater Plume – November 2004 PCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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Groundwater Plume - November 2004 TCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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Groundwater Plume - November 2004 cis 1,2-DCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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Groundwater Plume - November 2004 Vinyl Chloride
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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Remediation Techniques – Address vadose zone and source area soils
• •
Excavation and low temperature thermal desorption Soil vapor extraction
– Reductive dechlorination processes are occurring in situ
• • •
Build up of cis 1,2-DCE Presence of vinyl chloride Limited background organic carbon
Treated 4000 tons Destroyed 10 tons VOCs
Removed 19.1 tons VOCs
– Investigate ERD processes for full-scale groundwater remediation 11
Treatability Study
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Treatability Study – Investigate ERD at three locations
• • •
Source area (TW-2) Mid-plume (MW-24) Downgradient (MW-62)
TW-2 MW-24
– Laboratory microcosms
• •
High fructose corn syrup (HFCS) Lactate
– HFCS
• • •
MW-62
Soluble Inexpensive Bulk quantity 13
10
20
30
40
50
60 50 40 30 20 10 0
60
0
20
40
Days PCE
TCE
Sulfate
cis 1,2-DCE
Downgradient (MW-62)
100
VC
Ethene
Sulfate
120
12
VOCs - M
80
Days
14
HFCS Amended
60
100 90 80 70 60 50 40 30 20 10 0 120
Sulfate - mg/L
Mid-Plume (MW-24)
70
100
10
80
8 60 6 40
4
Sulfate - m g/L
0
100 90 80 70 60 50 40 30 20 10 0
VOCs - M
Source (TW-2)
450 400 350 300 250 200 150 100 50 0
Sulfate - mg/L
VOCs - M
Treatability Study Results
No Bioaugmentation
20
2 0 0
20
40
60
80
100
0 120
Days cis 1,2-DCE
VC
Ethene
Sulfate
14
Modeling and Design
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ERD Design and Groundwater Modeling – Phase I
• •
Source Areas 98 Injection Wells
– Phase II
• •
Downgradient Coupled 3-D fate and transport model MODFLOW RT3D MT3D
•
•
Optimization (trial and error) approach for design of fullscale ERD system 169 Injection Wells Phase I IW Phase II IW
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Modeled TOC Distribution – Three Year Cycle
Shaded Area TOC > 50 mg/L
Year 2 Year 1 3 Source Source Area AreaDowngradient and 17
Natural Attenuation – Vinyl Chloride
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Implementation
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ERD Implementation – HFCS storage tank
•
6,000 gallons
– Trailer-mounted injection
HFCS Storage Tank
– Initial Dosage
• •
Bi-weekly 200-400 gallons 10-20% HFCS Injection Trailer
Phase II Wells 20
IW
MWs
Injection Troubleshooting
Preferential flow to lower aquifer
– Injection changes
• • •
Grout bottom portion of screen in some injection wells Use lower percentage of HFCS (1 to 10 percent) Inject at slower rate (gravity feed)
35 ft
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20 ft
– Difficulty achieving HFCS distribution
– Inoculation
• •
Utilize groundwater with high Dehalococcoides spp.(DHC) as inoculant for injection wells DHC = 10E+5 cell/mL (MW-24)
300 ft
– Good distribution achieved
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Results
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TOC Distribution – February 2008
> 10 ppm > 100 ppm > 1,000 ppm
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Geochemical Conditions Phase I
Phase II
35
30
EPA Screening Value
25
Strong 20
Adequate 15
10
Limited 5
Inadequate 0 0.0
0.5
1.0
1.5
2.0
2.5
3.0
Years MW-6R
TW-2
TW-4
MW-24
MW-38A
24
VOC Concentrations – Source Area (TW-2) 14
400
12
10
350
VOCs - μM
300
8
250 6
200 150
Ethene - μM
450
Phase I
500
4
100 2 50 0 0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 3.5
Years PCE
TCE
cis 1,2-DCE
VC
Ethene
25
VOC Concentrations – Downgradient Well (MW-24) 180
9 8
Phase II
10
160
140
7 120
100 5 80
Ethene μM
VOCs - μM
6
4 60 3 40
2
20
1 0 2.0
2.2
2.4
2.6
2.8
3.0
3.2
0 3.4
Years PCE
TCE
cis 1,2-DCE
VC
Ethene
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November 2004 PCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2007 PCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2004 TCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2007 TCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2004 cis 1,2-DCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2007 cis 1,2-DCE
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2004 Vinyl Chloride
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2007 Vinyl Chloride
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2004 Ethene
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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November 2007 Ethene
> 1 ppb > 10 ppb > 100 ppb > 1,000 ppb > 10,000 ppb
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Conclusions – Successful full-scale implementation of ERD using HFCS – Native bacteria
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No addition of proprietary inocula
– No additional nutrients
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Exception - baking soda
– Re-evaluation of injection operations in 2008
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Questions
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