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PZ - Geotech Report
A PROFESSIONAL SERVICES CORPORATION �v�d-era-y Frowt a-/ze G�rroucld uP October 8, 2015 File: B014105A Mr. Brad Pfannmuller BHH Investments 1, LLC 1025 S. Bridgeway Place, Suite 290 Eagle, Idaho 83616 bradp@boisehunterhomes.com RE: Supplemental Ge®technical Exploration Southern Highlands Subdivision East Taconic Drive Meridian, Idaho Dear Brad: Strata, A Professional Services Corporation (STRATA) is pleased to present our authorized supplemental geotechnical exploration summary for the Southern Highlands Subdivision to be located north of East Taconic Drive in Meridian, Idaho. Our evaluation's purpose was to explore the subsurface conditions in the planned stormwater disposal area and provide revised stormwater disposal recommendations, as appropriate. To provide additional information regarding the anticipated seasonal high groundwater level in the northwestern portion of the development site, in September 2015 STRATA observed an additional test pit in near the previous TP-4, in the northwestern portion of the site. Soil conditions encountered in the test pit generally consist of near-surface lean clay overlying cemented silty sand with poorly graded gravel at depth. The depth to poorly graded gravel was measured to be approximately 10 feet below existing grade. We did not observe groundwater in the test pit excavation to a total depth of approximately 14.5 feet. A representative of Ada County Highway District observed the test pit excavation as well. Therefore, considering these observations, we recommend stormwater infiltration facilities constructed in this area be designed to extend into the native poorly graded gravel and utilize an allowable infiltration rate of 8 inches per hour. Based on these observations and our previous groundwater monitoring, we anticipate groundwater will occur at a depth of greater than 15 feet below existing grade throughout the year in the northwestern portion of the Southern Highlands development. We appreciate the opportunity to work with BHH Investments 1, LLC. We look forward to our continued involvement on this project throughout construction. Please do not hesitate to contact us if you have any questions or comments. Sincerely, MAL ° � STRATA M hael G. Woodwort P.E. ega qP 10. gineeringManager MGW 36e3 West 1-1acf(arno e Mille,Boise,Idaho 813703 E`hone.208,37 6.8200 Fex.208.76.20 www.stratagootech.com A PRorESSIONAL SERVICES CORPORATION �Ka-o5r a-y.6-o1u a-1--c-/ro"Kd up May 10 File: B014105A Mr. Chad Hamel BHH Investments 1, LLC 1025 S. Bridgeway Place, Suite 290 Eagle, Idaho 83616 chamel@boisehunterhomes.com RE: Geotechnical Engmeermg Evaluation Southern Highlands.Subdivision East Taconic Drive Meridian, Idaho Dear Chad: STRATA, A—Professional Services Corporation (STRATA) is pleased to present our autho4zed limited geotechnical engineering evaluation for the proposed Southern Highlands Subdivision to be located north of East Taconic Drive in Meridian, Idaho. Our evaluation's purpose was to explore the subsurface conditions in the proposed development area and provide geotechnical recommendations to assist project planning, design and Construction for the planned residential development including public roadways and associated infrastructure. The attached report summarizes our field and laboratory test results, and presents our geotechnical engineering opinions and recommendations. The following report provides specific geotechnical recommendations for preparing the site, including undocumented fill removal, earthwork activities,pavement design and stormwater design recommendations. It is our opinion that geotechnical continuity with the project team throughout construction will help identify undocumented fill during earthwork to allow its removal and replacementwith structural fill. The project design, owner, and construction team must read, understand and implement this report in its entirety. Portions of the report cannot be relied upon individually without the supporting text of remaining sections, appendices and 'plates. Our opinion`and-the success of the proposed construction will depend on following the report recommendations, good construction practices, and providing the necessary construction monitoring,testing and consultation to verify that Work has been constructed as recommended. We recommend STRATA be retained to provide monitoring, testing, and consultation services to verify our report recommendations are being followed. We appreciate the opportunity to work with BHH Investments 1, LLC. We look forward to I Our continued involvement on this project throughout construction. Please do not hesitate to contact us if you have any questions or comments. E A NAL Sincerely, pFcNS i STRATA, Inc. �'��Z�� F 5 i 1 416a I Woodworth, P.E. g®'�r�®�tO��A®� Adrian Mascorro, P.E. Engineering Manager 'Q/� ® Project Engineer AM/MGW/am 8653 West Flackamore Drive,Boise,Idaho 83709 Phone.208.376.8200 Pa)c.208.376.5201 www.stratageotech.com REPORT Limited Geotechnical Engineering Evaluation Southern Highlands Subdivision East Taconic Drive Meridian, Idaho Prepared For: Mr. Chad Hamel BHH Investments 1, LLC 1025 S. Bridgeway Place, Suite 290 Eagle, Idaho 83616 HOMESE HuNTE"n Prepared By: STRATA, Inc. 8653 W. Hackamore Drive j Boise, Idaho 83709 P.208.376.8200 F.208.376.8201 I I May 27, 2014 E I TABLE OF CONTENTS Page INTRODUCTION ............................................................................................................1 PROJECTUNDERSTANDING .......................................................................................2 ExistingSite Conditions ..................................................................................................2 ProposedConstruction....................................................................................................2 SUBSURFACE EVALUATION PROCEDURES ..............................................................3 SUBSURFACECONDITIONS........................................................................................3 LABORATORYTESTING...............................................................................................4 GEOTECHNICAL OPINIONS AND RECOMMENDATIONS ...........................................4 Geotechnical Constraints and Opportunities................................................................5 Earthwork....................................................................................................................5 FillRemoval..............................................................................................................5 Site an Subgrade Preparation...................................................................................5 StructuralFill ............................................................................................................6 Table 1. Structural Fill Specifications and Allowable Use.............................................6 Excavation Characteristics .......................................................................................6 Compaction..............................................................................................................7 UtilityTrench Backfill ................................................................................................8 Wet Weather/Soil Construction.................................................................................8 Geosynthetics...........................................................................................................8 ExistingSlope..............................................................................................................8 PavementSection Design.................................................................................I..........9 General ....................................................................................................................9 Trafficand Subgrade................................................................................................9 Table 3. Pavement Design Parameters .......................................................................9 Asphalt, Aggregate Base Course and Subbase Materials....................................... 