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11- 240th SP Geotech Evaluation Letter 2019-09-19.pdfJuly 26, 2019 Updated September 19, 2019 ES-6740 Adamant Homes, LLC P.O. Box 14790 Mill Creek, Washington 98082 Attention: Mr. Larry Sundquist Subject: Geotechnical Evaluation Proposed Residential Development 8717 — 240t" Street Southwest Edmonds, Washington Earth ( Solutions NW«C Earth Solutions NW LLC Geotechnical Engineering, Construction Observationjesting and Environmental Services Reference: J.P. Minard Geologic Map of the Edmonds East and parts of the Edmonds West quadrangles, Washington, 1983 United States Department of Agriculture (USDA) Natural Resources Conservation Service Online Web Soil Survey (WSS) resource City of Edmonds, Washington GIS Database Snohomish County, Washington Liquefaction Susceptibility Map for Snohomish County, October 2009 Dear Mr. Sundquist: Earth Solutions NW, LLC (ESNW) has prepared this letter providing pertinent geotechnical recommendations for the proposed residential development. This letter was prepared in general accordance with the scope of services outlined in our service agreement dated May 29, 2019 and approved by Adamant Homes, LLC. This letter has been updated to include the On -site Stormwater Management section. Project Description We understand the project is pursing construction of a new residential development (likely single- family residences or townhomes) and related infrastructure improvements on the subject site. At the time of letter submission, specific building load plans were not available for review; however, we anticipate the proposed buildings will be constructed utilizing relatively lightly loaded wood framing supported on a conventional foundation system. Perimeter footing loads will likely be 1 to 2 kips per lineal foot. Slab -on -grade loading is anticipated to be approximately 150 pounds per square foot (psf). 1805 - 136th Place N.E., Suite 201 • Bellevue, WA 98005 0 (425) 449-4704 • FAX (425) 449-4711 Adamant Homes, LLC July 26, 2019 Updated September 19, 2019 ES-6740 Page 2 If the design assumptions outlined above are incorrect or change, ESNW should be contacted to review the recommendations provided in this letter. This letter has been prepared for the exclusive use of Adamant Homes, LLC and their representatives. A warranty is neither expressed nor implied. The recommendations and conclusions provided in this letter are professional opinions consistent with the level of care and skill that is typical of other members in the profession currently practicing under similar conditions in this area. Variations in the soil and groundwater conditions encountered at the exploration locations may exist and may not be encountered until construction. Surface Conditions The subject site is located directly north of the 87th Avenue West and 240th Street Southwest intersection, in Edmonds, Washington. The approximate location of the subject site is illustrated on Plate 1 (Vicinity Map). The site is bordered to north, east, and west by residential development, and to the south by 240th Street Southwest. Topography descends to the north/northwest with about 15 feet of elevation change occurring within the confines of the property. The site is developed with a single-family residence, detached sheds, and associated infrastructure features. Undeveloped portions of the site are surfaced with landscaping features and/or mature tree growth with a moderately dense underbrush. Subsurface Conditions An ESNW representative observed, logged, and sampled four shallow test pits, excavated with hand tools on May 29, 2019. On June 24, 2019, ESNW observed, logged, and sampled three test pits, excavated within accessible areas of the site using a mini-trackhoe and operator retained by our firm. The approximate locations of the hand excavations and test pits are depicted on Plate 2 (Subsurface Exploration Plan). Please refer to the attached test pit logs for a more detailed description of subsurface conditions. Representative soil samples collected at the test pit locations were analyzed in accordance with both Unified Soil Classification System (USCS) and USDA methods and procedures. Topsoil and Fill Topsoil was encountered within the upper approximate 6 to 12 inches of existing grades at the exploration locations. The topsoil was characterized as such given its dark brown hue, presence of fine organic material, and root intrusions within the horizon. Silty sand fill soil was locally encountered at HA-3, extending to an approximate depth of about one foot below the existing ground surface (bgs). The fill was field characterized as being loose and moist. In our opinion, fill soils may be anticipated within proximity to the existing structure and within areas of infrastructure improvements. Earth Solutions NW, LLC Adamant Homes, LLC July 26, 2019 Updated September 19, 2019 Native Soil ES-6740 Page 3 Underlying topsoil and localized fill (where present), native soils were classified primarily as silty sand (USCS: SM). Areas of sand were observed but appeared localized in extent. Based on the encountered conditions, silty sand should be considered the predominate underlying soil type. In general, native soils were encountered in a medium dense to dense and moist condition, extending to the maximum exploration depth of about 10 feet bgs. Geologic Setting The referenced geologic map resource identifies the site as being underlain by Vashon glacial till (Qvt). The till is characterized as a non -sorted mixture of clay, silt, sand, pebbles, cobbles, and boulders in various amounts. The referenced WSS resource identifies soils of the Alderwood- Urban land complex and McKenna gravelly silt loam series (Map Unit Symbols: 6 and 32, respectively) as underlying the site and surrounding areas. The Alderwood series is typically associated with glacial till plains with designations of urban land complex indicative of historic earthwork and grading activities in the area. The McKenna series is associated with drainageways and depressions. Based on our field observations, native site soils are consistent with local geologic mapping and soil survey designations of glacial till. Groundwater Groundwater intrusions were not encountered during our May or June 2019 subsurface explorations. Seepage rates and elevations fluctuate depending on many factors, including precipitation duration and intensity, the time of year, and soil conditions. In general, groundwater flow rates are higher during the winter, spring, and early summer months. Geologically Hazardous Areas The city of Edmonds GIS database indicates the presence of isolated erosion hazards areas within the confines of the subject property. Per Edmonds City Code (ECC), an erosion hazard area is considered as those areas identified by the USDA Natural Resources Conversation Services as having a moderate, server, or very sever erosion hazard. Based on our site observations and encountered soil and groundwater conditions, the site does not appear to meet the criteria set forth in the ECC to be considered an erosion hazard, per the City of Edmonds. Earth Solutions NW, LLC Adamant Homes, LLC July 26, 2019 Updated September 19, 2019 Foundations ES-6740 Page 4 The proposed residences can be supported on conventional continuous and spread footing foundations bearing on competent native soil, recompacted native soil, or new structural fill placed directly on competent native soil. In general, competent soil bearing conditions for foundation support should be anticipated beginning at a depth of about two to three feet bgs. Where loose or unsuitable soil conditions are exposed at foundation subgrade elevations, compaction of soils to the specifications of structural fill, or overexcavation and replacernent with suitable structural fill, will be necessary. Provided the foundations are supported as prescribed, the following criteria may be used for design: • Allowable soil bearing capacity 2,500 psf • Passive earth pressure 300 pcf (equivalent fluid) • Coefficient of friction 0.40 A one-third increase in the allowable soil bearing capacity may be assumed for short-term wind and seismic loading conditions. The above passive pressure and coefficient of friction values include a factor -of -safety of 1.5. With structural loading as expected, total settlement in the range of one inch and differential settlement of approximately one-half inch is anticipated. The majority of anticipated settlement should occur during construction, as dead loads are applied. Seismic Design The 2015 International Building Code recognizes the American Society of Civil Engineers (ASCE) for seismic site class definitions. In accordance with Table 20.3-1 of the ASCE Minimum Design Loads for Buildings and Other Structures manual, Site Class D should be used for design. The referenced liquefaction susceptibility map indicates the subject site possesses a very low liquefaction susceptibility and we concur with a very low designation. The absence of a uniform, shallow groundwater table and medium dense to dense native soil conditions were the primary considerations for this opinion. Slab -on -Grade Floors Slab -on -grade floors for the proposed residences should be supported on a firm and unyielding subgrade. Unstable or yielding subgrade areas should be recompacted, or overexcavated and replaced with suitable structural fill, prior to slab construction. A capillary break consisting of at least four inches of free -draining crushed rock or gravel should be placed below each slab. The free -draining material should have a fines content of 5 percent or less (where the fines content is defined as the percent passing the Number 200 sieve, based on the minus three -quarter -inch fraction). In areas where slab moisture is undesirable, installation of a vapor barrier below the slab should be considered. If a vapor barrier is to be used, it should be a material specifically designed for that use and installed in accordance with the specifications of the manufacturer. Earth Solutions NW, LLC Adamant Homes, LLC July 26, 2019 Updated September 19, 2019 Retaining Walls ES-6740 Page 5 Retaining walls must be designed to resist earth pressures and applicable surcharge loads. The following parameters may be used for design: • Active earth pressure (unrestrained condition) At -rest earth pressure (restrained condition) • Traffic surcharge (passenger vehicles) • Passive earth pressure • Coefficient of friction • Seismic surcharge * Where applicable ** Where H equals the retained height (in feet) 35 pcf (equivalent fluid) 55 pcf 70 psf (rectangular distribution)* 300 pcf (equivalent fluid) 0.40 6H psf** The above passive pressure and coefficient of friction values include a factor -of -safety of 1.5 and are based on a level backfill condition and level grade at the wall toe. Revised design values will be necessary if sloping grades are to be used above or below retaining walls. Additional surcharge loading from adjacent foundations, sloped backfill, or other relevant loads should be included in the retaining wall design. Retaining walls should be backfilled with free -draining material that extends along the height of the wall and a distance of at least 18 inches behind the wall. The upper 12 inches of the wall backfill may consist of a less permeable soil, if desired. A sheet drain may also be considered in lieu of a free -draining backfill section. A perforated drainpipe should be placed along the base of the wall and connected to an approved discharge location. A typical retaining wall drainage detail is provided on Plate 3. If drainage is not provided, hydrostatic pressures should be included in the wall design. Drainage Discrete zones of perched groundwater seepage should be anticipated in site excavations depending on the time of year grading operations take place. Temporary measures to control surface water runoff and groundwater during construction would likely involve interceptor trenches, interceptor swales, and sumps. ESNW should be consulted during earthwork activities to both identify areas of seepage and provide recommendations to reduce the potential for seepage -related instability. Earth Solutions NW, LLC Adamant Homes, LLC July 26, 2019 Updated September 19, 2019 ES-6740 Page 6 Finish grades must be designed to direct surface drain water away from structures and slopes. Water must not be allowed to pond adjacent to structures or slopes. In our opinion, foundation drains should be installed along building perimeter footings. A typical foundation drain detail is provided on Plate 4. Infiltration Feasibility As indicated in the Subsurface section of this report, native soils encountered during our fieldwork were characterized primarily as silty sand with localized areas of poorly graded sand, with or without silt. In our opinion, full infiltration design should be considered infeasible for the proposal. Although areas of some sand were encountered during our explorations, they are not present in such an extent that would prove suitable for use as an infiltration media. Additionally, given the presence of glacial till deposits at depth, there are concerns with respect to offsite impacts from infiltrated water originating from the site. On -site Stormwater Management Pursuant to City of Edmonds stormwater management requirements, implementation of on -site stormwater BMPs are required for proposed developments in accordance with specified thresholds, standards, and lists. The intent of BMP implementation is to infiltrate, disperse, and retain stormwater runoff on site to the extent feasible. The table below summarizes our evaluation of low impact development methods, as outlined in the referenced stormwater manual, from a geotechnical standpoint. It is instructed in the referenced stormwater manual that BMPs are to be considered in the order listed (from top to bottom) for each surface type, and the first BMP that is determined to be viable should be used. For completeness, however, we have evaluated each listed BMP for the proposed surface types. Earth Solutions NW, LLC Adamant Homes, LLC July 26, 2019 Updated September 19, 2019 ES-6740 Page 7 BMP Viable? Limitations or Infeasibility,Criteria _ Lawns and Landscaped Areas T5.13: Post -construction soil quality and depth Yes None. No slopes greater than 33 percent are present. Volume V, Chapter 5) Roofs T5.30: Full dispersion Adequate vegetative flow paths are likely not available. (Volume V, Chapter 5) No Additionally, site current site gradients may result in water migration off site. T5.10A: Downspout full Based on our review, depths to hardpan (or other low permeability layer) from final grade and/or bottom of facility infiltration systems (Volume No elevation will not satisfy minimum specified by Volume III, III, Chapter 3) 3.1.1. T5.14A Rain Gardens and Based on our review, the minimum one foot of vertical T5.14B, T7.30 Bioretention No separation from hardpan (impervious layer) would not be (Volume V, Chapter 7) feasible per Volume V, 7.3. Adequate vegetative flow paths are likely not available. T5.1013: Downspout dispersion systems No Additionally, site current site gradients may result in water (Volume III, Chapter 3) mi ration off site. Per SCDM Volume III, 3.1.3, trench bottom must be at least T5.10C: Perforated stub -out one foot above seasonal water level; seasonal water level connections (Volume III, Maybe should be assumed as about one foot above unweathered till Chapter 