2006 Water Comprehensive Plan - City of Bellevue

CHAPTER 10Water QualityThis Chapter evaluates Bellevue’s compliance with applicable state and federal drinking waterregulations between 1998 and 2004. The discussion includes:• An overview of Bellevue’s supply with respect to source and supplier;• Voluntary monitoring conducted by Bellevue;• Stage 2 Disinfection By-Product (DBP) Rule, which has now been finalized butwas not effective during 1998-2004; and• A description of the future regulatory climate, with a focus on issues surroundingBellevue’s distribution system.REGIONAL AND LOCAL WATER QUALITY COMPLIANCERESPONSIBILITIESBellevue purchases 100% of its water from Cascade, and provides no additional treatment.Cascade is a regional water supply organization composed of local cities and water districts,formed so that regional drinking water purveyors, such as Bellevue, could cooperate in providingcurrent and future water supply. Purchased water reaches Bellevue’s system through 15 supplyinlets.Currently, Cascade supplies Bellevue with water purchased from Seattle Public Utilities (SPU).During typical operations, water is supplied from both the Cedar and South Fork Tolt Rivers.The Cedar is an unfiltered drinking water supply; the Tolt River has been filtered since the ToltWater Treatment Facility came online in 2001.With respect to the quality of the drinking water provided, Cascade’s contract with memberagencies states:“Cascade shall be responsible for water quality that meets or exceeds all federalor state requirements at the point of delivery from Cascade to the Member,consistent with applicable laws and regulations. Cascade assumes source waterquality responsibility and liability with respect to Water Supply Assets under itsownership or control (including water wheeled to a Member utility throughanother Member’s facilities). Cascade is also responsible for preparing andcarrying out water quality activities compatible with the water qualityrequirements of Regional water suppliers integrated with Cascade’s system (i.e..Tacoma, Everett, and Seattle).”While Cascade is responsible for ensuring the quality of water reaching its Member utilitiesCascade plans to purchase most of its water from SPU and Tacoma Public Utilities during the10-1