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HomeMy WebLinkAbout1988-05-09 Septic System Design ReportSITE EVALUATION REPORT & SYSTEM DESIGN FOR MCNULTY CONSTRUCTION OF LOT 4, BLOCK 2, McCulIey Farm ORONO, MINNESOTA 5-9-88 On April 29-30, 1988 two sites were tested for both a primary and an al­ ternate septic system site. Both areas were very flat with nice black loam soil on top but with a possible seasonal high water table which would require a mound system for either site. ^ ^ ,Additional information follows concerning results and design criteria. In addition, two septic tanks of at least 1000 gallons each will be needed along with a third pumping tank of 750 gallons. An alarm device is also needed to warn of any pump failure. r .All construction and materials mu^t^^dhere to the provisions of the City of Orono. All grading and construction-^must be kept off both the primary and the alternate sites. If any other information is needed, please contact me. Sincerely, PERCOR. INC. / * ■% /V* crz^/u/ />!< ^ £ff4^4foa/^ PUMP SELECTION PROCEDURE F-15 A. Determine pump capacity: 1. 2. 3. Minimum suggested Is 600 gallons per hour (10 gpm) - to stay ahead of water use rate Maximum suggested for delivery to a drop box of a home system Is 2700 gallons per hour (43 gpm) to prevent buildup of pressure In drop box Use value from design of pressure distribution system SELECTED PUMP CAPACITY gpm B. Determine head requirements: 1. 2. 3. 4. Elevation difference between pump and point of discharge _ If pumping to a pressure distribution system, add 5 feet for pressure required at manifold . . . . . . . . . . . . . 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. - 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_/70t * c. Calculate total friction loss by multiplying friction lo.s8 in ft/100 ft by equivalent pipe length. Total friction loss • V. o3/tAn x Z.iZ t ■ Total head required is the sum of elevation difference* special head requirements, and total friction loss. + s ^ r. 5 t feet ZUt feet S t feet TOTAL HFJU). . . . . . . . . . . . . . . . . . . . . . . . . . . C. Pump selection 1. A pump must be selected to deliver at least € gpm with at least t feet of total head. D. To maximize pump life select sump size for 4 to 5 pump operations per day. 2J.St feet K. Calculate drainback 1. 2. 3. 4. Determine total pipe length. Determine liquid volume of pipe, 100 feet. (See page E-18) Multiply length by volume: Drainback quantity _ _ _ _ _ _ feet x _ _ _ _ _ gallons/100 ft ■ _ Suggested drainback quantity is feet. gallons per gallons 10 percent of pumped quantity. A larger drainback percentage will decrease pump station efficiency slightly but pumping energy costs are usually a relatively small part of the total household energy costs. E-19 MOUND DESIGN PROCEDURE (For Flows up to 1200 gpd) A. Sewage Flow Rate See D-7 or 1-3, 4, or 5, or use metered value; Flow Rate » ^SO gpd F. Pressure Distribution System B. Septic Tank Liquid Volume (see C-3 or C-5) fooo gallons C. Soil Characteristics 1. Depth to restricting layer such as seasonally saturated soil, bedrock, coarse soil, ®tc.; inches 2. Depth of percolation tests; if Inches 3. Number of percolation test holes; ^ holes 4. Ave. percolation rate; //. O mpl Z X5. Landslope « D. Rock Layer Dimensions 1. Multiply gpd by 0.83 to .• obtain required area of rock layer; gpd X 0.83 ft 2. Select width of rock layer (10 feet or less) - jp feet 3. Length of rock layer ■ Area - WidthJ7/.5 sq ft - iP ft ' - ft E. Rock Volume 1. Multiply rock area by rock depth to get cubic feet of rock; sq ft y^P,75 tt - 2££cu ft 2. Divide cu ft by 27 cu ft/cu yd to get cubic yards; /^. y 3. Multiply cubic yards by 1.4 to get weight of rock In tons; /P,ycu yds X 1.4 - /y. 5 tons 1. Select number of perforated laterals € 2. Select perforation spacing - 3 ft 3. Select perforated lateral length; Note if manifold is at end of rock layer, lateral rock layer length a perforation If manifold is in rock layer, lateral one-half rock layer length, less half a perforation spacing. Perforated lateral length - /7. Z ft. length Is less half spacing, center of length Is 4, Divide lateral length by perfor­ ation spacing to get number of perforations per. lateral /7.2 feet f( ^ fjfeet “ C perfs Note: last\^ej;foratlon must be In end cap, (see page E-14) 5. Multiply perforations per lateral by number of laterals to get total number of perforations; < perfs/lat x ^ lats - SC 6. Determine required fl,ow rate by multiplying number of perforatiorxs^^ flow per perf orat; SC perfi r m^Ts^page E-17) x>7ygWperf "7^. Cgpm 7. Select minrsiuiiL^equlrcd lateral diameter from table on Page E-17; enter table with perforation spacing, perforation diameter, and number of perforations per lateral. Select minimum diameter for perforated lateral “ Inches " G. Basal width 1. Percolation rate in top 12 inches of soil is //. Q mpl 2. Select allowable soil loading rate from table on page E-16; use _gpd/ft^ E-20 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/ft^ by allowable soil loading rate; 1.20 gpd/ft* Check this value on page E-16. 4. Multiply basal width ratio by rock layer width to get required basal width; 2/0 X iO ft - 2 Q ft H. Downslope Dike Width 1. If landslope is 3Z or more, subtract rock layer width from basal width to obtain minimum downslope dike toe width _ _^ft -_ _ft - _ _^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: / feet b. Multiply rock layer width by landslope to determine drop in elevation; X 2 X \ 100 - ^>^ft c. Add drop in elevation to depth of clean sand at upslope edge of rock layer to get depth of clean sand at downslope edge • of rock layer. OX ft + / ft - ft 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; jX ft -K^75ft +/^ft - ?Xit e. Enter table on page E-18 with landslope and downslope dike ratio. Select dike multiplier of 3* /9_ _ _• Jit H.2.f. Multiply dike multiplier by downslope mound height to get downslope dike width; 3. n X 3X - /^. 2 ft g. Compare the values of step H.l and step H.2.f. Select the greater of the two values as the downslope dike width; ^feet h. Calculate upslope dike width using upslope mound height and upslope dike multiplier from page E-18; - - -X_ _ _ _ - - - - - - 1. Total mound width is the sum of upslope dike width plus rock layer width plus downslope dike width; _ _^ft +_ _ft +_ _ft - _ _ft 3. 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 H.2.a. through H.2.f; /^: Z feet b. Calculate upslope dike width 3 X using upslope mound height and dike multiplier from Page E-18; y.o xT^ft - 3.5 lx. c. Add downslope dike width to upslope dike width to rock layer width to get total mound wid th; /a,z ft -I-/.5ft ^ io ft •Tyjit d. Compare total mound width to required basal width from step G.A. 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. ^ —(■nf If. 7 PERCOLATIOH TEST DATA SHEET B-39 Wc.C.u\\eNl Teat hole location loV A . B\66k Z_ _ _ _’ Hole number_ _ _ _{_ _ _ _ Date teat hole vaa prepared Depth of hole bottom, /S Inches Diameter of hole, (y inches. Soil data from test hole: Depth, inches __ _0-/A Soil texture BI quJc |0C4/yy^ Method of scratching sidewall_ _ _ _Kc>\g Depth of pea-sized gravel in bottom of hole. Date and hour of initial water filling Depth of initial water filling. inches. / S inches above hole bottom. Method used to maintain at least 12 inches of water depth in hole for at least 4 hours _ _ _ _ _ _ _ _ _ll i _ _ _ _ _ _ _ _ _ _ _ Percolation test readings made by ^ _ _ _ _ _ _ _ _ _ _ on - - starting at _ //* 2 k> . Maximum water depth above hole bottom (date) P-*^‘ during test, /4^_ _ _ inches. Time Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch % Remarks It'iu A^ib 30 10.1 IlMO 34*1^6 /> >/b S ‘V/t.• 2. 