AWWA JAW10838

The research described in this article was an attempt to simulate local aquifer conditions in the laboratory and to subject a known contaminant of local groundwater to the activity of native microorganisms. Tetrachloroethene was injected into static microcosms, which were representative of the recharge basin and composed of muck and surface water in sealed septum bottles. During three weeks of incubation, the contents of these bottles were analyzed periodically by gas chromatography (GC) for products of biotransformation. Results of analyses of well water from the site of an industrial spill of trichloroethene into groundwater were compared with the results of the laboratory models (microcosms) that contained tetrachloroethene, because the latter results indicated that tetrachloroethene was biotransformed to trichloroethene and that both tetrachloroethene and trichloroethene were biotransformed to chloroethene, cis- and trans-1,2dichloroethene, and dichloromethane. The results of this study, which indicated successive transformation of tetrachloroethene to trichloroethene and then to chloroethene, cis- and trans-1,2dichloroethene, and dichloromethane imply that the source of any contaminant must be identified before the contamination can be remedied, and treatment methods developed to remove one contaminant from drinking water may be ineffective in removing its biotransformation products as time and succession advance. Includes 20 references, tables.