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

>10,000 ppb

>1000 ppb

>100 ppb

>10 ppb

CONCENTRATIONOF 1,1-DCE

Monitoring well

Capture Zone ModelLimit ofCaptureZone

WellWellW6

W3

Plume after Pump and Treat Starts

>1000 ppb

>100 ppb

>10 ppb

>1 ppb

CONCENTRATIONOF 1,1-DCE

Concentrations in Withdrawal Wells

0

1000

2000

3000

4000

5000

6000

7000

8000

12/15/1987 12/14/1988 12/15/1989 12/15/1990

Con

cent

ratio

n (u

g/L)

1,1-DCE in W31,1,1-TCA in W31,1-DCE in W61,1,1-TCA in W6

Concentrations in Withdrawal Wells

0

100

200

300

400

500

600

700

800

900

1000

12/15/1987 12/14/1988 12/15/1989 12/15/1990

Con

cent

ratio

n (u

g/L)

1,1-DCE in W3 1,1,1-TCA in W31,1-DCE in W6 1,1,1-TCA in W6MCL for 1,1-DCE MCL for 1,1,1-TCA

6/1/93 1/1/94 6/1/94 1/1/95 6/1/95

0

4000

8000

12000

16000

20000

Con

cent

ratio

n of

TC

E (u

g/L)

6/1/93 1/1/94 6/1/94 1/1/95 6/1/95

0

400

800

1200

Con

cent

ratio

n of

TC

E (u

g/L)

LegendRecovery Well 1Recovery Well 2MCL for TCE - 5 ug/L

Concentrations in Pump and Treat Recovery Wellsat manufacturing facility, Hutchinson, Kansas

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 DNAPLs1992 – EPA issues “Estimating Potential for DNAPLs

at Superfund Sites”1993 – EPA issues “Technical Impracticability”

guidance1994 – 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)

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.

Air/Water Separator

VaporTreatment

Unit

Contaminated Soil

Vapor Flow Vapor Flow

Vapor Extraction Well

Valve

Vacuum Gauge

Vacuum Pump

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.htmAccessed 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.htmAccessed 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?get=/Paulsboro_Pipeline/Fall_1999/gis_diagramAccessed May 11, 2004.

Paulsboro SVE System

See image at the Web site of Environmental Satellite, Paulsboro, New Jersey. http://www.paulsboroterminal.com/agrave.asp?get=/Paulsboro_Pipeline/Fall_2000/Treating_the_VaporsAccessed 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?get=/Paulsboro_Pipeline/Fall_2000/The_SVE_System_at_the_Paulsboro_TerminalAccessed 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

Vadose (Unsaturated) Zone

Air Sparging Concept

Air

Air Injection Well

Saturated Zone

Radius of Influence (ROI)

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

Low pressure →discontinuous air passage

High pressure →continuous air passage

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.

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.

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.

Bedrock or Compacted Till

TopsoilCollected Vapors

Sparging Air Backfilled Trench

Air SpargingWell

Groundwater Extraction Well

Groundwater Capture Zone

Aerated Zone

Treatment System

750 50 100 150

50

25

0

0 0

20

40

60

80

100

7-1-94 21-1-94 4-2-94 18-2-94

Date

Vacuum Step Test

Pid Concentrations-Vapor Probes Inside Pilot Cell (Screened 0'-2')

Comprehensive SamplingDeep Sparging

Pid

Con

cent

ratio

n (to

tal V

OC

s ppm

-v)

Air

Flow

Rat

e (c

fm)

4-3-94 18-3-94 1-4-94 15-4-94

10

20

30

40

Shallow Sparging Test

Recovery Period

PID mean Sparging flow rate Vacuum flow rate

20-10-930

0

500

1000

1500

50

100

150

200

250

300

17-1-94 21-1-94 07-2-94

TCE

(ug/

L)TC

E (u

g/L)

15-2-94 21-2-94 09-3-94

20-10-93 17-1-94 21-1-94 07-2-94 15-2-94 21-2-94 09-3-94

NP-1D, Groundwater-TCE

NP-2S, Groundwater-TCE

Baseline

Shallow Sparging Test

Comprehensive Sampling

Recovery Period

Date

Date