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Home My WebLink AboutMONTAVA - PHASE E TOWN CENTER - BDR220003 - MONTAVA SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT (2)SUPPLEMENTAL SUBSURFACE EXPLORATION REPORT MONTAVA DEVELOPMENT – APPROXIMATE 800 ACRE MIXED USE DEVELOPMENT SOUTH OF LCR 52 AND WEST OF ANHEUSER BUSCH FORT COLLINS, LARIMER COUNTY, COLORADO EEC PROJECT NO. 1172058 Prepared for: HF2M Colorado 430 N College Avenue, Suite 410 Fort Collins, Colorado 80524 Attn: Mr. Max Moss (Max@hf2m.com) Prepared by: Earth Engineering Consultants, LLC 4396 Greenfield Drive Windsor, Colorado 80550 4396 GREENFIELD DRIVE W INDSOR, COLORADO 80550 (970) 545-3908 FAX (970) 663-0282 May 20, 2022 HF2M Colorado 430 N College Avenue, Suite 410 Fort Collins, Colorado 80524 Attn: Mr. Max Moss (Max@hf2m.com) Re: Supplemental Subsurface Exploration Report Montava Development – Approximate 800-Acre Mixed Use Development South of LCR 52 and West of Anheuser Busch Fort Collins, Larimer County, Colorado EEC Project No. 1172058 Mr. Moss: Enclosed, herewith, are the results of the supplemental subsurface exploration completed by Earth Engineering Consultants, LLC (EEC) personnel for the referenced project. For this supplemental subsurface exploration, a total of eleven (11) soil borings were drilled on April 27 and 29, 2022, at the approximate locations as indicated on the enclosed Figures 1 and 2: Boring Location Diagrams included with this report. The supplemental borings were extended to depths of approximately 15 to 25 feet below existing site grades. It should be noted, that in 2017, EEC conducted a preliminary subsurface exploration for the site by drilling a series of thirty (30) test borings throughout the property and preparing a preliminary report with our findings. For further information and preliminary recommendations based on the 2017 subsurface exploration, please refer to our Preliminary Subsurface Exploration Report dated October 2, 2017, EEC Project No. 1172058. On January 11, 2022, we were requested to provide an estimate to perform a supplemental subsurface exploration based on the “Subsurface Investigation Civil Engineering Requirements” letter prepared by Martin/Martin dated November 1, 2021 to provide recommendations associated with the various culvert crossing structures, headwall/wingwall structures, grade separated crossing structure, and various manhole structures planned for construction at locations as presented on Figure 2 in the appendix of this report. To develop supplemental subsurface information for the proposed development, as requested by Martin/Martin and TST, EEC personnel advanced a total of eleven (11) soil borings, ten (10) as requested by Martin/Martin, and one (1) as requested by TST in the development area. Individual boring logs and results of laboratory testing are included as a part of the attached report. This supplemental exploration was completed in general accordance with our proposal dated January 11, 2022. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 3 cc: TST, Inc. – Consulting Engineers Don Taranto (dtaranto@tstinc.com) Jonathan Sweet (jsweet@tstinc.com) Martin/Martin Jeff A. White (JWHITE@martinmartin.com) Deborah Alvarado (DAlvarado@martinmartin.com) Stewart Environmental Consultants Dave Stewart (dave.stewart@stewartenv.com) SUPPLEMENTAL SUBSURFACE EXPLORATION REPORT MONTAVA DEVELOPMENT-APPROXIMATE 800 ACRE DEVELOPMENT SOUTH OF LCR 52 AND WEST OF ANHEUSER BUSCH FORT COLLINS, COLORADO EEC PROJECT NO. 1172058 May 20, 2022 INTRODUCTION The supplemental subsurface exploration for the proposed 800-acre mixed use development located southeast of Larimer County Road (LCR) 52 and LCR 50E in Fort Collins, Colorado has been completed. For this supplemental subsurface exploration, a total of eleven (11) soil borings were drilled on April 27, and 29, 2022, at the approximate locations as indicated on the enclosed Figures 1 and 2: Boring Location Diagrams included with this report. The supplemental borings were extended to depths of approximately 15 to 25 feet below existing site grades at pre-selected locations across the proposed development property to obtain information on existing subsurface conditions. On January 11, 2022, we were requested to provide an estimate to perform a supplemental subsurface exploration based on the “Subsurface Investigation Civil Engineering Requirements” letter prepared by Martin/Martin dated November 1, 2021 to provide recommendations associated with the various culvert crossing structures, headwall/wingwall structures, grade separated crossing structure, and various manhole structures planned for construction at locations as presented on Figure 2 in the appendix of this report. To develop supplemental subsurface information for the proposed development, as requested by Martin/Martin and TST, EEC personnel advanced a total of eleven (11) soil borings, ten (10) as requested by Martin/Martin, and one (1) as requested by TST in the development area. Individual boring logs and results of laboratory testing are included as a part of the attached report. This supplemental exploration was completed in general accordance with our proposal dated January 11, 2022. The purpose of this supplemental report is to describe the subsurface conditions encountered in the requested boring locations by Martin/Martin and TST Inc.- Consulting Engineers, analyze and evaluate the test data and provide supplemental geotechnical recommendations concerning site development including foundations/site preparation for the various culvert, grade crossing, wingwall and manhole structures. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 2 EXPLORATION AND TESTING PROCEDURES The boring locations were determined by Martin/Martin and TST and were established in the field by a representative of Earth Engineering Consultants, LLC (EEC) by pacing and estimating angles from identifiable site features. Ground surface elevations were obtained at each boring location by utilizing the latitude and longitude coordinates of the project’s Google Earth image and estimating the elevation accordingly. The boring locations and estimated ground surface elevations should be considered accurate only to the degree implied by the methods used to make the field measurements. Photographs of the site taken at the time of drilling are provided with this report. The borings were performed using a truck-mounted CME-55 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal diameter continuous flight augers. Samples of the subsurface materials encountered were obtained using split-barrel and California barrel sampling procedures in general accordance with ASTM Specifications D1586 and D3550, respectively. In the split-barrel and California barrel sampling procedures, standard sampling spoons are driven into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the samplers is recorded and is used to estimate the in-situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and hardness of weathered bedrock. In the California barrel sampling procedure, relatively intact samples are obtained in brass liners. All samples obtained in the field were sealed and returned to the laboratory for further examination, classification and testing. Laboratory moisture content tests were performed on each of the recovered samples. In addition, selected samples were tested for fines content and plasticity by washed sieve analysis and Atterberg limits tests. Swell/consolidation tests were completed on selected samples to evaluate the subgrade materials’ tendency to change volume with variation in moisture content and load. The quantity of water soluble sulfates was determined on select samples to evaluate the risk of sulfate attack on site concrete. Results of the outlined tests are indicated on the attached boring logs and summary sheets. As a part of the testing program, all samples were examined in the laboratory and classified in general accordance with the attached General Notes and the Unified Soil Classification System, based on the sample's texture and plasticity. The estimated group symbol for the Unified Soil Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 3 Classification System is shown on the boring logs and a brief description of that classification system is included with this report. SITE AND SUBSURFACE CONDITIONS The 800-acre development is located southeast of LCR 52 and LCR 50E in Fort Collins, Colorado. The project site is generally undeveloped farmland with a few existing structures scattered throughout. Surface water drainage across the site is generally to the south and to the east. Estimated relief across the site from northwest to southeast is approximately 25 to 30 feet (±). An EEC field engineer was on-site during supplemental drilling services to direct the drilling activities and evaluate the subsurface materials encountered. Field descriptions of the materials encountered were based on visual and tactual observation of disturbed samples and auger cuttings. The boring logs included with this report may contain modifications to the field logs based on results of laboratory testing and engineering evaluation. Based on results of field and laboratory evaluation, subsurface conditions can be generalized as follows. In summary, the subsurface soils encountered in the eleven (11) supplemental borings generally consisted of cohesive lean clay with varying amounts of sand subsoils, which extended to the underlying fine to course granular strata below and/or to the depths explored, approximately 15 to 25 feet below existing site grades, in the vicinity of supplemental borings S-4 through S-7 and S-11. The cohesive soils were generally medium stiff to very stiff and exhibited low to high swell potential at current moisture and density conditions. The lean clay with variable amounts of sand subsoils were underlain by sand/gravel with varying amounts of silt subsoils at depths of approximately 12 to 23 feet below existing site grades in the vicinity of supplemental borings S-1 through S-3, and S-8 through S-10. The sand/gravel subsoils extended to the depths explored, approximately 25 feet below existing site grades. The stratification boundaries indicated on the boring logs represent the approximate locations of changes in soil and rock types; in-situ, the transition of materials may be gradual and indistinct. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 4 GROUNDWATER CONDITIONS Observations were made while drilling and after the completion of drilling to detect the presence and level of groundwater. Groundwater was observed in the majority of the supplemental test borings at depths ranging from approximately 10 to 23 feet below existing site grades. Groundwater was not initially encountered in borings S-5 and S-6 to maximum depths of exploration, approximately 25 feet below site grades. A field/hand slotted 1-1/2-inch diameter PVC piezometer was installed in one of our previously drilled borings in 2017 and included herein as Boring B-6A, as well as in our supplemental Boring S-11. Subsequent measurements on May 6, 2022 indicated groundwater in borings B-6A and S-11 at depths of approximately 5 to 12-1/2 feet below site grades, respectively. A groundwater measurement was also obtained on May 6, 2022 from the previously completed boring B-5 in 2017 and was recorded at an approximate depth of 3 feet 4 inches below existing site grades, (a copy of our previously completed boring B-5 is also included in the Appendix of this report). The remaining supplemental borings were backfilled; therefore, subsequent groundwater measurements were not obtained. Groundwater measurements provided with this report are indicative of groundwater levels at the locations and at the time the borings/groundwater measurements were completed. Fluctuations in groundwater levels can occur over time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. Zones of perched and/or trapped groundwater may occur at times in more permeable zones in the subgrade soils. The location and amount of perched water is dependent upon several factors, including hydrologic conditions, type of site development, irrigation demands on or adjacent to the site, seasonal and weather conditions as well as when the canal is active. The observations provided in this report represent groundwater conditions at the time of the field exploration, and may not be indicative of other times, or at other locations. ANALYSIS AND RECOMMENDATIONS Swell – Consolidation Test Results The swell-consolidation test is performed to evaluate the swell, collapse, and consolidation potential of soils to assist in determining foundation, floor slab and pavement design criteria. In this test, relatively undisturbed/in-tact samples obtained directly from the ring barrel sampler are placed in a laboratory Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 5 apparatus and inundated with water under a predetermined load. The swell-index is the resulting amount of swell or collapse, expressed as a percent of the sample’s initial/preload thickness. All samples are inundated with water and monitored for swell and consolidation. After the inundation period, additional incremental loads are applied to evaluate the swell pressure and consolidation characteristics. For this assessment, we conducted thirteen (13) swell-consolidation tests on relatively intact soil samples obtained at various intervals/depths on the site. The swell index values for the in-situ soil samples analyzed revealed low to high swell characteristics as indicated on the attached swell test summaries. The (+) test results indicate the materials swell potential characteristics while the (-) test results indicate the materials collapse/consolidation potential characteristics when inundated with water. The following table summarizes the swell-consolidation laboratory test results for samples obtained during our field explorations for the subject site. TABLE I – Laboratory Swell-Consolidation Test Results No of Samples Tested Pre-Load / Inundation Pressure, PSF Description of Material In-Situ Characteristics Range of Swell – Index Test Results Range of Moisture Contents, % Range of Dry Densities, PCF Low End, % High End, % Low End, PCF High End, PCF Low End (+/-) % High End, (+/-) % 11 500 Lean Clay with Sand / Sandy Lean Clay 8.4 19.8 99.2 128.5 (-) 0.5 (+) 7.3 2 1000 Sandy Lean Clay 15.0 19.3 110.5 112.7 (-) 1.1 (-) 0.3 Colorado Association of Geotechnical Engineers (CAGE) uses the following information to provide uniformity in terminology between geotechnical engineers to provide a relative correlation of slab performance risk to measured swell. “The representative percent swell values are not necessarily measured values; rather, they are a judgment of the swell of the soil and/or bedrock profile likely to influence slab performance.” Geotechnical engineers use this information to also evaluate the swell potential risks for foundation performance based on the risk categories. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 6 TABLE II - Recommended Representative Swell Potential Descriptions and Corresponding Slab Performance Risk Categories Slab Performance Risk Category Representative Percent Swell (500 psf Surcharge) Representative Percent Swell (1000 psf Surcharge) Low 0 to < 3 0 < 2 Moderate 3 to < 5 2 to < 4 High 5 to < 8 4 to < 6 Very High > 8 > 6 Based on the laboratory test results, the in-situ samples analyzed for this project were within the low to high range, with an occasional sample indicating a slight tendency to hydro-compact when inundated with water and increased loads were applied. General Considerations The site appears suitable for the proposed development/construction of the various culvert, grade crossing, wingwall and manhole structures, based on the subsurface conditions; however due to the low to high swell potential characteristics as well as a slight tendency to hydro-compact, ground modification will be required at various locations. At this time we do not have proposed foundation/mat slab elevations for these various elements; therefore we are providing foundation preparation recommendations based on three (3) scenarios; 1) in areas in which the foundation bearing stratum consists of low to moderate to high swell potential cohesive subsoils; 2) in areas in which the foundation bearing stratum consists of soft compressible / slight tendency to hydro- compact cohesive subsoils, and 3) in areas in which the foundation bearing stratum consists of medium dense to dense fine to course granular subsoils. It is anticipated that excavations for the proposed structures could be accomplished with conventional earthmoving equipment. Site Preparation All existing vegetation and/or topsoil should be removed from beneath site fills, roadways and structure, along with previous construction debris, where applicable. Care should be taken to ensure that the foundations associated with any of the existing structures in the improvement areas are completely removed. Stripping depths should be expected to vary, depending, in part, on past agricultural activities as well as the presence of any existing in-place structures, and associated fill/backfill material which may exist, but were unknown at the time of this report. In addition, any Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 7 soft/loose native soils or any existing fill materials without documentation of controlled fill placement should be removed from improvement and/or new improvement areas. After stripping and completing all cuts, any over excavation, and prior to placement of any fill, or foundations for the various structures, we recommend the exposed soils be scarified to a depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material's maximum dry density as determined in accordance with ASTM Specification D698, the standard Proctor procedure. The moisture content of the scarified materials should be adjusted to be within a range of 2% of standard Proctor optimum moisture at the time of compaction. In general, fill materials required to develop the improvement areas should consist of approved, low- volume change materials which are free from organic matter and debris. The site lean clay soils with low swell potential and/or the underlying sand/gravel soils could be used as fill in these areas. The moderate to high swell potential cohesive subsoils will require reworking to a proper moisture content and recompacted as discussed. We recommend the fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and compacted to at least 95% of the material’s maximum dry density as determined in accordance with the standard Proctor procedure. The moisture content of predominately clay soils should be adjusted to be within the range of ± 2% of optimum moisture content at the time of placement. Granular soil should be adjusted to a workable moisture content. Care should be taken after preparation of the subgrades to avoid disturbing the subgrade materials. Positive drainage should be developed away from structures and across and away from pavement edges to avoid wetting of subgrade materials. Subgrade materials allowed to become wetted subsequent to construction of the various structures and/or pavements can result in unacceptable performance of those improvements. Areas of greater fills overlying areas with soft/compressible subsoils, especially within the deeper utility alignments, may experience settlement due to the soft/compressible subsoils below and within the zone of placed fill materials. Settlement on the order of 1-inch or more per each 10 feet of fill depth would be estimated. The rate of settlement will be dependent on the type of fill material placed and construction methods. Granular soils will consolidate essentially immediately upon placement of overlying loads. Cohesive soils will consolidate at a slower rate. Preloading and/or surcharging the fill areas could be considered to induce additional settlement in these areas prior to Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 8 construction of improvements in or on the fills. Unless positive steps are taken to pre-consolidate the fill materials and/or underlying soft subgrades, special care will be needed for construction of improvements supported on or within these areas. Foundation Systems – General Considerations The following foundation system was evaluated for use for the proposed structures as discussed herein.  Based on the subsoils observed at the supplemental borings, we believe the various structures could be supported on conventional type spread footings/mat slab foundations bearing on a zone of approved, placed and compacted fill material when the underlying subsoils are cohesive materials, or directly on the underlying fine to course medium dense to dense granular subsoils encountered beneath the cohesive zone. Foundation – Conventional Type Spread Footing / Mat Slab System As previously stated, at this time we do not have proposed foundation/mat slab elevations for these various elements; therefore, we are providing foundation preparation recommendations based on three (3) scenarios; 1) in areas in which the foundation bearing stratum consists of low to moderate to high swell potential cohesive subsoils; 2) in areas in which the foundation bearing stratum consists of soft compressible / slight tendency to hydro-compact cohesive subsoils, and 3) in areas in which the foundation bearing stratum consists of medium dense to dense fine to course granular subsoils. Scenarios 1 and 2: Due to the low to moderate to high swell potential subsoils across portions of the site, as well as the slight tendency to hydro-compacted/soft compressible cohesive subsoils at varying depths, it is our opinion the structures as presented herein should consist of a spread footing/mat slab system bearing on a minimum 2-foot zone of approved imported structural fill material. For design of the foundation system we recommend using a maximum net allowable total load soil bearing pressure not to exceed 2,500 psf. The bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. We were requested to provide AASHTO load and resistance factor design (LRFD) recommendations for the various structure. As per the typical CDOT Standard Plan No. M-601-20, the minimum Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 9 resistance for soil bearing equals 5.5 ksf, with a soil bearing resistance factor of 0.45. Converting this typical design criteria into a maximum net allowable bearing pressure, the equivalency would be 2475 psi; therefore, we recommend 2,500 psf. The bearing stratum should consist of a minimum 2-foot zone of properly placed and compacted imported granular structural fill. The over excavation below the footings/mat slabs should extend to depths of at least 2 feet below foundation bearing elevation and should extend laterally in all directions beyond the edges of the footing/mat slab at least 8 inches for each 12 inches of over excavation depth below the footing bearing. The structural fill material should be graded similar to a CDOT Class 5, 6 or 7 aggregate base. Recycled concrete base materials could also be used. The over excavation backfill structural fill materials should be adjusted to a workable moisture content, placed in maximum 8-inch thick loose lifts and compacted to at least 98% of the material's standard Proctor (ASTM D698) maximum dry density. Areas of soft/compressible cohesive subsoils across the site at or near the groundwater interface may require ground stabilization procedures to create a working platform for construction equipment prior to placement of any additional fill, and/or over excavation backfill. If necessary, consideration could be given to placement of a granular material, such as a 3-inch minus pit run and/or recycled concrete or equivalent material, embedded into the soft soils, prior to placement of additional fill material or operating heavy earth-moving equipment. Supplemental recommendations can be provided upon request and/or depending upon conditions encountered at the time of construction. Scenario 3: Depending on the foundation grades for the various structures, if the foundation /mat slab bearing strata consists of the underlying fine to course medium dense to dense silty sand with gravel subsoils, the structures could bear directly on the approved zone without the necessity to over- excavate or ground modify. For design of the foundation system bearing on approved granular subsoils, we recommend using a maximum net allowable total load soil bearing pressure not to exceed 2,500 psf. The bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. All foundation should bear on uniform type soils, (i.e., the entire foundation system for each structure should bear on either a zone of imported structural fill material or native granular subsoils as described herein) to reduce the potential for differential movement of dissimilar soil types. Close evaluation of the foundation bearing strata materials will be necessary during the construction phase. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 10 Care should be taken during construction to avoid disturbing the foundation bearing materials. Materials which are loosened or disturbed by the construction activities or materials which become dry and desiccated or wet and softened should be removed and replaced or reworked in-place prior to placement of foundation concrete. If unacceptable materials are encountered at the time of construction, it may be necessary to extend the footings to suitable strength soils or over-excavate unacceptable materials and replace those soils with approved fill materials. Those conditions can best be evaluated in open excavations at the time of construction. Based on the consistency of the subgrade soils observed at the boring locations, we anticipate the long term settlement of footing foundations / mat slabs designed and constructed as outlined above would be 1 inch or less. Support of the foundations on subgrade soils with moderate to high swell potential leaves some risk of post construction heaving of foundations. Over-excavation and backfill procedures greater than 2-feet may be necessary to further reduce the risk of post construction movement of the foundations. Greater depths of over excavation and backfill can be determined once foundation grades have been established and/or at the time of construction. Seismic Conditions The site soil conditions, based on our experience in the surrounding area consist of approximately 20 to 30 feet (+/-) of overburden cohesive and fine to course granular subsoils overlying bedrock. For those site conditions, the International Building Code indicates a Seismic Site Classification of D. According to the International Building Code® (Section 1613 Earthquake Loads), Every structure, and portion thereof, including nonstructural components that are permanently attached to structures and their supports and attachments, shall be designed and constructed to resist the effects of earthquake motions in accordance with ASCE 7, excluding Chapter 14 and Appendix 11A. The seismic design category for a structure is permitted to be determined in accordance with Section 1613 (2015 IBC) or ASCE 7.” Exceptions to this are further noted in Section 1613. Based on extrapolation of available data to depth and our experience in the project area, we consider the site likely to meet the criteria for a Seismic Site Classification of D according to the IBC classification (Section 1613.3.2). If, however, a quantitative assessment of the site seismic properties is desired, then sampling or shear wave velocity testing to a depth of 100 feet or more should be performed. Utilizing the OSHPD Seismic Design Maps online tool (https://seismicmaps.org//) and a Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 11 Site Class D the project area is indicated to possess an SDS value of 0.192g and an SD1 value of 0.092g for the site’s latitude and longitude. Lateral Earth Pressures Passive lateral earth pressures may help resist the driving forces for retaining wall or other similar site structures. Active lateral earth pressures could be used for design of structures where some movement of the structure is anticipated, such as retaining walls. The total deflection of structures for design with active earth pressure is estimated to be on the order of one half of one percent of the height of the down slope side of the structure. We recommend at-rest pressures be used for design of structures where rotation of the walls is restrained. Passive pressures and friction between the footing and bearing soils could be used for design of resistance to movement of retaining walls. Coefficient values for backfill with anticipated types of soils for calculation of active, at rest and passive earth pressures are provided in the Table III below. Those coefficient values are based on horizontal backfill with backfill soils consisting of essentially on-site lean clay / lean clay with sand subsoils with friction angles of 25 degrees and structural fill with friction angles of 35 degrees. Equivalent fluid pressure is equal to the appropriate coefficient times the appropriate soil unit weight. Care will be needed to account for buoyant soil weights and hydrostatic loading conditions as appropriate. For the at-rest and active earth pressures, slopes down and away from the structure would result in reduced driving forces with slopes up and away from the structures resulting in greater forces on the walls. The passive resistance would be reduced with slopes away from the wall. The top 30 inches of soil on the passive resistance side of walls could be used as a surcharge load; however, the top 30 inches of soil should not be used as part of the passive resistance value. Frictional resistance is equal to the tangent of the friction angle times the normal force. Surcharge loads or point loads placed in the backfill can also create additional loads on below grade walls. Those situations should be designed on an individual basis. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 12 TABLE III - Lateral Earth Pressures Soil Type On-Site Cohesive and Clayey Sand Imported Medium Dense Granular Wet Unit Weight (pcf) 110 135 Saturated Unit Weight (pcf) 130 140 Friction Angle () – (assumed) 25° 35° Active Pressure Coefficient 0.41 0.27 At-rest Pressure Coefficient 0.58 0.43 Passive Pressure Coefficient 2.46 3.69 The outlined values do not include factors of safety nor allowances for hydrostatic loads and are based on assumed friction angles and should be verified prior to construction. Care should be taken to develop appropriate systems in conjunction below grade walls to eliminate potential for hydrostatic loads developing on the walls and/or design the walls to accommodate hydrostatic load conditions. Water Soluble Sulfates – (SO4) The water soluble sulfate (SO4) testing of the on-site subsoil materials taken during our subsurface exploration at an approximate depth of 9-feet below site grades is provided below. Based on the reported sulfate contents test results, this report includes a recommendation for the CLASS or TYPE of cement for use for contact in association with the on-site subsoils. TABLE IV - Water Soluble Sulfate Test Results Sample Location Description Soluble Sulfate Content (mg/kg) Soluble Sulfate Content (%) B-1, S-3 at 9’ Sandy Lean Clay (CL) 3,500 0.35 B-6, S-1 at 4’ Lean Clay with Sand (CL) 11.400 1.14 B-10, S-2 at 9’ Sandy Lean Clay (CL) 14,600 1.46 Based on the results as presented above, ACI 318, Section 4.2 indicates the site soils have a moderate to severe risk of sulfate attack on Portland cement concrete. Therefore Class 2 cement with the use of fly ash should be used for concrete on and below site grades within the overburden soils. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. These results are being compared to the following table. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 13 TABLE V- Requirements to Protect Against Damage to Concrete by Sulfate Attack from External Sources of Sulfate Severity of Sulfate exposure Water-soluble sulfate (SO4) in dry soil, percent Water-cement ratio, maximum Cementitious material Requirements Class 0 0.00 to 0.10% 0.45 Class 0 Class 1 0.11 to 0.20% 0.45 Class 1 Class 2 0.21 to 2.00% 0.45 Class 2 Class 3 2.01 of greater 0.45 Class 3 Underground Utility Systems All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded gravel compacted to 75 percent of Relative Density ASTM D4253 be used as bedding. Where utilities and/or if the various structures are excavated below groundwater, temporary dewatering will be required during excavation, pipe placement, foundation placement, and backfilling operations for proper construction. Utility trenches should be excavated on safe and stable slopes in accordance with OSHA regulations as discussed above. Backfill should consist of the on-site soils or approved materials. The pipe backfill should be compacted to a minimum of 98 % of Standard Proctor Density ASTM D698 below a depth of 10 feet or great and to 95% of Standard Proctor Density for the upper 10-foot zone. All underground piping within or near the proposed structure should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in grade beams and/or foundation should be oversized to accommodate differential movements. Other Considerations and Recommendations Groundwater was observed at depths of approximately 3-1/2 (previously completed boring B-5) to 23 feet below present site grades. Excavations extending to the wetter soils could create difficulties for backfilling of the structure and utility trenches with drying of the subgrade soils required to use those materials as backfill. In general, the subgrade soils could be used as backfill soils although care will be necessary to maintain sufficient moisture to reduce potential for post-construction movement. Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 14 Although evidence of fills or underground facilities such as septic tanks, cesspools, basements, and utilities was not observed during the site reconnaissance, such features could be encountered during construction. If unexpected fills or underground facilities are encountered, such features should be removed, and the excavation thoroughly cleaned prior to backfill placement and/or construction. Excavations into the on-site soils will encounter a variety of conditions. Excavations into the clays can be expected to stand on relatively steep temporary slopes during construction; however, caving soils may also be encountered especially in close proximity to the groundwater table, as well as in the sand/gravel zones below the overlying clay soils. Groundwater seepage should also be anticipated for utility excavations. Pumping from sumps may be utilized to control water within the excavations. Well points may be required for significant groundwater flow, or where excavations penetrate groundwater to a significant depth. The individual contractor(s) should be made responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. Positive drainage should be developed away from the structures and pavement areas with a minimum slope of 1 inch per foot for the first 10 feet away from the improvements in landscape areas. Care should be taken in planning of landscaping (if required) adjacent to the buildings to avoid features which would pond water adjacent to the foundations or stemwalls. Placement of plants which require irrigation systems or could result in fluctuations of the moisture content of the subgrade material should be avoided adjacent to site improvements. Irrigation systems should not be placed within 5 feet of the perimeter of the buildings and parking areas. Spray heads should be designed not to spray water on or immediately adjacent to the structures or site pavements. Roof drains should be designed to discharge at least 5 feet away from the structures and away from the pavement areas. GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained from the soil borings performed at the indicated locations and from any other information discussed in this report. This report does not reflect any variations which may occur between borings or across the site. The nature and extent of such variations may not become evident until construction. If Earth Engineering Consultants, LLC EEC Project No. 1172058 May 20, 2022 Page 15 variations appear evident, it will be necessary to re-evaluate the recommendations of this report. Site specific explorations will be necessary for the proposed site buildings. It is recommended that the geotechnical engineer be retained to review the plans and specifications so that comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork and foundation construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of HF2M Colorado for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranty, express or implied, is made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that any changes in the nature, design or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the conclusions of this report modified or verified in writing by the geotechnical engineer. Earth Engineering Consultants, LLC DRILLING AND EXPLORATION DRILLING & SAMPLING SYMBOLS: SS: Split Spoon ‐ 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample ST: Thin‐Walled Tube ‐ 2" O.D., unless otherwise noted WS: Wash Sample R: Ring Barrel Sampler ‐ 2.42" I.D., 3" O.D. unless otherwise noted PA: Power Auger FT: Fish Tail Bit HA: Hand Auger RB: Rock Bit DB: Diamond Bit = 4", N, B BS: Bulk Sample AS: Auger Sample PM: Pressure Meter HS: Hollow Stem Auger WB: Wash Bore Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2‐inch O.D. split spoon, except where noted. WATER LEVEL MEASUREMENT SYMBOLS: WL : Water Level WS : While Sampling WCI: Wet Cave in WD : While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB : After Boring ACR: After Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION Soil Classification is based on the Unified Soil Classification system and the ASTM Designations D‐2488. Coarse Grained Soils have move than 50% of their dry weight retained on a #200 sieve; they are described as: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are described as : clays, if they are plastic, and silts if they are slightly plastic or non‐plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse grained soils are defined on the basis of their relative in‐ place density and fine grained soils on the basis of their consistency. Example: Lean clay with sand, trace gravel, stiff (CL); silty sand, trace gravel, medium dense (SM). CONSISTENCY OF FINE‐GRAINED SOILS Unconfined Compressive Strength, Qu, psf Consistency < 500 Very Soft 500 ‐ 1,000 Soft 1,001 ‐ 2,000 Medium 2,001 ‐ 4,000 Stiff 4,001 ‐ 8,000 Very Stiff 8,001 ‐ 16,000 Very Hard RELATIVE DENSITY OF COARSE‐GRAINED SOILS: N‐Blows/ft Relative Density 0‐3 Very Loose 4‐9 Loose 10‐29 Medium Dense 30‐49 Dense 50‐80 Very Dense 80 + Extremely Dense PHYSICAL PROPERTIES OF BEDROCK DEGREE OF WEATHERING: Slight Slight decomposition of parent material on joints. May be color change. Moderate Some decomposition and color change throughout. High Rock highly decomposed, may be extremely broken. HARDNESS AND DEGREE OF CEMENTATION: Limestone and Dolomite: Hard Difficult to scratch with knife. Moderately Can be scratched easily with knife. Hard Cannot be scratched with fingernail. Soft Can be scratched with fingernail. Shale, Siltstone and Claystone: Hard Can be scratched easily with knife, cannot be scratched with fingernail. Moderately Can be scratched with fingernail. Hard Soft Can be easily dented but not molded with fingers. Sandstone and Conglomerate: Well Capable of scratching a knife blade. Cemented Cemented Can be scratched with knife. Poorly Can be broken apart easily with fingers. Cemented Group Symbol Group Name Cu≥4 and 1<Cc≤3E GW Well-graded gravel F Cu<4 and/or 1>Cc>3E GP Poorly-graded gravel F Fines classify as ML or MH GM Silty gravel G,H Fines Classify as CL or CH GC Clayey Gravel F,G,H Cu≥6 and 1<Cc≤3E SW Well-graded sand I Cu<6 and/or 1>Cc>3E SP Poorly-graded sand I Fines classify as ML or MH SM Silty sand G,H,I Fines classify as CL or CH SC Clayey sand G,H,I inorganic PI>7 and plots on or above "A" Line CL Lean clay K,L,M PI<4 or plots below "A" Line ML Silt K,L,M organic Liquid Limit - oven dried Organic clay K,L,M,N Liquid Limit - not dried Organic silt K,L,M,O inorganic PI plots on or above "A" Line CH Fat clay K,L,M PI plots below "A" Line MH Elastic Silt K,L,M organic Liquid Limit - oven dried Organic clay K,L,M,P Liquid Limit - not dried Organic silt K,L,M,O Highly organic soils PT Peat (D30)2 D10 x D60 GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line. GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line. GP-GM poorly-graded gravel with silt PPI plots on or above "A" line. GP-GC poorly-graded gravel with clay QPI plots below "A" line. SW-SM well-graded sand with silt SW-SC well-graded sand with clay SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay Earth Engineering Consultants, LLC IIf soil contains >15% gravel, add "with gravel" to group name JIf Atterberg limits plots shaded area, soil is a CL- ML, Silty clay Unified Soil Classification System Soil Classification Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests Sands 50% or more coarse fraction passes No. 4 sieve Fine-Grained Soils 50% or more passes the No. 200 sieve <0.75 OL Gravels with Fines more than 12% fines Clean Sands Less than 5% fines Sands with Fines more than 12% fines Clean Gravels Less than 5% fines Gravels more than 50% of coarse fraction retained on No. 4 sieve Coarse - Grained Soils more than 50% retained on No. 200 sieve CGravels with 5 to 12% fines required dual symbols: Kif soil contains 15 to 29% plus No. 200, add "with sand" or "with gravel", whichever is predominant. <0.75 OH Primarily organic matter, dark in color, and organic odor ABased on the material passing the 3-in. (75-mm) sieve ECu=D60/D10 Cc= HIf fines are organic, add "with organic fines" to group name LIf soil contains ≥ 30% plus No. 200 predominantly sand, add "sandy" to group name. MIf soil contains ≥30% plus No. 200 predominantly gravel, add "gravelly" to group name. DSands with 5 to 12% fines require dual symbols: BIf field sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name.FIf soil contains ≥15% sand, add "with sand" to GIf fines classify as CL-ML, use dual symbol GC- CM, or SC-SM. Silts and Clays Liquid Limit less than 50 Silts and Clays Liquid Limit 50 or more 0 10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 110PLASTICITY INDEX (PI) LIQUID LIMIT (LL) ML OR OL MH OR OH For Classification of fine-grained soils and fine-grained fraction of coarse-grained soils. Equation of "A"-line Horizontal at PI=4 to LL=25.5 then PI-0.73 (LL-20) Equation of "U"-line Vertical at LL=16 to PI-7, then PI=0.9 (LL-8) CL-ML MONTAVA DEVELOPMENT FORT COLLINS, COLORADO EEC PROJECT NO. 1172058 APRIL 2022 MONTAVA DEVELOPMENT FORT COLLINS, COLORADO EEC PROJECT NO. 1172058 APRIL 2022 S-1B-6AS-11S-2S-3S-4S-5S-6S-7S-8S-9S-1012Figure 1: Boring Location DiagramMontava DevelopmentFort Collins, ColoradoEEC Project #: 1172058 Date: May 2022EARTH ENGINEERING CONSULTANTS, LLCAppro[imate BoringLocations1LegendSite PKotosPKotos taNen in appro[imatelocation, in direction oI arroZ S-1S-2S-3S-4S-5S-6S-7S-11S-8S-9S-10Supplemental BoringsFigure 2: Boring Location DiagramMontava DevelopmentFort Collins, ColoradoEEC Project #: 1172058 Date: May 2022EARTH ENGINEERING CONSULTANTS, LLC DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF SPARSE VEGETATION AND TOPSOIL _ _ 1 _ _ 2 _ _ 3 _ _ 4 LEAN CLAY with SAND (CL) _ _ brown, dry to moist to saturated, stiff to very stiff CS 5 17 9000+ 8.5 91.1 33 19 84.0 1100 PSF (+) 1.3% _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 9 3500 16.8 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _% @1000 PSF CS 15 13 2500 19.2 108.7 <1000 PSF (-) 1.1% _ _ 16 _ _ 17 _ _ SILTY SAND with GRAVEL (SM) 18 tan, gray, _ _ moist to saturated, medium dense 19 _ _ SS 20 15 12.0 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 12 11.4 125.4 BOTTOM OF BORING DEPTH 25' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 5009 24 HOUR N/A FINISH DATE 4/29/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/29/2022 WHILE DRILLING 10.5' MONTAVA DEVELOPMENT LOG OF BORING S-1PROJECT NO: 1172058 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ 1 _ _ 2 SANDY LEAN CLAY (CL) _ _ brown, dry to moist, medium stiff to stiff CS 3 21 9000+ 9.5 120.0 _ _ with gypsum crystals 4 _ _ SS 5 16 9000+ 13.6 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ CS 10 9 2500 19.1 106.2 32 22 52.8 <500 PSF (-) 0.1% _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 15 5000 19.0 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ CS 20 15 6000 19.2 109.4 _ _ 21 _ _ SILTY SAND with GRAVEL (SM) 22 tan, gray, moist to saturated, medium dense _ _ 23 _ _ 24 _ _ SS 25 17 9.6 BOTTOM OF BORING DEPTH 25.5' _ _ Earth Engineering Consultants, LLC MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-2 MAY 2022 FORT COLLINS, COLORADO SHEET 1 OF 1 WATER DEPTH START DATE 4/27/2022 WHILE DRILLING 20' APPROX. ELEV. 5005 24 HOUR N/A FINISH DATE 4/27/2022 AFTER DRILLING N/A A-LIMITS SWELL DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION AND TOPSOIL _ _ 1 _ _ 2 _ _ 3 SANDY LEAN CLAY (CL) _ _ brown, dry to moist to saturated, medium stiff to stiff 4 _ _ CS 5 21 9000+ 8.4 118.3 3000 PSF (+) 0.8% _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 5 1500 26.8 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 7 1000 23.0 94.2 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 8 2500 22.6 _ _ 21 _ _ 22 _ _ 23 _ _ SILTY SAND with GRAVEL (SM) 24 tan, gray, moist to saturated, medium dense _ _ CS 25 11 13.7 116.2 BOTTOM OF BORING DEPTH 25' _ _ Earth Engineering Consultants, LLC MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-3 MAY 2022 FORT COLLINS, COLORADO SHEET 1 OF 1 WATER DEPTH START DATE 4/27/2022 WHILE DRILLING 19' APPROX. ELEV. 5001 24 HOUR N/A FINISH DATE 4/27/2022 AFTER DRILLING 12' A-LIMITS SWELL DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION AND TOPSOIL _ _ 1 _ _ 2 SANDY LEAN CLAY (CL) _ _ brown, dry to moist to saturated, stiff to very stiff CS 3 23 9000+ 23.0 103.2 _ _ 4 _ _ SS 5 33 9000+ 10.0 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ CS 10 17 9000+ 12.0 118.4 ~4000 (+) 3.9% _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 18 5500 18.6 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ CS 20 11 3000 22.4 105.0 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ SS 25 5 1500 22.6 BOTTOM OF BORING DEPTH 25.5' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 5000 24 HOUR N/A FINISH DATE 4/27/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/27/2022 WHILE DRILLING 23' MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-4 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ 1 _ _ 2 _ _ 3 _ _ 4 SANDY LEAN CLAY (CL) _ _ brown, dry to moist to saturated, stiff to very stiff CS 5 29 9000+ 11.3 115.9 31 20 61.7 7500 (+) 7.3% _ _ with calcareous deposits 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 11 9000+ 13.5 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 11 2500 18.5 108.8 _ _ 16 _ _ 17 _ _ 18 *medium stiff lense with elevated in-situ moisture contents _ _ 19 _ _ SS 20 7 2000 25.4 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 14 6000 16.7 114.5 BOTTOM OF BORING DEPTH 25' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 5000 24 HOUR N/A FINISH DATE 4/27/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/27/2022 WHILE DRILLING None MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-5 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION AND TOPSOIL _ _ 1 _ _ 2 SANDY LEAN CLAY (CL) _ _ brown, dry to moist to saturated, stiff to very stiff 3 _ _ 4 _ _ CS 5 22 9000+ 11.1 114.5 2000 PSF (+) 3.1% _ _ with calcareous deposits 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 14 9000+ 10.8 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _% @1000 PSF CS 15 13 4000 15.0 112.3 36 22 64.9 <1000 PSF (-) 0.3% _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 14 4000 21.8 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 18 5000 17.9 112.0 BOTTOM OF BORING DEPTH 25' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 5001 24 HOUR N/A FINISH DATE 4/29/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/29/2022 WHILE DRILLING None MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-6 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION AND TOPSOIL _ _ 1 _ _ 2 _ _ SANDY LEAN CLAY (CL) 3 brown, dry to moist, very stiff to stiff _ _ 4 _ _ CS 5 24 9000+ 8.6 106.5 6000 (+) 5.9% _ _ with gypsum crystals 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 13 9000+ 12.2 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 10 3500 18.4 108.9 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 11 4000 17.8 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 16 5000 17.6 113.9 BOTTOM OF BORING DEPTH 25' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 5001 24 HOUR N/A FINISH DATE 4/27/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/27/2022 WHILE DRILLING 18' MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-7 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ 1 _ _ 2 SANDY LEAN CLAY (CL) _ _ brown, dry to moist, stiff to medium stiff 3 _ _ 4 _ _ CS 5 14 8000 18.7 96.7 <500 PSF (-) 0.5% _ _ with gypsum crystals 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 6 3000 21.7 _ _ 11 _ _ 12 _ _ 13 SILTY SAND with GRAVEL (SM) _ _ tan, gray, 14 moist to saturated, medium dense _ _ CS 15 13 13.0 121.9 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 18 9.9 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ CS 25 20 11.0 123.4 BOTTOM OF BORING DEPTH 25' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 4997 24 HOUR N/A FINISH DATE 4/29/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/29/2022 WHILE DRILLING 12' MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-8 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ 1 _ _ 2 SANDY LEAN CLAY (CL) _ _ brown, dry to moist, stiff CS 3 11 6500 18.2 102.7 _ _ with gypsum crystals 4 _ _ SS 5 10 3000 20.8 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ CS 10 13 4000 19.8 99.2 28 18 53.7 <500 PSF 0.0% _ _ 11 _ _ 12 _ _ SILTY SAND with GRAVEL (SM) 13 tan, gray, _ _ moist to saturated, medium dense 14 _ _ SS 15 21 7.7 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ CS 20 15 9.3 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ SS 25 14 14.4 BOTTOM OF BORING DEPTH 25.5' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 4995 24 HOUR N/A FINISH DATE 4/29/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/29/2022 WHILE DRILLING 10' MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-9 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF SPARSE VEGETATION AND TOPSOIL _ _ 1 _ _ 2 _ _ 3 _ _ 4 LEAN CLAY with SAND (CL) _ _ brown, dry to moist, hard to very stiff CS 5 34 9000+ 7.5 118.1 32 15 79 4500 (+) 4.7% _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 22 9000+ 13.2 _ _ 11 _ _ 12 _ _ 13 _ _ SILTY SAND with GRAVEL (SM) 14 tan, gray, _ _ moist to saturated, dense to medium dense CS 15 35 8.5 120.6 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ SS 20 31 8.3 _ _ 21 _ _ 22 _ _ 23 _ _ 24 _ _ SS 25 22 5.1 BOTTOM OF BORING DEPTH 25.5' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 4991 24 HOUR N/A FINISH DATE 4/29/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/29/2022 WHILE DRILLING 12' MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-10 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF _ _ 1 _ _ 2 _ _ 3 _ _ 4 SANDY LEAN CLAY (CL) _ _ brown CS 5 21 9000+ 11.8 120.7 <500 PSF (-) 0.3% _ _ with gypsum crystals 6 _ _ 7 _ _ 8 _ _ 9 _ _ SS 10 9 4000 16.3 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ CS 15 9 3000 18.1 109.1 BOTTOM OF BORING DEPTH 15' _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 *Note: Shallow piezometer installed in area identified _ _ as Supplemental Boring S-11. TST, Inc. requested in this 21 a shallow groundwater piezometer be installed _ _ for measurement of current groundwater conditions 22 _ _ 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 5008 5/6/2022 12' 10" FINISH DATE 4/27/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/27/2022 WHILE DRILLING None MONTAVA DEVELOPMENT PROJECT NO: 1172058 LOG OF BORING S-11 MAY 2022 FORT COLLINS, COLORADO DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION & TOPSOIL _ _ 1 _ _ LEAN CLAY with SAND (CL) 2 gray / brown / rust _ _ soft to medium stiff CS 3 6 1500 26.6 94.8 with organics _ _ 4 gray / rust _ _ SS 5 2 -- 44.3 _ _ 6 _ _ 7 _ _ 8 _ _ 9 _ _ CS 10 6 1000 26.0 97.8 33 19 81.3 <500 psf none _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ SS 15 7 1000 29.2 _ _ 16 _ _ 17 _ _ SILTY SAND / GRAVEL (SM / GM) 18 brown / rust / gray _ _ loose to medium dense 19 _ _ CS 20 15 _ _ 21 _ _ 22 _ _ 23 _ _ 24 intermittent clay seams _ _ SS 25 8 BOTTOM OF BORING DEPTH 25.5' _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL SURFACE ELEV N/A CHECKED ON 5/6/22 3.3' FINISH DATE 8/18/2017 CHECKED ON 9/8/2017 6.3' SHEET 1 OF 1 WATER DEPTH START DATE 8/18/2017 WHILE DRILLING 2.0' 800 ACRE MIXED USE DEVELOPMENT FORT COLLINS, COLORADO PROJECT NO: 1172058 LOG OF BORING B-5 SEPTEMBER 2017 DATE: RIG TYPE: CME55 FOREMAN: DG AUGER TYPE: 4" CFA SPT HAMMER: AUTOMATIC SOIL DESCRIPTION D N QU MC DD -200 TYPE (FEET)(BLOWS/FT)(PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF VEGETATION AND TOPSOIL _ _ 1 _ _ SANDY LEAN CLAY (CL) / CLAYEY SAND (SC) 2 brown/gray/rust, moist to saturate, medium stiff / loose _ _ 3 _ _ 4 _ _ 5 SS _ _5 1000 21.4 27 110 45.7 6 BOTTOM OF BORING DEPTH 6' _ _ 7 _ _ 8 _ _ 9 _ _ 10 _ _ 11 _ _ 12 _ _ 13 _ _ 14 _ _ 15 _ _ 16 _ _ 17 _ _ 18 _ _ 19 _ _ 20 _ _ 21 *Note: Shallow piezometer installed adjacent to previously _ _ completed Boring B-6 in 2017. TST, Inc. requested in this 22 area to installed a shallow groundwater piezometer _ _ for measurement of current groundwater conditions 23 _ _ 24 _ _ 25 _ _ Earth Engineering Consultants, LLC A-LIMITS SWELL APPROX. ELEV. 5003 5/6/2022 5' 2" FINISH DATE 4/27/2022 AFTER DRILLING N/A SHEET 1 OF 1 WATER DEPTH START DATE 4/27/2022 WHILE DRILLING None MONTAVA DEVELOPMENT FORT COLLINS, COLORADO PROJECT NO: 1172058 LOG OF BORING B-6A MAY 2022 Project: Location: Project #: Date: Montava Development Fort Collins, Colorado 1172058 May 2022 Beginning Moisture: 8.5% Dry Density: 105.9 pcf Ending Moisture: 13.3% Swell Pressure: 1100 psf % Swell @ 500: 1.3% Sample Location: Boring 1, Sample 1, Depth 4' Liquid Limit: 33 Plasticity Index: 19 % Passing #200: 84.0% SWELL / CONSOLIDATION TEST RESULTS Material Description: brown LEAN CLAY with SAND (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) Sample Location: Boring 1, Sample 3, Depth 14' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 19.3% Dry Density: 110.5 pcf Ending Moisture: 18.7% Swell Pressure: <1000 psf % Swell @ 1000: -1.1% Montava Development Fort Collins, Colorado 1172058 May 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development Fort Collins, Colorado 1172058 May 2022 Beginning Moisture: 19.1% Dry Density: 111.6 pcf Ending Moisture: 16.2% Swell Pressure: <500 psf % Swell @ 500: -0.1% Sample Location: Boring 2, Sample 3, Depth 9' Liquid Limit: 32 Plasticity Index: 22 % Passing #200: 52.8% SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) Sample Location: Boring 3, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 8.4% Dry Density: 128.5 pcf Ending Moisture: 12.6% Swell Pressure: 3000 psf % Swell @ 500: 0.8% Montava Development Fort Collins, Colorado 1172058 May 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: brown LEAN CLAY with SAND (CL) Sample Location: Boring 4, Sample 3, Depth 9' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 12.0% Dry Density: 123.8 pcf Ending Moisture: 16.1% Swell Pressure: % Swell @ 500: 3.9% Montava Development Fort Collins, Colorado 1172058 May 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development Fort Collins, Colorado 1172058 May 2022 Beginning Moisture: 11.3% Dry Density: 123.5 pcf Ending Moisture: 16.0% Swell Pressure: 7500 psf % Swell @ 500: 7.3% Sample Location: Boring 5, Sample 1, Depth 4' Liquid Limit: 31 Plasticity Index: 20 % Passing #200: 61.7% SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) Sample Location: Boring 6, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 11.1% Dry Density: 119 pcf Ending Moisture: 19.2% Swell Pressure: 2000 psf % Swell @ 500: 3.1% Montava Development Fort Collins, Colorado 1172058 May 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development Fort Collins, Colorado 1172058 May 2022 Beginning Moisture: 15.0% Dry Density: 112.7 pcf Ending Moisture: 15.2% Swell Pressure: <1000 psf % Swell @ 1000: -0.3% Sample Location: Boring 6, Sample 3, Depth 14' Liquid Limit: 36 Plasticity Index: 22 % Passing #200: 64.9% SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: brown LEAN CLAY with SAND (CL) Sample Location: Boring 7, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 8.6% Dry Density: 118.8 pcf Ending Moisture: 20.5% Swell Pressure: 6000 psf % Swell @ 500: 5.9% Montava Development Fort Collins, Colorado 1172058 May 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay Sample Location: Boring 8, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 18.7% Dry Density: 100.2 pcf Ending Moisture: 42.1% Swell Pressure: <500 psf % Swell @ 500: -0.5% Montava Development Fort Collins, Colorado 1172058 May 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development Fort Collins, Colorado 1172058 May 2022 Beginning Moisture: 19.8% Dry Density: 99.2 pcf Ending Moisture: 29.3% Swell Pressure: <500 psf % Swell @ 500: 0.0% Sample Location: Boring 9, Sample 3, Depth 9' Liquid Limit: 28 Plasticity Index: 18 % Passing #200: 53.7% SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: Montava Development Fort Collins, Colorado 1172058 May 2022 Beginning Moisture: 7.5% Dry Density: 124.5 pcf Ending Moisture: 16.3% Swell Pressure: % Swell @ 500: 4.7% Sample Location: Boring 10, Sample 1, Depth 4' Liquid Limit: 32 Plasticity Index: 15 % Passing #200: 79.0% SWELL / CONSOLIDATION TEST RESULTS Material Description: brown LEAN CLAY with SAND (CL) -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added Project: Location: Project #: Date: SWELL / CONSOLIDATION TEST RESULTS Material Description: brown SANDY LEAN CLAY (CL) Sample Location: Boring 11, Sample 1, Depth 4' Liquid Limit: - - Plasticity Index: - - % Passing #200: - - Beginning Moisture: 11.8% Dry Density: 116.5 pcf Ending Moisture: 15.4% Swell Pressure: <500 psf % Swell @ 500: -0.3% Montava Development Fort Collins, Colorado 1172058 May 2022 -10.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 8.0 10.0 0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added 2 1/2" (63 mm) 2" (50 mm) 1 1/2" (37.5 mm) 1" (25 mm) 3/4" (19 mm) 1/2" (12.5 mm) 3/8" (9.5 mm) No. 4 (4.75 mm) No. 8 (2.36 mm) No. 10 (2 mm) No. 16 (1.18 mm) No. 30 (0.6 mm) No. 40 (0.425 mm) No. 50 (0.3 mm) No. 100 (0.15 mm) No. 200 (0.075 mm) Project: Montava Development Location: Fort Collins, Colorado Project No: 1172058 Sample ID: Supplemental Boring 8 - Sample 3 @ 14-feet Sample Desc.: Poorly Graded Sand with Gravel (SP) Date: May 2022 EARTH ENGINEERING CONSULTANTS, LLC SUMMARY OF LABORATORY TEST RESULTS Sieve Analysis (AASHTO T 11 & T 27 / ASTM C 117 & C 136) 100 Sieve Size Percent Passing 100 100 97 97 94 92 78 61 19 8.3 58 47 36 32 28 0.37 0.09Fine25.77 0.69D30D10CuCCMay 202237.50 2.23 1.41Montava DevelopmentFort Collins, Colorado1172058Supplemental Boring 8 - Sample 3 @ 14-feet Poorly Graded Sand with Gravel (SP) D100D60D50EARTH ENGINEERING CONSULTANTS, LLCSummary of Washed Sieve Analysis Tests (ASTM C117 & C136)Date:Project:Location:Project No:Sample ID:Sample Desc.:CobbleSilt or ClayGravelCoarse FineSandCoarse Medium6"5"4"3"2.5"2"1.5"1"3/4"1/2"3/8"No. 4No. 8No. 10No. 16No. 30No. 40No. 50No. 100No. 20001020304050607080901000.010.11101001000Finer by Weight (%)Grain Size (mm)Standard Sieve Size