161031 MAD (Geotech Report).pdfGeotechnical Engineering Report
New Madrona K-8 Project
9300 236th Street SW
Edmonds, Washington
October 31, 2016
Submitted To:
Ms. Taine Wilton
Edmonds School District #15
20420 68th Avenue West
Lynnwood, Washington 98036
By:
Shannon & Wilson, Inc.
400 N 34th Street, Suite 100
Seattle, Washington 98103
21-1-22082-004
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
i
TABLE OF CONTENTS
Page
1.0 SITE AND PROJECT DESCRIPTION .................................................................................1
2.0 SITE CONDITIONS ..............................................................................................................2
2.1 Regional Geology .......................................................................................................2
2.2 Regional Seismicity ....................................................................................................2
3.0 SUBSURFACE EXPLORATION .........................................................................................3
4.0 FIELD INFILTRATION TESTING ......................................................................................4
5.0 LABORATORY TESTING ...................................................................................................5
6.0 SUBSURFACE CONDITIONS .............................................................................................5
6.1 Site Geology and Subsurface Conditions ...................................................................5
6.1.1 Subsurface Conditions at Proposed Building ..............................................5
6.1.2 Subsurface Conditions at Proposed Parking Lots and Driveways ...............6
6.2 Hydrogeologic Conditions .........................................................................................6
7.0 ENGINEERING STUDIES AND RECOMMENDATIONS ................................................6
7.1 General .......................................................................................................................6
7.2 Foundation Design .....................................................................................................7
7.3 Seismic Design ...........................................................................................................7
7.4 Lateral Earth Pressures and Retaining Walls .............................................................8
7.5 Lateral Resistance ......................................................................................................9
7.6 Slope Stability ............................................................................................................9
7.7 Pavement Design ......................................................................................................10
7.7.1 Traffic Load ...............................................................................................10
7.7.2 Subgrade Conditions ..................................................................................10
7.8 Non-Porous Pavement Section Recommendations ..................................................10
7.9 Porous Pavement Section Recommendations ..........................................................11
7.9.1 Grass Grid Pavers ......................................................................................11
7.9.2 Pervious Hot Mix Asphalt (HMA) and Concrete ......................................11
7.10 Pavement Sections Near Steep Slopes .....................................................................12
7.11 Frost Susceptibility ...................................................................................................12
8.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS .....................................13
8.1 Earthwork and Use of On-site Soils .........................................................................13
8.2 Pervious Pavement Materials ...................................................................................14
8.3 Construction and Maintenance Considerations for Pervious Pavement ..................14
8.4 Temporary and Permanent Excavation Slopes .........................................................15
8.5 Erosion Control ........................................................................................................16
TABLE OF CONTENTS (cont.)
Page
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
ii
8.6 Construction Drainage ..............................................................................................16
8.7 Subsurface Drainage ................................................................................................16
8.8 Utilities .....................................................................................................................16
8.9 Wet Weather Earthwork ...........................................................................................17
8.10 Plans Review and Construction Observation ...........................................................18
9.0 LIMITATIONS ....................................................................................................................18
10.0 REFERENCES .....................................................................................................................20
TABLES
1 Recommended Minimum Parking Lot and Driveway Section Thicknesses .........11
2 Recommended Minimum Porous Pavement Section Thicknesses ........................11
3 Imported Backfill Specifications Based on 2016 Washington State
Department of Transportation Standard Specifications .........................................13
FIGURES
1 Vicinity Map
2 Site and Exploration Plan
3 Typical Rockery Detail
4 Measured Water Level, Pilot Infiltration Test, Test Pit PIT-1
5 Measured Water Level, Pilot Infiltration Test, Test Pit PIT-2
6 Measured Water Level, Pilot Infiltration Test, Test Pit PIT-3
APPENDICES
A Subsurface Explorations
B Laboratory Test Results
C Analytical Laboratory Test Results
D Important Information About Your Geotechnical/Environmental Report
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
1
GEOTECHNICAL ENGINEERING REPORT
NEW MADRONA K-8 PROJECT
9300 236TH STREET SW
EDMONDS, WASHINGTON
1.0 SITE AND PROJECT DESCRIPTION
The Edmonds School District No. 15 plans to construct a new Madrona K-8 School on the south
side of the property at 9300 236th Street SW in Edmonds, Washington, as shown in the Vicinity
Map (Figure 1). The property contains the existing Madrona K-8 School and is bounded by
236th Street to the north, residential developments on the east and south sides, and the former
Woodway Elementary School on the west. The site has a number of distinct surface features
including a parking lot on the northwest side, track and large open field area on the southwest
side, and a baseball field on the southeast side. There is a densely wooded ravine area along the
east side of the property and a densely wooded slope on the west side of the property that slopes
down to the former Woodway Elementary School. The purpose of this study is to finalize our
geotechnical recommendations with data from additional subsurface explorations and testing to
aid in the final design of the proposed structure. Geotechnical recommendations were provided
previously in a preliminary geotechnical engineering report submitted on August 6, 2015.
Our scope of services for the design phase included drilling and sampling 12 geotechnical
borings and excavating 5 test pits. However, one of the proposed drilling locations was changed
to a test pit exploration for a total of 11 geotechnical borings and 6 test pits. The proposed
drilling location was changed to a test pit due to the close proximity to subsurface utilities and
access issues. Locations of the subsurface explorations were selected to coincide with the
planned location of the proposed building and associated facilities. Descriptions of the
subsurface exploration activities are discussed further in Section 3.0. The results of our pilot
infiltration testing (PIT) are discussed in Section 4.0.
This report presents updated geotechnical engineering recommendations to incorporate the
additional subsurface information gathered from the new explorations and information provided
by the design team. We have included recommendations for pavement design and a discussion
of buffer and setback distances when adjacent to steep slopes and other geologic hazard areas.
The results of the soil fertility testing are also provided to aid the design team in evaluating the
suitability of on-site topsoil for use in landscaping.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
2
2.0 SITE CONDITIONS
2.1 Regional Geology
The site is located in Edmonds, Washington, which is within a region known as the Puget
Lowland. The Puget Lowland is a structural depression bordered by the Olympic and Cascade
Mountain ranges that is generally within about 500 feet of sea level. The geology of the area has
been influenced by repeated cycles of glaciation, which worked to fill the lowland to significant
depths with a complex sequence of glacial and nonglacial deposits. The most recent glacier to
impact the area, the Vashon Stade of the Fraser Glaciation, overrode the area with up to
3,000 feet of ice in some locations. Following the last glaciations, the erosion of some of the
glacially overridden soil deposits, as well as local deposition and human placement of additional
soil deposits, have further complicated the local geology (Troost and Booth, 2008).
The project site itself is situated on a ridge underlain by Quaternary Vashon till (Qvt) that was
observed at relatively shallow depths during the current subsurface investigation. This geologic
unit was found to be a very dense, gray to gray-brown deposit consisting of silty sand with
variable gravel, cobble, and some boulder content. Other explorations performed on the site
(Shannon & Wilson, Inc. [Shannon & Wilson], 2016) encountered deposits of Quaternary
Vashon advanced glacial outwash (Qva) at depths of approximately 40 to 50 feet below ground
surface (bgs). This geologic unit is characterized by dense to very dense sands and gravels with
variable amounts of silt. Qva is typically less compact and more pervious than Qvt. Geologic
maps of the Snohomish County region indicate that the contact between the glacial till and
advanced outwash material is on the slope on the west side of the property. The Qva at the site
may be underlain by pre-Vashon interglacial and glacial soils, predominantly fluvial.
2.2 Regional Seismicity
The Puget Sound Lowland is located in the fore arc of the Cascadia Subduction Zone. The
seismicity of the region is largely derived from the subduction of the Juan de Fuca Plate beneath
the North American Plate. The convergence of these two plates results in a number of generally
east-west-trending faults, as well as basin and uplift regions (Troost and Booth, 2008). The
seismic hazard of the region comes from three major sources, a major subduction type events,
deep intraplate events (such as the 2001 Nisqually earthquake), and earthquakes due to rupture of
shallow crustal faults.
The site itself is located a reasonable distance from subduction and intraslab sources, and as a
result, the more local, crustal faults are believed to drive the seismic hazard for the site. The
closest known potentially active fault to the site is the South Whidbey Island Fault (SWIF). The
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
3
SWIF is a shallow, strike-slip fault that is believed to be capable of producing a magnitude 7.5
event, which could impose significant seismic demands on structures at the site.
3.0 SUBSURFACE EXPLORATION
Previously, we completed subsurface explorations as a part of a preliminary geotechnical
engineering study to aid in the selection of the proposed building location. Previous explorations
consisting of 16 test pits on the southern half of the property were completed on June 24, 2015.
Logs of the previous subsurface explorations are included in Appendix A.
Recent subsurface explorations consisted of test pits and geotechnical borings completed
between Monday, July 25, 2016, and Friday, July 29, 2016. Holocene Drilling (Holocene),
under subcontract to Shannon & Wilson, completed a total of 11 geotechnical borings with the
use of a track-mounted Diedrich D-50 drill rig. Holocene used the hollow-stem auger drilling
method to complete the borings to depths ranging from 15.5 to 16.5 feet bgs. Holocene collected
samples on approximate 2.5-foot intervals with the use of the Standard Penetration Test. Once
the geotechnical borings were completed, Holocene backfilled the holes with bentonite to within
approximately 1 to 2 feet bgs. Borings that were drilled in the asphalt parking area were patched
with concrete.
Clearcreek Contractors (Clearcreek), under subcontract to Shannon & Wilson, completed a total
of six test pits to depths ranging from 4 to 10 feet with the use of a rubber-tired John Deere
310SJ backhoe. Three of the test pits were used to characterize infiltration within the near-
surface soils. Infiltration testing within the near-surface soils is discussed below in Section 4.0.
Following the excavations and testing, Clearcreek backfilled the test pits with the excavated
material and tamped the material down using the excavator bucket in approximately 1-foot-thick
lifts. Once Clearcreek had completed backfilling the test pits, they rolled the surface for further
compaction and replaced the grass layer where it was possible to salvage.
The explorations were located throughout the site as shown in the Site and Exploration Plan,
Figure 2. Test pits designated with a PIT were the ones in which we performed the in situ
infiltration testing/PITs, while the test pits designated with a TP were not used for in situ
infiltration testing. During the exploration process, the soil and groundwater conditions were
observed by an engineer or a geologist from our office. Soil samples were collected and
transported to our Seattle laboratory for analysis and testing. Logs of the explorations are
presented in Appendix A.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
4
The geotechnical boring and test pit locations provided in Figure 2 are approximate, being based
on hand measurements from site features, and surface elevations shown in the logs are estimated
from a topographic survey of the site prepared by PACE Engineers, Inc.
4.0 FIELD INFILTRATION TESTING
We performed small-scale PITs within three of the six test pits excavated during the current
subsurface explorations. The PIT test pits were designated as PIT-1 through PIT-3, and the
locations are shown in the Site and Exploration Plan, Figure 2. All three of the infiltration tests
were performed on July 28, 2016. These test pits were over excavated following the PITs on
July 29, 2016. Details of the three tests are presented below and are summarized in the PIT data
plots (Figures 4 through 6).
The PIT-1 test pit bottom during the PIT was approximately 3.8 feet bgs, or about Elevation
440.7 feet. The tested soil unit was fill, consisting of reworked glacial till. After the water flow
was terminated, the test pit drained completely overnight. No free water was present below the
PIT test depth when we overexcavated it on July 29, 2016. A plot of the PIT-1 test data is
presented as Figure 4. The observed (short-term) infiltration rate was approximately 0.80 inch
per hour, based on the last hour of the constant head period. If these soils represented the
subgrade beneath a bioretention feature constructed with imported bioretention soil, the City of
Edmonds (City) will require the application of a correction factor of 2 due to the test being
performed during the dry season. This would result in a design (long-term) infiltration rate of
0.4 inch per hour.
The PIT-2 test pit bottom during the PIT was approximately 3.3 feet bgs, or about Elevation
452.7 feet. The tested soil unit was glacial till, with a short-term infiltration rate of 0.13 inch per
hour, based on the falling head data collected after the water flow into the test pit was
terminated. Applying the correction factor would result in a design infiltration of 0.06 inch per
hour. The test pit failed to drain completely overnight and this soil is considered to be a
hydraulic restriction to infiltration, due to its low infiltration rate. A plot of the PIT-2 test data is
presented as Figure 5.
The PIT-3 test pit bottom during the PIT was approximately 2.9 feet bgs, or about Elevation
447.1 feet. The tested soil unit was glacial till, with a short-term infiltration rate of 0.07 inch per
hour based on the falling head data collected after the water flow into the test pit was terminated.
Applying the correction factor would result in a design infiltration rate of 0.03 inch per hour.
The test pit failed to drain completely overnight and this soil is considered to be a hydraulic
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
5
restriction to infiltration due to its low infiltration rate. A plot of the PIT-3 test data is presented
as Figure 6.
If a shallow well were installed in the vicinity and read during the wet season, no correction
factor would be required, provided groundwater is at least 3 feet below the bottom of the facility.
5.0 LABORATORY TESTING
Laboratory testing was conducted on several soil samples collected from the test pit explorations
to assist in classification and characterization of the subsurface soils. The laboratory tests
included natural moisture content determination and grain size analysis. The natural moisture
contents are indicated on the test pit logs in Appendix A. The results of the grain size analyses
are presented in Appendix B. Most of the grain size tests were sieve analyses.
Combined sieve and hydrometer tests were performed on two samples (from B-4 at 5 feet deep
[about Elevation 440 feet] and from B-5 at 7.5 feet deep [about Elevation 439.5 feet]) so that the
U.S. Department of Agriculture (USDA) texture could be identified. Both samples are
considered to be “sandy loam,” based on the USDA textural system. Based on our discussions
with the City, the short-term infiltration rate for these soils is 1 inch per hour. Since the
explorations were completed during the dry season, a seasonal correction factor of 2 is required,
resulting in a design infiltration rate of 0.5 inch per hour. This assumes that these soils represent
the subgrade beneath bioretention features with imported bioretention soil.
In order to characterize the existing topsoil within the upper and lower field, we submitted two
samples to Spectra Laboratories (Spectra) in Poulsbo, Washington. The samples were tested for
soil fertility and the results with recommendations from Spectra are included in Appendix C.
6.0 SUBSURFACE CONDITIONS
6.1 Site Geology and Subsurface Conditions
Intact glacial till soils were encountered in all but one of the explorations performed under the
current scope of work. The test pit PIT-1 did not encounter intact glacial till, but did encounter
weathered till at a depth of approximately 7 feet bgs.
6.1.1 Subsurface Conditions at Proposed Building
Explorations performed within or near the proposed building footprint on the existing
upper play field in the southeast corner of the site indicate that this area is underlain by a thin
layer of topsoil followed by layers of fill, weathered or reworked glacial till, and intact glacial
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
6
till. Borings B-7, B-9, B-10, and B-12 indicate that there is a layer of fill soils at depths ranging
from 4.5 to 7 feet bgs. Fill soils consisted of medium dense to very dense, silty sand to silty sand
with gravel. Intact very dense glacial till underlying the building footprint was encountered at
depths ranging from approximately 1 to 7 feet bgs.
6.1.2 Subsurface Conditions at Proposed Parking Lots and Driveways
Explorations performed within the parking areas west of the existing school building and
north of the track indicated that fill soils overlying the glacial till are present at depths ranging
from 7 to 9.5 feet bgs. Borings and test pits on the north and east sides of the existing building
also encountered fill soils at depths ranging from 4.5 to 6 feet bgs. Intact, very dense glacial till
was found to underlie the fill soils.
6.2 Hydrogeologic Conditions
Groundwater was not encountered in the recent shallow soil borings and test pits, all of which
were performed during the dry season. Moist to wet layers were observed below about 15 feet in
borings B-2, B-3, and B-5, and below about 12 feet in boring B-9, which may indicate the
presence of perched groundwater. Subsurface explorations performed previously onsite as part
of our hydrogeologic study (Shannon & Wilson, 2016) identified a regional groundwater aquifer
at the site at about 180 feet deep and between approximate Elevations 276.3 to 277.2 feet.
Perched groundwater zones were also encountered during the previous hydrogeologic
explorations at depths ranging from 8.5 to 11 feet bgs (Shannon & Wilson, 2016). Note that
groundwater is not expected to be encountered during excavations for the new school building.
We understand that the project stormwater management system will consist of a series of shallow
bioretention swales combined with underground injection control (UIC) wells. The results of our
recent hydrogeological testing and analysis are presented in a separate report (Shannon &
Wilson, 2016). Please refer to this report for design recommendations regarding UIC
construction and infiltration rates.
7.0 ENGINEERING STUDIES AND RECOMMENDATIONS
7.1 General
Based on the observations made during the subsurface exploration program and information
reviewed for the project, we expect the glacial till material will provide good support for
conventional spread footing foundations with minimal settlements.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
7
The following subsections provide detailed recommendations on the following topics:
Foundation design
Seismic design
Lateral earth pressures
Lateral resistance
Slope stability
Pavement design
7.2 Foundation Design
The subsurface explorations encountered undisturbed, very dense, native glacial till soils across
the entire site. Spread footings founded in the dense, native till material may be designed with
an allowable bearing pressure of 10,000 pounds per square foot (psf). Spread footings that are
founded in compacted structural backfill placed above the glacial till may be designed for an
allowable bearing capacity of 4,000 psf. These allowable bearing values may be increased by
one-third for transient seismic loading. Any fill material that is to be reused should be evaluated
by a geotechnical engineer to see if they are suitable for use. Use of on-site fill material is
discussed in Section 8.1.
Based on the subsurface conditions, isolated overexcavation could be required due to the
presence of some existing fill within the building footprints. As an alternative to overexcavation
of fill material encountered at footing subgrade elevations, in situ densification of the fill could
be accomplished with the use of heavy vibratory compaction equipment (i.e., excavator-mounted
“ho-pac”). Footing subgrades should be observed by a qualified geotechnical engineer or
geologist.
If the native glacial till material or compacted structural backfill is used as the foundation
bearing soils, it is anticipated that any settlement that occurs will be essentially instantaneous as
the load is applied during construction. If the footings are designed for the bearing pressures
noted above, then the total footing settlements will be less than ½ inch. Differential settlements
would be about one-half of the total settlement. However, if the entire structure is founded on
the glacial till, then differential settlements would be insignificant.
7.3 Seismic Design
The seismic design of the structure should be in accordance with the International Code Council,
Inc. 2015 International Building Code (IBC) (International Code Council, Inc., 2014). The IBC
design criteria are based on a target risk of structural collapse of 1 percent in 50 years. The soil
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
8
profile is assessed by assigning a site class definition. It is our opinion that based on the soil
classification, i.e., very dense, the site can be classified as Site Class C.
Seismic inputs are the short-period maximum spectra acceleration, SS, and spectral acceleration
at a period of one second, S1. Using the map provided in the IBC, which corresponds to Site
Class B sites, the mapped values of SS and S1 are approximately 1.262 and 0.493g, respectively.
The site coefficients for the given spectral acceleration values and site class C are 1.0 and 1.31
for Fa and Fv, respectively. Seismic hazards such as liquefaction and fault rupture are not present
at the project site.
7.4 Lateral Earth Pressures and Retaining Walls
Lateral earth pressures will act on portions of the building as well as on retaining walls. The
magnitude and distribution of these lateral pressures will depend on many factors, including, but
not limited to, the type of backfill, the method of backfill placement, level of backfill
compaction, slope of backfill, drainage, and characteristics of the wall itself. If the wall is
allowed to move at least 0.001 times the wall height, the wall is considered flexible and active
earth pressures can be used. If the wall is considered to be inflexible then at-rest earth pressures
must be used.
The active and at-rest earth pressures, evaluated using an equivalent fluid unit weight, are
estimated to be on the order of 30 and 50 pounds per cubic feet (pcf), respectively. The values
given above assume a permanent wall structure, the ground surface behind the wall is level, and
that proper drainage is installed to prevent the buildup of pore water pressure behind the wall.
The total earth pressures should be analyzed for seismic loading conditions using a dynamic load
increment equal to a percentage of the static earth force. The percentage load increase for
seismic condition was developed to be consistent with a pseudo-static analysis using the
Mononobe-Okabe equation for lateral earth pressures (Kramer, 1996) and a horizontal seismic
coefficient of 0.2. The load increase for seismic conditions is recommended to be a uniformly
distributed load equal to 8H, where H is the height of the wall. Note the seismic coefficient is
not equal to the peak ground acceleration (PGA) expected to be encountered at the site in a
design event. The PGA is experienced only a few times within the record of earthquake shaking,
and the actual earthquake ground motion is cyclic in nature, not static. Values of the seismic
coefficient are thus typically one-third to one-half the value of the PGA that may be experienced
at the site during a design level event.
We understand that rockery walls may be installed. Rock walls have been used in numerous
locations around Puget Sound area primarily to provide erosion protection to cuts in stable
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
9
materials. Rockeries have also been used to retain fill slopes; however, this practice is not as
prevalent. In our opinion, rockeries could be used to retain cut slopes made in dense to very
dense native soil that are less than 6 feet high. Rockeries should be constructed in accordance
with the recommendations shown in Figure 3.
Rockeries could be used to retain fill slopes provided they are 5 feet high or less, or if they are
reinforced. If used with a reinforced slope, the rockery would form a façade or erosion
protection facing on an otherwise stable slope. Rockeries that are used to retain fill slopes that
are 5 feet high or less should be built in accordance with the recommendations shown in
Figure 3. We recommend that the fill be built out beyond the planned wall location and then cut
back. With this procedure, the fill can be fully compacted, as compared with the difficulty of
compacting the edge of a fill slope.
7.5 Lateral Resistance
Footings may resist lateral loads using a combination of base friction and passive pressure
against the buried or embedded portion of the footings and buried wall. We recommend that
base sliding resistance be determined using an allowable coefficient of friction of 0.7 for a
concrete foundation founded on on-site glacial till or compacted structural fill. Passive earth
pressures can be evaluated using an equivalent unit weight of 400 pcf. This value includes a
factor of safety of 1.5.
7.6 Slope Stability
The slope along the eastern perimeter of the property is mapped as a critical area by the City due
to the steepness of the slope and the presence of wetlands. We recommend that the Madrona K-8
school footprint be set back at least 10 feet from the top of slope. While we did not observe
active landsliding on this slope, the Edmonds Community Development Code requires that
buildings or other structures constructed near an environmentally critical area maintain a setback
of 15 feet from the edge of the critical area which in this case is the top of the slope (Edmonds,
Wash., 2016). However, the code also allows for setbacks to be determined by a Geotechnical
Engineering Report. In our opinion, after review of the subsurface conditions and the current
condition of the slope, a setback of 10 feet would not cause an increased potential for landslides
or surficial soil instability on the steep slope. In our opinion, buried utilities within this setback
distance are acceptable and will not be at risk due to slope instability.
We understand that dead or diseased tree removal is planned along the east, west, and south
perimeter of the property near the top of the slopes. We made a site visit on September 20, 2016,
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
10
to observe the slope areas where tree removal is planned. In our opinion, the planned tree
removal will not cause instability of the slope and the trees may be felled and chipped in-place.
7.7 Pavement Design
Pavement analyses were conducted using the American Association of State Highway and
Transportation Officials (AASHTO) method for flexible and rigid pavement design (AASHTO,
1993). The AASHTO method is a widely used empirical design procedure for the design of
flexible and rigid pavement structures. It considers strength of the base course materials, traffic
stresses, and the strength of the pavement subgrade. The pavement design life is assumed to be
20 years.
7.7.1 Traffic Load
Average daily traffic counts, including delivery trucks, school buses, and occasional
heavy vehicles such as fire trucks, were based on assumed conditions for similar projects.
Assumed traffic volumes were then converted into equivalent single-axle loads by using
equivalent load factors. We assume that there will not be a significant increase in traffic at this
location, but did include a 1 percent growth factor in the design life traffic counts for our
analysis.
7.7.2 Subgrade Conditions
The subgrade conditions at the proposed pavement locations are medium dense, silty
sand to silty sand with gravel fill suitable for pavement support. If loose or soft subgrade is
observed during construction, we recommend that it be removed and replaced with at least 1 foot
of compacted structural fill. A Resilient Modulus, MR, of 15,000 pounds per square inch is
recommended for pavement design where existing medium dense fill and newly placed
compacted structural fill are present.
7.8 Non-Porous Pavement Section Recommendations
For support of the proposed parking and driveway areas we propose pavement section
thicknesses shown in Table 1 below. Recommendations have been separated into lightly loaded
and heavily loaded pavement sections. Lightly loaded pavement sections are assumed to be
those that are utilized primarily by car and other passenger vehicle traffic. Heavily loaded
pavement sections are assumed to be those that are utilized by heavy vehicles such as buses,
delivery, and fire trucks.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
11
TABLE 1
RECOMMENDED MINIMUM PARKING LOT AND
DRIVEWAY SECTION THICKNESSES
Pavement
Type Pavement Layer
Light
Loading
Heavy
Loading
Flexible Asphalt 3 inches 4 inches
Base Course 4 inches 6 inches
Rigid Concrete 4 inches 6 inches
Base Course 4 inches 4 inches
Base course should correspond to crushed surfacing in accordance with the Washington State
Department of Transportation (WSDOT) Standard Specifications (WSDOT, 2016). Placement,
compaction, and material specification for crushed surfacing is discussed in Section 8.1 of this
report.
7.9 Porous Pavement Section Recommendations
7.9.1 Grass Grid Pavers
Grass grid pavers will be a proprietary product and should be designed in accordance
with the manufacturer’s recommendations. For design of the porous pavement sections, we
recommend that the compacted subgrade be assumed to have a California Bearing Ratio of
approximately 20.
7.9.2 Pervious Hot Mix Asphalt (HMA) and Concrete
As we understand, porous pavement sections consisting of pervious HMA or concrete
underlain by an underdrain are being considered within the fire lane to collect surface drainage.
Pervious pavement consists of porous asphalt or concrete overlying a stone bed.
For support of the proposed fire lane areas, we propose porous pavement section
thicknesses shown in Table 2 below.
TABLE 2
RECOMMENDED MINIMUM POROUS PAVEMENT
SECTION THICKNESSES
Pavement Type Pavement Layer Thickness
Pervious HMA Porous Asphalt 5 inches
Stone Bed 10 inches
Rigid Porous Concrete 9 inches
Stone Bed 12 inches
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
12
Please note that porous asphalt is susceptible to considerable wear due to heavy vehicle
loading especially in vehicle turning areas. Rutting due to surface abrasion is known to occur
between the wheel and the pavement during breaking and turning.
Also note that pervious concrete pavement is sensitive to the means and methods used in
mix design and placement. We recommend following the American Concrete Institute (ACI)
Specification for Pervious Concrete Pavement, ACI 522.1-13 for design and installation
practices of porous concrete pavement systems (ACI, 2013). This specification covers materials,
preparation, forming, placing, finishing, jointing, curing, and quality control of pervious concrete
pavement. Provisions governing testing, evaluation, and acceptance of pervious concrete
pavement are included. Pervious concrete pavement will require annual cleaning to maintain its
infiltration function. We recommend vacuum cleaning once or twice a year (depending on
conditions) with a regenerative sweeper and pressure washing as needed.
7.10 Pavement Sections Near Steep Slopes
Pavements constructed near the steep slopes on the east and west perimeters of the property
should have the same minimum pavement sections shown above in Table 1. Subsurface
conditions encountered in the explorations indicate that the site is underlain by glacial till at
relatively shallow depths, so slope stability is not an issue with regard to pavement construction.
7.11 Frost Susceptibility
Frost-susceptible soil is regarded as having greater than 3 percent finer that 0.02 millimeter
(mm). Soil with a fines content not exceeding 7 percent passing the No. 200 sieve, based on the
minus ¾-inch fraction, can normally be expected to have 3 percent or less finer than 0.02 mm.
The current subsurface explorations indicate the subgrade soil has an average fines content of
about 30 percent, which should be considered frost-susceptible.
The measured frost depth during cold winters of 1949 and 1950 was about 15 inches near
Edmonds, Washington. In accordance with the WSDOT Pavement Policy (WSDOT, 2015),
pavement can be designed for frost protection by providing a pavement section that is equal to or
thicker than half of the anticipated frost depth. The pavement section includes pavement and
non-frost susceptible base course. In our opinion, the minimum recommended pavement
sections presented in Table 1 above should provide adequate frost protection.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
13
8.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS
8.1 Earthwork and Use of On-site Soils
Fill placed beneath structures such as floor slabs, pavements, sidewalks, or backfill against
footings should be structural fill. Structural fill should be placed and compacted upon native soil
surfaces observed during construction by a geotechnical engineer or the engineer’s
representative. The fill soils encountered onsite generally contain sufficient fines to make them
moisture-sensitive. In our opinion, on-site soils may be difficult to place and compact to
adequate relative compaction levels, particularly during wet weather or in wet conditions. The
on-site glacial till soils may be used as structural fill material provided the following conditions
are met:
The soil is free from organics, debris, or other deleterious material.
The water content of the on-site soil at the time of compaction is close to its optimum
as determined by a Modified Proctor Test (ASTM International [ASTM], 2012).
On-site soils used for fills and backfills that become wet and unstable after placement
should be removed and replaced with suitable material.
Stockpiled on-site soils are protected when rainfall is anticipated in accordance with
Section 2-09.3(1)E (WSDOT, 2016).
If on-site soil becomes too difficult to compact or construction site space limitations prevent
stockpiling, we recommend using imported, granular, structural backfill. Imported backfill
should meet gradation requirements of the WSDOT Standard Specifications (WSDOT, 2016).
Table 3 provides material specifications for various backfill applications. On-site soil not
suitable for structural backfill could be used as backfill within landscaped areas.
TABLE 3
IMPORTED BACKFILL SPECIFICATIONS BASED ON
2016 WASHINGTON STATE DEPARTMENT OF TRANSPORTATION
STANDARD SPECIFICATIONS
Application Material Specification
Structural Fill 9-03.14(1)
Gravel Backfill for Walls 9-03.12(2)
Gravel Backfill for Pipe Zone Bedding 9-03.12(3)
Crushed Surfacing Base Course 9-03.9(3)
Structural fill should be placed in horizontal, uniform lifts and compacted to a dense and
unyielding condition, and to at least 95 percent of the Modified Proctor maximum dry density
(ASTM D1557 [ASTM, 2012]). Subgrades to receive structural fill should be dense and
unyielding and should be evaluated by the geotechnical engineer prior to the placement of fill.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
14
Preparation of subgrades should be in accordance with Section 2-06 of the WSDOT Standard
Specifications (WSDOT, 2016). In general, the thickness of soil layers before compaction
should not exceed 10 inches for heavy equipment compactors or 6 inches for hand-operated
mechanical compactors. The most appropriate lift thickness should be determined in the field
using the Contractor’s selected equipment and fill, and verified with in situ soil density testing
(nuclear gauge methods). All compacted surfaces should be sloped to drain to prevent ponding.
Structural fill placement operations should be observed and evaluated by an experienced
geotechnical engineer or technician.
8.2 Pervious Pavement Materials
We recommend the following material specifications for pervious pavement:
Porous Bituminous Asphalt. The bituminous surface course shall be a bituminous
mix of 6 percent by weight dry aggregate. Porous asphalt uses the same mixing and
application equipment as for conventional asphalt. A neat asphalt binder modified
with an elastomeric polymer is recommended. The polymer modified asphalt binder
shall be heat and storage stable. Aggregate shall be minimum 90 percent crushed
material and have a recommended gradation of:
U.S. Standard Sieve Size Percent Passing
½ (12.5 millimeter [mm]) 100
⅜ (9.5 mm) 92 to 98
4 (4.75 mm) 34 to 40
8 (2.36 mm) 14 to 20
16 (1.18 mm) 7 to 13
30 (0.60 mm) 0 to 4
200 (0.075 mm) 0 to 2
Stone Bed. Stone bed course aggregate shall be a crushed, ⅜- to 1-inch uniformly
graded coarse aggregate conforming to AASHTO size number 67 (or equivalent).
Stone bed aggregate shall be placed immediately after approval of subgrade
preparation. Clean (washed) stone bed aggregate should be in maximum 8-inch lifts.
Each layer shall be compacted to a dense condition with a smooth drum roller.
8.3 Construction and Maintenance Considerations for Pervious Pavement
Pervious pavement is susceptible to damage and clogging during construction and afterward.
We recommend that the construction be undertaken in such a way as to prevent:
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
15
Compaction of Subgrade: If the existing subgrade under the stone bed is to be used
for infiltration, then the subgrade shall not be compacted or subject to excessive
construction equipment traffic prior to stone bed placement.
Contamination of Stone Bed and Pervious Pavement with Sediment and Fines:
Control of sediment is critical and rigorous installation and maintenance of erosion
and sediment control measures is required to prevent sediment deposition on the
pavement surface or within the stone bed.
Staging, construction practices, and erosion and sediment control must all be taken into
consideration when using pervious pavements. Due to the nature of construction sites, pervious
pavement and other infiltration measures should be installed at the end of the construction
period.
All pervious pavement installations must have a backup method for water to enter the stone
storage bed in the event that the pavement fails or is altered. In uncurbed lots, this backup
drainage may consist of an unpaved 2-foot-wide stone edge drain connected directly to the bed
between the wheel stop. In curbed lots, inlets with 12-inch sediment traps may be required at
low spots. Backup drainage elements will ensure the functionality of the infiltration system if
the pervious pavement is compromised. These systems should be designed by the project civil
engineer.
8.4 Temporary and Permanent Excavation Slopes
Safe temporary excavations are the responsibility of the Contractor and depend on the actual site
conditions at the time of construction. Temporary cuts are the responsibility of the Contractor
and should comply with applicable Occupational Safety and Health Administration (OSHA) and
Washington Industrial Safety and Health Administration Standards. For trench safety purposes,
the fill material at the site should be considered as OSHA “Class C” material, which requires
side slopes no steeper than 1.5 Horizontal to 1 Vertical (1.5H:1V). Cut slopes during
construction, particularly during wet weather, should be compacted to achieve a dense surface
and covered with plastic sheeting to reduce erosion.
All traffic and/or construction equipment loads should be set back from the edge of the cut slopes
a minimum of 5 feet. Excavated material, stockpiles of construction materials, and equipment
should not be placed closer to the edge of any excavation than the depth of the excavation, unless
the excavation is shored and such materials are accounted for as a surcharge load on the shoring
system. Permanent slopes excavated in dense native soils should be no steeper than 1.5H:1V.
We recommend that permanent slopes in on-site fill materials be no steeper than 2H:1V.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
16
8.5 Erosion Control
Erosion control for the site will include the Best Management Practices incorporated in the civil
design drawings and may incorporate the following recommendations:
Limit exposed cut slopes.
Route surface water through temporary drainage channels around and away from
exposed slopes.
Use silt fences, straw, and temporary sedimentation ponds to collect and hold eroded
material on the site.
Seed or plant vegetation on exposed areas where work is completed and no buildings
are proposed.
Retain existing vegetation to the greatest possible extent.
8.6 Construction Drainage
Even during dry weather, we recommend that site drainage measures be incorporated into the
project construction. Perched water in the excavations (if present) and surface runoff can be
controlled during construction by careful grading practices. Typically, these include the
construction of shallow perimeter ditches or low earthen berms, and the use of temporary sumps
to collect runoff and prevent water from damaging slopes and exposed subgrades. All collected
water should be directed, under control, to a positive and permanent discharge system. The site
will need to be graded at all times to facilitate drainage and minimize the ponding of water.
8.7 Subsurface Drainage
We recommend installing a subdrain system along the outside of the perimeter footings to
prevent pooling of stormwater against the building foundations. The subdrain system should
consist of a perforated or slotted, 4-inch (minimum)-diameter plastic pipe bedded in ⅜-inch to
No. 8 size washed pea gravel.
Where a perforated or slotted drain pipe from a subdrain system connects into a tightline, we
recommend that a low permeability concrete collar or dam be placed along the first 2 feet of the
tightline to force all water into the tightline. Cleanouts should be provided at convenient
locations along all drain lines, such as at the building corners.
8.8 Utilities
In general, utilities at the site can be installed within the existing site soils, provided they are not
underlain by extremely loose, soft, or organic materials. Maintaining safe utility excavations is
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
17
the responsibility of the Contractor. Conventional excavation equipment can be used to excavate
the soils. The utility trenches should be backfilled as noted in Section 8.1. We recommend
utilities placed under the roadway have a minimum cover of 2 feet from the crown of the pipes or
conduits to the top of the pavement subgrade. Catch basins, utility vaults, and other structures
installed flush with the pavement should be designed and constructed to transfer wheel loads to
the base of the structure.
8.9 Wet Weather Earthwork
In the project area, wet weather generally begins about mid-October and continues through about
May, although rainy periods may occur at any time of the year. Therefore, it would be advisable
to schedule earthwork during the dry weather months of June through mid-October.
Most of the soils at the site contain sufficient fines to produce an unstable mixture when wet.
Such soils are highly susceptible to changes in water content, and may become muddy, unstable,
and difficult to compact if their moisture content significantly exceeds the optimum. Performing
earthwork during dry weather would reduce these problems and costs associated with rainwater,
trafficability, and handling of wet soil. However, should wet weather/wet condition earthwork
be unavoidable, the following recommendations are provided:
Earthwork should be accomplished in small sections to minimize exposure to wet
conditions. That is, each section should be small enough such that the removal of
unsuitable soils and the placement and compaction of clean structural fill can be
accomplished on the same day. If there is to be traffic over the exposed subgrade, the
subgrade should be protected with a compacted layer (generally 8 inches or more) of
clean crushed rock.
Fill material should consist of clean, well-graded granular soil, of which not more
than 5 percent by dry weight passes the No. 200 mesh sieve, based on wet sieving the
fraction passing the ¾-inch mesh sieve. The fines should be non-plastic.
The ground surface in the construction area should be sloped and sealed with a
smooth-drum roller to promote the rapid runoff of precipitation, to prevent surface
water from flowing into excavations, and to prevent ponding of water.
No soil should be left uncompacted and exposed to moisture. A smooth-drum
vibratory roller, or equivalent, should be used to seal the ground surface. Soils which
become too wet for compaction should be removed and replaced with clean granular
soil.
Excavation and placement of structural fill material should be observed on a full-time
basis by a geotechnical engineer or his/her representative, experienced in wet-weather
earthwork, to determine that all work is being accomplished in accordance with the
project plans and specifications, and our recommendations.
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
18
Covering of work areas, soil stockpiles, or slopes with plastic; sloping, ditching, and
installing sumps; dewatering; and other measures should be employed, as necessary,
to permit proper completion of the work. Bales of straw and/or geotextile silt fences
should be aptly located to control soil movement and erosion.
Grading and earthwork should not be accomplished during periods of heavy,
continuous rainfall.
8.10 Plans Review and Construction Observation
We recommend that Shannon & Wilson be retained to review those portions of the plans and
specifications that pertain to the geotechnical aspects of the project to determine if they are
consistent with our recommendations.
We also recommend that we be retained to observe the geotechnical aspects of construction,
particularly the pavement and shallow footing subgrade preparation, drainage installation, and
earthwork (structural fill placement and compaction). This observation would allow us to
witness the subsurface conditions as they are exposed during construction and to determine that
the work is accomplished in accordance with our recommendations.
9.0 LIMITATIONS
This report was prepared for the exclusive use of the Edmonds School District No. 15 for
specific application to the design of the Madrona K-8 School project at this site as it relates to the
geotechnical aspects discussed in this report. The data and report should be provided to
prospective contractors and/or the Contractor for factual information only. Our judgments,
conclusions, and interpretations presented in the report should not be construed as a warranty of
subsurface conditions and should not be relied upon by prospective contractors. Construction
period observation by our firm is necessary to confirm recommendations and interpretations
made in this report.
The analyses, conclusions, and recommendations presented in this report were prepared in
accordance with generally accepted professional geotechnical engineering principles and practice
in this area at this time. No other warranty, either express or implied, is made.
The analyses, conclusions, and recommendations contained in this report are based on site
conditions as they existed during our site visits and explorations, and further assume that the
explorations are representative of the subsurface conditions throughout the site; i.e., the
subsurface conditions everywhere are not significantly different from those disclosed by the
explorations. If subsurface conditions different from those described in this report are observed
21-1-22082-004-R1f.docx/wp/lkn 21-1-22082-004
20
10.0 REFERENCES
American Association of State Highway and Transportation Officials (AASHTO), 1993,
AASHTO guide for design of pavement structures, Washington, D.C., AASHTO, 2 v.
American Concrete Institute (ACI), 2013, Specification for pervious concrete pavement (ACI
522.1): Farmington Hills, Mich., American Concrete Institute, ACI 522.1-13, 7 p.
ASTM International (ASTM), 2012, Standard test methods for laboratory compaction
characteristics of soil using modified effort (56,000 ft-lbf/ft3 (2,700 kN-m/m3)), D1557-
12e1: West Conshohocken, Pa., ASTM International, Annual book of standards, v. 04.08,
soil and rock (I): D420 - D5876, 14 p., available: www.astm.org.
Edmonds, Wash., 2016, Natural resources: Edmonds, Wash., Edmonds City Code and
Development Code Title 23, available: http://www.codepublishing.com/WA/Edmonds/.
International Code Council, Inc., 2014, International building code 2015: Country Club Hills,
Ill., International Code Council, Inc., 700 p.
Kramer, S.L., 1996, Geotechnical earthquake engineering: Upper Saddle River, N.J., Prentice
Hall, 653 p.
Shannon & Wilson, Inc. (Shannon & Wilson), 2016, Hydrogeologic report, new Madrona K-8
project, Edmonds, Washington: Report prepared by Shannon & Wilson, Inc., Seattle,
Wash., 21-1-22082-003, for Edmonds School District No. 15, Edmonds, Wash.,
November.
Troost, K.G., and Booth, D.B., 2008, Geology of Seattle and the Seattle area, Washington, in
Baum, R.L., Godt, J.W. and Highland, L.M., eds., Landslides and Engineering Geology of
the Seattle, Washington, Area: Geologic Society of America Reviews in Engineering
Geology XX, p. 1-35.
Washington State Department of Transportation (WSDOT), 2015, WSDOT Pavement Policy:
Olympia, Washington, WSDOT, 131 p., available:
http://www.wsdot.wa.gov/NR/rdonlyres/EF9AAC9E-6323-4B09-A3D1-
DD2E2C905D02/0/WSDOTPavementPolicyJune2015.pdf
Washington Department of Transportation (WSDOT), 2016, Standard specifications for road,
bridge, and municipal construction: Olympia, Wash., WSDOT, Manual M 41-10, 1 v.,
January, available: http://www.wsdot.wa.gov/Publications/Manuals/M41-10.htm.
99
104
PROJECT
LOCATION
VICINITY MAP
FIG. 1
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
Map adapted from aerial imagery provided by
Google Earth Pro, reproduced by permission
JUDQWHGE\*RRJOH(DUWK0DSSLQJ6HUYLFH
NOTE
October 2016 21-1-22082-004
Fi
l
e
n
a
m
e
:
J
:
\
2
1
1
\
2
2
0
8
2
-
0
0
4
\
2
-
1
-
2
2
0
8
4
-
0
0
4
F
i
g
1
-
V
i
c
M
a
p
.
d
w
g
D
a
t
e
:
1
0
-
0
4
-
2
0
1
6
L
o
g
i
n
:
S
A
C
Edmonds
Washington
Project
Location
90
5
97
MT
0 800 1600
Approximate Scale in Feet
B-12
B-11
TP-3F
PIT-3
TP-2F
EXISTING
BUILDING
23704
TP-9
TP-5
TP-1
TP-13TP-2
TP-4
TP-6
TP-14
TP-3
TP-7
TP-8
TP-10
TP-16 TP-11
TP-15
TP-12
TP-3F
TP-2F
TP-1F
B-2
B-3
B-4
B-5
PIT-1
B-8
B-9
B-6
B-10
PIT-2
PROPOSED
BUILDING
B-7
FIG. 2
FI
G
.
2
SITE AND EXPLORATION PLAN
Filename: J:\211\22082-004\2-1-22084-004 Fig 2 - Site Plan.dwg Layout: Layout Date: 10-04-2016 Login: SAC
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
October 2016 21-1-22082-004
B-1 Boring Designation and
Approximate Location
Test Pit Designation and
Approximate Location (2016)
Infiltration Test Pit Designation
and Approximate Location
Previous Test Pit Designation and
Approximate Location (2015)
LEGEND
NOTE
Figure adapted from client file, Topo
and Survey.dwg, received 10-3-16.
0 100 200
Scale in FeetTP-1F
PIT-3
TP-1
Fi
l
e
:
J
:
\
2
1
1
\
2
2
0
8
2
-
0
0
4
\
2
-
1
-
2
2
0
8
4
-
0
0
4
F
i
g
3
-
R
o
c
k
e
r
y
D
e
t
a
i
l
.
d
w
g
D
a
t
e
:
1
0
-
0
4
-
2
0
1
6
A
u
t
h
o
r
:
S
A
C
Not to Scale
4
12" Min.
