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APPROVED BLD BLD2020-0831+Geo_Report+8.10.2020_5.09.50_PMa s s o c i a t e d earth sciences i n c o r p o r a t e d November 13, 2019 Project No. 20190373EO01 Ms. Charlie Lieu 16515 74th Place West Edmonds, Washington 98026 Subject: Subsurface Exploration and Geotechnical Engineering Report Lieu Residence Underpinning 16515 741h Place West Edmonds, Washington Dear Ms. Lieu: As requested, Associated Earth Sciences, Inc. (AESI) has completed this letter -report summarizing our subsurface exploration review and geotechnical recommendations for the subject project. Our work included a visual site assessment, review of exploration borings previously completed at the subject site, review of published geologic mapping, and preparation of this letter -report summarizing our findings, opinions, and conclusions. This letter -report has been prepared for the exclusive use of Ms. Charlie Lieu, and her agents, for specific application to this project. Our services have been performed in accordance with generally accepted geotechnical engineering and engineering geology practices in effect in this area at the time our letter -report was prepared. No other warranty, express or implied, is made. SITE AND PROJECT DESCRIPTION The site is the existing residential property at 16515 74th Place West in Edmonds, Washington (Snohomish County Parcel No. 00513100008803), as shown on the attached "Vicinity Map" (Figure 1). The existing home is a two-story structure built in 1950, with an addition to the north end of the original building footprint built, as we understand, in the 1980s. A wooden deck extends westward from the main structure. The project site and surrounding area slopes down to the west, and the site appears to have been graded to its current configuration when the existing house was built, with this grading likely including a cut for the southern/eastern portion of the site, including an access/parking area, and fill placed to create a level surface for Kirkland Office 1911 Fifth Avenue i Kirkland, WA 98033 P 1425.827.7701 Mount Vernon Office 1508 S. Second Street, Suite 101 i Mount Vernon, WA 98273 P 1425.827.7701 Tacoma Office i 1552 Commerce Street, Suite 102 i Tacoma, WA 98402 P i 253.722.2992 www.aesgeo.com Lieu Residence Underpinning Subsurface Exploration and Edmonds, Washington Geotechnical Engineering Report the northern/western portion. We understand that settlement has occurred, chiefly along the northern, added portion of the residence, and that voids are present at or near the northwest corner of the foundation. We understand that you currently wish to mitigate the observed foundation settlement for the residence. Our recommendations are preliminary in that project plans and construction methods were not available at the time this letter -report was written. We should be allowed to review the recommendations presented in this letter -report and modify them, if needed, once final project plans have been formulated. SUBSURFACE EXPLORATION AESI previously observed explorations at the subject site on February 5, 2007, as part of a geotechnical study for a then -proposed project. This previous field study included drilling three exploration borings. The various types of sediments, as well as the depths where the characteristics of the sediments changed, are indicated on the exploration logs presented in the Appendix. The depths indicated on the logs where conditions changed may represent gradational variations between sediment types. If changes occurred between sample intervals in our exploration borings, they were interpreted. Our explorations were approximately located in the field by measuring from known site features. The site and the approximate locations of the subsurface explorations are presented on the "Site and Exploration Plan" (Figure 2). The conclusions and recommendations presented in this letter -report are based, in part, on the exploration borings reviewed for this study. Because of the nature of exploratory work below ground, extrapolation of subsurface conditions between field explorations is necessary. It