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HomeMy WebLinkAbout020 Appendix L - Geotech Report 4c- CASTLE ROCK CIVIL & GEOTECHNICAL ENGINEERING PROJECT` 2020-The Lakes at Valley West(South) Bozeman,Gallatin County Montana CLIENT: The Lakes at Valley West Bozeman, LLC P.O. Box 1113 Suite 179 Bozeman, Montana 59715 PROJECT NO.: 020025CR DATE: April loth,2020 Executive Summary This report is to serve as record of the subgrade investigation and geotechnical recommendations prepared for the 2020-Lakes at Valley West. The Client requested the Geotechnical Evaluation in February, 2020 in phone correspondence for the above-referenced site. The purpose of the investigation is to evaluate the subsurface soils and current groundwater conditions, and to determine suitability and characteristics for proposed construction of the new phase of the Lakes at Valley West subdivision. Castle Rock Geotechnical has prepared 'Study of Grounds' (geotechnical) reports for multiple phases of the Lakes at Valley West Subdivision since 2014. This report will utilize information from the March 2020 field investigation. The 2020 geotechnical information within will be used in consideration of subgrade improvements, residential building foundations, finished grading and street and stormwater infrastructure. It is assumed that the majority of buildings will utilize an earthen supported,concrete foundation with concrete footing wall and slab on grade or crawl space. The legal description is 'located in a portion of the Southwest Y of the Northeast%of Section 9,Township 2 South, Range 5 East, of the Bozeman, Montana Quadrangle in Gallatin County'. The Property Record Card records the Primary Owners as Norton Properties LLC and the Subdivision as Norton East Ranch Subdivision Phase III, Plat J- 564. The site is located on the north side of west Babcock Street between Pond Lily Drive and Water Lily Drive. The Vicinity and Topographic Map are shown in Figure 1 of the report. The geotechnical evaluation was completed in general accordance with standard industry practices. Summary of Subsurface Findings The majority of ground surface consists of wild native grasses, cattails and willows, though a large part of the southeast portion of the property has been used for construction activities such as mining of gravels. See Figure 2, Test Hole Map. No recent aerial photos could be found to show the exact size of the mining activity and depth the excavated pits, since high groundwater has filled in the burrow pits. The aerial photo, Figure 2 shows the approximate boundaries of the disturbance due to mining activity but also stockpiled earthen spoils and some construction debris. This area will require significant resources to remove deleterious materials,soils such as topsoil P.O.Box 6217,Bozeman,Montana,59771 PHONE:(406)209-5573 CELL:(406)221-7236 2020-Lakes At Valley West SOG Bozeman MT April 101h 2020-Project: 020025CR or concrete debris, and unwanted clay and organics from the site. It is believed that the portion of this disturbed ground can be reclaimed for building lots once the earthen spoils and debris placed upon native grounds is removed. It is also believed that the burrow pits can be made into lakes that are landscaped and become part of the subdivision. The following subgrade summary is primarily for the'non-disturbed'grounds that were mostly used as Non-Qualified Agricultural Land. Depth to stiff alluvial fan type gravels is observed on average 50 inches below top of existing grade. Depth varies from location to location+10 inches. A thick dark brown topsoil horizon is found from 12 to 24 inches thick USCS symbol (OL). The topsoil is underlain by brown lean clay loam USCS symbol (CL) which is from 10 to 24 inches thick depending on location. The brown lean clay loam is underlain by 5 to 10 inches of brown-rust'lean clay'with gravels USCS,symbol (GC)or'fat'gray clay USCS Symbol(CL or CH). The gray clay is approximately 6 inches thick and typically underlain by poorly graded gravels with sand and pebbles USCS symbol (GP). The alluvial gravels were excavated several feet before groundwater inundated the pit. Groundwater was typically suppressed by the overlying clay and is estimated to be 36 inches below top of pre-development grade. Very little gray clay (hydric soils)was observed and when observed it was in locations where high groundwater exists for prolong periods of time and where soil mottling is occurring(redox depletion). See hydric soil rating in the NRCS data supplied. The grounds profiled in the test pit investigation match well with research information from the Montana Bureau of Mines and Geology and Department of Agricultures, Natural Resources and Conservation Service (NRCS) Data . This information will be shared in the report and NRCS soil documents are found in the Attachments at the end of the report. Summary of Observations&Recommendations for Residential Building Site Lots Based on the field investigation, and subsurface soil and conditions the following recommendations should be considered for residential construction. Each building will require a structural pad consisting of 1 inch diameter washed rock being placed upon approved native alluvial gravels 1 foot above existing groundwater elevations. On the washed rock 18 inches minimum, 3 inch minus pit run gravels is to be placed so that footing elevation is a minimum 20 inches above high groundwater. (Structural fill for any other need on this project can be either on-site processed, 3 inch minus pit run gravels containing less than 10%non-plastic fines and/or imported 3 inch minus pit run gravels.) Summary of Road Recommendations Dewatering will be necessary and will have to be continuous during road construction. Top of road grade (Surface Course) is assumed to be top of predevelopment grade. • All roadways are to be cleared and grubbed, removing organics and roots while stockpiling topsoil. • All native lean clays are to be removed down to native alluvial gravels,the road foundation material. J L l P.O.Box 6217,Bozeman,Montana,59771 _ _C:(400_209`5573 0:14061221-7236 2020-Lakes At Valley West SOG,Bozeman MT April&h,2020-Project: 020025CR • The native gravels(road foundation material)should be compacted to 95%of the native soil's maximum dry density and+3 percent of its optimum moisture content. • A loaded double axel dump truck should drive upon the road foundation after compacted and areas that are not firm but deflect or fail under the wheel load during these maneuvers should have the soft or yielding materials removed and replaced with competent structural fill placed and compacted. The road foundation should be re-tested until firm. • Once the entire roadway foundation is firm it should be covered with 6 inch minus sub-grade ade material placed in 12 inch lifts up to 19 inches below top of road grade. All road sub-grade material should be compacted to 95 percent of the material's maximum dry density and±3 percent of its optimum moisture content. • Upon the sub-grade material 12 inches of 3 inch minus pit run gravels sub-base material should be placed up to the base layer. All road sub-base material should be compacted to 95 percent of the material's maximum dry density and±3 percent of its optimum moisture content. • The base course is to consist of 3 inches of%inch diameter crushed aggregate compacted. • The base course is to be covered with 4 inches of hot plant mix surface course. General Other utility recommendations are given within the general report. All newly excavated grounds are to be observed and approved by the Geotechnical Engineer that prepared the Report. The Client inherits all site conditions and work not observed and approved by the Geotechnical Engineer. Construction observations and records by the Geotechnical Engineer are required. Please refer to the attached report for more detailed results of our fieldwork, engineering analyses, and recommendations. For greater understanding concerning Geotechnical Engineering Reports, please read Important Information about Your Geotechnical Report found in the Attachments. Castle Rock Geotechnical Engineering is a member of the Geoprofessional Business Association (GBA). Thank you for using Castle Rock Geotechnical Engineering. If you have any questions regarding this report,or require our services during the construction phase of this project, please call Andrew Pilskalns at(406)539-8439. Sincerely, Andrew Pilskalns,PE Geotechnical Engineer Attachment: Geotechnical Report 3 P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG.Bozeman,MT April 10`h 2020-Proiect• 020025CR Contents ExecutiveSummary..........................................................................................................................................................1 Summaryof Subsurface Findings.................................................................................................................................1 Summary of Observations&Recommendations for Residential Building Site Lots.....................................................2 Summary of Road Recommendations..........................................................................................................................2 General.........................................................................................................................................................................3 A. Introduction.................................................................................................................................................................6 A.1. Project...................................................................................................................................................................6 A.2. Purpose of this Evaluation ....................................................................................................................................7 A.3.Scope..........................................................................................................................................................•..........7 A.4.Test Hole Investigation(2020)..............................................................................................................................7 B.Field Investigation........................................................................................................................................................7 B.1. Logs.......................................................................................................................................................................7 B.2.Geologic Conditions............................................................................................................................................ 10 B.3.Soils.....................................................................................................................................................................12 B.3.a.Topsoil.......................................................................................................................................................... 14 B.3.b.Quaternary Gravels...................................................................................................................................... 15 B.4.Groundwater Observations................................................................................................................................. 15 B.4.a Groundwater Research.................................................................................................................................. 15 B.S.Laboratory Tests.................................................................................................................................................. 15 C.Analyses and Recommendations................................................................................................................................ 16 C.1. Proposed Construction........................................................................................................................................16 C.2.Discussion/Foundation Consideration................................................................................................................ 16 C.3.Site Preparation................................................................................................................................................... 18 C.3.a.Clearing&Grubbing..................................................................................................................................... 18 C.3.b. Backfill and Fill Criteria.................................................................................................................................19 C.4. Building Foundations...........................................................................................................................................19 C.4.a.Depth............................................................................................................................................................ 19 C.4.b. Footing Sub-Grade........................................................................................................................................ 19 C.4.c.Bearing Pressure...........................................................................................................................................20 C.4.d.Anticipated Settlement................................................................................................................................20 C.4.e. Reinforcement..............................................................................................................................................20 C.4.f.Foundation Wall Backfill................................................................................................................................20 C.4.g.Seismic Design Considerations.....................................................................................................................20 C.S.Earth-Supported Slab&Crawlspace...................................................................................................................21 C.5.a.Sub-Grade.....................................................................................................................................................21 C.5.b. Fill.................................................................................................................................................................21 C.5.c. Backfill...........................................................................................................................................................21 C.5.d.Vapor Retarder and Vertical Water Protection............................................................................................21 C.5.e.Leveling Course and Sub-Grade Modulus....................................................................................................22 C.6. Exterior Slabs.......................................................................................................................................................22 C.6.a.Sub-Grade.....................................................................................................................................................22 C.6.d. Bearing Pressure&Lateral Load Resistance................................................................................................24 C.7.Utilities................................................................................................................................................................24 C.7.a.Materials.......................................................................................................................................................24 C.7.b.Backfilling and Compaction..........................................................................................................................25 C.8.Site Grading and Drainage...................................................................................................................................25 C.9.Concrete..............................................................................................................................................................25 D.Construction...............................................................................................................................................................25 D.I. Excavation...........................................................................................................................................................25 D.2.Observations.......................................................................................................................................................26 D.3. Moisture Conditioning........................................................................................................................................26 4 P.O.Box 6217, Bozeman Montana 59771 C:(406)209-5573 0:006)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 10`h 2020-Proiect: 020025CR DATesting.................................................................................................................................................................26 D.5.Cold Weather Construction ................................................................................................................................26 E.Procedures..................................................................................................................................................................27 E.1.Test Hole Excavation............................................................................................................................................27 E.2.Soil Classification.................................................................................................................................................27 E.3.Groundwater Observations.................................................................................................................................27 F.General Recommendations........................................................................................................................................28 F.1. Basis of Recommendations..................................................................................................................................28 F.2. Review of Design .................................................................................................................................................28 F.3.Groundwater Fluctuations...................................................................................................................................28 FAUse of Report.......................................................................................................................................................28 F.5. Level of Care........................................................................................................................................................29 ProfessionalCertification...............................................................................................................................................29 References......................................................................................................................................................................31 Definitions......................................................................................................................................................................32 5 P.O.Box 6217 Bozeman,Montana 59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West 50G,Bozeman MT April 10`h.2020-Project: 020025CR A. Introduction A.1. Project The work as we understand it is to perform a geotechnical investigation on the proposed new phase of development for the Lakes at Valley West Subdivision. This report is to serve as a record of geotechnical information obtained as a result of research, field observations, and field testing for the above referenced phase of the project. Preliminary recommendations made within are based upon this information as well as experience with multiple phases of this development since 2014. The geotechnical information presented within this report is to be used by the Client to make educated decisions regarding the development of the subdivisions. Recommendations for subgrade improvements of individual lots are subject to change based on grade and soil conditions observed at the time of home construction.To determine subgrade improvements per lot site investigations are recommended. The foundation design for each residential building is assumed to consist primarily of a concrete footing wall with a slab on grade and crawlspace foundation. The Property Record Card records the primary owners as Norton Properties LLC and the Subdivision as Norton East Ranch Subdivision Phase III, Plat J-564. Note that only the east portion of the plated property was studied. The area of interest is located on the north side of West Babcock Street between Pond Lily Drive and Water Lily Drive as shown in Figure 1, Vicinity and Topographic Map. The legal description is 'located in a portion of the Southwest% of the Northeast%of Section 9, Township 2 South, Range 5 East, of the Bozeman, Montana Quadrangle in Gallatin County'. The property is 4800 feet above sea level and approximately 40 acres in size. Please note the marked location shown in Figure 1 which shows the general boundary of the project and labels the property as Lakes at Valley West(South)since the project is south of the Lakes at Valley West existing development. For simplicity,the lot can be best described as being a square shape with the northwest corner clipped. The west boundary of the lot is termed the Sewer Utility Road. Vicinity-Topographic Map ,.1, `. Sul�jeirt Property - ti_. '_ a �f v APortion ofth8�-- _ _ -r�en -_ _ !,Farr_A_ Southwest 1/4 of the Northeast 1/4 of Section 9 Township 2 South,Range 5 East of the Bow m ja Montana Quadrangle + T Sr ! \_A l:?- LAKES AT VALLEY WEST '` � _' - ;q r (SOUTH) �:_�.-- ' SCALE!a4 OW COMIM!¢NTtBVAL 9 FR1' 1 - I � p - Figure 1—Vicinity&Topographic Map 6 P.O.Box 6217.Bozeman.Montana,59771 C:(406)209-5573 0:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 101h,2020-Project: 020025CR A.2.Purpose of this Evaluation The purpose of the geotechnical evaluation is to provide geotechnical information to assist Architects and other design professionals in preparing plans and specifications for the proposed new building sites. A.3.Scope The scope of services was outlined in the proposal. The task list is given below. The authorization to proceed was in accordance with the verbal agreement with Greg Stratton. Our scope of services was limited to the following: • Executive Summary • Limited Study of Grounds Investigation with Excavator • Subsurface Soil Conditions • Groundwater Conditions • Test Hole Logs • General Earthwork Recommendations A.4. Test Hole Investigation(2020) Test Hole (TH) locations were selected by Andrew Pilskalns, P.E., Geotechnical Engineer with Castle Rock Geotechnical Engineering. The locations are shown in Figure 2,Test Hole Map. The Test Holes are used to define the subsurface characteristics of the property located just 2 miles west of Bozeman, Montana. The test holes are used to determine the 2020 geotechnical recommendations. Additional subsurface information should be gathered at the time of construction to verify subsurface materials and conditions. Not all subsurface conditions can be seen or know until a site is unearthed; therefore geotechnical hazards or conditions cannot be ascertained until sites are completely unearthed. Revisions to the geotechnical recommendations may be made during construction if hidden subsurface materials or conditions unearthed at the time of construction are observed which have not been accounted for. The Log of Test Holes is in the Attachments at the end of this report. B. Field Investigation B.I. Logs Twenty three Test Holes,TH-1—TH-23, were excavated on the lot as part of the subsurface investigation. The test holes were spatially located on the property to give the best understanding of the site. The investigation occurred on Thursday March 51h, 2020 with Scott Hardy(Sime Construction)operating a Komatsu PC 170 LC steel track excavator for excavation. The number of Test Holes used in an investigation such as this should be adequate and numerous enough to gain a fundamental understanding of subsurface conditions,to ascertain general geo-related risks and be proportional to the value of the development. Given that each building site is a large investment to every potential property Owner, each site should have site conditions approved by a licensed professional Geotechnical Engineer during construction. 7 P.O.Box 6217, Bozeman,Montana 59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West 50G,Bozeman,MT _ April 1&,2020-Proiect: 020025CR The approximate locations of the 23 test holes are shown in Figure 2, the Test Hole Map. The test holes were excavated to depths of 5 feet to 13 feet below top of existing grade at the time of this investigation. The southwest portion of the site was used for mining gravels and dumping of spoils and construction debris. Only a few test holes were completed in the area used for mining and stockpiling of grounds due to uneven, soft surfaces and mounds of dirt,access to locations and open ponds. Soils were described and visually classified utilizing the Unified Soils Classification System, (USCS). In general it could be said that the test holes were similar—a 1 to 2 foot thick topsoil horizon underlain by a 1 to 3 feet thick lean clay horizon underlain by alluvial gravels with groundwater at or 6 inches above where the alluvial gravels were encountered. The alluvial gravels are is 3 inches minus material size, round rock and gravels with pebbles and sand. a •r•X 4wila-t' •y Area + TF c i OPEN PIT VEL MINING AND SOIL SPOIL DEPOSIT AREA Th-13 WITHIN WHITE C• " Test Hole Map Norton • • ' Figure 2—Test Hole Map Along the southeast portion of the site,delineated by the white boundary in Figure 2,in the vicinity of TH-10-TH-12, and TH-22 and TH-23, open pit mining and stockpiling of soils and construction debris has occurred. Recent aerial images do show the disturbance; however they are not accurate in showing the size of mining activity since they are several years old. It is our understanding that the pits will be landscaping features transformed into lakes and properties can be constructed around the perimeter of the lakes. Test Holes 10, 11 and 12 are likely in a subsurface trough filled with silt and clay. Depth to gravel was not encountered and the materials are alluvial fan deposits. Depth to gravel was over 10 feet deep in Test Holes 10, 11 and 12. In Test Holes 10 and 11 undocumented fill was $ P.O.Box 6217 Bozeman,Montana,59771 C: 406)209-5573 0:006)221-7236 _ 2020-Lakes At Valley West SOG,Bozeman,MT April 101h,2020-Pro'ect: 020025CR observed. It is believed that after 2014 soils were starting to be stockpiled in this open pit mining area and that mining operations were to soon follow. The alluvial gravels and pebbles found approximately 50 inches below existing grade that underlie the majority of the site are rounded from mechanical (gravitational and water forces)and weathering. Well.log data shows that alluvial gravel horizons and similar alluvial deposits are from 40 to 100 feet thick. The fines are washed out of some of these gravel lenses due to what is believed high subsurface groundwater flow over time. Gaps in grading were observed and fines are estimated to be 10% or less. These soils are primarily in pockets where likely old stream channels existed. Footing grade is assumed to be 2 feet below existing grade. Castle Rock Geotechnical is not responsible for determining road surface elevations or finished floor elevations of buildings. All test hole measurements are made from the existing undisturbed top of ground surface downward prior to construction. The grounds slope downward approximately 1 to 2 percent to the south west and all streams are trending in this same direction North 30-West. The topographic map does show that the ground is relatively flat in slope because the contour units are in 20 feet intervals. The area mined for gravel extraction appears to have a similar profile as the other grounds observed. By observations of the cut embankment around the pond,alluvial gravels were observed to be 50 inches below grade. Fines within the soils matrix make up approximately 20%or less of the soil materials. Cobbles, gravels, and sands make up the other materials. Clay and silt fines can absorb moisture, decreasing soil shear strength, which can reduce the overall embankment strength and bearing capacity of the soils. From geologic maps and well logs in the area it is hypothesized that alluvium and colluvial gravels make up the upper 50 feet of ground and deeper. No clay deposits other than mentioned were encountered in the upper 12 feet below the ground during the test hole investigation. Several grab bag samples of the alluvial soils from Test Hole 1 and 14 at 5 feet below grade (gravel foundation material) were field analyzed for shrink swell potential and found to be (NP) Non-Plastic. The lean clays observed above the alluvial gravels were field tested and found to be from moderately to highly plastic and moist (typically above their optimum moisture content) making them very soft. Research data from the Department of Natural Resource and Conservation Services shows that the lean clay has a moderate shrink swell potential. If thick clayey horizons of soil other than those observed are encountered and logged in the 2020 field investigation additional testing should be completed to classify the soils and make recommendations based on findings. Log of Test Holes sheet(s) indicating the depth and identification of the various soil strata and water level information can be found in the Attachments at the end of this report. It should be noted the depths shown as boundaries between the strata are only approximate. The actual changes may be transitions and the depths of the changes vary between test holes. All measurements in the test holes are taken from the top of existing ground at the time of the March 2020 investigation downward. Figure 2 —Test Hole Map shows the approximate test-hole locations within the building footprint. Geologic origins presented for the stratum recorded on the Log of Test Hole sheet are based on the soil types and available knowledge of the depositional history of the site. Because of the complex glacial and post-glacial depositional environments, geologic origins are frequently difficult to ascertain. The limited geologic evaluation of 9 P.O.Box 6217,Bozeman,Montana,59771 _ C: 406 209-5573 O:(406)221-7236 _ 2020-Lakes At Valley West SOG,Bozeman MT _ April 10`h,2020-Proiect: 020025CR the site is based on research and test hole information to the depth of the 'limited' excavation investigation. The term 'limited'geo-investigation is used because understanding of ground conditions is based On the limited depth of test holes and research. More comprehensive subsurface information and soil strength can be obtained by drilling and Standard Penetration Testing (SPT) with depth at the Owners request. See Figure 3, Test Hole Map-Depth to Gravels to determine gravel depth at a location in the study area. Tf TH k.Test Hole Map - Depth to Gr�r 5 • Figure 3—Test Hole Map—Depth to Gravels B.2. Geologic Conditions The property topography is described as sloping 1% downhill to the northwest. The most significant topographic feature for this proposed phase is an Baxter Creek which trends in the north-west direction cutting through the east corner of the property. There are also a very large man made ponds centrally located on the east side of the property that has a longitudinal axis exceeding 500-ft. The ponds do not appear on the topographic map shown in Figure 1 or Figure 4. Montana Bureau of Mines and Geology(MBMG) record the geological formation of the property as Qafo—Alluvial- fan deposits, older than Qaf (Pleistocene). An alluvial fan is defined as an outspread, gently sloping mass of alluvium deposited by a stream, esp.in an and or semiarid region when a stream issues from a narrow canyon onto a plain or valley floor. Viewed from above, it has the shape of an open fan, the apex being at the valley mouth (Bates, 10 P.O.Box 6217 Bozeman Montana 59771 _ C:f 406 209-5573 O:(406)221-7236 2020-Lakes At Valley west SOG,Bozeman,MT __ April loth,2020-Pro ect: 020025CR 1984). Alluvium is material deposited by a stream or running water. See Figure 4, MBMG, Geologic Map of Project Area MBMG Open-File Report 648 _, Geologic Map of Bozeman 30'x 60' Quadrangle, 2014 �1 ` on g o jn 10 c Project Locatior i ( �J n Cro 03 � CL � t 7 1 t9! ' o t 1 o ■■ l ),Q. 0 gafo Alluvial Fan Deposit, older Kilometers Miles Q 1 IaEao Braid plain alluvium, older SCALE Figure 4—MBMG,Geologic Map of Project Area Definitions are given from Bates and Jackson, (1984) 'Dictionary of Geologic Terms'for the following geologic terms: Alluvium is soil or sediment "deposited by a stream or running water". Clay is hydrous silicate minerals, essentially of aluminum. They have a monoclinic layered crystal lattice. The extremely small particle size imparts ability to absorb water and ions on the particle surface. Most clay minerals belong to the kaolin, smectite, montmorillonite and illite groups. Colluvium is soils deposited"usually at the foot of a slope, brought there chiefly by gravity". Till is Unstratified drift, deposited directly by a glacier without reworking by meltwater and consisting of a mixture of clay, silt, sand, gravel, and boulders and cobbles ranging widely in size and shape." Loam is "a rich, permeable soil composed of a mixture of clay,silt,sand,and organic matter". A cobble is"a rock fragment between 64 and 256 mm 11 P.O.Box 6217,Bozeman,Montana,59771 C:AW 209-5573 0:AW 221-7236 2020-Lakes At Valley West SOG,Bozeman MT April 10th 2020-Project: 020025CR (2.5 and 10 in.) in diameter." A boulder is "a detached rock mass larger than a cobble, having a diameter greater than 256 mm(10 in.)". The main subsurface geologic feature hidden nearby is the normal fault that passes through Four Corners, Montana which is about 2 miles from the project. The mapping units show that glacial lakes, gravity, water and freeze thaw cycles strongly influence the Gallatin basin development. Remnants of very old stream terraces may be found in dissected country far from any present stream. Along many old established streams lie a whole series of alluvial deposits in terraces—young deposits in the immediate flood plain, up step by step to the very old deposits on the highest terraces.In some places recent alluvium covers older terraces. 8.3.Soils The Natural Resources Conservation Service(NRCS) records multiple soil units in the proposed future phase of Lakes at Valley West Subdivision. The two primary soils as mapped by the NRCS within the area of development are 510B, Medowcreek loam and 748A,Hyalite-Beaverton complex. See Figure 5—NRCS,Soil Map. Suitability ratings for these soils will be discussed. Suitability ratings such as dwellings with basements and without basements, risk of corrosion to both concrete and steel, and water features reports for Soil unit 510B, Medowcreek loam and 748A, Hyalite-Beaverton complex are in the Attachments. The soils mapped by the NRCS in this 2020 Phase study of the subdivision show that the Medowcreek loam has a high risk for corrosion to steel. Therefore, buried metal is to be either stainless steel, epoxy coated, encased in polyethylene wrap or have cathodic protection. The soil units have a moderate risk of corrosion to concrete. Sulphate resistant concrete should be used. 748A, Hyalite-Beaverton complex have a low risk to corrosion to concrete and steel. The other soil units shown on the map are in areas designated as Wet Lands and have a high risk to corrosion to metal as well. The parent material of the soil units mapped in the future Lakes at Valley West, 2020 study are loamy alluvium or alluvium associated with stream terraces or alluvial fans. Alluvium is soils deposited by water and loam is a soil mixture comprised of clay,silt and sand with organic matter. This information is congruent with field findings. Linear extensibility is a measurement of a soil's shrink-swell potential and is considered low if the linear extensibility is less than 3 percent, moderate for 3 to 6 percent, high if 6 to 9 percent, and very high if more than 9 percent. If linear extensibility is more than 3,shrinking and swelling can cause damage to buildings, roads,and other structures. For the soil units mapped in the vicinity of this 2020 Phase study,the linear extensibility varies from 0.00 up to 5.9. The soils within the 748A, Hyalite-Beaverton complex are found to have some moderately expansive soils. It is recommended that all clay soils be removed because they have been found to be overly moist and soft. For the most part the soils are considered to have a low to moderate shrink swell potential and should not be used as engineered fill and only approved backfill. It would not be prudent to construct slabs or other slab elements over the top of the Hyalite Beaverton complex soils. Our analysis and understanding of the subsurface materials and conditions are only to the depth of observations made. 12 P.O.Box 6217 Bozeman,Montana 59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG Bozeman.MT _ April 10`h,2020-Proiect: 020025CR The Plasticity Index for the gravels that underlies the lean clays (loam) is NP, Non-Plastic. The gravelly soils are classified as very extremely gravelly sand, USCS symbol GP. Additional testing may be completed at the time of construction as deemed necessary by the Geotechnical Engineer that prepared this report. Department of Natural Resources and Conservation Project Boundary Project Boundary Area -• for ExtractionGravel • stockpiling of undocumented North Figure 5—NRCS—Soil Map Most Type I, II and IV Concrete are sulphate resistant. Sulphate resistant concrete is recommended. The risk of corrosion pertains to the potential soil-induced electrochemical or chemical action that corrodes or weakens concrete or uncoated steel. For dwellings with and without basements, the NRCS rates the suitability of the soil as "somewhat limited"due to large stones,and 'depth to saturated zone'. To avoid all issues associated with soft loam soils and lean clay soils the recommendation is to remove them from the building footprint and to construct a solid building pad out of structural fill where finished footing elevation is above high groundwater and water elevations that may flood the crawl space. Basically,the higher the footing elevation is,the lower the risk of moisture issues to the crawl-space of the structure. I 13 1 P.O.Box 6217.Bozeman,Montana.59771 _ C:(406)209-5573 _O:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 10th 2020-Project: 020025CR For the proposed building on this site,it is recommended that steel structural elements in the soils be protected with coatings or have some other cathodic protection. The information from the NRCS correlates well with information for the field investigation. All of the soil's physical and engineering properties listed above can be found in the Attachments at the end of this report. Castle Rock Geotechnical cannot assume responsibility for the effects of sensitive soils on the building beyond the depth of the"limited"study area and width of the building footprint.The report is based on best information derived from typical geotechnical methods used and project budget constraints. If a more detailed bore study is desired, please contact our office for preparing a bore study. B.3.a. Topsoil In the majority of test holes with exception of TH-10,-12,the first material encountered was very dark loam,topsoil with organics, Unified Soil Classification System (USCS)Symbol(OL-ML)and or(ML-CL).This was underlain by native lean clay loam with clay and silt binder. Standard Penetration Test(SPT)blows per foot"N"was estimated based on experience and difficulty of excavation. The SPT "N" blow count was estimated to be 2 or less with a clay soil consistency of"very soft"for the upper 50 inches of ground and "N"value of 10-30 with a sand soil relative density of"medium"for depths greater than 50 inches below grade within the alluvial gravels. The topsoil can be used only as backfill for landscaping due to high organic content. Table 1 correlates standard penetration test results to Soil Consistency,Undrained Shear Strength and Saturated Unit Weight of the soil. Table 1—Soil Consistence based on SPT Soil Consistency SPT "N"Blow Undrained Shear Saturated Unit Description count Strength "c"-Ib/ft2 Weight (pcf) Very Soft 0-2 <250 <100-110 Soft 3-4 250-500 100-120 Firm 5-8 500-1,000 110-125 Stiff 9-16 1,000-2,000 115-130 Very Stiff 16-32 2,000-4,000 120-140 Hard >32 >4,000 >130 The optimum unit weight of the alluvial gravel soils with oversize correction is estimated to be 135 pcf at a moisture content of 7.0%, which correlates well with the soil consistency description. It is recommended that all topsoil be removed and stockpiled for later use. it is estimated that as much as the upper 24 inches will need to be excavated to remove all topsoil. However, shallower areas may exist. Under no circumstances is construction of subgrade improvements to occur upon topsoil or organic laden soils or soft clay. All organics from tree roots are to be "grubbed out" by excavation and removed from the building footprint. This construction process of removing topsoil, organics and roots is called clearing and grubbing. The soils profile in TH-10 through TH-12 was 4 feet to 6 feet of spoils overlying 2 feet of dark loam underlain by 4 to 5 feet of brown-gray clay loam underlain by gravelly clay. These three test holes were from 10 to 13 feet deep. I 14 I P.O.Box 621Z Bozeman.Montana,59771 __ __ C: 406)_209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG.Bozeman,MT And 10" 2020-Project: 020025CR B.3.b.Quaternary Gravels The topsoil, approximately 24 inches thick, is underlain by native clay soils that are underlain by alluvial gravels with either sand, clay or a silty-clay binder. These soils have a USCS symbol of GP, GM, GC, and often contain a large number of cobbles. No horizons of clean sand were observed with depth. Excavation into these gravels was found to be difficult, which indicates they are very tightly packed. The gravels are within groundwater and can easily be disturbed;therefore excavation near the alluvial gravels is to occur carefully or when groundwater is drawn down several feet below the top of the gravel's horizon. This stratum was given an estimated SPT"N" blow count of 10-30 for a soil relative density of"medium". The stiff gravels were encountered in the upper 7 feet of grounds and are assumed to continue down 40 feet or more. Groundwater was encountered near 36 to 50 inches below grade in all the test holes except TH-10,TH-11 and TH-12 where groundwater was observed as deep as 10 feet below grade. Weeping of the embankments was observed in these three test holes near 55 inches below grade, indicating entrapped near surface moisture in the clay horizon. Field findings correlates well with information researched from the NRCS. B.4. Groundwater Observations Groundwater was observed in all the test holes approximately 6 inches above where the native gravels were encountered. Groundwater in TH-10—TH-12 was significantly deeper due to spoils placed upon the ground. This report is not a detailed groundwater study completed over a period of time but rather, a quick evaluation based on research. B.4.a Groundwater Research Groundwater information was obtained from the Bureau of Mines and Geology, Groundwater Information Center, (GWIC)web mapper. Groundwater in this report is defined as that part of the subsurface water that is in the zone of saturation, including underground streams. It may also be interpreted as all subsurface water as distinct from surface water. The definitions are taken from Bates and Jackson, (1984) `Dictionary of Geologic Terms'. A well log located near the project site recorded static groundwater levels ranging 40 feet below ground surface. Stratigraphy of well logs within the same geologic unit was researched to better understand where subsurface soil units begin and end. The log of GWIC Well Id: 103496, located south of the project lot, shows topsoil underlain by 86 feet of clay bound gravels and chipped rock underlain by 59 feet of shale underlain by sandstone and shale rock sequences down to 400 feet below well casing. Depth of alluvial gravels will vary. The stratigraphy of the well logs described is congruent with MBMG's description of alluvial deposited geologic units and observations made onsite. The well logs described can be found in the Attachments at the end of this report. B.S. Laboratory Tests Laboratory testing of the soils was not deemed necessary due to'in situ'soil conditions, knowledge of the soils from previous projects in the,vicinity, and the similarities of soils observed in the test holes. The optimum moisture content for the poorly graded native gravels is assumed to be 7.0 percent. It is recommended that all spoils used as 15 P.O.Box 6217 Bozeman Montana 59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 10`h.2020-Project: 020025CR backfill be placed at +3 percent moisture content. The desired dry density of the backfill is 95 percent of its maximum dry density. It is recommended that all imported processed 3 inch minus pit run gravels be compacted to approximately 135 pcf. Additional testing may be requested by the Client if they would like to determine the use of either native soils or stockpiled spoils that exist on the property. C. Analyses and Recommendations C.1. Proposed Construction It is assumed that the proposed residential building(s) will be both single and two-story structures with an earth supported concrete footing, stem wall with crawl-space foundation and garage with concrete slab on grade. Castle Rock Geotechnical does not determine finished floor elevations. The finished grounds around the outside of the building should have positive drainage. Positive drainage is defined as grounds sloped 5%for the first 10 feet on all sides of the building to prevent flooding of the foundation as prescribed in the 2018 International Building Code. Exceptions are areas that have impermeable surfaces such as concrete pads and paved drives, etc. These surfaces can be sloped 2% positive drainage away from the building. No water is to be allowed to pond within the first 15 feet of the building. All backfill is to be free of boulders and consist of 3 inch minus native gravels. No gravels greater than 3 inches in size are to be placed around the building as backfill. The native materials are alluvial fan deposits and have slow to high permeability rates so care must be taken to remove all oversized rock. The assumed loading is as follows: (1)wall loads will be 1 to 2.5 kips per linear foot, (2) interior column loads will be between 30 and 40 kips and exterior column loads will be between 20 and 40 kips,and(3)distributed floor loads will be 150 psf. If the proposed loads exceed these values,finished grades differ by more than 1 foot from the assumed value,or if there are changes to the design,our office is to be informed. Additional analyses and recommendations may be necessary. These assumptions are based on groundwater not being within 24 inches of the bottom of footing. C.2. Discussion/Foundation Consideration Based on the field investigation, and subsurface soil and conditions the following recommendations should be considered. Structural fill will be 1 inch diameter washed gravels and 3 inch minus pit run gravels. The structural fill is to be properly placed on approved alluvial gravels as recommended. Each building will require this structural pad with finished footing elevation above high groundwater. (Structural fill for any other need on this project can be either on-site processed, 3 inch minus pit run gravels containing less than 10% non-plastic fines and/or imported 3 inch minus pit run gravels.) • The building footprint should be cleared and grubbed with all deleterious materials, organics and topsoil being removed. Topsoil should be salvaged, removing large rocks and high density organics and used as landscaping backfill. Topsoil, should be used as landscaping fill only on the exterior of the building once primary backfill has been completed. The topsoil horizon is of very high quality and will make for excellent landscaping backfill. I lb 1 P.O.Box 6217.Bozeman.Montana.59771 C: 406 209-5573 O:(406)221-7236 2020-Lakes At Valle,West SOG,Bozeman;MT April 10"'.2020-Project: 020025CR • Based on our findings and experience it is recommended that within a building's footprint the site be excavated down to native alluvial (non-plastic) gravels. Groundwater may or may not exist during site development depending upon time of the year or diversion practices. • All lean clay soils can be used as backfill next to the building once the concrete has properly cured and sufficiently strong. The native lean clay soils used as backfill should be free of gray clay ( if any is encountered) and placed at its optimum moisture content + 3 percent and compacted to 95 percent of its maximum dry density. • If possible all native alluvial gravels within the building footprint should be compacted and approved by the geotechnical engineer. If groundwater is present it can be temporarily pumped and controlled so that ground improvements can be constructed. Groundwater should be pumped 6 inches below where the native alluvial gravels are encountered. If groundwater is present the native alluvial gravel should not be compacted unless groundwater is lowered 2 feet below where the native alluvial gravels are first encountered. Dewater should be continuous during the construction of ground improvements or contact the GeoEngineer for alternate recommendations. • Based on current groundwater elevation it is recommended that for individual building footprints washed gravel be placed in the building footprint in 12 inch lifts, vibratory plate compacted 1 foot above groundwater. • Once placed the washed rock is to be covered with 18 inches of 3-inch minus non-plastic pit run gravels containing less than 10%non-plastic fines. Engineered fill and Structural fill are interchangeable within the report and defined as 1 inch diameter washed rock or imported 3-inch minus non-plastic pit run gravels containing less than 10%non-plastic fines. • Footing grade should be a minimum 20 inches above high groundwater. • Minimum footing depth and width recommended for single level residential buildings are 8 x 16 inches,with a net allowable bearing pressure of 2,000 Ibs/ft2. See Figure 6,Typical Crawl Space Foundation • Minimum footing depth and width recommended for two level structures proposed are 8 x 18 inches,with a net allowable bearing pressure of 2,500 Ibs/ft2. • The total anticipated settlement is less than 1-inch. • Typical concrete footing,stem-walls,slabs foundations,crawl-space is recommended. • Full basement homes require additional geotechnical considerations. Contact the Geotechnical Engineer for further consultation. 17 P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 0:006)221-7236 2020-Lakes At Valley West 50G Bozeman MT April 10'h,2020-Project: 020025CR • The foundation footing and slab are to bear upon a raft of structural fill and imported processed washed gravels. • It is recommended that all foundation stem walls be insulated. Rigid foam reflective insulation that does not absorb moisture should be used on the interior of the crawlspace or framed basement. Rigid score board, XPS foam insulation or Architectural-board that does not absorb water (or equivalent) should be used. All rigid insulation used on the exterior should be protected with metal flashing to a depth of 6 inches into the ground and should be reflective coated. It is the Contractor's responsibility to ensure that exterior insulation does not interfere with waterproofing membrane adhesive and materials. • Spread footings for 1-story buildings should bear minimum 3-feet below finished grade for frost protection, as required by the Montana State Code. Based on typical construction methods the combination of concrete foundation footing and wall height is typically 42 inches. • Based on groundwater elevations, no footing drains can be installed since there is no place to discharge individual drain system. Ensuring the footing grade is above high groundwater and having a waterproof interior polyethylene barrier installed in the crawl space will ensure moisture protection of the underside of the structure. • To achieve proper grading around the building after the exterior walls have been backfilled, native soils can be placed, moisture conditioned, and compacted. It must be remembered that all backfill placed next to the walls has to be processed native 3 inch minus gravels or imported 3 inch minus gravels. Based on the results of the soil test holes, it is our opinion the native gravel soils found from 38 inches to 55 below grade are stiff and can receive structural fill as designed within. Once the building pad is constructed to the engineer's specification the structural fill is suitable for spread footing foundations or isolated column loads. Surface flooding during excavation work is to be avoided with diversion ditches as needed. No water is to be allowed to pond or pool within a building site during construction. Dewatering may be necessary for each residential construction project. C.3.Site Preparation C.3.o. Clearing&Grubbing It is recommended that the topsoil horizon be removed from the excavation footprint. The excavation footprint is defined as the area of the building and the first 3 feet horizontally around the perimeter of the structure. Topsoil from the excavation may be recovered and used as non-structural fill and landscaping as approved by the geotechnical engineer. All trees with roots are to be grubbed out of the building footprint. No footings should be constructed upon roots. All construction excavation and associated worker safety are the responsibility of the Contractor in accordance with current Occupational Safety and Health Administration(OSHA)regulations. J 18 P.O.Box 6217,Bozeman,Montanat 59771 C:(406�209-5573 O:I406�221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 10t',2020-Proiect: 020025CR Based on the predominant soil types encountered during the field investigation,construction activities are to adhere to Type C,non-cohesive strength soil conditions,in accordance with OSHA regulations, 1:1 embankment(See Section F of OSHA Regulations for slopes of wet soils). Beneath footings and structural columns,sub-excavation is to extend down to native gravels and be replaced with compacted structural backfill. All critical exterior slabs will require frost protection such as polystyrene foam insulation to reduce the effects of frost heave. Isolated critical non-heated exterior slabs are to be constructed upon structural fill with insulation under the entire slab and extend 5 inches from the slab on all sides. A vapor barrier is recommended under all interior slabs or some other form of water block. C 3.b.Backfi0 and Fill Criteria One inch diameter washed rock will be used as structural fill under the footings and slab. One-quarter inch crushed rock can be used as a leveling course under slabs. This is also termed as structural fill material under slabs. Approved soils processed to remove all rock greater than 3 inch can be used as an engineered fill for non-structural elements such as road fill, site grading fill and other projects elements such as based material for sidewalk, parking lots and site grading material. All such fill is to be 3 inch minus material,free of debris, organics, and large cobbles and boulders. Architectural landscaping does not require the large rock to be removed. Boulders are defined as rock 10 inches in diameter and larger. All backfill against the building is to consist of 3-inch minus native gravel, processed. Non-structural backfill will be defined as native spoils processed as 3 inch minus pit run gravels containing less than 10 percent non-plastic fines. All non-structural fill is to be compacted to 95 percent of the soils maximum dry density as determined by ASTM D-698 (Standard Proctor) and moisture conditioned to +3 percent of the soils optimum moisture content. Washed rock is to be placed in maximum 12 inch lifts and vibratory plate compacted and moisture treated to reduce dust. C4. Building Foundations C4.a.Depth It is recommended footings bear a minimum of 4 feet below exterior grades for frost protection or utilize some type of water proof, reflective insulation for frost protection as required by 2018 International Building Code (2018 IBC). Interior footings in heated buildings may be placed immediately beneath the slabs, provided they bear on sub-grade soils as described below. C4.b.Footing Sub-Grade It is recommended spread footings bear on smooth, level compacted 3 inch minus pit run gravels. All grounds prior to placing structural fil are to be level and smooth with all voids filled. Disturbed native pit run soils will be re- compacted prior to placing structural fill. It is recommended all existing soil be removed from beneath proposed footings and slabs and an oversized zone extending 3 feet(horizontal) beyond the outer edge of footings vertically down to native gravels. Deep excavations 19 LP.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 10`h,2020-Project: 020025CR will have to be benched according to OSHA regulations as given within. Sub-excavation will extend down to native pit run soils with structural fill placed up to the desired footing grade after the newly excavated ground is compacted, level and smooth. All roots and organic debris are to be grubbed out from the building footprint. The Geo-Engineer is to approve the grounds prior to placing materials. Upon the engineer's approval the ground can be covered with structural fill. Structural fill is defined as 1 inch diameter washed rock to be placed in 12 inches compacted thickness. It is recommended that all washed rock be compacted in two directions twice with a vibratory plate compactor. Compaction of structural fill should not destroy existing work. Once compacted 3 inch minus pit run gravels can be moisture treated and placed up to footing grade in 12 inch lifts and compacted to specification. All newly excavated surfaces and placed fill are to be approved by the engineering firm that has prescribed the recommendations and those not approved in writing by the Geotechnical Engineering firm that has prepared the recommendations are inherited by the Owner and Contractor. C4.c.Bearing Pressure It is our opinion two story structures with footings placed on structural fill as described above may be designed for a net allowable bearing pressure up to 2,500 Ibs/ft2. (Net allowable bearing pressure is defined as that bearing pressure in excess of the final minimum overburden pressure.) See Figure 6,Typical Crawlspace Detail. C.4.d.Anticipated Settlement It is anticipated that total settlement of foundations designed and placed as recommended above will be less than 1 inch under the assumed loads. C4.e.Reinforcement Sufficient reinforcing steel should be placed in the foundation walls to span isolated zones where foundation support could be lost due to localized settlement, heave of the soils, or installation of subsurface utilities. This will also reduce the widths of cracks created by shrinkage of the concrete and local settlement and heave of the soils. The amount of reinforcing should be determined by the project structural engineer. Sulphate resistant concrete is typically standard practice. C4.f. Foundation Wall Backfill The native pit run soils are to be approved by the engineer prior to placement of non-structural fill. The on-site clay loam, (not topsoil) may be used as backfill if properly conditioned and compacted to 95%of the soils optimum dry density and + 3 percent of the soils optimum moisture content. For garage slabs it is recommended that imported structural fill be placed once all clays are removed. The levels of the exterior and interior backfills should not differ by more than 10 inches during placement or the walls should be braced, otherwise the foundation walls may be displaced or crack. Backfill is to be placed when walls are adequately strong and properly cured. C.4.g.Seismic Design Considerations Based on the results of our subsurface investigation and review of available geologic information, it is anticipated that the upper 100-foot profile is comprised of sedimentary deposits of clays,silts,sands,soft bedrock of gravels and 20 P.O.Box 6217 Bozeman,Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West 50G,Bozeman,MT April 10" 2020-Proiect• 020025CR shale horizons. Therefore, it is recommended to use Site Class "E" (firm soil profile) as defined by the 2018 International Building Code for design. The intermountain seismic belt is a zone with major ground shaking potential. The Bozeman area and surrounding mountains is part of this seismic zone. Seismic activity is possible in the Greater Rocky Mountain Region, which stretches from Canada to Utah with Montana in the middle. Montana is subject to significant seismic activity, and the study site is located in the Intermountain Seismic Belt (ISB). Two of the largest recorded earthquakes in the Northern Rocky Mountains occurred in the Centennial Seismic Belt, a part of the ISB. These were the August 18tn, 1959 Hebgan Lake, Montana, earthquake (M - 7.5), and the October 28th, 1983 Borah Peak, Idaho, earthquake(M - 7.3). Based on the interactive fault map provided by the Earthquake Hazards Program website offered by the USGS, Quaternary Age faults are not located within 15 miles of the project. C5. Earth-Supported Slab&Crawlspace CS.a.Sub-Grade It is recommended that all existing topsoil be removed. Good load bearing gravels are present below the topsoil and clay loam. Therefore,it is estimated that approximately 3 feet or more of structural fill will be needed to achieve the desired footing grade above high groundwater and additional fill, 4 feet to bring up the ground to slab grade. If structural fill is needed, it is recommended to consist of 1 inch diameter washed rock or imported 3 inch minus pit run gravels containing less than 10%non-plastic fines. C.5.b. Fill It is estimated that a minimum 2 to 3 feet of structural fill will be required and placed on native alluvial gravels to bring up the ground to footing grade. However, if additional structural fill is needed for some other use it should be imported 3 inch minus pit run gravels or fill approved by the Engineer. It is recommended that 3 inch minus structural fill materials be moistened to a moisture content of+3%of optimum,then compacted to a minimum of 97 percent of its standard Proctor maximum dry density. If 1 inch minus rock is used moisture conditioning is not required; however vibratory plate compaction is required with rock lifts no greater than 12 inches in thickness. All washed rock should be plate compacted. A minimum of 4 inches of% inch diameter frost free gravels (leveling or choker course)is required under all slabs. C5.c. Backfill It is recommended that backfill in footings and mechanical trenches is moistened to moisture content +3% of optimum and compacted to a minimum of 95 percent of its standard Proctor maximum dry density. All backfill is assumed to be native, 3 inch minus alluvial sandy gravels with some silt and clay that is properly moisture conditioned and screened. C.5.d. Vapor Retarder and Vertical Water Protection 21 P.O.Box 6217 Bozeman Montana 59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG Bozeman,MT _ April 101h.2020-Proiect: 020025CR It is recommended a vapor retarder/barrier(polyethylene)be placed directly upon the crawl space floor or under the concrete slab. (Some coverings, coatings, or situations may require a vapor barrier, i.e., a membrane with a permeance less than 0.01 perm.). Under slab (horizontal) water tight seam sealed 6 mil thickness polyethylene barrier is to be used;which is continuous and permanently attached 12 inches above the interior foundation footing onto the concrete wall. Manufacturer's equivalents or equals products may be substituted. The Contractor should be responsible for installing a water tight moisture barrier in the crawl space of residential building and under slabs so that moisture does not adversely affect any wood or other construction material of the building. The 6 mil vapor retarder/barrier is to be seam sealed water tight and it can be placed over the entire crawl space and mechanically or chemically welded (bonded)to the foundation crawlspace walls complying with all safety for human occupancy requirements. A continuous water tight vapor barrier is recommended under all slabs. See Figure 6. If a more robust water block is used directly under a slab or blindside water proofing is used in basements etc.,the 6 mil polyethylene barrier is not required. C.5.e. Leveling Course and Sub-Grade Modulus It is recommended that a leveling course beneath the floor slabs, preferably consisting of X-inch crushed, frost free base course, be provided. (Actual selection of the leveling course should be determined by the architect/civil engineer). Assuming a minimum of 4 inches of crushed base leveling course is provided, it is our opinion a modulus of sub-grade reaction,k,of 350 pounds per square inch per inch of deflection(pci)may be used to design the floor. C.5.Exterior Slabs C.6.a.Sub-Grade Non-critical exterior slabs may be supported on existing native gravel fill after all topsoil, organics and soft clay have been removed. The Contractor assumes all risk and liability if clay is not removed under slabs. Non-critical slabs require structural fill and a final 3-inches of%-inch diameter washed rock for leveling. Critical exterior slabs,such as those at entrances, require some additional sub-grade frost preparation as described previously and as below. Non- critical slabs built upon native clay soils are subject to freeze thaw and shrink-swell affects and will have very poor performance over time and likely fail quickly. C.6.b. Backfill and Fill Critical slabs require placement of structural fill followed by 4-inches of Y-inch diameter washed rock. Backfill and fill beneath proposed exterior slabs and their oversize zones should be placed in lifts and at moisture content +3% of optimum. It is recommended that all fill and backfill beneath exterior slabs be compacted to a minimum of 95 percent of its standard Proctor maximum dry density. C.6.c.Frost Protection of Critical Slabs Heaving of foundation elements and slabs during the winter are a hazard and a nuisance especially where doors open outward and at other critical grade areas. If the foundation is constructed to have a crawl space or footings, wall, and slab, it is recommended that the interior walls are insulated with R-12 or greater water protected XPS polystyrene. Basically any insulation that gets wet loses its ability to insulate and can become a very costly problem 22 P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 10`h,2020-Protect: 020025CR to remove and replace. Other issues may arise such as mold that can cause health issues. Insulation used in the basement or crawlspace should be projected from getting wet. NOTE: ICRAWLSPACE Flashing I ALL NEWLY EXCAVATED DETAIL \ ` Heated Interior SURFACES ARE TO BE APPROVED BY ENGINEER ..-- 5% for 10 feet �— - f/ / 4 Reflective Insulation- XPS (R-12) Properly Compacted Backfilf f or Moisture Protected Fiber Insulation R-12 4 Damp proofing protection as n prescribed by the 2018 IBC f CraWISjJaCe (2 381ntematienil Building Code�� / / Approved o Structural Fill v 6-mil.Polyethylene Improvements are to Extend 3 Feet �- Beyond Footing, Structural Fill- (Varjes) Continuous under 12 inches of 1 Inch Diam.Washed Rock placed over Building Footprint. - 18 inches of 3 Inch Minus Pit Run Gravels Approved Native Alluvial Gravels Not all subgrade improvements shown in detail. See Engineer Report. No Scale Given Figure 6—Typical Crawl Space Foundation For critical slab frost protection the following methods can be applied. Excavate the footprint of the slab and 4 feet beyond the slab. if a slab abuts a building it cannot be in direct contact because this would cause cold bridging. Vertical water proof insulation will have to separate the slab from the foundation wall. Ten inches of vertical excavation below the slab is required. The base is compacted and made level and smooth with a minimum 2%slope for positive drainage as prescribed by the 2018 International Building Code(2108 IBC). The water proof insulation can be placed directly onto the ground lying flat and smooth and extend 36 inches past the slab. The insulation is to be covered with 4 inches of % inch diameter washed rock. The washed rock and insulation will reduce frost penetration into the underlying sub-grade, utilize the heat of the ground and thereby reduce heave. The leveling course of pea gravel(frost free gravel)is generally required to seat the insulation panels, A minimum of 5 inches of crushed road base material should be placed over the panels to protect them during construction. The slab can be placed directly on the % inch minus gravel. Native topsoil can be placed over the remainder of the pea gravel and compacted with a hand tapper. I l3 I P.O.Box 6217,Bozeman,Montana,59771 C:(4061209-5573 0:(406)221-7236 2020-Lakes At Valle,West SOG,Bozeman;MT__ April loth,2020-Project: 020025CR C.6.d.Bearing Pressure&Lateral Load Resistance It is our opinion footings placed as described above may be designed for an allowable bearing pressure up to 2,000 Ibs/ft2 for footing dimension of 8 inches thick x 16 inches wide for single level homes. The allowable bearing pressure is 2,500 Ibs/ftz for footing dimension of 8 inches thick x 18 inches wide for two level homes. All footings must be a minimum 18 inches away from HIGH groundwater levels. Lateral Load Resistance: Footing drains cannot be installed as prescribed to reduce hydrostatic pressure on structures since there is no place to drain them and in periods of flooding the drain may bring water quicker to undesirable areas. It is assumed that the structure(s) will have a crawl space type foundation. To prevent water issues it is recommended that the building be elevated above high groundwater and flooding. All foundation walls are assumed to be fixed at the top. Both the passive and frictional resistance of the foundation can be assumed to act concurrently. The Structural Engineer may neglect the weight of the foundation and backfill when determining dead loads. When calculating resistance to vertical dead loads the coefficient of friction of the aggregate upon which the foundation is constructed is 0.40 and a passive equivalent fluid pressure of 500 pcf. For short-period loading from wind or seismic loads allowable bearing pressures may be increased by one-quarter. Lateral Earth Pressures coefficients for Processed native 3 inch minus structural fill & 1" diam. washed rock: (1) The active, Ka - 0.31 and.an equivalent fluid pressure is 35 pcf. (2) The passive, Kp— 3.20 and an equivalent fluid pressure of 500 pcf. (3) At rest, Ko - .41 and an equivalent fluid pressure of 55 pcf. (Non-sloped condition) Lateral Earth pressures coefficients for Imported 3 inch minus structural fill will be the same as given for the processed native soils. C Z Utilities C.Za. Materials The potential for sulfate attack is low or negligible and conventional Type II cement may be used according to Table 1904.3 of the 2018 IBC. The soils located on site are rated as having a moderate potential to corrode. It is recommended that crushed gravel road base with a maximum particle size of 3/4 inch or% inch be used as bedding material. On-site soils from the trench excavations can be used as backfill above the bedding if properly conditioned and placed at 95%of the soils maximum dry density as determined by ASTM D 698. Utility depths are assumed to be less than 10 feet. The embankment profile consists of non-plastic granular materials which will require OSHA trenching,and bracing requirements for Type C apply. In addition, native soils are _f 24 _P,O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 0:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman MT April loth 2020-Project: 020025CR not suitable for direct bedding and pipe support. Below 10 feet, rocky soils may be present that may require sub- excavation and replacement with Montana Public Works Standards and Specifications, MPWSS,Type If bedding. C.7.b. eackfilling and Compaction It is recommended that bedding material be thoroughly compacted around the pipes. It is recommended that trench backfill above the bedding be compacted to a minimum of 95 percent beneath proposed footings, slabs, and pavements. Backfilling around and above utilities should meet the requirements of MPWSS. C.8.Site Grading and Drainage It is recommended that the site be graded to provide positive run-off away from the proposed building. It is recommended that landscaped areas have a slope of at least 5 percent for the first 15 feet away from the building, then 2 percent to carry run-off away. To maintain this slope, it is essential that backfill against the foundation walls be adequately compacted. If it is not adequately compacted and stiff,the exterior foundation wall backfill will likely consolidate, settle or experience subsidence and water may pond and soak into the soil, causing settlement and future water issues. All finished grades are to be covered with a minimum 1 foot thick lift of low permeable topsoil that will prevent the easy absorption of water into the grounds around the building. Landscape features such as barriers with washed rock that will entrap surface water are not to be placed around the building drip irrigation and plants shrubs and trees are not recommended within 5 feet of the building unless in completed isolated growing units where root penetration will not damage the soils or foundation supporting the building. No permeable landscaped surfaces are to be within 10 feet of the building. C.9. Concrete It is recommended that cement meeting the requirements of ASTM C 150 Type II be used to provide moderate resistance to sulfate attack. It is recommended specifying 5 to 7 percent entrained air for exposed concrete to provide resistance to freeze-thaw deterioration. It is recommended a water-cement ratio of 0.50 or less be used for exposed concrete and a water-cement ratio of 0.45 or less for concrete exposed to deicers. D. Construction D.1.Excavation It is our opinion the soils encountered during our field investigation can be excavated with a steel track-excavator. The test holes indicate medium firm gravel deposits near 50 inches below grade. See Figure 3,Test Hole Log-Depth to Gravels,to determine depth of gravels in th vicinity of a particular location in the new Phase. Soils in the footing excavation will be Type C soils under Department of Labor Occupational Safety and Health Administration (OSHA) guidelines. Existing fill will be Type B. All earthwork and construction should be performed in accordance with OSHA guidelines. Dewatering during infra-structure construction will be necessary. For residential home construction it may or may not be required depending on several factors at the time of construction. The geotechnical engineer should be consulted for each site on how to proceed with residential construction dewatering. It is recommended that flow-on the site during excavation not be allowed. Road ditches, spoil piles, and diversion ditches are to be in place to 25 P.O.Box 6217 Bozeman,Montana,59771 _ C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG.Bozeman,MT Aoril 101h 2020-Proiect• 02002SCR prevent stormwater flow onto the site. A construction dewatering permit may not be required during residential construction if proper construction methods are adhered to. Montana Law requires a Storm Water Pollution Prevention Plan for infrastructure development. Castle Rock Geotechnical is a SWPPP Administrator and our office can be contacted to assist in providing a Storm Water Pollution Prevention Plan if needed. The pollution prevention plan implements measures such as constructing accesses from 3 inch minus pit run gravels to prevent soil debris,fines from going onto public roadways and washing into road storm water gutters and natural bodies of water and rivers. D.2.Observations All newly excavated ground and subgrade improvements are to be observed and approved by the Geotechnical Engineer who prepared the report and recommendations, prior to footing construction. All grounds and conditions and subgrade improvements not observed and approved by the Geotechnical Engineer in writing will be inherited by the Owner. Castle Rock Geotechnical is not responsible for unapproved work. The removal of topsoil and any undesirable material from beneath proposed building footprints is also to be verified by the engineer. D.3.Moisture Conditioning On site native soils that will be excavated and reused as backfill appeared to be well above the soil's optimum moisture content. It is anticipated that it will be necessary to dry them out or during hot months, moisture condition these soils to achieve the desired optimum moisture content. It is anticipated that imported fill and backfill materials will be below the soil's optimum moisture content and additional moisture will be necessary to achieve the desired moisture content near or slightly above optimum. All native or imported soils used as backfill are to be tested for moisture content and density when installed. D.4. Testing Density tests of fills and backfills placed beneath footings, slabs, and pavement should be completed however not required if proper equipment is implemented and compacting as prescribed within. It is recommended that density testing be conducted on the compacted pavement, sub-base, sub-grade, and gravel base courses. All density tests are to be completed with certified Troxler 3411-B nuclear gauges with 8-inch rod or equivalent. It is recommended that slump, temperature, air content, and strength tests on Portland cement concrete be performed. Samples of proposed backfill and rill materials should be submitted to our testing laboratory at least 5 days prior to placement on the site for evaluation and determination of their optimum moisture contents and maximum dry densities. All backfill placed that is not properly compacted is inherited by the Contractor. It is recommended that density testing of the asphaltic concrete pavement be performed (cores and nuclear density gauge). The maximum density of the asphaltic concrete mix should be determined by ASTM D 2041 (Rice). It is also recommended that Marshall tests of the asphalt mix be performed to evaluate strength and air voids. D.5. Cold Weather Construction If site grading and construction is anticipated during cold weather, it is recommended that good winter construction practices be observed. All snow and ice is to be removed from cut and fill areas prior to additional grading. No fill 26 I P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG Bozeman,MT April 10th,2020-Pro'ed: 020025CR should be placed on soils that are frozen or contain frozen material. No frozen soils are to be used as fill. The Contractor should be prepared to protect the site from freezing and/or flooding. Concrete delivered to the site should meet the temperature requirements of ASTM C 94. The concrete should meet all specifications strengths as prescribed or set forth by the Structural Engineer such as slump,water content,and air entrapment and for any additional additives that may be required. Concrete is not to be placed on frozen soils or soils that contain frozen material. Concrete is to be protected from freezing until the specified strength is attained. Frost should not be permitted to penetrate below footings bearing on frost-susceptible soil since such freezing could heave and crack the footings and/or foundation walls. All concrete should have a minimum (2) cylinder samples for every 150 cubic yards of concrete placed (more may be required by the Structural Engineer)with concrete sampled by a trained professional adhering to the following ASTM requirements for Concrete Test Cylinders. Please reference: • ASTM C 31,Standard Practice for Making and Curing Concrete Test Specimens in the Field • ASTM C 39,Standard Test Method For Compressive Strength of Cylindrical Concrete Specimens • ASTM C 172,Standard Practice for Sampling Freshly Mixed Concrete • ASTM C 617,Standard Practice for Capping Cylindrical Concrete Specimens. Concrete cylinders can be tested at 28 days for compressive strength to determine it meets the requirement of the specified strength for the job. E. Procedures E.1. Test Hole Excavation The investigation occurred on Thursday March 5tt', 2020 with Scott Hardy (Sime Construction) operating a Komatsu PC 170 LC steel track excavator for excavation. Observations of the embankment profiles were conducted in accordance with standard geotechnical engineering practices. Excavation proved to be without incident once the test hole locations were located by the Engineer. Additional excavated bore holes may be necessary during construction as deemed necessary by the Client or the Geotechnical Engineer. E.2.Soil Classification Andy Pilskalns,P.E.visually and manually classified the soils encountered in the test holes in accordance with ASTM D 2488, "Standard Practice for Description and Identification of Soils (Visual-Manual Procedures)." A summary of the ASTM classification system is attached. E3. Groundwater Observations Several of the test holes were left open for over one hour after excavation. This allowed ample time for any existing groundwater to enter and stabilize. Groundwater did appear to rise 2 inches higher than what was noticed at the time the hole was excavated. Based on research of existing wells in the vicinity of the project site, static groundwater is found from 3 to just over 4 feet below existing grade. If excavation occurs during spring runoff 27 P.O.Box 6217 Bozeman,Montana 59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT Aaril 10`h 2020-Project: 020025CR groundwater could rise a foot,this scenario is highly probable. The test holes were backfilled after final observations were made. F. General Recommendations F.1. Basis of Recommendations The analyses and recommendations submitted in this report are based upon observations obtained from the excavation of test holes performed at the locations shown in Figure 2. Often, variations occur between these test holes, the nature and extent of which do not become evident until additional exploration or construction is conducted. A reevaluation of the recommendations in this report should be made after performing on-site observations during construction to note the characteristics of any variations. The variations may result in additional foundation costs,and it is suggested a contingency be provided for this purpose. Please contact our office to perform observations during the construction phase of this project. This will allow correlation of the soil conditions encountered during construction to the test hole logs,and will provide continuity of professional responsibility. F.2.Review of Design This report is based on the design of the proposed structure as related to us for preparation of this report. Please contact our office to review the geotechnical aspects of the designs and specifications. With the review, our office will evaluate whether any changes in design have affected the validity of the recommendations, and whether our recommendations have been correctly interpreted and implemented in the design and specifications. F.3. Groundwater Fluctuations Water level observations were made in the test holes at the time of the field investigation,stated on the report. The period of observation was relatively short, and fluctuation in the groundwater level may occur due to rainfall, flooding, irrigation, spring thaw, drainage, and other seasonal and annual factors not evident at the time the observations were made. Design drawings and specifications and construction planning should recognize the possibility of fluctuations and surface flooding. The geologic unit is defined as 'Alluvial Fan Deposits.' These deposits may consist of covered hidden ancient stream beds where water can quickly flow through during spring runoff. The building foundation will act as a dam if constructed unbeknownst near an old channel. Erring on the side of caution would be best practice,which is building above high groundwater. F.4. Use of Report This report is for the exclusive use of The Lakes at Valley West Bozeman, LLC, and Castle Rock Geotechnical Engineering, to use for designing the proposed structure and preparing construction documents. In the absence of our written approval,we make no representation and assume no responsibility to other parties regarding this report. 28 P.O.Box 6217 Bozeman,Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG.Bozeman MT April le,2020-Proiect: 020025CR The data, analyses, and recommendations may not be appropriate for other structures or purposes. It is recommended that parties contemplating other structures or purposes contact us. Castle Rock Geotechnical Engineering cannot assume responsibility or liability for any of the recommendations within, subgrade conditions, materials used, and construction work, or performance of materials that are not observed, tested, and recorded by the Engineer that prepared this report. F.5. Level of Care Services performed by Castle Rock Geotechnical Engineering for this project have been conducted with that level of care and skill ordinarily exercised by members of the profession currently practicing in this area under similar budget and time restraints. The successful completion of the geotechnical engineering of this project is dependent on continued professional geotechnical services to ensure the proper interpretation and intentions of the recommendations herein and to observe the construction phases of the design(earthwork,foundation,site grading). Castle Rock Geotechnical Engineering Inc. is not responsible for quality of "Others" work or interpretation of the recommendations; furthermore no warranty, expressed or implied, is made. Castle Rock Geotechnical is a member of the Geoprofessional Business Association (GBA). To better understand how geotechnical reports are to be interpreted please read Important Information about Your Geotechnical Report found in the Attachments provided by GBA. Professional Certification I hereby certify this report was prepared by me and that I am a duly licensed Professional Engineer under the laws of the State of Montana. ;I�p�tT Andrew Pilskalns, PE Geotechnical Engineer = pILSK al = CASTLE ROCK GEOTECHNICAL ENGINEERING INC. w .X! ` m-al`- c tam 401 9 Cedar Lake Drive n� t/ �.,��+ Butte, Montana �$ Call rti iONAt S 59701 CONTACT INFORMATION C:(406)539-8439 0:(406)209-5573 andv@castlerockerc.com elise@castlerockerc.com Licensed—Montana, Utah,Colorado,Idaho,Wyoming, Hawaii, Nevada 29 P.O.Box 6217,B7 oeman,Montana,59771 C:(406)209-5573 O:006)221-7236 2020-Lakes At Valley West SOG Bozeman,MT April 10`h,2020-Project: 02002SCR ATTACHMENTS References Definitions USCS Soil Classification Chart Property Card Log of Test Holes NRCS Soil Data Important Information about Your Geotechnical Engineering Repot 30 P.O.Box 6217,Bozeman,Montana,59771 C:14061209-5573 O:[4061221-7236 2020-Lakes At Valley West SOG.Bozeman,MT April 10`h,2020-Project: 020025CR References Bates, R.L., and Jackson, J.A. 1984. Dictionary of Geological Terms. American Geological Institute. Anchor Books, New York,571 p. Google Earth 6.2.9200.0. (July 19, 2014) (November 20, 2011) (August 10, 2009) (July 21, 2005) (August 11, 1995). Big Sky, Montana. 45.267311% -111.284837', Eye alt 9907 ft. Borders and labels; roads; 3D buildings. < http://www.google.com/earth/index.html>.Accessed February 22,2016. Susan M.Vuke,Jeffery D. Lonn, Richard B.Berg,and Christopher J Schmidt V.S,2014,Geologic Map of Bozeman 30'x 60'Quadrangles Southwestern Montana,Montana Bureau of Mines and Geology Open-File Report 648,Scale 1:24,000. Lindeburg, M.R., 1999,Civil Engineering Reference Manual for the PE Exam,Seventh Edition: Professional Publications, Inc.,Belmont,35-19 p. Montana Bureau of Mines and Geology, Montana Groundwater Information Center Webpage. Available online at http://mbmggwic.mtech.edu/. Accessed March 18,2019. Soil Survey Staff,Natural Resources Conservation Service, United States Department of Agriculture.Web Soil Survey. Available online at http://websoilsurvey.nres.usda.gov/.Accessed April 03,2020. 31­1 P.O.Box 6M7,_Bozeman Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-Lakes At Valley West SOG,Bozeman,MT April 101h 2020-Project: 020025CR Definitions To assist the reader in understanding site conditions at a point in time,several definitions have been prepared. The terms include pre-development, development, and post-development grades. Other important terms and definitions are listed below. Unified Soil Classification System (USCS): USCS is a soil classification system used in engineering and geology to describe the texture and grain size of soils. Soil: a sediment or other accumulation of mineral particles produced by the physical or chemical disintegration of rock, plus the air,water,organic matter, and other substances that may be included. Soils are a foundation material upon which structures bear. Alluvium(Holocene)—Light gray to light brown gravel, sand,silt,and clay deposited in stream and river channels, on their floodplains, and on low terraces as much as about 6 m (20 ft) above modern streams and rivers. Moderately sorted to well sorted. Larger clasts subangular to well rounded. Composition varies, but includes clasts of Archean metamorphic rocks, Precambrian orthoquartzite, Paleozoic limestone and quartzite, vein quartz, and volcanic rocks. Clasts of some small streams originating in Tertiary uplands are dominantly granule size and smaller,and may include rip-up clasts. Pre-development grade:The topography of the property as observed during this investigation, prior to installation of infrastructure or commencement of additional earthwork activities. The attached soil test logs (test pit) are reflective of the pre-development grade. Development grade: The topography of the property after installation of infrastructure and general earthwork activities. Post-Development grade:The grades of the ground after homes are constructed and backfilled on a property. Overburden/Spoils: Soils that are disturbed by construction activities; including soils that have been placed upon undisturbed ground surfaces. Examples for this site are soils consisting of dark brown silt loam with organics, dark brown sandy gravels,mottled silt,clay loam,and non-plastic sandy gravels. Topsoil: Native soil material consisting of dark brown silt loam with a high amount of organics; usually undisturbed ground's first soil horizon. Topsoil remnants have been observed under spoils across the property. Lot subgrade improvements:Geotechnical recommendations given regarding the development of each residential lot for the benefit of the Builder. Road subgrade improvements:Geotechnical recommendations given regarding the development of subdivision road. Structural Fill: Soil upon which structural elements such as footings,sonotubes,slabs,etc. may be constructed upon. Two different types of material may be used as structural fill: imported 3-inch minus (well graded) pit run gravels with less than 10% non-plastic fines as described in Table 3 of this report, or 1 inch diameter washed rock. Other types of gravels and sand mixtures, USCS soil classification symbol—GP or GW may be used as approved structural fill if approved by the GeoEngineer upon request. Road Fill: Soils used to build the road section upon which may include: 3-inch minus(well graded) pit run gravels with less than 10%non-plastic fines See Table 3 Report. 1Yz minus,94-100 passing 1"sieve,45-80 passing Y2"sieve,25-60 passing No.4 sieve,25-55,passing No.10 sieve. %inch minus,40-70%passing No.4 sieve,2-10%,25-55%passing No.10 Sieve&2-10%passing No.200 sieve. 32 P.O.Box 6217,Bozeman,Montana,59771 C_(406)209-5573 O:006)221-7236 2020-Lakes At Valley West SOG Bozeman,MT April 10`h.2020-Pro'ect: 020025CR Asphaltic Concrete Aggregate—MT Public Works Specification Sieve Size-Type B grading Requirements Sieve Size %Passing Y" 100 %" 80-100 3/8" 70-90 No.4 45-65 No. 10 32-45 No.40 15-25 No.200 4-10 Building Footprint: The entire heated area of the foundation and three feet beyond (horizontally) including garage and covered porches. Road Footprint: width and length of subbase and aggregate footprint (extend a minimum one foot horizontally beyond curb and gutter)for city rural and collector roads as defined by MPW road sections. Soil Pumping: Movement of soils under load due to excess pore water pressure in the soils. Excavation footprint: The building foundation footprint plus an additional 3-feet horizontal around the perimeter. (sometimes interchangeable with Building Footprint) Settlement:is the result of consolidation of soils. Subsidence:is the sudden sinking of soils or gradual downward settlement with little or no horizontal movement. 33 P.O.Box 6217,Bozeman,Montana,59771 C:14061209-5573 O:i406)221-7236 2020-Lakes At Valle,West SOG Bozeman MT_- ---Aril loth,2020-Pro-eCt: 020025CR GEOTECHNICAL TERMINOLOGY GE-UMCHNiCA ENGIMEEMNG CR o Standard D 2497 Classification of soils for Engineering Purposes particle Size Identification (Unified Soil classification System) Boulders.........................over 12" Soif_ClassdKauon- __ Cobbles.............