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HomeMy WebLinkAboutSUB201800002 Calculations 2018-04-19 / F, NOKESVILLE ESIGN PLC Sewage Disposal System Water Mounding Analysis Greenloft Farm, Lot 7 April 19, 2018 References: Virginia Department of Health GMP #72 and Site and Soils Evaluations Conducted by J.T. Frazier, DPOR Licensed On Site Evaluator (AOSE) #1940-001384. Case Conditions: The proposed absorptions areas are contiguous and identical, therefore the calculations represent both the install and reserve. Install or Reserve Sewage Absorption Area, Site 117F Slope of the proposed absorption areas is approximately 8%. There are indications of potential limiting features at 3-4" redox in all holes. • Lc= 72' LI= 55' Average A =72/55 = 1.309 Q =J =600 gpd = 80.21 ft3/day Average K,= 0.150 ft/day = 90 mpi Average K2= 0.035 ft/day = 245 mpi (Ksat rate = 120 mpi) Proposed Installation Depth = +3" (above grade) Slope = 0.08 Calculations The analysis was performed using spread sheet calculations for the "Khan" solution. The attached spread sheet indicates that water mounding will not occur under the proposed drainfield installation and reserve area at the proposed treatment level, TL-3+ UV disinfection. >w 2).1,1 -` "?eye 'N lT ilb r+� / eke '.4; ifa tea.V wV u El IMMO P.O. BOX 635 NOKESVILLE, VA 20182 703.594.2425 www.nokesvilledesign_com Khan et al.(1976)Analytical Solution from Guidance for Evaluation of Potential Groundwater Mounding Associated with Cluster and High-Density Wastewater Soil Absorption Systems;Colorado School of Mines:Golden,CO:January,2005 Volume of Effluent Dispersed per Day= 600 gpd Number of Trenches in Dispersal Field(OF)= 1 Enter"1"for Drip or Pad r-4 Dispersal Area Width(down slope= 72 ft Dispersal Area Length(across slope)= 55 ft d Center-to-Center Trench Spacing= 0 ft Enter"0"for Drip or Pad Vadose Zone Permeability(Ki)= 0.1500 ft/day (Approx. 90 mpi) Restrictive Layer Permeability(K2)= 0.0350 ft/day (Approx. 245 mpi) 23.33%of K1 172.80%of q' El Installation Depth(+below grade/-above grade)_ -0.25 ft Depth to SHWT or WT= 0.25 ft Minimum Vertical Separation Required: Total= 0.50 ft Enter"1.5"for STE,"1.0"for TL-2 or TL-3 w/o disinfection,or'0.5'for TL-3 WI standard disinfe In situ Soil= 0.00 ft Enter"1.5"for STE,"0.5"for TL-2 or TL-3 w/o disinfection,or*0.0"for TL-3 w/standard disinfe Maximum Allowable Mound Height= 0.00 ft If Nearby Slope Cuts Through Restrictive Laver Horizontal Distance from Center of DF DF Width(W)= 72 ft to Exposed Restrictive Layer(Ls)= 50 tt DF Half-Width(w)= 36 ft DF Length= 55 ft If Nearby Slope Does Not Cut Through Restrictive Laver DF Area= 3,960 sqft Horizontal Distance from