COMPLIANCE INFO_1992 - Laserfiche WebLink

Home Browse Search

R 1 DETENTlON ' • 1 DESIGN CALCUIATIONS RUNOFF BASED ON 100 YEAR -24 HOURS HMNSITY,j The surface area at the J—M site was divided into subareas and runoff from each area was calculated based on the corresponding coefficient of runoff. The total runoff was calculated for a maximum of five (5) hours during which time the intensity is assumed to be the highest.The following table is a breakdown of the areas and runoff associated with each area. r� I� SUB—AREA CONTRIBUTING TO RUNOFF (sq. ft.) Coefficient of Runoff (C) hr hr hr hr hr For Different Areas: 1 2 3 4 S Area 1: C = OS 863,379.00 Area 2: C = 0.5 814,077.00 Area 3: C = 0.8 280,997.00 Area 4: C = OS 386,562.00 Area 5: C = 0.5 10f,024.00 Area 6: C = 0.8 1,697,960.00 Area 7: C = OS 1,082,834.00 Total Runoff Area: 1,946,213 814,077 280,997 2,084,522 101,024 The rational method was used to calculate the runoff at the J—M site, using the 100 year, 24 hours event: Runoff Flow Calculations Area 1 Area 2 Area 3 Area 4 Area 5 Q=CiA, (cls) 5.41 2.26 0.78 5.79 0.28 Total Flow From North of the C; 698 (cfs) 125,681 cubic feet % hr Total How From South of the Q 10.83 (cfs) 195,030 cubic feet / hr Using Stoke's Law to calculate the settling velocity: V = * ) / [ (2ga**2) (dl—d2) (9n) The following assumptions were made in calculating the settling verity of the asbestos fibers: a = radius 0.0000001 ft dl = density of fiber (Crysotofite) 2.55 lb/ft**3 d2 = density of runoff water (@ 20 deg. C) 62.43 lb/ft**3 * n = Coefficient of viscosity (@ 20 deg. C) 0.000673344 lb/(hr ft) g = aceeleratio due to gravity 32.2 ft/sec**2 Settling Volocity (V) : V = —229E-03 (U), (velocity in —y direction) V = —92M+00 (ft/h), (velocity in —y direction) r� I