Geotech Report Jan '18 - 234 Edmonds 022818.pdfZipperGeo
Geoprofessional Consultants
Project No. 1948.01
January 30, 2018
Johnny Vong
2442 Market Street, #562
Seattle, Washington 98107
Subject: Stormwater Infiltration Feasibility
Proposed Edmonds Apartments
23326 Highway 99
Edmonds, Washington
Dear Mr. Vong:
In accordance with your request and authorization, Zipper Geo Associates, LLC (ZGA) has completed
our stormwater infiltration feasibility analysis for the proposed Edmonds Apartments project located
at 23326 Highway 99 in Edmonds, Washington. Our services were complete in general accordance
with our proposal (P17342) dated January 2, 2018. Written authorization to proceed with our
evaluation was provided by you on January 2, 2018 through signature of our proposal.
The observations and conclusions summarized herein are based in part upon subsurface soil and
groundwater conditions observed in borings completed for this work. In the event that site
conditions or proposed improvements change, it may be necessary to modify the conclusions
presented in this report. This report is an instrument of service and has been prepared in general
accordance with locally accepted geotechnical engineering practice. This report has been prepared
for the exclusive use of you and your agents, for specific application to the subject property and
stated purpose.
PROJECT DESCRIPTION
The project site consist of an undeveloped 1.37 acre property located at 23326 Highway 99 in
Edmonds, Washington. The project will consist of developing the site with a new apartment building
and related site improvements. The new building will include 5 levels of living space over two levels
of parking. The lower levels of parking and a portion of the living spaces above will be buried to the
west and daylight to the east. The lower level of parking is currently planned with a finished floor
elevation of 408 feet. The project currently proposes to manage stormwater runoff through a buried
stormwater detention vault located in the northeast portion of the property. The bottom of the vault
is currently planned at elevation 402 feet, roughly 6 to 19 feet below existing site grades. Existing
19019 - 36" Avenue West, Suite E Lynnwood, Washington 98036 (425) 582-9928
Zipper Geo Associates, LLC
Edmonds Apartments — Infiltration Feasibility
Project No. 1948.01
January 30, 2018
site features and the proposed plan view layout of proposed improvements are shown on the
attached Figure 1, Site and Exploration Plan.
PURPOSE AND SCOPE
The purpose of our services was to conduct a stormwater infiltration feasibility analysis in the vicinity
of the proposes stormwater vault. Our scope of services generally included characterizing subsurface
soil and groundwater conditions in the vicinity of the vault and evaluating stormwater feasibility.
SUBSURFACE SOIL AND GROUNDWATER CONDITIONS
Mapped Geology
We reviewed published geologic mapping of the site vicinity through the Washington State
Department of Natural Resource's web -based mapping application Washington Geologic Information
Portal(https://geologyportal.dnr.wa.gov/). The published mapping indicates the site is underlain by
Vashon Till. The mapping describes Vashon Till as a nonsorted mixture of clay, silt, sand, pebbles,
cobbles, and boulders, all in variable amounts. The mapping further describes the Till as " It typically
is hard lodgement till and often is referred to as "hardpan." The "hardpan" is largely a result of
compaction caused by the great weight of the overriding ice, hundreds of meters thick."
Soil Conservation Service Hydrologic Soil Group Classification
We reviewed Soil Conservation Service (SCS) mapping of the site vicinity through USDA NRCS's Web
Soil Survey application (https://websoilsurveV.sc.egov.usda.gov/App/WebSoilSurvey.aspx). The
mapping indicates the site is underlain by Alderwood-Urban Land Complex soils.
Subsurface Soil Conditions
To characterize subsurface soil conditions, we completed five geotechnical testing borings on the site.