10 Pavement Section Thickness..................................................................................10 Table 4. Asphalt Pavement Design Section ............................................................... 11 Pavement Maintenance ......................11 SiteDrainage.............................................................................................................11 EStormwater Disposal ..............................................................................................11 I Seasonal High Groundwater...................................................................................11 i Surface Water Management for Individual Lots...................................................... 12 GEOTECHNICAL DESIGN CONTINUITY.....................................................................12 EVALUATIONLIMITATIONS........................................................................................13 i i E i Geotechnical Engineering Evaluation Southern Highlands Subdivision East Taconic Drive Meridian, Idaho INTRODUCTION STRATA, A Professional Services Corporation (STRATA) has performed our limited geotechnical engineering evaluation for the proposed residential development to be located north of East Taconic Drive in Meridian, Idaho. Our evaluation's purpose was to explore the subsurface soil conditions at the project site and to prepare geotechnical recommendations to assist project planning, design and construction. We accomplished our services referencing our authorized revised proposal dated March 18, 2014 and email correspondence dated March 28, 2014. To accomplish our evaluation, STRATA performed the following services: 1. Coordinated exploration with T-O Engineers and the local utility notification center to help reduce the potential for damage to existing utilities. 2. Observed the excavation of 11 exploratory_test pits within the planned development area. .,'Explorations extended 10 to '13.5 feet below existing site grades. Temporary standpipe groundwater.monitoring piezometers Were installed in 7 of the test pits excavated. Our field geologist visually described, classified and logged soil encountered referencing the Unified Soil Classification System (USCS). i 3. Performed laboratory tests with reference to ASTM International (ASTM) procedures including Atterberg limits, in-situ moisture content, grain size evaluation, r-value and proctor testing. We utilized these laboratory results to help characterize engineering parameters and to correlate soil engineering characteristics used in our design. 4. Performed and engineering evaluation in order to provide geotechnical design and earthwork construction recommendations. We worked closely with you and T-O Engineers to coordinate necessary elements of design and construction into a specific discussion of the related soil and geologic conditions. Our engineering analyses provides geotechnical recommendations and opinions for: 0 Earthwork • Fill removal • Site and subgrade preparation • Structural fill i • Excavation characteristics • Compaction • Utility trench backfill I'I Wet weather/soil construction I' • Geosynthetics 8653 West Hackarnore Drive,Boise,Idaho 83709 Phone.208.376.8200 Fax.208.376.8201 www.stratageotech.com Southern Highlands Subdivision File: B014105A Page 2 6 Existing Slope Information 0 Pavement Section Design • Traffic and subgrade • Asphalt, aggregate base course and subbase materials • Pavement section thickness • Pavement maintenance 0 Site Drainage • Stormwater disposal • Seasonal high groundwater(estimated) • Surface water management for individual lots 0 Geotechnical Design Continuity • Groundwater monitoring • Plan and specification review • Geotechnical design confirmation • Construction observation and testing 5. Prepared and provided an electronic copy of our final report of geotechnical findings, opinions and recommendations, including exploration logs and an exploration location plan. Hard copies of the report are available upon request. PROJECT UNDERSTANDING Existing Site Conditions The proposed development is undeveloped and is currently being actively farmed. The site is bounded by subdivision development to the southwest, East Taconic Drive to the southeast, and farm land on all other sides. An irrigation canal and the Ten Mile Creek are located approximately 200 and 700 feet east, respectively, of the eastern site boundary. Proposed Construction We understand the approximate 79-acre development will consist of residential lot construction with associated asphalt roads and utility infrastructure. We understand the proposed homes will most likely be constructed with shallow foundations and crawl spaces. We anticipate stormwater will be disposed of via seepage beds or other on-site infiltration facilities. Based on review of the grading plan provided by T-O Engineers, dated,May 12, 2014, we anticipate substantial cut and fill will be required for the proposed development. Specifically; grading plans indicate up to approximately 19 feet of cut and up to approximately 12 feet of fill is planned.;Graded slopes of 2 feet horizontal to 1'foot vertical (2H:1V) are planned. 4 _ www.stratageotech.com ©-,TI=zATs1, Inc. AN Righl,:s Reserved Southern Highlands Subdivision File: B014105A Page 3 SUBSURFACE EVALUATION PROCEDURES STRATA accomplished subsurface exploration on March 31, 2014 via 11 exploratory test pits extending 10 to 13.5 feet below existing ground surface. Standpipe piezometers were installed'in 7 test pits for future groundwater monitoring. The approximate exploration locations are illustrated on Plate 1, Exploration Location Plan, which also delineates the proposed development. Test pit locations were established in the field by taping from existing site features. A professional geologist visually evaluated the soil encountered in each test pit and logged the soil profile referencing the USCS. We provide a brief USCS explanation in Appendix A to help interpret the terms on the test pit logs. We also provide individual test pit logs in Appendix A. The test pits were backfilled with the excavated material to the ground surface following the completion of the excavations. STRATA accomplished previous exploration at this site on August 7, 2006. We have included the locations of test pits previously excavated within the site area on Plate 1 for your reference. Test pit logs for this previous exploration are also included in Appendix C. SUBSURFACE CONDITIONS Topsoil rooting and vegetation was observed to a depth of approximately 6 inches below grade within the southwest portion of the site, where active farming was not occurring. Soil conditions encountered within the test pits generally consist of lean clay or silt overlying silty sand with cementation, overlying poorly-graded gravel with sand with depth. We provide more specific discussion of each soil unit encountered below: 0 Silty Sand with Gravel (Fill) —Within the southwest,portion of the site, adjacent to the I hillside, we observed silty sand with gravel fill to depths of 2 to 4 feet below ground. We described fill soil as brown,loose to medium dense, and moist. 0 Surficial Lean Clay/Silt with Sand — Throughout majority of the site we observed native surficial lean clay and/or silt with-sand to--depths of 1 to 5.5,feet below.ground. We described surficial soil as brown, stiff to hard, and moist. Within TP-8 we observed a 1- foot-thick layer of fat clay at 1 to 2 feet below ground. 46 Silty Sand with Cementation — Underlying fill or surficial soil, we observed silty sand with varying amounts of calcium carbonate cementation to depths of 5.5 to 11.5 feet below ground. We described silty sand as brown, medium dense to dense, and moist. Within TP-4, below surficial soil, we observed brown, dense and moist clayey sand to 10.5 feet. 4 Gravel with Sand and Cobbles/Sand with Silt and Gravel -Underlying cemented silty' sand or clayey sand,we observed poorly-graded gravel with sand and cobbles or poorly- i www.stratageotech.com @ iTFZA fi A,9 1(?c. All R�g55'us Rt'=3f.[''1,e?a EE Io Southern Highlands Subdivision File: B014105A Page 4 graded sand with silt and gravel to test pit termination depths of 10 to 13.5 feet. We described these soils as light tan to brown, medium dense to very dense and moist. 