AWWA MTC64540

This slide presentation outlines information on three waste streams generated during operation of microfiltration (MF)/ultrafiltration (UF) that include: backwash (BW) or reverse flow (RF); maintenance wash (MW), or chemically enhanced backwash (CEB); and, Clean-in-Place (CIP) or recovery clean (RC). Two regulations are outlined: the U.S. Environmental Protection Agency (USEPA) Filter Backwash Rule which requires documentation of all recycling practices within water treatment plants (WTPs); and, the California Department of Health Services (DHS) who implements the Cryptosporidium Action Plan. Specific topics outlined include: considered methods of CIP disposal or treatment; Citric Acid CIP Waste Stream; Phosphoric acid CIP Waste Stream; Chlorine CIP Waste Stream; various California utility experience including Zone 7 Patterson Pass WTP, new Altamont WTP, Modesto Irrigation District, and Placer County. Conclusions drawn include: each waste (BW, MW, CIP) had different impacts on treatment and water quality; CIP waste is generally most challenging due to contaminant levels; and, CIP waste disposal options are limited; however, several utilities were able to select the best option for operability, water quality and regulatory requirements. Includes tables, figure.