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SUB2025-00007_Exhibit#11_Geotech
GEOTECHNICAL REPORT Jefferson County Rural Airport Light Industrial Park Four Corners Road Jefferson County, Washington Project No. T-9082 Prepared for: AHBL, Inc. Tacoma, Washington October 16, 2024 12220 113th Avenue NE, Ste. 130, Kirkland, Washington 98034 Phone (425) 821‐7777 • Fax (425) 821‐4334 October 16, 2024 Project No. T-9082 Mr. Bart Brynestad AHBL, Inc. 2215 North 30th Street Tacoma, Washington 98403 Subject: Geotechnical Report Jefferson County Rural Airport Light Industrial Park Four Corners Road Jefferson County, Washington Dear Mr. Brynestad: As requested, we conducted a geotechnical engineering study for the subject project. The attached report presents our findings and recommendations for the geotechnical aspects of project design and construction. Site soils generally consist of four to six inches of forest duff and topsoil overlying approximately one to seven feet of stiff to very stiff clay with sand (Glaciomarine Outwash) over medium dense to very dense, sandy gravel (Recessional Outwash) to the termination of the test pits. Minor groundwater seepage was observed at depths of approximately 10 feet below current site grades in 8 of the 23 test pits. In our opinion, there are no geotechnical conditions that would preclude the planned development. The structures can be supported on conventional spread footings bearing on competent native soils underlying the surface organic soils or on structural fill placed on the competent native soils. Floor slabs and pavements can be similarly supported. Detailed recommendations addressing these issues and other geotechnical design considerations are presented in the attached report. We trust the information presented is sufficient for your current needs. If you have any questions or require additional information, please call. Sincerely yours, TERRA ASSOCIATES, INC. John A. Manke, L.E.G. Project Geologist Carolyn S. Decker, P.E. President TABLE OF CONTENTS Page No. 1.0 Project Description .......................................................................................................... 1 2.0 Scope of Work ................................................................................................................. 1 3.0 Site Conditions ................................................................................................................ 2 3.1 Surface ................................................................................................................ 2 3.2 Soils .................................................................................................................... 2 3.3 Groundwater ....................................................................................................... 3 3.4 Geologic Hazards ............................................................................................... 3 3.4.1 Erosion Hazard Areas ........................................................................ 3 3.4.2 Landslide Hazard Hazard Areas ........................................................ 4 3.4.3 Seismic Hazard Areas ........................................................................ 4 3.5 Seismic Site Class ............................................................................................... 5 4.0 Discussion and Recommendations .................................................................................. 5 4.1 General................................................................................................................ 5 4.2 Site Preparation and Grading .............................................................................. 5 4.3 Slopes and Embankments ................................................................................... 7 4.4 Excavations ......................................................................................................... 7 4.5 Foundations ........................................................................................................ 7 4.6 Slab on Grade Floors .......................................................................................... 8 4.7 Lateral Earth Pressure for Below Grade Walls ................................................... 8 4.8 Infiltration Feasibility ......................................................................................... 9 4.9 Stormwater Facilities .......................................................................................... 9 4.10 Drainage............................................................................................................ 10 4.11 Utilities ............................................................................................................. 11 4.12 Pavements ......................................................................................................... 11 5.0 Additional Services ........................................................................................................ 12 6.0 Limitations ..................................................................................................................... 12 Figures Vicinity Map ......................................................................................................................... Figure 1 Exploration Location Plan .................................................................................................... Figure 2 Typical Wall Drainage Detail ............................................................................................... Figure 3 Appendix Field Exploration and Laboratory Testing ....................................................................... Appendix A Geotechnical Report Jefferson County Rural Airport Light Industrial Park Four Corners Road Jefferson County, Washington 1.0 PROJECT DESCRIPTION The project consists of developing the site with 11 light industrial building pads and associated access and utilities. Site stormwater will be collected and directed to a pond located east of the development. Grading and development plans were not available at the time of this report. Based on existing site topography, we expect grading to be moderate with cuts and fills ranging from approximately one to ten feet for the industrial buildings. We expect the buildings will be constructed using precast reinforced concrete tilt-up perimeter wall panels with interior isolated columns supporting a steel or wood-truss roof system. We expect structural loads will be light, about 100 to 150 kips for isolated columns and 4 to 6 kips per foot for continuous perimeter bearing walls. Maximum product loading on the floors is not expected to exceed 350 pounds per square foot (psf). The recommendations contained in the following sections of this report are based on the above design features. If actual features vary or changes are made, we should review them in order to modify our recommendations, as required. We should review the final design drawings and specifications to verify our recommendations have been properly interpreted and incorporated into project design and construction. 