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HomeMy WebLinkAboutGEOTECH 2013-03-05 1 Geotechnical Engineering Report Port Townsend U-Haul Facility Port Townsend, Washington March 5, 2013 Terracon Project No. 81135003 Prepared for: Amerco Real Estate Co. Phoenix, Arizona Prepared by: Terracon Consultants, Inc. Mountlake Terrace, Washington TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................... i  1.0 INTRODUCTION ............................................................................................................... 1  2.0 PROJECT INFORMATION ............................................................................................... 1  2.1 Site Delineation .......................................................................................................... 1  2.2 Previous Site Usage ................................................................................................... 2  2.3 Proposed Site Development ...................................................................................... 2  2.4 Scope of Work ............................................................................................................ 3   3.0 SITE SETTING .................................................................................................................. 4   3.1 Regional Geography .................................................................................................. 4  3.2 Regional Geology ....................................................................................................... 4  3.3 Regional Zoning ......................................................................................................... 5  4.0 SITE CONDITIONS ........................................................................................................... 5  4.1 Surface Features ........................................................................................................ 5  4.2 Soil Stratigraphy ......................................................................................................... 6  4.3 Soil Properties ............................................................................................................ 7  4.4 Groundwater Levels ................................................................................................... 7  5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................ 7  5.1 General Considerations ............................................................................................. 8  5.2 Site Preparation ......................................................................................................... 9   5.3 Spread Footings ....................................................................................................... 10  5.4 Slab-On-Grade Floors .............................................................................................. 12  5.5 Drainage Systems .................................................................................................... 13  5.6 Backfilled Walls ........................................................................................................ 14  5.7 Pavement Sections .................................................................................................. 16  5.8 Structural Fill ............................................................................................................ 18  6.0 GENERAL COMMENTS ................................................................................................. 19  FIGURES Figure 1 — Site Location Map Figure 2 — Site & Exploration Plan APPENDIX A – Field Exploration Procedures, General Notes, and Logs APPENDIX B – Laboratory Testing Procedures, Soil Classifications and Results APPENDIX C – Supplemental Information Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 EXECUTIVE SUMMARY Terracon has completed a geotechnical engineering evaluation for the proposed construction of a new U-Haul rental and storage facility at the project site. Our scope of work included fifteen exploratory test pits, four shallow field infiltration tests, limited laboratory soil testing, geotechnical analysis, and preparation of this report. Based on our findings, we have derived the following geotechnical conclusions and recommendations:  Subsurface Conditions: The entire site appears to be underlain by layered soils that include loose, organic silts; soft, clayey silts; loose to dense sands and gravels; hard, clayey silts; and dense to very dense glacial till. Perched groundwater was present at shallow depths in localized areas across the site.  Geological Hazards: Based on municipal zoning maps, the site does not appear to be subjected to any geological hazards that will affect the proposed development.  Grading Considerations: Due to the presence of unfavorable soils at or closely below existing ground surface, it would be advantageous to lower grades across the northern and eastern parts of the site before other construction work begins.  Foundations: The proposed buildings and canopies can be supported by conventional spread footings that bear on medium dense to dense or hard native soils. Any loose or soft soils existing below footings should be overexcavated vertically and laterally, and then be replaced with aggregate bearing pads.  Floor Support: Conventional slab-on-grade floors can be used within the new buildings if the floor subgrades are properly prepared and if a subbase is used in each case.  Site Drainage: We recommend installing a subsurface interceptor drain along the northern and eastern edges of the site to capture groundwater seepage emanating from the adjacent hillslopes.  Infiltration Considerations: The native sand and gravel outwash soils underlying the site will provide a favorable layer for rainwater infiltration through pervious surfacing materials. In contrast, the shallow and deeper silt layers possess a very low permeability and, therefore, are not well-suited for stormwater infiltration. This summary should be used only in conjunction with the entire report for design purposes. It should be recognized that geotechnical details were not included or not fully developed in this section; as such, the report must be read in its entirety for a comprehensive understanding of the items presented above. Also, please refer to the GENERAL COMMENTS section for a discussion of the report limitations. Page 1 of 24 Terracon Consultants, Inc. 21905 – 64th A venue, Suite 100 Mountlake Terrace, Washington 98043 P [425] 771-3304 F [425] 771-3549 terracon.com GEOTECHNICAL ENGINEERING REPORT PORT TOWNSEND U-HAUL FACILITY 14082 AIRPORT CUTOFF ROAD PORT TOWNSEND, WASHINGTON Terracon Project No. 81135003 March 5, 2013 1.0 INTRODUCTION This report presents the results of our geotechnical engineering evaluation performed for the proposed re-development of the subject site as a U-Haul rental and storage facility. The purpose of our evaluation was to provide geotechnical characterizations, conclusions, and recommendations concerning the following elements of the project:  Building & canopy foundations  Slab-on-grade floors  Flexible pavements  Rigid pavements  Geological hazards  Site drainage  Shallow infiltration  Low retaining walls  Site soil reuse  General earthwork 2.0 PROJECT INFORMATION The following sections present information regarding site delineation, previous site usage, proposed development features, and our geotechnical scope of work. Terracon should be notified if any significant changes are made in the proposed site location, layout, or details. 2.1 Site Delineation The project site comprises a commercial parcel located south of Port Townsend and north of Jefferson County International Airport in Jefferson County, Washington. Table 1 summarizes our understanding of the site delineation as gained from maps, survey plans, aerial photos, client communications, and a site reconnaissance. Figure 1 shows the general site location, and Figure 2 illustrates the approximate site boundaries in relation to surrounding features. Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 2 TABLE 1 SUMMARY OF PROJECT SITE DELINEATION Parameter General Description Township / Range / Section SW ¼ of SW ¼, Sect. 21, T30N, R1W Latitude / Longitude Lat = 48.072 deg. Lon = -122.818 deg. Geometry Overall Shape: roughly trapezoidal. Approximate Dimensions: 600 feet x 670 feet. Approximate Total Area: 8.44 acres. Visual Boundaries North Side: undeveloped, forested property. South Side: undeveloped, forested property. West Side: Highway 20 & Airport Cutoff Road. East Side: undeveloped, forested property. 2.2 Previous Site Usage We understand that an automobile dealership (Courtesy Ford) occupied on the site for several decades until ceasing operations in recent years. Remnants of this dealership include a 9853- square-foot, single-story building that is situated in the west-central part of the site, with asphaltic pavement surrounding the building. The remainder of the site appears to have been deforested but otherwise unused and undeveloped. 2.3 Proposed Site Development Project re-development plans call for construction of a U-Haul rental and storage facility that will occupy the entire site. According to preliminary layout plans (dated November 2, 2012) provided to us, this re-development will involve the following items:  Remodeling the interior of the existing structure (designated Building “A”), with no change to its footprint;  Constructing ten new single-story, at-grade storage buildings (designated Buildings “B” through “L” on the northern half of the site;  Constructing two new large canopies for RV storage on the southern part of the site;  Covering large portions of the site with permeable aggregate, to allow for rainwater infiltration;  Covering small portions of the site with asphalt concrete pavement or cement concrete pavement. We anticipate that foundation, floor, and pavement loads will be relatively low, as is typical for this type of small commercial development. Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 3 2.4 Scope of Work We performed all geotechnical services in general accordance with our previously mentioned proposal except where modifications were dictated by site conditions. It should be noted that we previously completed a Phase 1 environmental assessment of the project site, but our authorized scope of services for the current evaluation did not include any environmental characterization or testing services. We ultimately completed the following scope items:  Reviewed topographic maps, aerial photographs, municipal hazard maps, and geologic maps regarding the site vicinity.  Reviewed a Phase 1 Environmental Site Assessment report (dated December 10, 2010) prepared by Terracon Consultants, Inc. for the subject site.  Performed a surface reconnaissance of the site and immediate vicinity.  Advanced fifteen exploratory test pits (designated TP-1 through TP-15) to depths ranging up to about 10 feet below existing grades, at strategic locations across the site.  Conducted four small-scale field infiltration tests (designated FIT-1 through FIT-4) at strategic locations across the site.  Performed limited geotechnical laboratory testing on representative samples of the near- surface soils.  Analyzed subsurface conditions in relation to the proposed development and prepared this written report. The functional locations, elevations, and depths associated with our recent on-site explorations are summarized in Table 2, and their relative locations are illustrated on Figure 2. Appendix A describes our field exploration procedures, and Appendix B describes our laboratory testing procedures. TABLE 2 SUMMARY OF SITE EXPLORATION PROGRAM Exploration Functional Location Surface Elevation (feet) Termination Depth (feet) TP-1 TP-2 TP-3 TP-4 TP-5 TP-6 TP-7 TP-8 Proposed Building Area Proposed Building Area Proposed Building Area Proposed Building Area Proposed Building Area Proposed Building Area Proposed Building Area Proposed Building Area 282 283 292 288 298 298 298 298 9½ 6 5 7 4 5 7 6 Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 4 TABLE 2 SUMMARY OF SITE EXPLORATION PROGRAM Exploration Functional Location Surface Elevation (feet) Termination Depth (feet) TP-9 TP-10 TP-11 TP-12 TP-13 TP-14 TP-15 Proposed Building Area Proposed Building Area Proposed Canopy Area Proposed Canopy Area Proposed Canopy Area Proposed Canopy Area Proposed Canopy Area 293 294 286 284 283 278 296 4 5½ 6½ 8 10 8 4½ Note: All exploration depths and elevations should be regarded as only approximate values. Elevation datum: Topographic survey map by Bock & Clark’s National Surveyor’s Network. 3.0 SITE SETTING We obtained information concerning regional conditions in the site vicinity from a review of topographic and geologic maps published by the U.S. Geological Survey (USGS), from surficial soil maps published by the Natural Resources Conservation Service (NRCS), and from zoning maps published by Jefferson County. Our research findings are discussed below, and excerpts from pertinent maps are contained in Appendix C. 3.1 Regional Geography The project site is situated near the geographic center of the Quimper Peninsula, which separates Discovery Bay (on the west) from Port Townsend Bay (on the east). This peninsula consists of an upland area that measures approximately 3 to 5 miles wide and 15 to 20 miles long. Topographically, the peninsula surface can be described as rolling or broadly hummocky, with generally north–south trending ridges and valleys. Surface elevations range from approximately 100 feet to 500 feet (USGS datum). A low valley lies about 1 mile west of the site, a coastal bluff lies about 2 miles west, and a low coastal bench (the location of Jefferson County International Airport) lies about 2 miles south. A gravel pit occupies a large area of hillslope located immediately west of the site. 3.2 Regional Geology According to the 2005 USGS map titled Geologic Map of the Port Townsend South and Part of the Port Townsend North 7.5-minute Quadrangles, Jefferson County, Washington, the site vicinity is underlain by Quaternary-age glacial deposits. The primary deposit is glacial till (labeled Qgt), which generally comprises a very dense mixture of silts, sands and gravels; it Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 5 has a typical thickness on the order of 10 to 20 feet. The glacial till deposit is underlain by advance outwash (labeled Qga), which generally comprises a very dense mixture of sands and gravels; it is usually exposed only in valleys and other topographic low areas or in cuts, and it typically has a thickness on the order of 10 to 100 feet. The subject site appears to lie on or near a mapped contact between the advance outwash and glacial till deposits. Both of the aforementioned glacial deposits are often mantled by thin surficial soils such as man-placed fill or recessional outwash. According to NRCS maps, the surficial soils within the site vicinity consist of Hoypus gravelly loamy sand (labeled HuC). This soil unit is described as having 0% to 15% slopes and somewhat excessively drained. The depth to a restrictive layer, which we infer to be glacial till, is shown to be greater than 80 inches (6½ feet). 3.3 Regional Zoning Jefferson County’s regional zoning maps show approximate locations where geological hazards and other such critical areas are documented or suspected. According to these maps, there are no landslide hazard areas, seismic hazard areas, erosion hazard areas, or wetlands within the immediate site vicinity. Several Critical Aquifer Recharge Areas (CARAs) surround the greater site vicinity, but the closest of these is approximately 300 yards west of the site. 4.0 SITE CONDITIONS A Terracon representative visited the project site on January 29 and 31, 2013, to evaluate surface and subsurface conditions. No owner representatives were present during either visit. Our geotechnical observations, measurements, findings, and interpretations are described in the following text sections. 4.1 Surface Features The following paragraphs briefly discuss existing on-site surface features, as observed during our recent site reconnaissance.  Grades: The western portion of the site (closest to Airport Cutoff Road) is fairly flat, with surface elevations in the range of 275 to 280 feet (project datum). Toward the east, however, surface grades slope upward in a series of gradual steps, reaching a maximum elevation of about 310 feet at the northeastern corner of the site. As such, total topographic relief across the site is approximately 35 feet. Based on this existing topography, we infer that a small to moderate amount of cutting was performed in various portions of the site during previous development activities. * Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 6  Vegetation: Existing vegetation on the southern and eastern parts of the site is limited to grasses and low groundcover. It appears that the site was originally covered by dense forest but then cleared as part of the previous development activities.  Buildings: A single-story commercial building currently occupies the central-western part of the site. This building appears to be a relatively lightweight, wood-frame or metal-frame structure and in fairly good condition. We did not observe any obvious indications of settlement, distress, or other foundation movement around the exterior of the building.  Pavements: The area surrounding the existing site building is currently covered by asphaltic pavement. This pavement appears to be in generally fair to good condition. Our test pit TP-1, which was advanced through the pavement, revealed about 2 inches of asphalt concrete over 3 inches of gravel base course. 4.2 Soil Stratigraphy Our exploratory test pits revealed variable soils conditions below the site, as described in the following paragraphs. The test pit logs contained in Appendix A provide details regarding these soil conditions.  Surficial Silts & Sands: Most of our test pits disclosed a surficial layer of loose or soft, organic, sandy silt and/or loose, silty sands mantling the site. The organic silt layer ranged from about 1 to 3 feet thick, and the silty sand layer ranged from about 1 to 2½ feet thick. In several test pits, these soils were underlain by a soft, clayey silt layer ranging from about 1½ to 3½ feet thick. The greatest combined thickness of soft and loose layers (from about 3 to 6 feet) was observed in test pits TP-5, TP-8, TP-10, TP-11, and TP-12, which lie in a roughly linear alignment that extends diagonally across the northeastern portion of the site. We interpret these soft/loose layers to represent native soils, although they might have been disturbed in various locations by previous logging and/or development activities.  Outwash Sands & Gravels: Most of our test pits revealed medium dense to dense sands and gravels under the site, either below the surficial silts and sands or exposed at the ground surface. Thicknesses ranged from about 1 foot to more than 6 feet. We interpret the sands and gravels to represent native glacial outwash soils, although they might have been slightly disturbed in various locations by previous logging and/or development activities.  Hard Clayey Silts: Nearly all of our test pits encountered hard, clayey silts below, or interlayered with, the outwash sands and gravels. The depth to this layer ranged from about 1½ to 6 feet below ground surface. We interpret these hard silts to be an undisturbed, native, glacially overridden outwash or lacustrine deposit. Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 7 4.3 Soil Properties We conducted limited field and laboratory testing on the site soils to quantitatively assess their infiltration and textural properties, as summarized in the following paragraphs. Appendix A contains our field infiltration testing data sheets, and Appendix B contains our laboratory testing data sheets. Although our scope of work did not involve any sampling or testing for possible environmental soil contaminants, it should be noted that we did not detect any petroleum sheens or odors in any of the soil samples that we obtained, nor did 2010 Phase 1 environmental assessment disclose any evidence of soil contamination.  