November 14, Robert Peccia & Associates, Inc. PO Box 5653 Helena, MT Mr. Bill Burkland, P.E.

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1 November 14, 2018 Robert Peccia & Associates, Inc. PO Box Attention: Subject: Gentlemen: Mr. Bill Burkland, P.E. Final Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron Fort Benton Airport AIP Terracon Project Number C At your request and in accordance with our Agreement for Services dated April 9, 2018, we have performed a geotechnical investigation to evaluate the native soil subgrade conditions to aid in design of upgrades to the following five elements of the planned upgrades: 1. Construction of a Connecting and NE Hangar Taxiway (70 feet x 3 feet) - 3 Borings 2. Construction of an East Parallel Taxiway (1800 feet x 3 feet) - 7 Borings 3. Construction of a SE Hangar Taxiway (30 feet x 20 feet) - 1 Boring 4. Construction of an East Agricultural Operations Apron (120 feet x 120 feet) - 2 Borings. Construction of a West Parallel Taxiway (192 feet x 3 feet) - 9 Borings The purpose of the exploration program was to provide geotechnical information and recommendations for design and construction of the new pavement sections, generally to be located northwest of the existing Runway -23. Our investigation was based generally upon the scope of services requested in your of March 23, 2018, which included a scaled drawing of the five improvement elements described above. We ultimately drilled a total of 22 borings (as staked on the project), rather than the 20 borings described by the initial scope description and our proposal. FIELD INVESTIGATION At locations generally established by your firm in the field, a total of 22 borings were drilled to depths of approximately 1. feet below existing ground elevation to assess subgrade conditions for the five individual elements of the pavement upgrades as described above. Representative samples were obtained from all borings and returned to our materials laboratory for visual inspection and laboratory testing. Continuous logs of the subsurface conditions were recorded during the investigation, including Standard Penetration Testing (SPT). Bulk samples

2 Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron - Fort Benton, Montana November 14, 2018 Terracon Project No. C were obtained from auger cuttings to be used for index testing, along with moisture-density relationship and CBR testing. The Logs present delineations of subsurface strata as could be determined from the split barrel samples and auger cuttings recovered during the field investigation. Stratification lines shown on the Logs represent the approximate boundaries between subgrade types. Differences in stratification in situ of the subgrade soils are likely to occur between boring locations. LABORATORY INVESTIGATION Representative samples recovered during the field investigation were transported to our laboratory where they were carefully logged and visually classified, with soil descriptions provided in accordance with ASTM Methods D2487 / D2488 which are based on the Unified Soils Classification System. Representative samples were selected for tests to determine engineering and physical properties of the soils in general accordance with ASTM or other recognized procedures. Generalized descriptions of the laboratory testing conducted by Terracon for this investigation are listed as follows: Natural Moisture Water content as a percent of dry soil weight representative of in situ conditions Gradation and Hydrometer Analysis Grain size distribution indicated the percent by weight of clay, silt, sand, and gravel comprising the subgrade materials. Atterberg Limits Soil plasticity determined by the moisture range through which the soil passes from a plastic to liquid consistency. Standard Moisture-Density Relationship Determination of the laboratory maximum dry density and corresponding optimum moisture content for soil densification using a specified (standard) compactive effort/energy input. California Bearing Ratio Strength test indicating the load carrying capability of a compacted subgrade soil expressed as a ratio to a high-quality crushed stone material. In addition to the laboratory tests performed by Terracon, we subcontracted water soluble sulfate and ph testing to Energy Laboratories of Billings, MT. Results of all laboratory tests performed are presented on the attached Boring Logs and Exhibits Reliable Resourceful Responsive 2

3 Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron - Fort Benton, Montana November 14, 2018 Terracon Project No. C Site Geology SUBSURFACE CONDITIONS AND DISCUSSION The Fort Benton Airport is located northeast of Fort Benton, Montana on the plain north of the Missouri River Valley. The regional surface geology has been mapped as glacially derived till, lake bed and interglacial alluvial deposits comprised of an unsorted, unstratified, and heterogeneous mixture of sand, silt and clays. Wind deposited sand and silt soils are visible at the ground surface in several areas near the project site. Bedrock underlying the surface soils well beyond the depths drilled for the investigation has been mapped as shale and siltstone of the Kootenai aged Colorado Formation. Subgrade Soil Conditions Inclusive of all Five Improvement Elements The glacially derived and predominantly fine-grained soils encountered as subgrade beneath the proposed pavement sections were classified as silty sand to silty clayey sand; lean clay to lean clay with sand; along with poorly graded sand (fine) and silt with sand. Consistency of the fine sands ranged from very loose to medium dense with SPT recorded N-Values between 0 and 19 blows per foot; whereas the consistency of the silt and clay subgrade soils generally ranged from very soft to stiff, with N-Values between 1 and 13 blows per foot (one outlier of 32 blows per foot encountered in DH-22). Field moisture contents for all of the subgrade soils ranged from 1 to 32 percent, with moisture content values for the upper feet of subgrade occupying a range of 2 to 26 percent. Overall measured Liquid Limit values ranged from 24 to 48 percent and overall Plasticity Index values ranged from to 32 percent. Samples of sandy lean clay/silty clayey sand (composite) and silt with sand exhibited laboratory CBR values of 8.2 percent and 6.1 percent, respectively. A CBR test performed a lean clay sample, representing the controlling subgrade strength soil, indicated a value of 1.7 percent. Based upon our prior facility experience (Terracon Report No. C414309, dated January 7, 201), consolidation-swell response of the glacially derived near-surface subgrade soils is minimal for loadings associated with typical pavement. Results of four consolidation-swell tests performed as part of the cited previous investigation, on subgrade soils very similar to those encountered in the current investigation, are available and are attached. The maximum consolidation values measured at normal pressure of 00 psf was about 0.4 percent (sandy silt at 93 pcf dry density) and the maximum swell at normal pressure measured at 00 psf was about 0. percent (sandy lean clay at 11 pcf dry density). Subgrade soils encountered during the current investigation contained greater than 1 percent finer than the 0.02 mm grain size, which puts the subgrade soils within the FAA Frost Group FG-4 indicating the potential for significant frost effects associated with moisture contents approaching saturation at the lower face of the freezing zone during periods of subgrade frost penetration. Laboratory experimentation was performed during our previous investigation cited Reliable Resourceful Responsive 3

4 Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron - Fort Benton, Montana November 14, 2018 Terracon Project No. C above (reported January 7, 201) to establish the potential for frost related movement in the sandy silt subgrade. The laboratory testing for frost response indicated a volume increase on the order of one percent as degree of saturation approached about 60 percent. Ultimate frost related volume change on the order of 3 percent was measured with the degree of saturation approaching 90 percent. Published frost depths for north-central Montana range from about 3. feet to 6.0 feet, which are substantially greater than typical pavement section depths. Although annual precipitation is limited in central Montana and the project pavements are planned to be well drained, subgrade moisture contents may periodically attain degree of saturation values required for adverse frost effects. This could create perceptible surface movements during cyclical freezing as the buildup of ice crystals is followed by springtime subgrade weakening associated with ice crystal thawing. That is, frost response could occur during higher subsurface moisture (above about 0% as degree of saturation) coinciding with seasonal frost penetration. Where cyclical frost heave occurs, it typically appears at random spacing and differing levels of severity. A full discussion of pavement frost issues is presented in Report No. FAA-RD-74-30, Design of Civil Airfield Pavements for Seasonal Frost and Permafrost Conditions. Groundwater Conditions Groundwater was detected during the current field investigation in five () of the 22 borings at depths between and 1 feet. Numerous factors contribute to groundwater fluctuations; evaluation of these factors requires special study that is beyond the scope of this report. We note that the presence of groundwater amplifies the potential of frost impacts, since the groundwater provides an available water source within the subgrade freezing depth. ANALYSIS FOR PROJECT DESIGN AND CONSTRUCTION Based upon the subgrade conditions described above, the primary geotechnical issues for project pavement design and construction are as follows: 1. Highly variable and often very low subgrade stability, as indicated by SPT N-Values between 0 and 19 blows per foot for sand soils and SPT values between 1 and 13 blows per foot for clay/silt soils. The unfavorable stability conditions present an extremely challenging native subgrade upon which to begin construction of a new pavement section. Support for conventional construction equipment is not reliably provided by the native subgrade, suggesting the need to provide a stable construction platform to support the new pavement sections and the equipment required to construct the new pavement sections. Care should be taken to preclude disturbance to the native subgrade underlying the stable construction platform/subgrade replacement zone. Track mounted equipment will likely be required to prepare the native subgrade soils to support the stable construction platform, operating adjacent to limited areas of new pavement construction. Reliable Resourceful Responsive 4

5 Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron - Fort Benton, Montana November 14, 2018 Terracon Project No. C Very low subgrade strength in areas of lean clay subgrade soil, as indicted by a laboratory soaked CBR value of only 1.7 percent presents a central challenge for project pavement design and construction. The very low CBR value requires a robust pavement section to support light aircraft and snow removal equipment. 3. Extreme variability in subgrade moisture contents (from 1 percent to 32 percent) for sand/silt /clay deposits which have been subjected to extremely limited geologic preloading, indicates the possibility of varying subgrade deflection/settlement response to applied stresses associated with wheel/pavement loading. While prior consolidation testing of the soil deposit in the project vicinity did not indicate extreme load/swell response, the potential for extreme moisture content changes after project construction creates some concern for the development of surface unevenness in the future. Differing subgrade responses to pavement loading can be mitigated by the lower applied stresses associated with thicker pavement sections. 4. The potential for frost induced surface movements associated with development/expansion of icing zones in the frost susceptible subgrade soils, with subsequent settlement as the ice filled voids turn to water is of concern. Frost response associated with surface moisture sources are often best mitigated by limiting moisture intrusion below pavement sections. In the case of the subject project, however, the occasional presence of ground water at depths on the order of expected frosts depths encourages the use of a partially frost protected pavement section, to include the use of a reasonably frost-free subgrade replacement zone, to a depth balancing expected pavement performance improvement against the cost of such a special pavement section. As the central feature to address the geotechnical issues described above, a subgrade replacement zone will serve as a stable platform for construction traffic and as a reliable subgrade/lower pavement section component. The presence very high water soluble sulfate content in one of the three samples tested (9740 mg/kg) precludes consideration of lime/chemical stabilization of the subgrade. Construction of a substantial layer of subgrade replacement with controlled aggregate fill has proven to be effective over very low strength clay/silt/sand subgrades. Effective subgrade replacement material, compatible with the subgrade separation/reinforcing product recommended below can be provided by commonly available crushed aggregate product of 1-1/2 inch maximum size with a No. 4 requirement of percent and a No. 40 requirement of -30 percent. The subgrade replacement product can employ a maximum 0.02 mm requirement of percent for economy of production without impairment to performance, in our experience. A fracture requirement of 3% minimum is recommended for the subgrade replacement material. This subgrade replacement component described above is expected to provide a component CBR of at least 3% (and corresponding Resilient Modulus of 2,000 psi), based upon our past experience with laboratory CBR testing of similar crushed aggregate products. Reliable Resourceful Responsive

6 Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron - Fort Benton, Montana November 14, 2018 Terracon Project No. C As an alternative to the crushed aggregate product recommended above for subgrade replacement material, a thicker layer of uncrushed aggregate product of 3-inch maximum size, again with a No. 4 requirement of percent and a No. 40 requirement of -30 percent would be suitable for use over the subgrade separation/reinforcement product. The uncrushed subgrade replacement product can also employ a maximum 0.02 mm requirement of percent for economy of production without impairment to performance. The uncrushed aggregate subgrade replacement component described above will provide a component CBR of at least 20% (and corresponding Resilient Modulus of 17,000 psi), based upon our past experience with laboratory CBR testing of similar uncrushed aggregate products. The above recommendations for subgrade material are intended to provide pavement support characteristics for construction traffic and long-term truck traffic applied to the pavement by snow removal equipment or any other wheel loads exceeding light aircraft loading. A nominal subgrade replacement depth of 16-inches, with a composite separation/reinforcing fabric, Mirafi RS 380i or equivalent, between the undisturbed clay/silt/sand subgrade surface and the subgrade replacement material, will provide adequate confinement and load distribution for the support of reasonable construction traffic and long-term pavement section support. Based upon manufacture s literature and our experience, composite separation/reinforcing fabric inclusion provides support consistent with about an additional 2 percent thickness of the crushed gravel subgrade replacement material for heavy, short term (construction related) loading. The composite fabric may also provide some improvement to long term structural performance for flexible pavements, but reductions to pavement section design thickness for long term aircraft carrying pavements is generally not recommended. The reconstruction approach described above will also provide some improvement to the frost resistance characteristics of new pavements, amounting to a partial depth replacement of frost susceptible subgrade. Complete protection from frost effects for new pavement sections would require excavation and replacement of the subgrade to an extreme depth; construction cost of this approach to improve frost resistance characteristics is generally prohibitive in terms of economics. The subgrade improvement approach described above will provide an economical and partially frost protected pavement structure. New Pavement Sections RECOMMENDATIONS 1. The unstable subgrade clays/silt/sand subgrade soils require an adequate subgrade replacement thickness of crushed aggregate fill as described above and compacted as a single lift for constructability and the establishment of a stable subgrade (lower pavement section component). A three-component flexible pavement system is recommended to Reliable Resourceful Responsive 6

