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REVIEWED PLN BLD2020-1409+GEO+1.11.2021_12.58.51_PM+1983617NELSON GEOTECHNICAL ASSOCIATES. INC. January 6, 2021 Mr. Christian Santiago VIA Email: christiansantiago23@gmail.com Geotechnical Engineering Evaluation Santiago Deck Addition 18308 — 84th Place West Edmonds, Washington NGA File No. 1225420 17311-1351h Ave. N.E. Suite A-500 Woodinville, WA 98072 (425) 486-1669 www.nelsongeotech.com Dear Mr. Santiago: This letter summarizes our opinions and recommendations for the proposed deck addition located at 18308 — 84th Place West in Edmonds, Washington, as shown on the Vicinity Map in Figure 1. The parcel number for the property is 00596000000300. INTRODUCTION The property is rectangular in shape and covers 0.28 acres in area. It is currently occupied by a single- family residence. The property is bordered by 84th Place West to the east and neighboring residential properties on all other sides. Topographically, the site is situated on gentle- to moderate northwest - facing slopes. We understand the plans for development include a deck on the northwestern portion of the existing structure. Your design team has requested a geotechnical letter to address the steep slopes and recommendations for deck foundations and we have been requested to provide this proposal for determination of possible geological hazards affecting the site, as well as development considerations for the proposed deck. For our use in preparing this letter, we were provided with a preliminary site plan titled "Santiago Residence," dated October 16, 2020, and prepared by Maya Mincemoyer. SCOPE The purpose of this study is to explore and characterize the site surface and subsurface conditions within the vicinity of the proposed deck addition and provide geotechnical recommendations for the deck support. Specifically, our scope of services included the following: Geotechnical Engineering Evaluation NGA File No. 1225420 Santiago Deck Addition January 6, 2021 Edmonds, Washington Page 2 1. Reviewing available soil and geologic maps of the area, as well as other documentation pertaining to the site, as available. 2. Visiting the site to observe existing conditions and complete hand -augured excavations within the proximity of the proposed deck to verify subsurface conditions. 3. Mapping the conditions on the slope, constructing geological cross sections and performing shallow hand -tool excavations where necessary. 4. Evaluating current slope stability conditions, as needed. 5. Providing recommendations for deck foundation support. 6. Providing recommendations for site drainage and erosion control. 7. Providing recommendations for long-term slope maintenance, and erosion control, as needed. 8. Documenting the results of our findings, conclusions, and recommendations in a written geotechnical letter. SITE CONDITIONS Surface Conditions The property is rectangular in shape and covers 0.28 acres in area. It is currently occupied by a single- family residence with a newly constructed garage addition along the northwestern portion of the house. The property is bordered by 84th Place West to the east and neighboring residential properties on all other sides. Topography within the site is generally level to gently sloping with steeper northwest -facing slopes situated along and below the west -central to northwestern corners property boundaries. The ground surface within the near vicinity to the existing residence and proposed deck generally descends to the northwest at gradients in the range of 3 to 7 degrees (5.24 to 12.3 percent) towards the western property line. Near the western property line and below the ground surface steepens to gradients in the range of 15 to 27 degrees (26.8 to 51 percent) and extends down towards a relatively level backyard area on the neighboring property to the west. The overall vertical relief of the steeper slopes along and below the western property line is estimated 15 feet. The approximate ground surface profile is shown on Cross Section A -A' in Figure 3 attached to this letter. The gently sloping backyard area within the subject property is lightly terraced and landscaped with short rockery or timber walls. An approximately 3.5-foot tall dilapidated block wall retains a portion of the subject property backyard area directly along the western property line. Vegetation across the site generally consisted of grass, mulch -covered surfaces, landscaping plants, and few young to mature trees. We did not observe any surface water on the site during our site visit on December 2, 2020. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Santiago Deck Addition Edmonds, Washington Subsurface Conditions NGA File No. 1225420 January 6, 2021 Page 3 Geology: The geologic units for this area are shown on the map titled, Geologic Map of the Edmonds East and Part of the Edmonds West Quadrangles, Washington, by J. P. Minard (USGS, 1983). The geologic unit mapped for the site area is glacial till (Qvt). Till is generally described as a mixture of silt, sand, and gravel. Our explorations throughout the site were generally consistent with the description of glacial till at depth. Explorations: We visited the site on December 2, 2020 to explore the surface and subsurface conditions within the proposed development areas with hand auger explorations. The approximate locations of our explorations are shown on the Schematic Site Plan in Figure 2. A geologist from Nelson Geotechnical Associates, Inc. (NGA) completed the explorations, examined the soils and geologic conditions encountered, and maintained logs of the explorations. The soils were visually classified in general accordance with the Unified Soil Classification System, presented in Figure 4. The logs of our explorations are presented as Figure 5. The following paragraph contains a brief description of the subsurface conditions encountered in the explorations. For a detailed description of the subsurface conditions, the hand auger logs should be reviewed. At the surface of all explorations located within the backyard area, we generally encountered approximately 3.5 to 5.5 feet of topsoil, underlain by light to dark brown, silty fine to medium sand with varying amounts of gravel, roots, and organic debris, which we interpreted as undocumented fill soils, likely associated with previous grading for the single-family residence. Underlying the undocumented fill, in all of our explorations, we encountered light brown to gray fine to medium sand with varying amounts of silt and gravel that we interpreted as native glacial till soils. Hand Augers One through Four terminated at depths between 5.0 and 7.0 feet. Hydrogeologic Conditions No groundwater was encountered within our explorations. If groundwater were to be encountered during construction, we would interpret the seepage as perched groundwater. Perched water occurs when surface water infiltrates through less dense, more permeable soils, such as topsoil and the weathered horizon, and accumulates on top of a less permeable soil. Perched water does not represent a regional groundwater "table" within the upper soil horizons. Perched water tends to vary spatially and is dependent upon the amount of rainfall. We would expect the amount of groundwater to decrease during drier times of the year and increase during wetter periods. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Santiago Deck Addition Edmonds, Washington SENSITIVE AREA EVALUATION Seismic Hazard NGA File No. 1225420 January 6, 2021 Page 4 We reviewed the 2018 International Building Code (IBC) for seismic site classification for this project. Since dense native glacial soils are interpreted to underlie the site at depth, the site best fits the IBC description for Site Class D. Table 1 below provides seismic design parameters for the site that are in conformance with the 2018 IBC, which specifies a design earthquake having a two percent probability of occurrence in 50 years (return interval of 2,475 years), and the 2008 USGS seismic hazard maps. Table 1— 2018 IBC Seismic Design Parameters Site Class Spectral Acceleration Spectral Acceleration Site Coefficients Design Spectral at 0.2 sec. (g) at 1.0 sec. (g) Response SS S1 Parameters Fa Fv Sos Sol D 1.290 0.506 1.000 1.500 0.860 0.506 The spectral response accelerations were obtained from the USGS Earthquake Hazards Program Interpolated Probabilistic Ground Motion website (2008 data) for the project latitude and longitude. Hazards associated with seismic activity include liquefaction potential and amplification of ground motion. Liquefaction is caused by a rise in pore pressures in a loose, fine sand deposit beneath the groundwater table. It is our opinion that the dense deposits interpreted to underlie the site have a low potential for liquefaction or amplification of ground motion. Erosion Hazard The criteria used for determination of erosion hazard areas include soil type, slope gradient, vegetation cover, and groundwater conditions. The erosion sensitivity is related to the vegetative cover and the specific surface soil types, which are related to the underlying geologic soil units. The Soil Survey of Snohomish County Area, Washington, by the Natural Resources Conservation Service (NRCS), was reviewed to determine the erosion hazard of the on -site soils. The site surface soils were classified using the NRCS classification system as Alderwood Urban land complex, 2 to 8 percent slopes. These soils are listed as having a moderate erosion hazard. It is our opinion that the erosion hazard should be low in areas with vegetated, undisturbed soil. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation NGA File No. 1225420 Santiago Deck Addition January 6, 2021 Edmonds, Washington Page 5 CONCLUSIONS AND RECOMMENDATIONS General It is our opinion from a geotechnical standpoint that the proposed deck addition along the northwestern portion of the house is feasible. Our explorations within the proposed deck area generally encountered loose to medium dense undocumented fill soils underlain by medium dense or better native soils at a depth of approximately 3.5 to 5.0 feet below the ground surface. Based on the relatively shallow depth of undocumented fill encountered within the vicinity of the proposed deck, it is our opinion that the proposed deck foundations should consist of 8- to 12-inch diameter Sonotube foundations embedded a minimum of one foot into competent glacial soils. At the time of our site visits, the moderate northwest facing slopes situated below and to the west of the existing residence, appeared to be stable with no apparent indications of previous landslides or erosion hazards. We interpret that the core of the site slopes primarily consists of native glacial deposits which should be stable with respect to deep seated earth movements. There is a potential for shallow erosional events to occur on the moderate slope below and to the west of the existing residence, however it is our opinion that the proposed deck development will not adversely impact the currently stability conditions, given that the recommendations documented in this letter are closely followed. Under no circumstances should water be allowed to concentrate or uncontrollably flow onto site slopes. Similarly grass clippings or other yard debris should not be cast over slopes. Slopes should be protected from erosion; if exposed soils are encountered within the site they should be promptly revegetated or covered with erosion control matting, as needed. Along the western property line, there is an approximately 3.5-foot tall keystone block wall that is showing signs of distress. It is our opinion that the wall was poorly constructed and, if left unrepaired, future soil erosion and wall deterioration should be expected. We understand you plan to replace or improve this wall in the future. In our opinion the retaining wall could be removed and rebuilt safely without adversely impacting the steeper slopes below. If needed, NGA could be retained to provide additional recommendations for wall reconstruction. The planned earthwork associated with the deck addition should be minor if deck foundations are constructed as recommended in the Deck Foundations section of this letter. However, some of the soils encountered on this site are considered moisture -sensitive and may disturb easily when wet. To lessen the potential impacts of construction on the site and to reduce cost overruns and delays, we recommend that foundation preparation take place during dry weather if possible. If earthwork takes place during wet weather, additional expenses and delays should be expected. These extra expenses NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation NGA File No. 1225420 Santiago Deck Addition January 6, 2021 Edmonds, Washington Page 6 could include additional erosion control and temporary drainage measures to protect the site. In any case, the excavation spoils should be hauled off site. Any disturbed areas should be promptly repaired Erosion Control Surface water appears to be adequately controlled on the site under current conditions. We do not anticipate that the planned deck addition will significantly alter drainage patterns at the site. Adequate spaced decking on joist framing should not concentrate runoff from the deck. If the decking will not be spaced and will concentrate runoff from the deck, the water should be collected in gutters and downspouts and be directed to the roof drain system. The on -site soils are listed as having a low to moderate potential for erosion, depending on how the site is graded and how water is allowed to concentrate. Best Management Practices (BMPs) should be used to control erosion. Areas disturbed during construction should be protected from erosion. Erosion control measures may include diverting surface water away from any excavations. If any vegetation is removed from the site, silt fences or straw wattles should be erected to prevent muddy water from leaving the area. City of Edmonds guidelines for BMPs should be followed. Disturbed areas should be replanted with vegetation at the end of construction and the vegetation should be maintained until it is established. Site Preparation and Grading After erosion control measures are implemented, site preparation within the planned new deck foundations should consist of stripping the topsoil, undocumented fill and loose soils from structural areas, to expose competent, native, bearing, glacial deposits. The stripped soil should be removed from the site or stockpiled for later use as a landscaping fill. Based on our observations, we anticipate stripping depths of 3.5 to 5.5 feet, depending on the specific locations. However, additional stripping may be required if areas of deeper undocumented fill and/or loose soil are encountered in unexplored areas. After stripping, if the exposed subgrade is deemed loose, it should be compacted to a non -yielding condition and then, if possible, proof -rolled with a heavy rubber -tired piece of equipment. Areas observed to pump or weave during the proof -roll test should be reworked to structural fill specifications or over -excavated and replaced with properly compacted structural fill or rock spalls. If significant surface water flow is encountered during construction, this flow should be diverted around areas to be developed, and the exposed subgrades should be maintained in a semi -dry condition. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation NGA File No. 1225420 Santiago Deck Addition January 6, 2021 Edmonds, Washington Page 7 Deck Foundations We recommend the new deck foundations consist of Sonotube foundations with a minimum form diameter of 12 inches. Sonotube foundations should be embedded a minimum of one foot into competent native bearing glacial soils. Based on our explorations medium dense or better soils should be encountered between 3.5 and 5.0 feet below the existing ground surface in the vicinity of the proposed deck. We should be retained to verify subgrade conditions once foundations excavations are made. Where undocumented fill or less dense soils are encountered at footing bearing elevation, the subgrade should be over -excavated to expose suitable bearing soil. Footings should extend at least 18 inches below the lowest adjacent finished ground surface for frost protection and bearing capacity considerations. Foundations should be designed in accordance with the 2018 IBC. Footing widths should be based on the anticipated loads and allowable soil bearing pressure. Water should not be allowed to accumulate in footing trenches. All loose or disturbed soil should be removed from the foundation excavation prior to placing concrete. For foundations constructed as outlined above, we recommend an allowable design bearing pressure of not more than 2,000 pounds per square foot (psf) be used for the design of footings founded on the medium dense or