2012-00837 - new septic - Laserfiche WebLink

Home Browse Search

3. ABSORPTION AREA SIZING Note:Mound setbacks are measured from the Absorption Area. A. Calculate Absorption Width:Bed Width (2.B)X Mound Absorption Ratio (1.F)=Absorption Width 10.0 ft x 2.0 20.0 ft B. For slopes>1%,the Absorption Width is measured downhill from the upslope edge of the Bed. Calculate Downslope Absorption Width:Absorption Width (3.A)-Bed Width (2.6)-ft 20.0 ft - 10.0 ft 10.0 ft 4. MOUND SIZING A. Calculate Clean Sand Lift: 3 feet mime Depth to Limiting Condition (1.C)=Clean Sand Lift (1 ft minimum) 3.0 ft - 1.7 ft = 1.3 ft Design Sand Lift(optional): C�1.3 B. Calculate Upslope Height:Clean Sand Lift (4.A)+media depth (1 ft.)+cover (1 ft.)=Upslope Height 1.3 ft 1.0 ft + 1.0 ft= 3.3 ft D•34:Slope Multiplier Table land Slope% 0 1 1 1 2 1 3- 4 1 5 1 6 1>7 1 8'1 9 1101 11 11 13 14 15 -16'1 17 1 18 1 14 1 20 1 21 1 5-F-71-T-7-AT-7S7 l)psl0pe 31 3.00 L91 2.83 2.75 2.68 2.61 2.54 2.48 2.42 2.36 2.31 2.26 2.21 2.17 2:13 2.09 2.06 2.03 2.00 1.91 1.95 1.93 t.9i 1.89 1.87 1.85 Berm Ratio 4:t 4.00 3.85 3.10 3.57 3.45 3.33 3.23 3.12 3.03 2:94 2.86 2.78 2.70 2.62 2:55 2AB 2.41 1.35 1 L19.1.,2.23 IL18 12.13 1,.Z.08 I`2:03 11.9911.931 Lands ;*% 0 I 2 3 4 5 1 6 1 7 18 9' 10 ti 11 13 14 15 16 17 I8 19 20 21' 22 :23 I4 25 Donslope 3:1 3.00 3.09 3.19 3.30 3.4{ 3.53 3.66 3.80 3.95 4.11 4.29 4.48 4:69 4.95 5.24 5.55 5.88 634 6.63 7.04 7.47 7.93 8.42 8.93 9.46 10.02 Bean Ratio at 4:00 4.11 4.35 4.53 4.76 5.00 5:26 5:56 5.88 635 6.67 7.14 7.69 8.29 8.42 9.57 t0.I4 10.94 11.67 12.41:13.19 21!1!4M 15.67 16.54 17A4 C. Select Upslope Berm Multiplier (based on land slope): 3.03 (figure D-34) D. Calculate Upslope Berm Width:Multiplier (4.C)X Upslope Mound Height (4.B)=Upslope Berm Width 3.03 1 ft X 3.3 ft s 10.0 ft E. Calculate Drop in Elevation Under Bed:Bed Width (2.B) X Land Slope (1.D):100-Drop (ft) 10.0 1 ft x 8.0 % = 100= 0.80 ft F. Calculate Downslope Mound Height:Upslope Height (4.B)+Drop in Elevation (4.E)-Downslope Height 3.3 ft + 0.80 ft = 4.1 ft G. Select Downslope Berm Multiplier (based on land slope): 6.19 (figure D-34) H. Calculate Downslope Berm Width:Multiplier (4.G)X Downslope Height (4.F)=Downslope Berm Width 6.19 1 x 4.1 ft = 26.0 ft 1. Calculate Minimum Berm to Cover Absorption Area:Downslope Absorption Width (3.11 or 3.C)+4 ft.=ft 10.0 ft + ft = 14.0 ft J. Design Downslope Berm =greater of 414 and 41: 1 26.0 ft K. Select Endslope Berm Multiplier: 3.00 (usually 3.0 or 4.0) L. Calculate Endslope Berm (4.K)X Downslope Mound Height (4.F)=Endslope Berm Width 3.00 Ift X 4.1 ft - 13.0 ft M.Calculate Mound Width:Upslope Berm Width(4.D)+Bed Width (2.B)+Dawnslope Berm Width (4.J)=ft 10.0 ft + 10.0 ft + 26.0 ft = 46.0 ft N. Calculate Mound Length:Endslope Berm Width (4.L)+Bed Length (2.C)+Endslope Berm Width (41)=ft 13.0 ft + 63.0 ft + 13.0 ft = 89.0 ft Comments: