11.15.2012-Earth_Solutions-Geotech_Assessment.pdfNovember 15, 2012
ES-2479
Ardsley Homes, LLC
16108 Ash Way, Suite 201
Lynnwood, Washington 98087
Attention: Mr. Lyle Landrie
Subject: Geotechnical Assessment Letter
Proposed Hill Lake Property
24223 & 24227 — 76t" Avenue West
Edmonds, Washington
Dear Mr. Landrie:
Earth
( Solutions
NW«C
Earth Solutions NW LLC
• Geotechnical Engineering
• Construction Monitoring
• Environmental Sciences
In accordance with your request, Earth Solutions NW, LLC (ESNW) has prepared this letter
and geotechnical assessment for the subject property. The approximate location of the
property is illustrated on the attached Vicinity Map (Plate 1). Based on the results of this
geotechnical assessment, development of the site as proposed is feasible from a geotechnical
standpoint. The site is currently partially developed with three one-story single-family
residential buildings and several detached garage/shed structures located at the western end
of the property. The majority of the property is undeveloped with lightly forested landscaping
consisting of grass, ferns, and rhododendron bushes. We understand that the subject property
will be subdivided and redeveloped with approximately seven residential lots. The
development will also incorporate a stormwater tract and related detention vault facility. Based
on field observations, overall topography is gently sloping to the east toward Lake Ballinger
with an isolated shallow depression located at the southwest corner of the property along the
south property line.
Geotechnical Assessment
ESNW was onsite August 2, 2012 to conduct a subsurface field exploration by observing soil
conditions and collecting soil samples at a series of test pits excavated throughout the
proposed project. An excavator was utilized to excavate to a maximum exploration depth of 12
feet below current grades. The approximate locations of the test pit excavations are illustrated
the attached Test Pit Location Plan (Plate 2). The geologic map of the Edmonds East
Quadrangle (1983) identifies recessional outwash (Qvr) deposits at the site and surrounding
area. The geologic map of the Edmonds East Quadrangle (1983) also identifies the contact
between glacial till (Qvt) and recessional outwash (Qvr) deposits to be immediately west of the
property along 76t" Avenue West.
1805 - 136th Place N.E., Suite 201 0 Bellevue, WA 98005 9 (425) 449-4704 • FAX (425) 449-4711
Ardsley Homes, LLC ES-2479
November 15, 2012 Page 2
Evidence of existing fill was encountered at test -location TP-7. Existing fill soils were observed
at this location to a depth of approximately 1.5 feet below existing grades with organic rich
material underlying. Fill soils consisted primarily of medium dense, dry to moist silty sand
soils. Evidence of extensive, wide -spread existing fill was not encountered, however, shallow
existing fill soils may be encountered near and adjacent to the existing structures, the asphalt
access driveways, and at previously filled localized depressions.
Sod/Topsoil was encountered at all test sites extending to depths of approximately three to
eight inches below existing grades at the majority of the test pit locations. However, a thicker
topsoil horizon with peat like organic soil characteristics consisting of fibrous wood fragments
was encountered at TP-1 and TP-3 to a depth of 1.5 to 2.5 feet below existing grades. Topsoil
was also encountered below the existing fill soils at TP-7 from 1.5 to 3.0 feet below existing
grades This topsoil horizon likely represents the native surface elevation prior to placement of
existing fill. Topsoil is not suitable for foundation or pavement support, and should not be mixed
with soil to be used as structural fill. The topsoil can be considered for use in landscape or non-
structural areas, if desired.
Underlying the topsoil horizon, loose to medium dense silt with sand and medium dense to very
dense silty sand (native till soil), and well graded sand with silt and gravel (native outwash soil)
was observed to a maximum excavation depth of 12.0 feet. Please refer to the subsurface
exploration soil logs provided as an attachment to this report for a more detailed description of
the subsurface conditions. The soil conditions encountered during our fieldwork generally
correlate with the geologic map designation with soils consisting of glacial till (Qvt) soils thought
the majority of the property, and outwash sand (Qvr) deposits encountered at the eastern most
portion of the subject site.
Groundwater seepage was encountered at test pit locations TP-1, TP-2, and TP-3. Light
groundwater seepage was observed to be encountered at depths between 2.5 and nine (9)
feet below existing soil elevations. Seepage rates were observed to decrease approximately
10 minutes following initial exposure. Seepage should be anticipated in deeper site
excavations and utility installation depending on the time of the year excavations are made.
Groundwater encountered during our field exploration would be characterized as localized
perched groundwater seepage, and not a water bearing groundwater table condition, however,
based on the close proximity to Lake Ballinger, groundwater table should be anticipated within
deeper excavations (approximately 12 or more feet below the existing grade). Groundwater
seepage rates and elevations fluctuate depending on many factors, including precipitation
duration and intensity, the time of year, and soil conditions. In general, groundwater flow rates
are higher during the wetter, winter months.
Earth Solutions NW, LLC
Ardsley Homes, LLC
November 15, 2012
Site Preparation and Earthwork
ES-2479
Page 3
With respect to earthwork, the primary considerations at this site are related to grading for new
building lots, placement and compaction of fill, suitability of the native soils for use as structural
fill, soil bearing capacity, temporary excavations for utility structures, and erosion control
measures. The existing residential structures and associated improvements will be removed.
Once the existing structures have been removed and temporary erosion control measures have
been installed, clearing and grubbing of the property will commence.
In -Situ Soils
From a geotechnical standpoint, the soils encountered below the upper topsoil and organic rich
soil horizons are generally suitable for use as structural fill provided the soils are at or near
optimum moisture content during placement (and are free of organic materials). Successful use
of the on -site soils will largely be dictated by the moisture content of the soils at the time of
placement and compaction. The soils encountered at the test sites were generally in a moist to
wet condition at the time of the exploration (August 2012). Due to the relatively high fines
content of the onsite soils, an elevated moisture content may result in pumpy surface conditions
during site preparation and initial site fill activities. Soils encountered at or near perched
seepage elevations during site excavations that are excessively over the optimum moisture
content will require moisture conditioning prior to placement and compaction.
Highly organic or compressible soils encountered at the upper three to four feet adjacent to TP-
1 and TP-3 at the eastern portion of the property should not be used as structural fills below
roadway and building structures. Soils encountered at this location may require additional
overexcavation or recompaction within the building and roadway envelope to achieve suitable
soil bearing conditions. Organic and compressible soils cut from site excavations may be
placed in non-structural and landscape areas if desired.
During periods of dry weather, the on -site soils should generally be suitable for use as structural
fill, provided the soil moisture content is at or near the optimum level at the time of placement.
Successful placement and compaction of the on -site soils during periods of extended
precipitation will likely be difficult. If the on -site soils cannot be successfully compacted, the use
of an imported soil may be necessary. Imported soil intended for use as structural fill should
consist of a well graded granular soil with a maximum aggregate grain size of six inches, and a
moisture content that is at or near the optimum level. During wet weather conditions, imported
soil intended for use as structural fill should consist of a well graded granular soil with a fines
content of five percent or less defined as the percent passing the #200 sieve, based on the
minus three-quarter inch fraction.
Earth Solutions NW, LLC
Ardsley Homes, LLC
November 15, 2012
Structural Fill
ES-2479
Page 4
Structural fill is defined as compacted soil placed in foundation, slab -on -grade, and roadway
areas. Fills placed to construct permanent slopes and throughout retaining wall and utility
trench backfill areas are also considered structural fill. Soils placed in structural areas should
be placed in loose lifts of 12 inches or less and compacted to a relative compaction of 90
percent, based on the maximum dry density as determined by the Modified Proctor Method
(ASTM D-1557). In pavement areas, the upper 12 inches of the structural fill should be
compacted to a relative compaction of at least 95 percent. Utility trench backfill should be
compacted to the specifications of the controlling jurisdiction, where applicable.
Temporary Erosion Control
Temporary erosion control measures should include, at a minimum, silt fencing placed along
the downslope perimeter of the construction envelope. The temporary construction entrance
should consist of at least six inches of quarry spalls to help minimize off -site soil tracking and to
help provide a stable temporary road base. The quarry spall blanket should be underlain by a
woven geotextile.
Excavations and Slopes
The Federal Occupation Safety and Health Administration (OSHA) and the Washington
Industrial Safety and Health Act (WISHA) provide soil classification in terms of temporary slope
inclinations. Based on the soil conditions encountered during our fieldwork, the native soils
encountered in the upper approximately four feet are classified by OSHA/WISHA as Type C.