Center of OF Effluent Volume= 80.21 cuft/d to Base of Slope(Xs)= 0 ft Effective Infil.Rate(q')= 0.0203 ft/day Restrictive Layer Depth at Base of Slope(Hs)= 0.00 ft K2/K1= 0.2333 Lateral Extent of Mound from OF Center(L)= N/A ft q'/K2= 0.5787 (q"/K2)-1= -0.4213 Maximum DF Half-Width to Prevent Slope Breakout(wmsx)= 86.40 it K2/q"= 1.7280 Maximum DF Width to Prevent Slope Breakout(Wmsx)= 172.80 ft (Ki/K2)^0.5= 2.0702 Distance Distance from For 0<_x s w: H=w((K2/K1)((q"/K2)-1)((q'/K2)-(x^2fw'2))J^0.5 Increment Center of OF Mound Height For w_5 x 5 L: H=((K2/K1)^0.5)(L-x) 4.00 ft x H u flu (x^2)/(w^2) (g'/K2)-((x^2)/(w^211 Center of DF 0.0 0.00 0 0.578705211 4.0 0.00 0.012345679 0.566359532 8.0 0.00 0.049382716 0.529322495 12.0 0.00 0.111111111 0.4675941 16.0 0.00 0.197530864 0.381174347 20.0 0.00 0.308641975 0.270063235 24.0 0.00 0.444444444 0.134260766 28.0 0.00 0.604938272 -0.026233061 32.0 0.00 0.790123457 -0.211418246 Edge of OF 36.0 0.00 1 -0.421294789 40.0 0.00 1.234567901 -0.65586269 • Frazier Consultants SATURATED HYDRAULIC CONDUCTIVITY WORKSHEET Sheet No.: Project Name.: Greenloft Lot 7 Parcel • Lot 7 Terminology and Solution I (� Boring No • I Site 117F Hole A Date • 4/10/2018 Ksat: Saturated hydraulic conductivity Investigators.: evi ovum File Name Q: Steady-stale rate of water flow into the soil C•F=S) Boring Depth.: I 18" \ WCU Base.Ht.h: 15.0 cm _ H: Constant height of water in borehole �2' Boring Dia • I ---------J9.5 cm .WCU Susp.Ht.S: 0.0 cm r. Radius of cylindrical borehole ' r1--, Boring Rad.(r): I 4.75 cm Const.Wtr.Ht.H: 15.0 cm Ksat =Q[sinh-1(H/r)-(r2/H2+1).5+r/HI/(2pH2) [Glover Soli �� Volume(Start) Volume(End) Volume(Out) TIME Elapsed Time Flow Rate Q ---•-••- Ksat Equivalent Values----- (m1) (ml) (ml)[al (hr:min:sec alp) (hr:min:sec) (min)[b] (mi/min)[alb (cm/min) (cm/sec) (cm/day) (in/hr) (ft/day) El . H^j.� '+.J,-.wr Y sYe'i'-}QL '+."- 4 .� ,.e'. a 2020 i..r,. ,.._�_...--u.,.. . •:+,.4t:;• .a 3r. �,-i T MZ:..:.... sF `- d.-7>`Jt�.�G.,: +,..?_.,..-'Y�i�....r..,.. , .....& .7^> ,.F_,�-,. . 2020 970 1050 9:55:00 AM 1970 1970 50 10:05:00 AM 0:10:00 10.00 5.00 0.004 6.69E-05 5.8 0.095 0.19 19201 1920 50 10:15:00 AM 0:10:00 10.00 5.00 0.004 6.69E-05 5.8 0.095 0.19 1880 1880 40 10:25:00 AM 0:10:00 10.00 4.00 0.003 5.35E-05 4.6 0.076 0.15 18401 1840 40 10:35:00 AM 0:10:00 10.00 4.00 0.003 5.35E-05 4.6 0.076 0.15 18101 1810 30 10:45:00 AM 0:10:00 10.00 3.00 0.002 4.01E-05 3.5 0.057 0.11 17901 1790 20 10:55:00 AM 0:10:00 10.00 2.00 0.002 2.68E-05 2.3 _ _0.038 0.08 17501 1750 40 11:05:00 AM 0:10:00 10.00 4.00 0.003 5.35E-05 4.6 0.076 0.15 1710 1710 40 11:15:00 AM 0:10:00 10.00 4.00 0.003 5.35E-05 4.6 0.076 0.15 1680 