Reductive dehalogenation of organic halides in contaminated groundwater

The invention provides methods and microbial cultures for the bioremediation of organic halide contaminated groundwater contaminated with organic halides, such as di- and trichloroethene. The methods involve adding, in situ to organic halide-contaminated groundwater a carbohydrate and one or more reductive dehalogenation factors, usually in the form of a nutrient extract, both in amounts sufficient to permit in situ reductive dehalogenation of the organic halide by a microbial population. The microbial population may be endogenous to the ground water or added exogenously. The nutrient-enriched ground water is then maintained in situ under reducing conditions to reductively dehalogenate the contaminating organic halide. Enriched bioremediation cultures are produced by adding to organic halide contaminated groundwater which comprises an endogenous microbial population capable of reductive dehalogenation of the organic halide a carbohydrate and frequently, one or more reductive dehalogenation factors. Thereafter, the nutrient-enriched groundwater is incubated under reducing conditions whereby the organic halide is reductively dehalogenated and the microbial population is selectively and numerically expanded to yield a bioremediation culture.