This project is part of a proactive program undertaken by Tacoma Water to prepare for changes in water quality expected when the Corps of Engineers completes the construction of its new diversion structure. When the new diversion structure is available the Corps anticipates taking water from an appropriate depth nearer the surface where the fish are more prevalent during certain times of the year. Water is currently withdrawn from the hypolimnion and algae or algal byproducts are not typically found. Although it is difficult to quantify the changes in water quality that might occur, the changes can be inferred from a period when the Corps of Engineers increased the level of the water in Eagle Gorge to evaluate the integrity of the existing Dam. During this time the total organic carbon (TOC) concentration surface waters increased from 1.5 to 3.0 mg/L. Algae counts increased from 2000 per mL to 5000 per mL. In addition, the water was found to have an earthy or a musty smell. This study was developed to support the design of ozone treatment facilities for taste and odor control. The objectives of this research were to: determine the rate of oxidation and by extension, the amount of time needed for oxidation of geosmin and MIB, two of the most common taste and odor causing compounds; determine the benefits of pH adjustment before ozonation; and, better understand the relationships and synergies between ozone dose, pH, and hydrogen peroxide dose. Includes 5 references, tables, figures.