1. Air and Ozone Sparging of TCE Using a Directionally Drilled Horizontal Well Site 86, Camp Lejeune
Mark Strong, P.E. CH2M HILL
Christopher Bozzini, P.E. CH2M HILL
Daniel Hood, NAVFAC Mid-Atlantic
Bob Lowder, MCB Camp Lejeune EMD

2. Camp Lejeune Background
Second largest U.S. Marine Corps Base in the Country
Camp Lejeune was established near the city of Jacksonville, N.C, in 1942.
Base covers 236 square miles
CERCLA site since 1989
22 Operable Units (OUs), 97 Sites.

3. Site Location and History
Site 86 is associated with three former waste oil ASTs, used during the 70s and 80s
Over the course of several investigations since 1992, the solvent plume migrated away from the source area and now extends several hundred feet off-site
Bld. 25

4. Prevent further migration of the TCE plume off-site
Pilot Test Objectives
Prevent further migration of the TCE plume off-site
Evaluate air (and ozone) distribution using a horizontal well
Determine if ozone and/or air sparging can reduce TCE impacts to below regulatory standards within one year

5. TCE in Plume in 2002 (30-35’ bgs)

6. TCE in Plume in 2002 (40-45’ bgs)

7. TCE in Plume in 2002 (50-55’ bgs)

8. Site 86 Cross Section

9. Directional Drill Rig On-Site

10. Air Sparge ‘Screen” 0.020 Inch Wide Slots 0.5% Open Area
4” SDR 11 HDPE Pipe
0.020 Inch Wide Slots
0.5% Open Area

11. Directional Sparge Well Layout
Total Length of Drill = 950’
Total Slotted Length - 350’

12. Compressor and Ozone Generator Temporary Buildings (Connex Boxes)

13. Ozone Generator Chiller

14. Air Compressor, Receiver, Gas Cooler

15. Ozonia Generator (CFV-03, 60 ppd, air feed)
Photo courtesy Ozonia North America

16. Baseline TCE Concentrations, Feb ‘05 30-35 ft bgs

17. Baseline TCE Concentrations, Feb ‘05 40-45 ft bgs

18. Baseline TCE Concentrations, Feb ‘05 50-55 ft bgs

19. Three Months of Air Sparging (120-140 cfm)
Schedule
Three Months of Air Sparging ( cfm)
One Month of “Rebound” Monitoring
Six Months of Ozone Enhanced Air Sparging (~ 7000 ppmv)
Three Months of “Rebound” Monitoring (Recently Completed)

20. Ozone Injection Performance
Ozone production began in late July, 2005
Intermittent operation from July to December
Mechanical issues: desiccant dryer and chiller
Total aggregate run time ~ 2-1/2 months (50% up time)
Total mass of ozone delivered ~ 3900 pounds

21. Average TCE Concentrations Zone “A” Monitoring Wells (30-35’ Screen Depth)

22. Average TCE Concentrations Zone “B” Monitoring Wells (40 - 45’ Screen Depth)

23. Average TCE Concentrations Zone “C” Monitoring Wells (50 - 55’ Screen Depth)

24. Discussion
SVE was not conducted because of low permeability overburden; trace levels of TCE measured in shallow vapor during operation (ppbv)
Air was diverted horizontally by overburden; air bubbling was observed 300 feet from the well
Lateral propagation of air “fingering” was estimated to be 50 feet on either side of the well, as indicated by dissolved oxygen concentrations
Negligible increases in dissolved chloride from baseline levels

25. Conceptual Model

26. Example Dissolved Oxygen and ORP Trend

27. Summary of Analytical Data

28. Conclusions
90% average reduction of TCE within three months in wells with baseline TCE > 50 μg/L
99% average reduction within one year in wells with baseline TCE > 50 μg/L
No significant rebound after three months (greater than 25 µg/L)
Distance of influence ~ 50 ft on both sides of the well (as indicated by DO measurements)
Possible contribution of ozone to TCE mass reduction inconclusive - low TCE concentrations and limited period of operation

29. Horizontal Well, Compressed Air System, Container, Electrical ~ $250K
Summary of Costs
$750K Total Budget
Horizontal Well, Compressed Air System, Container, Electrical ~ $250K
Ozone System and Container ~ $300K
Monitoring ~ $100K
O&M ~ $100K