Infiltration Properties: All four of our on-site field infiltration tests were performed at a depth of 1 foot below existing ground surface, in order to assess the potential for direct percolation of rainfall on future stripped or pervious surfaces. We measured infiltration rates ranging from 2 to 5 inches per hour in these tests, with an average rate of 3.25 inches per hour.  Textural Properties: Our grain-size tests on three random samples of the outwash sand and gravel deposit disclosed a fines (silt and clay) content ranging from about 2 to 12 percent, with a moisture content of about 5 to 7 percent. Two samples of the surficial silt were found to have a fines content of 71 and 93 percent, each with a moisture content of 26 percent. 4.4 Groundwater Levels Only three of our exploratory test pits revealed shallow groundwater at the site. Specifically, test pits TP-6, TP-9, and TP-11 encountered groundwater seepage at a depth ranging from about 2½ to 3½ feet below ground surface. We infer this shallow seepage to represent perched water that has formed atop the relatively impervious soil layers. Over the entire site, groundwater levels and occurrences probably fluctuate with season, precipitation patterns, on- site or off-site usage, and other factors. 5.0 CONCLUSIONS AND RECOMMENDATIONS Based on our surface reconnaissance, subsurface exploration, and soil testing, we conclude that the proposed site development is feasible from a geotechnical standpoint. However, the existence of surficial, soft/loose silts and loose sands over most of the site will warrant special provisions concerning foundations, floors, pavements, and other development features. The following text sections present our geotechnical conclusions and recommendations concerning general considerations, site preparation, spread footings, slab-on-grade floors, Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 8 drains, retaining walls, pavement sections, and structural fill. ASTM specification codes cited herein refer to the current manuals published by the American Society for Testing & Materials, and WSDOT codes refer to the 2012 edition of Standard Specifications for Road, Bridge, and Municipal Construction published by Washington State Department of Transportation. 5.1 General Considerations We offer the following conclusions and recommendations concerning major geotechnical issues for the overall development. Geological Hazards: Jefferson County’s on-line regional maps do not show any geological hazard areas, such as erosion zones, landslide zones, seismic hazard zones, at or near the subject site. Our surface reconnaissance and subsurface exploration confirmed this regional mapping. Although there are Critical Aquifer Recharge Areas in the site vicinity, these are sufficiently far away so as to avoid adverse site development effects. Consequently, the proposed site development does not appear to be constrained by any geological hazard regulations. Grading Considerations: Our test pits disclosed from about 1 to 6 feet of soft or loose silts and loose sands mantling the site, with the greatest thicknesses extending diagonally across the northeastern half of the site. This zone of unfavorable soils roughly coincides with the highest site grades. As such, it would be advantageous from a development standpoint to lower the surface grades by at least several feet within the high areas of the site. Foundation Considerations: The aforementioned surficial soft/loose silts and loose sands are not well-suited for foundation bearing, because their moderate compressibility and low shear strength creates a risk of excessive post-construction footing settlements or displacements. However, given the lightweight nature of the proposed storage buildings and canopies, we conclude that conventional shallow spread footings can be used to support the new structures if appropriate subgrade improvements are performed. Furthermore, the necessary extent of subgrade improvement would be significantly reduced if the high areas of the site are lowered per our previous recommendation. Seismic Site Class: The 2009 International Building Code (IBC) assigns a seismic Site Class on the basis of geological conditions prevailing within a depth of 100 feet below the local ground surface. Although our explorations did not extend to a depth of 100 feet, we infer from near- surface soil observations and from available geologic maps that the overall subsurface conditions correspond to Site Class “C” as defined by the IBC. Infiltration Potential: We understand that runoff water from the new RV canopies will be allowed to percolate through gravel pavements and into the subgrade soils. Our four field infiltration tests revealed an average percolation rate of 3.25 inches per hour for the near- Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 9 surface site soils. However, our test pits disclosed considerable variation in the textural properties of the near-surface soils. Consequently, actual percolation rates of the near-surface soils should be expected to vary greatly depending on location and final grades. To account for these variations, we recommend that a minimum safety factor of 10 be applied to our average measured percolation rate, thereby resulting in a maximum allowable rate of 0.3 inches per hour for infiltration design purposes. Contaminated Soil Considerations: As mentioned, we did not detect any odors, sheens, or other evidence of contaminated soils at the site during the course of our geotechnical study. Furthermore, our previous Phase 1 environmental assessment of the site did not disclose any adverse “recognized environmental conditions.” However, the previous site utilization as a car dealership and repair facility presents some risk that contaminated soils might be encountered during future excavations for new buildings or utilities. If contaminated soils are encountered, it could affect certain geotechnical recommendations presented herein, such as for foundation subgrade preparations and reuse of on-site soils as structural fill. 5.2 Site Preparation Preparation of the project site will involve tasks such as temporary drainage, stripping, cutting, filling, erosion control, and subgrade compaction. The paragraphs below present our geotechnical comments and recommendations concerning these various issues. Temporary Drainage: Any sources of surface or near-surface water that could potentially enter the construction zone should be intercepted and diverted before stripping or grading activities begin. We tentatively anticipate that a system of temporary swales, French drains, or berms placed around the construction zone (particularly along the eastern and northern sides) will divert much of the surface water runoff. However, the selection of an appropriate drainage system will depend on the water quantity, season, weather conditions, construction sequence, and contractor's methods; therefore, final decisions regarding temporary drainage details are best made in the field at the time of construction. Clearing and Stripping: After surface and near-surface water sources have been controlled, the construction zone should be cleared and stripped of all remaining trees, bushes, topsoil, sidewalks, and pavements. Based on our explorations, we anticipate that 1 to 1½ feet of organic-rich soils will typically be encountered within the currently undeveloped portions of the site, with even greater thicknesses in localized areas. Stripping depths should be adjusted as needed to remove all root mats, organic silt, muck, and other deleterious materials. Weather Considerations: It should be realized that if the stripping or cutting operations proceed during wet weather, greater stripping depths might be necessary to remove disturbed moisture-sensitive subgrade soils. For this reason, site earthwork is best performed during a period of dry weather. Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 10 Permanent Slopes: All permanent cut slopes and fill slopes should be adequately inclined to minimize long-term raveling, sloughing, and erosion. We generally recommend that no slopes be steeper than 2H:1V, but the use of flatter slopes (such as 3H:1V) would further reduce long- term erosion and facilitate revegetation. 5.3 Spread Footings Conventional spread footings can be used to support the proposed buildings and canopies if appropriate subgrade improvements are first performed. We offer the following comments and recommendations concerning design and construction of spread footings. In the event that very unfavorable soil conditions are revealed during construction, then we might need to provide supplemental recommendations for additional subgrade improvements or an alternative foundation system. Footing Depths and Widths: For frost and erosion protection, the bottoms of all exterior footings should bear at least 18 inches below adjacent outside grades, whereas the bottoms of interior footings need bear only 12 inches below the surrounding slab or crawlspace level. To reduce post-construction settlements, continuous (wall) and isolated (column) footings should be at least 15 and 30 inches wide, respectively. Bearing Provisions: Because the existing surficial layer of soft and loose soils could lead to excessive settlements or distortion of the new buildings and canopies, we recommend that all footings either (1) bear directly on native, medium dense to very dense, granular soils or native, hard silts underlying the site, or (2) bear on a pad of structural fill material placed over these native bearing soils. The latter case will involve overexcavating the existing soft/loose soil downward to reveal native bearing soils (as indicated by “D” in the sketch below) and outward by a distance of 2/3(D). The resulting overexcavations should then be backfilled with a suitable bearing material, as discussed in the following paragraph.   Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 11 Bearing Pad Materials: We recommend using 2-inch-minus crushed aggregate (“railroad ballast”) as a convenient and effective material for the bearing pads beneath new footings. This material does not require rigorous compaction to achieve a firm and unyielding condition, but it should be bucket-tamped after placement. Other granular materials, such as well-graded sand and gravel mixtures (“pit run”) and uniform angular gravel (“crushed rock”) are also suitable for the bearing pads, but they will require rigorous compaction to achieve a uniform density of at least 95 percent (based on ASTM: D-1557). Bearing Capacities: Assuming that the above-described bearing provisions and material requirements are properly implemented, we recommend that all footings be designed for the following maximum allowable soil bearing capacities. These values incorporate static and transient (wind or seismic) safety factors of at least 2.0 and 1.5, respectively. Design Parameter Allowable Value Static Bearing Pressure Seismic Bearing Pressure 2500 psf 3300 psf Footing Settlements: We estimate that total post-construction settlements of properly designed footings bearing on properly prepared subgrades will not exceed 1 inch. Differential settlements between new foundation elements could approach ¾ inch over horizontal spans on the order of 50 feet. In all cases, these settlements would likely be reduced if the actual design bearing pressures are lower than our recommended maximum allowable pressures. Footing and Stemwall Backfill: To provide erosion protection and lateral load resistance, we recommend that all footing excavations be backfilled on both sides of the footings and stemwalls after the concrete has cured. Either imported or on-site granular soils can be used for this purpose. All footing and stemwall backfill soil should be compacted to a uniform density of at least 90 percent (based on ASTM: D-1557). Lateral Resistance: Footings and stemwalls that have been properly backfilled as described above will resist lateral movements by means of both passive earth pressure and base friction. We recommend using the following design values, which incorporate static and transient (wind or seismic) safety factors of at least 1.5 and 1.1, respectively. Base friction can be combined with the respective passive pressure to resist static and transient loads. Design Parameter Allowable Value Static Passive Pressure Transient Passive Pressure Base Friction Coefficient 300 pcf 400 pcf 0.4 Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 12 Subgrade Verification: Footings should never be cast atop loose, soft, organic, or frozen soil, slough, debris, existing uncontrolled fill, or surfaces covered by standing water. We recommend that the condition of all subgrades be verified by a Terracon representative before any bearing pad fill is placed, and then again before any footing concrete is poured. 5.4 Slab-On-Grade Floors In our opinion, a soil-supported slab-on-grade floor can be used in each of the proposed new buildings if the subgrade is properly prepared. We offer the following comments and recommendations concerning slab-on-grade floors. Floor Sections: A slab-on-grade floor section typically comprises a concrete slab over a vapor retarder/barrier over a base course. Where the exposed subgrade consists of silt or clayey silt soil, a subbase course should be used below the base course. We recommend the following minimum thicknesses for these layers. Our specific recommendations for subgrade preparation and layer materials are discussed below. Floor Layer (top to bottom) Minimum Thickness Concrete Slab Vapor Retarder/Barrier Base Course Subbase Course (where needed) (by others) 10 mil 4 inches 12 inches Subgrade Preparation: After the slab-on-grade floor area has been cut down to an elevation that will accommodate the appropriate layers, any localized zones of mucky, organic-rich, or debris-laden soils exposed over the subgrade should be overexcavated and replaced with structural fill material. The entire subgrade should then be compacted to a firm and unyielding condition, using a vibratory-drum roller for granular soils and a static-drum roller for fine-grained soils. If the subgrade is prepared during wet weather, it might be advantageous to cover it with a separation geotextile (such as Mirafi 500X) before the subbase course is placed. Subbase Course: A subbase course provides structural support for the floor slab and helps to isolate the base course. For this purpose, we recommend using imported, well-graded sand and gravel, such as “Ballast” per WSDOT: 9-03.9(1) or “Gravel Borrow” per WSDOT: 9-03.14. Alternatively, an angular material such as "Crushed Surfacing Base Course" per WSDOT: 9- 03.9(3) could be used, although this would likely be more expensive. In the interest of using recycled materials, it would also be acceptable to use crushed cement concrete, provided that it meets the same textural criteria as one of the aforementioned WSDOT materials. We recommend that the subbase be compacted to a uniform density of at least 90 percent (based on ASTM: D-1557). Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 13 Base Course: A base course provides a bearing and leveling surface for the floor slab, and it serves as a capillary break to retard the upward wicking of groundwater beneath the floor slab. Ideally, the base course would consist of clean, uniform, well-rounded gravel, such as 5/8-inch or 7/8-inch washed rock. However, it would also be acceptable to use a clean angular gravel, such as “Crushed Surfacing Base Course” per WSDOT: 9-03.9(3), for this purpose. Floor Settlements: If the subgrade is properly prepared and the floor layers are properly placed, we estimate that total post-construction settlements of the slab-on-grade floor will not exceed ½ inch. Differential settlements could approach one-half of the actual total settlement over horizontal spans on the order of 50 feet. Subgrade Verification: Floor slabs should never be cast atop loose, soft, organic, or frozen soil, slough, debris, existing uncontrolled fill, or surfaces covered by standing water. We recommend that the condition of all subgrade areas be verified by a Terracon representative before any underslab fill is placed, and then again before the slab is poured. 5.5 Drainage Systems In our opinion, the new development should be provided with permanent drainage systems to reduce the risk of future moisture problems. We offer the following recommendations and comments for drainage design and construction purposes. Interceptor Drain: We recommend that an interceptor drain be installed along the eastern and northern edges of the site to capture shallow groundwater seepage emanating from the adjacent slopes. This drain should consist of a trench measuring at least 4 feet deep by 1½ feet wide, containing a 4-inch-diameter perforated pipe, with pea gravel or washed rock backfill. The upslope sidewall and top of the trench should be lined with filter fabric (such as Mirafi 140N) to reduce the migration of fines into the gravel, whereas the downslope sidewall and bottom should be lined with plastic sheeting (10-mil minimum) to reduce seepage loss from the gravel. Foundation Drains: Due to the presence of relatively shallow groundwater below the site, along with higher grades to the north and east, we recommend that each building be encircled with a perimeter foundation drain to collect exterior seepage. This drain should consist of a 4- inch-diameter perforated pipe within an envelope of pea gravel or washed rock, extending at least 6 inches on all sides of the pipe. The gravel envelope should be wrapped with filter fabric (such as Mirafi 140N) to reduce the migration of fines from the surrounding soils. Ideally, the drain invert would be installed no more than 8 inches above or below the base of the perimeter footings. Subfloor Drains: Based on the groundwater conditions observed in our site explorations, we currently do not infer a need for drains beneath the floor slabs if the interceptor and foundation drains are properly installed. However, the final decision regarding the need for subfloor drains Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 14 should be made at the time of construction, after the floor subgrades have been exposed and the foundation walls have been cast. Runoff Water: We understand that runoff water from the new RV canopies will be allowed to percolate into the surrounding subgrades. All other water sources, including roof runoff from the new storage buildings, parking lot runoff, and groundwater captured by the interceptor drain, should be routed through a separate tightline piping system and then discharged to an appropriate off-site location. Also, final site grades should be sloped so that surface water flows away from the buildings rather than ponding near the foundation walls. 5.6 Backfilled Walls We understand that backfilled concrete retaining walls will be used to create exterior grade changes on the site. Our design and construction recommendations for backfilled concrete walls are presented below. Applied Loads: The overturning and sliding loads typically applied to a retaining wall can be classified as static earth pressures, static surcharge pressures, and seismic surcharge pressures. If an adequate drainage system is included with the retaining wall, hydrostatic pressures can be neglected. Our recommended design pressures, which are derived from measured and inferred properties, are discussed in the following paragraphs and summarized in Table 3.  Static Earth Pressures: Yielding (cantilever) retaining walls should be designed to withstand an appropriate active lateral earth pressure, whereas non-yielding (restrained) walls should be designed to withstand an appropriate at-rest lateral earth pressure. The at-rest case is applicable where retaining wall movement is confined to less than 0.005 times the wall height. If greater movement is possible, the active case applies. These pressures act over the entire back of the wall and vary with the backslope inclination. For retaining walls with a level or inclined backslope and well-drained conditions, we recommend using the values provided in Table 3.  Static Surcharge Pressures: Any superimposed vertical loading (such as adjacent footing loads) located within a 45-degree plane projected upward from the wall base will apply a lateral surcharge to the wall. This active or at-rest lateral surcharge can be approximated by multiplying the vertical load by 30 percent and 50 percent, respectively.  Seismic Surcharge Pressures: The total static pressures acting on a wall should be increased to account for seismic surcharge loadings resulting from lateral earthquake motions. These surcharge pressures act over the entire back of the wall and vary with the backslope inclination, the seismic acceleration, and the wall height. Based on a wall height of "H" feet, we recommend that these seismic loadings be modeled as the uniform pressures given in Table 3. Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 15 Resisting Forces: Lateral pressures acting on retaining walls are resisted by a combination of passive lateral earth pressure and base friction. Passive pressure acts over the embedded front of the wall and footing, although the upper 2 feet should be neglected. Interface friction along the bottom of a wall footing can be combined with passive pressure to resist sliding. Assuming a level foreslope, we recommend using the design values presented in Table 3. These values are derived from measured and inferred soil properties, and they incorporate a static safety factor of at least 1.5. TABLE 3 DESIGN CRITERIA FOR BACKFILLED RETAINING WALLS Design Parameter Wall Condition Static Case Seismic Case Active Earth Loading Level Backslope 35 pcf 4 H psf 2H:1V Backslope 55 pcf 8 H psf At-Rest Earth Loading Level Backslope 50 pcf 12 H psf 2H:1V Backslope 85 pcf 24 H psf Passive Earth Resistance Level Foreslope 300 pcf 400 pcf Base Friction Resistance Any angle 0.4 0.4 Note: Other values would apply for differing wall conditions or surcharge loads. Curtain Drains: A curtain drain is a vertical layer of drainage material that is placed against the back of a wall to dissipate hydrostatic pressures. We recommend using a clean, well-rounded aggregate, such as “Gravel Backfill for Drains” (per WSDOT: 9-03.12(4)), for this purpose. The curtain drain should extend outward at least 12 inches from the wall and extend upward to within about 12 inches of the ground surface. Heel Drains: A heel drain is a horizontal drainage element that is placed behind the rearward projection (heel) of a wall foundation to collect water from the curtain drain. We recommend that a heel drain be included with all on-site retaining walls. Each heel drain should comprise a 4-inch-diameter perforated pipe surrounded by at least 6 inches of drainage gravel, all wrapped with filter fabric. The drainpipe should then be connected to a tightline discharge pipe that routes water to an appropriate location. Backfill Soil: We recommend that all backfill placed behind the curtain drain consist of either on-site or imported granular material, as described in the Structural Fill section of this report. If the backfill soil contains more than 10 percent fines, a layer of filter fabric (such as Mirafi 140N) should be placed between the curtain drain and backfill. Soil Compaction: Because soil compactors place significant lateral pressures on walls, we recommend that only small, hand-operated compaction equipment be used within 3 feet of a Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 16 wall. Also, the soil within 3 feet should be compacted to a density as close as possible to 90 percent of the maximum dry density (based on ASTM: D-1557). A greater degree of compaction closely behind the wall would increase the lateral earth pressure, whereas a lesser degree of compaction might lead to excessive post-construction settlements. Backfill placed behind the curtain drain should be compacted to a density of 90 percent. 5.7 Pavement Sections We anticipate that some combination of flexible and rigid pavements will be used around the on- site buildings. The following comments and recommendations are given for pavement design and construction purposes. Soil Design Values: Soil conditions are typically defined by a California Bearing Ratio (CBR), which quantitatively predicts the effects of wheel loads imposed on a saturated subgrade. Because our scope of work did not include a CBR test on the surficial site soils, we have inferred CBR values based on our limited textural testing. The wide variety of near-surface soil conditions would suggest a wide range of CBR values. However, we assume that any areas of especially soft silts will be overexcavated and replaced with granular fill so as to achieve a CBR value of 7 or more. Correlation charts indicate that this CBR value corresponds to a subgrade reaction modulus range of about 100 to 200 pci. Traffic Design Values: Traffic conditions can be defined by a Traffic Index (TI), which quantifies the combined effects of projected car and truck traffic. Although no specific traffic data was available at the time of our analysis, we infer that a TI of 3.0 to 5.0 would likely be appropriate for the car-parking lots and access driveways, respectively. A slightly higher TI of about 6.0 would be more appropriate for an access driveway subjected to daily deliveries by heavy freight trucks, but we assume this will not be the case here. Flexible Pavement Sections: A flexible pavement section typically comprises an asphalt concrete pavement (ACP) over a crushed aggregate base (CAB) over a granular subbase (GSB). Although the GSB can be omitted in certain cases, we infer that it is necessary at this site in order to mitigate the variable subgrade conditions. Our recommended minimum thicknesses for flexible pavement sections, which are based on the aforementioned design values and a 20-year lifespan, are shown below. Flexible Pavement Layers (top to bottom) Minimum Thickness Parking Areas Access Driveways Asphalt Concrete Pavement (ACP) Crushed Aggregate Base (CAB) Granular Subbase (GSB) 3 inches 3 inches 6 inches 4 inches 4 inches 9 inches Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 17 Rigid Pavement Sections: A rigid pavement section typically comprises a cement concrete pavement (CCP) over a crushed aggregate base (CAB) over a granular subbase (GSB). Although the GSB can be omitted in certain cases, we infer that it is necessary at this site in order to mitigate the variable subgrade conditions. Our recommended minimum rigid pavement sections, which are based on the aforementioned design values, are shown below. Rigid Pavement Layers (top to bottom) Minimum Thickness Parking Areas Access Driveways Cement Concrete Pavement (CCP) Crushed Aggregate Base (CAB) Granular Subbase (GSB) 5 inches 3 inches 6 inches 6 inches 3 inches 9 inches Subgrade Preparation: All pavement subgrades should be compacted to a firm and unyielding condition before any pavement layers are placed. We recommend using a vibratory roller in granular (sand or gravel) subgrade areas and a static roller in cohesive (silt or clay) subgrade areas. The resulting subgrade condition should then be verified by proof-rolling with a loaded dump truck or other heavy construction vehicle, in the presence of a geotechnical representative. Any deficient zones revealed by proof-rolling should be overexcavated and replaced structural fill that meets the requirements for Granular Subbase material. Granular Subbase: We recommend that all GSB material consist of imported, well-graded sand and gravel, such as “Ballast” per WSDOT: 9-03.9(1) or “Gravel Borrow” per WSDOT: 9- 03.14. In the interest of using recycled materials from on-site or off-site sources, it would be acceptable to substitute up to 20 percent of the GSB with crushed asphalt concrete or up to 100 percent of the GSB with crushed cement concrete, provided that the final mixture meets the same textural criteria as the aforementioned WSDOT materials. Regardless of composition, all GSB material should be compacted to a minimum density of 95 percent of the Modified Proctor maximum dry density (per ASTM: D-1557). Crushed Aggregate Base: We recommend that all CAB material conform to the criteria for “Crushed Surfacing Base Course” per WSDOT: 9-03.9(3). In the interest of using recycled materials from on-site or off-site sources, it would be acceptable to substitute up to 20 percent of the CAB with crushed cement concrete, provided that the final mixture meets the same textural criteria as the aforementioned WSDOT material. Regardless of composition, all CAB material should be compacted to a minimum density of 95 percent of the Modified Proctor maximum dry density (per ASTM: D-1557). Asphalt Concrete Pavement: We recommend that the ACP aggregate gradation conform to the control points for a ½-inch mix (per WSDOT: 9-03.8(6)) and that the binder conform to PG Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 18 58-22 criteria (per WSDOT: 9-02.1(4)). We also recommend that the ACP be compacted to a target average density of 92 percent, with no individual locations compacted to less than 90 percent nor more than 96 percent, based on the Rice theoretical maximum density for that material (per ASTM: D-2041). Cement Concrete Pavement: We recommend using Portland cement concrete with a minimum compressive strength of 4,000 psi and a minimum rupture modulus of 580 for the CCP. We also recommend that the concrete be reinforced with a welded wire mesh such as W2-6x6, positioned at a one-third depth within the layer. Compaction Testing: Compaction of the CAB and GSB layers should be verified qualitatively by method observations, proof-rolling, and hand-probing, as well as quantitatively by nuclear densometer testing. Compaction of the ACP should be quantified by laboratory testing of core samples, along with in-situ nuclear densometer testing. Pavement Life and Maintenance: It should be realized that asphaltic pavements are not maintenance-free. The foregoing pavement sections represent our minimum recommendations for an average level of performance during a 20-year design life; therefore, an average level of maintenance will likely be required. Furthermore, a 20-year pavement life typically assumes that an overlay will be placed after about 10 years. Thicker asphalt, base, and subbase courses would offer better long-term performance, but would cost more initially; thinner courses would be more susceptible to "alligator" cracking and other failure modes. As such, pavement design can be considered a compromise between a high initial cost and low maintenance costs versus a low initial cost and higher maintenance costs. 