AN ABSTRACT OF THE THESIS OF Matthew Thomas Keeling for the degree of Master of Science in Civil Engineering presented on November 23, 1998. Title: Bench-Scale Study for the Bioremediation of Chlorinated Ethylenes at Point Mugu Naval Air Weapons Station,

approved. s Semprini Laboratory scale microcosm studies were conducted using site specific groundwater and aquifer solids to assess the feasibility of stimulating indigenous microorganisms in-situ to biologically transform Trichloroethylene (TCE) and its lesser chlorinated daughter products dichloroethylene (DCE) and vinyl chloride (VC). Three different treatments were conducted to determine the best approach for biologically remediating TCE under site specific conditions: anaerobic reductive dechlorination, aerobic cometabolism and sequential anaerobic/aerobic stimulation. Studies were conducted in batch serum bottles containing aquifer solids, groundwater and a gas headspace. Long-term (302 days) TCE anaerobic reductive dechlorination studies compared lactate, benzoate and methanol as potential anaerobic substrates. Site characteristic sulfate concentrations in the microcosms averaged 1,297 mg/L and TCE was added t