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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />------------------------------------------------------------------------------- <br />------------------------------------------------------------------------------- <br /> <br /> Table 3.7 <br /> Tank Inflow Volumes <br /> Required for 10-0ay Period <br />Peak Peak Total Lower r~iddle Uppe r <br />Oesi gn Desi gn lO-Day Tank Tank Tank <br />Flow (cfs) Flow (gpml Volume (mgl Volume (mg) Vol ume (mgl Volume (mgl <br />2.5 1122 16.2 7.53 4.90 3.77 <br />3.0 1346 19.4 9.02 5.86 4.52 <br /> <br />------------------------------------------------------------------------------- <br />------------------------------------------------------------------------------- <br /> <br />For this study, the pipeline was initially sized based on the 2.5 or 3.0 cfs <br />bei ng del i vered to the mi ddl e tank. Greater fl ows coul d be del i vered if the <br />only point of delivery was into the lower tank; when the only point of outflow <br />was the upper tank the pipeline flow would be lower. <br /> <br />In the later years of development when nearly full use is being made of the <br />1,000 af, arlditional system peaking capacity could be obtained by installing a <br />pump system from the mi ddl e or lower tank to the upper tank. The pumpi ng <br />woul d probably never have to occur more than in porti ons of two months duri ng <br />the year, when maximum peaking occurs Such a pump system may never be neederl <br />if the inrlustria1 demand or the majority of the population growth is located <br />in the lower pressure zone where higher flows can be de1ive~erl. <br /> <br />Subsequent sections will discuss potential pioe types, the variations of <br />internal diameters, and flow characteristics. Long-term friction factors tend <br />to be approximately equal for either mortar lined or plastic pipe, so a single <br />conservative friction resistance value has been used for all hydraulic <br />computations. The Hazen-l~illiams flow formula has been employed using a C <br />value of 135 for the pipe. For new pipe this value may be in the range <br />between 140 and 145. Two alternative alignments have been selected having <br />total lengths of approximately 105,000 and 113,000 feet respectively. Table <br />3.8 summarizes the lengths of various sizes of pipe that would have the <br />capacity to deliver 2.5 or 3.0 cfs peak flow to the middle (existing) storage <br />tank. The concrete cylinder pipe has been userl in this table because the <br /> <br />3-13 <br /> <br />l060c <br />