Ozonation treatment technology has been evaluated as an alternative for combating the source water tastes and odors (T&O) as well as inactivating Cryptosporidium at four Detroit Water and Sewerage Department (DWSD) water treatment plants. Ozonation feasibility tests include factor screening of main operational and water quality factors, dose-response relationship development of the key factors. A statistical dose-response model is also developed for determining the ozone dosage for various target odorant removals as function of initial odorant level. Integrated Disinfection Design Framework (IDDF) concept was adopted for evaluating ozone inactivation of Cryptosporidium. Detailed ozone decay studies under various temperature and water quality conditions were performed. The initial ozone residual level and ozone first-order decay constant were both expressed as function of ozone dose. Adopting the literature values of Cryptosporidium inactivation kinetics by ozone, and assuming a typical t10/HRT ratio for the contactor, the ozone dose required to meet the Cryptosporidium goal was developed. Ozonation process is thus demonstrated to be feasible for controlling T&O and inactivating Cryptosporidium at DWSD. Includes 13 references, tables, figures.