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TOWNZEN & ASSOCIATES Plans Reviewed The plans submitted have been reviewed in accordance with local state applicable standards. This review does not relieve the applicant of the responsibility of compliance with the applicable codes. Reviewed with no comments. 4 03/14/2024 20221909.001A/SEA21R133024 Page 1 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com EXECUTIVE SUMMARY ____________________________________________________________________________ This report presents the results of Kleinfelder’s geotechnical study for a proposed Costco Wholesale (Costco) Warehouse (CW20-0312) to be located near the northwest corner of I-5 and Pioneer Street (SR-501) in Ridgefield, Washington as shown in the Vicinity Map, Figure 1. The purpose of this study was to evaluate soil and groundwater conditions beneath the site in order to provide geotechnical recommendations for project design and construction. We based our study on Costco Wholesale Development Requirements (CWDRs), Version 2020, dated December 18, 2020. Kleinfelder understands Costco plans to develop this 19.6-acre site, currently used as farmland, as a new Costco Wholesale warehouse, including a fuel facility, and new paved parking areas. Per the preliminary site plan P11-05 provided to Kleinfelder by MG2 dated July 26, 2021, the proposed warehouse is designed to be a single-story, steel-framed structure approximately 30 feet in height and encompassing approximately 150,000 square feet to be located in the northwest corner of the site. The proposed fuel facility is expected to contain three 30,000-gallon underground storage tanks (UST), a fuel additive UST, five fueling islands, a metal canopy, and a pre-manufactured metal kiosk. The building surroundings will consist mainly of surface parking zones with some landscape areas. Kleinfelder conducted its field exploration program in accordance with the scope outlined in Kleinfelder Proposal No. MPCOSTCO.002C/SEA21P128684, dated August 3, 2021. A Kleinfelder representative was on site while the field exploration was performed, between August 17 and August 27, 2021, and observed drilling operations consisting of 32 Hollow Stem Auger (HSA) borings and the excavation of 9 test pits. 8 CPT soundings were also performed as part of this exploration. The HSA borings, test pits and CPT soundings were located within the proposed warehouse and gas station footprints as well as throughout the proposed paved parking areas as shown in the Site Exploration Map, Figure 2. Subsurface conditions encountered at the site generally consist of four soil layers: 1. Topsoil: An upper layer of topsoil was observed from surface elevations to depths ranging from approximately 6 to 12 inches below existing ground surface (bgs) across the site. This layer generally consisted of dark brown silt with sand. Standard Penetration Test (SPT) blow counts indicated a medium stiff material. 20221909.001A/SEA21R133024 Page 2 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 2. Lean Clay with Sand: Beneath the surface organic soils a layer of Lean Clay with Sand was identified at depths ranging between 12 inches to 30feet bgs. This layer was generally grayish brown to reddish brown in color with plasticity indexes ranging from 4 to 12. SPT blow counts indicated a soft material in borings KB-3, KB-4 and KB-13 near the loading dock. The soils were relatively stiff under the other portions of the warehouse. 3. Sandy Clay: Beneath the soft lean clay with sand layer a stiffer layer of sandy clay was encountered. These soils were gray to reddish brown in color, with plasticity index between 18 and 24 feet, transitioning into underlying sandy silt layers at approximately 40 feet bgs. 4. Sandy Silt: Light brown to yellowish gray stiff to very stiff sandy silt layer was found below 40 feet. All warehouse borings were terminated in this stiff to very stiff layer. Site explorations were completed during the summer following several drier-than-average months. Subsurface conditions were significantly drier than those described in the Columbia West geotechnical report, for which explorations were completed in the wet season (January 2021). The Kleinfelder test pit explorations did not encounter seepage; however, the test pits excavated by Columbia West encountered seepage between depths of 1½ and 5 feet bgs. Kleinfelder borings encountered wet soil samples and wet SPT samplers between depths of about 10 to 20 feet. Soil moisture contents were generally highest between depths of about 10 to 30 feet and soils became slightly drier at depth. Two monitoring wells were installed during the exploration program (in KB-15 and 31). On September 12, 2021, groundwater was measured at a depth of 15 feet in KB-15 and no water was observed in KB-31. Pore pressure readings indicated on the CPT logs indicate occasional zones of saturated soil generally between depths of 15 and 35 feet. Based on our observations and review of the data discussed above, we infer that shallow groundwater at the site is generally limited to perched layers, and that perched groundwater levels may fluctuate by as much as 10 to 15 feet seasonally. While we did not identify the depth to a regional, permanent groundwater table, we will read the monitoring wells in winter of 2022. The anticipated finished floor elevation (FFE) is approximately 271 to 272 feet. This will involve placing fills between 1 foot and 16 feet on the existing grades in the footprint of the warehouse and cuts of up to 5 feet in the pavement areas. Additionally, Kleinfelder anticipates the underground storage tank (UST) installation for the fuel facility will require an excavation of approximately 18 feet below existing ground surface and loading dock excavations will extend approximately 4 feet below the existing site grade. 20221909.001A/SEA21R133024 Page 3 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com Based on the results of the field exploration, laboratory testing, and geotechnical analyses, it is Kleinfelder’s professional opinion that the proposed project is geotechnically feasible, provided the recommendations presented in this geotechnical report are incorporated into the project design and construction. Kleinfelder has identified the following key geotechnical considerations as part of this study: The proposed Costco warehouse and fuel facility will bear on the native silty, clayey soils, or structural fill placed on these soils, and may be supported on a conventional shallow foundation system designed for a net allowable bearing pressure of 2,000 psf. Pursuant to 2020 Costco Wholesale standard design practices, and based on the geotechnical characteristics of the site, the proposed warehouse can be constructed with an unreinforced concrete slab-on-grade floor. Site grading will require fills up to about 15 feet and cuts up to about 5 feet. Loads imposed by new structural fill will result in the maximum long-term settlement in the northwest portion of the warehouse of about 7 inches. Footing and slab loads will indue additional settlement in excess of 1 inch. Therefore, we recommend use of a temporary surcharge to reduce long- term settlement of the warehouse footings and floor slab. We recommend a minimum surcharge thickness of 4 feet above the warehouse FFE and a surcharge duration of 90 days should be assumed for the project schedule. Refer to Section 4.2 for additional discussion. To maximize usable site area 2.5H:1V fill slopes are being considered in a portion of the site. Landscape plans should include measures to keep the topsoil from washing away until vegetation is well established. The site corresponds to Seismic Site Class D of the 2018 IBC. Seismic hazards at the site are considered to be low. Light-duty pavements should consist of at least 3 inches of asphalt over 6 inches of crushed rock base. Heavy-duty pavements should consist of at least 4 inches of asphalt over 8 inches of crushed rock base. Performance Grade (PG) Binder 58-16 is appropriate for the project. 20221909.001A/SEA21R133024 Page 4 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com Based on the Sandy silts and sandy lean clay soil types Kleinfelder anticipates that some screening, reworking, and moisture conditioning of the on-site soils will be required for grading and their re-use. The findings, conclusions, and recommendations presented in this executive summary should not be relied upon without consulting the associated geotechnical report for more information. The conclusions and recommendations presented in this report are subject to the limitations presented in Section 8. 20221909.001A/SEA21R133024 Page 5 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 1 INTRODUCTION ____________________________________________________________________________ 1.1 GENERAL This report presents the results of Kleinfelder’s geotechnical engineering study for the proposed Costco Wholesale (Costco) warehouse (CW20-0312). The proposed site is located near the intersection of I-5 and Pioneer Street (SR-501) in Ridgefield, Washington, as shown in the Vicinity Map, Figure 1. The purpose of this geotechnical study was to evaluate soil and groundwater conditions at the site and provide geotechnical recommendations for design and construction of this project. We based our study on the 2020 Costco Wholesale Development Requirements (CWDRs). Services were performed in general accordance with the Kleinfelder proposal dated August 3, 2021. 1.2 PROJECT DESCRIPTION The site and grading plans have not been finalized at this time. We anticipate that the warehouse will be approximately 150,000 square feet (sf) in size and consist of a single-story, steel-framed structure approximately 30 feet in height with a concrete slab on grade floor. The proposed fuel facility will contain three 30,000-gallon underground storage tanks and fuel additive tanks, fueling stations, and a pre-manufactured metal canopy. The warehouse surroundings will consist mainly of paved parking areas and drive lanes, with a loading dock and some landscaped areas. Proposed parking and drive lane areas will likely be paved with asphalt pavement. Based on the preliminary grading plans provided, the anticipated finished floor elevation (FFE) is about Elevation 271 to 272 feet. Rough site grading, which we understand will be performed by the developer, will require fills up to about 15 feet and cuts up to about 5 feet. In general, fills will be required in the western, northwestern, and northern one-half to two-thirds of the site, with the thickest fills at the northwest corner and north edge of the site. Cuts will be required in the southeast portion of the site. The northwest corner of the warehouse will require a fill of about 15 feet and the southeast corner of the warehouse will require a cut of about 1 foot, with the cut to fill thicknesses generally increasing uniformly across the warehouse footprint. We understand the developer may construct a retaining wall along the northern-most portion of the west side of the site. This wall should conform to Costco Wholesale Development Requirements, refer to Section 4.5 for additional discussion. 20221909.001A/SEA21R133024 Page 6 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com Maximum column loads for the warehouse are anticipated to be on the order of 160 kips, wall loads are anticipated to be approximately 4.5 kips per lineal foot, canopy column loads are anticipated to be approximately 50 kips, and the total slab load (dead plus live loads) is anticipated to be approximately 500 pounds per square foot (psf). Based on experience with fuel facilities in similar soil conditions, the canopy design will likely be governed by overturning moments from wind loading. Typical column dead loads are anticipated to be approximately 4 kips and typical live loads are anticipated to be approximately 16 kips, which is expected to result in bearing pressures of less than 500 psf if shallow spread footings are utilized. Based on experience with underground storage tank (UST) installation, the fuel facility will likely require an excavation of approximately 18 feet below finished grade and loading dock excavations will likely extend approximately 4 feet below finished grade. Both of these areas will receive fill ranging from about 2 to 10 feet in thickness. Kleinfelder’s understanding of the project is based on project team calls and emails with MG2 and the previously referenced preliminary site plan provided by MG2. If any changes are made to the site grade or building location or construction, Kleinfelder should be informed so that recommendations in this report can be modified, as appropriate. 1.3 SCOPE OF SERVICES The scope of this geotechnical study was completed in general accordance with the Kleinfelder Proposal dated August 3, 2021, and consisted of a site reconnaissance visit, a subsurface field exploration, geotechnical engineering analysis, and this report. The following paragraphs present a description of these services. 1.3.1 Task 1: Literature Review and Exploration Coordination Prior to performing site reconnaissance, Kleinfelder reviewed readily available data, including boring logs and CPT’s prepared by others, reports prepared by others, and geologic maps for the project area. Prior to accessing the site, an exploration plan that included the approximate depths and locations of the planned soil borings and test pits, and a schedule, were provided to Costco. The local One-Call utility locate service was notified approximately 3 business days before explorations began. 20221909.001A/SEA21R133024 Page 7 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 1.3.2 Task 2: Field Exploration The site exploration program was completed in August 2021 and consisted of drilling 32 borings, advancing 8 CPTs, and excavating 9 test pits within the proposed warehouse, fuel facility, and parking lot areas. Borings extended to depths of approximately 11.5 to 51.5 feet bgs, CPT’s were advanced to depths of approximately 60 to 87 feet bgs, and test pits were excavated to depths of approximately 9 to 10 feet bgs. The field explorations were located in the following areas of the original SP-17 site plan: 13 borings, 8 CPT’s and 6 test pits were completed within the proposed warehouse footprint; 15 borings and 2 test pits were completed within the pavement areas; and, 4 borings and 1 test pit were completed within the fuel facility area. The site exploration program was conducted under full-time observation of a Kleinfelder engineer or geologist. The Site Exploration Map, Figure 2, shows locations of Kleinfelder’s explorations. Exploration locations were staked in the field using a hand-held GPS and should be considered approximate. Appendix A presents additional information on the site exploration program and exploration logs. 1.3.3 Task 3: Laboratory Testing Laboratory tests were performed on selected soil samples in accordance with ASTM standards to evaluate index and engineering properties of the site soils. Tests included natural moisture content, proctors, unit weight, organic content, California Bearing Ratio, sieve analysis, Atterberg limits and consolidation. Laboratory test results are presented on the summary boring and test pit logs in Appendix A and/or on laboratory test reports included in Appendix B. AMTEST Laboratories performed resistivity, pH, chlorides, sulphides, redox and sulfates testing soil samples to support corrosivity evaluations. Analytical test results are summarized in Table 6 and detailed test reports are provided in Appendix D. 20221909.001A/SEA21R133024 Page 8 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 1.3.4 Task 4: Geotechnical Analyses Kleinfelder analyzed field and laboratory data in conjunction with the estimated finished grades and anticipated structural loads, as well as the warehouse and fuel facility layout, to provide geotechnical recommendations for project design and construction. Kleinfelder evaluated feasible foundation systems, concrete slab support, pavement design, earthwork, and seismic design considerations. The design recommendations in this report conform with the requirements of the CWDR’s and are summarized in Task 5. 1.3.5 Task 5: Report Preparation This report summarizes the services performed and the data acquired. This report also presents the findings, conclusions, and geotechnical recommendations for design and construction of the proposed improvements. This report includes the following items: Geotechnical Checklist; Executive Summary; Description of the proposed project; Site Vicinity Map, Figure 1; Discussion of general site conditions; Site Exploration Map, Figure 2; Discussion of regional and local geology; Description of the site geologic setting and the impact of the geologic site conditions; and a description of the geologic hazards to construction and means to mitigate such hazards; Summary of subsurface soil conditions; Summary of groundwater conditions; Boring and Test Pit logs (Appendix A); Cone Penetration Test logs (Appendix C); 20221909.001A/SEA21R133024 Page 9 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com Seismic Site Classification in accordance with the IBC; Recommendations for seismic design parameters in accordance with Building Code (2015 International Building Code); Results of geotechnical laboratory testing (Appendix B); Results of analytical laboratory testing (Appendix D); Preliminary evaluation of the corrosion potential of the on-site soils. Recommendations for foundation design, allowable bearing pressures and compatibility constraints under various loading conditions; Anticipated total and differential static settlements; Recommendations for site preparation, earthwork, temporary slope inclinations, fill placement, and compaction specifications, including the excavation characteristics of subsurface soil deposits and formational materials; Recommendations for support of floor slabs and slabs-on-grade; Recommendations for flexible and rigid pavement structural sections for light- and heavy-duty pavement; and, Recommendations for design of loading dock retaining structures, including active and at-rest lateral earth pressures, passive and frictional resistance, and applicable surcharge loads. 20221909.001A/SEA21R133024 Page 10 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 2 SITE CONDITIONS ____________________________________________________________________________ 2.1 SITE DESCRIPTION The proposed Costco site is located near the northwest corner of I-5 and Pioneer Street (SR-501) as shown in the Vicinity Map, Figure 1. The approximate 19.6-acre site is currently undeveloped and is used to cultivate feed hay. Surface topography grades from a low Elevation of about 251 feet at the northwest corner of the site to a high Elevation of about 278 feet towards the east- southeast portion of the site. Topographic variation is relatively gentle and rolling, with steepest slopes along the north edge of the site. The site is bounded to the north and west by undeveloped forested land and to the south and west by additional cultivated vacant land. The site is currently access by unpaved roads extending north from Pioneer Street. 20221909.001A/SEA21R133024 Page 11 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 3 GEOLOGY 3.1 GEOLOGIC SETTING According to the 1:24,000 scale geologic map from Washington Geologic Information portal, soils in project area are comprised of Pleistocene outburst flood deposits and include unconsolidated clay, silt, and fine to medium sand; grain size decreases gradually to north. The area is mantled with low-relief surfaces below about 300 ft elevation, which lie above Holocene floodplains. Rare fresh exposures reveal proglacial rhythmite beds several centimeters thick, each bed probably the product of a separate flood (Waitt, 1980, 1985, 1994; Clague and others, 2003). In most exposures the deposit is oxidized light brown, and bedding is inconspicuous. It is composed largely of quartz, feldspar, and conspicuous muscovite, which indicate deposition by Columbia River rather than by local streams. This deposit it interpreted as slack-water deposits of large floods initiated by failure of the ice dam at Glacial Lake Missoula in western Montana during the late Pleistocene. 3.2 PRIOR GEOTECHNICAL STUDIES We reviewed a prior geotechnical report prepared by Columbia West Engineering, Inc. (Columbia West) for Union Ridge Town Center, Ridgefield, provided to us by Costco. The geotechnical explorations consisted of 12 test pits and 2 CPT’s conducted in January 2021. Test pits were excavated to a maximum depth of 14 feet and CPT’s extended to 70 feet. Test pits encountered lean and fat clays with sand underlain by sandy silts. CPT’s encountered soft to medium stiff silt mixtures in the upper 25 feet. Below this, loose to medium dense sand and medium stiff to very stiff silt mixtures were encountered, which were in turn underlain by dense to very dense sand. 3.3 SOIL CONDITIONS Soils encountered during the field explorations are generally consistent with the referenced geologic mapping and prior geotechnical report. In general, below topsoil, explorations encountered soft to medium stiff lean clay soils with sand extending to a depth of about 30 feet. Between about 30- and 40-feet soils graded to stiffer sandy clay. Below 40 feet, soils were 20221909.001A/SEA21R133024 Page 12 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com generally stiff to very stiff sandy silt. Most warehouse borings were terminated in the stiff to very stiff sandy silt. 3.3.1 Topsoil Topsoil was encountered at the ground surface in most of the borings. Organic content test results, presented in Section 6.1.1, indicate organic contents ranging from about 4 to 7 percent in the upper 18 inches, likely due to past cultivation. 3.3.2 Lean Clay with Sand Soils encountered below the topsoil layer generally consisted of lean clay with sand, which extended to a depth of about 30 feet bgs. This layer was generally grayish brown to reddish brown with plasticity indices ranging from 4 to 12. SPT N-values in this layer ranged from 1 to 29. The softer soils were primarily encountered in borings KB-3, 4 and 13, which are located in the northeast corner of the warehouse near the loading dock. 3.3.3 Sandy Clay Below a depth of about 30 feet soils generally graded to sandy clay and became stiffer. This layer was generally gray to reddish brown with plasticity indices between 18 and 24. SPT N-values in this layer ranged from 5 to 29. 3.3.4 Sandy Silt Below a depth of about 40 feet soils generally graded to sandy silt and became stiff to very stiff. This layer was generally light brown to yellowish gray and non-plastic. All warehouse borings were terminated in this layer. SPT N-values in this layer ranged from 7 to 25 and the CPTs met refusal in this layer. 3.4 GROUNDWATER CONDITIONS Site explorations were completed during the summer following several drier-than-average months. Subsurface conditions were significantly drier than those described in the Columbia West geotechnical report, for which explorations were completed in the wet season (January 2021). The Kleinfelder test pit explorations did not encounter seepage; however, the test pits excavated 20221909.001A/SEA21R133024 Page 13 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com by Columbia West encountered seepage between depths of 1½ and 5 feet bgs. Kleinfelder borings encountered wet soil samples and wet SPT samplers between depths of about 10 to 20 feet. Soil moisture contents were generally highest between depths of about 10 to 30 feet and soils became slightly drier at depth. Two monitoring wells were installed during the exploration program (in KB-15 and 31). On September 12, 2021, groundwater was measured at a depth of 15 feet in KB-15 and no water was observed in KB-31. Pore pressure readings indicated on the CPT logs indicate occasional zones of saturated soil generally between depths of 15 and 35 feet. Based on our observations and review of the data discussed above, we infer that shallow groundwater at the site is generally limited to perched layers, and that perched groundwater levels may fluctuate by as much as 10 to 15 feet seasonally. While we did not identify the depth to a regional, permanent groundwater table, we will read the monitoring wells in winter of 2022. A detailed investigation of regional and local groundwater conditions and detailed evaluation of seasonal fluctuation was not included in this report and was outside the scope of this investigation. Construction excavations, including footing excavations, completed in the winter and spring will likely encounter slow to moderate seeps, some of which may persist well into the dry season. Some seepage may be encountered in late spring and early summer, depending on the level of precipitation. Deep utility and fuel facility UST excavations may encounter seeps any time of the year, though planned fills of 5 to 10 feet at the UST location mean this excavation is less likely to encounter groundwater seepage. Where encountered, seepage can likely be controlled by use of shallow sumps and pumps. The contractor should be pro-active in keeping water off trench and footing subgrades to prevent softening and the need for over-excavation. 20221909.001A/SEA21R133024 Page 14 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 4 GEOTECHNICAL CONSIDERATIONS ____________________________________________________________________________ 4.1 GENERAL The following sections present discussion of key geotechnical considerations for the project including a general discussion of anticipated soil conditions that must be addressed by the project team and contractor. 4.2 SITE SETTLEMENT AND WAREHOUSE SURCHARGE Site grading will require fills up to about 15 feet and cuts up to about 5 feet. The northwest corner of the warehouse will require a fill of about 15 feet and the southeast corner of the warehouse will require a cut of about 1 foot. Loads imposed by new structural fill will compress the underlying clays and result in settlement, which will generally increase proportionally to the fill thickness. We estimate that the maximum long-term settlement due to the thickest fill in the northwest portion of the warehouse will be about 7 inches. This settlement will result from immediate, elastic settlement in unsaturated soil layers, as well as some consolidation in saturated soil layers, which will occur over time at a slower rate. Without use of a surcharge, about 6 months is anticipated to achieve 90 percent of the consolidation settlement. Loads imposed by warehouse footings and the floor slab will cause additional settlement, which we estimate to range from about 1½ to 2¾ inches, depending on location. As these settlements would occur post-construction, Costco settlement criteria would be exceeded and there would be a high likelihood of slab cracking and panel rotation and misalignment. Therefore, we recommend use of a temporary surcharge to reduce long-term settlement of the warehouse footings and floor slab to about 1 inch or less. The surcharge should extend 10 feet beyond the warehouse building pad in all directions, which includes the entrance canopy, loading dock, bread door, and compactor slabs. Edges of the surcharge should be sloped 1.5H:1V, or flatter. We recommend a minimum surcharge thickness of 4 feet above the warehouse FFE, based on an assumed soil unit weight of 115 pcf, which can be achieved with the on-site clayey soils. A surcharge duration of 90 days should be assumed for the project schedule. Due to the fact that groundwater at the site is present in variable, perched layers, the thicknesses of saturated soils at the site will vary with time of year, and the required 20221909.001A/SEA21R133024 Page 15 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com surcharge time may be as short as about 60 days. A minimum of 10 settlement monitoring points should be established across the warehouse footprint to monitor settlement during the surcharge program. Considerations should be given to incorporating the temporary surcharge into the interim grading plan to be provided by the developer so that the site balances when the surcharge material is removed and placed in the parking lot. If the site will be delivered to Costco in the summer or fall with construction not planned until the following spring, the surcharge would have an added benefit of capping the building pad and protecting it from moisture through the winter. If this is the case, consideration should be given to crowning the pad in the center by at least one foot to promote drainage and prevent ponding. Low areas in the interim grading plan that will serve as stormwater ponds, if on the Costco site, should be located in areas that are either not in the critical path for construction, allowing more time to dry in the spring, or in areas where deep utility excavations will be required, which provides for removal and improved drying of these soils during the utility installation process. 4.3 ALTERNATIVE SITE SETTLEMENT MITIGATION MEASURES We performed preliminary evaluation of alternative settlement mitigation measures such as use of lightweight fill, rammed aggregate piers, and other ground improvement methods. Due to the relatively short settlement period required for the surcharge, and the fact that construction of alternatives would require roughly the same or longer amount of time, we do not anticipate that there are viable alternatives for accelerating the construction schedule. In addition, the costs of these alternatives are much higher than a conventional surcharge program and it is our opinion that detailed evaluation of alternatives is not warranted. We can provide preliminary recommendations for specialty contractors to develop preliminary pricing and cost estimates for alternatives, if desired by Costco. 4.4 MOISTURE SENSITIVE SOILS Site soils are predominantly clay and are highly moisture sensitive. To the greatest extent practical, we recommend that earthwork be performed in the late spring, summer, and early fall. We anticipate that the site will be dry by late spring and through the summer and early fall, with the exception of occasional rain. During this time, moisture conditioning will likely require adding water and reconditioning the soils to their optimum moisture content. A sheep’s foot-style roller is recommended to properly moisture condition and compact silty clay/ sandy clay soils. 20221909.001A/SEA21R133024 Page 16 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com If these soils are worked during or following the wet season, it will be necessary to moisture condition (dry) the soils in order to achieve proper compaction. Conventional wet weather earthwork practices should be employed, and the construction schedule should account for weather related delays associated with rain if earthwork is planned for the late fall, winter, or early spring. Haul roads should be incorporated into earthwork plans for the project. Sections 6.1.6 and 6.1.7 provide additional discussion of wet weather earthwork and haul roads. If footing excavation is planned for anytime other than June through September, we recommend a contingency in the event that wet soils are encountered in footing excavations. As a minimum this contingency should include over-excavating 6 inches of clay and replacing with WSDOT Crushed Surfacing Top Course. 4.5 EMBANKMENT SLOPES AND RETAINING WALL BY DEVELOPER We understand mass grading of the site by the developer will include embankment construction as well as construction of a retaining wall along the northern-most portion of the west side of the site. The type and height of the wall is unknown at this time. While the developer and their consultants and contractors will be responsible for design and construction of the embankments and retaining wall, they should confirm to Costco Wholesale Development Requirements Section 16 as a minimum. We understand Costco will retain Kleinfelder to provide peer review of the design, plans and specifications for the walls. Recommendations Section 6.2 of this report will be applicable for minimum fill and compaction requirements. It should be noted that all retaining wall backfill is required to consist of free-draining granular material. Steep grades are present at the north end of the site. We understand that 2.5H:1V slopes are being considered in lieu of the recommended 3H:1V slopes to maximize usable site area and minimize encroachment upon the wetland area. We completed a preliminary slope stability analysis using the computer program Slide v. 6.0 (Rocscience), which provides a two-dimensional limit equilibrium method for evaluating slope stability. Sections were selected considering a combination of wall height, subgrade conditions and external loads (i.e. traffic). Factors of safety against failure were computed using a conventional method of slices approach and the Morgenstern-Price method of analysis. Results indicated a static factor of safety of at least 1.5 for deep-seated failures. Erosion or sloughing along the slope may be a concern. Final design should 20221909.001A/SEA21R133024 Page 17 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com be the responsibility of the developer’s consultants and should coordinate with landscape plans, which should include measures to keep the topsoil from washing away until vegetation is well established. We understand that stormwater runoff will not be discharged on the embankment slopes. 20221909.001A/SEA21R133024 Page 18 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 5 GEOTECHNICAL DESIGN RECOMMENDATIONS ____________________________________________________________________________ 5.1 SEISMIC DESIGN CONSIDERATIONS 5.1.1 Design Ground Motions Based on information obtained from the investigation, published geologic literature and maps, and on our interpretation of the 2018 IBC criteria, it is our opinion that the project site may be classified as Site Class D, Stiff Soil. In accordance with Section 11.4.8 of ASCE 7-16, a site-specific ground motion analysis is required for Site Class D sites with an S1 greater than 0.2 g. However, a site-specific ground motion analysis is not required if the seismic response coefficient (Cs) is determined in accordance with requirements of Chapter 12 and exceptions as noted in Section 11.4.8. The assumption that Cs may be determined in accordance with the requirements of Chapter 12, and exceptions as noted in Section 11.4.8 will be used, should be verified by the project structural engineer during final design. The 2018 IBC Seismic Design Parameters (non-site-specific) for these structures are summarized in the following table. Table 1: 2018 IBC Seismic Design Parameters Design Parameter Recommended Value Site Class D Ss (g) 0.806 S1 (g) 0.380 Fa 1.178 Fv N/A* SMS (g) 0.949 SM1 (g) N/A SDS (g) 0.633 SD1 (g) N/A PGAM (g) 0.451 *N/A = Not Applicable; Section 11.4.8 of ASCE 7-16 requires a site-specific ground motion hazard analysis be performed for Site Class D sites with S1 values greater than or equal to 0.2g unless exceptions are taken. If exceptions are taken, then a Fv value of 1.92 could be used only to calculate the Ts value. 20221909.001A/SEA21R133024 Page 19 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 5.1.2 Seismic Hazards Due to the stiff nature of soils underlying the site, the depth to groundwater, and the lack of steep slopes, it is our opinion that the liquefaction and landslide hazards at the site are very low. Embankments and retaining walls should be designed to account for potential strong ground shaking. Based on a review of available geologic mapping for the area, subsurface information gathered during the field investigation, and fault research, surface rupture hazard at this site is considered to be low. As reflected in the seismic design parameters summarized in Table 1, the site may be subject to significant earthquake-induced ground shaking due to general proximity to active fault zones. 5.2 SHALLOW FOUNDATIONS 5.2.1 General Based on the results of the field exploration, laboratory testing, and geotechnical analyses, the proposed warehouse and fueling facility may be supported on conventional shallow spread footings provided a surcharge program is implemented as discussed in Section 4.2 and footing subgrade is prepared in accordance with Section 6.1.3. Recommendations for the design and construction of shallow foundations are presented below. 5.2.2 Shallow Foundation Design Allowable Soil Bearing Pressure Shallow spread footings, supported as described above and in Section 6.1.3, may be proportioned for a net allowable bearing pressure of 2,000 pounds per square foot (psf) for dead plus sustained live loads. Although the City of Ridgefield only requires a 12-inch embedment for frost protection, the recommended bearing pressures assume a minimum embedment of 18 inches. Footing dimensions and reinforcement should be designed by the structural engineer; however, continuous footings should have a minimum width of 18 inches, isolated spread footings should have a minimum width of 36 inches. A one-third increase in the above bearing pressures can be used for transient wind or seismic loads. 20221909.001A/SEA21R133024 Page 20 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com Estimated Settlements Footing settlements are expected to be less than 1 inch for a 160-kip column load and differential settlement between similarly loaded footings over a 50-foot span is expected to be less than ½- inch. Lateral Resistance Lateral load resistance may be derived from passive resistance along the vertical sides of the footings, friction acting at the base of the footing, or a combination of the two. An ultimate passive resistance of 320 pcf may be used for design, which assumes use of on-site clay soils. Allowable passive resistance values should not exceed 2,500 psf. An allowable coefficient of friction of 0.30 between the base of the footings and engineered fill soils can be used for sliding resistance using the dead load normal stresses. Friction and passive resistance may be combined without reduction. Kleinfelder recommends that the first foot of soil cover be neglected in the passive resistance calculations if the ground surface is not protected from erosion or disturbance by a slab, pavement, or in a similar manner. 5.3 BUILDING SLAB-ON-GRADE Concrete slab-on-grade floors are appropriate for the proposed warehouse, provided subgrade is prepared in accordance with Section 6.1.3. In accordance with the CWDRs, Kleinfelder based its recommendations on a minimum 6-inch-thick slab underlain by at least 6 inches of a base material consisting of compacted crushed rock conforming to the requirements of Section 9-03.9(3) for Crushed Surfacing Base Course of the WSDOT Standard Specifications. In addition, the percent fracture should 90 percent or greater, and the percent passing the 80 mm sieve should be 5 percent or less. Please note that Costco does not typically allow the use of recycled materials below the warehouse slabs. The proposed use of any recycled material will require the prior approval of Costco. Floor slabs supported on subgrades and base course that are prepared in accordance with the preceding recommendations may be designed for a standard modulus of subgrade/base course reaction (k) of 125 pounds per cubic inch for silty sandy clays. These k values are based on values typically obtained from 1-foot diameter plate load tests. Based on the geotechnical characteristics 20221909.001A/SEA21R133024 Page 21 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com of the site and an assumed surcharge program, the proposed warehouse can be built with a non- reinforced slab. Floor slab control joints should be used to reduce damage due to shrinkage cracking. Control joint spacing is a function of slab thickness, aggregate size, slump and curing conditions. The requirements for concrete slab thickness, joint spacing, and reinforcement should be established by the designer, based on experience, recognized design guidelines and the intended slab use. Placement and curing conditions will have a strong impact on the final concrete slab integrity. Kleinfelder typically recommends installation of a vapor barrier beneath the slab to mitigate potential moisture issues such as flooring performance and mold. However, we understand that Costco Wholesale has determined that moisture barriers are not to be used in construction of Costco Wholesale warehouses due to adverse effects on concrete curing and performance. Therefore, we have provided construction recommendations that do not include installation of a moisture barrier, with the understanding that there will be an increased risk for adverse moisture issues. 5.4 EXTERIOR FLATWORK Exterior concrete slabs for pedestrian traffic or landscape should be at least 6 inches thick and underlain by a minimum 4-inch layer of crushed rock. The subgrade should be prepared in accordance with Section 6.1.4. 5.5 DRAINAGE CONSIDERATIONS Positive drainage should be established away from the proposed structures and pavements. We do not recommend unpaved or landscape areas adjacent to the warehouse. Unpaved ground surfaces should be sloped away from the buildings at a minimum grade of five (5) percent for a distance of at least 15 feet, or to a bio-infiltration swale designed to quickly move water away from the building and pavement areas. Paved surfaces should be sloped away from the buildings at a grade of at least 2 percent grade to collection points from which surface water can be quickly and efficiently transported away from the buildings, exterior slabs and pavements. In no case should ponding of water be allowed around the perimeters of the buildings, or adjacent to exterior cast- on-grade slabs and pavements. 20221909.001A/SEA21R133024 Page 22 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com We recommend perimeter footing drains and additional drains at the entrance canopy, fuel station, and loading dock perimeters. Details should be consistent with standard Costco practices. Roof drains should be tight lined to a suitable discharge point and not be hydraulically connected to perimeter drains. Due to the relatively mild climate, frost-resistant fill details are not required around the warehouse. All utility trenches leading into the structure should be backfilled with compacted structural fill. Uniformly graded bedding and backfill material (such as pea gravel) tends to perform as conduit for water, and should not be used in utility trenches, where practicable. Utilities should meet the more stringent of minimum burial and sloping requirements per local City and Costco requirements. Clay subgrade soils are not anticipated to provide good drainage for landscape areas. The landscape architect should be consulted, and landscape drains should be incorporated into the design and/or the upper few feet of fill material in landscape islands should be specified to provide adequate drainage. 5.6 LOADING DOCK WALLS Design earth pressures for the loading dock walls depend primarily on the allowable wall movement, wall inclination, backfill material type, backfill slopes, surcharges, and drainage. Determination of whether the active or at-rest condition is appropriate for design depends on the flexibility of the walls. Walls that are free to rotate at least 0.1 degrees (deflection at the top of the wall of at least 0.1 x H, where H is the unbalanced wall height) may be designed for the active condition. Walls that are not capable of this movement should be assumed rigid and designed for the at-rest condition. The recommended active and at-rest earth pressures and passive resistance values are provided below in Table 2. Reductions on the ultimate passive resistance should be incorporated into design to account for displacement compatibility with active earth pressures. 20221909.001A/SEA21R133024 Page 23 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com Table 2: Lateral Earth Pressures for Loading Dock Walls Wall Movement Backfill Condition Ultimate Equivalent Fluid Pressure Granular Backfill Free to Deflect (active condition) Level Backfill 34 pcf Restrained (at-rest condition) Level Backfill 55 pcf Passive Resistance Level Toe Slope 500 pcf Resistance factor of .50 should be applied to passive resistances The above lateral earth pressures assume a unit weight of structural fill equal to 130 pcf and do not include the effects of surcharges (e.g., traffic, footings), compaction, or truck-induced wall pressures. Any surcharge (live, including traffic, or dead load) located within a 1:1 (horizontal to vertical) plane drawn upward from the base of the excavation should be added to the lateral earth pressures. The lateral contribution of a uniform surcharge load located immediately behind walls may be calculated by multiplying the surcharge by 0.33 for cantilevered walls under active conditions and 0.50 for restrained walls under at-rest conditions. Walls adjacent to areas subject to vehicular traffic should be designed for a vertical surcharge of 250 psf. Lateral load contributions from other surcharges located behind walls may be provided once the load configurations and layouts are known. If retaining walls taller than 6 feet in height are planned Kleinfelder should be contracted to provide a seismic surcharge pressure for wall design. Backfill placed within ½H of the wall should consist of imported, well-graded, free-draining granular material. Walls should be properly drained or designed to resist hydrostatic pressures. Adequate drainage is essential to provide a free draining backfill condition so that there is no hydrostatic buildup behind the wall. Walls should also be appropriately waterproofed to reduce the potential for staining. Drainage behind loading dock walls can consist of weep holes placed along the base of the wall. Weep holes should be spaced 10 to 15 feet apart and connected with a gravel drain behind the base of the wall consisting of approximately one cubic foot of clean gravel per foot of wall length wrapped with filter fabric. 5.7 PAVEMENT SECTIONS The required pavement structural sections will depend on the expected wheel loads, volume of traffic, and subgrade soils. This report provides asphalt concrete pavement sections based 20221909.001A/SEA21R133024 Page 24 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com anticipated vehicle loads of 30 trucks and 6,600 passenger vehicles per day as stated in the 2020 CWDR. Positive drainage of the paved areas should be provided as moisture infiltration into the subgrade can decrease the life of pavements. The following recommended pavement sections are based on the soil conditions encountered during the field exploration, as well as estimations based on anticipated grading, expected final site grades, and limited laboratory testing. 5.7.1 Costco Pavement Design Parameters Kleinfelder developed pavement design recommendations using traffic loading parameters provided in the 2020 CWDR and the following test data: 20-year pavement design life; Initial design serviceability index of 4.2; Terminal serviceability index of 2.5; Level of reliability of 90 percent; Modulus of Subgrade Reaction of 12,000 psi; Light-duty pavements subject to 6,600 passenger vehicle trips per day (Traffic Index of 5.0); Heavy-duty pavements subject to 30 tractor-trailer truck trips per day (Traffic Index of 7.0); For asphalt concrete pavements: a design CBR-value of 8 or greater; and For Portland Cement Concrete (PCC) Pavements: a 28-day flexural strength (modulus of rupture determined by the third-point method) of at least 650 pounds per square inch (psi); a modulus of subgrade reaction (k value) of 125 pounds per cubic inch (pci); and interlock at the control joints. 20221909.001A/SEA21R133024 Page 25 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 5.7.2 Asphalt Concrete Pavement Kleinfelder designed asphalt concrete pavement, also referred to as Hot Mix Asphalt (HMA), in accordance with the 1993 AASHTO Guide of Design of Pavement Structures. HMA materials and construction methods should conform to requirements of the Costco Wholesale Asphalt Pavement and Surfacing Specification Section 321216. The aggregate base (crushed rock base) should confirm to WSDOT Specification section 9-03.9(3). Pavement lifts should not exceed 3 inches. Table 3 presents recommended minimum HMA pavement sections. Prior to placement of aggregate base, pavement subgrade should be prepared in accordance with Section 6.1.4. Table 3: Recommended Minimum Asphalt Concrete Pavement Sections Traffic Use Traffic Index, TI Asphalt Concrete (inches) Aggregate Base (inches) Light-Duty Pavement 5.0 3.0 6.0 Heavy-Duty Pavement 7.0 4.0 8.0 Alternate Heavy-Duty Pavement 7.0 4.0 7.0 - with geotextile separator fabric on subgrade Alternative Heavy-Duty Pavement 7.0 4.0 4.0 - with 12.0 inches of cement treated subgrade 5.7.3 Portland Cement Concrete Pavement Kleinfelder designed PCC pavement in accordance with the Portland Cement Association (PCA) Thickness Design for Concrete Pavements (PCA, 1984). It was also assumed that aggregate interlock would be developed at the control joints. The recommended minimum PCC section is presented in Table 4. Prior to placement of aggregate base, pavement subgrade should be prepared in accordance with Section 6.1.4. Table 4: Recommended Minimum PCC Pavement Section Traffic Use Traffic Index, TI PCC (inches) Aggregate Base (inches) Heavy Duty Pavement 7.0 6 6 20221909.001A/SEA21R133024 Page 26 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com We recommend that PCC pavements be reinforced with a minimum of welded wire or an approved equivalent; the structural engineer should perform final reinforcement design. Longitudinal and transverse joint spacing should not exceed 12 feet and 15 feet, respectively. Joint details should conform to PCA guidelines. Expansion joints in concrete slabs should be sealed with petroleum resistant sealant to prevent minor releases from impacting subsurface soil. 5.7.4 Aggregate Base Crushed surfacing should conform to the requirements of Section 9-03.9(3) Crushed Surfacing Top Course or Base Course of the WSDOT Standard Specifications. Aggregate base should be compacted to a minimum of 95 percent of the material’s maximum density per ASTM D1557 using suitable compaction equipment. 5.7.5 Pavement Drainage Due to the drainage characteristics of the native clay and silt soils we recommend installation of radial pavement drains in the parking and drive areas. Curbing located adjacent to paved areas should be founded in the subgrade, not the aggregate base, in order to provide a cutoff, which reduces water infiltration into the base course. Parking areas should be sloped, and drainage gradients maintained to carry all surface water runoff away from building and pavement areas. 