1 \D'»61 eS»l li-lro-7 30 •2*y/(.n 4- 3 1 7 2 »//.,IZ.4-* \ ...1- - - - - - - -- Percolation rate ■/c?. 4-minutes per inch. PERCOLATIOH TEST DATA SHEET B-39 Test hole locatlon_J1tiiM!j(_______________________Hole number '2- Date test hole vas prepared- -^'2^-08 . Depth of hole bottom, /ftInches Dlaoccer of hole, Inches. Soil data from test hole: Depth, Inches _ _ _ _ Soil texture P/J1 Method of scratehlne sldeuall Kr>l< a- Depth of pea-sized gravel in bottom of hole, Z- inches. Date and hour of initial water filling 4-29 'S3 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 ^ hours_ _ _ _ _ _ _reVt l\; fsa_ _ _ _ _ _ _ _ _ _ Percolation test readings made by ^ ~~ (?a?e) ^^ Maximum water depth above hole bottom during test, / 4- inches. Time Time Interval, Minutes Measurement, Inches Drop in water level. Inches Percolation rate, minutes per inch Remarks //W7 to /4^U 5'‘V/(,5*. 4-Wi(34-//i^A 74 7^6 5/3i5e>^*^4. /4‘Vib 4>,o/'. JA S 5.1\ ^.5^/i3 4 7.7- % •_ Percolation rate y. 2_minutes per inch. B-39 PERCOLATIOH TEST DATA SHEET Test hole location Hole number Date test hole was prepared Diameter of hole, (o Inches. Soil data from test hole: Depth, Inches Depth of hole bottom, /3 inc!;es Soil texture .P>\<ar jg S oCl'Y^ I ft he It r“ ■2- Method of scratchlms sidewall Depth of pea-sized gravel in bottom of hole, Date and hour of Initial water filling 4- -z - S>3_ _ _ _ _ _ _ _ Depth of Initial water filling, / ^ inches above hole bottom. Method used to maintain at least 12 Inches of water depth In hole fur at least 4 hours re C i \ rx laches. Percolation test readings made by ^C>b <$o // (date) during test. starting at ja_ _ —p.m.Maximum water depth above hole bottom Inches. Time irX I !^0 Time Interval, Minutes a O 3 I Measurement, Inches ^ lU. ■•-♦to /6 '■'* Drop In water level, inches A ^/k> 3 7/0. 3 2 '^//w Percolation rate, minutes per inch 7.7 7.© 7.3 7^ Remarks Percolation rate /0.4-minutes per inch. PERCOLATION TEST DATA SHEET B-39 Test hole location F'Ac.Klull Hole nudbcr 4~ Date test hole vas prepared Dianeter of hole, (o inches. Soil data froo test hole: Depth, inches ,, Depth of hole bottom, /fe inches Soil texture Method of scratching sidewall Koie *ScrcxVc.U -« r inches. ^:oo pkw Depth of pea-sized gravel in bottom of hole, Date and hour of initial water filling Depth of Initial vater filling. /S Inches above hole boccon. Method used to oalntnln at least 12 Inches of vater depth In hole for at least * •‘ours_ _ _ _ _ _ _ _ _ _ _ _ _rg^.'W. re Percolation test readings made by -ge> starting at ' 1^ (date) during test. . / 4- Inches. S_o ''O c2lRI> —p.m.Maximum water depth above hole bottom Time Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks I4%(.5:43<iO 5 ■'//(,<S.4 4. 3 1 4- 'X ^>.4-^:c f 3o 2. 'V„./0.4- % • Percolation rate ■minutes per inch. B-39 PERCOLATION TEST DATA SHEET Test hole location Kl^iKJulV Hole number Date test hole vaa prepared Diameter of hole, Inches. Soil data from test hole: Depth, Inches /O ■ life Depth of hole bottom, /S Inches Soil texture Method of scratchlns; sidewall Greets S<l<r ^ e Depth of pea-slzcd ct’iivel In bottom of hole, ___^ Date and hour of Initial water filling Depth of Initial water filling, inches. 5;0O IS Inches above hole bottom. Method used to maintain at least 12 inches of water depth in hole for at least 4 hours_ _ _ _ _ _ _ _ _ _ _f ^_ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ Percolation test readings made by ^0 /rZ-» _ _ _ _ _ _ _ _ _ _ _ oi starting at / /• .? / (date) during test. CSSa:^ —p. m.Maximum water depth above hole bottom Inches. Time ikki tlOO Tine Interval, Minutes 3 I Measurement, Inches 6^ Drop in water level, inches 3 4- Percolation rate, minutes per inch 7*3 7.1 <7.5 s.o //. z. Remarks Percolation rate )L1 minutes per inch, PERCOLATIOII TEST DATA SHEET B-39 Test hole location Yy\ rVlixl-V t Hole number Date test hole vas prepared Diameter of hole, 6a inches. Soil data from test hole: Depth, inches -Q.r* ^_ _ _ _ 2.^* _ _ _I Depth of hole bottom, Inches Soil texture Method of scratching eidcvall T inches. S'crO Depth of pea-sized gravel in bottom of hole, ^ Date and hour of initial water filling 4* • 2.