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<br />model of the.collection system MWMC is able to estimate the current peak flow. DEQ <br />defines the peak flow as the peak hour or peak instantaneous flow that occurs during the <br />5-year, 24-hour storm (3.9 inches of rainfall). Under these rainfall conditions, the model <br />predicts a current flow of 264 mgd. Therefore, there is no available capacity in terms of peak <br />flow. Since the current average flow is 43.8 mgd, the current wet season III is 220.2 mgd <br />(264 less 43.8). <br /> <br />Using the projected future 2025 population and land use, the model predicts peak flows of <br />294 mgd without III reduction efforts outlined in the 2000 WWFMP and 277 m:gd with III <br />reduction efforts outlined in the 2000 WWFMP. Therefore, it is estimated that the III <br />reduction efforts will reduce III by approximately 17 mgd. <br /> <br />Wet season III in 2025 attributed to existing users is determined by ~ubtracting the <br />anticipated reduction in wet season III (17 mgd) from the current wet season III <br />(220.2 mgd) yielding 203.2 mgd. <br /> <br />Finally, wet season III attributed to growth in 2025 is 14.5 mgd and is determined by taking <br />the 2025 total peak flew projection of 277 mgd and subtracting both the 2025 average flow <br />(59.3 mgd) and the 2025 wet season III attributed to existing users (203.2 mgd). Therefore, <br />the peak flow in 2025 attributed to growth is 30 mgd (15.5 .mgd of average flow plus 14.5 of <br />wet season III flow). <br /> <br />TABLE C-2 <br />Projected 2025 Peak Flow Breakdown <br /> <br />Average flow attributed to.existing users (includes dry <br />season III) <br /> <br />Average flow attributed to future users (includes dry <br />season III) . <br /> <br />Wet season III attributed to existing users <br /> <br />Wet season III attributed to future users <br /> <br />43.5 mgd <br /> <br />15.5 mgd (59.3 - 43.8) <br /> <br />Total peak flow <br />Total peak flow attributed to growth <br /> <br />203.2 mgd (220.2 - 17) <br />14.5 mg~ (277 - 59.3 - 203.2 <br />277 mgd <br />30 mgd (15.5 +.14.5) <br /> <br />BOD <br /> <br />The methodology for BOD is similar to that of average flow. The existing capacity, although <br />not explicitly stated in the current NPDES permit, is 66,000 lbsl day, whiCh was the value <br />used for the original WPCF design. The current loading or current required capacity in <br />presented in DSMM terms is 54,800 lbs/day and is determined as follows: <br /> <br />Current BOD = (0.185 x 217,737 x 1.3) + 2,402 = 54,800 lbsl day (ac~al calculated value of <br />54,756lbsl day rounded to the nearest hundred pounds). <br /> <br />Where: <br /> <br />A-29 <br />