Boring B-5 was completed in the vicinity of the proposed stormwater detention vault. The locations
of the borings are shown on the attached Figure 1, Site and Exploration Plan. Soil conditions observed
in boring B-5 generally consisted of about 9 inches of topsoil underlain by dense, gray -brown, silty
sand with trace gravel extending to about 5 feet below existing site grade (Weathered Till). Below
the Weathered Till, the boring encountered dense, grading to very dense, silty sand with variable
amounts of gravel (Till) extending to the completion depth of about 30 feet below existing site grade.
The remaining borings (completed to depths ranging from about 20 to 40 feet below existing site
grade) generally encountered similar soil conditions (Weathered Till over Till), although some borings
encountered fill soils within the upper 10 feet of existing site grade. Soil conditions observed in the
borings were generally consistent with the mapped geology described above. Logs of the borings are
attached.
19019 36th Avenue West, Suite E Lynnwood, WA 98036 (425) 582-9928
Page 2
Zipper Geo Associates, LLC
Edmonds Apartments — Infiltration Feasibility
Project No. 1948.01
January 30, 2018
Groundwater Conditions
Groundwater was not encountered in any of the 5 borings completed. However, perched
groundwater conditions can typically develop at the contact between the Weathered Till and Till soils.
Perched groundwater typically consists of a thin layer of saturated soil that develops during wetter
times of the year.
Summary of Laboratory Testing
For purposes of evaluating infiltration feasibility, a grain size analysis test was completed on a
composite of samples S-4 through S-6 from boring B-5. These samples were obtained from
approximately elevation 395 to 400 feet as representative of the infiltration receptor soils (assuming
bottom of vault elevation of 402 feet). The grain size analysis on the composite sample indicated a
fines content of about 33 percent at a moisture content of about 7 percent. A copy of the grain size
analysis of the composite sample is attached.
CONCLUSIONS
Stormwater design in the City of Edmonds is regulated by the DOE's 2014 Stormwater Management
Manual for Western Washington (2014 SWMM) and the City of Edmonds June 8, 2017 Stormwater
Addendum. Appendix A of the June 2017 Edmonds Stormwater Addendum (ESA) outlines infeasibility
criteria for various stormwater management BMPs. For infiltration systems, the ESA requires at least
1 foot of permeable soil from the bottom of the infiltration system to the seasonal high groundwater
table or other impermeable layer. The 2014 SWMM defines permeable soil as "Soil materials with a
sufficiently rapid infiltration rate so as to greatly reduce or eliminate surface and stormwater runoff.
These soils are generally classified as SCS hydrologic soil types A and B." As indicated above, SCS
mapping indicates the site is underlain by the Alderwood group of soils. The 2014 SWMM classifies
the Alderwood group soils as hydrologic soil group C. The 2014 SWMM defines hydrologic soil group
as:
"Soils having low infiltration rates when thoroughly wetted and consist chiefly of soils with a
layer that impedes downward movement of water and soils with moderately fine to fine
textures. These soils have a low rate of water transmission (0.05-0.15 in/hr.)."
Additionally, in many areas, the 2014 SWMM generally refers to hardpan or glacial till as an
impermeable layer as related to stormwater infiltration. We agree with the DOE's classification of till
as an impermeable soil as related to stormwater infiltration. Additionally, the till at this site is
extremely dense and contains fines contents generally in excess of 30 percent further supporting the
generally impermeable nature of it. As such, it is our opinion that stormwater infiltration at the
currently proposed vault location and elevation is infeasible due to the impermeable nature of till
19019 36t' Avenue West, Suite E Lynnwood, WA 98036 (425) 582-9928
Page 3
Zipper Geo Associates, LLC
Edmonds Apartments — Infiltration Feasibility
Project No. 1948.01
January 30, 2018
soils at this site. Based on proposed site grades and soils encountered in other borings, it is further
our opinion that stormwater infiltration at other locations on the site is infeasible.
CLOSURE
We hope this letter meets your current needs. If you have any questions or comments, please contact
us at (425) 582-9928.
Sincerely,
Zipper Geo Associates, LLC
Robert A. Ross, P.E.
Principal Geotechnical Engineer
Attachments: Figure 1, Site and Exploration Plan
Boring Logs
Lab Test Analysis Results
19019 36t' Avenue West, Suite E Lynnwood, WA 98036 (425) 582-9928
Page 4
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hf/ II \ L = _ _ L — — _ _ _ _ _ _ s3p 20 LF 8` SEWER ® 0.5%
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LEGEND
-B-1 BORRING NUMBER AND \\\ Edmonds Apartments
APPROXIMATE LOCATION I Z 23326 Hwy 99
Edmonds, Washington
30 0 15 30 SITE AND EXPLORATION PLAN
SCALE IN FEET DATE: JANUARY 2018 Job No. 1948.01
Zipper Geo Associates, LLC FIGURE
REFERENCE: CONCEPT UTILITY PLAN PREPARED BY PATRICK HARRON & ASSOCIATES, LLC., DATED JANUARY 15, 2018 19019 36th Ave. W.,Suite E
Lynnwood, WA, 98036 SHT.1 of 1
Boring Location: See Figure 1, Site and Exploration Plan Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Top Elevation: 419' Drilling Method: Hollow Stem Auger Hammer Type: Auto
B-1
Date Drilled: 1/16/2018 Drill Rig: D50 Lopped by: TLW
v
E
SOIL DESCRIPTION
�U)
J
Z o 0
Q
U
o
o
0 0
PENETRATION RESISTANCE (blows/foot)
U)
o
U
m
0)
N
The stratification lines represent the approximate boundaries
between soil types. The transition may be gradual. Refer to
report text and appendices for additional information.
Standard Penetration Test
Q Hammer Weight and Drop:
g p
20 40 60
0
7 inches of topsoil over loose, brown, moist, silty SAND, trace
gravel
1++
'...II ',,II
IIIIIIIII
IIII '...
--------------------------------------------
Dense, moist, gray, silty SAND, some gravel (Weathered Till)
''...Illllli
+7-��-i-i-rrt
IIIIIIIII
rt-r-r-r-r-r-r-r-r
Illlii
-rr-rrrrr-
f
S-1 18"
I
0 �7
II
77-T-T-TTTT�T
IIIIIII
TTTT1-1-1-
IIIIIII.
37
--------------------------------------------
JJJ��1
'IIIIIII
11.11111.11
IIIIIIIII
1LLLLLL'_
IIIIIII
Medium, wet, light gray, silty SAND, some to trace gravel
5
(Weathered Till)
S-2 18"
I
'....IIIIIII
IIIIIIIII
IIII
13
'..IIIIIII
-1-7rt-trtrt-rt
IIIIIIIII
rtt-t t -r t..ttt
IIII .-
t t...r r T-'.. :...
-------------------------------------------
Very dense, moist, light gray, silty SAND, some to trace gravel
(Till)
20 S-5 2 3„
at 21.0 feet possible cobbles
p '...II11111 IIIIIIIII IIII
-+- --4-i-i-F + +-i 4 +++++ +++ i- -
''...Iliiili iilliiill IIIIIII
"I'll" I I t 441111
25 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
50/6
50/6
50/3
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING _
19019 36th Ave. W, Suite E LOG; B
Lynnwood, WA
Page 1 of 2
Boring Location: See Figure 1, Site and Exploration Plan
Top Elevation: 419'
Date Drilled: 1/16/2018
SOIL DESCRIPTION
The stratification lines represent the approximate boundaries
aa) between soil types. The transition may be gradual. Refer to
0 report text and appendices for additional information.
25
Very Dense, moist, light gray, SAND, with silt and gravel
at 29.0 feet possible cobbles to boulders
30
Boring completed at approximately 30 feet on 1/16/18.
No groundwater observed ATD.
