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HomeMy WebLinkAboutPZ - Geotech Report ALLWESTMATERIALS OTESTING I SPECIAL IINOSPECT ON AN EMPLOYEE-OWNED COMPANY July 16, 2024 Trilogy Development 9839 West Cable Car Street, Suite 101 Boise, Idaho 83709 Attention: Shawn Brownlee (shawnCcDtrilogyidaho.com) RE: Geotechnical Evaluation Mills Property Development 905 West Amity Road Meridian, Idaho ALLWEST Project No. 524-199G Mr. Brownlee, ALLWEST has completed the authorized geotechnical evaluation for the proposed Mills Property Development to be located at 905 West Amity Road in Meridian, Idaho. The purpose of this evaluation was to characterize the subsurface conditions at the project site and prepare the attached report with the results of the field evaluation and our geotechnical recommendations to assist with design and construction of the proposed development. We appreciate the opportunity to work with you on this project. Please contact us if you have any questions or need additional information. Sincerely, NAit 071�6/202a ALLWEST �oR OFESS10*411 �y ENS 7/�6/24 c`0 Q KEVIN ANDREW o W DYEKMAN � y Cf �iG� sTNO. 1727 4Tr OF \OP�� aeErt�� Kevin Dyekman, P.G. Samuel P. Sommers, P.E. (WA, ID, MT) Senior Engineering Geologist Senior Geotechnical Engineer 255 N. Linder Road, Meridian, ID 83642 Phone: 208.895.7898 Hayden, ID• Lewiston, ID •Meridian, ID •Missoula, MT•Spokane Valley, WA•Tri-Cities,WA www.allwesttesting.com GEOTECHNICAL EVALUATION MILLS PROPERTY DEVELOPMENT 905 WEST AMITY ROAD MERIDIAN, IDAHO PROJECT NO. 524-199G July 16, 2024 r.39c zMWIM Prepared for: TRILOGY DEVELOPMENT 9839 WEST CABLE CAR STREET, SUITE 101 BOISE, IDAHO 83709 Prepared by: ALLWEST 255 N. LINDER ROAD MERIDIAN, IDAHO TABLE OF CONTENTS GEOTECHNICAL EVALUATION MILLS PROPERTY DEVELOPMENT 905 WEST AMITY ROAD MERIDIAN, IDAHO Page 1.0 EXECUTIVE SUMMARY................................................................................................ 1 2.0 PROJECT DOCUMENTS............................................................................................... 2 3.0 PROJECT DESCRIPTION ............................................................................................. 2 4.0 SITE CONDITIONS........................................................................................................ 2 4.1 Published Subsurface Conditions..................................................................................... 2 4.2 Subsurface Exploration Program...................................................................................... 2 4.3 Soil Characterization ........................................................................................................ 3 4.4 Groundwater Conditions................................................................................................... 3 5.0 LABORATORY TESTING............................................................................................... 3 6.0 CONCLUSIONS AND RECOMMENDATIONS............................................................... 4 6.1 Site Preparation................................................................................................................ 4 6.2 Temporary Excavation and Trenching .............................................................................. 5 6.3 Materials........................................................................................................................... 6 6.4 Fill Placement and Compaction ........................................................................................ 6 6.5 Wet Weather Construction................................................................................................ 7 6.6 Cold Weather Construction............................................................................................... 7 6.7 Stormwater and Drainage................................................................................................. 8 6.7.1 Infiltration Recommendations..................................................................................... 8 6.8 Pavement......................................................................................................................... 9 7.0 ADDITIONAL RECOMMENDED SERVICES.................................................................10 8.0 EVALUATION LIMITATIONS ........................................................................................10 Appendix A—Vicinity Map, Site and Exploration Map Appendix B — Exploration Logs, Soil Classification Chart Appendix C — Laboratory Test Results GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY GEOTECHNICAL EVALUATION MILLS PROPERTY DEVELOPMENT 905 WEST AMITY ROAD MERIDIAN, IDAHO 1.0 EXECUTIVE SUMMARY ALLWEST has completed the authorized geotechnical evaluation for the proposed Mills Property Development located at 905 West Amity Road in Meridian, Idaho. Our services were provided in accordance with our proposal no. 524-199G dated April 5, 2024. The site is suitable for the proposed development provided the recommendations in this report are properly implemented during design and construction. Close monitoring of the construction operations discussed herein will be critical in achieving the design subgrade support and is required by the International Building Code (IBC). If we are not retained to provide required construction observation and materials testing services, we cannot be responsible for soil engineering related construction errors or omissions. The following summarizes select geotechnical information/recommendations from this evaluation: ♦ Natural soil generally consisted of lean clay with sand, sandy lean clay, sandy silt, clayey sand, silty sand, poorly graded sand, and poorly graded gravel. The silty sand contained gravel and cobbles, and the poorly graded sand/gravel commonly contained varying amounts of silt, sand, gravel, and cobbles. ♦ Varying thicknesses of weak to moderate cementation were regularly observed within the silty sand soil layers. ♦ We did not observe groundwater within most of the test pits to the maximum exploration depth of 13 feet below existing ground. Groundwater was observed within TP-10 at a depth of approximately 7.5 feet below existing ground. ♦ Based on the observed subsurface conditions, we anticipate approximately 4 to 12 inches of stripping will be required for most of the site. ♦ We recommend stormwater disposal occur within the on-site sand and gravel units, as observed during our field exploration. A design infiltration rate of 8 inches per hour (in/hr) may be utilized for stormwater disposal into these soil units. ♦ For local roadways we recommend pavement sections of 2.5-inches of asphalt concrete, over 4-inches of crushed aggregate base, over 10-inches of aggregate subbase. ♦ For collector roadways we recommend pavement sections of 3-inches of asphalt concrete, over 6-inches of crushed aggregate base, over 12-inches of aggregate subbase. This summary should be used in conjunction with the entire report. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 2 2.0 PROJECT DOCUMENTS The following documents were provided to ALLWEST to help our understanding of the planned development: ♦ LandproDATA Parcel Map, 905 W Amity, Mill Property, dated March 13, 2024. 3.0 PROJECT DESCRIPTION Based on communication with you and review of the project documents, we understand that development will consist of an approximately 49-acre residential subdivision with associated infrastructure, stormwater disposal facilities, and asphalt-paved roadways. We did not review grading plans, as they were not available at the time of this evaluation, but we anticipate cuts and fills for general site grading to be two feet or less. 4.0 SITE CONDITIONS At the time of exploration, the site was comprised of farmland with a residence near the center of the property. Calkins Lateral winds its way through the property, entering along the southern boundary generally trending toward the northwest, then curving towards the northeast corner of the site. The site is bordered by West Amity Road to the north, residences to the west, and undeveloped farmland to the south and east. The general location of the site is shown on Figure A-1: Vicinity Map in Appendix A. 4.1 Published Subsurface Conditions The geologic conditions at the site are mapped as Gravel of Amity Terrace (map symbol — Qag) on the "Geologic Map of the Boise Valley and Adjoining Area, Western Snake River Plain, Idaho", by K.L. Othberg, and L.R. Stanford, 1992. This unit is described as sandy pebble and cobble gravel to coarse pebbly sand approximately 33 feet thick mantled by approximately two to seven feet of loess. The USDA Natural Resources Conservation Service (NRCS) has mapped the near surface soil types on the project site as Elijah silt loams. The soil consists of silt loam, silty clay loam, loam, cemented material, extremely gravelly sand, and bedrock. The soil is well draining and forms from lacustrine deposits, loess, and/or alluvium. The capacity of the most limiting layer to transmit water is very low to moderately low. 4.2 Subsurface Exploration Program We observed the excavation of 19 test pits (TP-1 through TP-19) on April 16, 2024, utilizing a Case 580C backhoe with a 24-inch toothed excavation bucket. Test pits were advanced to maximum depths of 8 to 13 feet below existing ground. Maximum depths varied due to caving conditions encountered within select test pits. The soil conditions observed in the test pits were described and classified in general accordance with ASTM D2488. We obtained samples of representative soil from the test pit side walls or excavation spoil piles for further identification and GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 3 laboratory testing. The approximate locations of the test pits are shown on Figure A-2: Site and Exploration Map in Appendix A. Field infiltration testing was performed within select test pits to assess the rate at which water permeates into the subsurface soil. Infiltration testing was performed using general open pit-falling head methodology. Additional testing may be needed once stormwater disposal facility locations are determined and should be performed using methodology accepted by the governing jurisdiction. 4.3 Soil Characterization Detailed descriptions of the observed soil are presented on the exploration logs in Appendix B. The descriptive soil terms used on the exploration logs, and in this report, can be referenced on the Unified Soil Classification System (USCS) included as part of the Soil Classification Chart in Appendix B. Subsurface conditions may vary between exploration locations; such changes in subsurface conditions may not be apparent until construction. General descriptions of the observed soil units follow: Topsoil: Topsoil containing abundant roots and organics was observed in each test pit, except TP-4 and TP-11. Where present, the topsoil layer was observed to be approximately 4 to 12 inches thick. Natural Soil: Natural soil consists of lean clay with sand, sandy lean clay, sandy silt, clayey sand, silty sand, poorly graded sand, and poorly graded gravel. The silty sand contained gravel and cobbles, and the poorly graded sand/gravel commonly contained varying amounts of silt, sand, gravel, and cobbles. Varying thicknesses of weak to moderate cementation were regularly observed within the silty sand soil layers. 4.4 Groundwater Conditions We did not observe groundwater within most of the test pits to the maximum exploration depth of 13 feet below existing ground. Groundwater was observed within TP-10 at a depth of approximately 7'/2 feet below existing ground. Groundwater on-site may be influenced by local irrigation practices and canals, laterals, and ditches. Changes in precipitation, construction, and other factors may also impact the depth to groundwater on-site. As a result, actual groundwater conditions may be different during development. Groundwater will fluctuate throughout the year and will likely peak during snowmelt and irrigation seasons (typically March to October). We installed slotted PVC pipes within select test pits for future groundwater monitoring.ALLWEST is currently performing monthly groundwater monitoring to help establish seasonal high groundwater on-site. 5.0 LABORATORY TESTING We performed laboratory testing to supplement field classifications and to assess some of the soil engineering properties. The laboratory testing completed, and the information acquired, are GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 4 presented in Table 1. The laboratory test results are included in Appendix C and select results are also presented on the exploration logs in Appendix B. Table 1 - Laboratory Tests Test Performed Information Acquired Natural Water Content Water content representative of soil conditions at the time (ASTM D2216) and location samples were collected. Fines Content Portion of soil passing the No. 200 sieve (silt/clay). (ASTM D1140) Atterberg Limits Effects of varying water content on the consistency of fine- (ASTM D4318) grained soil present in a particular sample. California Bearing Ratio This test method is used to evaluate the strength and load- (ASTM D1883) bearing capacity of subgrade soil and/or materials for pavement design and construction. 6.0 CONCLUSIONS AND RECOMMENDATIONS Based on our understanding of the project and the subsurface conditions presented in the previous sections, the site is suitable for the proposed development provided the recommendations in this report are properly implemented during design and construction. If the proposed construction changes or if unforeseen conditions are encountered, we must be given the opportunity to review the new information and update our recommendations. Additionally, we should be given the opportunity to review development plans and specifications to confirm the recommendations presented in this report were properly incorporated. 6.1 Site Preparation Clearing and Stripping: Topsoil containing significant roots and organics should be removed (i.e., stripped) below proposed development areas. Based on the observed subsurface conditions, we anticipate approximately 4 to 12 inches of stripping will be required for most of the site. Stripped materials should be disposed of off-site or only used for topsoil within non-structural landscape areas. Where trees will be removed (i.e., cleared) as part of the development, large root systems should be completely over-excavated to suitable natural soil. We anticipate approximately 3 to 4 feet of over-excavation will be required to remove large tree root systems. Demolition: We anticipate existing improvements (structures, utilities, infrastructure, etc.) will be demolished and removed as part of development. Existing improvements should be completely over-excavated to suitable natural soil. This also includes basements, septic tanks, and wastewater drain fields. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 5 Unsuitable Soil: Unsuitable soil is present on-site and is not acceptable to support site grading fill, pavement sections, structural improvements, or any other type of development. The unsuitable soil should be completely over-excavated to undisturbed natural soil within proposed development areas. The following soil types are unsuitable: ♦ Organic-rich, loose/soft, and/or wet soil associated with existing irrigation ditches located throughout the site. Test Pit Remediation: Test pit excavations were loosely backfilled with the excavated soil following logging. To reduce the potential for future settlement, we recommend that test pit backfill be entirely over-excavated below development areas. The approximate test pit locations are shown on Figure A-2: Site and Exploration Map in Appendix A and their approximate depths are presented on the exploration logs in Appendix B. Over-Excavations: Depths and lateral limits of over-excavations may not fully be known until earthwork begins. Over-excavations associated with tree removal, demolition, unsuitable soil, and test pit remediation should be backfilled with suitably moisture-conditioned and compacted site grading fill in accordance with the following sections of this report. Subgrade Preparation: Subgrade refers to the natural soil exposed at the base of any excavation. Subgrades should be evaluated by the geotechnical engineer of record, or staff under their supervision, to determine that they are suitable and that the actual subsurface conditions are consistent with those observed during exploration. Exposed subgrades should be evaluated by proof-rolling using vibratory rollers, loaded dump trucks/front-end loaders, vibratory hoe-packs, or other suitable equipment. If natural subgrades are observed to significantly deflect or pump during proof-rolling, the subgrades will not be suitable and ALLWEST should be consulted to provide recommendations to achieve a stable subgrade based on the actual conditions observed during earthwork. 6.2 Temporary Excavation and Trenching Based on the conditions observed within our explorations, we anticipate excavation of the on-site soil can be achieved with typical excavation equipment. Temporary excavation slope stability is a function of many factors, including: ♦ The presence and abundance of groundwater. ♦ The type and density of the various soil strata. ♦ The depth of cut. ♦ Surcharge loadings adjacent to the excavation. ♦ The length of time the excavation remains open. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 6 It is exceedingly difficult under the variable circumstances to pre-establish a safe and "maintenance-free" temporary cut slope angle. Therefore, it is the responsibility of the contractor to maintain safe temporary slope configurations since the contractor is continuously at the job site, able to observe the nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater conditions encountered. Unsupported vertical slopes or cuts deeper than 4 feet are not recommended if worker access is necessary. The cuts should be adequately sloped, shored, or supported to prevent injury to personnel from local sloughing and spalling. The excavation should conform to applicable federal, state, and local regulations. Regarding trench wall support, the site soil is considered Type C soil according to OSHA guidelines and therefore should not exceed a 1.5H:1V (horizontal to vertical) temporary slope. 6.3 Materials Stripped soil containing significant roots and organics should be disposed of off-site or only used for topsoil within non-structural landscape areas. Based on our observations and laboratory testing, the on-site soil is suitable for use as site grading fill during earthwork. Site grading fill should have a liquid limit less than 50 and not contain materials greater than 6 inches in maximum dimension. Imported soil and aggregate should consist of granular soil that is free of organics, debris, and other deleterious material and meet the criteria presented in Table 2. Imported materials should be approved by the geotechnical engineer prior to delivery to the site. Table 2 - Imported Soil and Aggregate Recommendations. Type Criteria Maximum size <_ 6 inches, Granular Structural Fill / Retained on 3/4-inch sieve < 30%, Subbase Passing No. 200 Sieve <_ 15%, and non-plastic. Alternatively, meet ISPWC section 801 (6-inch maximum) or 802 (Type 11). Maximum size <_ 1 inch, Crushed Aggregate Base Retained on 3/4-inch sieve <010%, Passing No. 200 sieve < 10/o, and Non-plastic. Alternatively, meet ISPWC section 802 (Type 1) Maximum size <_ 2 inches; Utility Trench Backfill Retained on %-inch sieve < 30%; (above pipe bedding) Passing No. 200 sieve <_ 10%; Non-plastic Or meet ISPWC section 801 (3-inch maximum) 6.4 Fill Placement and Compaction Prior to fill placement, exposed subgrades should be observed and approved by the geotechnical engineer of record, or their representative. For roadway and utility construction, local governing agencies may supersede the criteria presented herein, and may provide their own minimum GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 7 compaction requirements and methods of determining maximum density. This also includes preparation and approval requirements for exposed subgrades. Fill should be placed in lift thicknesses which are appropriate for the compaction equipment used. Typically, 8-to 12-inch-thick lifts are appropriate for typical rubber tire and steel drum compaction equipment. Lift thickness should be reduced to 4 inches for hand operated compaction equipment. Fill should be moisture conditioned to within 2 percentage points of the optimum moisture content prior to placement to facilitate compaction. Fill should be compacted to the minimum relative compaction of the maximum dry density, as determined by ASTM D1557 (modified Proctor), provided in Table 3. Table 3 - Compaction Requirements Minimum Relative Type Compaction (%) Site Grading Fill 95 Granular Structural Fill / Subbase 95 Crushed Aggregate Base 95 Utility Trench Backfill 92 For materials that are too granular to test (generally greater than 30 percent retained on a 3/4-inch sieve), an appropriate method-based compaction specification should be used in accordance with local governing jurisdictions or as outlined in Section 202.3.8.C.3 of the Idaho Standards for Public Works Construction (ISPWC). Fine-grained soil (silts and clays) may be difficult to moisture-condition and compact in utility trenches. Therefore, we strongly recommend backfilling trench excavations with soil that meet the criteria presented in presented in Table 2. 6.5 Wet Weather Construction Due to the wet weather conditions in this climatic region during late fall, winter, and spring, we recommend construction (especially site grading) take place during the summer and early fall season, if possible. If construction occurs during or immediately after excessive precipitation, it may be necessary to over-excavate and replace wet subgrade soil which might otherwise be suitable. If construction is undertaken in wet periods of the year, it will be important to slope the ground surface to provide drainage away from construction. 6.6 Cold Weather Construction If site grading and construction are anticipated during cold weather, we recommend good winter construction practices be observed. Snow and ice should be removed from all fill placement surfaces prior to additional earthwork or construction. Improvements should not be placed on frozen ground, nor should the supporting soil be permitted to freeze during or after construction. Frozen soil should not be used as fill. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 8 Construction subgrades left exposed to freezing temperatures overnight can be protected with a temporary lift of loose soil or covered with heated construction blankets, so subgrades do not freeze. Frozen cover soil should be removed prior to any fill placement or construction. 6.7 Stormwater and Drainage We recommend the grading plan include ground slopes that direct water runoff away from buildings and pavement areas to a drainage management system (i.e., swales, yard drains, outlet pipes, etc.). We recommend the ground surface adjacent to foundations be sloped a minimum of 5 percent within 5 feet of the building. If the adjoining ground surface consists of hardscapes, it may slope a minimum of 2 percent in the first 5 feet. Water should not be allowed to infiltrate or pond adjacent to the foundations.We anticipate surface water runoff will be directed to stormwater disposal facilities (detention basins, seepage beds, etc.) for the overall development. 6.7.1 Infiltration Recommendations Locations of planned stormwater disposal facilities were not known at the time of this report. The infiltration recommendations provided below are for specific soil types and subsurface conditions observed during our exploration. We performed infiltration testing in test pits TIP-1, -2, -8, -9, -11, -14, and -19 within on-site sand and gravel units, which included poorly graded sand with silt, gravel, and/or cobbles, as well as poorly graded gravel with sand and cobbles. Varying levels of cementation were commonly observed during exploration within the silty sand, silty sand with gravel, and silty sand with gravel and cobbles soil layers. We do not recommend stormwater disposal be accomplished within cemented soil, as they typically exhibit very poor and inconsistent infiltration rates. Refer to the test pit logs in Appendix B to verify depths and contacts of soil which are not suitable for stormwater disposal. We recommend stormwater disposal occur within the on-site sand and gravel, as observed during our field exploration. Based on infiltration test results and our experience with similar soil conditions, the design infiltration rates provided in Table 4 may be utilized for on-site stormwater disposal. Table 4 - Infiltration Rates Field-Measured Design Infiltration Soil TvDe Infiltration Rate in/hr Rate (in/hr) Sand and Gravel >15 8 Stormwater disposal facilities should be constructed a minimum of 1 foot into the recommended receiving soil. Filter fabric should be properly utilized to separate natural soil from stormwater disposal facility drain rock and filter sand materials to help reduce the migration of fine soil into drain rock and filter sand void space. The proper separation from bottom of stormwater disposal facilities and seasonal high groundwater should be maintained in accordance with the governing jurisdiction. Groundwater monitoring should be performed throughout seasonal snowmelt and irrigation seasons (March to October) to help establish a seasonal high groundwater elevation at the site to assist civil design. If requested, ALLWEST can perform monthly groundwater monitoring for the site. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 9 6.8 Pavement Based on our exploration and understanding of the proposed development, we anticipate that pavement subgrade areas will consist of lean clays with sand, sandy silt, clayey sand, and/or silty sand. We performed California Bearing Ratio (CBR) testing on a sandy silt soil sample and obtained a value of 12.4 percent. Prior to pavement section construction, subgrades should be proof-rolled as recommended in section 6.1 Site Preparation or as required by local jurisdictions.Anticipated traffic conditions were not provided for our pavement design. The parameters used in our pavement section design were estimated based on our experience with similar projects. If actual traffic conditions vary from those stated in Table 5, we should be notified so we may redesign the recommended pavement sections. Table 5 - Pavement Design Parameters Design Parameter Value California Bearing Ratio (CBR) 12.4% Equivalent Single- Local Roadways 33,0001 Axle Loads (ESALs) Collector Roadways 370'0002 Pavement Reliability 90% Pavement Design Life 20- ear Initial Serviceability 4.2 Terminal Serviceability 2.5 Approximately equivalent to a Traffic Index of 6. 2Approximately equivalent to a Traffic Index of 8. The following sections were designed utilizing AASHTO methodology and our experience with local jurisdictions. Recommended flexible pavement sections are presented in Table 6. Table 6 - Recommended Pavement Sections Flexible Pavement Crushed Base Pavement Area Asphalt in.) Course (in.) Subbase (in.) Local Roads 2.5 4 10 Collector Roads 3 6 12 Pavements should be sloped to provide suitable drainage of surface water.Water allowed to pond on or adjacent to the pavements could saturate the subgrade and contribute to premature pavement deterioration. In addition, the pavement subgrade should be graded to provide positive drainage within the crushed base course/subbase subsections. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development July 16, 2024 Meridian, Idaho Page 10 The pavement sections provided in this report represent minimum recommended thicknesses. Preventive maintenance (crack/joint sealing, patching, overlay, etc.) should be planned as part of an on-going pavement management program. Preventive maintenance is intended to slow the rate of pavement deterioration and preserve the integrity of the pavement. 7.0 ADDITIONAL RECOMMENDED SERVICES ALLWEST should review final development plans and specifications to confirm the recommendations presented in this report were properly incorporated. Close monitoring of the construction operations discussed herein will be critical in achieving the design subgrade support and is required by the IBC. We recommend ALLWEST be retained to provide observation and testing services throughout construction. At a minimum, we recommend the following testing and observations be provided by ALLWEST: ♦ Observe site stripping, test pit remediation, and any other soil over-excavations and backfills. ♦ Observe subgrade proof-rolling and approve subgrades prior to fill/materials placement or roadway section/utility construction. ♦ Observe removal of disturbed soil and subgrade stabilization, if required. ♦ Observe stormwater disposal facility subgrade soil and overall stormwater disposal facility construction. ♦ Conduct compaction testing of any fill soil or aggregate placed for general site grading, utility backfills, and pavement section construction. ♦ Observe placement of/test asphalt for compaction, oil content, and gradation. If we are not retained to provide the recommended construction observation and materials testing services, we cannot be responsible for errors and omissions related to geotechnical aspects of the project construction. 8.0 EVALUATION LIMITATIONS This report has been prepared to assist the design and construction for the proposed Mills Property Development located at 905 West Amity Road in Meridian, Idaho. Reliance by any other party is prohibited without the written authorization of ALLWEST. Our services consist of professional opinions and conclusions made in accordance with generally accepted geotechnical engineering principles and practices in the local area at the time this report was prepared. This acknowledgement is in lieu of all warranties, express or implied. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development Meridian, Idaho Appendix A Vicinity Map Site and Exploration Map ALLWEBT I-K Eli Base Map:Google Earth ` ' } r =; tit'',t 'Ii rl -3 �'I .1 ��..�� a •y�r•� -� FT'::Y T, W ►sir-q• t. --- - - ��'��'I r. .: �Li' •.r. �,,� -��•��y +s-r, gyp, _ :^"T Y' _M �y�d , y:.� •;a,� r. ;; ] r A .'y,r Fra4 wq— ag c : IF tow �a, Site r L,. - ..WI, ho m. kf ' x i _:.•iC.: + 3�i°'.,.�1r,., it �'� ! t. oil r oil 0 6,000' 12,000' FIGURE A-1:VICINITY MAP GEOTECHNICAL EVALUATION ALLWESTMILLS PROPERTY DEVELOPMENT MERIDIAN, IDAHO 255 N.LINDER ROAD CLIENT:TRILOGY DEVELOPMENT MERIDIAN,IDAHO 83642 PHONE:(208)895-7898 FAX:(208)898-3959 PROJECT NO.:524-199G DATE:JULY 2024 v y.. ... Base Map: Google Earth,Imagery Date: 6/22/2022 \\� �c. JL {'. Q TP-1 Q TP-2 T 0 TP-3 i F} Lit TP-4 -:w = Boundary 0 TP-7 0 TP-6 ■ 0 TP-5 ': � Q TP-9 Q TP-11 f 0 TP-10 Q TP-12 tyc 1 TP-13 Q'T r �TP-17 EP-16 ` P-14.P 19•s Q TP 18 T s � f too E d LEGEND N � 0 Approximate location of test pit observed by ALLWEST. 0 350' 700' * Slotted PVC pipe was installed in test pit. FIGURE A-2: EXPLORATION LOCATION MAP GEOTECHNICAL EVALUATION ALLWESTMILLS PROPERTY DEVELOPMENT MERIDIAN, IDAHO 255 N.LINDER ROAD CLIENT:TRILOGY DEVELOPMENT MERIDIAN,IDAHO 83642 PHONE:(208)895-7898 FAX:(208)898-3959 PROJECT NO.:524-199G DATE:JULY 2024 Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development Meridian, Idaho Appendix B Exploration Logs Soil Classification Chart ALLWEBT Mills Property Development TP-1 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 11' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.560935, -116.408639 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E U, E o co a U n o 2 TOPSOIL;abundant roots and organics 0.5 Lean CLAY with sand(CL);medium stiff,moist, 1 ft dark brown Grab 3.0 Silty SAND(SM);dense,moist,brown 5 moderate cementation observed from 4.5 to 7 feet 7.0 7 ft Poorly graded GRAVEL with sand and cobbles(GP); •a Grab medium dense,moist,light brown subrounded gravel and cobbles up to 8 inches in •� maximum dimension ��•� Infiltration test performed at 7.5 feet;rate>15 in/hr. 9.0 9.5 ft Poorly graded SAND with gravel(SP);medium Grab 10 dense,moist,tan 11.0 Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-2 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 11.5' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.560930, -116.407103 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E E o co a U n o 2 TOPSOIL;abundant roots and organics 0.5 Lean CLAY with sand(CL);medium stiff,moist, dark brown 2.0 Silty SAND with gravel(SM);medium dense, moist,brown weak cementation throughout soil layer 4.5 4.5 ft Poorly graded GRAVEL with sand and cobbles 5 (GP);medium dense,moist,tan sulk e subrounded gravel and cobbles up to 12 inches •� in maximum dimension ��•� Infiltration test performed at 5.5 feet;rate>15 ' in/hr. ���•� �.41�. b l •i�i• b b6 10— 41� b4—b.� 11.5 � ' •�• Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-3 ALLI E T Meridian,Idaho Pagel of 1 Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 'I'll See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.560946, -116.405552 Samples Lab 0 0_ 0) J T E w a o Soil Description and Remarks a in U m n `o _ CO E L 2 o J (6 d m (n O N 9 O � Q TOPSOIL;abundant roots and organics 0.5 0.5 ft Clayey SAND(CL);medium dense,moist,dark Grab 30 36 40-19-21 brown 1.5 1 10 Silty SAND with gravel(SM);medium dense, moist,brown 3.5 Poorly graded GRAVEL with silt and sand (GP-GM);medium dense, moist,brown 15*A. subrounded gravel and cobbles up to 9 inches in •� 5 maximum dimension •� SAWS .i Test pit terminated due to caving.Slotted pipe installed. Water Levels V Groundwater not encountered. 1 - Mills Property Development TP-4 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 11' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.560116, -116.404191 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E 0 E co a n o 2 Lean CLAY with sand(CL);medium stiff,moist, dark brown 1.5 Silty SAND(SM);dense, moist,brown 2.5 ft Grab moderate cementation observed from 1.5 to 5 feet 5 7.0 Silty SAND with gravel and cobbles(SM);medium dense,moist,brown subrounded gravel and cobbles up to 5 inches in maximum dimension 10 11.0 Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-5 ALLI E T Meridian,Idaho Pagel of 1 Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 11.5' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.559263, -116.405019 Samples Lab 0 0_ 0) J T E w a o Soil Description and Remarks a in U m n `o _ 0 E L 2 o J (6 d m (n O N 9 O � Q Silty SAND(SM); medium dense,moist,brown weak cementation observed from 0 to 2 feet 3ft Grab 24 48 4.0 Silty SAND with gravel(SM);medium dense, moist,brown 5 subrounded gravel and cobbles up to 5 inches in maximum dimension 7.0 Poorly graded GRAVEL with silt and sand(GP-GM); medium dense,moist,tan subrounded gravel and cobbles up to 9 inches in •� ' maximum dimension ��•� b,%� 10 11.0 Test pit terminated due to caving.Slotted pipe installed. Water Levels V Groundwater not encountered. 1 - Mills Property Development TP-6 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 8' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.559762, -116.406797 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E E 2 o co a U n o 2 TOPSOIL;abundant roots and organics 0.5 Lean CLAY with sand(CL);medium stiff,moist, dark brown 1.0 Silty SAND with gravel(SM);medium dense, 1.5 ft moist,brown Grab subrounded gravel up to 3 inches in maximum dimension 4.0 Poorly graded SAND with gravel(SP);medium dense,moist,tan 5 subrounded gravel up to 3 inches in maximum dimension 5.0 Poorly graded SAND(SP);medium dense,moist, tan 8.0 Test pit terminated due to caving. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-7 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 12' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.559744, -116.408785 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E E o co a U n o 2 TOPSOIL;abundant roots and organics 1.0 Lean CLAY with sand(CL);medium stiff,moist, dark brown 3.0 Silty SAND(SM);medium dense to dense,moist, light brown j. moderate cementation observed from 3 to 9 feet 9ft Grab 28 28 10 12.0 Test pit terminated.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-8 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 11' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.558669, -116.408778 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E E o co a U n o 2 TOPSOIL;abundant of roots and organics 1.0 Lean CLAY with sand(CL);medium stiff,moist, dark brown 2.0 Silty SAND(SM);medium dense,moist,light brown 2.5 ft Grab 7 15 weak cementation observed throughout soil layer 5 6.0 Poorly graded SAND with gravel(SP);medium 6.5 ft dense,moist,tan Grab subrounded gravel up to 3 inches in maximum dimension Infiltration test performed at 7 feet; rate> 15 in/hr. 9.0 Poorly graded GRAVEL with sand and cobbles •� (GP);medium dense,moist,tan ��:�• 10 subrounded gravel and cobbles up to 6 inches in •� maximum dimension ��•� 11.0 1L.:�. Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-9 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 10.5' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.558596, -116.407085 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E o 0E o co a n o 2 TOPSOIL;abundant roots and organics o.3 Sandy lean CLAY(CL);medium stiff,moist,dark brown 2.0 Silty SAND(SM);medium dense,moist,brown weak cementation observed throughout soil layer 3.5 Poorly graded SAND with gravel and cobbles(SP); medium dense,moist,tan subrounded gravel and cobbles up to 4 inches in 4.5 ft 5 maximum dimension Grab 23 4 Infiltration test performed at 7 feet; rate> 15 in/hr. 7.0 Poorly graded GRAVEL with sand and cobbles •� (GP);medium dense,moist,tan e!:a subrounded gravel and cobbles up to 9 inches in •� A maximum dimension ��� ��•�� .i�i' lb 10.5 K.Oft Test pit terminated due to caving. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-10 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 8.5' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: 7.5' Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.558289, -116.405795 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E E 2 o co a U n o 2 TOPSOIL;abundant roots and organics 0.5 0.5 ft Sandy SILT(ML);medium stiff, moist,dark brown Bulk 59 32-24-8 2.0 Silty SAND(SM);dense,moist,light brown moderate cementation observed throughout soil pm layer 4.5 5 Silty SAND with gravel and cobbles(SM); medium dense,moist to wet,brown subrounded gravel and cobbles up to 6 inches in maximum dimension 0 8.5 Test pit terminated due to caving.Slotted pipe installed. Water Levels Water encountered @ 7.5' 1 - Mills Property Development TP-11 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 10, See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.558637, -116.404132 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E 0 E co a n Sandy lean CLAY(CL);medium stiff,moist,dark brown 1.5 Silty SAND with gravel(SM);medium dense, moist, brown 5 5.5 Poorly graded SAND with silt(SP-SM);medium 6 ft dense,moist,tan Grab 8 6 Infiltration test performed at 6.5 feet;rate>15 in/hr. 7.5 Poorly graded SAND with gravel(SP);medium dense,moist,tan subrounded gravel and cobbles up to 5 inches in maximum dimension 10 10.0 Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-12 ALLI E T Meridian,Idaho Pagel of 1 Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 8.5' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.558110, -116.403067 Samples Lab 0 0_ 0) J T E w a o Soil Description and Remarks a in U m n `o _ CO E L 2 o J (6 d m (n O N 9 O � Q TOPSOIL;abundant roots and organics 0.5 Lean CLAY with sand(CL);medium stiff, moist, dark brown 1.0 Silty SAND(SM);dense,moist,brown moderate cementation observed throughout soil layer 3.5 Silty SAND with gravel(SM);medium dense, moist,brown 5 7.0 Poorly graded GRAVEL with sand(GP);medium dense,moist,brown '. •� subrounded gravel up to 3 inches in maximum ' dimension 8.5 Test pit terminated due to caving. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-13 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 13' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.557979, -116.400610 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E 0 E co a n o 2 TOPSOIL;abundant roots and organics 0.3 Sandy SILT(ML);medium stiff,moist,dark brown 1.5 Silty SAND(SM); medium dense, moist, brown s. weak cementation observed throughout soil layer 6.5 ft Grab 35 25 10 13.0 Test pit terminated.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-14 ALLI E T Meridian,Idaho Pagel of 1 Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 'I'll See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.557436, -116.400457 Samples Lab 0 0_ 0) J T E w a o Soil Description and Remarks a in U m n `o _ CO E L 2 o J (6 d m (n O N 9 O � Q TOPSOIL;abundant roots and organics 0.7 Sandy SILT(ML);medium stiff, moist,dark brown 1 ft Grab 23 51 33-30-3 2.0 Silty SAND with gravel(SM);medium dense, moist,brown subrounded gravel up to 3 inches in maximum dimension 5 5.0 Poorly graded GRAVEL with sand and cobbles(GP); medium dense,moist,light brown �- subrounded gravel and cobbles up to 8 inches in maximum dimension Infiltration test performed at 7 feet; rate> 15 in/hr. bft� 4S.• 6 �0.• .�. 10 �41.6 •0.• 11.0 •� • Test pit terminated due to caving.Slotted pipe installed. Water Levels V Groundwater not encountered. 1 - Mills Property Development TP-15 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 9' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.557397, -116.402288 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) a o U LL E 0 E ca n n a) o -2 TOPSOIL;abundant roots and organics 0.3 Lean CLAY with sand(CL);medium stiff,moist, dark brown 1.5 Silty SAND with gravel(SM);dense,moist,brown subrounded gravel up to 3 inches in maximum dimension moderate cementation observed throughout soil layer 5 5.5 Poorly graded SAND with silt and gravel(SP-SM); 6 ft medium dense,moist,tan subrounded gravel up to 3 inches in maximum Bulk 6 dimension 9.0 Test pit terminated due to caving. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-16 ALLIET Meridian,Idaho Pagel oft Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 10, See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.557572, -116.404238 Samples Lab CL o a � � J U T E fA d a Soil Description and Remarks o a w a) n o U LL E U, E 2 o co a U n o 2 TOPSOIL;abundant roots and organics 0.5 Lean CLAY with sand(CL);medium stiff,moist, dark brown 2.0 Silty SAND(SM);dense,moist,light brown moderate cementation observed throughout soil layer 4.0 Poorly graded GRAVEL with sand and cobbles(GP); 4.5 ft medium dense,moist,li ht brown 0 a'�' g �'�� Grab 5— subrounded gravel and cobbles up to 8 inches in •� ' maximum dimension "�.� •i�i• b b 10.0 •� 10 Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-17 ALLI E T Meridian,Idaho Pagel of 1 Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 9' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.557431, -116.405529 Samples Lab 0 0_ 0) J T E w a o Soil Description and Remarks a in U m n `o _ CO E L 2 o J (6 d m (n O N 9 O 43 � Q TOPSOIL;abundant roots and organics 0.5 Lean CLAY with sand(CL);medium stiff, moist, dark brown 1.0 Silty SAND with gravel and cobbles(SM);dense, moist,light brown subrounded gravel and cobbles up to 6 inches in maximum dimension moderate cementation observed throughout soil •�. : layer 3.0 Y !�.• Poorly graded GRAVEL with sand and cobbles(GP); medium dense,moist,light brown gravel and cobbles up to 12 inches in maximum ! •• 5 dimension • . . A. •i�i• 9.0 •. Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-18 ALLI E T Meridian,Idaho Pagel of 1 Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 10.5' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.557448, -116.407035 Samples Lab 0 0_ 0) J T E w a o Soil Description and Remarks a in U m n `o _ CO E L 2 o J (6 d m (n O N 9 O � Q TOPSOIL;abundant roots and organics 0.5 Lean CLAY with sand(CL);medium stiff, moist, dark brown 1.0 Silty SAND with gravel and cobbles(SM);dense, moist,brown moderate cementation observed throughout soil layer subrounded gravel and cobbles up to 5 inches in maximum dimension 3.0 Poorly graded SAND with gravel(SP);medium dense,moist,tan subrounded gravel and cobbles up to 7 inches in 5 maximum dimension 6.0 Poorly graded GRAVEL with sand and cobbles(GP); medium dense,moist,light brown a. :�. subrounded gravel and cobbles up to 7 inches in ��� maximum dimension 6 b 10 �• 10.5 Test pit terminated due to caving. Water Levels v Groundwater not encountered. 1 - Mills Property Development TP-19 ALLI E T Meridian,Idaho Pagel of 1 Project No.: 524-199G Date: 04/16/2024 Comments: Contractor: Just Dig It Hole Depth: 12' See Figure A-2 for approximate test pit location. Equipment: Case 580C Initial Water: - Operator: Steve Just Logged By: Miko Diklic Method: 24-inch toothed bucket Coordinates: 43.557539, -116.408533 Samples Lab 0 0_ 0) J T E w a o Soil Description and Remarks a in U m n `o _ CO E L 2 o J (6 d m (n O N 9 O � Q TOPSOIL;abundance of roots and organics 1.0 1 ft Lean CLAY with sand(CL);medium stiff, moist, Grab 26 72 48-20-28 dark brown 4.0 Silty SAND with gravel(SM);medium dense, moist,brown 5 6.5 Poorly graded SAND with gravel(SP);medium dense,moist,tan Infiltration test performed at 7.5 feet; rate>15 in/hr. 8.0 6"' Poorly graded GRAVEL with sand and cobbles �p.• (GP); medium dense,moist,tan •�ib . subrounded gravel and cobbles up to 8 inches in !�! maximum dimension 0.4 10 �0.• 12.0 Test pit terminated due to caving.Slotted pipe installed. Water Levels v Groundwater not encountered. 1 - SOIL CLASSIFICATION CHART (ASTM D2487 & D2488) MAJOR GROUP TYPICAL SOIL NAMES TYPICAL SOIL DESCRIPTORS DIVISIONS SYMBOL GW Well-graded gravel,gravel-sand mixtures,little or no fines. Description SPT Blow Counts O Very loose less than 4 Loose 4 to 10 w GP Poorly-graded gravel,gravel-sand mixtures,little or no fines. Medium dense 11 to 29 C3� > O Dense 30 to 50 Very dense greater than 50 0 o O GM Silty gravel,gravel-sand-silt mixtures. o Material Sieve Sizes CC14 Boulders greater than 12" w r GC Clayey gravel,gravel-sand-silt-clay mixtures. Cobbles 3"to<12" z � Q o Coarse gravel 3/4"to<3" Fine gravel #4 to<3/4" SW Well-graded sand,gravelly sand,little or no fines. Coarse sand <#4 to#10 Medium sand <#10 to#40 Q w Fine sand <#40 to#200 oo SP Poorly-graded sand,gravelly sand, little or no fines. Silt or clay less than#200 n ¢ Sieve Number Aperture SM Silty sand,sand-silt mixtures. #4 4.76 mm(0.187 in) #10 2.00 mm(0.0787 in) #40 0.42 mm(0.0165 in) SC Clayey sand,sand-clay mixtures. #200 0.074 mm(0.00291 in) ML Inorganic silt,non-plastic to low plasticity,gravelly silt, Description SPT Blow Counts Q LO sandy silt,clayey silt. v Very soft less than 2 U '= Soft 2 to 3 o E Inorganic clay of low to medium plasticity,gravelly clay, v� o z i CL sandy clay,silty clay(CL-ML),lean clay. Medium stiff 4 to 8 J N Q -0 Stiff 9 to 15 r J J Very stiff 16 to 29 o - r OL Organic silt and organic silty clay of low plasticity. Hard 30 to 50 Lu z =; r Very Hard greater than 50 0 L MH Inorganic silt,micaceous or diatomaceous fine sandy or Plasticity Soil Characteristics C7 Q silty soils,elastic silt. uw °�' A Non-plastic Cannot be rolled at any water content. Qo : Low A thread can barely be rolled while moist. z 1D CH Inorganic clay of high plasticity,fat clay. Medium A thread can be rolled easily but cannot be o rerolled after reaching the plastic limit. J a High A thread can be rolled and re-rolled several F OH:-:: Organic clay of medium to high plasticity. times after reaching the plastic limit. Definitions ORGANIC SOILS W PTy Peat and other highly organic soils. Liquid Limit(LL) Moisture content at which soil changes state from plastic to liquid. Plastic Limit(PL) Moisture content at which soil Dry Absence of moisture in sample. Dusty,dry to the touch. changes state from semi-solid to plastic. Plasticity Index(PI) Range of moisture contents at which Slightly Moisture in sample is below the optimum moisture content. a soil behaves plastically(LL-PL-PI). Moist Grains adhere slightly though surface tension. MOISTURE Moist Moisture in sample is at or near optimum moisture content. PLASTICITY CHART (ASTM D4318) No free water is visible. Moisture in sample is above the optimum moisture content. a 50 Wet Free water is visible in sample. w 0 o G� Weak Crumbles or breaks with handling or slight finger pressure. � CL-ML i CL MH or OH CEMENTATION Moderate Crumbles or breaks with considerable finger pressure. a a ML 0 0 16 50 Strong Will not crumble or break with finger pressure. LIQUID LIMIT(LL) ALLWEST Geotechnical Evaluation ALLWEST Project No. 524-199G Mills Property Development Meridian, Idaho Appendix C Laboratory Test Results ALLWEBT Table C-1: Summary of Laboratory Test Results Gradation Atterberg Limits Depth Test Pit Content Gravel Sand Silt/Clay De Moisture p Liquid Plastic Plasticity CBR Sample Classification o (Feet) (%) M (%) N Limit Limit Index (�o) (USCS) (/o) (/o) (/o) TP-2 4.5-5.5 49 46 5 Poorly graded GRAVEL with sand and cobbles(GP) TP-3 0.5- 1 30 36 40 19 21 Clayey SAND (SM) TP-5 3-3.5 24 48 Silty SAND (SM) TP-7 9-9.5 28 28 Silty SAND (SM) TP-8 2.5-3 7 15 Silty SAND (SM) TP-9 4.5-5 23 4 1 Poorly graded SAND with gravel and cobbles (SP) TP-10 0.5- 1.5 59 32 24 8 12.4 Sandy SILT(ML) TP-11 6-6.5 8 6 Poorly graded SAND with silt(SP-SM) TP-13 6.5-7 35 25 Silty SAND SM TP-14 1 - 1.5 23 51 33 30 3 Sandy SILT(ML) TP-15 6-7 33 61 6 Poorly graded SAND with silt and gravel SP-SM TP-19 1 - 1.5 26 72 48 20 28 Lean CLAY with sand (CL) 255 N. Linder Road • Meridian, Idaho 83642 •(208)895-7895• Fax(208)898-3959 www.allwesttesting.com This report may not be reproduced, except in full,without the permission of ALLWEST. LIQUID AND PLASTIC LIMITS TEST REPORT 60 Dashed line indicates the approximate upper limit boundary for natural soils 50 O �0 ' G 40 U ' C / X W z_ U 30 CY c F- W ' 06 Q J / m 20 J / Q 10 o ; c O ----- L-ML ML or OL MH or OH E -- a) 0 0 10 20 30 40 50 60 70 80 90 100 110 w LIQUID LIMIT 0 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS 3• Clayey Sand 40 19 21 -- 36% SC c■ Sandy Silt 32 24 8 -- 59% ML a)♦ Sandy Silt 33 30 3 -- 51% ML X '0♦ Lean Clay with sand 48 20 28 -- 72% CL m U 7 O ` Project No. 524-199G Client: Trilogy Development Remarks: Project: Mills Property Location:TP-3 Depth: 0.5'-1' ■Location:TP-10 Depth: 0.5'-1.5' ALocation: TP-16 Depth: 1'-1.5' *Location: TP-19 Depth: F-1.5' T ALLWEST Figure C-1 Tested By: C. Downes Checked By:J.Varozza California Bearing Ratio ASTM D 1883 Project: Mills Property Project No.: 524-199G Client: Trilogy Development Location: TP-10 @ 0.5 - 1.5 ft Date Tested: 4/29/24 Compaction Method: ASTM D1557 Tested By: C. Downes Classification: Sandy Silt (ML) 275 250 225 200 175 PSI @ 0.2 inch penetration= 187 a 40 c 150 a o 125 v n 100 75 50 25 0 0 0.1 0.2 0.3 0.4 0.5 Penetration(inches) CBR @ 0.2 Inch Penetration: 12.4 Maximum Dry Unit Weight (pcf): 111.1 Swell (%): 2.0 Optimum Water Content (%): 16.2 Dry Unit Weight Before Soak (pcf): 100.4 Remold of Max. Dry Unt Wgt(%): 90 Water Content Before Soak (%): 17.8 Water Content After Soak, Top 1 Inch (%): 28.4 Surcharge (psf): 50 Immersion Period (hrs): 96 Reviewed By: Kevin Dyekman, P.G. Figure: C-2 LL E T 255 N Linder Rd,Suite 100•Meridian, ID 83642•(208)895-7898•Fax(208)898-3959 www.allwesttesting.com This report shall not be reproduced except in full without the permission of ALLW EST. TECHNICAL ALLWEST MATERIALS OTESTING I SPECIAL IINOSPECT ON AN EMPLOYEE-OWNED COMPANY March 27, 2024 Trilogy Development 9839 West Cable Car Street, Suite 101 Boise, Idaho 83709 Attention: Shawn Brownlee (shawn trilogyidaho.com) RE: Geotechnical Evaluation Townsquare Media Property Development 455 West Amity Road Meridian, Idaho ALLWEST Project No. 524-051 G Mr. Brownlee, ALLWEST has completed the authorized geotechnical evaluation for the proposed Townsquare Media Property Development to be located at 455 West Amity Road in Meridian, Idaho. The purpose of this evaluation was to characterize the subsurface conditions at the site and prepare the attached report with the results of our field evaluation and laboratory testing, and to provide geotechnical recommendations to assist planning, design, and construction of the proposed development. We appreciate the opportunity to provide services for this project. If you have any questions or need additional information, please contact us at (208) 895-7898. Sincerely, ALLWEST oQOf ESSIpNq! 