1680 30 11:25:00 AM 0:10:00 10.00 3.00 0.002 4.01E-05 3.5 0.057 0.11 1650 1650 30 11:35:00 AM 0:10:00 10.00 3.00 0.002 4.01E-05 3.5 0.057 0.11 1630 1630 20 11:45:00 AM 0:10:00 10.00 2.00 0.002 2.68E-05 2.3 0.038 0.08 16001 1600 30 11:55:00 AM 0:10:00 10.00 3.00 0.002 4.01E-05 3.5 0.057 0.11 1570 1570 30 12:05:00 PM 0:10:00 10.00 3.00 0.002 4.01E-05 3.5 0.057 0.11 1550 1550 20 12:15:00 PM 0:10:00 10.00 2.00 0.002 2.68E-05 2.3 0.038 0.08 1520 1520 30 12:25:00 PM 0:10:00 10.00 3.00 0.002 4.01E-05 3.5 0.057 0.11 1500 1500 20 12:35:00 PM 0:10:00 10.00 2.00 0.002 2.68E-05 2.3 0.038 0.08 1480 20 12:45:00 PM 0:10:00 10.00 2.00 0.002 2.68E-05 2.3 0.038 0.08 Avg.cm/day 3.7 (Natural Moisture: Init.Satur.Time: ESTIMATED FIELD KSAT: ITexture/Classif: Consistency: Depth to an Impermeable Notes: 1Structure/Fabric: Slope/Landsc: Depth to , ksatReportl.xls Precision Permeameter'm Rev.4/5/002 Frazier Consultants I SATURATED HYDRAULIC CONDUCTIVITY WORKSHEET Sheet No.: Project Name.: Greenloft Lot 7 Parcel • Lot 7 Terminology and Solution Boring No • Site 117F Hole B Date • 4/10/2018 Ksat: Saturated hydraulic conductivity Investigators.: Kevin Corum File Name Q: Steady-stale rate of water flow into the soil Cg Boring Depth.: I 18" WCU Base.Ht.h: 15.0 cm H: Constant height of water in borehole d Boring Dia.....: ! 9.5 cm WCU Susp.Ht.S: 0.0 cm r: Radius of cylindrical borehole Boring Rad.(r): 4.75 cm Const.Wtr.Ht.H: 15.0 cm Ksat =Q[sinh-1(H/r)-(r2/H2+1).5+rM]/(2pH2) [Glover Soh Volume(Start) Volume(End) Volume(Out) TIME Elapsed Time Flow Rate Q ----------Ksat Equivalent Values----------- El - (ml) (ml) (ml)[a] (hr:min:sec a/p) (hr:min:sec) (min)[b] /(mllmin)[a/b (cm/min) (cm/sec) (cm/day) (in/hr) (ft/day) 2020 1 _ _... wrv"ca �F .s=.. ;� .� '.. ,u.-.' .._ .ice � -ds,;.a + 4 2020 0 2020 9:55:00 AM _ _ 1330 1330 690 10:05:00 AM 0:10:00 10.00 69.00 0.055 9.23E-04 79.8 1.309 2.62 1990 650 680 10:15:00 AM 0:10:00 10.00 68.00 0.055 9.10E-04 78.6 1.290 2.58 1350 1350 640 10:25:00 AM 0:10:00 10.00 64.00 0.051 8.56E-04 74.0 1.214 2.43 1950 750 600 10:35:00 AM 0:10:00 10.00 60.00 0.048 8.03E-04 69.4 1.138 2.28 1420 1420 530 10:45:00 AM 0:10:00 10.00 53.00 0.043 7.09E-04 61.3 1.005 2.01 920 920 500 10:55:00 AM 0:10:00 10.00 50.00 0.040 6.69E-04 57.8 0.948 1.90 1980 240 680 11:05:00 AM 0:10:00 10.00 68.00 0.055 9.10E-04 78.6 1.290 2.58 1510 1510 470 11:15:00 AM 0:10:00 10.00 47.00 0.038 6.29E-04 54.3 0.891 1.78 970 970 540 11:25:00 AM 0:10:00 10.00 54.00 0.043 7.23E-04 62.4 1.024 2.05 2000 490 480 11:35:00 AM 0:10:00 10.00 48.00 0.039 6.42E-04 55.5 0.910 1.82 1390 1390 610 11:45:00 AM 0:10:00 10.00 61.00 0.049 8.16E-04 70.5 1.157 2.31 920 920 470 11:55:00 AM 0:10:00 