better native bearing soils or rock spalls extending to the competent native bearing material. The foundation bearing soil should be evaluated by a representative of NGA. We should be consulted if higher bearing pressures are needed. Current IBC guidelines should be used when considering increased allowable bearing pressure for short-term transitory wind or seismic loads. Potential foundation settlement using the recommended allowable bearing pressure is estimated to be less than 1-inch total and %-inch differential between adjacent footings or across a distance of about 20 feet, based on our experience with similar projects. Lateral loads may be resisted by friction on the base of the footing and passive resistance against the subsurface portions of the foundation. A coefficient of friction of 0.35 may be used to calculate the base friction and should be applied to the vertical dead load only. Passive resistance may be calculated as a triangular equivalent fluid pressure distribution. An equivalent fluid density of 150 pounds per cubic foot (pcf) should be used for passive resistance design for a level ground surface adjacent to the footing. This level surface should extend a distance equal to at least three times the footing depth. These recommended values incorporate safety factors of 1.5 and 2.0 applied to the estimated ultimate values for frictional and passive resistance, respectively. To achieve this value of passive resistance, the foundations should be poured "neat" against the native medium dense soils or compacted fill should be NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation NGA File No. 1225420 Santiago Deck Addition January 6, 2021 Edmonds, Washington Page 8 used as backfill against the front of the footing. We recommend that the undocumented fill be neglected when calculating the passive resistance. Structural Fill General: Fill placed beneath foundations, pavement, or other settlement -sensitive structures should be placed as structural fill. Structural fill, by definition, is placed in accordance with prescribed methods and standards, and is monitored by an experienced geotechnical professional or soils technician. Field monitoring procedures would include the performance of a representative number of in -place density tests to document the attainment of the desired degree of relative compaction. The area to receive the fill should be suitably prepared as described in the Site Preparation and Grading subsection prior to beginning fill placement. Materials: Structural fill should consist of a good quality, granular soil, free of organics and other deleterious material, and be well graded to a maximum size of about three inches. All-weather fill should contain no more than five -percent fines (soil finer than U.S. No. 200 sieve, based on that fraction passing the U.S. 3/4-inch sieve). Some of the more granular on -site soils may be suitable for use as structural fill, but this will be highly dependent on the moisture content of these soils at the time of construction. We should be retained to evaluate all proposed structural fill material prior to placement. Fill Placement: Following subgrade preparation, placement of structural fill may proceed. All filling should be accomplished in uniform lifts up to eight inches thick. Each lift should be spread evenly and be thoroughly compacted prior to placement of subsequent lifts. All structural fill underlying building areas and pavement subgrade should be compacted to a minimum of 95 percent of its maximum dry density. Maximum dry density refers to the density as determined by the ASTM D-1557 Compaction Test procedure. The moisture content of the soils to be compacted should be within about two percent of optimum so that a readily compactable condition exists. It may be necessary to over -excavate and remove wet soils in cases where drying to a compactable condition is not feasible. All compaction should be accomplished by equipment of a type and size sufficient to attain the desired degree of compaction and should be tested. Site Drainage Depending on the final design of the proposed deck we recommend that the finished ground surface underlying the deck should be graded such that runoff is directed away from the existing residence. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation NGA File No. 1225420 Santiago Deck Addition January 6, 2021 Edmonds, Washington Page 9 USE OF THIS LETTER This letter has been prepared for Mr. Christian Santiago and his agents, for use in the planning and design of the new deck planned on this site only. The scope of our work does not include services related to construction safety precautions and our recommendations are not intended to direct the contractors' methods, techniques, sequences, or procedures, except as specifically described in our letter. There are possible variations in subsurface conditions between the explorations and also with time. Our letter, conclusions, and interpretations should not be construed as a warranty of subsurface conditions. A contingency for unanticipated conditions should be included in the project budget and schedule. We recommend that NGA be retained to provide monitoring and consultation services during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not deck support installation complies with our recommendations. We should be contacted a minimum of one week prior to construction activities. Within the limitations of scope, schedule and budget, our services have been performed in accordance with generally accepted geotechnical engineering practices in effect in this area at the time this letter was prepared. No other warranty, expressed or implied, is made. Our observations, findings, and opinions are a means to identify and reduce the inherent risks to the owner. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Santiago Deck Addition Edmonds, Washington NGA File No. 1225420 January 6, 2021 Page 10 We appreciate the opportunity to provide service to you on this project. If you have any questions or require further information, please call. Sincerely, NELSON GEOTECHNICAL ASSOCIATES, INC. Katelyn S. Brower, GIT Staff Geologist II "Ir � 1411( Alex B. Rinaldi, LG Project Geologist Khaled M. Shawish, PE Principal KSB:ABR:KMS:sg Five Figures Attached NELSON GEOTECHNICAL ASSOCIATES, INC. VICINITY MAP N Not to Scale e A ti N CJ, x 11��S�e�Vi Southwest 4 County Park QVnpicviewDt Project 41 °o Site teislfl5w r � Stamm 0 erlook Park a 182nd St SW O�y�QWc�`¢ United States a W n Postal Service Fat Piq BBQ © Free De tvery Seaview Park on 1st order Q Mel and Mia's a 16S P S7/ n Hutt Park 18611 St sw Lynndale Park Skate Park v oly' se 1P.til V V 1 8'!1' 5t 4W < 1871h St SW c Seaview Elementary School PERRINVILLE - s -Lynndale s,W Iaft F4S-W i ( Picnic She 190th St SWA. m c z= m 19ifit 51 SW p` -o o a n E F 192nd PI SW ,- -•� I W Y W U N 0 Edmonds, WA N co O N N Ul 0 O LL U N O a` a Project Number NELSON GEOTECHNICAL No. Date Revision By z z CK R 1225420 Santiago Deck Development Vicinity Map NGA ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS 1 12/9/20 Original DPN ABR to E OU Figure 1 Woodinville Office Wenatchee Office 17311-135th Ave. NE, A-500 105 Palouse St. Woodinville, WA 11112 Wenatchee, WA 98801 J J (425) 486-16691 Fax: 481-2510—elsongeotech.com (509) 665-7696 /Fax: 665-7692 = -n .0 . CD Site Plan Z. N) 0 K3 C CD Ul z N) No 3 N 0- ID Approximate Location of Proposed Deck C/) Oz s 'I 0 Cn ;:w CD CD 0 ------------- CD-------- CD 0 -- ----------- 3 ------ --- -------- CD 0, > 0 OM z rn M 01 > z - ass ------- n > z r M M ---- z > r 0 Io M 0 z Existing House 0 3o rn 0 M -4 _17 A ---------------------- --- T 0 3: r 0 0 > r LE END z Property line SU iZ3 ;; HA-1 Number and approximate IE — X CD location of hand auger 0 30 60 A A' Approximate location Scale: finch 30 feet t J of cross-section Pnfn­n­ Qifn ninn h—ri nn n ninn rInt—I CZ—f—h— 'Ir) qn9r) fiti—i "T--r—hi, Q. ininxi Pnilin Qnnfinnn n—nn-4 by Qifn CZi inf—inn 1— \\HILL\company\2020 NGA Project Folders\12254-20 Santiago Deck Edmonds\Drafting\SP.dwg O T M. 1 N � N Ul CD N W o 3 m U) v nv o `0 c o in p & m CD 0 0 p 3 o' CD >o D_0 _3 ci n YJ W. r>' Z z >r m Z (n0 Io m 0 Z m n 3 N A M St, -► 0 m .i m m T'c=C) Z -Ni A N r M Northwest I 380 r 0 a� c 0 cu N LLI 0 cu X 0 Q E0 M 340 320 300 i� Existing House HA-1 HA-3 HA-2 H�A-4Fill 27� A' Southeast 380 0 20 40 60 80 100 120 140 Distance (feet) Exploration N v iB m fD Hand Auger Designation --> HA-1 o � 360 340 320 300 y' Groundwater Level 1 NOTES: During Exploration 1) Stratigraphic conditions are interpolated between the explorations. Actual conditions may vary. 0o Geologic Contact ? — —? 2) Elevations are approximate. (approximate) D (7 Reference: Cross Section is based on field measurements using a hand-held clinometer and 100-ft tape measure. UNIFIED SOIL CLASSIFICATION SYSTEM GROUP MAJOR DIVISIONS GROUP NAME SYMBOL CLEAN GW WELL -GRADED, FINE TO COARSE GRAVEL COARSE- GRAVEL GRAVEL GP POORLY -GRADED GRAVEL GRAINED MORE THAN 50 GM OF COARSE FRACTION OF SILTY GRAVEL RETAINED ON SOILS NO.4 SIEVE WITH FINES GC CLAYEY GRAVEL SAND CLEAN SW WELL -GRADED SAND, FINE TO COARSE SAND SAND SP POORLY GRADED SAND MORE THAN 50 % RETAINED ON MORE THAN 50 % NO. 200 SIEVE OF COARSE FRACTION SAND SM SILTY SAND PASSES NO. 4 SIEVE WITH FINES SC CLAYEY SAND FINE - SILT AND CLAY ML SILT INORGANIC GRAINED LIQUID LIMIT CL CLAY LESS THAN 50 % SOILS ORGANIC OL ORGANIC SILT, ORGANIC CLAY SILT AND CLAY MH SILT OF HIGH PLASTICITY, ELASTIC SILT INORGANIC MORE THAN 50 % PASSES LIQUID LIMIT CH CLAY OF HIGH PLASTICITY, FAT CLAY NO. 200 SIEVE 50 % OR MORE ORGANIC CH ORGANIC CLAY, ORGANIC SILT HIGHLY ORGANIC SOILS PT PEAT NOTES: 1) Field classification is based on visual SOIL MOISTURE MODIFIERS: examination of soil in general accordance with ASTM D 2488-93. Dry - Absence of moisture, dusty, dry to the touch 2) Soil classification using laboratory tests is based on ASTM D 2488-93. Moist - Damp, but no visible water. 3) Descriptions of soil density or Wet - Visible free water or saturated, consistency are based on usually soil is obtained from interpretation of blowcount data, below water table visual appearance of soils, and/or test data. Project Number NELSON GEOTECHNICAL No. Date Revision By CK 1225420 Santiago Deck Development Soil Classification Chart NGA ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS Woodinville Office Wenatchee Office 1 12/9/20 Original DPN ABR Figure 4 17311-135th Ave. NE, A-500 105 Palouse St. Woodinville, WA 98072 Wenatchee, WA 98801 (425) 486-16691 Fax: 481-2510 w.nelsongeotech.com (509) 665-7696 / Fax: 665-7692 LOG OF EXPLORATION DEPTH (FEET) USC SOIL DESCRIPTION HAND AUGER ONE 0.0 - 0.4 TOPSOIL 0.4 - 3.0 LIGHT BROWN, SILTY FINE TO MEDIUM SAND WITH GRAVEL AND TRACE ROOTS (LOOSE TO MEDIUM DENSE, MOIST) (FILL) 3.0 - 3.5 DARK BROWN TO BROWN, SILTY FINE TO MEDIUM SAND WITH GRAVEL, ROOTS, AND ORGANICS (LOOSE TO MEDIUM DENSE, MOIST) (BURIED TOPSOIL) 3.5 - 5.0 SP-SM LIGHT BROWN, FINE TO MEDIUM SAND WITH SILT, GRAVEL, AND IRON -OXIDE WEATHERING (MEDIUM DENSE TO DENSE, MOIST) 5.0 - 6.5 SP-SM GRAY, FINE TO MEDIUM SAND WITH SILT AND GRAVEL (MEDIUM DENSE TO DENSE, MOIST) SAMPLE WAS COLLECTED AT 6.5 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED HAND AUGER CAVING WAS NOT ENCOUNTERED HAND AUGER WAS COMPLETED AT 6.5 FEET ON 12/2/2020 HAND AUGER TWO 0.0 - 0.6 TOPSOIL 0.6 - 3.5 LIGHT BROWN, SILTY FINE TO MEDIUM SAND WITH GRAVEL, ORGANICS, AND ROOTS (LOOSE TO MEDIUM DENSE, MOIST) (FILL) 3.5 - 5.0 SP-SM GRAY, FINE TO MEDIUM SAND WITH SILT, GRAVEL, AND IRON -OXIDE STAINING (MEDIUM DENSE TO DENSE, MOIST) SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED HAND AUGER CAVING WAS NOT ENCOUNTERED HAND AUGER WAS COMPLETED AT 5.0 FEET ON 12/2/2020 HAND AUGER THREE 0.0 - 0.6 TOPSOIL 0.6 -4.7 BROWN TO DARK BROWN, SILTY FINE TO COARSE SAND WITH GRAVEL, ORGANICS, AND ROOTS (MEDIUM DENSE, MOIST) (FILL) 4.7 - 6.0 SP-SM LIGHT BROWN TO GRAY, FINE TO MEDIUM SAND WITH SILT AND GRAVEL (MEDIUM DENSE TO DENSE, MOIST) SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED HAND AUGER CAVING WAS NOT ENCOUNTERED HAND AUGER WAS COMPLETED AT 6.0 FEET ON 12/2/2020 HAND AUGER FOUR 0.0 - 0.6 TOPSOIL 0.6 - 5.5 BROWN TO DARK BROWN, SILTY FINE TO MEDIUM SAND WITH GRAVEL, ORGANICS, AND ROOTS (LOOSE TO MEDIUM DENSE, MOIST) (FILL) 5.5 - 7.0 SP-SM LIGHT BROWN TO GRAY, FINE TO MEDIUM SAND WITH SILT, TRACE GRAVEL, AND IRON -OXIDE STAINING (MEDIUM DENSE TO DENSE, MOIST) SAMPLE WAS COLLECTED AT 7.0 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED HAND AUGER CAVING WAS NOT ENCOUNTERED HAND AUGER WAS COMPLETED AT 7.0 FEET ON 12/2/2020 DPN:ABR NELSON GEOTECHNICAL ASSOCIATES, INC. FILE NO 1225420 FIGURE 5