Resolution No. 4900 - Laserfiche WebLink

Home Browse Search

other parameter not represented by BOD or TSS such as screenings, grit, or pathogens? These questions are answered by the functional performance component. The design basis considers what system capacity parameter or combination of parameters drives the sizing of the facility and, therefore, the constructed cost. The allocation basis for each facility . component presented in Table 3 combines both the functional performance and design basis considerations. In addition to these system parameters, because there can be projects that provide overall support for the wastewater system, a separate category of "indirect" . support facilities is used to provide for reallocation of these support-type costs across all of the system capacity parameters. TABLE 3 Summary of Facility Process Component Allocation to System Capacity Parameters System Capacity Parameter Average Peak Facility Process Component Flow Flow BOD TSS Indirect Total Collection system pipeline % * 1 Collection system pump stations % * 1 Preliminary treatment % *. 1 Primary treatment % % % 1 Secondary treatment % Y2 % 1 Disinfection/outfall % * 1 Biosolids (same for all three subcomponents) % % 1 Tertiary filters % % % 1 Reuse facilities 1 1 Odor control % % 1 Peak flow management Support facilities (Indirects) 1 Step Two. Growth Capacity Requirements In developing SDCs, costs relatedto growth (see 'Cost Basis' below) are spread over growth's total capacity requirements over the study period to determine the overall cost per unit of growth by capacity measure. The study period is defined as a 20-year period, consistent with facility planning requirements. The Department of Environmental Quality (DEQ) stipulates that entities that own and operate wastewater facilities assume a 20-year plamUng horizon when developing facility plans (see DEQ Guidance for Development of Wastewater Facilities Plans, 2000). To determine the capacity required by growth, the capacity required by existing users is subtracted from the capacity projected in the facility plan to be required at the end of the planning period. For peak flow estimates, existing users' current capacity requirements are adjusted for anticipated III reductions (see Guidelines for the Preparation of Facilities Plans and Environmental Reports for Community Wastewater Projects, 1999).