Region 8

Hill Air Force Base

Hill AFB site location map Site Type: Federal Facility Final NPL
City: Hill Air Force Base
County: Davis, Weber
Street Address: 00-ALC/EM
ZIP Code: 84056
EPA ID: UT0571724350
SSID: 0858
Site Aliases: Hill AFB
Congressional District: 1

Site Description

Hill Air Force Base has been active since the early 1940s. It is located in northern Utah, about 30 miles north of Salt Lake City. Covering 6,670 acres, the base lies in two counties, on a plateau roughly 300 feet above the valley floor. The base is surrounded by the communities of South Weber, Riverdale, Sunset, Clearfield, Clinton, Roy and Layton. Adjacent land use is residential and mixed agricultural, commercial and residential.

The base also administers environmental activities at the Utah Test and Training Range and Little Mountain Test Annex facilities.

Site Risk

The processes used in maintaining Air Force equipment and supporting flight-training missions produced a variety of wastes. Hill AFB began investigating releases in 1976, when a nearby resident reported an orange discharge from a spring on his property near the base boundary.

The most common contaminants that present health risks, including the risk of cancer, are chlorinated solvents, such as trichloroethene (TCE), trichloroethane (TCA), dichloroethane (DCA), dichloroethene (DCE) and tetrachlorethene (PCE). Metals that need to be addressed, including chromium, cadmium, manganese, and arsenic, are mostly on the base.

The Air Force, Utah Department of Environmental Quality (UDEQ) and the U.S. Environmental Protection Agency (EPA) are cooperatively investigating and cleaning up this contamination. EPA placed the AFB on the Superfund National Priorities List on July 22, 1987.

Areas used for past waste disposal are located along the outer edges of the AFB. These include landfills, disposal pits and spill areas. The topography of the land causes shallow groundwater to run off site. As a result, at least six contaminant plumes have been identified in the surrounding, low-lying communities.

The main potential risks to human health are from contaminated groundwater flowing off the base and from solvent vapors in basements. Off-base groundwater problems are being addressed, and vapor problems in homes are being monitored as needed to ensure the well-being of area residents. Alternative water supplies have been provided to ensure that residents are not using the groundwater. Municipal water supplies have not been affected by any contamination.

Media Affected Contaminants Source of Contamination
air, soil, groundwater arsenic, cadmium, chromium, dichloroethane, dichloroethene, manganese, tetrachlorethene, trichloroethane, trichloroethene processes used in maintaining Air Force equipment

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Cleanup Progress

Investigations and cleanups are progressing at a fast pace. The Hill AFB site was divided into nine operable units (OUs). Three more OUs have recently been added, for a total of 12. Each OU contains sites that are found in the same general area or have similar environmental problems.

Hill AFB has completed final Records of Decision (RODs) on six OUs.

Studies have been conducted at the AFB for many innovative technologies that offer promise in cleaning up soil and groundwater contamination. Most of the studies are in conjunction with nationally known universities. As some are the first small field-scale tests, the results are of national interest.

Innovative studies, done on behalf of the base by Utah State University, found traces of TCE in some fruit from trees grown on private land in or near OU5. The traces, found near groundwater contamination in Sunset and Clinton, are well below any risk to human health.

In February 2007, PCBs were detected in certain areas of base housing in Upper Area F. In March 2007, results of 352 soil samples, both surface and subsurface, identified just four areas with detections above 1 ppm. A summary report of the investigation will be issued in June 2007. A cleanup work plan will be developed by Hill AFB and reviewed by EPA and UDEQ in mid-2007. Cleanup of PCBs will be conducted in fall 2007 or spring 2008.

Hill AFB's third five-year review was completed on December 31, 2008.

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Community Involvement

A group of community members has received a Technical Assistance Grant (TAG) from EPA to hire an independent technical advisor to review issues related to the cleanup. Restoration Advisory Board meetings, held quarterly, are open to the public.

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Site Documents

You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.

Note: Best way to open a very large file: right-click and save it to a folder.

Update to the Five-Year Review, January 2011

Third Five-Year Review Report (PDF), December 31, 2008 (417 pp, 12.2 MB)

Records of Decision and related decision documents

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Sandra Bourgeois
Remedial Project Manager
U.S. Environmental Protection Agency, Region 8
1595 Wynkoop Street (8EPR-F)
Denver, CO 80202-1129
800-227-8917 ext. 312-6666 (toll free Region 8 only)


Bob Elliott
Restoration Division Chief
U.S. Air Force
7274 Wardleigh Road
Hill AFB, UT 84056-5137

Barbara Fisher
Chief of Environmental Public Affairs
U.S. Air Force
7274 Wardleigh Road
Hill AFB, UT 84056


Muhammad Slam
State Project Manager
Utah Department of Environmental Quality
Division of Environmental Response and Remediation
195 North 1950 West
Salt Lake City, UT 84116

Dave Allison
State Community Involvement Specialist
Utah Department of Environmental Quality
Division of Environmental Response and Remediation
195 North 1950 West
Salt Lake City, UT 84116

Neighborhood Group

Technical Assistance Grant:
South Weber Coalition
Brent Poll, President
7605 South 1375 East
Ogden, UT 84405-9418

Site Information Repositories:

Stewart Library
Weber State University
2901 University Circle
Ogden, UT 84408-2901
801- 626-6415
877-306-3140 (toll free)

Environmental Management Directorate
OO-ALC/EMR - Building 5
7274 Wardleigh Road
Hill AFB, UT 84056-5137

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The following links exit the site Exit

Hill Air Force Base

Hill Air Force Base Restoration Advisory Board

Utah Department of Environmental Quality

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