AWWA ACE65509

This powerpoint presentation begins by providing background information on standard backwash (STD BW), filter ripening, and filter-to-waste. Extended Terminal Subfluidization Wash (ETSW), a technique for managing filtrate turbidity spikes immediately following backwashing (filter ripening), is presented, along with a comparison between it and STD BW. A case study is provided of using ETSW at the Lakeview Water Treatment Plant (LWTP). Results show that overall, filtrate turbidity for both STD BW filters and ETSW filters was low, with a standard deviation of +2%; meeting MOE turbidity requirements; and, when the ETSW filters had a larger filtrate turbidity spike, this spike was only marginally greater than that of the STD BW filters, which was not the case for reverse situation.