The objective of this research project was to demonstrate the effectiveness of an in-line application of ozone and hydrogen peroxide for the removal of organic chemicals at much higher pressures than those in conventional systems. In-line application of ozone and hydrogen peroxide is defined as the injection, dissolution, and contacting of these oxidants under pressurized conditions as opposed to conventional application of these oxidants under atmospheric pressure. The water used for testing was obtained from active wells of the Ridgewood Water Department and the Spring Valley Water Company. The specific objectives of this research were to: determine engineering feasibility of in-line application of this process; determine process efficiency for organic contaminant removal in these specific waters; develop design criteria for the process; and develop cost estimates for full scale facilities. The results obtained from this research project are directly applicable to the water supplies that were tested under this project. Site-specific tests are needed to apply these results to other water supplies.