Alternative Landfill Capping at Marine Corps Base Hawaii, Kaneohe Bay, HI

Site Name:

Marine Corps Base Hawaii

Location:

Marine Corps Base Hawaii, Kaneohe Bay, HI

Period of
Operation:

Installed in 1994 to ongoing (data available for first 16 months of operation)

Cleanup
Type:

Field demonstration

Technology:
Containment - Alternative Landfill Cap
- Soil-based evaporaranspiration (ET) cap with engineered structures that limited infiltration of precipitation
- Three infiltration designs tested: 20% enhancement of runoff, 40% enhancement of runoff, and conventional ET cap (control)
- Rainfall exceeds 25 inches per year at demonstration site

Cleanup Authority:
RCRA

Navy Contracts:
Mr. Charles Reeter
Naval Facilities Engineering
Service Center
Phone: (805) 982-4991
E-Mail reetercv@nfesc.navy.mil

Mr. Jeff Heath
Naval Facilities Engineering
Service Center
Phone: (805) 982-4991
E-Mail reetercv@nfesc.navy.mil

Contaminants:
Not identified

Waste Source:
Not identified

Type/Quantity of Media Treated:
Soil

Purpose/Significance of Application:
Demonstration of evapotranspiration landfill caps as alternatives to conventional RCRA covers

Regulatory Requirements/Cleanup Goals:
- Purpose of the demonstration was to demonstrate the effectiveness of alternative caps

Results:
- After 16 months of operation, the relative amount of percolation, as a percentage of precipitation, averaged 2 percent for the ET cap plus enhanced runoff plots and 5% for the conventional ET cap

Cost Factors:
- Estimated capital costs for ET covers were $50,000 - $100,000 per acre
- Estimated capital costs for ET covers were lover than RCRA C or RCRA D caps and estimated to have lower operation and maintenance costs that conventional RCRA caps

Description:
A demonstration was conducted at Marine Corps Base Hawaii, Kaneohe Bay to determine the effectiveness of ET caps as alternatives to conventional RCRA caps. Three demonstration caps were installed in 1994 - a conventional ET cap to serve as a control, an ET cap with 20% runoff control, and an ET cap with 40% runoff control. The performance of the designs were evaluated by comparing the field monitoring data with the predicted performance of the RCRA design using the EPA HELP model.

After 16 months, percolation rates (as a percentage of precipitation) averaged 5% for the control ET cap, and 2% for the ET cap plus runoff control plots, supporting the concept of infiltration control by increasing runoff and reducing percolation. The estimated capital costs for an ET cap were $50,000 - $100,000 per acre, lower than the estimated costs for conventional RCRA caps. In addition, the operation and maintenance costs for ET caps was expected to be lower than for conventional RCRA caps.