Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Northwest of CR 31 and Cougar Run Lane Larimer County, Colorado

Transcription

1 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Northwest of CR 31 and Cougar Run Lane Larimer County, Colorado July 15, 2016 Terracon Project No Prepared for: Larimer County Colorado Fort Collins, Colorado Prepared by: Terracon Consultants, Inc. Fort Collins, Colorado

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3 TABLE OF CONTENTS EXECUTIVE SUMMARY... i 1.0 INTRODUCTION PROJECT INFORMATION Project Description Site Location and Description SUBSURFACE CONDITIONS Typical Subsurface Profile Laboratory Testing Corrosion Protection (Water-Soluble Sulfates) Groundwater RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION Geotechnical Considerations Expansive Soils Foundation Recommendations Earthwork Site Preparation Demolition Excavation Subgrade Preparation Fill Materials and Placement Compaction Requirements Utility Trench Backfill Grading and Drainage Foundations Spread Footings - Design Recommendations Spread Footings - Construction Considerations Seismic Considerations Floor Systems Floor System - Design Recommendations Floor Systems - Construction Considerations Roadways Roadways Subgrade Preparation and Design GENERAL COMMENTS...13

4 TABLE OF CONTENTS (continued) Appendix A FIELD EXPLORATION Exhibit A-1 Site Location Map Exhibit A-2 Exploration Plan Exhibit A-3 Field Exploration Description Exhibits A-4 to A-16 Boring Logs Appendix B LABORATORY TESTING Exhibit B-1 Laboratory Testing Description Exhibit B-2 Atterberg Limits Test Results Exhibits B-3 and B-4 Grain-size Distribution Test Results Exhibits B-5 and B-6 Swell-consolidation Test Results Exhibit B-7 Water-Soluble Sulfate Test Results Appendix C SUPPORTING DOCUMENTS Exhibit C-1 General Notes Exhibit C-2 Unified Soil Classification System Exhibit C-3 Description of Rock Properties Exhibit C-4 Laboratory Test Significance and Purpose Exhibits C-5 and C-6 Report Terminology

5 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No EXECUTIVE SUMMARY A geotechnical investigation has been performed for the proposed South Shore Carter Lake Campground expansion to be constructed northwest of CR 31 and Cougar Run Lane in Larimer County, Colorado. Thirteen (13) borings, presented as Exhibits A-4 through A-16 and designated as Boring No. 1 through Boring No. 13, were performed to depths of approximately 5 to 15½ feet below existing site grades. This report specifically addresses the recommendations for the proposed campground expansion. Borings performed in these areas are for informational purposes and will be utilized by others. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. However, the following geotechnical considerations were identified and will need to be considered: In general, subsurface conditions encountered in our borings consisted of about 1 to 6 feet of sand with varying amounts of silt, gravel and cobbles over about 3 to 13½ feet of lean clay with varying amounts of sand and gravel. Boulders were encountered during completion of Boring Nos. 1 through 3 at depths of about 5 to 6 feet below existing site grades causing practical auger refusal. Claystone bedrock was encountered below the lean clay in some of the borings at depths ranging from about 7 to 14 feet below existing site grades and extended to maximum depths explored. Hard to very hard bedrock was encountered at varying depths in several of our borings completed at this site. Excavation of the upper soils and portions of the comparatively softer portions of the bedrock can be accomplished with large, conventional excavation equipment. However, excavation into the very hard bedrock will require efforts including ripping, jack hammering and possibly drilling and blasting. Our subsurface exploration also indicates large boulders and bedrock fragments should be expected during excavation on portions of the site. The proposed vault toilets and shower buildings may be supported on shallow foundations bearing on properly prepared on-site soils or on newly placed engineered fill. A slab-on-grade floor system is recommended for the proposed buildings. The amount of movement of foundations and floor slabs will be related to the wetting of underlying supporting soils. Therefore, it is imperative the recommendations discussed in the Grading and Drainage section of this report be followed to reduce potential movement. The 2012 International Building Code, Table IBC seismic site classification for this site is C. Responsive Resourceful Reliable i

6 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Close monitoring of the construction operations discussed herein will be critical in achieving the design subgrade support. We therefore recommend that Terracon be retained to monitor this portion of the work. This summary should be used in conjunction with the entire report for design purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations. Responsive Resourceful Reliable ii

7 GEOTECHNICAL ENGINEERING REPORT South Shore Carter Lake Campground Expansion Northwest of CR 31 and Cougar Run Lane Larimer County, Colorado Terracon Project No July 15, INTRODUCTION This report presents the results of our geotechnical engineering services performed for the proposed South Shore Carter Lake Campground expansion to be located northwest of CR 31 and Cougar Run Lane in Larimer County, Colorado (Exhibit A-1). The purpose of these services is to provide information and geotechnical engineering recommendations relative to: subsurface soil and bedrock conditions foundation design and construction groundwater conditions floor slab design and construction seismic considerations access road construction earthwork grading and drainage excavation considerations Our geotechnical engineering scope of work for this project included the initial site visit, the advancement of thirteen test borings to depths ranging from approximately 5 to 15½ feet below existing site grades, laboratory testing for soil engineering properties and engineering analyses to provide excavation, foundation, floor system and roadway design and construction recommendations. Logs of the borings along with an Exploration Plan (Exhibit A-2) are included in Appendix A. The results of the laboratory testing performed on soil and bedrock samples obtained from the site during the field exploration are included in Appendix B. 2.0 PROJECT INFORMATION 2.1 Project Description Item Description Site layout Refer to the Exploration Plan (Exhibit A-2 in Appendix A) Structures Below-grade areas The proposed construction includes removing and replacing multiple vault toilets on site, a proposed shower building and additional campsites with associated access roads and parking areas. No below-grades areas planned Responsive Resourceful Reliable 1

8 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Traffic loading Item Description Project plans indicate the proposed construction will include new drive lanes and parking areas for the additional campsites. We anticipate gravelly-surfacing will be used for the proposed roadways. 2.2 Site Location and Description Item Location Existing site features Surrounding developments Current ground cover Existing topography Description The project site is located northwest of CR 31 and Cougar Run Lane in Larimer County, Colorado. The site is currently multiple drive-in campground sites with associated gravel-surfaced roads, bathrooms, picnic areas and a sand volleyball court. The site is surrounded by undeveloped land to the east, south and west and the southern edge of Carter Lake borders the north side of the site. The ground is currently covered with native grasses and weeds, some native forested areas and some areas of gravel for access roads around the campsites. The north side of the site has steep embankments and sits higher than the rest of the site. The site then slopes gradually down toward the south and is relatively flat with some rolling hills in the large field on the southern end of site. 3.0 SUBSURFACE CONDITIONS 3.1 Typical Subsurface Profile Specific conditions encountered at each boring location are indicated on the individual boring logs included in Appendix A. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. Based on the results of the borings, subsurface conditions on the project site can be generalized as follows: Material Description Sand with varying amounts of silt, gravel and cobbles Lean clay with varying amounts of sand, gravel and cobbles Boulders Approximate Depth to Bottom of Stratum About 1 to 6 feet below existing side grades. About 5 to 15½ feet below existing site grades. Encountered at varying depths causing practical auger refusal Consistency/Density/Hardness Loose to very dense Medium stiff to hard - Responsive Resourceful Reliable 2

9 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Material Description Claystone bedrock Approximate Depth to Bottom of Stratum To the maximum depth of exploration of about 15 feet. Only found in Boring Nos. 4, 5, 8, 9,, 11, 12 and 13 Consistency/Density/Hardness Hard to very hard 3.2 Laboratory Testing Representative soil samples were selected for swell-consolidation testing and exhibited no movement to 2.2 percent swell when wetted. The sands and bedrock are considered low-swelling to non-expansive. Samples of site soils selected for plasticity testing exhibited low to moderate plasticity with liquid limits ranging from non-plastic to 42 and plasticity indices ranging from nonplastic to 24. Laboratory test results are presented in Appendix B. 3.3 Corrosion Protection (Water-Soluble Sulfates) Results of water-soluble sulfate testing indicate that ASTM Type I or II, V portland cement should be specified for all project concrete on and below grade. Foundation concrete should be designed for low sulfate exposure in accordance with the provisions of the ACI Design Manual, Section 318, Chapter Groundwater The boreholes were observed while drilling and after completion for the presence and level of groundwater. In addition, delayed water levels were also obtained in some borings, using temporary piezometers. The water levels observed in the boreholes are noted on the attached boring logs, and are summarized below Boring Number Depth to groundwater while drilling, ft. Depth to groundwater 3 days after drilling, ft. Elevation of groundwater 3 days after drilling, ft. 1 Not encountered Backfilled after drilling Backfilled after drilling 2 Not encountered Backfilled after drilling Backfilled after drilling 3 Not encountered Backfilled after drilling Backfilled after drilling 4 Not encountered Backfilled after drilling Backfilled after drilling 5 Not encountered Backfilled after drilling Backfilled after drilling 6 (temporary piezometer) Not encountered Not encountered Not encountered 7 Not encountered Backfilled after drilling Backfilled after drilling 8 (temporary piezometer) Not encountered Not encountered Not encountered 9 Not encountered Backfilled after drilling Backfilled after drilling Responsive Resourceful Reliable 3

10 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Boring Number Depth to groundwater while drilling, ft. Depth to groundwater 3 days after drilling, ft. Elevation of groundwater 3 days after drilling, ft. (temporary piezometer) Not encountered Not encountered Backfilled after drilling Backfilled after drilling 12 Not encountered Backfilled after drilling Backfilled after drilling 13 (temporary piezometer) Not encountered Not encountered Not encountered These observations represent groundwater conditions at the time of the field exploration, and may not be indicative of other times or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions, and other factors. Groundwater level fluctuations occur due to seasonal variations in the water levels present in Carter Lake, amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structures may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4.1 Geotechnical Considerations Based on subsurface conditions encountered in the borings, the site appears suitable for the proposed construction from a geotechnical point of view provided certain precautions and design and construction recommendations described in this report are followed. We have identified geotechnical conditions that could impact design and construction of the proposed structures, access roads, and other campground enhancements Expansive Soils Laboratory testing indicates the native clay soils exhibited low to moderate expansive potential at the samples in-situ moisture content. However, it is our opinion these materials will exhibit a higher expansive potential if the clays undergo a significant loss of moisture. This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. However, even if these procedures are followed, some movement and cracking in the structures and flatwork should be anticipated. The severity of cracking and other damage such as uneven floor slabs will probably increase if any modification of the site results in excessive wetting or drying of the expansive clays. Eliminating the risk of movement and distress is generally not feasible, but it may be possible to further reduce the risk of movement if significantly more expensive measures are used during construction. It is imperative the recommendations described in section Grading and Drainage of this report be followed to reduce movement. Responsive Resourceful Reliable 4

11 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Foundation Recommendations The proposed vault toilets and shower building may be supported on a spread footing foundation system bearing on properly prepared on-site soils or newly placed engineered fill. We recommend a slab-on-grade for the interior floor system of the proposed building. Even when bearing on properly prepared soils, movement of the slab-on-grade floor system is possible should the subgrade soils undergo an increase in moisture content. We estimate movement of about 1 inch is possible. If the owner cannot accept the risk of slab movement, a structural floor should be used. 4.2 Earthwork The following presents recommendations for site preparation, excavation, subgrade preparation and placement of engineered fills on the project. All earthwork on the project should be observed and evaluated by Terracon on a full-time basis. The evaluation of earthwork should include observation of over-excavation operations, testing of engineered fills, subgrade preparation, subgrade stabilization, and other geotechnical conditions exposed during the construction of the project Site Preparation Prior to placing any fill, strip and remove existing vegetation and any other deleterious materials from the proposed construction areas. Stripped organic materials should be wasted from the site or used to re-vegetate landscaped areas or exposed slopes after completion of grading operations. Prior to the placement of fills, the site should be graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed structures. If fill is placed in areas of the site where existing slopes are steeper than 5:1 (horizontal:vertical), the area should be benched to reduce the potential for slippage between existing slopes and fills. Benches should be wide enough to accommodate compaction and earth moving equipment, and to allow placement of horizontal lifts of fill Demolition Demolition of the existing vault toilets should include complete removal of all foundation systems, below-grade structural elements, and exterior flat work within the proposed construction area. This should include removal of any utilities to be abandoned along with any loose utility trench backfill or loose backfill found adjacent to existing foundations. All materials derived from the demolition of existing structures should be removed from the site. Consideration could be given to re-using the concrete provided the materials are processed and uniformly blended with the on-site soils. Concrete materials should be processed to a maximum size of 2-inches and blended at a ratio of 30 percent concrete to 70 percent of on-site soils. Responsive Resourceful Reliable 5

12 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Excavation Excavation penetrating the upper strata of soils and portions of the comparatively softer bedrock can be accomplished with large, conventional excavation equipment. Excavation penetrating the bedrock or cemented soils or soil with large cobbles and boulders may require the use of specialized heavy-duty equipment, together with ripping or jack-hammering drilling and blasting to advance the excavation and facilitate rock break-up and removal. Consideration should be given to obtaining a unit price for difficult excavation in the contract documents for the project. The soils to be excavated can vary significantly across the site as their classifications are based solely on the materials encountered in widely-spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. Although evidence of fills or underground facilities such as septic tanks and utilities was not observed during the site reconnaissance, such features could be encountered during construction. If unexpected fills or underground facilities are encountered, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. Any over-excavation that extends below the bottom of foundation elevation for the proposed restroom building should extend laterally beyond all edges of the foundations at least 8 inches per foot of over-excavation depth below the foundation base elevation. The over-excavation should be backfilled to the foundation base elevation in accordance with the recommendations presented in this report. Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or groundwater may be encountered in excavations on the site. It is anticipated that pumping from sumps may be utilized to control water within excavations. The subgrade soil conditions should be evaluated during the excavation process and the stability of the soils determined at that time by the contractors Competent Person. Slope inclinations flatter than the OSHA maximum values may have to be used. The individual contractor(s) should be made responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local, and federal regulations, including current OSHA excavation and trench safety standards. As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral distance from the crest of the slope equal to the slope height. The exposed slope face should be protected against the elements Subgrade Preparation After the vegetative layer has been removed from the construction areas, the top 8 inches of the exposed ground surface should be scarified, moisture conditioned, and recompacted to at least Responsive Resourceful Reliable 6

13 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No percent of the maximum dry unit weight as determined by AASHTO T99 before any new fill or roadway material is placed. If pockets of soft, loose, or otherwise unsuitable materials are encountered at the bottom of the foundation excavations and it is inconvenient to lower the foundations, the proposed foundation elevations may be reestablished by over-excavating the unsuitable soils and backfilling with compacted engineered fill or lean concrete. In addition, large cobbles or boulder-sized materials may be encountered beneath foundation areas. Such conditions could create point loads on the bottom of foundations, increasing the potential for differential foundation movement. If such conditions are encountered in the foundation excavations, the cobbles and/or boulders should be removed and be replaced with engineered fill, conditioned to near optimum moisture content and compacted. After the bottom of the excavation has been compacted, engineered fill can be placed to bring the building pad and roadway subgrade to the desired grade. Engineered fill should be placed in accordance with the recommendations presented in subsequent sections of this report. The stability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unstable conditions develop, workability may be improved by scarifying and drying. Alternatively, over-excavation of wet zones and replacement with granular materials may be used, or crushed gravel and/or rock can be tracked or crowded into the unstable surface soil until a stable working surface is attained. Lightweight excavation equipment may also be used to reduce subgrade pumping Fill Materials and Placement The on-site soils or approved granular and low plasticity cohesive imported materials may be used as fill material. The soil removed from this site that is free of organic or objectionable materials, as defined by a field technician who is qualified in soil material identification and compaction procedures, can be re-used as fill for the building pad and roadway subgrade. The bedrock material excavated from this site may be used as fill materials provided the bedrock is broken down and processed to meet the criteria of fill materials and compaction provided in this report. It Responsive Resourceful Reliable 7

14 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No should be noted that on-site soils and broken down bedrock will require reworking to adjust the moisture content to meet the compaction criteria. Imported soils (if required) should meet the following material property requirements: Gradation Percent finer by weight (ASTM C136) No. 4 Sieve 50-0 No. 200 Sieve -50 Soil Properties Values Liquid Limit Plastic Limit 35 (max.) 6 (max.) Maximum Expansive Potential (%) Non-expansive 1 1. Measured on a sample compacted to approximately 95 percent of the maximum dry unit weight as determined by AASHTO T99 at optimum moisture content. The sample is confined under a 0 psf surcharge and submerged Compaction Requirements Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. Fill lift thickness Item Minimum compaction requirements Moisture content cohesive soil (clay) Moisture content cohesionless soil (sand) Description 9 inches or less in loose thickness when heavy, selfpropelled compaction equipment is used Fill less than 8 feet in thickness: 95 percent of the maximum dry unit weight as determined by AASHTO T99 Fill 8 feet or more in thickness: 98 percent of the maximum dry unit weight as determined by AASHTO T99-1 to +3 % of the optimum moisture content -3 to 3% of the optimum moisture content Responsive Resourceful Reliable 8

15 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Item Description 1. We recommend engineered fill be tested for moisture content and compaction during placement. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved. 2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to be achieved without the fill material pumping when proofrolled. 3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within these materials could result in an increase in the material s expansive potential. Subsequent wetting of these materials could result in undesirable movement Utility Trench Backfill All trench excavations for the proposed shower building or other areas of the site should be made with sufficient working space to permit construction including backfill placement and compaction. All underground piping within or near the proposed structures should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in foundation walls should be oversized to accommodate differential movements. It is imperative that utility trenches be properly backfilled with relatively clean materials. If utility trenches are backfilled with relatively clean granular material, they should be capped with at least 18 inches of cohesive fill to reduce the infiltration and conveyance of surface water through the trench backfill. It is strongly recommended that a representative of Terracon provide full-time observation and compaction testing of trench backfill within building area Grading and Drainage All grades must be adjusted to provide effective drainage away from the proposed building and existing buildings during construction and maintained throughout the life of the proposed project. Infiltration of water into foundation excavations must be prevented during construction. Water permitted to pond near or adjacent to the perimeter of the structures (either during or postconstruction) can result in significantly higher soil movements than those discussed in this report. As a result, any estimations of potential movement described in this report cannot be relied upon if positive drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or subgrade. 4.3 Foundations The proposed vault toilet and shower building can be supported by a shallow, spread footing foundation system. Design recommendations for foundations for the proposed structure and related structural elements are presented in the following paragraphs. Responsive Resourceful Reliable 9

16 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Spread Footings - Design Recommendations Bearing material Description Maximum allowable bearing pressure 1 Lateral earth pressure coefficients 2 Sliding coefficient 2 Moist soil unit weight Minimum embedment depth below finished grade 3 Estimated total movement Estimated differential movement Values Properly prepared on-site soil or new, properly placed engineered fill. On-site lean clay: On-site lean clay: 2,000 psf On-site granular soil: 2,500 psf On-site granular soil: On-site lean clay: On-site granular soil: On-site lean clay: On-site granular soil: Active, Ka = 0.27 Passive, Kp = 3.70 At-rest, Ko = 0.43 Active, Ka = 0.22 Passive, Kp = 4.60 At-rest, Ko = 0.36 µ = 0.56 µ = 0.67 ɣ = 115 pcf ɣ = 125 pcf 36 inches About 1 inch About ½ to ¾ of total movement 1. The recommended maximum allowable bearing pressure assumes any unsuitable fill or soft soils, if encountered, will be over-excavated and replaced with properly compacted engineered fill. The design bearing pressure applies to a dead load plus design live load condition. The design bearing pressure may be increased by one-third when considering total loads that include wind or seismic conditions. 2. The lateral earth pressure coefficients and sliding coefficients are ultimate values and do not include a factor of safety. The foundation designer should include the appropriate factors of safety. 3. For frost protection and to reduce the effects of seasonal moisture variations in the subgrade soils. The minimum embedment depth is for perimeter footings beneath unheated areas and is relative to lowest adjacent finished grade, typically exterior grade. Footings should be proportioned to reduce differential foundation movement. As discussed, total movement resulting from the assumed structural loads is estimated to be on the order of about 1 inch. Additional foundation movements could occur if water from any source infiltrates the Responsive Resourceful Reliable

17 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No foundation soils; therefore, proper drainage should be provided in the final design and during construction and throughout the life of the structure. Failure to maintain the proper drainage as recommended in the Grading and Drainage section of this report will nullify the movement estimates provided above Spread Footings - Construction Considerations Spread footing construction should only be considered if the estimated foundation movement can be tolerated. Subgrade soils beneath footings should be moisture conditioned and compacted as described in the 4.2 Earthwork section of this report. The moisture content and compaction of subgrade soils should be maintained until foundation construction. Footings and foundation walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. Unstable subgrade conditions are anticipated as excavations approach the groundwater surface. Unstable surfaces will need to be stabilized prior to backfilling excavations and/or constructing the building foundation, floor slab and/or project pavements. The use of angular rock, recycled concrete and/or gravel pushed or crowded into the yielding subgrade is considered suitable means of stabilizing the subgrade. The use of geogrid materials in conjunction with gravel could also be considered and could be more cost effective. Unstable subgrade conditions should be observed by Terracon to assess the subgrade and provide suitable alternatives for stabilization. Stabilized areas should be proof-rolled prior to continuing construction to assess the stability of the subgrade. Foundation excavations should be observed by Terracon. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required. 4.4 Seismic Considerations Code Used Site Classification 2012 International Building Code (IBC) 1 C 2 1. In general accordance with the 2012 International Building Code, Table The 2012 International Building Code (IBC) requires a site soil profile determination extending a depth of 0 feet for seismic site classification. The current scope requested does not include the required 0 foot soil profile determination. The borings completed for this project extended to a maximum depth of about 15½ feet and this seismic site class definition considers that similar soil and bedrock conditions exist below the maximum depth of the subsurface exploration. Additional exploration to deeper depths could be performed to confirm the conditions below the current depth of exploration. Alternatively, a geophysical exploration could be utilized in order to attempt to justify a more favorable seismic site class. However, we believe a higher seismic site class for this site is unlikely. Responsive Resourceful Reliable 11

18 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Floor Systems A slab-on-grade may be utilized for the interior floor system for the proposed vault toilets and shower building. If the estimated movement cannot be tolerated, a structurally-supported floor system, supported independent of the subgrade materials, is recommended. Subgrade soils beneath interior and exterior slabs should be scarified to a depth of at least 8 inches, moisture conditioned and compacted. The moisture content and compaction of subgrade soils should be maintained until slab construction Floor System - Design Recommendations Even when bearing on properly prepared soils, movement of the slab-on-grade floor system is possible should the subgrade soils undergo an increase in moisture content. We estimate movement of about 1 inch is possible. For structural design of concrete slabs-on-grade subjected to point loadings, a modulus of subgrade reaction of 0 pounds per cubic inch (pci) may be used for floors supported on recompacted existing soils at the site. A modulus of 200 pci may be used for floors supported on at least 1 foot of non-expansive, imported granular fill. Additional floor slab design and construction recommendations are as follows: Positive separations and/or isolation joints should be provided between slabs and all foundations, columns, or utility lines to allow independent movement. Control joints should be saw-cut in slabs in accordance with ACI Design Manual, Section 302.1R (tooled control joints are not recommended) to control the location and extent of cracking. Interior utility trench backfill placed beneath slabs should be compacted in accordance with the recommendations presented in the 4.2 Earthwork section of this report. Floor slabs should not be constructed on frozen subgrade. The use of a vapor retarder should be considered beneath concrete slabs that will be covered with wood, tile, carpet or other moisture sensitive or impervious floor coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 for procedures and cautions regarding the use and placement of a vapor retarder. Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1R are recommended. Responsive Resourceful Reliable 12

19 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Floor Systems - Construction Considerations Movements of slabs-on-grade using the recommendations discussed in previous sections of this report will likely be reduced and tend to be more uniform. The estimates discussed above assume that the other recommendations in this report are followed. Additional movement could occur should the subsurface soils become wetted to significant depths, which could result in potential excessive movement causing uneven floor slabs and severe cracking. This could be due to over watering of landscaping, poor drainage, improperly functioning drain systems, and/or broken utility lines. Therefore, it is imperative that the recommendations presented in this report be followed. 4.6 Roadways Roadways Subgrade Preparation and Design On most project sites, the site grading is accomplished relatively early in the construction phase. Fills are typically placed and compacted in a uniform manner. However as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, or rainfall/snow melt. As a result, the roadway subgrade may not be suitable for construction and corrective action will be required. The subgrade should be carefully evaluated at the time of roadway construction for signs of disturbance or instability. We recommend the roadway subgrades be thoroughly proofrolled with a loaded tandem-axle dump truck prior to final grading and placement of gravel-surfacing materials. All roadway areas should be moisture conditioned and properly compacted to the recommendations in this report immediately prior to surfacing. 5.0 GENERAL COMMENTS Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide observation and testing services during grading, excavation, foundation construction and other earth-related construction phases of the project. The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. The scope of services for this project does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, and bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. Responsive Resourceful Reliable 13

20 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project as described in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. Responsive Resourceful Reliable 14

21 APPENDIX A FIELD EXPLORATION

22 SITE Project Manager: EDB Drawn by: MGH Checked by: EDB Approved by: EDB TOPOGRAPHIC MAP IMAGE COURTESY OF THE U.S. GEOLOGICAL SURVEY QUADRANGLES INCLUDE: CARTER LAKE RESERVOIR, CO (1971). SITE LOCATION MAP Project No. Exhibit Scale: 1 =2,000 South Shore Carter Lake Campground File Name: 1901 Sharp Point Dr Ste C Expansion (LC #5022) A-1 Date: Fort Collins, CO /7/2016 Northwest of CR 31 and Cougar Run Lane, Larimer County, CO

23 DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES AERIAL PHOTOGRAPHY PROVIDED BY MICROSOFT BING MAPS Project Manager: EDB Drawn by: MGH Checked by: EDB Approved by: EDB Project No Scale: AS SHOWN File Name: Date: 7/7/ Sharp Point Dr Ste C Fort Collins, CO EXPLORATION PLAN South Shore Carter Lake Campground Expansion (LC #5022) Northwest of CR 31 and Cougar Run Lane, Larimer County, CO Exhibit A-2

24 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Field Exploration Description The locations of borings were selected by the client based upon the proposed development shown on the provided site plan. The borings were located in the field by measuring from existing site features and using a hand-held GPS unit. The ground surface elevation was estimated using topographic maps of the area. The borings were drilled with a CME-550 buggy-mounted rotary drill rig with solid-stem augers. During the drilling operations, lithologic logs of the borings were recorded by the field engineer. Disturbed samples were obtained at selected intervals utilizing a 2-inch outside diameter splitspoon sampler and a 3-inch outside diameter ring-barrel sampler. Disturbed bulk samples were obtained from auger cuttings. Penetration resistance values were recorded in a manner similar to the standard penetration test (SPT). This test consists of driving the sampler into the ground with a 140-pound hammer free-falling through a distance of 30 inches. The number of blows required to advance the ring-barrel sampler 12 inches (18 inches for standard split-spoon samplers, final 12 inches are recorded) or the interval indicated, is recorded as a standard penetration resistance value (N-value). The blow count values are indicated on the boring logs at the respective sample depths. Ring-barrel sample blow counts are not considered N-values. A CME automatic SPT hammer was used to advance the samplers in the borings performed on this site. A greater efficiency is typically achieved with the automatic hammer compared to the conventional safety hammer operated with a cathead and rope. Published correlations between the SPT values and soil properties are based on the lower efficiency cathead and rope method. This higher efficiency affects the standard penetration resistance blow count value by increasing the penetration per hammer blow over what would be obtained using the cathead and rope method. The effect of the automatic hammer's efficiency has been considered in the interpretation and analysis of the subsurface information for this report. The standard penetration test provides a reasonable indication of the in-place density of sandy type materials, but only provides an indication of the relative stiffness of cohesive materials since the blow count in these soils may be affected by the moisture content of the soil. In addition, considerable care should be exercised in interpreting the N-values in gravelly soils, particularly where the size of the gravel particle exceeds the inside diameter of the sampler. Groundwater measurements were obtained in the borings at the time of site exploration, temporary piezometers were installed in four of the borings across the site, borings that did not have a temporary piezometer installed were backfilled with auger cutters and sand (if needed) immediately after completion of drilling. Groundwater levels were checked in the borings with piezometers several days after drilling. After subsequent groundwater measurements were obtained, the temporary piezometers were removed and the borings were backfilled with auger cuttings and sand (if needed). Some settlement of the backfill may occur and should be repaired as soon as possible. Responsive Resourceful Reliable Exhibit A-3

25 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. 1 Surface Elev.: 5786 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SILTY SAND (SM), with varying amounts of gravel, cobbles and some boulders, brown to orange-brown, dense to very dense Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES /5" N=59/11" Auger refusal due to apparent boulders at 5 feet NP 27 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/16 Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-4

26 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. 2 Surface Elev.: 5784 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SILTY SAND, with gravel, cobbles and some boulders, dark brown to brown, dense Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES 2.0 POORLY GRADED GRAVEL WITH SILT AND SAND, with varying amounts of cobbles and boulders, orange-brown to brown, dense N= Auger refusal due to apparent boulders at 6 feet 5778 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/16 Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-5

27 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. 3 Surface Elev.: 5783 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SILTY SAND, with gravel, cobbles and some boulders, dark brown to brown, dense Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES 2.0 SANDY LEAN CLAY, with varying amounts of gravel, cobbles and some boulders, orange-brown, stiff N= Auger refusal due to apparent boulders at 5 feet THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/16 Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-6

28 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH 0.5 VEGETATIVE LAYER - 6 inches POORLY GRADED GRAVEL WITH SILT AND SAND (GP-GM), dark brown to brown, loose to medium dense BORING LOG NO. 4 Surface Elev.: 5773 (Ft.) ELEVATION (Ft.) Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= LEAN CLAY WITH SAND, with gravel, reddish-brown to brown, stiff NP 12 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ SEDIMENTARY BEDROCK - CLAYSTONE, reddish-brown, very hard Boring Terminated at 14.3 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO N=33 50/3" N=50/3" Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-7

29 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. 5 Surface Elev.: 5788 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SANDY LEAN CLAY, with gravel, dark brown to brown, stiff Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= N= 0.0/00 16 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ LEAN CLAY WITH SAND, with gravel, orange-brown to reddish-brown, stiff to very hard SEDIMENTARY BEDROCK - CLAYSTONE, reddish-brown, very hard Boring Terminated at 14.9 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO /5" N=72/11" Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-8

30 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH 0.5 VEGETATIVE LAYER - 6 inches CLAYEY SAND (SC), with gravel, dark brown to brown, medium dense BORING LOG NO. 6 Surface Elev.: 5776 (Ft.) ELEVATION (Ft.) Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= / THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ LEAN CLAY WITH SAND, with gravel, reddish-brown to orange-brown, very stiff Boring Terminated at 15.5 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS Temporary piezometer installed No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO N= N=14 Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-9

31 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH 0.5 VEGETATIVE LAYER - 6 inches SILTY SAND, with gravel, dark brown to brown, dense BORING LOG NO. 7 Surface Elev.: 5775 (Ft.) ELEVATION (Ft.) Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES SILTY CLAYEY SAND WITH GRAVEL (SM), white to pink, very hard, dense LEAN CLAY WITH SAND, with varying amounts of gravel, cobbles and boulders, reddish-brown to orange-brown, stiff Sample taken from auger cuttings due to caving of sands, gravel and cobbles Sample taken from auger cuttings due to caving of sands, gravel and cobbles 1 3 NP 38 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ Auger refusal due to apparent boulders at 13 feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed 5762 See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO Sample taken from auger cuttings due to caving of sands, gravel and cobbles Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-

32 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH 0.5 VEGETATIVE LAYER - 6 inches 1.0 SILTY SAND, with gravel, dark brown to brown SANDY LEAN CLAY, with gravel, orange-brown to reddish-brown, hard BORING LOG NO. 8 Surface Elev.: 5801 (Ft.) ELEVATION (Ft.) Larimer County Colorado CLIENT: Fort Collins, Colorado 5800 DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES N=36 12 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ SEDIMENTARY BEDROCK - CLAYSTONE, orange-brown to reddish-brown, very hard Boring Terminated at 14.3 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS Temporary piezometer installed No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO 50/3" N=50/3" 50/4" N=50/4" Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-11

33 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: DEPTH 0.5 VEGETATIVE LAYER - 6 inches SANDY LEAN CLAY, with gravel, dark brown to brown 1.5 LEAN CLAY WITH SAND (CL), with gravel, orange-brown to reddish-brown, hard BORING LOG NO. 9 Surface Elev.: 5805 (Ft.) ELEVATION (Ft.) Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS N=45 SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) 7 DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ SEDIMENTARY BEDROCK - CLAYSTONE, reddish-brown, very hard Boring Terminated at 15.5 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO N= N=82 Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-12

34 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. Surface Elev.: 5812 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SANDY LEAN CLAY (CL), with gravel, dark brown to brown, stiff Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= N=8 16 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ LEAN CLAY WITH SAND, with gravel, orange-brown to reddish-brown, very stiff SEDIMENTARY BEDROCK - CLAYSTONE, reddish-brown, very hard Boring Terminated at 14.4 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS Temporary piezometer installed 6' in temporary piezometer on 7/1/ See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO /5" N=50/5" Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-13

35 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. 11 Surface Elev.: 5807 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SANDY LEAN CLAY, with gravel, dark brown to brown, stiff to very stiff Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ LEAN CLAY WITH SAND, with gravel, orange-brown to reddish-brown, stiff SEDIMENTARY BEDROCK - CLAYSTONE, orange-brown to reddish-brown, very hard Boring Terminated at 14.2 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO N=21 50/6" N=50/6" 50/2" N=50/2" Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-14

36 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. 12 Surface Elev.: 5805 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SANDY LEAN CLAY (CL), with gravel, dark brown to brown, very stiff Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES N= N=19 THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ LEAN CLAY WITH SAND, with gravel, orange-brown to reddish-brown, very stiff SEDIMENTARY BEDROCK - CLAYSTONE, reddish-brown, very hard Boring Terminated at 14.4 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO /5" N=50/5" Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-15

37 PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado GRAPHIC LOG LOCATION See Exhibit A-2 Latitude: Longitude: BORING LOG NO. 13 Surface Elev.: 5790 (Ft.) DEPTH ELEVATION (Ft.) 0.5 VEGETATIVE LAYER - 6 inches SILTY SAND, with gravel, dark brown to brown, medium dense Larimer County Colorado CLIENT: Fort Collins, Colorado DEPTH (Ft.) WATER LEVEL OBSERVATIONS SAMPLE TYPE FIELD TEST RESULTS SWELL - CONSOL / LOAD (%/psf) WATER CONTENT (%) DRY UNIT WEIGHT (pcf) Page 1 of 1 ATTERBERG LIMITS LL-PL-PI PERCENT FINES 3.5 SANDY LEAN CLAY (CL), with gravel, orange-brown to reddish-brown, very stiff N= THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL GPJ TERRACON2015.GDT 7/15/ SEDIMENTARY BEDROCK - CLAYSTONE, reddish-brown, hard to very hard Boring Terminated at 14.9 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Advancement Method: 4-inch solid-stem auger Abandonment Method: Boring backfilled with soil cuttings upon completion. WATER LEVEL OBSERVATIONS Temporary piezometer installed No free water observed See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and abbreviations Sharp Point Dr Ste C Fort Collins, CO N= /5" N=75/11" Hammer Type: Automatic Notes: Boring Started: 6/28/2016 Drill Rig: CME-550 Project No.: Boring Completed: 6/28/2016 Driller: Terracon Consulting, Inc. Exhibit: A-16

38 APPENDIX B LABORATORY TESTING

39 Geotechnical Engineering Report South Shore Carter Lake Campground Expansion Larimer County, Colorado July 15, 2016 Terracon Project No Laboratory Testing Description The soil and bedrock samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer. At that time, the field descriptions were reviewed and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Laboratory tests were conducted on selected soil and bedrock samples. The results of these tests are presented on the boring logs and in this appendix. The test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. The laboratory tests were performed in general accordance with applicable locally accepted standards. Soil samples were classified in general accordance with the Unified Soil Classification System described in Appendix C. Rock samples were visually classified in general accordance with the description of rock properties presented in Appendix C. Procedural standards noted in this report are for reference to methodology in general. In some cases variations to methods are applied as a result of local practice or professional judgment. Water content Plasticity index Grain-size distribution Dry density Consolidation/swell Water-soluble sulfate content Responsive Resourceful Reliable Exhibit B-1

