AWWA ACE58266

In a constantly evolving regulatory environment, drinking water utilities consistently face increasing requirements for disinfection of pathogens while decreasing requirements for health threatening disinfection byproducts (DBPs). The disinfectants that the industry have relied heavily upon in the past, chlorine and chloramines, can no longer meet the requirements by themselves. Therefore, the time for the use of integrated disinfection has come. The disinfectants normally used in water treatment (free chlorine, chloramines, chlorine dioxide, ozone, and ultraviolet disinfection (UV)) all have advantages and disadvantages. The key, therefore, is to take advantage of positive characteristics of multiple disinfectants, resulting in improved finished water quality. Using integrated disinfectants also has the benefit of providing a multiple barrier of protection to disinfection while providing a possible capital and operating cost savings. Utilities can also improve public perception through the use of sequential disinfectants by providing increased disinfection effectiveness while limiting the formation of health threatening DBPs. Two example AWWA Research Foundation projects using integrated disinfectants, one evaluating chlorine dioxide with ozone and one evaluating ozone with UV, have demonstrated the benefits and practical application of integrated disinfection. Includes reference, table.