•.............3"to 12" Criteria for Assigning Group Symbols and Group Names Using raborataiy Tests svmbot Group Ma.n� Gravels Gravels Clean Gravels i s ce�c Gw cage s,aaed graYzrs° coarse............................314"to 3" More than 50% t Cu<4 el d5 r GP Poor raded rrvels° fine................................No,4 to 314" COARSE-GRAINED of coarse Less 1>Cc>3 b•s g Sand fraction SOILS rehin6don Gravels with FinesFvlesn�sM asFdt GM sihygravelma Coarse............................No.4t0 No.10 No.4 sieve - medium.........................No.10 to No.40 Mae than 12%firm-r'-"'a ayT- —« g f°,L4 More than 50% + � fine................................No.40 to No.200 retained On Sands Clean sands Cv26an c —SW Well-radedsand" „ _ li silt.................... ............No.200 to 0.005 mm No.200 sieve 50%or coarse C Less than S%fines u;�a "r of eoarse ; SP Poortygraded sand" Clay.................................less than 0.005 mm fraction Sand with Fines " c,a as SM Sdtysand"M No 4sieve M«e than 12%th F1lps aauify as Ll« SC d 4" Relative Densityof BPF=Slows Per Foot ayey sand`' Cohensionless Soils PI>7 a11d Otf Orl« CL ow verytoOSe............................Oto4BPF FINE-GRAINED Slits and Clays inorganic <a« on SOILS uquidlmir • ML SiIILIM loose....................................5 to10BPF kss than 50 OL ore•���<,t+,"LI" medium dense......................11 to 30 BPF Organic 50%or more -- Or�rnksdt . dense...................................31 to 50 BPF passes Slits and Clays! Inorganic ryP CH Fat�r very dense............................over 50 BPF the No.200 sieve w�r, �•Liquid Gmit 50 or more organic liyi�W<drs OH 1 anlc Consistency of Cohesive Soils LY ORGANIC very soft............................0 to i BPF H;`' Primarily organic matte,dark in color,and organic odor PT Peat soft....................................2 to 3 SPF . . •ap•d.r n..°,r.w waA v+t a.r.ns,"ax ca... rather soft.........................A to 5 BPF •e as rerdp w,wed°man a bbm,a bon,vm• caeara abvuap•a ban•b 9m rpm, medium.............................6 to 8 BPF apt u�,�il�pari•<d+ancbpevprwa. rather stiff.........................9 to 12 BPF •tI1MN'Mn 6 b 121 M rt0+,°apt q+rdaa. stiff..................................13 to 16 BPF ovrGltMV+dNdpbor wa,tp 'd AW—pt+ba PW n hoxp aa.W a a Rai avr My .......... NaoldaYrM15W2e% ft20b.aalN,nnnE•awbyaw••rBpn<'"pddmrpa very Stiff................. 17to308PF oP.aa d<oar vadvd aaw anm .r,a ir:e:s.=.so%0=4 2c°.¢.dat.p.ar.o.e,.ve�,d•bvaa1,pep. hard..................................over 308PF .aronasa IGP pa«o{rara+Wy "d vvra."aO Sad'•pta nv zoo d.adv *9-1.W�N.N�hd�CW11MM •w: aaoo.n-s. Moisture Content(MC) •vrrroa.n w�c.add+,n atamt<w•roywc�,.. ew<.ayan bw-••r "n,a<aw"p its sgad ads.npwRrov"P amv. .w�ya aapd -,.,t Description $w6ae s.;a',e„ve."�:°'rt`•0ep "" t •'•'n• ratherdry MC less than 5%,absence sp-sm ';;; of moisture,dusty sPsOPft1rrw;;WQ. cNy moist MC below optimum,but no visible water 60 wet MC over optimum,visible P«aaortmtena6ne edmes I free water,typically below °tlYp ° 0"a /c0 water table 60 — f-0to ot• saturated Clay soils where MC over iteniaralffiPW bLL•75.6. �"e• optimum s MwPt•oMUV,20) wS; V=ow.at trv-Lae e1 Ll•Ialb Pr•7 DastPlwslll-6l USDA Textural Soil Classification 1a 0 20 to ;• d`H sal i ort -- A,4 r - i � 11 , 0+7 _ CLptL a , I e to 40 '`\-- 50 60 70 00 90 HE lip r LIotaouiarl'Llr atl#_•Kaj` O4 t. Laboratory Tests Terminology ' DD Dry density,pcf OC Organic,content% LL Liquid Limit ty,pcf P20oPercentpassing2005ievePl Plastic Limit qu Unconfined compressive strength,psf PI Plasticity Index qp Pocket penetrometer strength,tsf MC Natural moisture content,% WD Wet densi i ty '•s a � s •s a •a � .5 34 P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 O:(406)221-7236 2020-_Lakes At Valley West SOG Bozeman MT April 101" 2020-Pro'ect: 020025CR Log of Test Holes — Page 1 Test Hole 1 USDA Classification Horizon Thickness Groundwater Depth OL,ML—Topsoil 1'-6" - CL — Brown Lean Clay Loam* 3'-0" 410" GP—Gravel w/Sand unknown * Portable static cone penetration tests record the native lean clay loam soils to be soft, 1/8 tonx/sqft. Test Hole 2 USDA Classification Horizon Thickness Groundwater Depth OL,ML—Topsoil 2'-0" - CL — Brown Lean Clay Loam 1'-3" 3'-0" GP—Gravel w/Sand unknown Test Hole 3 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 1'-10" no ML—Silt Loam* 1'-3" 2'-10" GC—Gravels w/Sand-Clay 1-6" GP—Gravelsw/Sand-Clay Unknown ** * Portable static cone penetration tests record the native silt loam soils to be stiff, 1/6 tonx/sqft **Total depth 525". Test Hole 4 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 1'-10" no ML—Silt Loam* 1'-10" no GC—Gravel with Clay 0'-6" 3'-8" GP—Sandy Gravels unknown Test Hole 5 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-0" no ML—Silt Loam* 2'-0" 3'-0" GP—Sandy Gravels Unknown ** * Portable static cone penetration tests record the native silt loam soils to be stiff,0 tonx/sqft **Total depth 5'-0" 35 P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 0:(406)221-7236 2020-Lakes At Valley West SOG;_Bozeman MT AFlril 10`h 2020-Project: 020025CR Log of Test Holes — Page 2 Test Hole 6 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 1'-10" no GP—Very Gravelly 0'-8" GW—Well Graded Gravels unknown Test Hole 7 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil - CL—Brown Clay Loam 2'-3" 3'-10" GW—Well Graded Gravels unknown Test Hole 8 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-0" - CL—Brown Clay Loam 1'-6" 3'-0" GW— ell Graded Gravels Unknown *Total Depth 4'-0" Test Hole 9 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 0'-10" - CL—Brown Clay Loam 2'-0" - GW—Well Graded Gravels unknown 3'-4" Test Hole 10 USDA Classification Horizon Thickness Groundwater Depth CL,ML,CH,OL,GC-SPOILS 5'-0" Weeping at 48" OL,ML-Topsoil CL-Brown Clay Loam 6'-6"** *NOTE:Top of Ground of TH-10 is 7'-0"in elevation than TH-9. ** Limited Reach of Excavator,Total Depth 12'-4" Test Hole 11 USDA Classification Horizon Thickness Groundwater Depth CL,ML,CH,OL,GC-SPOILS 7'-0" - CL,CH—Brown Gray Clay 3'-0" 10'-0" CH-GC Grey Clay w/Gravel 2'-6" * Limited Reach with Excavator,Total Depth, 12-6" I 36 I P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 O:006)221-7236 2020-Lakes At Valley West SOG,Bozeman MT _ April 101h.2020-Proiect: 020025CR Log of Test Holes — Page 3 Test Hole 12 USDA Classification Horizon Thickness Groundwater Depth CL,ML,CH,OL,GC—SPOILS* - CL—Grey Clay Unknown** - *Very soft soils—Embankment collapse at 4'below grade due to high hydrostatic pressure in soils. **Limited Reach of Excavator,Total Depth 12'-6" Test Hole 13 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-0" - CL—Brown Clay Loam 0'-10" - GW—Well Graded Gravels Unknown ** 3'-8" *This Test Hole is 200'north of TH-9 **Total Depth is 5'-0" Test Hole 14 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil - CL—Rust Brown Clay Loam - GW—Well Graded Gravels unknown 3'-0" Test Hole 15 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-0" - CL—Rust Brown Clay Loam 2'-3" - GW—Well Graded Gravels unknown 4'-11" Test Hole 16 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-0" - CL—Rust Brown Clay Loam 2'-2" 3'-9" GW—Well Graded Gravels* unknown *Very Stiff Gravels Test Hole 17 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil - CL—Rust Brown Clay Loam Z'-1" 3'-4" GW—Well Graded Gravels* Unknown Total Depth 4'-6" 37 P.O.Box 6217,Bozeman,Montana,59771 C:(406)209-5573 0:(406)221-7236 2020-Lakes At Valley West SOG Bozeman:MT Ajil l& 2020-Pro;ed: 020025CR Log of Test Holes — Page 3 Test Hole 18 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-6" - CL—Rust Brown Clay Loam 1'-11" * 5'-0" GW—Well Graded Gravels* Unknown** Penetration Resistance 0 tonx/sqft Total Depth 4'-6" Test Hole 19 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-0" - CL—Rust Brown Clay Loam 2'-4" 4'-4" GW—Well Graded Gravels* Unknown Test Hole 20 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-2" - CL—Rust Brown Clay Loam 2'-8" 4'-0" GW—Well Graded Gravels* Unknown Test Hole 21 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil - CL—Rust Brown Clay Loam GW—Well Graded Gravels* Unknown Test Hole 22 USDA Classification Horizon Thickness Groundwater Depth OL,ML-Topsoil 2'-2" - CL—Rust Brown Clay Loam 2'-8" 4'-10" GW—Well Graded Gravels* Unknown Test Hole 23 USDA Classification Horizon Thickness Groundwater Depth GP-Road Mix - OL,ML-Topsoil 2'-0" - CL—Rust Brown Clay Loam 2'-0" - GW—Well Graded Gravels* j Unknown Total Depth—6'-6" 38 P.O.Box 6217,Bozeman,Montana,59771 C:14061 209-5573 O:(406)221-7236 Property Record Card Summary Primary Information Property Category:RP Subcategory:Non-Qualified Ag Geocode:06-0798-09-1-01-13-0000 Assessment Code:OORGG67328 Primary Owner: PropertyAddress: NORTON PROPERTIES LLC 63026 NE LOWER MEADOW DR#200 COS Parcel: BEND,OR 97701-5877 (VOTE:See the Owner tab for all owner information Certificate of Survey: Subdivision:NORTON EAST RANCH SUB PH 3A Legal Description: NORTON EAST RANCH SUB PH 3A,S09,T02 S,R05 E,Lot R1,ACRES 79.3085,PLAT J-564 Last Modified:7/11/2019 1:28:25 PM General Property Information Neighborhood:206.010.B Property Type:VAC_U-Vacant Land-Urban Living Units:1 Levy District:06-035008-7C 08 Zoning: Ownership%:100 Linked Property: Linked Property Link Type 06-0798-09-1-01-14-0000 T 8-Split View f Exemptions: No exemptions exist for this property Condo Ownership: General:0 Limited:0 Property Factors Topography: Fronting: Utilities: Parking Type: Access: Parking Quantity: Location: Parking Proximity: Land Summary Land Type Acres Value Grazing 0.000 00.00 Fallow 0.000 00.00 Irrigated 0.000 00.00 Continuous Crop 0.000 00.00 Wild Hay 0.000 00.00 Farmsite 0.000 00.00 ROW 0.000 00.00 NonQual Land 79.309 4,085.00 Total Ag Land 79.309 4,085.00 Total Forest Land 0.000 00.00 Total Market Land 0.000 00.00 Deed Information: Deed Date Book' Page L Recorded Date Document Number Document Type Owners Party#1 Default Information: NORTON PROPERTIES LLC 63026 NE LOWER MEADOW DR#200 Ownership%: 100 Primary Owner: ..Yes" Interest Type: Conversion Last Modified: 3/22/2016 7:42:49 AM Other Names Other Addresses Name Type Appraisals Appraisal History Tax Year Land Value Building Value Total Value Method 2019 4085 0 4085 COST 2018 38832 0 38832 COST Market Land Market Land Info No market land info exists for this parcel Dwellings Existing Dwellings No dwellings exist for this oarc, Other Buildings/Improvements Outbuilding/Yard Improvements No other buildings or yard improvements exist for this parcel Commercial Existing Commercial Buildings No commercial buildings exist for this parcel Ag/Forest Land Ag/Forest Land Item#1 Acre Type:NQ-Non Qualified Ag Land Irrigation Type: Class Code:1701 Timber Zone: Productivity Quantity:0 Commodity: Units:Non Qual Valuation Acres:79.309 Per Acre Value:51.51 Value:4085 u Ctf u / ..." z t CL _ c o 0 C M wM.s r"' U ` ►_ c c I CU -, ... 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I`O y C - 0 z V �� c '� L.J ❑ ❑ x_ r Q h to Soil Taxonomy Classification—Gallatin County Area,Montana Soil Taxonomy,-Lakes 2020 Soil Taxonomy Classification Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 448A Hyalite-Beaverton Fine-loamy,mixed, 2.5 4.2% complex,moderately superactive,frigid wet,0 to 2 percent Typic Argiustolls slopes 509B Enbar loam,0 to 4 Fine-loamy,mixed, 2.2 3.7% percent slopes superactive,frigid Cumulic Haplustolls 510B Meadowcreek loam,0 to Fine-loamy over sandy 18.8 31.8% 4 percent slopes or sandy-skeletal, mixed,superactive, frigid Fluvaquentic Haplustolls 537A Lamoose silt loam,0 to Fine-loamy over sandy 8.9 15.0% 2 percent slopes or sandy-skeletal, mixed,superactive, calcareous,frigid Typic Endoaquolls 748A Hyalite-Beaverton Fine-loamy,mixed, 26.8 45.2% complex,0 to 4 superactive,frigid percent slopes Typic Argiustolls Totals for Area of Interest 59.2 100.0% usm Natural Resources Web Soil Survey 4/9/2020 E" Conservation Service National Cooperative Soil Survey Page 3 of 5 Soil Taxonomy Classification—Gallatin County Area,Montana Soil Taxonomy,-Lakes 2020 Description This rating presents the taxonomic classification based on Soil Taxonomy. The system of soil classification used by the National Cooperative Soil Survey. has six categories(Soil Survey Staff, 1999 and 2003). Beginning with the broadest,these categories are the order, suborder, great group, subgroup, family, and series. Classification is based on soil properties observed in the field or inferred from those observations or from laboratory measurements. This table shows the classification of the soils in the survey area.The categories are defined in the following paragraphs. ORDER. Twelve soil orders are recognized.The differences among orders reflect the dominant soil-forming processes and the degree of soil formation. Each order is identified by a word ending in sol.An example is Alfisols. SUBORDER. Each order is divided into suborders primarily on the basis of properties that influence soil genesis and are important to plant growth or properties that reflect the most important variables within the orders. The last syllable in the name of a suborder indicates the order.An example is Udalfs (Ud, meaning humid, plus alfs,from Alfisols). GREAT GROUP. Each suborder is divided into great groups on the basis of close similarities in kind, arrangement, and degree of development of pedogenic horizons; soil moisture and temperature regimes; type of saturation; and base status. Each great group is identified by the name of a suborder and by a prefix that indicates a property of the soil.An example is Hapludalfs (Hapl, meaning minimal horizonation, plus udalfs, the suborder of the Alfisols that has a udic moisture regime). SUBGROUP. Each great group has a typic subgroup. Other subgroups are intergrades or extragrades.The typic subgroup is the central concept of the great group; it is not necessarily the most extensive. Intergrades are transitions to other orders, suborders, or great groups. Extragrades have some properties that are not representative of the great group but do not indicate transitions to any other taxonomic class. Each subgroup is identified by one or more adjectives preceding the name of the great group. The adjective Typic identifies the subgroup that typifies the great group.An example is Typic Hapludalfs. FAMILY. Families are established within a subgroup on the basis of physical and chemical properties and other characteristics that affect management. Generally, the properties are those of horizons below plow depth where there is much biological activity. Among the properties and characteristics considered are particle-size class, mineralogy class, cation-exchange activity class, soil temperature regime, soil depth, and reaction class.A family name consists of the name of a subgroup preceded by terms that indicate soil properties. An example is fine-loamy, mixed, active, mesic Typic Hapludalfs. SERIES. The series consists of soils within a family that have horizons similar in color,texture, structure, reaction, consistence, mineral and chemical composition, and arrangement in the profile. Natural Resources Web Soil Survey 4/9/2020 Conservation Service National Cooperative Soil Survey Page 4 of 5 Soil Taxonomy Classification—Gallatin County Area,Montana Soil Taxonomy,-Lakes 2020 References: Soil Survey Staff. 1999. Soil taxonomy:A basic system of soil classification for making and interpreting soil surveys.2nd edition. Natural Resources Conservation Service. U.S. Department of Agriculture Handbook 436. Soil Survey Staff. 2006. Keys to soil taxonomy. 10th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. (The soils in a given survey area may have been classified according to earlier editions of this publication.) Rating Options Aggregation Method:Dominant Condition Component Percent Cutoff.-None Specified Tie-break Rule:Lower Natural Resources Web Soil Survey 4/9/2020 Conservation Service National Cooperative Soil Survey Page 5 of 5 Map Unit Description:Meadowcreek loam,0 to 4 percent slopes--Gallatin County Area, Lakes 2020 Montana Gallatin County Area, Montana 510B—Meadowcreek loam, 0 to 4 percent slopes Map Unit Setting National map unit symbol. 