At BEAK, we made many “field observation Firsts”, often soon after a first lab observation. At an 8,500 acre Superfund site in California we did NA investigations on numerous solvent plumes. At a former waste lagoon we made the 1st observation of natural sequential anaerobic-aerobic degradation of TCE and TCA (Cox et al. 1995). We also showed natural cometabolic biodegradation was occurring in the vadose zone due to methane (Cox et al. 1998b). In a 2nd plume with high CF and 1,2-DCA, we showed 1,2-DCA was degrading via vinyl chloride and ethene; CF was being transformed to methylene chloride or removed via cometabolic biodegradation (Cox et al. 1998a). At a landfill in New Hampshire, we made the 1st observation of natural sequential anaerobic-cometabolic degradation of TCE (Cox et al. 1997). In 1997, Frank Loffler showed dichloropropane (DCP) could be reduced to propene in the lab. Two months later we found stoichiometric conversion of DCP to propene at a California landfill (BEAK report).