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EarthSolutions
NW LLC
Geotechnical Engineering
Construction Observation/Testing
Environmental Services
15365 N.E.90th Street,Suite 100 Redmond,WA 98052
(425)449-4704 Fax (425)449-4711
www.earthsolutionsnw.com
GEOTECHNICAL ENGINEERING STUDY
HARMONY RIDGE
15509 –116TH AVENUE SOUTHEAST
RENTON,WASHINGTON
ES-8888
PREPARED FOR
ICHIJO USA CO., LTD.
November 21, 2022
Updated July 3, 2023
_________________________
Samuel E. Suruda, L.G.
Senior Staff Geologist
_________________________
Chase G. Halsen, L.G., L.E.G.
Senior Project Geologist
_________________________
Keven D. Hoffmann, P.E.
Associate Principal Engineer
GEOTECHNICAL ENGINEERING STUDY
HARMONY RIDGE
15509 – 116TH AVENUE SOUTHEAST
RENTON, WASHINGTON
ES-8888
Earth Solutions NW, LLC
15365 Northeast 90th Street, Suite 100
Redmond, Washington 98052
Phone: 425-449-4704 | Fax: 425-449-4711
www.earthsolutionsnw.com
07/03/2023
07/03/2023
Geotechnical-Engineering Report
Important Information about This
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.
While you cannot eliminate all such risks, you can manage them. The following information is provided to help.
The Geoprofessional Business Association (GBA)
has prepared this advisory to help you – assumedly
a client representative – interpret and apply this
geotechnical-engineering report as effectively as
possible. In that way, you can benefit from a lowered
exposure to problems associated with subsurface
conditions at project sites and development of
them that, for decades, have been a principal cause
of construction delays, cost overruns, claims,
and disputes. If you have questions or want more
information about any of the issues discussed herein,
contact your GBA-member geotechnical engineer.
Active engagement in GBA exposes geotechnical
engineers to a wide array of risk-confrontation
techniques that can be of genuine benefit for
everyone involved with a construction project.
Understand the Geotechnical-Engineering Services
Provided for this Report
Geotechnical-engineering services typically include the planning,
collection, interpretation, and analysis of exploratory data from
widely spaced borings and/or test pits. Field data are combined
with results from laboratory tests of soil and rock samples obtained
from field exploration (if applicable), observations made during site
reconnaissance, and historical information to form one or more models
of the expected subsurface conditions beneath the site. Local geology
and alterations of the site surface and subsurface by previous and
proposed construction are also important considerations. Geotechnical
engineers apply their engineering training, experience, and judgment
to adapt the requirements of the prospective project to the subsurface
model(s). Estimates are made of the subsurface conditions that
will likely be exposed during construction as well as the expected
performance of foundations and other structures being planned and/or
affected by construction activities.
The culmination of these geotechnical-engineering services is typically a
geotechnical-engineering report providing the data obtained, a discussion
of the subsurface model(s), the engineering and geologic engineering
assessments and analyses made, and the recommendations developed
to satisfy the given requirements of the project. These reports may be
titled investigations, explorations, studies, assessments, or evaluations.
Regardless of the title used, the geotechnical-engineering report is an
engineering interpretation of the subsurface conditions within the context
of the project and does not represent a close examination, systematic
inquiry, or thorough investigation of all site and subsurface conditions.
Geotechnical-Engineering Services are Performed
for Specific Purposes, Persons, and Projects,
and At Specific Times
Geotechnical engineers structure their services to meet the specific
needs, goals, and risk management preferences of their clients. A
geotechnical-engineering study conducted for a given civil engineer
will not likely meet the needs of a civil-works constructor or even a
different civil engineer. Because each geotechnical-engineering study
is unique, each geotechnical-engineering report is unique, prepared
solely for the client.
Likewise, geotechnical-engineering services are performed for a specific
project and purpose. For example, it is unlikely that a geotechnical-
engineering study for a refrigerated warehouse will be the same as
one prepared for a parking garage; and a few borings drilled during
a preliminary study to evaluate site feasibility will not be adequate to
develop geotechnical design recommendations for the project.
Do not rely on this report if your geotechnical engineer prepared it:
• for a different client;
• for a different project or purpose;
• for a different site (that may or may not include all or a portion of
the original site); or
• before important events occurred at the site or adjacent to it;
e.g., man-made events like construction or environmental
remediation, or natural events like floods, droughts, earthquakes,
or groundwater fluctuations.
Note, too, the reliability of a geotechnical-engineering report can
be affected by the passage of time, because of factors like changed
subsurface conditions; new or modified codes, standards, or
regulations; or new techniques or tools. If you are the least bit uncertain
about the continued reliability of this report, contact your geotechnical
engineer before applying the recommendations in it. A minor amount
of additional testing or analysis after the passage of time – if any is
required at all – could prevent major problems.
Read this Report in Full
Costly problems have occurred because those relying on a geotechnical-
engineering report did not read the report in its entirety. Do not rely on
an executive summary. Do not read selective elements only. Read and
refer to the report in full.
You Need to Inform Your Geotechnical Engineer
About Change
Your geotechnical engineer considered unique, project-specific factors
when developing the scope of study behind this report and developing
the confirmation-dependent recommendations the report conveys.
Typical changes that could erode the reliability of this report include
those that affect:
• the site’s size or shape;
• the elevation, configuration, location, orientation,
function or weight of the proposed structure and
the desired performance criteria;
• the composition of the design team; or
• project ownership.
As a general rule, always inform your geotechnical engineer of project
or site changes – even minor ones – and request an assessment of their
impact. The geotechnical engineer who prepared this report cannot accept
responsibility or liability for problems that arise because the geotechnical
engineer was not informed about developments the engineer otherwise
would have considered.
Most of the “Findings” Related in This Report
Are Professional Opinions
Before construction begins, geotechnical engineers explore a site’s
subsurface using various sampling and testing procedures. Geotechnical
engineers can observe actual subsurface conditions only at those specific
locations where sampling and testing is performed. The data derived from
that sampling and testing were reviewed by your geotechnical engineer,
who then applied professional judgement to form opinions about
subsurface conditions throughout the site. Actual sitewide-subsurface
conditions may differ – maybe significantly – from those indicated in
this report. Confront that risk by retaining your geotechnical engineer
to serve on the design team through project completion to obtain
informed guidance quickly, whenever needed.
This Report’s Recommendations Are
Confirmation-Dependent
The recommendations included in this report – including any options or
alternatives – are confirmation-dependent. In other words, they are not
final, because the geotechnical engineer who developed them relied heavily
on judgement and opinion to do so. Your geotechnical engineer can finalize
the recommendations only after observing actual subsurface conditions
exposed during construction. If through observation your geotechnical
engineer confirms that the conditions assumed to exist actually do exist,
the recommendations can be relied upon, assuming no other changes have
occurred. The geotechnical engineer who prepared this report cannot assume
responsibility or liability for confirmation-dependent recommendations if you
fail to retain that engineer to perform construction observation.
This Report Could Be Misinterpreted
Other design professionals’ misinterpretation of geotechnical-
engineering reports has resulted in costly problems. Confront that risk
by having your geotechnical engineer serve as a continuing member of
the design team, to:
• confer with other design-team members;
• help develop specifications;
• review pertinent elements of other design professionals’ plans and
specifications; and
• be available whenever geotechnical-engineering guidance is needed.
