The objective of this study was to determine if the application of an alternative preoxidant would be beneficial to water utilities treating water from the San Francisco Bay Delta area, which at times has elevated and highly variable TOC and bromide levels. The focus of this project was on determining which preoxidants had the greatest potential to reduce subsequent chlorination disinfection byproduct (DBP) formation. Experimental conditions were designed to enhance DBP formation in order to aid in this determination. Then the combinations that showed evidence of synergistic capabilities by reducing DBP formation were analyzed more thoroughly and in conditions more representative of a traditional treatment system, including preoxidation, alum coagulation, intermediate oxidation and filtration. Bench scale experiments were designed to compare the impact of alternative preoxidation on the subsequent formation of chlorination DBPs in natural waters. Raw water was used to enhance DBP formation and magnify any possible synergistic effects. Four primary disinfectants were tested including 2.0 mg/L chlorine (Cl₂), 1.0 mg/L chlorine dioxide (ClO₂), 1.0 mg/L ozone (O₃), and 1.5 mg/L potassium permanganate (KMnO₄), followed by chlorine as a secondary disinfectant. Primary oxidant doses were selected to be representative of water treatment in the San Francisco Bay area, and secondary chlorine doses were selected to ensure that there was at least 1 mg/L chlorine residual after 24 hours based on preliminary demand tests. The potassium permanganate dose was larger than typically applied in the San Francisco Delta (1.5 mg/L), however the literature review suggested that such a high dose would be required to have an effect on THM formation. Includes 25 references, figure.