3) (hardpan). Other Hard Surfaces _ Adequate vegetative flow paths are likely not available. T5.30: Full dispersion No Additionally, site current site gradients may result in water (Volume V, Chapter 5) migration off site. The unweathered till (hardpan) at depths of three to four feet (existing) would restrict vertical infiltration and create T5.15: Permeable saturated conditions within upper soils. Upper soils should pavement (Volume V, No be considered unsuitable for supporting traffic loads unless Chapter 5) compacted to a firm and unyielding condition which would effectively create a low permeability condition for the upper soils. T5.14A Rain Gardens and Based on our review, the minimum one foot of vertical T5.14B, T7.30 Bioretention No separation from hardpan (impervious layer) would not be _(Volume V, Chapter 7) feasible per Volume V, 7.3. _ T5.12: Sheet flow Adequate vegetative flow paths are likely not available. dispersion Additionally, site current site gradients may result in water T5.11: Concentrated flow No migration off site. dispersion (Volume V, Chapter 5) * Viability stated from a geotechnical standpoint and should be determined by site storm designer with respect to setbacks and flow paths. Earth Solutions NW, LLC Adamant Homes, LLC July 26, 2019 Updated September 19, 2019 Additional Services ES-6740 Page 8 ESNW should have an opportunity to review final project plans with respect to the geotechnical recommendations provided in this letter. ESNW should also be retained to provide testing, observation, and other consultation services during construction. We trust this evaluation meets your current needs. If you have questions regarding the content of this letter, or require additional information, please call. Sincerely, EARTH SOLUTIONS NW, LLC Chase G. Halsen Senior Staff Geologist Henry T. Wright, P.E. Senior Project Manager Attachments: Plate 1 — Vicinity Map Plate 2 — Subsurface Exploration Plan Plate 3 — Retaining Wall Drainage Detail Plate 4 — Footing Drain Detail Hand Auger Boring and Test Pit Logs Grain Size Distribution cc: RAM Engineering, Inc. Attention: Mr. Rob Long, P.E. (Email only) Earth Solutions NW, LLC 26 �am PI&W - �'A_ iR „w:. :. ' -4•.-tea a�ri •n �• s tH,l mi �011 it�1N1}+N'rrr '. Ft;x}N � •.� TN l71► :�' '$v r i;INK --. a f t: 4 1•- S � , � acc tl w,►,k�__ f �� jaVlov WGIFIEWAM now $DOM _ x. lrlli 3rsj StP�.i nt r»rrtr�7►? ;_ Pt r 3F r1p 0 t •: c . •X�n � n a'. jr wz I77t�• ' � . arr 3�nr. to t: a' �Ar 3� grs>t-ta A^ nrv�i�" M� w r ST •Hr« tr _ ,gACh71a + s, r<r; tr z � I M•C - - _ rC O T s �.Ri Itrt. e �s '�' Pic. �.= s I LAM .. w_s •5;r��! t �R-.H � to �! tw- :51K+Y tWj� �, + . ? S sll�«wu� �w •..rg+ :trs r ;+ilw�f IN ii 7t b :.xA %4 .! ;. � 44 �(M1� %. +IFIST .t Y•Sf 3+r�ialt ��rf7Ai) # ?Nb ��4 � n � :tst. t/ .�� Y� •:°' ?t; � �,Z& 'Y :tAr Sf2 �•s1:.tfr �II+�L j2 �¢ZT e_„ I ,r )1 {^• �.wypOTr u5� 1r rIX t VA :/�T .� Y NrTt a ; 7 a�•w •. M'7TfT7'� I) V-P 15E + ` ti4: IM -In ir •1.(1TH rot r u.D.Y �AN Irll s• i 5i� `.ttTrtr: t„'pit tCno IfkIfr'N �: ._ v_.�Nv s sf Z t7*1rr sr �y # ^ �� i � v/TrtN �� z'� i a 7T. n7rR h 1F a .. Ni► ..' _ R Y•� l�,l,� / . j'-•' { ` 'gym q: w ISST. y,_ I�tfBif Itftrrn F T�iN i s t Is,10ift $ ~�► c t ,.tt Nei �r f v .. q t} r fT MYis':� t � aq cr rJ�v IN i •i` tl Mt"fl �tti r7t Tfn �Tlt aCG� +-,� ~ 7.r.r..- tr� KART = �(� .w wna� ` F1tN ` & S .• IARr ,d : M I tf,• y+ �' 1 tt/71 ST C < - -Y ; r V .". t_ �4 Itn N AAW 1 = Y 1• L r rp�A ` r is TH 1R y!�} i ( € j� k z �sw 3Ltt• TTtN t «+� BMW , 1 t 5TM `�. f Nnv �s NNE 1WD tte a 'trlr.