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HomeMy WebLinkAbout1994-07-20 Septic System Design ReportSYSTEM DESI%.d FOR FTC HOMES OF LOT 9, BLOCK 1, SHADOWOOD FARM ORONO, MINNESOTA 7-20-94 Information follows for a pressure mound system for a four bedroom house proposed on the above property. All construction and mater- ials must be.in accordance with MPCA Chapter 7080 and City of Orono codes. All construction traffic must be kept off the primary and the alt- .. ornate septic'areas. These areas should be marked off prior to construction. A pumping tank will be needed to house the pump necessary for pressure distribution to the system. The manifold and supply line pipe must be constructed to drain back to the pumping tank. A weather proof enclosure will be needed for the controls and switches for the pump and a warning light/sound system will be needed to warn of pump failure. If any other information is needed, please contact me. Sincerely,. PERCOR, ZINC. Mark S. Gronberg MOUND DESIGN WORKSHEET (For Flows up to 1200 gpd) A. FLOW Estimated 6 v o gpd or measured x 1.5 = gpd. B. SEPTIC TANK LIQUID VOLUMES OAS Y2 SQ gallons 4 6a6 /,00 ,0 61GZ o,✓ f o�/E /000 6A�ta✓ /tIM/ivG Tifl/k. C. SOILS (refer to site evaluation) 1. Depth to restricting layer = -/ inches 2 Depth of percolation tests = /S inches 3. Percolation rate S. 3 mpi 4. Land slope 41 90 Eohad Some RM ill G4M= vw Day (SP4 �.,r r p.. 2.r br 750 sonbw of TM 1 Typo a lyes m Type 1v 2 300 225 180 Goa 3 630 300 218 of 4 s 600 730 375 2S6 4S0 294 •''" 6 7 900 1050 325 332 600 370 .�.r r„=„ 8 1 1200 675 M Nwa6rof �.,r r p.. 2.r br 750 1.126 3RI IAW 1.500 S W 6 1300 2330 7w$ 2= low @V W 9 Sin a& C-6 (z 13) D. ROCK LAYER DDdENSIONS 1. Multiply flow rate by 0.83 to obtain required area of rock layer: A x 0.83 = _ 6 �o gpd x 0.83 sq. ft./gpd = soo sq. ft. 2. Select width of rock layer (10 feet or less) _ /0 ft. 3. Length of rock layer = area + width = Rock Bed SDD sq. ft. + /V_ ft. = -T-0 ft. ;��i%`%•. .iieh 510 ft. =i?3`iTi •i.•.•?i� E. ROCK VOLUME 1. Multiply rock area by rock depth to get cubic feet of rock; SDo sq. ft. x / ft. _ 5W cu. ft. 2. Divide cu. ft: by 27 cu. 't./cu. yd. to get cubic yards; Seo cu. ft. + 27 - 12,15 cu. yd. 3. Multiply cubic yards by 1.4 to get weight of rock in tons; / .S cu. yd. x 1.4 ton/cu. yd. - 2 6 tons. F. ADSORPTION WIDTH 1. Percolation rate in top 12 inches of soil is _ .� mpi 2. Select allowable soil loading rate from table; us6 0.6o gpd/fe 3. Cali1date adsorption width ratio by dividing rock layer loading rate of 1.20 gpd/ft2 by allowable scu loading rate; 1.20 gpd/ft=+ . CO gpd/ft2 = 2.0 4. Multiply adsorption width ratio by rock layer width to get required adso tion width; • 0 x (�, �t = 2 �� ft AWWPGWWW1k29ftUb r p.. Soil Twum app+► Faster than 0.1 Comm Sand 120 1.00 0.1 to 5 Sand 1,20 0.1 to 5 Fine Sand- 0.60 2.00 6 to 15 5and.52Ly Loans 0.79 1 16 to 30 Loath 31 to 45 Silt Loath 0.500.45 240 46 to 60 Cly Loam 2.40 61 t0120 Clay 024 5.00 Slower than 120 Clay - "fa0 Irvf� SOAR � Www d do � rl�r ati awl 31 G. DOWNSLOPE DUM WIDTH I. If landslope is 3% or more, subtract rock layer width from adsorption width to obtain minimum downslope dike toe , 20 ft • L_ ft- _/0 feet 2.' Calculate Minimum mound size based on geometery: a. Determine depth of clean sand fill at upslope edge of rock layer. Separation L S feet b. Multiply rock layer width by landslope to determine drop in elevation; Slope Difference ssoorotloh /a x _Y 90 + 100 = 0• Y feet uos►tot width c. Add depth of dean sand for separation (2a) tett at upslope edge, depth of rock layer (1 foot) to depth of cover (1 foot) to find the mound height at the upslope edge of rock layer, 1,Sift+Ift+Ift=,Z.