Determining disinfection needs

The integrated disinfection design framework (IDDF) is a new approach for d etermining disinfection requirements for a water treatment facility. framew ork may be applied in place of the procedures in the US Environmental Prote ction Agency's surface Water Treatment Rule guidance manual. Potential bene fits include lower disinfectant dosages, reduced disinfectant costs, and re duced formation of disinfection by-products. The feasibility of the IDDF wa s presented in an AWWA Research Foundation-sponsored project completed in 1 998. A user-friendly this model allows utility personnel, consultants, and, regulators to determine site-specific disinfection requirements. The model has four components or modules: (1) hydraulic characteristics, (2) disinfe ctant, demand-decay, (3) inactivation kinetics, and (4) disinfection by-pro duct formation, Implementation of the IDDF at the Aurora (Colo.) Water Depa rtment is in progress with a chloro dioxide dosage reduction of approximate ly 15 percent. Other IDDF implementation studies have indicated that primar y disinfectant dosages can reduced by 8-35 percent with a corresponding red uction in disinfection by-products.