6" Min.
1
Clean, well-graded sand and gravel or
crushed rock, 2-inch maximum size, 40 to
60% gravel, less than 5% fines (passing
#200 sieve). Fines shall be non-plastic.
Compact in 4" lifts with minimum of 4
coverages by hand-operated tamper.
Compact to at least 92% of Modified
Proctor maximum dry density (ASTM
D-1557). Backfill and rock placement
should be built up together.
Opening Chinked with
2 to 4-inch Quarry Spalls
Stable Excavation Slope
in Very Dense Native Soil
(Contractor's Responsibility)
Backfill
H/3 Min. Width
for Base Rock
All loose soil at rockery foundation subgrade should be
overexcavated down to medium dense to very dense
soil and replaced with compacted backfill as described
above. The excavation shall be kept free of water.
The prepared foundation subgrade shall be evaluated
by a soils engineer prior to placement of rock.
8" Compacted Native
or Imported Soil
(Impervious Surface Layer)
16" Min. Width
for Top Rock
H = 6 Ft. Max.
Medium
dense to
Very Dense
Native Soil
6" Diameter Slotted Pipe
Bedded in washed 3/8" to No.8 sieve size
pea gravel (6" cover around pipe), sloped to
drain and connected by tightline to storm
drain outfall or other appropriate outlets.
No fabric around pipe.
Maximum slot width is 1/8".
Very Dense
Undisturbed Native Soil
Rock shall be sound and have a minimum
density of 160 pounds per cubic foot.
MINIMUM WEIGHT OF ROCK
TYPICAL ROCKERY DETAIL
FIG. 3
Ditch Drain to
Appropriate Outlets
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
October 2016 21-1-22082-004
PIT Results-Figure 4 PIT-1 Plot-9/28/2016-pvh
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 200 400 600 800 1000 1200 1400
Me
a
s
u
r
e
d
I
n
f
l
o
w
R
a
t
e
(
G
P
M
)
W
a
t
e
r
H
e
i
g
h
t
A
b
o
v
e
B
o
t
t
o
m
o
f
T
e
s
t
P
i
t
F
l
o
o
r
(
F
e
e
t
)
Time Since Start of Saturation (Minutes)
Transducer
Reading (Feet)
Manual Reading
(Feet)
Inflow Rate (GPM)
FI
G
.
4
Geotechnical Report
New Madrona K-8 Project
Edmonds,Washington
MEASURED WATER LEVEL
PILOT INFILTRATION TEST
PIT-1
September 2016 21-1-22082-004
FIG. 4SHANNON& WILSON, INC.
Geotechnical and Environmental Consultants
NOTE
1. This small-scale pilot infiltration test (PIT) was performed on 7/28/16. Water was added from 10:31
to 19:28. Approximate grade elevation 444.5 feet (NAVD88). Test pit floor depth 3.8 feet deep.
A flow rate of 0.75 to 0.12 gallons per minute (gpm) was maintained for the initial saturation period. During
the last hour of saturation, the flow rate was 0.11 gpm, with a water level of 14.25 inches above the test pit
bottom. Test test pit drained from 19:28 on 7/28/16 to about 6:00 on 7/29/16.
Test pit dimensions during the PIT were approximately 2.4 feet (north-south) by 5.5 feet (east-
west), or 13.2 square feet. The test pit was over-excavated on 7/29/16 (starting at 8:30) to 10 feet deep.
No sign of water was observed during over-excavation.
Transducer was inside a stilling tube.
Approx. 5" mud accumulated around
the tube bottom by end of test.
Water level in tube fell below
surrounding mud level.
Residual water
perched on silt
muck at test
pit bottom. Soils
immediately below
were moist.
PIT Results-Figure 5 PIT-2 Plot-9/28/2016-pvh
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 200 400 600 800 1000 1200 1400 1600
Me
a
s
u
r
e
d
I
n
f
l
o
w
R
a
t
e
(
G
P
M
)
W
a
t
e
r
H
e
i
g
h
t
A
b
o
v
e
B
o
t
t
o
m
o
f
T
e
s
t
P
i
t
F
l
o
o
r
(
F
e
e
t
)
Time Since Start of Saturation (Minutes)
Transducer
Reading (Feet)
Manual Reading
(Feet)
Inflow Rate (GPM)
FI
G
.
5
Geotechnical Report
New Madrona K-8 Project
Edmonds,Washington
MEASURED WATER LEVEL
PILOT INFILTRATION TEST
PIT-2
September 2016 21-1-22082-004
FIG. 5SHANNON& WILSON, INC.
Geotechnical and Environmental Consultants
NOTE
1. This small-scale pilot infiltration test (PIT) was performed on 7/28/16. Water was added from 11:28
to 18:53. Approximate grade elevation 456 feet (NAVD88). Test pit floor depth 3.3 feet deep.
A flow rate of 3.75 to 0.04 gallons per minute (gpm) was maintained for the initial saturation period. During
the last hour of saturation, the flow rate was 0.04 gpm, with a water level of 15.75 inches above the test pit
bottom. Test test pit drained from 18:53 on 7/28/16 to about 11:50 on 7/29/16.
Test pit dimensions during the PIT were approximately 2.1 feet (north-south) by 6.3 feet (east-
west), or 13.2 square feet. The test pit was over-excavated on 7/29/16 to 4.5 feet deep. The back hoe
scooped out the residual PIT water and found that it had been perched on moist till.
Residual water
remaining in test pit
over 16 hours after
ceasing inflow.
PIT Results-Figure 6 PIT-3 Plot-9/28/2016-pvh
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 200 400 600 800 1000 1200 1400
Me
a
s
u
r
e
d
I
n
f
l
o
w
R
a
t
e
(
G
P
M
)
W
a
t
e
r
H
e
i
g
h
t
A
b
o
v
e
B
o
t
t
o
m
o
f
T
e
s
t
P
i
t
F
l
o
o
r
(
F
e
e
t
)
Time Since Start of Saturation (Minutes)
Transducer
Reading (Feet)
Manual Reading
(Feet)
Inflow Rate (GPM)
FI
G
.
6
Geotechnical Report
New Madrona K-8 Project
Edmonds,Washington
MEASURED WATER LEVEL
PILOT INFILTRATION TEST
PIT-3
September 2016 21-1-22082-004
FIG. 6SHANNON& WILSON, INC.
Geotechnical and Environmental Consultants
NOTE
1. This small-scale pilot infiltration test (PIT) was performed on 7/28/16. Water was added from 13:07
to 20:38. Approximate grade elevation 450 feet (NAVD88). Test pit floor depth 2.9 feet deep.
A flow rate of 3.33 to 0.06 gallons per minute (gpm) was maintained for the initial saturation period. During
the last hour of saturation, the flow rate was 0.06 gpm, with a water level of 16.2 inches above the test pit
bottom. Test test pit drained from 20:38 on 7/28/16 to about 12:36 on 7/29/16 when we removed the
transducer. Inital ponded area dimensions during the PIT were approximately 2.2 feet (east-west) by 8 feet
(north-south), or 17.6 square feet. Due to sidewall slumping during the falling head test period, the final
ponded dimensions were approximate 2.5 feet by 8.2 feet (20.5 square feet). The test pit was over-excavated
on 7/29/16 to 3.4 feet deep. The back hoe scooped out the residual PIT water and found that it had
been perched on moist till.
Residual water
remaining in test pit
over 16 hours after
ceasing inflow.
21-1-22082-004
APPENDIX A
SUBSURFACE EXPLORATIONS
October 2016 21-1-22082-004
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
1Gravel, sand, and fines estimated by mass. Other constituents, such as
organics, cobbles, and boulders, estimated by volume.
2Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for
Description and Identification of Soils (Visual-Manual Procedure), copyright
ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA
19428. A copy of the complete standard may be obtained from ASTM
International, www.astm.org.
140 pounds with a 30-inch free fall.
Rope on 6- to 10-inch-diam. cathead
2-1/4 rope turns, > 100 rpm
NOTE: If automatic hammers are
used, blow counts shown on boring
logs should be adjusted to account for
efficiency of hammer.
10 to 30 inches long
Shoe I.D. = 1.375 inches
Barrel I.D. = 1.5 inches
Barrel O.D. = 2 inches
Sum blow counts for second and third
6-inch increments.
Refusal: 50 blows for 6 inches or
less; 10 blows for 0 inches.
RELATIVE
CONSISTENCY
N, SPT,
BLOWS/FT.5% to 12%
fine-grained:
with Silt or
with Clay 3
15% or more of a
second coarse-
grained constituent:
with Sand or
with Gravel 5
< 5%
5 to 10%
15 to 25%
30 to 45%
50 to 100%
Surface Cement
Seal
Asphalt or Cap
Slough
Inclinometer or
Non-perforated Casing
Vibrating Wire
Piezometer
N, SPT,
BLOWS/FT.
< 4
4 - 10
10 - 30
30 - 50
> 50
DESCRIPTION
< #200 (0.075 mm = 0.003 in.)
#200 to #40 (0.075 to 0.4 mm; 0.003 to 0.02 in.)
#40 to #10 (0.4 to 2 mm; 0.02 to 0.08 in.)
#10 to #4 (2 to 4.75 mm; 0.08 to 0.187 in.)
SIEVE NUMBER AND/OR APPROXIMATE SIZE
#4 to 3/4 in. (4.75 to 19 mm; 0.187 to 0.75 in.)
3/4 to 3 in. (19 to 76 mm)
3 to 12 in. (76 to 305 mm)
> 12 in. (305 mm)
Fine
Coarse
Fine
Medium
Coarse
BOULDERS
COBBLES
GRAVEL
FINES
SAND
Sheet 1 of 3
CONSTITUENT2
SOIL DESCRIPTION
AND LOG KEY
SHANNON & WILSON, INC.Geotechnical and Environmental Consultants
Absence of moisture, dusty, dry
to the touch
Damp but no visible water
Visible free water, from below
water table
FIG. A-1
Shannon & Wilson, Inc. (S&W), uses a soil
identification system modified from the Unified
Soil Classification System (USCS). Elements of
the USCS and other definitions are provided on
this and the following pages. Soil descriptions
are based on visual-manual procedures (ASTM
D2488) and laboratory testing procedures
(ASTM D2487), if performed.
STANDARD PENETRATION TEST (SPT)
SPECIFICATIONS
Hammer:
Sampler:
N-Value:
Dry
Moist
Wet
MOISTURE CONTENT TERMS
Modifying
(Secondary)
Precedes major
constituent
Major
Minor
Follows major
constituent
1All percentages are by weight of total specimen passing a 3-inch sieve.2The order of terms is: Modifying Major with Minor.3Determined based on behavior.4Determined based on which constituent comprises a larger percentage.5Whichever is the lesser constituent.
COARSE-GRAINED
SOILS
(less than 50% fines)1
NOTE: Penetration resistances (N-values) shown on
boring logs are as recorded in the field and
have not been corrected for hammer
efficiency, overburden, or other factors.
