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Corporate Office
17522 Bothell Way Northeast
Bothell, Washington 98011
Phone 425.415.0551 ♦ Fax 425.415.0311
www.riley-group.com
October 19, 2017
Norm and Cynthia Green
105 Harpeth Hills Drive
Franklin, Tennessee 37069
Subject: Pilot Infiltration Testing and Subsurface Conditions
Greens Landing
5008 Northeast 2nd Street
Renton, Washington
RGI Project No. 2017-207
Dear Mr. & Mrs. Green
As requested, The Riley Group, Inc. (RGI) is pleased to provide the results of our recent infiltration
testing and subsurface characterization services at the above-referenced Site (Figure 1). RGI
conducted one small Pilot Infiltration Test (PIT) at the Site per City of Renton guidelines.
Subsurface Conditions
RGI oversaw the excavation of a test pit in the proposed infiltration test location, as shown on
Figure 2, and as provided by Pacific Engineering Design, to document subsurface conditions and
determine the appropriate depth for the infiltration test. The excavation was done using a mini-
excavator operated by Ryatt Construction and subcontracted directly to the owner.
Soil conditions observed in test pit TP-1 in the infiltration test location include silty sand with debris
(wood, clay pipe fragments) to a depth of approximately 3 feet below grade, interpreted to be fill
soils. The fill soils are underlain by silty sand with with some gravel and occasional cobbles from 3
feet to approximately 6 feet below grade. These soils are interpreted to be recessional
outwash/weathered lodgment till deposits. Vashon-age lodgment till was observed from
approximately 6 feet to the depth of the exploration, 8 feet below grade. The soils observed at the
site are consistent with the regional geologic mapping in the area. No groundwater was observed.
Infiltration Testing
One Small Pilot Infiltration Test (Small PIT) IT-1 was completed on the area of the Site proposed for
infiltration (Figure 2). The infiltration pit measured approximately 4 feet by 4 feet. The small PIT
test was conducted at a depth of approximately 3.5 feet below existing grade. Approximately six
inches of water was maintained in the pit for the pre-soak period. The water supply source used
for the test was on-site hose bibs conveyed by standard garden hoses with a splash plate in the
base of the pit to reduce erosion. The pre-soak period was followed by a steady-state period and
then falling head readings were collected. The field measured infiltration rate was 1.8 inches/hour.
USGS, 2014, Renton, Washington
7.5-Minute Quadrangle
Approximate Scale: 1"=1000'
0 500 1000 2000 N
Site Vicinity Map
Figure 1
10/2017
Corporate Office
17522 Bothell Way Northeast
Bothell, Washington 98011
Phone: 425.415.0551
Fax: 425.415.0311
Greens Landing
RGI Project Number
2017-207
Date Drawn:
Address: 5008 Northeast 2nd Street, Renton, Washington 98059
SITE
TP-1
IT-1
N
Geotechnical Exploration Plan
Figure 2
Approximate Scale: 1"=50'
0 25 50 100
= Test pit location by RGI, 10/09/17
= Infiltration test location by RGI, 10/09/17
= Site boundary
10/2017
Corporate Office
17522 Bothell Way Northeast
Bothell, Washington 98011
Phone: 425.415.0551
Fax: 425.415.0311
Greens Landing
RGI Project Number
2017-207
Date Drawn:
Address: 5008 Northeast 2nd Street, Renton, Washington 98059
Project Name:Greens Landing
Project Number:2017-207
Client:Norm & Cynthia Green
Test Pit No.: TP-1
Date(s) Excavated:10/09/17
Excavation Method:Excavation
Excavator Type:Excavator
Groundwater Level:Not encountered
Test Pit Backfill:Native Soil
Logged By LC
Bucket Size:n/a
Excavating Contractor:Ryatt Construction
Sampling
Method(s)Grab
Location 5008 Northeast 2nd Street, Renton, Washington 98059
Surface Conditions:Top Soil
Total Depth of Excavation:8 feet bgs
Approximate
Surface Elevation n/a
Compaction Method n/a
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REMARKS AND OTHER
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MATERIAL DESCRIPTION
Top Soil
Brown, silty SAND with wood chunks and clay pipe
fragments (fill)
Light brown, silty SAND with gravel and some cobbles,
medium dense, moist
Brown, silty SAND with gravel, medium dense, moist
Test pit excavated to 8 feet bgs
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Sheet 1 of 1
The Riley Group, Inc.
17522 Bothell Way NE, Bothell, WA 98011
Project Name:Greens Landing
Project Number:2017-207
Client:Norm & Cynthia Green
Key to Logs
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1 2 3 4 5 6 7 8 9
COLUMN DESCRIPTIONS
1 Elevation (feet): Elevation (MSL, feet).
2 Depth (feet): Depth in feet below the ground surface.
3 PID Reading, ppm: The reading from a photo-ionization detector,
in parts per million.
4 Sample Type: Type of soil sample collected at the depth interval
shown.
5 Sample ID: Sample identification number.
6 USCS Symbol: USCS symbol of the subsurface material.
7 Graphic Log: Graphic depiction of the subsurface material
encountered.
8 MATERIAL DESCRIPTION: Description of material encountered.
May include consistency, moisture, color, and other descriptive
text.
9 REMARKS AND OTHER TESTS: Comments and observations
regarding drilling or sampling made by driller or field personnel.
FIELD AND LABORATORY TEST ABBREVIATIONS
CHEM: Chemical tests to assess corrosivity
COMP: Compaction test
CONS: One-dimensional consolidation test
LL: Liquid Limit, percent
PI: Plasticity Index, percent
SA: Sieve analysis (percent passing No. 200 Sieve)
UC: Unconfined compressive strength test, Qu, in ksf
WA: Wash sieve (percent passing No. 200 Sieve)
MATERIAL GRAPHIC SYMBOLS
Silty SAND (SM)
TYPICAL SAMPLER GRAPHIC SYMBOLS
Auger sampler
Bulk Sample
3-inch-OD California w/
brass rings
CME Sampler
Grab Sample
2.5-inch-OD Modified
California w/ brass liners
Pitcher Sample
2-inch-OD unlined split
spoon (SPT)
Shelby Tube (Thin-walled,
fixed head)
OTHER GRAPHIC SYMBOLS
Water level (at time of drilling, ATD)
Water level (after waiting)
Minor change in material properties within a
stratum
Inferred/gradational contact between strata
?Queried contact between strata
GENERAL NOTES
1: Soil classifications are based on the Unified Soil Classification System. Descriptions and stratum lines are interpretive, and actual lithologic changes may be
gradual. Field descriptions may have been modified to reflect results of lab tests.
2: Descriptions on these logs apply only at the specific boring locations and at the time the borings were advanced. They are not warranted to be representative
of subsurface conditions at other locations or times.
Sheet 1 of 1
The Riley Group, Inc.
17522 Bothell Way NE, Bothell, WA 98011