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Home My WebLink About1995-07-20 Septic System Design ReportS-P TESTING, INC,Steven B. Schirmers — MPCA Cert. No. 627 951 Katydid Lane NE • St. Michael. MN 55376 • (612) 497*3566 t-o-r 4 Fullerton Property 3350 Fox Street Main & Guest House Orono, Henn• Co.» MN July 20, 1995 This On-Site Sewage Treatment System is Designed for a Type 1, seven bedroom home & a one bedroom guest house in accordance with the Minnesota Pollution Control Agency Chapter 7080 and local ordinances. The soils on this site are a clay loam. A seasonally high water table was located at 14" to 42" (mottled soil). Due to the seasonally high water table, a Pressurized Mound System will need to be installed. The bottom of the rock bed must be located at least 3* above the seasonally high water table. Both the Main House & Guest House have Non-Conforming Systems due to not meeting the 3* seperation from the water table. All existing tanks will need to be abandoned due to being too old & undersized. They will need to be pumped & filled with soil. 2-1000 gallon tanks will be needed for the guest house & 2-1500 gallon for the main house. The soils at a depth of 12" have a percolation rate averaging 4.9 min/inch. A pumping chamber will need to be installed to lift the effluent to the treatment area. The manifold and supply line pipe must have back drainage to the pumping chamber. The distribution pipes shall have their ends capped. Be sure the rock and sand fill material are clean. The sod layer below the entire mounded area must be turned over, just break up the sod, be sure not to over work. The power supply and switches must be located outside the manhole and pumping chamber in a weather proof enclosure. A warning device must be installed with a light and sound device, this is in case of a pump failure. All neighboring wells are located greater than 100' away from the proposed treatment area.1 i i •i i CONT'D I ? . t Fullerton property 3350 Fox St. Orono (2) Keep all heavy equipment off of the propcsed treatment area before and after construction. The treatment area should be marked off before construction. This Design is not valid & the system will need to be relocated if failure to protect the areas proposed for On-Site Sewage Treatment occurs. With proper installation and maintenance, this system should have no problem in treating septic effluent effectively. Nothing other than gray water (laundry, showers, etc.) human waste & toilet tissue should be disposed into the septic tanks. Garbage disposals are not recommended. Excessive amounts of soaps, cleaning agents & chlorine agents may kill the bacteria needed to treat septic effluent. Additives are not recommended. Recommend to pump & clean your tank through the manhole by a certified pumper every year if you have 1 tank and every 2 years if you have two tanks. SBS/ds I _ ___ _ _ _i, o n I .J r g ifff3 »ft 5 t u<D t -P 5y1 C ? o d'•• A^'C:O saj^y C5»■1;cf»^5n '.■ f)>«■r Pi LM 2£c 5 'i'lCIilfH9?Ta ?A Q«> lO r ViInoCv ^ ^ •' J >i «/•470. :1 I1,1 III I -"je Pj ‘1II '■ (tr^ ^ 2sff -_J/ / A rfvk.sC-’ •I 9 x9 9^! s"S.f CD 3 •' 5 **ci§q.is ar g,/3OH-A Xw"-c II Ci?I' 5I*6: ? S II I li MA (}a u stU :i i y> !/i §o 5 ^I !«■t vhiv^iu t \15k B I irA w fhl iHillK f r> t A o o i k\ ?