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HomeMy WebLinkAbout1992-11-05 Septic System Design ReportC�i22CNOMM SYSTEM DESIGN FOR JENSEN HOMES OF LOT 3, BLOCK 1, HANSER ADDITION ORONO, MINNESOTA 11-5-92 'Nov a 1M System design information follows for a proposed house on the above lot. This will be a pressure mound system with construction and materials following the provisions of the City of Oronj and the Minnesota Pollution Control Agency. Both the primary and alternate septic system areas will be staked out and all construction traffic must be apt off of both sites. In addition to the septic tanks proposed, p—tping tank of 1250 gallons is needed. All runoff must be divertea from the mound system. If any other information is needed, please contact me. Sincerely, PERCOR, INC. IL ��i•t 1� �! 1� Mark S. Gronberq TENIF•✓ WO.'" FJ [ o r -7., Block, � /O/iI N-ftex AOI /Tian/ %**-� ) / / .i ��rtcw�rf / 11 Ct M 1 it sort qe E'' r`y � 2 O N 0 CITY Q BUILD1N::r r" iV REVIEW i = _ -i0 /�- A;�rRC�,'r,:. • ,�,�•,s�,_;'_�.:.T�C1,! � AS NOTED YC,; r• All work ^hall Cc done -onin„ core r•• o.�rf ; //- f-9L rw:cd ties rev,e4L .... JYAcf i KNEE' TH►5 t=;,,� SLT OU SITE AT ALL TIMES 60 F-15 PUMP 5 A. Determine pump capacity: I. Minimum suggested is 600 gallons per hour (10 gpm) to stay ahead of water ise 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. 3.1 Use value from design of pressure distribute n s stem. SELECTED PUMP CAPACITY gpm B. Determine head requirements: 1: Elevation difference between pump and point of discharge.. T { feet 2. If pumping to a pressure distribution system, add five 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. _ Ir. 2IL ft./100 ft of pipe b. Determine total pipe length from rump to discharge paint. Add 25 percent to pipe length for fitting loss, or use a fitting loss chart. Equivalent pipe length -1.25 times pipe length = /O 0 x 1.25 - /2S feet f C. Calculate total friction loss by multiplying friction loss in ft/100 ft by equivalent 1 e 1 Total friction loss =2.&3+frx /11 +100: ALES S feet 4. Total head required is the sum of elevation difference, 3� special head requirements, and total friction lo5�. + s 3' (><) (2) # 7 c) TOTAL HEAD feet + C. Pump selection 1. A pump must be selected to delivtir at least S7, >gpm (Step A) with at least 14.5 feet of total head (Step B). D. Total Pumpout Volume 1. To maximize pump life scllxt sump size for 4 to 5 pump operations per day. .900 gpd + 4 = 125 gallons per dose 2. Calculate drainback 1. Determine total pipe length, /00 feet. 2. Determine liquid volume of pipe, /?- y3gallons per 100 feet. (see page F-18) 3. Multiply length by volume: Drainback quantity = tO0 feet x /7.YJgallons/100 ft. _ /7. ygallons. Suggested drainback quantity is 10 percent of pumped quantity. A larger drainback percentage will decrease pump station efficiency slightly but.pumping energy costs are usually a relatively small pan of the total household anargy costs. 