3/27/24 G'� y KEVIN AND REW 3/27/24 ca - DYEKMAN � q 142 ���� * NO. 1727 dILM Kevin Dyekman, P.G. qTf OF t�P Adrian Mascorro, P.E � � OF Engineering Services Manager Area Manager 255 N. Linder Road, Meridian, ID 83642 Phone: 208.895.7898 • Fax: 208.898.3959 Hayden, ID • Lewiston, ID• Meridian, ID• Spokane Valley, WA•Tri-Cities, WA• Missoula, MT www.allwesttesting.com GEOTECHNICAL EVALUATION TOWNSQUARE MEDIA PROPERTY DEVELOPMENT 455 WEST AMITY ROAD MERIDIAN, IDAHO ALLWEST PROJECT NO. 524-051 G March 27, 2024 Prepared for: TRILOGY DEVELOPMENT 9839 WEST CABLE CAR STREET, SUITE 101 BOISE, IDAHO 83709 Prepared by: ALLWEST 255 NORTH LINDER ROAD MERIDIAN, IDAHO 83642 EXECUTIVE SUMMARY The following summarizes select geotechnical information/recommendations from this evaluation: ♦ We anticipate approximately 6 to 8 inches of site stripping will be required for most of the site to remove surficial vegetation and roots. ♦ In general, native subsurface soils within the observed test pits consisted of lean clays, lean clays with sand, sandy silts, silty sands, silty sands with gravel and cobbles, poorly-graded sands, poorly-graded sands with silt, poorly-graded sands with silt and gravel, poorly-graded gravels with sand, and poorly-graded gravels with sand and cobbles. ♦ Varying thicknesses of weak to strong cementation were commonly observed within the silty sand, poorly-graded sand, and poorly-graded sand with silt soil layers. ♦ At the time of exploration,we did not observe groundwater within the test pits to the maximum exploration depth of 13 feet below existing ground. Based on review of available well driller reports in the site vicinity (from Idaho Department of Water Resources), we anticipate groundwater may be encountered at depths greater than 100 feet below ground surface. However, shallower seasonal groundwater may be observed adjacent to on-site ditches and laterals. ♦ We anticipate existing on-site improvements (structures, utilities, infrastructure, etc.) will be demolished and removed as part of development. Existing improvements and any associated fill soils should be completely over-excavated to suitable native soils. ♦ Organic-rich, loose/soft, and/or wet soils associated with existing irrigation ditches are present on-site. These soils are not suitable to support site grading fill, pavement sections, or structural improvements. Within proposed development areas, these soils should be completely over-excavated to suitable native soils. ♦ We recommend stormwater disposal occur within non-cemented on-site"sands and gravels", as observed during our field exploration. An allowable seepage rate of 8 inches per hour (in/hr) may be utilized for stormwater disposal into the on-site "sands and gravels". ♦ For local roadways we recommend pavement sections of 2.5-inches of asphalt concrete, over 4-inches of crushed aggregate base, over 11-inches of aggregate subbase. ♦ For collector roadways we recommend pavement sections of 3-inches of asphalt concrete, over 6-inches of crushed aggregate base, over 14-inches of aggregate subbase. Our services were provided in accordance with ALLWEST proposal no. 524-051 P dated January 19, 2024. This summary should be used in conjunction with the entire report for design and construction purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY GEOTECHNICAL EVALUATION TOWNSQUARE MEDIA PROPERTY DEVELOPMENT 455 WEST AMITY ROAD MERIDIAN, IDAHO Page 1.0 PROJECT DOCUMENTS.......................................................................................................1 2.0 PROJECT DESCRIPTION......................................................................................................1 3.0 EVALUATION PROCEDURES...............................................................................................1 4.0 SITE CONDITIONS ................................................................................................................2 4.1 Published Geologic and Soil Information ............................................................................2 4.2 Subsurface Soil Conditions .................................................................................................2 4.3 Groundwater Conditions......................................................................................................3 5.0 LABORATORY TESTING.......................................................................................................3 6.0 CONCLUSIONS AND RECOMMENDATIONS.......................................................................3 6.1 Site Preparation...................................................................................................................4 6.1.1 Subgrade Stabilization..................................................................................................4 6.1.2 Utility Trenches.............................................................................................................6 6.2 Excavation...........................................................................................................................6 6.3 Materials..............................................................................................................................6 6.4 Fill Placement and Compaction...........................................................................................7 6.5 Wet Weather Construction ..................................................................................................8 6.6 Cold Weather Construction .................................................................................................8 6.7 Stormwater and Drainage ...................................................................................................8 6.8 Asphalt Pavement...............................................................................................................9 7.0 ADDITIONAL RECOMMENDED SERVICES .......................................................................10 8.0 EVALUATION LIMITATIONS................................................................................................11 Appendix A—Vicinity Map, Exploration Location Map Appendix B —Test Pit Logs, Unified Soil Classification System Appendix C — Laboratory Test Results GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY GEOTECHNICAL EVALUATION TOWNSQUARE MEDIA PROPERTY DEVELOPMENT 455 WEST AMITY ROAD MERIDIAN, IDAHO 1.0 PROJECT DOCUMENTS The following project documents were reviewed by ALLWEST to help our understanding of the planned development: ♦ LandproDATA Parcel Map, Townsquare Media Amity Rd Meridian, dated January 16, 2024. 2.0 PROJECT DESCRIPTION Based on communication with you and review of the project documents, we understand that development will consist of an approximate 26-acre residential subdivision with associated infrastructure, stormwater disposal facilities, and asphalt-paved roadways. We did not review grading plans, as they were not available at the time of this evaluation, but we anticipate cuts and fills for general site grading to be 2 feet or less. 3.0 EVALUATION PROCEDURES To complete this evaluation, we reviewed published geologic/soil information and observed the excavation of exploratory test pits to evaluate the on-site subsurface conditions. The general location of the site is shown on Figure A-1: Vicinity Map in Appendix A. We observed the excavation of 13 test pits (TP-1 through TP-13) on February 1, 2024, utilizing a Case 580C backhoe with a 24-inch-wide toothed excavation bucket. Test pits were advanced to maximum depths of 6 to 13 feet below existing ground. Maximum depths varied due to excavator refusal or caving conditions encountered within select test pits. The approximate locations of the test pits are shown on Figure A-2: Exploration Location Map in Appendix A. The soils observed in the test pits were visually described and classified in general accordance with ASTM D2488. We logged the subsurface profiles and obtained soil samples at select depths for further identification and laboratory testing. We also performed 6 field seepage tests within select test pits throughout the site, where suitable permeable soils were encountered. Information obtained from the field evaluation, laboratory testing, and geotechnical analysis was utilized to develop the recommendations in this report. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 2 4.0 SITE CONDITIONS At the time of exploration, the site generally consisted of undeveloped land with 4 radio broadcasting towers and associated infrastructure spanning the site. Additionally, there was a paved parking area and building located in the northern portion of the property that was used for office space and housing radio broadcasting equipment (i.e., transmitter house). We understand that infrastructure associated with the radio towers includes an array of bare copper wiring (approximately 10 to 12 gauge in size) radiating outward from each tower up to approximately 425 feet, as well as transmission lines connecting the towers to the transmitter house. The site is bordered by West Amity Road to the north, undeveloped farmland to the west and south, and Victory Greens landscaping supply store to the east. 4.1 Published Geologic and Soil Information The geologic conditions at the site are mapped as Gravel of Amity Terrace (map symbol — Qag) on the Geologic Map of the Boise Valley and Adjoining Area, Western Snake River Plain, Idaho, by K.L. Othberg, and L.R. Stanford, 1992. This unit is described as sandy pebble and cobble gravel grading at depth to coarse pebbly sand about 33 feet thick mantled with 2 to 7 feet of loess. The USDA Natural Resources Conservation Service (NRCS), which classifies the upper 5 feet of soil, has mapped the site as Colthorp cobbly loam and Elijah silt loam. These soils consist of loam, cobbly loam, silty clay loam, silt loam, cemented material, and extremely gravelly sand. The parent material of these soils consists of alluvium, mixed alluvium, lacustrine deposits, loess, and loess over bedrock derived from basalt. The soils encountered in test pits are generally consistent with the published information. 4.2 Subsurface Soil Conditions At the time of exploration, the site contained approximately 6 to 8 inches of surficial roots and vegetation at the ground surface. In general, native subsurface soils within the observed test pits consisted of lean clays, lean clays with sand, sandy silts, silty sands, silty sands with gravel and cobbles, poorly-graded sands, poorly-graded sands with silt, poorly-graded sands with silt and gravel, poorly-graded gravels with sand, and poorly-graded gravels with sand and cobbles. Varying thicknesses of weak to strong cementation were commonly observed within the silty sand, poorly-graded sand, and poorly-graded sand with silt soil layers. Detailed descriptions of the soils observed are presented on the individual test pit logs in Appendix B. The descriptive soil terms used on the test pit logs, and in this report, can be referenced by the Unified Soil Classification System (USCS). A summary of the USCS is included in Appendix B. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 3 Subsurface conditions may vary between exploration locations; such changes in subsurface conditions may not be apparent until construction. 