Septic design (2) - Laserfiche WebLink

Home Browse Search

3. ABSORPTION AREA SIZING Note:Mound seYbocks are meawred from the Absorption Area. A. Calculate Absorption Width:Bed Width (2.6)X Mound Absorption Ratio (1.F)=Absorption Width 10.0 ft x 2.6 = 26.0 ft B. For stopes>1%,the Abwrption Width is measured downhilt from the upslope edge of the Bed. Calculate Downsiope Abwrption Width:Absorption Width {3.A)-Bed Width (2.B)=ft 26.0 ft - 10.0 ft = 16.0 ft 4. MOUND SIZING A. Catculate Ctean Sand Lift: 3 feet minus Depth to Limiting Condition (1.C)=Ctean Sond Lift (t ft minimum) 3.0 ft - 1.0 ft = 2.0 ft Design Sand Lift(optional): �2.0 B. Calcutate Upslope Height:Clean Sand Lift (4.A)+media depth (1 ft.)+cover (1 ft.)=Ups(ope Height 2.0 ft + 1.0 ft + 1.0 ft= 4.0 ft D•34:Slope Mul±iptix 7able Land Slope� 0 I 2 3 4 5 5 7 8 4 10 11 11 13 14 13 18 17 18 I9 20 tt 2t 23 ?a 25 Upi10��? 3:1 3.� t.91 2.Si i.?5 T.68 2.51 T5s 2.d3 2,a2 i.34 2.31 2.25 2.11 i.i7 i.13 2.G5 2.06 2.0: 2.00 1.5J 1.9i 1.yi t.9i t.84 1.87 1.85 Berm Ratic a:i �.04 3.85�:3.70 3.57 3.ai 3.33 3.13 3.�2 3_03 2Ad 2.8b 2.78 1,7Q 1�.b2 2,55 2,�E 2:�1 2.39 229� 2.23 2.18 Z.i3 2.08� t�.03 t.98 L�3 LdRd SIOQ¢°� 0 I 1 3 4 5 6 7 9 9 10 I I {2 13 id f5 lb il 18 19 IO 21 22 23 24 35 �6llBSIOPP 3:1 3.OQ 3,Q� 3.19 3.30 3.di 3.53 ?.55 3.8G 3.5� 4.i1 d.29 d.d8�.69�.95 i.id 5.55 5.88 6.?d 6.Ei ?.fl: 7.�l1 1,9i @.42 8.93 9.4b ?OA2 6Pti�l R�lii�1 d:t 3.4Q 4.t7 d:35 d.5d d.76 i.00 5.2b i.56 5.$S 6.25 b.67 7.1d 7.b9 8.29 8.42 4.51 10,2d 10.44 I1.61 12.42 13.19 13.99 i�t.82 15,b1 ?b.SS 17.� Select Upslope 8erm Muttiplier �' (based on tand stope): 3.23 (figure D-34) D. Calcutate Upslope Berm VYidth:Muitip(ier (4.C)X Upslope Mound Height (4.6)=Upslope Berm�dth 3.23 n x 4.0 ft = 12.9 tc E. Calculate Drop in Elevation Under Bed:Bed Width (?.B) X Land 5(ope (1.D):100=Drop (ft) 10.0 ft X 7.0 % : 100= 0.70 ft F. Catcutate Downslope Mound Neight:Upslope Height (4.S)+Drop in E(evation (4.E)=Downs(ope Height 4.0 ft + 0.70 ft = 4.7 tt Select Downs(ope Berm Mu(tiplier G' (based on Land slope): 5.32 (figure D-34) H.Calculate Downstope Berm Width:Muttiplier (4.G)X Downslope Height (4.F)=Downsiope Berm Widtfi 5.32 x 4.7 n = 25.0 tt I. Calculate Minimum Berm Lo Cover Absorption Area:Downs(ope Absorption Width (3.B or 3.C)+4 ft.=ft 16.0 ft + � ft = 20.0 ft J. Design Downslope Berm =greater of 4H and 41: 25.0 ft K. Select Endsiope Berm Multiptier: 3.00 (usually 3.0 or 4.0) L. Calculate Endslope Berm (4.K)X Downslope Mound Height (4.F)=Ends(ope Berm Width 3.00 ft x 4.7 ft = 14.1 ft M.Calcutate Mound Width: Upslope Berm Width(4.D)+Bed Width (2.8)+Downslope Serm Width (4.J)=ft 12.9 ft + 10.0 ft + 25.0 ft = 47.9 ft N. Calcutate Mound Length:Ends(ope 8erm Width (4.L)+Bed Length (2.C)+Endslope Berm Width (4.L)=ft 14.1 tt + 63.0 ft + 14.1 ft = 91.2 fc Comments: