Pump and Treat for at OU1 and OU2 of the Marine Corps Air Station, Camp LeJeune, North Carolina

Site Name:

Camp LeJeune

Location:

Camp Lejeune, North Carolina

Period of
Operation:

OU1 - January 1995 to present
OU2 - January 1996 to present

Cleanup
Type:

Full scale

Technology:
Pump and Treat
OU1 system
- Three extraction wells; six-inch diameter stainless steel casing and wire-wrap screen; 35 feet deep
- 18 shallow monitoring wells (screened 5-25 ft deep), two intermediate wells (screened 55-75 ft deep), and two deep wells (screened 130 to 150 feet deep)
- Aboveground treatment - oil/water separation, flocculation/filtration, air stripping, and granular activated carbon adsorption; water discharged to a sanitary sewer; design flow rate - 80 gpm
OU 2 system
- Six shallow extraction wells, each 35 ft deep and four deep extraction wells ranging in depth from 101-154 ft; six-inch stainless steel casing with 10-slot wire wrap screen for shallow wells and 20-slot wire wrap screen for deep wells; shallow well pumping rate ranges from 4-8 gpm per well; deep well pumping rate ranges from 30 to 150 gpm per well
- Aboveground treatment - air stripping , filtration, and granular activated carbon adsorption; iron removal pretreatment for shallow well water; discharge to a creek

Cleanup Authority:
CERCLA
- ROD for OU1 signed September 1994; OU2 signed September 1993

Contact:
Naval Facilities Engineering Command
1100 23rd Avenue
Port Hueneme, CA 93043

Contaminants:
OU1 - PCBs, pesticides, metals, chlorinated solvents, and BTEX

OU2 - VOCs

Waste Source:
OU1 - disposal of transformer oil, wastes from pesticide mixing operations and industrial operations;

OU2 - disposal of PCBs, cleaning solvents, waste oils, used batteries, spent ammunition and other

Type/Quantity of Media Treated:
Groundwater
- OU1 - water table is 4 to 14 feet bgs; surficial aquifer extends 50 to 100 feet bgs with a transmissivity of 75 ft2/day and is unconfined; deeper water-bearing deposits comprise the Castle Hayne aquifer with a transmissivity of 4,300 to 7,300 ft2/day
- OU2 - water table is 2 to 15 ft bgs; surficial aquifer extends to 50 feet bgs with a transmissivity of 75 ft2/day; hydraulic characteristics of Castle Hayne aquifer underlying OU2 were not characterized

Purpose/Significance of Application:
Use of pump and treat system to remediate groundwater contaminated with organics and metals

Regulatory Requirements/Cleanup Goals:
OU1
- Groundwater cleanup goals - benzene (1 ug/L), 1,2-dichloroethene (70 ug/L), ethylbenzene (29 ug/L), heptachlor expoxide (0.2 ug/L), tetrachloroethene (0.7 ug/L), toluene (1,000 ug/L), trichloroethene (2.8 ug/L), vinyl chloride (0.015 ug/L), xylenes (400 ug/L), arsenic (50 ug/L), barium (1,000 ug/L), beryllium (4 ug/L), chromium (50 ug/L), manganese (50 ug/L), vanadium (110 ug/L); hydraulic control
- Effluent must meet federal and North Carolina standards prior to discharge to the sanitary sewer

OU2
- Groundwater cleanup goals - 1,2-dichloroethene (0.38 ug/L), trans-1,2-dichloroethene (70 ug/L), ethlybenzene (29 ug/L), tetrachloroethene (0.7 ug/L), trichloroethene (2.8 ug/L), vinyl chloride (0.015 ug/L), arsenic (50 ug/L), barium (1,000 ug/L), beryllium (4 ug/L), lead (15 ug/L), chromium (50 ug/L), manganese (50 ug/L), mercury (1.1 ug/L), vanadium (110 ug/L); hydraulic control
- Effluent must meet North Carolina standards prior to discharge to a creek

Results:
OU 1
- After 2.5 years of operation, cumulative mass removed - 12 pounds of total VOCs; six pounds removed during first three months of operation and six pounds removed during past 27 months - 0.22 pounds/month; monthly total VOC influent concentrations relatively low (<400 ug/L)
- Effluent from treatment plant has consistently met discharge limits; however, low hydraulic conductivity of the shallow aquifer has resulted in influent treatment plant flow rates of <9% of design capacity
OU2
- From January 1997 to March 1999, 41,000 pounds of total VOCs removed; influent VOC concentrations for deep zone show slight increase, indicating possible presence of DNAPL; influent VOC concentrations for shallow zone relatively stable
- Effluent from treatment plant has consistently met discharge limits with the exception of PCE on three occasions and mercury on two occasions

Cost Factors:
OU 1
- Average cost per pound of contaminant removed - $28,277
- Monthly O&M costs for the treatment plant were $12,300 during 1999; detailed O&M costs and system capital cost data were not available

OU2
- Average cost per pound of contaminant removed - $49
- Capital costs for the treatment plant were $4,660,000 and monthly O&M costs were $36,492 during 1999

Description:
The Marine Corps Air Station is co-located with the Marine Corps Base in Camp Lejeune, North Carolina. A ROD was signed for two operable units at the installation - OU1 consisting of three sites where pesticides, PCBs, waste oils, and other industrial waste had been disposed, and OU2 consisting of three sites where solvents, oils, spent ammunition, and other wastes has been disposed. Soil and groundwater at OU1 and OU2 were determined to be contaminated with organics and metals. The RODs specified pump and treat to remediate groundwater at these OUs.

An effectiveness evaluation for the pump and treat systems at this site was performed as part of a study by the Remedial Action Operation/Long Term Monitoring working group led by the Naval Facilities Engineering Service Center. The OU1 system has removed only 12 pounds of VOCs in 2.5 years and the treatment system is operating at less than 9% of design capacity. The OU2 system has removed more than 40,000 pounds of VOCs in a little more than two years of operation. The report includes detailed recommendations for each system.