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Home My WebLink AboutRS_Geotechnical_Report_210128_V1 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 USCS SymbolSoil SM SM SM REMARKS AND OTHER TESTSGraphic LogMATERIAL 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 bgsPID Reading, ppmDepth (feet)0 5 10 15 Sample IDSample TypeElevation (feet)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 USCS SymbolREMARKS AND OTHER TESTSGraphic LogMATERIAL DESCRIPTIONPID Reading, ppmDepth (feet)Sample IDSample TypeElevation (feet)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