Advancing CSO Treatment: Now and for the Future Confirming OVIVO RapidStorm Membrane Treatment of King County's CSO Discharge

King County (County) has been implementing a long-term CSO control program for over three decades. Over the years, the County has encountered issues at various CSO treatment facilities with consistently meeting discharge requirements for fecal coliform, settleable solids, and chlorine residual. The County faces the challenges of siting large CSO facilities in an urban area and rising costs for constructing facilities. The County is investigating innovative solutions that are operator friendly, fit within tight space constraints in highly developed portions of the City of Seattle, and consistently meet the current regulatory requirements. The County would also like to incorporate newer technologies that not only achieve today's water quality standards but also will meet future regulatory challenges. The County and project team identified a new technology for treating CSO discharges. The technology (RapidStorm manufactured by OVIVO) uses SiC membranes (0.1-micron filtration) in conjunction with the addition of a chemical coagulant. A pilot project was conducted at the County's West Point treatment facility. [i] (Graphic 1) [/i] The findings from the pilot project provide the basis of design criteria for potential future CSO treatment facilities when utilities are considering this technology