should be noted that differing subsurface conditions may sometimes be present due to the random nature of deposition and the alteration of topography by past grading and/or filling. The nature and extent of variations between the field explorations may not become fully evident until construction. If variations are observed at that time, it may be necessary to re-evaluate specific recommendations in this letter -report and make appropriate changes. Exploration Borings The borings were drilled using a track -mounted hollow -stem auger drill rig. During the drilling process, samples were generally obtained at 2%- or 5-foot depth intervals. The borings were continuously observed and logged by a representative from our firm. The exploration logs presented in the Appendix are based on the field logs, drilling action, and observation of the samples collected. Disturbed but representative samples were obtained by using the Standard Penetration Test (SPT) procedure in accordance with American Society for Testing and Materials (ASTM) D-1586. This test and sampling method consists of driving a standard 2-inch, outside -diameter, November 13, 2019 ASSOCIATED EARTH SCIENCES, INC. JPL/ms-20190373EO01-2 Page 2 Lieu Residence Underpinning Subsurface Exploration and Edmonds, Washington Geotechnical Engineering Report split -barrel sampler a distance of 18 inches into the soil with a 140-pound hammer free -falling a distance of 30 inches. The number of blows for each 6-inch interval is recorded, and the number of blows required to drive the sampler the final 12 inches is known as the Standard Penetration Resistance ("N") or blow count. If a total of 50 is recorded within one 6-inch interval, the blow count is recorded as the number of blows for the corresponding number of inches of penetration. The resistance, or N-value, provides a measure of the relative density of granular soils or the relative consistency of cohesive soils; these values are plotted on the attached exploration boring logs. The samples obtained from the split -barrel sampler were classified in the field and representative portions placed in watertight containers. The samples were then transported to our laboratory for further visual classification. SUBSURFACE CONDITIONS Stratigraphy Fill Exploration borings EB-1 and EB-3 encountered sediments consisting of loose to medium dense, moist to wet, silty sand with variable gravel content, interpreted as fill soils (those not naturally placed) to a depth of 13 feet below the ground surface. Due to the high variability of existing fill soils, we do not recommend that new foundations or underpinning elements be supported by these soils. Whidbey Formation Below the fill at exploration borings EB-1 and EB-3, and below the ground surface at EB-2, our 2007 explorations encountered very stiff to hard silt, with varying amounts of sand and sand interbeds, which extended below the maximum depths explored. This soil was interpreted to represent non -glacial deposits placed prior to the Fraser Glaciation and subsequently compacted by the weight of the overlying glacial ice. The very stiff to hard material is generally considered suitable for support of light to heavily loaded foundations when in an intact, undisturbed condition. This material is moisture -sensitive and susceptible to disturbance when wet. Published Geologic Map Review of the regional geologic map titled Geologic Map of the Edmonds East and Part of the Edmonds West Quadrangles, Washington (J.P. Minard, 1983, U.S. Geological Survey [USGS], Miscellaneous Field Studies Map MF-1541, scale 1:24,000) indicates that the area of the subject site is underlain by Transitional Bed deposits, with Olympia Gravel and Whidbey Formation November 13, 2019 ASSOCIATED EARTH SCIENCES, INC. JPL/ms-20190373EO01-2 Page 3 Lieu Residence Underpinning Subsurface Exploration and Edmonds, Washington Geotechnical Engineering Report deposits mapped downslope. Our interpretation of the sediments encountered at the subject site is in general agreement with the regional geologic map. Hydrology Groundwater was not encountered during our 2007 explorations, although