222 W MARINE VIEW DR 2016-01-01 MF Import

s :ontrot invert above the bottom �th during runoff and quiescent c :ed using equation 8.15. a x 43,560 ft=/acre x 1 ft/12 in. 43,560 �( 12 ) 50 x 5 x 3630 off is the same as the corre! s the same as rainfall volume: �d CV4 — 1.44 of runoff rate on rainfall excess (volume) tion 8.10 gives t—(°s��R) in the following table (z = 1.0). R,w (°k) R� (90) (Equation 8.10) (Figure 8.5) 5 5 41 20 91 77 100 100 100 100 R moval m 60qo = S t noved = 40% 8.2 MODEUN6 CONCEPTS FOR WET•DETENTION PONDS 283 pu�ng Quiucent Conditions: (Note: Assume that larger particles have yettled during the storm ovent, thus the partic!e size distribution has changed.) and pond volume VB runotf volume 6 VR VB 5000 VR — 4810 = 1.04 Sfl 85(u,)1260 E 6 VR 4810 = 22.28u, Average SetUing (u,) Percmt of Velociry (tt/h) Time E 0.03 25 0.7 0.33 25 7•4 ISO 25 33.4 7.0 25 156. ' 70 0 Overall average removal = 51% Fd or percentage not removed — 49% VEI VR (Figure 8.7) 0.60 1.00 1.04 1.04 RQ(%) (FiQure 6.6) 40 54 55 55 FoFQ 49(40) Overali percent removal = 100 — 1� � 100 — 1� = 80°Jo Note: During quiescent conditions, the efficiencies are less than during the runoff conditions. This is because some portion of the solids are not available tor quiescent settling or are removed from the pond. 9•2•7 Fate of Pollutents Nutrient and metal interactions with bottom sediments in wet-detention ponds have not been fully investigated. Cnly limited data from literature are available to describe the interaction, but the processes studied in small lakes may apply to stortnwater wet-detention ponds, To determine uptake and release rates from bottom sediments, aquatic polyethylene isolation chambers (IC) are constructed and submerged with the open top down on the bottom sediments of wet-detention ponds in Orange County, Florida (Yousef et al., 19866). 1'he exterior of the chambers was painted black with epoxy to m