Item 5: Resolution Adopting Amended SDC Methodologies and Rates

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Step One · CapacityParamete'rs The appropriate capacity measure relates to the sizing criteria of the wastewater system, and may, to improve equity, require consideration of multiple paranieters to assess the impact 'of the utility's various types of users. As wastewater systems must be sized to meet all of their customers' demands, flows and strength loadings are important sizing criteria. MWMC provides service to a diverse customer base,so consideration of varying flow and load requirements of different customer types is one facet that ensures the equity of the SDCs. The four capacity m~~sures.or.parameters used in the methodology are: . Average flow . Peak flow . BOD . TSS These parameters are defined as follows: . Average Flow- The average daily flow in the dry season as defined in the National Pollution Discharge Elimination System (NPDFS) permit. Because the NPDFS permit requires the Eugene-Springfield Water Pollution Control Facility (WPCF) to meet permit discharge limits on a monthly basis, the average flow is presented in terms of dry season maximum month values when discussing "capaqty." The dry season maximum month flow includes base flow (customer flow) and the baseline or dry season infiltration and inflow (III). . Peak Flow - The peak hour flow in the wet season associated with .the 5-year, 24-hour storm event. Peak flow includes ~yerage flow and the additional increment of wet weather III. . . Biochemical Oxygen Demand - The quantity of oxygen used in the biochemical oxidation of organic matter in a specified time and at a specified temperature. BOD is ~ . ~easurement of wastewater strength. .. Total Suspended S.olids - Solids in the wastewater that ar~ removable 'by laboratory filtering and approximate the quantity of solids that are' available to be removed from the wastewater.through sedimentation. TSS is a measurement of wastewater strength. Table 3 provides the allocations of. existing and future facility process components to the system capacity parameters: average flow, peak flow, BOD, and TSS. A 'description of process components is provided in Appendix A. The rationale for the allocation percentages is provided in Appendix B. These allocations are used to determine the pr~jected costs of capacity to be used by.new development that establish the reimbursement fee and improvement fee cost bases. The underlying approach is to evaluate the following criteria for each facility process component: ' . Functional performance' . Design basis The functional performance criterion considers the actual' purpose of the facility on a daily basis. Is the purpose of the facility to remove BOD or TSS from the wastewater? Or is the purpose of the facility to simply pass the flow (average an~1 or peak) and remove some