Temporary slopes over four feet in height in Type C soils should be sloped no steeper than
1.5H: 1 V (Horizontal: Vertical). The dense to very dense native soils encountered below about
five feet would be classified as Type A by OSHA/WISHA. Temporary slopes over four feet in
height in Type A soils should be no steeper than 0.75H: 1V. If the recommended temporary
slope inclination cannot be achieved, temporary shoring may be necessary to support the
excavations. Where groundwater is encountered, the soil should be treated as Type C. The
geotechnical engineer should observe the excavations to confirm soil and groundwater
conditions.
At the time this report was written, specific finished floor elevations had not been determined.
Based on the existing soil elevations and adjacent roadway elevations, we anticipate onsite
excavation for the stormwater detention vault and underground utilities will be on the order of
14 feet or less to achieve designed subgrade elevations. If the recommended temporary slope
inclination cannot be achieved, temporary shoring may be necessary to support the
excavations.
Permanent slopes should maintain a gradient of 2H:1V, or flatter, and should be planted with
vegetation to enhance stability and to minimize erosion.
Earth Solutions Nw, LLC
Ardsley Homes, LLC ES-2479
November 15, 2012 Page 5
Water should not be allowed to flow over temporary or permanent slopes. During rain events,
exposed temporary slopes should be covered with plastic sheeting and runoff should be
directed to an approved storm system and away from the slope.
The project geotechnical engineer should observe temporary and permanent slopes to confirm
the inclination is suitable for the exposed soil conditions, and to provide additional grading
recommendations, as necessary.
Foundations
Based on the expected subsurface conditions, the proposed building structures can be
supported on conventional continuous and spread footing foundations bearing on medium
dense native soils, or structural fill immediately underlain by competent (medium dense) native
soil. Where loose or unsuitable soils are exposed at the foundation subgrade elevation, the
soils should be overexcavated and replaced with suitable structural fill. Topsoil and organic rich
soils should be removed from foundation areas. Assuming the buildings will be supported as
described above, the following parameters can be considered for design of the new
foundations:
• Allowable Soil Bearing Capacity
■ Passive Resistance
■ Coefficient of Friction
• IBC Seismic Site Class
■ Liquefaction Susceptibility
2,500 psf
350 pcf (equivalent fluid)
M M
Site Class D (table 1613.5.2, 2009 IBC)
low
A one-third increase in the allowable soil bearing capacity can be assumed for short-term wind
and seismic loading conditions.
Competent soils suitable for support of foundations are anticipated to be encountered at depths
of about two to three feet below existing grades. Where existing fill and/or thickened topsoil
horizon is encountered (TP-1, TP-3, and TP-7), depth to bearing may be locally deeper. Where
loose or unsuitable soils are encountered at the foundation subgrade elevation, the soil should
be recompacted in place or overexcavated to competent (medium dense) soil conditions and
replaced with suitable structural fill.
Earth Solutions NW, LLC
Ardsley Homes, LLC
November 15, 2012
Vault Foundation
ES-2479
Page 6
Competent native soils suitable for support of vault foundations were generally encountered at
depths of roughly five to seven feet below existing grade (dense to very dense unweathered
till). Perched groundwater seepage was encountered throughout the eastern portion of the site
at depths of 2.5 to nine (9) feet, and was light to moderate at some locations. In this respect,
sumps and related construction dewatering techniques may be required during excavation and
construction of the vault. Due to the presence of perched groundwater seepage, a provision
for hydrostatic pressures should be incorporated into the design where use of a footing drain at
the base of the vault is not practicable. In this respect, assuming the vault excavation will be
advanced into the unweathered till, the following geotechnical parameters can be used:
• Allowable Soil Bearing Capacity 5,000 psf (unweathered till)
• Active Earth Pressure (Yielding Wall) 35 pcf
• At -Rest Earth Pressure (Restrained Wall) 50 pcf
• Hydrostatic Pressure At base — Applicable If No Ftg. Drain (per Geotech.)
• Hydrostatic Uplift — Applicable If No Ftg. Drain (per Geotech.)
• Soil Unit Weight 125 pcf
• Active Earth Pressure Coefficient (Ka) 0.28
• At -Rest Earth Pressure Coefficient (Ko) 0.40
Where applicable, a surcharge from adjacent traffic loading or structures should be added to
the calculated earth pressures. ESNW can provide surcharge loading values, as necessary.
Additionally, the geotechnical engineer should observe the vault excavation to confirm soil and
groundwater conditions. As necessary, supplement geotechnical recommendations for
foundation support (or drainage) will be provided. Additionally, recommendation for hydrostatic
pressures and related earth pressures will be provided as needed during the vault design
process.
Utility Trench Backfill
In our opinion, the soils observed at the test sites are generally suitable for support of utilities.
Organic or highly compressible soils encountered in the trench excavations should not be used
for supporting utilities. In general, the on -site soils observed at the test sites should be suitable
for use as structural backfill in the utility trench excavations, provided the soil is at or near the
optimum moisture content at the time of placement and compaction. Moisture conditioning of
the soils may be necessary at some locations prior to use as structural fill. The presence of
groundwater seepage should be expected in site excavations, such as the deeper utility trench
excavations. Utility trench backfill should be placed and compacted to the specifications of
structural fill provided in this report, or to the applicable specifications of the city or county
jurisdictions.
Earth Solutions NW, LLC
Ardsley Homes, LLC
November 15, 2012
Drainage
ES-2479
Page 7
Groundwater seepage was encountered at the time of our fieldwork (August, 2012). The
presence of isolated zones of perched seepage should be anticipated during deeper site and
utility excavations. Temporary measures to control groundwater seepage and surface water
runoff during construction will likely involve interceptor trenches and sumps, as necessary. In
our opinion, the proposed residential structures and detention vault should incorporate footing
drains around the outside perimeter of the foundations.
Pavement Sections
The performance of site pavements is largely related to the condition of the underlying
subgrade. To ensure adequate pavement performance, the subgrade should be in a firm and
unyielding condition when subjected to proofrolling with a loaded dump truck. Structural fill in
pavement areas should be compacted to the specifications detailed in the "Structural Fill
section of this report. It is possible that soft, wet, or otherwise unsuitable subgrade areas may
still exist after base grading activities. Areas containing unsuitable or yielding subgrade
conditions will require remedial measures such as overexcavation and thicker crushed rock or
structural fill sections prior to pavement.
For relatively lightly loaded (low frequency) pavements subjected to automobiles and
occasional truck traffic, we recommend the following pavement section:
• Two inches of asphalt concrete (AC) placed over four inches of crushed rock base
(CRB), or;
• Two inches of AC placed over three inches of asphalt treated base (ATB).
Heavier truck -traffic areas and main access drives generally require thicker pavement sections
depending on site usage, pavement life expectancy, and site traffic. ESNW can provide
appropriate pavement section design recommendations for heavier (high frequency) areas, as
necessary. Additionally, the City of Edmonds Road Standards (or applicable jurisdiction) may
supersede the recommendations provided in this report.
LIMITATIONS
The recommendations and conclusions provided in this geotechnical assessment are
professional opinions consistent with the level of care and skill that is typical of other members
in the profession currently practicing under similar conditions in this area. A warranty is not
expressed or implied. Variations in the soil and groundwater conditions observed at the test
sites may exist, and may not become evident until construction. ESNW should reevaluate the
conclusions in this geotechnical assessment if variations are encountered.
Earth Solutions NW, LLC
Ardsley Homes, LLC
November 15, 2012
Additional Services
ES-2479
Page 8
ESNW should have an opportunity to review the final design with respect to the geotechnical
recommendations provided in this report. ESNW should also be retained to provide testing and
consultation services during construction.
We trust this geotechnical assessment meets your current needs. If you have any questions
regarding the content of this document or require additional information, please call.
Sincerely,
EARTH SOLUTIONS NW, LLC
B. Tyler Scalise
Staff Geologist
Attachments: Plate 1 —Vicinity Map
Plate 2 — Test Pit Location Plan
Test Pit Logs and Lab Data
oN° A. �o
Q �
�8 3608 �4
Raymond A. Coglas, P.E.
Principal
Earth Solutions NW, LLC
NORTH
Reference:
Snohomish County, Washington
Map475
ByThe Thomas Guide
Rand McNally
32ndEditipn
NOTE: This plate may contain areas ofcolor. ESNWcannot be
responsible for any subsequent misinterpretation ofthe information
resulting from black & white reproductions ofthis plate. Checked BTS Date Aug. 2012 Plate 1
6--`
w
I I I I \ V
\ Z
I I \ Q
I I I I I I \
Existin I — —t
I g � Existing
TP-21
- - - - - - - i TP-5 I TP-31
A
ITP-6 \1/\
TP-4 I TP-11 - �L -
TP-7 1 Existing —■—�
—■— Existing House
t Garage � Existing —
Shed
I
I
LEGEND
TP-1-1l—Approximate Location of
ESNW Test Pit, Proj. No.
ES-2479, Aug. 2012
Subject Site
Existing Building
�y 71
Approximate Wetland
Area (Delineated By Others)
NOTE: The graphics shown on this plate are not intended for design
purposes or precise scale measurements, but only to illustrate the
approximate test locations relative to the approximate locations of
existing and / or proposed site features. The information illustrated
is largely based on data provided by the client at the time of our
study. ESNW cannot be responsible for subsequent design changes
or interpretation of the data by others.
NORTH
0 50 100 200
1 "=100' �I �
Scale in Feet
Test Pit Location Plan
Hill Lake Ballinger Plat
Edmonds, Washington
NOTE: This plate may contain areas of color. ESNW cannot be Drwn. GLS Date 08/16/2012 Proj. No. 2479
responsible for any subsequent misinterpretation of the information
resulting from black & white reproductions of this plate. Checked BTS Date Aug. 2012 Plate 2
Earth Solutions NWLLC
SOIL CLASSIFICATION CHART
MAJOR DIVISIONS
SYMBOLS
TYPICAL
DESCRIPTIONS
GRAPH
I LETTER
GRAVEL
AND
CLEAN
GRAVELS
��•��
�'
GW
WELL -GRADED GRAVELS, GRAVEL -
F NE) MIXTURES, LITTLE OR NO
° Qo oQo
0 0�0 0
O Q °O
GP
POORLY -GRADED GRAVELS,
GRAVEL - SAND MIXTURES, LITTLE
OR NO FINES
GRAVELLY
SOILS
(LITTLE OR NO FINES)
COARSE
GRAINED
SOILS
MORE THAN 50%
OF COARSE
GRAVELS WITH
FINES
°
00
°
`°
°
D
GM
SILTY GRAVELS, GRAVEL - SAND -
SILT MIXTURES
FRACTION
GC
CLAYEY GRAVELS, GRAVEL - SAND
CLAY MIXTURES
RETAINED ON NO.
4 SIEVE
(APPRECIABLE
AMOUNT OF FINES)
SAND
AND
CLEAN SANDS
SW
WELL-GDED SANDS, RAVELLY
SANDS, LITTLE OR NO FINES
MORE THAN 50%
OF MATERIAL IS
SP
POORLY -GRADED SANDS,
GRAVELLY SAND, LITTLE OR NO
FINES
LARGER THAN
NO. 200 SIEVE
SIZE
SANDY
SOILS
(LITTLE OR NO FINES)
SANDS WITH
SM
SILTY SANDS, SAND - SILT
MIXTURES
MORE THAN 50%FINES
OF COARSE
FRACTION
SC
CLAYEY SANDS, SAND - CLAY
MIXTURES
PASSING ON NO.
4 SIEVE
(APPRECIABLE
AMOUNT OF FINES)
INORGANIC SILTS AND VERY FINE
ML
SANDS, ROCK FLOUR, SILTY OR
CLAYEY FINE SANDS OR CLAYEY
SILTS WITH SLIGHT PLASTICITY
FINE
GRAINED
SOILS
SILTS
LIQUID LIMIT
AND LESS THAN 50
CLAYS
CL
INORGANIC CLAYS OF LOW TO
MEDIUM PLASTICITY, GRAVELLY
CLAYS, SANDY CLAYS, SILTY
CLAYS, LEAN CLAYS
OL
ORGANIC SILTS AND ORGANIC
SILTY CLAYS OF LOW PLASTICITY
MORE THAN 50%
OF MATERIAL IS
SMALLER THAN
NO.200 SIEVE
MH
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS FINE SAND OR
SILTY SOILS
SIZE
SILTS
LIQUID LIMIT
AND
CLAYS GREATER THAN 50
CH
INORGANIC CLAYS OF HIGH
PLASTICITY
MAMA
OH
ORGANIC CLAYS OF MEDIUM TO
HIGH PLASTICITY, ORGANIC SILTS
HIGHLY ORGANIC SOILS—''
'"' '
„„
PT
HUMUS, SWAMP SOILS WITH
HIGH
HIGH ORGANIC CONTENTS
DUAL SYMBOLS are used to indicate borderline soil classifications.
The discussion in the text of this report is necessary for a proper understanding of the nature
of the material presented in the attached logs.
Earth Solutions NW TEST PIT NUMBER TP-1
1805 136th Place N.E., Suite 201 PAGE 1 OF 1
oil Bellevue, Washington 98005
Telephone: 425-284-3300
CLIENT Ardsley Homes; LLC PROJECT NAME Hill Lake Ballinger Plat
PROJECT NUMBER 2479 PROJECT LOCATION Edmond, Washington
DATE STARTED 8/2/12 COMPLETED 8/2/12 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR NW Excavatinq GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY BTS CHECKED BY BTS AT END OF EXCAVATION ---
NOTES Depth of Topsoil & Sod 0"- 2": grass AFTER EXCAVATION —
w
_
HLu
N
U
a
a
w
V
0
p
MATERIAL DESCRIPTION
w
a�
<J
Q Z
C7
0
Brown to black TOPSOIL with "peat like" soil characteristics, loose, wet
TPSL
L'
Brown sandy SILT, loose, moist to wet
ML
3.0__
Dark brown poorly graded medium to coarse SAND with silt and gravel, medium dense to dense, moist
SP-
SM
-slight caving
5
5.0 -light seepage
Gray silty SAND with gravel, dense, moist to wet
-becomes very dense
SM
10
10.0
Test pit terminated at 10.0 feet below existing grade. Groundwater seepage encountered at 4.5 feet during
excavation
i
I
i
i
Bottom of test pit at 10.0 feet.
Earth Solutions NW
1805 136th Place N.E., Suite 201
Bellevue, Washington 98005
Telephone: 425-284-3300
CLIENT Ardsley Homes, LLC
PROJECT NUMBER 2479
DATE STARTED 8/2112 COMPLETED 8/2/12
EXCAVATION CONTRACTOR NW Excavating
EXCAVATION METHOD
LOGGED BY BTS CHECKED BY BTS
NOTES Depth of Topsoil & Sod 0"- 4": grass
w
>_
U
a
w Co
U
0_0
wQ"
Q z
c7
U)
ML
SP-
SM
10
TEST PIT NUMBER TP-2
PAGE 1 OF 1
PROJECT NAME Hill Lake Ballinger Plat
PROJECT LOCATION Edmond, Washington
GROUND ELEVATION TEST PIT SIZE
GROUND WATER LEVELS:
AT TIME OF EXCAVATION ---
AT END OF EXCAVATION ---
AFTER EXCAVATION —
MATERIAL DESCRIPTION
Gray SILT with trace gravel, loose to rrediun: dense, moist
Becomes blue -gray poorly graded SAND with silt, dense, moist
-becomes very dense
-light seepage
12.0
Test pit terminated at 12.0 feet below existing grade. Groundwater seepage encountered at 9.0 feet during
excavation.
Bottom of test pit at 12.0 feet.
TEST PIT NUMBER TP-3
Earth Solutions NW
1805 136th Place N.E., Suite 201 PAGE 1 OF 1
Bellevue, Washington 98005
Telephone: 425-284-3300
CLIENT _Ardsley Homes. LLC PROJECT NAME Hill Lake Ballinger Plat
PROJECT NUMBER 2479 PROJECT LOCATION Edmond,_ Washington
DATE STARTED 8/2/12 COMPLETED 8/2/12 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR NW Excavating GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY BTS CHECKED BY BTS AT END OF EXCAVATION
NOTES Depth of Topsoil & Sod 6"- 8": grass. AFTER EXCAVATION --
w
}W
Ui
a$
J
U
a p
MATERIAL DESCRIPTION
w"
�_j
Q Z
C7
U)
0
—
Brown to black TOPSOIL with "peat like" soil characteristics, loose, wet
TPSL
25 -light seepage at 2.5'
Gray SILT with fibrous wood fragments, loose to medium dense, moist to wet
ML
4.0 -increase in fine sand
Gray poorly graded SAND with silt, medium dense, moist to wet
5
SP-
SM
-gravel layer
9.0
Test pit terminated at 9.0 feet below existing grade. Groundwater seepage encountered at 2.5 feet during excavation.
Bottom of test pit at 9.0 feet.
