AWWA ACE61784

This slide presentation outlines several case studies dealing with unique design challenges and solutions for retrofitting chloramines in existing water plants. Topics covered include: history of chloramines; list of utilities having a long experience with chloramines; advantages/disadvantages; adding ammonia; existing plant retrofit challenges; mixing and time for reaction; example diffusers; pipeline for mixing; mechanical or static mixing; schematic for ammonia feed systems for disinfection and chloramine formation; ammonia feed modes of operation; first case study involved many feed points and large openings; nozzel assembly at clearwell baffle port; second case study involved disinfection in flume, pump wetwell, clearwells, and two flow schemes; schematic of the facility; schematic of ammonia addition; pump curves estimate flow; and plant modification.