wet soils were encountered within the fill. We expect groundwater seepage across much of the site to be limited to interflow. Interflow occurs when surface water percolates down through the surficial weathered or higher -permeability sediments and becomes perched atop underlying, lower -permeability sediments. The presence or absence, duration, and quantity of seepage and the levels of groundwater will largely depend on the soil grain -size distribution, topography, seasonal precipitation, on- and off -site land usage, and other factors, and may vary from the conditions encountered during our exploration. CONCLUSIONS AND RECOMMENDATIONS The area in the vicinity of the residence was apparently graded prior to its construction. It appears that the greatest fill thickness was created on the northern to western portion of the site where substantial filling likely occurred to establish the level building pad area. The observed distress is likely the result of settlement of this fill. To reduce the potential for future settlement and to allow some minor re -leveling of the structure, we recommend underpinning of the existing foundation using one of the methods described in the following section. Foundation Underpinning We understand that the piles, such as push piles, pipe piles, and helical anchors, are being considered to underpin portions of the residence to reduce the potential for future settlement and to allow some minor re -leveling. The underpinning would connect to the existing foundations, extend through the existing fill, and penetrate the competent native soils at depth. It should be understood that, given the apparent past grading activities at the site, a risk of future settlement remains outside of the remediated portion of the structure, and future repair/remediation may be required as a result. Push Piles The "push pile" approach is to install small -diameter pipe piles at regular spacing below the foundations to be underpinned. The piles are 2'/8-inch-diameter pipe sections with a 31/2-inch-diameter driving tip. The piles would be pushed into the ground using dual hydraulicjacks reacting against the building foundations. Prefabricated "L"-shaped brackets would then be placed between the pile tops and the base of the existing foundations. The foundation loads would then be transferred to the new pile foundations by jacking and shimming. November 13, 2019 ASSOCIATED EARTH SCIENCES, INC. JPL/ms-20190373EO01-2 Page 4 Lieu Residence Underpinning Subsurface Exploration and Edmonds, Washington Geotechnical Engineering Report Based on the fill thickness observed in our 2007 explorations, piles pushed through the existing fill and into the underlying native soils will likely reach refusal to jacking at about 15 to 20 feet below the ground surface. The jacking pressure that can be applied to each pile is determined by the available reaction load at each pile location. The actual jack pressure that can be applied depends on the dead load of the reaction (foundation load) above the pile and the need to limit vertical deflection (movement) of the foundation during jacking. Therefore, each pile jacking will need to be monitored to measure the actual jack pressure and the upward foundation movement during jacking. The maximum jacking load applied to each pile represents the ultimate pile capacity. The working or allowable capacity is determined by applying a safety factor of at least 2 to the ultimate capacity determined during pile installation. All of the piles and support brackets should be installed with appropriate -sized installation equipment in accordance with the manufacturer's recommendations. AESI should review the pile installation plan and confirm the jack pressure and allowable capacity of each pile. Pile spacing should be established based on the structural engineer's load requirements and the actual allowable capacity of each pile that can be achieved in the field. Piles should be spaced no closer than 1 foot center -to -center. A closer spacing would reduce the allowable vertical capacity of both piles and would need to be evaluated on a case -by -case