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HomeMy WebLinkAbout1989-09-14 Septic System Design Reporta SYSTEM DESIGN FOR LUNDGREN BROS. OF LOT 1, BLOCK 1, JANET ACRES ORONO, MINNESOTA 9-14-89 In addition to the enclosed information for the pressure mound system, two septic tanks of at least 1000 gallons are needed along with a 750 gallon pumping tank to house the pump. All construction and materials must adhere to the provisions of the City of Orono. All grading and construction traffic must be kept off of both the primary and alternate septic system areas. Runoff water should be diverted from the sites. if any additional information is needed, please contact me. Sincerely, PERCOR, INC. Mark S. Gronberg, PCA certified • MAW OW OrAl • � �FORoeaS F-15 oeLECTION PROCEDURE A. Determine pump capacity: 1. Minimum suggcsted 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.2700 gallons per hour (45 gpm) to prevent buildup of pressure in drop box 3. Use value from design of pressure distribution system SELECTED PUMP CAPACITY . . . . . . . . . . . . . . . . yy, y gpm B. Determine head requirements: 1. Elevation difference between pump and point of discharge :! �= feet 2. If pumping to a pressure distribution system, add 5 feet for pressure required at manifold . . . . . . . . . . -S feet 3. Friction loss a. Enter friction loss table with gpm and pipe diameter. Read friction loss in feet per 100 feet from page F-18. F. L. - Y. 2 8 ft/100 ft b. Determine total pipe length from pump to discharge point. Add 25 percent to pipe length for fitting loss, or use a fitting loss chart. Equivalent pipe length - 1..25 times pipe length - 1.25 x 62 - 77. feet c. Calculate total friction loss by multiplying _ , °riction loss in ft/100 ft by equivalent pine length. ` 'total friction loss x 77, ✓ a ?. �feet 4. Total head required is the sum of elevation difference, special head requirements, and total friction loss. J -+ S - 5 - TOTAL HEAD . . . . . . . . . . . . . . . . . . . . . . S feet C. Pump selection 1. A pump must be selected to deliver at least ��/.�/ gpm with at least //• . feet of total head. D. To maximize pump life select sump size for 4 to 5 pump operations per day. I:. Calculate drainback I. Determine total pipe length, 0,2 _ feet. 2. Determine -liquid volume of pipe, /T. y� _ gallons per 100 feet. (See page E-18) 3. Multiply length by volume: Drainback quantity = 6 2 _ feet x /7•'/.3 gallons/100 it - /D. gallons 4. Suggested drainback quantity is 10 percent of pumped quantity. A larger drainback percentage will decrease pump statiun efficiency -slightly but pumping energy costs are usually a relatively small part of the total household energy costs. MOUND DESIGN PROCEDURE (For Flows up to 1200 gptl) A. Sewage Flow Rate See D-7 or I-3, 4, or 5, or use metered value; Flow Rate = 7-To gpd B. Septic Tank Liquid Volume (see C-3 or C-5) L; J,i gallons C. Soil Characteristics 1. Depth to restricting layer such as seasonally saturated soil, bedrock, coarse soil, etc.; 3 O inches 2. Depth of percolation tests; /_inches 3. Number of percolation test holes; holes 4. Ave. percolation rate; 25. 1 mp i 5. Landslope 7 1% or: D. Rock Layer Dimensions' 1. Multiply gpd by 0.83 to obtain required area of rock layer; Z, 'o gpd x 0. 83 =9'Z1.5_ sq f t 2. Select width of rock layer (10 feet or less) - /O feet 3. Length of rock layer - Area Width Q7,$sq ft to ft - C2 3 ft E. Rock Volume 1. Multiply rock area by rock depth to get cubic feet of rock; �11.5 sq ft xQ,75ft = V"cu ft 2. Divide cu ft by 27 cu ft/cu yd to get cubic yards; 17.3 3. Multiply cubic yards by 1.4 to get weight of rock in tons; /7.3 cu yds x 1.4 - 16/. 2 tons E-19 F. Pressure Distribution System 1. Select number of perforated laterals 6 2. Select perforation spacing -3 ft 3. Select perforated lateral length; Note if manifold is at end of rock layer, lateral length is rock layer length less half a perforation spacing. If manifold is in center of rock layer, lateral length is one-half rock layer length less half c perforation spacing. Perforated lateral length = 29.7 ft. 4. Divide lateral length by perfor- ation spacing to get number of perforations per lateral ?/,Z feet 1. 3 feet = /Q perfs Note: last perforation must be in end cap, (see page E-14) 5. Multiply perforations per lateral by number of laterals to get total number of perf itions; /d perfs/lat x 4' lats n 60 6. Determine required flow rate by multiplying number of perforations by flow per perforation (see page E-17) -perfs xQj7ygpin/perf = iff.ygpm 7. Select minimum required lateral diameter from table on Page E-17; cater table with perforation spacing, perforation diameter, and number of perforations per lateral. Select minimum diameter for perforated lateral /Yy inches ute: 2 0" G. Basal Width 1. Percolation rate in top 12 inches of soil is ??:S&Lmpi 2. Select allowable soil loading rate from table on page E-16; &I 0, Y5gpd /f t2 MOUND DESIGN PROCEDURE (Continued) (For Flows up to 1200 gpd) G.3. Calculate basal width ratio by dividing rock layer loading rate of 1.20 gpd/ft2 by allowable soil loading rate; 1.20 gpd/ft2 ='.Y✓`'gpd/ft2 =? 67 Check this value on page E-16. 4. Multiply basal width ratio by rock layer width to get required basal width; 2,67 Y /c, ft =26.7ft • H. Do%.mslope Dike Width 1. If landslope is 3% or more, subtract rock layer width from basal width to obtain minimum downslope dike toe width 2C. Zfc - loft -/6.7ft 2. Calculate mound height at edge of rock layer on downslope side; a. Determine depth of clean sand fill at upslope edge of rock layer: / feet b. Multiply rock layer width by landslope to determine drop in elevation; /Ox 7`/.=1000.7ft c. Add drop in elevation to depth of clean sand at upslope edge of rock layer to get depth of r.lean sand at downslope edge of rock layer. 0.7 ft + _/ft = /- i `t d. Add depth of clean sand at down - slope edge to depth of rock layer to depth of soil backfill to get mound height at downslope edge of rock layer; /. 7 ft +0.75ft +/,2Sft j_ft e. Enter table on page E-18 with landslope and downslope dike ratio. Select dike multiplier of jr. S.6 y: / rloof E-20 11.2.f. Multiply dike multiplier by downslope mound height to get downslope dike width; 5-56x -7.7 a20.6ft g. Compare the values of step 11.1 and step 11.2.f. Select the greater of the two values as the downslope dike width; 20. 6 feet h. Calculate upslope dike width using; upslope mound height and upslope dike multiplier . %2 p.x _ E-18 f t i. Total mound width is the sum of upslope duce width plus rock layer width plus downslope dike width; 9_�ft + /0 ft +2'r ft ft 3. If landslope is 2.9 percent or less, basal width ?.--ludes both the upslope and :.)pe dike widths. a. Calculate downslope dike width using steps 11.2.a. through It. 2.f; feet b. Calculate upslope dike width using upslope mound height and dike multiplier from Page E-18; x ft = ft c. Add downslope dike width to upslope dike width to rock layer width to get total mound width; ft + ft + ft = ft d. Compare total mound width to required basal width from step G.4. If total mound width is greater than required basal width, use calculated dike widths. If required basal width is greater than total mound width. increase downslope dike width. FERCOLATION TTST DATA SM= = �s Test hole location (".o ,1 Lo T / Role number Date test hole was preparedG/ - - IA- — k-7 __. Depth of hole bottom, I % inches. Diameter of hole, ` /T_ inches. Soil data.from test bole; Depth, inches $oil texture eA*. /l,Paa ,v c airy, Method of scratching s:devall /I 4 Depth of pea -sized gravel in botto= of hole, inches. Date and hour of initial water filling 4./ Depth o: initial water filling •inches above hole bottom. Mcthod used to maintain at least 12 inches of water depth in hole for at least C hours P? - /- i ! Percolation test readings nade by 12ew .. tq "% starting at 7 Z-�' O.U. (date) .;4 during test, inches. 1) V. on Maximum water depth above hole bottom 2:9e Interval, Minutes Measurement, inches � Drop in water level, inches Percolation rate, minutes per Inch Remarks D iA, _ 7/ •2s, • - - • . - .1 �"� 0-4.,O,••• ear inch. S- 3S PERCOLATION TEST DATA SHEET It Test hole location_ C 064 4� a t Bole number 2 Date test hole was prepared Depth of hole bottom,-Zs-1 inches. Diameter of hole,_ inches. Soil data -from test bole: ltpth, inches Soil texture ,4WOZ." el_Ar ceJnt Method of scratching sidewall __S6,?A-re )/''/t Depth of pea -sired gravel in bottom of hole, -0), _ inches. Date and hour of initial water filling 4-JR -k7 Depth c: initial water filling, / G . inches above hole bottom. Mc:hod used to maintain at least.12 inches of water depth in hole for at least L hours jer %�/ L L Percolation test readings made by Q.O/Ao 4P,9"2 �7 Lr/llr on a.m. ,et - /Sr- k % starting at 2.3P_ . Maximum water depth above hole bottom (date) 'm' during test, , inches. (i Ume ?:ma (� Interval, v.:nutes i I Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks DI+ i& 0 .Q / J 1 1 - .. q �/ K I/ ..f•..►�� wft• fwrQ. f- 3S PERCOLATION TEST DATA SMET Test hole location_ C-*?/ �--.(' LaT / Bole number .3 Date test hole was prepared C./ - / �'- f , Depth of hole bottom. le? inches. Diameter of hole. 4 inches. Soil data from test bole: Depth, inches O - /Z A& - Soil texture Dd'. C oAn% .zAC✓e o LdY _CG'?Hs Method of scratching sidewall . Depth of pea -sired gravel in bottom of hole, 2 inches. Date and hour of initial water fillinc A/ -1 X -f -1 Depth o: initial water filling, / L . inches above hole bottom. wcthod used to maintain at least 12 inches of water depth in hole for at least 6 hours Percola 4 -- IS -NI starting at (date) , .m. during test, inches. . Maxi— water depth above hole bottom Time ! rime Interval, j Minutes I I = Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks v� L 2 "7 9 97 /i o o ;. J Za e ~ �-� ,t 2 �� i 2 / 131 — /b O ------ - • - _ ��•a (o .+mutes ver inch. PERCOI ATION TEST DATA SM= Teat hole location_ �':�r/I !-•l 4a7' Hole number tf, Date test hole was prepared e l— l ('-'I � Depth of hole bottom,_ inches. Diameter of hole, .�_ inches. Soil data -from tast bole: Depth. inches Soil texture «gnu Method of scratching s:dewall . elM TeAC Depth of pea -sized gravel in bottom of hole, 2 inches. Date and hour of initial water filling Depth o: initial water filling, / 4 inches above hole bottom. Mcthod used to asintain at least 12 inches of cater depth in hole for at least 4 hours �� /�/ .�►L Percolation test readings made by C-??.g&h CsP:: on t4--/S'- P-) starting at 7 71 a.m. . Maximum water depth above hole bottom (date) .0. during test, inches. Time Interval. Minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks • , 3 I . 'ram . . 90b -Pi v v �✓, : i . - . 7 O elautes •aT Wh. PERCOLATION TEST DATA SM= Test hole location_ ��I)) _�'_ IOr /_ Wt number Date test hole vas prepared 7 . Depth of hole bottom. inches . Diameter of hole. Ye inches. Soil data.from test bole: Depth, inches D-is Soil texture — AV t,t rw& Method of scratching sidevall _t:2C /lit %A % •'/e Depth of pea -sized gravel in bottom of hole, __ inches. Date and hour of initial water filling _ s.J--/,�-rs'7 20 Depth o: initial water filling, inches above hole bottom. Mcthod used to "maintain at least 12 inches of cater depth in hole for at least b hours Arr- ;—L 1. Percolation test readings made by Ll 0Aj (j: P n „� r.- n, G. on starting at 2 arm: . Maxi== water depth above hole bottom (date) - dur'-ng test. inches. (( rime Tama fr Intertial, Minutes 's Measurement. { inches Drop in water level, inches Percolation rate, minutes per inch Remarks !J / .?_ Y 9 0 I1 11 3 2 3 of . - �L/ / ' 941%11tes set inth. 1- 33 PERCOLATION TEST DATA SHUTas Test hole 2ocationn%; G--(,•- 107- / halt number Date test hole was prepared ZJ — 18 7 � D*ptfi of hole bottom, � inches.Diameter of bole, 6-9 inches. Soil data -from test bole: Depth, inches Soil texture AW *&jAn Method of scratching sidewall y!;', L: /.'i; % r i� ?"/, Depth of pea -sized gravel in bottom of hole, ` ? inches. Date and hour of initial water filling 41-!_ ; 7 �- 9. /S- Depth o: initial water filling, I G inches above hole bottom. Mcthod used to maintain at least 12 inches of water depth in hole for at least 6 hours Percolation test readings made by 4Q1Pr.1 �r/�,�/�i,n��'/�/, on y— le;- `:: % starting at _ % ��y a'm. . Maximus water depth above hole bottom (date) daring test, inches. ' =ire Time Interval, Y"nutes 4 Measurement, inches Drop in water level, inches Percolation rate, minutev per inch Remarks ,.h - ; s .. MY �I LRgs of Soil Borings -' 8-27 Location or Project C/CA6G eor / Borings made by-MA#TKg Date 11-4�-P7 Classification System: AAS1i0 USDA-SCS_; Unified ; other — Auger used (check two): Hand >< or Cower ; Flighf , or Bucket other Depth, Boring number / Depth, Boring. numberin Q feet Surface elevation feet in Surface elevation 0 0 PIC. catr+ 1 -- 2 -- I I &qJtfIwM J_o,(, J 3 CGAr ~4 4— S- 6 — 7— I s -- End of boring at y O feet. Standing water table:. Present at feat of depth, hours after boring. Not present in boring hole X Mottled soil: Observed at ?, O feet of depth. Not present in boring hole __• Observations and cornents: OK. • B,tow� tO�t �+ 2 —' Cur coA^ 4 — 6 — 1 7 — I 1 s — J — End of boring at + V. O feet. Standing water table: Present at feet of depth, hours after boring. Not present in boring hole Mottled soil: Observed at 2 feat of depth. Not present in bovine hole Observations and comments: • Loas of Soil Borings B-27 Location or Project L✓IN- CCax6F f or Borings made by M.fj'K , G�A/I&AV 6:&"ERCE Date y-/8'8% Classification System: MStiO USDA-SCS X_; Unified ; other Auger used (check two): Hand ,�, or Power ; F1i&E , or Bucket other Depth, Boring number •3 Depth, Boring number Ln feet Surface elevation feet in Surface elevation 0 0 prt. dr�rtai✓ Cal r+ 1 — 2 — .4 L0AM 4- 5- 6 7— 8 -- End of boring at Y. feet. Standing water table:, Present at feet -of depth, hours after boring. Not present in boring hole X mottled soil: Observed at Z • 8 _feet of depth. Not present in boring hole Observations and coamente: 1 -- 2 — 3 _. 4 — 5- 6 -- 7 -- 1 8 — :nd of boring at fact. handing water table: 'resent at feet of depth, hours after boring. lot present in boring hole Mottled soil: 3bsarvad at feat of depth. Not present in borinr. hole Observations and commentoz Ta 9-41I5 AN =SUJNT CROWS FOR BASSIM T POOTSR DRUM APILWAT1ONS Rs00 RM MORE FLOW TAM STANDARD 1/4 OR 1/3 HP FU11lS CAN DZLMW Also for use in residential effluent dosing systems where medium flow and low head are required Recessed vortex impeller allows tree passage of up to 3/4" solids through volute Contact your Myers distributor. or the Myers Ohio sales office at 419/289-1144 for more details S=4 4/ 10 HP Residential Submersible Sump and Effluent Pump ADVANTAGES BY DESIGN DURABLE MOTOR WUL DELIVER MANT TEARS OF REWARLE SRRVICE. • Oil -tilled motor for maximum heat dissipation and continuous beanng lubrication. • Shaded -pole motor eliminates starting switches. • Wide angle mercury float switch on automatic models • Vortex impeller has low radial loading for longer bearing life !ASSES U! TO 3/4 INCH SOLIDS. • Vortex impeller for maximum clearance in volute case THE S-4 IS ENGINSIRID FOR MAINTENANCE - FREE OPERATION. ■ It service is ever necessary. positive sealing. quick -disconnect power and switch cords make replacement simple. TECHNICAL INFORMATION �Capacilies To — 60 gpm 1 227 II pm Heads To 24 It 1 7 32 m Pump Down Range' - --t�— 8 to 203 2 min Solids handling Capacity (dia) 3/4 in 191 mm Uquids Handled ---� drain water and septic effluent Intermittent Uquid Temp up to 140'F up to to 60'C Motor 4/10 hp shaded -pole 1625 rpm Electrical 115V. 12 0 amps. 10, 60 Hz 230V. 6 0 amps 10, 60 Hz Acceptable pH Range 6-9 Specific Gravity 9. 1 1 Viscosity 28. 35 SSU Discharge. NPT — — 1-1/2 in 3e 1 trfrri Minimum Sump Dia (Simplex) ( Duplex) 24 in 30 in 6096 mm 762 mm 'Automatic model only - manual model vanes with switch used cousbuctics mal rms T Motor Housing cast iron Motor Cap flame-relardanl polypropylene Volule Case ABS. cycolac L Impeller valox Power Cord 16/3 S TW. 2011 Switch Cord 16/2 SLOW or SJOWA Mechanical Seal type 1. carbon and ceramic WHERE nMOVAnON MEETS 7RADn7ON. PUMP STATION REQUIRMOWTS J. MANIFOLD DISCHARGE ELEVATION O _FT J-1 ELEVATION AT PUMP FT J-2 DIFFBRBNCE (J-1 minus J-2)/�V4� (ELEV. HEAD) OV R. DISCHARGE LINE LENGTH (PUMP-TJ-MANIFOLD) 1� _FT N DISCHARGE LINE DIAMETER (BSTwEEN PUMP _ ? INCH ( 1.5' or 2' typ.) AND MANIFOLD) FRICTION LASS PER 100 FT OF PIPE: (FRICTION LASS IN FT/100 FT, PVC) BRIS GPM 1.50 PVC 2" PVC 3 26.6 4.21 1.25 3+10• i.8.8 4.87 18.01 1.44 12.37 4 37.7 4+10• 40.0 8.91 2.64 5 44.4 10.81 3.20 5+10% 53.3 14.50 3, 2 Q FT/100 FT O 1.25 x O xO / 100 = HEAD LASS DUE TO PIPE FRICTION 1.25 x 4po x .b.2-0 / 100 y L. ADD 5.0 FT BY DEFINITION FOR LOSSES IN LATERALS/MANIFOLD TOTAL HEAD REQUIREMENT = 5.0 +(2)+(2) =5.0+ ee +=I&L4 *******FT HEAD REQ•D TNIMUM REQUIRED PUMP RATING: / GPM AT J3, y FT TOTAL HEAD SIDE 2 SITE ADDRESS —7 �/ S PJ r`. �'.N 1aA L INSTALLER �� T"►'� PRESSURE DISTRIBUTION SYSTEM WORRSHEET - RESIDENTIAL , A. Number of laterals 6 ® C ( B. Perforation spacing 3 ftOB C. Rock layer length ft less 2 ft = ft (total length if end load) ( is total length if ctr load) D. Number of spaces between perf's = ©/OB = / spaces@D E. Number of perf's per lateral =OD + 1 = AV perfs /lat. F Total perforations =OA x ®_ imperforations OF G. Flow rate per perf: If 1/4' perfs, use If 7/32' perfs, use 0.56 gpm H. Required flow rate = FO x Q =* 7 qpm STANDARD REQUIRED FLOW RATES (1/4" perfs, 3' spacing) Rock Bed Length 37.5' 40.0' 50.0' 55.0' 63.0' 70.0' Bedrooms 3 3+10% 4 4+10% 5 5+10• Total # perfs 36 39 51 54 72 REQ'D GPM 26.6 28.8 37.7 40.0 L14.4 53.3 TO REDUCE RFc'D FLOW RATE: 1. Use 7; 12' perfs instead of 1/4" (Reduce GPM by 25%) OR 2. Reduce number of perfs by lasing spacing between perfs (Ma::mum spacing allowed = _-.01) (Re -calculate A thru H) MAXIMUM ALLOWED PERFS PER LATERAL: End load Center load Perf spacing, ft Lateral diam.: 1.5" 2.0" # 1.5" 2.00 2.5 - - - - - - - - - - - - - - 18 28 * 9 14 3.0 - - - - - - - - - - - - - - 17 26 ; 9 13 3.3 - - - - - - - - - - - - - - 16 25 * 8 13 4.0 - - - - - - - - - - - - - - 15 23 ,*t 8 12 5.0 - - - - - - - - - - - - - - 14 22 7 11 SIDE 1 OF 2 t I 11111102011 rn MONO I Ma 0 111 i I Ili Ellin It" r 2.,j �j k- I t.-), k, IRONER F", V L 1 1. NIHON larmounimmy, -n dLmuJ -9 r2 I :.j rnfl yj; ally q F, J, 0019 go 21`4 Ll" 0 7