10.00 47.00 0.038 6.29E-04 54.3 0.891 1.78 1910 420 500 12:05:00 PM 0:10:00 10.00 50.00 0.040 6.69E-04 57.8 0.948 1.90 1290 1290 620 12:15:00 PM 0:10:00 10.00 62.00 0.050 8.30E-04 71.7 1.176 2.35 830 830 460 12:25:00 PM 0:10:00 10.00 46.00 0.037 6.15E-04 53.2 0.872 1.74 1180 290 540 12:35:00 PM 0:10:00 10.00 54.00 0.043 7.23E-04 62.4 1.024 2.05 610 570 12:45:00 PM 0:10:00 10.00 57.00 0.046 7.63E-04 65.9 1.081 2.16 Avg.cm/day 65.1 Natural Moisture: snit.Satur.Time: ESTIMATED FIELD KSAT: ITexture/Ciassif: Consistency: Depth to an Impermeable Notes: (Structure/Fabric: _Slope/Landsc: ,Depth to ksatReportl.xts Precision Permeameter" Rev.4/5/002 Frazier Consultants SATURATED HYDRAULIC CONDUCTIVITY WORKSHEET Sheet No.: 1 , 0 Project Name.: Greenloft Lot 7 Parcel • Lot 7 Terminology and Solution =:0 Boring No......: I Site 117F Hole C Date • 4/10/2018 Ksat: Saturated hydraulic conductivity G Investi•ators.: I Kevin Corum File Name • Q: Steady-state rate of water flow into the soil Boring Depth.: f 18" WCU Base.Ht.h: 15.0 cm H: Constant height of water In borehole Boring Dia • 9.5 cm WCU Susp.Ht.S: 0.0 cm r: Radids of cylindrical borehole Boring Rad.(r): I 4.75 cm Const.Wtr.Ht.H: 15.0 cm Ksat =Q[sinh-1(H/r)-(r2/H2+1).5+rill]/(2pH2) [Glover Sol lia (Start) (End) (Out) TIME Elapsed Time Flow Rate a --- ----Ksat Equivalent Values----- - Volume Start Volume End Volume 2020 k;= [a] (hr:min:sec a/p) (hr min sec) (min)[b] (ml/min)[a/b (cm/min) (cm/sec) (cm/day) (in/hr) (ft/day) (mq (ml) - . ,y• -•. ?' o f.`',Al if4i13 ? *arm `y.w.;;f,:.ni f4 ' ' xb w _ 4 : x-. ..... ..- ._.......-� ''�i-fr. -. ..,...s�w+n..,. .- ...� ., 4 `xcY�;...;C+:h;}... T�.ti �.^bu 2020 490 1530 9:55:00 AM - 1670 1670 350 10:05:00 AM 0:10:00 10.00 35.00 0.028 ' 4.68E-04 40.5 0.664 1.33 1320 1320 350 10:15:00 AM 0:10:00 10.00 35.00 0.028 4.68E-04 40.5 0.664 1.33 960 960 360 10:25:00 AM 0:10:00 10.00 36.00 0.029 . 4.82E-04 41.6 0.683 1.374 1990 640 320 10:35:00 AM 0:10:00 10.00 32.00 0.026 4.28E-04 37.0 0.607 1.21 1710 1710 280 10:45:00 AM 0:10:00 10.00 28.00 0.022 3.75E-04 32.4 0.531 1.061 1410 1410 300 10:55:00 AM 0:10:00 10.00 30.00 0.024 4.01E-04 34.7 0.569 1.14 1050 1050 360 11:05:00 AM 0:10:00 10.00 36.00 0.029 4.82E-04 41.6 0.683 1.37 760 760 290 11:15:00 AM 0:10:00 10.00 29.00 0.023 3.88E-04 33.5 0.550 1.10 1950 430 330 11:25:00 AM 0:10:00 10.00 33.00 0.026 4.42E-04 38.1 0.626 1.25 1650 1650 300 11:35:00 AM 0:10:00 10.00 30.00 0.024 4.01E-04 34.7 0.569 1.14 1260 1260 390 11:45:00 AM 0:10:00 10.00 39.00 0.031 522E-04 45.1 0.740 1.48 910 910 350 11:55:00 AM 0:10:00 10.00 35.00 0.028 4.68E-04 40.5 0.664 1.33 1950 550 360 12:05:00 PM 0:10:00 10.00 36.00 0.029 4.82E-04 41.6 0.683 