9911
40
45
50 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Drilling Method: Hollow Stem Auger Hammer Type: Auto
Drill Rig: D50 Lopped by: TLW
PENETRATION RESISTANCE (blows/foot)
�U)
Standard Penetration Test
J
Z o
a 0
0 Hammer Weight and Drop:
0
U
Q
Z
0
rn
o
0
20 40 60
m
s-s s
soi
is
5oi5
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING _
19019 36th Ave. W, Suite E LOG;
Lynnwood, WA
Page 2 of 2
Boring Location: See Figure 1, Site and Exploration Plan Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Top Elevation: 430' Drilling Method: Hollow Stem Auger Hammer Type: Auto
B-2
Date Drilled: 1/16/2018 Drill Rig: D50 Lopped by: TLW
SOIL DESCRIPTION
PENETRATION RESISTANCE (blows/foot)
v
�U)
U)
o
0)
Standard Penetration Test
E
The stratification lines represent the approximate boundaries
J
Z o 0
o
Q Hammer Weight and Drop:
g p
U
N
between soil types. The transition may be gradual. Refer to
Q
report text and appendices for additional information.
U
o
m
0
0 20 40 60
0
8 inches of topsoil over medium dense, moist, brown, silty
SAND, trace gravel (Possible Fill)
5 1 -------------------------------------------
Dense, damp, light brown, silty SAND, some gravel (Possible
Fill)
�101 loose and wet from 10.0 feet and 12.0 feet
-------------------------------------------
Very dense, moist, light gray, gravelly SAND, with silt (Till)
15
20
25 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
S-3 I 18"
S-5 I 12"
'......
IIIIIII
IIIIIIII
II
�,II
hill
IIII
Iliiill
Iliiill
lill
iill
iill
Illlili
ililllll
ililllll
III
I��IIi
'�..Illilll
'..IIIIIII
Lii
�..illllll
'�..IIIIIII
'..IIIIIII
IIII '
IIII '�..-
IIII
25
44
8
69
50/6
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING
19019 36th Ave. W, Suite E LOG; B_ 2
Lynnwood, WA
Page 1 of 2
Boring Location: See Figure 1, Site and Exploration Plan
Top Elevation: 430'
Date Drilled: 1/16/2018
SOIL DESCRIPTION
The stratification lines represent the approximate boundaries
aa) between soil types. The transition may be gradual. Refer to
0 report text and appendices for additional information.
25
Very dense, moist, light gray, silty SAND, trace to some gravel
(Till)
grades to with gravel
30
9911
at 39.0 feet possible cobbles to boulders
40
Boring completed at approximately 40 feet on 1/16/18.
No groundwater observed ATD.
45
50 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Drilling Method: Hollow Stem Auger Hammer Type: Auto
Drill Rig: D50 Lopped by: TLW
PENETRATION RESISTANCE (blows/foot)
�U)
Standard Penetration Test
J
Z o
a 0
0 Hammer Weight and Drop:
0
U
Q
Z
0
rn
o
0
20 40 60
m
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING _n
19019 36th Ave. W, Suite E LOG; `
Lynnwood, WA
Page 2 of 2
Boring Location: See Figure 1, Site and Exploration Plan Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Top Elevation: 427' Drilling Method: Hollow Stem Auger Hammer Type: Auto
B-3
Date Drilled: 1/16/2018 Drill Rig: D50 Lopped by: TLW
SOIL DESCRIPTION
PENETRATION RESISTANCE (blows/foot)
v
�U)
U)
o
0)
Standard Penetration Test
E
The stratification lines represent the approximate boundaries
J
Z o 0
o
Q Hammer Weight and Drop:
g p
U
N
between soil types. The transition may be gradual. Refer to
Q
report text and appendices for additional information.
U
o
m
0
0 20 40 60
I
I . I
0 -
—
7 inches of topsoil over loose, moist, gray -brown, silty SAND,
� I
I I I I I
I I I I I I
trace gravel (Possible Fill)
i 1
---------------------------------------------
Dense, moist, gray, SAND, with gravel and silt (Weathered
Till)
--------------------------------------------
Very dense, moist, light gray, silty SAND, some gravel (Till)
S-t o.7
I
S-2 1.5
I
A p
1LL_
II II
TTTTTT -
IIIIII
LILLLLL'_
5
43
5
0
... III
IIIIIII
..-iyrt-trtrtrt
I
41 l l
IIIIIII
IIIIIIIII
rtt-tttt.ttt
♦
I II
IIII
.t.t...firr'..,...
20 grades to with silt S-5 = 3 11/4
at 21.0 feet possible cobbles to boulders
p (IIIIIII IIIIIIIII IIII
44-4-i-4-4+ +-i 4 +++++ +++-i--i-
..IIiIiII 111111111 1111111—
illiiili Iilliillilil
11 �44 fitfi t t t...tt Il tttt
25 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING
19019 36th Ave. W, Suite E LOG; B-3
Lynnwood, WA
Page 1 of 2
Boring Location: See Figure 1, Site and Exploration Plan
Top Elevation: 427'
Date Drilled: 1/16/2018
SOIL DESCRIPTION
The stratification lines represent the approximate boundaries
aa) between soil types. The transition may be gradual. Refer to
0 report text and appendices for additional information.
25
Very Dense, moist, light gray, silty SAND, some gravel (Till)
30
Boring completed at approximately 31 feet on 1/16/18.
No groundwater observed ATD.
9911
40
45
50 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Drilling Method: Hollow Stem Auger Hammer Type: Auto
Drill Rig: D50 Lopped by: TLW
PENETRATION RESISTANCE (blows/foot)
�U)
Standard Penetration Test
J
Z o
a 0
0 Hammer Weight and Drop:
0
U
Q
Z
0
rn
o
0
20 40 60
m
S-7 S 0.1
50/2
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING
19019 36th Ave. W, Suite E LOG; �_�
Lynnwood, WA
Page 2 of 2
Boring Location: See Figure 1, Site and Exploration Plan Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Top Elevation: 413' Drilling Method: Hollow Stem Auger Hammer Type: Auto
B-4
Date Drilled: 1/16/2018 Drill Rig: D50 Lopped by: TLW
SOIL DESCRIPTION
PENETRATION RESISTANCE (blows/foot)
v
�U)
U)
o
0)
Standard Penetration Test
E
The stratification lines represent the approximate boundaries
J
Z 0 o
o
Q Hammer Weight and Drop:
g p
U
N
between soil types. The transition may be gradual. Refer to
Q
report text and appendices for additional information.
U
o
m
0 0
20 40 60
0
7 inches of topsoil over medium dense, moist, light brown to
brown, silty SAND, trace gravel (Possible Fill)
S_1 T 7"
-------------------------------------------- ll
5 Medium dense, moist, light gray -brown, silty SAND
(Weathered Till)
S-2 181.
-------------------------------------------
Very dense, moist, light gray, silty SAND, with gravel (Till)
4 IS31181,
q
grades to with silt I T
s-a 1 181.
20
grades to silt S-5 I 9"
Boring completed at approximately 21 feet on 1/16/18.
No groundwater observed ATD.
25 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
VGroundwater
level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
17
23
56
74
50/3
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING
19019 36th Ave. W, Suite E LOG; B-4
Lynnwood, WA
Page 1 of 1
Boring Location: See Figure 1, Site and Exploration Plan Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Top Elevation: 412' Drilling Method: Hollow Stem Auger Hammer Type: Auto
B-5
Date Drilled: 1/16/2018 Drill Rig: D50 Lopped by: TLW
SOIL DESCRIPTION
PENETRATION RESISTANCE (blows/foot)
v
�U)
U)
o
0)
Standard Penetration Test
E
The stratification lines represent the approximate boundaries
J
Z o 0
o
Q Hammer Weight and Drop:
g p
U
N
between soil types. The transition may be gradual. Refer to
Q
report text and appendices for additional information.