2.0 SCOPE OF WORK Our work was completed in accordance with our authorized proposal dated May 13, 2024. Accordingly, on August 29 and 30, 2024, we investigated subsurface conditions at the site by observing soil conditions in 23 test pits excavated to maximum depths of about 11 feet below existing surface grades using a track-mounted excavator. Using the results of our field study and laboratory testing, analyses were undertaken to develop geotechnical recommendations for project design and construction. Specifically, this report addresses the following: Soil and groundwater conditions. Geologic Hazards per the Jefferson County Code. Seismic design parameters per the current International Building Code (IBC). Site preparation and grading. Excavations. Foundations. Floor Slabs. Stormwater facilities. October 16, 2024 Project No. T-9072 Page No. 2 Infiltration Feasibility. Drainage. Utilities. Pavements. It should be noted that recommendations outlined in this report regarding drainage are associated with soil strength, design earth pressures, erosion, and stability. Design and performance issues with respect to moisture as it relates to the structure environment are beyond Terra Associates’ purview. A building envelope specialist or contactor should be consulted to address these issues, as needed. 3.0 SITE CONDITIONS 3.1 Surface The primary site consists of a single tax parcel totaling approximately 23.6 acres located north of the intersection of Four Corners Road and Night Owl Road in Jefferson County, Washington. The proposed pond area is approximately one acre in size and is located a portion of four tax parcels east of the primary site. The approximate location of the site is shown on Figure 1. The primary parcel is predominantly undeveloped and covered with a moderate forest and associated understory. The four parcels where the proposed offsite pond is located are predominantly undeveloped and covered with a moderate forest in the southwestern portion of the area. The remainder of the area has been cleared and is covered with brush and trails. Site topography is relatively flat over the majority of the proposed development area. The offsite pond area has a slight slope that descends from the southwest to the northeast with an overall relief of approximately 25 feet. 3.2 Soils In general, the soil conditions observed in the test pits consisted of approximately four to six inches of topsoil overlying one to seven feet of stiff to very stiff clay with sand (Glaciomarine Outwash) over medium dense to very dense, sandy gravel (Recessional Outwash) to the termination of the test pits. The Geologic Map of the Port Townsend South and Part of the Port Townsend North 7.5-minute Quadrangles, Jefferson County, Washington, by Henry W Schasse and Stephen L. Slaughter (2005), maps the soils at the site as Vashon recessional outwash (Qgo). Schasse and Slaughter (2005) describe this unit as “pebble to cobble gravel and sand; gray to tan, generally unoxidized with little iron staining except in the upper 3 to 4 feet; generally well rounded, unconsolidated; planar to cross-bedded.” Glaciomarine outwash (Qgome) is also mapped in the site vicinity. This soil unit is described by Schasse and Slaughter (2005) as “sand with silt and lenses of gravel; tan to gray; loose; may be capped by silt and clay.” The mapped soil descriptions are consistent with our field observations. October 16, 2024 Project No. T-9072 Page No. 3 The preceding discussion is intended to be a general review of the soil conditions encountered. For more detailed descriptions, please refer to the Test Pit Logs in Appendix A. The approximate location of the test pits is shown on Figure 2. 3.3 Groundwater Light groundwater seepage was observed at approximately ten feet in Test Pits TP-3, TP-4, TP-5, TP-6, TP-9, TP- 10, TP-11, TP-20, and TP-21. The groundwater is interpreted to be a part of the regional groundwater table and would be present at the site year-round. We expect that groundwater levels and flow rates will fluctuate seasonally and will typically reach their highest levels during and shortly following the wet winter months (October through May). Based on the time of year of our exploration, the groundwater levels observed likely represent the seasonal low groundwater elevations. 3.4 Geologic Hazards Section 18.22.160.1 of the Jefferson County Code (JCC) defines geologically hazard areas as erosion hazard areas, landslide hazard areas, and seismic hazard areas. 3.4.1 Erosion Hazard Areas Section 18.22.160.2.a of the JCC defines surface erosion hazard areas as “areas containing soils or soil complexes described and mapped within the United States Department of Agriculture/Soil Conservation Service Soil Survey for Jefferson County as having a severe or very severe erosion hazard potential.” The site soils are classified as Agnew silt loam, 0 to 8 percent slopes (map unit AgB), Cassolary sandy loam, 0 to 15 percent slopes (map unit CfC), and Swantown gravelly sandy loam, 0 to 8 percent slopes (map unit StB) by the United States Department of Agriculture Natural Resources Conservation Services (NRCS). These soil units are described as glaciomarine deposits, glacial drift and/or marine deposits, and till, respectively. These soils are not categorized as having “severe” or “very severe” erosion hazards. The site topography is relatively flat over the majority of the proposed development area and not located above a coastal or stream erosion area. Therefore, in our opinion, the site is not an erosion hazard area as defined by the JCC. Regardless, the site soils would be susceptible to some erosion when exposed during construction. In our opinion, proper implementation, and maintenance of Best Management Practices (BMPs) for erosion prevention and sediment control would adequately mitigate the erosion potential in the planned development area. Erosion protection measures as required by Jefferson County will need to be in place prior to and during grading activities at the site. October 16, 2024 Project No. T-9072 Page No. 4 3.4.2 Landslide Hazard Areas Section 