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HomeMy WebLinkAboutSubsoil Study - 7.6.21Huddleston-Berry årrgine*rìng *t T*sting, T-tr-.f July 6,2021 Project#02293-0001 Lucky Seven LLC 336 Evergreen Drive Rifle, Colorado 81650 Attention: Mr. Javier Orozco Subject:Geotechnical Investigation 10991 CR320 Rifle, Colorado Dear Mr. Orozco, This letter presents the resuits of a geotechnical investigation conducted by Huddleston-Bemy Engineering & Testing, LLC GIBET) at 10991 CR 320 in Rifle, Colorado. The site location is shown on Figure 1. The proposed construction is anticipated to consist of a new single family residence. The scope of our investigation included evaluating the subsurface conditions at the site to aid in developing foundation recornmendations for the proposed construction and to evaluate the site soils for onsite wastewater treatment. Site Conditions At the time of the investigatio\ a garage structure occupied the northwest portion of the site. The remainder of the site was open and gradually sloping down towards the north. Vegetation consisted of weeds, grasses, and small to large trees. The site was bordered to the north by open land, to the west and east by residential properties, and to the south by CR 320. Subsurf'ace Investisation The subsurface investigation included four test pits as shown on Figure 2. The test pits were excavated to depths ranging from 3.0 to 8.0 feet below the existing ground surface. Typed test pit logs are included in Appendix A. As indicated on the logs, the subsurface conditions at the site were consistent. The test pits encountered 1.0 foot of topsoil above tan, moist, medium stiff to stiff sandy silty clay soils with some gravels and cobbles to the bottoms of the excavations. Groundwater was not encountered in the subsurface at the time of the investigation. Laboratorv Testins Laboratory testing was conducted on samples of the native soils encountered in the test pits. The testing included grain size analysis, Atterberg limits determination, natural moisture content determination, and maximum dry density and optimum moisture content (Proctor) determination. The laboratory testing results are included in Appendix B. 2789 Riverside Parkway Grand Junction, Colorado 81501 Phone: 97G255-8005 Info@huddlestonbeny. com 10991 cR 320 #02293-0001 07/06/21 ì!trír¡, The laboratory testing results indicate that the native clay soils are slightly plastic. In general, based upon the Atterberg limits and upon our experience with similar soils in the vicinity of the subject site, the native soils are anticipated to be slightly collapsible. F oundation Recommendations Based upon the results of the subsurface investigation and nature of the proposed construction, shallow foundations are recommended. Spread footings and monolithic (turndown) structural slabs are both appropriate foundation alternatives. However, the native soils are anticipated to be slightly collapsible. Therefore, in order to provide a stable bearing stratum and limit the potential for excessive differential movements, it is recommended that the foundations be constructed above a minimum of Z4-inches of structural fill. The native soils, exclusive of topsoil, are suitable for reuse as structural fiil. Imported structural fillshouldconsistofagranular'no1l-eXpansive,49!