7 Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron - Fort Benton, Montana November 14, 2018 Terracon Project No. C include 3 inches of asphalt concrete, 4 inches of crushed base course and 16 inches of crushed aggregate (or 22 inches of uncrushed aggregate) subgrade replacement fill as described above and in Exhibit C-1. The subgrade replacement layer should be compacted to a target density of 9 percent of standard laboratory density as determined by ASTM D698, based upon field density testing in the upper 6 inch zone of the subgrade replacement zone. The subgrade replacement component will serve as a platform for construction traffic and as a lower pavement section component. The subgrade should be neat cut to plan grade at the bottom of the subgrade replacement depth (with no attempt at native subgrade compaction or moisture content change)) limiting disturbance to to the moisture sensitive and marginally unstable native subgrade soils, which extend to substantial depths. As described above and shown in Exhibit C-1, a composite separation/reinforcement fabric should be included between the native subgrade and the subgrade replacement layer. The recommended pavement system is presented as a sketch on the attached Exhibit C-1. Several alternatives for a reinforced (or unreinforced) subgrade replacement component could also be considered. A large number of geo-synthetic products are available which could be incorporated into the design of a subgrade replacement layer. The recommended section described above reflects our literature review and our regional experience, but we recognize that a very large number of geosynthetic products are available and many alternatives exist, but substantial further research, along with the acceptance of some additional risk would be involved with the use of any approach for which we do not have first-hand experience. 2. The recommended pavement section presented in Recommendation No. 1 above should be verified using the FAA FAARFIELD Layered Analysis Program from the current AC /320-6F, Airport Pavement Design and Evaluation using facility traffic data and a design CBR value of 1.7 percent for the controlling lean clay subgrade soils underlying the subgrade replacement component. Sub-drainage 3. Edge drains are recommended as part of the planning for the new pavement features, since surface water infiltration along the pavement edges could provide a source of subsurface moisture along the the project. Surface Drainage 4. Surface runoff should be effectively removed from pavements and surrounding areas, both during and after construction. Reliable Resourceful Responsive 7

8 Report of Geotechnical Investigation Upgrades to Taxiways and East Agriculture Apron - Fort Benton, Montana November 14, 2018 Terracon Project No. C Materials Specifications. Standard FAA materials specifications should be carefully tailored to meet the unique requirements of this project. We can assist with project materials specification development for bulk materials and testing requirements, if so requested. Of special importance are the technical provisions for asphalt concrete, aggregate base course, and subgrade replacement components of the new pavement sections, along with special provisions relating to bulk materials testing. Special Construction Considerations 6. Construction contractors should be cautioned against the use of conventional heavy equipment, since the native subgrade soils may not provide reliable support for conventional truck and rubber-tired loader traffic. That is, the subgrade soils underlying the planned new pavement sections are often very loose/very soft and unstable, so the use of track mounted equipment is encouraged. LIMITATIONS AND CLOSURE Terracon has strived to prepare this report in accordance with generally accepted geotechnical engineering practices in this area solely for use by the client for preliminary design purposes and is not intended as a construction or bid document representing subsurface conditions in their entirety. The nature and extent of variations between the borings may not become evident until construction. If variations are then exposed, it will be necessary to reevaluate the recommendations of this report. If changes in the concept or design data of the project are planned, the recommendations contained in this report shall not be considered valid unless the changes are reviewed by our geotechnical engineer, and the recommendations of this report modified or verified in writing. Prepared By: Reviewed By: Kenneth D. Munski, P.E. Principal Senior Materials Engineer Matthew D. Hoffmann, P.E. Project Geotechnical Engineer Great Falls Office Manager Reliable Resourceful Responsive 8

9 th Ave. SW, B-18 B-19 B-16 B-17 B-22 B-21 B-14 B-1 B-11 B-12 B-13 B-20 N B- B-9 B-7 B-8 B- B-3 B-6 B-1 B-4 B-2 Borings Office Manager: MDH Drawn by: BE Checked by: Approved by: PH. (406) FAX. (406) Boring Layout Fort Benton Airport Exhibit

10 BORING LOG NO. B- 1 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY CLAYEY SAND (SC-SM), brown, loose to very loose, friable, fine sand, roots and root holes/pinholes DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS --3 N=8 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 8 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ very sandy, grading to silty 2.0' +/- LEAN CLAY WITH SAND (CL), brow, very soft, bedded, fine sand some oxidization, moderate plasticity, thin sand +/- 1.0' Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Abandonment Method: WATER LEVEL OBSERVATIONS See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N=8 Notes: Boring Started: Drill Rig: Project No.: C Boring Completed: Driller:

11 BORING LOG NO. B- 2 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.3 TOPSOIL SILTY CLAYEY SAND (SC-SM), brown, loose, friable, fine sand, roots and root holes/pinholes, becomes more clayey with depth DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS N= STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ SILTY SAND (SM), brown, loose, fine sand LEAN CLAY WITH SAND (CL), brown, medium stiff, bedded, fine sand, moderate plasticity 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Abandonment Method: WATER LEVEL OBSERVATIONS See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N= N=6 Notes: Boring Started: Drill Rig: Project No.: C Boring Completed: Driller:

12 BORING LOG NO. B- 3 Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.3 TOPSOIL SANDY LEAN CLAY, brown, medium stiff to stiff, faint 1.4 bedding, fine sand, roots SILTY CLAYEY SAND (SC), brown, very loose, fine sand SANDY LEAN CLAY (CL), brown, very soft, bedded, pinhole structure SILTY SAND (SM), brown, loose, bedded, fine sand LEAN CLAY WITH SAND (CL), brown, stiff, bedded, fine sand, moderate plasticity 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Abandonment Method: Liscum Bottom Rd See Exploration Plan WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS -4-4 N=8 bulk N= N= N= N= Notes: STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) Boring Started: Drill Rig: Project No.: C STRAIN (%) WATER CONTENT (%) Driller: DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI Boring Completed:

13 BORING LOG NO. B- 4 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.3 TOPSOIL SILTY CLAYEY SAND (SC-SM), brown, loose, friable, fine sand, roots DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS N=6 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 8 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ SANDY LEAN CLAY (CL), brown, medium stiff, fine sand, very sandy, pinhole structure SILTY SAND (SM), brown, loose, bedded, fine sand LEAN CLAY WITH SAND (CL), brown, medium stiff, bedded, fine sand 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: Abandonment Method: WATER LEVEL OBSERVATIONS See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N= Notes: Boring Started: Drill Rig: Project No.: C Boring Completed: Driller:

14 BORING LOG NO. B- Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.3 TOPSOIL SILTY CLAYEY SAND (SC-SM), brown, medium dense, friable, fine sand, roots SANDY LEAN CLAY (CL), brown, medium stiff, fine sand, very sandy, pinhole structure SILTY SAND (SM), brown, loose, bedded, fine sand LEAN CLAY WITH SAND (CL), brown, medium stiff, bedded, very fine sand, moderate plasticity 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS N= N= N= N= 3-- N= N= STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

15 BORING LOG NO. B- 6 Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.2 TOPSOIL 1.0 SANDY LEAN CLAY (CL), brown, stiff, friable, bedded, roots, fine sand LEAN CLAY (CL), brown, stiff, bedded with lenses of sand, salts, moderate plasticity.4.2 SILTY SAND (SM), brown, loose, bedded, fine sand, some clay LEAN CLAY WITH SAND (CL), brown, medium stiff to stiff, fine sand, gypsum, some more sandy zones 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS N=12 bulk 3-4- N= N= N= N=7 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

16 BORING LOG NO. B- 7 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY CLAYEY SAND (SC-SM), light brown, medium dense, friable, bedded, salts DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS -8-9 N=17 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 7 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ SANDY LEAN CLAY (CL), brown, stiff, bedded, root traces, very sandy, fine sand POORLY GRADED SAND (SP), brown, medium dense, bedded, fine sand, silty sand lenses and pockets, finer sand and more silt with depth 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. 7-- N= 4-4- N=9-6-6 N= N=1 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

17 BORING LOG NO. B- 8 Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.2 TOPSOIL 0.8 SILTY CLAYEY SAND (SC-SM), light brown, medium dense, friable, bedded SILTY SAND (SM), light brown, loose, bedded, root, very fine sand, some very thin clay lenses, salts 8.2 POORLY GRADED SAND (SP), brown, medium dense, bedded, fine sand 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS 6-6- N=11 bulk -3-4 N= N= N= N= N= STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

18 BORING LOG NO. B- 9 Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY CLAYEY SAND (SC-SM), light brown, medium dense, friable, bedded, trace salts, roots, very fine sand SILTY SAND (SM), light brown, loose, bedded, friable, very fine sand POORLY GRADED SAND (SP), brown, loose to medium dense, bedded, fine sand 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS N= N= N= N= 3--4 N=9 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

19 BORING LOG NO. B- Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.2 TOPSOIL 0.7 SILTY CLAYEY SAND (SC-SM), light brown, medium dense, friable, bedded, trace salts, roots, very fine sand SILTY SAND (SM), light brown, loose to medium dense, bedded, friable, very fine sand, thin clay lenses with depth 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS N= N= N= N=9-4-7 N=11 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

20 BORING LOG NO. B-11 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY CLAYEY SAND (SC-SM), light brown, medium dense, friable, bedded, roots, fine sand DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS -4-8 N=12 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ SILTY SAND (SM), brown, medium dense, bedded, friable, very fine sand, thin clay lenses with depth LEAN CLAY WITH SAND (CL), brown, stiff, bedded, very fine sand 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N=11 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

21 BORING LOG NO. B-12 Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.2 TOPSOIL SANDY LEAN CLAY (CL), light brown, medium stiff, 1.4 friable, bedded, roots, very fine sand, some silt SILTY SAND (SM), brown, loose to medium dense, bedded, friable, fine sand, trace clay, root traces, some oxidization, sandy silt +/- 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS 6--7 N=12 bulk N= N= N=9-4-6 N= -7-6 N=13 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

22 BORING LOG NO. B-13 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY SAND (SM), light brown/ brown, medium dense to loose, bedded, friable, fine sand, trace clay, roots, very silty DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS N=12 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 8 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18.3 very silty/sandy 4.0' +/- POORLY GRADED SAND (SP), brown, medium dense to loose, bedded, fine sand, trace silt, finer sand and more silt with depth 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N=9 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

23 BORING LOG NO. B-14 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL POORLY GRADED SAND (SP), brown, loose, fine to medium sand, massive DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS 2-3- N=8 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 3 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ LEAN CLAY (CL), brown, stiff, bedded, silty sand lenses, scattered coal fragments, moderate plasticity SILTY SAND (SM), brown/light brown, medium dense, bedded, friable, very fine sand 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N=17 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

24 BORING LOG NO. B-1 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILT WITH SAND (ML), brown, loose to medium dense, bedded, friable, trace roots, very fine sand DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS N=7 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 7 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 clay +/-, root traces, salts coarser sand with black laminae, bedded, light brown/grey in 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. bulk N= N= N= N= N=12 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

25 BORING LOG NO. B-16 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY SAND (SM), brown, loose, bedded, friable, very fine sand, very silty DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS N=8 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 8 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 4. POORLY GRADED SAND (SP), brown, loose, bedded, friable, fine sand, some silt thin silty sand +/- 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N=9 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

26 BORING LOG NO. B-17 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL LEAN CLAY (CL), brown/light brown, stiff, bedded, salts, roots, some very fine sand, some silt, moderate plasticity DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS 4-- N= STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ becoming more silty, 6.8' +/- SILTY SAND (SM), brown, medium dense, bedded, very fine sand, trace salts, some oxidization, very silty 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. bulk N= N= N= N= N=11 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

27 BORING LOG NO. B-18 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY SAND (SM), brown, medium dense to loose, bedded, friable, roots, trace clay in upper 0.', very silty, very fine sand DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS 6-- N= STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 7 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18.1 roots to.0' +/- POORLY GRADED SAND (SP), brown, loose, bedded, fine sand, some silt 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N=9 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

28 BORING LOG NO. B-19 Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.2 TOPSOIL 1.0 SILTY CLAYEY SAND (SC-SM), light brown, medium dense, bedded, friable, roots SANDY SILT (ML), light brown, stiff, bedded, friable, very fine sand 3. SILTY SAND, brown, loose to medium dense, bedded, very fine sand, friable, very silty coarser +/- 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS N= N= N= N= N=9 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) 3 3 DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

29 BORING LOG NO. B-20 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SANDY SILT (ML), light brown, stiff, bedded, friable, very fine sand, roots, some clay in upper 0.' DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS -4- N=9 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ SILTY SAND, brown, loose to medium dense, bedded, fine sand, friable 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N=8-7-9 N=16 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

30 BORING LOG NO. B-21 Robert Peccia & Associates CLIENT: Page 1 of 1 SITE: GRAPHIC LOG LOCATION Liscum Bottom Rd See Exploration Plan Latitude: Longitude: DEPTH 0.2 TOPSOIL SILTY CLAYEY SAND (SC-SM), brown, medium dense, bedded, friable, fine sand, roots and root traces, very silty, salts DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS N=12 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) WATER CONTENT (%) 7 DRY UNIT WEIGHT (pcf) ATTERBERG LIMITS LL-PL-PI THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/ SILTY SAND, brown, loose, bedded, friable, fine sand POORLY GRADED SAND (SP), brown, medium dense, bedded, fine sand, dark colored laminae, trace silt 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS 1 See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations N= N= N= N=12 Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C Boring Completed: Driller: J. Hefner

31 BORING LOG NO. B-22 Robert Peccia & Associates CLIENT: Page 1 of 1 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 11/1/18 SITE: GRAPHIC LOG LOCATION Latitude: Longitude: DEPTH 0.2 TOPSOIL SANDY LEAN CLAY (CL), brown/dark brown, very stiff, bedded, fine sand, roots SILTY SAND (SM), brown, medium dense to loose, bedded, friable, trace clay, some roots, fine sand LEAN CLAY WITH SAND (CL), brown, medium stiff to stiff, bedded, salt filled root traces, moderate plasticity POORLY GRADED SAND (SP), brown, loose to medium dense, faint bedding, fine sand, trace silt 1. Boring Terminated at 1. Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4" Solid Stem Auger Liscum Bottom Rd See Exploration Plan Abandonment Method: Boring backfilled with auger cuttings upon completion. WATER LEVEL OBSERVATIONS DEPTH (Ft.) 1 WATER LEVEL OBSERVATIONS SAMPLE TYPE See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. FIELD TEST RESULTS N=32 -- N= N=6-6-7 N= N= N=17 STRENGTH TEST TEST TYPE COMPRESSIVE STRENGTH (psf) STRAIN (%) Hammer Type: Automatic Notes: Boring Started: Drill Rig: CME- Project No.: C WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Driller: J. Hefner ATTERBERG LIMITS LL-PL-PI Boring Completed:

32 ATTERBERG LIMITS RESULTS ASTM D LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 9/7/18 P L A S T I C I T Y I N D E X Boring ID B- 3 B-12 B-1 B-17 "U" Line CL or OL CH or OH "A" Line MH or OH CL-ML ML or OL SITE: Liscum Bottom Rd Depth LL PL PI 8 32 Fines LIQUID LIMIT USCS CL CL ML CL Description SANDY LEAN CLAY SANDY LEAN CLAY SILT with SAND LEAN CLAY PROJECT NUMBER: C CLIENT: Robert Peccia & Associates

33 GRAIN SIZE DISTRIBUTION ASTM D422 / ASTM C136 U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS / /4 3/ HYDROMETER LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: AASHTO DESC-2 C FORT BENTON AIRPO.GPJ TERRACON_DATATEMPLATE.GDT 9/7/18 PERCENT FINER BY WEIGHT SITE: Liscum Bottom Rd 1 GRAIN SIZE IN MILLIMETERS Boring ID Depth AASHTO Classification WC (%) LL PL PI Cc Cu B- 3 B-12 B-1 B-17 Boring ID B- 3 B-12 B-1 B-17 COBBLES Depth coarse GRAVEL D 0 D fine coarse A-4 (1) A-4 (3) A-4 (3) A-7-6 (28) medium SAND PROJECT NUMBER: C CLIENT: Robert Peccia & Associates D 30 D %Gravel %Sand %Silt %Fines %Clay fine SILT OR CLAY

34 LABORATORY COMPACTION CHARACTERISTICS OF SOIL CLIENT NAME: Peccia and Associates DATE: 1-Nov-18 CURVE NO.: N/A Sampled: PROJECT NAME & LOCATION: Fort Benton Airport TEST RESULTS % OVERSIZED (ROCK CORRECTION): NA PROJECT NO.: C UN-CORRECTED MAXIMUM DENSITY, PCF 116. SOURCE MATERIAL: B-3, ' UN-CORRECTED OPTIMUM WATER CONTENT, 13.4 RAMMER: MECHANICAL X MANUAL SAMPLE DESCRIPTION: SANDY LEAN CLAY CL / SILTY CLAYEY SAND OVERSIZE ROCK CORRECTION ASSUMED SPECIFIC GRAVITY 2.70 MATERIAL DESIGNATION: Native Subgrade ASSUMED ABSORPTION, % 1 CORRECTED MAXIMUM DENSITY, PCF TEST METHOD: Method A CORRECTED OPTIMUM WATER CONTENT, % na TEST PROCEDURE: ASTM D698 REVIEWED BY: Brian Evans SAMPLE PREPARATION: Moist na Sieve Size SIEVE ANALYSIS % Passing LAB CURVE Poly. (LAB CURVE) 6" " 4" 3" 2" 1-1/2" 1" 3/4" 0 1/2" 99 3/8" 99 No No. 98 No No No No No DRY DENSITY, PCF WATER CONTENT, % ATTERBERG LIMITS LL 24 PI 8 Moisture - Density Relationship Terracon Consultants Inc th Ave. SW 940 ph (406) , fax (406) B-3 Proctor

35 LABORATORY COMPACTION CHARACTERISTICS OF SOIL CLIENT NAME: Peccia and Associates DATE: 1-Nov-18 CURVE NO.: N/A Sampled: PROJECT NAME & LOCATION: Fort Benton Airport TEST RESULTS % OVERSIZED (ROCK CORRECTION): NA PROJECT NO.: C UN-CORRECTED MAXIMUM DENSITY, PCF 3.6 SOURCE MATERIAL: B-1, ' UN-CORRECTED OPTIMUM WATER CONTENT, 1.7 RAMMER: MECHANICAL X MANUAL SAMPLE DESCRIPTION: SILT WITH SAND ML OVERSIZE ROCK CORRECTION ASSUMED SPECIFIC GRAVITY 2.70 MATERIAL DESIGNATION: Native Subgrade ASSUMED ABSORPTION, % 1 CORRECTED MAXIMUM DENSITY, PCF TEST METHOD: Method A CORRECTED OPTIMUM WATER CONTENT, % na TEST PROCEDURE: ASTM D698 REVIEWED BY: Brian Evans SAMPLE PREPARATION: Moist na Sieve Size SIEVE ANALYSIS % Passing LAB CURVE Poly. (LAB CURVE) 6" " 4" 3" 2" 1-1/2" 1" 3/4" 1/2" 3/8" No. 4 No. 0 No No No No No DRY DENSITY, PCF WATER CONTENT, % ATTERBERG LIMITS LL 26 PI Moisture - Density Relationship Terracon Consultants Inc th Ave. SW 940 ph (406) , fax (406) B-1 Proctor

36 DRY DENSITY, PCF LABORATORY COMPACTION CHARACTERISTICS OF SOIL CLIENT NAME: Peccia and Associates DATE: 7-Sep-18 CURVE NO.: N/A Sampled: PROJECT NAME & LOCATION:Fort Benton Airport TEST RESULTS % OVERSIZED (ROCK CORRECTION): NA PROJECT NO.: C UN-CORRECTED MAXIMUM DENSITY, PCF 1.7 SOURCE MATERIAL: B-17, ' UN-CORRECTED OPTIMUM WATER CONTENT, 21.2 RAMMER: MECHANICAL X MANUAL SAMPLE DESCRIPTION: LEAN CLAY CL OVERSIZE ROCK CORRECTION ASSUMED SPECIFIC GRAVITY 2.70 MATERIAL DESIGNATION: Native Subgrade ASSUMED ABSORPTION, % 1 CORRECTED MAXIMUM DENSITY, PCF TEST METHOD: Method A CORRECTED OPTIMUM WATER CONTENT, % na TEST PROCEDURE: ASTM D698 REVIEWED BY: Brian Evans SAMPLE PREPARATION: Sieve Size SIEVE ANALYSIS % Passing Moist LAB CURVE Poly. (LAB CURVE) na 6" " 4" 3" 2" 1-1/2" 1" 3/4" 1/2" 3/8" No. 4 0 No. 0 No No No No No ATTERBERG LIMITS LL 48 PI Moisture - Density Relationship Terracon Consultants Inc th Ave. SW 940 ph (406) , fax (406) WATER CONTENT, % B-17 Proctor

37 CBR Data Boring #: B-3 Soaked: X Max Dry Density Depth: ' Unsoaked: Opt. Moisture % 13.6 SANDY LEAN CLAY CL / Soil Type: SILTY CLAYEY SAND SC Surcharge: lbs MC% % Of Max % CBR CBR # of Blows Dry Density Obtained Dry Density Swell Load Penetration Curve PSI Blows 2 Blows 6 Blows Penetration (inches) 20 CBR Values CBR Ratio Percent of Max Dry Density 9% Max Dry Density = 8.2 Series3 Series4 Project: Fort Benton Airport California Bearing Ratio ASTM D1883 Terracon Consultants Inc 940 Job No.: Date: C /1/2018

38 CBR Ratio PSI CBR Data Boring #: B-1 Soaked: X Max Dry Density 3.6 Depth: Unsoaked: Opt. Moisture % 1.7 Soil Type: SILT WITH SAND ML Surcharge: lbs. MC% % Of Max % CBR CBR # of Blows Dry Density Obtained Dry Density Swell Load Penetration Curve Blows 2 Blows 6 Blows Penetration (inches) 30 CBR Values Percent of Max Dry Density 9% Max Dry Density = 6.1 Series3 Series4 Project: Fort Benton Airport California Bearing Ratio ASTM D1883 Terracon Consultants Inc 940 Job No.: Date: C /1/2018

39 CBR Ratio PSI CBR Data Boring #: B-17 Soaked: X Max Dry Density 1.7 Depth: Unsoaked: Opt. Moisture % 21.2 Soil Type: LEAN CLAY CL Surcharge: lbs. MC% % Of Max % CBR CBR # of Blows Dry Density Obtained Dry Density Swell Load Penetration Curve Blows 2 Blows 6 Blows Penetration (inches) 6 CBR Values Series Percent of Max Dry Density 9% Max Dry Density = 1.7 Series4 Project: Fort Benton Airport California Bearing Ratio ASTM D1883 Terracon Consultants Inc 940 Job No.: Date: C /1/2018

40 ANALYTICAL SUMMARY REPORT August 30, 2018 Terracon Consultants th Ave S W Work Order: Project Name: B Fort Benton Airport Energy Laboratories Inc Billings MT received the following 4 samples for Terracon Consultants on 8/20/2018 for analysis. Lab ID Client Sample ID Collect Date Receive Date Matrix Test B B-3; ft 07/09/18 0:00 08/20/18 Soil Anions, Water Extractable ph, 1:X Water Extractable DI Water Soil Extract ASA-3 B B-12; ft 07/09/18 0:00 08/20/18 Soil Same As Above B B-1; ft 07/09/18 0:00 08/20/18 Soil Same As Above B B ft 07/09/18 0:00 08/20/18 Soil Same As Above The analyses presented in this report were performed by Energy Laboratories, Inc., 1120 S 27th St., Billings, MT 91, unless otherwise noted. Any exceptions or problems with the analyses are noted in the Laboratory Analytical Report, the QA/QC Summary Report, or the Case Narrative. The results as reported relate only to the item(s) submitted for testing. If you have any questions regarding these test results, please call. Report Approved By: Digitally signed by Sonya Mallett Date: :1:19-06:00 Page 1 of 6