• CAm -Ii ?I /o'lir AsotiI?ut ryJm.tLi OI3*‘ I iriill«■ Mil %i ti 5F;it’ ‘ii o' 3 ^ "ft 1 * ?INU ti i- a iftpit5F«: i 1'cr \ f ^ ^ \\8ct \O \ IiII >c If [0 o [ftI\I 3 I ft ?•s>f OIIPI!&5? I • PS ” r / a8 '7F' ? q i |i E ill Isfjfli SsSSa i f 5 ’ Ul I t^rssiPPffP.p « I'll ! ^s i I I'lfr ” iH I < 'i ‘Ifi R 5 8 ES A i:s > ^'1 e » a? 3^1 ms. a ^ siNi < r?;■I :t's' „ I • I J! 4 I •fo o o Sf' .O'sP ■> J> A S^ i k w ffy r I uvr |U 1 L MOUND DESIGN WORKSHEET (For Flows up to 1200 gpd) A. FLOW Estimated gpd or measured x 1.5 «.gVd. B. SEPTIC TANK UQUID VOLUMES - - gallons C. SOILS (refer to site evaluation) ‘ 1. Depth to restricting layer = 3h'Wo ^r.' 2. Depth of percolation tests *___ 3. Percolation rate M.9 mpi 4. Land slope______>S % \ \ n u. V ^ •m’ H-j' inches inches EiiinuMdScMit FlewiiiCallaiitperDay (gpd) or TVl*I lyptii Type III Type IV 2 3 4 5 6 7 I 300 430 600 730 900 1090 1200 225 300 37S 430 523 600 675 110 211 236 294 332 370 406 •f lim tfm Ni ot H* 2ar Im 3«r4 3cr6 7arl b*«9 730 IJlOO IJOO 2J100 SM0t.C4 1.125 IJOO 2030 3.000 (• U) D. ROCK LAYER DIMENSIONS 1. Multiply flow rate by 0.83 to obtain required area of rock layen Ax 0S3« ID oo gpdX0S3sq.ft./gpd* sq.ft. 2. Select width of rode layer (10 feet or less) = /D _ ft. 3. Length of rock layer* area + width = RockBed L, sq. ft. + Jci ft. * loO ft. wmmsmmmm. E. ROCK VOLUME I-Length [Llth SlOft. 1 1. Multiply rock area by rock depth to get cubic feet of rock; <=22Lt-Sq.ft.Xji<ii:ft. =AiiiJ^cu. ft. 2. Divide cu. ft by 27 cu. ft/cu. yd. to get cubic yards; /£^cu.ft +27*^j:Lcu.yd. 3. Multiply cubic yards by 1.4 to get weight of rock in tons; cu.yd.x 1.4ton/cu.yd. = ♦ons. LL/iH L.cr»4»uF. ADSORPTION WIDTH 1. Percolation rate in top 12 inches of soil is mpi 1 Select allowable soil loading rate from table; gpd/fe 3. Calculate adsorption width ratio by dividing rock layer loading rate of 1.20 gpd/ft2 by allowable soil loading rate; 1.20gpd/fe = . 4. Multiply adsorption width ratio by rock layer width to get required adsorption width; O.uO X /O ft = 3.U.0 ft wudiSijte iku* P«<cote6«nlU» Hawinpirirdi SoU Texture Faster than 0.1 0.1 to 5 0.1 to S 6 to 15 16 to 30 31 to 45 46 to 60 6110120 Slower than 120 CherteSand Sand Fine Sand** Sandy Loam Loam SUt Loam Clay LoamavLoj Clay Clay 120 120 OM 0.79 060 050 0.45 024 1.00 2.00 152 2.00 2.40 267 3.00 ** Soil hi Viftg soa OTIMW of Am ar vary Am Mitd. ) <- lAi 1^Mb o 3 G. IX)WNSLOPE DIKE WIDTH 1. If landslope is 3% or more, subtract rock layer width from adsorption width to obtain nunimum downslope dike toe ft- yo ft =__iCLfcet 2. Calculate Minimum mound size based on geometery: a. Determine depth of dean sand fill at upslope edge of rock layer: Seporahbn J.O feet b. Multiply rock layer width by landslope to determine drop in elevation; Slope Difference _X_+100 = feet u9»iop# wtam c. Add depth of dean sand for separation (2a) 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; J.O Ift + Ift = z.o feet d. Enter taUe with landslope and upslope dike ratio. Select dike multiplier of “2 >3^1 e. Multiply dike multiplier by upslope mound height to find upslope dike width: x = yo feet f. Add depth of dean sand for slope difference (2b) at downslope edge, to the motmd height at the upslope edge of rock layer (2c) to find the downslope height; ^.0 ft + • r ft = feet g. Enter table with landslope and downslope dike ratio. Select dike multiplier of_____C h. Multiply dike multiplier by downslope mound height to get