in situ soil mixing and injection using large diameter...

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Joint Services Environmental Management Conference

May 21-24, 2007Columbus, OH

In Situ Soil Mixing and InjectionUsing

Large Diameter Auger

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Presented by:

Purshotam K. Juriasingani, P.E.Tetra Tech, Inc.

800 Oak Ridge TurnpikeOak Ridge, Tennessee 37830

In Situ Soil Mixing and Injection Using


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Contributing Authors

Purshotam K. Juriasingani, P.E.Mike Higgins, P.E.

(Tetra Tech, Inc., Oak Ridge, TN)

Mark Kershner (United States Air Force, Installation Restoration

Program, 45 CES/CEVR, PAFB, FL)

In Situ Soil Mixing and Injection Using


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Contents

ObjectiveSite InformationTechnologyData Collection Real Time DecisionsTreatment EffectivenessSummary & Conclusion

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Objective

Present the technology for the treatment of a dense non-aqueous phase liquid (DNAPL) source area through “in-situ soil mixing, with steam, hot air, and zero valent iron (ZVI) injection using large diameter auger (LDA)”

Evaluate the Effectiveness of the technology for the removal/treatment of VOC’s/DNAPL from the subsurface

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Site Information

Location: Cape Canaveral Air Force Station, Florida

Facilities

Security Police Confidence Course (SPCC)

Ordnance Support Facility (Facility 1381)

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Site Information (cont.)Security Police Confidence Course (SPCC)

Site currently used as an obstacle course for security forces. Disposal activities from former facilities /operations resulted in GW contamination.

Rocket Propellant and Chemical Storage Rocket Assembly Chemical Cleaning Lab

Contaminants: TCE and breakdown products Estimated DNAPL Source Area is 0.2 acre

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Site Information (cont.)Ordnance Support Facility (Facility 1381)

Since 1977 the facility was used as an ordnance support facility for the U.S. Coast Guard Disposal activities from past facility operations resulted in GW contamination

Metals Cleaning LabTanker Truck Waste Disposal

Contaminants of Concern: TCE and breakdown products Estimated DNAPL Source Area is 1.0 acre

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Technology

The technology consists of the following major elements:

Soil Mixing and Vapor Collection System

Off-gas Treatment System

Vapor Conditioning System

VOC Treatment System

Supervisory Control and Data Acquisition (SCADA) System

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Technology (cont.)

Soil Mixing and Vapor Collection SystemEquipped with 8-foot diameter auger with ½-inch injection ports along two blades for a total of 14 ports Shears and mixes the soil as the auger advances below the ground surface while injecting hot air and steamCauses thermal desorption and volatilization of the VOCs from soil particles and interstitial spaces Hot air helps carry the volatilized contaminants to the surfaceHot air and contaminants are captured in a containment shroud located at the surface operated under a vacuum

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Treatment Effectiveness (cont.)

Auger

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Crane

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Technology (cont.)

Off-gas Treatment SystemVapor Conditioning System (VCS)

Blower provides for the transport of vapor from the shroud to the VCS and through the treatment system

The VCS consists ofLiquid Vapor knock-out (KO)/demister tank

Course particulate filter (20 microns)

Chiller (To cool the gas temperature from approximately 170oF to less than 100oF)

Reheater (To raise the temperature by 10oF to 12oF to reduce the relative humidity to 80% , and

Particulate filter (< 1 micron)

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VOC mass in Performance Test Cell

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Technology (cont.)

VOC Treatment System

The conditioned vapor stream consisting of VOC’s is treated by the Flameless Thermal Oxidizer (FTO).

The FTO primarily includes The oxidizer (off-gas burns at 1700ºF)

Integral quench chamber (cool off-gas to 180°F)

Acid gas scrubber (remove the HCl gas from the vapor stream effluent prior to discharge into the atmosphere).

GAC absorption vessels were used for backup treatment purposes when the FTO was shut down

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Flameless Thermal Oxidizer

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Technology (cont.)

Supervisory Control and Data Acquisition SystemThe SCADA system allow effective coordination and control of various process parameters in the treatment trainCollects and Stores data The SCADA system helps in making real time decisions

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SCADA System

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Data Collection

Data CollectionField Instruments

Process Equipment

Gas Chromatographs (GC’s)Used to speciate the contaminants for decision making in the field

Also used for post treatment mass removal estimates.

Flame Ionization Detectors (FID’s)FID is used to collect instantaneous total VOC measurements from the off-gas stream.

Gives an instant gross estimate of where and how much contamination is present at a certain depth.

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Data Collection

The SCADA system integrates FIDs, GCs, and other instruments

The SCADA system collects and stores data in SQL Server Database for

Reporting

Trending

Analysis

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Data Collection (cont.)

Sample Conditioning System

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Gas Chromatographs

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Flame Ionization detector

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GC Software

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Real Time Decisions

Data from the FIDs and GCs were used to determine trends in depth, concentration, and location of contamination requiring treatment.

Identified data trends in contamination and enabled on-site field personnel and managers to make real-time decisions on treatment.

Real Time DecisionsDeeper Contamination Treatment

Expansion and Deletion of Cells

Additional Thermal Treatment Time

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Real Time Decisions (cont.)

Planned and Modified SPCC Treatment Area

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Treatment Effectiveness

Used "Multiple Lines of Evidence" to evaluate Treatment Effectiveness

Evaluation of Several Re-Treated Cells Total Mass RemovedPre and Post Treatment Sampling Comparison.

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SPCC

Performance Test Cell Location

Evaluation of VOC reduction in previously treated area


29VOC mass in Performance Test Cell


BB15BC14

BC16BC04

PCE

TCE

Cis-1,2-DCE

6.498

3.817 5.988

0.004

45.770

12.485 15.070

0.005

6.467

1.9482.299

0.000

0.000

5.000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

50.000

Mass (lbs)

Cell ID

Contaminants

Performance Test Cell (BC04) in the Cell Area Between B15, BC14 abd BC16

PCETCE Cis-1,2-DCE

30Total Mass Removed From SPCC


Contaminants PCE TCE Cis-1,2DCE

Trans-1,2-DCE VC Freon 113 Benzene Toluene Ethyl

benzene1,1-DCA 1,1,1-TCA

Mass (lbs) 37.97 173.05 176.52 0.427 0.47 0.38 0.000 0.001 0.000 0.093 0.088

Percent ofTotal Mass for SPCC

9.76 44.49 45.38 0.11 0.12 0.10 0.00 0.00 0.00 0.02 0.02

SPCCVOC Mass Removal (389 lbs)

31TCE Mass Removed Per Cell


SPCCMass and Concentration Profiles

32TCE Mass Removed in 15 Feet Intervals


33Profile Location


34TCE Max Concentration Per Foot (A-A’)


35TCE Max Concentration Per Foot (B-B’)


36TCE Mass Removed Per Foot (A-A’)


37TCE Mass Removed Per Foot (B-B’)


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SPCCComparison of baseline and post-remediation concentrations in soil & GW

Baseline and Post-remediation Sample Locations


39Comparison of Baseline and Post-remediation TCE in Soil


40Comparison of Baseline and Post-remediation TCE in GW


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Facility 1381

Performance Test Cell Location

Evaluation of VOC reduction in previously treated area


42Performance Test Cell Location


43BQ43 and BQ43 Retreatment-TCE Concentration vs. Depth

Treatment Effectiveness (cont.)TCE a nd D e pt h

B Q4 3

0 . 0

5 0 0 0 . 0

10 0 0 0 . 0

15 0 0 0 . 0

2 0 0 0 0 . 0

2 5 0 0 0 . 0

3 0 0 0 0 . 0

3 5 0 0 0 . 0

T ime

0 . 0

10 . 0

2 0 . 0

3 0 . 0

4 0 . 0

5 0 . 0

6 0 . 0

7 0 . 0

T CE- BQ4 3

DEPT H- BQ4 3

TCE a nd De pt hB Q4 3 Re t r e a t me nt ( AX4 3 )

0 . 0

10 . 0

2 0 . 0

3 0 . 0

4 0 . 0

5 0 . 0

6 0 . 0

7 0 . 0

T ime

0 . 0

10 . 0

2 0 . 0

3 0 . 0

4 0 . 0

5 0 . 0

6 0 . 0

7 0 . 0

T CE- AX4 3

DEPT H- AX4 3

44BQ43 and BQ43 Retreatment-Cis-1,2-DCE Concentration vs. Depth

Treatment Effectiveness (cont.)C i s- 1, 2 - D CE a nd De pt h

B Q4 3

0 . 0 0 0

5 0 0 . 0 0 0

10 0 0 . 0 0 0

15 0 0 . 0 0 0

2 0 0 0 . 0 0 0

2 5 0 0 . 0 0 0

3 0 0 0 . 0 0 0

T ime

0 . 0

10 . 0

2 0 . 0

3 0 . 0

4 0 . 0

5 0 . 0

6 0 . 0

7 0 . 0

Cis- 1, 2 - DCE- BQ4 3

DEPT H- BQ4 3

C i s- 1, 2 - D CE a nd De pt hB Q4 3 Re t r e a t me nt ( AX4 3 )

0 . 0 0 0

10 . 0 0 0

2 0 . 0 0 0

3 0 . 0 0 0

4 0 . 0 0 0

5 0 . 0 0 0

6 0 . 0 0 0

7 0 . 0 0 0

T ime

0 . 0

10 . 0

2 0 . 0

3 0 . 0

4 0 . 0

5 0 . 0

6 0 . 0

7 0 . 0

Cis- 1, 2 - DCE- AX4 3

DEPT H- AX4 3

45BQ43 and BQ43 Retreatment-TCE Concentration vs. Depth

Treatment Effectiveness (cont.)TCE vs. Depth (BQ43 and BQ43 Retreatment)

0.0

200.0

400.0

600.0

800.0

1000.0

1200.0

1400.0

1600.010

:29:

53

10:3

7:29

10:4

5:05

10:5

2:41

11:0

0:17

11:0

7:53

11:1

5:29

11:2

3:05

11:3

0:41

9:13

:08

9:20

:44

9:28

:20

9:35

:56

9:43

:32

9:51

:08

9:58

:44

10:0

6:20

10:1

3:56

10:2

1:32

10:2

9:08

10:3

6:44

Time

Con

cent

ratio

n (p

pm)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

TCEDEPTH

BQ43 BQ43 Retreatment

Iron

Iron Pass

Thermal

Iron Thermal

TCE vs. Depth (BQ43 Retreatment)

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

9:10

:27

9:14

:45

9:19

:03

9:23

:21

9:27

:39

9:31

:57

9:36

:15

9:40

:33

9:44

:51

9:49

:09

9:53

:27

9:57

:45

10:0

2:03

10:0

6:21

10:1

0:39

10:1

4:57

10:1

9:15

10:2

3:33

10:2

7:51

10:3

2:09

10:3

6:27

10:4

0:45

Time

Con

cent

ratio

n (p

pm)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

TCEDEPTH

Thermal Pass Iron Pass

Thermal Pass

BQ43 Retreatment

46VOC mass in Performance Test Cells (BQ43, BS44, and BQ45)


BQ43BQ43

Retre

atmen

t

BS44BS44

Retr

eatm

ent

BQ45BQ45

Retre

atmen

t

TCE

Cis-1,2-DCE

Total VOC Mass

309.92

0.52

259.19

0.40

409.87

0.66

19.48

0.12 17.830.09 18.20

0.14

274.37

0.03

220.68

0.03

364.75

0.23

0

50

100

150

200

250

300

350

400

450

Mass (lbs)

Cell ID

Contaminants

Mass Removal Comparison after Retreatment - BQ43, BS44, and BQ45

TCE Cis-1,2-DCETotal VOC Mass

47Total Mass Removed From Facility 1381


Contaminants PCE TCE Cis-1,2DCE

Trans-1,2-DCE VC Freon 113 Benzene Toluene Ethyl

benzene1,1-DCA 1,1,1-TCA

Mass (lbs) 1.318 9400.23 1229.51 2.72 108.38 616.46 0.00 0.88 0.003 9.489 31.71

Percent ofTotal Mass for SPCC

0.01 82.45 10.78 0.02 0.95 5.41 0.00 0.01 0.00 0.08 0.28

Facility 1381VOC Mass Removal (Up to 05/03/2007 - 11,401 lbs)

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Treatment at Facility 1381 is ongoingTreatment expected to be complete at the end of May

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Summary & Conclusions

In-situ soil mixing, with steam, hot air, and zero valent iron (ZVI) injection using large diameter auger (LDA) is an effective technology for the removal/treatment of VOCs/DNAPL from Subsurface

SPCCNumber of Cells Treated – 157

Total Volume - 9,000 cu. yds.

Total VOC Removed – 389 lbs.

Site 1381 (Up to May 03, 2007)Number of Cells Treated – 659

Total Volume – Approximately 36,000 cu. yds.

Total VOC Removed– 11,401 lbs.

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Acknowledgements

Project Team

United States Air Force, Installation Restoration Program, 45 CES/CEVR, PAFB, FLAir Force Center For Environmental Excellence, Brooks City-Base, TXEnvironmental Protection AgencyFlorida Department of Environmental Protection

SubcontractorsCORE Engineering & Construction, Inc.Florida Environmental Compliance CorporationKB Labs

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