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CC - Storm Drainage Calcs
Of THE LAN D GROUP Mogul Industrial Park Subdivision Phase 1 W. Grand Mogul Dr. Meridian Idaho Storm Water Management & Engineering Drainage Report Engineer The Land Group, Inc. ��S�G\ST ENGf� 462 East Shore Drive, Ste. 100 O Eagle, Idaho 83616 Contact: Jason Densmer, PE 109 1 Ph: 208.939.4041 July 23, 2025 -V 9TE'OF � N DEi TLG Project No. 124186 0-7/Z3/2025 462 East Shore Drive, Suite 100, Eagle, Idaho 83616 208,939.4041 thelandgroupinc.com Mogul Industrial Park Sub'd Phase 1 W.Grand Mogul Dr., Meridian Idaho Storm Water Management Report Project Description & Report Purpose The Mogul Industrial Park Subdivision — Phase 1 is a subdivision of the property under development as the Meridian Commerce Park. The project is located east of Black Cat Road, north of Interstate 1-84 and south of the Rosenlof Drain. The Phase 1 subdivision encompasses five (5) lots along Black Cat Rd which surround existing buildings for which no new improvements are required or proposed. In addition, this phase of subdivision will create two new buildable lots to the west,along an extension of W.Grand Mogul Dr. This report analyzes the storm drainage conditions for the proposed W. Grand Mogul Dr. extension and provides calculations demonstrating the adequacy of the proposed systems to meet the current requirements of the Ada County Highway District. Proposed Systems Storm Drainage Routing & Treatment Within each drainage basin, stormwater runoff is collected from roadways that are sloped to the gutters along the road edges,which then transport the collected drainage to catch basins.Once inside the system, stormwater flows through a drainage piping network to sand &grease traps,which provide pre-treatment prior to discharge into underground seepage beds for infiltration.The seepage beds designed per current ACHD policies and Best Management Practices (BMPs). Peak Rate of Discharge and Storage Volume The peak rate of discharge for the roadway drainage systems was calculated using the Ada County Highway District's published spreadsheets. Calculation worksheets for peak flow and required storage volume in each drainage basin are provided in Appendix B. :11 sO THE y LAND 462 East Shore Drive, Suite 100, Eagle, Idaho 83616 208.939.4041 - thelandgroupine.com =r GROUP Mogul Industrial Park Sub'd Phase 1 W.Grand Mogul Dr., Meridian Idaho Storm Water Management Report Appendix A Drainage Basin Map THE LAND 462 East Shore Drive, Suite 100, Eagle, Idaho 83616 208.939.4041 - thelandgroupine.com LEE GROUP lip I I �\ 0 I—W - I r� LAND %R GROUP I \ l I ' r � _ x O or +00 30+ 28+00 27 00m=26+00 —24+00 ^ VY = \, • CD �\ �} — + , - - - - - - - - - ` �A CD x CD M - AREA R - ' AREA A N _ �� \\ ;' _ - v� 449769 SF ANN 23,9��5 _ _ — \\ ��� ,, - III CL Cc Cc _ f _ \ --- ----- - I CD Cm Monson _ T CD CD o _— - - - - - - - - - - MINE J= Revisions Q Project No.: 124186 — � � I Date of Issuance: 07-23-2025 A � I STORM DRAIN CALCS NET Drainage Area Map 0 100' 200' DRAINAGE AREA MAP - orizonHtal Scale: 1" = 100' App Mogul Industrial Park Sub'd Phase 1 W.Grand Mogul Dr., Meridian Idaho Storm Water Management Report Appendix B Facility Sizing Calculations :1<0. THE y LAND 462 East Shore Drive, Suite 100, Eagle, Idaho 83616 208.939.4041 - thelandgroupine.com =r GROUP ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. steps tor Peak 1319CITINgle-Rate using the Rational Methodcalculated for post-development Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Mogul Industrial Park Sub'd Phase 1:W.Grand Mogul Drive 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 4 Enter number of storage facilities(25 max) 4 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 30 5 Area of Drainage Subbasin(SF or Acres) SF 23,927 Acres 0.55 6 Determine the Weighted Runoff Coefficient(C) 0.90 _ C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.90 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 Usercalculate min [10 Min. Estimated Runoff Coefficients for Various Surface Type of Surface Runoff Coefficients"( 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(QPeak) Qpeak 1.28 cfs Urban neighborhoods 0.50-0.70 Residential 3 Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 1,709 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,068 fts Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,Cemeteries 0.10-0.25 Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin streets Asphalt 0.95 Basin Forebay V 171 ft' concrete 0.95 Primary Treatm ent/Sto rage Basin V 1,538 ff' Brick 0.95 Roofs 0.95 Subsurface Storage Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 1,709 ffs Fields:Sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0.: Average:2-6% 0.09 0.12 0.15 0.. Steep:>6% 0.13 0.18 0.23 0.: Adapted from ASCE G:\2024\124186\CAD\Calcs and Reports\Mogul IP Subd Phs1\124186 ACHD_SD_CALCS.xlsm 7/23/2025,6:09 PM Version 10.5,November 2018 ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. steps tor Peak D191:11111111I using the Rational Methodcalculated for post-development Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Mogul Industrial Park Sub'd Phase 1:W.Grand Mogul Drive,Facility 2 2 Is area drainage basin map provided? YES (map must be included with stormwater calculations) 3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100 Click to Show More Subbasins ❑ Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin 1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10 5 Area of Drainage Subbasin(SF or Acres) SF 44,769 Acres 1.03 6 Determine the Weighted Runoff Coefficient(C) 0.90 C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted AvgJ 0.90 7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate min [10 Min. Estimated Runoff Coefficients for Various Surface Type of Surface Runoff Coefficients"( 8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business Downtown areas 0.70-0.95 9 Calculate the Post-Development peak discharge(Qeeak) Qp-k 2.39 cfs Urban neighborhoods 0.50-0.70 Residential Single Family 0.35-0.50 10 Calculate total runoff vol(V)(for sizing primary storage) V 3,197 ft Multi-family 0.60-0.75 V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40 11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70 Industrial and Commercial Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80 Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,998 ft' Heavy areas 0.90 12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,Cemeteries 0.10-0.25Playgrounds 0.20-0.35 Railroad yard areas 0.20-0.40 13 Volume Summary Unimproved areas 0.10-0.30 Surface Storage:Basin Streets Asphalt 0.95 Basin Forebay V 320 ft' Concrete 0.95 Primary Treatment/Storage Basin V 2,877 ft' Brick 0.95 Subsurface Storage Roofs 0.95 Gravel 0.75 Volume Without Sediment Factor(See BMP 20 Tab) V 3,197 fti Fields:sandy soil Soil Type Slope A B C D Flat:0-2% 0.04 0.07 0.11 0.: Average:2-6% 0.09 0.12 0.15 D.: Steep:>6% 0.13 0.18 0.23 0.: Adapted from ASCE G:\2024\124186\CAD\Calcs and Reports\Mogul IP Subd Phs1\124186 ACHD_SD_CALCS.xlsm 7/23/2025,6:09 PM Version 10.5,November 2018 ACHD Calculation Sheet for Sand/Grease Traps NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. User input in yellow cells. 1 Project Name Mogul Industrial Park Sub'd Phase 1 :W.Grand Mogul Drive 2 Enter number of Sand/Grease Traps(25 max) 4 Number Peak Baffle Throat Velocity Is the Vault Size of S/G Flow Q Spacing width Area (ft) 0.5 fps Velocity Traps cfs (inch) (inch) max. ok? 1000 G 1 1.28 18 48 6.00 0.21 Reference for Throat widths(inch) Boise ADS Vault Lar-ken WQU, BMP 16 1000 G 48.0 50.5 n/a 1500 G 60.0 61.5 n/a WQU1000 n/a n/a 60 WQU1500 n/a n/a 60 G:\2024\124186\CAD\Calcs and Reports\Mogul IP Subd Phs1\124186 ACHD_SD_CALCS.xlsm 7/23/2025, 6:09 PM Version 10.0, May 2018 ACHD Calculation Sheet for Sand/Grease Traps NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. User input in yellow cells. 1 Project Name Mogul Industrial Park Sub'd Phase 1 :W.Grand Mogul Drive,Tank 2 2 Enter number of Sand/Grease Traps(25 max) 2 Number Peak Baffle Throat Velocity Is the Vault Size of S/G Flow Q Spacing width Area (ft) 0.5 fps Velocity Traps cfs (inch) (inch) max. ok? 1000 G 1 2.39 18 48 6.00 0.40 Reference for Throat widths(inch) Boise ADS Vault Lar-ken WQU, BMP 16 1000 G 48.0 50.5 n/a 1500 G 60.0 61.5 n/a WQU1000 n/a n/a 60 WQU1500 n/a n/a 60 G:\2024\124186\CAD\Calcs and Reports\Mogul IP Subd Phs1\124186 ACHD_SD_CALCS.xlsm 7/23/2025, 6:09 PM Version 10.0, May 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Mogul Industrial Park Sub'd Phase 1:W.Grand Mogul Drive 2 Enter number of Seepage Beds(25 max) 4 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.90 Link to: Q.v Q,V2 5 Area A(Acres) 0.55 acres QV3 6 Approved discharge rate(if applicable) 0.00 cfs Q,V4 QV TR55 7 Is Seepage Bed in Common Lot? No V 2,136 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 15.0 ft 9 Set Total Design Depth of All Drain Rock D 3.4 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.35 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 0.50 in/hr 12 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 18.7 ft3/ft 15 Calculate Design Length L 0 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 0 ft 17 Variable Infiltration Window W SWW 15.0 ft 18 Time to Drain 0.0 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 0 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers wr Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft'/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft'/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ft, 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum G:\2024\124186\CAD\Calcs and Reports\Mogul IP Subd Phs1\124186 ACHD_SD_CALCS.xlsm 7/23/2025,6:09 PM Version 10.0,May 2018 ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the"Peak QV"tab Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab) User input in yellow cells. 1 Project Name Mogul Industrial Park Sub'd Phase 1:W.Grand Mogul Drive,Facility 2,Bed 2 2 Enter number of Seepage Beds(25 max) 2 3 Design Storm 100 4 Weighted Runoff Coefficient C 0.90 Link to: (Q,v J 5 Area A(Acres) 1.03 acres Q,v3 r 6 Approved discharge rate(if applicable) 0.00 cfs 4,v4 QV TR55 7 Is Seepage Bed in Common Lot? No V 3,996 ft3 25%Sediment 8 Set Total Design Width of All Drain Rock W 15.0 ft 9 Set Total Design Depth of All Drain Rock D 2.5 ft Rock Only,Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.35 0.4 for 1.5"-2"drain rock and 3/4"Chips 11 Design Infiltration Rate(8 in/hr max) Perc 0.50 in/hr 12 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in 13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in 14 Calculate Total Storage per Foot Spf 14.0 ft3/ft 15 Calculate Design Length L 0 ft Override Value Required for Chambers 16 Variable Infiltration Window L SWL 0 ft 17 Variable Infiltration Window W SWW 15.0 ft 18 Time to Drain 0.0 hours 90%volume in 48-hours minimum 19 Length of WQ&Overflow Perf Pipes 0 ft 20 Perf Pipe Checks.Qperf>=Qpeak; where Qperf=CdxAxV(2xgxH) Optional Storage Chambers wr Note:This assumes chambers are organized in a rectangular layout. 1-StormTech, 1 Type of Chambers SC740 2 Volume to Store V 0 ft3 3 Installed Chamber Width Cw 4.25 ft Installed Chamber Depth Cd 2.50 ft Installed Chamber Height Ch 7.12 ft 4 Chamber Void Factor 5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft'/Unit 6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft'/Unit 7 Total Number of Units Required 0 ea 8 Area of Infiltration Aperc ft, 9 Volume Infiltration Vperc 0 ft3/hr 10 Time to Drain hours 90%volume in 48-hours minimum G:\2024\124186\CAD\Calcs and Reports\Mogul IP Subd Phs1\124186 ACHD_SD_CALCS.xlsm 7/23/2025,6:09 PM Version 10.0,May 2018 Mogul Industrial Park Sub'd Phase 1 W.Grand Mogul Dr., Meridian Idaho Storm Water Management Report Appendix C Geotechnical Report & Addendum THE LAND 462 East Shore Drive, Suite 100, Eagle, Idaho 83616 208.939.4041 - thelandgroupine.com LEE GROUP 'PIN, - up r r 1 �.. a�:.. :'maw'-•• • , F. l E GEOTECHNICAL INVESTIGATION CHESTER INDUSTRIAL 955 South Black Cat Rd Meridian , ID "REPAIRED FOR: Mr. Brett Hardison AT Acquisition 12709 East Mirabeau Parkway, Suite 10 Spokane, WA 99216 PREPARED BY: Atlas Technical Consultants, LLC January 31, 2022 2791 South Victory View Way B211945G Boise, ID 83709 �TrT—G7T�l� 2791 South Victory View Way Boise, ID 83709 (208)376-4748 1 oneatlas.com January 31, 2022 Atlas No. B211945G Mr. Brett Hardison AT Acquisition 12709 East Mirabeau Parkway, Suite 10 Spokane, WA 99216 Subject: Geotechnical Investigation Chester Industrial 955 South Black Cat Rd Meridian , ID Dear Mr. Hardison: In compliance with your instructions, Atlas has conducted a soils exploration and foundation evaluation for the above referenced development. Fieldwork for this investigation was conducted on July 21 and October 6 through November 3, 2021. Data have been analyzed to evaluate pertinent geotechnical conditions. Results of this investigation, together with our recommendations, are to be found in the following report. We have provided a PDF copy for your review and distribution. Often, questions arise concerning soil conditions because of design and construction details that occur on a project. Atlas would be pleased to continue our role as geotechnical engineers during project implementation. If you have any questions, please call us at (208) 376-4748. Respectfully submitted, Clinton Wyllie, PG Elizabeth Brown, PE Staff Geologist Geotechnical Services Manager Page11 �TrT-G7T-�. CONTENTS 1. INTRODUCTION................................................................................................................. 1 1.1 Project Description ..................................................................................................... 1 1.2 Authorization .............................................................................................................. 1 1.3 Scope of Investigation................................................................................................ 1 2. SITE DESCRIPTION........................................................................................................... 2 2.1 Site Access ................................................................................................................ 2 2.2 Regional Geology....................................................................................................... 2 2.3 General Site Characteristics....................................................................................... 2 2.4 Regional Site Climatology and Geochemistry............................................................. 3 3. SEISMIC SITE EVALUATION ............................................................................................ 3 3.1 Geoseismic Setting .................................................................................................... 3 3.2 Seismic Design Parameter Values ............................................................................. 3 4. GEOLOGIC HAZARD ASSESSMENT ............................................................................... 4 4.1 Regional Faults .......................................................................................................... 4 4.2 Historical Seismicity ................................................................................................... 4 4.3 Seismically Induced Surface Rupture, Settlements, and Lateral Spreading................ 5 4.4 Liquefaction................................................................................................................ 5 4.5 Collapsible Soils......................................................................................................... 6 5. SOILS EXPLORATION....................................................................................................... L 5.1 Exploration and Sampling Procedures........................................................................ 6 5.2 Laboratory Testing Program....................................................................................... 7 5.3 Soil and Sediment Profile........................................................................................... 7 5.4 Volatile Organic Scan................................................................................................. 7 6. SITE HYDROLOGY............................................................................................................ 8 6.1 Groundwater.............................................................................................................. 8 6.2 Soil Infiltration Rates .................................................................................................. 8 6.3 Infiltration Testing....................................................................................................... 9 7. LATERAL EARTH PRESSURES ....................................................................................... 9 7.1 Retaining Wall Backfill Materials................................................................................10 7.2 Retaining Wall Drainage............................................................................................12 8. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS...........................12 8.1 Foundation Design Recommendations - Buildings A-E.............................................13 8.2 Foundation Design Recommendations - Buildings F-G ............................................14 8.3 Foundation Drain Recommendations ........................................................................15 8.4 Floor, Patio, and Garage Slab-on-Grade...................................................................15 9. PAVEMENT DISCUSSION AND RECOMMENDATIONS..................................................17 9.1 Flexible Pavement Sections - Private Paved Areas..................................................17 Atlas No. B211945G Page I i Copyright©2022 Atlas Technical Consultants �TrT-G7T-�. 9.2 Flexible Pavement Section — Public Collector Roads ................................................18 9.3 Pavement Subgrade Preparation ..............................................................................19 9.4 Common Pavement Section Construction Issues......................................................20 10. CONSTRUCTION CONSIDERATIONS ...........................................................................zu 10.1 Earthwork................................................................................................................20 10.2 Dry Weather............................................................................................................21 10.3 Wet Weather...........................................................................................................21 10.4 Soft Subgrade Soils.................................................................................................21 10.5 Frozen Subgrade Soils............................................................................................22 10.6 Structural Fill ...........................................................................................................22 10.7 Backfill of Walls.......................................................................................................24 10.8 Excavations.............................................................................................................24 10.9 Groundwater Control...............................................................................................24 11. GENERAL COMMENTS..................................................................................................25 12. REFERENCES.................................................................................................................26 TABLES Table 1 — Seismic Design Values................................................................................................4 Table2 — Groundwater Data.......................................................................................................8 Table 3 — Infiltration Test Results................................................................................................9 Table 4 — Lateral Earth Pressure Values for Native Soil............................................................10 Table 5 — Lateral Earth Pressure Values for Native Soil............................................................11 Table 6 — Lateral Earth Pressure Values for Fill Materials.........................................................11 Table 7 — Soil Bearing Capacity................................................................................................13 Table 8 — Soil Bearing Capacity................................................................................................14 Table 9 —AASHTO Flexible Pavement Specifications —Without Geogrid Reinforcement.........17 Table 10 —AASHTO Flexible Pavement Specifications —With Geogrid Reinforcement............18 Table 11 — Gravel Equivalent Method Flexible Pavement Specifications...................................19 APPENDICES Appendix I Warranty and Limiting Conditions Appendix II Vicinity Map Appendix III Site Map Appendix IV Foundation Cross Section Appendix V Geotechnical Investigation Test Pit Log Appendix VI Geotechnical Investigation Boring Log Appendix VI Geotechnical General Notes Appendix VIII AASHTO Pavement Design Appendix IX Gravel Equivalent Method Pavement Design Atlas No. B211945G Page i ii Copyright©2022 Atlas Technical Consultants slim I �TlTG7T�1 Appendix X CBR Laboratory Test Data Appendix XI Important Information About This Geotechnical Engineering Report Atlas No. B211945G Page I iii Copyright©2022 Atlas Technical Consultants 1. INTRODUCTION This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 2018 International Building Code (IBC). Information in support of groundwater and stormwater issues pertinent to the practice of Civil Engineering is included. Observations and recommendations relevant to the earthwork phase of the project are also presented. Revisions in plans or drawings for the proposed development from those enumerated in this report should be brought to the attention of the soils engineer to determine whether changes in the provided recommendations are required. Deviations from noted subsurface conditions, if encountered during construction, should also be brought to the attention of the soils engineer. 1.1 Project Description The proposed development is in the western portion of the City of Meridian , Ada County, ID, and occupies portions of the N'/z SE'/4 and the S'/2NE'/4 of Section 16, Township 3 North, Range 1 West, Boise Meridian. This project will consist of construction of 7 light industrial structures ranging from 68,640 to 288,600 square-feet in size. Additionally, multi-family residential structures may be constructed in the eastern portion of the site fronting Black Cat Road. The site to be developed is approximately 115.366 acres. Total settlements are limited to 1 inch. Loads of up to 8,000 pounds per lineal foot for wall footings, and column loads of up to 100,000 pounds were provided for settlement calculations. Additionally, assumptions have been made for traffic loading of pavements. Retaining walls in the form of loading docks may be constructed. Atlas has not been informed of the proposed grading plan. 1.2 Authorization Authorization to perform this exploration and analysis was given in the form of a written authorization to proceed from Mr. Brett Hardison of AT Acquisition to Clinton Wyllie of Atlas Technical Consultants (Atlas), on July 2, 2021. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between AT Acquisition and Atlas. Our scope of services for the proposed development has been provided in our proposal dated June 30, 2021 and repeated below. 1.3 Scope of Investigation The scope of this investigation included review of geologic literature and existing available geotechnical studies of the area, visual site reconnaissance of the immediate site, subsurface exploration of the site,field and laboratory testing of materials collected, and engineering analysis and evaluation of foundation materials. Atlas No. B211945G Page 11 Copyright©2022 Atlas Technical Consultants 2. SITE DESCRIPTION 2.1 Site Access Access to the site may be gained via Interstate 84 to the Ten Mile Road exit. Proceed north on Ten Mile Road approximately 0.8 mile to its intersection with Franklin Road. From this intersection, proceed west on Franklin Road 1.0 mile to Black Cat Road. Head south on Black Cat Road approximately 0.5 mile. The site is located on the west side of Black Cat Road. The location is depicted on site maps included in the Appendix. 2.2 Regional Geology The project site is located within the western Snake River Plain of southwestern Idaho and eastern Oregon. The plain is a northwest trending rift basin, about 45 miles wide and 200 miles long, that developed about 14 million years ago (Ma) and has since been occupied sporadically by large inland lakes. Geologic materials found within and along the plain's margins reflect volcanic and fluvial/lacustrine sedimentary processes that have led to an accumulation of approximately 1 to 2 km of interbedded volcanic and sedimentary deposits within the plain. Along the margins of the plain, streams that drained the highlands to the north and south provided coarse to fine-grained sediments eroded from granitic and volcanic rocks, respectively. About 2 million years ago the last of the lakes was drained and since that time fluvial erosion and deposition has dominated the evolution of the landscape. The project site is underlain by "Gravel of Sunrise Terrace" as mapped by Othberg and Stanford (1993). The Sunrise terrace is the third terrace above the modern Boise River in the eastern Boise Valley, composed of sandy pebble and cobble gravel, and is about 115 feet above river level. Quaternary faulting has probably truncated and tilted this terrace along with older surfaces. The surface of this deposit is mantled with 3-7 feet of loess containing a weakly to moderately developed duripan. Based on stratigraphic correlation the Sunrise terrace may be correlative with the Wilder terrace further to the west. 2.3 General Site Characteristics The site to be developed is approximately 115.36 acres in size. Currently, the majority of the site consists of agricultural land. Residential structures and associated outbuildings are present in the eastern portion of the site fronting Black Cat Road. The site is bounded to the north by the Rosenlof Drain. The site slopes gently downwards from the south to the north, with approximately 25 to 30 feet of relief across the site. Vegetation consists of agricultural crop remnants. Landscape trees and grasses are present surrounding the structures. Regional drainage is north and west toward the Boise River. Stormwater drainage for the site is achieved by percolation through surficial soils. From the south, intermittent off-site stormwater may drain onto the project site. Stormwater drainage collection and retention systems are not in place on the project site and were not noted within the vicinity of the project site. Atlas No. B211945G Page12 Copyright©2022 Atlas Technical Consultants 2.4 Regional Site Climatology and Geochemistry According to the Western Regional Climate Center, the average precipitation for the Treasure Valley is on the order of 10 to 12 inches per year, with an annual snowfall of approximately 20 inches and a range from 3 to 49 inches. The monthly mean daily temperatures range from 21°F to 95°F, with daily extremes ranging from roughly -25°F to 111°F. Winds are generally from the northwest or southeast with an annual average wind speed of approximately 9 miles per hour (mph) and a maximum of 62 mph. Soils and sediments in the area are primarily derived from siliceous materials and exhibit low electro-chemical potential for corrosion of metals or concretes. Local aggregates are generally appropriate for Portland cement and lime cement mixtures. Surface water, groundwater, and soils in the region typically have pH levels ranging from 7.2 to 8.2. J. SEISMIC SITE EVALUATION 3.1 Geoseismic Setting Soils on site are classed as Site Class D in accordance with Chapter 20 of the American Society of Civil Engineers (ASCE) publication ASCE/SEI 7-16. Structures constructed on this site should be designed per IBC requirements for such a seismic classification. See the Geologic Hazards Assessment section for discussion of hazards resulting from potential earthquake motions. Incidence and anticipated acceleration of seismic activity in the area is low. Seismic Design Parameter Values The United States Geological Survey National Seismic Hazard Maps (2008), includes a peak ground acceleration map. The map for 2% probability of exceedance in 50 years in the Western United States in standard gravity (g) indicates that a peak ground acceleration of 0.195 is appropriate for the project site based on a Site Class D. The following section provides an assessment of the earthquake-induced earthquake loads for the site based on the Risk-Targeted Maximum Considered Earthquake (MCER). The MCER spectral response acceleration for short periods, SMs, and at 1-second period, SM,, are adjusted for site class effects as required by the 2018 IBC. Design spectral response acceleration parameters as presented in the 2018 IBC are defined as a 5% damped design spectral response acceleration at short periods, Sps, and at 1-second period, So,. The USGS National Seismic Hazards Mapping Project includes a program that provides values for ground motion at a selected site based on the same data that were used to prepare the USGS ground motion maps. The maps were developed using attenuation relationships for soft rock sites; the source model, assumptions, and empirical relationships used in preparation of the maps are described in Petersen and others (1996). Atlas No. B211945G Page 13 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. Table 1 — Seismic Design Values Seismic Design Parameter Design Value Site Class D "Stiff Soil' Ss 0.284 (g) S1 0.104 (g) Fa 1.572 F 2.392 SMs 0.447 SMi 0.249 SDs 0.298 SD1 0.166 4. GEOLOGIC HAZARD ASSESSMENT This section provides an assessment of the geologic hazards for the site, including the potential for surface fault rupture, liquefaction, seismically induced settlements, lateral spreading, and collapsible soils. The hazard evaluation methodology involved one or two steps. First, the potential for occurrence of each type of geologic phenomenon is assessed. If there is a potential for a phenomenon to occur, the second step is to assess whether the phenomenon likely will result in a significant hazard for designated structures. For this evaluation, a significant hazard is defined as one that results in structural damage and threatens life-safety. 4.1 Regional Faults The subject site is located within the Western Snake River Plain. Per a map titled Geologic Map of the Boise Valley and Adjoining Area, Western Snake River Plain, Idaho (Othberg and Stanford, 1993), numerous Tertiary and Late Quaternary Period normal faults are mapped along the margins of the valley. Tertiary faults experienced movement between 1.6 and 66 million years ago, and Quaternary faults experienced movement within the last 1.6 million years. None of the faults in the region are known to be active. No faults are mapped on the project site, and no evidence of faulting was observed during the subsurface exploration. Based on research, the closest fault noted by Atlas is mapped approximately 0.35 mile to the southwest of the project site. 4.2 Historical Seismicity According to the USGS Earthquakes Program, there have been 3 earthquakes recorded within roughly 50 miles of the site with reported Richter magnitudes ranging from 2.6 to 3.2. All of these earthquakes occurred within the mountainous regions to the north and south of the Western Snake River Plain. The closest reported earthquake to the project site occurred in November 2012 approximately 28 miles to the southwest of the site, and had a magnitude of 2.9. Atlas No. B211945G Page14 Copyright©2022 Atlas Technical Consultants 1.3 Seismically Induced Surface Rupture, Settlements, and Lateral Spreading Earthquakes generally are caused by a sudden slip or displacement along a zone of weakness, termed a fault, in the Earth's crust. Surface fault rupture, which is a manifestation of the fault displacement at the ground surface, usually is associated with moderate to large-magnitude earthquakes (magnitudes of about 6 or larger) occurring on active faults having mapped traces or zones at the ground surface. The amount of surface fault displacement can be as much as 10 feet (3 meters) or more, depending on the earthquake magnitude and other factors. The displacements associated with surface fault rupture can have devastating effects on structures and lifelines situated astride the zone of rupture. As mentioned above, there is a lack of moderate to large-magnitude historic earthquakes in the region and no earthquakes have been reported within the Western Snake River Plain fault zone. Additionally, nearby faults are mapped off of the project site and no evidence of faulting was observed during the field investigation. It is the opinion of Atlas that the probability of the occurrence of seismically induced surface rupture, settlements, and lateral spreading is negligible. 4.4 Liquefaction Liquefaction is a soil behavior phenomenon in which a soil located below the groundwater surface loses a substantial amount of strength due to strong earthquake ground shaking. Some types of soil tend to compact during earthquake shaking, inducing excess pore water pressure in the saturated soil, which, in turn, causes a reduction in strength of the soil. Recently deposited (i.e., geologically young) and relatively loose natural soils, and uncompacted or poorly compacted fills, are potentially susceptible to liquefaction. Dense natural soils and well-compacted fills have a low susceptibility to liquefaction. Clayey soils, gravel sediments, and bedrock generally are not susceptible to liquefaction. Possible consequences of liquefaction include vertical settlement, lateral displacement, loss of bearing capacity for foundations supported by soil that liquefies, increased lateral loading on structures retaining soil that liquefies, and flotation of lightweight structures embedded in soil that liquefies. Based on the minimal presence of liquefiable soils, it is the opinion of Atlas that the probability of liquefaction at the project site is negligible. Atlas No. B211945G Page 15 Copyright©2022 Atlas Technical Consultants 4.5 Collapsible Soils Collapsible soils undergo a sudden decrease in volume due to the addition of water into the soil structure and/or additional loading. Collapsible soils in and climates are generally associated with alluvial fans produced by intermittent stream flow. The soils dry prior to subsequent deposition and do not become fully consolidated under the overburden stresses. Collapsible soils typically exhibit a loose, honeycomb structure. They typically have a low to relatively low unit weight, low degree of saturation, and a high dry strength. Wetting a collapsible soil results in the loss of capillary tension or the softening, weakening, and dissolving of cemented agents allowing the large particles to slip past each other into a denser soil structure. Typically, collapsible soils are made up of fine-grained soils. Collapse potential laboratory testing of onsite soils was outside the scope of work for the project. However, based on the soils conditions encountered onsite and experience with other projects in the vicinity of the site, it is our opinion that the potential for collapsible soils is negligible. 5. SOILS EXPLORATION 5.1 Exploration and Sampling Procedures Field exploration conducted to determine engineering characteristics of subsurface materials included a reconnaissance of the project site and investigation by soil boring and test pit. Test pit/borings were located in the field by means of a Global Positioning System (GPS) device and are reportedly accurate to within ten feet. Borings were advanced by means of a truck-mounted drilling rig equipped with continuous flight hollow-stem augers. At specified depths, samples were obtained using a standard split-spoon sampler, and Standard Penetration Test(SPT) blow counts were recorded. Uncorrected SPT blow counts are provided on logs, which can be found in the Appendix. Delayed water level observations were made in open borings to evaluate groundwater levels. At completion of exploration, borings were backfilled with bentonite holeplug. Upon completion of investigation, each test pit was backfilled with loose excavated materials. Re- excavation and compaction of these test pit areas are required prior to construction of overlying structures. Samples have been visually classified in the field by professional staff, identified according to test pit/boring number and depth, placed in sealed containers, and transported to our laboratory for additional testing. Subsurface materials have been described in detail on logs provided in the Appendix. Results of field and laboratory tests are also presented in the Appendix. Atlas recommends that these logs not be used to estimate fill material quantities. Atlas No. B211945G Page 16 Copyright©2022 Atlas Technical Consultants —TrT ME 7 tv 5.2 Laboratory Testing Program Along with our field investigation, a supplemental laboratory testing program was conducted to determine additional pertinent engineering characteristics of subsurface materials necessary in an analysis of anticipated behavior of the proposed structures. Laboratory tests were conducted in accordance with current applicable American Society for Testing and Materials (ASTM) specifications, and results of these tests are to be found in the Appendix. The laboratory testing program for this report included: Atterberg Limits Testing — ASTM D4318, Grain Size Analysis — ASTM C117/C136, and California Bearing Ratio analysis (CBR value) —ASTM D1883. ,oil and Sediment Profile The profile below represents a generalized interpretation for the project site. Note that on site soils strata, encountered between test pit/boring locations, may vary from the individual soil profiles presented in the logs, which can be found in the Appendix. The materials encountered during exploration were quite typical for the geologic area mapped as Gravel of the Sunrise Terrace. Silt with sand fills were encountered at ground surface in borings 1 and 2 and poorly graded gravel with sand fills were observed at ground surface in test pit 12. Fill materials were light brown to brown, dry to slightly moist, and medium dense/medium stiff to stiff, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Varying native silt-clay-sand mixtures were encountered beneath fill materials and at ground surface in the remaining test pits/borings. These soils were light brown to dark brown, dry to saturated, and soft to hard/medium dense to very dense, with fine to coarse-grained sand. Poorly graded gravel with silt and sand sediments and silty gravel with sand sediments were encountered beneath surficial silt-clay-sand mixtures in borings 1 through 3 and 5 through 7. These sediments were light brown to brown, saturated, and dense to very dense, with fine to coarse-grained sand and fine to coarse gravel. Poorly graded sand with varying silt and clay content were found beneath gravels in borings 1 through 3. These sediments were light brown to brown, saturated, and medium dense to very dense, with fine to coarse-grained sand and fine to coarse gravel. Lean clay soils were encountered at depth in borings 1 and 3. Lean clays were brown, saturated, and very stiff. Competency of test pit/boring sidewalls varied little across the site. In general, fine grained soils remained stable while more granular sediments readily sloughed. However, moisture contents will also affect wall competency with saturated soils having a tendency to readily slough when under load and unsupported. 5.4 Volatile Organic Scan No environmental concerns were identified prior to commencement of the investigation. Therefore, soils obtained during on-site activities were not assessed for volatile organic compounds by portable photoionization detector. Samples obtained during our exploration activities exhibited no odors or discoloration typically associated with this type of contamination. Groundwater encountered did not exhibit obvious signs of contamination. Atlas No. B211945G Page 17 Copyright©2022 Atlas Technical Consultants -r' T7E7 AV 6. SITE HYDROLOGY Existing surface drainage conditions are defined in the General Site Characteristics section. Information provided in this section is limited to observations made at the time of the investigation. Either regional or local ordinances may require information beyond the scope of this report. 6.1 Groundwater During this field investigation, groundwater was encountered in test pits at depths ranging from 6.8 to 20.0 feet bgs. In general, groundwater depths decreased from the south to the north. Soil moistures in the test pits were generally dry to slightly moist within surficial soils. Within the deeper horizons, soil moistures graded from slightly moist to saturated as the water table was approached and penetrated. In the vicinity of the project site, groundwater levels are controlled in large part by residential and agricultural irrigation activity and leakage from nearby canals. Maximum groundwater elevations likely occur during the later portion of the irrigation season. Atlas has previously performed 5 geotechnical investigations within 0.40 mile of the project site. Information from these investigations has been provided in the table below. Table 2 —Groundwater Data ApproximateDate from Site (mile) (feet • . November 2020 0.14 North 7.0 to 9.1 April 2019 0.15 East 7.6 to 9.4 October 2019 0.16 North 5.8 to 7.5 January 2021 0.35 North 7.2 to 7.9 March 2018 0.37 Northeast 7.0 to 7.3 For preliminary construction purposes, groundwater depth can be assumed to remain greater than 5 feet bgs throughout the year. Since this is an estimated depth and seasonal groundwater levels fluctuate, actual levels should be confirmed by periodic groundwater data collected from piezometers installed in test pits 1, 4, 7, 11, 14, and 16. If desired, Atlas is available to perform this monitoring. 6.2 Soil Infiltration Rates Soil permeability, which is a measure of the ability of a soil to transmit a fluid, was tested in the field. For this report, an estimation of infiltration is also presented using generally recognized values for each soil type and gradation. Of soils comprising the generalized soil profile for this study, lean clay with sand and silt with sand soils generally offer little permeability, with typical hydraulic infiltration rates of less than 2 inches per hour. Sandy silt soils will commonly exhibit infiltration rates from 2 to 4 inches per hour, and silty sand sediments typically exhibit infiltration rates of 4 to 8 inches per hour; though calcium carbonate cementation may reduce this value to near zero. Atlas No. B211945G Page 18 Copyright©2022 Atlas Technical Consultants arm I �lrT—G7T�� Clayey sand and poorly graded sand with clay sediments typically have infiltration rates ranging from 2 to 6 inches per hour. Poorly graded gravel with silt and sand sediments, silty gravel with sand sediments, and poorly graded sand with silt sediments usually have infiltration rates of 6 to 10 inches per hour; though the presence of groundwater may reduce these rates to near zero. 6.3 Infiltration Testing Infiltration testing was conducted in general accordance with the Ada County Highway District (ACHD) Policy Manual. Test pit areas will need to be re-excavated and compacted prior to construction of structures that will be sensitive to settlement. Test locations were presoaked prior to testing. Pre-soaking increases soil moistures,which allows the tested soils to reach a saturated condition more readily during testing. Saturation of the tested soils is desirable in order to isolate the vertical component of infiltration by inhibiting horizontal seepage during testing. Testing was conducted on October 7 and November 3, 2021. Details and results of testing are as follows: Table 3 — Infiltration Test Results Test Test Depth Stabilized Infiltration Design Infiltration Location (feet bgs) Soil Type Rate Rate (inches/hour) (inches per hour) TP-5 6.0 Silty Sand 5.76 2.88 TP-8 4.7 Silty Sand 3.6 1.8 TP-15 6.0 Silt with Sand 2.4 1.2 In accordance with the ACHD Policy Manual, a factor of safety of 2 has been applied to the stabilized infiltration rates achieved during testing to obtain the design infiltration rates listed above. The reason for the decreased infiltration rate is to account for long term saturation of the soils and the potential for less permeable soils to settle into the bottom of the infiltration facilities. Atlas recommends that all infiltration facilities be constructed in accordance with the local municipality requirements. 7. LATERAL EARTH PRESSURES Retaining, below-grade, or basement walls will be subject to lateral earth pressures. The magnitude of earth pressure is a function of both type and compaction of backfill behind walls within the "active" zone, and allowable rotation of the top of the wall. The active zone is defined as the wedge of soil between the surface of the wall and a plane inclined 31 degrees from vertical passing through the base of the wall. All clayey soils must be completely removed from within the active zone. The following recommendations should be used when dealing with lateral earth pressures on a gravity block: 1) a sliding frictional coefficient of 0.35 is appropriate considering native lean clay with sand soils, silt with sand soils, sandy silt soils, silty sand sediments, and clayey sand sediments, and 2) a sliding frictional coefficient of 0.45 is appropriate considering granular structural fill under typical conditions. Atlas No. B211945G Page 19 Copyright©2022 Atlas Technical Consultants arm I �lrT—G7T�� A state of plastic equilibrium is when the subject material is considered to be 1) homogeneous and unbounded and 2) at the point of incipient instability. This state is evaluated on the basis of unit weight, mechanical properties, and the definition of instability. For the purpose of this report, it is assumed that native silty soils and imported granular fill material will be the materials of concern regarding lateral earth pressures. If other materials are considered for use, Atlas must be contacted to provide alternate lateral earth pressure information. Furthermore, changes in natural soil moisture, such as can be imposed by site stormwater systems, can change the values listed below. Below-grade restrained walls, such as basement walls, should be designed based on at-rest pressures. Active pressures are appropriate under conditions where the wall moves or rotates away from the soil mass at failure. Passive pressures are used for conditions where the wall moves toward the soil mass at failure. Rotation, or lateral movement, of the top of the wall equal to 0.002 times the height of the wall will be necessary for on-site soil backfill to achieve an "active" loading condition. Lateral movement of the top of the wall equal to 0.001 times the height of the wall will be necessary for the "active" pressure condition for imported granular structural backfill. 7.1 Retaining Wall Backfill Materials For lateral earth pressure analysis, Atlas anticipates that the soils of interest will be the onsite native silt with sand soils, sandy silt soils, and silty sand sediments. Clayey soils are not suitable for use as backfill on the soil side of walls. Seismic lateral earth pressures have also been provided in the following tables, and were calculated per the Whitman method. For silt with sand and sandy silt soils, the following values are applicable under non-surcharged, drained conditions. Table 4— Lateral Earth Pressure Values for Native Soil Soil Type: Silt with Sand/Sandy Silt Internal Friction Angle: 28 ° Dry Unit Weight: 105 pcf Cohesion: 100 psf Bouyant Unit Weight: 68 pcf Natural Void Ratio: 0.7 Natural Moisture: 17 % Ground Acceleration2: 0.195 Backfill Slope: 0 ° At rest lateral earth pressure: 65 pcf Ko= 0.53 Active lateral earth pressure: 44 pcf Ka= 0.36 Passive lateral earth pressure: 340 pcf Kp= 2.77 Seismic active lateral earth pressure: 62 pcf Kae= 0.51 Seismic passive lateral earth pressure: 274 pcfl Kpe= 2.23 'Lateral earth pressure values are in pounds per square foot,per foot of wall(psf/ft). Alternately,the values presented may also be considered as equivalent fluid with units of pounds per cubic foot(pcf). 2Ground acceleration obtained from the USGS Seismic Design Maps. Atlas No. B211945G Page110 Copyright©2022 Atlas Technical Consultants �TrT—G7T�� For silty sand sediments, the following values are applicable under non-surcharged, drained conditions. Table 5 — Lateral Earth Pressure Values for Native Soil Soil Type: Silty Sand Internal Friction Angle: 30 Dry Unit Weight: 115 pcf Cohesion: 50 psf Bouyant Unit Weight: 76 pcf Natural Void Ratio: 0.6 Natural Moisture: 12 % Ground Acceleration2: 0.195 Backfill Slope: 0 ° At rest lateral earth pressure: 64 Pcf Ko= 0.50 Active lateral earth pressure: 43 Pcf Ka= 0.33 Passive lateral earth pressure: 386 Pcf Kp= 3.00 Seismic active lateral earth pressure: 62 Pcf Kae= 0.48 Seismic passive lateral earth pressure: 311 Pcf Kpe= 2.42 'Lateral earth pressure values are in pounds per square foot,per foot of wall(psf/ft). Alternately,the values presented may also be considered as equivalent fluid with units of pounds per cubic foot(pcf). 2Ground acceleration obtained from the USGS Seismic Design Maps. Imported, compacted, structural material, which is used to backfill the soil side of walls, must demonstrate the following characteristics: Table 6— Lateral Earth Pressure Values for Fill Materials Soil Type: Compacted Sandy Gravel Fill Internal Friction Angle: 35 Dry Unit Weight: 128 pcf Cohesion: N/A Bouyant Unit Weight: 83 pcf Natural Void Ratio: 0.4 Natural Moisture: 5 % Ground Acceleration2: 0.195 Backfill Slope: 0 ° At rest lateral earth pressure: 57 Pcf Ko= 0.43 Active lateral earth pressure: 36 Pcf Ka= 0.27 Passive lateral earth pressure: 496 Pcf Kp= 3.69 Seismic active lateral earth pressure: 56 Pcf Kae= 0.42 Seismic passive lateral earth pressure: 399 Pcf Kpe= 2.97 'Lateral earth pressure values are in pounds per square foot,per foot of wall(psf/ft). Alternately,the values presented may also be considered as equivalent fluid with units of pounds per cubic foot(pcf). 2Ground acceleration obtained from the USGS Seismic Design Maps. Please note that the values for seismic lateral earth pressures are calculated using both the static and seismic coefficients. The effect of seismic conditions alone is the difference between the static and seismic lateral earth pressures presented above. Also, the expected pressure diagram is considered to be an inverted triangular force, with the maximum force at the ground surface. Atlas No. B211945G Page 111 Copyright©2022 Atlas Technical Consultants TrT ME7V In the case that another material is used for backfill, Atlas should be consulted for alternate lateral earth pressure values. Granular structural fill should consist of 4-inch-minus select, clean, granular soil with no more than 30 percent oversize (greater than 3/4-inch) material and no more than 5 percent non-plastic fines (passing the No. 200 sieve). Retaining wall and basement backfill must be placed in accordance with recommendations in the Structural Fill section of this report and must be properly compacted and tested. Lateral earth pressure values do not incorporate specific factors of safety, and are only applicable for non-surcharged, drained conditions. Factors of safety, if applicable, should be integrated into the structural design of the wall. The preceding values are presented for idealized conditions relating to simple shallow structures. For complex structures, deep structures, or structures with significant perimeter landscaping, a soils engineer should be retained as part of the design team in developing appropriate project design parameters and construction specifications. 7.2 Retaining Wall Drainage Atlas recommends that a drainage system be incorporated into the retained soil mass. This can be accomplished by installing wall and toe drains as a part of each soil-supporting wall system. In areas where there is potential for significantly high soil moistures within the supported soil mass, installation of drains within the soil mass is recommended. Particular consideration of roof drain effluent and irrigation water must be made. Further, these drainage systems must be separate from other retaining wall/foundation systems. If the granular structural fill option to reduce lateral pressures is used, a compacted low permeability soil cap is recommended within the upper 2 feet of the surface to limit surface water infiltration behind the walls. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed structures. Two requirements must be met in the design of foundations. First, the applied bearing stress must be less than the ultimate bearing capacity of foundation soils to maintain stability. Second, total and differential settlement must not exceed an amount that will produce an adverse behavior of the superstructure. Allowable settlement is usually exceeded before bearing capacity considerations become important; thus, allowable bearing pressure is normally controlled by settlement considerations. Considering subsurface conditions and the proposed construction, it is recommended that the structures be founded upon conventional spread footings and continuous wall footings. Total settlements should not exceed 1 inch if the following design and construction recommendations are observed. Atlas No. B211945G Page112 Copyright©2022 Atlas Technical Consultants ME I �TrTG7T�� 8.1 Foundation Design Recommendations — Buildings A-E Based on data obtained from the site and test results from various laboratory tests performed, Atlas recommends the following guidelines for the net allowable soil bearing capacity: Table 7 — Soil Bearing Capacity JMFooting =PA a Subgrade CompactionCapacity Footings must bear on compacted native lean clay with sand soils, silt with sand soils, sandy silt soils, silty sand sediments, clayey sand sediments, or compacted structural fill. Existing fill materials, plow zones, and organics must be completely removed 95%for Native Soil and from below foundation elements.' Excavation 2,000Ibs/ft2 depths ranging from roughly 0.6 to 2.0 feet bgs Structural Fill should be anticipated to expose proper bearing soils.2 However, in areas where existing roads have been built up, excavation depths of up to 3.5 feet bgs should be anticipated. Footings must bear on at least 2.0 feet of compacted structural fill (ISPWC Type 1 crushed aggregate base) reinforced with three layers of Tensar TX 160 geogrid. Geogrid reinforced fill must bear on native lean clay with sand soils, silt with sand soils, sandy silt soils, silty sand sediments, or clayey sand sediments.' The exposed subgrade should be prepared as follows: 1. Six inches of structural fill should be placed over the native soils and be compacted to at least 95% of the maximum dry density as determined Not Required for Native by ASTM D1557. Soils 2 2. A layer of Tensar TX 160 geogrid should be 3,000 Ibs/ft placed over the compacted structural fill 95% for Structural Fill followed by 6 inches of compacted structural fill. This process should be continued until three layers of geogrid are in place. At least 6 inches of compacted structural fill should be placed over the top layer of geogrid. Geogrid should extend a minimum of 2 feet beyond the footings on all sides. Geogrid should be overlapped a minimum distance of 24 inches between splices. See the attached Figure 3 for graphical representation of this system. 'It will be required for Atlas personnel to verify the bearing soil suitability for each structure at the time of construction. 2Depending on the time of year construction takes place,the subgrade soils may be unstable because of high moisture contents. If unstable conditions are encountered,over-excavation and replacement with granular structural fill and/or use of geotextiles may be required. Atlas No. B211945G Page113 Copyright©2022 Atlas Technical Consultants ME I �TrTG7T�� 8.2 Foundation Design Recommendations — Buildings F-G Based on data obtained from the site and test results from various laboratory tests performed, Atlas recommends the following guidelines for the net allowable soil bearing capacity: Table 8 — Soil Bearing Capacity ,�Footing De ASTM D1557 Net Allowable Sol =PA a Subgrade Compaction . . Footings must bear on compacted native lean clay with sand soils, silt with sand soils, sandy silt soils, silty sand sediments, clayey sand sediments, or compacted structural fill. Existing fill materials, plow zones, and organics must be completely removed 95%for Native Soil and from below foundation elements.' Excavation 1,7501bs/ft2 depths ranging from roughly 0.6 to 2.0 feet bgs Structural Fill should be anticipated to expose proper bearing soils.2 However, in areas where existing roads have been built up, excavation depths of up to 3.5 feet bgs should be anticipated. Footings must bear on at least 2.0 feet of compacted structural fill (ISPWC Type 1 crushed aggregate base) reinforced with three layers of Tensar TX 160 geogrid. Geogrid reinforced fill must bear on native lean clay with sand soils, silt with sand soils, sandy silt soils, silty sand sediments, or clayey sand sediments.' The exposed subgrade should be prepared as follows: 3. Six inches of structural fill should be placed over the native soils and be compacted to at least 95% of the maximum dry density as determined Not Required for Native by ASTM D1557. Soils 2 4. A layer of Tensar TX 160 geogrid should be 2,500 Ibs/ft placed over the compacted structural fill 95% for Structural Fill followed by 6 inches of compacted structural fill. This process should be continued until three layers of geogrid are in place. At least 6 inches of compacted structural fill should be placed over the top layer of geogrid. Geogrid should extend a minimum of 2 feet beyond the footings on all sides. Geogrid should be overlapped a minimum distance of 24 inches between splices. See the attached Figure 3 for graphical representation of this system. 'It will be required for Atlas personnel to verify the bearing soil suitability for each structure at the time of construction. 2Depending on the time of year construction takes place,the subgrade soils may be unstable because of high moisture contents. If unstable conditions are encountered,over-excavation and replacement with granular structural fill and/or use of geotextiles may be required. Atlas No. B211945G Page114 Copyright©2022 Atlas Technical Consultants �lrl—G7T�11 Footings should be proportioned to meet either the stated soil bearing capacity or the 2018 IBC minimum requirements. Total settlement should be limited to approximately 1 inch, and differential settlement should be limited to approximately '/2 inch. Objectionable soil types encountered at the bottom of footing excavations should be removed and replaced with structural fill. Excessively loose or soft areas that are encountered in the footings subgrade will require over-excavation and backfilling with structural fill. To minimize the effects of slight differential movement that may occur because of variations in the character of supporting soils and seasonal moisture content, Atlas recommends continuous footings be suitably reinforced to make them as rigid as possible. For frost protection, the bottom of external footings should be 30 inches below finished grade. 8.3 Foundation Drain Recommendations Atlas recommends that foundation drains be installed. The drains should be placed at the footing elevation, sloped at least 2 percent, and be directed to suitable discharge points at least 10 feet away from the structures. Discharge points should be protected to prevent erosion. However, if hardscaping is present immediately surrounding the structures, foundation drains are not needed. 8.4 Floor, Patio, and Garage Slab-on-Grade Uncontrolled fill was encountered in the areas where existing roadways have been constructed. Atlas recommends that these fill materials be removed to a depth of at least 1'/2 feet below existing grade. If fill materials remain after excavation, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D1557. The excavated fill materials can be replaced in accordance with the Structural Fill section provided that all organic material and/or debris is completely removed. Once final grades have been determined, Atlas is available to provide additional recommendations. Plow zones with organic materials were encountered in portions of the site to depths of roughly 0.5 to 1.0 foot bgs. Atlas recommends that the organic materials be removed. If plow zones remain after organic materials have been removed, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined by ASTM D1557. Atlas personnel must be present during excavation to identify these materials. For raft or mat slabs bearing on native lean clay with sand soils, silt with sand soils, or sandy silt soils, a modulus of subgrade reaction, k value, of 105 pounds per cubic inch (pci) may be used for the slab design based on correlation to values typically resulting from a 1 foot by 1 foot plate load test. For slabs bearing on silty sand sediments or clayey sand sediments, a k value of 125 pci may be used. Additionally, for raft or mat slabs bearing on at least 12 inches of compacted structural fill material, a k value of 200 pci may be used. However, depending on how the slab load is applied, the value will need to be geometrically modified. The values should be adjusted for larger areas using the following expression: Atlas No. B211945G Page115 Copyright©2022 Atlas Technical Consultants Modulus of Subgrade Reaction for Square Mat Slabs: ks, = k B+1 2 ( 2B ) where: ks = coefficient of vertical subgrade reaction for loaded area, k= coefficient of vertical subgrade reaction for a 1 square foot area, and B = effective width of area loaded, in feet. ks(1+0.5(D) Modulus of Subgrade Reaction for Rectangular Mat Slabs: k = 1.5 where: k' = coefficient of vertical subgrade reaction for the loaded rectangular area, ks = coefficient of vertical subgrade reaction for loaded square area, B = effective width of area loaded, in feet, L = effective length of area loaded, in feet. Organic, loose, or obviously compressive materials must be removed prior to placement of concrete floors or floor-supporting fill. In addition, the remaining subgrade should be treated in accordance with guidelines presented in the Earthwork section. Areas of excessive yielding should be excavated and backfilled with structural fill. Fill used to increase the elevation of the floor slab should meet requirements detailed in the Structural Fill section. Fill materials must be compacted to a minimum 95 percent of the maximum dry density as determined by ASTM D1557. A free-draining granular mat should be provided below slabs-on-grade to provide drainage and a uniform and stable bearing surface. This should be a minimum of 4 inches in thickness and properly compacted. The mat should consist of a sand and gravel mixture, complying with Idaho Standards for Public Works Construction (ISPWC) specifications for 3/4-inch (Type 1) crushed aggregate. The granular mat should be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D1557. A moisture-retarder should be placed beneath floor slabs to minimize potential ground moisture effects on moisture-sensitive floor coverings. The moisture-retarder should be at least 15-mil in thickness and have a permeance of less than 0.01 US perms as determined by ASTM E96. Placement of the moisture-retarder will require special consideration with regard to effects on the slab-on-grade and should adhere to recommendations outlined in the ACI 302.1 R and ASTM E1745 publications. Upon request, Atlas can provide further consultation regarding installation. Atlas No. B211945G Page116 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. 