Earth Solutions NW
liq
1805 136th Place N.E., Suite 201
Bellevue, Washington 98005
Telephone: 425-284-3300
TEST PIT NUMBER TP-4
PAGE 1 OF 1
CLIENT Ardsley Homes, LLC PROJECT NAME Hill Lake Ballinger Plat
PROJECT NUMBER 2479 PROJECT LOCATION Edmond, Washington
DATE STARTED 8/2/12 COMPLETED 8/2/12 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR NW Excavating GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY BTS CHECKED BY BTS AT END OF EXCAVATION ---
NOTES Depth of Topsoil & Sod 6"- 8": grass AFTER EXCAVATION ---
w
}o
U
a
wm
U
ap
wo"
a�
¢z
U)
ML
5 1 1 SM
15
8.0
MATERIAL DESCRIPTION
Gray SILT with sand, medium dense, moist
Gray silty SAND with gravel, medium dense to dense, moist
-decrease in silt content
-becomes moist to wet
-slight caving
Test pit terminated at 8.0 feet below existing grade. No groundwater encountered during excavation.
Bottom of test pit at 8.0 feet.
Earth Solutions NW TEST PIT NUMBER TP-5
1 1805 136th Place N.E., Suite 201 PAGE 1 OF 1
No;=Bellevue, Washington 98005
Telephone: 425-284-3300
CLIENT Ardslev Homes. LLC PROJECT NAME Hill Lake Ballinger Plat
PROJECT NUMBER 2479 PROJECT LOCATION Edmond, Washington
DATE STARTED 8/2112 COMPLETED 8/2/12 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR NW Excavating_ GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY BTS CHECKED BY BTS AT END OF EXCAVATION ---
NOTES Depth of Topsoil & Sod 4"- 6": grass AFTER EXCAVATION --
w
H^
�
}Lu
U
a U
w
w CoL)
O
MATERIAL DESCRIPTION
aj
QZ
Z5
�
U
U)
0
Gray SILT, loose, moist
ML
-becomes medium dense
3.0
Becomes blue -gray silty SAND with gravel, dense, moist
5_
-increase in sand and gravel
SM
-decrease in fines content
-becomes very dense, increase in fines content
8.5
Test pit terminated at 8.5 feet below existing grade. No groundwater encountered during excavation.
i
i
l
Bottom of test pit at 8.5 feet.
Earth Solutions NW
1805 136th Place N.E., Suite 201
Bellevue, Washington 98005
Telephone: 425-284-3300
CLIENT Ardsley Homes, LLC
PROJECT NUMBER 2479
DATE STARTED 8/2112 COMPLETED 8/2/12
EXCAVATION CONTRACTOR NW Excavating
EXCAVATION METHOD
LOGGED BY BTS CHECKED BY BTS
NOTES Depth of Topsoil & Sod 3"- 4": grass
TEST PIT NUMBER TP-6
PAGE 1 OF 1
PROJECT NAME Hill Lake Ballinger Plat
PROJECT LOCATION Edmond, Washington
GROUND ELEVATION TEST PIT SIZE
GROUND WATER LEVELS:
AT TIME OF EXCAVATION ---
AT END OF EXCAVATION ---
AFTER EXCAVATION --
_
aZ
w"
0
w
W
wm
a�
¢z
0
U
vi
U
ap
�_j
Gray SILT with sand, medium dense, moist
-becomes dense
-
ML
-increase in clay content
-increase in moisture
5
-becomes moist to wet
SM
MATERIAL DESCRIPTION
Gray silty SAND with gravel, very dense, moist
Test pit terminated at 8.0 feet below existing grade. No groundwater encountered during excavation.
Bottom of test pit at 8.0 feet.
TEST PIT NUMBER TP-7
Earth Solutions NW
1805 136th Place N.E., Suite 201 PAGE 1 OF 1
Bellevue, Washington 98005
Telephone: 425-284-3300
CLIENT Ardslev Homes, LLC PROJECT NAME Hill Lake Ballinger Plat
PROJECT NUMBER 2479 PROJECT LOCATION Edmond Washington
DATE STARTED 8/2/12 COMPLETED 8/2/12 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR NW Excavating GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY BTS CHECKED BY BTS AT END OF EXCAVATION ---
NOTES Depth of Topsoil & Sod 0"- 4": grass AFTER EXCAVATION --
w
a - of
U
a
a p
MATERIAL DESCRIPTION
wv
o-�
vi
�_j
Q Z
C9
0
Brown silty SAND, medium dense, dry to moist (Fill)
SM
1.5
`—
Brown to black TOPSOIL, loose, wet
TPSL
—
3.0
Gray SILT, loose to medium dense, moist
ML
5
5.5
Blue -gray silty SAND with gravel, dense, moist
SM
-becomes very dense, moist to wet
10
10.0
Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation.
_
Bottom of test pit at 10.0 feet.