Location and Description: The former Lincoln Air Force
Base, Atlas Missile Site 7 is located approximately three miles
southwest of Firth, Nebraska in Gage County. It was one of 12
Lincoln Air Force Base missile sites that were used for the
maintenance, storage, and potential launch of Atlas “F” intercontinental ballistic missiles. Previous investigations
conducted at the site showed trichloroethene (TCE), a
chlorinated solvent (and its associated breakdown products),
present in the soil and groundwater. The TCE is presumably a
result of construction activities, site operations, and/or site
decommissioning.
Problem and Response: Mitigation of risk is to prevent landowners from ingestion,
inhalation, and skin contact with groundwater having TCE in excess of the regulatory limit. The response includes restoration of the groundwater. A
performance-based contract was awarded in July 2011 and associated work includes: a
remedial design; pilot study; performance monitoring; and, proposed plan and decision
document.
Since March 9, 2012 right of entry has been refused by all landowners,
except the silo area parcel property landowner. Thus,
groundwater remediation efforts have continued for the silo property, and have been halted for
all other properties. For the single landowner with an impacted drinking water well, a granular
activated carbon system was installed to provide clean drinking water, and responsibility for
operation and maintenance has been taken over by the landowner. An enhanced
bioremediation groundwater pilot study has been initiated on the silo property and has been
performing well. It is anticipated that this technology will be implemented as the remedy in
place and will achieve remediation of the groundwater below the silo property within seven
years.
Activities for 2015: A proposed plan and decision document will be completed along with
continued operation and performance monitoring of the pilot study for the silo property.
Proposed Activities for 2016: Implementation of the remedy in place for the silo
property, to include continued operation and performance monitoring for enhanced
bioremediation of the groundwater.
Issues and Other Information: Remedial efforts have been halted for all parcel
landowners with the exception of the silo area parcel, as property
access have not been granted. USACE has worked with NDEQ and EPA Region 7 to gain
landowner access through awareness of potentially responsible party liabilities to no avail. The
USACE continues to work with regulators and the silo property landowner to keep them
informed and involved in the remediation process.