40 ATTERBERG LIMITS RESULTS ASTM D LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS GPJ TERRACON2015.GDT 7/7/16 P L A S T I C I T Y I N D E X CL or OL CH or OH MH or OH CL-ML ML or OL Boring ID Depth LL PL PI Fines USCS Description PROJECT: South Shore Carter Lake Campground Expansion NP NP SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado NP NP NP NP NP "U" Line "A" Line LIQUID LIMIT SM GP-GM CL SC SM CL CL CL CL 1901 Sharp Point Dr Ste C Fort Collins, CO SILTY SAND POORLY GRADED GRAVEL with SILT and SAND SANDY LEAN CLAY CLAYEY SAND SILTY SAND with GRAVEL LEAN CLAY with SAND SANDY LEAN CLAY SANDY LEAN CLAY SANDY LEAN CLAY PROJECT NUMBER: CLIENT: Larimer County Colorado Fort Collins, Colorado EXHIBIT: B-2

41 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: USCS GPJ ATTERBERG ISSUE.GPJ 7/7/16 PERCENT FINER BY WEIGHT Boring ID Boring ID COBBLES 0 Depth Depth coarse PROJECT: South Shore Carter Lake Campground Expansion 4 GRAVEL D fine SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado 4 coarse GRAIN SIZE IN MILLIMETERS SAND USCS Classification D 60 medium SILTY SAND (SM) fine 0.1 POORLY GRADED GRAVEL with SILT and SAND (GP-GM) SANDY LEAN CLAY (CL) CLAYEY SAND (SC) SILTY SAND with GRAVEL (SM) D 30 D 1901 Sharp Point Dr Ste C Fort Collins, CO %Gravel NP NP SILT OR CLAY LL PL PI NP NP %Sand NP NP NP PROJECT NUMBER: CLIENT: Larimer County Colorado Fort Collins, Colorado EXHIBIT: B-3 Cc 0.09 %Fines Cu

42 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: USCS GPJ ATTERBERG ISSUE.GPJ 7/7/16 PERCENT FINER BY WEIGHT Boring ID Boring ID COBBLES 0 Depth Depth coarse PROJECT: South Shore Carter Lake Campground Expansion GRAVEL D fine SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado coarse GRAIN SIZE IN MILLIMETERS SAND USCS Classification D 60 medium LEAN CLAY with SAND (CL) SANDY LEAN CLAY (CL) SANDY LEAN CLAY (CL) SANDY LEAN CLAY (CL) fine D 30 D 1901 Sharp Point Dr Ste C Fort Collins, CO 0.1 %Gravel SILT OR CLAY LL PL PI %Sand PROJECT NUMBER: CLIENT: Larimer County Colorado Fort Collins, Colorado EXHIBIT: B-4 9 Cc %Fines Cu

43 SWELL CONSOLIDATION TEST ASTM D AXIAL STRAIN, % 2 LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS GPJ TERRACON2012.GDT 7/7/ ,000,000 PRESSURE, psf Specimen Identification Classification, pcf ft 115 NOTES: The sample exhibited no movement upon wetting under an applied pressure of 1,000 psf. PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado 1901 Sharp Point Dr Ste C Fort Collins, CO PROJECT NUMBER: CLIENT: Larimer County Colorado Fort Collins, Colorado EXHIBIT: B-5 WC, %

44 SWELL CONSOLIDATION TEST ASTM D AXIAL STRAIN, % 2 LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS GPJ TERRACON2012.GDT 7/7/ ,000,000 PRESSURE, psf Specimen Identification Classification, pcf WC, % ft CLAYEY SAND(SC) 112 NOTES: The sample exhibited 2.2 percent sweel upon wetting under an applied pressure of 500 psf. PROJECT: South Shore Carter Lake Campground Expansion SITE: Northeast of CR 31 and Cougar Run Lane Larimer County, Colorado 1901 Sharp Point Dr Ste C Fort Collins, CO PROJECT NUMBER: CLIENT: Larimer County Colorado Fort Collins, Colorado EXHIBIT: B-6

45 Analytical Results TASK NO: Report To: Eric D. Bernhardt Company: Terracon, Inc. - Fort Collins 1901 Sharp Point Drive Suite C Fort Collins CO Bill To: Accounts Payable Company: Terracon, Inc. - A/P W. 6th St Suite 300 Olathe KS Task No.: Client PO: Client Project: South Shore Carter Lake Date Received: 7/8/16 Date Reported: 7/15/16 Matrix: Soil - Geotech Customer Sample ID Lab Number: Test Sulfate - Water Soluble Result % Method AASHTO T290-91/ ASTM D4327 Customer Sample ID Lab Number: Test Sulfate - Water Soluble Result % Method AASHTO T290-91/ ASTM D4327 Customer Sample ID Lab Number: Test Sulfate - Water Soluble Result % Method AASHTO T290-91/ ASTM D4327 Abbreviations/ References: AASHTO - American Association of State Highway and Transportation Officials. ASTM - American Society for Testing and Materials. ASA - American Society of Agronomy. DIPRA - Ductile Iron Pipe Research Association Handbook of Ductile Iron Pipe. DATA APPROVED FOR RELEASE BY 240 South Main Street / Brighton, CO / Mailing Address: P.O. Box 507 / Brighton, CO / Fax: