Lecture 10
Soil vapor extraction, air sparging,
and soil flushing
Air stripper in Acton, MA. It is installed on an Acton public supply well affected by the W.R. Grace Superfund Site.
Image courtesy of Peter Shanahan.
1,1-DCE Plume in Palo Alto, California
CONCENTRATION
OF 1,1-DCE
>10,000 ppb
>1000 ppb
>100 ppb
>10 ppb
Monitoring well
Capture Zone Model
Limit of
Capture
Zone
W3
Well
Well
W6
Plume after Pump and Treat Starts
CONCENTRATION
OF 1,1-DCE
>1000 ppb
>100 ppb
>10 ppb
>1 ppb
Concentrations in Withdrawal Wells
8000
7000
1,1-DCE in W3
1,1,1-TCA in W3
1,1-DCE in W6
1,1,1-TCA in W6
Concentration (ug/L)
6000
5000
4000
3000
2000
1000
0
12/15/1987
12/14/1988
12/15/1989
12/15/1990
Concentrations in Withdrawal Wells
1000
900
Concentration (ug/L)
800
700
600
500
400
300
200
100
0
12/15/1987
12/14/1988
1,1-DCE in W3
1,1-DCE in W6
MCL for 1,1-DCE
12/15/1989
1,1,1-TCA in W3
1,1,1-TCA in W6
MCL for 1,1,1-TCA
12/15/1990
Concentrations in Pump and Treat Recovery Wells
at manufacturing facility, Hutchinson, Kansas
20000
Legend
Recovery Well 1
Recovery Well 2
MCL for TCE - 5 ug/L
Concentration of TCE (ug/L)
16000
12000
8000
4000
Concentration of TCE (ug/L)
0
6/1/93
1/1/94
6/1/94
1/1/95
6/1/95
6/1/93
1/1/94
6/1/94
1/1/95
6/1/95
1200
800
400
0
Historical Recognition of Limitations of Pump & Treat
1989 – Articles in Ground Water and ES&T question
pump and treat remediation
1989 – EPA review finds only 1 out of 19 systems
reached cleanup goals
1991 – EPA holds seminars on DNAPLs
1992 – EPA issues “Estimating Potential for DNAPLs
at Superfund Sites”
1993 – EPA issues “Technical Impracticability”
guidance
1994 – National Research Council study finds 69 out
of 77 systems did not reach cleanup
Source: U.S. EPA, 2002. Groundwater Remedies Selected at Superfund Sites. Report No. EPA-542-R-01-022. Office of Solid Waste and Emergency Response.
U.S. Environmental Protection Agency, Washington, D.C. January 2002.
Source: U.S. EPA, 2002. Groundwater Remedies Selected at Superfund Sites. Report No. EPA-542-R-01-022. Office of Solid Waste and Emergency Response. U.S.
Environmental Protection Agency, Washington, D.C. January 2002.
Soil Vapor Extraction (SVE)
Vacuum Pump
Vapor
Treatment
Unit
Vacuum Gauge
Air/Water Separator
Valve
Vapor Extraction Well
Vapor Flow
Vapor Flow
Contaminated Soil
Adapted from: Hansen Web Design, February 23, 2003. Environews. U.S. Army at Badger Army Ammunition Plant. Baraboo, WI.
http://www.badgeraap.org/environews/envmarapr99g.htm. Accessed February 27, 2003.
SVE System
See image at the Web site of Wayne Perry, Inc.,
Soil Vapor Extraction Systems,
http://www.wpinc.com/remedy/remedy30.html
Accessed May 11, 2004.
Source: Wayne Perry, Inc., undated. Soil Vapor Extraction Systems. Wayne Perry, Inc., Buena Park, CA. http://www.wpinc.com/remedy/remedy30.html. Accessed November 17, 2002.
SVE Vapor Treatment
See image at the Web site of Environmental
Support Technologies, Inc., Vapor Extraction
Vent Testing and Treatment Systems,
http://www.est-inc.com/vapext.htm
Accessed May 11, 2004.
SVE Instrumentation and Controls
See image at the Web site of Applied Hydrology
Associates, Inc., Soil Vapor Extraction, Air
Sparging, and Bioventing.
http://www.appliedhydrology.com/soil.htm
Accessed May 11, 2004.
Paulsboro, NJ Oil Terminal
See image at the Web site of Environmental
Satellite, Paulsboro, New Jersey.
http://www.paulsboroterminal.com/agrave.asp?g
et=/Paulsboro_Pipeline/Fall_1999/gis_diagram
Accessed May 11, 2004.
Paulsboro SVE System
See image at the Web site of Environmental
Satellite, Paulsboro, New Jersey.
http://www.paulsboroterminal.com/agrave.asp?g
et=/Paulsboro_Pipeline/Fall_2000/Treating_the_
Vapors
Accessed May 11, 2004.
BP Amoco, 2000. A Closer Look at Soil Vapor Extraction. Paulsboro Pipeline - Fall 2000. http://www.paulsboroterminal.com/agrave.asp?get=/Paulsboro_Pipeline/Fall_2000/Treating_the_Vapors
SVE System - Paulsboro
See image at the Web site of Environmental
Satellite, Paulsboro, New Jersey.
http://www.paulsboroterminal.com/agrave.asp?g
et=/Paulsboro_Pipeline/Fall_2000/The_SVE_Sy
stem_at_the_Paulsboro_Terminal
Accessed May 11, 2004.
BP Amoco, 2000. A Closer Look at Soil Vapor Extraction. Paulsboro Pipeline - Fall 2000.
http://www.paulsboroterminal.com/agrave.asp?get=/Paulsboro_Pipeline/Fall_2000/The_SVE_System_at_the_Paulsboro_Terminal
Air Sparging & SVE
Source: U.S. Environmental Protection Agency, undated. A Citizen’s Guide to Soil Vapor Extraction and Air Sparging. Technology Innovation Office, U.S. Environmental
Protection Agency. Washington D.C. http://www.epa.gov/swertio1/download/citizens/citsve.pdf. Accessed May 12, 2004.
Air Sparging
Concept
Air Sparging Concept
Air
Air Injection Well
Radius of Influence (ROI)
Saturated Zone
Vadose (Unsaturated) Zone
Adapted from: Sprague, Nicolle and Arnaud Delahay. Air Sparging. Groundwater Pollution Primer,
CE 4594: Groundwater and Soil Pollution. Department of Civil and Environmental Engineering. Virginia
Polytechnic Institute and State University, Blacksburg, Virginia, 1998.
www.ce.vt.edu/.../tech/gwprimer/airsparg2/airsparg.html
Moderate Air Injection
See Figure 7 in: Ji, W., A. Dahmani, D. P.
Ahlfeld, J. D. Lin and E. Hill, 1993.
"Laboratory study of air sparging: air flow
visualization." Ground Water Monitoring and
Remediation, Vol. 13, No. 4, Pp. 115-126.
High Air Injection – Uniform Medium
See Figure 8 in: Ji, W., A. Dahmani, D. P.
Ahlfeld, J. D. Lin and E. Hill, 1993.
"Laboratory study of air sparging: air flow
visualization." Ground Water Monitoring and
Remediation, Vol. 13, No. 4, Pp. 115-126.
High Air Injection – Mixed Medium
See Figure 11 in: Ji, W., A. Dahmani, D. P.
Ahlfeld, J. D. Lin and E. Hill, 1993.
"Laboratory study of air sparging: air flow
visualization." Ground Water Monitoring and
Remediation, Vol. 13, No. 4, Pp. 115-126.
Stratified Medium Setup
See Figure 13 in: Ji, W., A. Dahmani, D. P.
Ahlfeld, J. D. Lin and E. Hill, 1993.
"Laboratory study of air sparging: air flow
visualization." Ground Water Monitoring and
Remediation, Vol. 13, No. 4, Pp. 115-126.
Moderate Air Injection – Stratified Medium
See Figure 16 in: Ji, W., A. Dahmani, D. P.
Ahlfeld, J. D. Lin and E. Hill, 1993.
"Laboratory study of air sparging: air flow
visualization." Ground Water Monitoring and
Remediation, Vol. 13, No. 4, Pp. 115-126.
Air Sparging Microview
See Figure 7a in: Elder, C.
R. and C. H. Benson,
1999. "Air Channel
Formation, Size, Spacing,
and Tortuosity During Air
Sparging." Ground Water
Monitoring and
Remediation, Vol. 19, No.
3, Pp. 171.
Low pressure →
discontinuous air passage
See Figure 7b in: Elder, C.
R. and C. H. Benson,
1999. "Air Channel
Formation, Size, Spacing,
and Tortuosity During Air
Sparging." Ground Water
Monitoring and
Remediation, Vol. 19, No.
3, Pp. 171.
High pressure →
continuous air passage
Air Sparging – Bubble Movement
See Figure 5 in: Roosevelt, S. E. and M. Y. Corapcioglu,
1998. "Air bubble migration in a granular porous medium:
Experimental studies." Water Resources Research, Vol.
34, No. 5, Pp. 1131-1142.
Air Sparging Conceptual Models
See Figure 12 in: Clayton, W. S., 1998. "A Field and
Laboratory Investigation of Air Fingering During Air
Sparging." Ground Water Monitoring and Remediation,
Vol. 18, No. 3, Pp. 134-145.
Woburn
Wells G&H
Superfund Site,
Massachusetts
Source: Environmental Protection Agency, Region 1,
Waste Site Cleanup & Reuse in New England,
http://www.epa.gov/ne/superfund/sites/wellsgh/42364_
TOC_Text.pdf. Accessed May 11, 2004.
Collected Vapors
Topsoil
Treatment
System
Backfilled
Trench
Sparging Air
0
Groundwater Capture
Zone
Aerated Zone
25
Air Sparging
Well
50
Groundwater Extraction
Well
Bedrock or Compacted
Till
75
0
50
100
150
Pid Concentrations-Vapor Probes Inside Pilot Cell (Screened 0'-2')
Shallow Sparging
Test
40
80
30
60
20
40
20
10
0
0
7-1-94
21-1-94
4-2-94
18-2-94
4-3-94
18-3-94
1-4-94 15-4-94
Date
PID mean
Deep Sparging
Sparging flow rate
Vacuum Step Test
Vacuum flow rate
Comprehensive Sampling
Air Flow Rate (cfm)
Pid Concentration (total VOCs ppm-v)
100
Recovery Period
NP-1D, Groundwater-TCE
300
TCE (ug/L)
250
200
150
100
Baseline
50
0
20-10-93
17-1-94
21-1-94
07-2-94
15-2-94
21-2-94
09-3-94
Date
TCE (ug/L)
1500
Shallow Sparging Test
NP-2S, Groundwater-TCE
Comprehensive Sampling
1000
500
0
20-10-93
17-1-94
21-1-94
07-2-94
Date
Recovery Period
15-2-94
21-2-94
09-3-94