CL-Out Pilot Study Vandenberg AFB – successful aerobic cometabolism Case Study
A pilot study of the applicability of CL-Out aerobic cometabolism of PCE and other chlorinated solvents was completed at Vandenberg Air Force Base. The pilot study consisted of injection in a single well and groundwater sampling at four surrounding wells to monitor the progress of bioremediation. During the pilot study, samples were analyzed for the contaminants and breakdown products, microbial population, and dissolved oxygen.
After three months, sampling showed the following contaminant removal near the injection well:
- PCE reduced from 44 to 2.6 ug/L.
- TCE reduced from 330 to 57.3 ug/L.
- Cis 1,2-DCE reduced from 30.7 to 6.2 ug/L.
- Vinyl chloride was not detected before or after treatment.
The ground water stayed aerobic during the 90 day pilot study. The CL-Out population reached a maximum of 9 million cells per milliliters 14 days after injection. The CL-Out population was maintained above background populations for at least 60 days and reached as far as 50 feet down gradient.