4.3 Groundwater Conditions At the time of exploration, we did not observe groundwater within the test pits to the maximum exploration depth of 13 feet below existing ground. Based on review of available well driller reports in the site vicinity (from Idaho Department of Water Resources), we anticipate groundwater may be encountered at depths greater than 100 feet below ground surface. Seasonal groundwater in the area may be influenced by local irrigation and nearby canals, ditches, drains, and laterals. Groundwater may also be influenced by precipitation, on-site construction, and development to adjacent sites. Groundwater elevations will fluctuate throughout the different periods of the year and will likely peak during snowmelt and irrigation seasons (March to October). We installed slotted PVC pipes within select test pits for future groundwater monitoring.ALLWEST is planning to perform monthly groundwater monitoring for the upcoming snowmelt and irrigation season to help establish seasonal high groundwater on-site. 5.0 LABORATORY TESTING We performed laboratory testing to supplement field classifications and to assess some of the soil engineering properties and parameters. Laboratory testing included fines content(ASTM D1140), moisture content (ASTM D2216), liquid and plastic limits (ASTM D4318), and California Bearing Ratio (ASTM D1883). The laboratory test results are included in Appendix C and are also summarized on the test pit logs in Appendix B. 6.0 CONCLUSIONS AND RECOMMENDATIONS Based on our field observations, testing, and evaluation, in our opinion the site is suitable for the planned development provided our recommendations are properly implemented. The following recommendations are presented to assist planning, design, and construction of the development relative to earthwork, utilities, stormwater disposal, and asphalt pavement section design. These recommendations are based on our understanding of the proposed development, the conditions observed within exploration locations, laboratory test results, and engineering analysis. If the proposed development changes or if unforeseen conditions are encountered during construction, we should be given the opportunity to review the new information and, if necessary, update our recommendations. Additionally, we should be given the opportunity to review development plans and specifications to determine whether the recommendations presented in this report were properly incorporated. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 4 6.1 Site Preparation ♦ Prior to conducting site grading, surficial soil containing vegetation, roots, and organics should be removed below proposed site grading fill areas, pavement areas, structural areas, and any other development areas. In general, we anticipate approximately 6 to 8 inches of site stripping will be required for most of the site to remove surficial vegetation and roots. ♦ We anticipate the existing on-site structures, parking lot, utilities, radio towers, and transmission lines will be demolished and removed as part of development. These improvements, and any associated fill soils, should be completely over-excavated to suitable native soils. If not removed by typical earthwork/construction processes, the existing shallow-buried copper wiring arrays, associated with the on-site radio towers, may be left in-place due to their small diameters and low corrosion potential. ♦ Organic-rich, loose/soft, and/or wet soils associated with existing irrigation ditches are present on-site. These soils are not suitable to support site grading fill, pavement sections, or structural improvements. Within proposed development areas, these soils should be completely over-excavated to suitable native soils. ♦ Depths and lateral limits of over-excavations associated with site demolition and unsuitable soils may not fully be known until earthwork begins. The earthwork contractor should have continencies in place to ensure that these areas are fully over-excavated to suitable native soils within development areas. ♦ Loose test pit backfill will settle with time, so where any test pits are located below proposed pavement, structural, or any development areas, loose test pit backfill soil should be re-excavated to its entire depth and replaced with suitably moisture-conditioned and compacted fill soils. Over-excavated soils can be reused to backfill the test pits, provided the soils are not overly saturated, and they can achieve the compaction criteria provided in section 6.4 Fill Placement and Compaction. Approximate test pit locations are shown on Figure A-2: Exploration Location Map. ♦ After site stripping, over-excavations, loose test pit remediation, and prior to site grading, utility/roadway construction, or any other type of development, the exposed subgrades should be proof-rolled with a minimum 5-ton vibratory roller,with loaded dump trucks/front- end loaders, or with a vibratory hoe-pack, to confirm subgrade stability. This will also assist in identifying any soft subgrade areas. If native subgrades are observed to significantly deflect or pump, the subgrades should be over-excavated and replaced with properly compacted fill or stabilized as recommended in section 6.1.1 Subgrade Stabilization. 6.1.1 Subgrade Stabilization If needed, subgrades may be stabilized using geosynthetic (geogrid) or woven geotextile reinforcement in conjunction with imported granular structural fill. The required thicknesses of GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 5 granular structural fill (used in conjunction with geogrid or woven geotextile reinforcement)will be dependent on the construction traffic loading (which is unknown at this time), the type of reinforcement (geogrid or woven geotextile), and subgrade conditions. Therefore, a certain degree of trial and error may be required during construction to verify recommended stabilization section thicknesses and reinforcement types. Geogrid reinforcement should consist of Tensar TX-160, NX-750, or equivalent. Woven geotextile reinforcement should consist of Contech C200 or equivalent. Alternatives to these reinforcement types should be approved by the geotechnical engineer prior to use on site. The following recommendations are provided for subgrade stabilization using reinforcement materials. ♦ Subgrade soils that are disturbed by construction equipment (caused rutting or pumping) should be over-excavated down to undisturbed native soils, utilizing a smooth-blade bucket to limit further disturbance of native soils. Reinforcement materials should be placed on a properly prepared non-disturbed subgrade with smooth surface. ♦ If geogrid reinforcement is used, a minimum weight 4-ounce, non-woven filter fabric should first be placed on the properly prepared subgrade. The geogrid reinforcement should then be placed directly on top of the filter fabric and pulled taut to remove slack. The filter fabric and reinforcement materials should be unrolled in the primary direction of fill placement and should be over-lapped at least 3 feet or follow manufacturer's recommendations. Filter fabric is not required if a woven geotextile is used for reinforcement. ♦ Construction equipment should not be operated directly on reinforcement materials. Granular structural fill should be placed from outside the excavation to create a pad to operate equipment on. We recommend a minimum of 12 to 18 inches of granular structural fill be placed over the reinforcement materials before operating construction equipment on the fill. Low pressure, track-mounted equipment should be used to place granular structural fill over the reinforcement materials. ♦ Granular structural fill placed directly over reinforcement materials should be properly moisture-conditioned prior to placement, and once placed, be statically rolled. This combination of reinforcement materials and granular structural fill is considered the "bridge" section over soft subgrades. ♦ After the first"bridge"section has been placed, the remaining structural fill materials above the "bridge" section should be compacted to structural fill criteria in section 6.4 Fill Placement and Compaction, utilizing vibratory compaction methods. ♦ Vibratory compaction should be discontinued if it reduces the subgrade stability. If compaction criterion is not met within the fill lift above the "bridge" section, the "bridge" section is not thick enough, and subgrade stabilization should be attempted again with a thicker"bridge" section. GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 6 The geotechnical engineer or a representative of the geotechnical engineer should be on-site during subgrade stabilization to verify our recommendations are followed, and to provide additional recommendations, as needed. 6.1.2 Utility Trenches Existing subsurface soils should provide adequate support for utilities, provided utility subgrades are compacted utilizing vibratory methods, such as with a large vibratory hoe-pack. If utility pipe subgrades are soft, yielding, and/or saturated at the time of construction, subgrade over- excavation and replacement with competent fill may be required below utilities. If support soils yield and/or are saturated at the time of construction, we should be notified to observe these soils and provide additional recommendations, as necessary. 6.2 Excavation We anticipate most of the on-site soils can be excavated with typical excavation equipment. However, excavation refusal due to strongly cemented soils was encountered in test pit TP-4. Excavation of strongly cemented soils may require the use of larger excavation equipment, hydraulic breakers, and/or other construction methodology. Contingencies should be made during design and/or earthwork to account for potential excavation difficulties. Depths to refusal encountered during our field exploration are presented on the test pit logs in Appendix B. Stability of temporary excavations is a function of many factors, including the presence and abundance of groundwater, the type and density of various soil strata, the depth of cut, surcharge loadings adjacent to the excavation, and the length of time the excavation remains open. It is exceedingly difficult under the variable circumstances to pre-establish a safe and "maintenance- free" temporary cut slope angle. Therefore, it is the responsibility of the contractor to maintain safe temporary slope configurations since the contractor is continuously at the job site, able to observe the nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater conditions encountered. Unsupported vertical slopes or cuts deeper than 4 feet are not recommended if worker access is necessary. The cuts should be adequately sloped, shored, or supported to prevent injury to personnel from local sloughing and spalling. The excavation should conform to applicable federal, state, and local regulations. Regarding trench wall support, the site soil is considered Type C soil according to Occupational Safety and Health Administration (OSHA) guidelines and therefore should not exceed a 1.5H:1V (horizontal to vertical) temporary slope. 6.3 Materials Stripped soils containing vegetation or debris are only suitable for use in non-structural landscape areas. Existing on-site soils may be reused as site grading fill, provided they are stockpiled separately, they meet the criteria below, and they are moisture-conditioned and compacted as required in this report. Imported granular soils should be free of organics, debris, and other GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 7 deleterious material and meet the following criteria. Import materials should be approved by ALLWEST prior to delivery to the site. Fill Type Criteria Site Grading Fill Maximum size <_ 6 inches; 0 0 Retained on 3/4-inch sieve < 30/o; Liquid limit < 50/o Maximum size <_ 6 inches; Granular Structural Fill, Retained on %-inch sieve < 30%; Granular Subbase Passing No. 200 sieve <_ 15%; Non-plastic Alternatively, meet ISPWC section 801 (6-inch max) Maximum size <_ 1 inch; Crushed Base Course Retained on 3/4-inch sieve < 10%; Passing No. 200 sieve < 10%; Non-plastic Alternatively, meet ISPWC section 802 (Type 1) Maximum size <_ 2 inches; Utility Trench Backfill Retained on %-inch sieve < 30%; (above pipe bedding) Passing No. 200 sieve <_ 10%; Non-plastic Alternatively, meet ISPWC section 801 (3-inch max) 6.4 Fill Placement and Compaction Fill should be placed in lift thicknesses which are appropriate for the compaction equipment used. Typically, 8-to 12-inch-thick loose-lifts are appropriate for rubber-tire and steel-drum compaction equipment. Lift thickness should be reduced to 4 inches for hand-operated compaction equipment. Fill should be moisture-conditioned to within 2 percentage points of the optimum moisture content prior to placement to facilitate compaction. Fill should be compacted to the percentages of the maximum dry density, based on ASTM D1557 (modified Proctor), presented in the following table. Fill Type Compaction (/o) Subgrade' Proof-rol12 Site Grading Fill / Granular Structural Fill 95 Granular Subbase / Crushed Base Course 952 Utility Trench Backfill 922 'Subgrade stability should be verified and approved by a representative of the geotechnical engineer prior to any fill placement or construction. 