AWWA ACE92152

Planning for the implementation of disinfection requirements at the South Central Connecticut Regional WaterAuthority's (RWA) three treatment facilities has been an interesting if not frustrating case study. The Lake Saltonstall Water Treatment Plant (WTP) proved to be the easiest facility to bring into compliance by simply elevating the prechlorine dose. The West River WTP was somewhat more challenging as the existing filtered water reservoirs (FWRs) needed to be modified to enhance their hydraulic flow characteristics. Installing a single vertical baffle wall in both FWRs was sufficient to provide the required level of disinfection. The Lake Gaillard WTP was the most challenging facility in terms of upgrading disinfection. Attempts to introduce several variations of prechlorination have resulted in a myriad of physical and chemical problems. Additionally, the elevated levels of THMs resulting from this process change are still being evaluated.