5.7.6 Pavement Maintenance Pavements, particularly in cold regions, undergo seasonal movement due to changes in temperature and subgrade moisture content. This movement tends to accelerate pavement deterioration, particularly at cold joints. As cold joints open and localized areas of cracking develop, surface water infiltrates into the pavement section, exacerbating freeze-thaw action and softening subgrade. A crack sealing program should be performed annually to slow pavement deterioration. Any areas where surface water stands on the surface should be remediated. Over time as cracking becomes more pronounced, a slurry seal coat should be applied. 5.8 SOIL CORROSIVITY AND CONCRETE EXPOSURE CLASS Analytical laboratory testing was performed on select representative soil samples to evaluate the corrosion potential and concrete exposure class of the native site soils. Testing included pH, minimum resistivity, redox potential, sulphide and soluble chloride and sulfate content. Analytical 20221909.001A/SEA21R133024 Page 27 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com test results are summarized in Table 5. Full analytical test reports by AMTEST are included in Appendix D. Table 5: Analytical Laboratory Test Result Summary Boring Depth (ft) Minimum Resistivit y (ohm- cm) pH Redox Potential (mV) Sulfide (µg/g) Soluble Sulfate Content (µg/g) Soluble Chloride Content (µg/g) KB-1 2.5 - 4 27,000 6.3 539 <1 44 11 KB-3 5 - 6.5 40,000 6.2 543 <1 <10 <10 KB-17 2.5 – 4 49,000 5.9 528 <1 14 <10 KTP - 8 0.5 -1 - 6.3 - - - <10 Based on the “10-point” method developed by the American Water Works Association (AWWA) in standard AWWA C105/A21.5-10, the soils at the site have low to mild corrosion potential for buried ferrous metal piping, cast iron pipes, or other objects made of these materials. Other soils on-site may be more, less, or similarly corrosive in nature. Imported fill materials should be tested to confirm that their corrosion potential is not more severe than those noted. Kleinfelder’s scope of services does not include corrosion engineering, therefore a detailed analysis of the corrosion test results is not included. Kleinfelder understands refueling station equipment is constructed of corrosion resistant synthetic materials. It is recommended that the designer or engineer for the refueling station review these results and consult a corrosion expert for further evaluation, if necessary. The detected concentration of soluble sulfates indicates the native soils are exposure class S0 based on American Concrete Institute (ACI) 318-14 Table 19.3.1.1 (ACI, 2014). ACI code requires no restrictions or limits on cementitious materials for concrete mixtures for exposure class S0 soils. 20221909.001A/SEA21R133024 Page 28 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 6 CONSTRUCTION RECOMMENDATIONS ____________________________________________________________________________ 6.1 EARTHWORK 6.1.1 Clearing and Grubbing Prior to site grading, all organic material including grass, brush, trees, and crops should be removed and properly disposed of offsite. Roots greater than 1-inch in diameter should be removed along with all root balls. Most of the site has been used to cultivate feed hay and the root may is generally limited to 6 inches or less. Organic test results, which are summarized in Table 6, indicate 4 to 7 percent organic content in the upper 18 inches. Due to the significant fills planned for most of the warehouse footprint, we recommend a planned stripping depth of 6 inches, though actual stripping depths may vary. Table 6: Organic Content Test Results Exploration Name Sample Depth (inches) Organic Content (%) KTP-1 0-6 6.7 KTP-1 6 -18 6.3 KTP-2 0-6 6.6 KTP-2 6-18 4.2 KTP-4 0-6 7.7 KTP-4 6-12 5.6 KTP-8 0-6 7.0 6.1.2 Excavation Excavation of the on-site soils can generally be completed using conventional earthmoving equipment such as bulldozers, scrapers, and excavators. The excavation contractor should satisfy themselves regarding the subsurface soil conditions to be encountered during site grading and excavation and plan for the necessary equipment accordingly. 6.1.3 Footing Subgrade Preparation Excavations for footings should be performed with smooth-edged excavator buckets or other means to prevent disturbance of subgrade soils; disturbed soils may require removal and 20221909.001A/SEA21R133024 Page 29 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com replacement with compacted granular fill. Footing subgrade should be evaluated by a representative of the Geotechnical Engineer to identify soft or unstable areas. Provided footing excavation is performed during late spring or summer, conditions are anticipated to be relatively dry, though the contractor should be prepared to address seepage with sumps and pumps any time of year. If footing excavation is planned for anytime other than June through September, we recommend a contingency in the event that wet soils are encountered in footing excavations. As a minimum this contingency should include over-excavating 6 inches of clay and replacing with WSDOT Crushed Surfacing Top Course. 6.1.4 Site Subgrade Preparation Before placing new fill, the native soils should be proof-rolled with a loaded dump truck or water truck under the full-time observation of the Geotechnical Engineer to identify soft or unstable areas. Where identified, these areas should be over-excavated and replaced with structural fill as described in Section 6.2.1 of this report. Where severe instability and pumping are observed, these areas may require stabilization using a combination of geotextile and gravel as further described in Section 6.1.8. Where deep fills are planned, it may be practical to place a layer of granular material, rather than over-excavate the unsuitable soils. Following proof-rolling and stabilization, the exposed subgrade should be scarified to a minimum depth of 12 inches, moisture-conditioned to -1 to +3 percent of optimum moisture content and compacted. Clay subgrade should be compacted to a minimum of 98 percent of the maximum dry density as determined by ASTM D698. Granular subgrade should be compacted to a minimum of 95 percent of the maximum dry density as determined by ASTM D1557. It should be noted that repeated construction traffic over the exposed clay subgrade soils may result in pumping and instability of the subgrade, particularly under wet weather conditions. The contractor should consider the use of lightweight tracked equipment and a traffic routing plan to minimize disturbance of the subgrade soils, as necessary. Where instability occurs, the subgrade should be over-excavated and stabilized as recommended above. 6.1.5 Schedule Considerations Site soils are predominantly clay and are highly moisture sensitive. If exposed to excess moisture and repeated construction traffic, the native near surface soils will likely become unstable; especially during the wetter seasons of the year. 20221909.001A/SEA21R133024 Page 30 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com The earthwork contractor should have experience working with, and the equipment necessary to deal with these types of soils under wet conditions. The contractors bidding on this project should be informed of these conditions. If these soils become wet and unstable conditions occur, the geotechnical engineer should be contacted to observe the conditions. Mitigation of these conditions may require either over excavation and/or replacement with suitable structural fill, construction of gravel access roads, or if the schedule permits, the unstable soils can be scarified, tilled, and allowed to dry. Following drying, the soils should be recompacted in accordance with Section 6.1.4. Consideration should be given to establishing a start window with early and late start dates. Weather factors that should be considered are late winter and spring weather; time required for completion of earthwork and placement of base rock or asphalt prior to onset of fall rain, and other factors. Budget and schedule planning should include potential mitigation measures such as lime treatment, importing additional granular materials, and tilling and drying soils. If drying of soils is assumed, budget should be included for tilling of soils during dry weather and rolling to seal soils during wet weather. 6.1.6 Wet Weather Earthwork Kleinfelder recommends the following practices during wet weather or when the subgrade is wet: The contractor should take measures to protect the exposed subgrade surfaces and limit construction traffic. When possible, construction equipment should not operate directly on wet subgrade. Low ground pressure equipment or small equipment should be used. Care should be taken to cover all exposed surfaces with imported granular fill as soon as possible after exposure. Site grades should be maintained to prevent ponding and capture runoff before it can erode or damage subgrade. All runoff should be collected and disposed of properly. Earthen berms or other methods should be used to prevent runoff from draining into excavations. Earthwork should be planned to limit the area of disturbance to as small an area as possible in order to minimize the potential for soil saturation. 20221909.001A/SEA21R133024 Page 31 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com All stockpiles should be covered or rolled with a smooth drum to shed water when not actively being worked or dried. Subgrade should be graded and rolled with a smooth drum roller to minimize the infiltration of water into the subgrade during wet weather and at the end of each shift if wet weather is forecast. During dry periods, wet soils should be scarified or tilled to promote drying. Following wet weather, surficial soils should be allowed to dry to the greatest extent practical before traversing with construction equipment or handling. Kleinfelder should be contacted to review the contractor’s Best Management Practices. 6.1.7 Haul Roads and Subgrade Stabilization Wet weather conditions during construction may cause the building and pavement subgrade conditions to become unstable/disturbed under the construction traffic. The contractor should plan to repair subgrade conditions that become unstable/disturbed and should develop a plan to manage traffic on exposed subgrade across the site throughout the construction. Kleinfelder recommends construction of haul roads on routes routinely used by construction traffic and around the warehouse perimeter. Kleinfelder recommends the contractor construct a test section before constructing all haul roads. This means of stabilization can also be used to address severely unstable or pumping subgrade conditions in other areas of the site as directed by the Geotechnical Engineer. 6.1.8 Permanent Cut and Fill Slopes Permanent cut or fill slopes in native soils should be no steeper than 3:1 (horizontal to vertical) to maintain long-term stability and to provide ease of maintenance. Steeper slopes are susceptible to erosion, will be difficult to maintain, and could experience problems with instability. If a steeper slope is required, we recommend that the slope be ‘over-built’ and trimmed back and layers of geogrid be provided for additional stability at the face The minimum distances from the crest or toe of cut or fill slopes from the building or structures should meet the requirement of IBC 2015 Section 18 Figure 1808.7.1. It is recommended that permanent slopes be vegetated or otherwise protected, as soon as practical, in order to minimize the potential for erosion. 