Groundwater Containment at Sites SD-29 and ST-30, Shaw AFB, South Carolina

Site Name:

Shaw Air Force Base

Location:

South Carolina

Period of
Operation:

3/95 - 2/96

Cleanup
Type:

Full-scale cleanup

Vendor:

IT Corporation

Technology:
Interim action free product recovery systems at SD-29 and ST-30. The systems used pneumatic products skimmer pumps until 1/96. At that time, passive skimmer bailers were placed in the wells to reduce operating costs. Contaminated groundwater was treated using an air stripper.

Cleanup Authority:
Installation Restoration Program

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

Contaminants:
Petroleum Hydrocarbons, Free Product (JP-4 fuel), Chlorinated Solvents

- Estimated 60 gallons of JP-4 fuel spilled at SD-29; total petroleum hydrocarbon levels up to 592 ppm in soil at ST-30
- Free product in groundwater at both sites

Waste Source:
Fuel spill and leaking supply line

Type/Quantity of Media Treated:
Groundwater and free product - A total of 102 gallons of free product were recovered

Purpose/Significance of Application:
Interim action to recover free product from groundwater

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

Results:
A total of 102 gallons of free-phase JP-4 fuel was recovered during the year the system was operated (97 gallons from ST-30 and 5 gallons from SD-29). Monthly removal rates ranged from 0 to 50 gallons of free product. By October 1995, the removal rates had decreased to below 5 gallons/month. By February 1996, the removal rate had become negligible and the system was shut down.

Cost Factors:
The capital cost for the SD-29 groundwater containment system was $394,000. Data on the capital cost for the ST-30 system were not available.
Data on O&M costs were reported as a total for both systems. The total cumulative cost for the SD-29 and ST-30 was $17,000. Monthly O&M costs ranged from $0 to $6,021. In January 1996, after removal rates had decreased, passive bailers were installed in the wells to reduce operating costs. The operating cost for February 1996 was $500.
The average O&M cost per unit of contaminant removed was $166/gallon of JP-4.

Description:
Sites SD-29 and ST-30 at Shaw AFB, located in South Carolina, were the locations of soil and groundwater contamination as a result of leaks and spills of JP-4 fuel. An estimated 60 gallons of JP-4 fuel were spilled at site SD-29 when an oil/water separator pump failed. Eighty tons of soil were excavated from the site. In addition, the groundwater was determined to be contaminated with free phase JP-4 fuel, dissolved fuel components, and dissolved chlorinated solvents. A leaking jet fuel supply line was the source of contamination at the ST-30 site. Free phase JP-4 fuel was identified in the groundwater. Interim action groundwater containment systems were installed to remove free product and prevent continued contamination of surrounding soil and groundwater. The systems were operated from March 1995 through February 1996.

The groundwater containment systems included pneumatic product skimmer pumps to recover free product. These pumps were used until January 1996, when the removal rate has decreased and the system was evaluated to determine if operating costs could be reduced. Passive skimmer bailers were then installed to reduce operating costs. The system was shut down in February 1996, after the removal rates had remained negligible for several months. During the year of operation, a total of 102 gallons of JP-4 was recovered - 97 gallons from ST-30 and 5 gallons from SD-29. Monthly removal rates ranged from 0 to 50 gallons per month.

The total capital cost for the SD-29 system was $394,000. No data on capital costs were available for the ST-30 system. Data on O&M costs were reported as a total for the SD-29 and ST-30 systems. The total cumulative costs for the year of operation was $17,000. Monthly O&M costs ranged from $0 to $6,021. The operating cost for February 1996 was $500. The average O&M cost per unit of contaminant removed was $166/gallon of JP-4.