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HomeMy WebLinkAbout011_Stormwater Design Report_043026 1105 REEVES ROAD WEST, SUITE 6 BOZEMAN, MT 59718 406-581-5730 www.headwatersmt.net Page 1 of 7 Stormwater Drainage Report Kaufmann Overhead Door (KOHD) Facility 3480 Prince Lane Bozeman, Montana COB Application #26053 April 2026 Headwaters Engineering, Inc. Project # 2035.004 Prepared For: Kaufmann’s Overhead Door, Inc. 3480 Prince Lane Bozeman, MT 59718 H:\2035\004\DOCS\DESIGN\STORM\0_Stormwater Drainage Report.docx Page 2 of 7 I. Introduction The following report outlines the storm water analysis conducted for the proposed expansion of the Kaufmann’s Overhead Door (KOHD) property, and describes the storm water drainage and management facilities required for the facility. The storm water plan follows the design standards set forth in the City of Bozeman Design and Construction Standards, October 2024, (CBDCS) and subsequent addenda. Property Description The 2.14-acre parcel currently includes the KOHD main office and shop building, as well as a paved parking lot. The proposed expansion is planned to be completed in two phases. Phase 1 will include a 3,000 square foot shop and Phase 2 will include a 6,000 square foot shop. Said shops will be accessed via a paved parking lot connected to the existing parking lot on the site. The paved area and storm water facilities for both phases of the expansion will be completed with Phase 1. The majority of the property is already developed and equipped with storm water facilities sized to handle runoff from the existing impervious areas. The undeveloped area is well vegetated with mostly native upland grasses, and flows predominately to the north. The geologic features of the site are discussed in Appendix C – Geotechnical & Hydrogeological Evaluation. Runoff from the site starts as sheet flow before consolidating near the existing storm pond on the east end of the existing parking lot. From there, large flow events overtop the pond and flow through an existing culvert before discharging into the Cattail Creek drainage, which carries runoff to the north and away from the property. Cattail Creek runs adjacent to the property within a platted open space. Wetland delineations were conducted on the creek through the site and all relevant setbacks from waterways and wetlands are upheld throughout the site. No storm water will be routed directly into the Cattail Creek drainage, and only emergency storm water overflow runoff will be allowed to enter the drainage. The project is not located within a mapped flood floodplain of the East Gallatin River, which is located approximately 2860 feet to the east of the property. Existing Stormwater Studies Stormwater was analyzed by C&H Engineering in 2021 for the existing facility site plan development (COB Application 20439). The site currently operates as outlined in C&H’s report, and handles runoff in accordance with the City’s regulations at the time of submittal. State & Federal Regulations The City of Bozeman regulations exceed the DEQ stormwater requirements listed in DEQ Circular 8, and therefore all DEQ requirements are met or exceeded with the proposed design. Since no wetlands are to be impacted, no Section 404 Wetland Permitting will be required. II. Hydrology and Hydrogeology The site runoff has been modeled using the HydroCAD software and the SCS method for the storms ranging between the 2-year and 100-year event. The site is located adjacent to a creek drainage, that has historically conveyed runoff to the north and eventually into the East Gallatin River. The relief of the site allows for a direct route of excess runoff to Cattail Creek and the East Gallatin River without risk of flooding any structures. Design storm depths and intensities were taken directly from The City of H:\2035\004\DOCS\DESIGN\STORM\0_Stormwater Drainage Report.docx Page 3 of 7 Bozeman Design Standards Tables 6.5.1 and 6.5.2., while Table 6.6.2. was referenced to find the relevant SCS Curve Numbers for the predeveloped and post developed site. The attached Geotechnical/Hydrogeological Evaluation in Appendix C discusses the soils, in-situ conditions and groundwater for the site and surrounding area. Groundwater was reported at approximately 6 feet below existing ground elevation, which is low enough to not interfere with the proposes stormwater pond. The soils in the area are conducive to the proposed plan and do not raise any concern of risks associated with the stormwater plan. III. Existing Stormwater Drainage Conditions The existing ground slopes to the north/northeast at roughly 1% to 2%, starting as sheet flow then starting to collect into a shallow drainage path as it nears the existing culvert under the public trail. From the site, runoff continues north via the Cattail Creek drainage, and eventually into the East Gallatin River. Runoff within the existing paved areas is captured on-site via a drywell and on-site retention pond. The east portion of the parking lot and building surface flow across the asphalt and along the existing curb, through a curb cut into the existing pond. Overflow runoff from the pond then flows through the aforementioned trail culvert and into the Cattail Creek drainage. The west portion of the existing parking lot flows into an existing drywell located inside the paved parking area. The flow path of the proposed expansion site, and relief provided by the culvert and natural surface flow patterns provide a safe outlet for extreme flood events prior to damaging buildings. The Cattail Creek drainage acts strictly as emergency overflow conveyance, and remains within a platted open space until leaving the subdivision. Estimated pre-development flows are shown in Table 1. Table 1. Estimated Pre-Development Flows Sub Area Description Area (AC) Tc (min) Q10 (cfs) Q25 (cfs) Q100 (cfs) CN A On-Site Basin 0.84 8.3 0.22 0.39 0.69 74 B Off-site Basin 2.78 20.4 0.91 1.42 2.29 79 Version 10 of HydroCAD was used to model the storm basins using the SCS Method. Printouts for each basin are provided in the appendices. Time of concentration calculations were completed per Chapter 6 of the CBDCS. Basins were identified based on existing flow patterns and delineations are reflected on the Stormwater Basin Exhibit in Appendix A. IV. Proposed Stormwater Drainage System Runoff from the proposed expansion will be captured by the proposed retention pond located just north of the proposed parking lot. The pond is located in a manner that overtopping will flow to the east, and into the Cattail Creek drainage to be conveyed away from the site without inundating any buildings. Parking lot runoff will be directed to the pond via concrete curb, asphalt sheet flow, and a concrete valley gutter. Roof runoff will be collected via gutters and routed to the parking lot via downspouts, where it will flow across the pavement and into the retention pond. H:\2035\004\DOCS\DESIGN\STORM\0_Stormwater Drainage Report.docx Page 4 of 7 The proposed stormwater infrastructure was designed per the CBDCS. HydroCAD was used to determine the post development storm flows and retention pond volume. Since all the proposed expansion drains to a single storm pond, only one on-site drainage basin was utilized. The existing pond volume of approximately 1200 cft, which serves the existing development, was included in the proposed pond volume, on top of the required storage for the proposed expansion. Table 2 summarizes the anticipated on-site post development flows. Table 2. Estimated Post-Development Flows Sub Area Description Area (AC) Tc (min) Q10 (cfs) Q25 (cfs) Q100 (cfs) CN A On-Site Basin 0.84 2.9 1.4 1.73 2.22 91 Grading of the site will allow emergency overflow of the proposed pond to discharge to the east, away from all buildings. Flow will travel through the existing 12-inch HDPE culvert (or overtop the trail during large events) and into the Cattail Creek drainage. Sheet C-3 depicts the proposed site drainage with contours and flow arrows, as well as the storm pond and conveyance facilities. Version 10 of HydroCAD was used to model the storm basins using the SCS Method. Printouts for each basin are provided in the appendices. Time of concentration calculations were calculated per Chapter 6 of the CBDCS. The CN factor for an industrial site was chosen from Table 6.6.2. All said parameters were then entered into HydroCAD for their respective basins. Results from each model and calculations are included in the appendix. The only culverts to be utilized for the proposed expansion is the existing 12-inch culvert under the public trail. Said culvert will act as emergency overflow relief in the event the pond overtops. The culvert provides adequate capacity to pass the proposed 100-year flows. Flows in excess of the culvert capacity will be allowed to overtop the trail and enter the Cattail Creek drainage before inundating any buildings. The existing culvert has the capacity to convey 5.53 cfs, and the proposed expansion is estimated to produce 2.22 cfs during a 100-year event. Runoff from the proposed parking lot will discharge into an on-site retention pond, in the location of the existing pond. The existing pond was sized for the 10-year runoff associated with the existing building and parking lot areas. The existing pond volume of 1,200 cubic feet was added to the minimum pond volume for the proposed expansion to account for the existing pond and its contributing areas. The proposed expansion required storm pond volume was determined by the difference in pre- and post- development runoff, with respect to the 100-year event. Pond parameters are summarized in Table 3. Table 3. Storm Pond Volumes Pond Type Contributing Sub Areas 10-yr Volume (cft) 100-yr Volume (cft) Provided Volume (cft) A Retention Proposed Expansion 2,080 2,869 4,110 A Retention Existing Site 1,200 - 1,200* *Existing volume of 1,200 cf included in total Pond A volume. H:\2035\004\DOCS\DESIGN\STORM\0_Stormwater Drainage Report.docx Page 5 of 7 The proposed pond will retain the 100-year runoff associated with the proposed parking lot and building expansions, plus the original 10-year runoff from the existing building and parking lot. The site grading will provide relief for the pond to overtop to the east and enter into the Cattail Creek drainage to be conveyed away from the site. During the 100-year event, no storm water from the proposed parking lot expansion will back up into the parking lot or any of the proposed buildings. The overflow path is depicted on the Stormwater Exhibit (Ex. 1) in the appendices. Since the proposed storm pond is a retention pond, the initial storm volume and runoff treatment volume will be captured in the pond with zero runoff during the 10-year and 100-year events. Groundwater mounding was considered using the USGS Hantush equation. Based on the conditions observed on the site, mounding will peak at 3.4 feet directly below the pond, and taper off to approximately 0.5 feet at a distance of 120 feet from the pond. Groundwater depths are estimated at 3.5 to 4 feet deep at the pond location, suggesting that mounding of groundwater will not reach any buildings. Pretreatment within the proposed pond will be achieved via a forebay in the northwest portion of the pond, where parking lot runoff will enter the pond. The forebay was designed to retain 10% of the required storage volume. The existing 1,200 cft of pond storage, plus the required 2,869 cft 100-year runoff for the proposed development produce a total volume of 4,069 cft. The proposed forebay will hold approximately 414 cft, which exceeds the 10% requirement. The forebay will be formed via a 1- foot-tall check dam, where runoff will be allowed to settle prior to overtopping the dam and flowing into the remainder of the pond. The location and orientation of the forebay is shown on the civil plan sheets, as well as the Stormwater Exhibit (Ex. 1) in the following pages. The existing pond acts as an infiltration basin, and the proposed pond aims to build off the same concept. The proposed pond will be over-excavated to native gravels to match the existing pond, then filled with well-draining gravels to the design bottom elevation. A percolation test was conducted within the existing pond footprint and produced an infiltration rate consistent with Gravelly Sand, or 4.0 inches per hour as allowed by DEQ Circular 8. Using only the bottom area of the proposed pond, the total pond volume will fully drain in under 10 hours. A geological cross-section of the existing subsurface soils at the proposed pond location is provided on the Storm Pond Geologic Cross-Section sheet (Ex. 2) in the appendices. Evaluation of Major Storm Flood Risks The site was evaluated for risks during the major storm events, and considered both on- and off-site flows. Both proposed buildings were set to an elevation of at least 12 inches above native ground, and graded in a manner to allow relief around the buildings to provide adequate off-site flow passage without inundating the first floors. The proposed parking lot drains away from each building, and to the north. The most restrictive location between the two buildings was analyzed to ensure the major storm could pass safely and was determined to provide nearly 68 cfs to pass before reaching the main floor level. A cross-section representation (Section A-A) is shown on the Stormwater Exhibit (Ex. 1) in the appendices. The available capacity far exceeds the combined 100-year flows of both on- and off-site storm basins. Since the design provides storage of the 100-year event, the area will remain similar its current state during large storm events. The 2.22 cfs discharge will not increase flood risks along the historic flow path H:\2035\004\DOCS\DESIGN\STORM\0_Stormwater Drainage Report.docx Page 6 of 7 downgradient of the site. The Cattail Creek channel near the site can safely convey 16.14 cfs before leaving the banks. A cross-section (B-B) of the channel is shown on the stormwater exhibit in the appendices. The creek also enters a concrete box culvert adjacent to the site. Said culvert is a 9-ft by 5-ft box culvert with a capacity of 367 cfs. Based on the relief of the site and proposed grading, the box culvert would allow flows in excess of the stream capacity to pass before reaching the first floor of any proposed buildings. Furthermore, the centerline elevation of Prince Lane at the culvert crossing is lower than the floor elevation of the proposed buildings, which allows extreme flows to overtop Prince Lane and continue north before impacting the buildings. V. Operation, Inspection, and Maintenance Considerations The attached Stormwater Facilities Operation, Inspection, and Maintenance Manual addresses maintenance and upkeep of the stormwater related infrastructure. The Acknowledgement of Stormwater Facility Maintenance Requirement and Inspection form are also attached. Responsible Pary: DP&J, LLC Contact: Patrick Donnelly pdonnelly@kafmannsdoor.com 406-586-9636 3480 Prince Lane Bozeman, MT 59718 Finances for the stormwater maintenance activities will be sourced from a revolving fund initiated upon development for the purpose of stormwater maintenance. Estimated costs and frequency of maintenance are summarized below in Table 4. Table 4. Stormwater Maintenance Schedule & Costs Maintenance Item Maintenance Frequency (Yrs) Estimated Cost Annualized Cost Cleaning of Curb Lines, Valley Gutters, Curb Cuts 1 $250.00 $250.00 Cleaning of Gutters & Downspouts 1 $100.00 $100.00 Cleaning of Culverts 3 $150.00 $50.00 Storm Pond Sediment Removal 5 $1,500.00 $300.00 Total Annualized Maintenance Costs $700.00 The design life of the storm facilities is safely assumed to be 50 years. The account will be funded with an initial $4,000, repeated every 10 years, and $700 deposits every year in between. Forecasting the revolving fund balance using the estimated costs and schedules above, at the end of the system’s design life, the account balance will have been maintained and sufficiently funded throughout its life. A financial summary is included in Appendix D of this report. H:\2035\004\DOCS\DESIGN\STORM\0_Stormwater Drainage Report.docx Page 7 of 7 VI. References City of Bozeman Design and Construction Standards, October 2024, and all addenda Montana Post-Construction Storm Water BMP Design Guidance Manual, September 2017 Design Report, Stormwater Management, KOHD Building – C&H Engineering, June 2021 VII. Appendices Appendix A Civil Site Plan, Grading Plan, Civil Details Stormwater Exhibit Appendix B Time of Concentration Calculations Flowmaster Printouts Culvertmaster Printouts HydroCAD Printouts Groundwater Mounding Calculations Appendix C Geotechnical & Hydrogeological Evaluation & Soils Investigation Report USGS Soils Mapper Report Geologic Map Madison Groundwater Study Map Appendix D Stormwater Facilities Operation, Inspection, and Maintenance Manual Acknowledgement of Stormwater Facility Maintenance Requirements Stormwater Facility Inspection Form Stormwater Revolving Fund Balance Sheet ______________________________________________________________________________ ______________________________________________________________________________ 1105 Reeves Rd. W. Ste 6, Bozeman, MT 59718 (406)-581-5730 www.headwatersmt.net Appendix A Site Plans Stormwater Exhibit EEEEEEEEEEEG G G GGGGGGGGGGGGGGGGGGGGGGGGGSSSSSSSSSSSSSSSSSSSSSS SS SS SSSSTTTTTTTTWWWWW WWWWWWWWWWWWWWWWSDSDSDSDSDSDSDSDEEEWWWSSSSSS459.6514.918.3314.91110.37191.24391.09343.82 EGTSSWSD11"X17": 1"= 50 ftNGRAPHIC SCALE1 inch = ft.0( IN FEET )12.5252525HEADWATERSPROJECT NUMBERDRAWING NUMBERDRAWN BY:DATE:2026VERIFY SCALETHESE PRINTS MAY BEREDUCED. LINE BELOWMEASURES ONE INCH ONORIGINAL DRAWING. MODIFY SCALE ACCORDINGLYH:\2035\004\ACAD\SHEETS\SITE PLANS.dwg Plot Date: 4/24/2026 12:04 PM© HEADWATERS ENGINEERING, INC.REVISION DATE:1105 REEVES RD WEST, SUITE 6, BOZEMAN, MT 59718HEADWATERSMT.NET406-581-5730PROJECT LOCATIONMONTANABOZEMAN04/24/2026REEXISTING CONDITIONS3480 PRINCE LANEKAUFMANN'S OVERHEAD DOOR, INC.2035.004C1.0ROYAL WOLF WAYPRINCE LANELOT 16, BLOCK 42.14 ACRESLOT 17, BLOCK 40.97 ACRESLOT 18 , BLOCK 40.95 ACRESLOT 19, BLOCK 41.27 ACRES CO M M O N O P E N SP A C E 2 EXISTING SIDEWALKEXISTING SIDEWALKEXISTING SIDEWALKEXISTING SIDEWALKEXISTING TRUCKLOADING RAMPEXISTING BUILDING~ EXISTING ASPHALT ~EXISTING 25' PUBLIC TRAIL EASEMENTPER DOC. #2704913EXISTING 20' UTILITY EASEMENTPER DOC. #2704913EXISTING 20' UTILITY EASEMENTPER DOC. #2704913EXISTING 10' UTILITY EASEMENTPER DOC. #2704913EXISTING 10' UTILITY EASEMENTPER DOC. #270491360' ROADRIGHT-OF-WAY60' ROADRIGHT-OF-WAYDOC. #2704913EXISTING 24' APPROACHEXISTING 24' APPROACHEXISTING 24' APPROACHEXISTING GRAVEL TRAILEXISTING CURB CUTEXISTINGCONCRETE BOXCULVERTEXISTING 12" CULVERTEXISTINGSTORM PONDEXISTING STORMINLET MANHOLEEXISTING CONCRETE CURB, TYP.EXISTING 16" WATER MAINEXISTING 8" SEWER MAINEXISTING 15" STORM DRAINEXISTING WATER SERVICEEXISTING SEWER SERVICEEXISTING GAS LINEEXISTING POWER TRANSFORMER3' SETBACK20' SETBACKEXISTING HYDRANT, TYP.EXISTING STORMINLET, TYP.PROPERTY BOUNDARYPROPERTY BOUNDARYPROPERTY BOUNDARYPROPERTY BOUNDARYCATTAIL CREEKEXISTING BURIED POWER, GAS, COMMUNICATIONSEXISTING STREET LIGHT, TYP.EXISTINGBUILDINGEXISTING WETLAND EDGE, TYP.50' WATERCOURSE SETBACKEXISTING TRASH & RECYCLEDUMPSTERSEXISTING BIKE RACKS(2) "U-SHAPED" RACKS35' TBC TO TBCEXISTINGCURBSTOPEXISTINGCLUSTERMAILBOXLOCATIONLEGEND:EXISTING BURIED POWEREXISTING GAS LINEEXISTING COMMUNICATIONS LINEEXISTING 8" SEWER MAINEXISTING 16" WATER MAINEXISTING 15" STORM DRAIN LINEEXISTING CREEK CENTERLINESETBACK, AS NOTEDEASEMENT, AS NOTEDEXISTING WETLANDSEXISTING STORM PONDEXISTING MAJOR CONTOUR, 5' INTERVALEXISTING MINOR CONTOUR, 1' INTERVALTRAFFIC FLOW DIRECTIONSEXISTING HYDRANT, TYP. EG G G G GGGGGGGSSSSSSSSSSSSSSSSSSSSWWWWWWWWWWSDSDSDEEEEWWWWEWWWWSSSSSSWWWWEEEEEEEEEEEE E GGGGGGGGGGG G 459.65391.09343.82 EGTSSWSD11"X17": 1"= 40 ftNGRAPHIC SCALE1 inch = ft.0( IN FEET )10202020HEADWATERSPROJECT NUMBERDRAWING NUMBERDRAWN BY:DATE:2026VERIFY SCALETHESE PRINTS MAY BEREDUCED. LINE BELOWMEASURES ONE INCH ONORIGINAL DRAWING. MODIFY SCALE ACCORDINGLYH:\2035\004\ACAD\SHEETS\SITE PLANS.dwg Plot Date: 4/24/2026 12:16 PM© HEADWATERS ENGINEERING, INC.REVISION DATE:1105 REEVES RD WEST, SUITE 6, BOZEMAN, MT 59718HEADWATERSMT.NET406-581-5730PROJECT LOCATIONMONTANABOZEMAN04/24/2026RECIVIL SITE & UTILITY PLAN3480 PRINCE LANEKAUFMANN'S OVERHEAD DOOR, INC.2035.004C2.0LOT 16, BLOCK 42.14 ACRESLOT 17, BLOCK 40.97 ACRESLOT 18, BLOCK 40.95 ACRESEXISTING 25' PUBLIC TRAIL EASEMENTPER DOC. #2704913EXISTING 10' UTILITY EASEMENTPER DOC. #2704913EXISTING 10' UTILITY EASEMENTPER DOC. #2704913PROPOSEDPAVEMENTPROPOSED CURB & GUTTER, TYP.PROPOSEDBUILDING 1ROOF OVERHANGR31.5'(TBC)EXISTING BUILDINGEXISTING BUILDINGEXISTING TRUCKLOADING RAMPPEDESTRIAN CURBPROPOSED RETENTION POND EXPANSION2' DEEP W/ 4:1 SIDE SLOPESSEE DETAIL, SHEET C-3EXISTING 12" CULVERTEXISTING 9'x5'CONCRETE BOXCULVERT3' SETBACKCOMMON OPENSPACE 2EXISTING POWERTRANSFORMERSEXISTING GAS LINEPROPOSED POWER & GAS SERVICESPROPERTY BOUNDARYPROPERTY BOUNDARYEXISTING SIDEWALK20' SETBACKPERCOLATION TESTPROPERTY DESCRIPTION:LOT 16, BLOCK 4, NELSON MEADOWS SUBDIVISION (J-680)PROPERTY ZONING:M-1BLOCK FRONTAGE CLASSIFICATION:OTHEREXISTINGTREES, TYP.45.1'CATTAIL CREEKPROPOSED TURN WIDENING100' - 0"30' - 0"FUTURE BUILDING 2120' X 50'DELINEATED WETLANDEDGE, TYP.50' WATERCOURSE SETBACKPARKING NOTES1.EXISTING PARKING SPACES = 11 (EXISTING BUILDING SITE)2.PROPOSED PARKING SPACES = 63.ON STREET PARKING SPACES = N/A4.PROPOSED BIKE PARKING SPACES = 5 (2 SHORT TERM, 3 LONG TERM)5.NO ADDITIONAL ADA PARKING IS PROVIDED. NO WORKER OR CUSTOMER SPACE IS PROPOSEDIN BUILDING 1.SITE PLAN NOTES:1.NO WATER OR SEWER FACILITIES PLANNED FOR BUILDING 12.NO HISTORIC, CULTURAL OR ARCHAEOLOGICAL RESOURCES EXIST ON SITE3.WETLANDS WERE DELINEATED AS SHOWN ON THE SITE PLAN. NO WETLANDS EXIST WITHINTHE SUBJECT PROPERTY. APPLICABLE WETLAND/WATERWAY SETBACKS ARE SHOWN.4.NO SETBACK ENCROACHMENTS ARE PROPOSED.5.SNOW REMOVAL WILL BE PUSHED FROM THE SOUTHERN END OF THE PROPOSED EXPANSIONTO THE NORTH, INTO THE RETENTION POND AREA. LAYDOWN CURB IS TO BE INSTALLEDWHERE PLOWS WILL PUSH SNOW FROM THE PAVEMENT TO THE STORAGE AREA.6.PROPOSED PARKING LOT EXPANSION IS 10,023 SF AND 1,566 SF (15.6%) SNOW STORAGE PROVIDED7.MAIL TO BE DELIVERED TO EXISTING BUILDING MAILBOX ON ROYAL WOLF WAY. SEE SHEETC1.0 FOR LOCATION.8.BUILD-TO REQUIREMENTS ARE N/A FOR M-1 ZONING.9.SEE SHEETS C4.1 & C4.2 FOR PHASING AND CONSTRUCTION MANAGEMENT PLANS.10.NO SITE LIGHTING IS PROPOSED FOR THE EXPANSION.11.OPEN SPACE NOT REQUIRED FOR COMMERCIAL USE.PRINCE LANEEXISTING 8" PVC SEWER MAINEXISTING 16" D.I.P. WATER MAINFUTURE 34" COPPER WATER,4" FIRE & 4" PVC SEWERSERVICESLAYDOWN CURBEXISTING TRASH & RECYCLEDUMPSTERSROOF OVERHANG5' CONCRETE SIDEWALK,6" REINFORCED(PHASE 2)PROPOSED POWER & GAS SERVICES3' SETBACKVISION TRIANGLEVISION TRIANGLE120.0'50.006" THICKREINFORCEDCONCRETESIDEWALK2' FLAT CONCRETEEDGINGPROPOSED INVERTED "U"BIKE RACK (2 SPACES)REMOVE EXISTING CURBREMOVE EXISTING CURBSAW CUT ASPHALT &TACK PRIOR TO PAVINGPROPOSEDPEDESTRIAN RAMP4" STEEL BOLLARD,TYP. ALL DRIVE-INDOORS18'9'24'3' LANDSCAPEBUFFEREXISTINGRETENTIONPOND3' LANDSCAPE BUFFER(PHASE 2)8'35' TBC TO TBCEXISTING 60' R.O.W.DOC. #2704913EXISTING STREET LIGHT, TYP.5'EXISTING COPPER WATER SERVICEEXISTING CURB STOPEXISTING 15" STORM DRAINEXISTING FIRE HYDRANTPROPOSEDUTILITY METERSPROPOSEDUTILITYMETERS(PHS. 2)R9.5'TBCEXISTING GRAVEL TRAILSNOWSTORAGEAREA(3) BIKERACKS125 LF OF 3' WIDECONCRETEVALLEY GUTTERR10' (TBC)4" YELLOW PARKINGSTRIPES, TYP.TYP.TYP.LEGEND:EXISTING BURIED POWEREXISTING GAS LINEEXISTING COMMUNICATIONS LINEEXISTING 8" SEWER MAINEXISTING 16" WATER MAINEXISTING 15" STORM DRAIN LINEEXISTING CREEK CENTERLINESETBACK, AS NOTEDEASEMENT, AS NOTEDEXISTING WETLANDSEXISTING STORM PONDEXISTING MAJOR CONTOUR, 5' INTERVALEXISTING MINOR CONTOUR, 1' INTERVALPROPOSED 34" WATER SERVICEPROPOSED 4" SEWER SERVICEPROPOSED STORM PONDVISION TRIANGLEPROPOSED SNOW STORAGEPROPOSED CURB REMOVAL5' WIDE CONCRETESIDEWALK, 6"REINFORCEDPROPOSED 6' WIDE GRAVEL TRAIL(PHASE 2)EXISTING 4" SEWER SERVICE9'18'9'TYP.TYP. G G G GGGGSSSSSSSDSDEEWWWWEG WWWWWSSSSSSSSSSWWWWWEEEEEEEEEEEEEE E GGGGGGGGGGGGGG G 459.65391.09343.82 4594.004593.5045 9 3 . 5 0 4593.004593.504593.50 4592.50 4593.00 4592.504594.00 4594.00 4590.504592.504590.504591.504592.504593.504594.004593.504593.004592.50 4590.50 4590.504591.00GEEGEEEGGG11"X17": 1"= 30 ftNGRAPHIC SCALE1 inch = ft.0( IN FEET )7.5151515HEADWATERSPROJECT NUMBERDRAWING NUMBERDRAWN BY:DATE:2026VERIFY SCALETHESE PRINTS MAY BEREDUCED. LINE BELOWMEASURES ONE INCH ONORIGINAL DRAWING. MODIFY SCALE ACCORDINGLYH:\2035\004\ACAD\SHEETS\SITE PLANS.dwg Plot Date: 4/24/2026 12:16 PM© HEADWATERS ENGINEERING, INC.REVISION DATE:1105 REEVES RD WEST, SUITE 6, BOZEMAN, MT 59718HEADWATERSMT.NET406-581-5730PROJECT LOCATIONMONTANABOZEMAN04/24/2026REGRADING & DRAINAGE PLAN3480 PRINCE LANEKAUFMANN'S OVERHEAD DOOR, INC.2035.004C3.0LOT 16, BLOCK 42.14 ACRESLOT 17, BLOCK 40.97 ACRESLOT 18, BLOCK 40.95 ACRESEXISTING 25' PUBLIC TRAIL EASEMENTPER DOC. #2704913EXISTING 10' UTILITY EASEMENTPER DOC. #2704913EXISTING 10' UTILITY EASEMENTPER DOC. #2704913EXISTINGCURB CUTPROPOSED CURB& GUTTER, TYP.PROPOSEDBUILDING 1FFE=4594.50R31.5' (TBC)EXISTING BUILDINGEXISTING TRUCKLOADING RAMPPROPOSED 3' WIDECONCRETE VALLEYGUTTER0.5%PEDESTRIAN CURBSPILLSPILLPROPOSED RETENTION POND EXPANSIONTOP = 4592.10BTM = 4590.10REQUIRED VOL = 2,869 CFTPROVIDED VOL = 4,100 CFT*2' DEEP W/ 4:1 SIDE SLOPES (SEE DETAIL)EXISTING 12" CULVERTCAPACITY = 5.53 CFSEXISTING 9'x5' CONCRETE BOXCULVERT, CAPACITY = 367 CFS4:1 SLOPE4:1 SLOPENATIVE GRAVEL LAYEROVER-EXCAVATE BOTTOMTO NATIVE GRAVELS,BACKFILL WITHWELL-DRAINING GRAVELS3'-4'2' TYP.CAP WITH 6" OF TOPSOIL & SEEDESTIMATED SEASONAL HIGHGROUNDWATER ATAPPROXIMATE GRAVEL DEPTHTYPICAL RETENTION POND SECTIONSTORM POND NOTES:1.*EXISTING POND VOLUME = 1,200 CFT, PROPOSED IMPERVIOUS AREA REQUIRES 2,869 CFTOF STORAGE, FOR A COMBINED REQUIRED TOTAL OF 4,069 CFT. PROVIDED VOLUMEINCLUDES EXISTING POND VOLUME PLUS THE REQUIRED STORAGE FOR THE PROPOSEDBUILDINGS AND PARKING LOT.2.EXISTING POND IS 1.5' DEEP, CONSTRUCTED AS SHOWN ABOVE. BOTTOM OF EXISTINGPOND TO BE LOWERED 6" TO MATCH PROPOSED POND.3.NO EVIDENCE OF HIGH GROUNDWATER EXISTS IN THE EXISTING POND4.SEE SHEET D3.0 FOR ADDITIONAL SOILS DETAILSTOP=4592.10BTM=4590.103' SETBACKCOMMON OPENSPACE 2EXISTING POWERTRANSFORMERSEXISTING GAS LINEPROPOSED POWER & GAS SERVICESPROPERTY BOUNDARYPROPERTY BOUNDARYEXISTING SIDEWALK20' SETBACKPERCOLATION TESTPROPERTY DESCRIPTION:LOT 16, BLOCK 4, NELSON MEADOWS SUBDIVISION (J-680)PROPERTY ZONING:M-1BLOCK FRONTAGE CLASSIFICATION:OTHEREXISTINGTREES, TYP.CATTAIL CREEKPROPOSED TURN WIDENINGFUTURE BUILDING 2120' X 50'FFE = 4594.50EXISTING WETLANDEDGE, TYP.50' WATERCOURSE SETBACKNOTES:1.NO ROCK OUTCROPPINGS OR STEEP SLOPES EXIST ON SITE2.NO MAPPED FLOODPLAINS EXIST ON SITE3.CATTAIL CREEK IS THE NEAREST WATERWAY, LOCATED WITHIN THE PLATTED COMMONSPACE. WATERWAY SETBACKS DO ENCROACH ON THE SUBJECT PROPERTY.4.NO IRRIGATION DITCHES EXIST ON THE SITE.5.THE CONTRACTOR IS TO VERIFY ALL SIDEWALKS AND DOOR ACCESS AREAS HAVE ACROSS SLOPE OF LESS THAN 2% PRIOR TO PAVING OR PLACING CONCRETE.6.SNOW REMOVAL WILL BE PUSHED FROM THE SOUTHERN END OF THE PROPOSEDEXPANSION TO THE NORTH, INTO THE RETENTION POND AREA. LAYDOWN CURB IS TO BEINSTALLED WHERE PLOWS WILL PUSH SNOW FROM THE PAVEMENT TO THE STORAGEAREA.7.PROPOSED PARKING LOT EXPANSION IS 10,023 SF AND 1,566 SF (15.6%) SNOW STORAGEPROVIDED8.NO MAPPED FLOODPLAIN EXISTS ON THE PROPERTYPRINCE LANEFUTURE WATER &SEWER SERVICESLAYDOWN CURBEXISTING TRASH &RECYCLE DUMPSTERSROOF OVERHANG5' CONCRETE SIDEWALK(PHASE 2)PROPOSED POWER & GAS SERVICES3' SETBACKVISION TRIANGLE0.5%5' CONCRETESIDEWALK2' CONCRETE EDGINGEMERGENCYOVERFLOW PATHCL=94.04CL=93.78TBC=94.74TBC=92.62EC=93.96EC=93.90EC=94.43EC=94.50CUT EXISTING ASPHALT BACK~8' TO ELIMINATE LOW POINTREMOVE EXISTING CURBEC/EP=94.37(GB)EC/EP=94.37TBC=94.89EP=94.333.6%1.5%1.5% 1. 5 %TBC=93.63TBC=94.04TBC=93.84(MP)1.5%1.5%1.5%1.5%ROOFOVERHANGTBC=94.38(LAYDOWN)TBC=94.38(LAYDOWN)REMOVE EXISTING CURB & GUTTER, TYP.DETAIL ADETAIL A11"X17": 1"= 20 ftGRAPHIC SCALE1 inch = ft.0( IN FEET )5101010FFE=4594.501.5%INVERTED "U" BIKE RACKNEC/TBC=94.14FLATTEN CURB, SLOPE TOASPHALT4.1%2.2%1.4%1.1%1.6% 1.6%5%EXISTING RETENTION PONDINV.=4590.77INV.=4590.273.4%4:14:12%MAXGRADING ABBREVIATIONS:EP = EDGE OF PAVEMENTEC = EDGE OF CONCRETETBC = TOP BACK OF CURBGB = GRADE BREAKCL = CENTERLINEPC = POINT OF CURVATUREMP = MID POINTPT = POINT OF TANGENCYINV = INVERTFFE = FIRST FLOOR ELEVATIONCL=93.42EP=93.42TBC=93.76(GB)1.9%4.2%EP=92.17(LOW POINT)1% 1. 2 %TBC=93.02(FULL CATCH)TRANSITION TOLAYDOWN CURBEXISTING LOW POINTEXISTING GRAVEL TRAIL0.5%INV.=4587.304:1 MAXLONG-TERMBIKE RACK,TYP.FOREBAY1' DEPTH(414 CFT)CURB CUTEC=93.93EC=93.89L A N D I NG R AM P 1.5%5.9%1.5%LP=93.643. 6 % 1. 5 % 1. 5 % 5. 9 % 1. 5 %PROPOSED CURB5' AT 1.5%4'SNOWSTORAGE5'4'2' TAPER ON BACK OF CURB © 2026 Microsoft Corporation © 2026 Maxar ©CNES (2026) Distribution Airbus DS SSSSSSSSSSSSSSSSSSSS SSSS SS TTTTWWWWWWWWWWWWWWWWWWWWSDSDSDSDSDWSSSSSSSSWSSW11"X17": 1"= 100 ftNGRAPHIC SCALE1 inch = ft.0( IN FEET )25505050HEADWATERSPROJECT NUMBERDRAWING NUMBERDRAWN BY:DATE:2026VERIFY SCALETHESE PRINTS MAY BEREDUCED. LINE BELOWMEASURES ONE INCH ONORIGINAL DRAWING. MODIFY SCALE ACCORDINGLYH:\2035\004\ACAD\SHEETS\STORM SHEETS.dwg Plot Date: 4/24/2026 12:22 PM© HEADWATERS ENGINEERING, INC.REVISION DATE:1105 REEVES RD WEST, SUITE 6, BOZEMAN, MT 59718HEADWATERSMT.NET406-581-5730PROJECT LOCATIONMONTANABOZEMAN04/24/2026RESTORMWATER EXHIBIT3480 PRINCE LANEKAUFMANN'S OVERHEAD DOOR, INC. 2035.004EX. 1OFF SITE BASINPROPOSEDPONDON-SITE BASINEXISTINGASPHALTPROPOSEDASPHALTCATTAIL CREEKPROPOSEDBLDG. 1PROPOSEDBLDG. 2EXISTINGBUILDINGEXISTING 12" CULVERTEXISTING WETLANDS, TYP.PRINCE LANEROYAL WOLF WAYFRONTAGE ROADEXISTING TRAILEXISTING TRAILEXISTING 9'x5' CONCRETE BOX CULVERTCAPACITY = 367 CFSAAA-A: 100-YEAR FLOW CROSS-SECTIONPROPOSED CURBFIRST FLOORBUILDING 2FIRST FLOORBUILDING 1PROPOSED VALLEY GUTTERWATER SURFACE ELEVATIONAT 100-YEAR FLOW (2.22 CFS)HORIZONTAL SCALE: 1" = 10'VERTICAL SCALE: 1" = 10'11X17 HORIZONTAL: 1" = 20'11X17 VERTICAL: 1" = 2'LEGEND:EXISTING FLOW DIRECTIONPROPOSED FLOW DIRECTIONTOTAL CAPACITY = 67.97 CFSWITH WATER SURFACE AT4594.49'BBB-B: CATTAIL CREEK CHANNEL CAPACITYHORIZONTAL SCALE: 1" = 10'VERTICAL SCALE: 1" = 10'11X17 HORIZONTAL: 1" = 20'11X17 VERTICAL: 1" = 2'16.14 CFS @ 4590.34'EXISTING CREEK BOTTOMFOREBAY WWWWWWWSSSSSSSSSSSSSSWWWWWWW4593.004592.504593.504593.004591.504590.504590.504591.504592.504592.50 4590.50 11"X17": 1"= 20 ftNGRAPHIC SCALE1 inch = ft.0( IN FEET )5101010HEADWATERSPROJECT NUMBERDRAWING NUMBERDRAWN BY:DATE:2026VERIFY SCALETHESE PRINTS MAY BEREDUCED. LINE BELOWMEASURES ONE INCH ONORIGINAL DRAWING. MODIFY SCALE ACCORDINGLYH:\2035\004\ACAD\SHEETS\STORM SHEETS.dwg Plot Date: 4/30/2026 8:33 AM© HEADWATERS ENGINEERING, INC.REVISION DATE:1105 REEVES RD WEST, SUITE 6, BOZEMAN, MT 59718HEADWATERSMT.NET406-581-5730PROJECT LOCATIONMONTANABOZEMAN03/26/2026RESTORM POND GEOLOGIC3480 PRINCE LANEKAUFMANN'S OVERHEAD DOOR, INC. 2035.004EX. 24 59 1 .1 0 4 59 0 .1 0 CC11"X17": 1"= 10 ftGRAPHIC SCALE1 inch = ft.0( IN FEET )2.5555EXISTING PAVEMENTEXISTINGCURBEXISTING ROAD MIXEXISTING GRAVEL SUBBASEEXISTING TOPSOIL, TYP.NATIVE GRAVELSNATIVE GRAVELSEXISTING GRAVEL FILLBELOW POND BOTTOMEXISTING PONDPROPOSED PONDNATIVESILT/CLAYPROPOSED STORM PONDEXISTING STORM PONDEX I S T I N G C U R B CROSS-SECTIONPROPOSED BUILDING 2APPROXIMATE HIGHGROUNDWATER LEVELFINISHED GROUNDEXISTING GROUNDPERCOLATIONTEST LOCATIONNOTES:1.PROPOSED STORM POND TO BE OVER-EXCAVATED TO NATIVE GRAVELS ANDBACKFILLED WITH IMPORTED, WELL-DRAINING GRAVELS TO THE DESIGN BOTTOMELEVATION.2.HIGHEST GROUNDWATER RECORDED WITH SUBDIVISION GROUNDWATERMONITORING ON SUBJECT LOT WAS ~6.5' BELOW NATIVE GROUND,APPROXIMATELY 3-4' BELOW PROPOSED POND BOTTOM.3.GEOTECHNICAL INVESTIGATIONS SUGGEST HIGH GROUND WATER LEVEL ISCONSISTENT WITH NATIVE GRAVEL DEPTH.4.PERCOLATION TESTING SHOWED INFILTRATION RATES FASTER THAN 6 INCHESPER MINUTE.FOREBAY ______________________________________________________________________________ ______________________________________________________________________________ 1105 Reeves Rd. W. Ste 6, Bozeman, MT 59718 (406)-581-5730 www.headwatersmt.net Appendix B Calcula�ons Modeling Printouts KOHD Facility City of Bozeman  Time of Concentration Calculations Ryan Estep 3/3/2026 Onsite Storm Pond Basin Time of Concentration Tc=Tt1 + Tt2+Tt3 Pre Development Post Development Tt=K/p^.5*(nL/S^.5)^.8 Tt=K/p^.5*(nL/S^.5)^.8 Tt1 7.4 sheet flow (min) Tt1 2.2 sheet flow (min) n 0.05 mannings n 0.011 mannings L 100 flow length (ft) L 100 flow length (ft) P2 1.7 10yr 24 hour depth (in) P2 1.7 10yr 24 hour depth (in) s0.01slope (ft/ft) s 0.01 slope (ft/ft) Tt2= length / velocity Tt2= length / velocity Tt2= 0.9 minutes Tt2= 0.7 minutes Lunpaved= 88 ft Lunpaved= 0 ft Lpaved= 0 ft Lpaved= 88 ft V=16.1345xs^.5 unpaved V=16.1345xs^.5 unpaved Vunpaved= 1.61345 ft/s Vunpaved= 1.61345 ft/s slope 0.01 ft/ft slope 0.01 ft/ft V=20.3282*s^.5 paved V=20.3282*s^.5 paved Vpaved= 2.03282 ft/s Vpaved= 2.03282 ft/s slope 0.01 ft/ft slope 0.01 ft/ft Tt3= length / velocity Tt3= length / velocity Tt3= 0 minutes Tt3= 0 minutes L pipe/channel 0 ft L pipe/channel 0 ft Vel=1.49/n*R^(2/3)x S^.5 Vel=1.49/n*R^(2/3)x S^.5 V= 5.8 ft/s V= 5.8 ft/s n 0.03 mannings n 0.03 mannings R2.1Hydraulic radius R 2.1 Hydraulic radius S 0.005 slope ft/ft S 0.005 slope ft/ft R=Flow Area/Wetted Perimeter R=Flow Area/Wetted Perimeter Predevelopment Post Development Total Time of Concentration 8.3 minutes Total Time of Concentration 2.9 minutes 0.1 hours 0.0 hours Sheet Flow ‐ 150' max Sheet Flow ‐ 150' max Shallow Concentrated Shallow Concentrated Open Channel & Pipe Flow Open Channel & Pipe Flow KOHD Facility City of Bozeman  Time of Concentration Calculations Ryan Estep 3/3/2026 Offsite Storm Basin Time of Concentration Tc=Tt1 + Tt2+Tt3 Existing Conditions Tt=K/p^.5*(nL/S^.5)^.8 Tt1 17.7 sheet flow (min) n 0.15 mannings L 100 flow length (ft) P2 1.7 10yr 24 hour depth (in) s0.01slope (ft/ft) Tt2= length / velocity Tt2= 2.7 minutes Lunpaved= 260 ft Lpaved= 0 ft V=16.1345xs^.5 unpaved Vunpaved= 1.61345 ft/s slope 0.01 ft/ft V=20.3282*s^.5 paved Vpaved= 2.03282 ft/s slope 0.01 ft/ft Tt3= length / velocity Tt3= 0 minutes L pipe/channel 0 ft Vel=1.49/n*R^(2/3)x S^.5 V= 5.8 ft/s n 0.03 mannings R2.1Hydraulic radius S 0.005 slope ft/ft R=Flow Area/Wetted Perimeter Predevelopment Total Time of Concentration 20.4 minutes 0.3 hours Sheet Flow ‐ 150' max Shallow Concentrated Open Channel & Pipe Flow Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Channel Slope 0.01000 ft/ft Normal Depth 0.18 ft Discharge 2.22 ft³/s Cross Section Image Cross Section for A-A 2/20/2026 1:06:02 PM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 1of1Page Project Description Friction Method Manning Formula Solve For Discharge Input Data Channel Slope 0.00500 ft/ft Normal Depth 1.63 ft Discharge 16.14 ft³/s Cross Section Image Cross Section for B-B 2/20/2026 1:05:27 PM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 1of1Page Culvert Calculator Report Existing Box Culvert h:\2035\004\docs\design\storm\kohd.cvm 02/20/26 01:06:32 PM CAiHE Academic Site © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: headw CulvertMaster v3.3 [03.03.00.04] Page 1 of 1 Solve For: Discharge Culvert Summary Allowable HW Elevation 4,593.68 ft Headwater Depth/Height 1.20 Computed Headwater Eleva 4,593.68 ft Discharge 367.70 cfs Inlet Control HW Elev. 4,593.68 ft Tailwater Elevation 4,590.25 ft Outlet Control HW Elev. 4,593.67 ft Control Type Inlet Control Grades Upstream Invert 4,587.70 ft Downstream Invert 4,586.80 ft Length 103.00 ft Constructed Slope 0.008738 ft/ft Hydraulic Profile Profile S2 Depth, Downstream 2.97 ft Slope Type Steep Normal Depth 2.70 ft Flow Regime Supercritical Critical Depth 3.73 ft Velocity Downstream 13.77 ft/s Critical Slope 0.003551 ft/ft Section Section Shape Box Mannings Coefficient 0.013 Section Material Concrete Span 9.00 ft Section Size 9 x 5 ft Rise 5.00 ft Number Sections 1 Outlet Control Properties Outlet Control HW Elev. 4,593.67 ft Upstream Velocity Head 1.86 ft Ke 0.20 Entrance Loss 0.37 ft Inlet Control Properties Inlet Control HW Elev. 4,593.68 ft Flow Control Transition Inlet Type 90° headwall w 45° bevels Area Full 45.0 ft² K 0.49500 HDS 5 Chart 10 M 0.66700 HDS 5 Scale 2 C 0.03140 Equation Form 2 Y 0.82000 Culvert Calculator Report Existing 12" HDPE h:\2035\004\docs\design\storm\kohd.cvm 02/20/26 10:08:06 AM CAiHE Academic Site © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: headw CulvertMaster v3.3 [03.03.00.04] Page 1 of 1 Solve For: Discharge Culvert Summary Allowable HW Elevation 4,592.50 ft Headwater Depth/Height 2.08 Computed Headwater Eleva 4,592.50 ft Discharge 5.53 cfs Inlet Control HW Elev. 4,592.45 ft Tailwater Elevation 4,590.86 ft Outlet Control HW Elev. 4,592.50 ft Control Type Outlet Control Grades Upstream Invert 4,590.42 ft Downstream Invert 4,590.19 ft Length 20.00 ft Constructed Slope 0.011500 ft/ft Hydraulic Profile Profile CompositeM2PressureProfile Depth, Downstream 0.94 ft Slope Type Mild Normal Depth N/A ft Flow Regime Subcritical Critical Depth 0.94 ft Velocity Downstream 7.22 ft/s Critical Slope 0.017754 ft/ft Section Section Shape Circular Mannings Coefficient 0.012 Section MaterialCorrugated HDPE (Smooth Interior) Span 1.00 ft Section Size 12 inch Rise 1.00 ft Number Sections 1 Outlet Control Properties Outlet Control HW Elev. 4,592.50 ft Upstream Velocity Head 0.77 ft Ke 0.20 Entrance Loss 0.15 ft Inlet Control Properties Inlet Control HW Elev. 4,592.45 ft Flow Control Submerged Inlet Type Beveled ring, 33.7° bevels Area Full 0.8 ft² K 0.00180 HDS 5 Chart 3 M 2.50000 HDS 5 Scale B C 0.02430 Equation Form 1 Y 0.83000 1S Addition-POST 3S Offsite Basin 5S Addition-PRE 2P Proposed Pond Routing Diagram for KOHDPrepared by Headwaters Engineering, Inc, Printed 4/30/2026 HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Subcat Reach Pond Link KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 2HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC P2 (inches) 1 2yr-24hr Type II 24-hr Default 24.00 1 1.18 2 1.18 KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 3HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 121,050 79 50-75% Grass cover, Fair, HSG C (3S) 36,438 74 >75% Grass cover, Good, HSG C (5S) 36,438 91 Urban industrial, 72% imp, HSG C (1S) 193,926 80 TOTAL AREA KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 4HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (sq-ft) Soil Group Subcatchment Numbers 0 HSG A 0 HSG B 193,926 HSG C 1S, 3S, 5S 0 HSG D 0 Other 193,926 TOTAL AREA KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 5HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Sub Num 0 0 121,050 0 0 121,050 50-75% Grass cover, Fair 0 0 36,438 0 0 36,438 >75% Grass cover, Good 0 0 36,438 0 0 36,438 Urban industrial, 72% imp 0 0 193,926 0 0 193,926 TOTAL AREA Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 6HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=36,438 sf 72.00% Impervious Runoff Depth>0.49"Subcatchment 1S: Addition-POST Flow Length=188' Slope=0.0100 '/' Tc=5.0 min CN=91 Runoff=0.76 cfs 1,484 cf Runoff Area=121,050 sf 0.00% Impervious Runoff Depth>0.13"Subcatchment 3S: Offsite Basin Flow Length=360' Slope=0.0100 '/' Tc=24.0 min CN=79 Runoff=0.19 cfs 1,265 cf Runoff Area=36,438 sf 0.00% Impervious Runoff Depth>0.06"Subcatchment 5S: Addition-PRE Flow Length=188' Slope=0.0100 '/' Tc=9.7 min CN=74 Runoff=0.01 cfs 172 cf Peak Elev=4,590.56' Storage=775 cf Inflow=0.76 cfs 1,484 cfPond 2P: Proposed Pond Outflow=0.03 cfs 1,116 cf Total Runoff Area = 193,926 sf Runoff Volume = 2,921 cf Average Runoff Depth = 0.18" 86.47% Pervious = 167,691 sf 13.53% Impervious = 26,235 sf Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 7HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Addition-POST Runoff = 0.76 cfs @ 11.96 hrs, Volume= 1,484 cf, Depth> 0.49" Routed to Pond 2P : Proposed Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18" Area (sf) CN Description 36,438 91 Urban industrial, 72% imp, HSG C 10,203 28.00% Pervious Area 26,235 72.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.6 100 0.0100 0.63 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.18" 0.7 88 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.3 188 Total, Increased to minimum Tc = 5.0 min Subcatchment 1S: Addition-POST Runoff Hydrograph Time (hours)2423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 2yr-24hr Rainfall=1.18" P2=1.18" Runoff Area=36,438 sf Runoff Volume=1,484 cf Runoff Depth>0.49" Flow Length=188' Slope=0.0100 '/' Tc=5.0 min CN=91 0.76 cfs Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 8HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Offsite Basin Runoff = 0.19 cfs @ 12.25 hrs, Volume= 1,265 cf, Depth> 0.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18" Area (sf) CN Description 121,050 79 50-75% Grass cover, Fair, HSG C 121,050 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.3 100 0.0100 0.08 Sheet Flow, Grass: Short n= 0.150 P2= 1.18" 2.7 260 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 24.0 360 Total Subcatchment 3S: Offsite Basin Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 2yr-24hr Rainfall=1.18" P2=1.18" Runoff Area=121,050 sf Runoff Volume=1,265 cf Runoff Depth>0.13" Flow Length=360' Slope=0.0100 '/' Tc=24.0 min CN=79 0.19 cfs Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 9HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Addition-PRE Runoff = 0.01 cfs @ 12.11 hrs, Volume= 172 cf, Depth> 0.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18" Area (sf) CN Description 36,438 74 >75% Grass cover, Good, HSG C 36,438 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.8 100 0.0100 0.19 Sheet Flow, Fallow n= 0.050 P2= 1.18" 0.9 88 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 9.7 188 Total Subcatchment 5S: Addition-PRE Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.013 0.012 0.011 0.011 0.01 0.01 0.009 0.009 0.008 0.008 0.007 0.007 0.006 0.006 0.005 0.0050.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Type II 24-hr 2yr-24hr Rainfall=1.18" P2=1.18" Runoff Area=36,438 sf Runoff Volume=172 cf Runoff Depth>0.06" Flow Length=188' Slope=0.0100 '/' Tc=9.7 min CN=74 0.01 cfs Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 10HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Pond 2P: Proposed Pond Inflow Area = 36,438 sf, 72.00% Impervious, Inflow Depth > 0.49" for 2yr-24hr event Inflow = 0.76 cfs @ 11.96 hrs, Volume= 1,484 cf Outflow = 0.03 cfs @ 13.44 hrs, Volume= 1,116 cf, Atten= 96%, Lag= 88.3 min Discarded = 0.03 cfs @ 13.44 hrs, Volume= 1,116 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Peak Elev= 4,590.56' @ 13.44 hrs Surf.Area= 1,654 sf Storage= 775 cf Plug-Flow detention time= 284.3 min calculated for 1,116 cf (75% of inflow) Center-of-Mass det. time= 186.9 min ( 1,028.3 - 841.3 ) Volume Invert Avail.Storage Storage Description #1 4,590.10' 4,126 cf Custom Stage Data (Irregular) Listed below Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 4,590.10 1,310 172.6 0 0 1,310 4,591.10 2,051 197.8 1,667 1,667 2,076 4,592.10 2,892 222.9 2,459 4,126 2,942 Device Routing Invert Outlet Devices #1 Discarded 4,590.10'4.000 in/hr Exfiltration over Surface area above 4,590.10' Conductivity to Groundwater Elevation = 4,587.00' Excluded Surface area = 1,310 sf Discarded OutFlow Max=0.03 cfs @ 13.44 hrs HW=4,590.56' (Free Discharge) 1=Exfiltration ( Controls 0.03 cfs) Type II 24-hr 2yr-24hr Rainfall=1.18", P2=1.18"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 11HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Pond 2P: Proposed Pond Inflow Discarded Hydrograph Time (hours)2423222120191817161514131211109876543210Flow (cfs)0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=36,438 sf Peak Elev=4,590.56' Storage=775 cf 0.76 cfs 0.03 cfs 1S Addition-POST 3S Offsite Basin 5S Addition-PRE 2P Proposed Pond Routing Diagram for KOHDPrepared by Headwaters Engineering, Inc, Printed 4/30/2026 HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Subcat Reach Pond Link KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 2HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC P2 (inches) 1 10yr-24hr Type II 24-hr Default 24.00 1 1.70 2 1.70 KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 3HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 121,050 79 50-75% Grass cover, Fair, HSG C (3S) 36,438 74 >75% Grass cover, Good, HSG C (5S) 36,438 91 Urban industrial, 72% imp, HSG C (1S) 193,926 80 TOTAL AREA KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 4HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (sq-ft) Soil Group Subcatchment Numbers 0 HSG A 0 HSG B 193,926 HSG C 1S, 3S, 5S 0 HSG D 0 Other 193,926 TOTAL AREA KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 5HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Sub Num 0 0 121,050 0 0 121,050 50-75% Grass cover, Fair 0 0 36,438 0 0 36,438 >75% Grass cover, Good 0 0 36,438 0 0 36,438 Urban industrial, 72% imp 0 0 193,926 0 0 193,926 TOTAL AREA Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 6HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=36,438 sf 72.00% Impervious Runoff Depth>0.90"Subcatchment 1S: Addition-POST Flow Length=188' Slope=0.0100 '/' Tc=5.0 min CN=91 Runoff=1.40 cfs 2,747 cf Runoff Area=121,050 sf 0.00% Impervious Runoff Depth>0.35"Subcatchment 3S: Offsite Basin Flow Length=360' Slope=0.0100 '/' Tc=20.4 min CN=79 Runoff=0.91 cfs 3,568 cf Runoff Area=36,438 sf 0.00% Impervious Runoff Depth>0.22"Subcatchment 5S: Addition-PRE Flow Length=188' Slope=0.0100 '/' Tc=8.3 min CN=74 Runoff=0.22 cfs 667 cf Peak Elev=4,590.99' Storage=1,488 cf Inflow=1.40 cfs 2,747 cfPond 2P: Proposed Pond Outflow=0.07 cfs 2,128 cf Total Runoff Area = 193,926 sf Runoff Volume = 6,982 cf Average Runoff Depth = 0.43" 86.47% Pervious = 167,691 sf 13.53% Impervious = 26,235 sf Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 7HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Addition-POST Runoff = 1.40 cfs @ 11.96 hrs, Volume= 2,747 cf, Depth> 0.90" Routed to Pond 2P : Proposed Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70" Area (sf) CN Description 36,438 91 Urban industrial, 72% imp, HSG C 10,203 28.00% Pervious Area 26,235 72.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.2 100 0.0100 0.76 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.70" 0.7 88 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.9 188 Total, Increased to minimum Tc = 5.0 min Subcatchment 1S: Addition-POST Runoff Hydrograph Time (hours)2423222120191817161514131211109876543210Flow (cfs)1 0 Type II 24-hr 10yr-24hr Rainfall=1.70" P2=1.70" Runoff Area=36,438 sf Runoff Volume=2,747 cf Runoff Depth>0.90" Flow Length=188' Slope=0.0100 '/' Tc=5.0 min CN=91 1.40 cfs Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 8HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Offsite Basin Runoff = 0.91 cfs @ 12.17 hrs, Volume= 3,568 cf, Depth> 0.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70" Area (sf) CN Description 121,050 79 50-75% Grass cover, Fair, HSG C 121,050 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 17.7 100 0.0100 0.09 Sheet Flow, Grass: Short n= 0.150 P2= 1.70" 2.7 260 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 20.4 360 Total Subcatchment 3S: Offsite Basin Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)1 0 Type II 24-hr 10yr-24hr Rainfall=1.70" P2=1.70" Runoff Area=121,050 sf Runoff Volume=3,568 cf Runoff Depth>0.35" Flow Length=360' Slope=0.0100 '/' Tc=20.4 min CN=79 0.91 cfs Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 9HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Addition-PRE Runoff = 0.22 cfs @ 12.03 hrs, Volume= 667 cf, Depth> 0.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70" Area (sf) CN Description 36,438 74 >75% Grass cover, Good, HSG C 36,438 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.4 100 0.0100 0.23 Sheet Flow, Fallow n= 0.050 P2= 1.70" 0.9 88 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8.3 188 Total Subcatchment 5S: Addition-PRE Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type II 24-hr 10yr-24hr Rainfall=1.70" P2=1.70" Runoff Area=36,438 sf Runoff Volume=667 cf Runoff Depth>0.22" Flow Length=188' Slope=0.0100 '/' Tc=8.3 min CN=74 0.22 cfs Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 10HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Pond 2P: Proposed Pond Inflow Area = 36,438 sf, 72.00% Impervious, Inflow Depth > 0.90" for 10yr-24hr event Inflow = 1.40 cfs @ 11.96 hrs, Volume= 2,747 cf Outflow = 0.07 cfs @ 13.06 hrs, Volume= 2,128 cf, Atten= 95%, Lag= 66.1 min Discarded = 0.07 cfs @ 13.06 hrs, Volume= 2,128 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Peak Elev= 4,590.99' @ 13.06 hrs Surf.Area= 1,972 sf Storage= 1,488 cf Plug-Flow detention time= 278.7 min calculated for 2,128 cf (77% of inflow) Center-of-Mass det. time= 189.6 min ( 1,013.2 - 823.7 ) Volume Invert Avail.Storage Storage Description #1 4,590.10' 4,126 cf Custom Stage Data (Irregular) Listed below Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 4,590.10 1,310 172.6 0 0 1,310 4,591.10 2,051 197.8 1,667 1,667 2,076 4,592.10 2,892 222.9 2,459 4,126 2,942 Device Routing Invert Outlet Devices #1 Discarded 4,590.10'4.000 in/hr Exfiltration over Surface area above 4,590.10' Conductivity to Groundwater Elevation = 4,587.00' Excluded Surface area = 1,310 sf Discarded OutFlow Max=0.07 cfs @ 13.06 hrs HW=4,590.99' (Free Discharge) 1=Exfiltration ( Controls 0.07 cfs) Type II 24-hr 10yr-24hr Rainfall=1.70", P2=1.70"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 11HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Pond 2P: Proposed Pond Inflow Discarded Hydrograph Time (hours)2423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=36,438 sf Peak Elev=4,590.99' Storage=1,488 cf 1.40 cfs 0.07 cfs 1S Addition-POST 3S Offsite Basin 5S Addition-PRE 2P Proposed Pond Routing Diagram for KOHDPrepared by Headwaters Engineering, Inc, Printed 4/30/2026 HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Subcat Reach Pond Link KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 2HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC P2 (inches) 1 100yr-24hr Type II 24-hr Default 24.00 1 2.34 2 2.34 KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 3HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 121,050 79 50-75% Grass cover, Fair, HSG C (3S) 36,438 74 >75% Grass cover, Good, HSG C (5S) 36,438 91 Urban industrial, 72% imp, HSG C (1S) 193,926 80 TOTAL AREA KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 4HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (sq-ft) Soil Group Subcatchment Numbers 0 HSG A 0 HSG B 193,926 HSG C 1S, 3S, 5S 0 HSG D 0 Other 193,926 TOTAL AREA KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 5HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Sub Num 0 0 121,050 0 0 121,050 50-75% Grass cover, Fair 0 0 36,438 0 0 36,438 >75% Grass cover, Good 0 0 36,438 0 0 36,438 Urban industrial, 72% imp 0 0 193,926 0 0 193,926 TOTAL AREA Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 6HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.01 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=36,438 sf 72.00% Impervious Runoff Depth>1.46"Subcatchment 1S: Addition-POST Flow Length=188' Slope=0.0100 '/' Tc=5.0 min CN=91 Runoff=2.22 cfs 4,445 cf Runoff Area=121,050 sf 0.00% Impervious Runoff Depth>0.73"Subcatchment 3S: Offsite Basin Flow Length=360' Slope=0.0100 '/' Tc=17.8 min CN=79 Runoff=2.29 cfs 7,340 cf Runoff Area=36,438 sf 0.00% Impervious Runoff Depth>0.52"Subcatchment 5S: Addition-PRE Flow Length=188' Slope=0.0100 '/' Tc=7.2 min CN=74 Runoff=0.69 cfs 1,576 cf Peak Elev=4,591.43' Storage=2,484 cf Inflow=2.22 cfs 4,445 cfPond 2P: Proposed Pond Outflow=0.11 cfs 3,507 cf Total Runoff Area = 193,926 sf Runoff Volume = 13,361 cf Average Runoff Depth = 0.83" 86.47% Pervious = 167,691 sf 13.53% Impervious = 26,235 sf Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 7HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Addition-POST Runoff = 2.22 cfs @ 11.96 hrs, Volume= 4,445 cf, Depth> 1.46" Routed to Pond 2P : Proposed Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34" Area (sf) CN Description 36,438 91 Urban industrial, 72% imp, HSG C 10,203 28.00% Pervious Area 26,235 72.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.9 100 0.0100 0.89 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.34" 0.7 88 0.0100 2.03 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.6 188 Total, Increased to minimum Tc = 5.0 min Subcatchment 1S: Addition-POST Runoff Hydrograph Time (hours)2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type II 24-hr 100yr-24hr Rainfall=2.34" P2=2.34" Runoff Area=36,438 sf Runoff Volume=4,445 cf Runoff Depth>1.46" Flow Length=188' Slope=0.0100 '/' Tc=5.0 min CN=91 2.22 cfs Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 8HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 3S: Offsite Basin Runoff = 2.29 cfs @ 12.12 hrs, Volume= 7,340 cf, Depth> 0.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34" Area (sf) CN Description 121,050 79 50-75% Grass cover, Fair, HSG C 121,050 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.1 100 0.0100 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 2.34" 2.7 260 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 17.8 360 Total Subcatchment 3S: Offsite Basin Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)2 1 0 Type II 24-hr 100yr-24hr Rainfall=2.34" P2=2.34" Runoff Area=121,050 sf Runoff Volume=7,340 cf Runoff Depth>0.73" Flow Length=360' Slope=0.0100 '/' Tc=17.8 min CN=79 2.29 cfs Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 9HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Subcatchment 5S: Addition-PRE Runoff = 0.69 cfs @ 12.00 hrs, Volume= 1,576 cf, Depth> 0.52" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34" Area (sf) CN Description 36,438 74 >75% Grass cover, Good, HSG C 36,438 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.3 100 0.0100 0.27 Sheet Flow, Fallow n= 0.050 P2= 2.34" 0.9 88 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 7.2 188 Total Subcatchment 5S: Addition-PRE Runoff Hydrograph Time (hours) 2423222120191817161514131211109876543210Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 100yr-24hr Rainfall=2.34" P2=2.34" Runoff Area=36,438 sf Runoff Volume=1,576 cf Runoff Depth>0.52" Flow Length=188' Slope=0.0100 '/' Tc=7.2 min CN=74 0.69 cfs Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 10HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Summary for Pond 2P: Proposed Pond Inflow Area = 36,438 sf, 72.00% Impervious, Inflow Depth > 1.46" for 100yr-24hr event Inflow = 2.22 cfs @ 11.96 hrs, Volume= 4,445 cf Outflow = 0.11 cfs @ 12.98 hrs, Volume= 3,507 cf, Atten= 95%, Lag= 61.0 min Discarded = 0.11 cfs @ 12.98 hrs, Volume= 3,507 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.01 hrs Peak Elev= 4,591.43' @ 12.98 hrs Surf.Area= 2,330 sf Storage= 2,484 cf Plug-Flow detention time= 281.4 min calculated for 3,505 cf (79% of inflow) Center-of-Mass det. time= 197.4 min ( 1,007.4 - 810.0 ) Volume Invert Avail.Storage Storage Description #1 4,590.10' 4,126 cf Custom Stage Data (Irregular) Listed below Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 4,590.10 1,310 172.6 0 0 1,310 4,591.10 2,051 197.8 1,667 1,667 2,076 4,592.10 2,892 222.9 2,459 4,126 2,942 Device Routing Invert Outlet Devices #1 Discarded 4,590.10'4.000 in/hr Exfiltration over Surface area above 4,590.10' Conductivity to Groundwater Elevation = 4,587.00' Excluded Surface area = 1,310 sf Discarded OutFlow Max=0.11 cfs @ 12.98 hrs HW=4,591.43' (Free Discharge) 1=Exfiltration ( Controls 0.11 cfs) Type II 24-hr 100yr-24hr Rainfall=2.34", P2=2.34"KOHD Printed 4/30/2026Prepared by Headwaters Engineering, Inc Page 11HydroCAD® 10.20-8a s/n 14053 © 2025 HydroCAD Software Solutions LLC Pond 2P: Proposed Pond Inflow Discarded Hydrograph Time (hours)2423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=36,438 sf Peak Elev=4,591.43' Storage=2,484 cf 2.22 cfs 0.11 cfs use consistent units (e.g. feet & days or inches & hours)Conversion Table Input Values inch/hour feet/day 4.0000 R Recharge (infiltration) rate (feet/day)0.67 1.33 0.230 Sy Specific yield, Sy (dimensionless, between 0 and 1) 130.00 K Horizontal hydraulic conductivity, Kh (feet/day)*2.00 4.00 24.000 x 1/2 length of basin (x direction, in feet) 57.000 y 1/2 width of basin (y direction, in feet)hours days 1.000 t duration of infiltration period (days)36 1.50 10.000 hi(0) initial thickness of saturated zone (feet) 13.395 h(max) maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 3.395 Δh(max) maximum groundwater mounding (beneath center of basin at end of infiltration period) Ground- water Mounding, in feet Distance from center of basin in x direction, in feet 3.395 0 3.046 20 2.261 40 1.926 50 1.632 60 1.377 70 1.155 80 0.965 90 0.802 100 0.545 120 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S. Geological Survey Scientific Investigations Report 2010-5102 "Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate (R), specific yield (Sy), horizontal hydraulic conductivity (Kh), basin dimensions (x, y), duration of infiltration period (t), and the initial thickness of the saturated zone (hi(0), height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length (x = y). For a rectangular basin, if the user wants the water-table changes perpendicular to the long side, specify x as the short dimension and y as the long dimension. Conversely, if the user wants the values perpendicular to the short side, specify y as the short dimension, x as the long dimension. All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. The user MUST click the blue "Re-Calculate Now" button each time ANY of the user-specified inputs are changed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values (for example, feet and days) In the report accompanying this spreadsheet (USGS SIR 2010-5102), vertical soil permeability (ft/d) is assumed to be one-tenth horizontal hydraulic conductivity (ft/d). Re-Calculate Now 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 4.000 0 20406080100120140 Groundwater Mounding, in feet ______________________________________________________________________________ ______________________________________________________________________________ 1105 Reeves Rd. W. Ste 6, Bozeman, MT 59718 (406)-581-5730 www.headwatersmt.net Appendix C Geotechnical & Hydrogeological Evalua�on & Soils Inves�ga�on Report USGS Soils Mapper Report Geologic Map Madison Groundwater Study Map 1105 REEVES ROAD WEST, SUITE 6 BOZEMAN, MT 59718 406-581-5730 www.headwatersmt.net Page 1 of 4 Geotechnical/Hydrogeological Evaluation Report KOHD Facility 3480 Prince Lane Bozeman, Montana COB Application #26053 March 2026 Headwaters Engineering, Inc. Project # 2035.004 Prepared For: Kaufmann’s Overhead Door, Inc. 3480 Prince Lane Bozeman, MT 59718 H:\2035\004\DOCS\DESIGN\STORM\App C - Geotech-Hydrogeological Evaluation.docx Page 2 of 4 Project Description This evaluation summarizes the geotechnical findings from the available on-site soils information, as well as hydrogeological conditions of the site as they relate to the proposed stormwater disposal method for the KOHD Facility project. The evaluation follows the outline and methodology outlined in Chapter 6 of the City of Bozeman Design and Construction Standards, October 2024. The KOHD Facility consists of 2 new buildings, with a total of 9,000 square feet of indoor industrial shop space. The site currently consists of one office & shop building and associated parking lots. The site is located on Lot 16 of the Nelson Meadows Subdivison, and is includes 2.14 acres. The existing lot is located in the SE ¼ of Section 22, Township 1 South, Range 5 East, PMM in Bozeman, Gallatin County, Montana. The site of the proposed expansion is well vegetated as a result of seeding from the existing building construction. The vegetation mostly consists of dryland grasses, with irrigated vegetation residing along the existing public trail inside the lot’s eastern boundary. The existing ground slopes to the north- northeast at roughly 1-2%. The site was originally designed to utilize a combination of underground and surface storage for stormwater runoff. Storm drainage infrastructure exists beneath Prince Lane (to the north) and Royal Wolf Way (to the west). Runoff from the two new buildings will remain on the site, and not allowed to reach the existing in-street infrastructure. Storm runoff from the existing site breaks near the western entrance off of Royal Wolf Way. From there, the west parking area flows into an underground dry sump, and the eastern portion of the paved area travels east to the existing storm pond. The proposed expansion will utilize the drainage pattern of the eastern portion and send runoff to the location of the existing pond. The size of the pond will be increased with the proposed development in order to retain the increased 100-year runoff. Flows in excess of the pond’s capacity discharge to the east into Cattail Creek, where it travels within the drainage to the East Gallatin River. Investigations A soils investigation report was completed for Phase 1 of the project by Lee Evans, P.E. (Allied Engineering) in 2023. Twelve test pits and groundwater monitoring wells were installed during the subdivision design phase in 2018. Test pit number 9 (TP-9) resides in the northwest corner of the subject lot. The soil profile for TP-9 was reported in three distinct horizons, over the excavated depth of 12 feet BGS. The first horizon consisted of a 12-inch layer of native topsoil, which was reported as medium stiff; black; organic clayey silt with abundant roots; and moist. Underlying the topsoil was a 5-foot layer of native silt/clay, reported as very stiff; brown/tan; sandy silt to sandy lean clay; and moist. The third horizon extended from 6 feet to 12 feet BGS, and was reported as native sandy gravel, being dense; dark brown to brown; sandy gravel with abundant gravels and scattered cobbles; and moist to wet. The bottom layer was also noted as “clean” sandy gravel. Groundwater was monitored by Morrison-Maierle during the 2018 monitoring season. TP-9 showed a peak groundwater level of approximately 6.5’ below ground surface, which roughly correlated with the depth to gravels on Lot 16. Groundwater elevations throughout monitoring peaked in mid-late April. Page 3 of 4 The Potentiometric Surface Map of the Gallatin Valley by James P. Madison, 2022, shows the groundwater in this area flowing the same general direction of the ground contours. The site is located within the Tertiary Basin-Fill Aquifer, which is unconsolidated or weakly consolidated. The test pit logs from the Allied Geotechnical Report show silt/clay to approximately 6 feet below ground surface, followed by a sandy gravel with no plasticity. Once stormwater reaches the gravel layer, it will infiltrate quickly and have little to no effect on the structural capacity of the soil or impact groundwater levels. The existing storm pond was over-excavated to the native gravel layer, and backfilled to the design pond bottom elevation with coarse gravels to eliminate the silt/clay layer and promote faster infiltration. The proposed pond will utilize the same approach by removing the silt/clay layer and reaching native gravels, which are estimated at approximately 3-4 feet below the proposed pond bottom. A percolation test was performed inside the existing pond to verify its infiltration rate. The percolation test hole was filled and fully drained twice within 1 minute, which corresponds to an infiltration rate of less than 1 minute per inch. Soils The NRCS Soil Survey identifies two major soil types in the area of the proposed expansion. These soil types are listed as Blackdog silt loam, 0 to 4 percent slopes (50B) and Blackdog silt loam, 4 to 8 percent slopes (50C). Both are comprised primarily of silt loam and silty clay loam, with moderately high saturated hydraulic conductivity. Allied Engineering also prepared a Geotechnical summary for the Nelson Meadows Subdivision in 2018, also under the stamp of Lee Evans, P.E. In the 2018 report, the general geology of the area was noted to consist of Quaternary and Tertiary-aged alluvial fan deposits (QTa) with fluvial deposits (Qal) from the East Gallatin River to the north. Allied noted that from previous experience, the soil stratigraphy on the west side of Bozeman usually consists of around 1 foot of organic topsoil overlaying an intermediate silt/clay layer, which overlies alluvial sandy gravel. The report also notes that that well logs in the area show the alluvial gravel formation in the middle part of the Gallatin Valley extends to depths in excess of 100 feet. Figure 1 – NRCS Soil Map Page 4 of 4 Figure 2 – Madison Study Groundwater Contours Conclusion The groundwater records for the area indicate that groundwater remains deep enough as to not interfere with the proposed stormwater pond. Existing soils do not impose any foreseeable risks to the proposed stormwater plan. With the above referenced geotechnical investigation results from Allied Engineering, in combination with published data of the area, we feel the proposed storm plan is suitable for the site. Attachments: • Final Geotechnical Report, Lot 16, Nelson Meadows Sub. – Allied Engineering, August 21, 2023 • Geotechnical Summary, Park Place Industrial – Allied Engineering, March 12, 2018 • MBMG – Potentiometric Surface in Gallatin, Lower Madison, Lower Jefferson, and Upper Missouri River Valleys within Parts of Madison and Gallatin Counties, Montana – James P. Madison, 2022 • NRCS Soil Resource Report • Headwater Engineering Percolation Test Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 2 12 monitoring wells, which were then monitored throughout the spring/summer of 2018 by Morrison Maierle, the subdivision development engineer. Attached to this report are two figures from the 2018 summary report (Fig. 2 and 3) as well as test pit logs for TP-8 through TP-10 and the 2018 groundwater monitoring data. As stated earlier, TP-9 is located near the northwest corner of Lot 16; while TP-8 and TP-10 lie further to the south and north, respectively. PROJECT PLANS The project plans, including architectural, civil, and structural sheets, were received on August 10, 2023. This is the plan set that was reviewed and approved by the City of Bozeman on June 29, 2023. We have reviewed the plans to gain an understanding of the project components and foundation configuration. FOUNDATION EXCAVATION TO NATIVE GRAVEL The native sandy gravel that underlies Lot 16 at depths of approximately 6.0 feet (based on TP-9) is the “target” foundation bearing material bearing for all building footings, including perimeter, interior, and exterior footings. Based on our discussions, we understand all footing locations will be over-excavated down to native gravel and built back up to footing grade with compacted, granular structural fill. There are two options for this over-excavation and fill method. Option 1A, which is presented on Figure 4, is where only the footing alignments/locations are excavated. This option is most applicable in areas of the building with few interior footings, such as the large/open warehouse portion of the building. The other option is Option 1B, which is shown on Figure 5. Under this scenario, the entire foundation foot- print area of the building is mass excavated. This would be most applicable in areas of the building that contain many or closely spaced, interior footings. Parts (or all) of the office portion of the building may be a good candidate for mass excavation. RAMMED AGGREGATE PIER FOUNDATION SUPPORT As we understand it, rammed aggregate piers (RAPs) were initially considered for foundation support of the building. Due to higher costs, it sounds like BBG Contractors is not going in this direction. Rather, all footings will be over-excavated to native gravel and bear on compacted, granular structural fill. Just in case RAPs are still being considered, we have included a figure (Figure 6) that shows our RAP-related, foundation design and earthwork recommendations. PROJECT UNDERSTANDING Provided below is our understanding of the project and what it will include: • The building will be underlain by an at-grade slab and supported on a conventional foundation consisting of perimeter footings/frost walls. The thickness of the slab ranges from 4 to 6 inches, depending on the location. The building contains no crawl space or basement areas. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 3 • Some areas of the slab will be underlain by “thickened slab” interior footings. The larger ware- house portion of the building contains few interior footings; while the smaller office portion has a much higher concentration of interior footings, some of which are closely spaced. • A few exterior strip and pad footings lie around the outside of the perimeter foundation walls. These are for the support of loading docks, retaining walls, roof overhangs, and covered entries. • The building will be surrounded by asphalt-covered, parking lot, drive lane, and loading dock areas. Site access will be provided by two driveways that connect to Prince Lane (on the north) and one driveway that connects to Royal Wolf Way (on the west). • The building will be serviced by water, fire, and sewer services that connect to the existing city water and sewer mains in Prince Lane. • It appears that most of the stormwater drainage will be routed to an on-site retention pond on the northeast side of the lot. A single, stormwater dry well structure is proposed in the north- west corner of the parking lot. CONTENT OF GEOTECHNICAL REPORT The content of this geotechnical report includes: • A narrative report followed by several attachments. The attachments include three site maps that show test pit locations and soil conditions (throughout the Nelson Meadows Subdivision), three foundation details for at-grade slab configurations (that show footing excavation, mass excavation, and rammed aggregate pier foundation support scenarios), test pit logs for TP-8 through TP-10, 2018 groundwater monitoring data, and product sheets for the recommended vapor barrier, non-woven and woven fabrics, and geogrid materials. • A description of the expected soil and groundwater conditions based on our geotechnical work that was performed in 2018. • The geotechnical recommendations include: o Structural design criteria for foundations. o Foundation earthwork and bearing for at-grade slab foundation, including:  Option 1A: Over-excavation and replacement under individual footings.  Option 1B: Mass over-excavation and replacement under foundation footprint.  Option 2: Rammed aggregate piers under all footings.  Gravel section under interior slab. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 4 o Interior and exterior foundation wall backfill. o At-grade slab foundation moisture protection measures. o Exterior concrete slab sections for pedestrian and vehicle slabs. o Underground utilities, including:  Water, fire, and service installation and trench backfill.  Corrosion protection for DIP water and fire service lines.  Backfill of underslab plumbing trenches. o Underground stormwater drainage elements. o Pavement section for all site asphalt areas. SITE LOCATION AND EXISTING CONDITIONS The project site is Lot 16 of the Nelson Meadows Subdivision. This 2.1-acre lot lies on the southeast of the intersection of Prince Lane (on the north) and Royal Wolf Way (on the west). It is bounded by Lots 17 through 19 on the south and by the creek/drainage ditch corridor on the east. The legal description for the site is the SE1/4, SE1/4 of Section 22, T1S, R5E, Gallatin County; and the latitude/longitudinal coordinates (near the center of the site) are 45.731403°N and -111.086551°W. See Figure 1 for a plat map showing the site location. The property is undeveloped and has a gentle, planar ground surface slope that grades to the north and east. Historically, the Nelson Meadows Subdivision area has been used for agricultural purposes. There are no surface water features on the site. The closest surface water is the creek/ditch that runs along the east side. A large, high pressure gas transmission line cuts diagonally through the east half of the site in the southeast to northwest direction. DESIGN CONSIDERATIONS Provided below are some design considerations for the project: • Geotechnical Report included in Bid Documents: This geotechnical report should be included in the bidding documents and made part of the project specifications. All bidding contractors need to be informed of the site conditions and geotechnical recommendations. • Foundation Design and Support: The building foundation shall be designed as a conventional foundation for a design bearing pressure of 2,500 psf. All footings shall either be supported on granular structural fill that in turn bears on native gravel or on rammed aggregate piers. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 5 • Rammed Aggregate Piers: If rammed aggregate piers will be utilized, they must be installed under all footings and extend 1.0-foot (minimum) into the “target” bearing, native sandy gravel. Additionally, the RAP system shall be designed for 4,000 psf foundation loading (even though the footings are sized for 2,500 psf). By doing so, there will be an increased factor of safety and potentially tighter/closer pier spacing. CONSTRUCTION CONSIDERATIONS Provided below are some construction considerations for the project: • Foundation Excavation: As we understand it, all building footings will be over-excavated (down to “target” native gravel) and supported on granular structural fill as opposed to bearing them on rammed aggregate piers. In the parts of the building with few interior footings, individual footing over-excavation under all footing alignments/locations (per Option 1A) is the reasonable approach. However, in the parts of the building with more interior footings, it will likely be faster and more efficient to simply mass excavate these areas (per Option 1B). • Pavement Area Construction: We expect stable silt/clay subgrade soil conditions throughout most, if not all, of the site. Based on this, we have provided a design pavement section for stable subgrade. If some areas of the subgrade are overly moist, they may need to be scarified and dried out. However, if some areas are very moist and soft, then perhaps a thicker, geogrid- reinforced pavement section may be needed. We do not anticipate that this situation will arise, but we have also provided a pavement section option for unstable subgrade (just in case). EXPLORATIONS, TESTING, AND SUBSURFACE CONDITIONS Subsurface Explorations No test pits were dug on the lot for the preparation of this report. Note: In 2018, AESI dug 12 test pits across the Nelson Meadows Subdivision property. The closest test pit to Lot 16 is TP-9, which lies near the northwest corner of the lot. Two additional test pits are located nearby to the south (TP-8) and to the north (TP-10). See Figures 1 through 3 for the test pits locations. Test pit logs for TP-8 through TP-10 are also attached. Laboratory Testing No laboratory testing was conducted as part of the Lot 16 project. Note: As part of 2018 geotechnical work, we tested several samples of silt/clay and sandy gravel for soil corrosivity potential for DIP water pipe. The results showed that the silt/clay was slightly corrosive and the recommendation was to wrap all DIP pipe with V-bio enhanced polyethylene encasement. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 6 Soil Conditions (Expected) Based on the 2018 test pits, the west side of the Nelson Meadows Subdivision (west of the creek/ditch) is blanketed by 9 to 12 inches of topsoil that overlies a “relatively dry” silt/clay profile (as compared to the east side of the creek/ditch where the silt/clay is much more moist to wet). With increasing depth, the silt/clay often becomes more moist due to the seasonal presence of high groundwater. Throughout the west side, the silt/clay is underlain by “clean” sandy gravel beginning at depths of 4.0 to 10.0 feet. In TP-9, which is closest to Lot 16, the gravel depth was at 6.0 feet. In the test pits to the north and south, gravel depth was at 4.0 and 7.5 feet, respectively. We expect that the depth to gravel on Lot 16 likely will vary from 5.0 to 7.0 feet. See Figures 2 and 3 for the silt/clay moisture variations and the depth to gravel across the subdivision area. Groundwater Conditions (Expected) When the test pits were dug in February 2018, the groundwater depth in TP-9 was at 10.0 feet. Given that the pits were dug in the winter during the low water time of year, it is not unexpected that deeper groundwater conditions were found. During the spring/summer of 2018, Morrison-Maierle monitored groundwater levels in the 12 monitoring wells across the subdivision area. Based on their data, which is attached, seasonal high water occurred on April 27 and reached a depth of 6.6 feet in TP-9 (below the existing ground surface). In TP-9, the native gravel depth is at 6.0 feet, meaning the high water depth rose to near the top of the gravel. Their data shows the groundwater elevation drops in the summer and was about 2.0 feet below the top of gravel (in TP-9) by mid-July. GEOTECHNICAL ISSUES We do not expect any geotechnical issues based on the expected soil and groundwater conditions. Perhaps the only potential issue could be some overly moist silt/clay subgrade under asphalt pavement areas. We expect a fairly dry silt/clay profile in the shallow depths across the site; therefore, we do not anticipate that soft or wet subgrade will be an issue. If some areas of the silt/clay are too moist, they may simply need to be scarified and allowed to dry out. Most likely, the site areas that may be the most moist will be on the east side of the lot and closer to the adjacent creek/ditch corridor. If unstable soils are found that cannot be dried, then the use of a thicker, geogrid-reinforced pavement section may be triggered. GENERAL CONSTRUCTION RECOMMENDATIONS Re-Excavation of Test Pits The location of TP-9 lies near the northwest corner of the lot and may underlie the northwest side of the parking lot. During backfilling of the test pits, the spoils were not placed in lifts and compacted; as a result, they will undergo significant soil settlement over time. If TP-9 (which contains a monitoring well) Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 7 is found to lie under the building foundation or parking lot, we recommend that it be re-excavated back down to its original depth (12 feet) and properly backfilled and compacted with suitable material. Topsoil Stripping and Re-Use The site is likely blanketed by 9 to 12 inches of black, native topsoil. All topsoil must be completely removed from within the building foundation footprint areas and from under all exterior concrete slab and asphalt pavement areas. Final site grading (in landscape areas) and the reclamation of disturbed construction areas are the only recommended uses of this material. Groundwater Dewatering Depending on the time of year, groundwater dewatering may be required for some parts of project construction, specifically any deeper water and sewer installations. Assuming foundation excavation occurs in August or September, we expect that groundwater levels will be below the top of the native gravel at depths of > 6.0 feet. If water is found at or above the top of the gravel, some dewatering may be required along with the use of some fabric-covered, clean crushed rock to get above the wet gravel subgrade. Subgrade Scarification and Drying This is not expected; but if any subgrade soils under the asphalt pavement areas are overly moist, they may need to be scarified and allowed to dry out. Based on TP-9, the silt/clay soils (from 1.0 to 6.0 feet) are very stiff and slightly moist to moist (with moisture contents at 14 to 16 percent, which are below optimum moisture). Excavation and Re-Use of On-Site Soils The soils that will be excavated during foundation earthwork and site development will include topsoil, silt/clay, and sandy gravel. Provided below are the allowable re-uses of the on-site materials: • Organic topsoil materials shall only be used for final site grading in landscape areas. • Provided the silt/clay is “dry” and can be compacted to project specifications and geotechnical recommendations, the allowable re-uses for excavated, non-organic silt/clay include site fill, subgrade embankment under building slabs, subgrade embankment under asphalt pavement areas, exterior foundation wall backfill, and trench backfill (outside of the foundation footprint). • For interior foundation wall backfill (under interior slabs), we recommend the exclusive use of imported, granular structural fill (3”-minus sandy gravel) or 1”-minus, clean crushed rock. Both of these materials are easy to properly compact in tight and confined areas. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 8 • No on-site soils shall be used for any granular structural fill under building footings and slabs. All granular structural fill must consist of 3”-minus sandy gravel or 1.5”-minus roadmix gravel. STRUCTURAL DESIGN PARAMETERS Foundation Design The entire building will be underlain by an at-grade slab and supported on a conventional foundation consisting of perimeter footings/frost walls, interior “thickened slab” footings, and a few exterior strip and pad footings for the support of loading docks, retaining walls, roof over-hangs, and covered entries. Note: We have no geotechnical issues with the proposed foundation configuration. Note: The building will contain no crawl space or basement areas. Seismic Design Factors A main requirement of the Structural Engineer’s seismic analysis will be a determination of the site class. Based on our on-site explorations and knowledge of the underlying geology, the site class for the project site will be Site Class D (as per criteria presented in the 2021 IBC). This site class designation is valid as long as our foundation recommendations are followed. To obtain site-specific seismic loading and response spectrum parameters, a web-based application from the USGS Earthquake Hazards Program can be used. The link to their web page is as follows: https://earthquake.usgs.gov/hazards/designmaps/. Upon entering this page, there are links to three third- party interfaces that can be used to obtain the seismic information. The user needs to enter the design code reference document, site soil classification, risk category, site latitude, and site longitude. Foundation Bearing Pressure (Conventional Foundation/Footings) As long as our foundation support recommendations are followed (ie. excavation to native gravel), the allowable bearing pressure for all perimeter, interior, and exterior footings and any other foundation component is 2,500 pounds per square foot (psf). Allowable bearing pressures from transient loading (due to wind or seismic forces) may be increased by 50 percent. We estimate that the above-referenced design bearing pressure will result in total foundation settlements of one inch or less, with only minor differential settlements. Note: For this project, there are two options for excavation and granular structural fill replacement under footings. These are identified as Options 1A and 1B. For Option 1A, all footings are excavated on an individual basis along footing alignments and under footing locations. For Option 1B, the entire area of the foundation footprint is mass excavated. The decision as to which option to use will be dictated by the location and spacing of interior footings. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 9 Foundation Bearing Pressure (for Rammed Aggregate Piers) For Option 2 (rammed aggregate piers), we recommend designing the foundation (same as Options 1A and 1B) and sizing the footings based on an allowable bearing pressure of 2,500 pounds per square foot (psf) for all perimeter, interior, and exterior footings and any other foundation components. RAP Design Bearing Pressure (for Rammed Aggregate Piers) Even though the footings will be sized for a design bearing pressure of 2,500 psf, we recommend using an increased allowable bearing pressure of 4,000 pounds per square foot (psf) for the design of the rammed aggregate pier system. By doing so, the pier spacing may potentially be closer/tighter and the factor of safety will be increased. RAP Tip Elevation and Bearing Conditions (for Rammed Aggregate Piers) It is a requirement on this project that all rammed aggregate piers penetrate/extend a minimum of 1.0- foot into “target” bearing sandy gravel, which underlies the site at expected depths of 5.0 to 7.0 feet. The sandy gravel is defined as the “target” bearing stratum for all piers. Even though it is common for rammed aggregate pier ground improvement systems to be designed for shorter lengths/depths and to bear/“float” in soils above deeper bearing strata, we recommend on this project that all piers bear into the “target” sandy gravel. The sandy gravel is not overly deep and by bearing the piers in the gravels, the bottom of pier settlement potential will be minimal. All elements of the pier ground improvement system must penetrate into the gravel. Designing a pier improvement system with shorter length piers that “float” and end bear in the overlying silt/clay soils will not be allowed or accepted. RAP Stiffness Modulus (for Rammed Aggregate Piers) The recommended minimum RAP stiffness modulus is 200 pounds per square inch, per inch (pci). This design value must be confirmed in the field with a full-scale modulus test on a test pier at the on-set of pier installation. RAP Total Settlement (for Rammed Aggregate Piers) The rammed aggregate pier ground improvement system shall be designed for a total settlement under footings of 1.0” or less. RAP Differential Settlement (for Rammed Aggregate Piers) The rammed aggregate pier ground improvement system shall be designed for a differential settlement under footings of 0.5” or less. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 10 RAP Lateral Resistance (for Rammed Aggregate Piers) Rammed aggregate piers have no lateral resistance. The building’s lateral capacity must be provided by friction under the footing and lateral earth pressures against the perimeter foundation walls. Increased Frictional Resistance at Bottom of Footings (for Rammed Aggregate Piers) We are recommending the placement of a 12-inch thick, load transfer platform consisting of compacted granular structural under all footings and above the top of the rammed aggregate piers. The benefits of this are that it improves the strength of the footing grade, it covers/protects the silt/clay subgrade soils (from moisture) during construction, and it allows for the use of an increased coefficient of friction under the footings (for design). Assuming the load transfer platform recommendation is followed, a coefficient of friction of 0.5 is estimated between cast-in-place concrete and granular structural fill. 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). 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. 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, fine-grained backfill (silt/clay) should be assumed to have an equivalent fluid pressure of 280 pcf; while a coefficient of friction of 0.5 is estimated between cast-in-place concrete and the “target” sandy gravel (or granular structural fill that is placed to build back up to footing grade from the “target” gravel subgrade). 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 above-referenced, equivalent fluid pressures (for at rest, active, and passive conditions) assume that the wall will be backfilled with a suitable material that is compacted to an unyielding condition and it will lie above the groundwater table and/or be well drained; thereby, preventing the backfill from becoming saturated and the wall from experiencing hydrostatic pressure. Each of these design pressures is for static conditions and will need to be factored accordingly to represent seismic loading. We recommend that we be retained to evaluate lateral earth pressures for geometries and/or loading conditions that do not meet the previously mentioned criteria. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 11 Subgrade Reaction Modulus (under Slabs) As long as our interior slab support recommendations are followed (as presented later in the report), the subgrade reaction modulus (k) can be assumed to be 200 pounds/cubic inch (pci). This is a modified design value that uses the subgrade reaction modulus (k) of the native silt/cay and factors it (increases it) based on a minimum section thickness of imported gravel to be placed under the slab. This design value assumes the slab will be underlain by at least 18 inches of compacted gravel or crushed rock. Note: For this project, we are recommending a minimum 18-inch thick, gravel support section under the interior slab area that consists of an upper 6-inch section of clean crushed rock and a lower 12-inch section of granular structural fill. Note: In areas of the building where Option 1B is undertaken (mass over-excavation down to native gravel), the entire slab area will be underlain by a thicker section of compacted, granular structural fill that in turn bears on native gravel. Soil Corrosivity to Concrete According to Montana Department of Transportation (MDT) highway design standards, Type I-II cement is used when soil sulfate contents are less than 0.20%. However, if sulfate levels are between 0.20 and 2.00%, then Type V cement is used. Note: Over the years, we have tested several samples of Bozeman-area silt/clay and sandy gravel. All samples have been non-corrosive to standard concrete. There is no reason to use Type V cement. Note: Since the on-site soils at this project site are of the same composition as the other soils found around Bozeman, standard cement can be used in the foundation concrete. FOUNDATION RECOMMENDATIONS General Three detailed illustrations showing our excavation/fill/earthwork, foundation bearing, slab support, and moisture protection and drainage recommendations for an at-grade slab foundation configuration are included as Figures 4, 5, and 6. Please refer to these figures during the review of the report. • Figure 4: Shows excavation under individual footing alignments and locations. • Figure 5: Shows mass excavation under the entire foundation footprint area. • Figure 6: Shows rammed aggregate pier (RAP) support under all footings. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 12 Foundation Design and Support • The building foundation will be designed as a conventional foundation system that consists of perimeter footings/frost walls along with interior and exterior footings. • The entire building will be underlain by an at-grade slab (slab-on-grade). • The “target” foundation bearing material for all footings is the native sandy gravel at expected depths of 5.0 to 7.0 feet (in most areas). All footings must bear directly on the native gravel or on granular structural fill (or RAPs) that in turn is supported on the native gravel. • The minimum depth of cover for frost protection of perimeter and exterior footings is four feet. This dimension is measured from bottom of footing up to the final grade of the ground surface. Conventional Footings (Options 1A and 1B) • Refer to Figures 4 and 5 for design and construction recommendations. • For Option 1A (on Figure 4), all perimeter, interior, and exterior footings shall be over-excavated down to “target” native gravel and bear on granular structural fill (as needed) that is placed to build back up to footing grades. This option is most applicable for portions of the building with few interior footings. • For Option 1B (on Figure 5), the entire foundation footprint shall be mass over-excavated down to “target” native gravel and bear on a large/thick, granular structural fill building pad that is placed to build back up to footing/slab grades. This option is most applicable for portions of the building with many and/or closely spaced, interior footings. • The “target” bearing material for all footings (incl. perimeter, interior, and exterior footings) is the native sandy gravel that underlies the site at expected depths of 5.0 to 7.0 feet. In TP-9 in the northwest corner of the site, the gravel depth was at 6.0 feet. None of the overlying soil materials (incl. topsoil and silt/clay) shall be left in-place under any footings. • The “target” gravel is identifiable based on its brown color, “clean” sandy composition (in most locations), and abundant, rounded, 6”-minus, gravels and cobbles. • All footings must bear directly on the “target” gravel (ie. “clean” sandy gravel) or on compacted granular structural that in turn is supported on the native gravel. • Based on the native gravel depth, we do not expect that any footings will bear directly on the native gravel. Some over-excavation and structural fill replacement will likely be needed, even under the deeper perimeter and exterior footings. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 13 • All of the interior “thickened slab” footings located directly under the slab will need to bear on a thicker granular structural fill section that in turn is supported on the “target” gravel. • To minimize disturbance to the native gravel subgrade surface, the excavation should be dug with a smooth-edge foundation bucket. • Prior to pouring footings or placing granular structural fill, the native gravel subgrade shall be cleaned of loose spoil materials and re-compacted to a dense and unyielding condition with a smooth drum roller. Track packing of the gravel subgrade with the excavator (to smooth it out) prior to compaction with the roller works well. • In areas where the foundation will need to be over-excavated down to native gravel, the limits of the excavation will need to extend wide enough beyond the outside edge of footings such that enough compacted structural fill is placed to keep the footing load transfer in the structural fill materials down to the “target” gravel. • The required minimum width that the granular structural fill section must extend beyond the outside edge of footing is dependent on the structural fill thickness. The formula is as follows: Structural Fill Thickness / 2.0 = Min. Width of Structural Fill Beyond Edge of Footing. Here are some examples: For 2.0 feet of fill, the fill must extend 1.0-foot beyond the edge of footing; For 4.0 feet of fill, the fill must extend 2.0 feet beyond the edge of footing. To ensure the structural fill extends far enough beyond the outside edge of footing and can be properly compacted along the sides of the excavation, we recommend that the structural fill extend a minimum of 3.0 feet beyond the edge of footings (for all perimeter and exterior footings). Under interior footings, which will bear on an increased thickness of structural fill, the minimum excavation width needs to be increased to 4.0 feet (beyond the outside edge of footings). • All granular structural fill that is placed under footings must consist of either 3”-minus, sandy (pitrun) gravel or 1.5”-minus, crushed (roadmix) gravel. Specifications for these materials are provided in a later section of the report. We recommend 3”-minus gravel for the building pad. • The granular structural fill section should be placed in multiple lifts (depending on thickness of fill required and the size of the roller used) with each lift being vibratory compacted to a dense and unyielding condition. See a later report section for additional compaction specifications. A large, smooth drum roller should be used wherever possible. Small, walk-behind sheepsfoot rollers and hand-held, jumping jack compactors should be used in narrow/confined excavations and along edges and in corners of the excavation. • During most of the year, we expect that the site’s groundwater depth will be below the top of the “target” sandy gravel. Therefore, we do not expect the need for groundwater dewatering during foundation earthwork. The bottom of all excavations should be dry. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 14 • If the “target” gravel subgrade is wet or contains some areas of shallow standing water, then granular structural fill cannot be placed. Instead, the initial lift of gravel fill material will need to consist of 1”-minus, clean crushed rock. The crushed rock layer shall be vibratory compacted and covered with a layer of 8 oz. non-woven geotextile separator fabric (Mirafi 180N or equal) before placing the first lift of granular structural fill. • If the “target” gravel surface is wet or contains shallow standing water, it must be track-packed with the excavator and static rolled with a roller prior to placing the initial crushed rock layer. • If the “target” gravel surface is dry, it must be vibratory compacted with a large roller to a dense and unyielding condition prior to pouring footings or placing granular structural fill. Rammed Aggregate Pier-Supported Footings (Option 2) • Refer to Figure 6 for design and construction recommendations. • Option 2 is ground improvement with rammed aggregate piers under all perimeter, interior, and exterior footings. All piers must penetrate/extend a minimum of 1.0-foot into “target” bearing sandy gravel at a depth of 5.0 to 7.0 feet. This is a requirement on this project. • The sandy gravel is defined as the “target” bearing stratum for the end bearing condition of all rammed aggregate piers. • As stated in an earlier section of the report, it will not be acceptable or approved to design or install a pier improvement system that “floats” or end bears in the overlying silt/clay soils. • All footings must be underlain by a 12-inch layer of compacted, granular structural fill (aka load transfer platform). The load transfer platform shall lie between the bottom of footings and the top of the pier-improved, native silt/clay subgrade. The purpose for the 12-inch thick layer of gravel under footings is to protect the silt/clay subgrade during construction and also it allows for use of the higher 0.5 friction coefficient for foundation design. • All piers shall be initially installed to a minimum height of 1.0-foot above footing grade. During foundation excavation and earthwork (and depending on sequencing), the upper 1.0 to 2.0 feet of the pier will be clipped/shaved off during footing excavation and placement of the required 1.0-foot gravel load transfer platform under all footings. • The design and layout of the rammed aggregate pier system shall be developed by the pier installation contractor (or their engineer) based on the foundation plan and loading conditions provided by the Structural Engineer. The contractor will model the geotechnical and structural site conditions and specify the locations for all piers. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 15 • Typically, rammed aggregate piers have a 24 to 30-inch drilled diameter. The dimension of the pier will be specified by the contractor on the approved rammed aggregate pier submittal. • The typical aggregate material that is used for filling the drill holes/constructing the pier is an imported, 1.5”-minus crushed (roadmix) sandy gravel. This will be specified by the contractor. • All pier locations shall be staked and laid out prior to drilling/installation of the piers. • In addition to providing a pier design that is reviewed and approved by the project’s Structural and Geotechnical Engineers, the contractor is sometimes responsible (if it is written in the spec.) for pre-construction staking of the pier locations as well as post-construction survey of the pier locations (to record/verify the installed locations and ensure that all piers were in fact installed). Based on past experience, we would recommend that it be specified in the project specifications that the contractor is responsible for pre-construction staking (rather than the Civil Engineer) and the contractor shall conduct a post-construction, field topo survey of the installed locations immediately after installation. The post-construction survey file shall be issued to the Structural Engineer so the installed pier locations can be compared to the planned pier locations to make sure all piers were installed and are in the right location. • The pier contractor is responsible for the full-time, QC inspection and daily testing, including written installation records and test results. This shall be specified in the project specifications. • The project Geotechnical Engineer will be responsible for part-time QA inspection on behalf of the Owner. The Engineer shall be provided with the contractor’s daily records and test results. • Prior to the installation of any production piers, the contractor shall drill a test pier, setup, and conduct a full-scale RAP stiffness modulus load test to confirm the minimum design modulus value of 200 pci can be achieved and that the pier design/layout is valid. The test pier location shall be drilled in the area with the worst soil conditions (ie. deepest depth to sandy gravel) and the location shall be approved by the Geotechnical Engineer. The test pier shall be constructed to the same specifications as the production piers and must extend a minimum of 1.0-foot into the “target” bearing sandy gravel. • Besides the one-time stiffness modulus test (at the on-set of pier installation), two other tests shall be conducted by the contractor on a daily basis. These include base stabilization testing (BST) and dynamic cone penetrometer testing (DCPT). The typical frequency for BST testing is the first five production piles (at on-set), followed by at least five production piers per day for the remainder of installation. The typical frequency for DCPT testing is at least 5% of the total production piers that are installed on the project. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 16 FOUNDATION WALL BACKFILL RECOMMENDATIONS Provided below are our general recommendations for interior and exterior foundation wall backfill. • For interior foundation wall backfill (under interior slab areas), all backfill material must consist exclusively of either 3”-minus granular structural fill or 1”-minus, clean crushed rock. Both of these materials are easy to compact and will minimize any settlement potential under the slab. All backfill must be placed in thin lifts and be vibratory compacted to a dense and unyielding condition (even the crushed rock). We do not recommend using any native silt/clay soils for any interior backfill. • Select native silt/clay soils can be used for exterior foundation wall backfill. These materials must be well compacted to prevent unwanted settlements, especially under exterior slab areas. Use only the driest material available. All backfill must be placed in lifts and be well compacted. • To prevent any exterior slab settlement or exterior slab frost heaving issues for those slabs that are adjacent to doorways and for porch/patio/deck slabs, we are recommending a minimum 12- inch thick, clean crushed rock section under these slab areas, but prefer a minimum of 24 inches of gravel under these slab areas. During construction, additional consideration should be given (by the Contractor) to fully backfilling these relatively small areas (from perimeter footing grade up to slab grade), especially under doorway entry slabs, with granular structural fill or clean crushed rock. By doing so, all frost heaving risk would be removed. INTERIOR SLAB RECOMMENDATIONS For Options 1A and 2, interior slabs shall be supported on a minimum, 18-inch thick, compacted gravel section consisting of 6 inches of clean crushed rock underlain by 12 inches of granular structural fill. • Note: Prior to fill placement, all organic topsoil must be stripped • Note: Prior to fill placement, the silt/clay subgrade surface must be rolled/compacted. • Note: After topsoil stripping, if additional subgrade embankment fill is required to build up to the bottom of the gravel section, this can consist of more gravel (> 18 inches) or the subgrade embankment can be salvaged, on-site silt/clay that is at a moisture content that will allow of proper compaction. For Option 1B (mass over-excavation), the slab will be supported on an expected 6.0 to 8.0-foot thick, section of building pad granular structural fill section that in turn is supported on “target” native gravel. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 17 MOISTURE PROTECTION AND SUBSURFACE DRAINAGE RECOMMENDATIONS Provided below are our moisture protection and subsurface drainage recommendations for at-grade slab (slab-on-grade) configurations. At-Grade Slab (Slab-On-Grade) Foundations • See Figures 4, 5, and 6 for at-grade slab foundation details showing all the recommendations. • Damp proofing of foundation walls for at-grade slabs is not typical. • A perimeter footing drain is not needed/required. • A 15-mil, heavy-duty vapor barrier shall be installed under the slab (above crushed rock section). The barrier we recommend is a Stego vapor barrier. The barrier must be sealed at all seams, at all pipe penetrations, and to the top of the footings.  Note: Typically, vapor barriers are only installed under interior building slabs and not under “garage area” slabs. For this project, we recommend the placement of a vapor barrier under the warehouse slab portion of the building since products will be stored in this area. EXTERIOR SLAB RECOMMENDATIONS Provided in Table 1 is our recommendations for the design section under the light-duty, exterior slabs (including standard pedestrian sidewalks away from the building foundation and next to streets). Table 1. Exterior Concrete Slab (Light-Duty) – Sidewalks Away From Building – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Concrete Slab: 4 (min.) 1”-Minus Clean Crushed Rock: 6 Granular Structural Fill – 3”-Minus Gravel or 1.5”-Minus Roadmix: No 315 lb. Woven Geotextile Separation Fabric (Mirafi 600X or Equal): No Stable Subgrade Soils (Less Topsoil) or Embankment Fill: Rolled/Compacted TOTAL SECTION THICKNESS: 6 + Slab Thickness Notes: 1) We recommend this section for std. pedestrian sidewalks away from the building foundation and next to streets. 2) We expect pedestrian slabs will be 4 inches thick (min.). 3) City of Bozeman specs call for 3 inches (min.) of crushed rock; we recommend increasing this to 6 inches. 4) The purpose of the 6-inch thick, crushed rock section is to provide better support under the slab. 5) Stable subgrade is required for this section. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 18 Provided in Table 2 is our recommendations for the design section under the light-duty, exterior slabs (including pedestrian sidewalks next to the building foundation wall, slabs at all doorway entries, and “patio/porch/deck area” slabs). Note: In the table below, we recommend a minimum of 12 inches of crushed rock under these slabs. A better recommendation to further lower the potential for frost heaving is to increase the gravel section under the “doorway and patio/porch/deck area slabs” to 24 inches (instead of 12 inches). This 24-inch sub-slab section can consist of 12 to 18 inches of granular structural fill topped by 6 to 12 inches of clean crushed rock. Sidewalk slabs next to foundation walls (but not doors) can be underlain by 12 inches. Note: To remove all frost heaving risk under slabs adjacent to doorways, strong consideration should be given to fully backfilling these relatively small slab areas with granular structural fill and/or clean crushed rock from footing grade up to bottom of slab. Table 2. Exterior Concrete Slab (Light-Duty) – Sidewalks Next To Building – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Concrete Slab: 4 (min.) 1”-Minus Clean Crushed Rock: 12 (See Below for Recommendations) Granular Structural Fill – 3”-Minus Gravel or 1.5”-Minus Roadmix: No 315 lb. Woven Geotextile Separation Fabric (Mirafi 600X or Equal): No Stable Subgrade Soils (Less Topsoil) or Embankment Fill: Rolled/Compacted TOTAL SECTION THICKNESS: 12 + Slab Thickness Notes: 1) We recommend this section for pedestrian sidewalks next to the building, at doorways, and patios/porches/decks. 2) We expect pedestrian slabs will be 4 inches thick (min.). 3) City of Bozeman specs call for 3 inches (min.) of crushed rock; we recommend increasing this to 12 inches. 4) The purpose of the 12-inch thick, crushed rock section is to lower the frost heaving risk of the underlying silt/clay. 5) For doorway and patio/porch/deck slabs, we recommend the sub-slab gravel section be increased to 24 inches. 6) The purpose of the “expanded” 24-inch gravel section under slabs is to further reduce frost heaving potential. 7) Option 1: The 24-inch gravel section can consist of 6 inches of crushed rock and 18 inches of structural fill. 8) Option 2: The 24-inch gravel section can consist of 12 inches of crushed rock and 12 inches of structural fill. 9) Option 3: The 24-inch gravel section can consist entirely of 24 inches of crushed rock. 10) Stable subgrade is required for this section. 11) An option for removing all frost heaving risk next to doors is to fully backfill under slabs w/ granular structural fill. 12) The granular backfill material shall extend from footing grade up to the bottom of the layer of clean crushed rock. 13) In lieu of granular structural fill, the doorway slabs can be fully backfilled with clean crushed rock. Provided in Table 3 (on the following page) is our recommendations for the design section under the medium-duty, exterior slabs (including driveway apron slabs in front of garage doors and for slabs under garbage enclosures). Note: This section is not suitable for slabs in front of garbage enclosures that will subjected to garbage truck traffic or for any driveway apron slab areas that will be used by heavy trucks. Instead, see Table 4. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 19 Table 3. Exterior Concrete Slab (Medium-Duty) – Driveway Slabs (Front of Garages) – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Concrete Slab: 4 (min.) 1”-Minus Clean Crushed Rock: 12 Granular Structural Fill – 3”-Minus Gravel or 1.5”-Minus Roadmix: No 315 lb. Woven Geotextile Separation Fabric (Mirafi 600X or Equal): No Stable Subgrade Soils (Less Topsoil) or Embankment Fill: Rolled/Compacted TOTAL SECTION THICKNESS: 12 + Slab Thickness Notes: 1) We recommend this section for driveway slabs in front of garages and for slabs under garbage enclosures. 2) We expect driveway slabs will be 4 inches thick (min.). 3) Stable subgrade is required for this section. Provided in Table 4 is our recommendations for the design section under the heavy-duty, exterior slabs (including public right-of-way driveway aprons and driveway sidewalks; as well as any other heavy vehicle slabs such as slabs in front of garbage enclosures or in front of garage doors). Table 4. Exterior Concrete Slab (Heavy-Duty) – Public Right-Of-Way Vehicle Slabs – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Concrete Slab: 6 (min.) 1”-Minus Clean Crushed Rock or 1.5”-Minus Base Course Gravel: 6 Sub-Base Course – 6”-Minus Uncrushed Sandy (Pitrun) Gravel: 12 315 lb. Woven Geotextile Separation Fabric (Mirafi 600X or Equal): Yes Stable Subgrade Soils (Less Topsoil) or Embankment Fill: Rolled/Compacted TOTAL SECTION THICKNESS: 18 + Slab Thickness Notes: 1) We recommend this section for driveway aprons and driveway sidewalks in the public right-of-way. 2) We recommend this section for all vehicle slabs in parking lot areas, including slabs in front of garbage enclosures. 3) We expect driveway apron/sidewalk slabs and vehicle slabs will be 6 inches thick (min.). 4) City of Bozeman specs call for 3 inches (min.) of crushed rock; we recommend increasing this to 6 inches. 5) The purpose of the 18-inch thick, total gravel section is to provide better support under the vehicle slabs. 6) We recommend a 24-inch total section thickness for slabs that will be subjected to vehicle/truck traffic loading. 7) If the slab thickness will be 8 inches instead of 6 inches, then reduce the crushed rock thickness from 6 to 4 inches. 8) Stable subgrade is required for this section. SURFACE DRAINAGE RECOMMENDATIONS Final site grading next to the building must establish and promote positive surface water drainage away from the foundation footprint in all directions. Absolutely no water should be allowed to accumulate against or flow along any exposed wall (and thereby soak into the foundation wall backfill). Concrete or Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 20 asphalt surfacing that abut the foundation should be designed with a minimum grade of two percent; while adjacent landscaped areas should have a slope of at least five percent within ten feet of the wall. Steeper side slopes than five percent (in landscape areas) are encouraged wherever possible. By doing this, any minor settlements in the foundation backfill should not negatively affect the positive drainage away from the building. Note: The “dirt grade” in all adjacent backfill and landscape areas must be properly graded away from the foundation walls with positive slopes of five percent (min.) prior to the placement of the landscape bed/covering materials. This also applies to the subgrade surface under adjacent concrete areas (below the gravel/crushed rock section materials). To further reduce the potential for moisture infiltration along foundation walls, backfill materials should be placed in thin lifts and be well compacted, and in landscaped areas, they should be capped by four to six inches of topsoil. With the exception of 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 top of the interior concrete slab or below the bottom of the sill plate for framed floor applications. FOUNDATION-RELATED FILL MATERIAL RECOMMENDATIONS Provided below (on the following pages) are specifications for the fill materials that are recommended for use during foundation earthwork construction. These include on-site excavated soils, sandy (pitrun) gravel, crushed (road mix) gravel, and clean crushed rock. Fill placement and compaction criteria follow the specifications. Excavated Foundation Soils For more information on this, please refer to an earlier section of the report that is entitled “Excavation and Re-Use of On-Site Soils”. Sandy (pitrun) Gravel Sandy (pitrun) gravel is a granular structural fill alternative for placement under footings and slabs and behind walls. This material shall be a non-plastic, well-graded, mixture of clean, sand and gravel with 100 percent of its gravels/cobbles passing a three-inch screen and between 2 and 10 percent of its silt/clay particles (by weight) finer than the No. 200 sieve. It should meet all material and gradation specifications as presented in Section 02234 of the Montana Public Works Standard Specifications (MPWSS) for 3”-minus, uncrushed, sub-base course gravel. Note: We recommend the use of 3”-minus sandy gravel for all granular structural fill material (from the bottom of the foundation over-excavation at “target” native gravel back up to footing grades), under interior slabs, and for all interior foundation wall backfill (under interior slabs). Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 21 Crushed (road mix) Gravel Crushed (road mix) gravel is a granular structural fill alternative for placement under footings and slabs and behind walls. This material shall be a non-plastic, well-graded, mixture of clean, sand and gravel that is processed (crushed) such that 100 percent of its rock fragments pass a 1-1/2-inch screen and between 0 and 8 percent of its silt/clay particles (by weight) are finer than the No. 200 sieve. It should meet all material and gradation specifications as presented in Section 02235 of the MPWSS for 1-1/2”- minus, crushed, base course gravel. Clean Crushed Rock The primary uses for crushed rock include placement under concrete slabs and behind foundation and retaining walls for drainage-related purposes. Crushed rock shall be 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. This aggregate product needs to be manufactured by a crushing process and over 50 percent of its particles must have fractured faces. It is not acceptable to use rock containing abundant spherical particles for foundation-related applications. Fill Placement and Compaction All fill materials should be placed in uniform, horizontal lifts and compacted to an unyielding condition. This includes clean crushed rock, which can be readily compacted by vibratory means. In general, the maximum “loose lift thickness” for all fill materials (prior to compaction) should be limited to 12 inches for large, self-propelled rollers, 6 inches for remote-controlled, dual drum rollers and walk-behind, jumping jack compactors, and 4 inches for walk-behind vibratory plate compactors. The moisture content of any material to be compacted should be within approximately two percent (+/-) of its optimum value for maximum compaction. Provided in Table 5 are compaction recommendations for general foundation applications. These are presented as a percentage of the maximum dry density of the fill material as defined in ASTM D-698. Table 5. Compaction Recommendations (Application vs. Percent Compaction) APPLICATION % COMPACTION Granular Structural Fill Under Footings and Slabs: 97 Interior Wall Backfill under Slabs (Granular Structural Fill): 97 Exterior Wall Backfill (Native Soil or Granular Structural Fill): 95 Clean Crushed Rock Under Footings/Slabs and Behind Walls: N/A (Vibration Required) Site Fill Around Building and Under Concrete and Pavement Areas: 95 Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 22 UNDERGROUND UTILITIES General The underground utilities for this project will include water, fire, and sewer services, underslab piping and plumbing, and storm drainage piping and infrastructure. Note: See the following report section for a discussion on underground stormwater drainage systems. Installation The installation of all water, sewer, and storm drainage outside of the building should follow the project plans/specifications, Monana Public Works Standard Specifications, and City of Bozeman Modifications to the MPWSS. Soil Corrosivity Potential for DIP Pipes As part of our 2018 geotechnical work in Nelson Meadows Subdivision, we collected multiple samples of silt/clay and sandy gravel and tested them all for soil corrosivity potential for DIP water mains and DIP water/fire services. None of the sandy gravel samples were corrosive; but some of the silt/clay samples were either borderline or exceeded the lower threshold for corrosion protection using V-bio enhanced, polyethylene encasement. Based on the testing, here are the recommendations: • None of the soil conditions require the use of special, zinc-coated DIP pipe. • All DIP pipes shall be wrapped in V-bio enhanced, polyethylene encasement. Sub-Slab Plumbing Excavation and Trench Backfill In our opinion, the best material for trench backfill of sub-slab plumbing is 1”-minus, clean crushed rock. This material is easy to place and compact in tight and confined areas. We recommend that the crushed rock be placed in reasonable lifts and be vibratory compacted to a dense and unyielding condition. UNDERGROUND STORMWATER DRAINAGE SYSTEMS General As we understand it, the project will include an on-site retention pond (on the northeast side of the lot) and a dry well (in the northwest corner of the parking lot). Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 23 Hydraulic Connection under Dry Well We recommend that a “direct hydraulic connection” be made between the bottom of the dry well and the native gravel. The gravel is the best material for subsurface drainage. In contrast, the silt/clay is a tight soil that has a very slow infiltration/percolation rate. If the dry well does not bear in the native gravel, we recommend that it be over-excavated down to the native gravel. In order to re-fill the excavation area and build back up to bottom of dry well elevation, we recommend either 1”-minus, clean crushed rock or over-sized cobbles (available from a commercial pit) be used as the replacement material. Depending on thickness, simply placing more crushed rock bedding thickness under the structure (down to native gravel) may be the best. As another option, cobbles are free-draining and cheaper than 6”-minus pitrun gravel. When using “open-graded” cobbles, the top of the cobbles must be covered with a layer of 8 oz. non-woven geotextile separator fabric (Mirafi 180N or equal) before placing the bedding rock/gravel under the stormwater systems. A detail that shows the over-excavation and replacement material should be included on the civil plans. ASPHALT PAVEMENT SECTION RECOMMENDATIONS Pavement Section Design and Options (On-Site Parking Lots and Drive Lanes/Access Roads) Two pavement section options are provided for on-site parking lots and drive lanes/access roads in Tables 6 and 7 (below and on the following page). These are termed Option 1 for stable subgrade and Option 2 for unstable subgrade. Due to the stiff to very stiff and slightly moist to moist silt/clay soil conditions (in the upper part of the site’s soil profile), we expect stable subgrade. Therefore, Option 1 should be able to be constructed without issue. This section is designed for a traffic loading of 150,000 ESALs. This is our typical asphalt pavement section recommendation for commercial businesses as well as local city streets. Note: If overly moist silt/clay subgrade is found in some parts of the site, these soils may need to be scarified and allowed to dry out. The most likely area for potentially overly moist subgrade is on the east side of the lot closest to the creek/ditch corridor. Table 6. Pavement Section – Option 1 – Parking Lots/Drive Lanes/Access Roads – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Asphalt Concrete: 3 Base Course – 1.5”-Minus Crushed (Roadmix) Gravel: 6 Sub-Base Course – 6”-Minus Uncrushed Sandy (Pitrun) Gravel: 15 315 lb. Woven Geotextile Fabric (Mirafi 600X or Approved Equal): Yes (for Silt/Clay & “Dirty” Gravel) Stable Subgrade Soils (Less Topsoil): Hard and Compacted TOTAL SECTION THICKNESS: 24 Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 24 Notes: 1) This section shall be used for all on-site asphalt area improvements provided the subgrade soils are stable. 2) This is the standard pavement section design and requires dry, hard, compacted, and stable subgrade soils. 3) We recommend this design section be shown on the civil plans for all parking lots/drive lanes/access roads. 4) This design section can withstand a 20-year traffic loading of 150,000 ESALs. 5) If the subgrade ruts, deflects, and “moves around” under construction traffic, it is deemed unstable. 6) We expect stable subgrade conditions in all areas of the site. 7) To confirm the subgrade stability, all areas should be prepared and proof-rolled with a loaded gravel/water truck. 8) For silt/clay and/or “dirty” gravel subgrade, place a 315 lb. woven fabric for subgrade separation. 9) At all seams, over-lap the fabric by 12 inches (min.). Provided in Table 7 is an option (Option 2) for unstable subgrade conditions. We do not expect these conditions will be encountered. Therefore, this section modification should not be needed. Table 7. Pavement Section – Option 2 – Parking Lots/Drive Lanes/Access Roads – Unstable Subgrade COMPONENT COMPACTED THICKNESS (IN) Asphalt Concrete: 3 Base Course – 1.5”-Minus Crushed (Roadmix) Gravel: 6 Sub-Base Course – 6”-Minus Uncrushed Sandy (Pitrun) Gravel: 24 Tensar TriAx TX-190L Geogrid: Yes 8 oz. Non-Woven Geotextile Fabric (Mirafi 180N or Approved Equal): Yes Unstable Subgrade Soils (Less Topsoil): Relatively Smooth and Rut-Free TOTAL SECTION THICKNESS: 33 Notes: 1) This heavy-duty pavement section option is designed for unstable and soft, subgrade soil conditions. 2) We expect stable subgrade conditions in all site areas. 3) Therefore, the Option 2 section should not need to be used during construction. 4) The Option 2 section should be included on the civil plans as an option for unstable subgrade conditions only. 5) If the subgrade is overly moist and ruts/deflects/pumps under construction traffic, it is deemed to be unstable. 6) The design subgrade surface should first try and be dried out to a stable condition. 7) If drying does not work or is not an option, over-excavation and a thick gravel section w/ geogrid may be needed. 8) Prior to fabric placement, the soft unstable should be relatively smooth and rut-free. 9) The non-woven fabric and geogrid layers shall be installed with 12-inch (min.) over-laps at the seams. 10) The geogrid layer shall be zip-tied together at the seams. 11) Depending on severity, the 24-inch sub-base gravel section may or may not be able to be placed in two lifts. 12) For firmer subgrade, the lower lift of sub-base should be 15 to 21 inches (+/-) if the conditions will allow. 13) For very soft subgrade, the entire 24-inch thick section should be placed/compacted in one single lift. 14) If the 24-inch sub-base will not bridge the soft soils, then the sub-base will need to be thickened (> 24 inches). Pavement Section Materials, Placement, and Compaction The sub-base and base course materials that comprise the granular parts of the pavement section shall consist of 6-inch minus uncrushed sandy (pitrun) gravel and 1-1/2-inch minus crushed (road mix) gravel, respectively. Both gravel courses shall meet the material and gradation specifications as presented in the MPWSS, Sections 02234 and 02235. All gravels shall be placed in loose lifts not exceeding 12 inches Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 25 in thickness and be compacted to at least 95 percent of the material’s maximum dry density as defined in ASTM D-698. Asphalt pavement shall meet specifications in MPWSS Section 02510 and be compacted to a minimum of 93 percent of the Rice mix density. GEOTECHNICAL INSPECTION The City of Bozeman requires that the foundation earthwork be inspected by an Engineer and that an inspection letter that is signed and stamped by a Professional Engineer be submitted to the Building Department prior to the Contractor scheduling the first pre-pour inspection for the foundation concrete. If you would like AESI to perform this work, we can be retained prior to the beginning of the earthwork. We request that we be given about a week notice and we will need to be involved from the first day of foundation excavation. As part of our work, we will observe the bottom of the excavation (down to “target” native gravel) and the placement/compaction of granular structural fill (up to footing grade). PRODUCTS Provided in Table 8 is a reference guide for all products (other than foundation-related fill material) that have been recommended within this report. Listed below is the name of the product, its intended use, and where it can be obtained. The manufacturer specification sheet for each of these products is attached at the end of the report. Note: Several notes are presented under the table (and continuing on the following page) that describe the recommended products, where they can be obtained, and where they can be used. Table 8. Product Reference Guide PRODUCT USE SOURCE PHONE Stego 15-mil Vapor Barrier Moisture Protection under Bldgs MaCon Supply – Bozeman 551-4281 Mirafi 180N Non-Woven Fabric Wet Exc. & Soft Subgrade w/ Grid Multiple Sources – Bzn/Blgd N/A Mirafi 600X Woven Fabric Road Subgrade Separation Multiple Sources – Bzn/Blgd N/A Tensar TriAx TX-190L Geogrid Road Subgrade Stabilization Core & Main – Belgrade 388-5980 Notes: 1) Use Stego 15-mil vapor barrier only. There are no approved equals for this product. 2) Stego 15-mil vapor barrier has a water transmission rate that meets national standards for vapor barriers. 3) Stego 15-mil vapor barrier is a heavy-duty vapor barrier for placement under interior slabs and in crawl spaces. 4) Use Mirafi 180N non-woven fabric or an approved equal that meets or exceeds Mirafi 180N fabric specifications. 5) Approved equals for Mirafi 180N non-woven fabric are available from multiple sources in the Bzn/Blgd area. 6) Mirafi 180N is a medium-weight, 8 oz. non-woven fabric. 7) There are three potential uses for Mirafi 180N non-woven fabric on this project site. 8) Use 1: If the bottom of the foundation excavation is wet, an initial layer of clean crushed rock will be required. 9) Following vibratory compaction, the crushed rock layer must be covered with a layer of 8 oz. non-woven fabric. 10) The purpose of the fabric-covered rock is to provide separation from the overlying granular structural fill. 11) Use 2: If road or parking lot subgrade soils are soft and unstable (and cannot be dried), geogrid will be required. 12) An 8 oz. non-woven fabric must be installed for subgrade separation under the geogrid stabilization layer. Final Geotechnical Report Lot 16, Nelson Meadows Sub. – Bozeman, MT Project: 23-119 August 21, 2023 Allied Engineering Services, Inc. Page 27 enc: Figure 1 – Site Location Map w/ Test Pit Locations Figure 2 – Drier Silt/Clay vs. Moister Silt/Clay (Note: Fig. 6 from 2018 AESI Geotech Rpt) Figure 3 – Test Pit Locations w/ Native Gravel Depth (Note: Fig. 4 from 2018 AESI Geotech Rpt) Figure 4 – Foundation Detail – At-Grade Slab – Option 1A Figure 5 – Foundation Detail – At-Grade Slab – Option 1B Figure 6 – Foundation Detail – At-Grade Slab – Option 2 Test Pit Logs for TP-8 through TP-10 (Note: From 2018 AESI Geotech Rpt) 2018 Groundwater Monitoring Data Products (Vapor Barrier, Non-Woven Fabric, Woven Fabric, Geogrid) Limitations of your Geotechnical Report REFERENCES International Code Council, 2021, “International Building Code”. Montana Contractors’ Association, April 2021, “Montana Public Works Std. Specifications”, 7th Edition. P:\2023\23-119 Lot 16, Nelson Meadows Sub. - Geotech\Design\Geotech\Report\Text\Lot 16, Nelson Meadows - Geotech Report.08.21.23 Figure 4 23-119 Aug. 2023 Lot 16, Nelson Meadows Foundation Detail - At-Grade Slab - Option 1A Bozeman, Montana Damp-Proofing As Required (typ.) Foundation Wall (typ.)Approved Non-Woven Filter Fabric To Encase Bedding Gravel (typ.) Interior Floor Slab (typ.)Interior Steel Column (typ.)Interior Spread Footing (typ.) 6” Of 3/4" Minus Crushed Washed Gravel Hydraulically Connected To Sub-Drain or Existing Surface Drainage (typ.) Native Topsoil andRandom Surface Fill Imported 4-Inch Minus Sandy Pitrun Gravel Native Silt/ClayImported Flowable Fill Six Inch Diameter Sub-Drain Pipe (Graded To Drain To Sump Area) Concrete SidewalkLow Permeability Soils(Landscaped Area)LegendConcrete Wall and/or Footing Low Permeable Topsoil No Scale (Parts Of This Exhibit Have Been Exaggerated For Clarity) ALLIEDENGINEERING SERVICES, INC. Civil Engineering Geotechnical Engineering Land Surveying 32 Discovery Drive Bozeman, MT 59718 Phone: (406) 582-0221 Fax: (406) 582-5770 Slope Away @ 2% In All Concrete Or Pavement Areas (typ.) Footings 6’ max. depth below existing ground Native Topsoil 6” Minus Sandy (Pitrun) Gravel 4” Minus Sandy PitrunGravel (ie. Structural Fill)4’ max fill above existing ground 4' min. 4’ Max Fill Above Existing Ground 3” (min.) Thickness Will Vary Due To Depth Of Bedbrock Strata 6” (min.) 3” (min.) 8” (min.) 4.0’ (min.) 6” (min.) Of Rock Bedding To Be Placed Around Drain Piping (typ.) Under-Slab Rock Layer To Be Hydraulically Connected To Sub-Drain System By 3” Of Rock Or 2” Sch. 80 Piping Spaced On 10’ Centers (typ.) B H (Variable; Depends On Depth To Gravel) 18” (min.) 18” (min.) 6” (min.) 6” (min.) 1’ (min.) H = 3.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-4) H = 5.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-2) D D Woven Geotextile Filter Fabric (Amoco 2004)Vapor Barrier Under Slab (typ.) 9.5’ Deep (TP-2) 7.5’ Deep (TP-4) Non-Woven Filter Fabric To Encase 1-Inch Minus Rock 6” (min.) Rock Layer (typ.) Landscape Areas To Slope Away @ 5% (min.) Within 10’ Of Wall. Upper 4” - 6” Of Backfill Should Consist Of Low Permeable Topsoil. Note: Asphalt/Concrete Surfacing Placed Adjacent To Foundation Walls Shall Slope Away @ 2% (min.). 6” (min.) 6” (min.)4” PE Sub-Drain (typ.) Crawl Space Opening Must Be Properly Vented. Note: Elevation Difference Between The Top Back Of Curb And The Finished Floor Should Be Maximized. I Believe The Subdivision Covenants Call For A Minimum Separation Of 2.0’ And A Maximum Of 5.0’. Due To High Groundwater Concerns, An Elevation Difference Of More Than 2.0’ Is Recommended. This Should Be Thoroughly Considered On A Case By Case Basis. Please Refer To The Covenants For More Detail. Important Notes: The Three-Foot Wide (Min.) Over-Excavation From The Center Of The Footing Is Calculated Based On A 16-Inch Footing Width (B) And An Average Depth To Native Gravel (GD) Below The Footing Elevation Equal To Five Feet. If The Footing Is Substantially Wider Or The Depth To Gravel Substantially Deeper; The Width Of The Excavation Will Need To Be Increased. The Equation For Determining Excavation Width (EW) From The Center Of Footing Is: EW = (B + GD) / 2.0. If Caving (ie. Sloughing) Of The Excavation Side Walls Is A Problem; EW Will Need To Be Increased Accordingly. Since The Footings Are Supported On Structural Fill That Bears On Native Gravel; There Is No BenefitTo Increasing Footing Size Beyond What Is Shown On The Plans. If Groundwater Is Encountered In The Over-Excavation Above The Native Sandy Gravel Surface, We Recommend A Layer Of Crushed Rock First Be Used To Get Above The Groundwater Elevation. The Crushed Rock Should Be Placed In A Single Lift That Does Not Extend More Than Four Inches Above The Groundwater. After Placement, The Crushed Rock MUST Be Compacted By Vibratory Methods. Compactors That Are Suitable For Crushed Rock Include Walk-Behind Plate Compactors; Remote-Controlled Sheepsfoot Trench Rollers; And Self-Propelled Smooth Drum Rollers. Note: If Groundwater Is Not Encountered, The Use Of Crushed Rock Is Not Necessary. Compacted Structural Fill. Use Sandy Pitrun Gravel, Not Crushed Rock. Gravelly Materials Are Not Only Less Expensive But They Will Also Reduce The In-Flow Of Groundwater Into The Crawl Space In The Event That High Groundwater Exceeds The Crawl Space Elevation. Place The Pitun In Lifts (Six-Inch Thick Max. For Small Remote-Controlled Sheepsfoot Trench Rollers And Twelve-Inch Thick Max. For Self- Propelled Smooth Drum Rollers) And Compact To An Unyielding Condition. Note: A Material That Works Very Well For Foundation Structural FilI Is The 3” Minus Pitrun Gravel Product That Is Available From TMC In Belgrade. Pay Special Attention To Compaction Of Crushed Rock And Structural Fill Along Edges. Native Soils Could Be Soft. Rock / Fill Will Need To Be Compacted Into Side Of Excavation. Place Woven Geotextile Fabric Over The Crushed Rock. This Will Prevent Fines Migration Into The Rock After Placement Of The Structural Fill. 4” (max.) 3’ (min.) 3’ (min.) Interior Footing As A Precaution For Groundwater, Install 4” PE Slotted Drain Piping Along The Inside Of The Perimeter Footings And Grade To A Shallow Sump Chamber In The Crawl Space. If Water Becomes An Issue, Install Sump Pump And Discharge Out Of The Crawl Space. A Four-Inch Layer Of Crushed Rock Will Facilitate Rapid Drainage And Eliminate The Sight Of Standing Water. If A Vapor Barrier Is Placed Above The Crushed Rock; Ensure It Is A Material That Can Breathe (Not Polyethylene). All Interior Footings Shall Bear On Structural Fill. Finished Floor Elev. (At-Grade Slab) GD Existing Ground Surface Existing Ground 4” Slotted PE Pipe. Install Drain Piping Around Inside Perimeter Of Foundation. Piping Should Be Placed At Footing Grade Or Preferably Below The Top Of The Crushed Rock Fill (When Used). Connect Piping To Shallow Sump Chamber. If High Groundwater Is An Issue, A Pump Can Be Installed At A Later Time. 32” 48” Reviewed By: __________________ 4” To 6” (Min.) Thickness As Required 2.5’ 4’ (min.) Damp Proofing 4” Footing Drain (typ.) Min. Depth Of Cover For Frost Protection Min. Required Width Of Mass Over-Excavation Beyond Edge Of Footing 1.0’ - 17.0’ Depth To “Target” Bearing Material. Silt/Clay Below 2.5’ (+/-) Is Generally V. Moist To Wet. See TP Logs For Soil And Groundwater Conditions. 5.0’ - 13.5’ Depth To “Target” Bearing Material. Groundwater Depth Ranged From 6.0’ to 13.5’. Depending On Time Of Year, Groundwater May Be At Or Above The Sandy Gravel (“Target” Bearing Material). Therefore, Groundwater Dewatering May Be Needed. Dewatering Wells Are Recommended To Lower Water Below Gravel Surface. Strip, Remove, And Replace All Random Fill From Under The Entire Building Area, Including Under Interior House And Garage Slabs (typ.) Note: De-Watering Will Likely Not Be Required For Foundation Excavation. Based On Our Test Pits, All Evidence Suggests The Groundwater Table Stays Within The Sandy Gravel Most Of The Time. LSE, 8/17/23 Prior To The Placement Of Granular Structural Fill, The Site’s Shallow Groundwater Conditions May Require That An Initial Layer Of Clean Crushed Rock Be Placed And Compacted Up To A Height Of At Least 6 Inches Above The Level Of The Standing Water. Structural Fill: Use 4” Minus Sandy (pitrun) Gravel Due To Shallow, Seasonal High Groundwater Conditions, Footing And Crawl Space Depth Must Be Minimized Below The Existing Ground Surface. Bottom Of Footing Elevation Should Be Kept Within At Least 2.5’ To 3.0’ Of Existing Grades. As An Added Precaution Against High Groundwater In The Crawl Space (And Especially If Footing Depth Nears Or Exceeds 2.5’ To 3.0’ Below Existing Site Grades), We Strongly Encourage The Placement Of A 6” To 8” Layer Of Crushed Rock In The Crawl Space To Raise The Floor Elevation Up To The Top Of Footings. In The Event That Groundwater Ever Rises Above The Crushed Rock Layer, A Sump Chamber And Pump Can Easily Be Installed Later To Address The Problem. We Do Not Recommend Placing The Initial Layer Of Clean Crushed Rock In Standing Water Exceeding 10 Inches In Depth. Therefore, Depending On The Time Of Year, Some Groundwater De-Watering May Be Required During Foundation Earthwork. All Perimeter, Interior, And Exterior Footings Must Bear On A Minimum 2.0’ Thickness Of Granular Structural Fill That In Turn Is Supported On The Native Sandy Gravel (Which Is The ”Target” Foundation Bearing Material). Given The 4.5’ To 6.5’ Depth To Gravel, Along With The Anticipated Slab Grade, Perimeter Footings Will Likely Lie 2.0’ to 6.0’ Above The Top Of The “Target” Gravel. Mass Over-Excavate The Entire Foundation Footprint Area, Including All Exterior Footing Locations, Down To The “Target” Bearing Material (Native Sandy Gravel); Thereby, Completely Removing All Native Silt, Clay, Sand From Under The Building. Over-Dig The Excavation To The Minimum Width Dimensions As Shown On This Figure And As Stated In The Report. Important Note: Mass Over-Excavation Of The Foundation (As Illustrated By Option #2) Will Be Required If The Individual Footing Over-ExcavationsThat Are Depicted As Option #1 Will Not Stay “Open” Due To Trench Wall Collapse. Foundation Earthwork Notes: 1) Slab On Grade - Option “B” Consists Of Over-Excavating Under All Perimeter, Interior, And Exterior Footings.2) This Is Most Applicable Where The Building Is Underlain By Relatively Deep Gravels And The Foundation Contains Less Interior Footings.3) Where Present, All Random Surface Fill Material Must Be Fully Removed From Under The Entire Building Area Down To Native Soils. Foundation Excavation Recommendations: Due To The Large Number and Close Spacing Of Interior Footings (Many Of Which Are 13 To 14 Feet On-Center), We Recommend The Entire Foundation Footprint Area Of The Apartment Buildings Be Mass Over-Excavated Down to Native Sandy Gravel And Built Back Up To Footing And Slab Grades With Compacted Structural Fill. The Limits Of The Mass Excavation Must Encapsulate All Perimeter And Exterior Footings. Important Note: It Is Now COB Policy That The Foundation Earthwork Be Inspected And Certified By The Geotechnical Engineer. Suggestions: In Order To Reduce The Amount Of Required Structural Fill Under Footings And The Slab Area, The Finished Floor Elevation Should Be Minimized Above Existing Site Grades. Another Option To Reduce Fill Under Perimeter Footings Is To Use A 6’ Tall Foundation Wall. Foundation Backfill and Embankment Fill Granular Structural Fill(1.5”Minus Roadmix Gravel)Granular Structural Fill(1.5”Minus Roadmix Gravel)Sandy Gravel(”Target” Bearing Material) Low Permeable Topsoil Native Silt/Clay(Unsuitable Bearing Material) Native Silt Native Silt/Clay (Unsuitable Bearing Material) Native Topsoil Granular Structural Fill(4” Minus Sandy Gravel)Granular Structural Fill(1.5” Minus Roadmix Gravel)1” Minus CleanCrushed Rock Groundwater (on 4/19/16) Concrete Slab Exterior Foundation Wall Backfill Should Only Consist Of Excavated Soils That Are Not Overly Moist. It Must Be Placed In Multiple Lifts And Properly Compacted. Slab Grade Should Be Set Above Existing Grades. For The Mass Over- Excavation Option, There Is No Limit On Slab Height Above Existing Grades. H W = Footing Width + H; (5’ min.) All Foundation Fill Materials Should Be Placed In Uniform, Horizontal Lifts And Be Well Compacted. Granular Structural Fill Shall Be Compacted To A Dense, Unyielding Condition, While Clean Crushed Rock Or Lean Mix Concrete Must Be Compacted By Vibratory Means. In General, The “Loose” Thickness Of Each Lift Prior To Compaction Should Not Exceed 12 Inches For Large, Self- Propelled Rollers; 6 Inches For Remote-Controlled Trench Rollers And Walk-Behind Jumping Jack Compactors; And 4 Inches For Walk- Behind, Plate Compactors. Pay Special Attention To Compaction Of Structural Fill Along Edges And In Corners Of The Excavation. Place Crushed Rock As Fill Under Slab (6” min.) And Interior Wall Backfill Strip Topsoil Under Slab and Re-Compact The Subgrade Surface. Vapor Barrier Under Slab. Seal Barrier At Seams/Penetrations. Minimize New Fill Height For Settlement Reasons The Uppermost 6” Of Lean Mix Concrete Fill Can Be Replaced w/ Clean Crushed Rock For Easier Leveling Of Footing Grade. Bearing Pressure 4000 psf (max.) 6” (min.) Crushed Rock Layer Under Slab Areas (typ.) Important Note: To Stabilize The Trench Excavations And Minimize The Potential For Caving/Sloughing, Groundwater Dewatering May Be Required. Shallow Frost- Proof Foundation. Insulate As Per Applicable Codes. Interior Footing (typ.) Radon Mitigation System Should Be Considered Under Interior Slab. Important Note: If Foundation Construction Will Occur During The Cold/Winter Weather Season, The Contractor Shall Take All Necessary Precautions To Prevent The Earth- Work From Freezing And/Or From Being Contaminated With Snow. Note: At A Minimum, Use A Large, Smooth Drum Roller To Compact The Upper-Most Lift Of Structural Fill Under Footings And Slabs. Additional Thickness Of Gravel Building Pad As Req’d To Bear On “Target” Gravel. For Mass Excavation, Over-Excavation Width Beyond Perimeter Ftgs Is 5.0’ (typ.) See Fig. 6 For Over-Excavation Width Under Individual Ftg Excavations. Embankment Fill Can Be Used Below 18” Of Slab Grade. Note: No Topsoil Observed In On-Site Borings. Product Recommendation: A Stego 15-mil Vapor Barrier Is Recommended.Available From MaCon Supply In Bozeman. W = Footing Width + H; (5’ min.) Min. Width = 1/2(H); But Must Be 5’ Min. H H = 2’ Min. Important Note: If TP-3, A Clay Layer Was Observed Under The Native Sandy Gravel At A Depth Of 6.0’. It Is Recommended That All Footings Bear On A Minimum 24” Thickness Of Native Gravel Or Granular Structural Fill. This Should Be Confirmed With Test Pits Around The Perimeter Of The Building During Construction. Important Note: If The Trench Excavations Are Prone To Minor Caving, Their Width Will Have To Be Increased Accordingly To Prevent Slough From Underlying Or Being Mixed Into The Minimum Required Width Of Structural Fill. Given The 4.5’ To 6.0’ Depth To Native Sandy Gravel, We Do Not Expect That Most (If Any) Of The Perimeter Footings Will Bear Directly On Native Gravel. Most Likely, Footings Will Need To Be Supported On Structural Fill That In Turn Bears On Native Gravel (Similar To All Interior Footings). Excavation Alternative: In Lieu Of Only Excavating Footings, The Entire Foundation Footprint Area Of The Building Can Be Mass Over-Excavated Down To Native Sandy Gravel And Filled With Granular Structural Fill. Given The Gravel Depth, This Is Far Less Economical As Compared To The Above Recommendations. Prior To Granular Structural Fill Placement, The Excavated Gravel Surface (Under Entire Foundation Footprint Area) Must Be Vibratory Re-Compacted With A Large, Smooth Drum Roller In Order To Densify The Native Sandy Gravel. Due To Groundwater Depths Of 7.8’ To 9.8’, Wet Subgrade Conditions Should Not Be An Issue. Depending On Location, Groundwater Could Be At Or Above The Top Of Native Sandy Gravel During The Seasonal High Water Time Of Year. A Large, Smooth Drum Roller Must Be Used To Compact All Granular Structural Fill Whenever and Wherever Possible. Lean Mix Concrete(Flowable Fill)Embankment Fill(On-Site or Import Material) Non-Organic Embankment Fill (On-Site, Dry Silt/Clay) 2500 psf (max.) B 2500 psf (max.) B Mass Excavate Under Entire Foundation Footprint Area Down To Native, Clean Sandy Gravel; Thereby Removing All Of The Silt/Clay Under The Interior Slab. All Footings Must Bear On Native Sandy Gravel Or On Compacted Granular Structural Fill That In Turn Is Supported On This “Target” Bearing Material. Shallow Frost-Proof Foundation Per IBC Is Also Acceptable. H H If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. Min. Width = (B + H); But 5’ (min.) Crushed Rock Is Only Needed If Gravel Subgrade Is Wet Or Contains Standing Water. All Fill Material Placed Under Footings And Slabs To Consist Of Compacted Granular Structural Fill. No On-Site Soils Are To Be Used As Embankment Fill Under Slabs. Do Not Place Granular Structural Fill Materials Over Wet Subgrade Or In Shallow Standing Water. De-Water The Excavation If Required. If Bottom Of Excavation Is Wet, Place An Initial, Thin Layer Of Clean Crushed Rock Under The Structural Fill. The Crushed Rock Should Extend A Minimum Of About 4” Above The Wet Conditions. Vibratory Compact The Crushed Rock And Then Cover With A Medium-Weight, Non-Woven Fabric Prior To Structural Fill Placement. Overlap Seams Of Fabric By 12” Minimum. Over-Excavate Under All Perimeter, Interior, And Exterior Footings Down To Native, Clean Sandy Gravel; Thereby Removing All Silt/Clay Under Footings. All Footings Must Bear On Native Sandy Gravel Or On Compacted Granular Structural Fill That In Turn Is Supported On This “Target” Bearing Material. Embankment Fill Under Structural Fill Layer Must Be Compacted To Project Specifications. See Figure 7 For Recommendations For Foundation Fill Material Placement And Compaction. See Figure 7 For Recommendations For Ext. Foundation Wall Backfill Material And Compaction. For Basements, Additional SubsurfaceDrainage And Moisture Protection Recommendations Will Need To BeIncorporated That Are Not Shown On This Exhibit. See Report For More Details. No Scale (Parts Of This Exhibit Have Been Exaggerated For Clarity) Geotechnical Notes: 1) Figure 4 Illustrates Option 1A For Foundation Earthwork And Support. This Option Entails Trench Over-Excavating Under All Footings (Down To Native Gravel) And Placing Compacted, Granular Structural Fill (Back Up To Footing Grades). This Option Is Most Applicable In Areas Of The Building With Few Interior Footings (Such As The Large/Open Warehouse Portion Of The Building). Granular Structural Under Footings And Slabs Can Consist Of4”-Minus Sandy Pitrun Gravel Or 1.5”-Minus Roadmix Gravel. Based On Test Pits, Depth To “Target” Bearing Material Is 4’ To 5’ On Downhill Side And 3’ On Uphill Side Of The Lot. Legend Random Fill (Unsuitable Bearing Material) Random Fill (Unsuitable Bearing Material) Low Permeable Topsoil Granular Structural Fill(4”-Minus Sandy Gravel) Granular Structural Fill (*) Place In Thin Lifts And Vib. Compact To 97% (min). 1” Minus CleanCrushed Rock 1” Minus Clean Crushed Rock 1” Minus CleanCrushed RockExisting Grade (Ground Surface) Native Topsoil Topsoil or Asphalt/GravelSurfacing Materials Native Topsoil Floor Joist Exterior Foundation Backfill (On-Site, Dry Silt/Clay) Native Sandy Gravel (“Target” Bearing Material) Native “Dirty” Sandy Gravel(Unsuitable Bearing Material) Native Topsoil Interior Wall Backfill (3”-Minus Sandy Gravel Or 1”-Minus Clean Crushed Rock) “Target” Bearing Material Is The Glacial Till. It Is Identifiable Based On Its Clean Sandy Composition, Abundance Of 6”-Minus, Sub-Rounded Gravels, And Dense Configuration. It Looks Like “Clean Pitrun Gravel” w/ Large Cobbles And Boulders. All Footings Shall Bear On A Minimum Of 1’ Of Granular Structural Fill That In Turn Bears On “Target” Glacial Till (typ). Additional Structural Fill Thickness Will Be Required Under Some Footings In Order To Reach “Target” Bearing Material. Recompact Subgrade Prior To Fill Placement (typ). All Foundation Fill Materials Should Be Placed In Uniform, Horizontal Lifts And Be Well Compacted. Granular Structural Fill, Embankment Fill, And Wall Backfill Shall Be Compacted To A Dense, Unyielding Condition, While Clean Crushed Rock Must Be Compacted By Vibratory Means. In General, The “Loose” Thickness Of Each Lift Prior To Compaction Should Not Exceed 12 Inches For Large, Self-Propelled Rollers; 6 Inches For Remote-Controlled Trench Rollers And Walk-Behind Jumping Jack Compactors; And 4 Inches For Walk-Behind, Plate Compactors. Pay Special Attention To Compaction Of Fill Materials Along Edges And In Corners Of The Excavation; And Along Foundation Walls. Daylight Footing And Sub-Slab Drains (typ.) See Figures 8 And 9 For Note On Exterior Foundation Wall Backfill. Granular Structural Fill Should Be Used For Interior Wall Backfill Under Slabs. See Figures 8 And 9 For Note On Foundation Fill Material Placement And Compaction. All Excavated Soils Can Be Re-Used For Exterior Wall Backfill Or Embankment Fill Provided They Are Not Organic Or Overly Moist. All Fill Must Be Placed In Thin, Level Lifts And Properly Compacted. H = 1’ or 2’ (Depending On Ftg Width) H = 1.0’ (min.) H H = 1.0’ (min.) 15-mil Vapor Barrier Under Slab (Above Rock Layer). Note: We Recommend Placing Under Warehouse Slabs. Vapor Barrier Not Typ. Under Garage Slabs. Note: Due To Unheated/Non-Insulated Buildings, Consider Insulating Under Interior Slabs To Minimize Frost Heaving Potential Of Silt/Clay. (*) Granular Structural Fill Can Consist Of 3”-Minus Sandy (Pitrun) Gravel Or 1.5”-Minus Crushed (Roadmix) Gravel Note: Groundwater Will Likely Rise To Near The Top Of The Native Gravel During The Spring. By The Latter Part Of The Summer, It Will Be 1.0’ To 2.0’ Below The Top of Gravel. Note: In 2018, The Seasonal High Groundwater Depth In TP-9 Was At 6.6’ Below Ex. Grade (On 4/27/18). 4’ (min.) For Frost Protection No Ftg Drains Req’d Strip Topsoil And Bench Subgrade Level Prior To Placing Fill (typ.) About 6” Of Dirty Gravel Overlies The Clean Gravel.It Is Important To Vibratory Re-Compact The Excavated “Target” Gravel Subgrade Surface Prior To Pouring Ftgs Or Placing Struct. Fill. Where Possible, Enlarge The Excavation To Allow For Use Of Large, Smooth Drum Roller. Product Recommendation: A Stego 15-mil Vapor Barrier Is Recommended. Perimeter Footing Drain To Wrap Around The Exterior Of Home (typ.) Over-Excavate Under All Perimeter, Interior, And Exterior Footings Such That They Bear On A Minimum Of 1’ Of Compacted Granular Structural Fill That In Turn Bears On “Target” Glacial Till. Min. Width Is B+H, But It Shall Not Be Less Than 5’. Use Light-Weight Fabric Around Footing Drains (typ.). Over-Excavation Width Must Be Centered On The Footings (typ.) More Than 1.0’ Of Structural Fill Is Expected (typ.) Min. Width = (B + H); But Shall Be 5.0’ (min.) This Is A Bottom Of Exc. Dimension. Assumes No Sloughing Of Exc. Side Walls. Min. Width = (B + H); But Shall Be 5.0’ (min.) This Is A Bottom Of Exc. Dimension. Assumes No Sloughing Of Exc. Side Walls. A Large, Smooth Drum Roller Should Be Used To Vibratory Compact Subgrade Soils And Granular Structural Fill Wherever Possible. Concrete Slab The Excavated Gravel Surface (Under All Footings) Must Consist Of Dense, Clean, Native Sandy Gravel. Use A Smooth Foundation Bucket To Prevent Unnecessary Disturbance To The Native Gravel Subgrade. Do Not Stop Excavation In Lowermost Silt/Clay, Which Does Contain Some Scattered Gravels. The Silt/Clay w/ Gravels (Which Looks Like A “Dirty Gravel”) Does Not Constitute The Clean, Native Sandy Gravel (“Target” Bearing Material). Vibratory Re-Compact Subgrade Surface Whenever Possible. Re-Compact Subgrade Prior To Fill Placement. Additional Structural Fill Thickness As Required. For Strip Footings With Width Of 2.0’ Or Less, Min. Structural Fill Thickness (H) Is 1.0’. For Larger Pad Footings With Width Of 3.0’ To 6.0’, Min. Structural Fill Thickness (H) Is 2.0’. Exterior Wall Backfill Can Consist Of Any Non-Organic Soil. Suggest Removing Cobbles Over 6” Directly Next To Walls. Strip Topsoil/Surfacing Material And Cut To A Min. Depth Of 18 Inches Below Bottom Of Slab Grade. For Easier Compaction, Consider Using Only High Quality Granular Material Or Clean Crushed Rock For Interior Backfill. Place In Lifts / Vibratory Compact. “Target” Clean Gravel Surface. Re-Compact Prior To Placing Fill. Pad Footing Over-Excavation On Individual Basis “Target” Clean Gravel Surface. Re-Compact Prior To Pouring Ftgs Or Placing Struct. Fill. “Target” Clean Gravel Surface. Re-Compact Prior To Pouring Ftgs Or Placing Struct. Fill. All Footings Must Bear On “Target” Sandy Gravel Or On Granular Structural Fill That In Turn Bears On “Target” Gravel. All Excavations And Structural Fill Under Footings Must Be Centered Under The Footing. Note: If Native Gravel Is Wet, Place An Initial Thin Layer Of Clean Crushed Rock Covered By Non-Woven Fabric Prior To Structural Fill. Vibratory Compact The Rock. Excavations Should Be Wide Enough To Permit The Use Of A Large, Smooth Drum Roller For Compaction Of Gravel Subgrade And Granular Structural Fill. Footing Subgrade Will Consist Of Native Silt/Clay. Dig With Smooth- Edged Bucket To Prevent Disturbance. Vibratory Compact To Re-Tighten Soils And Induce Consolidation/Settlement. Due To Dry Soils, Construction Water May Need To Be Added To Facilitate Better Compaction. (Typ. All Locations) Over-Excavation And Structural Fill To Be Centered Under Footing And Extend A Minimum Of 2.0’ Beyond Outside Edge Of Ftg In All Directions. Over-Excavation And Structural Fill To Be Centered Under Footing And Extend A Minimum Of 2.0’ Beyond Outside Edge Of Ftg In All Directions. Strip Topsoil Before Placing Fill Material. Strip Gravel. Depending On The Number/Spacing Of Interior Footings. Consideration Should Be Given To Mass Excavating Down To “Target” Gravel Throughout Foundation Footprint And Increasing Thickness Of The 12-Inch Structural Fill Layer. By Doing This, Over-Excavation (On An Individual Basis) Under Interior Footings Could Be Avoided. H Min. Width = H / 2 Min. Width = H / 2 Existing Ground Damp Proofing Walls For At- Grade Slabs Is Not Typical Perimeter Footing And Foundation Wall (typ.) Depth To “Target” Sandy Gravel Should Be 5.0’ To 7.0’ In Bldg Site. In TP-9, It Was At 6.0’. (See Fig. 3) Note: Due To Expected 5.0’ To 7.0’ Gravel Depth, Perimeter Ftgs Will Likely Bear On Structural Fill. Note: Due To Expected 5.0’ To 7.0’ Gravel Depth, Interior Ftgs Will Need To Bear On Several Feet Of Structural Fill. Note: See Figure 5 For Foundation Fill Material And Compaction Note. Note: In Lieu Of Trench Excavation Under Footings, The Garage Area Can Be Mass Over-Exavated Down To Native Gravel Per Fig. 5. Thickness As Needed/Required To Build Up To Footing Grade From “Target” Gravel Surface. Strip All Topsoil Prior To Filling. Most Likely, Perimeter Footings Will Readily Bear In Or Near “Target” Gravel (Meaning Either No Req’d Structural Fill Or Only A Relatively Thin Amount). The Benefit Of Mass Over-Excavation And Replacement Is That Interior Footings Now Do Not Have To Be Over- Excavated On An Individual Basis. “Target” Clean Gravel Must Be Exposed Throughout The Bottom Of Excavation. Re-Compact Subgrade Prior To Structural Fill Placement. See Figure 5 For An Illustration That ShowsA Crawl Space Foundation Configuration. We Recommend Mass Over-Excavation Under Slab-On-Grade Foundations Down To “Target” Bearing (In Lieu Of Trench Excavating Under All Perimeter, Interior, And Exterior Footings On An Individual Basis). This Excavation Approach Is Faster; But It Requires In-Filling/Backfilling Inside The Foundation Walls With Granular Structural Fill Back Up To Interior Footing Grade. For Figure 6, We Have Shown A Deep Native Gravel Surface To Purposely Illustrate The Need For The Placement Of A Structural Fill Building Pad Back Up To Perimeter Footing Grade. Due To Shallow Gravels, Most Perimeter Footings Should Readily Bear In/Near The “Target” Gravels. Due To The Complexity Of Most Foundation Plans (Many/Closely Spaced Interior Footings),Individual Footing Over-Excavation Is Time Consuming, Difficult, And Not Recommended. Due To The Shallow Gravels, Assumed Complexity Of The Foundation Plan (Number And Spacing Of Interior Footings), And Need To Fully Remove All Fill Material (That Was Found In The NE Corner), The Best Approach Will Likely Be Mass Over-Excavation Of The Entire Foundation Footprint Area. Some Perimeter Ftgs May Require Some Struct. Fill. No Underslab Drains Req’d. Due To Shallow Gravels And Likely Complexity Of The Foundation Plan (Many/Closely Spaced Interior Footings), We Assume Most Building Foundations Will Be Mass Over-Excavated Down To “Target” Gravel And Re-Filled With Structural Fill Up To Interior Footing Grade. Interior Footings Will Most Likely Require Struct. Fill. Min. Exc. Width = H / 2; 3.0’ (min.) Min. Exc. Width = H / 2; 4.0’ (min.)Increase Width Under Int. Ftgs. Given The Shallow Gravel Depth In Most Areas, Footing Grade Should Be Close To “Target” Gravel. H H = 2.0’ (min.) As Required To Build Up To Footing Grade From “Target” Gravel Surface. Strip All Topsoil From Under Slabs. Rolled/Compacted Silt/Clay Subgrade. As Needed, Compacted On-Site Embankment Fill Can Be Placed Under The Min. Gravel Section. Where Possible, Use Large Smooth Drum Roller For Compaction Of Subgrade And Granular Structural Fill. “Target” Clean Gravel Surface At Bottom Of Mass Excavation. If The Surface Is Dry, Vibratory Re-Compact Prior To Pouring Footings Or Placing Granular Structural Fill. Dig Foundation Exc. With Smooth- Edged Bucket To Prevent Disturbance To Native Gravel Subgrade. “Target” Clean Gravel Surface At Bottom Of Mass Excavation. If The Surface Is Wet, Track-Pack With Excavator And Static Roll With Roller Prior To Placing Crushed Rock. Note: This Figure Illustrates The Possible Need For Some Fabric- Covered, Clean Crushed Rock To Get Above Wet Conditions Or Shallow Groundwater. If The Bottom Of Excavation Is Dry, Then No Crushed Rock Will Be Necessary. If Groundwater Is Above The Native Gravel, Lower Groundwater By De-Watering. If The Gravel Subgrade Is Wet Or Contains Areas Of Shallow Standing Water, Place And Vibratory Compact An Initial Layer Of 1”-Minus Clean Crushed Rock To Get Above The Wet Conditions. Cover The Crushed Rock Layer With A Layer Of 8 oz. Non-Woven Geotextile Fabric Prior To Placing The Granular Structural Fill. 12” (min.) Structural Fill Layer Under Slab Areas (typ.) Due To 2.0’ To 4.0’ Organic Fill And Native Topsoil Thickness, > 12” (min.) Structural Fill Will Be Req’d. Note: Where Gravel Depth Is > 2.0’ Below Footing Grade, Then > 2.0’ Of Structural Fill Will Be Req’d. Note: Where Gravel Depth Is < 2.0’ Below Footing Grade, Some Over-Exc. Into Gravel Will Be Req’d. H Thickness As Needed/Required To Build Up To Footing Grade From “Target” Gravel Surface. Figure 5 23-119 Aug. 2023 Lot 16, Nelson Meadows Foundation Detail - At-Grade Slab - Option 1B Bozeman, Montana Damp-Proofing As Required (typ.) Foundation Wall (typ.)Approved Non-Woven Filter Fabric To Encase Bedding Gravel (typ.) Interior Floor Slab (typ.)Interior Steel Column (typ.)Interior Spread Footing (typ.) 6” Of 3/4" Minus Crushed Washed Gravel Hydraulically Connected To Sub-Drain or Existing Surface Drainage (typ.) Native Topsoil andRandom Surface Fill Imported 4-Inch Minus Sandy Pitrun Gravel Native Silt/ClayImported Flowable Fill Six Inch Diameter Sub-Drain Pipe (Graded To Drain To Sump Area) Concrete SidewalkLow Permeability Soils(Landscaped Area)LegendConcrete Wall and/or Footing Low Permeable Topsoil No Scale (Parts Of This Exhibit Have Been Exaggerated For Clarity) ALLIEDENGINEERING SERVICES, INC. Civil Engineering Geotechnical Engineering Land Surveying 32 Discovery Drive Bozeman, MT 59718 Phone: (406) 582-0221 Fax: (406) 582-5770 Slope Away @ 2% In All Concrete Or Pavement Areas (typ.) Footings 6’ max. depth below existing ground Native Topsoil 6” Minus Sandy (Pitrun) Gravel 4” Minus Sandy PitrunGravel (ie. Structural Fill)4’ max fill above existing ground 4' min. 4’ Max Fill Above Existing Ground 3” (min.) Thickness Will Vary Due To Depth Of Bedbrock Strata 6” (min.) 3” (min.) 8” (min.) 4.0’ (min.) 6” (min.) Of Rock Bedding To Be Placed Around Drain Piping (typ.) Under-Slab Rock Layer To Be Hydraulically Connected To Sub-Drain System By 3” Of Rock Or 2” Sch. 80 Piping Spaced On 10’ Centers (typ.) B H (Variable; Depends On Depth To Gravel) 18” (min.) 18” (min.) 6” (min.) 6” (min.) 1’ (min.) H = 3.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-4) H = 5.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-2) D D Woven Geotextile Filter Fabric (Amoco 2004)Vapor Barrier Under Slab (typ.) 9.5’ Deep (TP-2) 7.5’ Deep (TP-4) Non-Woven Filter Fabric To Encase 1-Inch Minus Rock 6” (min.) Rock Layer (typ.) Landscape Areas To Slope Away @ 5% (min.) Within 10’ Of Wall. Upper 4” - 6” Of Backfill Should Consist Of Low Permeable Topsoil. Note: Asphalt/Concrete Surfacing Placed Adjacent To Foundation Walls Shall Slope Away @ 2% (min.). 6” (min.) 6” (min.)4” PE Sub-Drain (typ.) Crawl Space Opening Must Be Properly Vented. Note: Elevation Difference Between The Top Back Of Curb And The Finished Floor Should Be Maximized. I Believe The Subdivision Covenants Call For A Minimum Separation Of 2.0’ And A Maximum Of 5.0’. Due To High Groundwater Concerns, An Elevation Difference Of More Than 2.0’ Is Recommended. This Should Be Thoroughly Considered On A Case By Case Basis. Please Refer To The Covenants For More Detail. Important Notes: The Three-Foot Wide (Min.) Over-Excavation From The Center Of The Footing Is Calculated Based On A 16-Inch Footing Width (B) And An Average Depth To Native Gravel (GD) Below The Footing Elevation Equal To Five Feet. If The Footing Is Substantially Wider Or The Depth To Gravel Substantially Deeper; The Width Of The Excavation Will Need To Be Increased. The Equation For Determining Excavation Width (EW) From The Center Of Footing Is: EW = (B + GD) / 2.0. If Caving (ie. Sloughing) Of The Excavation Side Walls Is A Problem; EW Will Need To Be Increased Accordingly. Since The Footings Are Supported On Structural Fill That Bears On Native Gravel; There Is No BenefitTo Increasing Footing Size Beyond What Is Shown On The Plans. If Groundwater Is Encountered In The Over-Excavation Above The Native Sandy Gravel Surface, We Recommend A Layer Of Crushed Rock First Be Used To Get Above The Groundwater Elevation. The Crushed Rock Should Be Placed In A Single Lift That Does Not Extend More Than Four Inches Above The Groundwater. After Placement, The Crushed Rock MUST Be Compacted By Vibratory Methods. Compactors That Are Suitable For Crushed Rock Include Walk-Behind Plate Compactors; Remote-Controlled Sheepsfoot Trench Rollers; And Self-Propelled Smooth Drum Rollers. Note: If Groundwater Is Not Encountered, The Use Of Crushed Rock Is Not Necessary. Compacted Structural Fill. Use Sandy Pitrun Gravel, Not Crushed Rock. Gravelly Materials Are Not Only Less Expensive But They Will Also Reduce The In-Flow Of Groundwater Into The Crawl Space In The Event That High Groundwater Exceeds The Crawl Space Elevation. Place The Pitun In Lifts (Six-Inch Thick Max. For Small Remote-Controlled Sheepsfoot Trench Rollers And Twelve-Inch Thick Max. For Self- Propelled Smooth Drum Rollers) And Compact To An Unyielding Condition. Note: A Material That Works Very Well For Foundation Structural FilI Is The 3” Minus Pitrun Gravel Product That Is Available From TMC In Belgrade. Pay Special Attention To Compaction Of Crushed Rock And Structural Fill Along Edges. Native Soils Could Be Soft. Rock / Fill Will Need To Be Compacted Into Side Of Excavation. Place Woven Geotextile Fabric Over The Crushed Rock. This Will Prevent Fines Migration Into The Rock After Placement Of The Structural Fill. 4” (max.) 3’ (min.) 3’ (min.) Interior Footing As A Precaution For Groundwater, Install 4” PE Slotted Drain Piping Along The Inside Of The Perimeter Footings And Grade To A Shallow Sump Chamber In The Crawl Space. If Water Becomes An Issue, Install Sump Pump And Discharge Out Of The Crawl Space. A Four-Inch Layer Of Crushed Rock Will Facilitate Rapid Drainage And Eliminate The Sight Of Standing Water. If A Vapor Barrier Is Placed Above The Crushed Rock; Ensure It Is A Material That Can Breathe (Not Polyethylene). All Interior Footings Shall Bear On Structural Fill. Finished Floor Elev. (At-Grade Slab) GD Existing Ground Surface Existing Ground 4” Slotted PE Pipe. Install Drain Piping Around Inside Perimeter Of Foundation. Piping Should Be Placed At Footing Grade Or Preferably Below The Top Of The Crushed Rock Fill (When Used). Connect Piping To Shallow Sump Chamber. If High Groundwater Is An Issue, A Pump Can Be Installed At A Later Time. 32” 48” Reviewed By: __________________ 4” To 6” (Min.) Thickness As Required 2.5’ 4’ (min.) Damp Proofing 4” Footing Drain (typ.) Min. Depth Of Cover For Frost Protection Min. Required Width Of Mass Over-Excavation Beyond Edge Of Footing 1.0’ - 17.0’ Depth To “Target” Bearing Material. Silt/Clay Below 2.5’ (+/-) Is Generally V. Moist To Wet. See TP Logs For Soil And Groundwater Conditions. 5.0’ - 13.5’ Depth To “Target” Bearing Material. Groundwater Depth Ranged From 6.0’ to 13.5’. Depending On Time Of Year, Groundwater May Be At Or Above The Sandy Gravel (“Target” Bearing Material). Therefore, Groundwater Dewatering May Be Needed. Dewatering Wells Are Recommended To Lower Water Below Gravel Surface. Strip, Remove, And Replace All Random Fill From Under The Entire Building Area, Including Under Interior House And Garage Slabs (typ.) Note: De-Watering Will Likely Not Be Required For Foundation Excavation. Based On Our Test Pits, All Evidence Suggests The Groundwater Table Stays Within The Sandy Gravel Most Of The Time. LSE, 8/17/23 Prior To The Placement Of Granular Structural Fill, The Site’s Shallow Groundwater Conditions May Require That An Initial Layer Of Clean Crushed Rock Be Placed And Compacted Up To A Height Of At Least 6 Inches Above The Level Of The Standing Water. Structural Fill: Use 4” Minus Sandy (pitrun) Gravel Due To Shallow, Seasonal High Groundwater Conditions, Footing And Crawl Space Depth Must Be Minimized Below The Existing Ground Surface. Bottom Of Footing Elevation Should Be Kept Within At Least 2.5’ To 3.0’ Of Existing Grades. As An Added Precaution Against High Groundwater In The Crawl Space (And Especially If Footing Depth Nears Or Exceeds 2.5’ To 3.0’ Below Existing Site Grades), We Strongly Encourage The Placement Of A 6” To 8” Layer Of Crushed Rock In The Crawl Space To Raise The Floor Elevation Up To The Top Of Footings. In The Event That Groundwater Ever Rises Above The Crushed Rock Layer, A Sump Chamber And Pump Can Easily Be Installed Later To Address The Problem. We Do Not Recommend Placing The Initial Layer Of Clean Crushed Rock In Standing Water Exceeding 10 Inches In Depth. Therefore, Depending On The Time Of Year, Some Groundwater De-Watering May Be Required During Foundation Earthwork. All Perimeter, Interior, And Exterior Footings Must Bear On A Minimum 2.0’ Thickness Of Granular Structural Fill That In Turn Is Supported On The Native Sandy Gravel (Which Is The ”Target” Foundation Bearing Material). Given The 4.5’ To 6.5’ Depth To Gravel, Along With The Anticipated Slab Grade, Perimeter Footings Will Likely Lie 2.0’ to 6.0’ Above The Top Of The “Target” Gravel. Mass Over-Excavate The Entire Foundation Footprint Area, Including All Exterior Footing Locations, Down To The “Target” Bearing Material (Native Sandy Gravel); Thereby, Completely Removing All Native Silt, Clay, Sand From Under The Building. Over-Dig The Excavation To The Minimum Width Dimensions As Shown On This Figure And As Stated In The Report. Important Note: Mass Over-Excavation Of The Foundation (As Illustrated By Option #2) Will Be Required If The Individual Footing Over-ExcavationsThat Are Depicted As Option #1 Will Not Stay “Open” Due To Trench Wall Collapse. Foundation Earthwork Notes: 1) Slab On Grade - Option “B” Consists Of Over-Excavating Under All Perimeter, Interior, And Exterior Footings.2) This Is Most Applicable Where The Building Is Underlain By Relatively Deep Gravels And The Foundation Contains Less Interior Footings.3) Where Present, All Random Surface Fill Material Must Be Fully Removed From Under The Entire Building Area Down To Native Soils. Foundation Excavation Recommendations: Due To The Large Number and Close Spacing Of Interior Footings (Many Of Which Are 13 To 14 Feet On-Center), We Recommend The Entire Foundation Footprint Area Of The Apartment Buildings Be Mass Over-Excavated Down to Native Sandy Gravel And Built Back Up To Footing And Slab Grades With Compacted Structural Fill. The Limits Of The Mass Excavation Must Encapsulate All Perimeter And Exterior Footings. Important Note: It Is Now COB Policy That The Foundation Earthwork Be Inspected And Certified By The Geotechnical Engineer. Suggestions: In Order To Reduce The Amount Of Required Structural Fill Under Footings And The Slab Area, The Finished Floor Elevation Should Be Minimized Above Existing Site Grades. Another Option To Reduce Fill Under Perimeter Footings Is To Use A 6’ Tall Foundation Wall. Foundation Backfill and Embankment Fill Granular Structural Fill(1.5”Minus Roadmix Gravel)Granular Structural Fill(1.5”Minus Roadmix Gravel)Sandy Gravel(”Target” Bearing Material) Low Permeable Topsoil Native Silt/Clay(Unsuitable Bearing Material) Native Silt Native Silt/Clay (Unsuitable Bearing Material) Native Topsoil Granular Structural Fill(4” Minus Sandy Gravel)Granular Structural Fill(1.5” Minus Roadmix Gravel)1” Minus CleanCrushed Rock Groundwater (on 4/19/16) Concrete Slab Exterior Foundation Wall Backfill Should Only Consist Of Excavated Soils That Are Not Overly Moist. It Must Be Placed In Multiple Lifts And Properly Compacted. Slab Grade Should Be Set Above Existing Grades. For The Mass Over- Excavation Option, There Is No Limit On Slab Height Above Existing Grades. H W = Footing Width + H; (5’ min.) All Foundation Fill Materials Should Be Placed In Uniform, Horizontal Lifts And Be Well Compacted. Granular Structural Fill Shall Be Compacted To A Dense, Unyielding Condition, While Clean Crushed Rock Or Lean Mix Concrete Must Be Compacted By Vibratory Means. In General, The “Loose” Thickness Of Each Lift Prior To Compaction Should Not Exceed 12 Inches For Large, Self- Propelled Rollers; 6 Inches For Remote-Controlled Trench Rollers And Walk-Behind Jumping Jack Compactors; And 4 Inches For Walk- Behind, Plate Compactors. Pay Special Attention To Compaction Of Structural Fill Along Edges And In Corners Of The Excavation. Place Crushed Rock As Fill Under Slab (6” min.) And Interior Wall Backfill Strip Topsoil Under Slab and Re-Compact The Subgrade Surface. Vapor Barrier Under Slab. Seal Barrier At Seams/Penetrations. Minimize New Fill Height For Settlement Reasons The Uppermost 6” Of Lean Mix Concrete Fill Can Be Replaced w/ Clean Crushed Rock For Easier Leveling Of Footing Grade. Bearing Pressure 4000 psf (max.) 6” (min.) Crushed Rock Layer Under Slab Areas (typ.) Important Note: To Stabilize The Trench Excavations And Minimize The Potential For Caving/Sloughing, Groundwater Dewatering May Be Required. Shallow Frost- Proof Foundation. Insulate As Per Applicable Codes. Interior Footing (typ.) Radon Mitigation System Should Be Considered Under Interior Slab. Important Note: If Foundation Construction Will Occur During The Cold/Winter Weather Season, The Contractor Shall Take All Necessary Precautions To Prevent The Earth- Work From Freezing And/Or From Being Contaminated With Snow. Note: At A Minimum, Use A Large, Smooth Drum Roller To Compact The Upper-Most Lift Of Structural Fill Under Footings And Slabs. Additional Thickness Of Gravel Building Pad As Req’d To Bear On “Target” Gravel. For Mass Excavation, Over-Excavation Width Beyond Perimeter Ftgs Is 5.0’ (typ.) See Fig. 6 For Over-Excavation Width Under Individual Ftg Excavations. Embankment Fill Can Be Used Below 18” Of Slab Grade. Note: No Topsoil Observed In On-Site Borings. Product Recommendation: A Stego 15-mil Vapor Barrier Is Recommended.Available From MaCon Supply In Bozeman. W = Footing Width + H; (5’ min.) Min. Width = 1/2(H); But Must Be 5’ Min. H H = 2’ Min. Important Note: If TP-3, A Clay Layer Was Observed Under The Native Sandy Gravel At A Depth Of 6.0’. It Is Recommended That All Footings Bear On A Minimum 24” Thickness Of Native Gravel Or Granular Structural Fill. This Should Be Confirmed With Test Pits Around The Perimeter Of The Building During Construction. Important Note: If The Trench Excavations Are Prone To Minor Caving, Their Width Will Have To Be Increased Accordingly To Prevent Slough From Underlying Or Being Mixed Into The Minimum Required Width Of Structural Fill. Given The 4.5’ To 6.0’ Depth To Native Sandy Gravel, We Do Not Expect That Most (If Any) Of The Perimeter Footings Will Bear Directly On Native Gravel. Most Likely, Footings Will Need To Be Supported On Structural Fill That In Turn Bears On Native Gravel (Similar To All Interior Footings). Excavation Alternative: In Lieu Of Only Excavating Footings, The Entire Foundation Footprint Area Of The Building Can Be Mass Over-Excavated Down To Native Sandy Gravel And Filled With Granular Structural Fill. Given The Gravel Depth, This Is Far Less Economical As Compared To The Above Recommendations. Prior To Granular Structural Fill Placement, The Excavated Gravel Surface (Under Entire Foundation Footprint Area) Must Be Vibratory Re-Compacted With A Large, Smooth Drum Roller In Order To Densify The Native Sandy Gravel. Due To Groundwater Depths Of 7.8’ To 9.8’, Wet Subgrade Conditions Should Not Be An Issue. Depending On Location, Groundwater Could Be At Or Above The Top Of Native Sandy Gravel During The Seasonal High Water Time Of Year. A Large, Smooth Drum Roller Must Be Used To Compact All Granular Structural Fill Whenever and Wherever Possible. Lean Mix Concrete(Flowable Fill)Embankment Fill(On-Site or Import Material) Non-Organic Embankment Fill (On-Site, Dry Silt/Clay) 2500 psf (max.) B 2500 psf (max.) B Mass Excavate Under Entire Foundation Footprint Area Down To Native, Clean Sandy Gravel; Thereby Removing All Of The Silt/Clay Under The Interior Slab. All Footings Must Bear On Native Sandy Gravel Or On Compacted Granular Structural Fill That In Turn Is Supported On This “Target” Bearing Material. Shallow Frost-Proof Foundation Per IBC Is Also Acceptable. H H If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. Min. Width = (B + H); But 5’ (min.) Crushed Rock Is Only Needed If Gravel Subgrade Is Wet Or Contains Standing Water. All Fill Material Placed Under Footings And Slabs To Consist Of Compacted Granular Structural Fill. No On-Site Soils Are To Be Used As Embankment Fill Under Slabs. Do Not Place Granular Structural Fill Materials Over Wet Subgrade Or In Shallow Standing Water. De-Water The Excavation If Required. If Bottom Of Excavation Is Wet, Place An Initial, Thin Layer Of Clean Crushed Rock Under The Structural Fill. The Crushed Rock Should Extend A Minimum Of About 4” Above The Wet Conditions. Vibratory Compact The Crushed Rock And Then Cover With A Medium-Weight, Non-Woven Fabric Prior To Structural Fill Placement. Overlap Seams Of Fabric By 12” Minimum. Over-Excavate Under All Perimeter, Interior, And Exterior Footings Down To Native, Clean Sandy Gravel; Thereby Removing All Silt/Clay Under Footings. All Footings Must Bear On Native Sandy Gravel Or On Compacted Granular Structural Fill That In Turn Is Supported On This “Target” Bearing Material. Embankment Fill Under Structural Fill Layer Must Be Compacted To Project Specifications. See Figure 7 For Recommendations For Foundation Fill Material Placement And Compaction. See Figure 7 For Recommendations For Ext. Foundation Wall Backfill Material And Compaction. For Basements, Additional SubsurfaceDrainage And Moisture Protection Recommendations Will Need To BeIncorporated That Are Not Shown On This Exhibit. See Report For More Details. No Scale (Parts Of This Exhibit Have Been Exaggerated For Clarity) Geotechnical Notes: 1) Figure 5 Illustrates Option 1B For Foundation Earthwork And Support. This Option Entails Mass Over-Excavating Under The Foundation Footprint Area (Down To Native Gravel) And Placing Compacted, Granular Structural Fill (Back Up To Footing Grade). This Option Is Most Applicable In Areas Of The Building With Many Interior Footings (Such As The Office Portion Of The Building). Granular Structural Under Footings And Slabs Can Consist Of4”-Minus Sandy Pitrun Gravel Or 1.5”-Minus Roadmix Gravel. Based On Test Pits, Depth To “Target” Bearing Material Is 4’ To 5’ On Downhill Side And 3’ On Uphill Side Of The Lot. Legend Random Fill (Unsuitable Bearing Material) Random Fill (Unsuitable Bearing Material) Low Permeable Topsoil Granular Structural Fill(4”-Minus Sandy Gravel) Granular Structural Fill (*) Place In Thin Lifts And Vib. Compact To 97% (min.). 1” Minus CleanCrushed Rock 1” Minus Clean Crushed Rock 1” Minus CleanCrushed RockExisting Grade (Ground Surface) Native Topsoil Topsoil or Asphalt/GravelSurfacing Materials Native Topsoil Floor Joist Exterior Foundation Backfill (On-Site, Dry Silt/Clay) Native Sandy Gravel (“Target” Bearing Material) Native “Dirty” Sandy Gravel(Unsuitable Bearing Material) Native Topsoil Interior Wall Backfill (3”-Minus Sandy Gravel Or 1”-Minus Clean Crushed Rock) “Target” Bearing Material Is The Glacial Till. It Is Identifiable Based On Its Clean Sandy Composition, Abundance Of 6”-Minus, Sub-Rounded Gravels, And Dense Configuration. It Looks Like “Clean Pitrun Gravel” w/ Large Cobbles And Boulders. All Footings Shall Bear On A Minimum Of 1’ Of Granular Structural Fill That In Turn Bears On “Target” Glacial Till (typ). Additional Structural Fill Thickness Will Be Required Under Some Footings In Order To Reach “Target” Bearing Material. Recompact Subgrade Prior To Fill Placement (typ). All Foundation Fill Materials Should Be Placed In Uniform, Horizontal Lifts And Be Well Compacted. Granular Structural Fill, Embankment Fill, And Wall Backfill Shall Be Compacted To A Dense, Unyielding Condition, While Clean Crushed Rock Must Be Compacted By Vibratory Means. In General, The “Loose” Thickness Of Each Lift Prior To Compaction Should Not Exceed 12 Inches For Large, Self-Propelled Rollers; 6 Inches For Remote-Controlled Trench Rollers And Walk-Behind Jumping Jack Compactors; And 4 Inches For Walk-Behind, Plate Compactors. Pay Special Attention To Compaction Of Fill Materials Along Edges And In Corners Of The Excavation; And Along Foundation Walls. Daylight Footing And Sub-Slab Drains (typ.) See Figures 8 And 9 For Note On Exterior Foundation Wall Backfill. Granular Structural Fill Should Be Used For Interior Wall Backfill Under Slabs. See Figures 8 And 9 For Note On Foundation Fill Material Placement And Compaction. All Excavated Soils Can Be Re-Used For Exterior Wall Backfill Or Embankment Fill Provided They Are Not Organic Or Overly Moist. All Fill Must Be Placed In Thin, Level Lifts And Properly Compacted. H = 1’ or 2’ (Depending On Ftg Width) H = 1.0’ (min.) H H = 1.0’ (min.) 15-mil Vapor Barrier Under Slab (Above Rock Layer). Note: We Recommend Placing Under Warehouse Slabs. Vapor Barrier Not Typ. Under Garage Slabs. Note: Due To Unheated/Non-Insulated Buildings, Consider Insulating Under Interior Slabs To Minimize Frost Heaving Potential Of Silt/Clay. (*) Granular Structural Fill Can Consist Of 3”-Minus Sandy (Pitrun) Gravel Or 1.5”-Minus Crushed (Roadmix) Gravel Note: Groundwater Will Likely Rise To Near The Top Of The Native Gravel During The Spring. By The Latter Part Of The Summer, It Will Be 1.0’ To 2.0’ Below The Top Of Gravel. Note: In 2018, The Seasonal High Groundwater Depth In TP-9 Was At 6.6’ Below Ex. Grade (On 4/27/18). 4’ (min.) For Frost Protection No Ftg Drains Req’d Strip Topsoil And Bench Subgrade Level Prior To Placing Fill (typ.) About 6” Of Dirty Gravel Overlies The Clean Gravel.It Is Important To Vibratory Re-Compact The Excavated “Target” Gravel Subgrade Surface Prior To Pouring Ftgs Or Placing Struct. Fill. Where Possible, Enlarge The Excavation To Allow For Use Of Large, Smooth Drum Roller. Product Recommendation: A Stego 15-mil Vapor Barrier Is Recommended. Perimeter Footing Drain To Wrap Around The Exterior Of Home (typ.) Over-Excavate Under All Perimeter, Interior, And Exterior Footings Such That They Bear On A Minimum Of 1’ Of Compacted Granular Structural Fill That In Turn Bears On “Target” Glacial Till. Min. Width Is B+H, But It Shall Not Be Less Than 5’. Use Light-Weight Fabric Around Footing Drains (typ.). Over-Excavation Width Must Be Centered On The Footings (typ.) More Than 1.0’ Of Structural Fill Is Expected (typ.) Min. Width = (B + H); But Shall Be 5.0’ (min.) This Is A Bottom Of Exc. Dimension. Assumes No Sloughing Of Exc. Side Walls. Min. Width = (B + H); But Shall Be 5.0’ (min.) This Is A Bottom Of Exc. Dimension. Assumes No Sloughing Of Exc. Side Walls. A Large, Smooth Drum Roller Should Be Used To Vibratory Compact Subgrade Soils And Granular Structural Fill Wherever Possible. Concrete Slab The Excavated Gravel Surface (Under All Footings) Must Consist Of Dense, Clean, Native Sandy Gravel. Use A Smooth Foundation Bucket To Prevent Unnecessary Disturbance To The Native Gravel Subgrade. Do Not Stop Excavation In Lowermost Silt/Clay, Which Does Contain Some Scattered Gravels. The Silt/Clay w/ Gravels (Which Looks Like A “Dirty Gravel”) Does Not Constitute The Clean, Native Sandy Gravel (“Target” Bearing Material). Vibratory Re-Compact Subgrade Surface Whenever Possible. Re-Compact Subgrade Prior To Fill Placement. Additional Structural Fill Thickness As Required. For Strip Footings With Width Of 2.0’ Or Less, Min. Structural Fill Thickness (H) Is 1.0’. For Larger Pad Footings With Width Of 3.0’ To 6.0’, Min. Structural Fill Thickness (H) Is 2.0’. Exterior Wall Backfill Can Consist Of Any Non-Organic Soil. Suggest Removing Cobbles Over 6” Directly Next To Walls. Strip Topsoil/Surfacing Material And Cut To A Min. Depth Of 18 Inches Below Bottom Of Slab Grade. For Easier Compaction, Consider Using Only High Quality Granular Material Or Clean Crushed Rock For Interior Backfill. Place In Lifts / Vibratory Compact. “Target” Clean Gravel Surface. Re-Compact Prior To Placing Fill. Pad Footing Over-Excavation On Individual Basis “Target” Clean Gravel Surface. Re-Compact Prior To Pouring Ftgs Or Placing Struct. Fill. “Target” Clean Gravel Surface. Re-Compact Prior To Pouring Ftgs Or Placing Struct. Fill. All Footings Must Bear On “Target” Sandy Gravel Or On Granular Structural Fill That In Turn Bears On “Target” Gravel. All Excavations And Structural Fill Under Footings Must Be Centered Under The Footing. Note: If Native Gravel Is Wet, Place An Initial Thin Layer Of Clean Crushed Rock Covered By Non-Woven Fabric Prior To Structural Fill. Vibratory Compact The Rock. Excavations Should Be Wide Enough To Permit The Use Of A Large, Smooth Drum Roller For Compaction Of Gravel Subgrade And Granular Structural Fill. Footing Subgrade Will Consist Of Native Silt/Clay. Dig With Smooth- Edged Bucket To Prevent Disturbance. Vibratory Compact To Re-Tighten Soils And Induce Consolidation/Settlement. Due To Dry Soils, Construction Water May Need To Be Added To Facilitate Better Compaction. (Typ. All Locations) Over-Excavation And Structural Fill To Be Centered Under Footing And Extend A Minimum Of 2.0’ Beyond Outside Edge Of Ftg In All Directions. Over-Excavation And Structural Fill To Be Centered Under Footing And Extend A Minimum Of 2.0’ Beyond Outside Edge Of Ftg In All Directions. Strip Topsoil Before Placing Fill Material. Strip Gravel. Depending On The Number/Spacing Of Interior Footings. Consideration Should Be Given To Mass Excavating Down To “Target” Gravel Throughout Foundation Footprint And Increasing Thickness Of The 12-Inch Structural Fill Layer. By Doing This, Over-Excavation (On An Individual Basis) Under Interior Footings Could Be Avoided. H Min. Width = H / 2 Min. Width = H / 2 Existing Ground Damp Proofing Walls For At- Grade Slabs Is Not Typical Perimeter Footing And Foundation Wall (typ.) Depth To “Target” Sandy Gravel Should Be 5.0’ To 7.0’ In Bldg Site. In TP-9, It Was At 6.0’. (See Fig. 3) Note: Due To Expected 5.0’ To 7.0’ Gravel Depth, Perimeter Ftgs Will Likely Bear On Structural Fill. Strip All Topsoil Prior To Filling. Most Likely, Perimeter Footings Will Readily Bear In Or Near “Target” Gravel (Meaning Either No Req’d Structural Fill Or Only A Relatively Thin Amount). The Benefit Of Mass Over-Excavation And Replacement Is That Interior Footings Now Do Not Have To Be Over- Excavated On An Individual Basis. “Target” Clean Gravel Must Be Exposed Throughout The Bottom Of Excavation. Re-Compact Subgrade Prior To Structural Fill Placement. See Figure 5 For An Illustration That ShowsA Crawl Space Foundation Configuration. We Recommend Mass Over-Excavation Under Slab-On-Grade Foundations Down To “Target” Bearing (In Lieu Of Trench Excavating Under All Perimeter, Interior, And Exterior Footings On An Individual Basis). This Excavation Approach Is Faster; But It Requires In-Filling/Backfilling Inside The Foundation Walls With Granular Structural Fill Back Up To Interior Footing Grade. For Figure 6, We Have Shown A Deep Native Gravel Surface To Purposely Illustrate The Need For The Placement Of A Structural Fill Building Pad Back Up To Perimeter Footing Grade. Due To Shallow Gravels, Most Perimeter Footings Should Readily Bear In/Near The “Target” Gravels. Due To The Complexity Of Most Foundation Plans (Many/Closely Spaced Interior Footings),Individual Footing Over-Excavation Is Time Consuming, Difficult, And Not Recommended. Due To The Shallow Gravels, Assumed Complexity Of The Foundation Plan (Number And Spacing Of Interior Footings), And Need To Fully Remove All Fill Material (That Was Found In The NE Corner), The Best Approach Will Likely Be Mass Over-Excavation Of The Entire Foundation Footprint Area. Some Perimeter Ftgs May Require Some Struct. Fill. No Underslab Drains Req’d. Due To Shallow Gravels And Likely Complexity Of The Foundation Plan (Many/Closely Spaced Interior Footings), We Assume Most Building Foundations Will Be Mass Over-Excavated Down To “Target” Gravel And Re-Filled With Structural Fill Up To Interior Footing Grade. Interior Footings Will Most Likely Require Struct. Fill. Min. Exc. Width = H / 2; 3.0’ (min.) Given The Shallow Gravel Depth In Most Areas, Footing Grade Should Be Close To “Target” Gravel. H Thickness As Needed/Required To Build Up To Footing Grade From “Target” Gravel Surface. Granular Structural Fill In-Fill To 18” Below Slab. Use Large Smooth Drum Roller For Compaction Of Native Gravel Subgrade And Granular Structural Fill. “Target” Clean Gravel Surface At Bottom Of Mass Excavation. If The Surface Is Dry, Vibratory Re-Compact Prior To Pouring Footings Or Placing Granular Structural Fill. Dig Foundation Exc. With Smooth-Edged Bucket To Prevent Disturbance To Native Gravel Subgrade. “Target” Clean Gravel Surface At Bottom Of Mass Excavation. If The Surface Is Wet, Track-Pack With Excavator And Static Roll With Roller Prior To Placing Crushed Rock. Note: This Figure Illustrates The Possible Need For Some Fabric- Covered, Clean Crushed Rock To Get Above Wet Conditions Or Shallow Groundwater. If The Bottom Of Excavation Is Dry, Then No Crushed Rock Will Be Necessary. If Groundwater Is Above The Native Gravel, Lower Groundwater By De-Watering. If The Gravel Subgrade Is Wet Or Contains Areas Of Shallow Standing Water, Place And Vibratory Compact An Initial Layer Of 1”-Minus Clean Crushed Rock To Get Above The Wet Conditions. Cover The Crushed Rock Layer With A Layer Of 8 oz. Non-Woven Geotextile Fabric Prior To Placing The Granular Structural Fill. 12” (min.) Structural Fill Layer Under Slab Areas (typ.) Note: Due To Expected 5.0’ To 7.0’ Gravel Depth, Interior Ftgs Will Need To Bear On Several Feet Of Structural Fill. Note: Due To Expected 5.0’ To 7.0’ Gravel Depth, A Thick Structural Fill Bldg Pad Will Be Required. Figure 6 23-119 Aug. 2023 Lot 16, Nelson Meadows Foundation Detail - Slab-On-Grade - Option 2 Bozeman, Montana Damp-Proofing As Required (typ.) Foundation Wall (typ.)Approved Non-Woven Filter Fabric To Encase Bedding Gravel (typ.) Interior Floor Slab (typ.)Interior Steel Column (typ.)Interior Spread Footing (typ.) 6” Of 3/4" Minus Crushed Washed Gravel Hydraulically Connected To Sub-Drain or Existing Surface Drainage (typ.) Native Topsoil andRandom Surface Fill Imported 4-Inch Minus Sandy Pitrun Gravel Native Silt/ClayImported Flowable Fill Six Inch Diameter Sub-Drain Pipe (Graded To Drain To Sump Area) Concrete SidewalkLow Permeability Soils(Landscaped Area) Legend Concrete Wall and/or Footing Low Permeable Topsoil No Scale (Parts Of This Exhibit Have Been Exaggerated For Clarity) ALLIEDENGINEERING SERVICES, INC. Civil Engineering Geotechnical Engineering Land Surveying 32 Discovery Drive Bozeman, MT 59718 Phone: (406) 582-0221 Fax: (406) 582-5770 Slope Away @ 2% In All Concrete Or Pavement Areas (typ.) Footings 6’ max. depth below existing ground Native Topsoil Native Topsoil 6” Minus Sandy (Pitrun) Gravel 4” Minus Sandy PitrunGravel (ie. Structural Fill)4’ max fill above existing ground 4' min. 4’ Max Fill Above Existing Ground 3” (min.) Thickness Will Vary Due To Depth Of Bedbrock Strata 6” (min.) 3” (min.) 8” (min.) 4.0’ (min.) 6” (min.) Of Rock Bedding To Be Placed Around Drain Piping (typ.) Under-Slab Rock Layer To Be Hydraulically Connected To Sub-Drain System By 3” Of Rock Or 2” Sch. 80 Piping Spaced On 10’ Centers (typ.) B H (Variable; Depends On Depth To Gravel) 18” (min.) 18” (min.) 6” (min.) 6” (min.) 1’ (min.) H = 3.