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Home My WebLink AboutGeotechnical Investigation 05.14.2026CMTTECHNICALsE R V I C E GEOTECHNICAL STUDY Water Tank at Ranch at Roaring Fork HOA 14913 Highway 82 Carbondale, Colorado Prepared for: Mr. Chip Geber Ranch at Roaring Fork HOA 14913 Highway 92 Carbondale, CO 81623 Project No. 501666 May 14, 2026 Colorado Regional Office: 7108 South Alton Way, Building B " Centennial, CO 80112 Arizona • Colorado • Idaho • Texas Utah Phone 303-220-0300 • www.cmttechnicalservices.com I CMTTECHNICAL GEOTECHNICAL STUDY Water Tank at Ranch at Roaring Fork HOA 14913 Highway 82 Carbondale, Colorado Prepared for: Mr. Chip Geber Ranch at Roaring Fork HOA 14913 Highway 92 Carbondale, CO 81623 Project No. 501666 May 14, 2026 Prepared by: ;r 38814 g; p '•,05/14/2026,� Noom T. Aksharadananda, P.E. Project Engineer Reviewed by: Darin R. Duran, P.E. Southwest Colorado Office Manager/ Senior Principal - Colorado 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 CMT TECHNICAL SERVICES - COLORADO TABLE OF CONTENTS 1. PURPOSE.....................................................................................................................................1 1AGENERAL....................................................................................................................................1 1.2 SCOPE OF SERVICES...................................................................................................................1 2. SUMMARY OF FINDINGS AND CONCLUSIONS............................................................................1 3. SITE CONDITIONS...................................................................................................................... 2 4. PROPOSED CONSTRUCTION....................................................................................................... 4 S. GEOLOGIC CONDITIONS............................................................................................................. 4 5.1 SURFICIAL DEPOSITS..................................................................................................................4 5.2 BEDROCK................................................................................................................................... 5 6. FIELD EXPLORATION.................................................................................................................. 6 7. LABORATORY TESTING............................................................................................................... 9 S. SUBSURFACE CONDITIONS........................................................................................................ 9 9. GROUNDWATER........................................................................................................................10 10. GEOTECHNICAL CONSIDERATIONS.........................................................................................10 10.2. GEOLOGIC HAZARDS.............................................................................................................. 11 10.2.1 COLLAPSIBLE SOIL........................................................................................................... 11 10.2.2 EAGLE VALLEY EVAPORITE BEDROCK................................................................................ 11 10.2.3 SEISMIC CONSIDERATIONS.............................................................................................. 11 11. FOUNDATION RECOMMENDATIONS.......................................................................................11 11.2 DRILLED PIERS....................................................................................................................... 11 12. LATERAL EARTH PRESSURES..................................................................................................13 12.1 FOUNDATION WALLS............................................................................................................... 13 13. EXCAVATIONS.........................................................................................................................13 14. STRUCTURAL FILL/BACKFILL SOIL........................................................................................14 14.1 IMPORT FILL........................................................................................................................... 15 15. SUBSURFACE DRAINAGE........................................................................................................16 16. SURFACE DRAINAGE...............................................................................................................16 17. SOIL CHEMICAL TESTING....................................................................................................... 16 17.1 SULFATE EXPOSURE................................................................................................................ 16 17.2 SOIL CORROSIVITY................................................................................................................. 17 18. GEOTECHNICAL RISK..............................................................................................................17 19. LIMITATIONS..........................................................................................................................17 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 iii CMT TECHNICAL SERVICES - COLORADO TABLES TABLE 7.1. Laboratory Testing Performed...................................................................................... 9 TABLE 9.1. Depths to Bedrock and Groundwater Measurements.................................................10 TABLE 10.1. Summary of Swell/Consolidation Laboratory Testing..............................................10 TABLE 12.1. Lateral Earth Pressures and Coefficients of Sliding Resistance for Backfill.............13 TABLE 13.1. Allowable Slope Configuration for Onsite Material..................................................14 TABLE 14.1. Compaction Specifications........................................................................................15 TABLE 15.2. Import Fill Specifications..........................................................................................15 TABLE 15.3 CDOT Class 1 Structural Fill or Class 5 ABC Specifications........................................15 TABLE 17.1 Information from ACI 318-08 - Table 4.3.1...............................................................17 TABLE 17.2. Summary of Soil Chemical Test Results...................................................................17 FIGURES VICINITYMAP................................................................................................................... FIGURE 1 BORINGLOCATIONS......................................................................................................... FIGURE 2 APPENDICES FIELD EXPLORATION................................................................................................... APPENDIX A LABORATORY TESTING................................................................................................ APPENDIX B 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 iv CMT TECHNICAL SERVICES - COLORADO COMMON ABBREVIATIONS AND ACRONYMS AASHTO ......... American Association of State Highway and Transportation Officials ABC ................ aggregate base course ACI ................American Concrete Institute ADA ...............Americans with Disabilities Act ADSC ............. Association of Drilled Contractors AI .................. Asphalt Institute APM .............. asphalt paving material ASCE..............American Society of Civil Engineers ASTM ............. American Society for Testing and Materials AWWA ........... American Water Works Association bgs................. below ground surface CDOT ............. Colorado Department of Transportation CBR................ California Bearing Ratio CFR................ Code of Federal Regulations CGS ................ Colorado Geological Survey CKD ............... cement of kiln dust stabilized subgrade CMU...............concrete masonry unit CTB ................ cement treated base course deg ................ degree EDLA..............equivalent daily load application en, .................edge moisture variation distance EPS ................ expanded polystyrene ESAL .............. equivalent single axle loads f'c .................. specified compressive strength of concrete at the age of 28 days Fa ................... seismic site coefficient FHWA ............ Federal Highway Administration FS .................. factor of safety Fv................... seismic site coefficient GSA ................ global stability analysis GVW .............. gross vehicle weight IBC ................International Building Code ICC-ES ........... International Code Council Evaluation Services, Inc. IRC ................International Residential Code kip .................1,000 pounds -force km ................. kilometer LTS ................ lime treated subgrade MDD .............. maximum dry density mg/L ............. milligrams per liter MGPEC........... Metropolitan Government Pavement Engineers Council mm ................ millimeter Mr .................. resilient modulus MSE ............... mechanically stabilized earth mV................. millivolts NAPA ............. National Asphalt Pavement Association NDESIGN ........... design gyrations ODEX.............overburden drilling eccentric OMC............... optimum moisture content 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 CMT TECHNICAL SERVICES - COLORADO OSHA.............Occupational Safety and Health Administration OWTS ............ onsite wastewater treatment system PCA................ Portland Cement Association PCC................ Portland cement concrete pcf ................. pounds per cubic foot pci.................. pounds per cubic inch pH .................. power of hydrogen psf ................. pounds per square foot psi .................. pounds per square inch PT .................. post -tension SS ................... mapped spectral accelerations for short periods UBC ............... Uniform Building Code USGS ............. United States Geological Survey 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 A CMT TECHNICAL SERVICES - COLORADO 1. PURPOSE 1.1 GENERAL CMT Technical Services - Colorado (CMT) performed a geotechnical study for a new water tank at the Ranch at Roaring Fork HOA on the north side of Highway 82, adjacent to an existing water tank. The study was made to characterize existing subsurface conditions at a proposed location of the new tank; to assist in determining design criteria for planning, site development, foundation systems, and surface drainage of the new tank; and to address other pertinent geotechnical considerations. Information gathered during the field exploration and laboratory testing is summarized in Figures 1 and 2 and Appendices A and B. CMT's opinions and recommendations presented in this report are based on data generated during this field exploration, laboratory testing, and its experience. 1.2 SCOPE OF SERVICES The scope of services performed is detailed in CMT's Proposal Agreement No. 501666.P01A, which was executed on March 3, 2026. 2. SUMMARY OF FINDINGS AND CONCLUSIONS This section is intended as a summary only and does not include design details. The report should be read in its entirety and utilized for design. Three borings were drilled using the ODEX (overburden drilling eccentric) drilling method. • CMT's borings encountered 11 to 23 feet of medium dense to dense poorly -graded gravel, with cobbles and boulders in a silty clay matrix. • 6 to 9 feet of soft to very stiff clay with silt, classified as CL or CL-ML, was encountered below the medium dense to dense poorly graded gravel. • Very dense gravels and boulders underlie the clay with silt extending to the maximum depth explored of 33 feet. • Groundwater was encountered in one boring at the time of drilling at a depth of 24 feet, and was not observed in the borings, 10 to 11 days after drilling. • A boring at the new tank location was converted to a monitoring well. • Due to the known debris fan of the site and bedrock of the Eagle Valley Evaporite, an inclinometer well was installed, south of the new tank. • Based on the soils encountered, the site is classified as seismic Site Class D and seismic Design Category II. • A tank with a concrete ring foundation with a welded steel shell is planned. Due to the consolidation potential of the soft clay, the tank foundation should be supported by piers with a mat pier cap (conformed to ANSI/AWWA D103-19). • A 6 inch compacted granular leveling layer over 6 inch compacted structural fill is recommended beneath the mat pier cap to improve uniformity of support. • Imported material or onsite sand soils may be reused as structural fill. • A consolidation potential of the clay with silt layer was tested to be -0.1% upon wetting at a surcharge load of 1,884psf. • Good surface drainage should be established, and positive drainage away from the new tank should be provided during construction and maintained throughout its life. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 1 CMT TECHNICAL SERVICES - COLORADO 3. SITE CONDITIONS The site is located at 14913 Highway 82, Carbondale, Colorado. A vicinity map is shown in Figure 1. The site is currently undeveloped land. The site is bounded by an irrigation ditch to the north and by undeveloped land to the south, east, and west. The topography of the site is gently to moderately sloping with a grade change of approximately 12 feet within a lateral distance of 120 feet from the existing tank to the west, and a grade change of approximately 17 feet within a lateral distance of 120 feet from the existing tank to the south. According to survey information from the client, the bottom of the existing tank is at an elevation of 6,306.5 feet. Vegetation onsite consists of trees along the banks of the irrigation ditch and grasses and sparse brush at the proposed new tank site. Bedrock outcrops were not observed. There is an irrigation ditch behind the existing tank, see Photo 3. The ditch did not contain water during drilling on March 19 and 20, 2026, but it was filled up to approximately 1.5 feet lower than the bottom of the existing tank on March 30, 2026, 10 to 11 days after drilling. CMT understands the client has a concern about land movement due to the known debris fan of the Eagle Valley Evaporite, evidenced by a continuing trench from the western side to the southern side of the existing tank. Photo 1. View looking northeast at the existing tank. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 t t rxi lr0��';.a �� • .t .:-� .S: � A?,►•: � _s- •+=-�• • i ♦ �- ''ice ential land ♦� ♦ jI •.� r� 0000 0 '( f ' ,within the trench 0,00 n Y![r T ��+.��i. _ l '��',. �� y.• � �� 'tea - .. ' �r� '.... ' 1�}',3 ` .� �.4f•��,� .• ;,� I06 .t Vu J Irrigation ditch on the northern side of the existing tank Potential land movement within ' {{f.ug •':� 2 - ti_ j ,� �' +�v �,• - ` - trench_. CMT TECHNICAL SERVICES - COLORADO Photo 4. Aerial view of the site. 4. PROPOSED CONSTRUCTION The proposed construction will be a steel tank approximately 39.2 feet outside diameter and approximately 28.2 feet in height and located approximately 50 feet west of the existing tank. The tank is still in the design phase. CMT understands preliminary design is a concrete ring foundation with a welded steel shell. Excavations are estimated to be approximately 5 feet with anticipated changes to site grades limited to approximately 5 feet. CMT understands tank design will follow the guidelines of ANSI/AWWA D103-19. If the final tank elevation differs by more than 2 feet from the proposed grade, CMT should be informed so the recommendations in this report can be re-evaluated. S. GEOLOGIC CONDITIONS 5.1 SURFICIAL DEPOSITS As shown in Exhibit 1, the Geologic Map of the Carbondale Quadrangle, Ganield County, Colorado, prepared for the USGS by Kirkham, R.M., and Widmann, B.L., dated 2008, indicates surficial deposits onsite likely consist of: • 'Alluvium and Mass Wasting Deposits, sediments in debris fans, stream channels, flood plain, and hillslopes along tributary valleys, including Qdry': • 'Mass Wasting Deposits, sediments on valley sides, valley floors, and hil/slopes transported and deposited primarily by gra vity, including Qc': • "Alluvium Deposit, sediments deposited in stream channels, flood plains, glacial outwash terraces, and sheetwash areas, including Qty and Qtm ". 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 4 CMT TECHNICAL SERVICES - COLORADO I, a•^"kL�� ....aa `tip • �. Ve - J • •- 4 � _ { _. � Lam_ _ - • -- Qdty Qdiy ,Q Sit • \ . ,, Younger terrace alluvium (late Pleistocene{ —Mostly �'J1 .• Site �r r "a.rlq —tied. .•1a+1-.tlpp..rlyd• LKaIIv h.uld.«y- r.-bble 1-:r: and cobble nra%vi In a .and and Mit main♦ fkpn.n� 1 ... l;l.t. l.d stun.•">h Unde'l.— lerraat. 1"5 It al•.ni, Q �.1 modern slteam level, May include line greened _ overbank deposits _ OIT.: 1Intermediate terrace alluvium (late Pleisloeene)— Depuslts teAluratly and depo.ltivnally simildr It' +f - younger terrace alluvium (Qty). Underlies terraces 1 51-110 It above modern streams - - -__- �jColluvium (Holocene and late Pleistocene) —Ranges from �r+ un."triad, ch-t- uri ortcd, rrbblr I,- b.•ulder grave; .n n + �_- _ - sandy .ill ln.drn to m.drix .uppnrlad gravelly", cldvv.% san dy sill. Utasallynerer graort d upper ttvdttx..1 40 atlluvlal slopes finer and rgnundistill in t+lal an++s V „ Younger debrio-no% doposity (Holocene and late Qra 1'loklocenrl--PMnly ...rted In mtxlor tely wrll-vut.rl. matrix- and cans► -supported deposits mnging from gravelly clayey sill to candy, silly, cobk.ly. r lbly, and bouldery gravel- tan head., tend to be h uldcry. while ' ►Betel fan an•as an, firm grained. inrludrs debri._flow. r hyrvrcon,entr.ued•tlna, fluvial, and Sheetwash a0" Ich••.1 ..., active fans and in some dr.mitige channels EXHIBIT 1. Portion of the Geologic Map of the Carbondale Quadrangle, Garfield County, Colorado, prepared for the USGS by Kirkham, R.M., and Widmann, B.L., dated 2008. The approximate location of the site is shown with a red star. 5.2 BEDROCK The Geologic Map of Colorado prepared for the USGS by Tweto, dated 1979, as shown in Exhibit 2, indicates bedrock onsite likely consists of: "Pee: Evaporatic Facies, gypsum, siltstone and shale" • 11Qg: Gravel and Alluviums (Pinedale and Bull Lake age) • °Tbb•• Basalt Flows and Associated Tuff, Breccia, and Conglomerate of Late Volcanic Bimodal Suite': 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 5 CMT TECHNICAL SERVICES - COLORADO W 7 . 1 41 jaw�4 .lam /mow. •.;v ��:;. n/�+c �4��'�� aW �( f 7 ♦ i FVAPURMCFACIES--i1'pwnt tt1!elonc .mW,otml, .dtrr:sunlmde,phrnlnyc Inlartun uec with Minlum and Louvr Mate nFor, a.oas U.alMnc :iruciwe,, many *Cer (9 Qg GRAVELS AND ALLL110UhtS it NEDALE AND HIM LAkE AfE:—In Ju das 6ro d—,V cnd -ou.vn 7l`luvwu� psiHfuALT FLOWS AND ASSOCIATED TUFF, BUCC14a AND COT GLOMERA rE OFLATE VOLCANICRLMODALSUITEvAGE33-26MYl-IndLd�b—di—! ►r Km'e Formadon w 5ar. Jwn Sin%ern F_:nnat.n Luis VdRav and r Am, dhn; xcuren. r: EXHIBIT 2. Portion of the Geologic Map of Colorado, prepared for the USGS by Tweto, dated 1979. The approximate location of the site is shown with a red star. 6. FIELD EXPLORATION Subsurface conditions were explored on March 19 and 20, 2026, by drilling three borings using the ODEX drilling method at the locations indicated in Figure 2. Borings were drilled 24.3 to 33 feet deep. CMT initially had Boring B-1 advanced within the proposed tank footprint at the location provided by the client during the proposal preparation, as indicated by the yellow circle in Photo 4. After the completion of Boring B-1, the client representative visited the site and provided revised information identifying an updated tank location. CMT advanced a replacement boring, Boring B-1A, at the updated tank location and installed temporary groundwater monitoring wells within the boring. Boring B-1A was advanced approximately 50 feet east of the original B-1 location (i.e., closer to the existing tank), as shown by the red circle in Photo 4. Photos 5 through 8 show Borings B-1, B-1A, and B-2 during the exploration. The State of Colorado's Division of Water Resources (DWR) considers monitoring wells to be temporary for the initial period of 18 months. After 18 months, DWR requires wells to be permitted and maintained as such or abandoned onsite (removed and/or plugged). If requested by Client, CMT can assist with well abandonment and/or the process of permitting when the 18 month period is coming to an end. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 6 CMT TECHNICAL SERVICES - COLORADO Prior to drilling and installing the monitor well, CMT filed the appropriate "Notice of Intent" forms (Form GWS-51) with DWR. After constructing the monitor wells, CMT filed the appropriate "Well Construction Reports" (Form GWS-31) with DWR. The groundwater monitoring wells were constructed using a 2 inch diameter PVC pipe consisting of screened/slotted intervals and solid/riser intervals. The screen intervals were placed from the bottom of the boring up to the approximate water level, with the solid portion continuing from there to the ground surface, in the case of flush mount wells, or to 2 to 3 feet above ground surface, in the case of stick up wells. 10/20 silica sand was placed around the screen portions of the pipe and to 1 to 2 feet above the screen portion. Bentonite pellets were placed on top of the silica sand to the ground surface. The bentonite was "charged" by adding water to encourage expansion and sealing. The monitor well was constructed as stick up monuments where a steel protective cover is placed around the PVC pipe, and a concrete pad is constructed at the ground surface around the cover, see Photo 8 below. Graphical details of the monitor wells and graphical logs of the subsurface conditions observed, locations of sampling, and further explanation of the exploration are presented in the boring logs contained in Appendix A. Due to the known debris fan of the site and bedrock of the Eagle Valley Evaporite, CMT installed an inclinometer at Boring B-2. The inclinometer was installed with PVC casing and a grouted outside collar. CMT will check the inclinometer on a 3 to 6 month interval for a designated time frame, agreed upon by the client and the HOA. The inclinometer can remain onsite during construction and after the water tank is operational to provide additional risk management monitoring if desired. The purpose of the inclinometer is to measure potential subsurface movement, to help with designs, and to provide risk management methods for the proposed water tank. Photo 5. View looking north at Boring B-1 during drilling. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 7 CMT TECHNICAL SERVICES - COLORADO Photo 6. View looking west at Boring B-1A. Photo 7. View looking north at Boring B-2 (inclinometer) during drilling. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 CMT TECHNICAL SERVICES - COLORADO ---.. t � ,� `��_ z1� •., '.{,, - Y '�1 _may;,_ ;J:, , '�, �., .f Photo 8. View looking north at Boring B-1A (monitoring well) after completion. 7. LABORATORY TESTING CMT personnel returned samples obtained during field exploration to its laboratory, where professional staff visually classified them and assigned testing to selected samples to evaluate pertinent engineering properties. Laboratory tests performed are listed in Table 7.1. Further discussion of laboratory testing and the laboratory test results are presented in Appendix B. TARLF 7.1• Laboratnry Testina Performed Laboratory Test To Evaluate Grain size analysis Grain size distribution for classification purposes. Atterberg limits Soil plasticity for classification purposes. Swell/consolidation Effect of wetting and loading on the soil. Water soluble sulfate content Potential corrosivity of the soil on cementitious material. H water soluble chloride content, and resistivity Potential corrosivity of the soil to metal. S. SUBSURFACE CONDITIONS CMT's borings encountered: • 11 to 23 feet of medium dense to dense poorly -graded gravel, with cobbles and boulders, in a silty clay matrix. • 6 to 9 feet of soft to stiff clay with silt layer, classified as CL-ML, was encountered below the medium dense to dense poorly graded gravel. • Very dense gravels and boulders were encountered below the clay with silt extending to the maximum depth explored of 33 feet. • Groundwater was encountered in Boring B-1 at the time of drilling at a depth of 24 feet and was not encountered in the borings, 10 days after drilling. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 9 CMT TECHNICAL SERVICES - COLORADO The subsurface conditions encountered in CMT's borings are consistent with those described in Section S. GEOLOGIC CONDITIONS. These observations represent conditions at the time of field exploration and may not be indicative of other times or other locations. 9. GROUNDWATER Borings were checked for the presence of groundwater during drilling and Boring B-1 was temporarily covered and checked for water 10 days after drilling. Measurements are summarized in Table 9.1. TABLE 9.1. Denths to Bedrock and Groundwater Measurements No. of Last *Ground Actual Depth of Water Days Water Elevation Depth Date Bedrock During After Check Boring ID (ft) (ft Drilled ft Drillinq Drilling ft B-1 5,893.4 24.3 03/19/26 NE* 24 11 NE B-1A(MW) 5,893.4 24.3 03/19/26 NE* NE* 11 NE B-2(INCL) 5,893.4 33 03/20/26 NE* NE* 10 NE *Not encountered Groundwater can be expected to fluctuate and can be influenced by variations in seasons, weather, precipitation, drainage, vegetation, landscaping, irrigation, and leakage of water and/or wastewater systems both onsite and offsite. Discontinuous zones of perched water may exist or develop within the overburden material and/or upper zones of the bedrock. CMT's field explorations were performed during the winter when groundwater levels are usually low. Groundwater levels may be higher or lower at other times of the year. 10. GEOTECHNICAL CONSIDERATIONS 10.1 COMPRESSIBLE SOIL A sample of the clay with silt, in its present conditions, was tested and has moderate consolidation potential and a low to moderate collapse potential and -0.1% volume change at an inundation pressure of 1,884 psf, . Negative values indicate collapse upon wetting. Results of swell/consolidation testing performed are summarized in Table 10.1. TABLE 10.1. Summary of Swell/Consolidation Laboratory Testin Swell (+) or Compression Generalized Inundation (-) Upon Swell Volume Pressure Wetting Pressure Change Material Type (psf) (%) f0sf) Cateaory B-1 at 19 feet I Clay matrix, silty � 1,884 1 -0.1 1 NA I Low NA = not applicable Silty clay encountered onsite may be prone to movement upon an increase in moisture content (i.e., wetting). Laboratory results reflect the sample's behavior, while the soil's collapse potential at the site could be greater, increasing the risk of settlement. Foundations bearing on these materials should be anticipated to experience settlement, potentially of approximately 1 to 2 inches or greater. Subsurface explorations performed by CMT indicate clay layers are present at variable depths and 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 10 CMT TECHNICAL SERVICES - COLORADO with varying thicknesses across the site. This variability may contribute to the differential settlement of foundations. Due to the inherent variability of subsurface conditions and the limited extent of the exploration, variations in soil conditions may exist between boring locations. Accordingly, the potential for total and differential settlement may be greater than indicated. 10.2. GEOLOGIC HAZARDS 10.2.1 Collapsible Soil Collapsible soils are typically low -density, partially saturated deposits (often silty or sandy with weak clay bonding) that appear stable in a dry condition but undergo sudden and significant volume reduction when wetted under load. This collapse occurs as moisture weakens interparticle bonds and the soil structure rearranges into a denser configuration, leading to rapid settlement that can distress foundations, slabs, and pavements. In geotechnical design, awareness focuses on identifying susceptible soils through density, moisture, and collapse potential testing and recognizing triggers such as irrigation, leakage, or rising groundwater. Mitigation measures commonly include moisture control, prewetting or compaction, removal and replacement, or the use of deep foundations to bypass the collapsible layer, depending on the severity and project sensitivity. 10.2.2 Eagle Valley Evaporite Bedrock The Eagle Valley Formation evaporite bedrock consists of gypsum, anhydrite, and locally halite -rich strata interbedded with weaker clastic soils and is associated with significant geotechnical risk due to its solubility and variable behavior. Dissolution of evaporite minerals can create subsurface voids, karst features, and irregular rock profiles that lead to differential settlement or sudden collapse, while hydration of anhydrite to gypsum may cause localized heave. Groundwater conditions play a critical role, as fluctuations can accelerate dissolution and reduce material strength over time. In geotechnical design, careful site characterization (often including supplemental methods beyond conventional borings), conservative foundation selection, the use of deep foundations, and strict groundwater and surface water control are essential to mitigate long-term performance risks. 10.2.3 Seismic Considerations The soil types present onsite are classified as Type D according to the 2021 IBC (ASCE 7, Chapter 20), based on penetration tests and CMT's experience. Additional geophysical studies are necessary to justify a different site classification. 11. FOUNDATION RECOMMENDATIONS 11.2 DRILLED PIERS A concrete ring foundation supporting a welded steel shell was initially considered; however, a mat foundation supported by drilled piers is considered more suitable for the proposed ground -level storage tank. The mat foundation is designed to accommodate the specific tank geometry and loading conditions and functions to support the tank shell while transferring loads from the foundation, tank, and contained water to the drilled piers. The proposed foundation system should consist of straight - shaft drilled piers designed in accordance with the following recommendations: a) Dead load plus full live load of the tank and its foundation should be used for pier sizing. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 11 CMT TECHNICAL SERVICES - COLORADO b) A 6 inch compacted granular leveling layer over 6 inch compacted structural fill is recommended beneath the mat pier cap to improve uniformity of support, by using CDOT Class 1 Structural Fill or Class 5 aggregate base course, well -graded granular material (e.g., minus 3/4 inch crushed rock) compacted to specifications. c) Piers will be drilled after the completion of the leveling layer. d) Depth of wetting zone below ground surface assumed for design is 24 feet. e) Maximum allowable end bearing pressure of 20,000 psf in dense gravel (blow counts of 50 blows per 6 inches or denser). f) No side shear shall be used to resist downward axial load (compression load) for the pier in natural soil or manmade fill. g) Allowable side shear of 2,000 psf for the portion of pier in dense gravel. h) Minimum dead load pressure is assumed to be zero. i) The soft clay with silt fill below and above the gravel layers will continue to settle. The portion of the piers in the clay layer will experience downdrag. The design of piers should account for downdrag on the piers from the clay with silt layer. CMT recommends the downdrag be calculated for the upper gravel layer._The downdrag should be calculated as a friction force using 440 psf. j) Piers should be reinforced their full length to resist tension forces. k) Piers should have a center -to -center spacing of at least 3 pier diameters when designing for vertical loading conditions or be designed as a group. 1) Piers aligned in the direction of lateral forces should have center -to -center spacing of at least 6 pier diameters. m) Piers shall have a minimum diameter of 18 inches. n) Piers shall have a minimum length of 30 feet below the mat pier cap. o) It is anticipated casing will be needed for most of the drilled shafts Casing of a portion of the drilled shafts may be necessary to permit proper cleaning and observation prior to concrete placement because of potential influx of groundwater and/or caving. Concrete should not be placed by freefall through more than 3 inches of water. If more than 3 inches of water is present at the base of the shaft, proper tremie techniques shall be utilized to place concrete from the bottom of the shaft or the water shall be removed. Drilled shafts are not allowed to remain open overnight. p) Difficult drilling may be encountered in the dense gravel and boulders. Use of coring equipment may be required. Pier penetration may not be decreased unless acceptable by the project structural and geotechnical engineers. q) Concrete for each pier should be formed at the top of the pier, if necessary, to achieve a uniform. diameter at the top of the pier. Excess concrete or overpour resulting in enlargement of the pier shall be removed. r) Proper concrete mixture design for drilled shafts varies with the design stress intensity, anticipated concrete placement procedures, and spacing of the reinforcement. It is recommended current design and construction procedures outlined by the ACI and the International ADSC be followed. Per these guidelines, current practice is to use a concrete mixture design slump in the range of 5 to 7 inches if casing is to be utilized or the shaft is heavily reinforced. A design slump in the range of 7 to 9 inches with 3/4 inch maximum 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 12 CMT TECHNICAL SERVICES - COLORADO size aggregate is recommended if concrete is to be placed by tremie or pumping methods. Additional recommendations as outlined by ACI and ADCS should also be followed. s) Pier drilling should be observed by a CMT representative in an effort to confirm actual subsurface conditions are consistent with those presented in this study. If conditions deviate significantly, recommendations may need to be modified. 12. LATERAL EARTH PRESSURES 12.1 FOUNDATION WALLS Lateral pressures on walls depend on the type of wall, hydrostatic pressure behind the wall, type of backfill material, and allowable wall movements. Where anticipated wall movements are greater than 0.5% of the wall height, lateral earth pressures can be estimated for an "active" condition. Where anticipated wall movement is less than approximately 0.5% of the wall height or wall movement is constrained, lateral earth pressures should be estimated for an "at rest" condition. Recommended lateral earth pressures for onsite material are provided in Table 12.1. The recommended values for lateral earth pressures provided in Table 12.1 are given in terms of an equivalent unit Weight. The equivalent unit weight multiplied by the depth below the top of the ground surface is the horizontal pressure against the wall at that depth. The resulting pressure distribution is a triangular shape. These soil pressures are for horizontal backfill with no surcharge loading or hydrostatic pressures. If these criteria cannot be met, CMT should be contacted for additional criteria. CMT understands resistance to lateral loading for footing foundations may be a concern, particularly for the structural fill be placed below the tank. The unfactored or ultimate coefficients of sliding resistance between concrete and bearing soils are provided in Table 12.1. TABLE 12.1. Lateral Earth Pressures and Coefficients of Sliding Resistance for Backfill. Backfill Material Type Equivalent Unit Weight Coefficient of Sliding Resistance Active At Rest Passive Structural Fill 40 60 330 0.45 13. EXCAVATIONS Conventional earthmoving equipment should be adequate to excavate the onsite soil. Excavations should be properly sloped and/or braced, and local and federal safety codes observed. Slopes and other areas void of vegetation should be protected against erosion. If temporary shoring is required, a contractor specializing in design and construction of shoring should be contacted. It is the contractor's responsibility to provide safe working conditions and comply with the regulations in OSHA Standards -Excavations, 29 CFR Part 1926. The following guidelines are provided for planning purposes. Sloping and shoring requirements must be evaluated at the time of construction by the contractor's competent person as defined by OSHA. The geotechnical engineer is NOT the contractor's "competent person" in any circumstance, including but not limited to, by way of default or delegation. OSHA classifications for various material types and the steepest allowable slope configuration corresponding to those classifications are shown in Table 13.1. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 13 CMT TECHNICAL SERVICES - COLORADO TABLE 13.1. Allowable Slope Configuration for Onsite Material Material Type OSHA Classification Steepest Allowable Slope Configuration* Clay with silt Type B 1:1 Gravel Type C 1-1/2:1 ,units horizontal to units vertical. I he values shown apply to excavation less than 20 feet in height. Conditions can change and evaluation is the contractor's responsibility. The classifications and slope configurations in Table 13.1 assume excavations are above the groundwater table, there is no standing water in the excavations, and there is no seepage from the slope into the excavations, unless otherwise specified. The above classifications and slope configurations assume the material in the excavations is not fractured, adversely bedded, jointed, nor left open to desiccate, crack, or slough, and are protected from surface runoff. There are other considerations regarding allowable slope configurations the contractor is responsible for, including proximity of equipment, stockpiles, and other surcharge loads to the excavation. The contractor's competent person is responsible for decisions regarding slope configuration and safety conditions for excavations. Excavations should not undermine existing foundation systems of structures or infrastructure unless they are adequately protected. At a minimum, new excavations should not intersect a line drawn using the steepest allowable slope configuration from Table 13.1 down and away from the bottom edge of the existing foundation systems or bottom edge of infrastructure. If this condition cannot be met, shoring or staged excavations may be required. If shoring is required, a condition survey of the adjacent structures is recommended before construction starts and upon completion of construction. In CMT's experience, condition surveys include, but may not be limited to, photographs of distress to adjacent structures. Permanent slopes should be no steeper than 2:1 and revegetated or otherwise protected from erosion. 14. STRUCTURAL FILL/BACKFILL SOIL Where fill/backfill soil is necessary, the suitable onsite inorganic soil may be used. At this site, unsuitable material is defined as topsoil, organics, trash, ash, frozen material, hard lumps and clods, claystone, and particles larger than 3 inches. Existing onsite fill material and sand soils can be reused for structural fill/backfill, provided they are free of unsuitable material. If unsuitable material is encountered in the existing fill, it must be removed before the existing fill can be reused as fill/backfill. Recommendations for fill/backfill placement are: a) Fill/backfill material should be placed in loose lifts and compacted in accordance with Table 14.1. b) Maximum loose lift thickness shall be 9 inches, depending on the type of equipment used to apply compactive effort and shall be reduced if the specified compaction cannot be obtained with the equipment used. c) Fill/backfill should not be placed if material is frozen or if the placement surface is frozen. d) Fill/backfill material should be placed and spread in horizontal lifts of uniform thickness in a manner that avoids segregation. e) Placement surface should be kept free of standing water, debris, and unsuitable material during placement and compaction of fill/backfill material. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 14 CMT TECHNICAL SERVICES - COLORADO f) Fill/backfill maximum allowable particle size is 3 inches. Do not incorporate oversize material in the fill/backfill that is incapable of being broken down by the equipment and methods being employed to process and compact the fill/backfill. Process and compact material in the lift, as necessary, to produce the specified fill/backfill characteristics. If oversize particles remain in the lift after processing and compacting, remove oversize material to produce a fill/backfill within specified requirements. TART F 1 A [ mmnartinn CnPrifiratinnc Material Moisture Relative Fill Type AASHTO Content Compaction Compaction Location General Classification %) (0/01 Standard Granular 0% to Standard Proctor Structural fill material with A-2-6 A-2-7 of OMC >95%* (ASTM D698 plastic fines I I AASHTO T99 * If a fill thickness greater than 15 feet is planned, additional requirements may apply. 14.1 IMPORT FILL Material imported for structural fill should be tested and approved- for use onsite by the -project geotechnical engineer prior to hauling to the site. Proctor and classification tests should be conducted to determine if the fill meets required specifications. Fill material should be well graded, meeting the specifications in Table 14.2. CDOT Class 1 Structural Fill or Class 5 aggregate base course below mat footing should meet specifications in Table 14.3 TABLE 15.2. Imnert Fill Specifications Soil Parameter Specification Maximum particle size 1 inch Percent finer than no. 200 sieve Less than 20% Liquid limit less than 35% Plasticity index less than 20% Swell potential under anticipated loads less than 1%* * Upon inundation, when remolded to 97% maximum dry density at 11/b below the optimum moisture content per ASTM D698 at a surcharge pressure of 100 psf. TABLE 15.3 CDOT Class 1 Structural Fill or Class 5 ABC Specifications Soil Parameter Specification* Maximum particle size 2 inch Percent of 2 inch aggregate 100% Percent finer than no. 4 sieve 30% to 100% Percent finer than no. 50 sieve 10% to 60% Percent finer than no. 200 sieve 5% to 20% Liquid limit less than 35 Plasticity index less than 6 *Per CDOT Table 703-12 Classification for Aggregate Base Course Due to the quantity of the gravel in the onsite material, placement shall be controlled via a method specification (i.e., through observation). Material shall be placed in loose lifts not exceeding 12 inches thick. Each lift shall be compacted using vibratory methods. The vibratory equipment must be capable of exerting a minimum of 15,000 pounds of centrifugal force. The gravel particles shall be in a surface 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 15 CMT TECHNICAL SERVICES - COLORADO saturated condition. Each lift shall be rolled with a minimum of four passes or until no visible compaction of the layer is observed, whichever is greater. 15. SUBSURFACE DRAINAGE Groundwater was measured at a depth of 24 feet below the existing ground surface at the tank location during drilling and was not observed 10 to 11 days after drilling. The groundwater depth is greater than 3 feet from the bottom of the foundation of the proposed tank at the time of this study. Since the structure has no below grade construction, a subsurface drain is not considered necessary for this tank. If below grade construction is considered for this tank, CMT should be notified to review this recommendation. 16. SURFACE DRAINAGE Good drainage and surface water management are important. Performance of site improvements, such as foundations and hardscape are often adversely affected by failing to establish and/or maintain good site drainage. Grades must be adjusted to provide positive drainage away from the tank and other site improvements during construction and maintained throughout the life_ of the proposed facility. The following drainage precautions are recommended: a) Ground surface around the tank foundation should be sloped to drain away from the tank. At the completion of construction, CMT recommends a continuous slope away from the tank foundation of 12 inches in the first 10 feet (10%), where site constraints permit. Maximum grades practical should be used for paving and flatwork to prevent areas where water can pond. b) Ground surface should be sloped so water will not pond between or adjacent to tank foundation and other site improvements. Other improvements should not block, impede, or otherwise disrupt surface runoff. Use of chases and weep holes to promote drainage is encouraged. c) Drainage swales should be located as far away from the tank foundation as practicable. d) If site constraints do not allow for the recommended slopes, the project civil engineer shall provide a method for drainage equivalent to the recommendations herein. Water should not be allowed to pond adjacent to or near foundations, flatwork, or other improvements. e) The project civil engineer shall perform measurements to document positive drainage, as described in this section or as otherwise designed by the project civil engineer is achieved. Maintenance of surface drainage is imperative subsequent to construction and is the responsibility of the owner and/or tenant. 17. SOIL CHEMICAL TESTING 17.1 SULFATE EXPOSURE A water-soluble sulfate content of 0.00% were measured on samples of clay. The result is summarized in Appendix B. The PCA publication titled Design and Control of Concrete Mixtures 2002 and the ACI publication titled Building Code Requirements for Structural Concrete and Commentary consider this range SO for water soluble sulfate exposure. Recommendations for concrete which will be in contact with or within 6 inches of the clay are shown in Table 17.1. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 16 CMT TECHNICAL SERVICES - COLORADO TART F 171 Tnfnrmatinn frnm ACT -119-138 - Table 4.3.1 Water Soluble Sulfates j Exposure, Maximum Minimum Pc, Cementitious materialst es Calcium Chloride ASTM ASTM ASTM Class w cm *(psi) C150 C595 C1157 Admixture <0.10 SO N/A 2,500 No type No type No type No restriction restriction I restriction I restriction *For lightweight concrete, see ACI 318-08 4.1.2. tAlternative combinations of cementitious materials listed in Table 4.3.1 shall be permitted when tested for sulfate resistance and meeting the criteria in ACI 318-08 4.5.1. *For seawater exposure, other types of Portland cements with tricalcium aluminate (CA) contents up to 10 percent are permitted if the w/cm does not exceed 0.40. Refer to ACI 318-08 R4.3.1 for further interpretation of this table. 17.2 SOIL CORROSIVITY Results of soil chemical testing are presented in Table 17.2. Table A.1 of the AWWA Standard for Polyethylene Encasement for Ductile Iron Pipe Systems assigns point values to the results of soil chemical tests. If the sum of the points assigned to a given sample is 10 points or greater, AWWA considers the soil corrosive to ductile iron pipe, and states protection is needed. CMT recommends manufacturers be consulted by the design team prior to selection and installation of products that will be in contact with the onsite material. Chemical Test Test Results Chloride content m /L 8.8 H 7.9 Laboratory resistive ohm -cm 2,500 TA BLE 17.2. Summary of Soil Chemical Test Results 18. GEOTECHNICAL RISK The concept of risk is an important aspect of geotechnical studies. The primary reason for this is the analytical methods used by geotechnical engineers are typically empirical and must be tempered by engineering judgment and experience. The solutions or recommendations presented in a geotechnical study should not be considered risk free and, more importantly, are not a guarantee the interaction between the soil and the proposed construction will perform as predicted, desired, or intended. The engineering recommendations presented in the preceding sections constitute CMT's evaluation of those measures necessary to help the structure/pavement perform in a satisfactory manner based on the information generated during this study/evaluation, training, and experience in working with these conditions. 19. LIMITATIONS This document has been prepared as an instrument of service for the exclusive use of Ranch at Roaring Fork HOA for the specific application to the project as discussed herein and has been prepared in accordance with geotechnical engineering practices typically accepted in the state of Colorado at the date of its preparation. No warranties, either expressed or implied, are intended or made. This document should not be assumed to contain information for other parties or other purposes. The findings of this study are valid as of the date of its preparation. Changes in the conditions of a 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 17 TA BLE 17.2. Summary of Soil Chemical Test Results 18. GEOTECHNICAL RISK The concept of risk is an important aspect of geotechnical studies. The primary reason for this is the analytical methods used by geotechnical engineers are typically empirical and must be tempered by engineering judgment and experience. The solutions or recommendations presented in a geotechnical study should not be considered risk free and, more importantly, are not a guarantee the interaction between the soil and the proposed construction will perform as predicted, desired, or intended. The engineering recommendations presented in the preceding sections constitute CMT's evaluation of those measures necessary to help the structure/pavement perform in a satisfactory manner based on the information generated during this study/evaluation, training, and experience in working with these conditions. 19. LIMITATIONS This document has been prepared as an instrument of service for the exclusive use of Ranch at Roaring Fork HOA for the specific application to the project as discussed herein and has been prepared in accordance with geotechnical engineering practices typically accepted in the state of Colorado at the date of its preparation. No warranties, either expressed or implied, are intended or made. This document should not be assumed to contain information for other parties or other purposes. The findings of this study are valid as of the date of its preparation. Changes in the conditions of a 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 17 CMT TECHNICAL SERVICES - COLORADO property can occur with the passage of time, whether due to natural processes or the works of people on this or adjacent properties. Standards of practice evolve in engineering and changes in applicable or appropriate standards may occur, whether a result from legislation or the broadening of knowledge. Accordingly, the findings of this study may be invalidated wholly or partially by changes outside of CMT's control; therefore, this study is subject to review and should not be relied upon without such review after a period of 3 years. In the event changes, including, but not limited to, the nature, type, design, size, elevation, or location of the project or project elements as outlined in this report, are made, the conclusions and recommendations contained in this report shall not be considered valid unless CMT reviews the changes and either confirms or modifies the conclusions of this report in writing. CMT should be retained to review final plans and specifications that are developed for proposed construction to judge whether the recommendations presented in this report and addenda have been appropriately interpreted and incorporated in the project plans and specifications as intended. The exploration locations for this study were selected to obtain a depiction of underground conditions for design purposes and these locations are often modified based on accessibility and the presence of underground or overhead utility conflicts. Variations from the soil conditions encountered are possible. These variations may necessitate modifications to CMT's design recommendations; therefore, CMT should be retained to observe subsurface conditions, once exposed, to evaluate whether they are consistent with the conditions encountered during CMT's exploration and that the recommendations of this study remain valid. If parties other than CMT perform these observations and judgements, they must accept responsibility to judge whether the recommendations in this report remain appropriate. CMT's scope of services for this report did not include either specifically, or by implication, an environmental assessment of the site or identification of contaminated or hazardous material or conditions. Additionally, none of the services performed in connection with this study were designed or conducted for the purpose of mold prevention. Proper implementation of the recommendations conveyed in this report will not, of itself, be enough to prevent mold from growing in or on the structures involved. At a minimum, CMT should be retained during construction to observe and/or test: • completed excavations. • placement and compaction of fill. • pier/pile drilling operations. • proposed import or onsite fill material. • placement and compaction of pavement subgrade, subbase, base course and asphalt. CMT offers many other construction observations, materials engineering, and testing services and can be contacted to discuss further. 501666 Water Tank at Ranch at Roaring Fork Report 05.14.26 18 CMTTECHNICALsE R V I C E FIGURES CMTTECHNICALsE R V I C E APPENDIX A Field Exploration CMT TECHNICAL SERVICES - COLORADO FIELD EXPLORATION Samples of the subsoil were obtained using modified California and standard split spoon samplers. Modified California and standard split spoon samplers were driven into the soil by dropping a 140 pound hammer through a free fall of 30 inches. The modified California sampler is a 2-1/2 inch outside diameter by 2 inch inside diameter device lined with brass tubes. The split spoon sampler is a 2 inch outside diameter by 1-3/8 inch inside diameter device. The procedure to drive these samplers into the soil and to record the number of blows required to drive the sampler into the soil is known as a penetration test. The number of blows required for the sampler to penetrate 12 inches gives an indication of the relative stiffness of cohesive soil, relative density of non -cohesive soil, and relative hardness of sedimentary bedrock material encountered. Bulk samples were collected from cuttings generated during drilling. Locations of sampling and penetration test results are presented on the boring logs contained in this appendix. CMT installed temporary monitoring wells in Boring B-1A. Groundwater level measurements within the temporary monitoring wells are included in Table 9.1. Groundwater can be expected to fluctuate with variations in seasons, drainage, site vegetation, irrigation, or weather conditions. CMT installed inclinometers in Boring B-2 to measure slope movement. Inclinometer casing (2.75 inch diameter casing) was installed in Boring B-2 to the maximum depth drilled of 33 feet and the annular space was filled with grout. The casing installed has two sets of groves on the inside of the casing. The probe used to measure the change in inclination of the pipe has wheels that fit into the grooves and guide the probe along the casing. The inclinometer casing was placed so that one set of grooves was perpendicular to the slope (the A -Axis). The second set of grooves were parallel with slope (the B-Axis). Movement downhill was recorded as positive on the A -Axis and movement uphill was recorded as negative on the A -Axis. When looking downhill, movement to the right was recorded as positive on the B-Axis and movement to the left was recorded as negative on the B-Axis. Measurements of the change of inclination of the pipe will be made at regular intervals. 501666 Water Tank at Ranch at Roaring Fork Appendix A PROJECT NAME Ranch at Roaring Fork HOA PROJECT NUMBER 501666 B_ 1 BORING LOCATION 39.410444,-107.162339 BORING ELEVATION 6290 ft. DRILLING COMPANY/RIG HRL Drilling/3667 GP CMT REP. C. Whittington DRILLING METHOD 5.5 in. Diameter ODEX DATE STARTED 3/19/2026 HAMMER SYSTEM Automatic Hammer DATE COMPLETED 3/19/2026 Page 1 of 1 �r �F o G CL C V^. = a> 8 go 3 ELEVATION (ft) MATERIAL DESCRIPTION DEPTH (ft) p GRAVEL, poorly graded to clayey, in a silty clay matrix, slightly moist, light brown, granite chips. Increased clay at 4 Feet. 16279 5 i 11 :-III CLAY, with silt, with gravel, medium plasticity, soft to stiff, moist, reddish brown. III III ]II III —All 1 III III ill III 6270 2 Q GRAVEL poorly , p y graded, with cobbles and boulders, likely boulder, with sand, dense, very moist to wet, brown to gray. 2 Q _ 6265.7 24.3 Boring terminated at 24.3 feet LEGEND V WATER LEVEL AT TIME OF DRILLING �Z# WATER LEVEL # DAYS AFTER DRILLING �# DEPTH OF CAVE # DAYS AFTER DRILLING 1 DEPTH OF REFUSAL TECHNICAL T S E R V I C E S PROJECT NAME Ranch at Roaring Fork HOA PROJECT NUMBER 501666 B-1A BORING LOCATION 39.410653,-107.161977 BORING ELEVATION 6306.5 ft. DRILLING COMPANY/RIG HRL Drilling/3667 GP CMT REP. C. Whittington DRILLING METHOD 5.5 in. Diameter ODEX DATE STARTED 3/19/2026 HAMMER SYSTEM Automatic Hammer DATE COMPLETED 3/19/2026 Page 1 of 1 SAMPLEI t7 Yn'L O"IWn j� YJW OJ = n po Ste. O� W f7Woz. IV.I '� U �Z W 'v � 6 6a'Q6 W W G f 3 2 j RCF Y �f 7V1 F 7 C LL 6 V V1JVJ 1' W 3 ELEVATION (ft) MATERIAL DESCRIPTION DEPTH (ft) WELL DIAGRAM p O m z u z G c�7 vi J H n �• o v GRAVEL, poorly graded to clayey, in a Flush silty clay matrix, slightly moist, light mount brown, granite chips, (GP -GC, CL, A-4). with stickup 31/12 Increased clay at 4 feet. Bh PS Hite 14/12 10.7 2 30 68 25-15-10 5 -2" Dia. . — PVC 6293.5 13 CLAY, with silt, with gravel, medium ' I I plasticity, soft to very stiff, moist, �11 reddish brown, (CL-ML, A-4). -2 Dia. I I Slotted I I PVC III III III Il ill 6286.5 20 10/20 Q GRAVEL, poorly graded, with cobbles Silica and boulders, likely boulder, with sand, sand very dense, very moist to wet, brown to Q gray. 6282.2 24.3 Boring terminated at 24.3 feet 13/12 4/12 22/12 15.0 109.8 LEGEND 1 WATER LEVEL AT TIME OF DRILLING SPLIT SPOON —V# WATER LEVEL # DAYS AFTER DRILLING MODIFIED CALIFORNIA SAMPLER �# DEPTH OF CAVE # DAYS AFTER DRILLING BULK SAMPLE 1 DEPTH OF REFUSAL *Converted to monitoring well 23-17-6 1 1884/-0.1/NA CmTTECHNICA s PROJECT NAME Ranch at Roaring Fork HOA PROJECT NUMBER 501666 B_2 BORING LOCATION 39.410549,-107.162115 BORING ELEVATION 6298.6 ft. DRILLING COMPANY/RIG HRL Drilling/3667 GP CMT REP. C. Whittington DRILLING METHOD 5.5 in. Diameter ODEX DATE STARTED 3/19/2026 HAMMER SYSTEM Automatic Hammer DATE COMPLETED 3/19/2026 Page 1 of 1 SAMPLE W F2F W O rJVi 7 pV e c e ' C O Q% 3 x ELEVATION (ft) MATERIAL DESCRIPTION DEPTH (ft) tti o O m TH 99z �Z ;Cu w W 2 N LL p 6 d QC GRAVEL, poorly graded, in a silty sand matrix, medium dense to dense, dry, tan to light brown, (GP, A-1-a). - Q 34/12 1.4 67 24 9 NV-NP-NP Cl 5 24/12 Q Q 6289.6 9 GRAVEL, in a silty clay matrix, with sand, with cobbles and boulders, dry, reddish brown, (GC, A-4). 40/12 7.6 34 28 38 24-16-8 10 15 32/12 2 19/12 fi2n.6 21 — CLAY, sandy, medium plasticity, stiff, moist, brown, (CL, A-4). — 25 11/12 13.5 11 33 56 24-16-8 — 6271.6 27 Q GRAVEL, poorly graded, with cobbles and boulders, likely boulder, very dense, moist, brown to gray. Q 50 5 3 iQ 6265.6 33 Boring terminated at 33 feet LEGEND 1 WATER LEVEL AT TIME OF DRILLING SPLIT SPOON *Converted to inclinometer -'�7# WATER LEVEL # DAYS AFTER DRILLING BULK SAMPLE --►# DEPTH OF CAVE #DAYS AFTER DRILLING _ r E C -,` A!4 C A L 1 DEPTH OF REFUSAL S E R V I C E S CMTTECHNICALsE R V I C E APPENDIX B Laboratory Testing CMT TECHNICAL SERVICES - COLORADO LABORATORY TESTING Swell/consolidation testing was performed on samples collected using a modified California sampler to evaluate the effect of wetting and loading on the soil. The samples were loaded to approximate overburden pressure considering a unit weight of 100 psf, per foot of soil then inundated with water. 501666 Water Tank at Ranch at Roaring Fork Appendix B 1 CfIl T r e I N N i c A L SUMMARY OF LABORATORY TEST RESULTS s rE R v t e Et s water Tank at Ranch at Roaring Fork, Colorado ,, cn—c Sam a Location Natural Dry Density ( Natural Mouiture Content (%) Soluble Sulfate (%) PH Soluble Chloride (/L Resistivity (ohm--) Gradation Atte Limits Swell Consolidation Material Type Boring Depth (feet) Graver (%1 Sand rasa) Silt/ Clay 04 Liquid :. (%) Plastic Limtt of Plasticity Index fold Inundation Pressure Volume Chang: wn Swell Pressure fpsn B-1A 4 107 0 0 79 R R 2.500 2 30 fie ?5 5 11, C1AV sand, reddish brown (CL A-4) R-1A 1n9R 15.0 2 32 66 7a 1' RR4 -01 NA CLAY silty.sand hrown CL-ML A-41 9-2 2 L4 67 24 9 NV NP NP GRAVEL with silt and sand brown. (GP A-1-a) R-2 0 16 34 29 38 74 :6 a GRAVEL, davev. with sand reddish hrown fGC. A-41 9-3 14 13.5 11 1 33 56 74 a d 1 CLAY. sandy hrown.(CL A-4) -o water ram,at — at aaanna Fork Sun,mary err tat—ta,y— aesmts E:Mmr TECHNICAL S E R V I C E S SWELL/CONSOLIDATION PLOT 3 2 1 0 c1 �a 0 -2 o m 11 le Inundated i 3 � Compression Upon Wetting -4 -5 -6 -7 10 100 1,000 10,000 100,000 Applied Pressure (ps17 Sample Dry Moisture Inundation Volume Swell Sample Depth Density Content Pressure Change Pressure Location (ft) Visual Description of Sample (pcf) (%) (psf) (%) (psf) B-1A 19 CLAY, with silt, reddish brown 109.8 15.0 1,884 -0.1 NA Project Number Project Name Lab ID Number 501666 Water Tank at Ranch at Roaring Fork 262345 Colorado Regional Office: 7108 South Alton Way, Building B • Centennial, Colorado 80112 Rev. 04/15/22 Swell 262345 Phone 303-220-0300 • www.cmttechnicalservices.com Page 1 of 1