5.8 Structural Fill The term structural fill refers to any materials placed under foundations, retaining walls, slab-on- grade floors, sidewalks, pavements, and other such features. Our comments, conclusions, and recommendations concerning structural fill are presented in the following paragraphs. Structural Fill Materials: For general use, a well-graded mixture of sand and gravel with a low fines content (commonly called "gravel borrow" or "pit-run") provides an economical structural fill material. For specialized applications, it may be necessary to use a highly processed material such as crushed rock, quarry spalls, clean sand, granulithic gravel, pea gravel, drain rock, controlled-density fill (CDF), or lean-mix concrete (LMC). Recycled asphalt or concrete, which are derived from pulverizing the parent materials, are also potentially useful as structural fill in certain applications. Soils used for structural fill should not contain any significant amount of organic matter or debris, nor any individual particles greater than about 6 inches in diameter. Soil Moisture Considerations: The suitability of soils used for structural fill depends primarily on their grain-size distribution and moisture content when they are placed. As the fines content Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 19 (that soil fraction passing the U.S. No. 200 Sieve) increases, soils become more sensitive to small changes in moisture content. Soils containing more than about 5 percent fines (by weight) cannot be consistently compacted to a firm, unyielding condition when the moisture content is more than 2 percentage points above or below optimum. On-Site Soils: We anticipate that moderate cuts might be performed at the site after surface stripping; therefore, moderate quantities of on-site native soils will be generated during earthwork activities. Much of these on-site soils will likely consist of silts, clayey silts, and sandy silts, all of which are highly moisture-sensitive and not suitable for reuse. Some native sands and gravels will also be generated, and these granular soils will likely be reusable as structural fill. In all cases, any zones of organic soil should be excluded from reuse except in landscaping areas. Wet-Weather Earthwork: As discussed above, any of the on-site native silts and sandy or clayey silts would be difficult or impossible to reuse as structural fill during wet weather. Consequently, the project specifications should include provisions for using imported, clean, granular fill. As a general structural fill material, we recommend using a well-graded sand and gravel such as “Ballast” or “Gravel Borrow” per WSDOT: 9-03.9(1) and 9-03.14, respectively. For combined structural fill and drainage purposes, a relatively clean and uniform angular material such as “Crushed Surfacing Base Course” per WSDOT: 9-03.9(3) is preferable. Fill Placement and Compaction: Structural fill materials should be placed in horizontal lifts not exceeding about 12 inches in loose thickness. Unless stated otherwise in this report, we recommend that each lift then be thoroughly compacted with a mechanical compactor to a uniform density of at least 90 percent, based on the Modified Proctor test (ASTM: D-1557). Compaction is not necessary for certain structural fill materials, such as pea gravel, drain rock, quarry spalls, CDF, and LMC. Subgrade Verification and Compaction Testing: Regardless of material or location, all structural fill should be placed over firm, unyielding subgrades prepared in accordance with our various recommendations for site preparation. The condition of all subgrades should be verified by a Terracon representative before soil or concrete placement begins. Also, fill soil compaction should be verified by means of in-place density testing, hand-probing, proof-rolling, or other appropriate methods performed during fill placement so that the adequacy of soil compaction efforts may be evaluated as earthwork progresses. 6.0 GENERAL COMMENTS Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide observation and Geotechnical Engineering Report Port Townsend U-Haul Facility ■ Port Townsend, WA March 5, 2013 ■ Terracon Project No. 81135003 Reliable ■ Responsive ■ Convenient ■ Innovative 20 testing services during grading, excavation, foundation construction and other earth-related construction phases of the project. The analysis and recommendations presented in this report are based upon the data obtained from the explorations performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between explorations, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. The scope of services for this project does not include either specifically or by implication any environmental or biological (such as mold, fungi, and bacteria) assessment of the site, nor any identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. This report has been prepared for the exclusive use of our client, for specific application to the currently proposed project, and in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. N Project Mngr: Approved By: Checked By: Drawn By: Project No. Scale: Date: File No. FIG. No. Consulting Engineers and Scientists 21905 64th Avenue W., Ste 100 Mountlake Terrace, WA 98043 FAX. (425) 771-3549PH. (425) 771-3304 SITE LOCATION MAP AMERCO Real Estate Co. Port Townsend, Washington Port Townsend U-Haul Facility January 2013 81135003.dwg NOT TO SCALE 81135003 D. Baska J. Brisbine S. Probert J Brisbine 1 Basemap image obtained via Google Maps and modified by TERRACON. PROJECT SITE T P - 9 T P - 2 T P - 1 T P - 3 T P - 5 T P - 6 T P - 7 T P - 1 0 T P - 1 1 T P - 1 2 T P - 1 3 T P - 4 / F I T - 4 T P - 8 / F I T - 3 T P - 1 4 / F I T - 2 T P - 1 5 / F I T - 1 TEST PIT NUMBER ANDAPPROXIMATE LOCATION LEGEND:TP-1 N B a s e m a p p d f p r o v i d e d b y A M E R C O R e a l E s t a t e C o . a n d m o d i f i e d b y T E R R A C O N . P r o j e c t M n g r : A p p r o v e d B y : C h e c k e d B y : D r a w n B y : P r o j e c t N o . S c a l e : D a t e : F i l e N o . C o n s u l t i n g E n g i n e e r s a n d S c i e n t i s t s F I G . N o . 2 1 9 0 5 6 4 t h A v e n u e W , S t e 1 0 0 M o u n t l a k e T e r r a c e , W A 9 8 0 4 3 F A X . ( 4 2 5 ) 7 7 1 - 3 5 4 9 P H . ( 4 2 5 ) 7 7 1 - 3 3 0 4 A M E R C O R e a l E s t a t e C o . P o r t T o w n s e n d , W a s h i n g t o n P o r t T o w n s e n d U - H a u l F a c i l i t y S I T E A N D E X P L O R A T I O N P L A N 2 J a n u a r y 2 0 1 3 8 1 1 3 5 0 0 3 . d w g 1 i n c h = 8 0 f e e t 8 1 1 3 5 0 0 3 D . B a s k a J . B r i s b i n e S . P r o b e r t J . B r i s b i n e FIT-1FIELD INFILTRATIONTEST NUMBER AND APPROXIMATELOCATION 81135003 APPENDIX A FIELD EXPLORATION PROCEDURES, NOTES, AND LOGS 81135003 FIELD EXPLORATION PROCEDURES The following paragraphs describe our procedures associated with the on-site subsurface explorations and field tests that we conducted for this project. Interpretive stratigraphic logs of our auger borings are enclosed in this appendix. Our scope of work did not include a precise survey of each exploration location. Instead, all horizontal positions were determined by pacing or taping distances from existing site features, and all depths were referenced to existing site grade. As such, the locations and depths given in the report text, shown on the report figures, and stated on the stratigraphic logs should be considered accurate only to the degree implied by our measuring methods. Test Pit Procedures Our exploratory test pits were advanced with a rubber-tired backhoe operated by an independent excavating firm (Boone’s Excavating, Inc.) working under subcontract to Terracon. A geotechnical specialist from our firm continuously observed the test pit excavations, logged the subsurface conditions, and obtained representative soil samples. All samples were stored in watertight containers and later transported to our laboratory for further visual examination and testing. After we logged each test pit, the hoe operator backfilled it with excavated soils and tamped the surface. The enclosed Test Pit Logs indicate the vertical sequence of soils and other materials encountered in each test pit, based primarily on our field classifications and supported by our subsequent laboratory examination and/or testing. Where a soil contact was observed to be gradational or undulating, our logs indicate the average contact depth. We estimated the relative density and consistency of the in-situ soils by means of the excavation characteristics and the stability of the test pit sidewalls. Our logs also indicate the approximate depths of any sidewall caving or groundwater seepage observed in the test pits, as well as all sample numbers and sampling locations. Infiltration Test Procedures Our field infiltration tests were performed in general accordance with the procedures prescribed in the EPA manual entitled On-Site Wastewater Treatment and Disposal Systems. Specifically, a test hole was excavated to the desired infiltration test depth, then a 12-inch-diameter PVC pipe was tamped into the soil at the bottom, and the hole was partially backfilled with soil. This pipe was then filled with a minimum of 12 inches of water, and the water level was monitored. The water level was measured every 5 minutes until infiltration appeared to reach a steady state. Due to the small-scale nature of the tests, a full 4-hour soaking period was deemed to be unnecessary. Following the saturation period at each test location, the test was filled with at least 12 inches of water. The water level was recorded every 10-15 min for approximately an hour after reaching steady state. Water was replenished periodically to maintain at least 12 inches of water. After completion of each test sequence, we extracted the test pipe. 81135003 0.2 0.4 9.5 2 inches of asphalt FILL - SILTY GRAVEL (Basecoarse) , 3 inches of basecoarse POORLY GRADED GRAVEL WITH SAND (GP), trace cobbles and silt, red-brown, loose to medium dense, moist, grades to light brown grades to with silt and grey Test Pit Terminated at 9.5 Feet 282 281.5 272.5 35 Within existing pavement section (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-1 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--1 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 282 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 0.1 5.5 6.0 FILL - CRUSHED ROCK POORLY GRADED GRAVEL WITH SAND (GP), brown, medium dense, moist grades to grey-brown, approximately 1.5 inches of penetration with 1/2 inch steel rod SAND WITH SILT AND GRAVEL (SW-SM), grey, medium dense to dense, moist Test Pit Terminated at 6 Feet 283 277.5 277 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-2 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--2 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 283 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 0.3 2.0 5.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist SILTY SAND WITH GRAVEL (SM), brown, loose to medium dense, moist CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp approximately 0.5 inches of penetration with 1/2 inch steel rod Test Pit Terminated at 5 Feet 292 290 287 Alongside existing gravel road (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-3 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--3 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 292 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 1.5 6.0 7.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist POORLY GRADED GRAVEL WITH SAND (GP), light brown, medium dense, moist, noted ~4 inch silt layer (Individually sampled as S-2) CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp Test Pit Terminated at 7 Feet Field infiltration test FIT-4 performed at a depth of 1.5 feet on January 31st, 2013 286.5 282 281 12 93 7 26 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-4 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--4 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 288 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 1.3 3.5 4.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist CLAYEY SILT WITH SAND (CL-ML), light brown/orange, soft, moist-wet CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp, 0.5 inches of penetration with 1/2 steel rod Test Pit Terminated at 4 Feet 297 294.5 294 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-5 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--5 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 298 (Ft.)DE P T H ( F t . ) SA M P L E T Y P E 1.0 2.0 4.0 5.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist SILTY SAND WITH GRAVEL (SM), brown, medium dense to dense, moist POORLY GRADED GRAVEL WITH SAND (GP), brown, medium dense, saturated CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp Test Pit Terminated at 5 Feet 297 296 294 293 28 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: 2.5' - Perched Water Observed WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-6 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--6 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 298 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 1.5 6.0 7.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist POORLY GRADED GRAVEL WITH SAND (GP), brown, medium dense, moist CLAYEY SILT WITH SAND (CL-ML), light brown, hard, damp Test Pit Terminated at 7 Feet 296.5 292 291 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-7 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--7 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 298 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 1.5 4.0 5.5 6.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist SILTY SAND WITH GRAVEL (SM), brown, medium dense, moist CLAYEY SILT WITH SAND (CL-ML), light brown and orange, soft, wet CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp Test Pit Terminated at 6 Feet Field infiltration test FIT-3 performed at a depth of 1.5 feet on January 31st, 2013 296.5 294 292.5 292 7126 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-8 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--8 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 298 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 2.0 3.5 4.0 COBBLY SILTY SAND (SM), red-brown, loose to medium dense, moist SILTY SAND WITH GRAVEL (SM), brown, medium dense, moist CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp Test Pit Terminated at 4 Feet 291 289.5 289 Alongside existing gravel road (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: 3' - Perched Seepage Observed WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-9 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--9 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 293 (Ft.)DE P T H ( F t . ) SA M P L E T Y P E 3.0 5.0 5.5 SANDY ORGANIC SILT (OL), dark brown, loose, moist SILTY SAND (SM), trace gravel, light brown, medium dense, wet to saturated CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp Test Pit Terminated at 5.5 Feet 291 289 288.5 Undeveloped vegetated area, between slope and ponded water (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: 3.5' - Perched Seepage Observed WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-10 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--10 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 294 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 2.5 6.0 6.5 SILTY SAND (SM), light brown, loose to medium dense, moist CLAYEY SILT WITH SAND (CL-ML), light brown and orange, soft, wet CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp Test Pit Terminated at 6.5 Feet 283.5 280 279.5 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-11 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--11 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 286 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 3.0 7.0 8.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist WELL GRADED SAND WITH SILT AND GRAVEL (SW-SM), brown, medium dense to dense, moist SILTY SAND WITH GRAVEL (SM), grey, dense to very dense, moist Test Pit Terminated at 8 Feet 281 277 276 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-12 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--12 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 284 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 0.3 1.0 10.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist SANDY ORGANIC SILT (OL), red-brown, soft, moist (excessive caving observed within this layer) SILTY SAND WITH GRAVEL (SM), brown to grey, medium dense to dense, moist 1 foot thick CLAYEY SILT, trace sand, light brown, very stiff to hard, damp Test Pit Terminated at 10 Feet 283 282 273 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-13 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--13 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 283 (Ft.)DE P T H ( F t . ) 5 10 SA M P L E T Y P E 1.5 4.5 5.5 8.0 SANDY ORGANIC SILT (OL), dark brown, loose, moist SILTY SAND WITH GRAVEL (SM), brown, loose to medium dense, moist grades to grey CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp POORLY GRADED SAND WITH SILT AND GRAVEL (SP-SM), grey, medium dense to dense, moist Test Pit Terminated at 8 Feet Field infiltration test FIT-2 performed at a depth of 1 foot on January 31st, 2013 276.5 273.5 272.5 270 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-14 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--14 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 278 (Ft.)DE P T H ( F t . ) 5 SA M P L E T Y P E 0.5 1.5 4.5 SANDY ORGANIC SILT (OL), dark brown, loose, moist CLAYEY SILT WITH SAND (CL-ML), light brown, stiff, moist CLAYEY SILT (CL-ML), trace sand, light brown, hard, damp Test Pit Terminated at 4.5 Feet Field infiltration test FIT-1 performed at a depth of 1 foot on January 31st, 2013 295.5 294.5 291.5 Undeveloped vegetated area (See Figure 2) Stratification lines are approximate. In-situ, the transition may be gradual. LOCATION DEPTH GR A P H I C L O G TH I S B O R I N G L O G I S N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . 14082 Airport Cutoff Rd Port Townsend, Washington SITE: Groundwater not encountered WATER LEVEL OBSERVATIONS PROJECT: Port Townsend U-Haul Facility Page 1 of 1 Advancement Method: Excavator Abandonment Method: Backfilled with soil cuttings upon completion. 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington Notes: Project No.: 81135003 Excavator: Backhoe Test Pit Started: 1/29/2013 TEST PIT LOG NO. TP-15 AMERCO Real Estate Co.CLIENT: Operator: Boone Excavation Test Pit Completed: 1/29/2013 Exhibit:TP--15 ELEVATION (Ft.)PE R C E N T F I N E S WA T E R CO N T E N T ( % ) FI E L D T E S T RE S U L T S WA T E R L E V E L OB S E R V A T I O N S Surface Elev.: 296 (Ft.)DE P T H ( F t . ) SA M P L E T Y P E Project Name: Project Number: Client: Date: (ft/min) (in/hr) 0.0 0.56 0.00 5.0 0.69 0.13 0.03 19 10.5 0.75 0.19 0.01 8 15.5 0.60 0.22 0.01 4 20.0 0.64 0.26 0.01 6 25.0 0.67 0.29 0.01 4 30.0 0.71 0.33 0.01 6 35.0 0.60 0.37 0.01 6 45.0 0.67 0.44 0.01 5 55.0 0.75 0.52 0.01 6 72.0 0.83 0.60 0.00 3 5 (ft/min) (in/hr) 0.0 0.52 0.00 5.0 0.56 0.04 0.008 6 10.0 0.60 0.08 0.008 6 15.0 0.63 0.11 0.006 4 20.0 0.64 0.12 0.002 1 25.0 0.51 0.13 0.002 1 35.0 0.53 0.15 0.002 1 50.0 0.59 0.21 0.004 3 60.0 0.61 0.23 0.002 1 75.0 0.64 0.26 0.002 1 115.0 0.73 0.35 0.002 2 2 Notes: Where "Depth to Water" decreases water was added to preserve head differential Steady State Infiltration Rate refers to the average of the last four readings Field Infiltration Tests FIT‐1 (TP‐15) Steady State Infiltration Rate (in/hr): FIT‐2 (TP‐14) Time Elapsed (min) Depth to Water (ft) Drop of Water (ft)Instantaneous Infiltration Rate  PROJECT INFORMATION Port Townsend U-Haul Facilities 81135003 AMERCO Real Estate Co. 1/31/2013 Instantaneous Infiltration Rate Time Elapsed (min) Depth to Water (ft) Drop of Water (ft) Steady State Infiltration Rate (in/hr): Project Name: Project Number: Client: Date: (ft/min) (in/hr) 0.0 0.53 0.00 5.0 0.67 0.14 0.028 20 10.0 0.74 0.21 0.014 10 15.0 0.60 0.29 0.016 12 20.0 0.65 0.34 0.010 7 25.0 0.69 0.38 0.008 6 30.0 0.52 0.40 0.004 3 35.0 0.55 0.43 0.006 4 40.0 0.58 0.46 0.006 4 45.0 0.61 0.49 0.006 4 