0 Groundwater — We did not encounter groundwater within test pits to the depths explored, with-the exception of TP-8 where we observed groundwater at 6 feet below ground at the time of exploration. We-performed groundwater monitoring at the site on April 22 2014 and observed groundwater within TP-8 at a depth of 5.5 feet. The remaining on-site piezometers were dry at the time of our monitoring. We anticipate the depth to groundwater in the eastern portion of the site could potentially fluctuate primarily as a function of irrigation in the area. Subsurface variations may exist between exploration locations and may not be apparent until construction. Test pits only allow us to observe a portion of the site subsurface conditions. Where such variations exist, they may impact opinions and recommendations presented in this report, as well as construction timing and costs. We provide a USCS classification summary and specific soil contacts and descriptions on test pit logs provided as Appendix A to this report. LABORATORY TESTING We returned soil samples collected in the field to our laboratory for further classification and testing and accomplished laboratory testing referencing ASTM procedures. We developed our laboratory testing program for this project primarily to evaluate subsurface characteristics and engineering properties. Specifically, we accomplished moisture content, minus No. 200 wash, Atterberg limits, R-value, and proctor testing. We present index laboratory test results on test pit logs in Appendix A and laboratory test results and graphs in Appendix B. We will retain soil samples for 90 days and discard after this time period unless we are notified to store the samples for an extended period of time. t GEOTECHNICAL OPINIONS AND RECOMMENDATIONS j We present the following geotechnical recommendations to assist preliminary planning, design and construction of the proposed Southern Highlands Subdivision in Meridian, Idaho as illustrated on Plate 1 attached to this report. This report provides specific earthwork and other geotechnical design criteria.for the development which the civil design and construction teams must review to verify the applicability to the planned development. We base our recommendations on the results of our field evaluation, laboratory testing, our experience with similar soil conditions, and our understanding of the proposed construction. If design plans change or if the subsurface conditions encountered during construction vary from those www.stratageotech.com I Southern Highlands Subdivision File: B014105A Page 5 observed during our field evaluation, we must be notified to review the report recommendations and make necessary revisions. Geotechnical Constraints and Opportunities We provide the following discussion of what we consider to be important geotechnical items which will impact the development. 6 Potential Uncontrolled Fill: During test pit explorations we encountered uncontrolled fill within the southwestern portion of the site, adjacent to the existing slope. However, we anticipate potential undocumented fill may be encountered throughout farming areas, and may not be evident until earthwork construction is commenced. As such, we recommend we observe the subgrade conditions after site grading to confirm unsuitable soil removal and subgrade soil are consistent with the recommendations in this report. Our report specifically outlines our opinions and recommendations regarding these soil conditions and relies on geotechnical continuity, communication between project team members specific to risk and cost-based decisions, and good construction practices to achieve the desired project outcome. Earthwork Fill Removal 1. Any existing, non-native soil at the project site is considered undocumented fill that is not suitable to support future structures and flatwork. 2. Remove all non-native soil to sufficient depth to expose existing native soil. 3. We estimate approximately 6 to 12 inches of fill removal will be required, depending on the amount of topsoil thickness in farming areas. I E Site and Subgrade Preparation l 1. Test pits have been marked in the field with labeled stakes and/or standpipe piezometers. The test pits should be located prior to any earthwork site grading and test pits which are located beneath paving, structural fill or building lot areas should be re- excavated and replaced with structural fill in accordance with the recommendations in this report. 2. Strip existing topsoil and vegetation. Topsoil and vegetation was noted to extend approximately 6 inches below existing grade. j 3. Scarify existing subgrade to a depth of 8 inches and moisture condition to within 3 percent of optimum moisture. 4. Compact the native subgrade soil as defined in Table 2 below. 5. Place and compact structural fill, as necessary, to achieve final grades. E i www.stratageotech.com i Southern Highlands Subdivision File: B014105A Page 6 Structural Fill 1. All fill placed must be placed as structural fill. 2. Fill placed on existing slopes greater than 5H:1V will require benching, as depicted on Plate 2, Benching Schematic. 3. Structural fill requirements described in Table 1 below, in general, correlate to Idaho State Public Works Construction (ISPWC) material specifications: Table 1. Structural Fill Specifications and Allowable Use "Pro, uct = Sieue Mafenal Specifications Size :Passin Allovriable Use _ g ' • Soil classified as GW, GP, GP-GM, GM, SW, SP, 6 Inch 100 General Structural Fill SP-SM, SM, or ML according to the USCS. General site grading ' Maximum particle size must be less than 6 inches. • • Soil consisting of inert earth materials with less than 3 percent organics or other deleterious substances wood, metal, plastic, waste, etc). Granular Structural Fill • Soil classified as GW, GP, GP-GM, according to 6 Inch 100 • General structural fill the USCS, and meeting the gradation provided. 3 Inch 90-100® Over-excavations • Soil meeting requirements stated in the latest No.4 30-60' Pavement section edition of the Idaho Standard for Public Works No. 200 <10 Construction (ISPWC), Section 801-Aggregate granular subbase Subbase • Soil may not contain particles larger than 1 inch in 1 Inch 100 Utility Trench Bedding median diameter and must meet the required 3/Inch 80-100 ® Utility trench gradation. 3/8 Inch 20-70 construction • Soil meeting requirements stated in the latest No.4 5-20 edition of the Idaho Standard for Public Works No. 8 0-5 Construction (ISPWC), Section 305—Pipe No. 200 0-3 [ Bedding. • Soil may not contain particles larger than 1 inch in 1 Inch 100 Aggregate Base Course median diameter and must meet the required • General structural fill gradation. 3/Inch 90-100 • Granular structural fill • Soil meeting requirements stated in the latest No.4 40-65 • Pavement section edition of the Idaho Standard for Public Works No. 8 30-50 base course Construction (ISPWC), Section 802—Aggregate No. 200 3-9 Base. • Soil classified as CL, CH, MH, OH, OL or PT may Unsatisfactory Soil not be used at the project site for structural fill. • No structural • Soil not maintaining moisture contents within 3 i applications percent of optimum. • Landscaping per . Any soil containing more than 3 percent organics landscape engineer by weight or other deleterious substances (wood, metal, plastic,waste, etc) is.unsatisfactory soil. €' Excavation Characteristics 1. Site soil is expected to be excavatable using conventional excavation techniques and equipment. 2. Bedrock is not expected within the planned construction limits. 3. Temporarily excavate, slope, shore or brace excavations in accordance with Occupational Safety and Health Administration (OSHA) guidelines. Regulations outlined www.stratageotech.com ©. T i„'TA, Inc. All ryipjht i eseg�vod Southern Highlands Subdivision File: B014105A Page 7 in OSHA provide temporary construction slope requirements for various soil types and slopes less than 20 feet tall. 4. Site soil is classified as Type C soil referencing OSHA, and must be temporarily sloped back at least 1.5H:1V. 5. Construction vibrations, seepage, or surface loading can cause excavations to slough or cave and should be avoided. 6. Ultimately, the contractor is solely responsible for site safety and excavation configurations and maintaining OSHA approved personnel for excavation monitoring. 7. Plan excavations carefully, allowing water collection points and utilizing conventional sumps and pumps to remove nuisance water from runoff, seeps, springs or precipitation. 