�; feet d. Enter table with landslope and upslope dike ratio'. Select dike multiplier )f e. Multiply dike multiplier by upslope mound height to find upslope dike width:._ VS x -2.5— = /1.1 feet f. Add depth of dean sand for slope difference (2b) at downslope edge, to the mound height at the upslope edge of rock layer (20 to find the downslope height; ...5 ft+eft=,,tfeet g. Enter table with landslope and downslope dike ratio. Select dike multiplier of V. 7 6 It. Multiply dike multiplier by downslope mound height to get downslope dike width: 9.9 x JL7L = /gO. 6 feet i. Compare the values of step G.1 and Step G.2h Select the greater of the two values as the downslope dike width; feeter— I toot Cove t't••t RtZtt.d rut . Slope Difference �. Rocr old width feet °ownsloot width tett j. Total mound width is the sum of toot .. upslope dike (G.2e) width plus rock layer width (D.2) plus "s u••i::• M1list downslope dike width(G.2i); `e" a�.. /2. / ft + /a ft + /8. 6 ft = o• 7 feet k. Total mound length is the sum of °i"�"`N•f.sta upslope dike width (G.2e) plus rock layer length (D3) plus upslope dike widtah (G.2e); [.- ...�. Z.L Z� Z. / ft + S ft + 2 ft = 2 feet "I� • Tttel letdtt 31 u W r fa 7:1 u u -r$-1 ` 61 7:1 a • o � 38 ao sa fro 7J 1.8 ao to u sa N 1 301 u7 LN •io Til 2.111 3i 4.76 Lff am 741 3 311 &A a% as Lu 3Jt in aft 363• ltI L7t alt uo 3 3M aft Lao lit am o77 371 lY to is aft 4.17 i+a alt Lff aol • 3a ax am as a0 Tit a77 167f tY 331 lOD a+i L» 1171 1 33 3 3A La 7.1• did UN 236 Lal 1•l an l0 4" 36.1 L13 f 7 3A0 1156 7Y 1636 Ulf 34 3.13 3.70 as a0 aft •N d LA LN to lssm ups less US 236 :um M u u •� • au to! tLad 7331 Sit � •r •if 11 w af7 7u tut l� 30,41 i Sao 7US 7s Lin am s.d0 40 I= 731 3711 3u 12 w fes �.,�• a �� � . • ; to tea. �c A. Determine pump capacity: Gravity Distribution 1. Minimum suggested is 600 gallons per hour (10 gpm) to stay ahead of water use rate. 2. Maximum suggested for delivery to a drop box of a home system is 2,700 gallons per hour (45 gpm) to prevent build-up of pressure in drop box. Pressure Distibution 3 3. a. Select number of perforated laterals b. Select perforation spacing a 3 feet c. • Su�ct 2 fL from the layer length. y-�- 2 fL s Y �feel d. Determine the number of spaces between perforations. Length perf. spacing - W fL * 3 ft. - _6 spaces e. L_ spaces + i = /_ perforations/lateral f. Multiply perforations per lateral by number of laterals to t t total number of perforations. t,WL x Q7 r� perforations. g. x gwr 38 Spm, SELECTED PUMP CAPACrrY 3 S gpm B. Determine head requirements: 1. Elevation difference between pump and point of discharge. _feet 2. if pumping to a pressure distribution system, five feet for pressure required at manifold if gravity system, zero. S feet 5. Friction loss a. Enter friction loss table with gpm and pipe diameter. Read friction loss in feet per 100 feet from table. F.L.- 3,W fL/100 (t of pipe woe ?.O'' AWC b. Determine total pipe length from pump to discharge potnL Add 25 percent to pipe length for fitting loss, or use a fitting loss chart. Equivalent pipe length -1.25 times pipe length= �VO x 1.25 - SG feet c. Calculate total friction toss by multiplying friction Ioss in ft/100 ft by equivalent pipe length. Total friction loss - 2 - V/ x _J-.0 loo. A 2 feet 4. Total head required is the sum of elevation difference, special head requirements, and total friction loss. 6 + S + 1.2 (1) W (3d TOTAL HEAD /2•. feet G Pimp selection 1. A pump must be selected to deliver at least P gpm .(Step A) with at least _,ZZ, feet of total head (Step B). F-17 DO PCFWORATt' 1 Or • INDWORATO LATEU-1 C~ Coal, tar dar of b r . carr to ra- r/ tical Lora � �i iti. M �, .r.......� wHooam%bobo abboa4 yi Y lW get. to" V Ara Lora Coma Same WW R.qubad Pwhrad= • !n aaltaru pmmirwta ar Disc 04160 0.69 0.20 1.0a 0.56. 0.:4 2.Ob 0.80. 1.04 a. Use for single family homes b. Use for all other applications Pipe L cn8th Point of D'Lscharg Ej;:-�Etvttdan Diffarnce.. P F -18b .. 13 inch 2.0 inch Minch am r wmlr.p.10ondpips 10 0.69 0.20 12 0.96 0.28 14 1.28 038 16 1.63 0.48 18 203 0.60 20 Z.47 0.73 0.11 25 3.73 1.11 0.16 30 533 1.55 0.23 35 7.90 Z06- 030 40 1I.07 L64 039 45 14.73 3.28 0.48 so 3.99 0.58 55 4.76 0.70 60 5.60 0.82 /Me�tXf• Al QTc //oma f f 0taek /� I1.1-4,04"40 Azrm 3. o0 low /-b �I�O/0J1f 0�1 { o T/AvKI m pw ty sire /o x So' ,*vex QEo /Mbooroo Al F arc //o/v Fr 00 Uri /6 /-y /0.*Pivjp 1 ° Z T�'( 1ut) wKf �Y r�rf COCO or POW�-z Loos of Soil Borings 11-18 ,-- Lo%'—cL i.ocation or Project g�.1v 164,<164,< /—_ ---------•— U Bor'-^ made by CiV-1 re/-- --. 17ate TU_39-_ - _---- Classification System: AASHO USDA -SCS x Unified ._her ;Auger used (check. two): Hand �, or Power _: Flight _, or Bucket 4—t other Depth, Boring, number: : in Surf"ce elevation feet BLAc k L, o,'M GRCY t3L.,4ck L oA :o, ,tS - se NO?-GxxS.C- .(I►�7) A orn« j p 0�i �Be CIA M 9- SoMr S4NP End of boring at _ eee Standing water table: Present at —I I Eeat of depth, hours after boring. Not present in boring hole .icttled soil: Observed at i go" of depth. vot rresent in boring hole _ Obsurvations and comments: Depth, in feet n— I�— 3 -- 4 — 5 — 6 — 7 — 8 Boring number Surface elevation BLhck 110415 (. C—Y �L�c/< L a�!� ,n•CGRSy J_V,1M sAA,C{ >r F End of boring at �_ Z4"• Standing water table: Present at feet of depth, i Q hours after boring.. Not present 'in boring,. hole — Mottled soil: Observed at �_ Soon of depth. INot present in boring hole Observations, and commsnts: Logs of Soil Borings 11-18 Location or Pro Inct LLTAil L of 9 Borings made by a& e f-nko'Wh iU6= _ Date— Classification System: AASHO USDA -SCS —; Unified other _ Auger used (check two): Hand �, or Power P1iFitt _, or DjckLt ; other Depth, Boring, numher.-_3 Depth, Boring numherin 7 in feet Surface elevation' feet Surface elevation - - 0 — -- -- 3L,1cK L0'6jV BLic k' L - o 1/41. /'�/oTTLsYO GRE 13R, Fin�L Lc���lyS�+M —LT�cL�l 3 — 4 — I'• 5 — 6 — •7 — End of boring at _�_ Saar_ Standing i4ater table: Present at 1w fee-tr Of depth, hours after borinc. Not present in boring sole Mottled soil: Observed at �_ JWW% of depth. llot present in boring. hole Observations and comments: GQy�3�,a�/� -pot-,0"-/'A C- GRcy.'.S-CA��? r . P L977 L E M 3 -- 4 — 5 — 6 — 7 — 8 — End of borinc: at ZZ &a -:.c. Standing water 1111c: Present at fsar.. of - depth, hours aftei boring. Not present in borin.p. hole Mottled soil: I/ I - Observed at _ L�_ Joe* of depth. INot present in boring: hole Observations. and comments: If i f C-39 PERCOLATION TEST DA'!':; SHEET Test hole location &ZL ng Tom — & Hole number Date test hole was prepared Dcpth of hole bottom, :..... Diameter of hole, �� inches. Soil data fro_ test hole: Depth, inches Soil texture --I S Lac Xethoe of scratching .sidewall Depth of pea-sized gravel in bottom of hole, _ ? inchc!;. Date and hour of initial eater filling !�Elk•9'6 11+/I' Depth of initial filling, . 3 inches above hole botto:a. `Sethod used to tain at least 12 inches of Nater depth in hole for at le::;t n % . 