20221909.001A/SEA21R133024 Page 32 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 6.2 FILL MATERIAL AND COMPACTION CRITERIA 6.2.1 General All material placed below foundation elements, structural elements, slabs, or parking areas should be considered structural fill. A representative of the Geotechnical Engineer should be on site to verify that the native subgrade soils are properly proof rolled, stabilized and compacted as recommended in Sections 6.1.3 and 6.1.4 prior to structural fill placement. Also, prior to construction of structural or foundation elements the competency of the element’s subgrade should be evaluated by a representative of the Geotechnical Engineer. The native sandy clay soils are acceptable for use as structural fill under warehouse, parking and drive areas if placed under dry weather conditions only and they are screened of all material greater than 3 inches in diameter and have a plasticity index less than 25. In wet weather conditions, the soils may become overly moist, resulting in instability and difficulty in achieving compaction. These soils will likely require moisture conditioning, drying in early spring, and adding water in the dry season. Use of disking equipment and/or sheep’s foot rollers will likely be required. Imported fill should consist of a well-graded granular material (at least 50 percent sand and gravel) with a maximum particle size of 3 inches and no more than 15 percent passing the No. 200 sieve. The fines portion should be non-plastic and the material should be within 3 percent of its optimum water content at the time of placement and compaction. Imported structural fill and native material used as structural fill should be moisture conditioned to their optimum moisture condition and compacted utilizing suitable compaction equipment to a minimum of 95% of the maximum dry density as determined by ASTM D1557. Native sandy clay material used as structural fill areas should be compacted utilizing a vibratory sheep’s foot roller, or similar equipment. Granular structural fill should be compacted using a smooth face vibratory roller, plate compactor, jumping jack, or similar compaction equipment. Following compaction, the finished surface of structural fill should be proof rolled under the observation of the Geotechnical Engineer using a fully loaded, tandem-axle truck with a minimum total weight of 40,000 pounds, such as a fully loaded dump truck or fully loaded water truck. The truck should make a minimum of two passes per lane to identify any loose or unsuitable areas of subgrade. If instability is 20221909.001A/SEA21R133024 Page 33 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com observed, the Geotechnical Engineer will evaluate the issue with the contractor and develop recommendations to address the instability as needed. The contractor should submit informational data and samples of each of the required earthwork materials to the geotechnical engineer for evaluation and approval as part of the bid package and for approval prior to use. The samples should be submitted at least one week prior to their use and sufficiently in advance of the work to allow the contractor to identify alternative sources if the material proves unsatisfactory. Imported fill should be documented to be free of hazardous materials, including petroleum or petroleum byproducts, chemicals and harmful minerals. All structural fill should be moisture conditioned, placed in maximum 8-inch loose lifts, and compacted to the minimum percentages presented in Table 7. Where two or more compaction specifications coincide, the more stringent specification should be utilized. Table 7: Compaction Criteria Fill Location Material Type Percent Compaction Moisture Content Minimum Compaction Testing Frequency Per Lift Beneath interior and exterior concrete slab subgrade Approved aggregate base 95 minimum, Modified Proctor (ASTM D 1557) -1 to +3% of optimum 10,000 Square Feet Beneath pavement profile Approved granular soils 95 minimum, Modified Proctor (ASTM D 1557) -1 to +3% of optimum 10,000 Square Feet Pavement and warehouse fill and subgrade Approved suitable on-site clay soils 98 minimum, Standard Proctor (ASTM D 698) -1 to +2% of optimum 10,000 Square Feet Foundation wall backfill, and retaining wall backfill Approved granular soils 95 minimum, Modified Proctor (ASTM D 1557) -1 to +3% of optimum 1,000 Square Feet Utility trenches backfill Approved suitable on-site clay soils 100 minimum, Standard Proctor (ASTM D 698) -1 to +2% of optimum 150 Linear Feet Lawns or Unimproved Non- Structural areas Suitable on-site soils 85 minimum, Modified Proctor (ASTM D 1557) -3 to +4% of optimum 20,000 Square Feet 20221909.001A/SEA21R133024 Page 34 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 6.2.2 Trench Backfill Particular care should be taken to ensure bedding or fill material is properly compacted in place to provide adequate support to the pipe. Pipe zone backfill (placed immediately around the pipe) should meet pipe manufacturer’s specifications or local building requirements. Trench backfill (placed between the pipe zone backfill and finished subgrade) should consist of on site or imported fill that meets the requirements provided in Table 7 above and should be compacted accordingly. Jetting or flooding are not acceptable substitutes for mechanical compaction and should not be allowed. In general, it is anticipated that trench subgrades will be suitable for supporting pipe bedding provided soil moisture is controlled. Native subgrade soils will soften when subject to excess moisture and may require over-excavation and replacement with an approved granular bedding, stabilization with a geotextile fabric, or cement treatment. 6.3 TEMPORARY EXCAVATIONS AND SLOPES All excavations and slopes must comply with applicable with applicable Federal, State, and Local Occupational Safety and Health Administration regulations. Construction site safety is the sole responsibility of the Contractor, who shall also be solely responsible for the means, methods, and sequencing of construction operations. Kleinfelder is providing excavation sloping information solely as a service to our client for planning purposes. Under no circumstances should the information be interpreted to mean that Kleinfelder is assuming responsibility for construction site safety or the Contractor’s activities; such responsibility is not being implied and should not be inferred. For planning purposes, un-shored excavations should be inclined no steeper than 1.5H:1V. If seepage or perched groundwater conditions are observed, further flattening or buttressing of slopes may be required. Heavy construction equipment, building materials, excavated soil, and vehicular traffic should not be allowed near the top of any excavation. Where the stability of adjoining buildings, walls, or other structures is endangered by excavation operations, support systems such as shoring, bracing, or underpinning may be required to provide structural stability and to protect personnel working within the excavation. Earth retention, bracing, or underpinning required for the project (if any) should be designed by a professional engineer registered in the State of Washington. 20221909.001A/SEA21R133024 Page 35 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com Temporary excavations and slopes should be protected from the elements by covering with plastic sheeting or some other similar impermeable material. Sheeting sections should overlap by at least 12 inches and be tightly secured with sandbags, tires, staking, or other means to prevent wind from exposing the soils under the sheeting. Perched groundwater in trench subgrades is not anticipated, however, the contractor should be prepared to control water by means of sumps and pumps and prevent accumulation of water to the greatest extent practical. 6.4 PAVEMENTS The pavement sections provided above are contingent on the following recommendations being implemented during construction. Pavement subgrade should be prepared as recommended in Section 6.1.4. Aggregate base materials should be compacted to at least 95 percent their maximum dry density as determined by ASTM D1557. Asphalt paving materials and placement methods should meet current Costco Wholesale Specifications Section 321216. Adequate drainage should be provided such that the subgrade soils and aggregate base materials are not allowed to become wet. Note that pavement materials and construction must be completed in strict accordance with the Costco’s specifications that contain very specific pavement material (asphalt, aggregate and concrete) criteria and construction practices to be used (compaction and material sampling). The general contractor and pavement construction subcontractor should be aware that asphalt and concrete mix designs must be submitted to the design architect and the Geotechnical Engineer of Record at least 45 days prior to the scheduled production and laydown for review and approval. 20221909.001A/SEA21R133024 Page 36 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 7 ADDITIONAL SERVICES ____________________________________________________________________________ 7.1 PLANS AND SPECIFICATIONS REVIEW It is recommended that Kleinfelder perform a review of geotechnical related portions of the project plans and specifications before they are finalized to see that geotechnical recommendations have been properly interpreted and implemented during design. If Kleinfelder is not accorded the opportunity of performing this review, we can assume no responsibility for misinterpretation of these recommendations. 7.2 CONSTRUCTION OBSERVATION AND TESTING The construction process is an integral design component with respect to the geotechnical aspects of a project. Because we sample only a limited portion of the soils affecting the performance of the proposed structure, unanticipated or changed conditions can be encountered during grading. Proper geotechnical observation and testing during construction are imperative to allow the geotechnical engineer the opportunity to verify assumptions made during the design process. Therefore, Kleinfelder should be retained during the construction of the proposed improvements to observe compliance with the design concepts and geotechnical recommendations, and to recommend design changes in the event that subsurface conditions or methods of construction differ from those this report is based on. Kleinfelder’s services are typically needed at the following stages of grading: Following site grubbing and during subgrade stabilization, compaction, and proof rolling; During structural fill placement; During utility trench backfill; During base placement and site paving; and, After excavation for foundations. 20221909.001A/SEA21R133024 Page 37 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 8 LIMITATIONS This geotechnical study has been prepared for the exclusive use of Costco Wholesale and their agents for specific application to the proposed Costco Wholesale Warehouse in Ridgefield, WA. The findings, conclusions and recommendations presented in this report were prepared in accordance with accepted geotechnical engineering practices. No other warranty, express or implied, is made. The scope of services was limited to a background data review and the field exploration described in Section 1. It should be recognized that definition and evaluation of subsurface conditions are difficult. Judgments leading to conclusions and recommendations are generally made with incomplete knowledge of the subsurface conditions present due to the limitations of data from field studies. The conclusions of this assessment are based on our field exploration and laboratory testing programs, and engineering analyses. Kleinfelder offers various levels of investigative and engineering services to suit the varying needs of different clients. Although risk can never be eliminated, more detailed and extensive studies yield more information, which may help understand and manage the level of risk. Since detailed study and analysis involves greater expense, our clients participate in determining levels of service, which provide information for their purposes at acceptable levels of risk. The client and key members of the design team should discuss the issues covered in this report with Kleinfelder, so that the issues are understood and applied in a manner consistent with the owner’s budget, tolerance of risk and expectations for future performance and maintenance. Recommendations contained in this report are based on our field observations and subsurface explorations, limited laboratory tests, and our present knowledge of the proposed construction. It is possible that soil or groundwater conditions could vary between or beyond the points explored. If soil or groundwater conditions are encountered during construction that differ from those described herein, the client is responsible for ensuring that Kleinfelder is notified immediately so that we may reevaluate the recommendations of this report. If the scope of the proposed construction, including the estimated Traffic Index or locations of the improvements, changes from that described in this report, the conclusions and recommendations contained in this report are not considered valid until the changes are reviewed, and the conclusions of this report are modified or approved in writing, by Kleinfelder. 