1.37 1500 1500 450 12:15:00 PM 0:10:00 10.00 45.00 0.036 6.02E-04 52.0 0.853 1.71 1150 1150 350 12:25:00 PM 0:10:00 10.00 35.00 0.028 4.68E-04 40.5 0.664 1.33 760 760 390 12:35:00 PM 0:10:00 10.00 39.00 0.031 5.22E-04 45.1 0.740 1.48 340 420 12:45:00 PM 0:10:00 10.00 42.00 0.034 5.62E-04 48.6 0.796 1.59 Avg.cm/day 40.5 Natural Moisture: Init.Satur.Time: ESTIMATED FIELD KSAT: ITexturelClassit: Consistency: Depth to an Impermeable Notes: Structure/Fabric: Slope/Landsc: Depth to icsatReportf xis Precision Permeameter"" Rev.4/5/002 Frazier Consultants I SATURATED HYDRAULIC CONDUCTIVITY WORKSHEET Sheet No.: , Project Name.: Greenloft Lot 7 Parcel • Lot 7 Terminology and SolutionEl Boring No • I Site 117F Hole D Date • 4/10/2018 Ksat: Saturated hydraulic conductivity Investigators.: I Kevin Corum File Name Q: Steady-state rate of water flow into the soil LL Boring Depth.: I 18" WCU Base.Ht.h: 15.0 cm H: Constant height of water in borehole d Boring Dia • I 9.5 cm WCU Susp.lit.S: 0.0 cm r: Radius of cylindrical borehole d Boring Rad.(r): I 4.75 cm Const.Wtr.Ht.H: 15.0 cm Ksat =Qjsinh-1(H/r)-(r2/H2+1).5+r/HJ/(2pH2) [Glover Sol Volume(Start) Volume(End) Volume(Out) TIME Elapsed Time Flow Rate 0 -----------Ksat Equivalent Values - ---- (ml) (ml) (ml)[a] (hr:min:sec a/p) (hr:min:sec) (min)[b] jmllmin)[a/b (cm/min) (cm/sec) (cm/day) (in/hr) (ft/day) 0 2020{.t-...--- , :_h. #r. - . Fk. ` b R�,�-N -Vic i irg r.3 i.°1 s" XMT: ��� . r ivV.n , r.--_ *.z.r ` r 2020 1060 960 9:55:00 AM 1880 1880 140 10:05:00 AM 0:10:00 10.00 14.00 0.011 1.87E-04 162 0.265 0.53 1750 1750 130 10:15:00 AM 0:10:00 10.00 13.00 0.010 • 1.74E-04 15.0 0.247 0.49 1570 1570 180 10:25:00 AM 0:10:00 10.00 18.00 0.014 2.41E-04 20.8 0.341 0.68 1390 1390 180_ 10:35:00 AM 0:10:00 10.00 18.00 0.014 2.41E-04 20.8 0.341 0.68 1260 1260 130 10:45:00 AM 0:10:00 10.00 13.00 0.010 1.74E-04 15.0 0.247 0.49 1180 1180 80 10:55:00 AM 0:10:00 10.00 8.00 0.006 1.07E-04 9.2 0.152 0.30 1090 1090 90 11:05:00 AM_ 0:10:00 10.00 9.00 0.007 120E-04 10.4 0.171 0.34 980 980 110 11:15:00 AM 0:10:00 10.00 11.00 0.009 1.47E-04 12.7 0.209 0.42 860 860 120 11:25:00 AM 0:10:00 10.00 12.00 0.010 1.61E-04 13.9 0.228 0.46 730 730 130 11:35:00 AM 0:10:00 10.00 13.00 0.010 1.74E-04 15.0 0.247 0.49 1870 540 190 11:45:00 AM 0:10:00 10.00 19.00 0.015 2.54E-04 22.0 0.360 0.72 1710 1710 160 11:55:00 AM 0:10:00 10.00 16.00 0.013 2.14E-04 18.5 0.303 0.61 1550 1550 160 12:05:00 PM 0:10:00 10.00 16.00 0.013 2.14E-04 18.5 0.303 0.61 1390 1390 160 12:15:00 PM 0:10:00 10.00 16.00 0.013 2.14E-04 18.5 0.303 0.61 1290 1290 100 12:25:00 PM 0:10:00 10.00 10.00 0.008 1.34E-04 11.6 0.190 0.38 1080 1080 210 12:35:00 PM 0:10:00 10.00 