@i4gmaterialapprovedbyHBET. For spread footing foundations, the footing areas may be trenched. However, for monolithic slab foundations, the structural fill should extend across the entire building pad area to a depth of 24- inches below the lowest portion of the foundation. Structural fill should extend laterally beyond the edges of the foundation a distance equalto the thickness of structural fill for both foundation types. Prior to placement of structural fill, it is recommended that the bottom of the foundation excavation be scarified to a depth of 6 to 9 inches, moisture conditioned, and compacted to a minimum of 95o/o of the standard Proctor maximum dry density. within + 2o/o of the optimum moisture content as determined in accordance with ASTM D698. Structural fill should be moisture conditioned, placed in maximum 8-inch loose lifts, and compacted to a minimum of 95o/o of the standard Proctor maximum dry density for fine grained soils and 90% of the modified Proctor maximum dry density for coarse grained soils, within + 2o/o of the optimum moisture content as determined in accordance with ASTM D698 and D1557, respectively. Structural fill should be extended to within 0.l-feet of the bottom of the foundation. No more than 0.l-feet of gravel shoulcl be placed below the footings or turndown edge as a leveling course. For structural fill consisting of the native soils or imported granular materials and foundation building pad preparation as recommended, a maximum allowable bearing capacity of 1.500 psf may be used. In addition, a modulus of subgrade reaction of 150 pci may be used for structural fill consisting of the native soils and a modulus of 200 pci may be used for approved imported structural fill. Foundations subject to frost should be at least 24-inches below the finished grade. Any stemwalls or retaining walls should be designed to resist lateral earth pressures. For backfrll consisting of thc nativc soils or importcd granular, non-frcc draining, non-cxpansive material, we recommend that the walls be designed for an active equivalent fluid unit weight of 45 pcf in areas where no surcharge loads are present. An at-rest equivalent fluid unit weight of 65 pcf is recommended for braced walls. Lateral earth pressures should be increased as necessary to reflect any surcharge loading behind the walls. 2Z:\2008 ALL PROJECTS\02293 - Lucþ Seven LLC\02293-0001 10991 CR 320V00 - Geo\02293{001 LR070ó2l.doc 10991 cR 320 #02293-0001 07/46/2t Water soluble sulfates are common to the soils in Western Colorado. Therefore, at a minimum, Type I-II sulfate resistant cement is recommended for construction at this site. Non-Structural Floor Slab and Exterior Flatwork Recommendations In order to reduce the potential for excessive differential movements, it is recommended that non-structural floating floor slabs be constructed above a minimum of 18-inches of structural fill with subgrade preparation, structural fill materials, and fill placement be in accordance with the Foundalion Recommendatíons section of this report. It is recommended that exterior flatwork be constructed above a minimum of l2-inches of strucfural fill. Drainase Recommendations Grødíns and d.røinage are crìtìcul for the lons-term performance of the structure and grading around the structure should be designed to carry precipitation and runoff away from the structure. It is recommended that the finished ground surface drop at least twelve inches within the first ten feet away from the structures. It is also recommended that landscaping within five feet of the sttuctures include primarily desert plants with low water requirements. In addition, it is recommended that irrigation, including drip lines, within ten feet of foundations be minimized. HBET recommends that surface downspout extensions be used which discharge a minimum of 15 f-eet from the sttuctures or beyond the backfill zones, whichever is greater. However, if subsurface downspout drains are utilized, they should be oarefully constructed of solid-wall PVC and should daylight a minimum of 15 feet from the structures. In addition, an impermeable membrane is recommendsd below subsurface downspout drain lines. Dry wells should not be used. Onsite Wastewater Treatment S)¡stem F easibilitv In order to evaluate the site soils for onsite wastewater treatment, percolation testing was conducted at the site in accordance with Galfield County regulations, The percolation rate in the native soils ranged from 5 to 20 minutes-per-inch. The percolation testing data are included in Appendix C. In acoordance with Garfreld County regulations, a percolation rate of between 5 to 60 minutes- per-inch is requirecl for soils to be deemed suitable for onsite wastewater treatment. Therefore, based upon the results of the percolation testing, HBET believes that the native soils are suitable for onsite wastewater treatment. In addition to the percolation rate of the subsurface materials, the seasonal high groundwater elevation is an important factor in determining the suitability of the site for Onsite Wastewater Treatment Systems. For OWTS suitability, the seasonal high groundwater elevation should be at least four feet below the bottom of the proposed absorption bed. As discussed previously, groundwater was not encountered at the time of the investigation. In general, based upon the results of the subsurface investigations, HBET believes that the seasonal high groundwater level is deeper than 8.0 feet below the existing grade at this site. General Notes The recommendations included above are based upon the results of the subsurface investigation and on our local experience. These conclusions and recommendations are valid only for the proposed construction. 2ì2008 ALL PROJECTS\02293 - Lucky Ser.en LLC\02293-000 I 1099 I CR 320U00 - Ceo\02293-000t LR070ó2 l.doc 3 1099r cR 320 #022e3-0001 07106t2r ìçttrlÀr As discussed previously, the subsurface conditions encountered in the test pits were fairly consistent. However, the precise nature and extent of any subsurface variability may not become evident until construction. As discussed previously, it is recommended that HBET provide construction materials testing and engineering oversight during the entire construction process. It is important to note thøt the recommendøtions hereín øre intended to reduce the risk of structurøl movement ønd/or dømage, to vawìng degrees, øssociated with volume change of the natíve soils. Howeven HBET cønnot predíct long-term changes ín subsurface moisture conditions and/or the precise meænitude or extent of volume change in the native soils. Where signifícant increases in subsurface moisture occur due to poor grødíng, imoroner stormwøter mønøpetnent. atilí1v líne failure. excess iwísøtíon, or other cause. either durìne constructìon or the result of øctìons o.f the orooertv owner. several inches of movement øre oossible. In nddition, anv føilure to comolv with the recommendøtions in this reoort releøses Huddleston- Berrv Ensineeríns & Testins. LLC of ønv liabílílv wíth resørd to the structure nerformønce. We are pleased to be of service to your project. Please contact us if you have any questions or comments regarding the contents of this report. Respectfully Submitted: Huddleston-Berry Engineering and Testing, LLC Michael A. Berry, P.E. Vice President of Engineering 42:\2008 ALL PROJECTS\02293 - Lucþ Ser.en LLC\02293-0001 10991 CR 320V00 - Geo\02293{001 LR070621.doc FIGURES Location APPEI{DIX A Typed Test Pit Logs GEOTECH BH320!7oLmo-{zg3@mnoN)l\)(o(¡t(f,ot-mzrcc)xØoorro€^¡.JtrôÞ æ='! - >'e*Þ 0I=:+øi fuÔ Õ-w=oo" *Eô o-<2tæ.<æ!¡'< ã=.0eR.,.tGÉ.Fo!noLmo5c)-{ız4-oc)o!noemo{z3mo(o(oc)7(¡lNo-{raCN{!{zc=-[ExmËí i0- -.1çT.Jã6{G)BRo@mxC)ÞIozm¿o¡t-loc)xJ(Dß)c)-fooqC.)Iozooz-tvc,ov-T'nEoIman{v{mo(¡(ol\)(too¿moãmtr,@GIoo3Tt-m{mI(¡(oN)ono>Þ>ç+É==m:m=tãYqSËËsH9ãf.--| 29oÐoczommÞo-zèao¿mut{!g,NmPDEPTH(ft)GRAPHICLOG-.1mF-omU,oÐ!-lozSAMPLE TYPENUMBERRECOVERY %(ROD)BLOWCOUNTS(N VALUE)POCKET PEN.(ts0DRY UNIT WT(pcf)MOISTUREcoNrENT (%)+rl=m=l-l tD(nmvoFINES CONTENT(Y.)LIQUIDLIMITPLASTICLIMITPLASTICITYINDEX: ' .ñ . ¡-'. tr. ¡z-ì . [2-..1+. jr..ls-i.r\ . v¿. t\ . .tr)ØO)A}=ô=.Jo@s)=ø-lo-tØIf-r-0)ıaq¡øao@=cnØ;.3U,ä€aÞ+<O=:9;=sIoUJıoØ0)o-ooú6o@oîf-YfÞf-2-ot!N)N)(,O)\¡@oofo(DøE.ûllooo:- LAB.GDT 6/29/21!ÐoLmo-{zc=@mÐoNl\)(o(¡ooot-2lrlc)t-FØoô=-r€^ôÞ,:, Fi¡-u=æiJôouoôoæ=-NIrlllqooùcR",.1oûalr-o!Fgmo5c)-{ı4=fDc)o-0vPmoz=mo(oqo7r\,oIÍl@-{!{zc=EnIn-{!¡N!omo-Ttzoman5oomç'@U)omxoIoz3m¿oomxc'Iozôoz7tct+ovTT'noc,-{mv,-{v{mgotNo-moxmoTD@-lıoFDB)oJoooo=!mImo(¡N)6,no>Þ>9'r't++=#¡=i#qñlËËËÊ| 29o7ocz0mmÞ{ızo-ao-e{mat{!aNmPôDEPTH(ft)GRAPHICLOG+mÐrUmU)on!IozSAMPLE TYPENUMBERRECOVERY %(RaD)BLOWCOUNTS(N VALUE)POCKET PEN.(tsf)DRY UNIT WT(pcf)MOISTURËcoNTENT (%)--{--l=ms.Ð--t tDln ltl7oFINES CONTENT('/.1LIQUIDLIMITPLASTICLIMITPLASTICITYINDEX.\¡.rÌ-..r-. rs.. lzt,4'. .i.s.'Ë_.liaa,o)=o=.J(aÂ)=.oØ-lo-EU)Ir.U,ã$Ø^3Øo=q<Ec)JTe>É<--59ø=sJ(Doıoaoogo@a3vg)=@oo=oott,p.0)90Ooo BH COLUMNS 02293.0001 CR 320 RIFLE,GPJ GINT US LAB-GDT!noLmc,{zc3EmÐoN)N(o(¡)Õoac)t-mz-{T-Eo-(t)oT-T-!Jþ^l.Jñ{*'!äôÈ æ=-'- !J ú*æÞ ¡i oa9ã ?uó ôw5ôOO o-ko*Fæ.<cRG<H:'ùasjô'i'"-h!vo(-mç)t-ooIız4.=Pc)o!voLmo-.1z=mo(o(oon(¡)r\,o{fira{!{zc=trmn+!t(¡tItomo'rtzo-{m(t5*OQE32çU,=om-oomx(lIozoozu(lovIî'7ooImU)IÞv{moolcol\)C)¿moxmotD@-tñc)r@ù)oxoooo!|.m-{mo6:6NIm7nrxo-.1ız-{mztr'o-nmxoÞ{ızoleo7o>,-gl1ñtotr-fl à)8E>uJfhızoÐoczommIız-{mat,{!g.NmoDEPTH(ft)GRAPHICLOG{mÐr-om(ton!IozSAMPLE TYPENUMBERRECOVERY %(ROD)BLOWCOUNTS{N VALUE)POCKET PEN(tsf)DRY UNIT WT(pcr)MOISTUREcoNTENr (%)+r --{=m=¡-.t Eørm7oFINES CONTENT{Y.)LIQUIDLIMITPLASTICLIMITPLASTICITYINDEXi\-. ¡/j .. 1s.. jll- . .ç ..r-i rs.. 1...i.r..rs-.. lr-.. r\ì . Ê. .ri. lr'-. ..lsìØ.a)Âlfo.É.5o(oo,=ı'a-JoIJØIr(,N)I1Øão-^-d3Ø4qøÞtÉoaø-=eIooıo60)CLoo6doØo3v0)J@oo3ooû=of¡)o(D COLUMNS 0229}OOO1 CR 320 RIFLE.GPJ GINT US LAB.GDT 6/29/21!noLmç)-{zc=EmvoNN(o(,Õootrmz-{r-cxU,oort-ooôoæ:'ôanqqoo=.qqs,J@t'ûaÉFô!7o(-mo-.1t-oc)ìo4.=-(Dc)o!vPmo-{z=mÕ(oqo7of\)o{nra{!{zc=trEI7{!¡È1tomoftzo-{ma,6*G)oô>sted'zu)=UMIoomxc)Iozl)ozvoov-T'nooImU,{A-{mc'(,l(oñoImoxmoÞtr,-lıoñJæß)oF:toooo3!m-{mc,(¡(oN)o7o>>>ç#Ë*;ãHqSãgËrt 29o7ocz0mmÞızo-e¿mtn-{ctANmoDEPTH(ft)GRAPHICLOG3--lmÃ-umU)onIt-tozSAMPLE TYPENUMBERRECOVERY %(ROD)BLOWCOUNTS(N VALUE)POCKET PEN(tsf)DRY UNIT WT(pcr)MOISTUREcoNTENT (%)-lr -'l=m<I--I TD(nm7oFINES CONTENT\%lLIQUIDLIMITPLASTICLIMITPLASTICITYINDEX{ì- ¡4 .Ls. jtl- t\l'- ¿-1 l\-- t/..¡..;. Js-.. ¡¿... k: ¡,-. .ls. ¡;..ì*¡ØU'0)=ô.É.Jo(oB}=Ø-l!ØIr(nl"aØ?l-=ØëqEc)l-øÞ-s.O=9-=eIooıo60)foooctoooq-3vû)_f@oo3o(D<hp.o)ftfDolt APPENDIX B Laboratory Testing Results NoN Foq of Engineering & Testing, LLC GRAIN SIZE DISTRIBUTION Riverside Junction, CO 81501 CUENT Luçky Seven LLC PROJECT NAME 10çt91 CR 320 PROJECT NUMBER q2293-OOO',l PROJECT LOCATION Rifle, CO U-S. SIEVE OPENING IN INCHES I 1t2318 3 4 U.S. SIEVE NUMBERS HYDROMETER6 4 3 2'1.5 1 6 810 1416 20 1 l--Io t! =otulz l.L F'z LrJO ú. uJ o_ 100 95 90 85 80 75 7A 65 60 55 50 45 40 35 30 25 20 15 10 à U 100 l0 1 GRAIN SIZE IN MILLIMETÊRS 0.1 0.01 0.001 COBBLES GRAVEL SAND SILT OR CLAYcoaÍsefinecoarsemediumfine -!-I I lt u I \ \ \ Specimen ldentification Classification LL PL PI Cc Cu o TP-1, GB-1 5t19 SANDY Sr LTY C |-AY(CL-ML)23 16 7 Specimen ldentification D100 D60 D30 D10 %Gravel %Sand %silr o/o9lay o TP-1, GB-1 5/19 l9 UNØz4É Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway Crand Junction, CO 81501 970-255-8005 ATTERBERG LIMITS' RESULTS CUENT Lucky Seven LLC PROJECT NAME 10991 CR 320 PROJECT NUMBER 02293-OOO1 PROJECT LOCATION Rifle CO @ P L A ê T I c I T I N D E X 50 40 30 20 10 CL-ML @ 0 0 LIQUID LIMIT Specimen ldentification LL PL PI #200 Classification o TP.I, GB.1 5/19 23 l6 7 SANDY Sr LTY CLAY(CL-ML) t--ott. m 5 v)l F1 I L? UJL EoN É, oôo oNN øts =J Nıq Fôqúf Øf t--zo zo ts0 ù oo Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway Cr¿nd Ju¡ction, CO 81501 970-255-800s MOISTU RE.DENSITY RELATION SHI P PROJECT LOCATION Rifle, CO PROJECT NAME 10991 CR 320 PROJECT NU MBER 02293-000r CUENT LucKLSeven LLC )ul \ \ \ \ \ 7 \ \ I /\ / I \ / Sample Date: Sample No.: Source of Material: Descri ption of Material 5119t2021 21-0417 145 TP.1 GB-I SANDYS|LTY CLAY(CL-ML) Test Method ASTM D698A 140 135 TEST RESULTS Maximum Drv Densitv 120.0 PCF Optimum Water Content 1'1.5 % 130 125 GRADAnON RESULTS (% PASSTNG) #200 #4 3t4" 63 98 100 oo.tEØzulo to ATTERBERG LIMITS 1 20 LL PL PI 23 16 7 115 Curves of 100% Saturation for Specific Gravity Equalto: 110 2.80 2.70 2.60 105 100 95 90 5 15 WATER CONTENT, % 0 10 20 25 30 APPENDIX C Percolation Testing Results PERCOLATION TESTING STP322trIuddleston-Berxy fi s,',riñccrin g.&. T{ì$åÌnìr. :,1. C Project Name:10991 CR 320 Location: Rifle, CO Testing Conducted By: S. Dinterman Supervising Engineer: M. Berry TEST PIT DIMENSIONS Dspth (ft)Ðepth fftÌ Nêt Encıuntered I x SOIL PROFILE 02296-0001 TP-2 511 Project No. Test Pit No. Date: D.spth ffil Desoription Remarke 0-'1 $!lty Sand with Organics (TOPSOIL) 1-B Sandy Silty CLAY with some Gravels and Cobbles (cl-ml), tan, moist, medium stiff to stiff Test Number'. 1 Top of Hole Depth: ¡ Ctl Diameter of Hole: a_ (in) Depth of Hole: I A 1in¡ Tirne ,,1rnìn.), Water. Depth ('in.) ühange {iin.} 0 1.125 5 2.5 1.375 10 4 1.5 't5 5.5 1.5 20 6.5 1 25 7.5 1 30 o 0.5 35 8.25 0.25 40 9 0.75 g5 10Rate (min/in): Test Number'. 2 Top of Hole Depth: O tttl Diameter of Hole: a_ (in) Depth of Hole: f e 1in¡ Test Number: Top of Hole Depth: (ft) Diameter of Hole: _ (in) Depth of Hole: - (in) ïirne {min,) Water Depth fin.)(in.¡ Water Depth (in-) Change 0 1.375 à 4.25 2.875 10 5.75 1.5 15 7 1.25 20 8.25 1.25 25 9;25 2ft Drv 6 Average Percolation Rate (nrin/in): Rate (min/in):Rate (min/in): Huddleston-Berr¡r' üngüw¡lüg.ç T"sirr¡¡, ¡"'L{) PERCOLATION TESTING sTP322 Project Name:10991 CR 320 Location: Rifle, CO Testing Conducted By: Supervising Engineer: S. Dinterman M. Berry TEST PIT DIMENSIONS SOIL PROFILE Test Number: 3 Top of Hole Depth: g tftl Diameter of Hole: a (in) Depth of Hole: 17 (in) Rate (min/in): Test Number: _ Top of Hole Depth: -(ft)DiameterofHole: _(in) Depth of Hole: _ (in) Test Number: Top of Hole Depth: Diameter of Hole: Depth of Hole: (ft) (in) (in) TP-3Test Pit No. No. !-;.;-,"i;;,,1i.r,;;r;;::i'..:[.]:;;fä;ji"| ,**,.1,*ã,it:lt:,i:l:¡];::,¡_îjîl]-.fiìì1ffi¡l¡:il,¡.#Xî$ ' .: ''....r':,:: ... .. 1..i- . ::::,::: ::r':i:ì.. tí4'ir: ::Ì.::il:::... .¡: rl| jr:,/. ' {lfil¡l,rri: .: ù.1 Silty Sand with Orqanics (TOPSOIL) 1-3 Sandy Silty CLAY with some Gravels and Cobbles (cl-ml), tan, moist, medium stiff to stitf 0 1.5 5 4.2s 2.75 '10 6.75 2.5 15 7.75 1 2A 8.75 1 25 9.375 0.62s 30 10.375 1 35 't0.75 0.375 40 11.25 0.5 45 11.75 0.5 50 12.25 0.5 55 12.75 0.5 20 ii:..:t_":,1- - -- '::. ,-r,i',ri.I<rT-.r:l l -- :t ri.:;:--., : :::::j::;;i,fi;:.---j ::-.:. .-:. ,:,,i,,,.1i.i fil:;lsi.. t. , r: :j: : q*Èf ¡t .. ^.--a :i_.._' ltIr.r :i.:i rjf :;r #/ :.r']:i Þ.: r...:: :, .. I.i.,;{:.', : :..',j.:-}?... ...:r.; i:1r1:.: .:.:. rli-:/----ri,üf,¡¡! l',:-iii:+' - ! !l : -ii-rrr r-:i.:¡1:¿ IIII I ,rii;iì..T.til -: ..::::::ì:.::"j::':;::. I j ,::iil(i;"it: :¡ : :::J : iii:' r'.ì jÈ : :: .r.: i,,.'.-,.i .!!f : - ...,,. I', ..¡,"E! i, ". !i i Average Percolation Rate (min/in): Rate (min/in):Rate (min/in Ifuddleston-Berry PERCOLATION TESTING STP322 ü*giùi..ri¡¡g "Sì'l'rstir{, Ll,{ì Project Name 10991 CR 320 Testing Conducted By:S. Dinterman Supervising Engineer: M. Berry TEST PIT DIMENSIONS SOIL PROFILE Test Number'. 4 Top of Hole Depth: f Atl Diameter of Hole: a (in) Depth of Hole: 18 (in) Location: Rifle, CO Test Number: Top of Hole Depth: (ft) Diameter of Hole: _ (in) Depth of Hole: _ (in) Test Number: Top of Hole Depth: (ft) Diameter of Hole: _ (in) Depth of Hole: - (in) Time {min.i Water Depttr (in.) Rate (min/in): 02293-0001 ïP-4 Rt,l Project Test Pit No. Date: ûepth (ftì È.lot. Encountered D X WW 0-1 Siltv Sancl with Oroanics (TOPSOIL) 1-3 Sandy Silty CLAY with sorne Gravels and Cobbles (cl-ml), tan, moist, medium stiff to stiff 0 1.5 5 2.75 1.25 10 3.5 0.75 15 4 0.5 20 4.5 0.5 4.75 0.25 5'5 0.25 fr,iïtñ 0.25 ,A.25 o.25 20 Tirne {mîn.i Water Depth fin.) Change (in.) Average Percolation Rate (min/in): Rate (min/in):Rate (min/in):