downslope dike width: z x = re: feet i. Compare the vdues of step G.l and Step G.2h Select the greater of the two values as the downslope dike width; / ^___feet LQ. rttt td St f t Rock etd width /P toot Downfloot widthIflQOt wid IjL loot j. Total mound width is the sum of upslope dike (G.2e) width plus rock layer width G3.2) plus | downslope dike width(G.2i); | JO ft4 JO ft + y*/ ft = feet 5 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); /o ft + ft + /o ft = feet fo kifilL (Ml UfBiMO wioinw Id y 01 ■..............................................r::^ /■» Tom Langth 1.1 UOWBilOpC S:1 fct 71 1:1 41 Lpslopc St fct 71 ■a ID 4i)SjO (.0 7.0 IjOI 417 SJS 4M 751 S5t 4S 411 SJi 751 4M 4S 7JI 9.72 Uff 4S7 1077 1507 1171 SJi Ul 1134 IS.*I 9m lUM 14*1 2151 3041 434 731 12M 2141 417S 1.1* 418 150 434 141 474 131 300 133 354 7.14 958 1.B 334 730 1014 1J8 411 4JI 45* 437 100 1300 448 754 1151 1743 1.0 40 SO 40 7.0 Itl ISS 474 544 454 40 741 251 2.7S 170 157 454 554 414 4*0 455 SOI 57* 445 544 404 241 111 400 442 51* S7l 254 111 131 441 4*1 541 za 112 170 421 470 551 242 lO 157 408 4«l 431 254 2*4 145 1*0 450 436 la 145 417 434 211 214 in ITS 224 221 271 270 121 112 141 14* 412 444 1*5 454 130 408 9 tg F-I7 PUMPSELECnON PROCEDURE CM) PCRFOtUTlON OF A FCRrOAATCD I.ATCRM. A. Detcnninc pump capacity: Gfavily 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 2700 gallons per hour (45 gpm) to prevent build-up of pressure in drop box. t jr-' -----: Xi — TL'*"*^* 3 Picssttie Dbtibution 3. a. Select number of perforated laterals_____ b. Select perforation spacing * 3 c. Subtract 2 ft. from the ro^ layer length. fact d. Determine the number of spaces between perforations. Length perf. spacing■ oy ft. ♦ ^ ft. * spaces e. spacea-»l« perforadons/lateral f. Multiply perforations per lateral by number of laterals to get totol number of peif6iatiori». *5;^ x perforations. S- ^ x^M^gpm. SELECTED PUMP CAPACITY 5.^^ gpm B. Dclcraiine head ' *’ncnti: 1. Elevation J etween pump and point of discharge. Cr feet If pumping cj •« pressure distribution system, five feet for pressure2. 3. required at manifold if gravity system, zero. _,ij__feet Friction loss a. Enter friction loss table with gpm and pipe diameter. Read friction loss in feet per 100 feet from table. F.L ® ft/lOO ft of pipe b. Determine total pipe length from pump to discharge point Add 25 percent to pipe length for fitbng loss, or use a fitting loss chart. Equivalent pipe length -1.25 times pipe length « X 1.25 g Jot>feet 4. c. Calculate total friction loss by multiplying friction loss in ft/100 ft by equivalent pipe length. Total friction loss « ^.*7 x /OQ •»100 s _feet Total head required is the sum of elevation difference, special head requirements, and total friction loss. ♦C + (1) (2) TOTALHEAD _Jiy (3c) feet C Pump selection 1. A pump must be selected to deliver at least gpm (Step A) with at least 76 feet of total head (Step B). idibi JSi, ••^^srpsans uwiad ei CPPI tM UW •• iMi tm* L»fm Rcquirad Pcrfonbon Duch«nt m galloiu pg mimut (gptnf DischuM Hod dm)Jj P^FiR 1.0a 2.0b 0.56 0.80 0.74 1.04 a. Use for single family homes b. Use for all other applications h Pipe Lengih ■4 Poiniof Oischaiia Elcvition Differtnce Pump F-I8b 1.5 inch 2.0 inch 3.0 inch ipm FimiMBleap* toon«rp.