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Home My WebLink AboutEngineering Report - StormEngineering Report Stormwater Design Six Range Condominiums June 2022 Submitted to: City of Bozeman Engineering Department 20 East Olive Bozeman, MT 59715 Prepared by: Stahly Engineering and Associates 851 Bridger Drive, Suite 1 Bozeman, MT 59715 (406) 522-9526 Stormwater Plan 1 6/20/2022 Engineering Report Table of Contents General Information and Design Criteria Existing Site Conditions Storm Drainage Plan Description Estimation of Runoff Retention Facilities Storm Event Analysis Pipe and Curb Conveyance Capacity Facilities Maintenance Figures and Tables Figure 1. Vicinity Map Figure 2. Stormwater Plan Table 1. Storm Runoff Calculations Table 2. Retention Basin Capacities Table 3. Drywell Capacities Table 4 Permeable Paver Storage Calculations Table 5. Enhanced Infiltration Capacities Table 6. Pipe Conveyance Capacities Table 7. Curb and Gutter Conveyance Calculations Table 8. Bozeman Rainfall Analysis (1990-2020) Appendices Geotechnical Report Stormwater Plan 2 6/20/2022 General Information and Design Criteria The proposed Six Range Condominiums Development is located on the southwest intersection of West Babcock Street and South Ferguson Avenue. The Six Range Condominiums Development consists of 3 large apartment buildings,4 triplexes, and a smaller commercial building. This project is located on a currently undeveloped 8.64-acre lot, Tract A1 of Minor Subdivision #338. The proposed apartment buildings consist of units ranging from one to three- bedrooms, and each triplex unit will be three bedrooms. The apartment buildings will provide 63 one-bedroom units, 102 two-bedroom units, and 15 three-bedroom units. The four triplexes will provide 12 additional three-bedroom units. The commercial building will provide 2500 sf of office space and 1300 sf of retail space. Stormwater mitigation is achieved by 8 traditional retention ponds in addition to using efficient stormwater management design utilizing Low Impact Design (LID) methodology to retain stormwater under permeable pavers. The LID stormwater mitigation will be designed in accordance with City of Bozeman Design Standards and Specifications Policy for retention/infiltration facilities. Plans are provided showing proposed grading, drainage flow paths, and stormwater retention/infiltration details. The developer’s contact information is: Paine Group Matt Paine P.O. Box 418 Bozeman, MT 59771 Stormwater Plan 3 6/20/2022 Figure 1: Vicinity Map, Bozeman, Montana Existing Site Conditions The Six Range Condominiums Development project is located on the southwest quadrant of Babcock Ave. and Ferguson Ave. and is currently undeveloped. The site slopes slightly to the north at a fairly consistent slope of 1.5%- 2% within the project limits, with some moderately sloped terrain around the drainage ditch that runs along the east side of the site. The adjacent development’s stormwater is currently mitigated by 3 detention and retention ponds located on the perimeter of the site, as well as a drainage swale on the east side of the side along the west side of the Ferguson ROW; this swale conveys stormwater from the south side of Huffine at its intersection with Ferguson. A geotechnical evaluation was conducted by Allied Engineering and is provided in a separate appendix of this submittal. The soil conditions across the site are consistent. The geotechnical investigation revealed that the site consists of predominantly native soils including 12 to 18 inches of topsoil overlaying sandy gravel. Full geotechnical evaluation results are available in the attached appendix. Stormwater Plan 4 6/20/2022 Groundwater monitoring was conducted throughout the 2021 groundwater season. During the initial site evaluation and monitoring well installation, groundwater depths ranged from 5-6’ below existing grade. Based on these results, seasonally high groundwater is assumed to be at least 5’ below existing grade. The site is not located within a 100-year floodplain. Storm Drainage Plan Description The storm drainage plan for the Six Range Condominiums consists of a combination of traditional stormwater retention ponds and LID retention solutions designed to infiltrate stormwater and replicate the natural hydrology of the site. The overall storm drainage plan for the Six Range Condominiums is depicted on Figure 2, attached to this report. The plan shows proposed drainage path flows, mitigation areas, and drainage basins. With development, the site will be divided into 8 primary basins. Basin 1 contains the southeastern portion of the site, extending to the southern edge of Building C. Basin 2 contains the southwestern portion of the site. Basin 4 contains the central portion of the site. Basin 3 is comprised of the northwest section of the site, including the western half of Building A and the adjacent grassed area. Basin 5 includes the central portion of the site including a breezeway/common area. Basin 7 is central-eastern portion of the site and includes a portion of Building C. Basin 6 is along the northern property line and includes a portion of Building C. Basin 8 is located near the northeast corner of the property and includes Building D. Basins 1,2, and 4 are each split into sub basins. These basins each have multiple retention basins referred to as 1A, 1B, 2A, 2B, 2C, 2D, 4A, 4B, and 4C respectively. Storm runoff from Basins 1-8 will be mitigated by retention/infiltration systems located on common open spaces. A 10-yr, 2-hr design storm is utilized for these basins. All retention facilities will utilize enhanced infiltration to improve performance and provide additional storage volume. Runoff from Basin 3 will be mitigated via permeable pavers designed to contain runoff from a 100-yr, 24-hr design storm. Storm runoff from Basins 1 and 8 are planned to retain the 10-yr, 2-hr storm. Basin 1 has adequate storage to hold a 2yr,24-hr storm event (1.4in) and Basin 8 can store a 1.15in storm. Both capacities are greater than the City of Bozeman Design Storm (0.82in) Survivability of LID systems through conventional development is difficult. Erosion control Best Management Practices (BMP’s) will be utilized during construction to reduce the impacts of construction site runoff, until the LID systems are constructed. Stormwater Plan 5 6/20/2022 Estimation of Runoff Runoff estimates were obtained for each sub-basin using City of Bozeman standards. For the stormwater retention calculations, the design storm is a 10- year, 2-hour storm. The Bozeman IDF (Intensity, Duration, and Frequency) curves show a rainfall intensity of 0.41 in/hour for the 10-year, 2-hour storm, totaling a 0.81-inch storm event. For the purposes of sizing conveyance facilities, the design storm is a 25-year event at a time of concentration of 5 minutes. This storm has an intensity of 3.826 in/hour, but due to its short duration, only represents a 0.32-inch event. Table 1 shows the storm runoff calculations for the 8 drainage sub-basins. Specifically, the design uses the volume of the 10-year, 2-hour storm (for retention calculations), and the flow rate from the 25-year event (for conveyance calculations). Table 1 – Storm Runoff Calculations Retention Facilities The site contains 13 basins directing surface flows and roof drains to 8 retention ponds. Table 2 describes the characteristics of each retention basin and total site storage. Table 3 details the number of additional drywells intended for each basin. Drywells will be installed with a connection to underlying gravels for enhanced infiltration rates. Table 2 – Retention Basin Capacities Retention Basin ID 1a 1b 2a 2b 2c 2d 4a 4b 4c 5 6 7 8 Mitigation Type Retention Retention Retention Retention Retention Retention Retention Retention Retention Retention Retention Retention Retention Ponding Depth (ft)1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 Pond Bottom Area (ft^2)288 195 885 529 1389 529 2413 5287 532 1244 1478 1983 505 Pond Top Area (ft^2)2148 1494 2716 1694 3661 1694 3823 7862 1510 2178 2561 3300 2172 Average Ponding Area (ft²)1218 845 1801 1112 2525 1112 3118 6575 1021 1711 2020 2642 1339 Ponding Storage (ft³)1827 1267 2701 1667 3788 1667 4677 9862 1532 2567 3029 3962 2008 Basin Characteristics 1 2 3 4 5 6 7 8 Area (ft²)39451 65101 16554 102947 36228 23790 44266 40770 Area (acre)0.91 1.49 0.38 2.36 0.83 0.55 1.02 0.94 Design ( C )0.60 0.60 0.60 0.60 0.60 0.60 0.60 0.60 Runoff Volume (cf) 10-yr 2-hr storm 1617 2669 679 4221 1485 975 1815 1672 Flow Rate Q (cfs) 25-yr 5-min Storm 2.079 3.431 0.872 5.425 1.909 1.254 2.333 2.149 Stormwater Plan 6 6/20/2022 Table 3 – Drywell Capacities In addition to providing adequate ponding storage, the retention facilities will have enhanced infiltration. Approximately 30% of the surface area of the bottom of each retention basin will have a strip of gravel that extends to native gravel to facilitate infiltration. This design provides superior infiltration as compared to a typical retention basin. The effects of enhanced infiltration have been included in design values, so it is possible for these basins to provide greater mitigation performance than indicated in this design report. Even with the additional mitigation measures, there are no deficiencies in the design storage volumes for any basins. In the greater than design storm event, there is still additional capacity and stormwater will still be contained within the site and will back up into the parking lot via curb scuppers to the north of the individual sub-basins before the water recedes into the retention pond for infiltration. Table 4 – Permeable Paver Calculations Basin 1 2 3 4 5 6 7 8 Total Ponding Storage (ft^3)3094 9823 0 16070 2567 3029 3962 2008 # OF BUILDING DRY WELLS 1 3 1 6 1 0 0 1 Building Dry Well Storage 166 498 166 996 166 0 0 166 # OF POND DRY WELLS 0 3 1 3 2 2 4 1 Pond Dry Well Storage 0 498 166 498 332 332 664 166 System Storage Capacity (ft³)3260 10819 3212 17564 3065 3361 4626 2340 Rain Event Captured (in)1.65 3.32 3.88 3.41 1.69 2.83 2.09 1.15 Parameter Value Length (ft)300 Width (ft)6 Depth (ft)4 Porosity 0.4 Storage (cf)2880 Paver Strip Storage Calcs Stormwater Plan 7 6/20/2022 Conveyance Capacity Stormwater runoff will not be conveyed into any collection system as there was adequate capacity in the individual basins for retention. A new 36” HDPE pipe will be installed to convey flows from the 36” CMPA pipe that empties onto the Six Range site at its southeast corner and connect to the 36” RCPA pipe at the site’s northeast corner. This 36” pipe runs north along Ferguson and empties into detention ponds on the southwest corner of Ferguson and Durston, and eventually released into an unnamed tributary of Baxter Creek. The Six Range site has no basins that will discharge into the new the eastern 36” pipeline; The outlet of Storm Sewer #3 from the Cottonwood Condominiums produces a 25-yr, 5-min flow of 3.04 cfs, but only releases 0.85 cfs into the existing drainage swale1. This flow will be received by the new 36” pipe that the Six Range project will install—using less than 2% of the pipe’s capacity. It is believed that the 36” pipe also conveys stormwater from the south side of Huffine Lane at its intersection with Ferguson; there is approximately 52 cfs of capacity within the new 36” storm main for additional flows that flow into the new pipe. Table 7 – Curb and Gutter Conveyance Calculations Curb and Gutter Capacity Calcs Max Curb Conveyance Req'd (ft^3/sec) 0.80 Right-side Slope X:1 0.06 Left-side Slope X:1 33.00 Channel Bottom Width (ft) 0 Flow Depth (ft) 0.350 Flow Area (ft^2) 2.025 Wetted Perimeter (ft) 11.906 Width 0.044 Hydraulic Radius (ft) 0.170 Manning's Roughness 0.013 Slope (ft/ft) 0.005 Average Velocity (ft/sec) 2.49 Flow (ft^3/sec) 5.04 Curb and gutter & chases are primarily used on the site to direct runoff into the storm sewer network. To ensure the standard curb design will provide adequate conveyance capacity for peak flows, the length of curb with the greatest flow was identified and analyzed for conveyance capacity. 1 C&H Engineering, “Design Report Water, Sewer & Storm Water Management Cottonwood Condominiums,” 2004, pgs 10 & 14 Stormwater Plan 8 6/20/2022 The critical curb required to convey the maximum flow was identified as the approximately 170’ length of curb channeling runoff to Retention Basin 1B, serving a catchment area of approximately 14,621 sf. This catchment area produces a peak flow of 0.80 cfs for the 25-year design storm. As shown in Table 7 above, At the minimum slope of 0.5%, the curb on site has a conveyance capacity of 5.04 cfs. Storm Event Analysis To get a sense of how the site stormwater facilities would have performed in past storm events, a storm event analysis was conducted to determine the percentile storm events in the City of Bozeman. The exercise analyzed 30 years of recorded 24-hour rainfall events using precipitation data collected at MSU rain gauge Station USC00241044. The analysis excluded snow fall events and 24- hour rainfall events that accumulated less than 0.1-inches. The table below summarizes the percentile storm events produced by the analysis. As indicated in Table 8 and comparing to the calculated storm captured within the individual drainage basins, the site’s stormwater system will retain the 98-99 per cent of storms on site. Table 8 – Bozeman Rainfall Analysis (1990-2020) Percentile Storm Event Volume (in) 80th 0.41 85th 0.49 90th 0.57 95th 0.74 99th 1.2 100th 2.29 Facilities Maintenance The proposed stormwater mitigation systems are located within public rights-of- ways and open spaces and will be operated and maintained by the Six Range Owners’ Association. A detailed operations and maintenance plan will be developed and will be included in the final covenants. At a minimum, the owners’ association is responsible for quarterly inspection and annual maintenance of all stormwater facilities. The inspection and maintenance responsibilities include, but are not limited to, general housekeeping responsibilities, visual inspection for performance, removal of sediment from mitigation facilities, vegetative maintenance, as well as any necessary repairs to the facilities themselves. Stormwater Plan 9 6/20/2022 Dry wells should be inspected annually to ensure no trash, vegetation or sediment is building up in the bottom of the structures. Curb scuppers should be inspected annually to ensure flows are not obstructed to the receiving ponds. Downspouts connected to dry wells should have leaf filters that are inspected annually as well. Additionally, the permeable pavers will require monthly sweeping during summer months an annual vacuuming to ensure flow through the paver joints. W. BABCOCK ST. (90' ROW)N. FERGUSON AVE. (50' ROW) S. HANLEY AVE.KIMBALL AVE.HANLEY AVE.SLOUGH CREEK DR.S Hanley Ave.Palisade Dr.Mill Creek Dr.DRAINAGEBASIN 1DRAINAGEBASIN 2DRAINAGEBASIN 3 DRAINAGEBASIN 4DRAINAGEBASIN 5DRAINAGEBASIN 6DRAINAGEBASIN 7DRAINAGEBASIN 8SCALE:DRAWN:PROJECT NO:3081-001204270 W Babcock Street, Bozeman MT Contractor Note: All site conditions and dimensions to be varified on-site. Inform Architect of design discrepancies.PO box 1001 Bozeman, MT 5977106/20/2022DATE:PROFESSIONALENGINEERS &SURVEYORSSTAHLYENGINEERING& ASSOCIATESSix Range Condominiums Site Plan Submittal Paine Group DRC Site Plan Resubmittal 2022.06.20C5.01" = 40'Drainage Plan Civil Engineering ● Geotechnical Engineering ● Land Surveying ● Construction Services ALLIED ENGINEERING 32 Discovery Dr. Bozeman, MT 59718 Ph: (406) 582-0221 www.alliedengineering.com June 8, 2021 Matt Paine The Paine Group 402 E Main Street Bozeman, MT 59715 e-mail: accounting@painegroup.com (sent via e-mail only) Re: Geotechnical Exploration and Design Recommendations Six Range Condominiums – Bozeman, Montana Dear Mr. Paine: This letter presents our geotechnical report for the proposed Six Range Condominiums project to be built southwest of the intersection of West Babcock Street and South Ferguson Avenue in Bozeman, Montana. Presented is a description of our involvement with the project, the site’s soil and groundwater conditions, and our geotechnical analysis and recommendations for foundation support and drainage. Based on a site plan provided by MFGR Designs dated May 3, 2021, the project will include four condominium buildings and four townhome triplexes. The project will also include driveways, parking, and access from surrounding streets. For the purposes of this report, we have assumed that the townhome buildings will be two-story, wood-frame structures on a concrete slab-on- grade foundation system supported by conventional spread footings. We understand from conversations with the Design Team that the larger condominium buildings will be three and four stories (10-foot story heights) and that the structural system for these buildings will consist of a combination of light framing and steel moment frames. We also understand that the condominium foundations will primarily consist of slabs on grade construction with exterior frost walls/footings and interior spread footings. Note that if a crawlspace foundation with a structural floor is proposed, some thought should be given to the elevated groundwater levels found at the site and the potential impacts of this water on crawlspaces. In our estimation, crawlspace foundations are best avoided. SITE LOCATION The Six Range Condominiums site is located at the southwest corner of the intersection of West Babcock Street and South Ferguson Avenue in Bozeman, Montana. The subject property is legally Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 2 described as Lot A1 of Minor Subdivision 338, located in the Northeast One-Quarter of the Southwest One-Quarter of Section 10, Township 2 South, Range 5 East, City of Bozeman, Gallatin County, Montana. Please refer to Figures 1 and 2 for details. The topography of the site is relatively flat, sloping gently to the north and west. Long native grasses cover the site. Fill piles (from previous construction adjacent the property), are also found on the site. All random fill will need to be removed from under the footprint of buildings and exterior hardscapes. SUBSURFACE EXPLORATIONS On May 6th and 7th, 2021, we observed the completion of ten (10) boreholes across the project site (see Figure 3 for locations). Hollow-stem auger boring was conducted by O’Keefe Drilling under the direction of Sumner Anacker, EI, Jessi Ellingsen, EI, and Joe Souther, PE, with Allied Engineering. Boreholes one, three, four, five, six, nine, and ten (BH-1, BH-3, BH-4, BH-5, BH-6, BH-9, BH-10) were completed in the proposed structure locations. Boreholes two, seven, and eight (BH-2, BH-7, BH-8) were completed in the proposed parking areas. During the explorations, soil and groundwater conditions were visually characterized, measured, and logged. The relative densities of the soil profiles were estimated based on the ease or difficulty of drilling and blow counts (N-Values) taken at 2.5 foot intervals. Blow counts consist of driving a 2-inch O.D. split spoon sampler in three 6-inch drives using a 140 pound hammer dropped 30 inches. The number of blows required to drive the sampler each of the 6-inch increments are counted with the total blows required to drive the sampler the last two 6-inch drives added together and recorded as the N-Value. The soil samples collected in the split spoon samplers were bagged for later classification in the laboratory. In addition to the split spoon samples, drill cuttings were also collected of representative soil samples for laboratory testing and geotechnical analysis. Copies of our borehole logs are attached (see Appendix A). These logs provide assorted field information, such as soil depths and descriptions, groundwater conditions, relative density data, and a sketch of the soil stratigraphy. Please be aware that the detail provided on the logs cannot be accurately summarized in a paragraph; therefore, it is important to review the logs in conjunction with this report. Following completion of the fieldwork, monitoring wells were installed in two of the boreholes, and all the borehole locations were cleaned up to the extent possible. Each borehole was staked with a wooden lathe that identified it accordingly. Subsurface Conditions The soil conditions were consistent across the site and consisted of 12 to 18 inches of organic topsoil and silty clay soil. Beginning at a depth of about 1.5 feet and extending to the depth of the boreholes at 15.5 feet was medium dense to very dense, brown, alluvial sandy gravel with abundant sub-rounded cobbles. Generally, the gravels were dirtier (contained more silt and clay) near the surface, but became cleaner with depth. Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 3 All boreholes extended to a depth of 15.5 feet with the exception of borehole eight (BH-8), which extended to 25.5 feet. The soil conditions in BH-8 were very similar to the rest of the boreholes. We encountered 1.5 feet of organic silty clay topsoil underlain by dense to very dense, brown, alluvial sandy gravel with abundant sub-rounded cobbles. At a depth of about 23 feet, we found a soft, brown, clay layer that was seven inches thick. Underlying the clay layer was more very dense sandy gravel with sub-rounded cobbles. Cobble size increased with depth from 1.5-inch- minus to 3-inch-minus. For further details about soil conditions, please refer to the borehole logs found in Appendix A. The site is mapped by the Montana Bureau of Mines and Geology as alluvium (coarse-grained river and stream deposits), which is consistent with our explorations. Please see Figure 4 for an excerpt of the geology map. Groundwater Conditions Groundwater was observed in all ten boreholes at the time of our explorations. Groundwater depth ranged from 5.2 feet in BH-10 in the northwest corner of the site to 6.6 feet in BH-3 on the northeastern side of the site. Two (2) piezometers were installed in BH-2 and BH-7. The groundwater depths in BH-2 and BH-7 were measured following subsurface explorations. See Table 1 below for results. Table 1. Groundwater Monitoring Results DATE DEPTH TO GROUNDWATER BELOW GROUND, BH-2 (FT) DEPTH TO GROUNDWATER BELOW GROUND, BH-7 (FT) May 7, 2021 5.97 5.56 May 17, 2021 5.76 5.36 June 2, 2021 5.38 4.93 Based on our monitoring results and experience in the area, we believe groundwater may impact construction depending on the time of year and will likely require dewatering to install utilities and foundations. Laboratory Testing Results Select samples were tested for moisture content, moisture-density (Standard Proctor), and chemical analysis for corrosivity to ductile iron pipe. Chemical analysis was performed by Energy Laboratories and included resistivity, chlorides, pH, sulfide ions, and redox potential. Test results are presented on the borehole logs (Appendix A) and in Appendix B. The chemical analysis results are also summarized in Table 2 below. Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 4 Table 2. Chemical Analysis Results TEST RESULT UNITS pH 8.5 s.u. Chloride 6 mg/kg Oxidation-Reduction Potential 270 mV Sulfide 0.06 mg/L Resistivity 9630 ohm-cm FOUNDATION, SLAB, AND DRAINAGE RECOMMENDATIONS Seismic Design Factors Based on our on-site explorations and knowledge of the geology, the project site class is Site Class D “stiff soil” (per criteria presented in the 2018 IBC). Note that this is not the “Default Site Class D.” Foundation Support Design We understand that the buildings will be supported on a slab-on-grade supported by exterior frost walls/footings and interior spread footings. To provide structural support, we recommend removing the upper organics and overlying fine-grained soils down to the sandy gravel under the entire footprint of each building. Based on the conditions observed in the boreholes, the depth to the sandy gravel is likely about 1.5 to 2.0 feet deep. However, this depth may vary across the site. All footings/slabs should be founded on the dense native gravels or structural fill that in turn bears on the native gravels. The over-excavation should extend laterally a minimum of 18 inches outside the footprint of each building. The native subgrade soils should be recompacted to an unyielding condition prior to the placement of the structural fill or footings/slabs. All granular structural fill should be compacted to a minimum of 98 percent of its Standard Proctor Density based on ASTM D-698. An appropriate bearing capacity for design assuming this foundation configuration is 3,000 pounds per square foot (psf). For foundations placed as described above, we expect that the total settlement will be less than one inch, with differential settlements of not more than 0.75 inches. Allowable bearing pressures during earthquakes may be increased by 50 percent. The bottom of exterior footings should be situated a minimum of 4 feet below the lowest adjacent exterior grade to provide frost protection. While we did not encounter any areas of random fill on the site, we believe they may be present based on the historical aerial imagery for this property and the presence of some of the apparent fill piles. We recommend a bid item for the removal and replacement of random fill areas, typically identified by a buried topsoil layer, debris, or some combination thereof. Any areas of Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 5 random fill that are identified on the site should be removed and replaced in their entirety with structural fill. Random fill is prone to excessive settlement under buildings and exterior hardscapes. In the event groundwater is encountered at the bottom of the excavation, clean crushed drainage rock may be placed to raise the bottom of the excavation above the groundwater before switching to more traditional structural fill (pit run or crushed sandy gravel). Providing separation from groundwater using non-moisture-sensitive clean crushed rock will avoid the saturation of the structural fill and subsequent difficulty with compaction. Clean crushed rock should be placed in lifts not exceeding 12 inches and vibratory compacted. Clean crushed rock should be covered with a nonwoven geotextile fabric such as a Mirafi 180N or equal prior to structural fill placement to prevent the migration of fines into the crushed rock. Lateral Earth Pressures All foundation walls that will be fixed at the top prior to the placement of backfill should be designed for an “at rest” equivalent fluid pressure of 60 pounds per cubic foot (pcf). In contrast, cantilevered retaining walls may be designed for a lower, “active” equivalent fluid pressure of 45 pcf, provided either some slight outward rotation of the wall is acceptable upon backfilling or the wall is constructed in such a way that accommodates the expected rotation. These “at rest” and “active” design values are only applicable for walls that will have backfill slopes of less than ten percent and which will not be externally loaded by surface pressures applied above and/or behind the wall. If there will be any slopes greater than 10 percent within 10 feet of the wall or significant surface loads within 10 feet of the wall, we should be consulted to provide appropriate lateral earth pressures for design. These lateral earth pressures also assume proper subsurface drainage provisions (footing drains, weep holes, etc.) are installed to prevent the development of hydrostatic pressures. Lateral forces from wind, earthquakes, and earth pressures on the opposite side of the structure will be resisted by passive earth pressure against the buried portion of the foundation wall and by friction at the bottom of the footing. Passive earth pressures in compacted backfill should be assumed to have an equivalent fluid pressure of 280 pcf, and a coefficient of friction of 0.4 should be used between cast-in-place concrete and the native soils or granular structural fill. Actual footing loads (not factored or allowable loads) should be used for calculating frictional resistance to sliding along the base of the footing. Please be aware that the friction coefficient has no built- in factor of safety; therefore, an appropriate safety factor should be selected and used in all subsequent calculations for each load case. The lateral earth pressures summarized above are for static conditions and should be factored for seismic conditions. Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 6 Foundation Wall Backfill Exterior wall backfill can consist of any excavated foundation soil, other than topsoil, if it is not overly moist, expansive, or too rocky in composition. All select backfill materials should be placed in multiple lifts and properly compacted to 95 percent of its Standard Proctor density based on ASTM D-698. To prevent damaging foundation walls during the backfilling process, only hand- operated compaction equipment is recommended within three feet of walls that are not buried on both sides. The level of care (with respect to the selection of backfill materials and the compactive effort that is used) should be increased in those areas along the foundation wall that will either receive concrete/asphalt surfacing or that will support a retaining wall to minimize the potential for future settlement problems. Finally, the re-use of topsoil as backfill should be limited to the uppermost four to six inches in landscape areas. Interior Slabs Interior slabs should be underlain by a vapor barrier (directly under the slab) and 6 inches of crushed drainage rock, which in turn overlies granular structural fill bearing on native gravels (see earlier foundation discussion). Vapor Barrier To control moisture vapor, we recommend installing a heavy-duty vapor barrier under interior slabs. We recommend a vapor barrier with a water vapor transmission rate of 0.006 or lower as established by ASTM E 96, such as a Stego 15-mil Vapor Barrier. The vapor barrier should be installed as per the manufacturer recommendations and ASTM E 1643, ensuring it is properly attached to footings/walls and sealed at the seams. Subsurface Drainage For slab-on-grade foundations, footing drains may be eliminated provided the exterior grade is maintained at least 6 inches below the top of slab at all locations. Surface Drainage Recommendations No water should be allowed to accumulate against or flow along any exposed walls. Concrete or asphalt surfacing that abuts the foundation should be designed with a minimum grade of two percent, and adjacent landscaped areas should have a slope of at least five percent within ten feet of the wall. To further reduce the potential for moisture infiltration along foundation walls, backfill materials should be well compacted, and capped in landscaped areas by four to six inches of low permeability topsoil. Apart from the locations that will be surfaced by concrete or asphalt, finished grades (next to foundation walls) should be set no less than six inches below the bottom of the sill plate for framed floors. Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 7 Exterior Concrete Slabs Traffic loaded exterior slabs should be supported on 6 inches of clean, crushed rock and 12 inches of compacted granular structural fill over non-organic, native soils. If soft or wet subgrade areas are identified, they should be over-excavated and replaced with suitable, compacted granular structural fill. FOUNDATION-RELATED FILL MATERIAL RECOMMENDATIONS Excavated Foundation Soils All topsoil should be stripped and stockpiled for re-use during site reclamation. On-site soils suitable for re-use as site fill or backfill should be separated from wet, rocky, debris- contaminated, or otherwise unsuitable soils during excavation. The suitability of the non-organic excavated soils will depend on their rockiness, plasticity, natural moisture content, and ability to be re-compacted. The driest soils containing an even mixture of soil matrix and smaller gravels should be selected for use as compacted fill, while the wettest and rockiest soils should either be hauled off-site or used for general site grading in non-critical locations. Depending on the time of year, some of the native soil that is excavated may be wet of optimum and will require drying prior to re-use. This may necessitate the import of easily compacted fill material if work is conducted during the wet or winter season when drying is not an option. Structural Fill If needed, granular structural fill should consist of organic-free, well-graded 4-inch-minus sandy (pit-run) gravel or 1.5-inch-minus crushed road mix gravel. Cleaner gravels excavated on site may be used as structural fill provided they are not overly wet and do not contain organics, deleterious materials, or cobbles over 4 inches. The gravels shall meet the material and gradation specifications as presented in the Montana Public Works Standard Specifications (MPWSS) for sub-base course and base course gravel. Clean Crushed Rock The primary uses for clean crushed rock include placement under concrete slabs and behind foundation and retaining walls for drainage-related purposes. It may also be used to bring the subgrade up above the groundwater level in below foundation applications. Crushed rock shall consist of a clean assortment of angular fragments with 100 percent passing a one-inch screen and less than 1 percent (by weight) finer than the No. 100 sieve. Over 50 percent of the rock particles must have fractured faces. FILL PLACEMENT AND COMPACTION All fill materials should be placed in uniform, horizontal lifts and compacted to an unyielding condition. The “loose” thickness of each layer of fill prior to compaction should not exceed 10 inches for self-propelled rollers, 8 inches for remote-controlled trench rollers, and 4 inches for Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 8 plate compactors. The moisture content of any fill material to be compacted should be within 2 percent of its optimum value. Provided in Table 3 are compaction recommendations for general site applications. These recommendations apply to all fill materials and are presented as a percentage of the maximum dry density of the material being placed as defined by ASTM D-698. A common misconception is that washed or screened crushed rock does not require compaction. This material requires compaction with a vibratory plate or smooth drum roller. Table 3. Compaction Recommendations (Application vs. Percent Compaction) APPLICATION % COMPACTION Fill under exterior slabs and pavements 95 Structural fill under footings and interior slabs 98 Backfill behind foundation and retaining walls 95 Clean crushed rock under slabs N/A – Vibratory Compaction ASPHALT PAVEMENT SECTION RECOMMENDATIONS FOR DRIVEWAY AND PARKING AREAS Subgrade Preparation Since sandy gravel soils are located relatively close to the surface, it may be the most advantageous to simply remove the upper organics and overlying fine-grain soils down to the sandy gravel in the driveway, parking, and access road areas. Based on the conditions observed in the boreholes, the depth to the sandy gravel is about 1.5 to 2.0 feet deep. However, this depth may vary across the site. The over-excavation should extend laterally a minimum of 12 inches beyond the pavement. The exposed native subgrade soils should be scarified to a minimum depth of 8 inches and compacted to a minimum of 95 percent of its ASTM D-698 density. The subgrade should then be brought back up to the sub-base course elevation using granular structural fill (or suitable excavated on-site gravels) compacted to a minimum of 98 percent of ASTM D-698. If the final road grade will be brought up significantly higher than the present grade, it may not be cost advantageous to take the subgrade down to the native gravels. In that case, we suggest at a minimum stripping the topsoil and leaving the fine-grain soils under the pavement section. If that is the case, the subbase section of roads/parking areas should be thickened by 6 inches. Asphalt Pavement Section Using conservative estimates for soil strength (CBR = 3.0) and vehicular equivalent single axle loadings (ESAL = 50,000), the compacted design thickness for a pavement section designed for a 20-year service life is 18 inches assuming the subgrade is dense sand and gravel and is prepared as described above. Table 4 presents our pavement design. Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 9 Table 4. Pavement Design MATERIAL COMPACTED THICKNESS (IN.) Asphalt 3 Base Course Gravel (1.5-inch-minus crushed) 6 Sub-Base Course Gravel (4-inch-minus pit-run) 9 Woven Geotextile Fabric (Mirafi 600X) Only if necessary Subgrade Soils (Upper 8 Inches of Native Sandy Gravel Plus Structural Fill as Needed) Compacted to 95% TOTAL 18 If some fine-grain soil is left under the parking/pavement area, we suggest thickening the subbase section from 9 to 15 inches. Material selections and construction practices should be in accordance with the Montana Public Works Standard Specifications. The native gravels are suitable for re-use as sub-base gravel assuming it meets the above indicated specifications and rock over 4 inches in diameter are removed. COLD/WINTER WEATHER CONSTRUCTION If foundation construction will occur during the cold/winter weather season, the Contractor shall take all necessary precautions to prevent the earthwork from freezing and/or from being contaminated with snow. Exposed subgrade and fill materials (under footings, slabs, and walls) should be covered with concrete insulation blankets to prevent frost penetration and to protect them from snow. All soils that are used for filling under or around foundation components should be dry, free of intermixed snow and frozen clods, and must not be placed when it is snowing. Fill materials or foundations should not be placed over frozen soils, which may be in a “frost-heaved condition,” or over layers of snow. When earthwork will proceed during the non-optimal times of the year, we recommend that it be performed expeditiously to minimize the time that the foundation excavation is open and exposed to the elements. AESI FUTURE INVOLVEMENT We suggest that we be retained during the design to ensure that the recommendations provided herein are followed and to provide additional recommendations as needed. We further recommend that we be allowed to view the construction excavation to verify that the appropriate target bearing materials (native gravels) have been reached. LIMITATIONS This report provides our geotechnical recommendations for the construction of the proposed Six Range Condominiums in Bozeman, Montana. Please be advised that the report is only applicable for the above-referenced project and shall not be used for any other nearby sites. Since Matt Paine, The Paine Group June 8, 2021 Six Range Condominiums – Geotechnical Report Bozeman, Montana Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582-0221 Page 10 geotechnical-related conditions can change in a short distance, we recommend that all properties be evaluated on a site-specific basis. The recommendations that are presented herein are based on our observation and evaluation of the site’s subsurface conditions, along with our previous geotechnical engineering experience in similar situations. Therefore, if during earthwork construction, soil and groundwater conditions are found to be inconsistent with those described in the report, we should be advised immediately such that we can analyze the situation and modify our recommendations if need be. All individuals associated with this project should consult this report during the planning, design, and construction of the site improvements. It should be made available to other parties for information on factual data only and not as a warranty of actual subsurface conditions such as those interpreted herein. If you have any questions regarding this letter, please call. Thank you. Allied Engineering Services, Inc. Craig R. Madson, PE Jessi Ellingsen, EI Principal Geotechnical Engineer Design Engineer enc: Figure 1 - Vicinity Map Figure 2 – Quadrangle Map Figure 3 – Borehole Location Map Figure 4 – Geology Map Figure 5 – Groundwater Map Appendix A - Borehole Logs Appendix B - Laboratory Testing Appendix C - Limitations of Your Geotechnical Report REFERENCES 1.International Code Council, 2018. “2018 International Building Code.” 2.Lonn, J. and English, A., 2002. “Preliminary Geologic Map of the Eastern Part of the Gallatin Valley, Montana,” Montana Bureau of Mines and Geology Open-File Report 457. 3.Montana Contractors’ Association, April 2010. “Montana Public Works Standard Specifications,” Sixth Edition. P:\2021\21-079 West Babcock Apartments - Geotech\05 Design\Geotech\Report\Six Range Condominiums Geotechnical Report - June 2021.docx LIST OF FIGURES FFiigguurree 11 –– VViicciinniittyy MMaapp FFiigguurree 22 –– QQuuaaddrraannggllee MMaapp FFiigguurree 33 –– BBoorreehhoollee LLooccaattiioonn MMaapp FFiigguurree 44 –– GGeeoollooggyy MMaapp FFiigguurree 55 –– GGrroouunnddwwaatteerr MMaapp FIGURECivil Engineering Geotechnical EngineeringLand Surveying 32 DISCOVERY DRIVE . BOZEMAN, MT 59718PHONE (406) 582-0221 . FAX (406) 582-5770www.alliedengineering.com SIX RANGE CONDOMINIUMS VICINITY MAP BOZEMAN, MONTANA 1 N FIGURECivil Engineering Geotechnical EngineeringLand Surveying 32 DISCOVERY DRIVE . BOZEMAN, MT 59718PHONE (406) 582-0221 . FAX (406) 582-5770www.alliedengineering.com SIX RANGE CONDOMINIUMS QUADRANGLE MAP BOZEMAN, MONTANA 2 N FIGURECivil Engineering Geotechnical EngineeringLand Surveying 32 DISCOVERY DRIVE . BOZEMAN, MT 59718PHONE (406) 582-0221 . FAX (406) 582-5770www.alliedengineering.com SIX RANGE CONDOMINIUMS BOREHOLE LOCATION MAP BOZEMAN, MONTANA 3 N FIGURECivil Engineering Geotechnical EngineeringLand Surveying 32 DISCOVERY DRIVE . BOZEMAN, MT 59718PHONE (406) 582-0221 . FAX (406) 582-5770www.alliedengineering.com SIX RANGE CONDOMINIUMS GEOLOGY MAP BOZEMAN, MONTANA 4 N FIGURECivil Engineering Geotechnical EngineeringLand Surveying 32 DISCOVERY DRIVE . BOZEMAN, MT 59718PHONE (406) 582-0221 . FAX (406) 582-5770www.alliedengineering.com SIX RANGE CONDOMINIUMS GROUNDWATER MAP BOZEMAN, MONTANA 5 N LIST OF APPENDICES AAppppeennddiixx AA –– BBoorreehhoollee LLooggss AAppppeennddiixx BB –– LLaabboorraattoorryy TTeessttiinngg RReessuullttss AAppppeennddiixx CC –– LLiimmiittaattiioonnss ooff YYoouurr GGeeootteecchhnniiccaall RReeppoorrtt APPENDIX A BBoorreehhoollee LLooggss DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/06/21 PAGE:1 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 6.4' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE/SAA BORING: BH-1 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilStiff; dark brown; silty CLAY with roots and scattered rocks; very moist. {1.5' - 5.0'}: Alluvial DepositDense; light brown; sandy GRAVEL withsilt/clay; moist to very moist. ·Tailings include 2"-minus sub-roundedto rounded cobbles. {5.0' - 15.5'}: Alluvial Deposit Medium dense to very dense; brown; sandyGRAVEL; very moist to wet. ·Sand seams at 9.5'-10.0' and 12.0'-12.5'. ·Tailings include 3"-minus sub-roundedto rounded cobbles. S1-A @0'-1.5'10 16.8% General Notes:1. Grinding at 1.5'.2. Slow drilling at 5.5'.3. Groundwater encountered at6.4'. ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S1-B @2.0'-3.5'45 16.6% S1-C @4.0'-5.5'75 3.0% S1-D @7.0'-8.5'29 S1-E @9.0'-10.5'53 S1-F @12.0'-13.5'75 S1-G @14.0'-15.5'56 Geotechnical EngineeringLand SurveyingCivil Engineering DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 Geotechnical Engineering 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221Land SurveyingCivil Engineering LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/06/21 PAGE:2 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 6.5' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE/SAA BORING: BH-2 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.0'}: TopsoilVery stiff; dark brown; silty CLAY with roots and scattered rocks; very moist. {1.0' - 4.0'}: Alluvial DepositDense; light brown; sandy GRAVEL withsilt/clay; moist to very moist. ·Tailings include 2"-minus sub-roundedto rounded cobbles. {4.0' - 15.5'}: Alluvial Deposit Dense to very dense; brown; sandyGRAVEL; very moist to wet. ·Sand seams at 12.0'-12.5'. ·Tailings include 3"-minus sub-roundedto rounded cobbles. S2-A @0'-1.5'20 19.8% General Notes:1. Grinding at 3.5' and 8.5'.2. Slow drilling at 5.5' - 8.5'.3. Groundwater encountered at6.5'.4. Piezeometer placed with 5.0' ofscreen between approximately4.5' and 9.5' below groundsurface.5. Piezometer height = 6.5" fromground surface to top of casing.6. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S2-B @2.0'-3.5'47 10.2% S2-C @4.0'-5.5'58 3.6% S2-D @7.0'-8.5'46 S2-E @9.0'-10.5'45 S2-F @12.0'-13.5'50-6" S2-G @14.0'-15.5'50-5" DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/06/21 PAGE:3 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 6.6' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE/JTS BORING: BH-3 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilStiff; dark brown; silty CLAY with roots and scattered rocks; very moist. {1.5' - 5.0'}: Alluvial DepositVery dense; light brown; sandy GRAVELwith silt/clay; slightly moist. ·Tailings include 2"-minus sub-roundedto rounded cobbles. {5.0' - 15.5'}: Alluvial Deposit Very dense; brown; sandy GRAVEL; verymoist to wet. ·Tailings include 3"-minus sub-roundedto rounded cobbles. S3-A @0'-1.5'9 26.0% General Notes:1. Grinding at 3.5'.2. Groundwater encountered at6.6'.3. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S3-B @2.0'-3.5'61 3.4% S3-C @4.0'-5.5'50-3" 3.1% S3-D @7.0'-8.5'57 S3-E @9.0'-10.5'52 S3-F @12.0'-13.5'67 S3-G @14.0'-15.5'63 Geotechnical EngineeringLand SurveyingCivil Engineering DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/06/21 PAGE:4 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 6.3' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE BORING: BH-4 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilStiff; dark brown; silty CLAY with roots and scattered rocks; very moist. ·Pocket Penetrometer = 2.25 tsf. {1.5' - 5.0'}: Alluvial DepositDense; light brown; sandy GRAVEL withsilt/clay; dry to slightly moist. ·Tailings include 2"-minus sub-rounded to rounded cobbles. {5.0' - 15.5'}: Alluvial DepositVery dense; brown; sandy GRAVEL; verymoist to wet. ·Tailings include 3"-minus sub-roundedto rounded cobbles. ·Broken gravel pieces encountered in split spoon. S4-A @0'-1.5'10 24.9% General Notes:1. Grinding at 3.0'.2. Groundwater encountered at6.3'.3. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S4-B @2.0'-3.5'45 3.8% S4-C @4.0'-5.5'50-5" 2.4% S4-D @7.0'-8.5'53 S4-E @9.0'-10.5'61 S4-F @12.0'-13.5'65 S4-G @14.0'-15.5'79-8" Geotechnical EngineeringLand SurveyingCivil Engineering DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/06/21 PAGE:5 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 6.4' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE BORING: BH-5 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilStiff; dark brown; silty CLAY with roots and scattered rocks; very moist. ·Pocket Penetrometer = 2.25-3.25 tsf. {1.5' - 5.0'}: Alluvial DepositDense; light brown; sandy GRAVEL withsilt/clay; slightly moist. ·Tailings include 2"-minus sub-rounded to rounded cobbles. {5.0' - 15.5'}: Alluvial DepositDense to very dense; brown; sandyGRAVEL; slightly moist to wet. ·Tailings include 1.5"-minussub-rounded gravel. ·Broken gravel pieces encountered in split spoon. S5-A @0'-1.5'11 18.0% General Notes:1. Grinding at 1.5'.2. Groundwater encountered at6.4'.3. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S5-B @2.0'-3.5'42 3.0% S5-C @4.0'-5.5'50-5" 2.9% S5-D @7.0'-8.5'34 S5-E @9.0'-10.5'53 S5-F @12.0'-13.5'62 S5-G @14.0'-15.5'50-5" Geotechnical EngineeringLand SurveyingCivil Engineering DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/06/21 PAGE:6 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 6.4' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE BORING: BH-6 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilMedium stiff; dark brown; silty CLAY with roots and scattered rocks; very moist. ·Pocket Penetrometer = 2.25-2.5 tsf. ·Tailings include 0.5"-minus gravel. {1.5' - 5.0'}: Alluvial DepositDense; light brown; sandy GRAVEL withsilt/clay; slightly moist ·Tailings include 1.5"-minussub-rounded to rounded cobbles. {5.0' - 15.5'}: Alluvial DepositDense to very dense; brown; sandyGRAVEL; slightly moist to wet. ·Tailings include 2"-minus sub-roundedto rounded cobbles. ·Broken gravel pieces encountered insplit spoon. S6-A @0'-1.5'7 21.6% General Notes:1. Groundwater encountered at6.4'.2. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S6-B @2.0'-3.5'49 5.1% S6-C @4.0'-5.5'70 4.7% S6-D @7.0'-8.5'30 S6-E @9.0'-10.5'45 S6-F @12.0'-13.5'35 S6-G @14.0'-15.5'84-9" Geotechnical EngineeringLand SurveyingCivil Engineering DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/06/21 PAGE:7 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 6.0' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE BORING: BH-7 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilStiff; dark brown; silty CLAY with roots and scattered rocks; very moist. ·Pocket Penetrometer = 2.0-2.5 tsf. {1.5' - 5.0'}: Alluvial DepositVery dense; light brown; sandy GRAVELwith silt/clay; moist. {5.0' - 15.5'}: Alluvial DepositMedium to very dense; brown; sandy GRAVEL; slightly moist to wet. ·Sand seam from 15.0'-15.5'. ·Tailings include 3"-minus sub-roundedto rounded cobbles. ·Broken gravel pieces encountered insplit spoon. S7-A @0'-1.5'9 22.2% General Notes:1. Grinding at 1.5'.2. Groundwater encountered at6.0'.3. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials).4. Piezeometer placed with 5.0' ofscreen between approximately4.5' and 9.5' below groundsurface.5. Piezometer height = 5.5" fromground surface to top of casing. ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S7-B @2.0'-3.5'83-9" 9.1% S7-C @4.0'-5.5'50-4" 2.8% S7-D @7.0'-8.5'26 S7-E @9.0'-10.5'37 S7-F @12.0'-13.5'51 S7-G @14.0'-15.5'74 Geotechnical EngineeringLand SurveyingCivil Engineering DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 2.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/07/21 PAGE:8 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 25.5' GW: 6.0' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE BORING: BH-8 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilMedium stiff to stiff; brown; silty CLAY with roots and scattered rocks; very moist. {1.5' - 5.0'}: Alluvial DepositVery dense; light brown; sandy GRAVELwith silt/clay; moist. ·Tailings include 2"-minus sub-roundedto rounded cobbles. {5.0' - 15.5'}: Alluvial Deposit Dense to very dense; brown; sandyGRAVEL; slightly moist to wet. ·Tailings include 3"-minus sub-roundedto rounded cobbles. ·Broken gravel pieces encountered insplit spoon. {15.5' - 25.5'}: Alluvial DepositVery dense; brown; sandy GRAVEL; slightlymoist to wet. ·Sand seam at 19.0'-19.5'. ·Tailings include 3"-minus sub-roundedto rounded cobbles. ·Clay from 22.8' to 23.4' (PocketPenetrometer = 1.25 tsf). S8-A @0'-1.5'8 17.3%General Notes:1. Grinding from 1.5' to 5.5'.2. Groundwater encountered at6.0'.3. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 24.0 26.0 28.0 30.0 32.0 S8-B @2.0'-3.5'87-10"4.2% S8-C @4.0'-5.5'83 4.6% S8-D @7.0'-8.5'34 S8-E @9.0'-10.5'47 S8-F @12.0'-13.5'55 S8-G @14.0'-15.5'50-5" Geotechnical EngineeringLand SurveyingCivil Engineering S8-H @17.0'-18.5' S8-I @19.0'-20.5' S8-J @22.0'-23.5' S8-K @24.0'-25.5' 50-3.5" 87 58 50-2" DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/07/21 PAGE:9 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 5.8' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE BORING: BH-9 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilStiff; dark brown; silty CLAY with roots and scattered rocks; very moist. ·Pocket Penetrometer = 2.0-2.5 tsf. {1.5' - 5.0'}: Alluvial DepositVery dense; light brown; sandy GRAVELwith silt/clay; slightly moist. {5.0' - 15.5'}: Alluvial DepositDense to very dense; brown; sandy GRAVEL; moist to wet. ·Broken gravel pieces encountered insplit spoon. S9-A @0'-1.5'10 21.2% General Notes:1. Grinding at 1.5'.2. Groundwater encountered at5.8'.3. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S9-B @2.0'-3.5'74 3.2% S9-C @4.0'-5.5'66 9.5% S9-D @7.0'-8.5'39 S9-E @9.0'-10.5'63 S9-F @12.0'-13.5'98-11" S9-G @14.0'-15.5'91-9" Geotechnical EngineeringLand SurveyingCivil Engineering DEPTH (FT)GEOLOGYLOGDESCRIPTIONOF MATERIALS SAMPLESN(UNCOR)BLOWS/FTMOISTURECONTENTOTHER FIELD ORSAMPLEINFORMATION 1.0 32 DISCOVERY DRIVE BOZEMAN, MT 59718 FAX (406) 582-5770 PHONE (406) 582-0221 LOG OF BORING PROJECT: Six Range Condominiums JOB #: 21-079 DATE: 05/07/21 PAGE:10 LOCATION: Bozeman, MT ELEVATION: N/A DEPTH: 15.5' GW: 5.2' DRILL TYPE: Hollow Stem Auger/Mobile B-61 FIELD ENGINEER: JGE BORING: BH-10 DRILLER: Steve with O'Keefe CASING/HAMMER/SAMPLER: 8"/4.25"/140#SSS {0.0' - 1.5'}: TopsoilStiff; dark brown; silty CLAY with roots and scattered rocks; very moist. ·Pocket Penetrometer = 4.25-4.5 tsf. {1.5' - 5.0'}: Alluvial DepositVery dense; light brown; sandy GRAVELwith silt/clay; slightly moist. {5.0' - 15.5'}: Alluvial DepositDense to very dense; brown; sandy GRAVEL; moist to wet. ·Tailings include 3"-minus sub-roundedto rounded cobbles. ·Broken gravel pieces encountered insplit spoon. S10-A @0'-1.5'12 25.0% General Notes:1. Grinding at 2.0'.2. Groundwater encountered at5.2'.3. Composite sample collected inupper 1.0' of material (added tobucket and combined withother composite samplematerials). ·SSS - 2.0'' O.D. Split SpoonSample ·The beginning and endingdepths of the individual soillayers are approximate. End of Boring 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 S10-B @2.0'-3.5'69 3.0% S10-C @4.0'-5.5'54 S10-D @7.0'-8.5'43 S10-E @9.0'-10.5'49 S10-F @12.0'-13.5'44 S10-G @14.0'-15.5'86 Geotechnical EngineeringLand SurveyingCivil Engineering APPENDIX B LLaabboorraattoorryy TTeessttiinngg RReessuullttss MOISTURE CONTENT DETERMINATION (ASTM D-2216) Project: Six Range CondominiumsProject Number: 21-079 Sample Identification: See Below Soil Classification: Varies Date Sampled: 5/6/2021 Date Tested: 5/10/2021 Tested By: HT, ZL, HD Sample Identification:S1-A S1-B S1-C S2-A S2-B S2-C Exploration Location:BH-1 BH-1 BH-1 BH-2 BH-2 BH-2 Sample Depth (ft):0-1.5 2-3.5 4-5.5 0-1.5 2-3.5 4-5.5 Container Number:S O M U GG R Weight of Container:50.55 48.98 50.56 51.13 48.24 50.61 Container + Wet Soil:179.41 135.57 190.20 203.49 158.20 152.26 Container + Dry Soil:160.83 123.27 186.11 178.32 148.01 148.71 Weight of Water:18.58 12.30 4.09 25.17 10.19 3.55 Weight of Dry Soil:110.28 74.29 135.55 127.19 99.77 98.10 Moisture Content:16.8%16.6%3.0%19.8%10.2%3.6% Sample Identification:S3-A S3-B S3-C S4-A S4-B S4-C Exploration Location:BH-3 BH-3 BH-3 BH-4 BH-4 BH-4 Sample Depth (ft):0-1.5 2-3.5 4-5.5 0-1.5 2-3.5 4-5.5 Container Number:CC HH DD EE T Y Weight of Container:49.76 48.35 48.76 48.99 51.58 50.88 Container + Wet Soil:161.24 184.01 181.60 171.72 180.86 136.28 Container + Dry Soil:138.23 179.60 177.59 147.22 176.11 134.29 Weight of Water:23.01 4.41 4.01 24.50 4.75 1.99 Weight of Dry Soil:88.47 131.25 128.83 98.23 124.53 83.41 Moisture Content:26.0%3.4%3.1%24.9%3.8%2.4% Reviewed By: 32 Discovery Drive Bozeman, MT 59718 Phone (406) 582-0221Fax (406) 582-5770 MOISTURE CONTENT DETERMINATION (ASTM D-2216) Project: Six Range CondominiumsProject Number: 21-079 Sample Identification: See Below Soil Classification: Varies Date Sampled: 5/6/2021 Date Tested: 5/10/2021 Tested By: HT, ZL, HD Sample Identification:S5-A S5-B S5-C S6-A S6-B S6-C Exploration Location:BH-5 BH-5 BH-5 BH-6 BH-6 BH-6 Sample Depth (ft):0-1.5 2-3.5 4-5.5 0-1.5 2-3.5 4-5.5 Container Number:V AA P W Q Z Weight of Container:51.04 49.02 49.27 50.52 51.08 49.51 Container + Wet Soil:175.10 174.40 175.25 178.62 181.48 203.39 Container + Dry Soil:156.17 170.79 171.68 155.90 175.14 196.52 Weight of Water:18.93 3.61 3.57 22.72 6.34 6.87 Weight of Dry Soil:105.13 121.77 122.41 105.38 124.06 147.01 Moisture Content:18.0%3.0%2.9%21.6%5.1%4.7% Sample Identification:S7-A S7-B S7-C S8-A S8-B S8-C Exploration Location:BH-7 BH-7 BH-7 BH-8 BH-8 BH-8 Sample Depth (ft):0-1.5 2-3.5 4-5.5 0-1.5 2-3.5 4-5.5 Container Number:BB C E LL JJ B Weight of Container:48.47 31.76 31.64 31.06 30.93 31.58 Container + Wet Soil:157.72 137.62 113.64 61.77 108.33 89.59 Container + Dry Soil:137.84 128.80 111.42 57.25 105.23 87.06 Weight of Water:19.88 8.82 2.22 4.52 3.10 2.53 Weight of Dry Soil:89.37 97.04 79.78 26.19 74.30 55.48 Moisture Content:22.2%9.1%2.8%17.3%4.2%4.6% Reviewed By: 32 Discovery Drive Bozeman, MT 59718 Phone (406) 582-0221Fax (406) 582-5770 MOISTURE CONTENT DETERMINATION (ASTM D-2216) Project: Six Range CondominiumsProject Number: 21-079 Sample Identification: See Below Soil Classification: Varies Date Sampled: 5/6/2021 Date Tested: 5/10/2021 Tested By: HT, ZL, HD Sample Identification:S9-A S9-B S9-C S10-A S10-B Exploration Location:BH-9 BH-9 BH-9 BH-10 BH-10 Sample Depth (ft):0-1.5 2-3.5 4-5.5 0-1.5 2-3.5 Container Number:H K OO G D Weight of Container:31.56 31.73 31.04 31.56 31.76 Container + Wet Soil:117.90 112.68 120.58 112.44 140.96 Container + Dry Soil:102.80 110.14 112.84 96.26 137.78 Weight of Water:15.10 2.54 7.74 16.18 3.18 Weight of Dry Soil:71.24 78.41 81.80 64.70 106.02 Moisture Content:21.2%3.2%9.5%25.0%3.0% Sample Identification: Exploration Location: Sample Depth (ft): Container Number: Weight of Container: Container + Wet Soil: Container + Dry Soil: Weight of Water: Weight of Dry Soil: Moisture Content: Reviewed By: 32 Discovery Drive Bozeman, MT 59718 Phone (406) 582-0221Fax (406) 582-5770 STANDARD PROCTOR COMPACTION TEST (ASTM D-698) Project: Six Range Condominiums Project Number: 21-079 Sample Identification: BH 2-10 Soil Classification: Silty CLAY Date Sampled: 05/06/2021 Date Tested: 05/11/2021 Tested By: HT Note: No Oversize Correction Applied Natural Moisture Content: 19.3 % Optimum Moisture Content: 20.0 % Maximum Dry Unit Weight: 101.5 pcf Reviewed By: Summary of Lab Test Data 85 90 95 100 105 110 115 120 125 8% 13% 18% 23% 28%Dry Unit Weight (pcf)Moisture Content PROCTOR COMPACTION CURVE Compaction CurveZ.A.V. for S.G.=2.50Z.A.V. for S.G.=2.65Z.A.V. for S.G.=2.80Poly. (Compaction Curve) 32 Discovery Drive Bozeman, MT 59718 Phone (406) 582-0221Fax (406) 582-5770 ANALYTICAL SUMMARY REPORT The analyses presented in this report were performed by Energy Laboratories, Inc., 3161 E. Lyndale Ave., Helena, MT 59604, unless otherwise noted. Any exceptions or problems with the analyses are noted in the Laboratory Analytical Report, the QA/QC Summary Report, or the Case Narrative. Any issues encountered during sample receipt are documented in the Work Order Receipt Checklist. The results as reported relate only to the item(s) submitted for testing. This report shall be used or copied only in its entirety. Energy Laboratories, Inc. is not responsible for the consequences arising from the use of a partial report. If you have any questions regarding these test results, please contact your Project Manager. Lab ID Client Sample ID Collect Date Receive Date Matrix Test Report Approved By: H21050337-001 Composite Sample, all boreholes 05/07/21 12:00 05/14/21 Soil Anions, Water ExtractableOxidation Reduction PotentialpH, 1:X Water ExtractableDI Water Soil Extract ASA10-3ResistivitySoil Preparation USDA1Sulfide, Methylene Blue Colorimetric Allied Engineering Services Inc Project Name:21-079 W. Babcock Apartments Work Order:H21050337 32 S Discovery Dr Bozeman, MT 59718-6958 June 03, 2021 Energy Laboratories Inc Helena MT received the following 1 sample for Allied Engineering Services Inc on 5/14/2021 for analysis. Page 1 of 10 Project:21-079 W. Babcock Apartments CLIENT:Allied Engineering Services Inc Work Order:H21050337 CASE NARRATIVE 06/03/21Report Date: Tests associated with analyst identified as ELI-B were subcontracted to Energy Laboratories, 1120 S. 27th St., Billings, MT, EPA Number MT00005. Page 2 of 10 LABORATORY ANALYTICAL REPORT Client:Allied Engineering Services Inc Project:21-079 W. Babcock Apartments Lab ID:H21050337-001 Client Sample ID:Composite Sample, all boreholes Collection Date:05/07/21 12:00 Matrix:Soil Report Date:06/03/21 DateReceived:05/14/21 Prepared by Helena, MT Branch Analyses Result Units Analysis Date / ByRLMethod MCL/ QCLQualifiers 1:X SOIL:WATER 05/20/21 09:05 / swj0.1s.u.8.5pH, 1:2 ASA10-3 WATER EXTRACTABLE 05/21/21 13:52 / JAR1mg/kg6Chloride, 1:2 E300.0 PHYSICAL PROPERTIES 06/02/21 12:00 / eli-b23mV270Oxidation-Reduction Potential A2580 BM INORGANICS H 06/02/21 18:58 / eli-b0.04mg/L0.06Sulfide A4500-S D RESISTIVITY OF SOIL 05/25/21 10:53 / swj1ohm-cm9630Resistivity A2510 B Report Definitions: RL - Analyte Reporting Limit MCL - Maximum Contaminant Level QCL - Quality Control Limit ND - Not detected at the Reporting Limit (RL) H - Analysis performed past the method holding time Page 3 of 10 Client:Allied Engineering Services Inc Work Order:H21050337 QA/QC Summary Report 06/03/21Report Date: Analyte Result %REC RPDLow Limit High Limit RPDLimitRLUnits QualCount Prepared by Helena, MT Branch Method:A2510 B Batch: R165206 Lab ID:H21050337-001ADUP 05/25/21 10:53Sample Duplicate Run: SOIL EC_210525A Resistivity 101.0 2.49410ohm-cm Qualifiers: RL - Analyte Reporting Limit ND - Not detected at the Reporting Limit (RL) Page 4 of 10 Client:Allied Engineering Services Inc Work Order:H21050337 QA/QC Summary Report 06/03/21Report Date: Analyte Result %REC RPDLow Limit High Limit RPDLimitRLUnits QualCount Prepared by Helena, MT Branch Method:A2580 BM Batch: B_R361665 Lab ID:LCS1 06/02/21 11:56Laboratory Control Sample Run: SUB-B361665 Oxidation-Reduction Potential 99 95 105233mV Lab ID:H21050337-001B 06/02/21 12:08Sample Duplicate Run: SUB-B361665 Oxidation-Reduction Potential 104.2282mV Qualifiers: RL - Analyte Reporting Limit ND - Not detected at the Reporting Limit (RL) Page 5 of 10 Client:Allied Engineering Services Inc Work Order:H21050337 QA/QC Summary Report 06/03/21Report Date: Analyte Result %REC RPDLow Limit High Limit RPDLimitRLUnits QualCount Prepared by Helena, MT Branch Method:A4500-S D Batch: B_R361718 Lab ID:MBLK 06/02/21 18:58Method Blank Run: SUB-B361718 Sulfide 0.0100.02 mg/L Lab ID:LCS 06/02/21 18:58Laboratory Control Sample Run: SUB-B361718 Sulfide 107 85 1150.0400.254 mg/L Lab ID:B21060172-001DMS 06/02/21 18:58Sample Matrix Spike Run: SUB-B361718 Sulfide 99 70 1300.202.47 mg/L Lab ID:B21060172-001DMSD 06/02/21 18:58Sample Matrix Spike Duplicate Run: SUB-B361718 Sulfide 100 70 130 200.20 1.12.49 mg/L Lab ID:H21050337-001B 06/02/21 18:58Sample Duplicate Run: SUB-B361718 Sulfide 200.040 3.50.0637 mg/L Qualifiers: RL - Analyte Reporting Limit ND - Not detected at the Reporting Limit (RL) Page 6 of 10 Client:Allied Engineering Services Inc Work Order:H21050337 QA/QC Summary Report 06/03/21Report Date: Analyte Result %REC RPDLow Limit High Limit RPDLimitRLUnits QualCount Prepared by Helena, MT Branch Method:ASA10-3 Analytical Run: SOIL PH METER - ORION A211_210525A Lab ID:ICV_1_210519_1 05/20/21 08:51Initial Calibration Verification Standard pH, 1:2 100 98.6 101.40.107.02 s.u. Lab ID:CCV_1_210519_1 05/20/21 08:52Continuing Calibration Verification Standard pH, 1:2 100 98.6 101.40.107.01 s.u. Lab ID:CCV1_1_210519_1 05/20/21 08:53Continuing Calibration Verification Standard pH, 1:2 100 97.5 102.50.104.00 s.u. Lab ID:ICV_1_210521_1 05/21/21 09:27Initial Calibration Verification Standard pH, 1:2 100 98.6 101.40.107.03 s.u. Lab ID:ICV_1_210524_1 05/24/21 11:47Initial Calibration Verification Standard pH, 1:2 100 98.6 101.40.107.03 s.u. Method:ASA10-3 Batch: 56316 Lab ID:LCS-56316 05/20/21 08:55Laboratory Control Sample Run: SOIL PH METER - ORION A2 pH, 1:2 99 95 1050.108.25 s.u. Lab ID:H21050337-001ADUP 05/20/21 09:05Sample Duplicate Run: SOIL PH METER - ORION A2 pH, 1:2 200.10 1.08.63 s.u. Qualifiers: RL - Analyte Reporting Limit ND - Not detected at the Reporting Limit (RL) Page 7 of 10 Client:Allied Engineering Services Inc Work Order:H21050337 QA/QC Summary Report 06/03/21Report Date: Analyte Result %REC RPDLow Limit High Limit RPDLimitRLUnits QualCount Prepared by Helena, MT Branch Method:E300.0 Batch: 56316 Lab ID:MB-56316 05/21/21 12:12Method Blank Run: IC METROHM_210521A Chloride, 1:2 0.008NDmg/kg Lab ID:LCS-56316 05/21/21 12:26Laboratory Control Sample Run: IC METROHM_210521A Chloride, 1:2 117 70 1301.0181mg/kg Lab ID:H21050337-001ADUP 05/21/21 14:07Sample Duplicate Run: IC METROHM_210521A Chloride, 1:2 201.0 4.35.46 mg/kg Lab ID:H21050337-001AMS 05/21/21 14:21Sample Matrix Spike Run: IC METROHM_210521A Chloride, 1:2 100 90 1101.0508mg/kg Qualifiers: RL - Analyte Reporting Limit ND - Not detected at the Reporting Limit (RL) Page 8 of 10 Shipping container/cooler in good condition? Custody seals intact on all shipping container(s)/cooler(s)? Custody seals intact on all sample bottles? Chain of custody present? Chain of custody signed when relinquished and received? Chain of custody agrees with sample labels? Samples in proper container/bottle? Sample containers intact? Sufficient sample volume for indicated test? All samples received within holding time?(Exclude analyses that are considered field parameterssuch as pH, DO, Res Cl, Sulfite, Ferrous Iron, etc.) Container/Temp Blank temperature: Water - VOA vials have zero headspace? Water - pH acceptable upon receipt? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No No No No No No No No No No No No R £ £ £ R R £ R R R R £ £ £ £ £ £ R £ £ £ £ £ £ Not Present Not Present Not Present £ R R No VOA vials submitted Not Applicable R R 22.1°C No Ice 5/14/2021Jessica C. Smith Priority US Mail wjj Date Received: Received by: Login completed by: Carrier name: BL2000\sdull 5/19/2021 Reviewed by: Reviewed Date: Contact and Corrective Action Comments: Date on COC is 5/6 + 5/7 2021 and time on COC is varies. ID on COC is Composite Sample, all boreholes - ID on sample is 21-079 W. Babcock Apts. Mulitple depths listed on sample. Used ID and latest date from COC and estimated time in the laboratory. JCS 05/14/2021 Temp Blank received in all shipping container(s)/cooler(s)?Yes No£R Not Applicable £ Lab measurement of analytes considered field parameters that require analysis within 15 minutes of sampling such as pH, Dissolved Oxygen and Residual Chlorine, are qualified as being analyzed outside of recommended holding time. Solid/soil samples are reported on a wet weight basis (as received) unless specifically indicated. If moisture corrected, data units are typically noted as –dry. For agricultural and mining soil parameters/characteristics, all samples are dried and ground prior to sample analysis. Radiochemical precision results represent a 2-sigma Total Measurement Uncertainty. Standard Reporting Procedures: Work Order Receipt Checklist Allied Engineering Services Inc H21050337 Page 9 of 10 Page 10 of 10 APPENDIX C LLiimmiittaattiioonnss ooff YYoouurr GGeeootteecchhnniiccaall RReeppoorrtt LIMITATIONS OF YOUR GEOTECHNICAL REPORT GEOTECHNICAL REPORTS ARE PROJECT AND CLIENT SPECIFIC Geotechnical investigations, analyses, and recommendations are project and client specific. Each project and each client have individual criterion for risk, purpose, and cost of evaluation that are considered in the development of scope of geotechnical investigations, analyses and recommendations. For example, slight changes to building types or use may alter the applicability of a particular foundation type, as can a particular client’s aversion or acceptance of risk. Also, additional risk is often created by scope‐of service limitations imposed by the client and a report prepared for a particular client (say a construction contractor) may not be applicable or adequate for another client (say an architect, owner, or developer for example), and vice‐versa. No one should apply a geotechnical report for any purpose other than that originally contemplated without first conferring with the consulting geotechnical engineer. Geotechnical reports should be made available to contractors and professionals for information on factual data only and not as a warranty of subsurface conditions, such as those interpreted in the exploration logs and discussed in the report. GEOTECHNICAL CONDITIONS CAN CHANGE Geotechnical conditions may be affected as a result of natural processes or human activity. Geotechnical reports are based on conditions that existed at the time of subsurface exploration. Construction operations such as cuts, fills, or drains in the vicinity of the site and natural events such as floods, earthquakes, or groundwater fluctuations may affect subsurface conditions and, thus, the continuing adequacy of a geotechnical report. GEOTECHNICAL ENGINEERING IS NOT AN EXACT SCIENCE The site exploration and sampling process interprets subsurface conditions using drill action, soil sampling, resistance to excavation, and other subjective observations at discrete points on the surface and in the subsurface. The data is then interpreted by the engineer, who applies professional judgment to render an opinion about over‐all subsurface conditions. Actual conditions in areas not sampled or observed may differ from those predicted in your report. Retaining your consultant to advise you during the design process, review plans and specifications, and then to observe subsurface construction operations can minimize the risks associated with the uncertainties associated with such interpretations. The conclusions described in your geotechnical report are preliminary because they must be based on the assumption that conditions revealed through selective exploration and sampling are indicative of actual Allied Engineering Services, Inc. ● 32 Discovery Drive. Bozeman, Montana 59718 ● Ph: (406) 582‐0221 Page 2 conditions throughout a site. A more complete view of subsurface conditions is often revealed during earthwork; therefore, you should retain your consultant to observe earthwork to confirm conditions and/or to provide revised recommendations if necessary. Allied Engineering cannot assume responsibility or liability for the adequacy of the report’s recommendations if another party is retained to observe construction. EXPLORATIONS LOGS SHOULD NOT BE SEPARATED FROM THE REPORT Final explorations logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results, and laboratory and/or office evaluation of field samples and data. Only final exploration logs and data are customarily included in geotechnical reports. These final logs should not be redrawn for inclusion in Architectural or other design drawings, because drafters may commit errors or omissions in the transfer process. To reduce the likelihood of exploration log misinterpretation, contractors should be given ready access to the complete geotechnical report and should be advised of its limitations and purpose. While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with Allied Engineering and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. OWNERSHIP OF RISK AND STANDARD OF CARE Because geotechnical engineering is much less exact than other design disciplines, there is more risk associated with geotechnical parameters than with most other design issues. Given the hidden and variable character of natural soils and geologic hazards, this risk is impossible to eliminate with any amount of study and exploration. Appropriate geotechnical exploration, analysis, and recommendations can identify and reduce these risks. However, assuming an appropriate geotechnical evaluation, the remaining risk of unknown soil conditions and other geo‐hazards typically belongs to the owner of a project unless specifically transferred to another party such as a contractor, insurance company, or engineer. The geotechnical engineer’s duty is to provide professional services in accordance with their stated scope and consistent with the standard of practice at the present time and in the subject geographic area. It is not to provide insurance against geo‐hazards or unanticipated soil conditions. The conclusions and recommendations expressed in this report are opinions based our professional judgment and the project parameters as relayed by the client. The conclusions and recommendations assume that site conditions are not substantially different than those exposed by the explorations. If during construction, subsurface conditions different from those encountered in the explorations are observed or appear to be present, Allied Engineering should be advised at once such that we may review those conditions and reconsider our recommendations where necessary. RETENTION OF SOIL SAMPLES Allied Engineering will typically retain soil samples for one month after issuing the geotechnical report. If you would like to hold the samples for a longer period of time, you should make specific arrangements to have the samples held longer or arrange to take charge of the samples yourself.