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Fact Sheet
February 2008
Proposed Soil and Groundwater Cleanup, Permit Modifications, Offutt Air Force Base (AFB), Nebraska
INTRODUCTION
The U.S. Environmental Protection Agency (EPA) Region 7 invites the public to review and comment on proposed modifications to Part II of the Hazardous Waste Storage Permit for Offutt Air Force Base and proposed remedies for certain solid waste management units (SWMUs). EPA proposes to select and incorporate into the permit, the final remedies for the Landfill 4 Trench Area (LF4T) and the Hardfill 2 Composite (HF2C) solid waste management units. EPA also proposes to modify the permit to note that corrective measures have been completed at the Hardfill No.6 (HF6) solid waste management unit.
Backgrounds and Actions
LF4T: is located in the southeast part of Offutt and consists of a mounded landfill area and an open field. The landfill was operational in the late 1960s. Records suggest materials disposed in the trenches may have included municipal wastes, sludge, waste solvents, petroleum, oil and lubricant materials, contaminated meat, and waste paints and thinners. It was suspected that
small vessels containing mustard agent may have been buried in the landfill.
Relatively low levels of chlorinated solvents were found in the groundwater in the area of the disposal trenches. The contamination that exceeds the drinking water standards is confined to within the Base boundary.
Attend a Public Availability Session
When:
Monday, March 10, 2008
Anytime from 4 to 6 p.m.
Where:
Bellevue Public Schools
Welcome Center
1600 Hwy 370
Bellevue, Nebraska
Send Comments to:
Jeff Johnson, Ph.D.EPA Region 7
AWMD/RCAP
901 N. Fifth St.
Kansas City, KS 66101
Phone: (913) 551-7849
Toll-free: (800) 223-0425
As an interim treatment, granular iron filings mixed with clean sand were installed in a deep trench to form a permeable barrier where contaminants would be stopped from leaving the Base boundary. Upon reaching the barrier, the contaminants in the groundwater react naturally with the iron, creating non-toxic byproducts such as carbon dioxide, ethane, and water.
The proposed remedy includes injecting areas of concentrated contamination with soy-based vegetable oil mixed with other non-toxic additives. This technology uses naturally occurring bacteria to assist in breaking down the contamination into common byproducts.
The proposed remedy also includes the continued monitoring of groundwater in the area.
Land use controls will be incorporated into the permit and Base General Plan because residual contamination remains at a level that does not allow for unlimited use and unrestricted exposure. Administrative actions would prevent unauthorized digging within the landfill area and preventing installation of drinking water wells in the area.
HF2C: is located in the south central part of Offutt and covers about 97 acres. It is composed of multiple former SWMUs and several smaller release areas where the records searches in 1985 identified areas of concern for contamination.
High levels of chlorinated solvents were found coming from several sources within the HF2C area. The proposed remedy addresses groundwater, soil vapor, and contaminated soil using corrective and administrative actions. These include groundwater pumping and discharge to a constructed treatment wetland, the use of granular iron permeable barrier trench technology, vegetable oil injection technology, restrictive fencing, and administrative land use controls that include prohibiting drinking water wells in the area. Land use controls will be incorporated into the permit and Base General Plan because residual contamination remains at a level that does not allow for unlimited use and unrestricted exposure.
EPA also proposes a technical impracticability waiver from drinking water standards for the HF2C source area.
HF6: is located in the eastern part of the Base, and was used primarily for disposal of construction rubble between 1959 and 1979 and for a 1983 runway replacement project. The site is near the ammunition storage area and a portion is in the end-of-runway clear zone. There are no buildings on the site and its current land use is restricted by Offutt.
Residual chlorinated solvent contamination from a previous Fire Training Area was identified in soils beneath the runway demolition rubble. The remedy was to excavate contaminated soils and ship them to an approved off-site landfill.
As a result, residential clean-up standards have been attained and the EPA proposes to modify the permit to note that corrective measures have been completed at HF6.
Additional Information
EPA encourages the community to review the Administrative Record and comment on the proposed remedies and other evaluated alternatives. It is available at these locations:
Bellevue Public Library
Mon - Thu 9 - 9
1003 Lincoln Rd.
Fri & Sat 9 - 5
Bellevue, NE 69005 Sun Noon - 5
(402) 293-3157
EPA Records Center Mon - Fri 7 - 5
901 N. Fifth St.
Kansas City, KS 66101
(913) 551-7166
A public availability session is scheduled March 10, 2008 to allow the public an opportunity to discuss the permit modifications and final remedies with EPA officials and representatives of Offutt AFB (details in box on page one.)
A more formal public hearing has not been scheduled for these actions, but will be held if there is sufficient public interest.
Requests for a public hearing must be made in writing to the EPA contact on page one and must state the nature of issues to be raised at the hearing. EPA will evaluate any request and hold a formal hearing, if it finds that a hearing will contribute to the decision-making process by clarifying significant issues affecting the cleanup remedy.
The comment period begins February 27, 2008 and ends April 14, 2008.
Comments or requests should be submitted prior to April 14, 2008,
EPA will finalize a remedy only after the public comment period ends and all comments are reviewed. EPA may modify the proposed remedy or choose another one, based on any new information and comments from the public.
Questions or requests for information can be submitted to:
Fritz Hirter
Office of Public Affairs
EPA Region 7
901 N. Fifth St.
Kansas City, KS 66101
Toll free: (800) 223-0425
e-mail: hirter.fritz@epa.gov