9. PAVEMENT DISCUSSION AND RECOMMENDATIONS Atlas was provided traffic loading information of approximately 575,000 ESALs for light duty pavements and 1,280,000 ESALs for heavy duty flexible pavements. Atlas collected a sample of near-surface soils for California Bearing Ratio (CBR) testing representative of soils to depths of 2.0 to 2.5 feet bgs. This sample, consisting of lean clay with sand collected from test pit 4, yielded a CBR value of 4 with a swell of 2.6 percent. The following are minimum thickness requirements for assured pavement function. Depending on site conditions, additional work, e.g. soil preparation, may be required to support construction equipment. These have been listed within the Soft Subgrade Soils section. Results of the test are graphically depicted in the Appendix. 9.1 Flexible Pavement Sections — Private Paved Area, The American Association of State Highway and Transportation Officials (AASHTO) design method has been used to calculate the following pavement sections. Calculation sheets provided in the Appendix indicate the soils constant, traffic loading, traffic projections, and material constants used to calculate the pavement sections. Atlas recommends that materials used in the construction of asphaltic concrete pavements meet requirements of the ISPWC Standard Specification for Highway Construction. Construction of the pavement section should be in accordance with these specifications and should adhere to guidelines recommended in the section on Construction Considerations. Table 9 — AASHTO Flexible Pavement Specifications —Without Geogrid Reinforcement Componenteways; and Parking Driveways and Parkin Pavement Section Asphaltic Concrete 3.0 Inches 3.5 Inches Crushed Aggregate Base 6.0 Inches 6.0 Inches Structural Subbase 16.0 Inches 20.0 Inches Compacted Subgrade See Pavement Subgrade See Pavement Subgrade Preparation Section Preparation Section 'It will be required for Atlas personnel to verify subgrade competency at the time of construction. Asphaltic Concrete: Asphalt mix design shall meet the requirements of ISPWC, Section 810. Materials shall be placed in accordance with ISPWC Standard Specifications for Highway Construction. Aggregate Base: Material complying with ISPWC Standards for Crushed Aggregate Materials. Structural Subbase: Granular structural fill material complying with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than 2/3 the component thickness. Gradation and suitability requirements shall be per ISPWC Section 801, Table 1. Atlas No. B211945G Page117 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. Table 10—AASHTO Flexible Pavement Specifications —With Geogrid Reinforcement Pavement Section Component Driveways • Parking Driveways and Parking Light Duty Heavy Duty Asphaltic Concrete 3.0 Inches 3.5 Inches Crushed Aggregate Base 6.0 Inches 6.0 Inches Geogrid2 Tensar TV Tensar TV Structural Subbase 6.0 Inches 8.0 Inches Compacted Subgrade See Pavement Subgrade See Pavement Subgrade Preparation Section Preparation Section 'It will be required for Atlas personnel to verify subgrade competency at the time of construction. 2Geogrid must be placed in accordance with manufacturers specifications. • Asphaltic Concrete: Asphalt mix design shall meet the requirements of ISPWC, Section 810 Class III plant mix. Materials shall be placed in accordance with ISPWC Standard Specifications for Highway Construction. • Aggregate Base: Material complying with ISPWC Standards for Crushed Aggregate Materials. • Structural Subbase: Granular structural fill material complying with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than 2/3 the component thickness. Gradation and suitability requirements shall be per ISPWC Section 801, Table 1. 9.2 Flexible Pavement Section — Public Collector Roads As required by Ada County Highway District (ACHD), Atlas has used a traffic index of 6 to determine the necessary pavement cross-section for the site. The CBR was converted to a R- value of 9 for design calculations. The Gravel Equivalent Method, as defined in Section 500 of the State of Idaho Department of Transportation (ITD) Materials Manual, was used to develop the pavement section. ACHD parameters for traffic index and substitution ratios,which were obtained from the ACHD Policy Manual, were also used in the design. A calculation sheet provided in the Appendix indicates the soils constant, traffic loading, traffic projections, and material constants used to calculate the pavement section. Atlas recommends that materials used in the construction of asphaltic concrete pavements meet the requirements of the ISPWC Standard Specification for Highway Construction. Construction of the pavement section should be in accordance with these specifications and should adhere to guidelines recommended in the section on Construction Considerations. Atlas No. B211945G Page118 Copyright©2022 Atlas Technical Consultants �TrT-G7Tdr-W� Table 11 — Gravel Equivalent Method Flexible Pavement Specifications Pavement Section Component Asphaltic Concrete 3.5 Inches Crushed Aggregate Base 6.0 Inches Structural Subbase 16.0 Inches Compacted Subgrade See Pavement Subgrade Preparation Section 'It will be required for Atlas personnel to verify subgrade competency at the time of construction. Asphaltic Concrete: Asphalt mix design shall meet the requirements of ISPWC, Section 810. Materials shall be placed in accordance with ISPWC Standard Specifications for Highway Construction. Aggregate Base: Material complying with ISPWC Standards for Crushed Aggregate Materials. Structural Subbase: Granular structural fill material complying with the requirements detailed in the Structural Fill section of this report except that the maximum material diameter is no more than 2/3 the component thickness. Gradation and suitability requirements shall be per ISPWC Section 801, Table 1. 9.3 Pavement Subgrade Preparation Uncontrolled fill was encountered in the areas where existing roadways have been constructed. Atlas recommends that these fill materials be removed to a depth of at least 1'/2 feet below existing grade. If fill materials remain after excavation, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined bV ASTM D698. The excavated fill materials can be replaced in accordance with the Structural Fill section provided that all organic material and/or debris is completely removed. However, the existing fill materials are not suitable for use as either the base or subbase components of the recommended pavement section. Once final grades have been determined, Atlas is available to provide additional recommendations. Plow zones with organic materials were encountered in portions of the site to depths of roughly 0.5 to 1.0 foot bgs. Atlas recommends that the organic materials be removed. If plow zones remain after organic materials have been removed, the exposed subgrade must be compacted to at least 95 percent of the maximum dry density as determined bV ASTM D698. Atlas personnel must be present during excavation to identify these materials. Atlas No. B211945G Page119 Copyright©2022 Atlas Technical Consultants �TrT—G7Tdr—W� 9.4 Common Pavement Section Construction Issues The subgrade upon which above pavement sections are to be constructed must be properly stripped, compacted (if indicated), inspected, and proof-rolled. Proof rolling of subgrade soils should be accomplished using a heavy rubber-tired, fully loaded, tandem-axle dump truck or equivalent. Verification of subgrade competence by Atlas personnel at the time of construction is required. Fill materials on the site must demonstrate the indicated compaction prior to placing material in support of the pavement section. Atlas anticipated that pavement areas will be subjected to moderate traffic. Subgrade clayey and silty soils near and above optimum moisture contents may pump during compaction. Pumping or soft areas must be removed and replaced with structural fill. Fill material and aggregates in support of the pavement section must be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D698 for flexible pavements and by ASTM D1557 for rigid pavements. If a material placed as a pavement section component cannot be tested by usual compaction testing methods, then compaction of that material must be approved by observed proof rolling. Minor deflections from proof rolling for flexible pavements are allowable. Deflections from proof rolling of rigid pavement support courses should not be visually detectable. Atlas recommends that rigid concrete pavement be provided for heavy garbage receptacles. This will eliminate damage caused by the considerable loading transferred through the small steel wheels onto asphaltic concrete. Rigid concrete pavement should consist of Portland Cement Concrete Pavement (PCCP) generally adhering to ITD specifications for Urban Concrete. PCCP should be 6 inches thick on a 4-inch drainage fill course (see Floor Slab-on-Grade section), and should be reinforced with welded wire fabric. Control joints must be on 12-foot centers or less. 10. CONSTRUCTION CONSIDERATIONS Recommendations in this report are based upon structural elements of the project being founded on compacted native lean clay with sand soils, sandy silt soils, silty sand sediments, clayey sand sediments, or compacted structural fill. Structural areas should be stripped to an elevation that exposes these soil types. Earthwork Excessively organic soils, deleterious materials, or disturbed soils generally undergo high volume changes when subjected to loads, which is detrimental to subgrade behavior in the area of pavements, floor slabs, structural fills, and foundations. It is recommended that organic or disturbed soils, if encountered, be removed to depths of 1 foot (minimum), and wasted or stockpiled for later use. However, in areas where trees are/were present, deeper excavation depths should be anticipated. Atlas No. B211945G Page 120 Copyright©2022 Atlas Technical Consultants Stripping depths should be adjusted in the field to assure that the entire root zone or disturbed zone (plow depths) or topsoil are removed prior to placement and compaction of structural fill materials. Exact removal depths should be determined during grading operations by Atlas personnel, and should be based upon subgrade soil type, composition, and firmness or soil stability. If underground storage tanks, underground utilities, wells, or septic systems are discovered during construction activities, they must be decommissioned then removed or abandoned in accordance with governing Federal, State, and local agencies. Excavations developed as the result of such removal must be backfilled with structural fill materials as defined in the Structural Fill section. Atlas should oversee subgrade conditions (i.e., moisture content) as well as placement and compaction of new fill (if required) after native soils are excavated to design grade. Recommendations for structural fill presented in this report can be used to minimize volume changes and differential settlements that are detrimental to the behavior of footings, pavements, and floor slabs. Sufficient density tests should be performed to properly monitor compaction. For structural fill beneath building structures, one in-place density test per lift for every 5,000 square feet is recommended. In parking and driveway areas, this can be decreased to one test per lift for every 10,000 square feet. 10.2 Dry Weather If construction is to be conducted during dry seasonal conditions, many problems associated with soft soils may be avoided. However, some rutting of subgrade soils may be induced by shallow groundwater conditions related to springtime runoff or irrigation activities during late summer through early fall. Solutions to problems associated with soft subgrade soils are outlined in the Soft Subgrade Soils section. Problems may also arise because of lack of moisture in native and fill soils at time of placement. This will require the addition of water to achieve near-optimum moisture levels. Low-cohesion soils exposed in excavations may become friable, increasing chances of sloughing or caving. Measures to control excessive dust should be considered as part of the overall health and safety management plan. 10.3 Wet Weather If construction is to be conducted during wet seasonal conditions (commonly from mid-November through May), problems associated with soft soils must be considered as part of the construction plan. During this time of year, fine-grained soils such as silts and clays will become unstable with increased moisture content, and eventually deform or rut. Additionally, constant low temperatures reduce the possibility of drying soils to near optimum conditions. 10.4 Soft Subgrade Soils Shallow fine-grained subgrade soils that are high in moisture content should be expected to pump and rut under construction traffic. During periods of wet weather, construction may become very difficult if not impossible. The following recommendations and options have been included for dealing with soft subgrade conditions: Atlas No. B211945G Page 121 Copyright©2022 Atlas Technical Consultants • Track-mounted vehicles should be used to strip the subgrade of root matter and other deleterious debris. Heavy rubber-tired equipment should be prohibited from operating directly on the native subgrade and areas in which structural fill materials have been placed. Construction traffic should be restricted to designated roadways that do not cross, or cross on a limited basis, proposed roadway or parking areas. • Soft areas can be over-excavated and replaced with granular structural fill. • Construction roadways on soft subgrade soils should consist of a minimum 2-foot thickness of large cobbles of 4 to 6 inches in diameter with sufficient sand and fines to fill voids. Construction entrances should consist of a 6-inch thickness of clean, 2-inch minimum, angular drain-rock and must be a minimum of 10 feet wide and 30 to 50 feet long. During the construction process, top dressing of the entrance may be required for maintenance. • Scarification and aeration of subgrade soils can be employed to reduce the moisture content of wet subgrade soils. After stripping is complete, the exposed subgrade should be ripped or disked to a depth of 1'/2 feet and allowed to air dry for 2 to 4 weeks. Further disking should be performed on a weekly basis to aid the aeration process. • Alternative soil stabilization methods include use of geotextiles, lime, and cement stabilization. Atlas is available to provide recommendations and guidelines at your request. 10.5 Frozen Subgrade Soils Prior to placement of structural fill materials or foundation elements, frozen subgrade soils must either be allowed to thaw or be stripped to depths that expose non-frozen soils and wasted or stockpiled for later use. Stockpiled materials must be allowed to thaw and return to near-optimal conditions prior to use as structural fill. The onsite, shallow clayey and silty soils are susceptible to frost heave during freezing temperatures. For exterior flatwork and other structural elements, adequate drainage away from subgrades is critical. Compaction and use of structural fill will also help to mitigate the potential for frost heave. Complete removal of frost susceptible soils for the full frost depth, followed by replacement with a non-frost susceptible structural fill, can also be used to mitigate the potential for frost heave. Atlas is available to provide further guidance/assistance upon request. 10.6 Structural Fill Soils recommended for use as structural fill are those classified as GW, GP, SW, and SP in accordance with the Unified Soil Classification System (USCS) (ASTM D2487). Use of silty soils (USCS designation of GM, SM, and ML) as structural fill may be acceptable. However, use of silty soils (GM, SM, and ML) as structural fill below footings is prohibited. These materials require very high moisture contents for compaction and require a long time to dry out if natural moisture contents are too high and may also be susceptible to frost heave under certain conditions. Therefore, these materials can be quite difficult to work with as moisture content, lift thickness, and compactive effort becomes difficult to control. Atlas No. B211945G Page 122 Copyright©2022 Atlas Technical Consultants If silty soil is used for structural fill, lift thicknesses should not exceed 6 inches (loose), and fill material moisture must be closely monitored at both the working elevation and the elevations of materials already placed. Following placement, silty soils must be protected from degradation resulting from construction traffic or subsequent construction. Recommended granular structural fill materials, those classified as GW, GP, SW, and SP, should consist of a 6-inch minus select, clean, granular soil with no more than 50 percent oversize (greater than %-inch) material and no more than 12 percent fines (passing No. 200 sieve). These fill materials should be placed in layers not to exceed 12 inches in loose thickness. Prior to placement of structural fill materials, surfaces must be prepared as outlined in the Construction Considerations section. Structural fill material should be moisture-conditioned to achieve optimum moisture content prior to compaction. For structural fill below footings, areas of compacted backfill must extend outside the perimeter of the footings for a distance equal to the thickness of fill between the bottom of foundation and underlying soils, or 5 feet, whichever is less. All fill materials must be monitored during placement and tested to confirm compaction requirements, outlined below, have been achieved. Each layer of structural fill must be compacted, as outlined below: • Below Structures and Rigid Pavements: A minimum of 95 percent of the maximum dry density as determined by ASTM D1557. • Below Flexible Pavements: A minimum of 92 percent of the maximum dry density as determined by ASTM D1557 or 95 percent of the maximum dry density as determined by ASTM D698. The ASTM D1557 test method must be used for samples containing up to 40 percent oversize (greater than%-inch) particles. If material contains more than 40 percent but less than 50 percent oversize particles, compaction of fill must be confirmed by proof rolling each lift with a 10-ton vibratory roller(or equivalent) until the maximum density has been achieved. Density testing must be performed after each proof rolling pass until the in-place density test results indicate a drop (or no increase) in the dry density, defined as maximum density or"break over" point. The number of required passes should be used as the requirements on the remainder of fill placement. Material should contain sufficient fines to fill void spaces, and must not contain more than 50 percent oversize particles. Atlas No. B211945G Page123 Copyright©2022 Atlas Technical Consultants 7 Backfill of Walls Backfill materials must conform to the requirements of structural fill, as defined in this report. For wall heights greater than 2.5 feet, the maximum material size should not exceed 4 inches in diameter. Placing oversized material against rigid surfaces interferes with proper compaction, and can induce excessive point loads on walls. Backfill shall not commence until the wall has gained sufficient strength to resist placement and compaction forces. Further, retaining walls above 2.5 feet in height shall be backfilled in a manner that will limit the potential for damage from compaction methods and/or equipment. It is recommended that only small hand-operated compaction equipment be used for compaction of backfill within a horizontal distance equal to the height of the wall, measured from the back face of the wall. Backfill should be compacted in accordance with the specifications for structural fill, except in those areas where it is determined that future settlement is not a concern, such as planter areas. In nonstructural areas, backfill must be compacted to a firm and unyielding condition. 