8. Coordinate construction activities and excavation backfilling as rapidly as possible following excavation to reduce the potential for subgrades to degrade under construction traffic. 9. Subgrades must be graded to aggressively direct surface water away from subgrades to avoid infiltration. 10. Maintain dewatering systems to facilitate good drainage during construction and reduced over-excavation. Compaction Backfill to support any structure, embankment or improvement must be compacted to structural fill requirements presented in Table 2 below. Table 2. Required Compaction and Products for Designated Project Areas Required Structural Compaction Project Area Requirement Fill Product ,(ASTM D1557) Structural Subgrades Existing Soil Subgrade 92% i j Within 10 feet of building structural or General or Granular 95% pavement footprints Structural Fill Utility Trench Backfill Below Pavements, Utility Trench Fill 95% s Slabs, and Buildings E All Other Fills (more than 10 feet outside General Structural Fill 92o /o the building) Landscape Areas Sloped Flatter than o 5H:1V General Structural Fill 88/0 1. Fill placed outside any building or pavement envelope can be placed as non-structural fill (i.e. landscape fill) providing there are no structures (sidewalk, curbs, utilities, signs, etc.) or embankment planned directly above the landscape fill. Landscape fill compaction requirements also apply to stemwall or basement wall backfill that does not support overlying structures such as asphalt, slabs or other improvements free of no structures. 2. Structural fill products must be moisture conditioned to near optimum moisture content and placed in maximum 10-inch-thick, loose lifts. 3. Structural fill shall be compacted in 8 to 10-inch-thick, loose lifts providing compaction equipment weighs a minimum of 5 tons. If smaller or lighter compaction equipment is www.stratageotech.com Inic. All a ilgh5.'s Rec;eVvc-KI [V r Southern Highlands Subdivision File: BO14105A Page 8 provided, reduce the lift thickness to meet the compaction requirements presented herein. 4. The site soil is expected to be suitable for reuse as general structural fill providing it can meet the criteria presented in Table 1 above. We anticipate existing silt and silty sand soil will exhibit an average shrinkage factor of 20 percent to 22 percent, when placed as structural fill. Existing sand and gravel soil will likely exhibit shrinkage factors of 16 percent to 18 percent. The shrinkage factors above are applicable considering in-place (bank) conditions. Utility Trench Backfill 1. Remove all saturated, loose or disturbed soil from the bottom of the utility trenches prior to placing pipe bedding. 2. Accomplish bedding for pipes and utility trenches in accordance with ISPWC Specifications. 3. Backfill the remainder of utility trenches in accordance with the Structural Fill specification. Wet Weather/Soil Construction 1. Ideally, perform earthwork construction during dry weather conditions. 2. The site soil is susceptible to pumping or rutting from heavy loads such as rubber-tired equipment or vehicles any time of the year. 3. Complete earthwork by track-mounted equipment that reduces vehicular pressure applied to the soil if construction commences in wet areas or before soil can dry. 4. Depending on precipitation, runoff and perched groundwater conditions, the site soil will be over optimum moisture content. Contractor shall expect these conditions and be prepared to install runoff management facilities and to replace wet or disturbed soil with granular structural fill. 5. If significant soft/wet soil conditions are encountered, the use of a woven geotextile fabric may be necessary. These material requirements are presented in the Geosynthetics report section below. Geosynthetics 1. Where required, apply geosynthetics directly on approved subgrade, free of wrinkles and over-lapped at least 12 inches. 2. Woven geosynthetic fabrics for subgrade stabilization and soil improvements shall have the following minimum properties of 700 pounds (CBR Puncture, ASTM D6241) and 200 j pounds (Grab Tensile Strength ASTM D4632). 3. STRATA must be consulted prior to using geosynthetics for subgrade stabilization. I Existing and Proposed Slopes The existing slope located along the southwest portion of the site consists of previously E placed structural fill associated with the adjacent development. STRATA provided construction monitoring and testing services during the construction of this slope. Any excavation planned I along or adjacent to the slope should not increase the slope to greater than a 2 horizontal to 1 E I www.stratageotech.com g� 1 Southern Highlands Subdivision File: BO14105A Page 9 vertical (2HAV). This slope requirement is necessary to maintain slope stability for adjacent lots and to help with erosion control measures. Proposed cut and fill slopes planned for the development should be constructed at a maximum slope of 2HAV. Additionally, building setbacks for structures both above and below existing or constructed slopes must adhere to the 2012 International Building Code. STRATA can evaluate a possible reduction in slope setback distance on an individual basis, if desired. Any soil excavated along or adjacent to this slope area may be utilized as project structural fill, provided it meets the requirements as stated in the Structural Fill section of this report. -Pavement Section Design General The following flexible asphalt pavement section design is provided referencing the Idaho Transportation Department (ITD) Gravel Equivalent Design Method using Ada County Highway District substitution ratios. STRATA estimated traffic loading and design parameters based on our proposed construction understanding and our understanding of the subsurface conditions. i Traffic and Subgrade The following tables present our traffic loading, geotechnical design parameters and references, as well as the resulting flexible pavement section design recommendations. I Table 3. Pavement Design Parameters Design Parameter Value Used References 33,000 ESALs Traffic Loading (Local Road, TI=6) Ada County Highway District 375,000 ESALs Standard (Collector Road, TI=8) Design Life 20 years Assumed Subgrade R-value 20 Based on R-value correlations (see paragraph below) Ada County Highway District [SEubbase sphalt Layer Substitution Ratio 1.95 Standard Ada County Highway District e SuESubstitution Ratio 1.1 Standard ours Ratio 1.0 Ada County Highway District Standard Equivalent Single Axle Loads(ESALs). l www.stratageotech.com ©ST,rRIA A., inc. .Ull MgNE. V 61Ge-5.•ve..l Southern Highlands Subdivision File: B014105A Page 10 .Laboratory testing of lean clay with sand resulted in an R-value of 33`. However, based on the variability of surficial fine grained soil, and our experience with previous R-value testing for East Taconic Drive, we recommend ;an'R-value of 20 be utilized for pavement section design. To help improve subgrade characteristics, the pavement subgrade should be prepared as recommended in this report's Site Preparation section. Subgrades must be shaped (crowned) and graded to facilitate positive drainage and inverted crowns must be avoided. Asphalt Aggreqate Base Course and Subbase Materials Crushed aggregate base course and granular subbase shall conform to the Structural Fill requirements and be placed directly over a properly prepared subgrade. A non-woven geotextile should be used for constructability during wet and inclement weather and to increase performance at the subgrade. The non-woven geotextile should have material properties and be placed as outlined in this report's Geosynthetics section. We recommend STRATA observe final subgrade preparations, geotextile placement and all aggregate placements. Asphalt concrete must be compacted to 92 percent of the maximum density for a Hveem or Superpave mix design. The final traveling surface of asphalt concrete shall meet ISPWC 3/- inch asphalt mix design requirements. Asphalt mix designs and all appropriate aggregate source certificates should be accepted by STRATA at least 5 days prior to initiating asphalt paving. Asphalt construction and final surface smoothness, joints and density should meet i j ISPWC specifications. If subgrade conditions appear significantly different during construction, traffic loading conditions change or traffic volumes increase, STRATA should be notified to amend our design accordingly. i Pavement Section Thickness STRATA evaluated the pavement sections utilizing the ITD pavement design methodology, soil-engineering parameters from previous field and laboratory testing and the estimated traffic-loading conditions. Based on subgrades prepared as recommended and the traffic criteria provided, Table 4 provides the recommended asphalt section for the anticipated pavement application. If traffic loading or subgrade conditions change as design is finalized or during construction, STRATA must review our pavement analyses and resulting sections. i I i i { www.stratageotech.com ©Sytl�_q , Inc. All MCArits �3`Zes-;lrved Southern Highlands Subdivision File: B014105A Page 11 Table 4. Asphalt Pavement Design Section gs,phalt ,Aggregate.