Drycleaner Site Profiles

Building 25, Morale, Welfare and Recreation (MWR) Dry Cleaners, Camp Lejeune Marine Corps Base, Camp Lejeune, North Carolina

Description
Historical activity that resulted in contamination.

Active perchloroethylene (PCE) drycleaner facility that has been in operation since the 1940s. The drycleaner used petroleum drycleaning solvent (Varsol™) until the 1970s when it was replaced by PCE. The facility is located in the industrial portion of the installation.

Contaminants
Contaminants present and the highest amount detected in both soil and groundwater.


Contaminant Media Concentration (ppb) Nondetect
cis-1,2-Dichloroethene groundwater 3,725 ppb
Tetrachloroethene (PCE) groundwater 170,000 ppb
Trichloroethene (TCE) groundwater 3,030 ppb
trans-1,2-Dichloroethene groundwater 38 ppb
No corresponding contaminant groundwater 7,100 ppb
Vinyl Chloride groundwater 4 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   85ft bgs
Plume Size:   Plume Length: 1,500ft
Plume Width: 500ft
Average Depth to Groundwater:   13ft

Lithology and Subsurface Geology

Upper Surficial Aquifer
  Very fine-grained quartz sand with lenses and discontinuous layers of clay, silt, and peat
Depth: 0-40ft bgs
40ft thick
Conductivity: 1.4ft/day
Gradient: 0.02ft/ft
 
  clay
Depth: 40-47ft bgs
7ft thick
Lower Surficial Aquifer
  Fine-grained quartz sand with varying amounts of silt
Depth: 47-62ft bgs
15ft thick
Conductivity: 65ft/day
Gradient: 0.003ft/ft
Upper Castle Hayne Aquifer
  Fine-grained quartz sand and silt with shell fragments
Depth: 62-102ft bgs
40ft thick
Conductivity: 5.1ft/day
Gradient: 0.0005ft/ft

Pathways and DNAPL Presence

checkGroundwater
Sediments
Soil
checkDNAPL Present

Remediation Scenario

Cleanup Goals:
 

Technologies

In Situ Surfactant/Cosolvent Flushing
 

Final remediation design:
Treatment Area was 20 x 30 ft. to a maximum depth of 20 ft. Treatment consisted of injecting 9,718 lb of a custom surfactant (Alfoterra 145-4-PO sulfate™ ), 38,637 lb isopropanol and 427 lb calcium chloride. 19% (1,800 lb) of the total surfactant injected was recycled. 4,800 and 4,200 gal. of water containing partition tracers (alcohols) were injected into the well field before and after the SEAR, respectively. Tracer tests required about 40 days each.

Results to date:
A mass reduction of 72% (74-88 gal) of DNAPL was achieved in the test zone. 23-29 gal remain. The pre-SEAR PITT did not sweep low permeability zone. Therefore, percent DNAPL removed (above) represents DNAPL removed from permeable zones only. Post-SEAR PITT unusable.

Next Steps:
Additional Site delineation in the intermediate and deep aquifers will occur in 2004. Building 25 will be removed in 2004 and contaminated soil removal will follow in 2004-2005. This will be followed by a Record of Decision for treatment of groundwater.

Costs

Cost for Assessment:
 
Cost for Operation and Maintenance:
 
Total Costs for Cleanup:
  Unknown. Several crews were on-site from March 15 to August 15, 1999. High-cost surfactant used. Technologies require a large number of sample analyses, laboratory bench test, and considerable computer simulation.

Lessons Learned

1. SEAR and PITT technologies are ineffective for sediments with permeability of less than 1.4 ft/day.

2. At this test, permeability reduction associated with a downward-fining depositional sequence kept the tracer and surfactants from reaching all of the DNAPL. The nature and impact of geologic contacts and/or transition zones needs to be evaluated before selecting technology.

3. An estimated 92-96% of the DNAPL swept by the surfactant flood was removed; however, the surfactant flood did not sweep a significant portion of the DNAPL.

4. There is no evidence of aquifer plugging as a result of surfactant injection.

5. Surfactant apparently biodegraded during the SEAR. Biodegradation was a result of the aquifer conditions (sulfate reducing) and the time required moving surfactant through low permeability sediments. The impact of surfactant biodegradation should be considered before applying these technologies.

6. The results of the post-SEAR PITT test were unusable apparently because surfactant degradation products sorbed on the sediment, then reacted with the tracer during the PITT.

7. The SEAR did not reduce Varsol™ contamination. Underground Injection Control regulators were told that there would be a 90% overall reduction in Varsol™. This requirement was necessary for regulatory approval of recycled surfactant re-injection.

8. Detailed borehole data (geotechnical and geologic) are needed to evaluate technologies that rely on aquifer parameters to be effective. Relying on pump and/or tracer tests without an adequate geologic model can lead to erroneous interpretations.

9. Expensive, custom-made surfactant was selected to test recycling. New surfactant had to be mixed with recycled surfactant before it could be injected. The cost-effectiveness of using recycled surfactant was not shown.

Contacts

Randy McElveen
North Carolina Division of Waste Management
(919) 733-2801

Rick Raines
Camp Lejeune Installation Restoration Program
(910) 451-9461