0.8 Excavations Shallow excavations that do not exceed 4 feet in depth may be constructed with side slopes approaching vertical. Below this depth, it is recommended that slopes be constructed in accordance with Occupational Safety and Health Administration (OSHA) regulations, Section 1926, Subpart P. Based on these regulations, on-site soils are classified as type "C" soil, and as such, excavations within these soils should be constructed at a maximum slope of 1'/2 feet horizontal to 1 foot vertical (11/2:1) for excavations up to 20 feet in height. Excavations in excess of 20 feet will require additional analysis. Note that these slope angles are considered stable for short-term conditions only, and will not be stable for long-term conditions. During the subsurface exploration, test pit sidewalls generally exhibited little indication of collapse; however, sloughing of native granular sediments from test pit sidewalls was observed, particularly after penetration of the water table. For deep excavations, native granular sediments cannot be expected to remain in position. These materials are prone to failure and may collapse, thereby undermining upper soil layers. This is especially true when excavations approach depths near the water table. Care must be taken to ensure that excavations are properly backfilled in accordance with procedures outlined in this report. 10.9 Groundwater Control Groundwater was encountered during the investigation but is anticipated to be below the depth of most construction. Excavations below the water table will require a dewatering program. Dewatering will be required prior to placement of fill materials. Placement of concrete can be accomplished through water by the use of a treme. It may be possible to discharge dewatering effluent to remote portions of the site, to a sump, or to a pit. This will essentially recycle effluent, thus eliminating the need to enter into agreements with local drainage authorities. Should the scope of the proposed project change, Atlas should be contacted to provide more detailed groundwater control measures. Atlas No. B211945G Page 124 Copyright©2022 Atlas Technical Consultants arm I �lrT—G7T�� Special precautions may be required for control of surface runoff and subsurface seepage. It is recommended that runoff be directed away from open excavations. Silty and clayey soils may become soft and pump if subjected to excessive traffic during time of surface runoff. Ponded water in construction areas should be drained through methods such as trenching, sloping, crowning grades, nightly smooth drum rolling, or installing a French drain system. Additionally, temporary or permanent driveway sections should be constructed if extended wet weather is forecasted. 11. GENERAL COMMENTS Based on the subsurface conditions encountered during this investigation and available information regarding the proposed development, the site is adequate for the planned construction. When plans and specifications are complete, and if significant changes are made in the character or location of the proposed structures, consultation with Atlas must be arranged as supplementary recommendations may be required. Suitability of subgrade soils and compaction of structural fill materials must be verified by Atlas personnel prior to placement of structural elements. Additionally, monitoring and testing should be performed to verify that suitable materials are used for structural fill and that proper placement and compaction techniques are utilized. Atlas No. B211945G Page 125 Copyright©2022 Atlas Technical Consultants 12. REFERENCES Ada County Highway District (ACHD) (2017). Ada County Highway District Policy Manual (August 2017). [Online] Available: <http://www.achdidaho.org/AboutACHD/PolicyManual.aspx> (2021). American Association of State Highway and Transportation Officials (AASHTO)(1993). AASHTO Guide for Design of Pavement Structures 1993. Washington D.C.: AASHTO. American Concrete Institute (ACI) (2015). Guide for Concrete Floor and Slab Construction: ACI 302.1 R. Farmington Hills, MI: ACI. American Society of Civil Engineers (2021). ASCE 7 Hazards Tool: Web Interface [Online] Available: <https://asce7hazardtool.online/> (2021). American Society of Civil Engineers (ASCE) (2013). Minimum Design Loads for Buildings and Other Structures: ASCE/SEI 7-16. Reston, VA: ASCE. American Society for Testing and Materials (ASTM) (2017). Standard Test Method for Materials Finer than 75-um (No. 200) Sieve in Mineral Aggregates by Washing: ASTM C117. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2014). Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates: ASTM C136. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort: ASTM D698. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2012). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort: ASTM D1557. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2014). Standard Test Methods for California Bearing Ratio: ASTM D1883. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2013). Standard Test Methods for Resistance Value (R-Value) and Expansion Pressure of Compacted Soils: ASTM D2844. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Practice for Classification of Soils for Engineering Purposes(Unified Soil Classification System):ASTM D2487.West Conshohocken, PA:ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils: ASTM D4318. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2011). Standard Specification for Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill Under Concrete Slabs: ASTM E1745. West Conshohocken, PA: ASTM. Desert Research Institute.Western Regional Climate Center. [Online]Available: <http://www.wrcc.dri.edu/> (2021). International Building Code Council (2018). International Building Code, 2018. Country Club Hills, IL: Author. Atlas No. B211945G Page126 Copyright©2022 Atlas Technical Consultants arm I �lrT—G7Tdr-W� Local Highway Technical Assistance Council (LHTAC) (2017). Idaho Standards for Public Works Construction, 2017. Boise, ID: Author. Othberg, K. L. and Stanford, L. A., Idaho Geologic Society (1993). Geologic Map of the Boise Valley and Adioining Area, Western Snake River Plain, Idaho. (scale 1:100,000). Boise, ID: Joslyn and Morris. U.S. Department of Labor, Occupational Safety and Health Administration. CFR 29, Part 1926, Subpart P: Safety and Health Regulations for Construction, Excavations (1986). [Online] Available: <www.osha.gov> (2021). U.S. Geological Survey. (2016). Interactive Fault Map: Web Interface. [Online] Available: <https://usgs.maps.arcgis.com/apps/webappviewer/index.htmI?id=5a6038b3a1684561 a9b0aadf88412fc> (2021). Atlas No. B211945G Page 127 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. Appendix I WARRANTY AND LIMITING CONDITIONS Atlas warrants that findings and conclusions contained herein have been formulated in accordance with generally accepted professional engineering practice in the fields of foundation engineering, soil mechanics, and engineering geology only for the site and project described in this report. These engineering methods have been developed to provide the client with information regarding apparent or potential engineering conditions relating to the site within the scope cited above and are necessarily limited to conditions observed at the time of the site visit and research. Field observations and research reported herein are considered sufficient in detail and scope to form a reasonable basis for the purposes cited above. Exclusive Use This report was prepared for exclusive use of the property owner(s), at the time of the report, and their retained design consultants ("Client"). Conclusions and recommendations presented in this report are based on the agreed-upon scope of work outlined in this report together with the Contract for Professional Services between the Client and Atlas Technical Consultants ("Consultant"). Use or misuse of this report, or reliance upon findings hereof, by parties other than the Client is at their own risk. Neither Client nor Consultant make representation of warranty to such other parties as to accuracy or completeness of this report or suitability of its use by such other parties for purposes whatsoever, known or unknown, to Client or Consultant. Neither Client nor Consultant shall have liability to indemnify or hold harmless third parties for losses incurred by actual or purported use or misuse of this report. No other warranties are implied or expressed. Report Recommendations are Limited and Subject to Misinterpretation There is a distinct possibility that conditions may exist that could not be identified within the scope of the investigation or that were not apparent during our site investigation. Findings of this report are limited to data collected from noted explorations advanced and do not account for unidentified fill zones, unsuitable soil types or conditions, and variability in soil moisture and groundwater conditions. To avoid possible misinterpretations of findings, conclusions, and implications of this report, Atlas should be retained to explain the report contents to other design professionals as well as construction professionals. Since actual subsurface conditions on the site can only be verified by earthwork, note that construction recommendations are based on general assumptions from selective observations and selective field exploratory sampling. Upon commencement of construction, such conditions may be identified that require corrective actions, and these required corrective actions may impact the project budget. Therefore, construction recommendations in this report should be considered preliminary, and Atlas should be retained to observe actual subsurface conditions during earthwork construction activities to provide additional construction recommendations as needed. Since geotechnical reports are subject to misinterpretation, do not separate the soil logs from the report. Rather, provide a copy of, or authorize for their use, the complete report to other design Atlas No. B211945G Page128 Copyright©2022 Atlas Technical Consultants arm I �lrT—G7T�� professionals or contractors. Locations of exploratory sites referenced within this report should be considered approximate locations only. For more accurate locations, services of a professional land surveyor are recommended. This report is also limited to information available at the time it was prepared. In the event additional information is provided to Atlas following publication of our report, it will be forwarded to the client for evaluation in the form received. Environmental Concerns Comments in this report concerning either onsite conditions or observations, including soil appearances and odors, are provided as general information. These comments are not intended to describe, quantify, or evaluate environmental concerns or situations. Since personnel, skills, procedures, standards, and equipment differ, a geotechnical investigation report is not intended to substitute for a geoenviron mental investigation or a Phase II/III Environmental Site Assessment. If environmental services are needed, Atlas can provide, via a separate contract, those personnel who are trained to investigate and delineate soil and water contamination. Atlas No. B211945G Page 129 Copyright©2022 Atlas Technical Consultants '� ► � — � .~ice '� • MAP NOTES: -Not to Scale B, MU Ol ���■r� - Approximate Site re ra Location ��■■■■ SEEM ■.�■■■■.■■�■w■ _ -W FRANKUN RD --Site Location � 1 1 - ■ Womi � _ ChesterIndustrial 955 Black Cat Road Meridian,ID Modified . .wing: l` :. .: ' Site Map Figure 2 NOTES: J I N •Not to Scale ---- --- -- -- -- ---- -- -- -- -- B-2 -- —. -.;_,j ROSENLOF DRAIN I'. I II , TP-6 In TP 5 ® TP-7 LEGEND ® ® - Approximate Site Boundary Approximate Atlas Test I a TP-8 Pit Location ARCELC Approximate Atlas Test ' o - Pit Location r a with Piezometer B-6 TP-10 Approximate Atlas j • B-8 • 8 B-7 W Boring Location ILL o D y - - (-uuLJ 1111,,,,. _ TP 2 p TP-9 -- B A _ _ _ ' u p ffi TP 16„ --__ Lg - TP 12 sIDEN11u Dv T- ® _ +t ,— PARCEL B TP 13 -~-- - �_`- --�` ------------ - --�— --_ B 5 T B-4 f T r1+ — — _- T—r L_ .N• — _J 1_ I' _ —+-.1 TP-15 REVIDENTIAL TP-14 �- L r Chester Industrial 955 South Black Cat Road Meridian,ID -- - _ - --_-wvw __ �ttl WTERTgTE g4 - --___ - ---__ __ Modified by:CCW November 15,2021 Drawing:B211945g Ill�l T T7� 2791 S.Victory View Way Phone: (208)376-4748 Boise,ID 83709 Fax: (208)322-6515 Web: oneatlas.com Foundation Cross Section Figure 3 NOTES: NOTES: • Structural fill must consist of ISPWC 314"Type 1 crushed aggregate. •Not to Scale •Fill material must be compacted to at least 95%of the maximum dry density as determined by ASTM D1557. • Geogrid to be installed in accordance with manufacturer's recommendations. LEGEND •a, Footing e •, Structural Fill (crushed 2'min �'.• aggregate) • ° 4 .°a a1' eN 2.0' j• Chester Industrial 955 South Black Cat Road Meridian,ID Drawn by:CCW November 16,2021 Tensar TX 160 Geogrid Drawing:B211945g 6"separationIll A Native Soil ,--1 T 1 T7� 2791 S.Victory View Way Phone: (208)376-4748 Boise,ID 83709 Fax: (208)322-6515 Web: oneatlas.com �Tr 7ME7V Appendix V GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-1 Latitude: 43.596869 Date Advanced: October 6, 2021 Longitude: -116.454513 Excavated by: Turn of the Century Homes Depth to Water Table: 9.2 feet bgs Logged by: Bailey Hereford Total Depth: 9.5 feet bgs Depth Field Description and USCS Soil and Sample Sample Depth Lab h . . . • • • • . Test ID Lean Clay with Sand (CL): Brown, slightly 0.0-3.8 moist, medium stiff to stiff, with fine-grained 0.75- sand. 1.25 --Organics noted to 0.6 foot bgs. Silty Sand (SM): Brown, slightly moist to saturated, medium dense, with fine to coarse- 3.8-9.5 grained sand. --Intermittent weak cementation encountered from 8.4 to 9.2 feet bgs. --Some clay content noted throughout. Notes:See Site Map for test pit location. Piezometer installed to a depth of 9.5 feet bgs. Atlas No. B211945G Page 133 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-2 Latitude: 43.597938 Date Advanced: October 6, 2021 Longitude: -116.459219 Excavated by: Turn of the Century Homes Depth to Water Table: 9.0 feet bgs Logged by: Bailey Hereford Total Depth: 10.0 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Dark brown to brown, slightly moist, medium stiff to stiff, with 0.0-3.7 fine-grained sand. --Plow zone and organics noted to 0.8 foot bgs. Clayey Sand (SC): Brown, slightly moist to 3.7-10.0 saturated, medium dense, with fine to coarse- grained sand. Notes:See Site Map for test pit location. Atlas No. B211945G Page 134 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-3 Latitude: 43.598627 Date Advanced: October 6, 2021 Longitude: -116.460713 Excavated by: Turn of the Century Homes Depth to Water Table: 9.2 feet bgs Logged by: Bailey Hereford Total Depth: 11.5 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Brown, slightly moist, stiff to very stiff, with fine-grained sand. 0.0-2.9 --Plow zone and organics noted to 0.6 foot 1.5-2.0 bgs. Clayey Sand (SC): Brown, slightly moist to saturated, medium dense, with fine to coarse- 2.9-11.5 grained sand. Intermittent weak cementation encountered from 6.0 to 8.0 feet bgs. Notes:See Site Map for test pit location. Atlas No. B211945G Page 135 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-4 Latitude: 43.599663 Date Advanced: October 6, 2021 Longitude: -116.463087 Excavated by: Turn of the Century Homes Depth to Water Table: 9.0 feet bgs Logged by: Bailey Hereford Total Depth: 10.3 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Brown, slightly 0.0-4.1 moist, soft to stiff, with fine-grained sand. GS 2.0-2.5 0.5-1.5 A --Plow zone and organics noted to 0.8 foot Bulk CBR bgs. Silty Sand (SM): Brown, moist to saturated, 4.1-10.3 medium dense, with fine to coarse-grained sand. Notes:See Site Map for test pit location. Piezometer installed to a depth of 10.3 feet bgs. MoistureLab Test ID A�ff A 24.5 37 17 100 99 93 90 82.6 Atlas No. B211945G Page 136 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-5 Latitude: 43.600460 Date Advanced: October 6, 2021 Longitude: -116.461322 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Bailey Hereford Total Depth: 6.0 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Brown, slightly moist, medium stiff to very stiff, with fine- 0.0-2.5 grained sand. 1.0-2.0 --Plow zone and organics noted to 1.0 foot bgs. Silty Sand (SM): Brown, slightly moist, 2.5-6.0 medium dense, with fine to coarse-grained sand. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 6.0 feet bgs. Atlas No. B211945G Page 137 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-6 Latitude: 43.600803 Date Advanced: October 6, 2021 Longitude: -116.459374 Excavated by: Turn of the Century Homes Depth to Water Table: 8.7 feet bgs Logged by: Bailey Hereford Total Depth: 9.8 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Dark brown to brown, slightly moist, stiff, with fine-grained 0.0-4.3 sand. 1.5 --Plow zone and organics noted to 0.6 foot bgs. Silty Sand (SM): Brown, slightly moist to saturated, medium dense, with fine to coarse- 4.3-9.8 grained sand. --Intermittent weak cementation encountered throughout. Notes:See Site Map for test pit location. Atlas No. B211945G Page 138 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TF Test Pit Log #: TP-7 Latitude: 43.600588 Date Advanced: October 6, 2021 Longitude: -116.457599 Excavated by: Turn of the Century Homes Depth to Water Table: 8.6 feet bgs Logged by: Bailey Hereford Total Depth: 9.5 feet bgs V. Depth eld Description and USCS Soil and Sample Sample Depth a st IL � • •• • • • •• rTe Lean Clay with Sand (CL): Dark brown to brown, slightly moist, medium stiff to stiff, with 0.0-3.8 fine-grained sand. 1.0-1.5 --Plow zone and organics noted to 0.7 foot bgs. Silty Sand (SM): Brown, slightly moist to saturated, medium dense, with fine to coarse- 3.8-9.5 grained sand. --Intermittent weak cementation encountered throughout. Notes:See Site Map for test pit location. Piezometer installed to a depth of 9.5 feet bgs. Atlas No. B211945G Page 139 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-8 Latitude: 43.599395 Date Advanced: October 6, 2021 Longitude: -116.456046 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Bailey Hereford Total Depth: 4.7 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Dark brown to brown, slightly moist, medium stiff to stiff, with 0.0-2.4 fine-grained sand. 0.75-1.5 --Plow zone and organics noted to 0.7 foot bgs. Silty Sand (SM): Brown, slightly moist, 2.4-4.7 medium dense, with fine to coarse-grained sand. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 4.7 feet bgs. Atlas No. B211945G Page140 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-9 Latitude: 43.598036 Date Advanced: October 6, 2021 Longitude: -116.456012 Excavated by: Turn of the Century Homes Depth to Water Table: 8.1 feet bgs Logged by: Bailey Hereford Total Depth: 10.2 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Dark brown to brown, slightly moist, medium stiff to stiff, with 0.0-2.7 fine-grained sand. 1.0-1.75 --Plow zone and organics noted to 0.7 foot bgs. Silty Sand (SM): Brown, slightly moist, 2.7-10.2 medium dense, with fine to coarse-grained sand. --Some clay content noted throughout. Notes:See Site Map for test pit location. Atlas No. B211945G Page 141 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-10 Latitude: 43.598417 Date Advanced: October 6, 2021 Longitude: -116.454622 Excavated by: Turn of the Century Homes Depth to Water Table: 6.8 feet bgs Logged by: Bailey Hereford Total Depth: 8.3 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- 0.0-3.2 grained sand. 1.5-2.0 --Plow zone and organics noted to 0.7 foot bgs. Silty Sand (SM): Brown, slightly moist to saturated, medium dense, with fine to coarse- 3.2-8.3 grained sand. --Intermittent weak cementation encountered throughout. Notes:See Site Map for test pit location. Atlas No. B211945G Page142 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TF Test Pit Log #: TP-11 Latitude: 43.600550 Date Advanced: October 6, 2021 Longitude: -116.454577 Excavated by: Turn of the Century Homes Depth to Water Table: 7.2 feet bgs Logged by: Bailey Hereford Total Depth: 8.0 feet bgs V. Depth eld Description and USCS Soil and Sample Sample Depth a st IL � • •• • • • •• I Ten Lean Clay with Sand (CL): Dark brown to brown,slightly moist, stiff to very stiff,with fine- 0.0-3.4 grained sand. 1.5-2.5 --Plow zone and organics noted to 0.7 foot bgs. Silty Sand (SM): Brown, slightly moist to saturated, medium dense, with fine to coarse- 3.4-8.0 grained sand. --Intermittent weak cementation encountered throughout. Notes:See Site Map for test pit location. Piezometer installed to a depth of 8.0 feet bgs. Atlas No. B211945G Page143 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-12 Latitude: 43.597642 Date Advanced: November 1, 2021 Longitude: -116.455370 Excavated by: Turn of the Century Homes Depth to Water Table: 9.8 feet bgs Logged by: Bryar Jensen, El Total Depth: 12.5 feet bgs Depth .,Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Poorly Graded Gravel with Sand Fill (GP- 0.0-1.0 FILL): Brown, dry, medium dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. 