18.22.160.2.b of the JCC defines landslide hazard areas as “areas potentially subject to mass movement due to a combination of geologic, topographic, and hydrologic factors including: (i) Areas of historic failures or potentially unstable slopes, such as: (A) Areas described and mapped as having severe or very severe building limitations for dwellings without basements within the United States Department of Agriculture/Soil Conservation Service Soil Survey for Jefferson County; (B) Areas described and mapped as recent or old landslides or slopes of unstable materials within the Washington State Department of Ecology Coastal Zone Atlas of Jefferson County; and (C) Areas described and mapped as areas of poor natural stability, former landslides and recent landslides by the Washington State Department of Natural Resources, Division of Geology and Earth Resources; ii) Areas potentially unstable as a result of rapid stream incision, stream bank erosion, or undercutting by wave action; and iii) Areas with any indications of earth movement, such as: (A) Rockslides; (B) Earthflows; (C) Mudflows; (D) Landslides.” Site topography is relatively flat over the majority of the proposed development area. The offsite pond area has a slight slope that descends from the southwest to the northeast with an overall relief of approximately 25 feet. Based on our observations while onsite and review of the Jefferson County GIS map, in our opinion, no landslide hazard areas are present at the subject site as defined by the JCC. 3.4.3 Seismic Hazard Areas Section 18.22.160.2.c of the JCC defines seismic hazard areas as “areas subject to severe risk of damage as a result of earthquake induced ground shaking, slope failure, settlement, soil liquefaction, or surface faulting. These areas are identified by the presence of: poorly drained soils with greater than 50 percent silt and very little coarse material; loose sand or gravel, peat, artificial fill and landslide materials; or soil units with high organic content.” October 16, 2024 Project No. T-9072 Page No. 5 Liquefaction is a phenomenon where there is a reduction or complete loss of soil strength due to an increase in water pressure induced by vibrations. Liquefaction mainly affects geologically recent deposits of fine-grained sands underlying the groundwater table. Soils of this nature derive their strength from intergranular friction. The generated water pressure or pore pressure essentially separates the soil grains and eliminates this intergranular friction; thus, eliminating the soil’s strength. Based on the soil and groundwater conditions we observed at the site, it is our opinion that the risk for damage resulting from soil liquefication or subsidence during a severe seismic event is negligible. Therefore, in our opinion, unusual seismic hazard areas do not exist at the site, and design in accordance with local building codes for determining seismic forces would adequately mitigate impacts associated with ground shaking. 3.5 Seismic Site Class Based on the site soil conditions and our knowledge of the area geology, per the current International Building Code (IBC), site class “D” should be used in structural design. 4.0 DISCUSSION AND RECOMMENDATIONS 4.1 General Based on our study, there are no geotechnical conditions that would preclude the planned development. The light industrial buildings can be supported on conventional spread footings bearing on competent native soils underlying the surface organic soils or on structural fill placed on the competent native soils. Floor slabs and pavements can be similarly supported. The upper site soils contain a sufficient amount of fines (silt- and clay-sized particles) such that they will be very difficult to compact as structural fill when too wet or too dry. Accordingly, the ability to use the soils from site excavations as structural fill will depend on their moisture content and the prevailing weather conditions at the time of construction. If grading activities take place during the winter season, the owner should be prepared to import free-draining granular material for use as structural fill and backfill. The cleaner sand and gravel should be suitable for use as structural fill year-round. Detailed recommendations regarding these issues and other geotechnical design considerations are provided in the following sections of this report. These recommendations should be incorporated into the final design drawings and construction specifications. 4.2 Site Preparation and Grading To prepare the site for construction, all vegetation, organic surface soils, and other deleterious materials should be stripped and removed from the site. We expect surface stripping depths of about four to six inches will be required to remove the organic surficial soils. Organic soils will not be suitable for use as structural fill but may be used for limited depths in nonstructural areas or for landscaping purposes. October 16, 2024 Project No. T-9072 Page No. 6 Once clearing and stripping operations are complete, cut and fill operations can be initiated to establish desired grades. Prior to placing fill, all exposed bearing surfaces should be observed by a representative of Terra Associates, Inc. to verify soil conditions are as expected and suitable for support of new fill. Our representative may request a proofroll using heavy rubber-tired equipment to determine if any isolated soft and yielding areas are present. If excessively yielding areas are observed, and they cannot be stabilized in place by compaction, the affected soils should be excavated and removed to firm bearing and grade restored with new structural fill. Beneath embankment fills or roadway subgrade if the depth of excavation to remove unstable soils is excessive, the use of geotextile fabrics, such as Mirafi 500X, or an equivalent fabric, can be used in conjunction with clean granular structural fill. Our experience has shown that, in general, a minimum of 18 inches of a clean, granular structural fill placed and compacted over the geotextile fabric should establish a stable bearing surface. Our study indicates the upper site soils contain a sufficient percentage of fines (silt- and clay-sized particles) that will make them very difficult to compact as structural fill if they are too wet or too dry. Accordingly, the ability to use the upper soils as structural fill will depend on their moisture content and the prevailing weather conditions when site grading activities take place. If wet soils are encountered, the contractor will need to dry the soils by aeration during dry weather conditions. Alternatively, the