Edwards AFB, California

Site 51 is located on the Main Base Flight Line and is comprised of Aircraft Pad 4 as shown on attached figures 6-1 and 6-2. During the 1960’s and 1970’s Pad 4 was used for parking and maintenance of XB-70 aircraft. The fuel tanks were purged and cleaned with TCE and the jet fuel/TCE waste liquids were discharged onto the ground adjacent to the pad. Groundwater sampling showed TCE concentrations of 12 ug/l and PCE at 18 ug/l as well as minor levels of DCE.

The near-surface geology consists of alluvium composed of poorly graded sand and silty and clayey sands interbedded with silts and clays. Groundwater is approximately 40 feet below the land surface.  

EcoVac Services Inc was contracted by an environmental contractor to perform five one day EFR® events at site 51 extracting on four wells individually and combined to dewater and reduce concentrations of TCE and PCE in the groundwater below the site. Field work was performed once per month between August, 2000 and January 2001. A total of 11,142 gallons of impacted groundwater was removed and vapor phase removal of TCE was 10.6 pounds.