1.0-3.8 Lean Clay with Sand (CL): Brown, slightly moist, stiff, with fine to medium-grained sand. 3 8 7 7 Sandy Silt (ML): Brown, slightly moist, stiff to very stiff, with fine-grained sand. Silty Sand (SM): Brown, dry to saturated, 7.7-12.5 dense, with fine to coarse-grained sand. --Intermittent weak calcic cementation encountered throughout. Notes:See Site Map for test pit location. Atlas No. B211945G Page 144 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-13 Latitude: 43.597405 Date Advanced: November 1, 2021 Longitude: -116.459064 Excavated by: Turn of the Century Homes Depth to Water Table: 10.9 feet bgs Logged by: Bryar Jensen, El Total Depth: 12.2 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Brown, slightly 0.0-5.2 moist, very stiff, with fine-grained sand. 2.5-3.5 --Plow zone and organics noted to 1.0 foot bgs. 5.2-7.3 Silt with Sand (ML): Brown, slightly moist, stiff, with fine to medium-grained sand. Silty Sand (SM): Brown, dry to saturated, dense, with fine to coarse-grained sand. 7.3-12.2 --Intermittent weak calcic cementation encountered throughout. --Some clay content noted throughout. Notes:See Site Map for test pit location. Atlas No. B211945G Page145 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-14 Latitude: 43.595957 Date Advanced: November 1, 2021 Longitude: -116.458512 Excavated by: Turn of the Century Homes Depth to Water Table: 15.5 feet bgs Logged by: Bryar Jensen, El Total Depth: 17.0 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Brown, slightly 0.0-3.1 moist, stiff, with fine to medium-grained sand. --Plow zone and organics noted to 1.0 foot bgs. 3.1-7.7 Silt with Sand (ML): Brown, slightly moist, stiff, with fine to medium-grained sand. Silty Sand (SM): Brown, dry to saturated, dense, with fine to coarse-grained sand. 7.7-17.0 --Intermittent weak calcic cementation encountered throughout. --Some clay content noted throughout. Notes:See Site Map for test pit location. Piezometer installed to a depth of 17.0 feet bgs. Atlas No. B211945G Page146 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-15 Latitude: 43.596353 Date Advanced: November 1, 2021 Longitude: -116.461507 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Bryar Jensen, El Total Depth: 6.0 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Brown, slightly 0.0-2.6 moist, stiff, with fine to medium-grained sand. --Plow zone and organics noted to 1.0 foot bgs. 2.6-6.0 Silt with Sand (ML): Brown, slightly moist, stiff, with fine to medium-grained sand. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 6.0 feet bgs. Atlas No. B211945G Page147 Copyright©2022 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-16 Latitude: 43.597654 Date Advanced: November 1, 2021 Longitude: -116.461346 Excavated by: Turn of the Century Homes Depth to Water Table: 15.0 feet bgs Logged by: Bryar Jensen, El Total Depth: 15.7 feet bgs Depth Eield Description and USCS Soil and Sample Sample Depth Qp Lab •• Jiment Classification • bgs) Test ID Lean Clay with Sand (CL): Brown, slightly 0.0-3.3 moist, stiff, with fine to medium-grained sand. --Plow zone and organics noted to 1.0 foot bgs. 3.3-6.9 Silt with Sand (ML): Brown, slightly moist, stiff, with fine to medium-grained sand. Silty Sand (SM): Brown, dry to saturated, dense, with fine to coarse-grained sand. 6.9-15.7 --Intermittent weak calcic cementation encountered throughout. --Some clay content noted throughout. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.7 feet bgs. Atlas No. B211945G Page148 Copyright©2022 Atlas Technical Consultants FIELD BORING LOG Mi" Am BORING NO.: B-1 TOTAL DEPTH: 51.5' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian, ID SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: July 21, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.601120, -116.455722 70 IN Z Water level during drilling ❑ Standard Split Spoon Auger Sample I M California Sampler LEI Lu 2 IL Lu CO J U) I Z U1 w J DESCRIPTION F O U p o p v) J o m 00 U) O m 0 - 355 -X_—x SILT WITH SAND FILL (ML-FILL): Brown, dry to slightly moist, medium stiff to stiff, ® 3,2,3 5 with fine-grained sand. kL 5,10,12 0. 30 6 SILT WITH SAND (ML): Brown, slightly moist to saturated, medium stiff to very stiff, ❑ 317,13 10 - with fine-grained sand. ® 14,12,21 0 3 6 --Intermittent weak cementation encountered from 5.0 to 6.5 feet bgs. 15 Groundwater encountered at 7.1 feet bgs. 10,15,21 0 30 6 SILTY SAND (SM): Brown, saturated, dense, with fine to medium-grained sand. 20 Q 50 for 4" 01 30 6 POORLY GRADED SAND WITH CLAY (SP-SC): Light brown, saturated, dense, 25 �1�- with fine to medium-grained sand. 0 bJ 49, 50 for 01 30 6 POORLY GRADED GRAVEL WITH SILT 3" -�� AND SAND (GP-GM): Light brown, 30 .0. saturated, very dense, with fine to coarse- IL23,20,48 01 0 6 Q - grained sand and fine to coarse gravel. 35 = POORLY GRADED SAND WITH SILT (SP- ® 7,16,22 01 30 6 - - SM): Light brown, saturated, dense, with - - fine to coarse-grained sand. 40 17,14,21 0160 45 = _ ® 13,18,19 01 3 6 . 7. LEAN CLAY (CL): Brown, saturated, very 50 stiff. 3,6,12 0. 30 6 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG Mi" Am BORING NO.: B—Z TOTAL DEPTH: 51.5' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian, ID SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: July 21, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.601135, -116.463314 IN Z Water level during drilling Standard Split Spoon Auger Sample I M California Sampler LEI Lu 2 IL Lu CO J U) I Z U1 w J DESCRIPTION F O U p o p v) J o m 00 U) O m 0X-X 3,4,3 . -X X. SILT WITH SAND FILL (ML-FILL): Brown, dry to slightly moist, medium stiff, with fine- ® 3,4,2 5 —_= grained sand. _ kL 8,6,6 0 30 6 SILT WITH SAND (ML): Brown, dry to saturated, medium stiff to hard, with fine- 15,16,20 10 grained sand. ® 15,12,15 01 0 6 —_—_—_ --Intermittent weak cementation encountered from 7.5 to 9.0 feet bgs. 15 Groundwater encountered at 9.5 feet bgs. 17,12,16 01 6 POORLY GRADED SAND WITH CLAY - - (SP-SC): Light brown, saturated, medium 20 dense, with fine to medium-grained sand. 50 for 4" 01 30 6 p7 POORLY GRADED GRAVEL WITH SILT AND SAND (GP-GM): Light brown, 25 _� _ saturated, dense to very dense, with fine to ® 17,19,50 01 30 6 0 coarse-grained sand and fine to coarse _0. j_ gravel. 30 0 50 for 5' 01 30 35 . kL23,17,18 01 3 6 _ 0 40 _��_ ® 26,36,26 01 3..0 POORLY GRADED SAND WITH CLAY 45 (SP-SC): Light brown, saturated, dense, hL 18,20,14 01 3 60 With fine to coarse-grained sand. 50 13,20,22 0 30 6 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG mi" AL A BORING NO.: B-3 I TA TOTAL DEPTH: 51.5' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRIVING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: G" Hollow Stem Auger Meridian, ID SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: July 21, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.595280, -116.455099 s Water level during drilling ❑ Standard Split Spoon z A Auger Sample California Sampler w Lu = D_ W o W U) Z ~ DESCRIPTION ? 4 g 0 p o p c) J � o < m 0 0 m 0 -._.- 4,3,4 SILT WITH SAND FILL (ML-FILL): Light brown to brown, dry to slightly moist, ❑ 4,12,15 5 _ _ medium stiff, with fine-grained sand. ® 14,22,21 0 30 6 SANDY SILT (ML): Light brown, dry to ® 16,28,29 — = slightly moist, very stiff to hard, with fine- 10 grained sand. ❑ 11,13,18 0 6 SILTY SAND (SM): Light brown to brown, 15 - dry to slightly moist, medium dense to very 27,14,9 0 30 6 dense, with fine to medium-grained sand. --Intermittent weak to moderate s 20 cementation encountered throughout. 4,4,3 0 30 6 _= SILT WITH SAND (ML): Brown, moist to saturated, soft to very stiff, with fine-grained 25 sand. ® 2,2,2 30 6 Groundwater encountered at 20.0 feet bgs. 30 ® 6,11,8 0 0 6 = SILTY GRAVEL WITH SAND (GM): Brown, 35 24,50 for 0 30 6 0= = saturated, very dense, with fine to coarse- = grained sand and fine to coarse gravel. 3" 00..= 40 = _ 41,50 for 0 30 6 00.. . ... ... ... .. 5„ POORLY GRADED SAND (SP): Light 45 brown, saturated, medium dense to very o 25,50 for 0 30 dense, with fine to coarse-grained sand and 3„ fine to coarse gravel. 50 FLEAN CLAY (CL): Brown, saturated, very ❑ 7,9,11 0 30 6 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG Mi" Am BORING NO.: B-4 TOTAL DEPTH: 21.5' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian Road SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: October 14, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.597411, -116.457902 70 IN Z Water level during drilling Standard Split Spoon Auger Sample I M California Sampler LEI Lu 2 ILLu CO J U) I Z U1 w J DESCRIPTION F it [ O U p o p v) J o m O 0 U) O m 0 LEAN CLAY WITH SAND (CL): Brown, slightly moist, soft to medium stiff, with fine- grained sand. --Plow zone and organics noted to 1.0 foot bgs. 3,2,2 5 3,1,2 30 6 SILTY SAND (SM): Brown, slightly moist to $ $ saturated, medium dense, with fine to coarse-grained sand. --Intermittent weak cementation 10 _ _ encountered throughout. 10,13,16 0 0 6 s Groundwater encountered at 13.2 feet bgs SILT WITH SAND (ML): Brown, saturated, 15 very soft to very stiff, with fine to medium- 13,13,10 01 0 6 grained sand. 20 30 6 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG Mi" Am BORING NO.: B-5 TOTAL DEPTH: 20.9' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian Road SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: October 14, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.597529, -116.461850 70 IN Z Water level during drilling Standard Split Spoon Auger Sample I M California Sampler LEI Lu 2 IL Lu CO J U) I Z U1 w J DESCRIPTION F O U p o p v) J o m O 0 U) O m 0 LEAN CLAY WITH SAND (CL): Brown, slightly moist, stiff, with fine-grained sand. --Plow zone and organics noted to 1.0 foot bgs. 3,8,15 SILT WITH SAND (ML): Brown, slightly moist, very stiff, with fine-grained sand. 5 SILTY SAND (SM): Brown, slightly moist to ® 25,50 for 01 30 saturated, loose to very dense, with fine to 3" coarse-grained sand. -: --Intermittent weak to moderate cementation encountered throughout. 20,14,13 --Some clay content noted throughout. 10 5,5,2 0 30 6 Groundwater encountered at 13.3 feet bgs 0 POORLY GRADED GRAVEL WITH SILT 15 AND SAND (GP-GM): Brown, saturated, 12,21,24 0 30 6 _�1�_ dense to very dense, with fine to coarse- grained sand and fine to coarse gravel. 0 0 20 _�1_ 14,50 for 01 30 6 5" 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG -i" Am BORING NO.: B-6 TOTAL DEPTH: 20.3' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian Road SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: October 14, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.598600, -116.457709 Water level during drilling ® Standard Split Spoon Auger Sample California Sampler W � _ W CD J d Z ~ ~ DESCRIPTION F N �' U) ~ _ v v 2 O O W J 0 O J o o Q m 0 0 U) Q J LL � 00 0 LEAN CLAY WITH SAND (CL): Brown, slightly moist, medium stiff to stiff, with fine- grained sand. --Plow zone and organics noted to 1.0 foot bgs. 3,6,8 SILTY SAND (SM): Brown, slightly moist to -:-: moist, medium dense, with fine to coarse- 5 grained sand. 6,6,6 00 6 --Intermittent weak cementation encountered throughout. --Some clay content noted throughout. CLAYEY SAND (SC): Brown, moist to 7,11,10 s saturated, medium dense, with fine to medium-grained sand. Groundwater encountered at 8.7 feet bgs. 10 4,5,6 0 30 6 15 6,12,12 0 0 00 POORLY GRADED GRAVEL WITH SILT -01�_ AND SAND (GP-GM): Brown, saturated, 0 very dense, with fine to coarse-grained _Q sand and fine to coarse gravel. 13,50 for 20 3" 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG Mi" Am BORING NO.: B-7 TOTAL DEPTH: 20.4' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian Road SAMPLING METHODS: Split Spoon JOB NO.: B21945g DATES DRILLED: October 14, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.598253, -116.459452 70 IN Z Water level during drilling Standard Split Spoon Auger Sample I M California Sampler LEI Lu 2 IL Lu CO J U) I Z U1 w J DESCRIPTION F O U p o p v) J o m O 0 U) O m 0 LEAN CLAY WITH SAND (CL): Brown, slightly moist, stiff, with fine-grained sand. --Plow zone and organics noted to 1.0 foot -= bgs. 6,17,23 -- SANDY SILT (ML): Brown to light brown, ------- dry to moist, hard, with fine to coarse- ------- grained sand. 5Intermittent weak cementation 17.7 NP 98 57.3 12,27,35 01 30 6 == encountered throughout. =— --Some clay content noted throughout. CLAYEY SAND (SC): Brown, moist to 7,16,18 saturated, dense to very dense, with fine to medium-grained sand. Groundwater encountered at 8.4 feet bgs. 10 14,21,26 01 30 6 oa 15 9,37,31 01 30 6 POORLY GRADED GRAVEL WITH SILT AND SAND (GP-GM): Brown to light brown, saturated, very dense, with fine to coarse- _�1�_ grained sand and fine to coarse gravel. 0 22,50 for 20 4" 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG -i" Am BORING NO.: B-8 TOTAL DEPTH: 21.5' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian Road SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: October 14, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.598430, -116.461373 Water level during drilling ® Standard Split Spoon Auger Sample California Sampler W � _ W CD J d Z ~ ~ DESCRIPTION F N �' U) ~ _ v v 2 O O W J 0 O J o o Q m 0 0 U) Q J LL � 00 0 LEAN CLAY WITH SAND (CL): Brown, slightly moist, medium stiff to stiff, with fine- grained sand. --Plow zone and organics noted throughout. 6,10,11 SILTY SAND (SM): Brown, slightly moist, -:-: medium dense, with fine to coarse-grained 5 sand. --Intermittent weak cementation 3,5,7 0 30 6 encountered throughout. CLAYEY SAND (SC): Brown, slightly moist to saturated, very loose to dense, with fine 6,12,20 to medium-grained sand. 10 9,9,5 0 30 60 Groundwater encountered at 11.0 feet bgs 15 30 6 20 5,8,7 0 30 6 2791 S.Victory View Way • Boise, ID 83709 • (208)376-4748 . Fax(208)322-6515 oneatlas.com FIELD BORING LOG Mi" Am BORING NO.: B-9 TOTAL DEPTH: 21.5' PROJECT INFORMATION DRILLING INFORMATION PROJECT: Chester Industrial DRILLING CO.: Haztech Drilling, Inc. LOCATION: 955 South Black Cat Road METHOD OF DRILLING: 6" Hollow Stem Auger Meridian Road SAMPLING METHODS: Split Spoon JOB NO.: B211945g DATES DRILLED: October 14, 2021 LOGGED BY:Jack Hood LATITUDE/LONGITUDE: 43.599364, -116.454920 70 IN Z Water level during drilling Standard Split Spoon Auger Sample I M California Sampler LEI � 2 IL Lu CO J U) I Z U1 w J DESCRIPTION F O U p o p v) J o m O 0 U) O m 0 LEAN CLAY WITH SAND (CL): Brown, dry to slightly moist, medium stiff to hard, with fine-grained sand. --Plow zone and organics noted to 1.0 foot bgs. 3,2,3 5 9,19,22 01 30 6 CLAYEY SAND (SC): Brown, slightly moist 9,10,13 to saturated, medium dense to dense, with fine to coarse-grained sand. Groundwater encountered at 8.2 feet bgs. 10 19.4 26/8 94 44.5 8,10,8 0 30 6 15 13,26,24 01 30 20 14,22,14 01 30 6 2791 S.Victory View Way • Boise, ID 83709 . (208)376-4748 . Fax(208)322-6515 oneatlas.com Appendix VII GEOTECHNICAL GENERAL NOTES Unified Soil Classification System Major Divisions Symbol Soil Descriptions Gravel & GW Well-graded ravels; ravel/sand mixtures with little or no fines Coarse- Gravelly Soils GP Poorly-graded ravels; ravel/sand mixtures with little or no fines Grained < 50% GM Silty gravels; poorly-graded ravel/sand/silt mixtures Soils < coarse GC Clayey ravels; poorly-graded raded gravel/sand/clay mixtures 50% Y Y g p Y-9 9 Y passes Sand & Sandy SW Well-graded sands; ravel) sands with little or no fines No.200 Soils > 50% SP Poorl - raded sands; ravel) sands with little or no fines sieve coarse SM Silt sands; poorly-graded sand/gravel/silt mixtures fraction SC Clayey sands; poorly-graded sand/gravel/clay mixtures Fine- ML Inorganic silts; sandy, gravellyor clayey silts Grained Silts & Clays CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium- Soils > LL < 50 lasticit cla s 50% OL Organic, low-plasticity clays and silts passes MH Inorganic, elastic silts; sandy, gravellyor clayey elastic silts No.200 Silts & Clays CH Fat clays; high-plasticity, inorganic clays sieve LL > 50 OH Organic, medium to high-plasticity clays and silts Highly Organic Soils PT Peat, humus, h dric soils with high organic content Relative Density and Consistency Moisture Content and Cementation Classification Classification Coarse-Grained Soils SPT Blow Counts N Description Field Test Very Loose: <4 Dry Absence of moisture, dry to touch Loose: 4-10 Slightly Moist Damp, but no visible moisture Medium Dense: 10-30 Moist Visible moisture Dense: 30-50 Wet Visible free water Very Dense: > 50 Saturated Soil is usually below water table Fine-Grained Soils SPT Blow Counts N Description Field Test Very Soft: < 2 Weak Crumbles or breaks with handling or Soft: 2-4 slight finger pressure Medium Stiff: 4-8 Moderate Crumbles or breaks with Stiff: 8-15 considerable finger pressure Very Stiff: 15-30 Strong Will not crumble or break with finger Hard: > 30 pressure Particle Size Acronym List Boulders: > 12 in. GS grab sample Cobbles: 12 to 3 in. LL Liquid Limit Gravel: 3 in. to 5 mm M moisture content Coarse-Grained Sand: 5 to 0.6 mm NP non-plastic Medium-Grained Sand: 0.6 to 0.2 mm PI Plasticity Index Fine-Grained Sand: 0.2 to 0.075 mm Qp penetrometer value, unconfined compressive Silts: 0.075 to 0.005 mm strength, tsf Clays: < 0.005 mm V vane value, ultimate shearing strength, tsf Atlas No. B211945G Page 158 Copyright©2022 Atlas Technical Consultants Appendix VIII AASHTO PAVEMENT DESIGN Pavement Section Design Location: Chester Industrial,Light Duty Average Daily Traffic Count: 600 All Lanes&Both Directions Design Life: 20 Years Percent of Traffic in Design Lane: 50% Terminal Seviceability Index(Pt): 2.5 Level of Reliability: 95 Subgrade CBRValue: 4 Subgrade Mr: 6,000 Calculation of Design-18 kip ESALs Daily Growth Load Design Traffic Rate Factors ESALs Passenger Cars: 245 2.0% 0.0008 1,738 Buses: 0 2.0% 0.6806 0 Panel&Pickup Trucks: 26 2.0% 0.0122 2,813 2-Axle,6-Tire Trucks: 3 2.0% 0.1890 5,028 Emergency Vehicles: 1.0 2.0% 4.4800 39,731 Dump Trucks: 0 2.0% 3.6300 0 Tractor Semi Trailer Trucks: 25 2.0% 2.3719 525,882 Double Trailer Trucks 0 2.0% 2.3187 0 Heavy Tractor Trailer Combo Trucks: 0 2.0% 2.9760 0 Average Daily Traffic in Design Lane: 300 Total Design Life 18-kip ESALs: 575,193 Actual Log(ESALs): 5.760 Trial SN: 3.68 Trial Log(ESALs): 5.765 Pavement Section Design SN: 3.70 Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 3.00 0.42 n/a Asphalt-Treated Base: 0.00 0.25 n/a Cement-Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 6.00 0.14 1.0 Subbase: 16.