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formula to size the line for the two-hour peak wet weather flow. The required diameters of the force mains were determined using the two-hour peak wet weather flow for the design year of the line and allowing a maximum velocity of 5 feet per second. The WWTP expansions were sized to treat the average dry weather flow for the basin. The expansions and upgrades to the WWTP were evaluated assuming the modifications would be made at a treatment level of 10 mg/1 BOD and 15 mg/1 TSS. The values in the tables which show flows in :\IGD refer to the average dry weather flow in million gallons per day at that location in the basin. D. Collector Line Sizing Collector lines were sized to serve the _sub-basins based on the same flow projections as the chosen interceptor alternative. Collector lines have been located along existing or planned roadways where possible, to service those areas believed to be developed by the year 2005 (Figure 5). 'I" he costs were then found for the proposed collector lines using data obtained from recently bid projects in the area, as were the interceptor lines. These costs were not included in the system costs because the collector line costs are expected to be funded by the appropriate developers. To determine the location and Bow for the collector lines the sub-basins were divided up into smaller areas, or sub-sub-basins. These areas were arrived at based on the contour of the area, to allow grav"ity flow collector lines to be connected to the interceptor. Flow projections were then derived for each collection line based on the projected flow for each sub-basin. The collector lines were then sized and their costs were determined. Collector sizes and costs are shown in Table 5. The collector lines proposed for the study area do not involve the area inside the Lowmans 1 Ranch and Cottonwood Creek Park developments. This is due to the fact that collector lines intended JONES ð: "'EUSE i i I j 21