use of an additive such as Portland cement or lime to stabilize the soil moisture can be considered. If the soil is amended, additional Best Management Practices (BMPs) addressing the potential for elevated pH levels will need to be included in the Stormwater Pollution Prevention Program (SWPPP) prepared with the Temporary Erosion and Sedimentation Control (TESC) plan. The cleaner sand and gravel should be suitable for use year-round. If grading activities are planned during the wet winter months, or if they are initiated during the summer and extend into fall and winter, the owner should be prepared to import wet-weather structural fill. For this purpose, we recommend importing a granular soil that meets the following grading requirements. U.S. Sieve Size Percent Passing 6 inches 100 No. 4 75 maximum No. 200 5 maximum* *Based on the 3/4-inch fraction. Prior to use, Terra Associates, Inc. should examine and test all materials planned to be imported to the site for use as structural fill. Structural fill should be placed in uniform loose layers not exceeding 12 inches and compacted to a minimum of 95 percent of the soil’s maximum dry density, as determined by American Society for Testing and Materials (ASTM) Test Designation D-1557 (Modified Proctor). The moisture content of the soil at the time of compaction should be within two percent of its optimum, as determined by this ASTM standard. In nonstructural areas, the degree of compaction may be reduced to 90 percent. October 16, 2024 Project No. T-9072 Page No. 7 4.3 Slopes and Embankments All permanent cut and fill slopes should be graded with a finished inclination of no greater than 2:1 (Horizontal: Vertical). Upon completion of grading, the slope face should be appropriately vegetated or provided with other physical means to guard against erosion. Final grades at the top of the slope must promote surface drainage away from the slope crest. Water must not be allowed to flow uncontrolled over the slope face. If surface runoff must be directed towards the top of a slope, it may be necessary to route collected water to an appropriate point of discharge beyond the toe in a closed system. 4.4 Excavations All excavations at the site associated with confined spaces, such as utilities and lower building level retaining walls, must be completed in accordance with local, state, and federal requirements. Based on the Washington Industrial Safety and Health Administration (WISHA) regulations, the site soils would typically be classified as Type C soils. Accordingly, temporary excavations in Type C soils should have their slopes laid back at an inclination of 1.5:1 (Horizontal: Vertical) or flatter, from the toe to the crest of the slope. If there is insufficient room to complete the excavations in this manner, or if excav ations greater than 20 feet deep are planned, you may need to use temporary shoring to support the excavations. For utility trenches, properly designed and installed trench boxes may be used for excavation support. Based on our study, groundwater should be anticipated within excavations extending below a depth of about ten feet below native surface grades. Excavations extending below this depth will likely encounter groundwater with volumes and flow rates sufficient to require some level of dewatering. Shallow excavations that do not extend more than two to three feet below the groundwater table can likely be dewatered by conventional sump-pumping procedures along with a system of collection trenches. Deeper excavations will require dewatering by well points or isolated deep-pump wells. The utility subcontractor should be prepared to implement excavation dewatering by well point or deep-pump wells, as needed. This will be an especially critical consideration for any deep excavations such for lift stations and sanitary sewer tie-ins. The above information is provided solely for the benefit of the owner and other design consultants and should not be construed to imply that Terra Associates, Inc. assumes responsibility for job site safety. It is understood that job site safety is the sole responsibility of the project contractor. 4.5 Foundations The light industrial buildings may be supported on conventional spread footing foundations bearing on competent native soils or on structural fills placed above these native soils. Foundation subgrades should be prepared, as recommended in Section 4.2 of this report. Perimeter foundations exposed to the weather should bear at a minimum depth of one and one-half feet below final exterior grades for frost protection. Interior foundations can be constructed at any convenient depth below the floor slab. October 16, 2024 Project No. T-9072 Page No. 8 We recommend designing foundations bearing on competent native soils or on new structural fill for a net allowable bearing capacity of 2,500 pounds per square foot (psf). For short-term loads, such as wind and seismic, a one-third increase in this allowable capacity can be used in design. With the anticipated loads and this bearing stress applied, building settlements should be less than one inch total and one-half inch differential. For designing foundations to resist lateral loads, a base friction coefficient of 0.35 can be used. Passive earth pressure acting on the sides of the footings may also be considered. We recommend calculating this lateral resistance using an equivalent fluid weight of 300 pounds per cubic foot (pcf). We recommend not including the upper 12 inches of soil in this computation because they can be affected by weather or disturbed by future grading activity. This value assumes the foundations will be constructed neat against competent native soil or the excavations are backfilled with structural fill, as described in Section 4.2 of this report. The recommended passive and friction values include a safety factor of 1.5. 4.6 Slab-on-Grade Floors Slab-on-grade floors may be supported on subgrade prepared as recommended in Section 4.2 of this report. Immediately below the floor slab, we recommend placing a four-inch-thick capillary break layer composed of clean, coarse sand or fine gravel that has less than five percent passing the No. 200 sieve. This material will reduce the potential for upward capillary movement of water through the underlying soil and subsequent wetting of the floor slab. Installation of a capillary break layer will not be necessary where the floor subgrade is composed of the clean native outwash or structural fill comprised of the clean outwash. A representative of Terra Associates should observe the subgrade at the time of construction to verify this condition and determine if an imported capillary break layer is required. The capillary break layer will not prevent moisture intrusion through the slab caused by water vapor transmission. Where moisture by vapor transmission is undesirable, such as covered floor areas, a common practice is to place a durable plastic membrane on the capillary break layer and then cover the membrane with a layer of clean sand or fine gravel to protect it from damage during construction, and aid in uniform curing of the concrete slab. It should be noted that if the sand or gravel layer overlying the membrane is saturated prior to pouring the slab, it will be ineffective in assisting uniform curing of the slab and can actually serve as a water supply for moisture seeping through the slab and affecting floor coverings. Therefore, in our opinion, covering the membrane with a layer of sand or gravel should be avoided if floor slab construction occurs during the wet winter months and the layer cannot be effectively drained. 4.7 Lateral Earth Pressure for Below Grade Walls The magnitude of earth pressure development on lower level building concrete retaining walls will partly depend upon the quality of the wall backfill. We recommend placing and compacting wall backfill as structural fill. To guard against hydrostatic pressure development, wall drainage must also be installed. A typical recommended wall drainage detail is shown on Figure 3. October 16, 2024 Project No. T-9072 Page No. 9 With wall backfill placed and compacted as recommended and drainage properly installed, we recommend designing unrestrained walls for an active earth pressure equivalent to a fluid weighing 35 pcf. For restrained walls, an additional uniform lateral pressure of 100 psf should be added to the 35 pcf. For evaluating wall performance under seismic loading, an additional uniform pressure equivalent to 8H psf, where H is the below-grade portion of the wall in feet, should be used. These values assume a horizontal backfill condition and that no other surcharge loading, such as traffic, sloping embankments, or adjacent buildings, will act on the wall. If such conditions exist, then the imposed loading must be included in the wall design. Friction at the base of foundations and passive earth pressure will provide resistance to these lateral loads. Values for these parameters are provided in Section 4.5. 4.8 Infiltration Feasibility On a preliminary basis, it is our opinion that the outwash gravel and sand formation observed contains relatively low fines contents and will support infiltration of project stormwater. Minor groundwater seepage was observed at depths of approximately ten feet below existing site grades during the summer months. A minimum separation distance of five feet must be maintained between the seasonal high groundwater and the bottom of the infiltration facility. The distance can be reduced to three feet provided a mounding analysis is completed. We used the Soil Grain Size Analysis Method as outlined in Volume V, Chapter 5.4 of the Washington State Department of Ecology 2024 Stormwater Management Manual for Western Washington to determine a preliminary long-term design infiltration rate. This method correlates the saturated hydraulic conductivity with the D10, D60, and D90 particle sizes determined from gradation testing of the soils in accordance with ASTM Test Designation D-422. The D10 particle size represents the grain size below which ten percent of the soil is smaller in size. The D60 particle size represents the grain size below which 60 percent of the soil is smaller in size. The D90 particle size represents the grain size below which 90 percent of the soil is smaller in size. Gradation curves from laboratory testing on the soils are attached in Appendix A. Based on the testing results, a preliminary long-term design infiltration rate of ten inches per hour can be used. We should review the stormwater infiltration facility plans, when available, to confirm facility design and location is consistent with the ground conditions observed at the site. The permeability of the native outwash soils will be significantly impacted by the intrusion of soil fines (silt- and clay-sized particles). A relatively minor amount of soil fines can reduce the permeability of the formation by a factor of ten. The greatest exposure to soil fines contamination will occur during mass grading and construction. Therefore, we recommend that the Temporary Erosion and Sedimentation Control (TESC) plans route construction stormwater to a location other than the permanent infiltration facility. 4.9 Stormwater Facilities As discussed, site stormwater will be collected and directed to a detention pond located on a portion of four parcels located east of the site project area. October 16, 2024 Project No. T-9072 Page No. 10 If fill berms are constructed, the berm locations should be stripped of topsoil, duff, and soils containing organic material prior to the placement of fill. The fill berms should be constructed by placing structural fill in accordance with recommendations outlined in Section 4.2 of this report. Material used to construct pond berms should consist of predominately granular soils with a maximum size of three inches and a minimum of 20 percent fines. Terra Associates, Inc. should examine and test all onsite or imported materials proposed for use as berm fill prior to their use. Due to the exposure to fluctuating stored water levels and wave action, soils exposed on the interior side slopes of the ponds may be subject to some risk of periodic shallow instability or sloughing. Establishing interior slopes at a 3:1 gradient will significantly reduce or eliminate this potential. Exterior berm slopes and interior slopes above the maximum water surface should be graded to a finished inclination no steeper than 2:1. Finished slope faces should be thoroughly compacted and vegetated to guard against erosion. 4.10 Drainage Surface Final exterior grades should promote free and positive drainage away from the site at all times. Water must not be allowed to pond or collect adjacent to foundations or within the immediate building areas. We recommend providing a positive drainage gradient away from the building perimeters. If this gradient cannot be provided, surface water should be collected adjacent to the structures and disposed to appropriate storm facilities. Surface water from developed areas must not be allowed to flow in an uncontrolled and concentrated manner over the crests of site slopes and embankments. Surface water should be directed away from the slope crests to a point of collection and controlled discharge. If site grades do not allow for directing surface water away from the slopes, then the water should be collected and tightlined to an approved point of controlled discharge. Subsurface In our opinion, with the area immediately adjacent to the structure paved, and positive surface drainage maintained, perimeter foundation drains would not be necessary. If the grade is not positively drained away from the structure or if the perimeter is landscaped, perimeter foundation drains should be installed. Where foundation drains are installed, the drains should be laid to grade at an invert elevation equivalent to the bottom of footing grade. The drains can consist of four-inch diameter perforated PVC pipe that is enveloped in washed pea gravel-sized drainage aggregate. The aggregate should extend six inches above and to the sides of the pipe. The foundation drains should be tightlined to an approved point of controlled discharge independent of the roof drain system. All drains should be provided with cleanouts at easily accessible locations. These cleanouts should be serviced at least once every year. October 16, 2024 Project No. T-9072 Page No. 11 4.11 Utilities Utility pipes should be bedded and backfilled in accordance with American Public Works Association (APWA) or Jefferson County requirements. At minimum, trench backfill should be placed and compacted as structural fill, as described in Section 4.2 of this report. As noted, soils excavated onsite should be suitable for use as backfill material. However, some of the site soils are fine grained and moisture sensitive; therefore, moisture conditioning may be necessary to facilitate proper compaction. If utility construction takes place during the winter, it may be necessary to import suitable wet weather fill for utility trench backfilling. 4.12 Pavements Pavement subgrades should be prepared as described in Section 4.2 of this report. Regardless of the degree of relative compaction achieved, the subgrade must be firm and relatively unyielding before paving. The subgrade should be proofrolled with heavy rubber-tired construction equipment such as a loaded 10-yard dump truck to verify this condition. The pavement design section is dependent upon the supporting capability of the subgrade soils and the traffic conditions to which it will be subjected. We expect traffic will consist mostly of loaded and unloaded tractor-trailer rigs. For design considerations, we have assumed traffic can be represented by an 18-kip Equivalent Single Axle Loading (ESAL) of 300,000 over a 20-year design life. This ESAL represents loading approximately equivalent to 18 fully loaded (80,000-pound GVW) tractor-trailer rigs traversing the pavement daily. With a stable subgrade prepared as recommended, we recommend the following options for pavement sections: Three inches of HMA over six inches of CRB. Full depth HMA – five inches. For exterior Portland cement concrete (PCC) pavement, we recommend the following: 6 inches of PCC over two inches of CRB. o 28-day compressive strength – 4,000 psi. o Control joints spaced at a maximum of 15 feet. The paving materials used should conform to the Washington State Department of Transportation (WSDOT) specifications for ½-inch class HMA, PCC, and CRB. Long-term pavement performance will depend on surface drainage. A poorly-drained pavement section will be subject to premature failure resulting from surface water infiltrating the subgrade soils and reducing their supporting capability. For optimum performance, we recommend surface drainage gradients of at least two percent. Some degree of longitudinal and transverse cracking of the pavement surface should be expected over time. Regular maintenance should be planned to seal cracks as they occur. October 16, 2024 Project No. T-9072 Page No. 12 5.0 ADDITIONAL SERVICES Terra Associates, Inc. should review the final designs and specifications in order to verify that earthwork and foundation recommendations have been properly interpreted and implemented in project design. We should also provide geotechnical services during construction in order to observe compliance with our design concepts, specifications, and recommendations. This will allow for design changes if subsurface conditions differ from those anticipated prior to the start of construction. 6.0 LIMITATIONS We prepared this report in accordance with generally accepted geotechnical engineering practices. No other warranty, expressed or implied, is made. This report is the copyrighted property of Terra Associates, Inc. and is intended for specific application to the Jefferson County Rural Airport Light Industrial Park project in Jefferson County, Washington. This report is for the exclusive use of AHBL, Inc. and its authorized representatives. No other warranty, expressed or implied, is made. The analyses and recommendations presented in this report are based on data obtained from the subsurface explorations completed onsite. Variations in soil conditions can occur, the nature and extent of which may not become evident until construction. If variations appear evident, Terra Associates, Inc. should be requested to reevaluate the recommendations in this report prior to proceeding with construction. © 2024 Microsoft Corporation © 2024 TomTom SITE Environmental Earth Sciences Terra Associates, Inc. Consultants in Geotechnical Engineering Geology and Figure 1 VICINITY MAP 0 2000 4000 APPROXIMATE SCALE IN FEET REFERENCE: https://www.bing.com/maps ACCESSED 2024 Proj.No. T-9082 Date: OCT 2024 PORT TOWNSEND, WASHINGTON JEFFERSON COUNTY INTERNATIONAL RURAL AIRPORT LIGHT INDUSTRIAL PARK TP-1TP-2TP-3TP-4TP-5TP-6TP-7TP-8TP-9TP-10TP-11TP-12TP-13TP-14TP-15TP-16TP-17TP-18TP-19TP-20TP-21TP-22TP-23REFERENCE:REFERENCE ONLY AND SHOULD NOT BE USED FORDESIGN OR CONSTRUCTION PURPOSES.DIMENSIONS ARE APPROXIMATE. IT IS INTENDED FORNOTE:THIS SITE PLAN IS SCHEMATIC. ALL LOCATIONS ANDConsultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth SciencesEXPLORATION LOCATION PLANFigure 2LEGEND:0150300APPROXIMATE SCALE IN FEETSITE PLAN PROVIDED BY CLIENT.APPROXIMATE TEST PIT LOCATIONProj.No. T-9082Date: OCT 2024PORT TOWNSEND, WASHINGTONJEFFERSON COUNTY INTERNATIONAL RURALAIRPORT LIGHT INDUSTRIAL PARK 12" COMPACTED STRUCTURAL FILL EXCAVATED SLOPE (SEE REPORT TEXT FOR APPROPRIATE INCLINATIONS) SLOPE TO DRAIN 12" MINIMUM 3/4" MINUS WASHED GRAVEL 3" BELOW PIPE 12" OVER PIPE 4" DIAMETER PERFORATED PVC PIPE SEE NOTE 6"(MIN.) NOT TO SCALE NOTE: MIRADRAIN G100N PREFABRICATED DRAINAGE PANELS OR SIMILAR PRODUCT CAN BE SUBSTITUTED FOR THE 12-INCH WIDE GRAVEL DRAIN BEHIND WALL. DRAINAGE PANELS SHOULD EXTEND A MINIMUM OF SIX INCHES INTO 12-INCH THICK DRAINAGE GRAVEL LAYER OVER PERFORATED DRAIN PIPE. Environmental Earth Sciences Terra Associates, Inc. Consultants in Geotechnical Engineering Geology and TYPICAL WALL DRAINAGE DETAIL Figure 3Proj.No. T-9082 Date: OCT 2024 PORT TOWNSEND, WASHINGTON JEFFERSON COUNTY INTERNATIONAL RURAL AIRPORT LIGHT INDUSTRIAL PARK Project No. T-9082 APPENDIX A FIELD EXPLORATION AND LABORATORY TESTING Jefferson County Rural Airport Light Industrial Park Jefferson County, Washington On August 29 and 30, 2024, we investigated subsurface conditions at the site by excavating 23 test pits to a depth of approximately 10 feet below existing surface grades using a track-mounteded excavator. The test pit locations were approximately determined in the field using GPS coordinates and by pacing from existing surface features. The approximate test pit locations are shown on Figure 2. The Test Pit Logs are presented on Figures A-2 through A-24. An engineering geologist from our office maintained a log of each test pit as it was excavated, classified the soil conditions encountered, and obtained representative soil samples. All soil samples were visually classified in the field in accordance with the Unified Soil Classification System. A copy of this classification is presented as Figure A-1. Representative soil samples obtained from the test pits were placed in sealed plastic bags and taken to our laboratory for further examination and testing. The moisture content of selected samples was measured and is reported on the corresponding Test Pit Logs. Atterberg limits and grain size analyses were also performed on select samples. The results of the Atterberg limits tests are on the individual Test Pit Logs. The results of the Grain Size Analysis are shown on Figures A-25 through A-27. Environmental Earth Sciences Terra Associates, Inc. Consultants in Geotechnical Engineering Geology and MAJOR DIVISIONS LETTER SYMBOL TYPICAL DESCRIPTION GRAVELS More than 50% of coarse fraction is larger than No. 4 sieve Clean Gravels (less than 5% fines) GW Well-graded gravels, gravel-sand mixtures, little or no fines. GP Poorly-graded gravels, gravel-sand mixtures, little or no fines. Gravels with fines GM Silty gravels, gravel-sand-silt mixtures, non-plastic fines. GC Clayey gravels, gravel-sand-clay mixtures, plastic fines. SANDS More than 50% of coarse fraction is smaller than No. 4 sieve Clean Sands (less than 5% fines) SW Well-graded sands, sands with gravel, little or no fines. SP Poorly-graded sands, sands with gravel, little or no fines. Sands with fines SM Silty sands, sand-silt mixtures, non-plastic fines. SC Clayey sands, sand-clay mixtures, plastic fines. SILTS AND CLAYS Liquid Limit is less than 50% ML Inorganic silts, rock flour, clayey silts with slight plasticity. CL Inorganic clays of low to medium plasticity. (Lean clay) OL Organic silts and organic clays of low plasticity. SILTS AND CLAYS Liquid Limit is greater than 50% MH Inorganic silts, elastic. CH Inorganic clays of high plasticity. (Fat clay) OH Organic clays of high plasticity. HIGHLY ORGANIC SOILS PT Peat.COARSE GRAINED SOILSMore than 50% material largerthan No. 200 sieve sizeFINE GRAINED SOILSMore than 50% material smallerthan No. 200 sieve sizeDEFINITION OF TERMS AND SYMBOLS COHESIONLESSCOHESIVE Standard Penetration Density Resistance in Blows/Foot Very Loose 0-4 Loose 4-10 Medium Dense 10-30 Dense 30-50 Very Dense >50 Standard Penetration Consistancy Resistance in Blows/Foot Very Soft 0-2 Soft 2-4 Medium Stiff 4-8 Stiff 8-16 Very Stiff 16-32 Hard >32 2" OUTSIDE DIAMETER SPILT SPOON SAMPLER 2.4" INSIDE DIAMETER RING SAMPLER OR SHELBY TUBE SAMPLER WATER LEVEL (Date) Tr TORVANE READINGS, tsf Pp PENETROMETER READING, tsf DD DRY DENSITY, pounds per cubic foot LL LIQUID LIMIT, percent PI PLASTIC INDEX N STANDARD PENETRATION, blows per foot UNIFIED SOIL CLASSIFICATION SYSTEM Figure A-1Proj.No. T-9082 Date: OCT 2024 PORT TOWNSEND, WASHINGTON JEFFERSON COUNTY INTERNATIONAL RURAL AIRPORT LIGHT INDUSTRIAL PARK Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-2 T-9082 JAM Jefferson County, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-1 NA NA NA 1 2 3 5.1 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GP) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Caving from approximately 8 to 10 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-3 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-2 NA NA 8 - 10 ft 1 2 3 Medium Dense to Dense (6 Inches of Topsoil) Gray-brown sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Caving from approximately 8 to 10 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-4 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-3 NA 10 ft NA 1 2 3 4.4 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL with silt, fine to coarse gravel, fine to coarse sand, moist, cobbles, occasional boulders. (GW-GM) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 10 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-5 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-4 NA 10 ft NA 1 2 3 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 10 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-6 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-5 NA 10 ft NA 1 2 3 1.9 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GP) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 10 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-7 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-6 NA 8 ft NA 1 2 3 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown, silty CLAY with sand, fine sand, moist, low plasticity. (CL-ML) (Glaciomarine Outwash) LL = 27 PL = 20 PI = 7 Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 8 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-8 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-7 NA NA NA 1 2 3 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown GRAVEL with silt and sand, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW-GM) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-9 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO.TP- 8 NA NA NA 1 2 3 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) LL = 36 PL = 22 PI = 14 Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-10 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-9 NA 8 ft NA 1 2 3 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown sandy, GRAVEL with silt, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW-GM) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 8 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-11 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-10 NA 8 ft NA 1 2 3 4.0 Very Stiff to Hard Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL with silt, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW-GM) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 8 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-12 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-11 NA 8 ft NA 1 2 3 4.0 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 8 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-13 T-9082 JAM Port Townsend, Washington Forest Duff August 30, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-12 NA NA NA 1 2 3 4.0 Very Stiff Medium Dense to Dense (4 inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-14 T-9082 JAM Port Townsend, Washington Forest Duff August 30, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-13 NA NA NA 1 2 3 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-15 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-14 NA NA NA 1 2 3 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-16 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-15 NA 8NA 1 2 3 Very Stiff Medium Dense to Dense (6 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 8 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-17 T-9082 JAM Port Townsend, Washington Forest Duff August 30, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-16 NA NA NA 1 2 3 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-18 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-17 NA NA NA 1 2 3 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL with silt, fine gravel, fine to coarse sand, moist, cobbles. (GP-GM) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-19 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-18 NA NA NA 1 2 3 3.6 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) LL = 27 PL = 19 PI = 8 Gray-brown, sandy GRAVEL with silt, fine gravel, fine to coarse sand, moist, cobbles. (GP-GM) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-20 T-9082 JAM Port Townsend, Washington Forest Duff August 29, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-19 NA NA NA 1 2 3 Very Stiff to Hard Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-21 T-9082 JAM Port Townsend, Washington Forest Duff August 30, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-20 NA 10 ft NA 1 2 3 31.9 5.2 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) LL = 32 PL = 22 PI = 10 Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 10 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-21 T-9082 JAM Port Townsend, Washington Forest Duff August 30, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-21 NA 10 ft NA 1 2 3 Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. Light groundwater seepage at approximately 10 feet. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-23 T-9082 JAM Port Townsend, Washington Grass August 30, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-22 NA NA NA 1 2 3 2.6 Stiff to Very Stiff Medium Dense to Dense (4 Inches of Topsoil) Light brown CLAY with sand, fine sand, moist, low plasticity. (CL) (Glaciomarine Outwash) Dark gray to dark brown CLAY with sand, fine sand, moist, low plasticity, occasional organics. (ML) (Glaciomarine Outwash) Gray-brown sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GM) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY: LOCATION: DATE LOGGED: APPROX. ELEV: DEPTH TO CAVING: FIGURE DEPTH TO GROUNDWATER: SURFACE CONDITIONS: Description Consistency/ Relative Density W (%)interpreted as being indicative of other locations at the site. NOTE: This subsurface information pertains only to this test pit location and should not be 0 1 2 3 4 5 6 7 8 9 10 11 12 A-24 T-9082 JAM Port Townsend, Washington Grass August 30, 2024 Jefferson County Rural Light Industrial Park LOG OF TEST PIT NO. TP-23 NA NA NA 1 2 3 3.4 Loose Medium Dense to Dense (4 Inches of Topsoil) FILL: Dark brown, silty SAND with gravel, moist, some organics. (SM) Gray-brown, sandy GRAVEL, fine to coarse gravel, fine to coarse sand, moist, cobbles. (GW) (Recessional Outwash) Test pit terminated at approximately 10 feet. No groundwater seepage. Tested By: ZA LL PL D85 D60 D50 D30 D15 D10 Cc Cu Material Description USCS AASHTO Project No. Client:Remarks: Project: Location: TP-1 Depth: 5' Location: TP-3 Depth: 5' Location: TP-5 Depth: 3' Terra Associates, Inc. Kirkland, WA Figure 24.7432 15.3920 13.1116 8.5390 1.1982 0.4250 11.15 36.22 17.7569 10.1525 7.2329 2.7576 0.9425 0.3489 2.15 29.10 25.0377 13.5058 10.4244 4.0942 0.7457 0.3411 3.64 39.60 Sandy GRAVEL GW Sandy GRAVEL with trace silt GW Sandy GRAVEL GW T-9082 ABLH, Inc. A-25PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 27.3 48.3 5.7 8.7 6.2 3.8 0.0 12.4 45.3 19.1 12.2 5.9 5.1 0.0 25.6 42.1 11.6 8.7 7.8 4.26 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Jefferson County Rural Airport Light Industrial Park Tested September 26, 2024 Tested September 26, 2024 Tested September 26, 2024 Tested By: ZA LL PL D85 D60 D50 D30 D15 D10 Cc Cu Material Description USCS AASHTO Project No. Client:Remarks: Project: Location: TP-10 Depth: 6' Location: TP-12 Depth: 10' Location: TP-18 Depth: 4' Terra Associates, Inc. Kirkland, WA Figure 25.9026 15.2664 12.5484 6.8270 0.2873 20.8648 12.4183 9.9551 2.5945 0.6583 0.3787 1.43 32.79 9.6146 6.1712 5.2755 3.6768 2.4552 1.6136 1.36 3.82 Sandy GRAVEL with silt GW-GM Sandy GRAVEL GW Sandy GRAVEL with trace silt GW T-9082 ABLH, Inc. A-26PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 28.7 45.5 6.2 2.7 5.4 11.5 0.0 18.6 43.6 11.6 14.9 9.0 2.3 0.0 0.0 56.4 33.0 2.1 2.5 6.06 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Jefferson County Rural Airport Light Industrial Park Tested September 26, 2024 Tested September 26, 2024 Tested September 26, 2024 Tested By: ZA LL PL D85 D60 D50 D30 D15 D10 Cc Cu Material Description USCS AASHTO Project No. Client:Remarks: Project: Location: TP-20 Depth: 10' Location: TP-22 Depth: 10 Location: TP-23 Depth: 6' Terra Associates, Inc. Kirkland, WA Figure 20.4087 11.6566 9.2904 4.5348 1.8637 0.8715 2.02 13.38 26.7333 15.2704 12.1437 5.9529 2.0579 1.0686 2.17 14.29 13.9730 7.3445 6.1369 4.0940 2.4297 1.7282 1.32 4.25 Sandy GRAVEL GW Sandy GRAVEL GW Sandy GRAVEL GW T-9082 ABLH, Inc. A-27PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 17.5 51.5 15.2 8.6 4.1 3.1 0.0 29.9 43.7 11.7 7.7 3.5 3.5 0.0 9.3 54.2 24.7 9.1 2.1 0.66 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report Jefferson County Rural Airport Light Industrial Park Tested September 26, 2024 Tested September 26, 2024 Tested September 26, 2024