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 Atlas No. B211945G Page 159 Copyright©2022 Atlas Technical Consultants AASHTO PAVEMENT DESIGN Pavement Section Design Location: Chester Industrial,Heavy Duty Average Daily Traffic Count: 600 All Lanes&Both Directions Design Life: 20 Years Percent of Traffic in Design Lane: 50% Terminal Seviceability Index(Pt): 2.5 Level of Reliability: 95 Subgrade CBRValue: 4 Subgrade Mr: 6,000 Calculation of Design-18 kip ESALs Daily Growth Load Design Traffic Rate Factors ESALs Passenger Cars: 198 2.0% 0.0008 1,405 Buses: 0 2.0% 0.6806 0 Panel&Pickup Trucks: 35 2.0% 0.0122 3,787 2-Axle,6-Tire Trucks: 10 2.0% 0.1890 16,762 Emergency Vehicles: 2.0 2.0% 4.4800 79,462 Dump Trucks: 1 2.0% 3.6300 32,193 Tractor Semi Trailer Trucks: 30 2.0% 2.3719 631,059 Double Trailer Trucks 20 2.0% 2.3187 411,270 Heavy Tractor Trailer Combo Trucks: 4 2.0% 2.9760 105,571 Average Daily Traffic in Design Lane: 300 Total Design Life 18-kip ESALs: 1,281,508 Actual Log(ESALs): 6.108 Trial SN: 4.18 Trial Log(ESALs): 6.114 Pavement Section Design SN: 4.31 Design Depth Structural Drainage Inches Coefficient Coefficient Asphaltic Concrete: 3.50 0.42 n/a Asphalt-Treated Base: 0.00 0.25 n/a Cement-Treated Base: 0.00 0.17 n/a Crushed Aggregate Base: 6.00 0.14 1.0 Subbase: 20.00 0.10 1.0 Special Aggregate Subgrade: 0.00 0.09 0.9 Atlas No. B211945G Page 160 Copyright©2022 Atlas Technical Consultants �TrTG7T�� Appendix IX GRAVEL EQUIVALENT METHOD PAVEMENT DESIGN Pavement Section Design Location: Chester Industrial, Public Collector Roads Average Daily Traffic Count: All Lanes &Both Directions Design Life: 20 Years Traffic Index: 8.00 Climate Factor: 1 R-Value of Subgrade: 9.00 Subgrade CBRValue: 4 Subgrade Mr: 6,000 R-Value of Aggregate Base: 80 R-Value of Granular Borrow: 60 Subgrade R-Value: 9 Expansion Pressure of Subgrade: 1.40 Unit Weight of Base Materials: 130 Total Design Life 18 kip ESAL's: 371,659 ASPHALTIC CONCRETE: Gravel Equivalent, Calculated: 0.512 Thickness: 0.2625641 Use = 3.5 Inches Gravel Equivalent,ACTUAL: 0.57 CRUSHED AGGREGATE BASE: Gravel Equivalent(Ballast): 1.024 Thickness: 0.414 Use = 6 Inches Gravel Equivalent,ACTUAL: 1.119 SUBBASE: Gravel Equivalent(Ballast): 2.330 Thickness: 1.211 Use = 16 Inches Gravel Equivalent,ACTUAL: 2.452 TOTAL Thickness: 2.125 Thickness Required by Exp. Pressure: 1.551 Design ACHD Depth Substitution Inches Ratios Asphaltic Concrete (at least 2.5): 3.50 1.95 Asphalt Treated Base (at least 4.2): 0.00 Cement Treated Base (at least 4.2): 0.00 Crushed Aggregate Base (at least 4.2): 6.00 1.10 Subbase (at least 4.2): 16.00 1.00 Atlas No. B211945G Page 161 Copyright©2022 Atlas Technical Consultants �TrT-G7Tdr-W� Appendix X CBR LABORATORY TEST DATA Source and Description: TP-4: 2.0'-2.5', Lean Clay with Sand Date Obtained: October 12, 2021 Sample ID: 21-8008 Soak Period & Swell: 96 Hrs & 2.6% Sampling and Preparation: ASTM D75: X AASHTO T2: ASTM D421: X AASHTO T87: Test Standard: ASTM D1883: X AASHTO T193: Sample Compaction: ASTM D 698: X AASHTO T 99: Method ASTM D 1557: AASHTO T A 180: Sample Condition: Soaked: X Unsoaked: Sample#1 Sample#2 Sample#3 #1 Depth #1 CBR #2 Depth #2 CBR #3 Depth #3 CBR Load Inches psi Value Load Inches psi Value Load Inches psi Value 0 0.000 0 0 0.000 0 0 0.000 0 14 0.025 5 22 0.025 7 32 0.025 11 25 0.050 8 48 0.050 16 65 0.050 22 32 0.075 11 72 0.075 24 98 0.075 33 39 0.100 13 1 93 0.100 31 3 128 0.100 43 4 45 0.125 15 111 0.125 37 155 0.125 52 50 0.150 17 127 0.150 42 180 0.150 60 53 0.175 18 140 0.175 47 202 0.175 67 56 0.200 19 1 155 0.200 52 3 223 0.200 74 5 65 0.300 22 1 182 0.300 61 3 263 0.300 88 5 75 0.400 25 1 207 0.400 69 3 294 0.400 98 4 84 0.500 28 1 230 0.500 77 3 333 0.500 111 4 Sample#: 1 2 3 Before Soak Maximum Dry Density: 97.9 CBR Value: 1 3 4 Moisture Content Before Compaction: 17.2 As Molded Dry Density: 79.6 86.9 92 Moisture Content After Compaction: 33.4 %Compaction: 81.3% 88.8% 94.0% Moisture Content Top 1 Inch: 33.4 Corrected CBR Value: 1 3 4 %Passing 3/4": 100 Surcharge Amount(Ib): 10.0 120 Load vs. De th 5 CBR& Compaction 100 4 80 a 3 c 60 a 40 2 c m 20 1 d v' 0 0 0.0 0.1 0.2 0.3 0.4 0.5 75% 80% 85% 90% 95% Penetration in Inches Compaction Sample#1 -Sample#2 -Sample#3 Atlas No. B211945G Page 162 Copyright©2022 Atlas Technical Consultants IMPOPIOnt InfOPM81100 Rhout ■ GeolechnicalmEngineeping Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help. The Geoprofessional Business Association (GBA) will not likely meet the needs of a civil-works constructor or even a has prepared this advisory to help you—assumedly different civil engineer.Because each geotechnical-engineering study a client representative—interpret and apply this is unique,each geotechnical-engineering report is unique,prepared geotechnical-engineering report as effectively as solely for the client. possible. In that way, you can benefit from a lowered Likewise,geotechnical-engineering services are performed for a specific exposure to problems associated with subsurface project and purpose.For example,it is unlikely that a geotechnical- conditions at project sites and development of engineering study for a refrigerated warehouse will be the same as them that,for decades, have been a principal cause one prepared for a parking garage;and a few borings drilled during of construction delays, cost overruns, claims, a preliminary study to evaluate site feasibility will not be adequate to and disputes. If you have questions or want more develop geotechnical design recommendations for the project. information about any of the issues discussed herein, contact your GBA-member geotechnical engineer. Do not rely on this report if your geotechnical engineer prepared it: Active engagement in GBA exposes geotechnical • for a different client; engineers to a wide array of risk-confrontation • for a different project or purpose; techniques that can be of genuine benefit for • for a different site(that may or may not include all or a portion of everyone involved with a construction project. the original site);or before important events occurred at the site or adjacent to it; e.g.,man-made events like construction or environmental Understand the Geotechnical-Engineering Services remediation,or natural events like floods,droughts,earthquakes, Provided for this Report or groundwater fluctuations. Geotechnical-engineering services typically include the planning, collection,interpretation,and analysis of exploratory data from Note,too,the reliability of a geotechnical-engineering report can widely spaced borings and/or test pits.Field data are combined be affected by the passage of time,because of factors like changed with results from laboratory tests of soil and rock samples obtained subsurface conditions;new or modified codes,standards,or from field exploration(if applicable),observations made during site regulations;or new techniques or tools.If you are the least bit uncertain reconnaissance,and historical information to form one or more models about the continued reliability of this report,contact your geotechnical of the expected subsurface conditions beneath the site.Local geology engineer before applying the recommendations in it.A minor amount and alterations of the site surface and subsurface by previous and of additional testing or analysis after the passage of time-if any is proposed construction are also important considerations.Geotechnical required at all-could prevent major problems. engineers apply their engineering training,experience,and judgment to adapt the requirements of the prospective project to the subsurface Read this Report in Full model(s). Estimates are made of the subsurface conditions that Costly problems have occurred because those relying on a geotechnical- will likely be exposed during construction as well as the expected engineering report did not read the report in its entirety.Do not rely on performance of foundations and other structures being planned and/or an executive summary.Do not read selective elements only.Read and affected by construction activities. refer to the report in full. The culmination of these geotechnical-engineering services is typically a You Need to Inform Your Geotechnical Engineer geotechnical-engineering report providing the data obtained,a discussion About Change of the subsurface model(s),the engineering and geologic engineering Your geotechnical engineer considered unique,project-specific factors assessments and analyses made,and the recommendations developed when developing the scope of study behind this report and developing to satisfy the given requirements of the project.These reports may be the confirmation-dependent recommendations the report conveys. titled investigations,explorations,studies,assessments,or evaluations. Typical changes that could erode the reliability of this report include Regardless of the title used,the geotechnical-engineering report is an those that affect: engineering interpretation of the subsurface conditions within the context - the site's size or shape; of the project and does not represent a close examination,systematic inquiry,or thorough investigation of all site and subsurface conditions. the elevation,configuration,location,orientation, function or weight of the proposed structure and Geotechnical-Engineering Services are Performed the desired performance criteria; the composition of the design team;or for Specific Purposes, Persons, and Projects, . project ownership. and At Specific Times Geotechnical engineers structure their services to meet the specific As a general rule,always inform your geotechnical engineer of project needs,goals,and risk management preferences of their clients.A or site changes-even minor ones-and request an assessment of their geotechnical-engineering study conducted for a given civil engineer impact.The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical conspicuously that you've included the material for information purposes engineer was not informed about developments the engineer otherwise only.To avoid misunderstanding,you may also want to note that would have considered. "informational purposes"means constructors have no right to rely on the interpretations,opinions,conclusions,or recommendations in the Most Of the "Findings" Related in This Report report.Be certain that constructors know they may learn about specific Are Professional Opinions project requirements,including options selected from the report,only Before construction begins,geotechnical engineers explore a site's from the design drawings and specifications.Remind constructors subsurface using various sampling and testing procedures.Geotechnical that they may perform their own studies if they want to,and be sure to engineers can observe actual subsurface conditions only at those specific allow enough time to permit them to do so.Only then might you be in locations where sampling and testing is performed.The data derived from a position to give constructors the information available to you,while that sampling and testing were reviewed by your geotechnical engineer, requiring them to at least share some of the financial responsibilities who then applied professional judgement to form opinions about stemming from unanticipated conditions.Conducting prebid and subsurface conditions throughout the site.Actual sitewide-subsurface preconstruction conferences can also be valuable in this respect. conditions may differ-maybe significantly-from those indicated in this report.Confront that risk by retaining your geotechnical engineer Read Responsibility Provisions Closely to serve on the design team through project completion to obtain Some client representatives,design professionals,and constructors do informed guidance quickly,whenever needed. not realize that geotechnical engineering is far less exact than other engineering disciplines.This happens in part because soil and rock on This Report's Recommendations Are project sites are typically heterogeneous and not manufactured materials Confirmation-Dependent with well-defined engineering properties like steel and concrete.That The recommendations included in this report-including any options or lack of understanding has nurtured unrealistic expectations that have alternatives-are confirmation-dependent.In other words,they are not resulted in disappointments,delays,cost overruns,claims,and disputes. final,because the geotechnical engineer who developed them relied heavily TO confront that risk,geotechnical engineers commonly include on judgement and opinion to do so.Your geotechnical engineer can finalize explanatory provisions in their reports.Sometimes labeled"limitations,' the recommendations only after observing actual subsurface conditions many of these provisions indicate where geotechnical engineers' exposed during construction.If through observation your geotechnical responsibilities begin and end,to help others recognize their own engineer confirms that the conditions assumed to exist actually do exist, responsibilities and risks.Read these provisions closely.Ask questions. the recommendations can be relied upon,assuming no other changes have Your geotechnical engineer should respond fully and frankly. occurred.The geotechnical engineer who prepared this report cannot assume responsibility or liabilityfor confirmation-dependent recommendations fyou Geoenvironmental Concerns Are Not Covered fail to retain that engineer to perform construction observation. The personnel,equipment,and techniques used to perform an environmental study-e.g.,a"phase-one"or"phase-two"enviromnental This Report Could Be Misinterpreted site assessment-differ significantly from those used to perform a Other design professionals'misinterpretation of geotechnical- geotechnical-engineering study.For that reason,a geotechnical-engineering engineering reports has resulted in costly problems.Confront that risk report does not usually provide environmental findings,conclusions,or by having your geotechnical engineer serve as a continuing member of recommendations;e.g.,about the likelihood of encountering underground the design team,to: storage tanks or regulated contaminants.Unanticipated subsurface • confer with other design-team members; environmental problems have led to project failures.If you have not • help develop specifications; obtained your own environmental information about the project site, review pertinent elements of other design professionals'plans and ask your geotechnical consultant for a recommendation on how to find specifications;and environmental risk-management guidance. • be available whenever geotechnical-engineering guidance is needed. Obtain Professional Assistance to Deal with You should also confront the risk of constructors misinterpreting this Moisture Infiltration and Mold report.Do so by retaining your geotechnical engineer to participate in While your geotechnical engineer may have addressed groundwater, prebid and preconstruction conferences and to perform construction- water infiltration,or similar issues in this report,the engineer's phase observations. services were not designed,conducted,or intended to prevent migration of moisture-including water vapor-from the soil Give Constructors a Complete Report and Guidance through building slabs and walls and into the building interior,where Some owners and design professionals mistakenly believe they can shift it can cause mold growth and material-performance deficiencies. unanticipated-subsurface-conditions liability to constructors by limiting Accordingly,proper implementation of the geotechnical engineer's the information they provide for bid preparation.To help prevent recommendations will not of itself be sufficient to prevent the costly,contentious problems this practice has caused,include the moisture infiltration.Confront the risk of moisture infiltration by complete geotechnical-engineering report,along with any attachments including building-envelope or mold specialists on the design team. or appendices,with your contract documents,but be certain to note Geotechnical engineers are not building-envelope or mold specialists. GEOPROFESSIONAL BUSINESS SEA ASSOCIATION Telephone:301/565-2733 e-mail:info@geoprofessional.org www.geoprofessional.org Copyright 2019 by Geoprofessional Business Association(GBA).Duplication,reproduction,or copying of this document,in whole or in part,by any means whatsoever,is strictly prohibited,except with GBAs specific written permission.Excerpting,quoting,or otherwise extracting wording from this document is permitted only with the express written permission of GBA,and only for purposes of scholarly research or book review.Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm,individual,or other entity that so uses this document without being a GBA member could be committing negligent or intentional(fraudulent)misrepresentation. �TrT-G7T_�. January 16, 2023 Atlas No. B222595g Mr. Clay Sammis Meridian BC Holdings, LP 12709 East Mirabeau Parkway, STE 10 Spokane Valley, WA 99216 Subject: Addendum #1 — Infiltration Testing Black Cat Industrial 955 South Black Cat Road Meridian, ID Dear Mr. Sammis: This addendum report presents additional test pit logs and test results not requested at the time of the previously issued Atlas Geotechnical Engineering Report (13210945g). Descriptions of general site characteristics and the proposed project are available in the previous report. Unless otherwise noted in this addendum, all initial recommendations, limitations, and warranties expressed in the previous report must be adhered to. INFILTRATION TESTING Infiltration testing was conducted in general accordance with the Ada County Highway District (ACHD) Policy Manual. Test pit areas will need to be re-excavated and compacted prior to construction of structures that will be sensitive to settlement. Test locations were presoaked prior to testing. Pre-soaking increases soil moistures, which allows the tested soils to reach a saturated condition more readily during testing. Saturation of the tested soils is desirable in order to isolate the vertical component of infiltration by inhibiting horizontal seepage during testing. Details and results of testing are as follows: Table 1 — Infiltration Test Results rTe mor Test Depth Ilrbilized Infiltratillb esign Infiltration Type Rate Rate ation IW9 im (inches/hour) (inches per hour) TP-2 5.1 Silty Sand 5.0 2.5 TP-4 6.0 Cemented Silty Sand 3.6 1.8 TP-6 4.0 Cemented Silty Sand 1.8 0.9 TP-7 3.0 Cemented Silty Sand 1.0 0.5 TP-9 3.4 Cemented Silty Sand 2.0 1.0 TP-12 4.5 Poorly Graded Gravel 3.0 1.5 with Clay and Sand TP-15 3.0 Sandy Silt 0.8 Not Suitable* TP-17 5.0 Silt with Sand 0.7 Not Suitable* TP-20 4.5 Silt with Sand 1.2 0.6 *Per the ACHD Policy Manual,a minimum design infiltration rate of 0.5 inch per hour is required. Atlas No. B222595g Page11 Copyright©2023 Atlas Technical Consultants In accordance with the ACHD Policy Manual, a factor of safety of 2 has been applied to the stabilized infiltration rates achieved during testing to obtain the design infiltration rates listed above. The reason for the decreased infiltration rate is to account for long term saturation of the soils and the potential for less permeable soils to settle into the bottom of the infiltration facilities. Atlas recommends that all infiltration facilities be constructed in accordance with the local municipality requirements. If you have any questions, please call us at (208) 376-4748. Respectfully submitted, Clinton Wyllie, PG Monica Saculles, PE Staff Geologist Senior Geotechnical Engineer Attachments: Site Map Geotechnical Investigation Test Pit Logs Geotechnical General Notes Distribution: Jason Densmer, The Land Group, Inc. (PDF Copy) Atlas No. B222595g Page12 Copyright©2023 Atlas Technical Consultants NOTES: :� r�` . t to Scale �I ■�.� . . . I• FSA Aerial I+�I 1'SPhotography ■1111 - -- 11 rr:::`.... IMP!M LEGEND Approximate Site ■■�■■■■11.■ OMENS" ::■1111■I■■ with Piezometer Approximate Atlas Test MFO�Fom Pit Location ::■■■■■11:: ■■■■■" ::■lIf it.-.J i■j it i■li�! IN ::■r�l■■11:: BOSOM.. ::■llil■I■� _ :`■■■r■ill= -.■.■■.■. �N■■■■11 ■MOON:: ::■I111■iE■ _ ■:--�■■l '=mac» �i■■■■11 ■■■■■:: ::■lilt■IE■ = ■■--l■el ° - .■■■■■■11■. .. ■. lllt��l■ ■■■■■ 111E=5I■■ � �■M--1►�{■I - ::■■�■■11:: ■■M■■.. >.■11111■�■■ - ■■■�■■■I' •"tmmT'mmmr' �� S■■■■■11■ ■M■■E•• ■.■liil■I■7 !! :=W■OR■■f= I..ar..r . _i - - - - - - - - - - - - ■1.1...111 Lr-� z� s - -- lilt��� 11 IQ N_-ism, o ■.�■i�■i�■i 7■■■_■1■_.. mom _ ®III■�■M■■Air `.��■■■����IL®�i�I�A■■■�■■01'rw !.�l�iq�i - ...a�y��..7I�Al��■ ..�r!rwl �' — -- li f�' �lil■e■■■O■:: - Ji4■■llllsil= 1�11= ■i■■ 3l� ..■Io Ia1 mom l .� �■I�:l■■IIII■■. JII■O■■■■e!■� - Ems 1� !!11�■■io■S:l :■■■if llll■:: I won T11;-�!llC�Ei®:�■■■lIIIQOiI - ; ;ll�s■!■■�■■�� �..a■■1!� mom �OII■A� i�■OEM .�■11��■...�■:: lll_7■■■■�7■�* ��SE■■ mom Cat 1133 Bosom no:: 2 0 Meridian,ID ill■■■!e■��■" ��� ��0■■■■Kl 'ai■■■■ I rrr fModified b _ 1: �TrT—G7T�1 APPENDIX II GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-1 Latitude: 43.600673 Date Advanced: December 28, 2022 Longitude: -116.463222 Excavated by: Turn of the Century Homes Depth to Water Table: 9.8 feet bgs Logged by: Colby Meyer, GIT Total Depth: 15.3 feet bgs Depth • . • bgs) OP Test ID Lean Clay with Sand (CL): Dark brown,slightly moist, stiff to very stiff, with fine to medium- 0.0-1.6 grained sand. 1.5-2.0 --Organic material encountered to 0.4 foot bgs. --Plow zone encountered to 1.2 feet bgs. Silty Sand (SM): Brown to light brown, dry to 1.6-6.9 slightly moist, medium dense, with fine to coarse-grained sand. Clayey Sand with Gravel (SC): Brown, moist 6.9-15.3 to saturated, medium dense to dense,with fine to coarse-grained sand and fine to coarse gravel. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.3 feet bgs. Atlas No. B222595g Page14 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-2 Latitude: 43.600726 Date Advanced: December 28, 2022 Longitude: -116.461165 Excavated by: Turn of the Century Homes Depth to Water Table: 9.5 feet bgs Logged by: Colby Meyer, GIT Total Depth: 12.2 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e —k s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, medium stiff to stiff, with fine-grained 0.0-1.2 sand. 1.0-1.5 --Organic material encountered to 0.4 foot bgs. --Plow zone encountered to 1.2 feet bgs. Sandy Silt (ML): Light brown, dry, very stiff to 1.2-3.2 hard, with fine to coarse-grained sand. --Weak cementation encountered from 1.2 to 2.2 feet bgs. Silty Sand (SM): Brown to light brown, dry to 3.2-9.8 saturated, medium dense to dense, with fine to coarse-grained sand. Poorly Graded Gravel with Clay and Sand 9 8-12 2 (GP-GC): Light brown, saturated, medium dense to dense, with fine to coarse-grained sand and fine to coarse gravel. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 5.1 feet bgs. Piezometer installed to a depth of 12.2 feet bgs. Atlas No. 13222595g Page15 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-3 Latitude: 43.600710 Date Advanced: December 28, 2022 Longitude: -116.459345 Excavated by: Turn of the Century Homes Depth to Water Table: 9.4 feet bgs Logged by: Colby Meyer, GIT Total Depth: 11.1 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgAmr —k s Sediment • • • • Lean Clay with Sand (CL): Dark brown to brown, slightly moist, stiff to very stiff, with fine to medium-grained sand. 0.0-1.6 --Organic material encountered to 0.3 foot 2.0 bgs. --Plow zone encountered to 1.0 foot bgs. Silty Sand (SM): Brown to light brown, slightly moist to wet, medium dense to dense,with fine 1.6-9.4 to coarse-grained sand. --Intermittent weak to moderate cementation encountered from 3.4 to 6.4 feet bgs. Poorly Graded Gravel with Clay and Sand 9.4-11.1 (GP-GC): Light brown, saturated, medium dense, with fine to coarse-grained sand and fine to coarse gravel. Notes:See Site Map for test pit location. Piezometer installed to a depth of 11.1 feet bgs. Atlas No. B222595g Page16 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-4 Latitude: 43.600670 Date Advanced: December 28, 2022 Longitude: -116.457163 Excavated by: Turn of the Century Homes Depth to Water Table: 9.4 feet bgs Logged by: Colby Meyer, GIT Total Depth: 13.0 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e —k s Sediment • • • • Lean Clay with Sand (CL): Dark brown to light brown, slightly moist, stiff to very stiff, with fine 0.0-3.7 to medium-grained sand. 1.5-2.5 --Organic material encountered to 0.4 foot bgs. --Plow zone encountered to 0.8 foot bgs. Silty Sand (SM): Brown, slightly moist to wet, medium dense to dense, with fine to coarse- 3.7-9.4 grained sand. --Intermittent weak cementation encountered throughout. Poorly Graded Gravel with Clay and Sand 9.4-13.0 (GP-GC): Light brown, saturated, medium dense, with fine to coarse-grained sand and fine to coarse gravel. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 6.0 feet bgs. Piezometer installed to a depth of 13.0 feet bgs. Atlas No. B222595g Page17 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-5 Latitude: 43.600843 Date Advanced: December 28, 2022 Longitude: -116.454960 Excavated by: Turn of the Century Homes Depth to Water Table: 10.0 feet bgs Logged by: Colby Meyer, GIT Total Depth: 10.8 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e —k s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff to very stiff, with fine to medium- 0.0-3.9 grained sand. 1.5-2.0 --Organic material encountered to 0.3 foot bgs. --Plow zone encountered to 0.8 foot bgs. Silty Sand (SM): Dark brown to brown, slightly moist to saturated, medium dense to dense, 3.9-9.3 with fine to coarse-grained sand. --Intermittent weak cementation encountered throughout. Poorly Graded Gravel with Clay and Sand 9.3-10.8 (GP-GC): Light brown, saturated, medium dense, with fine to coarse-grained sand and fine to coarse gravel. Notes:See Site Map for test pit location. Piezometer installed to a depth of 10.8 feet bgs. Atlas No. B222595g Page18 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-6 Latitude: 43.598335 Date Advanced: December 28, 2022 Longitude: -116.462192 Excavated by: Turn of the Century Homes Depth to Water Table: 11.6 feet bgs Logged by: Colby Meyer, GIT Total Depth: 15.5 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept • • )AMM Sediment Classification • • • Lean Clay with Sand (CL): Dark brown to brown, slightly moist, stiff, with fine-grained sand. 0.0-1.8 --Organic material encountered to 0.4 foot 1.5 bgs. --Plow zone encountered to 0.8 foot bgs. Silt with Sand (ML): Brown to light brown, 1.8-3.2 slightly moist, very stiff, with fine to medium- grained sand. Silty Sand (SM): Brown, slightly moist to saturated, medium dense to dense, with fine 3.2-15.5 to coarse-grained sand. --Intermittent weak to moderate cementation encountered from 3.2 to 10.4 feet bgs. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 4.0 feet bgs. Piezometer installed to a depth of 15.5 feet bgs. Atlas No. B222595g Page19 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-7 Latitude: 43.598170 Date Advanced: December 28, 2022 Longitude: -116.460130 Excavated by: Turn of the Century Homes Depth to Water Table: 11.4 feet bgs Logged by: Colby Meyer, GIT Total Depth: 14.0 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept • • )AMM Sediment Classification • • • Lean Clay with Sand (CL): Dark brown to brown, slightly moist, medium stiff to very stiff, 0.0-2.7 with fine-grained sand. 1.0-2.0 --Organic material encountered to 0.3 foot bgs. --Plow zone encountered to 0.8 foot bgs. Silty Sand (SM): Brown, slightly moist to saturated, medium dense to dense, with fine 2.7-14.0 to coarse-grained sand. --Intermittent weak cementation encountered from 2.7 to 11.4 feet bgs. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 3.0 feet bgs. Piezometer installed to a depth of 14.0 feet bgs. Atlas No. B222595g Page110 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-8 Latitude: 43.497662 Date Advanced: December 28, 2022 Longitude: -116.459099 Excavated by: Turn of the Century Homes Depth to Water Table: 12.6 feet bgs Logged by: Colby Meyer, GIT Total Depth: 13.5 feet bgs Depth Field Description and USCS Soil and Sample Sample Deptl • • )AMM Sediment Classification • • • Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- 0.0-2.4 grained sand. 1.5-2.5 --Organic material encountered to 0.3 foot bgs. --Plow zone encountered to 1.0 foot bgs. Silty Sand (SM): Brown to light brown, slightly moist to saturated, medium dense to very dense, with fine to coarse-grained sand. 2.4-13.5 --Weak cementation encountered from 2.4 to 3.2 feet bgs. --Intermittent weak to moderate cementation encountered from 7.0 to 9.4 feet bgs. Notes:See Site Map for test pit location. Piezometer installed to a depth of 13.5 feet bgs. Atlas No. B222595g Page 111 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-9 Latitude: 43.598131 Date Advanced: December 28, 2022 Longitude: -116.457986 Excavated by: Turn of the Century Homes Depth to Water Table: 9.0 feet bgs Logged by: Colby Meyer, GIT Total Depth: 14.1 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept • • )AMM Sediment Classification • • • Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- 0.0-2.0 grained sand. 2.0-2.5 --Organic material encountered to 0.4 foot bgs. --Plow zone encountered to 0.8 foot bgs. Silty Sand (SM): Brown to light brown, slightly moist to saturated, medium dense to dense, 2.0-14.1 with fine to coarse-grained sand. --Intermittent weak to moderate cementation encountered from 3.4 to 14.1 feet bgs. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 3.4 feet bgs. Piezometer installed to a depth of 14.1 feet bgs. Atlas No. B222595g Page112 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-10 Latitude: 43.597741 Date Advanced: December 28, 2022 Longitude: -116.455824 Excavated by: Turn of the Century Homes Depth to Water Table: 8.1 feet bgs Logged by: Colby Meyer, GIT Total Depth: 12.1 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept • • )AMM Sediment Classification • • • Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- grained sand. 0.0-3.2 --Organic material encountered to 0.4 foot 2.0 bgs. --Plow zone encountered to 0.8 foot bgs. Sandy Silt (ML): Brown to light brown, slightly moist, very stiff to hard, with fine to medium- 3.2-5.1 grained sand. --Moderate cementation encountered throughout. Clayey Sand (SC): Brown to light brown, 5.1-12.1 slightly moist to saturated, medium dense, with fine to medium-grained sand. Notes:See Site Map for test pit location. Piezometer installed to a depth of 12.1 feet bgs. Atlas No. B222595g Page113 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-11 Latitude: 43.597814 Date Advanced: December 28, 2022 Longitude: -116.463300 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 16.0 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e —k s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff to very stiff, with fine-grained sand. 0.0-0.9 --Organic material encountered to 0.5 foot 2.0 bgs. --Plow zone encountered to 0.9 foot bgs. Sandy Silt (ML): Brown, slightly moist, very 0.9-3.4 stiff, with fine to medium-grained sand. 3.0 Poorly Graded Gravel with Silt and Sand (GP- 3.4-5.2 GM): Brown, slightly moist, dense, with fine to coarse-grained sand and fine to coarse gravel. Silty Sand(SM): Brown,slightly moist to moist, very dense, with fine to coarse-grained sand 5.2-16.0 and minor fine gravel. --Intermittent moderate cementation encountered from 5.2 to 8.8 feet bgs. Notes:See Site Map for test pit location. Piezometer installed to a depth of 16.0 feet bgs. Atlas No. B222595g Page 114 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-12 Latitude: 43.596978 Date Advanced: December 28, 2022 Longitude: -116.463291 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 14.3 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e A- s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff, with fine-grained sand. 0.0-0.9 --Organic material encountered to 0.3 foot 1.5 bgs. --Plow zone encountered to 0.9 foot bgs. Silt with Sand (ML): Light brown, dry to slightly moist, very stiff to hard, with fine to medium- 0.9-2.4 grained sand. --Moderate calcium carbonate cementation encountered from 1.6 to 2.4 feet bgs. Poorly Graded Gravel with Clay and Sand 2.4-6.0 (GP-GC): Brown to light brown, dry to slightly moist, very dense, with fine to coarse-grained sand and fine to coarse gravel. Clayey Sand (SC): Brown, slightly moist, dense, with fine to coarse-grained sand and 6.0-14.3 minor fine gravel. --Strong cementation encountered from 6.0 to 8.5 feet bgs. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 4.5 feet bgs. Piezometer installed to a depth of 14.3 feet bgs. Atlas No. 13222595g Page115 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-13 Latitude: 43.596369 Date Advanced: December 28, 2022 Longitude: -116.462150 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 14.5 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e —k s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff to very stiff, with fine-grained sand. 0.0-1.1 --Organic material encountered to 0.4 foot bgs. --Plow zone encountered to 0.8 foot bgs. Sandy Silt (ML): Light brown, slightly moist, 1.1-4.0 very stiff to hard, with fine to coarse-grained sand. Poorly Graded Gravel with Clay and Sand 4.0-8.5 (GP-GC): Light brown, dry to slightly moist, dense, with fine to coarse-grained sand and fine to coarse gravel. Clayey Sand (SC): Brown to light brown, 8.5-14.5 slightly moist, medium dense to dense, with fine to coarse-grained sand. Notes:See Site Map for test pit location. Piezometer installed to a depth of 14.5 feet bgs. Atlas No. B222595g Page116 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-14 Latitude: 43.596905 Date Advanced: December 28, 2022 Longitude: -116.461092 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 13.8 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e —k s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff to very stiff, with fine-grained sand. 0.0-0.8 --Organic material encountered to 0.6 foot 2.0 bgs. --Plow zone encountered to 0.8 foot bgs. Silt with Sand (ML): Brown to light brown, 0.8-3.5 slightly moist, stiff to very stiff, with fine- 2.0 grained sand. --Weak cementation encountered throughout. Silty Sand (SM): Brown to light brown, slightly moist, medium dense to very dense, with fine 3.5-13.8 to coarse-grained sand. --Intermittent weak to moderate cementation encountered throughout. Notes:See Site Map for test pit location. Piezometer installed to a depth of 13.8 feet bgs. Atlas No. B222595g Page117 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-15 Latitude: 43.596131 Date Advanced: December 28, 2022 Longitude: -116.460143 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 16.0 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e A- s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff to very stiff, with fine to coarse- grained sand. 0.0-1.0 --Organic material encountered to 0.5 foot 2.0 bgs. --Plow zone encountered to 1.0 foot bgs. Sandy Silt (ML): Brown to dark brown, slightly 1.0-5.2 moist, very stiff to hard, with fine to medium- 2.5-4.5+ grained sand. Silty Sand (SM): Brown to light brown, slightly moist to moist, medium dense to very dense, with fine to coarse-grained sand. 5.2-16.0 --Moderate cementation encountered from 5.2 to 9.2 feet bgs. --Intermittent moderate to strong cementation encountered from 9.2 to 13.2 feet bgs. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 3.0 feet bgs. Piezometer installed to a depth of 16.0 feet bgs. Atlas No. B222595g Page118 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-16 Latitude: 43.459694 Date Advanced: December 28, 2022 Longitude: -116.459117 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 15.8 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgA e —k S s Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff to very stiff, with fine-grained sand. 0.0-0.9 --Organic material encountered to 0.9 foot 1.5-2.0 bgs. --Plow zone encountered to 0.9 foot bgs. Silt with Sand (ML): Brown, slightly moist, stiff 0.9-5.7 to very stiff, with fine to medium-grained sand. 2.0 Silty Sand (SM): Brown to light brown, slightly moist to moist, medium dense to very dense, 5.7-15.8 with fine to coarse-grained sand. --Intermittent moderate to strong cementation encountered from 5.7 to 11.6 feet bgs. Notes:See Site Map for test pit location. Piezometer installed to a depth of 15.8 feet bgs. Atlas No. B222595g Page119 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-17 Latitude: 43.597319 Date Advanced: December 28, 2022 Longitude: -116.456702 Excavated by: Turn of the Century Homes Depth to Water Table: 11.2 feet bgs Logged by: Colby Meyer, GIT Total Depth: 14.8 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept Ma • •s9A M Sediment • • • • Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- 0.0-4.2 grained sand. 1.5-2.0 --Organic material encountered to 0.4 foot bgs. --Plow zone encountered to 1.0 foot bgs. Silt with Sand (ML): Brown to light brown, 4.2-6.3 slightly moist, very stiff to hard, with fine to medium-grained sand. Silty Sand (SM): Brown to light brown, slightly moist to saturated, dense to very dense, with 6.3-14.8 fine to coarse-grained sand. --Intermittent weak to moderate cementation encountered from 6.3 to 11.0 feet bgs. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 5.0 feet bgs. Piezometer installed to a depth of 14.8 feet bgs. Atlas No. B222595g Page 120 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-18 Latitude: 43.596222 Date Advanced: December 28, 2022 Longitude: -116.456663 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 16.2 feet bgs Depth ield Description and USCS Soil and Sample Sample Dept bgs Sediment • • • • Lean Clay with Sand (CL): Dark brown,slightly moist, stiff, with fine to coarse-grained sand. 0.0-1.1 --Organic material encountered to 0.4 foot 1.5 bgs. --Plow zone encountered to 1.1 foot bgs. Silt with Sand (ML): Brown, slightly moist, stiff 1.1-4.9 to very stiff, with fine to medium-grained sand. 1.5-2.5 Silty Sand (SM): Brown to light brown, slightly moist, medium dense to very dense, with fine 4.9-16.2 to coarse-grained sand. --Intermittent weak cementation encountered from 4.9 to 11.0 feet bgs. Notes:See Site Map for test pit location. Piezometer installed to a depth of 16.2 feet bgs. Atlas No. B222595g Page 121 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-19 Latitude: 43.595531 Date Advanced: December 28, 2022 Longitude: -116.455744 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 12.5 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept • • )AMM Sediment Classification • • • Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- 0.0-1.0 grained sand. 1.5-2.0 --Organic material encountered to 0.4 foot bgs. --Plow zone encountered to 1.0 foot bgs. Silt with Sand (ML): Light brown to brown, 1.0-5.0 slightly moist, stiff to very stiff, with fine- grained sand. Silty Sand (SM): Brown to light brown, slightly moist, medium dense to very dense, with fine 5.0-12.5 to coarse-grained sand. --Moderate to strong cementation encountered from 9.0 to 10.8 feet bgs. Notes:See Site Map for test pit location. Piezometer installed to a depth of 12.5 feet bgs. Atlas No. B222595g Page 122 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-20 Latitude: 43.595848 Date Advanced: December 28, 2022 Longitude: -116.455230 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Colby Meyer, GIT Total Depth: 16.0 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept • • )AMM Sediment Classification • • • M —k 27 Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- grained sand. 0.0-0.8 --Organic material encountered to 0.6 foot 1.5 bgs. --Plow zone encountered to 0.8 foot bgs. 0.8-6.8 Silt with Sand (ML): Brown, slightly moist, very stiff to hard,with fine to medium-grained sand. Silty Sand (SM): Light brown, slightly moist to wet, medium dense to very dense, with fine to 6.8-16.0 medium-grained sand. --Strong cementation encountered from 9.8 to 13.8 feet bgs. Notes:See Site Map for test pit location. Infiltration testing conducted at a depth of 4.5 feet bgs. Piezometer installed to a depth of 16.0 feet bgs. Atlas No. 13222595g Page 123 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log#: TP-21 Latitude: 43.596891 Date Advanced: December 28, 2022 Longitude: -116.455292 Excavated by: Turn of the Century Homes Depth to Water Table: 12.0 feet bgs Logged by: Colby Meyer, GIT Total Depth: 13.8 feet bgs Depth Field Description and USCS Soil and Sample Sample Dept • • )AMM Sediment Classification • • • Lean Clay with Sand (CL): Dark brown to brown,slightly moist,stiff to very stiff,with fine- 0.0-3.7 grained sand. 1.5-2.0 --Organic material encountered to 0.8 foot bgs. --Plow zone encountered to 0.8 foot bgs. 3.7-4.0 Silt with Sand(ML): Light brown,slightly moist, medium stiff, with fine-grained sand. Silty Sand (SM): Light brown, slightly moist to saturated, medium dense to very dense, with 4.0-13.8 fine to medium-grained sand. --Strong cementation encountered from 7.5 to 11.0 feet bgs. Notes:See Site Map for test pit location. Piezometer installed to a depth of 13.8 feet bgs. Atlas No. B222595g Page 124 Copyright©2023 Atlas Technical Consultants �TrT-G7Tdr-W� GEOTECHNICAL GENERAL NOTF Major Divisions Symbol Soil Descriptions Gravel & GW Well-graded gravels; gravel/sand mixtures with little or no fines Coarse- Gravelly Soils GP Poorly-graded gravels; gravel/sand mixtures with little or no fines Grained < 50% GM Silty gravels; poorly-graded gravel/sand/silt mixtures Soils < coarse GC Clayey gravels; poorly-graded gravel/sand/clay mixtures 50% Sand & Sandy SW Well-graded sands; gravelly sands with little or no fines passes Soils > 50% SP Poorl - raded sands; gravelly sands with little or no fines No.200 coarse SM Silty sands; poorly-graded sand/gravel/silt mixtures sieve fraction SC Clayey sands; poorly-graded sand/gravel/clay mixtures Fine- ML Inorganic silts; sandy, gravelly or clayey silts Grained Silts & Clays CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium- Soils > LL < 50 plasticity clays 50% OL Organic, low-plasticity clays and silts passes MH Inorganic, elastic silts; sand ravel) or clayey elastic silts No.200 Silts & Clays CH Fat clays; high-plasticity, inorganic clays sieve LL > 50 OH Organic, medium to high-plasticity clays and silts Highly Organic Soils PT Peat, humus, h dric soils with high organic content 'it Relative Density and Consistency 'k Moisture Content and Cementation Classification Classification Coarse-Grained Soils SPT Blow Counts N Description Field Test Very Loose: <4 Dry Absence of moisture, dry to touch Loose: 4-10 Slightly Moist Damp, but no visible moisture Medium Dense: 10-30 Moist Visible moisture Dense: 30-50 Wet Visible free water Very Dense: > 50 Saturated Soil is usually below water table Fine-Grained Soils SPT Blow Counts N Description Field Test Very Soft: < 2 Weak Crumbles or breaks with handling or Soft: 2-4 slight finger pressure Medium Stiff: 4-8 Moderate Crumbles or breaks with Stiff: 8-15 considerable finger pressure Very Stiff: 15-30 Strong Will not crumble or break with finger Hard: > 30 pressure Particle Size 1001�7,11 Boulders: > 12 in. GS grab sample Cobbles: 12 to 3 in. LL Liquid Limit Gravel: 3 in. to 5 mm M moisture content Coarse-Grained Sand: 5 to 0.6 mm NP non-plastic Medium-Grained Sand: 0.6 to 0.2 mm PI Plasticity Index Fine-Grained Sand: 0.2 to 0.075 mm QP penetrometer value, unconfined compressive Silts: 0.075 to 0.005 mm strength, tsf Clays: < 0.005 mm V vane value, ultimate shearing strength, tsf Atlas No. B222595g Page 125 Copyright©2023 Atlas Technical Consultants