You should also confront the risk of constructors misinterpreting this
report. Do so by retaining your geotechnical engineer to participate in
prebid and preconstruction conferences and to perform construction-
phase observations.
Give Constructors a Complete Report and Guidance
Some owners and design professionals mistakenly believe they can shift
unanticipated-subsurface-conditions liability to constructors by limiting
the information they provide for bid preparation. To help prevent
the costly, contentious problems this practice has caused, include the
complete geotechnical-engineering report, along with any attachments
or appendices, with your contract documents, but be certain to note
conspicuously that you’ve included the material for information purposes
only. To avoid misunderstanding, you may also want to note that
“informational purposes” means constructors have no right to rely on
the interpretations, opinions, conclusions, or recommendations in the
report. Be certain that constructors know they may learn about specific
project requirements, including options selected from the report, only
from the design drawings and specifications. Remind constructors
that they may perform their own studies if they want to, and be sure to
allow enough time to permit them to do so. Only then might you be in
a position to give constructors the information available to you, while
requiring them to at least share some of the financial responsibilities
stemming from unanticipated conditions. Conducting prebid and
preconstruction conferences can also be valuable in this respect.
Read Responsibility Provisions Closely
Some client representatives, design professionals, and constructors do
not realize that geotechnical engineering is far less exact than other
engineering disciplines. This happens in part because soil and rock on
project sites are typically heterogeneous and not manufactured materials
with well-defined engineering properties like steel and concrete. That
lack of understanding has nurtured unrealistic expectations that have
resulted in disappointments, delays, cost overruns, claims, and disputes.
To confront that risk, geotechnical engineers commonly include
explanatory provisions in their reports. Sometimes labeled “limitations,”
many of these provisions indicate where geotechnical engineers’
responsibilities begin and end, to help others recognize their own
responsibilities and risks. Read these provisions closely. Ask questions.
Your geotechnical engineer should respond fully and frankly.
Geoenvironmental Concerns Are Not Covered
The personnel, equipment, and techniques used to perform an
environmental study – e.g., a “phase-one” or “phase-two” environmental
site assessment – differ significantly from those used to perform a
geotechnical-engineering study. For that reason, a geotechnical-engineering
report does not usually provide environmental findings, conclusions, or
recommendations; e.g., about the likelihood of encountering underground
storage tanks or regulated contaminants. Unanticipated subsurface
environmental problems have led to project failures. If you have not
obtained your own environmental information about the project site,
ask your geotechnical consultant for a recommendation on how to find
environmental risk-management guidance.
Obtain Professional Assistance to Deal with
Moisture Infiltration and Mold
While your geotechnical engineer may have addressed groundwater,
water infiltration, or similar issues in this report, the engineer’s
services were not designed, conducted, or intended to prevent
migration of moisture – including water vapor – from the soil
through building slabs and walls and into the building interior, where
it can cause mold growth and material-performance deficiencies.
Accordingly, proper implementation of the geotechnical engineer’s
recommendations will not of itself be sufficient to prevent
moisture infiltration. Confront the risk of moisture infiltration by
including building-envelope or mold specialists on the design team.
Geotechnical engineers are not building-envelope or mold specialists.
Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly
prohibited, except with GBA’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of
GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind.
Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent or intentional (fraudulent) misrepresentation.
Telephone: 301/565-2733
e-mail: info@geoprofessional.org www.geoprofessional.org
15365 N.E. 90th Street, Suite 100 • Redmond, WA 98052 • (425) 449-4704 • FAX (425) 449-4711
Earth Solutions NW LLC
Geotechnical Engineering, Construction
Observation/Testing and Environmental Services
November 21, 2022
Updated July 3, 2023
ES-8888
Ichijo USA Co., Ltd.
1406 – 140th Place Northeast, Suite 104
Bellevue, Washington 98007
Attention: Kanon Kupferer
Greetings, Kanon:
Earth Solutions NW, LLC (ESNW) is pleased to present this geotechnical report to support the
proposed project. Based on the results of our investigation, the construction of a residential
development is feasible from a geotechnical standpoint. Our study indicates the site is underlain
by ground moraine deposits (glacial till) that consist primarily of silty sand with gravel, with an
isolated area of near-surface fill. Groundwater was not exposed at the test pit locations during
the October 2022 exploration.
Based on our findings, the proposed single-family residences may be constructed on
conventional continuous and spread footing foundations that bear directly on competent native
soil, recompacted native soil, or new structural fill that is placed and compacted directly on
competent native soil. Native soil conditions considered suitable for support of the proposed
structures will likely be encountered beginning at a depth of about two feet below existing grades
across most of the property. Areas of existing fill will need to be removed or reworked to establish
suitable bearing conditions in proposed structural areas, as recommended by ESNW at the time
of construction. Where loose or unsuitable soil conditions are exposed at foundation subgrade
elevations, compaction of the soil to the specifications of structural fill or overexcavation and
replacement with suitable structural fill will be necessary.
From a geotechnical standpoint, full infiltration designs are not recommended for the project due
to the widespread prevalence of glacially consolidated soils. The dense to very dense nature of
these deposits, in addition to areas of appreciable fine contents, are the primary bases for this
opinion. Further discussion of infiltration feasibility is provided within this report.
Pertinent geotechnical recommendations are provided in this study. We appreciate the
opportunity to be of service to you on this project. If you have any questions regarding the content
of this geotechnical engineering study, please call.
Sincerely,
EARTH SOLUTIONS NW, LLC
Chase G. Halsen, L.G., L.E.G.
Senior Project Geologist
Earth Solutions NW, LLC
Table of Contents
ES-8888
PAGE
INTRODUCTION ................................................................................. 1
General .................................................................................... 1
Project Description ................................................................. 2
SITE CONDITIONS ............................................................................. 2
Surface ..................................................................................... 2
Subsurface .............................................................................. 2
Topsoil and Fill ............................................................. 3
Native Soil and Geologic Setting ................................ 3
Groundwater ................................................................. 3
Geologically Hazardous Areas .............................................. 4
Erosion Hazard ............................................................. 4
Coal Mine Hazard ......................................................... 4
Steep Slopes ................................................................. 5
DISCUSSION AND RECOMMENDATIONS ....................................... 5
General .................................................................................... 5
Site Preparation and Earthwork ............................................. 6
Temporary Erosion Control ......................................... 6
Stripping ....................................................................... 6
Excavations and Slopes .............................................. 7
In-situ and Imported Soil ............................................. 7
Subgrade Preparation .................................................. 8
Structural Fill ................................................................ 8
Foundations ............................................................................ 8
Seismic Design ....................................................................... 9
Slab-on-Grade Floors ............................................................. 10
Retaining Walls ....................................................................... 10
Drainage................................................................................... 11
Infiltration Feasibility ................................................... 11
Preliminary Detention Vault Design ............................ 12
Preliminary Pavement Sections ............................................. 13
Utility Support and Trench Backfill ....................................... 14
LIMITATIONS ...................................................................................... 14
Additional Services ................................................................. 14
Earth Solutions NW, LLC
Table of Contents
Cont’d
ES-8888
GRAPHICS
Plate 1 Vicinity Map
Plate 2 Test Pit Location Plan
Plate 3 Retaining Wall Drainage Detail
Plate 4 Footing Drain Detail
APPENDICES
Appendix A Subsurface Exploration
Test Pit Logs
Appendix B Laboratory Test Results
Earth Solutions NW, LLC
GEOTECHNICAL ENGINEERING STUDY
HARMONY RIDGE
15509 – 116TH AVENUE SOUTHEAST
RENTON, WASHINGTON
ES-8888
INTRODUCTION
General
This geotechnical engineering study was prepared for the proposed residential development to
be constructed at the United Christian Church campus in Renton, Washington. This study was
prepared to provide geotechnical recommendations for currently proposed development plans
and included the following geotechnical services:
Test pits to characterize soil and groundwater conditions.
Laboratory testing of representative soil samples collected at the test pit locations.
Geotechnical engineering analyses.
The following documents and maps were reviewed as part of the preparation of this study:
Web Soil Survey (WSS), maintained by the Natural Resources Conservation Service
under the United States Department of Agriculture (USDA).
Preliminary Utility Map for Harmony Ridge, prepared by Barghausen Consulting
Engineers, Inc., dated June 15, 2023.
Geologic Map of the Renton Quadrangle, King County, Washington, prepared by D.R.
Mullineaux, 1965.
Soil Survey of the King County Area, Washington, prepared by Dale E. Snyder, Philip S.
Gale, and Russell F. Pringle, in association with the USDA SCS, November 1973.
Map of the Seattle Electric Co.’s Renton Coal Mine, Map ID K31, 1919.
Mine Workings from George Watkins Evans’ Report for Renton Coal Company, Map ID
K32, 1920.
COR Maps (City of Renton GIS database).
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 2
Updated July 3, 2023
Earth Solutions NW, LLC
Project Description
The proposed project is currently pursuing construction of 20 single-family residences and
associated infrastructure improvements, which will be targeted to the central and southern site
areas. The existing church and associated improvements located within the northeast site corner
are to remain. Site ingress and egress will be provided via the west edge of 116th Avenue
Southeast, with a future potential road extension to the west. Stormwater management is
currently proposed via detention within the southwest site corner (Tract A).
At the time of report submission, specific building load plans were not available for review;
however, based on our experience with similar developments, the proposed residential structures
will likely be two stories and constructed using relatively lightly loaded wood framing supported
on conventional foundations. Perimeter footing loads will likely be about 2 to 3 kips per lineal
foot. Slab-on-grade loading is anticipated to be approximately 150 pounds per square foot (psf).
Grade cuts and/or fills of up to about five feet are expected to achieve the design elevation of
most lots. More extensive earthwork operations will likely be required to install site utilities and
construct the stormwater facility. We understand that a sewer connection will be provided through
an easement via the parcel to the northwest of the subject property.
If the above design assumptions either change or are incorrect, ESNW should be contacted to
review the recommendations provided in this report. ESNW should review the final designs to
confirm that appropriate geotechnical recommendations have been incorporated into the plans.
SITE CONDITIONS
Surface
The subject site is located southwest of the intersection between Southeast 16th Street and 116th
Avenue Southeast, in Renton, Washington. The approximate site location is depicted on Plate 1
(Vicinity Map) and consists of King County parcel number 202305-9067, totaling a gross site area
of about 6.23 acres. The northeast site corner is currently developed with a church and
associated improvements. The remaining portions of the site are surfaced with trees and an
understory of brush and brambles. Topography generally descends to the south and southwest,
with about 25 feet of elevation change occurring within the property confines.
Subsurface
An ESNW representative observed, logged, and sampled the excavation of 12 test pits within
readily accessible areas of the site on October 17, 2022. The test pits ranged in depths from
about 8 to 14 feet below the existing ground surface (bgs) and were excavated using a trackhoe
and operator retained by ESNW. The approximate locations of the test pits are depicted on Plate
2 (Test Pit Location Plan). Please refer to the test pit logs provided in Appendix A for a more
detailed description of the encountered subsurface conditions.
Representative soil samples collected at the exploration locations were analyzed following the
Unified Soil Classification System (USCS) and USDA methods and procedures. Samples were
analyzed in our laboratory for moisture content and grain size distribution in general accordance
with ASTM procedures. Laboratory test results are provided in Appendix B.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 3
Updated July 3, 2023
Earth Solutions NW, LLC
Topsoil and Fill
Topsoil was encountered in approximately the upper 6 to 12 inches of existing grades at the test
pit locations. The topsoil was characterized by a dark brown color, the presence of fine organic
material, and small root intrusions. Based on our observations, an average topsoil thickness of
about six inches was encountered at the test locations during the field exploration.
Silty sand with gravel fill soil was exposed at TP-4 and observed extending to a depth of about
five feet bgs. The fill was characterized by a dense and damp condition at the time of the field
exploration. Fill was not encountered at any of the other test pit locations during the October
2022 fieldwork.
Native Soil and Geologic Setting
Underlying topsoil, native soils were classified primarily as silty sand with gravel (USCS: SM),
consistent with local geologic mapping designations of ground moraine deposits (Qgt), otherwise
known as glacial till. Variations in soil gradation were locally observed and included areas of
increased gravel, silt, and sand contents; however, silty sand with gravel sand should be
considered the predominant underlying soil type. Soils within the upper approximate three to five
feet of existing grades were generally characterized as medium dense; thereafter, native soils
become dense to very dense, extending to the terminus of each test pit location, which occurred
between about 8 and 14 feet bgs. An exception occurred at TP-4, where the native soil was
characterized as medium dense to the terminus of the test pit. Native soils were primarily
observed in a moist condition at the time of the October 2022 fieldwork.
The referenced WSS resource indicates the site is underlain by Alderwood gravelly sandy loam
(Map Unit Symbol: AgC). This soil series is associated with ridges and hills and is derived from
glacial drift. Based on the soil conditions encountered during the subsurface exploration, native
soils are considered representative of ground moraine deposits, in accordance with local mapping
designations.
In our opinion, soil conditions within the off-site easement area will be of similar composition to
the soils encountered on site. This opinion is based on review of the referenced WSS and
geologic map resources, which depict similar soil conditions (Alderwood gravelly sandy loam and
ground moraine deposits) across the easement area.
Groundwater
Groundwater was not encountered within the explored depths of the test pit locations during the
October 2022 exploration. Groundwater seeps are common within glacial deposits, and the
elevations and/or flow volumes of seepages can fluctuate depending on many factors, including
precipitation duration and intensity, the time of year, and soil conditions. In general, groundwater
elevations are higher during the winter, spring, and early summer months.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 4
Updated July 3, 2023
Earth Solutions NW, LLC
Geologically Hazardous Areas
Renton Municipal Code (RMC) 4-3-050 classifies geologically hazardous areas as those areas
susceptible to damage relating to sensitive and protected slopes, landslides, erosion, seismic
activity, and coal mines. Based on review of COR Maps, the site has been designated as a
potential moderate coal mine hazard area. Steep slope areas are depicted on the adjacent
property in the area of the proposed sewer easement. Furthermore, based on our review of the
RMC, the site is considered to possess low erosion hazard potential.
Erosion Hazard
RMC 4-3-050G5ci defines a low erosion hazard (EL) as areas with soil characterized as having
a slight or moderate erosion potential and a slope less than 15 percent. Based on review of the
referenced King County Soil Survey, on-site Alderwood series (AgC) soils are considered to have
a moderate erosion potential. As such, the site may be considered to possess a low erosion
hazard. A review of the development standards table presented in section 4-3-050G2 indicates
there are no required buffers or setbacks associated with EL areas. From a geotechnical
standpoint, typical best management practices (BMPs) and permanent landscaping installations
can successfully mitigate any potential soil erosion both during and after construction.
Coal Mine Hazard
COR Maps indicates the subject site is within a moderate coal mine hazard (CM) area. As defined
in RMC 4-3-050G5eii, CM areas are defined as areas where mine workings are deeper than 200
feet for steeply dipping seams, or deeper than 15 times the thickness of the seam or workings for
gently dipping seams. These areas may be affected by subsidence.
Review of the referenced coal mine hazard maps suggests the site is within the vicinity of a
historical coal mine operation. However, it appears that mining activity beneath the site area is
greater than 200 feet. On this basis, the subject site is considered appropriately mapped within
a CM area per the RMC definition. Per the development standards table presented in RMC 4-3-
050G2, there are no code-specified buffers or setbacks for CM areas “based on the results of a
geotechnical report and/or independent review.” From a geotechnical standpoint, it is our opinion
buffers and/or setbacks need not be applied to the project with respect to the CM area.
Construction of the proposed residential development is not expected to increase the potential
for ground subsidence on the subject site. This opinion relies on the validity of the information
presented in the referenced coal mine maps.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 5
Updated July 3, 2023
Earth Solutions NW, LLC
Steep Slopes
According to RMC 4-3-050G5a, steep slopes are categorized into two types and are based on
identification in the city’s Steep Slope Atlas or another method approved by the city:
i. Sensitive Slopes: A hillside, or portion thereof (excluding engineering retaining walls),
characterized by:
a. An average slope of 25 percent to less than 40 percent.
b. An average slope of 40 percent or greater, with a vertical rise of less than 15 feet.
c. Abutting an average slope of 25 percent to 40 percent.
ii. Protected Slopes: A hillside, or portion thereof, characterized by an average slope of 40
percent or greater grade and having a minimum vertical rise of 15 feet.
The referenced COR Maps designates the site and the adjacent easement area as meeting the
criteria of sensitive slopes, and the neighboring property is designated as meeting the criteria of
both sensitive slopes and protected slopes. Based on review of the referenced utility plan (which
depicts baseline survey data), the maximum slope gradients for the subject project are as follows:
Across the subject site, slope averages do not exceed 25 percent over a minimum vertical
rise of 15 feet, and there are no slopes that exceed 40 percent over at least 10 feet of
vertical rise.
Along the off-site sewer easement, there is at least one slope area with an average grade
of approximately 30 percent over a vertical distance of 15 feet.
Based on our review, neither sensitive slopes nor protected slopes are present across the subject
property per RMC criteria. However, along the off-site sewer easement, at least one area meets
the RMC definition of a sensitive slope (but not a protected slope). Per RMC 4-3-050G2, there
is no applicable critical area buffer width or structure setback for sensitive slopes unless
recommended in a geotechnical report, as a result of independent review, or pursuant to a
requirement of the building code and/or official. Based on our understanding of the site geology
and competent slope makeup, it is our opinion that buffer and setback distances need not be
applied to the proposed off-site sewer easement.
DISCUSSION AND RECOMMENDATIONS
General
Based on the results of our investigation, the construction of the proposed residential
development is feasible from a geotechnical standpoint. The primary geotechnical
considerations for the proposed development concern structural fill placement and compaction,
foundation design, utility installation, and stormwater management design.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 6
Updated July 3, 2023
Earth Solutions NW, LLC
Site Preparation and Earthwork
Initial site preparation activities will consist of installing temporary erosion control measures,
establishing grading limits, and site clearing and stripping activities. Subsequent earthwork
activities will involve mass site grading and installation of infrastructure and stormwater
management improvements.
Temporary Erosion Control
The following temporary erosion and sediment control Best Management Practices (TESC
BMPs) are offered:
Temporary construction entrances and drive lanes should be constructed with at least six
inches of quarry spalls to both minimize off-site soil tracking and provide a stable access
entrance surface. A woven geotextile fabric can be placed beneath the quarry spalls to
provide greater stability, if needed.
Silt fencing should be placed around the site perimeter.
When not in use, soil stockpiles should be covered or otherwise protected.
Temporary measures for controlling surface water runoff, such as interceptor trenches,
sumps, or interceptor swales, should be installed before beginning earthwork activities.
Dry soils disturbed during construction should be wetted to reduce dust.
When appropriate, permanent planting or hydroseeding will help to stabilize site soils.
Additional TESC BMPs, as specified by the project civil engineer on the plans, should be
incorporated into construction activities. TESC measures will require upkeep and potential
modification during construction to ensure proper function; such upkeep should be coordinated
with the site erosion control lead, where applicable.
Stripping
Topsoil was generally encountered in the upper approximately 6 to 12 inches of existing grades
at the test pit locations. For stripping estimations, an average topsoil thickness of about six inches
can be assumed, based on our field observations. Where encountered, organic-rich topsoil
should be stripped and segregated into a stockpile for later use on site or to be exported.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 7
Updated July 3, 2023
Earth Solutions NW, LLC
Excavations and Slopes
Based on the soil conditions observed at the test pit locations, the following allowable temporary
slope inclinations, as a function of horizontal to vertical (H:V) inclination, may be used. The
applicable Federal Occupation Safety and Health Administration (OSHA) and Washington
Industrial Safety and Health Act (WISHA) soil classifications are also provided:
Loose to medium dense soil 1.5H:1V (Type C)
Areas exposing groundwater seepage 1.5H:1V (Type C)
Dense to very dense, undisturbed native soil 0.75H:1V (Type A)
Steeper temporary slope inclinations within undisturbed, very dense native soil may be feasible
based on the soil and groundwater conditions exposed within the excavations. ESNW can
evaluate the feasibility of utilizing steeper temporary slopes on a case-by-case basis at the time
of construction. In any case, an ESNW representative should observe temporary slopes to
confirm inclinations are suitable for the exposed soil conditions and to provide additional
excavation and slope stability recommendations, as necessary.
If the recommended temporary slope inclinations cannot be achieved, temporary shoring may be
necessary to support excavations. Permanent slopes should be graded to 2H:1V (or flatter) and
planted with vegetation to enhance stability and minimize erosion potential. Permanent slopes
should be observed by ESNW before vegetation and landscaping.
In-situ and Imported Soil
Successful use of the on-site soil as structural fill will largely be dictated by the moisture content
at the time of placement and compaction. Based on the conditions observed during the
subsurface exploration, the native soils are considered to possess a moderate to high moisture
sensitivity. Depending on the time of year construction occurs, remedial measures (such as soil
aeration) may be necessary as part of site grading and earthwork activities. If the on-site soil
cannot be successfully compacted, the use of imported soil may be necessary. In our opinion, a
contingency should be provided in the project budget for the export of soil that cannot be
successfully compacted as structural fill, particularly if grading activities take place during periods
of extended rainfall activity. In general, soils with fines contents greater than 5 percent typically
degrade rapidly when exposed to periods of rainfall.
Imported structural fill soil should consist of well-graded, granular soil that can achieve a suitable
working moisture content. During wet weather conditions, imported soil intended for use as
structural fill should consist of a well-graded, granular soil with 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).
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 8
Updated July 3, 2023
Earth Solutions NW, LLC
Subgrade Preparation
Foundation and slab subgrade surfaces should consist of competent, undisturbed native soil or
structural fill placed and compacted atop competent native soil. ESNW should observe subgrade
areas before placing formwork. Supplementary recommendations for subgrade improvement
may be provided at the time of construction; such recommendations would likely include further
mechanical compaction effort or overexcavation and replacement with suitable structural fill.
Structural Fill
Structural fill is defined as compacted soil placed in foundation, slab-on-grade, roadway,
permanent slope, retaining wall, and utility trench backfill areas. The following recommendations
are provided for soils intended for use as structural fill:
Moisture content At or slightly above optimum
Relative compaction (minimum) 95 percent (per ASTM D1557)
Loose lift thickness (maximum) 12 inches
Existing site soil may only be considered suitable for use as structural fill if a suitable moisture
content is achieved at the time of placement and compaction. If the on-site soil cannot achieve
the above specifications, the use of imported structural fill material will likely be necessary.
Concerning underground utility installations and backfill, local jurisdictions will likely dictate soil
type(s) and compaction requirements.
Foundations
Based on our findings, the proposed single-family residences may be constructed on
conventional continuous and spread footing foundations that bear directly on competent native
soil, recompacted native soil, or new structural fill that is placed and compacted directly on
competent native soil. Native soil conditions considered suitable for support of the proposed
structures will likely be encountered beginning at a depth of about two feet bgs across most of
the site. Areas of existing fill (such as at TP-4) will need to be removed or reworked to establish
suitable bearing conditions in proposed structural areas, as recommended by ESNW at the time
of construction. Where loose or unsuitable soil conditions are exposed at foundation subgrade
elevations, compaction of the soil to the specifications of structural fill or overexcavation and
replacement with suitable structural fill will be necessary.
Provided the foundations will be supported as prescribed, the following parameters may be used
for the design:
Allowable soil bearing capacity 2,500 psf
Passive earth pressure 300 pcf (equivalent fluid)
Coefficient of friction 0.40
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 9
Updated July 3, 2023
Earth Solutions NW, LLC
The above passive pressure and friction values include a factor-of-safety (FOS) of 1.5. A one-
third increase in the allowable soil bearing capacity may be assumed for short-term wind and
seismic loading conditions. With structural loading as expected, total settlement in the range of
one inch and differential settlement of about one-half inch is anticipated. Most settlements should
occur during construction when dead loads are applied.
Seismic Design
The 2018 International Building Code (2018 IBC) recognizes the most recent edition of the
Minimum Design Loads for Buildings and Other Structures manual (ASCE 7-16) for seismic
design, specifically concerning earthquake loads. Based on the soil conditions encountered at
the test locations, the parameters and values provided below are recommended for seismic
design per the 2018 IBC.
Parameter Value
Site Class C*
Mapped short-period spectral response acceleration, SS (g) 1.407
Mapped 1-second period spectral response acceleration, S1 (g) 0.48
Short period site coefficient, Fa 1.2
Long-period site coefficient, Fv 1.5
Adjusted short-period spectral response acceleration, SMS (g) 1.689
Adjusted 1-second period spectral response acceleration, SM1 (g) 0.72
Design short-period spectral response acceleration, SDS (g) 1.126
Design 1-second period spectral response acceleration, SD1 (g) 0.48
* Assumes very dense soil conditions, encountered to a maximum depth of 14 feet bgs during the October 2022
field exploration, remain very dense to at least 100 feet bgs. Based on our experience with the project geologic
setting (glacial till) across the Puget Sound region, soil conditions are likely consistent with this assumption.
Further discussion between the project structural engineer, the project owner (or their
representative), and ESNW may be prudent to determine the possible impacts on the structural
design due to increased earthquake load requirements under the 2018 IBC. ESNW can provide
additional consulting services to aid with design efforts, including supplementary geotechnical
and geophysical investigation, upon request.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 10
Updated July 3, 2023
Earth Solutions NW, LLC
Liquefaction is a phenomenon that can occur within a soil profile as a result of an intense ground
shaking or loading condition. Most commonly, liquefaction is caused by ground shaking during
an earthquake. Soil profiles that are loose, cohesionless, and present below the groundwater
table are most susceptible to liquefaction. During the ground shaking, the soil contracts, and
porewater pressure increases. The increased porewater pressure occurs quickly and without
sufficient time to dissipate, resulting in water flowing upward to the ground surface and a liquefied
soil condition. Soil in a liquefied condition possesses very little shear strength in comparison to
the drained condition, which can result in a loss of foundation support for structures. In our
opinion, site susceptibility to liquefaction may be considered negligible. The absence of a shallow
groundwater table and the dense characteristics of the native soil were the primary bases for this
opinion.
Slab-on-Grade Floors
Slab-on-grade floors for the proposed residential structures should be supported by competent,
firm, and unyielding subgrades. Unstable or yielding subgrade areas should be recompacted or
overexcavated and replaced with suitable structural fill before 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, the installation of a vapor
barrier below the slab should be considered. Vapor barriers should be made from material
specifically designed for use as a vapor barrier and should be installed in accordance with the
manufacturer’s recommendations.
Retaining Walls
Retaining walls must be designed to resist earth pressures and applicable surcharge loads. The
following parameters may be used for the design:
Active earth pressure (unrestrained condition) 35 pcf (equivalent fluid)
At-rest earth pressure (restrained condition) 55 pcf
Traffic surcharge* (passenger vehicles) 70 psf (rectangular distribution)
Passive earth pressure 300 pcf (equivalent fluid)
Coefficient of friction 0.40
Seismic surcharge 8H psf†
* Where applicable.
† Where H equals the retained height (in feet).
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 11
Updated July 3, 2023
Earth Solutions NW, LLC
The above passive pressure and friction values include a FOS 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 with 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 less permeable soil, if desired. A sheet drain may be considered instead
of using free-draining backfill. 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
Zones of perched groundwater seepage could develop in site excavations depending on the time
of year grading operations take place, particularly within deeper excavations for utilities and
stormwater facilities. 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 preliminary grading to both identify areas of seepage and
provide recommendations to reduce the potential for seepage-related instability.
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
From a geotechnical standpoint, full infiltration designs are considered infeasible for the project.
The site is predominately underlain by glacially consolidated deposits that consist primarily of
silty sand with gravel. As a result of the dense in-situ condition of the native soil and areas of
appreciable fines contents, large-scale infiltration implementations would likely exhibit poor to
negligible functionality and would not be expected to have suitable long-term performance.
Small-scale BMP or LID designs (such as permeable pavement or shallow gravel-filled trenches)
may be viable for the project; however, feasibility will largely depend on the grading plan, since
any such implementation would need to target the weathered soil horizon located within the upper
few feet of existing grades. As such, if significant grade cuts are proposed, small-scale BMP or
LID designs will likely not be feasible from a geotechnical standpoint. If desired, ESNW can
further evaluate the feasibility of incorporating small-scale BMP or LID designs into the project.
If pursued, in-situ infiltration testing will likely be necessary to confirm the feasibility of utilizing
such designs and to develop a suitable design infiltration rate.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 12
Updated July 3, 2023
Earth Solutions NW, LLC
Preliminary Detention Vault Design
We presume that stormwater management will likely be provided via a stormwater detention vault
located within the southwestern site corner (Tract A). We anticipate grade cuts of 10 or more
feet will be necessary to achieve the subgrade elevation of the vault foundation. Based on our
field observations, grade cuts for the vault are likely to expose competent, native glacial till
deposits.
The vault foundation should be supported directly on very dense native soil or quarry spalls
placed directly on competent native soil. The final vault design must incorporate adequate space
from property boundaries such that temporary excavations to construct the vault structure may
be successfully completed using the recommended temporary slope inclinations provided in this
report. Perimeter drains should be installed around the vault and conveyed to an approved
discharge point. In our opinion, perched groundwater seepage should be anticipated along the
temporary excavation made for construction of the vault; however, buoyancy is not expected to
impact the vault design.
The following preliminary design parameters may be used for the vault:
Allowable soil bearing capacity 5,000 psf
Active earth pressure (unrestrained) 35 pcf
Active earth pressure (unrestrained, hydrostatic) 80 pcf
At-rest earth pressure (restrained) 55 pcf
At-rest earth pressure (restrained, hydrostatic) 100 pcf
Coefficient of friction 0.40
Passive earth pressure 350 pcf
Seismic surcharge 8H psf*
* Where H equals the retained height (in feet).
The passive earth pressure and coefficient of friction values include a FOS of 1.5. Vault retaining
walls should be backfilled with free-draining material or suitable sheet drainage that extends
along the height of the walls. The upper one foot of the wall backfill may consist of a less
permeable soil, if desired. A perforated-rigid drainpipe should be placed along the base of the
wall and connected to an approved discharge location. If the elevation of the vault bottom is such
that gravity flow to an outlet is not possible, the portions of the vault below the drain should be
designed to include hydrostatic pressure.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 13
Updated July 3, 2023
Earth Solutions NW, LLC
It is our recommendation that ESNW, the owner, and the contractor observe the excavation of a
test pit within the vault area prior to excavation activities. The test pit exploration will assist in
confirming anticipated soil conditions at the vault subgrade and characterizing seasonal
groundwater conditions, which may impact the temporary excavation and grading plan.
Preliminary Pavement Sections
The performance of site pavements is largely related to the condition of the underlying subgrade.
To ensure adequate pavement performance, the subgrade should be in a firm and unyielding
condition when subjected to proofrolling with a loaded dump truck. Structural fill in pavement
areas should be compacted to the specifications previously detailed in this report. Soft, wet, or
otherwise unsuitable subgrade areas may still exist after base grading activities. Areas
containing unsuitable or yielding subgrade conditions will require remedial measures, such as
overexcavation and/or placement of thicker crushed rock or structural fill sections, before
pavement.
We anticipate new pavement sections will be subjected primarily to passenger vehicle traffic. For
lightly loaded pavement areas subjected primarily to passenger vehicles, the following
preliminary pavement sections may be considered:
A minimum of two inches of hot-mix asphalt (HMA) placed over four inches of crushed
rock base (CRB).
A minimum of two inches of HMA placed over three inches of asphalt-treated base (ATB).
Heavier traffic areas generally require thicker pavement sections depending on site usage,
pavement life expectancy, and site traffic. For preliminary design purposes, the following
pavement sections for occasional truck traffic and access roadways areas may be considered:
Three inches of HMA placed over six inches of CRB.
Three inches of HMA placed over four-and-one-half inches of ATB.
An ESNW representative should be requested to observe subgrade conditions before the
placement of CRB or ATB. As necessary, supplemental recommendations for achieving
subgrade stability and drainage can be provided. If the on-site roads will be constructed with an
inverted crown, additional drainage measures may be recommended to assist in maintaining road
subgrade and pavement stability.
Final pavement design recommendations, including recommendations for heavy traffic areas,
access roads, and frontage improvement areas, can be provided once final traffic loading has
been determined. Road standards utilized by the governing jurisdiction may supersede the
recommendations provided in this report. The HMA, ATB, and CRB materials should conform to
WSDOT specifications, where applicable. All soil base material should be compacted to a relative
compaction of 95 percent, based on the laboratory maximum dry density as determined by ASTM
D1557.
Ichijo USA Co., Ltd. ES-8888
November 21, 2022 Page 14
Updated July 3, 2023
Earth Solutions NW, LLC
Utility Support and Trench Backfill
In our opinion, the native soil will generally be suitable for the support of utilities. Remedial
measures may be necessary for some areas to provide support for utilities, such as
overexcavation and replacement with structural fill and/or placement of geotextile fabric.
Groundwater seepage may be encountered within utility excavations, and caving of trench walls
may occur where groundwater is encountered. Depending on the time of year and conditions
encountered, dewatering or temporary trench shoring may be necessary during utility excavation
and installation.
The native soil is not considered suitable for use as structural backfill throughout the utility trench
excavations unless the soil is at (or slightly above) the optimum moisture content at the time of
placement and compaction. Moisture conditioning of the soil may be necessary at some locations
before use as structural fill. Each section of the utility lines must be adequately supported by the
bedding material. Utility trench backfill should be placed and compacted to the structural fill
specifications previously detailed in this report or to the applicable specifications of the presiding
jurisdiction.
LIMITATIONS
This study has been prepared for the exclusive use of Ichijo USA Co., Ltd. and its representatives.
The recommendations and conclusions provided in this study 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. No warranty, express or implied, is
made. Variations in the soil and groundwater conditions observed at the test locations may exist
and may not become evident until construction. ESNW should reevaluate the conclusions
provided in this study if variations are encountered.
Additional Services
ESNW should have an opportunity to review the final project plans concerning the geotechnical
recommendations provided in this report. ESNW should also be retained to provide testing and
consultation services during construction.
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drawn MRS
Checked SES Date June 2023
Date 06/30/2023 Proj.No.8888.01
Plate 1
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
Vicinity Map
Harmony Ridge
Renton,Washington
Reference:
King County,Washington
OpenStreetMap.org
NORTH
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.
SITE
Renton
Plate
Proj.No.
Date
Checked
DrawnEarthSolutionsNWLLC GeotechnicalEngineering,ConstructionObservation/TestingandEnvironmentalServicesEarthSolutionsNWLLCEarthSolutionsNWLLCMRS
NORTH
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.
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.
LEGEND
Approximate Location of
ESNW Test Pit,Proj.No.
ES-8888,Oct.2022
Subject Site
Proposed Lot Number
0 1 0 0 2 0 0
Scale in Feet1"=2 0 0 '
SES
06/30/2023
8888.01
2TestPitLocationPlan HarmonyRidgeRenton,WashingtonTP-1
10
TP-1
TP-2
TP-3
TP-4
TP-5TP-6
TP-7
TP-8 TP-10
TP-11
TP-12
TP-9
1
2
3
4
5
67
8
9
10
11
1213
14
15
16
17
18
19
20
116TH AVENUE S.E.S.E. 157THSTREET
118
T
H
A
V
E
N
U
E
S.E.
21
22
Tract A
Tract B
Tract C Tract D
Sewer
Easement
S.E. 19
T
H
S
T
R
E
E
T
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drawn MRS
Checked SES Date June 2023
Date 06/30/2023 Proj.No.8888.01
Plate 3
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
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:
Free-draining Structural Backfill
1-inch Drain Rock
18"Min.
Structural
Fill
Perforated Rigid Drain Pipe
(Surround in Drain Rock)
SCHEMATIC ONLY -NOT TO SCALE
NOT A CONSTRUCTION DRAW ING
Retaining Wall Drainage Detail
Harmony Ridge
Renton,Washington
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drawn MRS
Checked SES Date June 2023
Date 06/30/2023 Proj.No.8888.01
Plate 4
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
Slope
Perforated Rigid Drain Pipe
(Surround in Drain Rock)
18"Min.
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.