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-4) H = 5.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-2) D D Woven Geotextile Filter Fabric (Amoco 2004)Vapor Barrier Under Slab (typ.) 9.5’ Deep (TP-2) 7.5’ Deep (TP-4) Non-Woven Filter Fabric To Encase 1-Inch Minus Rock 6” (min.) Rock Layer (typ.) Landscape Areas To Slope Away @ 5% (min.) Within 10’ Of Wall. Upper 4” - 6” Of Backfill Should Consist Of Low Permeable Topsoil. Note: Concrete Surfacing Placed Adjacent To Foundation Walls Shall Slope Away @ 2% (min.). (*) Granular Structural Fill Can Consist Of 3”-Minus Sandy (Pitrun) Gravel Or 1.5”-Minus Crushed (Roadmix) Gravel 6” (min.)4” PE Sub-Drain (typ.) Crawl Space Opening Must Be Properly Vented. Note: Elevation Difference Between The Top Back Of Curb And The Finished Floor Should Be Maximized. I Believe The Subdivision Covenants Call For A Minimum Separation Of 2.0’ And A Maximum Of 5.0’. Due To High Groundwater Concerns, An Elevation Difference Of More Than 2.0’ Is Recommended. This Should Be Thoroughly Considered On A Case By Case Basis. Please Refer To The Covenants For More Detail. Important Notes: The Three-Foot Wide (Min.) Over-Excavation From The Center Of The Footing Is Calculated Based On A 16-Inch Footing Width (B) And An Average Depth To Native Gravel (GD) Below The Footing Elevation Equal To Five Feet. If The Footing Is Substantially Wider Or The Depth To Gravel Substantially Deeper; The Width Of The Excavation Will Need To Be Increased. The Equation For Determining Excavation Width (EW) From The Center Of Footing Is: EW = (B + GD) / 2.0. If Caving (ie. Sloughing) Of The Excavation Side Walls Is A Problem; EW Will Need To Be Increased Accordingly. Since The Footings Are Supported On Structural Fill That Bears On Native Gravel; There Is No BenefitTo Increasing Footing Size Beyond What Is Shown On The Plans. If Groundwater Is Encountered In The Over-Excavation Above The Native Sandy Gravel Surface, We Recommend A Layer Of Crushed Rock First Be Used To Get Above The Groundwater Elevation. The Crushed Rock Should Be Placed In A Single Lift That Does Not Extend More Than Four Inches Above The Groundwater. After Placement, The Crushed Rock MUST Be Compacted By Vibratory Methods. Compactors That Are Suitable For Crushed Rock Include Walk-Behind Plate Compactors; Remote-Controlled Sheepsfoot Trench Rollers; And Self-Propelled Smooth Drum Rollers. Note: If Groundwater Is Not Encountered, The Use Of Crushed Rock Is Not Necessary. Compacted Structural Fill. Use Sandy Pitrun Gravel, Not Crushed Rock. Gravelly Materials Are Not Only Less Expensive But They Will Also Reduce The In-Flow Of Groundwater Into The Crawl Space In The Event That High Groundwater Exceeds The Crawl Space Elevation. Place The Pitun In Lifts (Six-Inch Thick Max. For Small Remote-Controlled Sheepsfoot Trench Rollers And Twelve-Inch Thick Max. For Self- Propelled Smooth Drum Rollers) And Compact To An Unyielding Condition. Note: A Material That Works Very Well For Foundation Structural FilI Is The 3” Minus Pitrun Gravel Product That Is Available From TMC In Belgrade. Pay Special Attention To Compaction Of Crushed Rock And Structural Fill Along Edges. Native Soils Could Be Soft. Rock / Fill Will Need To Be Compacted Into Side Of Excavation. Place Woven Geotextile Fabric Over The Crushed Rock. This Will Prevent Fines Migration Into The Rock After Placement Of The Structural Fill. 4” (max.) 3’ (min.) 3’ (min.) Interior Footing As A Precaution For Groundwater, Install 4” PE Slotted Drain Piping Along The Inside Of The Perimeter Footings And Grade To A Shallow Sump Chamber In The Crawl Space. If Water Becomes An Issue, Install Sump Pump And Discharge Out Of The Crawl Space. A Four-Inch Layer Of Crushed Rock Will Facilitate Rapid Drainage And Eliminate The Sight Of Standing Water. If A Vapor Barrier Is Placed Above The Crushed Rock; Ensure It Is A Material That Can Breathe (Not Polyethylene). All Interior Footings Shall Bear On Structural Fill. Finished Floor Elev. (At-Grade Slab) GD Existing Ground Surface Ex. Ground 4” Slotted PE Pipe. Install Drain Piping Around Inside Perimeter Of Foundation. Piping Should Be Placed At Footing Grade Or Preferably Below The Top Of The Crushed Rock Fill (When Used). Connect Piping To Shallow Sump Chamber. If High Groundwater Is An Issue, A Pump Can Be Installed At A Later Time. 32” 48” Reviewed By: __________________ 4” To 6” (Min.) Thickness As Required 2.5’ 4’ (min.) Min. Depth Of Cover For Frost Protection Min. Required Width Of Mass Over-Excavation Beyond Edge Of Footing 12’ - 14’ Depth To “Target” Bearing Material Strip Topsoil Prior To Filling Strip Topsoil Prior To Filling Damp-Proofing Not Req’d (typ.) Note: Groundwater Will Likely Rise To Near The Top Of The Native Gravel During The Spring. By The Latter Part Of The Summer, It Will Be 1.0’ To 2.0’ Below The Top Of Gravel. Foundation Design: Design The Foundation With Conventional Ftgs. Thick Grade Beam Ftgs Are Not Necessary With RAP Systems. All RAPs Must Extend 1.0’ (min.) Down Into “Target” Sandy Gravel. All RAPs Must Extend 1.0’ (min.) Down Into “Target” Sandy Gravel. Silt/Clay Below 2.5’ (+/-) Is Generally V. Moist To Wet. See TP Logs For Soil And Groundwater Conditions. 5.0’ - 13.5’ Depth To “Target” Bearing Material. Groundwater Depth Ranged From 3.0’ to 11.5’. Depending On Time Of Year, Groundwater May Be At Or Above The Sandy Gravel (“Target” Bearing Material). Therefore, Groundwater Dewatering May Be Needed. Dewatering Wells Are Recommended To Lower Water Below Gravel Surface. Strip All Organic Topsoil And Re-Compact Subgrade. Note: De-Watering Will Likely Not Be Required For Foundation Excavation. Based On Our Test Pits, All Evidence Suggests The Groundwater Table Stays Within The Sandy Gravel Most Of The Time. Prior To The Placement Of Granular Structural Fill, The Site’s Shallow Groundwater Conditions May Require That An Initial Layer Of Clean Crushed Rock Be Placed And Compacted Up To A Height Of At Least 6 Inches Above The Level Of The Standing Water. Structural Fill: Use 4” Minus Sandy (pitrun) Gravel Due To Shallow, Seasonal High Groundwater Conditions, Footing And Crawl Space Depth Must Be Minimized Below The Existing Ground Surface. Bottom Of Footing Elevation Should Be Kept Within At Least 2.5’ To 3.0’ Of Existing Grades. As An Added Precaution Against High Groundwater In The Crawl Space (And Especially If Footing Depth Nears Or Exceeds 2.5’ To 3.0’ Below Existing Site Grades), We Strongly Encourage The Placement Of A 6” To 8” Layer Of Crushed Rock In The Crawl Space To Raise The Floor Elevation Up To The Top Of Footings. In The Event That Groundwater Ever Rises Above The Crushed Rock Layer, A Sump Chamber And Pump Can Easily Be Installed Later To Address The Problem. We Do Not Recommend Placing The Initial Layer Of Clean Crushed Rock In Standing Water Exceeding 10 Inches In Depth. Therefore, Depending On The Time Of Year, Some Groundwater De-Watering May Be Required During Foundation Earthwork. All Perimeter, Interior, And Exterior Footings Must Bear On A Minimum 2.0’ Thickness Of Granular Structural Fill That In Turn Is Supported On The Native Sandy Gravel (Which Is The ”Target” Foundation Bearing Material). Given The 4.5’ To 6.5’ Depth To Gravel, Along With The Anticipated Slab Grade, Perimeter Footings Will Likely Lie 2.0’ to 6.0’ Above The Top Of The “Target” Gravel. Mass Over-Excavate The Entire Foundation Footprint Area, Including All Exterior Footing Locations, Down To The “Target” Bearing Material (Native Sandy Gravel); Thereby, Completely Removing All Native Silt, Clay, Sand From Under The Building. Over-Dig The Excavation To The Minimum Width Dimensions As Shown On This Figure And As Stated In The Report. Important Note: Mass Over-Excavation Of The Foundation (As Illustrated By Option #2) Will Be Required If The Individual Footing Over-ExcavationsThat Are Depicted As Option #1 Will Not Stay “Open” Due To Trench Wall Collapse. Geotechnical Notes: 1) Figure 6 llustrates Option 2 For Foundation Earthwork And Support. 2) All Perimeter, Interior, And Exterior Footings Shall Bear On Rammed Aggregate Piers That Extend A Minimum Of 1.0’ Into “Target” Native Gravel. 3) All Footings Shall Be Underlain By A 1.0’ Thick Gravel Layer (Load Transfer Platform) And The Slab Shall Be Supported On A 1.5’ Thick Gravel Section. Foundation Excavation Recommendations: Due To The Large Number and Close Spacing Of Interior Footings (Many Of Which Are 13 To 14 Feet On-Center), We Recommend The Entire Foundation Footprint Area Of The Apartment Buildings Be Mass Over-Excavated Down to Native Sandy Gravel And Built Back Up To Footing And Slab Grades With Compacted Structural Fill. The Limits Of The Mass Excavation Must Encapsulate All Perimeter And Exterior Footings. Important Note: It Is Now COB Policy That The Foundation Earthwork Be Inspected And Certified By The Geotechnical Engineer. Suggestions: In Order To Reduce The Amount Of Required Structural Fill Under Footings And The Slab Area, The Finished Floor Elevation Should Be Minimized Above Existing Site Grades. Another Option To Reduce Fill Under Perimeter Footings Is To Use A 6’ Tall Foundation Wall. Exterior Foundation Backfill (On-Site, Dry Silt/Clay) Granular Structural Fill(1.5”Minus Roadmix Gravel)Granular Structural Fill(1.5”Minus Roadmix Gravel) Native Sandy Gravel (“Target” Bearing Material) Low Permeable Topsoil Native Silt/Clay (Unsuitable Bearing Material) Native Topsoil Granular Structural Fill (*) Place In Thin Lifts And Vib. Compact To 97% Min. Rammed Aggregate Pier (1.5” Minus Roadmix Gravel) 1” Minus Clean Crushed Rock Groundwater (On 03/17/15) Concrete Slab Exterior Foundation Wall Backfill Should Only Consist Of Excavated Soils That Are Not Overly Moist. It Must Be Placed In Multiple Lifts And Properly Compacted. Slab Grade Should Be Set Above Existing Grades. For The Mass Over- Excavation Option, There Is No Limit On Slab Height Above Existing Grades. H W = Footing Width + H; (5’ min.) All Foundation Fill Materials Should Be Placed In Uniform, Horizontal Lifts And Be Well Compacted. Granular Structural Fill Shall Be Compacted To A Dense, Unyielding Condition, While Clean Crushed Rock Or Lean Mix Concrete Must Be Compacted By Vibratory Means. In General, The “Loose” Thickness Of Each Lift Prior To Compaction Should Not Exceed 12 Inches For Large, Self- Propelled Rollers; 6 Inches For Remote-Controlled Trench Rollers And Walk-Behind Jumping Jack Compactors; And 4 Inches For Walk- Behind, Plate Compactors. Pay Special Attention To Compaction Of Structural Fill Along Edges And In Corners Of The Excavation. Place Crushed Rock As Fill Under Slab (6” min.) And Interior Wall Backfill Strip Topsoil Under Slab and Re-Compact The Subgrade Surface. 15-mil Vapor Barrier Under Slab (Above Rock Layer). Note: We Recommend Placing Under Warehouse Slabs. Minimize New Fill Height For Settlement Reasons The Uppermost 6” Of Lean Mix Concrete Fill Can Be Replaced w/ Clean Crushed Rock For Easier Leveling Of Footing Grade. Bearing Pressure 4000 psf (max.) 6” (min.) Crushed Rock Layer Important Note: To Stabilize The Trench Excavations And Minimize The Potential For Caving/Sloughing, Groundwater Dewatering May Be Required. Shallow Frost- Proof Foundation. Insulate As Per Applicable Codes. Standard Interior Strip Or Spread Footing (typ.) Interconnected Network Of Perforated PipingFor Possible Future Radon Mitigation Needs.Install Piping With Perforations Pointed Down.Connect To Mechanical System Such That TheUnderslab Piping Is Power Vented/ExhaustedTo The Atmosphere. StandardPerimeter Footing (typ.) The Excavated Gravel Surface (Under All Per., Int., And Ext. Footings) Must Consist Of Dense, Clean, Sandy Gravel. Dewater As Necessary And Vibratory Compact The Subgrade Prior To Granular Structural Fill Placement. Do Not Stop Excavation In Lowermost Silt/Clay, Which Does Contain Some Scattered Small Gravels. The Gravelly Silt/Clay (Which Looks Like A “Dirty Gravel”) Does Not Constitute The Clean, Sandy Gravel (“Target” Bearing Material). Also, Do Not Stop Of The Bottom Of The Excavation In The Clayey, “Old Wetland Gravel” Deposits. Important Note: If Foundation Construction Will Occur During The Cold/Winter Weather Season, The Contractor Shall Take All Necessary Precautions To Prevent The Earth- Work From Freezing And/Or From Being Contaminated With Snow. Note: At A Minimum, Use A Large, Smooth Drum Roller To Compact The Upper-Most Lift Of Structural Fill Under Footings And Slabs. 12” (min.) Structural Fill Layer Embankment Fill Can Be Used Below 18” Of Slab Grade. Note: No Topsoil Observed In On-Site Borings. W = Footing Width + H; (5’ min.) Min. Width = 1/2(H); But Must Be 5’ Min. H H = 2’ Min. Important Note: If TP-3, A Clay Layer Was Observed Under The Native Sandy Gravel At A Depth Of 6.0’. It Is Recommended That All Footings Bear On A Minimum 24” Thickness Of Native Gravel Or Granular Structural Fill. This Should Be Confirmed With Test Pits Around The Perimeter Of The Building During Construction. Important Note: If The Trench Excavations Are Prone To Minor Caving, Their Width Will Have To Be Increased Accordingly To Prevent Slough From Underlying Or Being Mixed Into The Minimum Required Width Of Structural Fill. Given The 4.5’ To 6.0’ Depth To Native Sandy Gravel, We Do Not Expect That Most (If Any) Of The Perimeter Footings Will Bear Directly On Native Gravel. Most Likely, Footings Will Need To Be Supported On Structural Fill That In Turn Bears On Native Gravel (Similar To All Interior Footings). Excavation Alternative: In Lieu Of Only Excavating Footings, The Entire Foundation Footprint Area Of The Building Can Be Mass Over-Excavated Down To Native Sandy Gravel And Filled With Granular Structural Fill. Given The Gravel Depth, This Is Far Less Economical As Compared To The Above Recommendations. Prior To Granular Structural Fill Placement, The Excavated Gravel Surface (Under Entire Foundation Footprint Area) Must Be Vibratory Re-Compacted With A Large, Smooth Drum Roller In Order To Densify The Native Sandy Gravel. Due To Groundwater Depths Of 7.8’ To 9.8’, Wet Subgrade Conditions Should Not Be An Issue. A Large, Smooth Drum Roller Must Be Used To Vibratory Compact Subgrade Soils And Granular Structural Fill Wherever Possible. A Large, Smooth Drum Roller Must Be Used To Compact All Granular Structural Fill Whenever and Wherever Possible. 4,000 psf Design Bearing Pressure B 3000 psf (max.) B Mass Excavate Under Entire Foundation Footprint Area Down To Native, Clean Sandy Gravel; Thereby Removing All Of The Silt/Clay Under The Interior Slab. All Footings Must Bear On Native Sandy Gravel Or On Compacted Granular Structural Fill That In Turn Is Supported On This “Target” Bearing Material. Shallow Frost-Proof Foundation Per IBC Is Also Acceptable. Min. Width = (B + H); But 5’ (min.) H H If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. Crushed Rock Is Only Needed If Gravel Subgrade Is Wet Or Contains Standing Water. All Fill Material Placed Under Footings And Slabs To Consist Of Compacted Granular Structural Fill. No On-Site Soils Are To Be Used As Embankment Fill Under Slabs. If Gravel Subgrade Is Wet Or Contains Some Shallow Standing Water, Do Not Place Structural Fill Materials Directly Over These Conditions. Instead, Place An Initial, Thin Layer Of Clean Crushed Rock Over Wet Gravel Surface and Vibratory Compact. Crushed Rock Should Extend A Minimum Of 4” Above The Wet Conditions. See Figure 7 For Recommendations For Foundation-Related Fill Material Placement And Compaction. 1.0’ Deep Footing Over-Excavation And Gravel Replacement. Re-Compact Subgrade. Rammed Aggregate Pier (RAP) Ground Improvement Rammed Aggregate Pier (RAP) Ground Improvement RAPS Are 24” to 30” Dia. (typ.) RAPS Are 24” to 30” Dia. (typ.) Install Rammed Aggregate Piers Under All Perimeter, Interior, And Exterior Footings That In Turn Bear Within Native, Clean Sandy Gravel (“Target” Bearing Material); Thereby Removing All Silt/Clay And Any Clayey, “Old Wetland Gravel” From Under The Footings. Interior Wall Backfill (3”-Minus Sandy Gravel Or 1”-Minus Clean Crushed Rock) 3000 psf (max.) B 18” (min.) Gravel Section Under Slab Areas (typ.) Strip/Remove All Topsoil From The Bldg’s Foundation Footprint Area. Re-Compact Silt/Clay Subgrade To A Dense And Unyielding Condition. For Easier/Better Compaction, Use Only High Quality Granular Material Or Clean Crushed Rock For Interior Backfill. Place In Lifts / Vibratory Compact. 4’ (min.) For FrostProtection (typ.) Exterior Wall Backfill Can Consist Of Any Non-Organic, Non- Overly Moist Soil. Suggest Removing Cobbles Over About 6” Directly Next To Walls. 12” (min.) Structural Fill Layer Under All Footings 4,000 psf Design Bearing Pressure More Than 2.0’ Of Gravel Will Be Required Under Slabs In Areas Of Deep Random Fill Removal. Suggest Mass Over-Excavating To A Depth Of 1.0’ Below Interior Footing Grade And Increasing 2.0’ (min.) Underslab Gravel Section. This Will Prevent The Need To Over-Excavate And Fill Under Individual Interior Ftg Locations. LSE, 8/17/23 1.0’ Perimeter Footing Over-Excavation And Gravel Replacement. 1.0’ Deep Footing Over-Excavation And Gravel Replacement. The Sandy Gravel Is Defined As The “Target” Bearing Stratum For All Rammed Aggregate Piers. All Piers Must Be Designed To End Bear In The Native Gravel. Note: A Short Length Rammed Aggregate Pier System That “Floats”/End Bears In The Silt/Clay Is Not Allowed. 1.0’ Deep Footing Over-Excavation And Gravel Replacement. Re-Compact Subgrade. Note: In 2018, The Seasonal High Groundwater Depth In TP-9 Was At 6.6’ Below Ex. Grade (On 4/27/18). Non-Organic Embankment Fill (On-Site, Dry Silt/Clay) 2500 psf (max.) B 6” (min.) Existing Ground Strip All Topsoil Prior To Filling. 4’ (min.) For Frost Protection No Ftg Drains Req’d Damp Proofing Walls For At- Grade Slabs Is Not Typical Perimeter Footing And Foundation Wall (typ.) Depth To “Target” Sandy Gravel Should Be 5.0’ To 7.0’ In Bldg Site. In TP-9, It Was At 6.0’. (See Fig. 3) 6” (min.) Crushed Rock Layer Under Slab Areas (typ.) Interior Footing (typ.) Strip All Topsoil From Under Slabs. Rolled/Compacted Silt/Clay Subgrade. Where Possible, Use Large Smooth Drum Roller For Compaction Of Subgrade And Granular Structural Fill. 2500 psf (max.) B 12” (min.) Structural Fill Layer Under Slab Areas (typ.) As Needed, Compacted On-Site Embankment Fill Can Be Placed Under The Min. Gravel Section.RAP Design: We Recommend Designing The RAP System For 4000 psf Foundation Bearing (Even Though The Footings Will Be Sized For 2500 psf Bearing). By Doing So, There Will Be An Increased Factor Of Safety And Potentially Tighter RAP Spacing. Note: See Figure 5 For Foundation Fill Material And Compaction Note. 12” (min.) Structural Fill Layer Under All Footings (Load Transfer Platform) 12” (min.) Structural Fill Layer Under All Footings (Load Transfer Platform) 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. 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 lesson 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. GALLATIN COUNTYPARK COUNTYMADISON COUNTYGALLATIN COUNTYGALLATIN COUNTYBROADWATER COUNTYGALLATIN COUNTYMADISON COUNTYGALLATIN COUNTYBROADWATER COUNTY455045504550550055005500540054005400530053005300520052005200510051005100500050005000490049004900480048004800470047004700460046004600450045004500440044004400430043004300420042004200410041004100460046004600 450045004500440044004400430043004300 420042004200 410041004100 500050005000 490049004900480048004800470047004700460046004600450045004500440044004400430043004300 510051005100 520052005200 480048004800470047004700460046004600 450045004500440044004400430043004300420042004200410041004100 480048004800470047004700460046004600450045004500 490049004900550055005500560056005600570057005700540054005400400040004000475047504750465046504650445044504450435043504350425042504250415041504150405040504050415041504150425042504250435043504350445044504450445044504450570057005700560056005600530053005300570057005700560056005600445044504450435043504350%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%9090909086191191848586N 7th Ave28728728722287284287Bozeman CreekBridger CreekHyalite Creek East Gallatin River Gallatin R i v e r Camp CreekGallatin RiverCherry CreekHot Springs CreekMadison RiverWillow CrJefferson RiverTrail CreekHyaliteReservoirEast Gallatin RiverDry CreekDry CreekSixteen Mile CreekSixteen Mile CreekMiddle Fk Sixteen Mile CrSo Fk Sixteen Mile Cr Brackett CreekJackson CreekMissouri RiverMissouri RiverHarrisonLakeBelgradeBozemanManhattanThree ForksGallatinGatewayHarrisonWillow CreekAmsterdamAnceneyChurch HillClarkstonLoganLombardMaudlowMenardNorrisSappingtonSedanTridentFourCornersQTbfTbfTbfTbfp_fbKlvgsKshaleTfuTbfPzlCMirp_fbKlvgsTbfKlvgsCMirp_fbp_fbPzlTbfPzlPzlTbfTbfPzlKshalep_fbp_fbKkotnCMirCMirCMirPzlPzlp_fbPzlPzlKegleKkotnKkotnMmdsnMmdsnMmdsnKkotnPzlMPsedMPsedMPsedPzlKshaleMmdsnMPsedMmdsnPzlMmdsnMmdsnMPsedMmdsnPzlPzlPzlMmdsnMPsedKeglePzlMmdsnMPsedCMirKegleKkotnMPsedMmdsnKkotnCMirKkotnMPsedMmdsnMmdsnMmdsnKkotnMmdsnMmdsnKkotnKkotnMPsedKegleMmdsnMmdsnMPsedMmdsnMmdsnMPsedKegleMPsedMmdsnMPsedMPsedMPsedMmdsnMPsedMPsedMmdsnMPsedKkotnKkotnKkotnKkotnMPsedMmdsnMPsedMmdsnMmdsnMPsedMmdsnMmdsnPzlTbfTbfQTbfQTbfMmdsnPzlp_fbp_fbTbfQTbfQTbfTbfp_fbp_fbTbfTbfp_fbTbfTbfTbfQTbfQTbfQTbfQTbfTbfp_fbPzlMmdsnTfuTfuKshaleKshalep_fbPzlMPsedKlvgsPzlQTbfTbfPzlPzlKshaleMPsedKkotnMmdsnPzlQTbfKlvgsKegleKshaleKshaleKkotnMPsedMmdsnPzlTbfTbfTbfTbfQTbfQTbfQTbfQTbfTfuKshaleKshaleMmdsn###########################################################################################!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!38793964398539943995399740014015401740244042404340454050405540584060406140624063406540674068407040714074407440754076407640764078407940954098409941024108411241214135413741384141414341474148415041514156415741584158416141624162416341634166416641674168416841694170417141724178417941824184418641884188418941894191419141974200420042024203421042154222422342244229423442344237423842394239424042484251425242554257425742584262426542674269427342754277428142824283428342844287429042934295429642964296429643034308431143134317431743214326432643294329433543364337433743374338433843414343434943504351435243554364436643684369436943714373437343734378437843784379437943794380438043804382438443884391439444044406440744094410441444144416442144254426442944314433443344334434444044424444444744514455445644594464446844784481448544874490449044914492449744994505451745284533453445354541454845494550455445584559456245634565456745684575457645784579457945794584459045914592460146034605460746124616461746214623462446524654465546564660466246634664467650885098510851105115513151315147514951515165517446774687469046984702471047114715471847194722472447324734473447354738474047414742474347524760476147624765476747694779478147844786478747924793479447984803480348044811481648244825482748354837483848504854485548564861486248624862486348704871488348844889489248944896489848984901491049134915491649184922493049334933493649414942494549464950495149634966496849734977498349874988499749985005500550065007500950195020502350305030503550405041504250435045504850495060506350655067507350745176518551865187519451945201520152075222523752395248526152625267527652795291529152945310532053275339534153485356537153815397541654185418543054325449545354595524553555455553556055665568557155775582561156255633566356685677571057265760577059584074BRIDGE R R A N G E GALLATIN RANGEMADISON RANGEHORSESHOE HILLSCAMP CREEKHILLS5,0007,0006,5006,0005,5004,5004,0003,5003,000Figure 2. Cross Section A–A'AA'Elevation above sea level (ft)QTbfQTbfQTbfTbfTbfMmdsnPzl=fbMmdsnPzl=fbJefferson RiverMadison River226763 (Bend in cross section)763Gallatin River133165 (Bend in cross section)235475 (Bend in cross section)96132=fb— Belgrade— Manhattan— Logan— Three Forks— BozemanBased on Vuke and others, 2014.AA'KlvgsPzlMmdsnTertiary Basin-FillCenezoic and Mesozoic Igneous RocksCretaceous Eagle AquiferPrecambrian Fractured Igneous,Metasedimentary, and Metamorphic RocksTertiary Fort Union AquiferCretaceous Kootenai AquiferMississipppian Madison Group AquiferMesozoic–Paleozoic Sedimentary RocksCenezoic Basin-Fill/Alluvial AquiferQTbfCMirTbfTfuKegleKshaleKkotnMPsed=fbKshaleKshaleUnconsolidated to weakly consolidated basin-fill. Lenticular beds of clay, silt, sand, gravel.Cretaceous sandstone beds within Kootenai, Eagle, and Fort Union Formations. Primary porosity and permeability in combination with secondary permeability along fractures.Fractured bedrock with mostly secondary porosity and permeability along fractures and/or solution cavities.Hydrogeologic FrameworkRegional Aquifers1RegionalConfining Units2Bearpaw FmClaggett FmColorado GroupLower Paleozoic Sedimentary RocksCretaceous Livingston GroupModified after Crowley and others, 2017.1Aquifer where saturated with water.2Locally may yield water to wells from sandstone.LegendTownRoadStreamInventoried well and measured altitude of water in feet above mean sea level.Generalized Potentiometric Contour—Shows altitude at which water would have stood in tightly cased well. Dashed where approximately located. Contour interval 100 ft. Datum is sea level. Arrow shows direction of groundwater flow. Light line is supplemental 50' contour. Shaded relief created from 10 m digital elevation model of the U.S. Geological Survey National Elevation Dataset.Projection: Montana State Plane FIPS 2500 International feet.Datum: North American Datum of 1983 (NAD83).ReferencesCarstarphen, C.A., LaFave, J.I., Crowley, J., Mason, D.C., Richter, M.G., Madison, J.P. and Blythe, D.D., 2015, Data for water wells, springs, and streams visited during the Gallatin-Madison Ground Water Characterization Study: Montana Bureau of Mines and Geology Montana Ground-Water Assessment Atlas 8-01, 40 p., 1 sheet.Crowley, J.J., LaFave, J.I., Bergantino, R.N., Carstarphen, C.A. and Patton, T.W., 2017, Principal aquifers of Montana: Montana Bureau of Mines and Geology Hydrogeologic Map 11, 1 sheet, scale 1:1,000,000.Hackett, O.M Visher, F.N., McMurtrey, R.G., Steinhilber, W.L., Stermitz, Frank, Boner, F.C., and Krieger, R.A., 1960, Geology and ground-water resources of the Gallatin Valley, Gallatin County, Montana, with a section on Surface-water, and a section on chemical quality of the water: U.S. Geological Survey Water Supply Paper 1482.Michalek, T., and Sutherland, M., 2020, Hydrogeologic investigation of the Four Corners area, Gallatin County, Montana: Interpretive report: Montana Bureau of Mines and Geology Open-File Report 735, 74 p.Slagle, S.E., 1995, Geohydrologic conditions and land use in the Gallatin Valley, southwestern Montana, 1992-93; U.S. Geological Survey Water-Resources Investigations Report 95-4034.Vuke, S.M., Lonn, J.D., Berg, R.B., and Schmidt, C.J., 2014, Geologic map of the Bozeman 30' x 60' quadrangle, southwestern Montana: Montana Bureau of Mines and Geology Open-File Report 648, 44 p., 1 sheet, scale 1:100,000.Waren, K.B., and LaFave, J.I., 2011, Potentiometric surface map of basin fill and selected bedrock aquifers: Deer Lodge, Granite, Powell, and Silver Bow Counties, Montana: Montana Bureau of Mines and Geology Montana Ground-Water Assessment Atlas 5-03, 1 sheet.Potentiometric Surface in Gallatin, Lower Madison, Lower Jefferson, and UpperMissouri River Valleys within Parts ofMadison and Gallatin Counties, MontanaJames P. Madison2022NBasin-fill wellFractured-bedrock well%#47624792%%TD Total depth of well Author’s Note: This map is part of the Montana Bureau of Mines and Geology Groundwater Assessment Atlas for the Gallatin–Madison Area groundwater characterization. It is intended to stand alone and describe a single hydrogeologic aspect of the study area, although many of the area’s hydrogeologic features are interrelated. For an integrated view of the hydrogeology of the Gallatin–Madison Area, the reader is referred to the other maps of Montana Groundwater Assessment Atlas 8 (http://mbmggwic.mtech.edu). This map represents the potentiometric surface for the unconsolidated basin-fill and fractured-bedrock aquifer system in the Gallatin, lower Madison, lower Jefferson, and upper Missouri river valleys within Madison and Gallatin Counties (fig. 1). In the map area, wells are completed mostly within the surficial unconsolidated alluvial and Tertiary basin-fill deposits or in fractured bedrock on the valley margins (fig. 2). On a basin scale, the basin-fill aquifer and surrounding bedrock typically function as a single hydrogeologic unit. A potentiometric surface represents the altitude to which water levels rise in wells completed in an aquifer; it is useful for determining the general direction of groundwater flow and estimating depth to water at a given location. In unconfined conditions, the potentiometric surface is generally a subdued representation of the regional topography; the highest groundwater altitudes coincide with the regional topographic highs and the lowest altitudes with the regional topographic lows. Lateral groundwater movement will be in a direction perpendicular to potentiometric contours from higher to lower altitudes, as indicated by the flow arrows on this map. Across the map area, groundwater generally flows away from mountainous recharge areas and the valley margins (regional topographic highs) towards and parallel to the major surface drainages (regional topographic lows). The potentiometric surface altitude at a site may be subtracted from the land-surface altitude at that location to yield the approximate depth to water. Groundwater levels fluctuate in response to natural and anthropogenic causes such as wet or dry climate anomalies, groundwater withdrawals, and land use. The fluctuations occur at seasonal, annual, or multi-year frequencies and provide insights on groundwater recharge and stresses acting on aquifers. Long-term (10+ year) hydrographs for 19 wells are included on the map to show representative groundwater-level fluctuations. Across the map area, groundwater levels fluctuate annually between 1 and 45 ft. The hydrographs show two main patterns of seasonal fluctuation that reflect different sources of recharge: (1) a natural pattern that reflects seasonal and interannual climate variability, and (2) an “irrigation” pattern that reflects recharge from leaky irrigation canals and over-applied irrigation water. Although the seasonal water-level fluctuations vary with respect to timing and magnitude, Michalek and Sutherland (2020) determined that long-term hydrographs from this region do not show declining trends. Hydrographs that show a natural (unirrigated) recharge pattern reflect water levels generally rising in spring and early summer due to infiltration of snowmelt and increased precipitation. These water levels decline during the late summer and fall, reaching seasonal lows in the winter months (hydrograph 213610). Changes in climate such as droughts or wet periods manifest as multi-year water-level declines or increases. Well hydrograph 234909 shows a declining trend from 2012–2015, increasing from 2016–2019, and decreasing from 2020–present. A similar response is observed in other wells east of the East Gallatin River, which is also located outside the area of intense irrigation practices. On the hydrographs that show an irrigation pattern (e.g., 201713, 226769, or 235473), water levels rise sharply at the beginning of the irrigation season, in late spring. Water levels remain elevated (a blunt peak or plateau) during the summer months while irrigation is ongoing, and sharply decline when irrigation water is “turned off.” Water level decline persists until the next irrigation period begins in the spring of the following year. The irrigation response is observed in wells 226763, 235475, 226769, 235473, and 96132 between Jackson Creek/East Gallatin River and the Camp Creek Hills. In this area, a 2,000-mi network of irrigation canals and laterals distribute water to about 5,350 acres (Michalek and Sutherland, 2020). The timing and magnitude of water-level fluctuation is consistent from year to year because irrigation practices that affect groundwater recharge have not significantly changed in the past 30 years. As demonstrated by Michalek and Sutherland (2020), some land has been taken out of production and flood irrigation has been replaced by wheel lines and center pivots. Although such changes may cause decreased groundwater recharge, these hydrographs demonstrate that water levels have not changed appreciably over the past decade. This potentiometric surface map builds upon and expands the potentiometric maps of Hackett and others (1960) and Slagle (1995).The map is based on about 500 measured water levels gathered during site visits between January 2008 and December 2012 (Carstarphen and others, 2015).1 Water levels were measured over a 4-year period across multiple seasons. Both of these factors can introduce variations in water levels and introduce error into the potentiometric contour configuration. Long-term well hydrographs for wells completed in the basin-fill and surrounding bedrock do not show water-level trends that would change the configuration of the potentiometric contours; these hydrographs show seasonal water-level fluctuations of 15 ft or less. Relative to the scale of this potentiometric map and the contour intervals, use of water levels measured across a 4-year period and during different seasons does not introduce noticeable error in interpretation. This potentiometric surface map is a general interpretation of regional conditions and groundwater flow directions. Readers interested in site-specific interpretations should reevaluate the data with an appropriate contour interval. This map and an ArcGIS Map Package with contours and point data are available at the Montana Bureau of Mines and Geology’s publication website, http://www.mbmg.mtech.edu/mbmgcat/catmain.asp. 1Water-level measurements and other site information are available from the Montana Bureau of Mines and Geology’s Ground Water Information Center (GWIC) database, http://mbmggwic.mtech.edu. Scale 1:100,000KILOMETERS 1 0 1 2 345678910MILES 1 0 1 2 3 4 7 8 9 1056Figure 1. Location Map909415159090KalispellMissoulaHelenaGreat FallsBillingsBozemanButte116°104°106°108°110°112°114°49°45°46°47°48°MONTANA100 0 100 Miles160 0 160 KilometersThis mapGallatin–MadisonStudy Area45° 26' 35"111° 49' 52"46° 09' 40"111° 52' 00"45° 27' 48"110° 47' 05"46° 10' 55"110° 48' 23"R 6 ER 5 ER 4 ER 3 ER 7 ER 2 ET 4 S T 3 ST 2 ST 1 ST 1 NT 2 NT 3 NT 4 NT 5 N46° 00' 00"111° 45' 00"111° 30' 00"111° 15' 00"111° 00' 00"45° 45' 00"45° 30' 00"R 1 ER 1 WR 2 W111° 45' 00"111° 30' 00"111° 15' 00"111° 00' 00"MONTANA BUREAU OF MINES AND GEOLOGYA Department of Montana Technological UniversityMontana GroundwaterAssessmentAtlas 8, Map 4, Plate 1 2022 United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Gallatin County Area, MontanaNatural Resources Conservation Service March 2, 2026 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 Soil Map..................................................................................................................5 Soil Map................................................................................................................6 Legend..................................................................................................................7 Map Unit Legend..................................................................................................8 Map Unit Descriptions..........................................................................................8 Gallatin County Area, Montana.......................................................................10 50B—Blackdog silt loam, 0 to 4 percent slopes..........................................10 50C—Blackdog silt loam, 4 to 8 percent slopes..........................................11 Soil Information for All Uses...............................................................................13 Soil Properties and Qualities..............................................................................13 Soil Erosion Factors........................................................................................13 K Factor, Whole Soil....................................................................................13 Soil Physical Properties..................................................................................16 Saturated Hydraulic Conductivity (Ksat)......................................................16 Water Features...............................................................................................19 Depth to Water Table...................................................................................19 References............................................................................................................24 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 6 Custom Soil Resource Report Soil Map 506414050641505064160506417050641805064190506420050642105064220506423050642405064250506414050641505064160506417050641805064190506420050642105064220506423050642405064250493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 45° 43' 54'' N 111° 5' 15'' W45° 43' 54'' N111° 5' 7'' W45° 43' 50'' N 111° 5' 15'' W45° 43' 50'' N 111° 5' 7'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84 0 35 70 140 210 Feet 0 10 20 40 60 Meters Map Scale: 1:816 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Gallatin County Area, Montana Survey Area Data: Version 29, Aug 30, 2025 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 18, 2022—Aug 29, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 7 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 50B Blackdog silt loam, 0 to 4 percent slopes 1.6 76.7% 50C Blackdog silt loam, 4 to 8 percent slopes 0.5 23.3% Totals for Area of Interest 2.1 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, Custom Soil Resource Report 8 onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 9 Gallatin County Area, Montana 50B—Blackdog silt loam, 0 to 4 percent slopes Map Unit Setting National map unit symbol: 56vq Elevation: 4,350 to 5,500 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 37 to 43 degrees F Frost-free period: 90 to 110 days Farmland classification: All areas are prime farmland Map Unit Composition Blackdog and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Blackdog Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Calcareous loess Typical profile A - 0 to 10 inches: silt loam Bt - 10 to 19 inches: silty clay loam Bk - 19 to 60 inches: silt loam Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches 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 content: 30 percent Available water supply, 0 to 60 inches: High (about 10.9 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: R044BC032MT - Loamy (Lo) 15-19" PZ Frigid North Hydric soil rating: No Minor Components Meagher Percent of map unit: 4 percent Landform: Alluvial fans, Stream terraces Down-slope shape: Linear Across-slope shape: Linear Custom Soil Resource Report 10 Ecological site: R044BC032MT - Loamy (Lo) 15-19" PZ Frigid North Hydric soil rating: No Bowery Percent of map unit: 3 percent Landform: Alluvial fans, Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: R044BC032MT - Loamy (Lo) 15-19" PZ Frigid North Hydric soil rating: No Quagle Percent of map unit: 3 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: R044BC030MT - Limy (Ly) 15-19" PZ Frigid North Hydric soil rating: No 50C—Blackdog silt loam, 4 to 8 percent slopes Map Unit Setting National map unit symbol: 56vr Elevation: 4,500 to 5,750 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 37 to 43 degrees F Frost-free period: 90 to 110 days Farmland classification: Farmland of statewide importance Map Unit Composition Blackdog and similar soils: 90 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Blackdog Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Calcareous loess Typical profile A - 0 to 10 inches: silt loam Bt - 10 to 19 inches: silty clay loam Bk - 19 to 60 inches: silt loam Properties and qualities Slope: 4 to 8 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Custom Soil Resource Report 11 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 content: 30 percent Available water supply, 0 to 60 inches: High (about 10.9 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: R044BC032MT - Loamy (Lo) 15-19" PZ Frigid North Hydric soil rating: No Minor Components Meagher Percent of map unit: 4 percent Landform: Alluvial fans, Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: R044BC032MT - Loamy (Lo) 15-19" PZ Frigid North Hydric soil rating: No Quagle Percent of map unit: 3 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: R044BC030MT - Limy (Ly) 15-19" PZ Frigid North Hydric soil rating: No Bowery Percent of map unit: 3 percent Landform: Stream terraces, Alluvial fans Down-slope shape: Linear Across-slope shape: Linear Ecological site: R044BC032MT - Loamy (Lo) 15-19" PZ Frigid North Hydric soil rating: No Custom Soil Resource Report 12 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Erosion Factors Soil Erosion Factors are soil properties and interpretations used in evaluating the soil for potential erosion. Example soil erosion factors can include K factor for the whole soil or on a rock free basis, T factor, wind erodibility group and wind erodibility index. K Factor, Whole Soil Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The estimates are based primarily on percentage of silt, sand, and organic matter and on soil structure and saturated hydraulic conductivity (Ksat). Values of K range from 0.02 to 0.69. Other factors being equal, the higher the value, the more susceptible the soil is to sheet and rill erosion by water. "Erosion factor Kw (whole soil)" indicates the erodibility of the whole soil. The estimates are modified by the presence of rock fragments. Factor K does not apply to organic horizons and is not reported for those layers. 13 14 Custom Soil Resource Report Map—K Factor, Whole Soil 506414050641505064160506417050641805064190506420050642105064220506423050642405064250506414050641505064160506417050641805064190506420050642105064220506423050642405064250493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 45° 43' 54'' N 111° 5' 15'' W45° 43' 54'' N111° 5' 7'' W45° 43' 50'' N 111° 5' 15'' W45° 43' 50'' N 111° 5' 7'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84 0 35 70 140 210 Feet 0 10 20 40 60 Meters Map Scale: 1:816 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Lines .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Soil Rating Points .02 .05 .10 .15 .17 .20 .24 .28 .32 .37 .43 .49 .55 .64 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Gallatin County Area, Montana Survey Area Data: Version 29, Aug 30, 2025 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 18, 2022—Aug 29, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 15 Table—K Factor, Whole Soil Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 50B Blackdog silt loam, 0 to 4 percent slopes .37 1.6 76.7% 50C Blackdog silt loam, 4 to 8 percent slopes .37 0.5 23.3% Totals for Area of Interest 2.1 100.0% Rating Options—K Factor, Whole Soil Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable) Soil Physical Properties Soil Physical Properties are measured or inferred from direct observations in the field or laboratory. Examples of soil physical properties include percent clay, organic matter, saturated hydraulic conductivity, available water capacity, and bulk density. Saturated Hydraulic Conductivity (Ksat) Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a saturated soil transmit water. The estimates are expressed in terms of micrometers per second. They are based on soil characteristics observed in the field, particularly structure, porosity, and texture. Saturated hydraulic conductivity is considered in the design of soil drainage systems and septic tank absorption fields. For each soil layer, this attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used. The numeric Ksat values have been grouped according to standard Ksat class limits. Custom Soil Resource Report 16 17 Custom Soil Resource Report Map—Saturated Hydraulic Conductivity (Ksat)506414050641505064160506417050641805064190506420050642105064220506423050642405064250506414050641505064160506417050641805064190506420050642105064220506423050642405064250493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 45° 43' 54'' N 111° 5' 15'' W45° 43' 54'' N111° 5' 7'' W45° 43' 50'' N 111° 5' 15'' W45° 43' 50'' N 111° 5' 7'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84 0 35 70 140 210 Feet 0 10 20 40 60 Meters Map Scale: 1:816 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons = 8.0467 Not rated or not available Soil Rating Lines = 8.0467 Not rated or not available Soil Rating Points = 8.0467 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Gallatin County Area, Montana Survey Area Data: Version 29, Aug 30, 2025 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 18, 2022—Aug 29, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 18 Table—Saturated Hydraulic Conductivity (Ksat) Map unit symbol Map unit name Rating (micrometers per second) Acres in AOI Percent of AOI 50B Blackdog silt loam, 0 to 4 percent slopes 8.0467 1.6 76.7% 50C Blackdog silt loam, 4 to 8 percent slopes 8.0467 0.5 23.3% Totals for Area of Interest 2.1 100.0% Rating Options—Saturated Hydraulic Conductivity (Ksat) Units of Measure: micrometers per second Aggregation Method: Dominant Component Component Percent Cutoff: None Specified Tie-break Rule: Fastest Interpret Nulls as Zero: No Layer Options (Horizon Aggregation Method): All Layers (Weighted Average) Water Features Water Features include ponding frequency, flooding frequency, and depth to water table. Depth to Water Table "Water table" refers to a saturated zone in the soil. It occurs during specified months. Estimates of the upper limit are based mainly on observations of the water table at selected sites and on evidence of a saturated zone, namely grayish colors (redoximorphic features) in the soil. A saturated zone that lasts for less than a month is not considered a water table. This attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used. Custom Soil Resource Report 19 20 Custom Soil Resource Report Map—Depth to Water Table 506414050641505064160506417050641805064190506420050642105064220506423050642405064250506414050641505064160506417050641805064190506420050642105064220506423050642405064250493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 493180 493190 493200 493210 493220 493230 493240 493250 493260 493270 493280 493290 493300 493310 493320 493330 493340 493350 45° 43' 54'' N 111° 5' 15'' W45° 43' 54'' N111° 5' 7'' W45° 43' 50'' N 111° 5' 15'' W45° 43' 50'' N 111° 5' 7'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84 0 35 70 140 210 Feet 0 10 20 40 60 Meters Map Scale: 1:816 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons 0 - 25 25 - 50 50 - 100 100 - 150 150 - 200 > 200 Not rated or not available Soil Rating Lines 0 - 25 25 - 50 50 - 100 100 - 150 150 - 200 > 200 Not rated or not available Soil Rating Points 0 - 25 25 - 50 50 - 100 100 - 150 150 - 200 > 200 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Gallatin County Area, Montana Survey Area Data: Version 29, Aug 30, 2025 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 18, 2022—Aug 29, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 21 Table—Depth to Water Table Map unit symbol Map unit name Rating (centimeters)Acres in AOI Percent of AOI 50B Blackdog silt loam, 0 to 4 percent slopes >200 1.6 76.7% 50C Blackdog silt loam, 4 to 8 percent slopes >200 0.5 23.3% Totals for Area of Interest 2.1 100.0% Custom Soil Resource Report 22 Rating Options—Depth to Water Table Units of Measure: centimeters Aggregation Method: Dominant Component Component Percent Cutoff: None Specified Tie-break Rule: Lower Interpret Nulls as Zero: No Beginning Month: January Ending Month: December Custom Soil Resource Report 23 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 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. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 24 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 25 Percolation Test Results Owner Name: Kaufman Overhead Door Soak Date 1/6/2026 Project Name: 2035.004 Soak Start 8:00 AM Legal Description:Fully Drained < 1min Test Number: 1 Soak Start 8:00 AM Confirmation #: Fully Drained < 1min.  Test Date: 1/6/2026 Weather: Cloudy/windy Ambient Temp: 44 oF Eval by: JCH Hole Depth (in): 8 Hole Diam (in): 6 Distance of ref point above the bottom of the hole (in) 6 Test Start Time 8:00 AM Time Interval (min) 0:01 Start Time of Day End Time of  Day Time Interval  (min) Initial Dist  Above Ref Point  (in) Final Distance  Above Ref  Point Drop in Water  Level (in) Percolation  Rate (min/in) 8:00 AM 8:01 AM 0:01 6.00 0.00 6.00 >1 8:02 AM 8:03 AM 0:01 6.00 0.00 6.00 >1 NELSON MEADOWS SUB, S22, T01 S, R05 E, BLOCK 4, Lot 16,  ACRES 2.14 ______________________________________________________________________________ ______________________________________________________________________________ 1105 Reeves Rd. W. Ste 6, Bozeman, MT 59718 (406)-581-5730 www.headwatersmt.net Appendix D Stormwater Facili�es Opera�on, Inspec�on, and Maintenance Manual Acknowledgement of Stormwater Facility Maintenance Requirements Stormwater Facility Inspec�on Form KOHD Facility 3480 Prince Lane Storm Water Facili�es Opera�on & Maintenance Manual Responsible Party: DP&J, LLC Contact: Patrick Donnelly Address: 3480 Prince Lane, Bozeman, MT 59718 Email: pdonnelly@kaufmannsdoor.com Phone: 406-586-9636 Overview The lot owner is responsible for opera�on, inspec�ons, and maintenance of all the onsite Storm Water Facili�es, curb cuts, guters, culverts, and storm pond per the schedule below and using the included Stormwater Facility Inspec�on Form. The inspec�on forms shall be kept for a period of 3 years. This en�ty is also responsible for the replacement of any drainage facili�es that are no longer func�oning as designed. Maintenance The curb cuts, curb lines, and valley guter are to have sediment removed by hand on an annual basis, or an updated maintenance schedule as determined by monitoring the sediment buildup. Any sediment removed shall be transported off the site and disposed of properly as to not discharge into state waters. Guters and downspouts from the buildings are to be inspected each year to check for debris buildup and clogging. Sediment removal shall be performed in a manner that does not place the sediment on the asphalt or concrete surface, allowing it to migrate into the curb, valley guter, or storm pond. The stormwater pond shall be monitored every year for sediment build-up. When sediment build-up exceeds three (3) inches, it shall be removed mechanically and hauled off the site. If extrac�on of the sediment causes vegeta�on removal from the botom of the pond, it should be re-seeded. A sta�c measuring device shall be placed in the pond in order to quickly iden�fy when three inches of sediment has accumulated. The device could be a visual ruler, a concrete pad, or 24” steel stake set at exactly 3 inches above the botom of the pond. Culverts shall be inspected annually for sediment build-up and blockages. Any blockages shall be removed immediately and disposed of properly off site. Sediment buildup shall also be removed if more than one (1) inch of visible sediment is present, as measured from the inside edge of the pipe. The areas upstream and downstream of the culverts shall also be inspected to ensure no obstruc�ons are present that would block runoff from reaching the culvert, and that no objects are present that may be swept into the culvert, causing a blockage. Budget It is es�mated that the annual budget to complete the above items is approximately $200 for inspec�ons and an average of $800 for maintenance in 2026 value. Since most of the maintenance is not expected to be needed yearly, the lot owner shall budget or set moneys aside for larger maintenance tasks as described below. Inspec�on & Maintenance Cost Item Inspection Frequency Responsible Party Yearly Inspection Cost Design Life Maintenance Cost Estimated Maintenance Frequency Curbs, Curb Cuts, Valley Gutter Yearly Lot Owner $50.00 70 yrs $250.00 1 Year Gutters & Downspouts Yearly Lot Owner $50.00 70 yrs $100.00 1 Year Culverts Yearly Lot Owner $50.00 70 yrs $150.00 3 Year Storm Pond Yearly Lot Owner $50.00 70 yrs $1,500.00 5 Year Acknowledgement of Stormwater Facility Maintenance Requirements KOHD Facility 3480 Prince Lane Bozeman, Montana COB Applica�on #26053 March 2026 Acknowledgement of Stormwater Facili�es Maintenance Requirements PROPERTY OWNER: DP&J, LLC NAME OF PLAN/DEVELOPMENT: KOHD Facility LOT/BLOCK/SUBDIVISION: Lot 16, Block 4 of Nelson Meadows Subdivision Property Owner hereby acknowledges that they are required to maintain all stormwater facili�es on the Property pursuant to Bozeman Municipal Code sec. 40.04.720. This requirement is binding on any successor or assign of the Property Owner listed above. The City requires stormwater facili�es be constructed and adequately maintained on the Property in order to maintain the health, safety and welfare of City residents. Adequate maintenance is defined as keeping the stormwater facili�es and all components thereof in good working condi�on so that these stormwater facili�es con�nue to perform in accordance with the design intent. Should the Property Owner fail to adequately maintain stormwater facili�es, the City may enter upon the Property and take such steps as are necessary to correct deficiencies. The City may assess against the Property Owner for the cost of any repairs or necessary maintenance by any means provided for in the Bozeman Municipal Code. By signing below Property Owner acknowledges they have read this document and the applicable provisions of the Bozeman Municipal Code, and they agree to the maintenance requirements for all stormwater facili�es on their Property. BY:_____________________, Patrick Donnelly, member, DP&J, LLC Stormwater Facility Inspection Form Section 1: General Information Facility ID: Facility Type: Choose an item. Date/Time: Click or tap to enter a date. Owner: Contact: Inspector’s Name, contact info: Choose an item. Location/Access info: Type of Inspection: ☐Routine, Dry Weather ☐ Routine, Wet Weather ☐ Complaint Driven ☐ Other: __________________ Section 2: Weather and Discharge Information Most recent precipitation or melt: Temperature: Is a stormwater discharge occurring? ☐ Yes ☐ No If yes, what is the source and quality of discharge? Is an illegal discharge occurring? ☐ Yes ☐ No If yes, what is the source and quality of discharge? Section 3: Facility Maintenance Priority ☐Low: Stormwater facility appears to be functioning as designed. Continue scheduled maintenance. ☐Medium: Stormwater facility requires minor to moderate sediment and vegetation maintenance to mitigate the risk of flooding, waterway pollution, and infrastructure failure. ☐High: Stormwater facility requires significant sediment dredging, vegetation removal, and/or infrastructure repairs to restore function. Notes, Findings & Recommendations: Inspector’s Signature: ________________________________ Date: ___________________ Section 4: Qualitative Analysis Components # Items Conditions Results Notes and Required Actions General Degraded, missing, or inadequate Yes 1.1 Accessibility maintenance access? No ☐☐ Trash, sediment, and waste within 1.2 Debris ☐Yesand around the facility? ☐No Overgrown or dead cattails, Yes 1.3 Vegetation woody shrubs, weeds, grass, and ☐ trees? ☐No Infrastructure Damaged inlet pipe, outlet pipe, Yes1.4 ☐Condition outfall structure, or fencing? ☐No Facility Condition Pretreatment Bay Clogged, obstructed, or filled 2.1 ☐Yesor Facility pretreatment forebay or facility? ☐No 2.2 Storage Bay Clogged or filled storage bay? ☐Yes☐No Stagnant water with infiltration Groundwater or Yes 2.3 greater than 48 hours post-rain ☐Standing Water event? ☐No 2.4 Flow Path Clogged or obstructed flow path? ☐Yes☐No Barren or exposed surfaces on Yes2.5 Side Slopes ☐Facility’s side slopes and bottom? ☐No Maintenance Maintenance Plan Is there a written plan specific to ☐Yes3.1 or Agreement this facility? ☐No Yes3.2 Implementation Is there evidence of maintenance? ☐☐No Section 5: Quantitative Analysis Vegetation Cover type % Within facility Notes Bare ground Aquatics Grasses/Herbaceou Trees >3” DBH Shrubs Total 100 Elevation Analysis Location Reading (ft) Elevation (ft) Notes SRV#CP Control Point SRV#1 Inlet SRV#2 Outlet SRV#3 Center SRV#4 North of Center SRV#5 East of Center SRV#6 South of Center SRV#7 West of center SRV#8 Berm or overflow SRV#9 Summary Section 6: Facility Maintenance Inspection Exhibit Photo 1 description Photo 2 description Section 7: Photo Log KOHD Facility Storm Water Maintenance Revolving Fund Balance Sheet YearDeposit (Today's Dollars)Year-End Cost (With Inflation*)Year-End BalanceYearDeposit (Today's Dollars)Year-End Cost (With Inflation*)Year-End Balance1 $4,000.00 $350.00 $3,650.00 26 $700.00 $525.00 $5,625.00 2 $700.00 $357.00 $3,993.00 27 $700.00 $760.00 $5,565.00 3 $700.00 $520.00 $4,173.00 28 $700.00 $539.00 $5,726.00 4 $700.00 $371.00 $4,502.00 29 $700.00 $546.00 $5,880.00 5 $700.00 $1,998.00 $3,204.00 30 $4,000.00 $3,160.00 $6,720.00 6 $700.00 $550.00 $3,354.00 31 $700.00 $560.00 $6,860.00 7 $700.00 $392.00 $3,662.00 32 $700.00 $567.00 $6,993.00 8 $700.00 $399.00 $3,963.00 33 $700.00 $820.00 $6,873.00 9 $700.00 $580.00 $4,083.00 34 $700.00 $581.00 $6,992.00 10 $4,000.00 $2,183.00 $5,900.00 35 $700.00 $3,108.00 $4,584.00 11 $700.00 $420.00 $6,180.00 36 $700.00 $850.00 $4,434.00 12 $700.00 $610.00 $6,270.00 37 $700.00 $602.00 $4,532.00 13 $700.00 $434.00 $6,536.00 38 $700.00 $609.00 $4,623.00 14 $700.00 $441.00 $6,795.00 39 $700.00 $880.00 $4,443.00 15 $700.00 $2,560.00 $4,935.00 40 $4,000.00 $3,293.00 $5,150.00 16 $700.00 $455.00 $5,180.00 41 $700.00 $630.00 $5,220.00 17 $700.00 $462.00 $5,418.00 42 $700.00 $910.00 $5,010.00 18 $700.00 $670.00 $5,448.00 43 $700.00 $644.00 $5,066.00 19 $700.00 $476.00 $5,672.00 44 $700.00 $651.00 $5,115.00 20 $4,000.00 $2,553.00 $7,119.00 45 $700.00 $3,760.00 $2,055.00 21 $700.00 $700.00 $7,119.00 46 $700.00 $665.00 $2,090.00 22 $700.00 $497.00 $7,322.00 47 $700.00 $672.00 $2,118.00 23 $700.00 $504.00 $7,518.00 48 $700.00 $970.00 $1,848.00 24 $700.00 $730.00 $7,488.00 49 $700.00 $686.00 $1,862.00 25 $700.00 $2,738.00 $5,450.00 50 $4,000.00 $3,663.00 $2,199.00 * Inflation assumed at 2% per year 4,000.00$ Initial Contribution & Every 10 Years (Today's Dollars) 700.00$ Annual Contribution (Today's Dollars)