4 hours /5 E /-/ L L ` - ?ercolation test readings made by s-1-916s.MI. starting at (date) during test, inches. 16? MaXiV..:um Ovate_• depth aLovu ::j.. .. _ Time Time Interval, Measurement, Minutes inches ::cop in water level, inches Percolation rate, minutes per inch 2 . -1. /S- it 2.I to minutes per i"ch. ?ercolation rate Sr n , L L PERCOLATION 'rzsT DATA SHE-&" Test hole location��/LL[� / O/t/ — ��%/ —;� Hole Dace test holt was prepared !y. --3D •-,?n DepLh of hole bottom,_L� Diameter of hole, _� inches. Soil data from test hole: Depth, inches Soil texture —/3 ka Xathod of scratching .s idcwall ,54 Depch of pea-sized gravel in bOCLOIn of 1101c, L _ inches. Date and hour of initial water filling -4-:30- 9!6 Depth of initial water filling, % inches above hole bOL'L'0::1. Method used tomaintainat least 12 inchc;; of water depth in hole for at li:-';L 4 hours Percolation test readings glade by �r>/IJ^/1/ .6' u:: a.m. �— yQ starting at 1I Maximum water dcnr_h above ,,,`.. -- (dace) during test, inchas. Time Ti--e Interval, Measurement, Minutes inches I Drop in water level, inclies Percolation rate, minutes per inch �- o 7 51 � i 17 I) *14 2 �--- ------------- -��-}-�'`� minutes per inch. Percolation rate L ;D i:- 3'; I--- Mcchod of scratching sidc:4allL.P�i Depth of pea-sized gravel in bottom of bole, �_ inciter. Date and hour of initial water filling Depth of initial water filling, /3 inches above hole bot ton:. `Sethod used to maintain at least 12 inches of water depth in hole for at lc PD 4� . I 4 hours A F j—I L L PercoI ation test read`-ngs made by starting at a. in. , (date) n during test, r inches. U:: i•lax::. m water depth above i:u_c b:;tt. Time Ti=e I cerval, Measurement, Minutes inches Drop in water level, inches PE.T?COLATION TEST DATA SHEET joLk / Test hole location "I—LI&T � G� — ? !� Hole number �� _ Date test hole was prepared y--.�jJ (� Depth o: Bole hottoni,_J�— _.. Dia=eter of hole, �_ inches. Soil data from test hole: L © Depth, inches - /,r I B L &C-9 Soil texture -. 214 el _ ... I--- Mcchod of scratching sidc:4allL.P�i Depth of pea-sized gravel in bottom of bole, �_ inciter. Date and hour of initial water filling Depth of initial water filling, /3 inches above hole bot ton:. `Sethod used to maintain at least 12 inches of water depth in hole for at lc PD 4� . I 4 hours A F j—I L L PercoI ation test read`-ngs made by starting at a. in. , (date) n during test, r inches. U:: i•lax::. m water depth above i:u_c b:;tt. Time Ti=e I cerval, Measurement, Minutes inches Drop in water level, inches Percolation rate, minutes per inch l;aIna rk o ' S2- 12-36 L __ Q 3 1/ Percolation rate__._— minutes por inch. J PERCOLATION TEST DATA SHEET Test hole location U��/Q O/fJ _Zd/' Hole number b Dace test hole was prepared Depth Depth of hole bottom,�� Diaxeter of hole, A inches. Soil data frcm test hole: Depth, inches Soil texture n-13 I3—/S c Loa/ Xcthod of scratching sidc'Jall .S41(�r C: Depch of pea-sized gravel in bottom of hole, `Z inches. Date and hour of initi;:1 water filling ii0— 9Q Depth of initial water filling, 13 inches above hole bottom. Xechod used to maintain at least 12 inches of water depth in hole for at lL:L;c n r.. 4 hours�E1`, L L Percolation test readings made by L2,11V GAOr �-2 a.m. C/ e9 starting at (date) '' 1:11 during test, inches. a:: Maximum .,iater depth above is _ Time Time Interval, Measurec:enc, Minutes inches _ Drop in water level, inches Percolation rate, minutes per inch l:e:aarks D • L._. 12 D < < P.3 L2I A's ' , L .3S, ok 1.09 1 / IS -131,4 y. 89 1 i Percolation rate 5,73 minutes per inch.