PARTICLE SIZE DEFINITIONS
RELATIVE DENSITY / CONSISTENCYSand or Gravel 4
30% or more
coarse-grained:
Sandy or Gravelly 4
More than 12%
fine-grained:
Silty or Clayey 3
15% to 30%
coarse-grained:
with Sand or
with Gravel 4
30% or more total
coarse-grained and
lesser coarse-
grained constituent
is 15% or more:
with Sand or
with Gravel 5
Very soft
Soft
Medium stiff
Stiff
Very stiff
Hard
Very loose
Loose
Medium dense
Dense
Very dense
RELATIVE
DENSITY
FINE-GRAINED SOILS
(50% or more fines)1
COHESIVE SOILS
< 2
2 - 4
4 - 8
8 - 15
15 - 30
> 30
COHESIONLESS SOILS
Silt, Lean Clay,
Elastic Silt, or
Fat Clay 3
PERCENTAGES TERMS 1, 2
Trace
Few
Little
Some
Mostly
WELL AND BACKFILL SYMBOLS
Bentonite
Cement Grout
Bentonite Grout
Bentonite Chips
Silica Sand
Perforated or
Screened Casing
S&W INORGANIC SOIL CONSTITUENT DEFINITIONS
20
1
3
_
B
O
R
I
N
G
_
C
L
A
S
S
1
2
1
-
22
0
8
2
.G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
5
/
1
5
/
1
4
October 2016 21-1-22082-004
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
GC
SC
Inorganic
Organic
(more than 50%of coarsefraction retainedon No. 4 sieve)
MAJOR DIVISIONS GROUP/GRAPHICSYMBOL
CH
OH
ML
CL
TYPICAL IDENTIFICATIONS
Gravel
Sand
Silty Sand; Silty Sand with Gravel
Clayey Sand; Clayey Sand with Gravel
Clayey Gravel; Clayey Gravel withSand
Sheet 2 of 3
Gravels
Primarily organic matter, dark incolor, and organic odor
SW
(more than 12%fines)
Silts and Clays
Silts and Clays
(more than 50%retained on No.200 sieve)
(50% or more of
coarse fraction
passes the No. 4
sieve)
(liquid limit less
than 50)
(liquid limit 50 ormore)
Organic
Inorganic
FINE-GRAINEDSOILS
SM
Sands
Silty or ClayeyGravel
Silt; Silt with Sand or Gravel; Sandy orGravelly Silt
Organic Silt or Clay; Organic Silt orClay with Sand or Gravel; Sandy orGravelly Organic Silt or Clay
HIGHLY-ORGANIC SOILS
COARSE-GRAINEDSOILS
OL
(less than 5%
fines)
GW
Geotechnical and Environmental Consultants
SHANNON & WILSON, INC.
(less than 5%fines)
PT
FIG. A-1
(more than 12%
fines)
MH
SP
GP
GM
Silty orClayey Sand
Silty Gravel; Silty Gravel with Sand
(50% or more
passes the No.
200 sieve)
SOIL DESCRIPTION
AND LOG KEY
Elastic Silt; Elastic Silt with Sand or
Gravel; Sandy or Gravelly Elastic Silt
Fat Clay; Fat Clay with Sand or
Gravel; Sandy or Gravelly Fat Clay
Organic Silt or Clay; Organic Silt or
Clay with Sand or Gravel; Sandy or
Gravelly Organic Silt or Clay
Poorly Graded Sand; Poorly Graded
Sand with Gravel
Well-Graded Sand; Well-Graded Sand
with Gravel
Well-Graded Gravel; Well-GradedGravel with Sand
Poorly Graded Gravel; Poorly GradedGravel with Sand
Lean Clay; Lean Clay with Sand or
Gravel; Sandy or Gravelly Lean Clay
NOTES
1. Dual symbols (symbols separated by a hyphen, i.e., SP-SM, Sand
with Silt) are used for soils with between 5% and 12% fines or when
the liquid limit and plasticity index values plot in the CL-ML area of
the plasticity chart. Graphics shown on the logs for these soil types
are a combination of the two graphic symbols (e.g., SP and SM).
2. Borderline symbols (symbols separated by a slash, i.e., CL/ML,
Lean Clay to Silt; SP-SM/SM, Sand with Silt to Silty Sand) indicate
that the soil properties are close to the defining boundary between
two groups.
Peat or other highly organic soils (see
ASTM D4427)
20
1
3
_
B
O
R
I
N
G
_
C
L
A
S
S
2
2
1
-2
2
0
8
2
.G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
5
/
1
5
/
1
4
NOTE: No. 4 size = 4.75 mm = 0.187 in.; No. 200 size = 0.075 mm = 0.003 in.
UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)
(Modified From USACE Tech Memo 3-357, ASTM D2487, and ASTM D2488)
October 2016 21-1-22082-004
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
SHANNON & WILSON, INC.Geotechnical and Environmental Consultants FIG. A-1
Sheet 3 of 3
SOIL DESCRIPTION
AND LOG KEY
1Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for
Description and Identification of Soils (Visual-Manual Procedure), copyright
ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A
copy of the complete standard may be obtained from ASTM International,
www.astm.org.
2Adapted, with permission, from ASTM D2488 - 09a Standard Practice for
Description and Identification of Soils (Visual-Manual Procedure), copyright
ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A
copy of the complete standard may be obtained from ASTM International,
www.astm.org.
Interbedded
Laminated
Fissured
Slickensided
Blocky
Lensed
Homogeneous
ATD
Diam.
Elev.
ft.
FeO
gal.
Horiz.
HSA
I.D.
in.
lbs.
MgO
mm
MnO
NA
NP
O.D.
OW
pcf
PID
PMT
ppm
psi
PVC
rpm
SPT
USCS
qu
VWP
Vert.
WOH
WOR
Wt.
Crumbles or breaks with handling or slight
finger pressure.
Crumbles or breaks with considerable finger
pressure.
Will not crumble or break with finger
pressure.
PLASTICITY2
CEMENTATION TERMS1
GRADATION TERMS
STRUCTURE TERMS1
ACRONYMS AND ABBREVIATIONS
Alternating layers of varying material or
color with layers at least 1/4-inch thick;
singular: bed.
Alternating layers of varying material or
color with layers less than 1/4-inch thick;
singular: lamination.
Breaks along definite planes or fractures
with little resistance.
Fracture planes appear polished or
glossy; sometimes striated.
Cohesive soil that can be broken down
into small angular lumps that resist further
breakdown.
Inclusion of small pockets of different
soils, such as small lenses of sand
scattered through a mass of clay.
Same color and appearance throughout.
Narrow range of grain sizes present or, within
the range of grain sizes present, one or more
sizes are missing (Gap Graded). Meets
criteria in ASTM D2487, if tested.
Full range and even distribution of grain sizes
present. Meets criteria in ASTM D2487, if
tested.
Poorly Graded
Well-Graded
Weak
Moderate
Strong
Irregular patches of different colors.
Soil disturbance or mixing by plants or
animals.
Nonsorted sediment; sand and gravel in silt
and/or clay matrix.
Material brought to surface by drilling.
Material that caved from sides of borehole.
Disturbed texture, mix of strengths.
VISUAL-MANUAL CRITERIA
A 1/8-in. thread cannot be rolled
at any water content.
A thread can barely be rolled and
a lump cannot be formed when
drier than the plastic limit.
A thread is easy to roll and not
much time is required to reach
the plastic limit. The thread
cannot be rerolled after reaching
the plastic limit. A lump
crumbles when drier than the
plastic limit.
It takes considerable time rolling
and kneading to reach the plastic
limit. A thread can be rerolled
several times after reaching the
plastic limit. A lump can be
formed without crumbling when
drier than the plastic limit.
Sharp edges and unpolished planar surfaces.
Similar to angular, but with rounded edges.
Nearly planar sides with well-rounded edges.
Smoothly curved sides with no edges.
Width/thickness ratio > 3.
Length/width ratio > 3.
PARTICLE ANGULARITY AND SHAPE TERMS1
ADDITIONAL TERMS
Angular
Subangular
Subrounded
Rounded
Flat
Elongated
DESCRIPTION
Nonplastic
Low
Medium
High
At Time of Drilling
Diameter
Elevation
Feet
Iron Oxide
Gallons
Horizontal
Hollow Stem Auger
Inside Diameter
Inches
Pounds
Magnesium Oxide
Millimeter
Manganese Oxide
Not Applicable or Not Available
Nonplastic
Outside Diameter
Observation Well
Pounds per Cubic Foot
Photo-Ionization Detector
Pressuremeter Test
Parts per Million
Pounds per Square Inch
Polyvinyl Chloride
Rotations per Minute
Standard Penetration Test
Unified Soil Classification System
Unconfined Compressive Strength
Vibrating Wire Piezometer
Vertical
Weight of Hammer
Weight of Rods
Weight
Mottled
Bioturbated
Diamict
Cuttings
Slough
Sheared
APPROX.
PLASITICITY
INDEX
RANGE
< 4
4 to 10
10 to 20
> 20
20
1
3
_
B
O
R
I
N
G
_
C
L
A
S
S
3
2
1
-
22
0
8
2
.G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
5
/
1
5
/
1
4
0.4
4.5
16.5
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Asphalt.
Dense, red-brown, Silty Sand with Gravel
(SM); moist; fine, subrounded to subangular
gravel; fine to coarse sand; nonplastic fines;
few organics.
Topsoil/Weathered Glacial Till
Very dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine, subrounded to
angular gravel; fine to coarse sand; nonplastic
fines; diamict.
Glacial Till
- Moist to wet below about 15 feet.
BOTTOM OF BORING
COMPLETED 7/26/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-2
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-2SHANNON & WILSON, INC.
16.5 ft.
~ 449 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
94/9"
90/10"
88/10"
50/4"
0.4
4.5
15.9
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Asphalt.
Dense, gray-brown, Silty Sand with Gravel
(SM); moist; fine to coarse, subrounded to
subangular gravel; fine to coarse sand;
nonplastic fines; diamict.
Weathered Glacial Till
Very dense, gray-brown, Silty Sand (SM) to
Silty Sand with Gravel (SM); moist; fine,
subrounded to subangular gravel; fine to
coarse sand; nonplastic fines; diamict.
Glacial Till
- Diamict pockets from 7.5 to 9 feet.
- Moist to wet below about 15 feet.
BOTTOM OF BORING
COMPLETED 7/26/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-3
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-3SHANNON & WILSON, INC.
15.9 ft.
~ 447.5 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
50/6"
50/6"
50/5"
50/5"
0.4
9.5
15.8
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Asphalt.
Medium dense, brown, Silty Sand (SM) to Silty
Sand with Gravel (SM); moist; fine to coarse,
subrounded to angular gravel; fine to coarse
sand; nonplastic fines; trace to few organics;
trace diamict pockets below about 7 feet.
Fill
Very dense, gray-brown, Silty Sand (SM) to
Silty Sand with Gravel (SM); moist; fine,
subrounded to subangular gravel; fine to
coarse sand; nonplastic fines; diamict.
Glacial Till
BOTTOM OF BORING
COMPLETED 7/26/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-4
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-4SHANNON & WILSON, INC.
15.8 ft.
~ 445 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
90
78
50/3"
0.5
4.5
7.0
16.0
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Topsoil.
Medium dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine, subrounded to
angular gravel; fine to coarse sand; nonplastic
fines; trace organics.
Fill
Loose, red-brown, Silty Sand with Gravel
(SM); moist; fine, subrounded to subangular
gravel; fine to coarse sand; nonplastic fines;
trace organics.
Topsoil/Weathered Glacial Till
Dense to very dense, gray-brown, Silty Sand
(SM) to Silty Sand with Gravel (SM); moist;
fine, subrounded to subangular gravel; fine to
coarse sand; nonplastic fines; diamict.
