AWWA REUSE52116

Washoe County, Nevada, conducted a five-week pilot test at the South Truckee Meadows Water Reclamation Facility (STMWRF) to evaluate cloth-membrane filtration and sodium hypochlorite disinfection in meeting state water quality regulations for unrestricted reclamation uses. Based on the Nevada Water Quality Regulations, the targeted performance conditions for the filter included effluent quality of total suspended solids (TSS) concentrations less than 5 mg/L and turbidity levels less than 2.0 NTU. The disinfection effluent quality standards included a maximum total coliform limit of 2.2 MPN. Since the STMWRF supplements secondary effluent with diverted creek water to meet the local reuse water demand, the pilot unit was operated in three modes: plant effluent only; blended effluent and creek water; and creek water only. The pilot test results showed that, while the cloth-membrane filter unit effectively produced filtered secondary effluent meeting the performance criteria, the unit was unsuccessful in treating the blended and creek-water only conditions. Includes tables, figures.