20221909.001A/SEA21R133024 Page 38 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com The scope of services for this subsurface exploration and geotechnical report did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or groundwater at this site. Kleinfelder cannot be responsible for interpretation by others of this report, or the conditions encountered in the field. Kleinfelder must be retained so that all geotechnical aspects of construction will be monitored on a full-time basis by a representative from Kleinfelder, including site preparation, preparation of foundations, and placement of engineered fill and trench backfill. These services provide Kleinfelder the opportunity to observe the actual soil and groundwater conditions encountered during construction and to evaluate the applicability of the recommendations presented in this report to the site conditions. If Kleinfelder is not retained to provide these services, we will cease to be the engineer of record for this project and will assume no responsibility for any potential claim during or after construction on this project. If changed site conditions affect the recommendations presented herein, Kleinfelder must also be retained to perform a supplemental evaluation and to issue a revision to our original report. This report, and any future addenda or reports regarding this site, may be made available to bidders to supply them with only the data contained in the report regarding subsurface conditions and laboratory test results at the point and time noted. Bidders may not rely on interpretations, opinion, recommendations, or conclusions contained in the report. Because of the limited nature of any subsurface study, the contractor may encounter conditions during construction which differ from those presented in this report. In such event, the contractor should promptly notify the owner so that Kleinfelder’s geotechnical engineer can be contacted to confirm those conditions. We recommend the contractor describe the nature and extent of the differing conditions in writing and that the construction contract include provisions for dealing with differing conditions. Contingency funds should be reserved for potential problems during earthwork and foundation construction. This report may be used only by the client and only for the purposes stated, within a reasonable time from its issuance, but in no event later than one year from the date of the report. Land use, site conditions (both on site and off site) or other factors may change over time, and additional work may be required with the passage of time. Any party, other than the client who wishes to use this report shall notify Kleinfelder of such intended use. Based on the intended use of this report and the nature of the new project, Kleinfelder may require that additional work be performed and that an updated report be issued. Non-compliance with any of these requirements by the client or anyone else will release Kleinfelder from any liability resulting from the use of this report 20221909.001A/SEA21R133024 Page 39 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com by any unauthorized party and the client agrees to defend, indemnify, and hold harmless Kleinfelder from any claims or liability associated with such unauthorized use or non-compliance. 20221909.001A/SEA21R133024 Page 40 of 40 November 24,2021 © 2021 Kleinfelder www.kleinfelder.com 9 REFERENCES 2018 International Building Code, International Code Council, www.codes.iccsafe.org. American Concrete Institute (ACI), 2014, Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14). American Association of State Highway and Transportation Structures (AASHTO), AASHTO Guide for Design of Pavement Structures, 1993. American Water Works Association, 2010, Polyethylene Encasement for Ductile-Iron Pipe Systems, ANSI/AWWA C105/A21.5-10. Costco, 2020, Costco Wholesale Development Requirements, Version 2020 National Association of Corrosion Engineers (NACE), 2006, “Corrosion Basics, An Introduction, 2nd Edition” National Association of Corrosion Engineers. Portland Cement Association (PCA), 1984, Thickness Design for Concrete Highway and Street Pavements, Skokie, Illinois: Portland Cement Association. Liquefaction Susceptibility Map of Clark County, Washington, September 2004 Washington Geological Survey, 2019, Surface geology, 1:24,000--GIS data, November 2019: Washington Geological Survey Digital Data Series DS-10, version 3.1, previously released September 2017. FIGURES ____________________________________________________________________________ Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P, NRCan, Esri Japan, METI, Esri China (Hong Kong), Esri Korea, Esri (Thailand), NGCC, (c) OpenStreetMap contributors, and the GIS User Community Copyright:(c) 2018 Garmin 1 20221909 RS The information included on this graphic representation has been compiled from a variety of sources and is subject to change without notice. Kleinfelder makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. This document is not intended for use as a land survey product nor is it designed or intended as a construction design document. The use or misuse of the information contained on this graphic representation is at the sole risk of the party using or misusing the information. PROJECT NO. DRAWN BY: CHECKED BY: DATE: FIGURE Area MapBase: DeLorme World Base, ESRI REVISED: 09-21-2021 JDS SITE 0 3,000 6,000 Feet VICINITY MAP PROPOSED COSTCO RIDGEFIELD NW CORNER OF I-5 AND PIONEER STREET (SR-501) RIDGEFIELD, WASHINGTON CW20-0312 KB-27 KB-28KB-30 KB-29 KB-26 KB-31 KB-7 KB-8 KB-6 KB-21 KB-5 KB-22 KB-1 KB-12KB-9 KB-10 KB-13 KB-4 KB-3 KB-19 KB-16 KB-17 KB-15 KB-14 KB-2 KB-32 KB-20 KB-18 KB-23 KB-24 KB-11 KB-25 CPT-2 CPT-1 CPT-6 CPT-7 CPT-5 CPT-8 CPT-4CPT-3 KTP-1 KTP-2 KTP-4 KTP-8 KTP-5 KTP-7 KTP-6 KTP-3 KTP-9 LEGEND SOIL BORING LOCATION TEST PIT LOCATION CPT LOCATION 0 SCALE IN FEET 100 200 SCALE: 1" = 100' N REFERENCE: BASE MAPPING CREATED FROM THE FOLLOWING:PLAN TITLED "PRELIMINARY SITE PLAN, P11-05",DATED: 7-26-21, PREPARED BY MG2;BASE MAP IMAGE CREATED FROM DATA COMPILEDBY 2021 MICROSOFT CORP. Theinformation included onthisgraphicrepresentationhasbeencompiledfromavarietyofsourcesandissubjecttochangewithoutnotice.Kleinfeldermakesnorepresentationsorwarranties,express or implied,as to accuracy,completeness,timeliness,or rights to the use of suchinformation.Thisdocumentisnotintendedforuseasalandsurveyproductnorisitdesignedorintendedasaconstructiondesigndocument.The use or misuseof theinformationcontainedonthisgraphicrepresentationisatthesole risk of the party using or misusing the information. CAD FILE:W:\2022\02221909.001A - Costco Ridgefield\SITE PLAN.dwg LAYOUT:F2 PLOTTED:8/27/2021 12:24 PM BY: jeff sala DRAWN BY DATE: PROJECT NO. CHECKED BY REVISED: FIGURE20221909 JDS RS 08-27-2021 2PROPOSED COSTCO RIDGEFIELD NW CORNER OF I-5 AND PIONEER STREET (SR-501)RIDGEFIELD, WASHINGTONCW20-0312 APPENDIX A EXPLORATION LOGS ____________________________________________________________________________ The site exploration program was completed in August 202 and consisted of 32 borings, 8 CPT and 10 test pit explorations within the warehouse and fuel facility footprints, and in the parking lot areas. Additionally, two (2) standpipe piezometers were installed. The site exploration program was conducted under full-time observation of a Kleinfelder geotechnical engineer or geologist. The Site and Exploration Plan, Figure 2, shows locations of explorations performed by Kleinfelder for this study. Prior to drilling or excavating, boring and test pit locations were cleared for buried utilities through the One-Call Utility Locate Service and by a private utility locator. Boring and test pit logs are presented in this Appendix. An explanation to the logs is presented on Figures A-1 and A-2. The boring and test pit logs describe the earth materials encountered, samples obtained and show field and laboratory tests performed. The logs also show the location, boring or test pit number, exploration date and the name of the drilling or excavation subcontractor. The explorations were logged by a Kleinfelder geotechnical engineer or geologist using the Unified Soil Classification System. The boundaries between soil types shown on the logs are approximate because the transition between different soil layers may be gradual. Bulk samples of selected earth materials were obtained from the test pits. A Standard Penetration Test (SPT) sampler was used to obtain the drive samples of the soil encountered in the borings. Standard Penetration Test (SPT) sampling techniques (ASTM D1586) consisted of driving a 1-3/8-inch inside diameter (2-inch outside diameter) split spoon sampler a distance of 18 inches into the bottom of the boring. The sampler was driven with a 140-pound hammer falling 30 inches. The hammer was controlled using an auto-hammer mechanism. The number of blows required to drive the sampler each of three 6-inch increments was recorded on the boring logs. The number of blows required for the last 12 inches of penetration is called the standard penetration resistance (N value). This value is an indicator of the relative density of granular soils or the consistency of fine-grained soils. Bulk and grab samples were retrieved from auger cuttings and the excavated material in the test pits. APPENDIX B GEOTECHNICAL LABORATORY TESTING ____________________________________________________________________________ GENERAL Laboratory tests were performed on selected samples as an aid in classifying the soils and to evaluate physical properties of the soils that may affect foundation design and construction procedures. The tests were performed in general conformance with the current ASTM standards. A description of the laboratory-testing program is presented below. MOISTURE CONTENT Moisture content tests were performed on selected samples recovered from the explorations. Moisture contents were determined in general accordance with ASTM Test Method D 2216. Results of these tests are presented on the boring logs. GRAIN-SIZE DISTRIBUTION Grain-size distribution analyses were performed on samples in general accordance with ASTM Test Method D422 to determine the grain-size distribution of the on-site soil. Additionally, we analyzed percent fines to determine the amount of material passing the U.S. Standard No. 200 sieve (material less than 0.075 mm). The information gained from this analysis allows us to provide a detailed description and classification of the in-place materials. In turn, this information helps us to understand how the in-place materials will react to conditions such as loading, potential liquefaction, and so forth. PLASTICITY INDEX Plasticity Index (liquid and plastic limit) testing was performed on selected samples of the on-site soils to determine plasticity characteristics and to aid in the classification of the soil. The tests were performed in accordance with ASTM Test Method D 4318. The results are presented on the boring logs STANDARD PROCTOR Standard Proctor tests were performed on bulk samples of the on-site soils to investigate the moisture-density relationship of a soil, the compaction characteristics of soil under variable moisture content, and the optimum moisture content that will result in the maximum soil unit weight when compacted with a particular effort. The tests were performed in accordance with ASTM D 698. CBR The California Bearing Ratio (CBR) test is a bearing test that compares the relative stiffness of a material with that of a well-graded crushed stone. It is primarily intended for, but not limited to, evaluating the strength of cohesive materials having maximum particle sizes less than 19 mm (0.75 in.) The tests were performed in accordance with ASTM D 1833. Test Method: ASTM D2435, Method B Sample Type: Intact Sample Description: Sandy Fat Clay (CH) Gs: 2.65 LL: 57 PI: 36 Amount of Material Finer than the No. 200, %: 42.2 86.6 92.6 Remarks: PROJECT NO.: 20221909 ENTRY BY:bco CHECKED BY:mbb Height, in. Diameter, in. Water Content, % Dry Density, lb/f3 Saturation, % Void Ratio Assumed Final 0.936 2.500 30.8 100.0 0.787 Initial 1.000 2.500 28.4 82.7 Wet Density, lb/f3 113.2 121.0 S-6 Boring: KB-12 Test Date: 10/22/21 Depth, ft: 20 CW20-0312 0.911 , , PAGE: 1 of 1 DATE:11/2/2021 B-13 ONE DIMENSIONAL CONSOLIDATION TEST PROPOSED COSTCO RIDGEFIELD NW Corner of I-5 and Pioneer Street (SR-501) Ridgefield, Washington APPENDIX Sample: -2.00 0.00 2.00 4.00 6.00 8.00 10.00 100 1,000 10,000 Strain, %Vertical Effective Stress, psf 0.700 0.800 0.900 10 100 1,000 10,000 100,000Void RatioVertical Effective Stress, psf APPENDIX C CONE PENETRATION TEST LOGS ____________________________________________________________________________ Cone Penetration Test Summary and Standard Cone Penetration Test Plots Job No: 21 59 22816 Client: Kleinfelder Project: Ridgefield WA CPT Start Date: 17 Aug 2021 End Date: 18 Aug 2021 CONE PENETRATION TEST SUMMARY Sounding ID File Name Date Cone Assumed Phreatic Surface 2 (ft) Final Depth (ft) Shear Wave Velocity Tests Latitude1 (deg) Longitude1 (deg) CPT 1 21 59 22816_SP01.COR 2021 08 17 780:T1500F15U35 Not detected 82.0 25 45.81915 122.69382 CPT 2 21 59 22816_CP02.COR 2021 08 17 780:T1500F15U35 Not detected 60.2 45.82033 122.69359 CPT 3 21 59 22816_CP03.COR 2021 08 17 780:T1500F15U35 Not detected 60.2 45.82052 122.69336 CPT 4 21 59 22816_CP04.COR 2021 08 17 780:T1500F15U35 Not detected 62.5 45.82030 122.69245 CPT 5 21 59 22816_CP05.COR 2021 08 17 780:T1500F15U35 Not detected 60.7 45.81949 122.69250 CPT 6 21 59 22816_CP06.COR 2021 08 17 780:T1500F15U35 Not detected 60.9 45.81918 122.69278 CPT 7 21 59 22816_CP07.COR 2021 08 17 780:T1500F15U35 Not detected 61.0 45.81955 122.69312 CPT 8 21 59 22816_SP08.COR 2021 08 18 780:T1500F15U35 Not detected 87.0 27 45.82014 122.69318 Totals 8 soundings 534.5 52 1. Coordinates were collected using a handheld GPS WGS 84 Lat/Long. 2. Phreatic surface was not confirmed at any location during all testing. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-17 11:02 Site:Ridgefield WA CPT Sounding:CPT-1 Cone:780:T1500F15U35 Max Depth: 25.000 m / 82.02 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_SP01.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.81914 Long: -122.69382 Sands Sand Mixtures Silt MixturesSilt MixturesSand Mixtures Sand Mixtures Silt MixturesSilt MixturesSilt Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Sand Mixtures Silt Mixtures ClaysSilt MixturesSilt Mixtures Silt Mixtures Clays ClaysSilt MixturesSilt Mixtures Silt Mixtures ClaysClaysSilt MixturesClaysClays Silt Mixtures ClaysClaysClaysClays ClaysSilt Mixtures Clays Silt MixturesClays Silt MixturesUndefined Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-17 16:20 Site:Ridgefield WA CPT Sounding:CPT-2 Cone:780:T1500F15U35 Max Depth: 18.350 m / 60.20 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_CP02.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.82033 Long: -122.69359 Sand MixturesSands Sand Mixtures Silt Mixtures ClaysSilt MixturesSilt MixturesSilt MixturesSilt MixturesSand Mixtures Silt MixturesClaysSilt MixturesSilt MixturesSilt Mixtures Silt Mixtures Silt Mixtures Sand Mixtures Silt Mixtures ClaysClaysSilt MixturesSilt Mixtures Silt Mixtures ClaysSilt Mixtures Clays Undefined Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-17 15:27 Site:Ridgefield WA CPT Sounding:CPT-3 Cone:780:T1500F15U35 Max Depth: 18.350 m / 60.20 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_CP03.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.82052 Long: -122.69335 Silt Mixtures Sand Mixtures Silt MixturesVery Stiff Fine GrainedStiff Sand to Clayey SandStiff Sand to Clayey SandSilt Mixtures Silt Mixtures Silt MixturesClays Sand Mixtures Silt MixturesSilt MixturesSilt MixturesSilt MixturesSilt MixturesSilt MixturesClays Sand MixturesSand MixturesSilt MixturesSilt MixturesSilt MixturesSand MixturesSand MixturesSand MixturesSilt MixturesSilt MixturesClays ClaysSilt Mixtures ClaysSilt Mixtures Silt MixturesSilt Mixtures Silt MixturesClays Clays Clays Undefined Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-17 14:42 Site:Ridgefield WA CPT Sounding:CPT-4 Cone:780:T1500F15U35 Max Depth: 19.050 m / 62.50 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_CP04.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.82030 Long: -122.69245 Silt Mixtures Sand Mixtures Sand MixturesSand MixturesSand Mixtures Silt Mixtures ClaysSilt MixturesSilt MixturesClaysSilt MixturesSilt MixturesSand Mixtures Sand MixturesClaysClaysClaysClaysClaysSand Mixtures Silt Mixtures Sand MixturesSilt MixturesClaysClays ClaysSilt Mixtures ClaysClaysSilt MixturesClaysSilt MixturesClaysSilt Mixtures Clays Silt Mixtures Clays Undefined Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-17 13:49 Site:Ridgefield WA CPT Sounding:CPT-5 Cone:780:T1500F15U35 Max Depth: 18.500 m / 60.69 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_CP05.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.81949 Long: -122.69250 Sand MixturesSands Sand Mixtures Silt MixturesSilt Mixtures Silt Mixtures Sand MixturesSand Mixtures Silt Mixtures Sand MixturesSilt Mixtures ClaysSilt MixturesSand Mixtures Sand MixturesSilt Mixtures Clays Silt Mixtures ClaysSilt MixturesSilt MixturesSilt Mixtures Silt MixturesClaysClays Silt MixturesSilt MixturesClays Sand Mixtures Silt Mixtures Clays Silt Mixtures ClaysSilt MixturesClays Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-17 07:51 Site:Ridgefield WA CPT Sounding:CPT-6 Cone:780:T1500F15U35 Max Depth: 18.550 m / 60.86 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_CP06.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.81918 Long: -122.69278 Silt MixturesSands Sand Mixtures Sand MixturesSilt MixturesSilt Mixtures Sand Mixtures Silt Mixtures Sand Mixtures Silt MixturesSand Mixtures Silt Mixtures Sand Mixtures Sand Mixtures Stiff Sand to Clayey SandSand MixturesSand Mixtures Silt Mixtures Sand Mixtures Silt Mixtures ClaysClays Silt MixturesClays ClaysClays Silt MixturesSilt MixturesSilt Mixtures Sand MixturesSand Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-17 09:56 Site:Ridgefield WA CPT Sounding:CPT-7 Cone:780:T1500F15U35 Max Depth: 18.600 m / 61.02 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_CP07.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.81955 Long: -122.69312 ClaysSandsSand Mixtures Sand MixturesSilt Mixtures Silt Mixtures Sand Mixtures Sand MixturesSand Mixtures Silt Mixtures Sand Mixtures Silt Mixtures Sand Mixtures Silt MixturesSand MixturesSilt MixturesClays Silt Mixtures ClaysSilt Mixtures Sand Mixtures Silt Mixtures ClaysSilt MixturesSilt Mixtures Silt MixturesClaysSilt MixturesSilt Mixtures ClaysSilt MixturesClays Silt Mixtures Clays Ueq(ft) Target Depth Target Depth Target Depth Target Depth Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. 0 100 200 300 400 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 qt (tsf)Depth (feet)0 5 10 15 fs (tsf) 0.0 2.5 5.0 7.5 Rf (%) 0 500 10000 u (ft) 0 3 6 9 SBT Qtn Kleinfelder Job No: 21-59-22816 Date:2021-08-18 07:15 Site:Ridgefield WA CPT Sounding:CPT-8 Cone:780:T1500F15U35 Max Depth: 26.525 m / 87.02 ftDepth Inc: 0.025 m / 0.082 ftAvg Int: Every Point File:21-59-22816_SP08.CORUnit Wt: SBTQtn (PKR2009)SBT:Robertson, 2009 and 2010Coords:Lat: 45.82014 Long: -122.69318 Sand MixturesSands Sand MixturesSilt MixturesSilt MixturesSilt MixturesSand Mixtures ClaysSilt Mixtures Sand Mixtures Silt MixturesSand MixturesSilt Mixtures Silt Mixtures Sand Mixtures Silt MixturesClaysSilt MixturesSilt Mixtures Silt MixturesClaysClaysSilt Mixtures Silt MixturesClays Silt Mixtures ClaysClaysClays ClaysClaysClaysClaysClaysSilt Mixtures Silt Mixtures Clays Silt MixturesClaysSilt MixturesSilt Mixtures Clays Silt Mixtures Silt MixturesSilt Mixtures Ueq(ft) Refusal Refusal Refusal Refusal Equilibrium Pore Pressure (Ueq)Assumed Ueq Dissipation, Ueq achieved Dissipation, Ueq not achieved Hydrostatic LineThe reported coordinates were acquired from hand-held GPS equipment and are only approximate locations. The coordinates should not be used for design purposes. APPENDIX D ANALYTICAL LABORATORY TESTING ____________________________________________________________________________ Am Test Inc. 13600 NE 126TH PL Suite C Kirkland, WA 98034 (425) 885-1664 www.amtestlab.com ANALYSIS REPORT KLEINFELDER Date Received: 09/08/21 14710 NE 87th St Date Reported: 10/ 1/21 Redmond, WA 98052 Attention: WILL ROSSO Project Name: RIDGEFIELD WAREHOUSE Project #: 20221909.001A PO Number: 20221909.001A All results reported on an as received basis. _________________________________________________________________________________________________ AMTEST Identification Number 21-A013457 Client Identification KB-1-1@2.5 Sampling Date 08/25/21 Conventionals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE pH 6.3 unit 1 SW-846 9045D KW 09/20/21 Resistivity 27000 ohms cm 100 ASTM G-187 MD 09/24/21 Redox Potential 539. unit 200 ASTM D1498-76 MD 09/14/21 Sulfide < 1 ug/g 1 SM 4500 S2 MD 09/21/21 Minerals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE Chloride 11. ug/g 10 EPA 300.0 KS 09/15/21 Sulfate 44. ug/g 10 EPA 300.0 KS 09/15/21 KLEINFELDER Project Name: RIDGEFIELD WAREHOUSE AmTest ID: 21-A013458 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013458 Client Identification KB-3-2@5 Sampling Date 08/24/21 Conventionals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE pH 6.2 unit 1 SW-846 9045D KW 09/20/21 Resistivity 40000 ohms cm 100 ASTM G-187 MD 09/24/21 Redox Potential 543. unit 200 ASTM D1498-76 MD 09/14/21 Sulfide < 1 ug/g 1 SM 4500 S2 MD 09/21/21 Minerals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE Chloride < 10 ug/g 10 EPA 300.0 KS 09/15/21 Sulfate < 10 ug/g 10 EPA 300.0 KS 09/15/21 KLEINFELDER Project Name: RIDGEFIELD WAREHOUSE AmTest ID: 21-A013459 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013459 Client Identification KB-17-1@2.5 Sampling Date 08/26/21 Conventionals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE pH 5.9 unit 1 SW-846 9045D KW 09/20/21 Resistivity 49000 ohms cm 100 ASTM G-187 MD 09/24/21 Redox Potential 528. unit 200 ASTM D1498-76 MD 09/14/21 Sulfide < 1 ug/g 1 SM 4500 S2 MD 09/21/21 Minerals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE Chloride < 10 ug/g 10 EPA 300.0 KS 09/15/21 Sulfate 14. ug/g 10 EPA 300.0 KS 09/15/21 KLEINFELDER Project Name: RIDGEFIELD WAREHOUSE AmTest ID: 21-A013460 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013460 Client Identification KTP8.1G Sampling Date 08/18/21 Conventionals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE pH 6.3 unit 1 SW-846 9045D KW 09/20/21 Minerals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE Calcium 1700 ug/g 140 EPA 6010D JDR 09/23/21 Potassium 1070 ug/g 700 EPA 6010D JDR 09/23/21 Magnesium 3000 ug/g 35. EPA 6010D JDR 09/23/21 Sodium 204.0 ug/g 140 EPA 6010D JDR 09/23/21 Chloride < 10 ug/g 10. EPA 300.0 KS 09/15/21 KLEINFELDER Project Name: RIDGEFIELD WAREHOUSE AmTest ID: 21-A013460 Total Metals PARAMETER RESULT UNITS Q D.L. METHOD ANALYST DATE Acid Digestion Y SW-846 3050B JDR 09/23/21 Silver < 7.03 ug/g 7.0 EPA 6010D JDR 09/23/21 Aluminum 21900 ug/g 350 EPA 6010D JDR 09/23/21 Arsenic < 14.1 ug/g 14. EPA 6010D JDR 09/23/21 Boron 27.3 ug/g 21. EPA 6010D JDR 09/23/21 Barium 162. ug/g 7.0 EPA 6010D JDR 09/23/21 Beryllium 4.65 ug/g 3.5 EPA 6010D JDR 09/23/21 Cadmium < 3.517 ug/g 3.5 EPA 6010D JDR 09/23/21 Cobalt 8.49 ug/g 7.0 EPA 6010D JDR 09/23/21 Chromium 25.3 ug/g 14. EPA 6010D JDR 09/23/21 Copper 16.4 ug/g 14. EPA 6010D JDR 09/23/21 Iron 22300 ug/g 70. EPA 6010D JDR 09/23/21 Lithium 38.3 ug/g 21. EPA 6010D JDR 09/23/21 Manganese 646. ug/g 7.0 EPA 6010D JDR 09/23/21 Molybdenum < 7.03 ug/g 7.0 EPA 6010D JDR 09/23/21 Sodium Absorption Ratio 0.06 USDA 20b JDR 09/24/21 Nickel 16.4 ug/g 7.0 EPA 6010D JDR 09/23/21 Phosphorus 1310 ug/g 350 EPA 6010D JDR 09/23/21 Lead 17.5 ug/g 14. EPA 6010D JDR 09/23/21 Sulfur < 352 ug/g 350 EPA 6010D JDR 09/23/21 Antimony < 7.03 ug/g 7.0 EPA 6010D JDR 09/23/21 Selenium < 14.1 ug/g 14. EPA 6010D JDR 09/23/21 Silicon 2330 ug/g 350 EPA 6010D JDR 09/23/21 Tin < 70.3 ug/g 70. EPA 6010D JDR 09/23/21 Strontium 23.5 ug/g 3.5 EPA 6010D JDR 09/23/21 Titanium 1290 ug/g 7.0 EPA 6010D JDR 09/23/21 Thallium < 7.03 ug/g 7.0 EPA 6010D JDR 09/23/21 Vanadium 64.5 ug/g 14. EPA 6010D JDR 09/23/21 Zinc 86.9 ug/g 14. EPA 6010D JDR 09/23/21 Mercury 0.0470 ug/g 0.0100 SW-846 7471B MD 09/13/21 KLEINFELDER Project Name: RIDGEFIELD WAREHOUSE AmTest ID: 21-A013460 Miscellaneous PARAMETER RESULT UNITS Q D.L. METHOD ANLST DATE Soluble Salts 40. mmhos/cm 0.5 SM 2510 B KF 09/21/21 Organic Matter 7.0 %SM 2540G MD 09/14/21 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013461 Client Identification KTP1.2G Sampling Date 08/18/21 Miscellaneous PARAMETER RESULT UNITS Q D.L. METHOD ANLST DATE Organic Matter 6.3 %SM 2540G MD 09/14/21 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013462 Client Identification KTP2.2G Sampling Date 08/18/21 Miscellaneous PARAMETER RESULT UNITS Q D.L. METHOD ANLST DATE Organic Matter 4.2 %SM 2540G MD 09/14/21 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013463 Client Identification KTP4.2G Sampling Date 08/18/21 KLEINFELDER Project Name: RIDGEFIELD WAREHOUSE AmTest ID: 21-A013463 Miscellaneous PARAMETER RESULT UNITS Q D.L. METHOD ANLST DATE Organic Matter 5.6 %SM 2540G MD 09/14/21 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013464 Client Identification KTP4.1G Sampling Date 08/18/21 Miscellaneous PARAMETER RESULT UNITS Q D.L. METHOD ANLST DATE Organic Matter 7.7 %SM 2540G MD 09/14/21 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013465 Client Identification KTP2.1G Sampling Date 08/18/21 Miscellaneous PARAMETER RESULT UNITS Q D.L. METHOD ANLST DATE Organic Matter 6.6 %SM 2540G MD 09/14/21 _________________________________________________________________________________________________ AMTEST Identification Number 21-A013466 Client Identification KT1.1G Sampling Date 08/18/21 Miscellaneous PARAMETER RESULT UNITS Q D.L. METHOD ANLST DATE Organic Matter 6.7 %SM 2540G MD 09/14/21 KLEINFELDER Project Name: RIDGEFIELD WAREHOUSE AmTest ID: 21-A013466 _________________________________ Kathy Fugiel President