Region 8
Serving Colorado, Montana, North Dakota, South Dakota, Utah, Wyoming and 27 Tribal Nations
Superfund Program
National Information
Regional Information
Site Information
National Priorities List (NPL) History
Proposed Date
10/26/1989
Final Date
8/30/1990
Construction Completion Date
9/10/1999
Ellsworth Air Force Base
Click here for an interactive map |
Site Type: Completed NPL City: Ellsworth AFB County: Meade, Pennington Street Address: Ellsworth AFB Zip Code: 57706 EPA ID#: SD2571924644 Site ID#: 0800585 Site Aliases: None Congressional District: At Large |
Site Description
Ellsworth Air Force Base (the "EAFB") (the "Site") is a U.S. Air Force Air Combat Command base six miles east of Rapid City, South Dakota. It is next to the town of Box Elder. EAFB covers about 4,858 acres in Meade and Pennington Counties. The Base includes runways, airfield operations, industrial areas, housing and recreational facilities. EAFB is surrounded by farming and ranching lands, rural housing and light commercial activities.
EAFB began in July 1942 as the Rapid City Army Air Base, a training facility for B-17 bomber crews. In 1948, as part of the 28th Strategic Reconnaissance Wing, it became a permanent facility.
Historically, EAFB has been operations headquarters for a variety of aircraft, as well as the Titan I Intercontinental Ballistic Missile system and the Minuteman missile system. Presently, the 28th Bombardment Wing (B-1B bombers) is the host unit of EAFB.
A half century of military activities left contamination on the base and on private land beyond its boundaries. The Environmental Protection Agency (the "EPA") added EAFB to its National Priorities List (the "NPL") on August 30, 1990. The Air Force, EPA, and the State of South Dakota have worked as partners to clean up EAFB.
Site Risk
Studies to identify hazardous substances were conducted in 12 general areas of EAFB, including landfills, a fire protection training area, spill Sites, industrial areas, and an explosive-ordnance disposal area. The hazardous substances found most often on the Base are solvents and jet fuels, located in both soils and groundwater.
Some ground-water contaminants have moved beyond the EAFB boundary to the east and to the south at low concentrations, but above federal drinking-water standards. Continued use of the contaminated groundwater over long periods for household purposes, particularly as drinking water, could pose unacceptable health risks.
| Media Affected | Contaminants | Source of Contamination |
| Soil, sediment, surface water, groundwater | Solvents, jet fuels | Military activities |
Cleanup Progress
Construction Complete
The Air Force installed cleanup systems to address possible future health risks. Construction of cleanup systems is complete at all contaminated areas. The cleanup includes ground-water pump-and-treat systems, bio-dechlorination, landfill covers, soil treatment systems, excavation activities and natural attenuation (lessening). The systems are functioning properly.
Ground-water contamination has impacted the drinking water wells of some homes adjacent to the east and south of EAFB. The Air Force has provided potable water to these homes via water main extensions from the EAFB water-supply system. Eventually, the mains will be transferred to the City of Box Elder for operation and maintenance.
The Air Force capped landfills and has enforced institutional controls to prevent unauthorized access to those landfills and to prevent the caps from being disturbed.
Contaminated groundwater is pumped out of the ground and purified to drinking water standards. The treated water is then either discharged to a local drainage, to the EAFB wastewater treatment plant or re-injected into the aquifer.A contaminated groundwater plume extends off-site to the east. However, the plume has been stopped at the Site boundary and a gap in the plume is now evident. Natural attenuation of the remaining contamination will continue to be monitored.
These ground-water cleanup systems will be in operation for 20 to 30 years to complete the cleanup. However, treatability studies are being implemented to enhance and possibly replace current pump and treat technologiesThe relatively low levels of contamination in off-Base areas are expected to lessen within the same time frame.
Cleanup of the entire EAFB, including 20 years of groundwater treatment, is expected to cost approximately $30 million. All cleanup activities are being performed by the Air Force. EPA and the state of South Dakota provide regulatory oversight.
Five-Year Review
In September 2005, the Air Force conducted a five-year review of all remedies constructed on EAFB. EPA and the State of South Dakota reviewed and commented on the results. The primary recommendations from the 2005 Five-Year Review are:
1) Consolidate all groundwater management into one Operable Unit, OU11, base-wide groundwater
2) Continue pursuit of alternative clean-up technologies for groundwater and
3) Pursue partial deletion of portions of the base from the NPL.
All three actions are underway or completed.
All existing remedial systems require monitoring and occasional minor modifications. The EAFB environmental flight staff continue to conduct these efforts and ensure that the remedies remain protective of human health and the environment.
Community Involvement
Community interviews were held for the Five-Year Review completed in September 2000.
Site Documents
Most of the documents below are Adobe PDF documents
About PDF Documents
Five-Year Review, September 30, 2005 (PDF, 184 pages, 7.51 MB)
Note: this file takes a long time to load. Another way to download the file is to go to the Ellsworth ftp folder, right-click on the file called "EllsworthAFB5yrrev2005.pdf" (the 2005 Five-Year Review), and copy the file to a folder on your computer.
Annual Five-Year Review Update, December 2008 (PDF, 43K, 3 pages)
Contacts
|
EPA Patricia Smith John Dalton |
South Dakota Joane Lineburg |
|
View Documents at: The Administrative Record Holbrook Library The EAFB Information Repository |
Air Force Dell Peterson |