^ ~ 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 A hours_ _ _ _ _ _ _ _ _ _ _ _ _rv( onPercolation test readings made by ^ //g^ _ _ _ _ _ _ _ _ _ _ _ - 4"^^ ~ ^8 starting at f . Maximum water depth above hole bottom (date) during test, / 4_ _ _ _inches. Time Time Interval, Minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks IV oi S* /3 BA 3^ 1:_ __ ^0 7 ' - I* 53 5 1 3 V/u,^.1 ?o Z V/i,f^A % ;i_ _ _^.1- - - - - - - Percolation rate •lAl minutes per inch. Logs of Soil Borings Location or Project Borings iDsda* by _ _ _b D-31 Date 4-39-aa Classification System: AASHO _ _ _; USDA-SCS Auger used (check tvo): Hand ox Power _ ; Unified ; ocher j Flight _ _, or Bucket other Depth, in feat Boring number / Surface elevation loaivN B^o^orv Grcvj 2 — 3 — 4 — 5 — 6 — 7 — 8 — End of boring at 4“ feet. Standing water cable: Present at _ _ _ _ feet of depth, _ _ _ _ _ _ hours after boring. Not present in boring hole V Mottled soil: Observed at A feet of depth. Not present in boring hole -« Observations and conaaents: Depth, in feet 1 — 2 — 3 — 4 — 5 — 6 — 7 — Boring number 2-. Surface elevation Brov^OA C\a\^ lo0kwv\ l3,OU.>VV *ScV.%€]iv^ End of boring at 4-feet. Standing water table: Present at _ _ _ _ feet of depth, _ _ _ _ _ _ hours after boring. Hoc present in boring hole X' Mottled soil: Observed at feet of depth. Hot present in boring hole Observations and conaaents: Logs of Soil Borings Location or Project Ifi Beringo nada* by l^oi^ ll- D-31 Date 4*^SOK*n^a maw wj i e j n » t-g Classification System: AASHO_ _ _; USDA-SCS Unified _ _ _; other _ _ _ _ Auger used (check two): Hand or Power _ _; Flight _ _, or Bucket other Depth, in feet 1 — 2 — 3 — 4 — 5 — 6 — 7 — 8 — Boring number Surface elevation B1 acJ< loam Gre\| Cto-v^ lottm _ 6reei^ Grew igum ' CU\| —1 ^OM>v^ loft.rv\ End of boring at feet. Standing water table: Present at_ _ _ _ feet of depth, _ _ _ _ _ _ hours after boring. Mot present In boring hole A Mottled soil: Observed at g? feet of depth. Not present in boring hole Observations and consnents: Depth, in feet 1 — 2 —• 3 — A — 6 —. 7 —- 8 — Boring number Surface elevation End of boring at feet. Standing water table: Present at _ _ _ _ feet of depth, _ _ _ _ _ _ hours after boring. Hot present in boring hole Mottled soil: Observed at feet of depth. Hot present in boring hole Obsoxrvatlons and conoents: M0.4 Features I /I,' Pump ImpuMm *» «K:i»i.o«*d ly|m opftfMlivt <;um|)li>liilv out ul vuliilo pvMayo oiviiki full opening lot flow of liquids •nd solids Motor Housinfl is heavy cast iron. Stator is pressed in for perfect alignment, best heat transfer. Powerful 4 fO HP Molor is in! IiHinI tin iiimmI III iul.ilHm iiihI lulitH •itmn ijl iNiiiniHri iIIhI simI Overload proteciHin buill-in. has no starting switch or relay mechanism. Thruol Wbshors and Sle e ve Boeringe are oil lubricated lor smooth operation, long pump life SearlMs • •ulnmRofary Shaft SeiWJi.is i ailnm ■ iinI ^l•Mll•M l.ni". Ini |h**.iIi\,** mmI IhHly IS .l.lll•llMly imi'vihiIs Siring or Irash troin winding on seal Switch Housing |SSM4A) is complelely sealed from sump liquid easily remowixl lor repl.iciMiienl if n^•l»d^^. Mercury Switch ;*i' AMI* r.ilni'i .1 I vlindi’i *N' .lin|lf ••piM.l lllMI |)t(lv|lll)|>>l|MII' lll.tlfll.il Miniinurn icvoininended tidher length IS 3'«~ from cord clip to switch case (Pump Down 7-0") Pump Down' can be increased by increasing the Tether length iimensions OCT I 91988 mm ptw) psiiii Acce ssories V- Performance Curve eaiwonfv uTMe SMI iMtifi 20 40 60 to too 120 MO ISO 100 200 220 240 nis20 2saoM40 4es0M~i0 CMIOTV OAUOMe MR MMHS Performance Table Iitai fast ?4 6 8 10 i:u 16 13 20 7 ’ HaM dm*bl 177 1 ii 7 44 t'J-. j 366 4.i 4 »e 549 j1 0 111 bM SaUM NrNasr 3 600 3600 315C 3 300 3150 ?9i)Q 2 550 ;'250 I vjO ! ICO 66'] Ulsn Nr Itoir 13 6?5 13 625 13 058 i;i9c 119:310 9?6 9 65?!:16 6 513 i9?l ?39! Performance Capabilities CijKitif s to MMIsto 60 GPM j 24feer" 22J LPM 7 32 meters PsMp Down ian|t *7 lo 14 inches 177 8 to 355 6 mm SOM NM«fj!|/i inch dia solids 19 1 mm dia solids UsmMsNmM Fresh, drainage ettiuent waste water IfilirMtttiirt LiwiM Ttmp.ISO^F 65 C Motor Vio HP Eloctricol 115 230 V. 120 A60 A 1 d», 60 Hertzl Dischano 1 / inch i 38 1 mm 'Aulomalc Modal (manual pump vanaua tmtt) ttfkM F E MYERS a Pantan company 400 Orange Street. AsMand OH 4480S-2?es 4I9(289 H44 Teiei 96 7443