` Granular Asphalt Pavement Appli�;cation .Concrete Base Subbase -,(in (in.ches) (inches) Local Roads &Access Drives (TI = 6) 2.5 4.0 10.0 Collector Roads and Heavy Duty Access (TI = 8) 3.0 6.0 13.0 Pavement Maintenance We recommend crack maintenance be accomplished on all pavement surfaces every 3 to 5 years to reduce the potential for surface water infiltration into the underlying pavement subgrade. Surface and subgrade drainage are extremely important to the performance of the pavement section. Therefore, we recommend the subgrade, base and asphalt surfaces slope at no less than 2 percent to an appropriate stormwater disposal system or other appropriate location that does not impact adjacent buildings or properties. The pavement's lifespan is dependent on achieving adequate drainage throughout the section, especially at the subgrade elevation. Ponding water at the pavement subgrade surface can induce heaving during the freeze-thaw process. Site Drainage Stormwater Disposal We recommend all subsurface infiltration facilities extend a-minimum of 12 inches into l poorly-graded gravel with sand. Based on our test pit explorations, we anticipate excavation depths of 5.-5' to 11'feet will be required to"expose gravel with sand. Stormwater facilities constructed into gravel with sand may be designed utilizing the following allowable infiltration =rate: O Allowable infiltration rate (gravel with sand) 12 inches-per hour Seasonal High Groundwater As stated previously, groundwater on April 22, 2014 was encountered at 5.5 feet within the northeast portion of the site (TP-8). Subsequent groundwater monitoring in May 2014 identified groundwater in TP-8 at a depth of 5.1 feet and in TP-10 at 7.9 feet. Groundwater levels are typically at the peak for the season during the late summer irrigation season. Based on our experience in the area, we anticipate seasonal high groundwater level near the eastern portion of the site (near TP-8 and TP-10), will occur at a depth of approximately 4.5 feet below' existing grade. Additionally, based on previous monitoring, groundwater in the northern portion www.stratageotech.com Southern Highlands Subdivision File: B014105A Page 12 of-:the property (near'TP-4 and TP-5), may occur at depths as shallow as approximately 6 feet below grade. It is our opinion groundwater within the remainder of the site will occur at depth of 14 to 15 feet below existing site ,grades'. However, groundwater monitoring must be accomplished during irrigation season, April to October, to confirm seasonal high groundwater levels for design. We accomplished groundwater monitoring at the time of our site exploration in 2006. We provide results of that groundwater monitoring in Appendix C, along with previous test pit exploration logs. Surface Water Management for Individual Lots Surface water associated with rain, snow and irrigation water can become perched above the relatively impermeable native and structural fill soils which presently exist and is planned beneath the proposed individual lots. Improper management of near-surface water, by not providing an effective grading and drainage design for each lot, can result in moisture or water entering the crawl spaces or basement areas of the residences. Possible sources of near-surface water include pressurized irrigation water, rainwater, snowmelt, or leaking water lines. These water sources can be transmitted to the foundation stem wall and pond beneath a structure via irrigation, roof downspout discharge, and snow melt. Possible conduits for water to enter into crawl spaces or basements can include loose or porous backfill placed adjacent to foundation walls and loose or porous backfill in utility trenches that extend through or beneath foundations. Considering the above discussion we recommend that consideration be given to the i potential for surface water intrusion and be considered during planning, design, and construction of individual lots. Additionally, we recommend roof drains for individual residences i be connected to the overall subdivision stormwater drainage system. i I GEOTECHNICAL DESIGN CONTINUITY Geotechnical design continuity will be an important aspect of this project's successful completion. In our opinion, geotechnical continuity can occur in 4 stages in the planning, design and construction project aspects. Specifically, we recommend STRATA maintain the l geotechnical design continuity in the following aspects: !' 690 Groundwater Monitoring: The groundwater level should be monitored during the upcoming irrigation season to verify the seasonal high groundwater level beneath the site. Piezometers were installed to monitor groundwater levels. Monitoring typically E www.stratageotech.com Southern Highlands Subdivision File: B014105A Page 13 should be accomplished on a monthly basis between April and October. STRATA remains available to perform groundwater monitoring at your request. • Plan and Specification Review: We recommend STRATA be retained to review final design and construction plans and specifications to verify our geotechnical recommendations are incorporated into project bidding and construction documents as well as to provide additional recommendations based on the final design concepts. These efforts can help provide document continuity across the engineering disciplines and reduce the potential for errors as the project concepts evolve. • Geotechnical Design Confirmation: The information contained in this report is based on preliminary development plans. The grading elevation as well as site geometry can significantly alter our opinions and design recommendations. Specifically, changes in the soil cut and fill geometry may require additional analyses specific to the actual anticipated construction conditions. Therefore, it is critical STRATA provide geotechnical continuity through final planning and design for the planned construction as individual aspects become available during design development phases of the project. It has been our experience that having consultants from the design team review the construction documents prior to bidding helps reduce the potential for errors, and also reduces costly changes to the contract during construction. If we are not provided such opportunities, we cannot be responsible for soil-related design or construction-related errors, omissions, delays or increased costs that are identified during construction. • Construction Observation and Testing: We recommend STRATA be retained to provide construction monitoring to verify the soil conditions and that report recommendations are incorporated into the actual construction. Such observation is an important part of the geotechnical design process and can help reduce the potential for soil engineering- or construction-related errors or omissions. For this project it is especially important to maintain this geotechnical continuity during uncontrolled fill identification, removal and replacement as well as during the subgrading process. If we are not retained to provide the recommended plan review and construction monitoring services, we cannot be responsible for soil engineering- related construction errors or omissions. Further, the selected firm must be required to document in writing to the design team and BHH Investments 1, LLC that they have read and will implement this report and its recommendations in their entirety as the geotechnical engineer of record. EVALUATION LIMITATIONS This report has been prepared to assist project planning design and construction of the proposed Southern Highlands Subdivision to be located north of East Taconic Drive in Meridian, Idaho. Our geotechnical findings and opinions have been developed based on the authorized subsurface exploration and laboratory testing, as well as our understanding of the project at this time. Our geotechnical design recommendations are specific to the planned design and infrastructure construction and should not be extrapolated to other future site developments without allowing adequate geotechnical consultation by STRATA. STRATA's scope provides recommendations for infrastructure construction, which does NOT include recommendations for www.stratageotech.com ©S l;?rn P ,' inc. fiyff (zee)ht�t, i esef,'ved Southern Highlands Subdivision File: B014105A Page 14 individual residential lots or residential structures, and STRATA does NOT assume the role of geotechnical engineer of record for individual residential lot construction. Our services consist of professional opinions and findings made in accordance with generally accepted geotechnical engineering principles and practices in southwest Idaho at the time of this report. The geotechnical recommendations provided herein are based on the premise that appropriate geotechnical consultation during subsequent design phases is implemented and an adequate program of tests and observations will be conducted by STRATA during construction to verify compliance with our recommendations and to confirm conditions between exploration locations. This acknowledgment is in lieu of all warranties either express or implied. The following plate and appendix accompany and complete this report: Plate 1: Exploration Location Plan Plate 2: Benching Schematic Appendix A: Unified Soil Classification System (USCS) & Exploratory Test Pit Logs Appendix B: Laboratory Test Results Appendix C: 2006 Test Pit Logs and Groundwater Monitoring #-4 www.stratageotech.com © 'ftFRierA, 9nc. A� RiQ) t3 s ens;orvedl Z Y Z C . Q OH �`—O-d 5 E.'Ie Nd cc LU y Q. .� C \ W .n F- Al Q Q W f/1 E Q (A m V m ry U O I; J Z W n a E ti d O aq qa x (� o c'a=i c o I, d X O o o W n,u 1O n W a J ¢� n ¢¢ �q 7 F s 9 so r r i Y }A aR I \ I ° �9� 6� ;h hl�I h r1 Ih h hI� Ih q A ��. ih m� h1�1' h "n, hlz Ih �Rj Ln I ��55 `\ F a s�i I a s h hbi ss s 8 .tag, y1' IS e I'�d q n�a \\\\ $ ` � _fix\`\v\✓',// �� \� r� �? '��/ "� � an a.^-.� •ty �•G*aY /r �"R \4.4 � �� h cjr�r m� i / §� is RN gg �h rah hllCL a 9 COL m 0 I s I COMPACTED FILL(SEE FILL SURFACE NOTES) EXISTING GROUND \ . . . ,-....T SURFACEO� p LIMITS OF . : --'.'_ Jam: EXCAVATION \�\\/\\\\\\ EXISTING\ • . _ \/DAM SOIL\ \ \ \ BENCHES: 6 FEET WIDE (MINIMUM) NOTES: 1.BACKFILL TO BE PLACED IN 8-INCH,LOOSE LIFTS AND COMPACTED TO A MINIMUM OF 95%OF THE MAXIMUM DRY DENSITY AS DETERMINED BY ASTM D 1557.FILL SHOULD CONSIST OF APPROVED,ON-SITE SOIL OR STRUCTURAL FILL. 2.BENCHES MAXIMUM OF 4 FEET VERTICAL. BENCHING SCHEMATIC A PROFESSIONAL SERVICES CORPORATION ky.From 4-lt--(:�7rouKd Vp INFDRMATIOW ONLY (NOT TO SCALE) "BHH INVESTMENTS 1 LLC rolec o. 6014105A PLATE:2 i r APPENDIX A UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GRAPH LETTER TYPICAL NAMES SYMBOL SYMBOL GW Well-Graded Gravel, CLEAN Gravel—Sand Mixtures. GRAVELS GP Poorly-Graded Gravel, , GRAVELS Gravel—Sand Mixtures. GRAVELS GM Silty Gravel, Gravel— Sand—Silt Mixtures. WITH Clayey Gravel, Gravel— COARSE FINES GC Sand—Clay Mixtures. GRAINED 0 0 0 0 0 0 Well—Graded Sand, SOILS CLEAN 0 0 0 0 0 0 SW Gravelly Sand. SANDS 0 0 0 0 0 0 SP Poorly—Graded Sand, SANDS 0 0 0 0 0 0 Gravelly Sand. SANDS 0 0 0 0 0 6 SM Silty Sand, WITH 0 © 0 © 0 Sand—Silt Mixtures. 0 � 0 00 0 Clayey Sand, FINES 0©0 0 0 0 Sc Sand—Clay Mixtures. ML Inorganic Silt, Sandy or Clayey Silt. SILTS AND CLAYS Inorganic Clay of Low LIQUID LIMIT CL to Medium Plasticity, LESS THAN 50% Sandy or Silty .Clay. I I I I I OL Organic Silt and Clay I I I of Low Plasticity. FINE Inorganic Silt, Mica— GRAINED MH ceous Silt, Plastic SOILS Silt. SILTS AND CLAYS Inorganic Clay of High CH Plasticity, Fat Clay. LIQUID LIMIT Organic Clay of Medium GREATER THAN 50% OH to High Plasticity. PT Peat, Muck and Other Highly Organic Soils. BORING LOG SYMBOLS GROUNDWATER SYMBOLS TEST PIT LOG SYMBOLS i Standard 2—Inch OD V Groundwater gG Baggie Sample Split—Spoon Sample = After 24 Hours f ACalifornia Modified 3—Inch (7-3-07) Indicates Date of BK Bulk Sample OD Split—Spoon Sample Reading E �I Rock Core [R�GGroundwater Ring Sample e � — at Time of Drilling I aShelby Tube 3—Inch OD Undisturbed Sample I Shorthand Notation: BGS = Below Existing Ground Surface N.E. = None Encountered irm air a i A PROFESSIONAL SERVICES CORPORATION _TK4-o� -y V p E' j o m Remarks N O c' N NN a USCS Description m U E E a m w d o a u�m m Y p cn— a Eo a d 5� Y— Note:BGS=Below ~ o z o 7 a a Ground Surface 0.0 LL PI LEAN CLAY,(native),(CL)brown,very stiff, moist CL Trace vegetation and organics BG 3.5 to about 6 inches BGS. SILTY SAND,(SM)light brown,dense, e c Strong cementation(caliche) moist , < from 1 to 4 feet BGS 0 C 0 a a e BG 20.3 2.5 e 0 C' 0 J ° O O 5.0 SM ' 'a` Moderate cementation a` (caliche)from 5 to 9 feet BGS e 0 a 0 j c d o F O. Fa- J f W O W 7.5 _ e a o a c0 00 0 z O. _ F = POORLY GRADED SAND WITH SILT AND w GRAVEL,(SP-SM)brown,dense,moist 10.0 '. BK SP- 8.0 SM m a w 0 12.5 a Test Pit Terminated at 13.0 Feet. 0 a a F 0 I � i a F Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-1 F- Project: B014105A Date Excavated: 03-31-2014 EXPLORATORY W s-r�ta-�'a TEST PIT LOG aBackhoe: CASE 580 Bucket Width: 2' A PROFESSIONAL SERVICES CORPORATION cc Depth to Groundwater: N.E. Logged By: SW �"` Fes"' `7—"dVr Sheet 1 Of 1 i Cn Z-' o R, Remarks i� � e �r �' Note:BGS=BelowUSCS Description I IT � o0 a �in o o o a 0.0 LL PI Ground Surface SILTY SAND WITH GRAVEL,(fill),(SM) brown,loose,moist °e Trace vegetation and organics o to about 6 inches BGS. 0 SM c 0 0 0 SILTY SAND,(native),(SM)light tan, 0 F dense,moist 2.5 ' e` Moderate cementation (caliche)from 2 to 5.5 feet .®Q BGS. 0 e 0 SM a� 0 c 0 0 5.0 0 E 0 POORLY GRADED SAND WITH SILT,And Cobble And Gravel,(SP-SM)light tan,very dense,moist 4. a U) w 7.5 B K 0 v O m 3 = SP- i SM w M 0 10.0 a 0 v O rn m <r In LU O 12.5 n. Test Pit Terminated at 13.0 Feet. cc v a 0 c� a a F Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-2 EXPLORATORY w Project: B014105A Date Excavated: 0331-2014 STRaTa TEST PIT LOG aBackhoe: CASE 580 Bucket Width: 2' A PROFESSIONAL SERVICES CORPORATION Depth to Groundwater: N.E. Logged By: SW s"ram'"'F'"f 4 "d°P Sheet 1 Of 1 I 2 o 21 Remarks °� U� E E a yaw� ° N m u H USCS Description o , a d o g e 0 �, Note:BGS=Below �' `� o z o a ¢ Ground Surface 0.0 LL PI SILTY SAND WITH GRAVEL,And Cobbles 3 (fill),(SM)brown,medium dense,moist °C Moderate vegetation and 0 organics to about 6 inches o BGS. ©, BG SM ®� 3 C 0 2.5 31 C a' o,. Q j ©C Grass roots observed from 3.5 o to 4 feet BGS SILTY SAND,(native),(SM)light brown, dense,moist C 0 5.0 SM I 1 1,01 Moderate cementation . e (caliche)from 5 to 6 feet BGS e SILTY SAND,(SM)tan,very dense,moist 3 a C o a 3 H Q, w 3 7.5 3 C, o BK 20.0 0 C a o o C C CI o C z g � C x SM ' a z x a w F Q, 0 10.0 < C Q. o_ s ca to ©. s m o WTest Pit Terminated at 12.0 Feet. o cc I m a a U) F F Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-3 EXPLORATORY Project: 6014105A Date Excavated: 03 31 2014 STFR&-r2a TEST PIT LOG w [' ¢ Backhoe: CASE 580 Bucket Width: 2' A PROFESSIONAL SERVICES CORPORATION t' ZnF 9.ay Fro,u aim 1571-1d up P Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 i E E 6; vi o m Remarks USCS Description m 6T m Fes- n.d°' o a o 2 m J Note:BGS=Below `� `o o z o a° ¢ Ground Surface LL PI LEAN CLAY,With Sand(native),(CL) 0.0 brown,stiff to hard, moist BG 1.0 BG 4.0 CL 2.5 CLAYEY SAND,With Gravel,(SC)brown, 0 medium dense,moist 0 0 0 BG 0 0 0 0 0 0 0 0 0 0 5.0 0 0 0 0 0 0 0 0 0 0 0 0 0©0 0 Light cementation from 6 to 10 0 0 0 0 feet BGS a 0 0 C'3 0 0 1 0 0 SC 0 0 In o 0 � o 0 < 7.5 0 0 o 0 0 0 0 v 0 0 O 0 0 m 0 0 0 0 0 0 0 i 0 0 = 0000 0 = 0 0 Z 1 0 0 0 0 = 1 0 0 F 0 0 0 0 10.0 00 0 0 0 0 � 0 0 0 SILTY SAND,(SM)brown,medium dense, 0 moist 2 ° Light calcium carbonate o in � a 0 o SM 5 ° c U O 12.5 Piezometer installed to 13 feet 0 c 0. o BGS E d m Test Pit Terminated at 13.0 Feet. cc v E a 0 c� E i F Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-4 a EXPLORATORY W Project: BO14105A Date Excavated: 03 31 2014 S T R aT a TEST PIT LOG aBackhoe: CASE 580 Bucket Width: 2' A PFOPESSIONALSEAVlas CORPORATION 9y Frov-F/4ourtd UP N Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 4' co y o ( Remarks USCS Description o -.Sg a � a o in o a o D J Note:BGS=Below (1) o z o 0 a Ground Surface 0 LL PI SILT,(native),(ML)brown,firm,moist 0.5 ML 1.0 LEAN CLAY WITH SAND,(CL)brown,stiff, CL BK 2.0 33 11 moist SILTY SAND,(SM)brown,dense,moist 3 2.5 Q, a Moderate cementation a (caliche) from 3 to 4 feet BGS. 0 3 f- O O o Strong cementation(caliche) 5.0 from 4 to 5 feet BGS c 0 SM a O. 0 0 cs o � c a o N c W ° a 7.5 In a o c � O O m 0 U) O Z g = POORLY GRADED GRAVEL WITH SAND, W (GP)tan brown,dense,moist 2.3 10.0 0 s ep.: GP m �A d � O 0 12.5 0 Piezometer installed to 13 feet BGS. Test Pit Terminated at 13.0 Feet. ! a r � 0 E E F- E Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-5 EXPLORATORY a Project: B014105A Date Excavated: 03-31-2014 STRa-ra Lu TEST PIT LOG FBackhoe: CASE 580 Bucket Width: 2' APFOfF5510IlAL SENVICFS COflPOFAiiON Depth to Groundwater: N.E. Logged By: SW ''4'�""eUP Sheet 1 Of 1 i o a)o a Remarks �� ar, rye USCS Descri tion (6 E e a �N� o Q N r ;- p o vi , W a.d to o �� Note:BGS=Below CID `� o z o 0 ¢ Ground Surface 0.0 LL PI SILT,(native),(ML)brown,firm,moist ML rBG 0.5 LEAN CLAY WITH SAND,(CL)brown,stiff, CL 1.0 moist SILTY SAND,(SM)brown,medium dense to dense,moist o. o' 2.5 O 0 0 C Moderate cementation j a (caliche)from 3 to 12 feet BGS c 0 0 5.0 0 e 0 . E a I C 0 c a. o SM ' o O 3 BG 7.5 < o a d05 Q m E p OC If g c� o _ o Z E W � o $ 10.0 Q. o o �u o. En o o m o d 9 C o O C POORLY GRADED GRAVEL,With Sand, b' o (GP)brown,dense,wet 12.5 J. CL GP Q fl i Q. a Test Pit Terminated at 13.5 Feet. p ( a m Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-6 EXPLORATORY W Project: B014105A Date Excavated: 03 31 2014 �•e•Ra�a TEST PIT LOG FBackhoe: CASE 580 Bucket Width: 2' A PROFESSIONAL SERVICES CORPORATION xnr�nJy Fro,v7-/4 eNnd up � Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 m o Remarks co �.^ U - s Q-o. 0 N > m Y c a m s USCS Description N E T � o N �,E p a vi 0 , n. in o Note:BGS=Below U) t p z o 2. a° a 0.0 LL PI Ground Surface LEAN CLAY,(native),(CL)brown,very stiff, moist CL 2.5 BG SILTY SAND,(SM)brown,medium dense ' a Strong cementation(caliche) to dense,moist , from 1 to 6 feet BGS o. ® BK 28.0 a 2.5 0 a , 0 SM 9 C,0 3 - c 0 0 a 0 5.o : 0. C 0 D C 0 c POORLY GRADED GRAVEL WITH SAND, And Cobbles,(GP)brown,moist a Q �. C7 r Q. ••. CL W N 7.5 Q. m a. 0 0. g �a . x p'p Z ,(��• BG W GP 0 10.0 riQa:. 0 0 0 3C. o pO Q m aQq.• 0 12.5 0•p Piezometer installed to 13 feet a Q, BGS. .n Test Pit Terminated at 13.0 Feet. I o a 0 i m Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-7 EXPLORATORY Project: B014105A Date Excavated: 03 31 2014 TEST PIT LOG w z a Backhoe: CASE 580 Bucket Width: 2' � A PROFESSIOIIAL SERVICES CORPORATION ¢ S..r�..ryroMri e�o....euP � Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 i I E I I o a) m Remarks U °� N a' USCS Description ° y d r 9 E o mm E E F a o o g s Note:BGS=Below `� o z o �� a ¢ Ground Surface 0.0 LL PI LEAN CLAY,(native),(CL)brown,stiff, moist CL 1.0 BG FAT CLAY,(CH)brown,stiff,moist 1.5 CH EG am 90.0 29.1 52 34 SILTY SAND,(SM)brown,medium dense to dense,moist 2.5 Q e a e 0 C 0 C, Moderate cementation SM 0 (caliche)from 3.5 to 6 feet BGS. 0 e 0 0 5.0 3 C 0 0 C O POORLY GRADED GRAVEL WITH SAND, And Cobbles,(GP)brown,dense,saturated 4,Qp. w 7.5 Q, a Q b GP d .p m 0 0. g oa . z a o 6:• Piezometer installed to 10 feet D O: BGS. a Test Pit Terminated at 10.0 Feet. to.o 0 v O m U) O m a 0 F- W O m a m_ o_ v a f F f Q 12 Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-8 a EXPLORATORY co Project: B014105A Date Excavated: 03 31 2014 S,T RaT a TEST PIT LOG a Backhoe: CASE 580 Bucket Width: 2' A PROFESSIONAL SERVICES CORPORATION Depth to Groundwater: 6' Logged By: SW s r9`"P'F`"" 4 �P Sheet 1 Of 1 I E : i o Remarks viN a� �o� ° U2 E EQ ma0 a) �m m of USCS Description o a F- n. d o � ju Note:BGS=Below `� `� o z o 0 ¢ Ground Surface 0.0 LL PI SILT,(native),(ML)brown,stiff,moist ML BG 1.0 LEAN CLAY,(CL)brown,stiff,moist BG 1.5 CL BK RG 2.5 SILTY SAND,(SM)light brown,very dense, moist ,°e 0 3 a` Strong cementation(caliche) a from 4 to 6.5 feet BGS SM o 5.0 0 0 3 0 e 0 > c 0 POORLY GRADED GRAVEL WITH SAND, a And Cobbles,(GP)brown,dense,moist ° `b': fl' F Q• < 7.5 0 o Q(fib•: BG GP p .� _ Q' C; Z) o� ° 10.0 C o ' U) m Q•tr'• Piezometer installed to 12 feet BGS, Test Pit Terminated at 12.0 Feet. W o EL d m � o a a j F 0 ( d a Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-9 iL Project: B014105A Date Excavated: 03-31-2014 EXPLORATORY a Backhoe: CASE 580 Bucket Width: 2' �"1"A�a"�'� TEST PIT LOG i A PAOPP$SIONA[Swim CONPONATION Depth to Groundwater: N.E. Logged By: SW sK+�.,y Fo + E,o.,dUp Sheet 1 Of 1 030 :�' �:-. C a)� Remarks r- W T�-� 2). U5CL a. a) E -�!*E Z, �2 E M USCS Description g '5 a 0'V, 12 a, WD Note:BGS=Below 0 0) W z L, 2i 0 0 Ground Surface 0 SILT WITH SAND,(ML)brown,stiff to hard, LL PI —0.0— moist 1.0 BG 78.0 23.1 >4.5 No cementation in silt 2.5 ML >4.5 >4.5 -5.0 POORLY GRADED GRAVEL WITH SAND, And Cobbles,(GP)brown,dense,moist J. fL 3b 7.5 oa .0 0 99 z GP 0 —10.0 0 b 0 ca C9 0 Ir Piezometer installed to 13 feet BGS. Test Pit Terminated at 13.0 Feet. Client- BHH INVESTMENTS 1,LLC. Test Pit Number: TP-1 0 EXPLORATORY a. Project: B014105A Date Excavated: 03-31-2014 w w TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' A Pnoussioiw SEavias Conpmnon Depth to Groundwater: N.E. Logged By: SW 4-1—,5i',.-td Vr Sheet 1 Of 1 W C" �,o C Remarks USCS Descri tion "Cq E E Q 2 N T o a N p o vi a Ic F 3 cn o — Note:BGS=Below �' U' o z o 2� a a Ground Surface LL PI LEAN CLAY,(CL)brown,firm to stiff,moist 0.0 BG 1.0 CL BG 24.2 2.0 35 16 2.5 SILTY SAND,With Sand,(SM)brown, ' C°. medium dense to dense,moist 9 O ' °` Moderate cementation ° (caliche)observed from 4 to 6 feet BGS. 0 5.0 SM ° - c 0 e c ° ( c a ° C) 3 C a u) POORLY GRADED GRAVEL WITH SAND, b' a (GP)brown,dense,moist 5 o Q fl. m oo°. 65 o.•6 E z �. I = GP o(�° E o p :o. I ° o Op: W OD Q. •: Piezometer installed to 12 feet e�°• BGS. Test Pit Terminated at 12.0 Feet. w a m 0 l � I � I F" 0 N [ cc Client: BHH INVESTMENTS 1,LLC. Test Pit Number: TP-11 EXPLORATORY w Project: B014105A Date Excavated: 03-31-2014 TEST PIT LOG aBackhoe: CASE 580 Bucket Width: 2' A PAOFESSIONALSEBVICES CORPORATION f/Q SnJ-�r/hy Frew -4—d UP Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 t r; S I' i i I i t I I I i c i E j G E a) LL U) lt� CD (Y) 21 < Lr) I 0 Q) IX) (Y)IJ LO: (yO 00 dam' a) ce) co & CC) C\l M I-- C� O ,o LL (D C) of cyi .(n N M C\l 041 cc cc .E OL AM U) 4) UT > U) w 1 3: �: Wu W CC a) m 3: 0 12CL 0 16 C <M 00 0 Uj LL a) (D 04 E C) C: a) -i Co > a) 0- 0- cn _0 (D (D to 0 ca 0 -0 LO C\l C4 t m 1� , _ > CL (D 4� IL W -C >c 0 > U) T La .> o Lo in, I- oo� (D CL a) a) GRADATION ANALYSIS ASTM D 1140 Project: Southern Highlands Development Client: BHH Investments Project Number: B014105A Lab Number: B01400230B Sample Identification: TP-1 @ 10-11 ft Sample Classification: P. G. Sand with Silt and Gravel Date tested: 4/8/14 By: J Sanders U) Gravel Sand 0 U Coarse Fine Coarse Medium Fine Inches Screen Sizes O O LO CV O O O O O O O O O 100 `�' <r ih CO m 90 85 80 70 6 z 60 � 5 50 z W w 40 4 30 20 1 10 8 0 100 10 1 0.1 SOIL GRAIN DIAMETER, millimeters Reviewed by. A PROFESSIONAL SERVICES CORPORATION Kk�cjrrkr Frowt 4-1—4!!