56vt Elevation: 4,200 to 5,950 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 39 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: Prime farmland if irrigated Map Unit Composition Meadowcreek and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Meadowcreek Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile A -0 to 11 inches: loam Bg- 11 to 25 inches: silt loam 2C-25 to 60 inches: very gravelly sand Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat poorly drained Capacity of the most limiting layer to transmit water(Ksat). Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: About 24 to 42 inches Frequency of flooding: None Frequency of ponding: None Salinity, maximum in profile: Nonsaline to slightly saline(0.0 to 4.0 mmhos/cm) Available water storage in profile: Low(about 5.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: Subirrigated (Sb) 15-19"p.z. (R044XS359MT), Subirrigated Grassland (R044BP815MT) Hydric soil rating: No Natural Resources Web Soil Survey 4/9/2020 Conservation Service National Cooperative Soil Survey Page 1 of 2 Map Unit Description:Meadowcreek loam,0 to 4 percent slopes---Gallatin County Area, Lakes 2020 Montana Minor Components Blossberg Percent of map unit. 10 percent Landform: Terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Wet Meadow(WM) 15-19" p.z. (R044XS365MT) Hydric soil rating: Yes Beaverton Percent of map unit. 5 percent Landform: Stream terraces, alluvial fans Down-slope shape: Linear Across-slope shape: Linear Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT) Hydric soil rating: No Data Source Information Soil Survey Area: Gallatin County Area, Montana Survey Area Data: Version 23, Sep 16, 2019 Natural Resources Web Soil Survey 4/9/2020 Conservation Service National Cooperative Soil Survey Page 2 of 2 Map Unit Description:Hyalite-Beaverton complex,0 to 4 percent slopes—Gallatin County Lakes 2020 Area,Montana Gallatin County Area, Montana 748A—Hyalite-Beaverton complex, 0 to 4 percent slopes Map Unit Setting National map unit symbol. 570v Elevation: 4,350 to 6,150 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 39 to 45 degrees F Frost-free period. 90 to 110 days Farmland classification: Farmland of local importance Map Unit Composition Hyalite and similar soils: 70 percent Beaverton and similar soils: 20 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hyalite Setting Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Loamy alluvium Typical profile A -0 to 5 inches: loam Bt1 -5 to 9 inches: clay loam Bt2-9 to 17 inches: silty clay loam 2Bt3- 17 to 26 inches: very cobbly sandy clay loam 3C-26 to 60 inches: very cobbly loamy sand Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water(Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Available water storage in profile: Low(about 4.4 inches) Interpretive groups Land capability classifcation (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT), Upland Grassland (R044BP818MT) Natural Resources Web Soil Survey 4/9/2020 Conservation Service National Cooperative Soil Survey Page 1 of 3 Map Unit Description:Hyalite-Beaverton complex,0 to 4 percent slopes—Gallatin County Lakes 2020 Area,Montana Hydric soil rating: No Description of Beaverton Setting Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material. Alluvium Typical profile A - 0 to 5 inches: cobbly loam Bt-5 to 21 inches: very gravelly clay loam Bk-21 to 25 inches: very cobbly coarse sandy loam 2Bk-25 to 60 inches: extremely cobbly loamy coarse sand Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water(Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Low(about 3.7 inches) Interpretive groups Land capability classification (irrigated): 4s Land capability classification (nonirrigated): 6s Hydrologic Soil Group: B Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Minor Components Turner Percent of map unit. 5 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty(Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No Hyalite Percent of map unit. 5 percent Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear ;5 Natural Resources Web Soil Survey 4/9/2020 Conservation Service National Cooperative Soil Survey Page 2 of 3 | t # Q » » _ _ _ OBEM _ o n =ate Mz 2 ■ zg @ » - * e \% �/ ■ § ■ ■ � 7 2 t ( } < \ > f/ ! JC14 3 / ] t* 2j \ 2 /� ! � . § ) m_� ƒ CD ® f \ ) % § k k £ \ f $ 7 � ■ ■ c a � \ � % $ 2 §� / � 2 ,If7 ® �U-) $ ' §.2 . if». CL � �f ■ � � k z0 k B ■ ■ # & 2020-Lakes At Valley West SOG,Bozeman,MT April 101h 2020-Protect: 020025CR Impoplant IntoI ahout This Geolechnicel-Engineeping Sub ns. claims,and di sputes, While . provided to help. The Ge"rofessional Business Association(GBA) will ttsl likely meet the needs of a civil-uvrks 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-engineerhig 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,gmtechnial-engineeringservicesare performedfora specific exposure to problems associated with subsurface project andpurpose.For example,it is uaiiMythat 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 plincipal cause on e prepared for a paddng garage;and a few b orings drilled during of construction delays,cost overruns,claim, a preliminary study to evaluate site feasibility will=be adequate to and disputes.if you have questions or want more develop geoteehalcal design recommendations for the project. information about arty ofthe issues discussed herein, conrtact you rG BA-member geotechnleaIenginoor. fotiat try air this report If your geotecludcal engineer prepared it: Active engagement in GSA exposes geobechnical 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 remedlation,or natural events like floods,droughts,earthquakes, Provided for this Report or groundwater fluctuations. Geotechnical•englneering services typically include theplanning, collection.Interpretation,and analysis of exploratory data from Note,too,dic reliability of a geotechaical-engineering report an widely spaced borings and/or test pits.Field data are combined be affected by die passage of tine,because of factors like changed with results from laboratory tests of soil androcksamples obtained subsurface conditions;new or modified codes,standards,or from field cxploratiao(dapplicable),observations made during site regulations;or new techniques or took.lfymt are die least bit tmcertain reconnaissance,and historical information to form one or more models about the continued reliability of this report,contact your geotcchnical of the expected subsurface conditions beneath the site.Local geology engineer before applying,he recommendations in it.A minor amount and alterations ofthe site surface and subsurface by previous and of additional testing or analysis after the passage oftlme-if any is proposed construction are also important considerations.Geotechnicai required at all-could prevent major problems. engineers apply their engineering training,experience,andjudgment to adapt the requirements of the prospective project to the subsurface Read this Report in Full model(O. Estimates arc made of the subsurface conditions that Costly problems have occurred because those relying an a geotechnical- will likely be exposed during construction as well as the expected en&ecring report did not.read the report in its entirety.Do_pgl rely on performance of foundations and other structures b eingplanned an d/or an executi ve s ummary.Do tmt read selective elements only..Read and affected by construction activities. refer to the report in ftdl. 'flaeculmination of dim gentecftnlcal-engineering services is typically You Heed to Inform Your Geoteehnical Engineer geotechnical-eagineeringreportprovidingthedataobtained.adiscussion About Change oflhesubsurfacenwdel(s),the engineering and geologic engineering Your geotechnical engineer considered unique.project-spedfictaetors assessments and analyses made.and the recommendations developed when developing the scope ofstudybehind this report anddeveloping to satisfy dte given requirements of the project.These reports may be the confirmation-dependent recommendations the report conveys, titled irwestigatlom explorations,studies,assessments,or evaluations. Typical changes that could erode the reliability ofthis report Include Regardless ofthe title used.the geotechnlcai-engincering report isan t�sethataBcct: engineering Interpretation ofthe subsurface conditions within themnrext tthata affect. or shape; ofthe project and does not represent adase examination,systematic the he sitesclev size configuration,locadon,oricntatioo, Inquiry,or thorough Investigation of a!l site and subsurface condlttons function or weight of the proposed structure and Geotectinkall-Engineering Services are Performed the desired performance criteria for Specific Purposes,Persons,and Projects, the eat ownershiionp. of the design team;or and At Specific Times project ownership. 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-coin minor ones-and request an assessment of their g techrikat-engineering study conducted for a given civil engineer Impact.7begeolechnftal ergfneer who prepared this reportcannot accept 39 P.O.Box 6217,Bozeman,Montana,59771 __ __ C:(406)209-5573 0:1406)221-7236 2020-Lakes At Valley West SOG Bozeman MT April 10tn 2020-ProLect; 020025CR respotrsibilityorBabililyfbrproblans that arise because thegeotech»teal conspicuotulythatymrbe included lhemnteriedforinfarmatio»purposes engineer was trot hrforaitad about deselopmems the engineer otherwise wily.To avoid misusidersiand ng,you may also watt to note that would have considered. `informational purposes'means constructors have no right to relyon 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 projectrequfrements,Including options seleetedfromthercpai%ondy Before construction begins,geotechnical engineers explore a sites from the design dratvlags and specifications.Remind constructors substtrfaceusiagvarioussampllngandtestingprocedures.Geoted1nical that theymsyperform their own studies iftheywant to,andbesimeto engineers cot observe actual subsurfateconditio s onlyat dimespecific allow enough time to permit than to do so.Only then might you be in Iota Units where sanipling and testing is performed.7be data derived from a position to give constructors the Information available to you,while that sampling and testingwere reviewed by your geotechnical engineer, requiring them to at least share some,ofthe financial responsibilities who thou applied prolonionaljudgementto form opinions about stemmingfrom unanticipated conditions.Conductingprebidand subsurface conditions throughout the site Actual sftewide-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 geatechnicalengineer Read Responsibility Provisions Closely to serve on the design tearrithrough project completion to obtain Some client representatives,design professionals,and construciorsdo informed guidance quickly,whenever needed not realize that gootechnical engiaceringis far less exact than other engineering disciplines,Ibis happens in part because soil and rock on This Report's Recommendations Are project sites are typicaifyhetcrogeneous and not manufactured materials Confirmation-Dependent with well-defused engineering properties hike steel and concrete.Tiat 1herecommendations included in this repon-including any options or lack ofunderstanding has nurtured un realistic expectations that have alternatives-are confirmation-dependent.in other words,they are not resulted in disappointments,delays,cost overruns,claims,and disputes. final,became thegcotechnicalengineer who developed them relied heavily To confront that risk,geotechnical engineers commonly include onjudgement and opinion todo to.Ycmrgeotechnical engineer can finalize explanatory provisioas in their reports.Sometimes labeled'limitations," the recommendations wdyrfterobsawig"AWsebsurfkeconiftiont many oftheseprovfsiotsindicate where geotechnical engmeas exposed during construction.Ifthrough observation yourgeotechnical responsibilities begin and end,to help others recognizethelrown engineer confirms that the corxlitionsassumedtoexistactuallydoexist, responsibilities and risks.&adfheseprouisionsdosely.Ask questious. the recommendations can be relied upon.assurnIngno othcrchanges have Your geotechnlcalengincer should respond fully andfrankly. occurred Ylregeotedinictd eiNhwer whoprepared this report caimotassume respansibilftyorliabifityforeonfirnrati4ii-A(miklit raorr nerula►iwu ifjou Geoenvirattmelttal Concerns Are hW Covered fail ro ratabr that engineer ro perform constructfon observwtior_ The personnel.equipment•and techniques used to perform an environmental study- �+hose-one'or"phase-twu environmental This Report Could Be Misinterpreted site assessment-differ signffirmtly from those used to perform a Other design professionals misinterpretation of geotechnical- gooteclutical•engineeringstudy.For that reason,ageotechnieal-engineering enginecring reports has resultedin costly problem.Confront that risk report does not usuallyprovideemironmental findings,con dusions,or by having your geotechnicalengineer serve asa cot tinuingmetnberof recormtrendatiorm,ag,about the likdihoodofencountaingunderground the design team,to: storage tanks or regttlatedcontaminants.Unanticipated itibsurface confer with other design-team members; eavnramrenWpmbleuishaveledtopr*ctf lures.ifyoubavenot help develop specifications; obudned your cm'n environmental information about the project site, review pertinent elements of other design professionals'plans and ask your gcotechnical consultant for a recommendation on how to Stud specifications;and environmental risk-mvvagementguldance. • be available whenever geoteduitcal-engineering guidance is needed. Obtain Professional Assistance to Deal with You should also confrort the risk ofconstruclors misinterpreting this Moisture lnfiItration and Mold report.Do so by retaining your geotechnical engineer to participate in Whileyour geotechnicd 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 die soil Give Constructors a Complete Report and Guldame through building slabs and walls and into the buildinginterlor,where Some owners and design professionals mistakeniybelieve they coif shift it can cause mold growth and material-performauce deficiencies. auuviticipated•subsurface.condidons liability to constructors by Umiting Accordingly,proper implementation of fhegeofechnical engineer's the Information theyprovideforbidpreparation.Tohdpprevent recommendations xdiiLtela tselfbesnffecicnfloprevent the costly,contentious problems this practice has caused,include the nooisfure infiltration.Confront the risk of tnofsture infiltration by complete geotechnical=eng6ueerirtgrepor4 along with any atiaclunents Includingbuflding-envelope or mold specialists on the design tears or appendices,with your contract docunreits,but,becertoin to note Gcotechnical engineers are not building envelope or mold specialists. SE� GEOPROFESSIONAL ASSOCIUM1105ATiG1N Telephone:301/565-2733 e-inafl:infoC�geoprofessiotutl.org tvwtiegeoprofessional.org Comiga 2019 by CAmprofr ianuf Rusnacis Association(GRA).Dupttcsnomrepmdurtimu,orrapyinitofdots docnmen6 in whole min part by any meats wiimsene4 hnriNy prohbrrA.eusptxnitGMi spectbcvanwnperiamioaFxorptL .quoting,.or odxnelse extracting wordaogrram this documentisperrwted only with the sswnaca aPR permunoo of G1W and only forparposes orsdwlady rastardt or book nwkw.Only members ofGBA may use ads document or its wordtag as a comtitmentto oral am ekmrnt nfa report otarry kind Any odwr rush.individud.oroba entity Out so uxs aiisdocum ent wrdmut being a GBA member could be commit"negligent or iatentronsi(faudtaicno misieprmentatioa 40 P.O.Box 6217,Bozeman,Montana,59771 C;(406)209-5573 O:(406)221-7236