|M 10 12 14 16 18 20 « 30 35 40 45 50 55 60 0.69 0.96 1.28 I. 63 2.03 2.47 3.73 5.23 7.90 II. 07 14.73 0.20 0.28 0.38 0.48 0.60 0.73 1.11 1J5 2.06 2.64 3.28 3.99 4.76 5.60 0.11 0.16 0.23 0.30 0.39 0.48 0.58 0.70 0.82 L-1 J CERT I FI CAT 101J .) 00627 Logs of Soil Borings * Location or Project Fullerton Prop. 3350 Fox St. Main & Guest House,Orono Borings madr by s~P Testing. Inc. Steve Schirmers_ _ _Date 7-6-95_ _ _ _ _ _ Classificti: System: AASHO_ _ _; USDA-SCS__X ; Unified_ _ _; Other_ _ _ _ _ , Flight_ _, or Bucket^ i Auger used (check two): Hand X , or Power X Depth, in feet 0 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - Boring number^1 Surface elevation 948.2 Topsoil dark brown loam" C - 6" trown clay loam 6" - 1-1/2' Brown loam 1-1/2* - 2'-MOTTLED 2* Rusty olive brown loar 2* - 5* End of boring at 5 *feet. Standing water table: present at_ _ _ _ _ feet of depth, _ _ _ _ _ _ hours after boring. Not present in hole_ _ _ _x Mottled soil: Observed at 2'feet of depth. Not present in hole Comments: Depth, in feet 0 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - Boring number^2 Surface elevation 946.9 Topsoil dark brown loam 0 - 1-1/2* Brown clay loam 1-1/2* - 2'4'*-MOTTLED2* Rusty olive brown clay loam 2'4*’- 4'2" Rusty olive brown loam 4*2" - 5* 4 N End of boring at 5*feet. Standing water table: present at_ _ _ _ _ feet of depth, _ _ _ _ _ _ _ hours after boring. Not present in hole_ _ _ _jj_ _ _ Mottled soil: Observed at 2*4"feet of depth. Not present in hole Comments: L.- X J CERTIFICATIOIJ »l 00627 Logs of Soil Borings • Ldtation or Project Fullerton Prop.3350 Fox St. Main & Guest Houser Orono Borings made by s~P Testing, Inc. Steve Schirmers_ _ _Date 7“6“95_ _ _ _ _ Classifiction System; AASHO_ _; USDA«SCS X ; Unified_ _ _; Other_ _ _ _ _ Auger used (check two): Hand X ^ or Power_ _, Flight_ _ _, or Bucket X ; Depth, in feet 0 - 1 “ 2 - 3 - 4 - 5 - 6 - 7 - & - Boring number.3 Surface elevation 947.7 Topsoil dark brown 0 — 1' ^ oam Brown loam 1* - 1'8" Brown clay loam 1«8” - 2'8"-MOTTLED 2 Rusty gray brown clay loam 2*8" - 3'2” Rusty gray brown sandy loam 3•2” - 4* 8" Depth in feet 0 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - Boring number 4 Surface elevation 951.0 Topsoil dark brown loam 0 - 2'2'' Gray brown loam 2»2” - 3”l/2*~MOTpgp^ Rusty gray brown clay 3-1/2* - 4* Rusty olive brown sandy loam 4' - 5' End of boring at 4 feet.End of boring at.5'feet. Standing water table; present at_ _ _ _ _ feet of depth, _ _ _ _ _ _ hours after boring. Not present in hole_ _ _X_ _ _ _ _. Mottled soil: Observed at 2'8"feet of depth. Standing water table: present at_ _ _ _ _ feet of depth, _ _ _ _ _ _ _ hours after boring. Not present in hole_ _ _ _X_ _ _ _ Not present in hole Comments: Mottled soil: Observed at 3-1/2* feet of depth. Not present in hole_ _ _ _ _ _ _ _ _ _. Comments: L-i J CERTIFICATION li 00627 Logs of Soil Borinqs * Location or Project Fullerton Prop. 3350 Fox St.Main & Guest House» Orono Borings made by s^P Testing, Inc» Steve Schirmers Date 7-6~95_ _ _ _ _ Classifiction System: AASHO_ _; USDA-SCS_X_; Unified_ _ _; Other_ _ _ _ _ Auger used (check two); Hand X , or Power_ _, Flight_ _ _, or Bucket X Depth, in feet 0 - 1 - 2 - 3 -2»10" - 3*2" iS88y^Y8SB 5 - 6 - 7 - 8 - Boring number.5 Surface elevation 951.5 Topsoil dark brown loam 0 - 1*4” Brown sandy loam 1*4" - 2*10"-MOTTLED 2'10 Rusty 3.3. 3.i/2.gi8g^bg^|0 Rusty olive brown sandy 4 - _ _ _ _3-1/2* - 4* loam tfi Depth, in feet 0 - 1 - cfS 2 - 3 - 4 - 5 - 6 - 7 - 8 - Boring number 6 Surface elevation .7 Topsoil dark brown loam 0 - 10" ?^!?Oam 10" - l'2"-MOTTLED 1'2'' Rusty olive brown clay loam 1'2" - 3*4" Rusty olive brown silty clay loam 3*4" - 4-1/2’ Rusty olive brown loam 4-1/2' - 5' End of boring at 4 I feet.End of boring at 5 feet. Standing water table: present at_ _ _ _ _ feet of depth, _ _ _ _ _ _ hours after boring. Not present in hole_ _ _^_ _ _ _. Standing water table: present at_ _ _ _ _ feet of depth, _ _ _ _ _ _ _ hours after boring. Not present in hole_ _ _ _ _X_ _ _ _ Mottled soil: 2*10"Observed at- - - -feet of depth. Not present in hole_ _ _ _ _ _ _ _. Comments: Mottled soil: Observed at 1'2"feet of depth. Not present in hole Comments: CERT.#00627 PERCOLATION TEST DATA SHEET Percolation test readings made by-----S-P Tes t ing y—IjtCj— Test hole location__3350 Fox ---------------------number. oa ^ - •aTm. , 7-7-95_____<unrtino .11 11:28_______ p ni. 1 Date hole was prepared.7-6-95 Depth of hole bottom_JL?_-inches. Diameter of hole------5--------inches Soil data from test hole: Depth, inches Soil texture 0-6" Topsoil dark brown loam 6" - 12"Brown clay loam Method of scratching sidewall__ Depth of gravel in bottom of hole. 2 .inches Date and hour of initial water rilling_Z—^bept^oV initial water filling.12 .inches above hole bottom Method usea to maintain at least 12 inches of water depth in hole for at least 4 hours.Automatic siphon ., Maximum w ater depth above hole bottom during tesL 6 .inches rime Time interval, minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks 11:15 11:28 prefill 6 11:43 It 3-1/4 11:54 12:10 12:09 H 4.6 15 min 3-3/16 4.7 n II 12:25 11 It II II n 12:37 12:52 II II II II II Percolation rate =____----------minutes per inch. CERT.#00627 PERCOLATION TEST DATA SHEET Pcrcolaiion tcsi readings made hy S-? Testing » Inc. 3350 Fox St. -on_7-7-95 iii.iifi -Starling aL J-l:29 a. nr p.nv Test hole location. Depth of hole boitonv 12 .inches. Diameter if hole , Hole number____ 6 .. Date hole was prepared.7-6-95 .inches Soil data from lest hole: Depth, inches 0 - 12" Soil tcxtuic Topsoil dark brown loam Method of scratching sidewall__ Depth of gravel in bottom of hole.2 Date and hour of initial water filling __inche; 7-6-9^2:.y^Pi?ofinitiJ water rilling_ii..inches above hole bottom Method usco to maintain at least 12 inches of water depth in hole for at leaci 4 hmir*; Automatic siphon Maximum water depth above hole bottom during tesL 6 -inches Time Time interval, minutes Measurement, inches Drop in w; ter level, inclies Percolation rate. minutes per inch Remarks 11:15 11:29 prefill 11:44 6 II 11:53 12:08 n 3-3/4 12:11 12:26 II 3-5/ 8 4.0 12:6 12:51 II 3-9/16 4.1 15 min II •I 3-9/.’6 4.2 tl tl 4.2 II II Percolation rate =___4.2 minutg< per inch. • ■* "cert. #00627 PERCOLATION TEST DATA SHEET Pcrcol.nion lest readings made by-----S~P Testing— Tes, hole location ^350 Fox_S^--------------- Depth of hole bottom_____L?____inches. Diameter of hole nn 7-7-9S ■ starling at___LLt.in a.tii^ p.m. . Hole number. 