1-inch Drain Rock
SCHEMATIC ONLY -NOT TO SCALE
NOT A CONSTRUCTION DRAW ING
Footing Drain Detail
Harmony Ridge
Renton,Washington
Earth Solutions NW, LLC
Appendix A
Subsurface Exploration
Test Pit Logs
ES-8888
Subsurface conditions at the subject site were explored on October 17, 2022. Twelve test pits
were excavated using a trackhoe and operator retained by ESNW. The approximate locations of
the test pits are illustrated on Plate 2 of this study. The test pit logs are provided in this Appendix.
The test pits were advanced to a maximum depth of approximately 14 feet bgs.
The final logs represent the interpretations of the field logs and the results of laboratory analyses.
The stratification lines on the logs represent the approximate boundaries between soil types. In
actuality, the transitions may be more gradual.
>12%Fines<5%FinesHighlyOrganicSoilsSiltsandClaysLiquidLimit50orMoreSiltsandClaysLiquidLimitLessThan50Fine-GrainedSoils-50%orMorePassesNo.200SieveCoarse-GrainedSoils-MoreThan50%RetainedonNo.200SieveSands-50%orMoreofCoarseFractionPassesNo.4SieveGravels-MoreThan50%ofCoarseFractionRetainedonNo.4Sieve>12%Fines<5%FinesGW
GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PT
Well-graded gravel with
or without sand,little to
no fines
Poorly graded gravel with
or without sand,little to
no fines
Silty gravel with or without
sand
Clayey gravel with or
without sand
Well-graded sand with
or without gravel,little to
no fines
Poorly graded sand with
or without gravel,little to
no fines
Silty sand with or without
gravel
Clayey sand with or
without gravel
Silt with or without sand
or gravel;sandy or
gravelly silt
Clay of low to medium
plasticity;lean clay with
or without sand or gravel;
sandy or gravelly lean clay
Organic clay or silt of
low plasticity
Elastic silt with or without
sand or gravel;sandy or
gravelly elastic silt
Clay of high plasticity;
fat clay with or without
sand or gravel;sandy or
gravelly fat clay
Organic clay or silt of
medium to high plasticity
Peat,muck,and other
highly organic soils
EEaarrtthh SSoolluuttiioonnss NNWW LLC
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
EXPLORATION LOG KEYFillFILLMadeGround
Classifications of soils in this geotechnical report and as shown on the exploration logs are based on visual
field and/or laboratory observations,which include density/consistency,moisture condition,grain size,and
plasticity estimates,and should not be construed to imply field or laboratory testing unless presented herein.
Visual-manual and/or laboratory classification methods of ASTM D2487 and D2488 were used as an
identification guide for the Unified Soil Classification System.
Terms Describing Relative Density and Consistency
Coarse-Grained Soils:
Fine-Grained Soils:
SPT blows/foot
SPT blows/foot
Test Symbols &Units
Fines =Fines Content (%)
MC =Moisture Content (%)
DD =Dry Density (pcf)
Str =Shear Strength (tsf)
PID =Photoionization Detector (ppm)
OC =Organic Content (%)
CEC =Cation Exchange Capacity (meq/100 g)
LL =Liquid Limit (%)
PL =Plastic Limit (%)
PI =Plasticity Index (%)
Component Definitions
Descriptive Term Size Range and Sieve Number
Smaller than No.200 (0.075 mm)
Boulders
Modifier Definitions
Percentage by
Weight (Approx.)
<5
5 to 14
15 to 29
>30_
Modifier
Trace (sand,silt,clay,gravel)
Slightly (sandy,silty,clayey,gravelly)
Sandy,silty,clayey,gravelly
Very (sandy,silty,clayey,gravelly)
Moisture Content
Dry -Absence of moisture,dusty,dry to
the touch
Damp -Perceptible moisture,likely below
optimum MC
Moist -Damp but no visible water,likely
at/near optimum MC
Wet -Water visible but not free draining,
likely above optimum MC
Saturated/Water Bearing -Visible free
water,typically below groundwater table
Symbols
Cement grout
surface seal
Bentonite
chips
Grout
seal
Filter pack with
blank casing
section
Screened casing
or Hydrotip with
filter pack
End cap
ATD =At time
of drilling
Static water
level (date)
_>50
Density
Very Loose
Loose
Medium Dense
Dense
Very Dense
Consistency
Very Soft
Soft
Medium Stiff
Stiff
Very Stiff
Hard
<4
4 to 9
10 to 29
30 to 49
<2
2 to 3
4 to 7
8 to 14
15 to 29
_>30
EEaarrtthh
NNWWLLC
EarthSolutions
NW LLC
Cobbles
Gravel
Coarse Gravel
Fine Gravel
Sand
Coarse Sand
Medium Sand
Fine Sand
Silt and Clay
Larger than 12"
3"to 12"
3"to No.4 (4.75 mm)
3"to 3/4"
3/4"to No.4 (4.75 mm)
No.4 (4.75 mm)to No.200 (0.075 mm)
No.4 (4.75 mm)to No.10 (2.00 mm)
No.10 (2.00 mm)to No.40 (0.425 mm)
No.40 (0.425 mm)to No.200 (0.075 mm)
MC = 5.3
MC = 3.0
MC = 5.5
Fines = 8.7
MC = 10.9
MC = 8.8
Fines = 7.6
OC = 0.8
CEC = 4.8
TPSL
SM
SP-
SM
Dark brown TOPSOIL, root intrusions to 2'
Brown silty SAND with gravel, medium dense to dense, damp
-becomes dense
-probed 2"
-becomes weakly cemented
Brown poorly graded SAND with silt, loose to medium dense, damp
[USDA Classification: slightly gravelly SAND]
-becomes medium dense, moist
-increasing gravels
[USDA Classification: gravelly SAND]
Test pit terminated 13.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
6.5
13.0DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46358 LONGITUDE -122.188
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-1
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 6.8
MC = 4.7
MC = 6.2
TPSL
SM
SP-
SM
Dark brown TOPSOIL, root intrusions to 2'
Brown silty SAND with gravel, medium dense, damp
-probed 2"
-becomes gray, dense
-probed 1"
-weakly cemented
Gray poorly graded SAND with silt and gravel, medium dense, damp
Test pit terminated at 11.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
7.5
11.0DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46387 LONGITUDE -122.18776
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-2
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 4.4
Fines = 36.0
MC = 9.9
MC = 6.1
MC = 4.1
TPSL
SM
SP-
SM
Dark brown TOPSOIL, root intrusions to 1.5'
Brown silty SAND with gravel, medium dense, damp
[USDA Classification: gravelly sandy LOAM]
-probed 1"
-becomes dense
-probed <1"
-weakly cemented
Brown poorly graded SAND with silt, medium dense, damp
Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
9.0
10.0DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46418 LONGITUDE -122.1872
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-3
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 6.0
MC = 5.8
MC = 4.8
MC = 3.8
TPSL
SM
SM
Dark brown TOPSOIL, shallow root intrusions (Fill)
Brown silty SAND with gravel, dense, damp (Fill)
-becomes gray, dense pieces
-probed <1"
-topsoil horizon at 5'
Brown silty SAND with gravel, medium dense, damp
-weathered soils
Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
5.0
10.0DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46371 LONGITUDE -122.18641
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-4
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 4.4
MC = 9.9
MC = 6.8
Fines = 53.5
MC = 6.4
TPSL
SM
ML
Dark brown TOPSOIL, root intrusions to 3'
Brown silty SAND with gravel, medium dense to dense, damp
-probed 2"
Brown sandy SILT, dense, damp
-probed <1"
-becomes gray, dense to very dense
[USDA Classification: slightly gravelly LOAM]
Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
3.5
10.0DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46325 LONGITUDE -122.18844
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-5
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 6.5
MC = 8.9
MC = 3.2
TPSL
SM
SM
Dark brown TOPSOIL, root intrusions to 2'
Brown silty SAND with gravel, medium dense, damp
-probed 1"
-becomes gray, weakly cemented
-becomes dense
Brown silty SAND, dense, moist
Test pit terminated at 14.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
1.0
13.0
14.0DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46336 LONGITUDE -122.18776
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-6
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 3.7
MC = 4.7
OC = 0.7
CEC = 3.0
MC = 6.1
MC = 4.5
Fines = 13.8
TPSL
GM
SM
Dark brown TOPSOIL, root intrusions to 3'
Brown silty GRAVEL with sand, medium dense, damp
-probed <1"
-becomes dense
-weakly cemented
Brown silty SAND, dense, damp
[USDA Classification: gravelly loamy SAND]
Test pit terminated at 12.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
6.5
12.0DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46364 LONGITUDE -122.18817
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-7
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 2.9
MC = 4.5
MC = 4.1
Fines = 15.2
MC = 7.2
OC = 0.7
CEC = 3.4
TPSL
GM
SM
Dark brown TOPSOIL, root intrusions to 2'
Brown silty GRAVEL with sand, medium dense, damp
-probed 1.5"
-becomes gray, dense
-probed <1"
Brown silty SAND with gravel, medium dense, damp
[USDA Classification: very gravelly loamy SAND]
Test pit terminated at 10.5 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
1.0
7.5
10.5DEPTH(ft)0
5
10 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46361 LONGITUDE -122.18772
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-8
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 7.2
MC = 3.0
TPSL
SM
Dark brown TOPSOIL, minimal root intrusions
Brown silty SAND with gravel, medium dense, damp
-becomes gray, dense
-weakly cemented
Test pit terminated at 8.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
8.0DEPTH(ft)0
5 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46352 LONGITUDE -122.18669
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-9
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 8.6
MC = 9.4
TPSL
SM
Dark brown TOPSOIL, minimal root intrusions
Brown silty SAND with gravel, medium dense, damp
-probed 1"
-becomes gray, dense
-weakly cemented
Test pit terminated at 9.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
9.0DEPTH(ft)0
5 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46357 LONGITUDE -122.1873
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-10
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 5.0
MC = 12.2
MC = 3.2
TPSL
GM
SM
Dark brown TOPSOIL, minimal root intrusions
Brown silty GRAVEL with sand, medium dense, damp
-probed <1"
Gray silty SAND with gravel, dense, moist
-becomes damp
Test pit terminated at 9.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
4.0
9.0DEPTH(ft)0
5 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46386 LONGITUDE -122.18699
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-11
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 6.8
MC = 5.4
MC = 7.0
TPSL
SM
Dark brown TOPSOIL, root intrusions to 2'
Brown silty SAND with gravel, medium dense, damp
-probed 1.5"
-becomes gray, dense
-probed <1"
-weakly cemented
Test pit terminated at 9.0 feet below existing grade. No groundwater encountered during excavation.
No caving observed.
LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed.
Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a
standalone document. Refer to the text of the geotechnical report for a complete understanding of
subsurface conditions.
0.5
9.0DEPTH(ft)0
5 SAMPLE TYPENUMBEREXCAVATION CONTRACTOR NW Excavating
DATE STARTED 10/17/22 COMPLETED 10/17/22
GROUND WATER LEVEL:
GROUND ELEVATION
LATITUDE 47.46394 LONGITUDE -122.18649
LOGGED BY SES CHECKED BY KDH
NOTES
SURFACE CONDITIONS Duff
AT TIME OF EXCAVATIONAT TIME OF EXCAVATION
AFTER EXCAVATION
PAGE 1 OF 1
TEST PIT NUMBER TP-12
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GENERAL BH / TP / WELL - 8888.GPJ - GINT US.GDT - 7/3/23Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 4254494711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
Earth Solutions NW, LLC
Appendix B
Laboratory Test Results
ES-8888
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
3
D100
140
Specimen Identification
1
fine
6
HYDROMETER
304
8.7
7.6
36.0
53.5
13.8
101/2
COBBLES
Specimen Identification
4
coarse
20 401.5 8 14
USDA: Brown Slightly Gravelly Sand. USCS: SP-SM.
USDA: Brown Gravelly Sand. USCS: SP-SM with Gravel.
USDA: Brown Gravelly Sandy Loam. USCS: SM with Gravel.
USDA: Gray Slightly Gravelly Loam. USCS: Sandy ML.
USDA: Brown Gravelly Loamy Sand. USCS: SM.
6 60
PERCENT FINER BY WEIGHTD10
0.232
0.315
0.259
0.362
0.544
0.399
0.156
0.486
GRAIN SIZE DISTRIBUTION
100
4.02
3.45
LL
TP-01
TP-01
TP-03
TP-05
TP-07
0.09
0.158
3/4
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
GRAVEL SAND
4.75
19
37.5
19
19
%Silt
1.65
1.16
TP-01
TP-01
TP-03
TP-05
TP-07
2 2003
Cc CuClassification
%Clay
16
PID60 D30
coarse SILT OR CLAYfinemedium
GRAIN SIZE IN MILLIMETERS
3/8 50
7.5ft.
13.0ft.
2.0ft.
5.5ft.
12.0ft.
7.50ft.
13.00ft.
2.00ft.
5.50ft.
12.00ft.
PL
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GRAIN SIZE USDA ES-8888 UNITED CHRISTIAN CHURCH PROPERTY.GPJ GINT US LAB.GDT 10/21/22Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
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
3
D100
140
Specimen Identification
1
fine
6
HYDROMETER
304
15.2
21.8
101/2
COBBLES
Specimen Identification
4
coarse
20 401.5 8 14
USDA: Brown Very Gravelly Loamy Sand. USCS: SM with Gravel.
USDA: Brown Very Gravelly Sandy Loam. USCS: GM with Sand.
6 60
PERCENT FINER BY WEIGHTD10
0.33
0.266
4.135
9.182
GRAIN SIZE DISTRIBUTION
100
LL
TP-08
TP-11
3/4
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
GRAVEL SAND
37.5
37.5
%Silt
TP-08
TP-11
2 2003
Cc CuClassification
%Clay
16
PID60 D30
coarse SILT OR CLAYfinemedium
GRAIN SIZE IN MILLIMETERS
3/8 50
8.0ft.
3.0ft.
8.00ft.
3.00ft.
PL
PROJECT NUMBER ES-8888 PROJECT NAME United Christian Church Property
GRAIN SIZE USDA ES-8888 UNITED CHRISTIAN CHURCH PROPERTY.GPJ GINT US LAB.GDT 10/21/22Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
Earth Solutions NW, LLC
Report Distribution
ES-8888
EMAIL ONLY Ichijo USA Co., Ltd.
1406 – 140th Place Northeast, Suite 104
Bellevue, Washington 98007
Attention: Kanon Kupferer
EMAIL ONLY Barghausen Consulting Engineers, Inc.
18215 – 72nd Avenue South
Kent, Washington 98032
Attention: Barry Talkington, P.E.
Ivana Halvorsen
Vicente Varas, P.E.