21.00 0.017 2.81E-04 24.3 0.398 0.80 880 200 12:45:00 PM 0:10:00 10.00 20.00 0.016 2.68E-04 23.1 0.379 0.76 Avg.cm/day 16.8 'Natural Moisture: Init.Satur.Time: ESTIMATED FIELD KSAT: (Texture/Classlf: Consistency: Depth to an Impermeable Notes: IStructure/Fabric: Slope/Landsc: Depth to ksatReportl.xis Precision Permeameter" Rev.4/5/002 Frazier Consultants SATURATED HYDRAULIC CONDUCTIVITY WORKSHEET Sheet No.: 0 Project Name.: Greenloft Lot 7 Parcel • Lot 7 Terminology and Solution Boring No • Site 117E Hole E Date • 4/10/2018 Ksat: Saturated hydraulic conductivity () Investigators.: I Kevin Co rum File Name • Q: Steady-state rate of water flow into the soil Cg Boring Depth.: 1 18' WCU Base.Ht.h: 15.0 cm H: Constant height of water in borehole Boring Dia 9.5 cm WCU Susp.Ht.S: 0.0 cm r: Radius of cylindrical borehole Boring Rad.fir): I 4.75 cm Const.Wtr.Ht.H: 15.0 cm Ksat =Q[sinh-1(H/r)-(r2/H2+1).5+r/H]/(2pH2) [Glover Soli Volume(Start) Volume(End) Volume(Out) TIME Elapsed Time Flow Rate O Ksat Equivalent Values------- in - (ml) (mp (ml)[a] (hr•min:sec alp) (hr•min•sec) (min)[b] (mi/min)[a/b (cm/min) (cm/sec) (cm/day) (in/flr) (ft/day) 2020 i' v; ' 2020_ 1060 960 9:55:00 AM _ _ 1970 1970 50 10:05:00 AM 0:10:00 10.00 5.00 0.004 6.69E-05 5.8 0.095 0.19 1870 1870 100 10:15:00 AM 0:10:00 10.00 10.00 0.008 1.34E-04 11.6 0.190 0.38 1780 1780 90 10:25:00 AM 0:10:00 10.00 9.00 0.007 1.20E-04 10.4 0.171 0.34 1690 1690 90 10:35:00 AM 0:10:00 10.00 9.00 0.007 1.20E-04 10.4 0.171 0.34 1620 1620 70 10:45:00 AM 0:10:00 10.00 7.00 0.006 9.37E-05 8.1 0.133 0.27 1560 1560_ 60 10:55:00 AM 0:10:00 10.00 6.00 0.005 8.03E-05 6.9 0.114 0.23 1470 1470 90 11:05:00 AM 0:10:00 10.00 9.00 0.007 1.20E-04 10.4 0.171 0.34 1410 1410 60 11:15:00 AM 0:10:00 10.00 6.00 0.005 8.03E-05 6.9 0.114 0.23 1320 1320 90 11:25:00 AM 0:10:00 10.00 9.00 0.007 1.20E-04 10.4 0.171 0.34 1240 1240 80 11:35:00 AM 0:10:00 10.00 8.00 0.006 1.07E-04 9.2 0.152 0.30 1160 1160 80 11:45:00 AM 0:10:00 10.00 8.00 0.006 1.07E-04 9.2 0.152 0.30 1050 1050 110 11:55:00 AM 0:10:00 10.00 11.00 0.009 1.47E-04 12.7 0.209 0.42 1000 1000 50 12:05:00 PM 0:10:00 10.00 5.00 0.004 6.69E-05 5.8 0.095 0.19 920 920 80 12:15:00 PM 0:10:00 10.00 8.00 0.006 1.07E-04 9.2 0.152 0.30 840 840 80 12:25:00 PM 0:10:00 10.00 8.00 0.006 1.07E-04 9.2 0.152 0.30 760 760 80 12:35:00 PM 0:10:00 10.00 8.00 0.006 1.07E-04 9.2 0.152 0.30 670 90 12:45:00 PM 0:10:00, 10.00 9.00 0.007 1.20E-04 10.4 0.171 0.34 Avg.cm/day 9.2 _ iNatural Moisture: Init.Satur.Time: ESTIMATED FIELD KSAT: (Texture/Classif: Consistency: Depth to an Impermeable Notes: `Structure/Fabric: Slope/Landsc: Depth to ksalReporti.xls Precision Permeameter"' Rev.4/5/002