U
o
m
0
0 20 40 60
0
9" of topsoil over dense, light gray -brown, silty SAND, trace
gravel (Weathered Till)
1++
''...Ill�lli
''...Iliiill
Illllli
Illllli
Illlii
IIIIIII
S-1 18"
I
III
-1-I-f7i�l-f�
I �T-TT
I TJTTl-1-1-
45
III III
JJJ� �J
'...illlli
IIII
111_
'... II
I1� LLLLILIIIIL.
v
IIIIIIII
5
--------------------------------------------
ii
A
IIIIIII
Dense, wet, light gray, silty SAND, trace gravel (Till)
T
S-2 1 10"
35
at 6.0 feet possible trace cobbles
'.,...
-�yrt�rtrtrt
rtrt7-rtrt7-*trt
t t r r r,,
grades to very dense and moist........
10
grades to with gravel
S-3 16"
S-4 I
15 1 is-5 2 8"
grades to some gravel I S-6 2 7"
20 1 I S-7 I 6„
at 21.0 feet possible cobbles to boulders
S-8 = T
25 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
'..... III
...IIIIIII
IIIIIIII
'�.. '�..II
'..IIIIIII
Illlllli)
..III III
IIII
IIIIIIII
50/6
'..IIIIIII
'..IIIIIII..IIII
'.. ..IIII
IIIIIIII
IIIIIIII
50/4
ills ''�...II
i _i 1+ 1-4
'�...Illilll
(IIIIIIII
4.+++++++
IIII
+++ -
''...Ilillll
''...Ilillll
IIII..-A
k 50/4
�AkIO16
'..IIIIIII (IIIIIIII IIII -..
- 4-i-i-F + + t +++++ +++
''...Iliiili iilliiill IIIIIIII
''Illiiili iilliiill IIII 50/4
11�� fifi� t t t.+tfi fifi rt
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING
19019 36th Ave. W, Suite E LOG; B-5
Lynnwood, WA
Page 1 of 2
Boring Location: See Figure 1, Site and Exploration Plan
Top Elevation: 412'
Date Drilled: 1/16/2018
SOIL DESCRIPTION
The stratification lines represent the approximate boundaries
aa) between soil types. The transition may be gradual. Refer to
0 report text and appendices for additional information.
25
Very dense, moist, light gray, silty SAND, some gravel
grades to with silt
30
Boring completed at approximately 30 feet on 1/16/18.
9911
40
45
50 '
SAMPLE LEGEND
GROUNDWATER LEGEND
I2-inch O.D. split spoon sample
❑
Clean Sand
3-inch I.D. Shelby tube sample
®
Bentonite
Grout/Concrete
®
Screened Casing
TESTING KEY
❑
Blank Casing
GSA = Grain Size Analysis
V
Groundwater level at
time of drilling (ATD) or
20OW = 200 Wash Analysis
N
on date of
Consol. = Consolidation Test
N
measurement.
Att. = Atterberg Limits
Drilling Company: Holocene Drilling Bore Hole Dia.: 7"
Drilling Method: Hollow Stem Auger Hammer Type: Auto
Drill Rig: D50 Lopped by: TLW
PENETRATION RESISTANCE (blows/foot)
�U)
Standard Penetration Test
J
Z o
a 0
0 Hammer Weight and Drop:
0
U
Q
Z
0
rn
o
0
20 40 60
m
10 2 4"
50/3
Q % Fines (<0.075 mm)
O % Water (Moisture) Content
Plastic Limit Liquid Limit
Natural Water Content
Edmonds Apartments
23326 Hwy 99
Edmonds, WA
Date: Jan. 2018 Project No.: 1948.01
Zipper Geo Associates BORING
19019 36th Ave. W, Suite E LOG; �_`�C
Lynnwood, WA
Page 2 of 2
GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422
100
90
2 80
(9
W
70
m
W 60
W
Z
LL
�- 50
Z
W
U
W 40
W
a
30
20
10
0
1000.000
100.000 10.000 1.000 0.100 0.010 0.001
PARTICLE SIZE IN MILLIMETERS
Coarse
Fine
Coarse
Medium
Fine
Silt
Clay
BOULDERS
COBBLES
GRAVEL
SAND
FINE GRAINED
Comments:
Exploration
Sample
Depth (feet)
Moisture (%)
Fines (%)
Description
B-2
S2
5 ft.