2For roadway and utility trench construction, the local governing jurisdiction may provide their own method of determining the maximum dry density and compaction requirements (including subgrade). GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 8 On-site fine-grained soils (silts and clays) may be difficult to moisture-condition and compact in utility trenches. Therefore, we strongly recommend backfilling trench excavations with soils that meet the Utility Trench Backfill criteria presented in the table in section 6.3 Materials. 6.5 Wet Weather Construction We recommend earthwork for the site be scheduled for the drier seasons of the year. If construction is undertaken in wet periods of the year, it will be important to slope the ground surface to provide drainage away from construction. If construction occurs during or immediately after excessive precipitation, it may be necessary to over-excavate and replace saturated subgrade soil, which might otherwise be suitable. The on-site soils are sensitive to disturbance when wet. If these soils become wet and unstable, we recommend construction traffic is minimized where these soils are exposed. Low ground- pressure (tracked) equipment should be used to minimize disturbance. Soft and disturbed subgrade areas should be excavated to undisturbed soil and backfilled with structural fill, compacted to requirements stated in this report. In addition, it should be noted the on-site soils tend to have notable adhesion when wet and may be easily transported off-site by construction traffic. 6.6 Cold Weather Construction The on-site soils are frost susceptible. If site grading and construction are anticipated during cold weather, we recommend good winter construction practices be implemented. Snow and ice should be removed from excavated areas and fill areas, prior to additional earthwork or construction. Pavement and flatwork portions of the construction should not be placed on frozen ground, nor should the supporting soils be permitted to freeze during or after construction. Frozen soils should not be used as fill. If native subgrades, or suitably moisture-conditioned and compacted fill lifts, will be left exposed to freezing temperatures overnight, those areas should be protected with a minimum of 12 inches of loose soil, or covered with heated construction blankets, so construction subgrades do not freeze. Frozen soils should be removed prior to any fill placement or construction of any kind. Earthwork construction during cold inclement weather will require a higher level of attention and detail to achieve required construction and compaction criteria, and may lead to additional earthwork requirements and extended construction schedules. 6.7 Stormwater and Drainage During exploration, we performed field seepage testing in test pits TP-1, -3, -5, -6, -7, and -9 within non-cemented on-site "sands and gravels", which included poorly-graded sands with silt and gravel, poorly-graded gravel with sand, and poorly-graded gravels with sand and cobbles. We GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 9 obtained field-measured seepage rates of greater than 15 in/hr within the on-site "sands and gravels". Varying levels of cementation were commonly observed during field exploration within the silty sand, poorly-graded sand, and poorly-graded sand with silt soil layers. We do not recommend stormwater disposal be accomplished within these cemented soils, as they typically exhibit very poor and inconsistent seepage rates. Refer to the test pit logs in Appendix B to verify depths and contacts of soils which are not suitable for stormwater disposal. We recommend stormwater disposal occur within non-cemented on-site "sands and gravels", as observed during our field exploration. Based on field seepage test results and our experience with similar soil types, we recommend the following allowable seepage rate be utilized for on-site civil stormwater disposal into the "sands and gravels". ♦ Sands and Gravels............................................................. 8 in/hr Stormwater disposal facilities should be constructed a minimum of 1 foot into the recommended receiving soil. Filter fabric should be properly utilized to separate native soils from stormwater disposal facility drain rock and filter sand materials to help prevent fine-soil migration into drainable/filtering media, as required by civil design. The proper separation from bottom of stormwater disposal facilities and seasonal high groundwater should be maintained. As such, groundwater monitoring should be performed throughout seasonal snowmelt and irrigation seasons (March to October) to help establish a seasonal high groundwater elevation at the site. We installed slotted PVC pipes within select test pits for future groundwater monitoring.ALLWEST is planning to perform monthly groundwater monitoring for the upcoming snowmelt and irrigation season to help establish seasonal high groundwater on-site. We recommend final grading include slopes that direct stormwater run-off away from buildings and pavement areas toward stormwater management systems. Water should not be allowed to infiltrate or pond adjacent to foundations or development areas. 6.8 Asphalt Pavement Prior to pavement section construction, the pavement subgrade should be proof-rolled as recommended in section 6.1 Site Preparation (or as recommended by local jurisdictions). Local and collector roadways were designed for a 20-year Equivalent Single Axle Load (ESAL) of 33,000 and 370,000, respectively, which is equivalent to Traffic Index (TI) values of 6 and 8, GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 10 respectively. If traffic conditions are different than what is stated, we should be notified so that we may modify our pavement section design. Based on existing site grades, we anticipate that the majority of pavement subgrade areas will consist of lean clays, lean clays with sand, sandy silts, and/or silty sands. We performed California Bearing Ratio (CBR) testing on a sandy silt soil, where we obtained a CBR value of 11.0, which is approximately equivalent to an R-value of 20. However, based on the presence of lean clays we utilized an R-value of 15 in our pavement section design. The following flexible asphalt pavement sections were designed utilizing AASHTO pavement methodology and our experience with local jurisdictions. Based on subgrade preparation requirements and design assumptions, we recommend the following pavement sections be utilized for subdivision construction of local and collector roadways. Asphalt Crushed Granular Pavement Application Concrete Base Course Subbase (inches) (inches) (inches) Local Roadway 2.5 4 11 Collector Roadway 3 6 14 Base course and subbase should conform to the material recommendations as noted in this report and should be placed over a properly prepared subgrade. Finished asphalt surfaces should slope no less than 2% to help reduce the potential for surface water to infiltrate into the underlying pavement sections and subgrade soils. If the overall site is relatively flat, then finished asphalt surfaces should be constructed with crowns that slope away at a minimum gradient of 2% toward stormwater collection areas. Crack maintenance on pavements should be performed at least every 3 years, or when cracking is evident. Crack sealing will help reduce surface water from infiltrating into the supporting soils. 7.0 ADDITIONAL RECOMMENDED SERVICES To maintain continuity and efficiency, we recommend ALLWEST be retained to provide observations and testing throughout earthwork construction. As an independent testing company, ALLWEST can document the recommendations included in this report are followed, provide quality control testing, and observe earthwork for conformance to project specifications. As a minimum, we recommend the following testing and observations be provided by ALLWEST: GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Geotechnical Evaluation ALLWEST Project No. 524-051 G Townsquare Media Property Development March 27, 2024 Meridian, Idaho Page 11 ♦ Observe site stripping, over-excavations, test pit remediation, and any other soil over- excavations and backfills. ♦ Observe subgrade proof-rolling and approve subgrades prior to fill/materials placement or roadway section/utility construction. ♦ Observe removal of disturbed soil and subgrade stabilization, if required. ♦ Observe stormwater disposal facility subgrade soils and overall construction. ♦ Conduct compaction testing of any fill soils placed for general site grading, utility backfills, and roadway construction. ♦ Observe placement of/test asphalt for compaction, oil content, and gradation. If we are not retained to provide the recommended construction observation and testing services, we shall not be responsible for soil engineering-related construction errors or omissions. 8.0 EVALUATION LIMITATIONS This report has been prepared to assist planning, design, and construction of the proposed Townsquare Media Property Development located in Meridian, Idaho. Reliance by any other party is prohibited without the written authorization of ALLWEST. Our services consist of professional opinions and conclusions made in accordance with generally accepted geotechnical engineering principles and practices in the local area at the time this report was prepared. This acknowledgement is in lieu of all warranties, whether express or implied. The following appendices complete this report: Appendix A—Vicinity Map, Exploration Location Map Appendix B —Test Pit Logs, Unified Soil Classification System Appendix C— Laboratory Test Results GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Appendix A A-1 : Vicinity Map A-2: Exploration Location Map GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Base Map:Google Earth I�3 i .. � 'Y ;� } ; s.-I �' I it ul TL �_l ar! �.-I►+� � I'• � , •i� ,, a..�, -I_ �.....��•' }y�ta��"� ''+S�•1J�i��.i,is. S��`-�f 'L I;:-, - F .-,� ._:. ' (• ?1r`S !� 'w t_ CIE �.i [L• -�+A -`,. _4171 L' O A3 �� ' I. ❑ o o r-n "a L n'4�' i F511", :0.1 lv ~ . 1 _ �' ' Site " � .. ' t� f0 N 0' 3,000' 6,000' FIGURE A-1:VICINITY MAP GEOTECHNICAL EVALUATION ALLWESTTOWNSQUARE MEDIA PROPERTY DEVELOPMENT MERIDIAN, IDAHO 255 N.LINDER ROAD CLIENT:TRILOGY DEVELOPMENT MERIDIAN IDAHO,83642 PHONE:(208)895-7898 FAX:(208)898-3959 PROJECT NO.:524-051 G DATE: MARCH 2O24 Base Map:Google Earth Li �► F 1 t4:' f� ' I r!� Boundary AL Amit Ave .. a14 ■ TP-3:...4 TP-4 0 TP-5 � 1' 4 TP-6 ■ I I 91 I TP-7 I r ■9� TP-8 TP-A,( a. ram. 'ems, 0 TP-11 0 TP-12 -13 ■ LEGEND N 0 Approximate location of test pit observed by ALLWEST. * Slotted PVC pipe was installed in test pit. o zoo' 400 Will FIGURE A-2: EXPLORATION LOCATION MAP GEOTECHNICAL EVALUATION ALLWESTTOWNSQUARE MEDIA PROPERTY DEVELOPMENT MERIDIAN, IDAHO 255 N.LINDER ROAD CLIENT:TRILOGY DEVELOPMENT MERIDIAN IDAHO,83642 PHONE:(208)895-7898 FAX:(208)898-3959 PROJECT NO.:524-051 G DATE: MARCH 2O24 Appendix B Test Pit Logs Unified Soil Classification System GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY ALLWEST DATE STARTED: 2/1/2024 TP - 1 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'40.3344"(43.561204°) U U LONGITUDE(DEGREES):W-116°24'1.4904" (-116.400414°) U u) TOTAL DEPTH: 10' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 6 CL inches. 1 Silty SAND;tan,dense,moist 2 sm .moderate cementation observed throughout soil layer 3 Poorly-graded GRAVEL with Sand;tan, medium dense,moist o� Q Bag 3.5'-4' 4— 0 Field seepage test performed at 4 feet. Field seepage rate> 15 in/hr. 0 Q o� 5- 6— GP 0 Q 7 o� 0 Q 8 o� 9 o Q o� 0 10— Test pit terminated at 10 feet due to caving. O Slotted PVC pipe installed. 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 2 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'39.7944"(43.561054°) U U LONGITUDE(DEGREES):W-116°23'59.6688" (-116.399908°) U u) TOTAL DEPTH: 10.5' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Poorly-graded SAND with Silt;tan, medium dense to dense,moist 2- 3— Passing No.200 sieve= 11% Bag 3.5'-4' Moisture content=26% 4 sP-snn weak to moderate cementation observed throughout soil layer 5- 6- 7 Poorly-graded GRAVEL with Sand;tan, medium dense,moist ° 8 0 Q ° g GP Q ° O Q 1 0� 0 Test pit terminated at 10.5 feet due to caving. Slotted PVC pipe installed. 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 3 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'38.952"(43.56082°) U U LONGITUDE(DEGREES):W-116°23'54.4848" (-116.398468°) U a u) TOTAL DEPTH:9.5' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Silty SAND with Gravel and Cobbles;tan,dense,moist ...subrounded gravel and cobbles up to 10 inches in maximum 2 dimension 3 sm 4 5 Poorly-graded GRAVEL with Sand and Cobbles;tan,dense, moist °b ...subrounded gravel and cobbles up to 10 inches in maximum o dimension O 6 0 Q 7 ° Field seepage test performed at 7 feet. GP Q Field seepage rate> 15 in/hr. a O 0 Q 9 0 Test pit terminated at 9.5 feet due to caving. Slotted PVC pipe installed. 