AWWA ACE61664

In August of 2003, Southern Nevada Water System (SNWS) implemented ozonation into its treatment process to achieve Cryptosporidium inactivation. Due to the addition of ammonia for bromate control, biological filtration is planned to remove ozonation byproducts and residual ammonia. In order to initiate and maintain biological activity, chlorination prior to filtration must be ended to promote biological growth in the filters. As a result, treatment plant staff decided to investigate the potential for manganese release as observed at other utilities. The following study includes bench-scale and pilot-scale investigations of the impact of pH on manganese release. Includes reference, table, figures.