7.7
41.2
Silty SAND,
some gravel
Project No.: 1948.01 PROJECT NAME:
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants DATEOFTESTING: 1/19/2018 Edmonds Apartments
GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422
100
90
2 80
(9
W
70
m
W 60
W
Z
LL
�- 50
Z
W
U
W 40
W
a
30
20
10
0
1000.000
100.000 10.000 1.000 0.100 0.010 0.001
PARTICLE SIZE IN MILLIMETERS
Coarse
Fine
Coarse
Medium
Fine
Silt
Clay
BOULDERS
COBBLES
GRAVEL
SAND
FINE GRAINED
Comments:
Exploration
Sample
Depth (feet)
Moisture (%)
Fines (%)
Description
B-2
S4
15 ft.
5.2
14.5
Gravelly SAND,
with silt
Project No.: 1948.01 PROJECT NAME:
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants DATEOFTESTING: 1/19/2018 Edmonds Apartments
GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422
100
90
2 80
(9
W
70
m
W 60
W
Z
LL
�- 50
Z
W
U
W 40
W
a
30
20
10
0
1000.000
100.000 10.000 1.000 0.100 0.010 0.001
PARTICLE SIZE IN MILLIMETERS
Coarse
Fine
Coarse
Medium
Fine
Silt
Clay
BOULDERS
COBBLES
GRAVEL
SAND
FINE GRAINED
Comments:
Exploration
Sample
Depth (feet)
Moisture (%)
Fines (%)
Description
B-3
S2
5 ft.
7.7
24.0
Silty SAND, with
gravel
Project No.: 1948.01 PROJECT NAME:
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants DATEOFTESTING: 1/19/2018 Edmonds Apartments
GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422
100
90
2 80
(9
W
70
m
W 60
W
Z
LL
�- 50
Z
W
U
W 40
W
a
30
20
10
0
1000.000
100.000 10.000 1.000 0.100 0.010 0.001
PARTICLE SIZE IN MILLIMETERS
Coarse
Fine
Coarse
Medium
Fine
Silt
Clay
BOULDERS
COBBLES
GRAVEL
SAND
FINE GRAINED
Comments:
Exploration
Sample
Depth (feet)
Moisture (%)
Fines (%)
Description
B-4
S3
loft.
7.9
31.7
Silty SAND, with
gravel
Project No.: 1948.01 PROJECT NAME:
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants DATEOFTESTING: 1/19/2018 Edmonds Apartments
GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422
100
90
2 80
(9
W
70
m
W 60
W
Z
LL
�- 50
Z
W
U
W 40
W
a
30
20
10
0
1000.000
100.000 10.000 1.000 0.100 0.010 0.001
PARTICLE SIZE IN MILLIMETERS
Coarse
Fine
Coarse
Medium
Fine
Silt
Clay
BOULDERS
COBBLES
GRAVEL
SAND
FINE GRAINED
Comments:
Exploration
Sample
Depth (feet)
Moisture (%)
Fines (%)
Description
B-5
S4 - S6
12.5 to 17.5 ft.
6.6
33.4
Silty SAND, with
gravel
Project No.: 1948.01 PROJECT NAME:
Zipper Geo Associates, LLC
Geotechnical and Environmental Consultants DATEOFTESTING: 1/19/2018 Edmonds Apartments