1 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 4 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'39.2112"(43.560892°) U U LONGITUDE(DEGREES):W-116°23'57.8616" (-116.399406°) U u) TOTAL DEPTH:6' = SAMPLE 0- CL Lu DESCRIPTION W NOTES Lean CLAY(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. Passing No.200 sieve=90% cL Bag 0.5'-1' Moisture content=24% 1 LL=37, PL= 19,PI= 18 Silty SAND;tan,dense to very dense,moist 2 3 sm ...moderate to strong cementation observed throughout soil layer 4 5 6 Test pit terminated at 6 feet due to excavator refusal on strong cementation. 7 8 9 1 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 5 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'35.01"(43.559725°) U U LONGITUDE(DEGREES):W-116°23'51.5544" (-116.397654°) U u) TOTAL DEPTH: 10.5' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Silty SAND;tan,medium dense, moist 2 sm 3 4 Poorly-graded GRAVEL with Sand and Cobbles;tan, medium dense,moist ° ...subrounded gravel and cobbles up to 6 inches in maximum o dimension O 5 0 O o� 6 0 O o� 7 O GP 0 O O $ o� O O ° Field seepage test performed at 9 feet. 9 O Field seepage rate> 15 in/hr. o� 0 1 Q 0 Test pit terminated at 10.5 feet due to caving. 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 6 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'33.7104"(43.559364°) U U LONGITUDE(DEGREES):W-116°23'54.726" (-116.398535°) U u) TOTAL DEPTH:8' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 CL inches. 1 Silty SAND;tan,medium dense, moist 2 SM 3 Passing No.200 sieve=23% Bag 3' 3.5' Moisture content=26% 4— Poorly-graded SAND with Silt and Gravel;tan,medium dense, moist 5 Bag 5'-5.5' Field seepage test performed at 5.5 feet. Field seepage rate> 15 in/hr. 6 SP-SM 7 8 Test pit terminated at 8 feet due to caving. Slotted PVC pipe installed. 9 1 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 7 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'32.4108"(43.559003°) C0 U LONGITUDE(DEGREES):W-116°23'54.8304" (-116.398564°) U u) TOTAL DEPTH:9' = SAMPLE CL w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native);brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Silt SAND; b to light brown,dense, moist Observed bare copper wire at 1.5 feet on a y brown g portion of test pit sidewall. 2 3 sm .moderate cementation observed throughout soil layer 4 5 Poorly-graded GRAVEL with Sand and Cobbles; light brown, medium dense, moist ° 6 ...subrounded gravel and cobbles up to 6 inches in maximum o dimension O ° Field seepage test performed at 6.5 feet. Field seepage rate> 15 in/hr. 0 7 Q GP 0 O Q $ o� O Q 0 9 Test pit terminated at 9 feet due to caving. Slotted PVC pipe installed. 1 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 8 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'29.1276"(43.558091°) U U LONGITUDE(DEGREES):W-116°23'53.6928" (-116.398248°) U u) TOTAL DEPTH: 13' = SAMPLE CL w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Silty SAND;tan to brown,dense,moist 2 3 4 5 6 sm ...moderate cementation observed throughout soil layer 7 8 Passing No.200 sieve=21 Bag 8' 8.5' Moisture content= 19% 9 1 1 1 Poorly-graded GRAVEL with Sand;light brown,medium dense, moist °U GP o Q 1 Test pit terminated at 13 feet. Slotted PVC pipe installed. 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 9 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'29.988"(43.55833°) U U LONGITUDE(DEGREES):W-116°23'52.7064" (-116.397974°) U u) TOTAL DEPTH: 10' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Silty SAND;tan,medium dense, moist 2- 3- 4— ...weak cementation observed throughout soil layer Passing No.200 sieve=24% sm Bag 4' 4.5' Moisture content= 12% 5- 6- 7 Poorly-graded GRAVEL with Sand;tan, medium dense,moist o� Q Bag 7.5'-8' 8— 0 Field seepage test performed at 8 feet. Field seepage rate> 15 in/hr. GP O Q o� g o Q o� O 1 Test pit terminated at 10 feet due to caving. Slotted PVC pipe installed. 1 1 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 10 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'29.1276"(43.558091°) U U LONGITUDE(DEGREES):W-116°23'53.6928" (-116.398248°) 01 U u) TOTAL DEPTH: 13' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Silty SAND;tan to light brown,medium dense to dense, moist 2 3 4 5 SM T. 6 ...weak to moderate cementation observed throughout soil layer 7- 8- 9 1 Poorly-graded GRAVEL with Sand and Cobbles; light brown to tan,medium dense, moist ° ...subrounded gravel and cobbles up to 8 inches in maximum o dimension O 1 °b GP O o� 1 0 O 0 1 Test pit terminated at 13 feet. Slotted PVC pipe installed. 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 11 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'29.9196"(43.558311°) U U LONGITUDE(DEGREES):W-116°23'53.6676" (-116.398241°) 01 U u) TOTAL DEPTH: 12' = SAMPLE a CL Lu DESCRIPTION W NOTES Sandy SILT(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. ML Passing No.200 sieve=62% 1 Bulk 0.5'-1.5' ILL=46, PL=29,PI= 17 CBR=11.0 Silty SAND;tan,medium dense to dense, moist 2- 3— Passing No.200 sieve= 19% Bag 3' 3.5' Moisture content=24% 4 5 6 sm ...weak to moderate cementation observed throughout soil layer 7- 8- 9 1 1 1 Test pit terminated at 12 feet. Slotted PVC pipe installed. 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 12 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'29.988"(43.55833°) U U LONGITUDE(DEGREES):W-116°23'52.7064" (-116.397974°) 01 U u) TOTAL DEPTH: 12' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. CL 1 Silty SAND;tan to brown,medium dense to dense, moist 2 3 4 5 6 sm ...weak to moderate cementation observed throughout soil layer 7- 8- 9 1 1 1 Test pit terminated at 12 feet. Slotted PVC pipe installed. 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 ALLWEST DATE STARTED: 2/1/2024 TP - 13 DATE FINISHED: 2/1/2024 EXCAVATOR: CASE 580C MERIDIAN,IDAHO OPERATOR:Steve Just EXCAVATION METHOD:24-inch wide GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc. toothed bucket LOGGER:Parker Norris TEST PIT LOG WEATHER:Cloudy PROJECT:524-051 G NOTES:See Figure A-2 in Appendix A for approximate test pit location. Townsquare Media Property Development LATITUDE(DEGREES):N 43°33'29.988"(43.55833°) U U LONGITUDE(DEGREES):W-116°23'52.7064" (-116.397974°) 01 U u) TOTAL DEPTH: 12.5' = SAMPLE w Q DESCRIPTION W NOTES Lean CLAY with Sand(Native); brown, medium stiff, moist Significant roots and vegetation observed to 8 inches. Passing No.200 sieve=72% cL Bag 0.5'-1' Moisture content=25% 1 LL=38, PL=22,PI= 16 Poorly-graded SAND;tan,dense, moist 2 3 ...moderate cementation observed throughout soil layer SIR 4 Passing No.200 sieve=2% Bag 4'-4.5' Moisture content= 18% 5 Silty SAND; brown, medium dense,moist Bag 5'-5.5' Passing No.200 sieve=33% Moisture content=20% 6 7 SM $ ------------------------------------------------ .. . ...weak cementation observed from 8 to 10 feet 9 1 Poorly-graded GRAVEL with Sand and Cobbles; light brown, medium dense, moist ° ...subrounded gravel and cobbles up to 6 inches in maximum o dimension O GP 0 O o� 1 0 O Test pit terminated at 12.5 feet. Slotted PVC pipe installed. 1 1 WATER LEVELS a WHILE EXCAVATING Y AT COMPLETION 1 AFTER EXCAVATING Sheet 1 of 1 SOIL CLASSIFICATION CHART (ASTM D2487 & D2488) MAJOR GROUP TYPICAL SOIL NAMES TYPICAL SOIL DESCRIPTORS DIVISIONS SYMBOL GW Well-graded gravel,gravel-sand mixtures,little or no fines. Description SPT Blow Counts O Very loose less than 4 Loose 4 to 10 w GP Poorly-graded gravel,gravel-sand mixtures,little or no fines. Medium dense 11 to 29 C3� > O Dense 30 to 50 Very dense greater than 50 0 o O GM Silty gravel,gravel-sand-silt mixtures. o Material Sieve Sizes CC14 Boulders greater than 12" w r GC Clayey gravel,gravel-sand-silt-clay mixtures. Cobbles 3"to<12" z � Q o Coarse gravel 3/4"to<3" Fine gravel #4 to<3/4" SW Well-graded sand,gravelly sand,little or no fines. Coarse sand <#4 to#10 Medium sand <#10 to#40 Q w Fine sand <#40 to#200 oo SP Poorly-graded sand,gravelly sand, little or no fines. Silt or clay less than#200 n ¢ Sieve Number Aperture SM Silty sand,sand-silt mixtures. #4 4.76 mm(0.187 in) #10 2.00 mm(0.0787 in) #40 0.42 mm(0.0165 in) SC Clayey sand,sand-clay mixtures. #200 0.074 mm(0.00291 in) ML Inorganic silt,non-plastic to low plasticity,gravelly silt, Description SPT Blow Counts Q LO sandy silt,clayey silt. v Very soft less than 2 U '= Soft 2 to 3 o E Inorganic clay of low to medium plasticity,gravelly clay, v� o z i CL sandy clay,silty clay(CL-ML),lean clay. Medium stiff 4 to 8 J N Q -0 Stiff 9 to 15 r J J Very stiff 16 to 29 o - r OL Organic silt and organic silty clay of low plasticity. Hard 30 to 50 Lu z =; r Very Hard greater than 50 0 L MH Inorganic silt,micaceous or diatomaceous fine sandy or Plasticity Soil Characteristics C7 Q silty soils,elastic silt. uw °�' A Non-plastic Cannot be rolled at any water content. Qo : Low A thread can barely be rolled while moist. z 1D CH Inorganic clay of high plasticity,fat clay. Medium A thread can be rolled easily but cannot be o rerolled after reaching the plastic limit. J a High A thread can be rolled and re-rolled several F OH:-:: Organic clay of medium to high plasticity. times after reaching the plastic limit. Definitions ORGANIC SOILS W PTy Peat and other highly organic soils. Liquid Limit(LL) Moisture content at which soil changes state from plastic to liquid. Plastic Limit(PL) Moisture content at which soil Dry Absence of moisture in sample. Dusty,dry to the touch. changes state from semi-solid to plastic. Plasticity Index(PI) Range of moisture contents at which Slightly Moisture in sample is below the optimum moisture content. a soil behaves plastically(LL-PL-PI). Moist Grains adhere slightly though surface tension. MOISTURE Moist Moisture in sample is at or near optimum moisture content. PLASTICITY CHART (ASTM D4318) No free water is visible. Moisture in sample is above the optimum moisture content. a 50 Wet Free water is visible in sample. w 0 o G� Weak Crumbles or breaks with handling or slight finger pressure. � CL-ML i CL MH or OH CEMENTATION Moderate Crumbles or breaks with considerable finger pressure. a a ML 0 0 16 50 Strong Will not crumble or break with finger pressure. LIQUID LIMIT(LL) ALLWEST Appendix C Laboratory Test Results GEOTECHNICAL I ENVIRONMENTAL MATERIALS TESTING I SPECIAL INSPECTION ALLWEST AN EMPLOYEE-OWNED COMPANY Table C-1: Summary of Laboratory Test Results Gradation Atterberg Limits Depth Test Pit Content Gravel Sand Silt/Clay De Moisture p Liquid Plastic Plasticity CBR Sample Classification ° (Feet) (%) ° ° ° Limit Limit Index (/°) (USCS) TP-2 3.5-4 26 11 Poorly-graded SAND with Silt(SP-SM) TP-4 0.5- 1 24 90 37 19 18 Lean CLAY(CL) TP-6 3 -3.5 26 23 Silty SAND (SM) TP-8 8-8.5 19 21 Silty SAND (SM) TP-9 4 -4.5 12 24 Silty SAND (SM) TP-11 0.5- 1.5 62 46 29 17 11.0 Sandy SILT(ML) TP-11 3 -3.5 24 19 Silty SAND (SM) TP-13 0.5- 1 25 72 38 22 16 Lean CLAY with Sand (CL) TP-13 4 -4.5 18 2 Poorly-graded SAND (SP) TP-13 5-5.5 20 33 Silty SAND SM 255 N. Linder Road • Meridian, Idaho 83642• (208)895-7895 • Fax(208)898-3959 www.allwesttesting.com This report may not be reproduced, except in full,without the permission of ALLWEST. LIQUID AND PLASTIC LIMITS TEST REPORT 60 Dashed line indicates the approximate upper limit boundary for natural soils 50 O �0 ' G 40 U C � X W N— Z_ ' v 30 c F- LU C/) ' Q i J / a: 20 0� H / ■ w A , J / J Q 10 0 ; c L-ML ML or OL MH or OH 0 0 10 20 30 40 50 60 70 80 90 100 110 LIQUID LIMIT 0 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS • Lean Clay 37 19 18 90% CL c■ Sandy Silt 46 29 17 62% ML CD♦ Lean Clay with sand 38 22 16 72% CL X m m U 7 O ` Project No. 524-051G Client: Trilogy Development Remarks: Project: Townsquare Media Property Development c *Location: TP-4 Depth: 0.5'-l' ■Location: TP-11 Depth: 0.5'- 1.5' ALocation: TP-13 Depth: 0.5'-1' 0 cn ALLWEST E H Figure C-1 Tested By: C. Downes Checked By:J.Varozza California Bearing Ratio ASTM D 1883 Project: Townsquare Media Property Development Project No.: 524-051 G Client: Trilogy Development Location: TP-11 @ 0.5 - 1.5 ft Date Tested: 2/19/2024 Compaction Method: ASTM D1557 Tested By: C. Downes Classification: Sandy Silt (ML) 325 300 275 250 225 Q 200 c 175 a c 150 125 100 PSI @ 0.1 inch penetration = 110 75 50 25 0 - 0 0.1 0.2 0.3 0.4 0.5 Penetration(inches) CBR @ 0.1 Inch Penetration: 11.0 Maximum Dry Unit Weight(pcf): 101 Swell (%): 1.5 Optimum Water Content (%): 20.1 Dry Unit Weight Before Soak(pcf): 91.6 Remold of Max. Dry Unt Wgt (%): 91 Water Content Before Soak(%): 21.3 Water Content After Soak, Top 1 Inch (%): 31.4 Surcharge (psf): 50 Immersion Period (hrs): 96 Reviewed By: James Varozza Figure: C-2 ALLWESY 255 N Linder Rd,Suite 100•Meridian,ID 83642•(208)895-7898•Fax(208)898-3959 www.allwesttesting.com This report shall not be reproduced except in full without the permission of ALLWEST.