Tecumseh, NE: Former Lincoln Air Force Base, Atlas “F” Missile Site 6

Formerly Used Defense Sites (FUDS) Program

Published April 7, 2015

Location and Description: The former Lincoln Air Force Base Atlas Missile Site 6 is located four miles north of Tecumseh in Johnson County, NE. The site is typical of the Atlas “F” design and construction. Facilities included: the underground reinforced concrete launch silo and the connecting underground launch control center; water treatment plant with four underground water storage tanks; a cooling tower; a septic tank with subsurface sand filter; a holding pond; an incinerator; two Quonset huts; and one underground fuel tank. A helicopter landing pad was located outside the fence east of the site. In addition, an industrial waste pond was constructed to hold the overflow material from the bottom of the missile silo. The site within the security fence encompasses approximately 4.25 acres. The United States Air Force used the site between 1962 and 1965. Activities conducted at the site included repair, maintenance, and operation of the on-site missile facility.

Problem and Response: A 2010 site inspection report shows trichloroethylene (TCE) groundwater contamination at 1,500 micrograms per liter, which is above the maximum contaminant level in groundwater.

Activities for 2015: Complete a remedial investigation and supplemental feasibility study of the site to identify the nature and extent of the TCE plume. Complete a pilot study to investigate using activated carbon to remediate a TCE plume in the shallow perched aquifer.

Proposed Activities for 2016: Complete the feasibility study and start preliminary work on remedial activities.

Issues and Other Information: The TCE contamination is present at the north end of the site and groundwater flow is to the north-northeast. A remedial investigation was completed for the site in 2012, and a data gap investigation was completed in early 2015. The data gap sampling involved installing several groundwater monitoring wells at the 50-foot depth and the 150-foot depth. The feasibility study scheduled for 2015 will determine the most feasible clean-up approach.