basis. These small -diameter pipe piles are not intended to carry a significant lateral load. Lateral loads should be taken as passive resistance of the existing foundations against the surrounding soil. At least one pile should be load -tested to two times the allowable capacities. Pipe Piles An alternative to push piles for underpinning would be small -diameter pipe piles consisting of thick-walled, 2-inch-diameter steel pipe driven by a pneumatic impact hammer. Pipes are typically provided in sections and joined as needed with couplers that are suitable for transmission of vertical compressive loads. The pipe piles are driven until a suitable refusal criterion or penetration rate is achieved within the native sediments. The pipe piles are then attached to the existing foundations, which together act as the new foundation system. Two -inch -diameter, Schedule 80 pipe piles driven to refusal in the very stiff or dense native sediments should be capable of supporting loads on the order of 2 tons per pile. A refusal criterion of 60 seconds per inch is appropriate during sustained driving with a 90-pound pneumatic hammer and operator. Larger -diameter piles, such as 3- or 4-inch-diameter pipe piles, may provide greater axial compressive capacities. However, installation of larger piles is likely infeasible due to equipment access constraints. Different hammer sizes/types may have different driving characteristics and refusal criteria. If an alternate hammer is used, AESI should be notified prior to pile -driving activities. We estimate the specified refusal criterion will be reached within 15 to 20 feet below existing ground surface, based on the exploration log review and reconnaissance completed for the project. November 13, 2019 ASSOCIATED EARTH SCIENCES, INC. JPL/ms-20190373EO01-2 Page 5 Lieu Residence Underpinning Edmonds, Washington Helical Anchors Subsurface Exploration and Geotechnical Engineering Report A third alternative would be helical anchors. Helical anchor design and installation should be in accordance with Designing Helical Piles per the IBC, dated September 2013, or similar Chancel" Earth Anchor or equivalent system guidelines. Helical anchor shaft size should be selected based on the following soil parameters: Soil Type - silt (SPT blow count <15) Internal Angle of Friction - 30 degrees Cohesion - 0 psf Ultimate Shaft Adhesion (soil to steel) - 300 psf Depending on the helix that is selected and assuming a minimum anchor depth of about 15 feet, we anticipate individual helical anchor capacities of 3,000 to 5,000 pounds. All helical anchors should, however, be advanced through the existing fill and terminate in the very stiff to hard native soils. We recommend that we be allowed to review the completed design to verify that our recommendations have been incorporated and that the planned system is feasible based on our current knowledge of the site. All of the helical anchors should be installed with appropriate -sized installation equipment in accordance with the manufacturer's recommendations contained in the referenced design manual. AESI should review the installation of all of the anchors. Anchor spacing should be at least three times the largest helix center -to -center. A closer spacing would reduce the allowable vertical capacity of both anchors and would need to be evaluated on a case -by -case basis. Care should be used during installation so that the anchors do not "spin" in place. The anchors should "screw" into undisturbed soil for their entire length. Spinning anchors will disturb the bearing soils and will reduce the allowable anchor capacity. At least one anchor should be load -tested to two times the allowable capacity. Pile Inspections The actual total length of each pile may be adjusted in the field, based on required capacity and conditions encountered during driving, and may be different than estimated above. Since completion of the pile takes place below ground, the judgment and experience of the geotechnical engineer or their field representative must be used as a basis for determining the required penetration and acceptability of each pile. Consequently, use of the presented capacities in the design requires that all piles be inspected by a qualified geotechnical engineer or engineering geologist from our firm who can interpret and collect the installation data and observe the contractor's operations. AESI, acting as the owner's field representative, would determine the required lengths of the piles and keep records of pertinent installation data. A final summary report would then be distributed following completion of pile installation. These services may be a permit requirement for work completed in the City of Edmonds. November 13, 2019 ASSOCIATED EARTH SCIENCES, INC. JPL/ms-20190373EO01-2 Page 6 Lieu Residence Underpinning Subsurface Exploration and Edmonds, Washington Geotechnical Engineering Report As part of the underpinning system design, a qualified structural engineer would, using the design guidelines presented herein, determine the number of piles required, the minimum spacing between adjacent piles, and the connections between the new piles and the existing foundations. Prior to design completion, AESI should review the plans and specifications and verify proper interpretation of our recommendations. Erosion Hazard and Mitigation The erosion potential of the site soils is moderate to high. We understand that the project will involve only minor earthwork in the form of excavations for foundation underpinning. Also, construction will occur on a fully developed lot with well -established landscaping. Therefore, provided that the subsequent recommendations provided in this letter -report are followed, it is our opinion that the impacts to erosion will be minimal. Maintaining cover measures atop disturbed ground typically provides the greatest reduction to the potential generation of turbid runoff, sediment transport, and slope erosion. We recommend that the following Best Management Practices (BMPs) are followed during construction to reduce the potential for erosion activity at the site: • Preserve and maintain existing vegetation at the project site where possible; • Route surface water away from sloping ground to an approved discharge location; • Stripped areas not actively being worked on should have cover measures; • Complete earthwork during dry weather and site conditions, if possible; • Install silt fencing along the lower perimeter of the project site; and • Cover temporary excavation spoils with plastic sheeting. Ground -cover measures can include erosion control matting, plastic sheeting, straw mulch, crushed rock or recycled concrete, or mature hydroseed. Project planning and construction should follow local standards of practice with respect to temporary erosion and sediment control (TESC). CLOSURE We are available to provide geotechnical engineering services during construction. Construction monitoring services are not part of this current scope of work. If these services are desired, please let us know, and we will prepare a cost proposal. November 13, 2019 ASSOCIATED EARTH SCIENCES, INC. JPL/ms-20190373EO01-2 Page 7 Lieu Residence Underpinning Edmonds, Washington Subsurface Exploration and Geotechnical Engineering Report We have enjoyed working with you on this study and are confident these recommendations will aid in the successful completion of your project. If you should have any questions or require further assistance, please do not hesitate to call. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Jeffrey P. Laub, L.G., L.E.G. Senior Engineering Geologist Attachments: Figure 1: Vicinity Map Figure 2: Site and Exploration Plan Appendix: Exploration Logs (2007) �GE 8 L. 4 T �¢WASJy7^ Bruce L. Blyton, P.E Senior Principal Engineer November 13, 2019 ASSOCIATED EARTH SCIENCES, INC. JPL/ms-20190373EO01-2 Page 8 Q. adow.dale MeUNN 0RPORATE D -o; - ?� BeAch -%92 I I f -j / SITE Bro -wag So-uthwesh ___ I •' Ptty pp. Inx Ao-- / N D'S .41 sxn �*cb leg N N:U1V O O D�•.,� �, �4 w •�� Flrl�-ram �/� ;� �` .� ' �, 99 ark • • nn t•az + �. �6 H -524 • R " f SF` ` Copyright? 201.Na I • r,ic Society, cubed a s s o c i a t e d N �t A earth sciences Snohomish County Inc o r p o r a t e d ,DOD j VICINITY MAP FEET DATA SOURCES/REFERENCES: LIEU RESIDENCE USGS: 7.5' SERIES TOPOGRAPHIC MAPS, ESRI/1-CUBED/NATIONAL NOTE: BLACK AND WHITE GEOGRAPHIC SOCIETY2013 REPRODUCTION OF THIS COLOR EDMONDS, WASHINGTON SNOHOMISH CO: STREETS, CITY LIMITS, PARCELS, 2/19 ORIGINAL MAY REDUCE ITS EFFECTIVENESS AND LEAD TO PROD NO. DATE: FIGURE: LOCATIONS AND DISTANCES SHOWN ARE APPROXIMATE INCORRECT INTERPRETATION 190373EO01 11/19 1 LEGEND: • EB EXPLORATION BORING - 2007 SITE BOUNDARY \ _ p 24'15 E / \ 1 III �r CONTOUR INTERVAL = 2' 00 NOTE: LOCATION AND DISTANCES SHOWN ARE APPROXIMATE. 2oa / . \ I /% FOUND R I I _ AND CAP PLANTERS 11E EB-2 "RMA4§61 1 G CONCRETE � h f e� i �. �Q N Q P NOTES: I . /GRAVEL i1 / /// l Ol y 1. BASE MAP REFERENCE: PACIFIC GEOMATIC SERVICES, INC., ti� I I ✓ / / N 1 1 I + ELITE CONSTRUCTION ENGINEERING CONSORTIUM, INC., o ,✓ I ti f .. �'. . �1-� : I�1 • // / � I I � � O�, SERENE CREEK PRD, TOPOGRAPHIC MAP, 11/18/05 �RESIDENCE I I I 1 / ►� °p\\ 16514 74TH PL. 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DATE: FIGURE: 20190373EO01 11/19 2 APPENDIX Exploration Logs U EZ °o Well -graded gravel and Terms Describing Relative Density and Consistency o p o o OW g ravel with sand, little to 2) Density SPT blows/foot w o no fines Very Loose 0 to 4 Coarse-4 to 10 o o o 0 o 0 0 o o o GP Poorly -graded gravel 0)Loose > U) c> o o - v, o �,o w Grained Soils Medium Dense 10 to 30 Test Symbols 0 0 o 0 0 0 o and gravel with sand, Dense 3o to 50 little to no fines Very Dense >50 G = Grain Size M = Moisture Content ° 0° 0 Silty gravel and silty 6 Z C LO o Consistency SPT(2�blows/foot Y A= Atterberg Limits c a S GM gravel with sand Very Soft 0 to 2 C = Chemical Fine - v ~ ` .Soft ° 0 ° 0 2 to 4 DID =Dry Density Grained Soils c E 0 .i Medium Stiff 4 to 8 K = Permeability g o Stiff 8 to 15 Clayey gravel and Very Stiff 15 to 30 N NI Gc clayey gravel with sand Hard >30 o L Component Definitions o Well -graded sand and t Descriptive Term Size Range and Sieve Number m SW sand with gravel, little Boulders Larger than 12" o Li u e to no fines Cobbles 3" to 12" m ;n a� _ eveeeveeee Gravel 3" to No. 4 (4.75 mm) Poorly -graded sand con c i °' A SP and sand with gravel, Coarse Gravel 3" to 3/4" Fine Gravel 3/4to No. 4 75 mm " 4 (� ) 4) c cn o v N o little to no fines Sand No. 4 (4.75 mm) to No. 200 (0.075 mm) 0 z Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) 6 o y � SM Silty Sand and Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) silty sand with Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) N v c N o a tp.-::'::. gravel Silt and Clay Smaller than No. 200 (0.075 mm) (3) Estimated Percentage Moisture Content Na sc Clayey sand and co NI clayey sand with gravel Component Percentage by Weight Dry - Absence of moisture, Trace <5 dusty, dry to the touch Slightly Moist - Perceptible Silt, sandy silt, gravelly silt, moisture o ML silt with sand or gravel Some 5 to <12 Moist - Damp but no visible u7 c T w Modifier 12 to <30 water Clay Of low to medium o `—° (silty, sandy, gravelly) Very Moist - Water visible but d CL plasticity; silty, sandy, or not free draining z •= gravelly clay, lean clay Very modifier 30 to <50 Wet -Visible free water, usual) Y NE (silty, sandy, gravelly) from below water table 0- a == Organic clay or silt of low Symbols 2 — OL plasticity Blows/6" or 0 Sampler portion of 6" Cement grout o Type / i surface seal Elastic silt, clayey silt, silt 2.0" OD Sampler Type o o �, MH with micaceous or Split Spoon p Description (4) Bentonite seal � o or fine sand or Sampler p 3.0" OD Split -Spoon Sampler - :-= Filter pack with A o silt (SPT) 3.25" OD Split -Spoon Ring Sampler (4) . - ; . :: blank casing :: Clay of high plasticity, v) U o c � CH sandy or gravelly Clay, fat _ Bulk sample 3.0" OD Thin Wall Tube Sampler section Screened casing m E J clay with sand or ravel Y g (including Shelby tube) _ or Hydrotip =with filter pack U — c Grab Sample - End cap c ;% Organic clay or silt of o Portion not recovered OH medium to high (1) (4) Percentage by dry weight Depth of ground water plasticity (2) (SPT) Standard Penetration Test 1 ATD = At time of drilling ASTM D-1586 (3) ( ) Q Static water level (date) In General Accordance with w Peat, muck and other rn _ c a, 0 PT highly organic soils Standard Practice for Description (5) Combined USCS symbols used for and Identification of Soils (ASTM D-2488) fines between 5% and 12% Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and g plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory classification 3 methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. T O! ° a s s o c i a t e d earth sciences EXPLORATION LOG KEY FIGURE Al N o i n c o r p o r a t e d a Associated Earth Sciences, Inc. Exploration Log aProject Number Exploration Number Sheet EE070062A EB-1 1 of 1 Project Name 16515 74th Place West Ground Surface Elevation (ft) Location Edmonds, WA Datum NIA Driller/Equipment Boretec/Track Rig Date Start/Finish 2/5/0712/5/07 Hammer Weight/Drop 140# 30". Hole Diameter (in) a .2 > a) J �e U) Blows/Foot fA 15L E cD- 2 E >, E �5 3: 0 Q) a) 0 T Um) 0 u) DESCRIPTION 0 m M 10 20 30 40 :5 0 --Grass lawn. Fill Loose, wet, gray, silty SAND, trace gravel. T S-1 3 3 A6 3 5 Loose, wet, dark brown and gray, silty SAND, trace to few gravel, 2 S-2 T 2 A3 10 2 S-3 3 A5 (Increase in moisture) 5 --Increase in gravel) Whidbey Formation 15 Stiff to hard, moist, brown, SILT, with medium sand, interbeds, trace 4 S-4 gravel. 15 31 16 20 Hard, moist, blue -gray, SILT, with fine sand interbeds. 9 T S-5 13 A 39 26 25 S-6 Bedded SILT, some fine sand intervals 9 A2 8 11 17 30 5 S-7 10 A 2 i 16 35 Hard/very dense, moist, light brown, silty SAND/sandy SILT- 15 S-8 21 J 6 57 4 36 Bottom of exploration boring at 36 5 feet No water Sampler Type (ST): 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: EG 3" OD Split Spoon Sampler (D & M) U Ring Sample Water Level Approved by: Grab Sample Z Shelby Tube Sample Water Level at time of drilling (ATD) J J Associated Earth Sciences, Inc. Exploration Log N [i] &J Q M Project Number Exploration Number Sheet EE070062A EB-2 1 of 1 Project Name 16515 74th Place West Ground Surface Elevation (ft) Location Edmonds, WA Datum NIA Driller/Equipment Boretec/Track Rig Date Start/Finish 215107 2/5/07 Hammer Weight/Drop 140# 130" Hole Diameter (in) Cn c', U a E r- .2 Z >= Blows/Foot 2 E 12 >, E ?: 0 T 0 u) DESCRIPTION 0 76 .2 co -E 0 10 20 30 40 Whidbey Formation Medium dense, moist, gray and brown, silty SAND/sandy SILT. TS-1 18 3 A ♦' 27 14 5 S-2 Stiff, moist, gray and brown, bedded silt, few sand and sand interbeds. 10 14 A28 14 10 S-3 Stiff, moist, gray, thinly bedded SILT, with block structures, 6 A23 10 13 15 T S-4 9 13 29 16 20 S-5 T 9 13 'k33 20 25 S-6 7 10♦2i A� 16 Bottom of exploration boring at 26.5 feet No water, 30 35 Sampler Type (ST): [fl 2" OD Split Spoon Sampler (SPT) No Recovery M - Moisture Logged by: EG [E 3" OD Split Spoon Sampler (D & M) U Ring Sample -V Water Level Approved by: N Grab Sample Z Shelby Tube Sample -T Water Level at time of drilling (ATD) Associated Earth Sciences, Inc. Exploration Lo --71 �, I F M F7--- Lai nEg 0 Project Number Ex ploration Number Sheet EE070062A EB-3 1 of 1 Project Name 16515 74th Place West Ground Surface Elevation (ft) Location Edmonds, WA Datum NIA Driller/Equipment Boretec/Track Rig Date Start/Finish 2/.9/07 2/5/07 Hammer Weight/Drop 140# 30" Hole Diameter (in) to T cL cL E .0 > a) -J f, -- in Blows/Foot (n CD T ca T 0 u) 5, E 3E 0 a) V) DESCRIPTION 0 09 0 10 20 30 40 Fill Loose, moist, dark brown, silty SAND. S-1 3 2 Medium dense, wet, light brown, silty SAND, some mottling. 5 S-2 4 7 A 8 10 S-3 21 7 Al2 5 Whidbey Formation Stiff, moist, light brown, thinly bedded SILT, trace sand, with occasional thin sand inte,beds, 15 S-4 1317 17 A44 27 20 T S-5 Hard, moist, gray, bedded SILT 9 13 29 16 25 S-6 T Light brown and gray, bedded SILT, with sand interbeds, 11 12 A32 20 30 T S-7 Hard, moist, gray, bedded SILT, thin sand interbeds 12 15 A34 19 Bottom of exploration boring at 31 5 feet 35 Sampler Type (ST): [fl 2" OD Split Spoon Sampler (SPT) F] No Recovery M - Moisture Logged by: EG Y OD Split Spoon Sampler (D & M) U Ring Sample V- Water Level Approved by: Grab Sample Z Shelby Tube Sample T- Water Level at time of drilling (ATD)