Natural attenuation of TCE and cis-DCE was previously observed at a fractured rock site in southern California, and was attributed to both biological and abiotic reactions (Darlington et. al. 2008, see project "Abiotic Natural Attenuation"). Enhanced bioremediation was to be evaluated as part of the feasibility study (FS) for the site. I review the laboratory work carried out at Clemson University by Dr. David Freedman and graduate student Rong Yu. Preliminary results yielded a surprising finding; Dehalococcoides or equivalent microorganisms live in the pore spaces in the rock, as indicated by dechorination of TCE to ethene with the addition of lactate in microcosms constructed from deep (900-1200') rock cores (Rong Yu et. al. 2013). Recently, microorganisms known to degrade acetylene anaerobically were detected, indicating acetylene (an abiotic degradation product), could be removed as fast as it is produced. I have just reviewed their final report to the client.
Do not be fooled by the man with his hands in the anaerobic glove box; the grad student does all the work.