•[�- Kl S., /WO ' LT tl L ~fl}b1O+ �Jto look Reference: NORTH Snohomish County, Washington Map 474 By The Thomas Guide Rand McNally 32nd Edition NOTE: This plate may contain areas of color. ESNW cannot be Drwn. MRS Date 07/15/2019 Proj. No. 6740 responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. Checked CGH Date July 2019 Plate 1 TP-1 I —■— HA-1 1 140 400 \ �n LEGEND I I WA-1 — Approximate Location of I I,� ESNW Test Pit, Proj. No. I TP-2 —I ES-6740, June 2019 i�,� 1— —rHA-2 Approximate Location of -400 - DTP-31 ESNW Hand Auger Boring, I Proj. No. ES-6740, May 2019 I i i HA-31 Subject Site f r 1 I I Existing Building HA� 1 `TIP-1 / NORTH 410,�� / I ----1=--=—/--I--------- 1PP NOT - TO - SCALE NOTE: The graphics shown on this plate are not intended for design purposes or precise scale measurements, but only to illustrate the approximate test locations relative to the approximate locations of existing and / or proposed site features. The information illustrated is largely based on data provided by the client at the time of our study. ESNW cannot be responsible for subsequent design changes or interpretation of the data by others. NOTE: This plate may contain areas of color. ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. 240TH STREET S.W. Subsurface Exploration Plan Jodar Short Plat Edmonds, Washington Drwn. MRS Date 07/15/2019 Proj. No. 6740 Checked CGH Date July 2019 Plate 2 18" Min. 00 o 0o o o oUoo 00 o 00o 0o0 0 �o 00000 o B 00 o o 0 o. 0 0 0 o o 0 0 0�0 0 -o 00 'o o o �o o 0 a 0 o) 00 000 80 00 0 0 0 0 0 o o O o O o 0 o 00 o -0 000 0 0 00 oo 0 0 0 o 0 0 o Ooo ..000 00 oo oo 00 o O o O o0 0 0 O co0 0 o o O o00o O oo o 0 0 o O o o (D o o oo o o o o oo oo o o o 0 o 0 0 o0 o 0 00 o o 00o 0�� 0.o0 o o o. oo o ° , o 0 0 0o O o o Oo 0 o 0 d o 0 O 6 o o O000 o Oo O 0 o O o O 9/P..P. 0 NOTES: • Free -draining Backfill should consist of soil having less than 5 percent fines. Percent passing No. 4 sieve should be 25 to 75 percent. • Sheet Drain may be feasible in lieu of Free -draining Backfill, per ESNW recommendations. • Drain Pipe should consist of perforated, rigid PVC Pipe surrounded with 1-inch Drain Rock. LEGEND: 0 .0o O 0 00 00 Free -draining Structural Backfill 1-inch Drain Rock fti fti fti fti Structural Fill Perforated Rigid Drain Pipe (Surround in Drain Rock) SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Retaining Wall Drainage Detail Jodar Short Plat Edmonds, Washington Drwn. MRS Date 07/15/2019 Proj. No. 6740 Checked CGH Date July 2019 Plate 3 NOTES: Do NOT tie roof downspouts to Footing Drain. • Surface Seal to consist of 12" of less permeable, suitable soil. Slope away from building. LEGEND: Surface Seal: native soil or other low -permeability material. ti•ti•ti•ti• s•s•s•s•s 1-inch Drain Rock f�ftif~ftif ti•ti•ti•ti• Perforated Rigid Drain Pipe (Surround in Drain Rock) SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Earth lutions NWLLC Solutions NW LLC Engineering, Construction ng and Environmental Services Footing Drain Detail Jodar Short Edmonds, • • �.-1 1 •Proi.No. • 41 Checked CGH�. 1 • Earth Solutions NWLLC SOIL CLASSIFICATION CHART MAJOR DIVISIONS SYMBOLS TYPICAL DESCRIPTIONS GRAPH LETTER GRAVEL AND CLEAN GRAVELS ��•�� ' GW WELL GRADED GRAVELS, GRAVEL - SAND F NESMIXTURES, LITTLE OR NO °O° ,Q° o O<Z)o 0 Q Q oQ GP POORLY -GRADED GRAVELS, GRAVEL- SAND MIXTURES, LITTLE OR NO FINES GRAVELLY SOILS (LITTLE OR NO FINES) COARSE GRAINED SOILS MORE THAN 50% OF COARSE GRAVELS WITH FINES ' ) (] o iQ ° °° Q ° D GM SILTY GRAVELS, GRAVEL -SAND - SILT MIXTURES FRACTION GC CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES RETAINED ON NO. 4 SIEVE (APPRECIABLE AMOUNT OF FINES) MORE THAN 50% OF MATERIAL IS SAND AND CLEAN SANDS SW WELL -GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES SP POORLY -GRADED SANDS, GRAVELLY SAND, LITTLE OR NO FINES LARGER THAN NO. 200 SIEVE SIZE SANDY SOILS (LITTLE OR NO FINES) SANDS WITH FINES SM SILTY SANDS, SAND - SILT MIXTURES MORE THAN 50% OF COARSE FRACTION S`+ CLAYEY SANDS, SAND - CLAY MIXTURES PASSING ON NO. 4 SIEVE (APPRECIABLE AMOUNT OF FINES) INORGANIC SILTS AND VERY FINE ML SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY FINE GRAINED SOILS SILTS LIQUID LIMIT AND LESS THAN 50 CLAYS CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS OL ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY MORE THAN 50% OF MATERIAL IS MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SMALLER THAN NO.200 SIEVE SILTY SOILS SIZE SILTS LIQUID LIMIT AND CLAYS GREATER THAN 50 CH INORGANIC CLAYS OF HIGH PLASTICITY OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY. ORGANIC SILTS HIGHLY ORGANIC SOILS PT PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS DUAL SYMBOLS are used to indicate borderline soil classifications. The discussion in the text of this report is necessary for a proper understanding of the nature of the material presented in the attached logs. Earth Solutions NW BORING NUMBER HA-1 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-6740 PROJECT NAME Jodar Short Plat DATE STARTED 5/29/19 COMPLETED 5/29/19 GROUND ELEVATION 398 ft HOLE SIZE DRILLING CONTRACTOR ESNW Rep GROUND WATER LEVELS: DRILLING METHOD AT TIME OF DRILLING --- LOGGED BY CGH CHECKED BY HTW AT END OF DRILLING --- NOTES Depth of Topsoil & Sod 6"- 8": ivy AFTER DRILLING --- w H w �? _ w w g TESTS Li Q O MATERIAL DESCRIPTION p (LZ) Q Z W 0 U) 0 TPSL — Dark brown TOPSOIL, root intrusions to 3' 0.6 3974 Brown poorly graded SAND with silt, loose, moist MC = 8.50% SP- Fines = 10.00% SM [USDA Classification: slightly gravelly SAND] -becomes medium dense to dense 40 -becomes gray/tan, decreased fines content 394.0 MC = 7.80% Hand auger boring terminated at 4.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. Bottom of hole at 4.0 feet. Earth Solutions NW BORING NUMBER HA-2 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 PAGE 1 OF 1 lowTelephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-6740 PROJECT NAME Jodar Short Plat DATE STARTED 5/29/19 COMPLETED 5/29/19 GROUND ELEVATION 406 ft HOLE SIZE DRILLING CONTRACTOR ESNW Rep GROUND WATER LEVELS: DRILLING METHOD AT TIME OF DRILLING --- LOGGED BY CGH CHECKED BY HTW AT END OF DRILLING --- NOTES Depth of Topsoil & Sod 6"- 8": grass AFTER DRILLING --- w 2 } X w v? U a- w TESTS Uj Q O MATERIAL DESCRIPTION p Z OY :� Q U) 0 TPSL - Dark brown TOPSOIL, root intrusions to 2.5' 0-6 405.4 Brown silty SAND with gravel, loose to medium dense, moist SM 25 -organic wood debris 403.5 MC = 4.70% SP 3•� Gray poorly graded SAND with gravel, medium dense to dense, moist 403'0 Fines = 3.70% -- \ (USDA Classification: gravelly SAND) J—~ MC = 6.00% Hand auger boring terminated at 3.0 feet below existing grade due to refusal on rock obstruction. No groundwater encountered during excavation. No caving observed. Bottom of hole at 3.0 feet. Earth Solutions NW BORING NUMBER HA-3 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-6740 PROJECT NAME Jodar Short Plat DATE STARTED 5/29/19 COMPLETED 5/29/19 GROUND ELEVATION 405 ft HOLE SIZE DRILLING CONTRACTOR ESNW Rep GROUND WATER LEVELS: DRILLING METHOD AT TIME OF DRILLING - LOGGED BY CGH CHECKED BY HTW AT END OF DRILLING - NOTES Depth of Topsoil & Sod 6": grass AFTER DRILLING --- W EL _ ~ W wW g TESTS _ Q O MATERIAL DESCRIPTION ❑ 2z C7 ¢ U) 0 TPSL 0.5 Dark brown TOPSOIL, root intrusions to 1' (Fill) 404.5 1.0 Brown silty SAND with gravel, loose, moist (Fill) 404.0 SM Brown silty SAND, loose to medium dense, moist MC = 10.30% SM MC = 6.20% -becomes gray, dense 4-0 401.0 Hand auger boring terminated at 4.