�Vrowtd Up MOISTURE-DENSITY RELATIONSHIP CURVE ASTM D 1557 Method B GRADING ANALYSIS Project: Southern Highlands Development SCREEN SIZE %PASSING AS TESTED Client: BHH Investments, LLC 6 inch Project Number: B014105A 3 inch Sample Number: B01400230B 3/2 inch 100 inch Sample Identification: TP-1 @ 10-11 ft 3/8 inch 87 100 Sample Classification: P. G. Sand with Silt and Gravel #a screen Date Tested: 4/2/14 By: K Barnett Soil Tempered: No Rammer Type: Manual Corrected Dry Density, pcf: 111.3 Maximum Dry Density, pcf : 106.7 Corrected Moisture Content, W 14.3 Optimum Moisture Content, W 16.6 Coarse Aggregate Correction,%: 13 125 Bulk Specific Gravity(assumed):2.56 O Optimum Point ® Proctor Points 120 e it 115 c U °'110 V5 z w n 106.7 Na y;105 0 100 95 I 90 11 12 13 14 15 16 17 18 19 20 21 22 MOISTURE% i Reviewed By: A PROFESSIONAL SERVICES CORPORATION € 3�4t-Y—_✓✓gr/4y -vom 4-A--G� uc rotd UP i E S GRADATION ANALYSIS ASTM D 1140 Project: Southern Highlands Development Client: BHH Investments Project Number: B014105A Lab Number: B01400230C Sample Identification: TP-3 @ 8 - 9 ft Sample Classification: Silty Sand Date tested: 4/9/14 By: J Sanders a Gravel Sand 0 () Coarse Fine Coarse Medium Fine Inches Screen Sizes p o in c{ co N M V rLo ((O N 100 m CV th 9 90 80 70 C7 Z 60 co Q 50 z w v AIM W 40 o_ 30 20zu 10 0 100 10 1 0.1 SOIL GRAIN DIAMETER, millimeters 0@- ill Reviewed A PROFESSIONAL SERVICES CORPORATION K/�9ribyFrawr-f-h--C�7rvuKd Up RNALUE Idaho T 8 Project: Southern Highlands Development Project No: B014105A Client: BHH Investments Lab Number: B01400230D Sample Identification: TP-5 @ 1.5 - 2 ft Date Received: 3/31/14 Sample Classification: Lean Clay with Sand Date Tested: 4/8/14 By: J Sanders SOIL CONSTANTS R VALUE DATA Percolation: None Point1 Point2 MM3 R VALUE: 33 Exudation, PSI 123 160 349 Dry Density, PCF 96.9 98.5 99.6 Moisture Content, % 22.2 21.0 19.6 Exp. Pressure, PSI 0.00 0.00 0.89 0 0 GRADATION:AASHTO T-11,T27 SCREEN AS RECEIVED AS TESTED SIZE %PASSING %PASSING LO o 0 ri 00 4" 0 3" 0 0 cei 2" ❑ d 1„ 0 LO oo � 3M' 100 100 N co -J v 1/2" U) w 2 O 0o N 3/8" d N � 0 C o No.4 o 16 lb No.8 tL W No.16 No.30 o O o No.50 No.100 L o No.200 CDN O O Oo O W Co r to � d' � N O� O `- R value Note:This report covers only material as represented by this sample and does not necessarily cover all _ soil from this layer or source. i A PROFESSIONAL SERVICES CORPORATION Reviewed by: -_--^� �K-i� ria y Frowt dl�c�roucgd U� i i 'r i APPENDIX C REMARKS J W S N<n p J ',n CDy m USCS Description 4 cn W o v o c Note: BGS = Below Ground G " N z o z n c Surface Lean CLAY (Native) — brown, CL Moderate vegetation stiff to very stiff, moist. and organics observed 1.5-2 to 6 inches BGS. 1 Sandy SIT — tan, very stiff, ML 2-2.5 slightly moist. 3 Silty SAND — tan, dense, SM • : • moist. 4 • Poorly—Graded GRAVEL with GP �_'••. Sand — tan, dense, moist to saturated. p: 6 .0• 7 4: Test pit terminated at 8 Standpipe iezometer feet BGS due to caving installed to 8 feet conditions. BGS. 9 10 11 i 12 i 13 I t 14 I 15 Client: Test Pit Number: TP-4 EXPLORATORY { Project: B06167A Date Excavated: 8-7-2006 TEST PIT LOG Backhoe: CASE 580 SUPER Bucket Width: 2' :c[pi[�,LsG{;t tyc7dFav{:!u.rzfn+,irir,Ha I Depth to Groundwater: 4.3' Logged By: BN Sheet 1 of 1 pi 1 4 r. REMARKS C CD a) 8USCS Description o12 N o 0 0 Note: BGS = Below Ground d o =tom N �t ° z a s a> a e Surface Fat CLAY(Native) — brown, CL Moderate vegetation stiff to very stiff, moist. and organics observed 4.5+ to 6 inches BGS. 1 BG 95 28.1 Atterberg Limits: Silty SAND — ton, dense, SM • • • 2.0 LL=57, PI=35 moist. • • O 3 • • ° Weak cementation observed from 3 to ® ° 4 feet BGS. 4 • BG • • • 5 ® ' • • • (B-28-88) • • o • Poorly—Graded GRAVEL with _GP Sand — tan, dense, moist to p' saturated. 7 O: 8 :p 9 Test pit terminated at 10 10 p Standpipe i e iezometer feet BGS, j installed to 10 feet BGS. i 11 I I f7 12 I 13 i i 14 i 15 Client: Test Pit Number: TP-5 EXPLORATORY Project: B06167A Date Excavated: 8-7-2006 TEST PIT LOG Backhoe: CASE 580 SUPER Bucket Width: 2' `p,R,mcr,,_sE ivcilUctui�rnf. Depth to Groundwater: 6.2' Logged By: BN Sheet') of 1 3 _ REMARKS Cn USCS Description a U2v"i o o Note: BGS = Below Ground z � o z Q 0- E Surface SILT — brown, stiff, moist. ML Moderate vegetation and organics observed to 6 inches BGS. Lean CLAY (Native) — brown, CL stiff to very stiff, moist. BK 2 Sandy SILT — tan, firm, ML slightly, moist. 3 BG 7- 4 6 7 Poorly—Graded GRAVEL with zGP Sand — tan, dense, moist to saturated. 9 0• 10 Test pit terminated at 11 Standpipe piezometer feet BGS. installed to 11 feet BGS. 12 13 14 15 Client: 41IMM Test Pit Number: TP-7 - EXPLORATORY Project: B06167A Date Excavated: 8-7-2006 TEST PIT LOG Backhoe: CASE 580 SUPER Bucket Width: 2' 4uP¢ de tXa4tP4Nb.S varzn njT nHd Sheet 11 of 1 Depth to Groundwater: N/A Logged By: BN _ REMARKS Cn USCS Description 4 v"i a e ;5 o a� Note: BGS = Below Ground Surface t.. A Lean CLAY (Native) — brown, CL Moderate vegetation stiff to very stiff, moist. and organics observed FB GI to 6 inches BGS. 1 Sand SILT — tan, ver stiff ML Weakly cemented from y y FLK 1.5 to 4.5 feet BGS. to hard, slightly, moist. 2 ' 3 BG 4 Silty SAND — tan, dense, SM o • moist. 5 ° • ° • ® s BG 6 0 ® • • e • o • o • • • 7 ® a ° • • • 8 • e • • • 9 • ® • • o 10 • ® • O 0 • • o • 0 0 I Test pit terminated at 11 feet BGS. 12 I 13 I E i 14 tE E 15 Client: Test Pit Number: TP-8 EXPLORATORY Project: B06167A Date Excavated: 8-7-2006 TEST PIT LOG E Backhoe: CASE 580 SUPER Bucket Width: 2' €q ,, Gyi,� ;�u nquir3i p Sheet 1 of 1 Depth to Groundwater: N/A Logged By: BN _ T REMARKS AR d U Coil m O�. CL .N CV > USCS DescriptionL L2 Note: BGS = Below Ground n E Surface a SILT (Fill) — brown, firm, ML Moderate vegetation slightly moist. With grass and organics observed clippings. to 4 feet BGS. 1 G 2 B 3 Sandy SILT (Native-)— tan, ML firm, slightly, moist. BG Moderate cementation Silty SAD — tan, dense,'- SM • • • observed from 5 to moist. • ® • 6.5feet BGS. • o • Silty SAND with Cobbles — SM ® . tan, dense, moist. ® • 7 ® o ° o • 8 • . • Maximum cobble size • ® • 12 inch diameter. Poorly—Graded SAND with SP ° ® • Cobbles — tan, dense, moist. ' ® ° • Test pit terminated at 10 feet BGS. i 11 i 12 13 i 14 I 15 Client: 411111,11111110 Test Pit Number: TP-9 EXPLORATORY Project: 806167A Date Excavated: 8-7-2006 TEST PIT LOG Backhoe: CASE 580 SUPER Bucket Width: 2' . C'tOt� ?=ti[x ez�A.vu6✓rttnwtte,.xit;' Depth to Groundwater: N/A Logged By: BN 0 �-[' a ^''°r Sheet 1 of 1 ('s E f e w REMARKS .N J COO Q�Iv N O N USCS Description N �> a N o g o Note: BGS = Below Ground � 43 o c ° a E Surface Clayey SAND (Native) — SC •• 0 4.5+ Moderate vegetation brown, dense, moist. ON, • ° and organics observed ® • ° to 6 inches BGS. • 1 • °• • o • • • •®• �g� 19 18.5 1.5-1.0 Atterberg Limits: LL=37, P1=18 Lean CLAY with Sand — tan, CL stiff, moist. 3 rB G Silty SAND with Gravel — tan, SM • • • dense, moist. • ° • • • • 5 e • ° • • ° • a e • o . 6 • • • • • • ° • • ° e 7 ° tl ° • • • o • • • • o 8 • • • ® ® • e • • ° e O ° • 9 ® • ® e ° • • • • r e o 10 0 s • e Test pit terminated at 11 Standpipe piezometer feet BGS. installed to 11 feet BGS. 12 I 13 i 14 15 Client: ONNOW Test Pit Number: TP-10 EXPLORATORY Project: B06167A Date Excavated: 8-7-2006 - TEST PIT LOG Backhoe: CASE 580 SUPER Bucket Width: 2' VE O�SIn:kN[MCabktiP6[NTLN AG TRiMd N Sheet of Depth to Groundwater: N/A Logged By: BN nr�rxyfca {tr�e�;W+.rylUr i i _ i ^ REMARKS N LEA J. p, •�O N .s-. C .� USCS Description T o N o 0 0 Note: BGS = Below Ground Surface Leon CLAY — brown, hard, CL Moderate vegetation moist. and organics observed to 6 inches BGS. 1 4.5+ Moderate cementation observed from 1.5to FB G 3.5feet BGS. Sandy SILT — tan, firm, ML 4.5+ slightly, moist. 3 i y — on, ense, e moist. 4 s °o • o ® • o • • e o • o • • 5 o e o ® • 0 oe • oo • Poor y—Gra ed GRAVEL witF GP Sand — tan, dense, moist to saturated. 7 p 8 9 Test pit terminated at 10 feet BGS. 11 12 13 14 15 Client: Test Pit Number: TP-15 EXPLORATORY Project: B06167A Date Excavated: 8-7-2006 TEST PIT LOG Backhoe: CASE 580 SUPER Bucket Width: 2' Sheet 1 of 1 Depth to Groundwater: N/A Logged By: BN I I _ w REMARKS USCS Description n U3� M a n N ; o CL v o , Note: BGS = Below Ground N v`zi~ z o c ° a E Surface U � Lean CLAY (Native) - brown, CL Moderate vegetation stiff to very stiff, moist, and organics observed 3.5 to 6 inches BGS. 1 g� 82 18.2 1.5-2.0 Atterberg Limits: 2 LL=30, PI=8 3 1.5-2.0 Silty tan, dense, SMe ® , moist. 4 a ® e e e o e o e e e o 0 0 5 ee ® o ® e Poorly—Graded GRAVEL with GP Sand — tan, dense, moist to 6 saturated. ,0 7 p; ; 8 9 10 Test pit terminated at 11 Standpipe piezometer feet BGS. installed to 11 feet BGS. 12 13 14 15 Client: 1111M Test Pit Number: TP-16 EXPLORATORY Project: B06167A Date Excavated: 8-7-2006 TEST PIT LOG Backhoe: CASE 580 SUPER Bucket Width: 2' ,piR!i'.C7L FN° tNG6a rzhuic lCm+HIL Depth to Groundwater: 8.6 Logged, By: BN `r"'`�"rr " �`. Sheet 1 of 1 il(1 N. Q r� mrn : rnm, rn �r _ . a C i +ual T- ` co o rn Ila M. n an - r - N � 0 � n 06. r g n d a t- nN nn _ o o (n � o �..� 2 9 CD IT Off' � - a- i d cod o _ cn 1 Q Wl N ~ QUIT- LN, N LM IN d r (0t� 4 ki .......... 4 f i E 4 3 E