Glacial Till
- Slight iron oxide staining from 7 to 9 feet.
- Moist to wet below about 15 feet.
BOTTOM OF BORING
COMPLETED 7/26/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-5
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-5SHANNON & WILSON, INC.
16 ft.
~ 447 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
50/5"
83/9"
50/6"
9.0
15.9
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Medium dense to very dense, gray-brown,
Silty Sand with Gravel (SM); moist; fine,
subrounded to subangular gravel; fine to
coarse sand; nonplastic fines; diamict.
Weathered Glacial Till
Very dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine, subrounded to
angular gravel; fine to coarse sand; nonplastic
fines; diamict.
Glacial Till
BOTTOM OF BORING
COMPLETED 7/25/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-6
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-6SHANNON & WILSON, INC.
15.9 ft.
~ 455 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
68/11"
84/10"
50/5"
0.2
4.5
15.9
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Asphalt.
Medium dense, brown, Silty Sand (SM); moist;
few fine, subrounded to subangular gravel;
fine to coarse sand; nonplastic to low plasticity
fines; diamict; trace organics.
Topsoil/Weathered Glacial Till
Very dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine to coarse, subrounded
to subangular gravel; fine to coarse sand;
nonplastic fines.
Glacial Till
- Trace pockets of poorly graded sand with silt
below about 15 feet.
BOTTOM OF BORING
COMPLETED 7/26/2016
*
*
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-7
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-7SHANNON & WILSON, INC.
15.9 ft.
~ 454 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
50/3"
50/5"
50/4"
50/5"
50/5"
0.2
15.8
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Asphalt.
Very dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine to coarse, subrounded
to angular gravel; fine to coarse sand;
nonplastic fines; diamict.
Glacial Till
- Gray below about 12 feet.
BOTTOM OF BORING
COMPLETED 7/25/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-8
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-8SHANNON & WILSON, INC.
15.8 ft.
~ 456 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
50/3"
50/5"
50/4"
50/3"
50/2"
50/4"
0.5
7.0
15.5
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Topsoil.
Dense to very dense, brown and gray, Silty
Sand with Gravel (SM); dry to moist; fine to
coarse, subrounded to angular gravel; fine to
coarse sand; nonplastic fines; trace organics;
diamict pockets.
Fill/Weathered Glacial Till
Very dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine to coarse, subrounded
to subangular gravel; fine to coarse sand;
nonplastic fines; diamict.
Glacial Till
- Few pockets of poorly graded, fine to
medium sand with silt pockets below about
12 feet; moist to wet from about 12 to 14
feet.
BOTTOM OF BORING
COMPLETED 7/25/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-9
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-9SHANNON & WILSON, INC.
15.5 ft.
~ 456 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
78
91/11"
62
50/4"
50/6"
0.5
7.0
15.8
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Topsoil.
Medium dense, brown, Silty Sand (SM); dry to
moist; few fine, subrounded to subangular
gravel; fine to medium sand; nonplastic fines;
diamict pockets; trace organics.
Fill
- Roots at about 5 feet.
Very dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine to coarse, subrounded
to angular gravel; fine to coarse sand;
nonplastic fines; diamict.
Glacial Till
- Mottled orange and gray-brown with pockets
of iron oxide staining from 7 to 9 feet.
BOTTOM OF BORING
COMPLETED 7/25/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-10
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-10SHANNON & WILSON, INC.
15.8 ft.
~ 454.5 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
71/9"
50/5"
50/3"
50/4"
0.5
4.5
16.4
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Topsoil.
Dense, gray-brown, Silty Sand with Gravel
(SM); moist; fine, subrounded to subangular
gravel; fine to coarse sand; nonplastic fines;
diamict.
Weathered Glacial Till
Very dense, gray-brown, Silty Sand (SM) to
Silty Sand with Gravel (SM); moist; fine,
subrounded to subangular gravel; fine to
coarse sand; nonplastic fines; diamict.
Glacial Till
BOTTOM OF BORING
COMPLETED 7/25/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-11
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-11SHANNON & WILSON, INC.
16.4 ft.
~ 456 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
84/11"
62
50/6"
50/5"
85/5"
0.5
4.5
16.3
No
n
e
O
b
s
e
r
v
e
d
D
u
r
i
n
g
D
r
i
l
l
i
n
g
1
2
3
4
5
6
Topsoil.
Medium dense, brown, Silty Sand with Gravel
(SM); dry to moist; fine, subrounded to
subangular gravel; fine to medium sand;
nonplastic fines; trace organics.
Fill
Very dense, gray-brown, Silty Sand with
Gravel (SM); moist; fine, subrounded to
subangular gravel; fine to coarse sand;
nonplastic fines; diamict.
Glacial Till
- Trace organics from about 4.5 to 8.5 feet.
BOTTOM OF BORING
COMPLETED 7/25/2016
De
p
t
h
,
f
t
.
Geotechnical Report
New Madrona K-8 Project
Edmonds, Washington
De
p
t
h
,
f
t
.
2
4
6
8
10
12
14
16
18
Drilling Method:
Drilling Company:
Drill Rig Equipment:
Other Comments:
Lo
g
:
K
J
W
Northing:
Easting:
Station:
Offset:
SOIL DESCRIPTION
20 40 60
Sa
m
p
l
e
s
6 in.
2-inch
Refer to the report text for a proper understanding of the
subsurface materials and drilling methods. The stratification
lines indicated below represent the approximate boundaries
between material types, and the transition may be gradual.
*
LOG OF BORING B-12
0 60
0
Total Depth:
Top Elevation:
Vert. Datum:
Horiz. Datum:
Gr
o
u
n
d
Wa
t
e
r
NOTES
20 40
2.0" O.D. Split Spoon Sample
Hole Diam.:
Rod Diam.:
Hammer Type:
LEGEND
Sy
m
b
o
l
1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions.
2. Groundwater level, if indicated above, is for the date specified and may vary.
3. USCS designation is based on visual-manual classification and selected lab testing.
Hollow Stem Auger
Holocene Drilling
Diedrich D-50
FIG. A-12SHANNON & WILSON, INC.
16.3 ft.
~ 456 ft.
NAVD 88
Re
v
:
E
A
S
September 2016 21-1-22082-004
Ty
p
:
L
K
N
Geotechnical and Environmental Consultants
Sample Not Recovered
REV 3 - Approved for Submittal
MA
S
T
E
R
_
L
O
G
_
E
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
1
0
/
3
/
1
6
PENETRATION RESISTANCE
Hammer Wt. & Drop:
(blows/foot)
140 lbs / 30 inches
% Water Content
% Fines (<0.075mm)
50/6"
50/5"
50/2"
90/9"
LOG OF TEST PIT PIT-1
SOIL DESCRIPTION
Sketch of ________ Pit Side
0 2 4 6 8 10 12
Horizontal Distance in Feet
Gr
o
u
n
d
Wa
t
e
r
%
W
a
t
e
r
Co
n
t
e
n
t
Sa
m
p
l
e
s
De
p
t
h
,
F
t
.
0
2
4
6
8
10
12
Topsoil and grass.
Dense, brown, Silty Sand with
Gravel (SM); moist.
Fill (Reworked Till)
Very loose to dense, brown-gray,
Silty Sand with Gravel and Cobbles
(SM); moist; few cobbles, fine to
coarse subrounded to subangular
gravel; fine to coarse sand;
non-plastic fines; minor iron-oxide
staining at 3.8 feet; diamict pockets.
Fill
Medium dense to dense, brown to
red-brown, Silty Sand with Gravel
(SM); moist; fine to coarse
subrounded to angular gravel; fine
to coarse sand; non-plastic fines.
Fill
Medium dense to dense, red-brown
to brown, Silty Sand with Gravel
and Cobbles (SM); moist; few
rounded cobbles; fine to coarse
subrounded to subangular gravel;
fine to coarse sand; non-plastic
fines; roots and conifer duff at top.
Weathered Till
2
3
S-1
North
No
n
e
O
b
s
e
r
v
e
d
FI
G
.
A
-
13
1
File: J:\211\22082-004\2-1-22084-004 TPs.dwg Date: 08-30-2016 Author: SAC
3
4
5
Fine Roots
JOB NO:DATE:
PROJECT:Madrona K-8
LOCATION:See Site and Exploration Plan
Surface Elevation: Approx. 445 Ft.
4
5
1
2
S-2
S-3
S-4
S-5
S-6
S-7
Test Pit Floor During
Pilot Infiltration Test (PIT)
T-Probe 1" Penetration (before PIT)
T-Probe 2.5" Penetration (after PIT)
T-Probe 1.5" Penetration (after PIT)
T-Probe 0.5" Penetration (after PIT)
T-Probe 17" Penetration (after PIT)
Roots and Conifer
Duff/Needles
1. Small-scale PIT performed
at 3.8 feet on 7-28/7-29-16.
2. PIT ponded area 2.4' x 5.5'.
NOTES
21-1-22082-004 7-28-16 to
7-29-16
Test Pit Floor After PIT
LOG OF TEST PIT PIT-2
SOIL DESCRIPTION
Sketch of ________ Pit Side
0 2 4 6 8 10 12
Horizontal Distance in Feet
Gr
o
u
n
d
Wa
t
e
r
%
W
a
t
e
r
Co
n
t
e
n
t
Sa
m
p
l
e
s
De
p
t
h
,
F
t
.
0
2
4
6
8
10
12
Topsoil.
Very dense, brown to gray-brown,
Silty Sand with Gravel and Cobbles
(SM); dry to moist; few cobbles; fine to
coarse subrounded to subangular
gravel; fine to medium sand;
non-plastic fines; diamict.
Till
2
North
No
n
e
O
b
s
e
r
v
e
d
FI
G
.
A
-
14
1
File: J:\211\22082-004\2-1-22084-004 TPs.dwg Date: 08-30-2016 Author: SAC
JOB NO:DATE:21-1-22082-004 7-28-16 to
7-29-16PROJECT:Madrona K-8
LOCATION:See Site and Exploration Plan
Surface Elevation: Approx. 456 Ft.
1
2
Test Pit Floor During
Pilot Infiltration Test (PIT)
T-Probe 0.5" Penetration (after PIT)
T-Probe 0" Penetration (after PIT)
Test Pit Floor After PIT
1. Small-scale PIT performed
at 3.3 feet on 7-28/7-29-16.
2. PIT ponded area 2.1' x 6.3'.
NOTES
S-1
S-2
LOG OF TEST PIT PIT-3
SOIL DESCRIPTION
Sketch of ________ Pit Side
0 2 4 6 8 10 12
Horizontal Distance in Feet
Gr
o
u
n
d
Wa
t
e
r
%
W
a
t
e
r
Co
n
t
e
n
t
Sa
m
p
l
e
s
De
p
t
h
,
F
t
.
0
2
4
6
8
10
12
Topsoil.
Medium dense to dense, brown, Silty
Sand with Gravel (SM); dry to moist;
scattered cobbles and boulders.
Fill (Reworked Till)
Very dense, gray-brown, Silty Sand
with Gravel and Cobbles and
Boulders (SM); dry to moist; few
cobbles and boulders; fine to coarse
subrounded to subangular gravel;
fine to coarse sand; non-plastic fines;
diamict.
Weathered Till to Till
2
West
No
n
e
O
b
s
e
r
v
e
d
FI
G
.
A
-
15
1
File: J:\211\22082-004\2-1-22084-004 TPs.dwg Date: 08-30-2016 Author: SAC
1. Small-scale PIT performed at 2.9 feet on
7-28/7-29-16.
