Pacific Southwest, Region 9: Superfund
Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations
EPA #: HI7210090026
City: Wahiawa, Oahu
Congressional District: 02
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Description and History
NPL Listing History
NPL Status: Final
Proposed Date: 07/14/89
Final Date: 08/30/90
Deleted Date: 08/30/00
The 17,725-acre Schofield Barracks site was established in 1908 to provide a base for the Army's mobile defense of Pearl Harbor and the entire island. Industrial operations involved maintenance, repair, painting, and degreasing, all of which required using various organic solvents. In 1985, the Hawaii Department of Health informed the Army that high levels of volatile organic compounds (VOCs) contaminated wells that supply drinking water to 25,000 people at Schofield Barracks. In 1986, the Army began removing the contaminants from the water by using an air stripping facility. Most of the area around the barracks is rain forest. Approximately 55,000 people in Wahiawa and Mililani obtain drinking water from public wells located within three miles of the base. Three miles downstream of the base is Wahiawa Reservoir, which is used to irrigate 3,000 acres of pineapple fields. The reservoir also is used for recreational activities. The site was delisted from the National Priorities List (NPL) in 2000 after the Army completed all work necessary to protect human health and the environment.
Contaminants and Risks
- Soil and Sludges
- Environmentally Sensitive Area
Groundwater contains trichloroethylene (TCE). The Army has installed treatment systems to remove TCE from the water prior to any use.
Who is Involved
This site was being addressed through Federal actions. The United States Army is the land owner and responsible party. The Army completed the cleanup under oversight from USEPA and Hawaii Department of Health. The site was deleted from the National Priorities List in 2000.
Immediate Actions: In 1986, the Army installed a groundwater treatment system, consisting of an air stripper, on four existing production wells to remove or reduce concentrations of TCE in the drinking water used at the base. The State has been monitoring the groundwater since the contamination was discovered.
Suspected TCE Sources: The Army initiated a thorough investigation of suspected TCE sources in late 1991. Based on the results of the investigation, a Record of Decision (ROD) was signed in January 1996 stating that the investigation did not locate the source. No further action is planned for this part.
Groundwater: A study of the nature and extent of groundwater contamination at the site began in late 1991. A ROD was signed in 1997 stating that wellhead treatment will continue at the currently contaminated wells and that wellhead treatment would be installed on any well that has contamination from Schofield in the future.
Non-TCE Sources: The Army completed studies of soil contamination around the base in 1996. Contaminated soil was removed from several locations and a subsequent No Further Action ROD was signed in August of 1996.
Landfills: In late 1991, the Army began a study of the presence of landfill gases and the nature and extent of contamination of the soils and groundwater. Based on the results of the study, a ROD was signed calling for regrading and vegetating the landfill cover.
The Site was delisted from the NPL in August of 2000.
The second Five-Year Review was completed in 2007, and the third Five-Year Review was completed in 2012. Site inspections showed that the landfill and groundwater remedies are functioning properly.
Cleanup Results to Date
The groundwater treatment system has reduced the potential for exposure to contamination at the Schofield Barracks site. All cleanup remedies are in-place and Schofield Barracks has been removed from the National Priorities List. Five-year reviews of the cleanup will still be conducted.
The third Five-Year Review, completed in August 31, 2012, concluded that the landfill and groundwater remedies are functioning properly,
Potentially Responsible Parties
Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.
The United States Army is the PRP.
Documents and Reports
Public Information Repositories
The public information repositories for the site are at the following locations:
Contact the Region 9 Superfund Community Relations Office.
EPA Site Manager
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
Mail Code SFD-6-3
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
P.O. Box 3378
Honolulu, HI 96801
After Hours (Emergency Response)