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. Bottom of hole at 4.0 feet. Earth Solutions NW BORING NUMBER HA-4 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-6740 PROJECT NAME Jodar Short Plat DATE STARTED 5/29/19 COMPLETED 5/29/19 GROUND ELEVATION 405 ft HOLE SIZE DRILLING CONTRACTOR ESNW Rep GROUND WATER LEVELS: DRILLING METHOD AT TIME OF DRILLING --- LOGGED BY CGH CHECKED BY HTW AT END OF DRILLING - NOTES Depth of Topsoil & Sod 8"- 10": grass AFTER DRILLING --- w o- = Hw U a- Uj g TESTS Q O MATERIAL DESCRIPTION p 0-Z � Q 0 TPSL — Dark brown TOPSOIL, root intrusions to 1' _ . P.7 404.3 Brown silty SAND, loose to medium dense, wet SM MC = 25.10% MC = 15.40% 2.5 -becomes gray, dense, moist 402.5 Fines = 33.80% _ _ _ \(USDA Classification: slightly gravelly sandy LOAM) Hand auger boring terminated at 2.5 feet below existing grade due to refusal on very dense native soil. No groundwater encountered during excavation. No caving observed. Bottom of hole at 2.5 feet. Earth Solutions NW TEST PIT NUMBER TP-1 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 PAGE 1 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-6740 PROJECT NAME Jodar Short Plat DATE STARTED 6/24/19 COMPLETED 6/24/19 GROUND ELEVATION 410 ft TEST PIT SIZE _ EXCAVATION CONTRACTOR NW Excavating_ _ GROUND WATER LEVELS: EXCAVATION METHOD AT TIME OF EXCAVATION -- LOGGED BY CGH CHECKED BY HTW AT END OF EXCAVATION --- NOTES Depth of Topsoil & Sod 12": grass AFTER EXCAVATION --- W _ ~ W N = wJ TESTS Q O MATERIAL DESCRIPTION p 2Z 0 0 Q U) 0 Dark brown TOPSOIL, root intrusions to 2.5' TPSL 1.0 4090 Brown silty SAND, loose to medium dense, wet MC = 28.40% MC = 15.70% Fines = 44.10% -becomes gray, dense, moist [USDA Classification: slightly gravelly LOAM] SM -moderate iron oxide staining to 6.5', weakly cemented 5 MC = 10.30% 7.0 403.0 Test pit terminated at 7.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. Bottom of test pit at 7.0 feet. Earth Solutions NW TEST PIT NUMBER TP-2 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 PAGE 1 OF 1 MORETelephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-6740 PROJECT NAME Jodar Short Plat DATE STARTED 6/24/19 COMPLETED 6/24/19 GROUND ELEVATION 406 It TEST PIT SIZE EXCAVATION CONTRACTOR NW Excavating GROUND WATER LEVELS: EXCAVATION METHOD AT TIME OF EXCAVATION --- LOGGED BY CGH CHECKED BY HTW AT END OF EXCAVATION --- NOTES Depth of Topsoil & Sod 12": grass AFTER EXCAVATION --- of U 2 a TESTS v cn 0_0 MATERIAL DESCRIPTION wv o <J Q z C7 0 Dark brown TOPSOIL, root intrusions to 7.5' TPS ,, 1.0 405.0 Brown silty SAND with gravel, loose to medium dense, damp SM - MC = 2.00% 3.0 403.0 Gray poorly graded SAND, medium dense, moist - MC = 3.50% Fines = 1.80% [USDA Classification: slightly gravelly SAND] 5 - SP 7,0 _ 399.0 Gray silty SAND, dense, moist - MC = 9.10% SM -trace silt erratic, very light iron oxide staining 90 -weakly cemented 397.0 MC = 10.00% Test pit terminated at 9.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. Bottom of test pit at 9.0 feet. Earth Solutions NW 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 Telephone: 425-449-4704 Fax: 425-449-4711 PROJECT NUMBER ES-6740 DATE STARTED 6/24/19 COMPLETED 6/24/19 EXCAVATION CONTRACTOR NW Excavating EXCAVATION METHOD LOGGED BY CGH CHECKED BY HTW NOTES Depth of Topsoil & Sod 6": heavy brush TEST PIT NUMBER TP-3 PAGE 1 OF 1 PROJECT NAME Jodar Short Plat GROUND ELEVATION 402 ft TEST PIT SIZE GROUND WATER LEVELS: AT TIME OF EXCAVATION - AT END OF EXCAVATION - AFTER EXCAVATION --- w a. of = d $ H w CO TESTS U _ a 0 MATERIAL DESCRIPTION w " 0 2 cn Q Z C7 0 Dark brown TOPSOIL, root intrusions to 4' Brown silty SAND, loose to medium dense, moist MC = 9.50% _ MC = 9.60% Fines = 20.00% SM -becomes tan, medium dense 5 [USDA Classification: slightly gravelly loamy fine SAND] MC = 11.70% becomes gray, dense to very dense, heavy iron oxide staining MC = 5.30% SW - Gray well -graded SAND with silt, very dense, moist MC = 5.00% SM 8.5 10 _ MC = 7.90% SM 10,0 Gray silty SAND with gravel, very dense, moist Fines = 18.90% [USDA Classification; gravelly loamy SAND) Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. Bottom of test pit at 10.0 feet. 7a■ 401.51 IIlls NN Ills 0Specimen I Ills 1 ME Il 1 0 milli Is E III I oil 01111 111111110011111111111111 solilin Mill soon of Identification COBBLES GRAVEL SAND coarse medium fine SILT OR CLAY coarse fine i iL11,11 'kill