2. PIT ponded area 2.2' x 8.0' on 7-28-16.
PIT ponded area 2.5' x 8.2' on 7-29-16.
NOTES
JOB NO:DATE:
PROJECT:Madrona K-8
LOCATION:See Site and Exploration Plan
Surface Elevation: Approx. 450 Ft.
1
2
Test Pit Floor During
Pilot Infiltration Test (PIT)
T-Probe 0.5" Penetration (after PIT)
Test Pit Floor After PIT3
T-Probe 0" Penetration (after PIT)
3
21-1-22082-004 7-28-16 to
7-29-16
S-1
S-2
LOG OF TEST PIT TP-1F
SOIL DESCRIPTION
Sketch of ________ Pit Side
0 2 4 6 8 10 12
Horizontal Distance in Feet
Gr
o
u
n
d
Wa
t
e
r
%
W
a
t
e
r
Co
n
t
e
n
t
Sa
m
p
l
e
s
De
p
t
h
,
F
t
.
0
2
4
6
8
10
12
Topsoil
Loose to medium dense, brown
Silty Sand with Gravel (SM); moist.
Fill
Very dense, gray to gray-brown,
Silty Sand with Gravel, Cobbles,
and Boulders (SM); moist; fine to
coarse, subrounded to subangular
gravel; fine to coarse sand;
nonplastic fines; diamict.
Till
2
3
East
No
t
E
n
c
o
u
n
t
e
r
e
d
FI
G
.
A
-
1
6
1
File: J:\211\22082-004\PDFs 2016-09-06\2-1-22084-004 TP-XF.dwg Date: 09-06-2016 Author: drtemp
JOB NO:DATE:
PROJECT:Madrona K-8
LOCATION:Edmonds, WA
Surface Elevation: Approx.
S-1
1. 9 feet long and 4'-6" wide.
2. 6-inch diameter concrete storm
drain encountered 3 feet below
ground surface. Repaired with
SDR 35 pipe and rubber coupling.
NOTES
21-1-22082-004 7-28-16
3
1
Broke/Repaired
Storm Drain Pipe
2
LOG OF TEST PIT TP-2F
SOIL DESCRIPTION
Sketch of ________ Pit Side
0 2 4 6 8 10 12
Horizontal Distance in Feet
Gr
o
u
n
d
Wa
t
e
r
%
W
a
t
e
r
Co
n
t
e
n
t
Sa
m
p
l
e
s
De
p
t
h
,
F
t
.
0
2
4
6
8
10
12
Topsoil
Loose to medium dense, brown,
Silty Sand with Gravel (SM); moist;
fine to coarse, subrounded to
subangular gravel; fine to coarse
sand; nonplastic fines.
Fill
Very dense, gray to gray-brown,
Silty Sand with Gravel (SM); moist;
diamict.
Till
Cobbles present.
2
3
East
No
n
e
FI
G
.
A
-
1
7
1
File: J:\211\22082-004\PDFs 2016-09-06\2-1-22084-004 TP-XF.dwg Date: 09-06-2016 Author: drtemp
JOB NO:DATE:
PROJECT:Madrona K-8
LOCATION:Edmonds, WA
Surface Elevation: Approx.
S-1
1. 9 Feet long and 4'-6" wide.
NOTES
21-1-22082-004 7-28-16
1
2
3
LOG OF TEST PIT TP-3F
SOIL DESCRIPTION
Sketch of ________ Pit Side
0 2 4 6 8 10 12
Horizontal Distance in Feet
Gr
o
u
n
d
Wa
t
e
r
%
W
a
t
e
r
Co
n
t
e
n
t
Sa
m
p
l
e
s
De
p
t
h
,
F
t
.
0
2
4
6
8
10
12
Loose to medium dense, brown,
Poorly Graded Sand with Silt and
Gravel (SP-SM); dry to moist; few
roots.
Fill
Very dense, gray-brown; Silty Sand
with Gravel (SM); moist; diamict.
Till
2
S-1
South
No
t
E
n
c
o
u
n
t
e
r
e
d
FI
G
.
A
-
1
8
1
File: J:\211\22082-004\PDFs 2016-09-06\2-1-22084-004 TP-XF.dwg Date: 09-06-2016 Author: drtemp
JOB NO:DATE:
PROJECT:Madrona K-8
LOCATION:Edmonds, WA
Surface Elevation: Approx.
S-2
NOTES
21-1-22082-004 8-25-16
1
2
Roots
21-1-22082-004
APPENDIX B
LABORATORY TEST RESULTS
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
7.5
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFLAKV8.7345511
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand
USCS
Group Name
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
BORING B-3
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
B-3, S-31
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
5.0
10.0
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFL
JFL
AKV
AKV
10.2
9.7
41529
40
64
50
8
10
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand
Silty Sand
USCS
Group Name
D422
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
BORING B-4
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
B-4, S-21
B-4, S-41
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
7.5
15.0
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFL
JFL
AKV
AKV
15.0
10.0
82232
33
54
52
14
15
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand
Silty Sand with Gravel
USCS
Group Name
D422
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
BORING B-5
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
B-5, S-31
B-5, S-61
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
5.0
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFLAKV8.1345313
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand
USCS
Group Name
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
BORING B-11
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
B-11, S-111
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
3.0
7.0 13
1 Test specimen did not meet minimum mass recommendations. 2 Cobble percentages are calculated using the pre-removal, oven-dried mass of the
total specimen. USCS Group Symbol, Soil Classification Group Name, Gravel %, Sand %, Fines %, <0.02mm %, <2um%, Cu, and Cc values are
calculated from particles smaller than 76.2mm (3 inches) only, per ASTM D2487.
Fines
%
Tested
ByllGravel
%
Sand
%
JFL
JFL
AKV
AKV
5.7
13.9
29
21
56
51
15
28
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand with Gravel
Silty Sand with Gravel and Cobbles
Cobbles
%2USCS
Group Name
C136
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
TEST PIT PIT-1
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
PIT-1, S-11
PIT-1, S-61
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
3.5
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFLAKV8.7335512
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand
USCS
Group Name
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
TEST PIT PIT-2
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
PIT-2, S-21
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
3.0
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFLAKV5.9274726
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand with Gravel
USCS
Group Name
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
TEST PIT PIT-3
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
PIT-3, S-21
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
7.0
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFLAKV7.5315513
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand
USCS
Group Name
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
TEST PIT TP-1F
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
TP-1F, S-11
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
4.7
5
8
Depth
(ft)
Sample
Identification
6.0
1 Test specimen did not meet minimum mass recommendations.
Fines
%
Tested
ByllGravel
%
Sand
%
JFLAKV7.3135829
Fine
Mesh Opening in Inches Grain Size in Millimeters
Preliminary Hydrogeologic Report
New Madrona K-8 Project
Edmonds, Washington
GRAIN SIZE DISTRIBUTION PLOT
SiltCoarse
Mesh Openings per Inch, U.S. Standard
2 10 0.0
6
0.0
4
0.0
0
3
0.0
0
1
0.0
0
2
0.0
0
3
0.0
0
8
0.0
1
0.0
7
50.10.2136204060
76.
2
Grain Size (mm)
Pe
r
c
e
n
t
C
o
a
r
s
e
r
b
y
M
a
s
s
1 1/2 3/8 4 20
USCSGroupSymbol
SM
3 100
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Silty Sand with Gravel
USCS
Group Name
C136
0.0
0
1
0.0
0
4
0.0
0
6
0.0
4
0.0
60.3
0.0
2
0.0
3
FinesSand
2410
Pe
r
c
e
n
t
F
i
n
e
r
b
y
M
a
s
s
200 0.0
2
0.0
0
2
SHANNON & WILSON, INC. • 400 NORTH 34TH STREET • SUITE 100 • SEATTLE, WASHINGTON • 98103 • MAIN (206) 632-8020 • FAX (206) 695-6777
TEST PIT TP-2F
WC
%
60
Review
By
ASTM
Std.
< 2um
%
< 20um
%
0.6
40
30 0.4
TP-2F, S-11
Gravel
Clay-SizeMediumFineCoarse
1 1
/
2
3/4 0.0
3
0.0
1
0.0
0
8
0.0
0
6
0.0
0
4
0.8
21
-
1
-
2
2
0
8
2
-
0
0
3
A
_
G
S
A
_
M
A
I
N
2
1
-
2
2
0
8
2
.
G
P
J
S
H
A
N
_
W
I
L
.
G
D
T
9
/
1
5
/
1
6
21-1-22082-004
APPENDIX C
ANALYTICAL LABORATORY TEST RESULTS
21-1-22082-004
APPENDIX D
IMPORTANT INFORMATION ABOUT YOUR
GEOTECHNICAL/ENVIRONMENTAL REPORT
Page 1 of 2 1/2016
SHANNON & WILSON, INC.
Geotechnical and Environmental Consultants
Attachment to and part of Report 21-1-22082-004
Date: October 31, 2016
To: Ms. Taine Wilton
Edmonds School District #15
IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL
REPORT
CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS.
Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be
adequate for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report
expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended
purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally
contemplated without first conferring with the consultant.
THE CONSULTANT'S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS.
A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project-specific
factors. Depending on the project, these may include: the general nature of the structure and property involved; its size and
configuration; its historical use and practice; the location of the structure on the site and its orientation; other improvements such as
access roads, parking lots, and underground utilities; and the additional risk created by scope-of-service limitations imposed by the
client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report
may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of
the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated
warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation,
or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when
there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that
may occur if they are not consulted after factors which were considered in the development of the report have changed.
SUBSURFACE CONDITIONS CAN CHANGE.
Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report
is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose
adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for
example, groundwater conditions commonly vary seasonally.
Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also
affect subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept
apprised of any such events, and should be consulted to determine if additional tests are necessary.
MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS.
Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data
were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual
interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may
differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work
together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly
beneficial in this respect.
Page 2 of 2 1/2016
A REPORT'S CONCLUSIONS ARE PRELIMINARY.
The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions
revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can
be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide
conclusions. Only the consultant who prepared the report is fully familiar with the background information needed to determine
whether or not the report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by
applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of
the report's recommendations if another party is retained to observe construction.
THE CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION.
Costly problems can occur when other design professionals develop their plans based on misinterpretation of a
geotechnical/environmental report. To help avoid these problems, the consultant should be retained to work with other project design
professionals to explain relevant geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of
their plans and specifications relative to these issues.
BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT.
Final boring logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test
results, and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in
geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or
other design drawings, because drafters may commit errors or omissions in the transfer process.
To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete
geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared
for you, you should advise contractors of the report's limitations, assuming that a contractor was not one of the specific persons for
whom the report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was
prepared. While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss
the report with your consultant and perform the additional or alternative work believed necessary to obtain the data specifically
appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming
responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available
information to contractors helps prevent costly construction problems and the adversarial attitudes that aggravate them to a
disproportionate scale.
READ RESPONSIBILITY CLAUSES CLOSELY.
Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design
disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem,
consultants have developed a number of clauses for use in their contracts, reports, and other documents. These responsibility clauses
are not exculpatory clauses designed to transfer the consultant's liabilities to other parties; rather, they are definitive clauses that
identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual
responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are
encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions.
The preceding paragraphs are based on information provided by the
ASFE/Association of Engineering Firms Practicing in the Geosciences, Silver Spring, Maryland