Septic design - Laserfiche WebLink

Home Browse Search

3. ABSORPTION AREA SIZING Note:Mound setbocks are measured 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 slopes>1%, the Absorption Width is measured downhilt from the upslope edge of the Bed. Calculate Downslope Abwrption Width:Absorption Width (3.A)-Bed Width (2.6)=ft 26.0 ft - 10.0 ft = 16.0 ft 4. MOUND SIZING A. Calculate C(ean Sand Lift: 3 feet minus Depth to Limiting Condition (1.C)=C(ean Sand Lift (t ft minimum) 3.0 ft - 1.3 ft = 1.7 ft Design Sand Lift(optional): �1.7 B. Cdlculate Ups(ope Height:C(ean Sand�ift (4.A)+media depth (1 ft.)+cover (1 ft.)=Upslope Height 1.7 ft + 1.0 ft + 1.0 ft= 3.7 ft U 3::)Inp'r Multi0lier`t able ; Land Slope'� 0 I 2 3 d 5 6 1 8 9 10 I I 12 13 14 15 16 il 18 19 20 21 �2 23 24 25 � UpS(Ope l.:l ?.(�':� 2.Si,i.i3�?.75 2.SE 2.5! 25!i:.�+3 1.�i i.?5�2,?I 2.25 2.21 [.'.'"2.13 2.G4 ?.n� 2.0; Ll�' 1.9? I.ii 1.4i I.it 1.Ev I 1.6? 1.9i i Feim RdiQ 'd:l d.�li 3,&5 's.7i� 3,57 3,a5 3.3i 3.2i 3.1i 3.Oi 2.91�2.65 2.)b 2.10 2.62 2.55 2.�18 ?.�ll 2.?5 2.29 2.2's 2.1$ 2.f3 2.Q8 2.C� t.y8 L9i LB�d$IOpE''v 0 1 2 3 4 $ 6 7 8 9 ;4� II It� 13 Id! I`, 16 17 i$ l9 '10 tl 22 23 24 "15 i I ��C�.','I1SIrDP i 3:l :lk� 3.CS�i.'>'i.'s� i.al 3.5? i.55�3.80 J.iS J.1� 1.24 :.,8 :.59 i45':i.21 i.i`� �E8 6.., S.Ei 1.0: 1..{7 1.i's 3.Jt E.4i 9.� i.n.5[i ', 6?fNRd:'r ;�:i a0('4.!1 d.3s a.5d..lb 5.60 5.2hj5.55 5.fi8 6.25 6.b? l.ta 7.69 E.25 8.92 9.51 t0.t�! 10.45 11.6? 12.�2 !3.19 i3.4i N.Bi 15.6' '6.'.1 Il.�j Seled Ups(ope Berm Mu(tiplier �' (based on land slope): 2.71 (figure D-34) D. Catculate!lpsfope Berm Width:Multip(ier (4.C)X Upslope Mound Height (4.6)=Ups(ope Berm Width 2.71 ft X 3.7 ft = 10.0 ft E. Catculate Orop in E(evation Under Bed:Bed Width (2.6) X Land Slope (1.D): 100=Drop (ft) 10.0 ft X 12.0 % _ �00= 1.20 ft F. Calculate Downslope Mound Height:Upslope Height (4.B)+Drop in E(evation (4.E)=Downs(ope Height 3.7 ft + 1.20 ft = 4.9 ft Select Downstope Berm Mu(tiplier �' (based on land slope): 5.11 (fi�ure D-34) H. Calculate Downsfope Berm Width:Mu(tip(ier (4.G)X Downslope Height (4.F)=Downslope Berm Width 5.11 x 4.9 ft = 25.0 ft I. Calculate Minimum Berm to Cover Absorption Area:Downslope Absorption Width (3.6 or 3.C)+4 ft. =ft 16.0 ft + �4 ft = 20.0 ft J. Design Downslope Berm =greater of 4H and 41: 25.0 ft K. Select Ends(ope Berm Multiplier: 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 4.9 ft = 15.0 ft M.Calculate Mound Width: Upslope Berm Width(4.D)+Bed Width (2.6)+Downs(ope Berm Width (4.J)=ft 10.0 ft + 10.0 tt + 25.0 ft = 45.0 fc N. Calculate Mound Length:Endslope Berm Width (4.L)+Bed Length (2.C)+Endsiope Berm Width (4.l)=ft 15.0 ft + 63.0 ft + 15.0 ft = 93.0 ft Comments: