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HomeMy WebLinkAbout1994-10-31 Septic System Design Report1(300 rc� I—at SYSTEM DESIGN FOR BRUCE­-BREN HOMES OF LOT 8, BLOCK 1, .HADOWOOD FARM ORONG, MINNESOTA 10-31-94 Information follows for a presure-mound system for a four bedroom ' house proposed on the above propertv. All construction and mater- ials must be in accordance with MPCA Chapter 7080 and the City of Orono codes. All construction traffic must be kept off the primary and alter- nate septic areas. These areas should be marked off prior to con- structio:i. A pumping tank will be needed to house the pump necessary for pressure distribution to the system. The manifold and supply line pipes must be constructed to drain back to the pumping tank. A weather proof enclosure will be needed for the controls and swit- ches 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, INC. Mark S. Gronberg MOUND DESIGN WORKSHE;r I' (For Flows up to 1200 gpd) FLOW Estimated Co n gpd or measured x 1.5 = gpd. SEPTIC TANK LIQUID VOLUIN'ES gallons f O�� F / U<� ; r- t Q, . 7.4 CIL SOILS (refer to site evaluation) .. Depth to restricting layer = /If inches 2. Depth of percolation tests = ! inches 3. Percolation rate S• 6 mpi .. Land slope 1V Esdrnued Setrate Flow in Gallons N..ber SoilTcxture C.:_(•i pd �rvw S.por Td Ly�__�+1r+ of Type 1 Type 11 11'1 Be_:Ooml 750 1.125 1.00 2 300 225 1 500 3 450 300 3.000 4 600 375 1.52 5 750 450 2.00 6 900 525 2.40 7 1050 600 2.67 8 1200 675 5.00 r ROCK LAYER DIMENSIONS :. Multiply flow rate by 0.83 to obtain required area of rock layer: A x 0.83 = KC C gpd x 0.83 sq. ft./gpd sq. ft. :. Select width of rock layer (10 feet or less) _ �' ft. Length of rock layer = area -�- width = Rock Bed C 6 sq. ft. y i C ft. = sy ft. •i�i�i�� i�ir'"i� i�i�:�. 1 ~r iii iii i:i'•i~J�i i�i�i~i� i�. Width 510 ft. .I././././.J•J•I. J.l.I. J. J.J././.. ROCK VOLUME i Length Multiply rock area by rock depth to get cub- = feet of rock; Sv 10 sq. ft. x / ft. = SDO cu. ft. Divide cu. ft. by 27 cu. ft./cu. yd. to get cubic yards; S� ^ cu ft. + 27 cu. yd. Multiply cubic yards by 1.4 to get weight of rock in tons; L cu. yd. x 1.4 ton/cu. yd. = Z C tons. .aDSORPTION WIDTH Percolation rate in top 12 inches of soil is 3 mpi Select allowable soil loading rate from table; t"': f o. 6 O gpd/ft' Calculate adsorption width ratio by dividing rock layer loading rate of 1.20 gpd/ft2 by allowable soil loading rate,- 1.20 ate;1.20 gpd/fe+ . 60 gpd/ft2 = 2 • O Multiply adsorption width ratio by rock layer width to get required adsorption width; 2. U x /D ft= 2,9 ft AbsorpdonKSdthSiunRLble J' nulaSonR+ie per rch :nutn i SoilTcxture C.:_(•i pd �rvw S.por Td Ly�__�+1r+ �+1' po:r D.- Faster than 0.1 750 1.125 1.00 1.000 1.500 1.20 1 500 2250 F nc S.ind- 2.000 3.000 ovc9 Set fQ.0-6 (41.5 r ROCK LAYER DIMENSIONS :. Multiply flow rate by 0.83 to obtain required area of rock layer: A x 0.83 = KC C gpd x 0.83 sq. ft./gpd sq. ft. :. Select width of rock layer (10 feet or less) _ �' ft. Length of rock layer = area -�- width = Rock Bed C 6 sq. ft. y i C ft. = sy ft. •i�i�i�� i�ir'"i� i�i�:�. 1 ~r iii iii i:i'•i~J�i i�i�i~i� i�. Width 510 ft. .I././././.J•J•I. J.l.I. J. J.J././.. ROCK VOLUME i Length Multiply rock area by rock depth to get cub- = feet of rock; Sv 10 sq. ft. x / ft. = SDO cu. ft. Divide cu. ft. by 27 cu. ft./cu. yd. to get cubic yards; S� ^ cu ft. + 27 cu. yd. Multiply cubic yards by 1.4 to get weight of rock in tons; L cu. yd. x 1.4 ton/cu. yd. = Z C tons. .aDSORPTION WIDTH Percolation rate in top 12 inches of soil is 3 mpi Select allowable soil loading rate from table; t"': f o. 6 O gpd/ft' Calculate adsorption width ratio by dividing rock layer loading rate of 1.20 gpd/ft2 by allowable soil loading rate,- 1.20 ate;1.20 gpd/fe+ . 60 gpd/ft2 = 2 • O Multiply adsorption width ratio by rock layer width to get required adsorption width; 2. U x /D ft= 2,9 ft AbsorpdonKSdthSiunRLble J' nulaSonR+ie per rch :nutn i SoilTcxture C.:_(•i pd �rvw ..�.., Faster than 0.1 Coarse Sand 1.20 1.00 0.1 to 5 Sand 1.20 1.00 0.1 to 5 F nc S.ind- 0.60 2.00 6 to 15 3andy Loam 0.79 1.52 16 to 30 Loan 0.60 2.00 31 to 45 Silt Loam 050 2.40 46 to 60 Clay Loam 0.45 2.67 61 t0120 Clay 0.24 5.00 Slower than 120 Clay --- I - M")ti.i'6 W% - .- d nry or VO1Y R1V Ynd. k DOWNSLOPE DIKE WIDTH If landslope is 3% or more, subtract rock layer width from adsorption width to obtain minimum downslope dike toe .70 ft - /,,;� ft= /O feet Calculate Minimum mound size based on geometery: a. Determine depth of clean sand fill at upslope edge of rock layer: Separation /. S feet b. Multiply rock layer width by landslope to deterndne drop in elevation; Slope Difference seperotlee %+-100= O. `/ feet Wslope width c. Add depth of clean sand for separation (2a) feet at upslope edge, depth of rock layer 0 foot) to.depth of cover 0 foot) to find the mound height at the upslope edge of rock layer; /. S ft + Ift + ift = S feet d. Enter table with landslope and upslope dike ratio. Select dike multiplier of 3. y S e. Multiply dike multiplier by upslope mound height to find upslope dike width: ?-Y5 x Z. s = /2. / feet f. Add depth of clean 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; s ft + z). y ft = 3.? feet g. Enter table with lar dslope and downslope dike ratio. Select dike multiplier of t/. -16 h. Multiply dike multiplier by downslope mound height to'get downslope dike width: 3 • •9 x �f.7S = /8. C 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; /�• 6 feet <' vouoo j. Total mound width is the sum of _ upslope dike (G.2e) width plus rock layer width (D.2) plus a „p,;o; downslope dike width(G.2i); ft + /O ft+/j.6 ft= 1/G.%feet k. Total mound length is the sum of upslope dike width (G.2e) plus rock layer length (D.3) plus upslope dike width (G.2e); /f • f t + SG ft+ /2-i ft= !yi feet I toot Cover fool feet Rota pea Wlath feet slope Olftorenco ---,tA-ot Downslope Mtoth lett Total loh0th oven ope --- Ps 33 4.1 fa 41 7:t f:1 4.1 11 41 7:1 o3 0 34 U 3.0 LO 7.0 1.0 CO 3.0 40 7.0 eD 1 1D0 417 316 W 7M Its 1. AS 473 1. 6A LU 741 2 1.11 41S 3S3 4Q tat LO 7.70 t51 f3s L11 3.00 7 130 4S/ $31 7.32 4K 273 25F 153 5.03 3.79 SAS 1 741 4 73 3 :3 731 1.72 2Y 3.45 1.17 464 413 3GL 3 79 Up L37 IS7 to" 231 233 /.W 437 5.11 f71 3 343 S.26 7.11 151 1207 2-33 3.".. 3-U 411 4% $At 7 330 SS3 7Ae tau 1773 1 2.12 7.70 &Z L70 3.17 e 7.1f SL Lit Its& 1f31 2.32 1.0 737 LOS 0.00 /3e 1 1.11 L2f 1D1 1743 1407 iii 1.001 3.15 3.10 3]0 GAS 111 L37 10.0 Ism 2331 231 2."731 3.73 412 1M 10 11 143 7.16 1151 ITAS 3043 216 US 3z 333 'At 3.41 SAS 3.00 136 449 12 1H 730 1750 7tA1 4325 121 2.70 ':_ li •�MUM Select number of perforated laterals 3- . Select perforation spacing = 2 feet. Since perforations should not be placed closer than 1 ft. to the edge of the rock layer (see diagram), subtract 2 ft. from the rock: layer length. So ko<kt,yer�,, Lti=2ft. = r/b' feet.' Determine the number of spaces between perforations. Divide the length above by perforation spacing and round down to nearest whole number. Length perf. spacing = `l,p ft. + ? ft. = 6• spaces (3) (2) Number of perforations is equal to one plus the number of perforation spaces . I° spaces + I= /7 perforations/lateral Multiply perforations per lateral by number of late>;als to get total number of perforations. -? /7 utaj x pe,iw� = / perforations. Determine required flow rate by multiplying number of perforations by flow per perforation C. �y gpm. If laterals are connected to header pipe as shown on upper example, to select minimum required lateral diameter; enter table with perforation spacing and number of perforations per lateral. Select minimum diameter for perforated lateral = i inches. :f perforated lateral system is attached to manifold pipe near the center, lower diagram, 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 = inches. END PERFORATIOft OF A PERFORATED LATERAL CJ.J �i6 Toowl, p 1� •: Lor.. d Go4.111. Fowc (" I- L.aany San" Irr.r.' ,• k�,cy.r .1 Iry er .Iro. ta..r.d 1 i P.r laralbn 0,111.1 1W111-1.1, a in 1. CA r:. o. Toa Y/.* Plw ut 12' to El;c ti0101, F1.1d P -k3.,• . ,",:l of P UTtr ,. `�••Parforatlor�•Loco r.d of Clan S4„4 Lar. Ooilom of Laftrol Orlghol .So11 PToiler lr Sca'It.0 0.1we PTP Sand Loyw R.y.0 w.1 Pobr.. an fT.cA.,a. N F+%b ti W r en uwu (dy enr o�tira. 41e.d y 1 r r•+ � � � (k..l ig 1; 1.0a 0.56 0.74 2.Ob 0.80 1.04 a. Use for single family hom s b. Usc for all other applications Maximum number of quarter inch perforations pe lateral to guarnantee < 10% discharge variation Perforation Sr ig 1; n 2 2.5 14 18 28 3.0 13 17 26 3.3. 12 16 25 4.0 11 15 23 5.0 1 10 14 22 ......OLD LOCATro AT rb V ••L mK 6:T •i�yi rtn S.^Sr R - F-17 A. Determine pump capacity: Gravity Distribution 1. Minimum suggested is '-W gallons per hour (10 gpm) to stay ahead of water use rate. 2. Maximum suggested for delivery to a drop box of a holre system is 2,7CO gallons per hour (45 gpm) to prevent build-up of pressure in drop box. Pressure Distibution 3. a. Select number of perforated laterals b. Select perforation spacing = 3 feet. C. Subtract 2 ft- from the rock layer length. „�,ur-,'4', - 2 Et. _- �! �P feet d. Determine the number of spaces between perforations. Length perf.spacing .'/P ft.+ _? ft._ 6 spaces e. IC spaces + 1 = /7 perforations/lateral f. Multiply perforations per lateral by3 number of laterals to t total number of perforations. x-�= 5/ perforations. 9�.7'Ti-rr =-L?- gpm. SELECTED PUMP CAPACITY ? 3 -gpm Determine head requirements: Elevation difference between pump and point of di ., feet If pumping to a pressure distribution system, five feet 'or pressure required at manifold if gravity system, zero. feet Friction loss a. Enter friction Ioss table with gpm and pipe diameter. Read friction loss in feet per 100 feet from table. F.L = . / ft./100 ft of pipe ro- 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 = SD x 1.25 = / 8 feet c. Calculate total friction loss by multiplying friction loss in ft/100 ft by equivalent pipe length. Total friction loss= ! • x / .5'0 +100 = 3. 6 feet Total head required is the sura of elevation difference, spacial head requirements, and total friction loss. Y + 7 + _l (1) (2) (3c) TOTAL HEAD _5 feet C Pump selection 1. A pump must be selected to deliver at least C = ' gpm (Step A) with at least /5 feet of total head (Step B). C/D PCTFC:LTIC. OF . K,"FrnaTED LATCAAL kr Tp.W • rl G..I.IIY. FobN (r lo,• ' Lb1 �� I.trti � YaA M ,•tw. r.r-IYP .wwM �M • . M CM I�.r 1 � Nor.l on l.11, •r ��i ►Iw �Y lMu I=• t. I.{r f-11 rl Pr[{ Lq.r " Prlr Mbn 1.u1.� .1 RNuimd Pcrfontion Dinha Te 1n gallons per minute (gprn Discharge Head UCCO .Si .ap..r ­% PM 1.0a 0.56 0.74 2.0b' 0.80 1.04 a. Use for single family homes b. Use for all other applications Pipe Length Point of TTDischar Elevation DifferencePtunp F•18b 1.5 inch 2.0 inch 3.0 inch 91-M Fria m lou pv I N ft c(p;pc 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 0.11 25 3.73 1.11 0.16 30 5.23 1.55 0.23 35 7.90 2.05 0.30 40..11.07 2.64 0.39 45 14.73 3.23 0.48 50 3.99 0.58 55 4.76 0.70 60 5.60 0.82 Lofts or Soil Borinr.s 11-18 �s�-- r.ncation or Pro 10.ct !L ��% —_(�/ JCk l �, ? Borings made by �r r���-�--�--=='1 � �- �t� ,"' •--. i)atc Classification System: AASM USDA -SCS _>—; Unified other — Auzer used (check two): Fand or Power Flight —, or Bucket 4: other Depth, Boring nu-mber. Depth, Boring nur.,her in in 1 feet Surface elevation feet Surface elevation n t--� -- -- - n --� — --- - { 2 _. GIS � r 9.Qou.,✓ C 4O/ok 4 — IIt 7 — End of boring at .3 feet. Standing hater table: F3•esent at _?-O ft feet of depth, hours after boring. tIot present in boring hole t Mottled soil: Observed at _ �S feet of depth. tlot present in boring. hole Obsurvations and comments. 1 11 d«Ck (o/.rt 3 6',Ou r eR..G�,v 3 --- 4 L•nd o -F boring at .3 feet. Standing crater table: ♦ J Present at �— feet of depth, hours after boring. Not present in boring hole Mottled soil: Observed at /. !s feet of depth. Not present in boring hole Observations and comments: Logs of Soil Borinr.s I3_18 / - - — J� �j d t � Location or Project L/L� E �L/iJ _ _—� eT J <_i — Borings made by I�.V"J�r/ii l� C'L� -- natey�2e. t�;`----- Classification System: AASi:0 UgDA-SCS Unified other -- Auper used (check two): Hand Y, Cr Flight _, or Bucket : c.i.�r _ Depth, TBoring numher _ - Depth, Boring numher Surface elevation � i Surface elevation feec feet --- n -- - - n — -- --� End of boring at 3 feet. Standing water table: Present at 27i1 &ee-r of depth, hours after 'oorinp. Not present in boring hole mottled soil: Observed at feet of dr-Tlth. i'.ot present in boring. hole — Obs,rvations and cc-ments: t 2 3 4 S 6 7 s — id of boring at feet. :anding water table: :esenc at feet of depth, hours after horinr.. it present in boring hole zttled soil: bserved at facet of depth. of present in boring hole _ ibservations and comments: I PERCOLATION TEST DATA SHEET Test hole location /:-& LLL 2 Te — L D / - Bole number Date test ho__ was prepared Z -/-2 p Depch of Bole bottom,-/�' _..'I 1L. . Di__eter o: Soil data _. leJV }tole. ^1•/� Depth, inches Soil texture G Z.02 , , IT o 1 1; Method of scratching siacwall SG!(/1•%G " Depth of pea-sized gravel in bottom o� hole, _2 inchc::. Date and hour of initial .later filling LV —,2!? —ZQ =� f Depth of initial water filling, / 3 i^chcs above Bole botto:::. `cthoc used to =aintain at 12 _: che5 of water dcpt!t in hole ::or ,.. __.. 4 hours E /�� L L Percolaticn test readings Nadu b -- l./ '?D - /?j star;._^g at /2 ;faxi^:us ..ate: Depth at:o. _ .... _ ,�li (date) 1/9, during test, inches. g— Time Ti=e Interval, Minutes �G Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Rema:-ks L Z.02 , , IT o 1 1; " Percolation rate winutes per inch. f Z PERCOLATION 'rzs'r DAT.'. SHUT Test hole location /f4j L �ER ) o& Hole number 2 Data test hole was prepared Y-2k-�,n , Depth of Bole bottom, Dia::ace:• of hole, inches. Soil data from t 1;olc: Dept' :•:.�::es Soil texture Xachod of scratching side:aall 54%1%iTc f'J L /z Depth of pea-sized S,.avcl in botto:a o hole, 2 inches. Date and 'hour of initial eater filli, .` -�— Z —`�Q 2 _._.A..l`1_ Depth of initial Water fill ng, ��� inches above hole botto:a. Xethod used to maintain at least 12 inclics or cuter depth in hole or at 4 hours A G %i LL ?ercotiation test readings made by QA/✓ ��Q sta_L'i.. at J ' 1 M. � ^s 2 3^ sa r[axir.:urs waCer depth above iiolu v .cc. (date) A during test, d inches. Time Tice Interval, Measurement, Minutes inches Drop in waccr level, inches Percolation rate, minutes per inch I:e:,.iarks /2 3Z 1 63 / f 3 d �— 2 eel++ / ,17 JYM 114 I 4f 6 I 1_31 s. 92 f -- _ -- 1-06 I rcolation rate i minutes per inch. K; '.echod of ,scratching sidcaall Depth of pea-sized &ravel in bottom o hole, Date and hour of initial water filling Depth of initial water filling,, inches above Bole bottom. `fethod used to maintain at least 12 inches of water depth in hole for at 1�...._ 4 hours #T I-+ L L' Percolation test readings made by Li -30 — 5 10 starting at 2 3 (dace) ' • D �. during test, inches. . Ila:cimum water depth abovQ ! _ _ Time Time Interval, Measurement, Minutes inches QQ,2 2 PERCOUTION TEST DATA SHEET 2 B -e k I Test hole location_ z' -z/ LLEnT II N �L-OT — hole iL 3 S- num.bcr Dace test hole was prepared 2Ir- y� y� , DCpI'�1 - 0= hOIC bOCtO:::, Diameeer of hole, 4— inches. Ii Soil data fro= test Depth, incises Soil texture '.echod of ,scratching sidcaall Depth of pea-sized &ravel in bottom o hole, Date and hour of initial water filling Depth of initial water filling,, inches above Bole bottom. `fethod used to maintain at least 12 inches of water depth in hole for at 1�...._ 4 hours #T I-+ L L' Percolation test readings made by Li -30 — 5 10 starting at 2 3 (dace) ' • D �. during test, inches. . Ila:cimum water depth abovQ ! _ _ Time Time Interval, Measurement, Minutes inches QQ,2 2 Drop in water level, inches Percolation race, I:e;^arks minutes per inch 2 Oh i i iL 3 S- 1.36 2. O to 2.07 t 3 JN + Ii Percolation rate m PSO minutes per inch. L .• . CtiE�iC Mcthod of scratching side:rall SG e%: Depch of pea-sized gravel in bottom ot. Bole, 2 inchus. Date and hour of initial water filling 2!? Depth of initial water fill=ng,3 inches above hole bULLo:::. • / Xct:^od used to maintain at lease 12 inches o_! waccr depth in hole for at lu::::L 4 hours ALF -/ L L ?ercolation test readings made by '` 30— Q StarLin r z `'� — S at a. Ill. 2 , � 3 �1 i•ta:<ir.:ur� water c.epth auovc iiv_u b•. �t: (date) ' `- durin3 test, S inches. Time Time Interval, Minutes Measurement, Drop in water inches level, inches 9 Percolation rate, minutes per inch Rema:ks; �� LLC / Ui Z S I PERCOLATION TEST DATA SHEET 'N Test hole location f/J L /- 'C- j/J ---��V/'� elle r.ut^uer Date test hulc was prepared !V-% 9- Depch of hole bottom., Diameter of hole, _� irches. -t- Soil data froe test hole: Depth, itches Soil texture ---- CtiE�iC Mcthod of scratching side:rall SG e%: Depch of pea-sized gravel in bottom ot. Bole, 2 inchus. Date and hour of initial water filling 2!? Depth of initial water fill=ng,3 inches above hole bULLo:::. • / Xct:^od used to maintain at lease 12 inches o_! waccr depth in hole for at lu::::L 4 hours ALF -/ L L ?ercolation test readings made by '` 30— Q StarLin r z `'� — S at a. Ill. 2 , � 3 �1 i•ta:<ir.:ur� water c.epth auovc iiv_u b•. �t: (date) ' `- durin3 test, S inches. Time Time Interval, Minutes Measurement, Drop in water inches level, inches 9 Percolation rate, minutes per inch Rema:ks; �� LLC / Ui Z S I / 'N — Z -t- 2.31 — 2 2 1 97 i /O r Percolation rate �� - minutes per inch. _ PERCOLATIO`1 'rEST DATA SEtBrT 'j'' BLS ' Test ho: -e vocation 11 �G��D�/�� ZO/ '� Hole number____ Data test hole was prepared L1/^2�—%d Dept!t of hole bottom, Dia=eter of hole, is Chcs. Soil data :row test hole: Depth, inches Soil texture ".c:hod of scra:--hing sidc:rali Depth of pea -steed gravel ttort o_ hole, _ i11C1'.Cs. Dace and hour of initial iillin De?ch of initial water L'il:_rnE _ _ i.chas above hole bottot::. `:ct'.^.od used to =aintain at least 12 i::ches of vacer depth in hole for at 4 hours OfEF, G L -Y o Oib Percolation test readings made b :1 L . t'1 . starting at Maximut:t Nater depth above (date) during test, d inches. Titre Ti --e Interval, Measure: ant, Minutes inch --a Drop in water level, inches Percolation rate, minutes per inch Ram'I Ram'tes V YO AA D 3 e __ 1.07 % i31g 7 F 1.39 1 3AL�--- 08 ?.09 I.--- I j --- Percolation rate , 2 h a,inutoI per inc. C. PERCOLATION TEST DATA SHEET 1 "�� OAK � Test hole location Elj LLLeIe / �J�/— ��� !!ole iiu:::ber�__ _ Data test hole was prepared Depth of Bole bottoia,L_- Dia=ecer of hole, incites. Soil data frc= test hole: Depth, inches Soil toxture Q - /-C 1 9,40 4.l 4 0AM -- ".a_hod 0-4�, scratching sidc:aall Depth of pca-sized gravel in boCt•O:n of hole, _z _ inchus. Date and hour of initial water filling —29'9 _-�,..•P/"% Depth of initial water filling, /3 inches above hole bottom. Hathod used to eaintain at lease 12 inches of waccr depth in hole for at lu.: 4 hours #4eda F/ L L L Percolation test readings made by DOW C -,P GA4,CR 4._ 0:1 a '1. - jQ starting at /2, 3 �1 Etaxirwm uatcr depth above (dace) during test, 7 �JP inchas . Time 2 Time Interval, Minutes Measurement, inches Percolation Drop in water rate, level, inclies minures per inch - 2 -- - .09 t,77 Ik _..._. D 3 _ I-/ Yz - 3 t/ -7. �S _ - O'D ------- '7 minutes per inch. Percolation rate