3. Total pump out volume equals dose volume + drainback 2 2 5 gallons per dose + /7. Y gallons - .2 V2. Y Total Gallons pipe Length t Point of TTDisch. Elevation Diffcrcncel Pump F-18b 1.5 inch .0 inch 3.0 inch SPM rytaim tmFPWIMIrorope 10 0.69 0.20 12 0.96 0.28 14 1.28 0.38 16 1.63 0.48 18 2.03 0.60 20 2.47 0.73 0.II 25 3.73 1.11 0.16 30 5.23 1.55 0.23 35 7.90 0.30 40 I LC7 0.39 45 14.73 3 0.48 50 .99 0.58 55 4.76 0.70 60 5.60 0.82 1 _3.0 •,WAGQ FLOWS IN GALLON: PER pay TyrE 0I REs1nENCE 4 -- 1 13 1>Z rz 300 225 160 cox 430 300 210 of 4" 373 256 1o1i� 730 900 450 525 294 332 Tj; 1050 600 370 01 e 1200 675 406 columns 100 1.25 7.77 115 14.58 2 17.43 2.5 24.87 3 38.4 i - 4 66.1 MOUND DESIGN WORKSHEET (For Flows up to 1200 gpd) A. FLOW Estimated 73"0 gpd (seepages D-7 or I-3, 4, 5) or measured gpd. arc 900 C-po B'.SEPTIC TANK LIQUID VOLUMES /1 So A /D 00 gallons (see pages C-3 or C-5) /ZJ.9 ir,4ti v PNMIivG f, Aht C.' SO11S (refer to site evaluation) 1. Depth to restricting layer = 2,2 inches 2. Depth of percolation tests = /6 inches 3. Percolation rate _ 13.7 mpi 4. Land slope I % D. ROCK LAYER DIMENSIONS I. Multiply flow rate by 0.83 to obtain required area of rock layer: A x 0.83 = 0 D gpd x 0.83 sq. ft./gpd = 7S0 sq. ft, . 2. Select width of rock layer (10 feet or less) _ /0 ft. 3. Length of rock layer = area + width = 75-41 sq. ft. + 10 ft. = 7- . Oft. E. ROCK VOLUME 1. Multiply rock area by rock depth to get cubic feet of rock; 7So sq. ft. x / ft. = 7So cu, ft. 2. Divide cu. ft. by 27 cue ft. /cu. yd. to get cubic yards; 7SO cu. ft. + 27 =.27.78 cu. yd. 3. Multiply cubic yards by 1.4 to get weight -of rock in tons; 27.78 cu. yd. x 1.4 ton/cu. yd. =3� tons. r. AUbUX. FTION WIDTH 1. Percolation rate in top 12 inches of soil is /is 7 mpi 2. Select allowable soil loading rate from table on page E-16; afE o.60. gpd/ft2 3. Calculate adsorption width ratio by dividing rock layer loading rate of 1.20 gpd/ft2 by allowable.soil loading rate; 1.20 gpd/ft2+0. 60 gpd/ft2 = 2 . o O Check this value on page E-16. 4. Multiply adsorption width ratio by rock layer width to get required adsorption width; 2, go x / 0 ft = 20. Oft E-19 D-7 C-3 .w lw. IAl1A GA/ACITIES. IN GALLONS N i , op LIOYIo C"ACRt mum r .14 Y.e•s, tmemom LN*M OAIAel1. 6,09sI v clause is* /ul emle lose logo some lose list T. e. m s veto etoo Rock Bed •r•�.r.r rer.r r r r r r r r r i.r•r.+•+.r.r.i.r•i.i•r•r•r•r I•ti.I.� ti.ti. Idth SlUft. I--,�3iI •hh .r•f.I•Hh� I~rtirtir e Lw8th E-16 WMM•e Aowomoo.•Ies OF •011 W.". lo—es ,- Ah- f-• -- l.N !M N •". eM eel• .N .l ..e !.N •N ; N ;.N • . N •l .INsit•.N •.N e •.I! .o •N I I.•t •,N E-20 13. DOWNSLOPE DIKE WIDTH 1. If landslope is 3% or more, subtract rock layer width from �- adsorption width to obtain minimum downslope dike toe 20.0 ft - /0 ft = /a, o ft 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: Separation /. 2 feet b. Multiply rock layer width by landslope to determine drop in elevation; Slope Difference c. Add depth of clean sand depth of clean sand for separation at downslope edge to depth of rock layer to depth of soil backfill to get mound height at downslope edge of rock layer; /, 2 ,ft + /, o ft + /. o ft+ V. Y ft = 3, a ft d. Enter table on page E-18 with landslope and downslope dike ratio. Select dike multiplier of S! 76 e. Multiply dike -multiplier by downslope mound_height to get downslope dike width: Y. 76 x j?. 6 =. /7. / ft g. Compare the values of step G.1 and Step G.2.f. Select the greater of the two values as the downslope dike width; 17,1 feet h. Calculate upslope dike width using upslope mound height and upslope dike multiplier from page E-18; 2 x 3, S = //.oft i. Total mound width is the sum of upslope dike width plus rock layer width plus downslope dike width; //. G ft + /o ft + /7. / ft = 39. / ft 13. If landslope is 2.9 percent or less, basal width includes both the upslope and downslope dike widths. a. Calculate downslope dike width using steps G.2..a. through G.21, 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 ft + ft + ft. = ft .TOPSOM..I fLO►•t tee I MOCK "Urrt! Nark layer width (d21 UNbM dice width W Oodtutd W d Ike width (. 3:1 5:1 5:1 0 3D 4.0 $O 7A 7A 2.11 LA 32i $O 476 6A SA4 7A 134 1A ?At 1 3A1 d.17 $26 �729 7" 9.14 23,1 370 �31 $3� k11 1•W 2 3 3 3.11 330 e3S eS.L SSL 6AS S.S1 US 337 SAS �31 1.17 1A1 eM 17f JA1 •AS 6A1 3A1 17i 13f SA S72 f0.77 IAS 2A1 333 LAD 1A2 1.11 1.71 fAt S • 3S3 ]As Sm S2s 1A7 7.0 f3S 12A7 231 323 3.12 SAS 37D ul 123 d.f1 470 $.13 1151 1373 IL91 SAS 2A2 3z 337 L.fi 1.Lf L30 4M LAS 1 Y 3.�i 1.11 SL i25 S33 ID1 11-% tS.q 231 231 Lid 2311 SAS 133 1.90 37S ••l2 4A4 10 421 1A7 IQA 17AS 2333 3>lA3 226 2.75 1� 3A1 1.41 7.1f 3.10 426 e a 11 . i 4AS a Le 7.1• 7 % 11.11 1230 21.41 43 75 2 1 2.70 -? E-26 1. Select number of perforated laterals 6 2. Select perforation spacing = ___j- ft. 3. Since perforations should not be placed closer than 1 ft. to the edge of the rock layer (see p. E-14), subtract 2 ft. from the rock layer length. 75 Rock layer length_,? f t. ', Z = 36. S 6- rya 4. Determine the number of spaces between perforations. Divide the length above by perforation spacing and round down to nearest whole number. Length perf. spacing =36. S ft. + 3 ft. _ /Z spaces (3) (2) 5. Number of perforations is equal to one plus the number of perforation spaces. spaces + 1 =1 ? perforations/lateral 6. Multiply perforations per lateral by number of laterals to get total number of perforations. /.3 Q laterals x perf./lateral= 78 perforations. I Determine required flow rate by multiplying number of perforations by flow per perforation (see page E -17) 78_y Pais x apm/perf - gpm• 8. If laterals are connected to header pipe as shown on page E- 15, select minimum required lateral diameter from table oft page E-17, enter table with perforation spacing and number of perforations per lateral. Select minimum diameter for perforated lateral = inches. 9. If perforated lateral system is attached to manifold pipe near the center, as on page E-12, perforated lateral length and number of perforations per lateral will be approximately one half of that in step 8. Using these values, select minimum diameter for perforated lateral from page E-17 as inches. E-17a Head Perforation diameter (inches) o, O 1a 1.5 0.90 2.Ob 0.90 1.04 2.5 0.89 1.17 3.0 0.98 1.29 '4.0 1.13 1.47 5.0 1.2( aUse 1.0 foot of head for residential systems. bUse 2.0 feet of head for other establishments E-17b WNWIM -��M tr'lw �Wdr ,moon�I trw M inmeh 1.5 inch 2.0 inch 2 14 18 28 3.3 13 12 17 4.0 5.o 11 10 16 15 14 23 22 E-15 E-12 w-.asrsae M v- - • U-39 PERCOLATION TEST DATA SHEET 7. Test hole location t — Hole number �-' Date test hole was prepared y — / y — j f Depth of hole bottom, inches. Diameter of hole,_ inches. --Soil data from test hole:_ Depth, inches . Soil texture o -/Y _ ✓3LA-o-4M Method of scratching sidewall Depth of pea -sized gravel in bottom of hole, _ Z inches. Date and hour of initial water filling 91"/9— 9/ P / Depth of initial water filling, 16, inches above hole bottom. Method used to maintain at least 12 inches of water'de_pttC.in_hole for.at least 6 hours_ f / L Percolation test readings made by L2 /V G ,e G / on' startinga.m. at ,� O'>7 Maxi:aum water depth above hula buttu (date) during test, / inches. Time Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation -rater •. minutes per inch Remarks uL L Percolation rate . 9, ?_ 3 minutes per inch.... V - - e-/ P - / B-39 PERCOLATION TEST DATA SHEET ....._._.. Test hole location yA/1/.S F/t' '—� D T L� Bole number �-' Date test hole was prepared y / :Z—__9/ Depth of hole bottom, _L� inch,ts. Diameter of hole, 6 inches. Soil data from test holey Depth, inches Soil texture Method of scratching sidewall Depth of pea -sized gravel in bottom of hole, Z inches. Date and hour of initial water filling 9 / 9 — 9/ 4� /Y Depth of initial water filling, / G inches above hole bottom. Method used to maintain at least 12 inches of water depth"in hole for *at least 4 hours Percolation test readings made by &A.1 L1,—,ToA/OERG- on —20 — y/ starting at _?_ �- a_m. . Maximum water . epth above hole buC (date) during test, inches. Time Time Interval, Minutes Measurement, inches Drop in water level, inches Perr.,:! .:,.ion rate, minutes per inch Remarks a L iL 12.0-0 o'a �-c�,. , _._. Ff,i- l- ii 0 ,, ,, i210 Percolation rate - 2 0 Zar y P--Z minutes per inch. ' PERCOLATION TEST DATA SHEET 8-39 Test hole location --L p T� L� — Hole number 3 �-' Date test hole was preparedf q — 9� Depth of hole bottom,, inches. --Diameter of hole, �_ inches. Soil data from test hole:_ Depth, inches Soil texture - 0-9 Method of scratching sidewall . c RAT < A GR Depth of pea -sized gravel in bottom of hole, 1pinches. -- Date and hour of initial water filling Depth of initial water filling, inches abake.hole.bottom. Method used to maintain at least 12 inches of water depth"'in hole _or at least, 4 hours[ L Percolation test readings made by DoAl Gn oN Rc_ on 9-.701 5�/ starting at a.m. . Maximum water depth above hole boLLL (date) s during test, inches. Time Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation rate, asinutes per inch Remarks / 30 L ,3 6 _ 7 ►. a I /7 .0 Is of A i Percolation rate - %- minutes per inch. PERCOLATION TEST DATA SIIEET Test hole location /i/i/s-OR T— {{ole number Date test hole was prepared 9 - / q - GJ / Depth of hole bottom, inches. Diameter of hole, �_ inches. Soil data from test hole: Depth, inches Soil texture L, Method of scratching sidewall Depth of pea -sized gravel in bottom of liole, inches. .T Date and hour of initial water filling Depth of initial water filling, 14 inches above dole bottom. Method used to maintain at least 12 inches of water depth'•in.hole for 'at least 4 hours L Percolation test readings made by 00& 6 /x-o V,6E,eG on -20- 9/ startinb at g a.m. .� m. Maximum water depth above tivla i>uc.tu (date) is" during test, / �� inches. Time Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation rate,. c,inutes per inch Remarks 30 12, ,, ..:._......... _ _� LL O P iN S Vo ,� 6 „ _ So �� 1 _EE Percolation rate 2r� %-j minutes per inch. � Q r 9,, /- y Lor,,n OF Soil borillf's tf-18 LocaCiOn .or 1'rofeet Borinps madc by / 0 classification System: AAS110 US1?�-SCS UniLic.d ; ; other ;. Auger uncd (check. turo) : t!and or Poster Flight _, or Bucket ; othu'. T--___ -- ----- -----• Depth, Boring nu:rher• �Dr.pth, 13oring number 21 In Surface elevation in !ear. feetSurface elevation------• .n ,BK L o.rM 1 — DoRk 13R SR, e_•< <o.4,-7 ��TF�Ro�.ti cL�y Lo��y Got LiTFI3R►CL End of boring at 3. S feet. Standin.g stater table: i,•escnt at 2, 7 feet of depth, hours after borinp. Vot present in boring hole Mottlad soil: Observed at fact of depth. Clot rr.escnt In boring. hole _ Observations and comuants: 5 — 6 — 1 — II— land of bori•r•c at —3— feet. I Standing aster -Cable.'.. present at feet: of deptii, hours after horins_. i Not prevent •'in borin,s!.-hole. i Mottled coil: I ohcarvad at 47 fact of depth. tlot prarant In boring hole Ohsc_'vation! :aid couunont�: B-39 PERCOLATION TEST DATA SHEET Test hole location 16171s4fp � T- i Hole number_ Date test hole was prepared 9 -. T_� � / Depth of hole bc,tton;�_ inches. Diameter of hole, _ 6 inches. Soil data from test hole: Depth, inches Soil texture 9C /o'lM Method of scratching sidewall .SCeA/C Depth of pea -sized gravel in bottom of hole, 2 inches. Date and hour of initial wz :er filling 9-/s- - 9/ d-, _W P,/I. Depth of initial water filling, (0 inches above hole bottom. Method used to maintain at least 12 inches of water depth•in hole for at least 4 hours Percolation test readings made by 0,0,9 9-/9- 9/ starting at 2-V a.m. �— -.m. (date) during test, 3411 inches. on Maximum water depth above hole bottoi: Time Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks iL /! ri AS- z i� i 9 _ it ,, , , p . p 2! Percolation rate = _/0_ minutes per inch. or ' P-S - B-39 PERCOLATION TEST DATA SHEET Test hole location _'H/fIV5 E/ —L� �- — Hole number Date test hole was prepared 9 / r- q / Depth of hole bottom,_ inches. Diameter of hole, __. b inches. Soil data from test hole: - Depth, inches Soil texture Method of scratching sidewall SC^97C RR Depth of pea -sized gravel in bottom of hole, inches. ' Date and hour of initial water filling Depth of initial water filling, /` inches above hole bottom. Method used to maintain at least 12 inches of water depth in hole. for at least 4 hours /i L- Fi L L Percolation test readings made by aeoy lr ,e OP✓ %/ starting at f Z 2Z a.m. . (date) `—�:B en- during test, // ��/ inches. .R G. on Maximum water depth above hole botLOI Tim Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks �2 IF2 12 Percolation rate = 1 minutes per inch. Low. of Soil Borinp.s 11-1II .a -�-_-. - _ Location .or Pro Inct—__-.-- Borinps made by classification System: AASHO USDA-SCS X Unified other_ - Auger used (check: two) : F?and or Power _; Flight or Bucket Y-1: other Depth, Boring nticrher' —J- Dr-pth, Boring numher 'in Surface elevation ' feet in Surface elevation .0 r--T- 1 — _. 3 — 4 — 5 — 6 — 7 — . 8— ,QL/9cK 4 o .4 M 13P L o �► M po7T «o BR. e- L.rX- End of boring at _3 feet. Standing wacer table: i'l-esent at feet of depth, hours after boring. Not•present in boring hole �_• r '• Mottled soil: Observed at �- feet of depth. t:ot present in bocinp. hole — — Obsurvations and co=ients: o,aRlt 'BR. L' o AM' a� < <.4 y L o •Y '41 n o7r.L a 0 ER, c l pry L o11 4 — 5 -- 6 — 7 8 — End of boring at —Z- Standinp- water table: Present at fee hours aft Not present 1n borins .lottled soil: 'Ibsorved at /. feet of dopth. . Clot present in boring hole Observations and COIT-ents: Lois of Soil Borim-.p T.oclrio:l or Pro Inct , Borings made by Date classification system: AAS110 USDA-!;(;;; Ut, if I .-(I (Ithe'. Aurcr used (check two): Itand ,*K or Flj*jjj*C or BuCkCL Dcptjj, Boring numhcr*_._3______ nriltiii norifist amoier in fact Surface elevation fact in Surface elevation R L L. 7-r- 3 4 4 6 .7 Fnd of boring ac rec-c. Scand-4-7 wntcr cable: r-resenc at 3,1 feet of dri)th, hours after boring. t.'oc.prcscnt in boring hole Mottled Soil Observed at fact Of I!ot prcscnt in boring, hole ObsQtvatlons and comments' 1:11d of borillf. ac ,IL fact of: -LIC1,010 hours after borinn. loc pru!;cnt In borimst hale �,.Otticd -coil: n1luarved at foot ne t1ot 1)rQUaltt in boring hole 0b!;c%-,.j;,tjo%it;.nnd COUIX.100CU: