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Home My WebLink AboutOWTS Design ReportMOUNTAIN CROSS ENGINEERING, INE. Civil and Environmental Consulting and Design William & Catherine Kenworthy 223W. Menomonee St. Chicago, IL 60614 June23,2025 R!:CHM:1.] RE:Kenworthy Residence, Lot 21 Ranch at Coulter Creek, Garfield County, CO - OWTS Report .jtjhl {J ? J{l?5 GAI:- trtF:: l.-f,i [:'.-r i ;'] CC[i,,ilillil'r' i.ii-Vi-i i,i. ,'' ' Dear Mr. & Mrs. Kenworthy: The purpose of this correspondence is to inform you about the onsite wastewater treatment system (OWTS) designed for the Kenworthy Residence. The project proposes to construct a new residence located in Garfield County, Lot2l in the Ranch at Coulter Creek subdivision off of Saddle Drive. The main and upper floors of the residence will be a gravity system to a conventional septic tank where a pump will pressure dose to a leach field comprised of a sand filter bed. There is no lower/basement level proposed. If a basement is constructed in the future, it will need a sewer ejector to pump into the OWTS. The residence will be served from an existing community water system. The OWTS is not within a 100-year flood plain boundary. There are practical constraints that you should be aware of when considering the propsr design, construction, and operation. Subsurface The soil was determined to be R-2 with 2A' soils; rocky, silty sandy to very silty sand. This corresponds to a long-term acceptance rate (LTAR) approximated as 0.50 gallons per day per square foot (GPD/sq.ft.) from soil evaluations performed Kumar and Associates. Their analysis was done in a different location than the designed location. A profile hole will need to be excavated and an inspection performed to verify that the design location has similar soils and that that no bedrock nor groundwater is within an 8' depth of the leaching area. A copy of the soils report is attached. Desisn Calculations The residence is proposed to be 3 bedrooms with a 1 bunk room (4 beds). Using Garfield County Table 6-1 for a S-bedroom residence, this yields 600 gallons per day (GPD) total. The design calculations for sizing of the septic system and the leach field follow: o Kenworthy Residence: 5 bedrooms: 600 GPD o Based on soil evaluation and percolation tests results, LTAR: 0.50 GPD/sq.ft. o Minimum absorption area : 600 GPD / 0.50 : 1,200 sq. ft. o No reductions are allowed for rocky soils. o Required septic tank volume : 1,500 gallons per Garfield County Table 9-l o Dosing frequency:4 doses per day; dose volume : 600 GPD / 4 doses : 150 gal./dose o Pump(s) should provide 35 gpm at25' of Total Dynamic Head 826f, Grand Avenue, Glenwood Springs, CO 81601 P: 970.945.5544 F: 970.945.5558 www.mountaincross-eng.com Kenworthy Residence Jrtne,2025 Page 2 of3 . PVC lateral supply and distribution pipes should be Schedule 40,l-112" in diameter. o Each lateral pipe should have seven /t" diameter holes drilled in the lateral at7' spacing with the first hole located at 4' from the start of the bed' The components manufacturers are typical for the area. Alternatives may be considered by contacting this office. Construction must be in accordance with the specifications of Garfield County Environmental Health, the OWTS permit, and this design' Topsoil should be placed over the OWTS and planted with native grasses. No large vegetation andlor plants with taproots should be planted over the absorption area nor grasses that require excessive irrigation. Calculations are attached. Setbacks The location for the septic and dosing tanks are limited by setback requirements per Garfield County and the State of Colorado. These include: o 50' FROM WELL o 10' FROM WATER SUPPLY LINE o 5, FROM BUILDING WITH BASEMENT o l0' FROM PROPERTY LINE o 10' FROM LINED POND, DITCH, OR STREAM o 50' FROM WATER BODY o 10' FROM CREST OF BANK o 5, FROM LEACH FIELD o 100' FROM WELL o 25'FROM WATER SUPPLY LINE o 20, FROM BUILDING WITH BASEMENT o 10' FROM PROPERTY LINE o 10' FROM LINED POND, DITCH, OR STREAM o 50' FROM WATER BODY o 25'FROM CREST OF BANK o 5,FROM SEPTIC TANK The setback requirements deal primarily with buildings and potential contamination from the septic tank, dosing tank, and leach field to either culinary water or surface water. These setbacks have been included on the plans for reference. Oneration Infor and Maintenance The Owner will need to be responsible for the operation and management of the OWTS. Geo- fabrics or plastics should not be used over the absorption area. No heavy equipment, parking of machinery, or materials should be placed on the absorption area. Livestock should not graze on Mountain Cross Enoineering. lnc. Civil and Environmental Consulting and Design 826'/, Grand Avenue, Glenwood Springs, CO 81 601 P: 970.945.5 544 F : 970.945. 5558 www. mountaincross-eng.com The leach field setback requirements are: l(cu worthy l{csitlcltcc .ltrtrc,2025 l)age .3 ol J the llrsorlrtiorr area. PlLtnlbing lixtrrres shoLrld hc checl<c:d 1o etrsttLe that tto aclditionnl water is lrcing clischirrgerl to OSi'lS; firr exanrplc, runring triilcts ot' lcnk1, flttccts catt tlischiu'gc ltuttrlrcds of gallons o1'rvatcr a rlaf illill ltarnt the absorptioti arca. Garbagc clisposal use shoulcl be rrrinirrrizccl. and non-bioclegraclahlc ntatet'izrls sltottlcl ltot be placetl inlo (lrc (lW'l'S, (ircirse should n<rt bc plncccl in rlrains aurl glcasc traps shoulcl bc irrstallcd upstrcaln of thc scptic tanlt llut clorvnstlcnrtt ll'ottt any hitchcn. l,oacling ltnttt a rvntcr sollcltcr shoulcl nol lre clischargecl into thc OW'['S. No har.arclrrus rvastcs sltoulcl bc dilcctccl into tltc OW'l'Si. 't'hc OW'l'S is engitrcet'ecl [irr tbrucstic rvastc ortly. -l'lrc Orvncl rvill lilccly necrl to contract r.vith a sc:ptic systcnr clcancl to cican thc sc;ltic tanl< evcty {wo years, ur ls nscclcd garrgcrd b}, ,,-r.'r",tt'c:ntertt ol- solids irr the latrl<. 'l'hc sl.attchrtls ol' pcrfirlrrrancc lirr'1he sclttic systcru clc,ancr ilt$ r'cL:onrrtctttlctl to lrc thc hrllorvilrg, a[ a nriltitttttnr: l. 'l'he Systcrrrs (lkrarter shnll be licensecl, 2. 'l'hc Systcrtrs (llcRnrjl', \\,hen clcarting a scptic tatrk, shrtll l'elrlove tlrc liclrrid. slutlge, ltttl sculn, lcaving nc) morc than thlcc (3) inchcs rlcpth o1's*va14c in a scptic tanl<. l. 'l'hc Systcnrs Cleaner^ shall rnaintain his crluipntcttt sct as to cttsulc that no spillagc o1' st:1ys1g$ rvill ocrcur clLn'ing trnnsporlatit-rn, itrttl tlrtrt il,s cnrltlol,ecs irrc rtot sulrject tii uttclurr lrcallh hazitrcls. 4. 'l'hc Systr:nrs Lllcnncl sliall disposc ol thc collcotccl sowago ortly lt tt dcsigttatcil ,silc rccognizccl try thc IJoarcl o1'llcallh. (l gns t ru ctio rL O b.scrv a tio rr l'rior to bcing lrackllllerl, lhc constnrctiorr ol thc OW'l'S and all ol'tltcr c:onrpottcnls lvill ncctl to [rc obscrverl by reltresentatirres ol' Mountaitt Ct'oss Iingirtcct'irrg, Ittc. 'l'hc conclrrsions anrl opiniolis that r-u'o cxpresssrl itblrvc flrs Lritsccl ott thu inlirrrttitlion avirilnblc at tlrc tirne of ltrcpnlation o1'this rcllolt. Any acklitiortal ittlcrrntittiott pt'cscntcel it{icrt'nat'tl tttity t'celuirr: lhll llrese opirtiotts attcl tlte tlcsigrt bc rutrcliliccl. 'l'hnnl< yorr l-ul tlic oppor'tunily to provitlc lhis lcport. ll'ccI li'r-,c to call il'1,,-rt, l]nvc ntt)'rlttcsliotts, c() ltcclls, oL r:ttp'l nterilts. Sinccrc:ly, /r4ottttl tt, , \.. lr in ( lros,'^ Iitt nt!ittg, lttt: I Ialc:. Irli lz Mourrtain Cross Engineering. lnc. Civil anrJ Envlronrnental Oonsultlng and Deslgn 826 lt Grand Avenue, Glertwood Springs, CO 81601 P : 970.945,5544 F: 970.945.5558 www, tnotttttaitrcross'errg.conr )fls Step 1: Flows MOUNTAIN CROSS ENGINEERING, INC. Givil and Environmental Consulting and Design 826 l/2 Grand Avenue Glenwood Springs, CO 8160'l ph 970.945.5544 tx 970.945.5558 w,mountaincroe*ng.mm 5 Bedrooms 10 assumed people 600 gallons per day 4 doses per day 150 gallons perdose 7466.5 7462.5 7461.9 7458.22 DOSING DESIGN CALCULATIONS, foT Lot 21 Coulter Creek Ranch, Garfield County, CO 6t21t2025 Table 6-1 Step 2: BOD5 '10 persons 600 gpd used by residence BOD5 for domestic uses: 0.2 lb/person/day from CDPHE Step 3: Dosing Basin Third Compartment of Septic Tank 70 inch length 38 inch width 18.47 square feet depth of dose volume = lnvert at dosing tank Sump = bottom of third compartment Pump "Off' 1 Pump On "Lead" Float 2.09 Pump On "Lag" Float 2.59 High Alarm (min) 3.09 High Alarm (max) in -12" 1.00 minutes of run time per dose = (5 minute rule of thumb) Step 4: Elevations, Orifices, and Head loss Septic Tank Rim Elevation = High Point Elevation = lnvert at dosing = SumP = Elev Diff = y',.3 feet Length from pump to leach field of 1-1-2" = Length of 1-112" in leach field = 1-112" fittings in equivalent pipe length: 0.6 average day in gallons per minute 1.25 peak day in gallons per minute 2.50 peak hour in gallons per minute 2 lb BODS/day 138.2 gallons per foot of depth 1.09 feet of depth in manhole 4.3 7462.30 7458.22 7459.22 7460.30 7460.80 7461.30 7461.30 35 gpm Design analysis for only one of leaching areas 50 feet 212 feet check 90 90 check 90 gate tee 4-45 13.4 4 4 13.4 4 1.1 8.1 B.B Equivalent 2" Length from pump = 140.7 feet from Fig F, using 8.82 ft of friction head per 100' of 2" plastic pipe = from Fig F, using 0.83 ft of friction head per 100' of 1-112" plastic pipe = check 13.4 2-tee 16.2 86.4 feet 12.4 head loss @ 35 gpm 1.8 head loss @ 9 gpm 1.04 gpm Dynamic Head (TDH) 18.5 system condition use TDH of 25 feet Per Table 7-13 in OWTS Design Manual, 114 " dia. orifice @2' of Head yields 4 Laterals 7 orifices per lateral 29.12 gpm Step 5: Velocity verification 35 gpm in 1.5 inch pipe 0.012 -- area 0.078 = flow in cfs 6.355 = velocity in feet per second, must be greater than 2.0 feet per second but less than 10 feet per second 9 gpm in 1.5 inch pipe 0.012 = area 0.020 = flow in cfs 1.634 = velocity in feet per second Step 6: Pipe Volume & Drain Back assume only drainback from d-valve Discharge Assembly Size Transport Length Transport Pipe Class Transport Line Size Distributing Valve Model Max Elevation Lift Manifold Length Manifold Pipe Class Manifold Pipe Size Number of Laterals per Cell Lateral Length Lateral Pipe Class Lateral Pipe Size Orifice Size Orifice Spacing Residual Head Flow Meter 'Add-on' Friction Losses Pump Selection for a Pressurized System - Single Family Residence Project Parameters 1.50 50 40 1.50 None 5 12 40 1.50 4 50 40 1.50 114 8 2 None 5.6 Galculations Minimum Flow Rate per Orifice 1.09 Number of Orifices per Zone 28 Total Flow Rate perZone 30.8 Number of Laterals per Zone 4 % Flow Differential l sulast Orifice 1 .7 Transport Velocity 4.9 Frictional Head Losses gpm gpm inches feet inches feet feet inches feet inches inches feet feet inches feet 100 90 80 70 oool!r60oFd {Ed,.50 .9 El! o40 E o o/o fps 30 20 10 Loss through Discharge Loss in Transport Loss through Valve Loss in Manifold Loss in Laterals Loss through Flowmeter 'Add-on' Friction Losses Pipe Volumes 2.8 2.7 0.0 0.2 0.1 0.0 5.6 feet feet feet feet feet feet feet 0 02040 60 80 100 Net Discharge (Spm) 120 140 160 Vol of Transport Line Vol of Manifold Vol of Laterals per Zone Total Volume 5.3 1.3 21.2 27.7 gals gals gals gals PumpData nd PFEF40 Effluent Pump 4t10HP,1151230V 1@ Minimum Pump uirements Design Flow Rate Total Dynamic Head 30.8 18.5 gpm feet I l I I I I I I I I / LI I J I I I A {/) System Curve: - Pump Curve: ' ' PUmp uptrmal Hange: Operating Point: o Design Point: rcn Kumar & Associales, lnc.' Geotechnical and Materials Engineers and Environmental Scienlists An Employse Owned Compony 5020 County Road 154 Glenwood Springs, CO 81601 phone: (970)945-7988 fax: (970) 945-8454 ernail : kaglenwood@kumarusa.com rvu'n,. k ttntaru sa. cott.t Office Locations: Denver'(HQ), Parker, Colorado Springs. Fort Collins, Clenwood Springs, and Surnrnit County, Colorado October 21,2021 Lisa McPherson 78 River Glen Carbondale, Colorado 81623 ldrn47 4 5 (rD,i c I oud. corr Project No.2I-7-764 Subject: Subsoil Study for Foundation Design, Proposed Residence, Lot2l, Ranch at Coulter Creek, Saddle Drive, Garfield County, Colorado Dear Ms. McPherson: As requested, Kumar & Associates, Inc. performed a subsoil study for design of foundations at the subject site. The study was conducted in accordance with our agreement for geotechnical engineering services to you dated September 16,2021 The data obtained and our recommendations based on the proposed construction and subsurface conditions encountered are presented in this report. Proposed Construction: Residence building plans were not available at the time of our study. In general, a single-family residence is proposed in the northeast part of the lot roughly between the exploratory borings located as shown on Figure 1. Ground floors could be a combination of structural over crawlspace and slab-on-grade. Cut depths are assumed to range between about2 to 6 feet. Foundation loadings for this type of construction are assumed to be relatively light and typical of the proposed type of construction. If building conditions or foundation loadings are significantly different from those described above, we should be notified to re-evaluate the recommendations presented in this report. Site Conditions: The subject site was vacant at the time of our field exploration. The proposed building site is a broad hilltop with gentle to moderate side slopes down away from Boring 2 shown on Figure 1. Vegetation consists of sagebrush, grass and scrub oak with basalt rocks exposed on the ground surface throughout the lot including the proposed building area. Subsurface Conditions: The subsurface conditions at the site were evaluated by drilling 2 exploratory borings at the approximate locations shown on Figure 1. The logs of the borings are presented on Figure 2. The subsoils encountered, below about 4 inches of topsoil, consist of dense basalt gravel, cobbles and boulders in a calcareous sand and silt matrix to the maximum boring depth of 7 feet. Drilling in the dense cobbles and boulders was difficult and practical -2- auger refusal was encountered in the borings. Results of gradation analyses performed on small diameter drive samples of the sand and silt matrix soils (minus llz-inch fraction) of the coarse granular subsoils are presented on Figure 3. The laboratory test results are summarized in Table 1. No free water was encountered in the borings at the time of drilling and the soils were slightly moist. Foundation Recommendations: Considering the subsoil conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend spread footings placed on the undisturbed natural rocky soil designed for an allowable bearing pressure of 2,500 psf for support of the proposed residence. Foundation settlement potential should be low, up to around 1 inch. Footings should be a minimum width of 16 inches for continuous walls and 2 feet for columns. The topsoil and loose disturbed soils encountered at the foundation bearing level within the excavation should be removed and the footing bearing level extended down to the undisturbed natural rocky soils. Voids created by boulder removal should be backfilled with compacted road base or concrete. We should observe the completed building excavation for bearing conditions prior to forming footings. Exterior footings should be provided with adequate cover above their bearing elevations for frost protection. Placement of footings at least 36 inches below the exterior grade is typically used in this area. Continuous foundation walls should be reinforced top and bottom to span local anomalies such as by assuming an unsupported length of at least 12 feet. Foundation walls acting as retaining structures should be designed to resist a lateral earth pressure based on an equivalent fluid unit weight of at least 50 pcf for the on-site soil as backfill, excluding organics and rock larger than 6 inches. A sliding coefficient of 0.45 and equivalent fluid lateral passive earth pressure of 375 pcf can be used to resist lateral loading on the foundation. Floor Slabs: The natural on-site soils, exclusive of topsoil, are suitable to support lightly loaded slab-on-grade construction. To reduce the effects of some differential movement, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab controljoints should be used to reduce damage due to shrinkage cracking. The requirements for joint spacing and slab reinforcement should be established by the designer based on experience and the intended slab use. A minimum 4-inch layer of free-draining gravel should be placed beneath basement level slabs to facilitate drainage. This material should consist of minus Z-inch aggregate with less than 50o/o passing the No. 4 sieve and less than 2%o passing the No. 200 sieve. All fill materials for support of floor slabs should be compacted to at least 95o/o of maximum standard Proctor density at a moisture content near optimum. Required fill can consist of the onsite soils devoid of vegetation, topsoil and oversized rock or imported gravel such as road base. Kumar & Associates, lnc, @ Project No. 21-7-764 -3- Underdrain System: Although free water was not encountered during our exploration, it has been our experience in the area that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoffcan create a perched condition. We recommend below-grade construction, such as retaining walls, crawlspace and basement areas, be protected from wetting and hydrostatic pressure buildup by an underdrain system. The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free-draining granular material. The drain should be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum Io/o to a suitable gravity outlet. Free-draining granular material used in the underdrain system should contain less than ZVo passing the No. 200 sieve, less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at least 1/z feet deep. Surface Drainage: The following drainage precautions should be observed during construction and maintained at all times after the residence has been completed: 1) Inundation ofthe foundation excavations and underslab areas should be avoided during construction. 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95o/o of the maximum standard Proctor density in pavement and slab areas and to at least 90o/o of the maximum standard Proctor density in landscape areas. Free-draining wall backfill should be covered with filter fabric and capped with about 2 feet of the on-site, finer graded soils to reduce surface water infiltration. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of 12 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in pavement and walkway areas. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. 5) Landscaping which requires regular heavy irrigation should be located at least 5 feet from the building. Consideration should be given to the use of xeriscape to limit potential wetting of soils below the foundation caused by irrigation. Limitations: This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 1 and to the depths shown on Figure 2, the proposed type of construction, and our experience in Kumar & Associates, lnc. ^Project No. 21-7-764 4- the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified at once so re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. If you have any questions or if we may be of further assistance, please let us know. Respectfully Submitted, Kumar & Associates, Inc. Steven L. Pawlak, P.E. Reviewed by: Daniel E. Hardin, P.E. SLP/kac Attachments: Figure 1 - Location of Exploratory Borings Figure 2 - Logs of Exploratory Borings Figure 3 - Gradation Test Results Table 1 - Summary of Laboratory Test Results Kumar & Associates, lnc. ^Project No. 21-7-764 l:l ::. ! ! : .l 5STELLOF I TRACT D ttt$).w1 q746l{' 1 ENft@r Ef,bTAn 7 a.aarg,ril *o.r&tto Fi { ril! vsfrt T hEMI Ju rat rl tB tna ns969q :mra Htr^t ( ibo €G rD.cl l!s \rrn"n I LL ttL, Ldt t6 a4 I I I , I II Lpr18 I I I I I I I I I I I tr. cstArct Mli 4r mir G ,4lm aoNret rlr Y qtE &m! nuE N trct' q ilffI Srd qlr ffffiati'o E6a n, ffi ^t a I 3!!tr rl@!r -adr4{ rt@lr-o_N_tlaoJ.,_n!, 50 0 50 100 APPROXIMATE SCALE _FEET f--rf;lr7-+-*--r-rtr;r.Fir_hl uzt^tridr.---\\\\\_ BORING 2 o FfEIIa Altft alL3 r:llt I I I BORING 1 O tor 2t Zq02a .$rlt &2la oc'',tt v c xf, t{.TD I I I I t .bt i?E8r 4t R atattI Artnl Ct'Lr lrart ,l er El t I I t I t I\, L' fi (+,. tt' v\ ral .t.l, cxal arl{ i--{!i ffitD,|lln(nql ?t, I I I I I I I ucr, rtred (@ tr:,at 6 rtgtarux4r( r,lru 14 ttt t, frpa Ll at6ll,*l t xt4a ,(tano u,rt agttl f,{j#e .i.sf?f N 4 si 21 -7 -764 Kumar & Associates LOCATION OF EXPLORATORY BORINGS Fig. 1 I ! E WC=11.5 +4=1 9 -2OO=37 BORING 1 BORING 2 0 0 F trJ trJu- I-F(L trJo so/3 28/6,50/3.5 F trJ UJtL I-Fo- LJo R 26/6,35/3 WC=12.8 +4=21 -2O0=48 5so/3.5 10 10 LEGEND N TOPSOIL; ORGANIC SAND AND SILT WITH BASALT GRAVEL, COBBLES AND BOULDERS, BROWN BASALT COBBLES AND BOULDERS (GM); CALCAREOUS SAND AND SILT MATRIX, DENSE, SLIGHTLY MOIST, GRAY. I DRTVE SAMpLE, 1 5/8-|NCH t.D. SPL|T SPOON STANDARD PENETRATION TEST 28/6 DRIVE SAMPLE BLOW COUNT. INDICATES THAT 28 BLOWS OF A 14o-POUND HAMMER FALLING 50 INCHES WERE REQUIRED TO DRIVE THE SAMPLER 6 INCHES. t PRACTICAL AUGER REFUSAL. NOTES 1. THE EXPLORATORY BORINGS WERE DRILLED ON SEPTEMBER 23, 2021 WITH A 4-INCH DIAMETER CONTINUOUS-FLIGHT POWER AUGER. 2. THE LOCATIONS OF THE EXPLORATORY BORINGS WERE MEASURED APPROXIMATELY BY PACING FROM FEATURES SHOWN ON THE SITE PLAN PROVIDED. 3. THE ELEVATIONS OF THE EXPLORATORY BORINGS WERE NOT MEASURED AND THE LOGS OF THE EXPLORATORY BORINGS ARE PLOTTED TO DEPTH. 4. THE EXPLORATORY BORING LOCATIONS SHOULD BE CONSIDERED ACCURATE ONLY TO THE DEGREE IMPLIED BY THE METHOD USED. 5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY BORING LOGS REPRESENT THE APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUAL. 6. GROUNDWATER WAS NOT ENCOUNTERED IN THE BORINGS AT THE TIME OF DRILLING. 7. LABORATORY TEST RESULTS: WC = WATER CONTENT (%) (ASTM D2216); +4 = PERCENTAGE RETAINED ON NO. 4 SIEVE (NSTV OOSIS); _2OO= PERCENTAGE PASSING NO. 2OO SIEVE (ASTM D1140). 21 -7 -764 Kumar & Associates LOGS OF EXPLORATORY BORINGS Fig. 2 I TIME READINGS 100 90 ao 70 80 50 10 30 20 10 o HRS !'llN 0 t0 20 30 ,+o 50 60 70 80 90 to0 , 6 -g .o37 .o75 DIAMETER OF .125 PARTICLES IN CLAY TO SILT COBBLES GRAVEL 19 % SAND 41 LIQUID LIMIT SAMPLE OF: Sllty Sond with Grovel Molrlx % PLASTICITY INDEX SILT AND CLAY 37 % FROM: Borlng 1 O 2.5' & 5' (Combined) n 100 90 ao 70 60 50 10 50 20 lo o o 10 20 3o 10 50 60 70 80 90 ro0 - .o37 .o75 .1 50 IAMETER OF .125 PARTICLES IN MI RS CLAY TO SILT COBBLES GRAVEL 21 % LIQUID LIMIT SAND 31 % PLASTICITY INDEX SILT AND CLAY 4A % SAMPLE OF: Very Silty Sond wiih Grovel FROM: Boring 2 @ 5' Thos€ lssl rssulls qpply only lo the somples whlch were lesled. The lssllng report shqll nol b6 r€producod, oxcepl ln full, wllhoul lhs wrlllenqpprovql ot Kumqr & Associol€s, lnc. Sl6vo onolysls losllng ls porformcd ln occordoncs wlth ASTM 069|3, ASTM D7928, ASTM C156 ond/or ASTM D1140, Motrix HYDROMETER ANALYSIS SIEVE ANALYSIS CLEAR SQUARE OPENINCS il:o110 : I I I i I I I I I i l I,r L l GRAVELSAND FINE MEDIUM COARSE FINE COARSE HYDROMETER ANALYSIS SIEVE ANALYSIS CLEAR SOUARE OPENINGS .trr ./^, . trr' IITIE READINGS 24 HRS 7 HRS i MINlutN Itoo U.S. STANDARD SERIES a50 {ao {50 {t6 4io ta ./', ,l ll :i : I r rl l GRAVELSAND FINE MEDIUM ICOARSE FINE COARSE 21 -7 -7 64 Kumar & Associates GRADATION TEST RESULTS Fig. 3 rcn *iffil[##l:fifn"'n3; n''** TABLE 1 SUMMARY OF LABORATORY TEST RESULTS Silty Sand with Gravel Matrix Very Silty Sand with Gravel Matrix SOIL TYPE (ps0 UNCONFINED COMPRESSIVE STRENGTH PLASTIC INDEX g"l ATTERBERG LIMITS (%l LIQUID LIMIT PERCENT PASSING NO. 200 stEVE 37 48 (/"\ SAND 44 31 I1 I2 GRADATION (7") GRAVEL (ocfl NATURAL DRY DENSITY (Y"l NATURAL MOISTURE CONTENT 1 1.5 12.8 (ft) DEPTH 2r/z andS combined 52 SAMPLE LOCATION BORING 1 No. 21-7-764