With the increasing costs and liabilities associated with the disposal of chlorinated solvents and increased concern over the occupational health effects of chlorinated solvents, substitution of a chlorinated solvent with an aqueous cleaner is a desirable alternative to consider. This paper describes a vapor degreasing operation at Vandenberg Air Force Base where 1,1,1-trichloroethane is used; an aqueous cleaning system reduces solvent wastes by 70%, solvent emissions by 100%, and annualized costs by 40%. Solvent substitution was compared to other alternatives including on-site distillation and reduction of solvent losses by either installing a refrigerated freeboard chiller and/or increasing the height of the freeboard. Substitution of 1,1,1-trichloroethane with an aqueous cleaner appears to be the best alternative.