6 _£______ Date hole was prepared—1_ .inches Soil data from test hole: Depth, inches 0 - 12” Soil texture Topsoil dark brown loam Method of scratching sidewall— Depth of gravel in bottom of hole. 2 .inches Date and hour of initial water filling-ZlillL.i.t^^R'Sf initial water filling.12 .inches above hole bottom Method uscQ to maintain at least 12 inches of water depth in hole for at least 4 hours.Automatic siphon Maximum water depth above hole bottom during tesL 6 .inches ■fime Time interval, minutes Measurement. inches Drop in water level, inches Percolation rate, minutes per inch Remarks 11:15 11:30 prefill 11:52 11:45 12:12 12:07 6 It n 2-15/16 M 5.1 ti 15 min 11 tl 12:27 12:35 12:50 tl It It It ft It II It It II Percolation rate — 5.1 minutes per inch. CERT.#00627 PERCOLATION TEST DATA SHEET Pcrcolaiion ccsi readings made hy S~P Testing f Inc.______nn oartino nr 11^31 Test hole location—^^ *------------------------- Hole number____-______ Date hole was prepared 7-6-95 Depth of hole bottom___12______inches. Diameter of hoIc__^_____inches Soil data from test hole: Depth, inches Soil texture 0 - 12"Topsoil dark brown loam Method of scratching sidewall__Knife 2 Depth of gravel in bottom of hole___________inches 7-6-95 2:30piti Date and hour of initial water filling____________ Depth of initial water filling. 12 -inches above hole bottom Method usea to njaintain at least 12 inches of water depth in hole for at least 4 hnnr< Automatic siphon Maximum water depth above hole bottom during tesL 6 -inches .'ime Time interval, minutes Measurement, inches Drop in water level, inches Percolation rate. minutes per inch 11:15 prefill 6 Remarks 11:31 11:46 «5-1/8 2.9 15 min 11:51 12:06 n 12:13 12:28 4-7/8 3.1 M n 4-3/4 3.2 H H 12:34 12:49 It 4-3/4 3.2 M tl Percolation rate 3.2 jninuies per inch. 4 .* fc, CERT.#00627 PERCOLATION TEST DATA SHEET Pcrcolaiiori test readings made by.S-P Testing, Inc..on.7*'7-95 ij-iifi .starting aL 11:32 a.m^ Test hole location.3350 Fox St. Depth of hole bottom.12 .inches. Diameter of hole , Hole number. 6 5 Date hole was prepared.7-6-95 inches Soil data from test hole: Depth, inches 0-12 It Soil texture Topsoil dark brown loam Method of scratching sidewall__ Depth of gravel in bottom of hole. 2 Date and hour of initial water filling. __inches 7-6-95 2 initial water Hlling.12 .inches above hole bottom Method used to maintain at least 12 inches of water depth in hole for at least 4 hours—Automatic siphon Maximum water depth above hole bottom during tesL 6 .inches .'ime Time interval, minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks 11:15 11:32 prefill 6 11:47 n 11:50 12:05 n 3-1/4 4.0 15 min 3-1/2 4.3 II II 12:14 12:29 It 3-7/16 4.4 II II 12:33 12:48 II 3-3/8 4.4 II II Percolation rate = , f .li____minutes per inch. A •CERT.#00627 PERCOLATION TEST DATA SHEET Percolation lest readings made by___S-P Testing y Inc.____ Test hole Inratinn 3 350 Fox St.___________ Hole number. 12 6 Depth of hole bottom______ . . .on__, ..starting aL 11:33------------- p.m. 6 Date hole was prepared 7-6-95 .inches. Diameter of hole..inches Soil data from test hole: Depth, inches 0 - 12" Soil lex’ure Topsoil dark hrown loam Method of scratching sidewall Knife 2 .inchesDepth of gravel in bottom of hole_ 7-6-95 2:30pin 12 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 Automatic siphon Maximum water depth above hole bottom during tesL 6 .inches Time Time interval, minutes Measurement, inches Drop in water level, inches Percolation rate, minutes per inch Remarks 11:15 prefill 6 11:33 11:48 If 2-1/8 7.1 11:49 12:04 It 2 15 min 7.5 If N 12:15 12:30 It II n II If 12:32 12:47 If II If n It Percolation rate 7.5 jninutes per inch.