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Edwards AFB JP-4 Site 58
Site 58 is located ease of Taxiway E on the Main Base Flight Line and is adjacent to Rogers Dry Lake as shown on Figure 7-1. The site consists of Pad 19 and is used as an engine run-up and tuning area for various aircraft as shown on Figure 7-2.
The geology of the site consists of granitic bedrock overlain by alluvium and lacustrine (playa) deposits. The playa deposits of Rogers Dry Lake are less than an inch thick in this area and are composed of clay-sized particles. The alluvial deposits are composed primarily of silty sands and silts. Depth to weathered bedrock ranges from 15 to 25 feet below the land surface. Groundwater exists at approximately 10.5 feet.
EcoVac Services Inc was contracted to remove JP-4 from as many as eight wells adjacent to the pad ranging from 0.76 to 3.30 feet in any well. Five EFR® events were performed over a five month period ending in January of 2001 and removed a total of 567 gallons of JP-4 and 9,419 gallons of impacted groundwater.
Project Summary for Edwards AFB TCE Site 51
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 consultant 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.