Groundwater Containment at Site SS-07, Pope AFB, North Carolina

Site Name:

Pope Air Force Base


North Carolina

Period of

11/93 - ongoing (as of 4/98)
Data reported through November 1996


Full-scale cleanup


Parsons Engineering Science

Free product recovery system consisting of a dual pump recovery system with one free product cut-off trench. JP-4 was recovered using pneumatic skimmer pumps and stored in a product recovery tank. The system operates at an average flow rate of 1 gallon per minute (gpm).

Cleanup Authority:
Installation Restoration Program

Regulatory Point of Contact:
Information not provided.
Additional Point of Contact:
U.S. Air Force Air Combat Command

Volatile Organic Compounds (VOCs), free product (JP-4 fuel) -
- VOCs in soil detected as high as 1,000 ppm
- 75,000 gallons of JP-4 fuel estimated to be floating on groundwater

Waste Source:
Fuel Spill

Type/Quantity of Media Treated:
Groundwater - Groundwater is encountered between 22.5 and 27 feet below ground surface.

Purpose/Significance of Application:
Recovery of free product using active pumping

Regulatory Requirements/Cleanup Goals:
The operational objective of the free product recovery was to remove liquid-phase contamination as quickly and cost-effectively as possible to prevent continued contamination of surrounding soil and groundwater.

Data on system performance were available for the first three years of operation (through November 1996). The total amount of JP-4 product recovered during this time was 3,516 gallons. Monthly removal rates ranged from 1 to 340 gallons.

Cost Factors:
The capital cost for the system was $394,000. The total cumulative O&M costs from November 1993 through November 1996 was $96,200. According to the report, accurate month-to-month O&M data were not available; however, the average monthly O&M costs were reported as $2,600. After three years of operation, the average O&M costs per unit of contaminant removed was $27.36/gallon of JP-4.

Site SS-07, the Blue Ramp Spill Site, is located at the Pope AFB in North Carolina. Soil and groundwater at the site were contaminated with JP-4 fuel and VOCs. VOC concentrations as high as 1,000 ppm were detected in the vadose zone at the site, and the areal extent of the soil vapor plume was estimated to be 25 acres. Dissolved VOCs were detected in the groundwater and an estimated 75,000 gallons of free product was floating on the groundwater. In November 1993, a free product recovery system were installed at the site to recover JP-4 fuel.

The groundwater free product recovery system was a dual pump recovery system with one free product cut-off trench. JP-4 is recovered with pneumatic pumps and stored in a product recovery tank. The trench was extended in 1993 and again in 1995. The system was operational at the time of this report (April 1998) and is expected to operate for 40 years. Data on cost and performance are available for the first three years of operation (through November 1996). During this time, 3,516 gallons of JP-4 fuel was recovered, with the monthly removal rates ranging from 1 to 340 gallons. The report includes a graph of JP-4 recovered versus time. After April 1995, the curve began to flatten, indicating that the removal rate for the system is slowing. According to the report, it is recommended that the system be evaluated to determine how to increase product removal.

The total capital cost for this system was $394,000. The total O&M costs through November 1996 were $96,200. Although accurate monthly O&M costs were not available, the average monthly O&M cost was $2,600. The average O&M cost per unit of JP-4 fuel recovered was $27.36 per gallon.