55.0 0.66 0.54 0.005 4 70.0 0.74 0.62 0.005 4 85.0 0.62 0.69 0.005 3 100.0 0.69 0.76 0.005 3 4 (ft/min) (in/hr) 0.0 0.38 0.00 5.0 0.40 0.02 0.004 3 10.0 0.42 0.04 0.004 3 15.0 0.44 0.06 0.004 3 20.0 0.46 0.08 0.004 3 30.0 0.50 0.12 0.004 3 40.0 0.53 0.15 0.003 2 50.0 0.57 0.19 0.004 3 60.0 0.61 0.23 0.004 3 2 Notes: Where "Depth to Water" decreases water was added to preserve head differential Steady State Infiltration Rate refers to the average of the last four readings Steady State Infiltration Rate (in/hr): 1/31/2013 FIT‐3 (TP‐8) Time Elapsed (min) Depth to Water (ft) Drop of Water (ft)Instantaneous Infiltration Rate  Field Infiltration Tests PROJECT INFORMATION Port Townsend U-Haul Facilities 81135003 AMERCO Real Estate Co. FIT‐4 (TP‐4) Instantaneous Infiltration Rate  Steady State Infiltration Rate (in/hr): Time Elapsed (min) Depth to Water (ft) Drop of Water (ft) 81135003 APPENDIX B LABORATORY TESTING PROCEDURES, CLASSIFICATIONS, AND RESULTS 81135003 LABORATORY TESTING PROCEDURES The following paragraphs describe our procedures associated with the laboratory tests that we conducted for this project. Our test results are enclosed in this appendix and/or are shown on the exploration logs contained in Appendix A. As part of our testing program, the samples were examined in our laboratory and classified in accordance with the attached General Notes or the Unified Soil Classification System (USCS), based on the texture and plasticity of the soil. A brief description of the USCS is included with this appendix. Visual Classification Procedures Visual soil classifications were conducted on all samples in the field and on selected samples in our laboratory. All soils were classified in general accordance with the United Soil Classification System, which includes color, relative moisture content, primary soil type (based on grain size), and any accessory soil types. The resulting soil classifications are presented on the exploration logs contained in Appendix A. Moisture Content Determination Procedures Moisture content determinations were performed on representative samples to aid in identification and correlation of soil types. All determinations were made in general accordance with ASTM: D-2216. The results of these tests are shown on the exploration logs contained in Appendix A. 200-Wash Analysis Procedures A 200-wash analysis indicates the percentage of fines (silt and clay particles) included in a particular sample. We performed a 200-wash on representative samples in general accordance with the initial steps described by ASTM: D-422. The results of these tests were used in soil classifications shown on the exploration logs contained in Appendix A. Grain Size Analysis Procedures A grain size analysis indicates the range of soil particle diameters included in a particular sample. Grain size analyses were performed on representative samples in general accordance with ASTM: D-422. The results of these tests are presented on the enclosed grain-size distribution graphs and were used in soil classifications shown on the exploration logs. 81135003 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 6 16 20 30 40 501.5 2006810 3.236.80.225 14 LL PL PI %Clay%Silt 413/4 1/2 60 fine HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 0.23 D100 Cc Cu SILT OR CLAY 4 %Sand%GravelD30D10 TP-1 POORLY GRADED GRAVEL with SAND(GP) 0.6428.06425TP-1 35.802.0 GRAIN SIZE IN MILLIMETERS PE R C E N T F I N E R B Y W E I G H T coarse fine 3/8 3 100 14032 COBBLES GRAVEL SAND USCS Classification 48.1 D60 coarse medium 2.0 Boring ID Depth Boring ID Depth GRAIN SIZE DISTRIBUTION ASTM D422 EXHIBIT: B-1 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington PROJECT NUMBER: 81135003PROJECT: Port Townsend U-Haul Facility SITE: 14082 Airport Cutoff Rd Port Townsend, Washington CLIENT: AMERCO Real Estate Co. LA B O R A T O R Y T E S T S A R E N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . G R A I N S I Z E : U S C S - 2 8 1 1 3 5 0 0 3 , T E S T P I T L O G S , 0 1 - 2 9 - 2 0 1 3 . G P J F E N C E P R O J E C T 1 - 8 - 1 3 . G P J 2 / 2 5 / 1 3 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 6 16 20 30 40 501.5 2006810 11.925.9 14 LL PL PI %Clay%Silt 413/4 1/2 60 fine HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 0.33 D100 Cc Cu SILT OR CLAY 4 %Sand%GravelD30D10 TP-4 0.3797.49137.5TP-4 130.303.0 GRAIN SIZE IN MILLIMETERS PE R C E N T F I N E R B Y W E I G H T coarse fine 3/8 3 100 14032 COBBLES GRAVEL SAND USCS Classification 42.7 D60 coarse medium 3.0 Boring ID Depth Boring ID Depth GRAIN SIZE DISTRIBUTION ASTM D422 EXHIBIT: B-1 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington PROJECT NUMBER: 81135003PROJECT: Port Townsend U-Haul Facility SITE: 14082 Airport Cutoff Rd Port Townsend, Washington CLIENT: AMERCO Real Estate Co. LA B O R A T O R Y T E S T S A R E N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . G R A I N S I Z E : U S C S - 2 8 1 1 3 5 0 0 3 , T E S T P I T L O G S , 0 1 - 2 9 - 2 0 1 3 . G P J F E N C E P R O J E C T 1 - 8 - 1 3 . G P J 2 / 2 5 / 1 3 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 6 16 20 30 40 501.5 2006810 1.972.80.307 14 LL PL PI %Clay%Silt 413/4 1/2 60 fine HYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 5.26 D100 Cc Cu SILT OR CLAY 4 %Sand%GravelD30D10 TP-6 POORLY GRADED GRAVEL with SAND(GP) 5.43918.30650TP-6 59.593.0 GRAIN SIZE IN MILLIMETERS PE R C E N T F I N E R B Y W E I G H T coarse fine 3/8 3 100 14032 COBBLES GRAVEL SAND USCS Classification 25.3 D60 coarse medium 3.0 Boring ID Depth Boring ID Depth GRAIN SIZE DISTRIBUTION ASTM D422 EXHIBIT: B-1 21905 64th Ave. W, Suite 100 Mountlake Terrace, Washington PROJECT NUMBER: 81135003PROJECT: Port Townsend U-Haul Facility SITE: 14082 Airport Cutoff Rd Port Townsend, Washington CLIENT: AMERCO Real Estate Co. LA B O R A T O R Y T E S T S A R E N O T V A L I D I F S E P A R A T E D F R O M O R I G I N A L R E P O R T . G R A I N S I Z E : U S C S - 2 8 1 1 3 5 0 0 3 , T E S T P I T L O G S , 0 1 - 2 9 - 2 0 1 3 . G P J F E N C E P R O J E C T 1 - 8 - 1 3 . G P J 2 / 2 5 / 1 3 81135003 APPENDIX C SUPPLEMENTAL INFORMATION Map created with Map created with Map created with Map created with Map created with Map created with Map created with Map created with Map created with TOPO!®TOPO!®TOPO!®TOPO!®TOPO!®TOPO!®TOPO!®TOPO!®TOPO!® ©2010 National Geographic ©2010 National Geographic ©2010 National Geographic ©2010 National Geographic ©2010 National Geographic ©2010 National Geographic ©2010 National Geographic ©2010 National Geographic ©2010 National Geographic Excerpt from 1981 USGS map titled "Port Townsend South" (contour interval = 20 feet) 0.0 0.5 miles 0.0 0.5 1.0 km 01/21/13 TNMN 16½ Qf Qga Qga gta Qml Qml Qgt Qgt Qga ed lty e y d lts he e ure f st ,yQgie,p about 50 ft. The eskers lose their character to the north, where they grade into ablation till (unit Qgta). To the south a few of these features survived reworking by meltwater depositing unit Qgo. Lodgment till—Mix of clay, silt, sand, and gravel with isolated boulders deposited as diamicton directly by advancing glacier ice; gray where fresh, light yellowish brown where oxidized; cobbles and boulders commonly faceted and (or) striated and glacially polished; unsorted and highly compacted; permeability very low; most commonly matrix supported, but locally clast supported; matrix more angular than water-worked sediments; varies in thickness from 1 ft to about 80 ft and averages about 50 ft thick; may include loose ablation till (unit Qgta) too thin to map; commonly capped by 0.5 to 4 ft of dark brown wind-deposited sand (see unit Qd) with loose till-colored clasts near the till–sand interface; up to 10 ft diameter erratic boulders commonly associated with till and ablation till; typically forms a vertical face in coastal bluffs. Unit Qgt lies stratigraphically between recessional outwash (unit Qgo) above and advance outwash (unit Qga) below. Local and nearby age control constrains the age of the unit to between about 15,200 14C yr B.P. (see Geologic Setting and Swanson, 1994; Porter and Swanson, 1998; Booth, 1991) and 13,650 ±350 14C yr B.P. (see Geologic Setting). Ablation till—Unsorted, unstratified, loose deposits of gravel, sand, silt and clay; gray to tan, usually oxidized; thickness generally ranges from 3 to 10 ft, but mapped only where sufficiently thick (5 ft or more) to mask underlying lodgment till (unit Qgt); thickest in northern part of the map area where it contains numerous kettles, in many cases filled with peat deposits (unit Qp); only overlies lodgment till (unit Qgt); a somewhat poor source of aggregate due to lack of sorting. Advance outwash—Sand and pebble to cobble gravel with some bouldery facies; minor silts and clays; may contain till fragments; gray to grayish brown and grayish orange; clasts well rounded; well sorted; coarsens upward; compact, but in many exposures only minimally cohesive; parallel bedded, locally cross-bedded; approximately 130 ft of section is exposed near Glen Cove; crops out dominantly on fairly steep slopes where side streams have eroded through the overlying lodgment till; commonly forms angle-of-repose benches within coastal bluffs; advance lake beds (silts and clays) have been deformed due to overriding by Vashon ice; commonly overlain by unit Qgt along a sharp contact and stratigraphically above unit Qco. Subscript ‘s’ denotes a sand-dominated deposit. The age of unit Qga is bracketed by local and nearby age control from the underlying unit Qco (Table 1 and Geologic Setting) and an estimate of Vashon ice arrival by Porter and Swanson (1998) (see Geologic Setting). Undivided Fraser and Pre-Fraser Deposits Glacial and nonglacial deposits, undivided—Sand, gravel, silt, clay, Em Qga Qgas Qgt Qgta Q Jefferson County Critical Areas FOR INFORMATIONAL PURPOSES ONLY- Jefferson County does not attest to the accuracy of the data contained herein and makes no warranty with respect to its correctness or validity. Data contained in this map is limited by the method and accuracy of its collection. Mon Jan 21 15:48:42 2013 Page 1 of 1Map Output 1/21/2013http://maps.co.jefferson.wa.us/servlet/com.esri.esrimap.Esrimap?ServiceName=ovmap&Cl...