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Home My WebLink AboutHWA 8919-300 UW' I flONGWEST & ASSOCIATES, INC. Geotechnical Engineering Hydrogeology July 22, 1997 Geoenvi ron mental Services HWA Project No. 8919-300 �1 Testing &Inspection R.W. Beck / 1001 Fourth Avenue, Suite 2500 Seattle, Washington 98154 Attention: Mr. Michael Giseburt, P.E. Subject: MONITORING WELL INSTALLATIONS Wetland Bank Site Renton, Washington Dear Mr. Giseburt: Pursuant with your request, Hong West& Associates, Inc. installed three monitoring wells at the Wetland Bank Site in Renton, Washington. A proposal for the monitoring well installations was submitted to R.W. Beck on June 3, 1997. Authorization for the work was subsequently given by Mr. Michael Giseburt. The scope of work completed for this project was consistent with that described in our proposal and included drilling and installing three monitoring wells at locations selected by the City of Renton, and preparing this letter report summarizing our activities and monitoring well logs. FIELD METHODS On June 23, 1997, a geotechnical engineer from HWA logged the drilling and installation of three monitoring wells (BH-1 through BH-3), at locations shown on Figure 1 and designated by the City. Explorations were performed to determine the presence and depth to groundwater, and soil conditions at the site. The monitoring wells were drilled to 16'/2 feet below the existing ground surface using a Mobile B-61 track-mounted drill rig owned and operated by Holocene Drilling of Pacific, Washington under subcontract to HWA. After completing the drilling, piezometers were installed. Piezometers consist of slotted PVC pipe backfilled with sand and capped with a concrete and steel monument cover. As part of the exploration program, HWA personnel recorded pertinent information including soil sample depths, stratigraphy, soil engineering characteristics, and groundwater occurrence. Soils were classified in the field in general accordance with the classification system described on Figure 2. A key to the exploration log symbols is also presented on Figure 2. The exploration logs are presented on Figures 3 through 5. 19730-64th Avenue West Lynnwood,WA 98036-5904 Tel. 206-774-0106 Fax. 206-775-7506 July 22, 1997 HWA Project No. 8919-300 Representative soil samples obtained at selected intervals from the explorations were placed in air-tight bags and taken to our laboratory for further examination. Soil samples will be sent to the City for storage. O.O We appreciate the opportunity to provide geotechnical services on this project. Sincerely, HONG WEST& ASSOCIATES, INC. David L. Sowers, P.E. Scott L. Hardman, P.E. Geotechnical Engineer Senior Geotechnical Engineer DLS:SLH:dls Enclosures: Figure 1. Site and Exploration Plan Figure 2. Legend of Terms and Symbols Used on Explorations Logs Figure 3-5. Logs of Monitoring Wells BH-1 through BH-3 8919300.DOC 2 HONG WEST&ASSOCIATES,INC. � � r r i 16 �w Vn Ir II y II I I /i 11 1 1 II ► ! +` ` �- zx J1 SITE AND �j Bank Site Monitoring Well Installations EXPLORATION PLAN flONGWEST Renton, Washington &ASSOCIATES. INC. PROJECT NO.: 8919-300 FIGURE: C: J00S 95035 95W5002DMtG RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N-VALUE TEST SYMBOLS COHESIONLESS SOILS COHESIVE SOILS GS Grain Size Distribution Approximate Approximate °GF Percent Fines Consistency N(blows/ft) Undrained Shear CN Consolidation Density N(blows/ft) Relative Density(%) Strength(psf) TX Triaxial Compression Very Loose 0 to 4 0 - 15 Very Soft 0 to 2 <250 UC Unconfined Compression Loose 4 to 10 15 - 35 Soft 2 to 4 250 - 500 DS Direct Shear Medium Dense 10 to 30 35 - 65 Medium Stiff 4 to 8 500 - 1000 M Resilient Modulus Dense 30 to 50 65 - 85 Stiff 8 to 15 1000 - 2000 PP Pocket Penetrometer Very Dense over 50 85 - 100 Very Stiff 15 to 30 2000 - 4000 Approx.Compressive Strength (tsf) Hard over 30 >4000 TV Torvane Approximate Shear Strength(tsf) ASTM SOIL CLASSIFICATION SYSTEM CBR California Bearing Ratio MAJOR DIVISIONS GROUP DESCRIPTIONS MD Moisture/Density Relationship PID Photoionization Device Reading Gravel and A o GW Well-graded GRAVEL AL Atterberg Limits: PL Plastic Limit Coarse Clean Gravel ILL Liquid Limit Gravelly Soils (little or no fines) ' Grained GP Poorly-graded GRAVEL Soils More than SAMPLE TYPE SYMBOLS 50%of Coarse Gravel with . (II GM Silty GRAVEL Fraction Retained Fines(appreciable ® 2.0"OD Split Spoon (SPT) on No.4 Sieve amount of fines) GC Clayey GRAVEL (140 lb.hammer with 30 in.drop) IShelby Tube Sand and Clean Sand SW Well-graded SAND Sandy Soils (little or no fines) • 3.0" OD Split Spoon with Brass Rings More than SP Poorly-graded SAND 50%Retained 50%or More O Small Bag Sample of Coarse on No. Sand with SM Silty SAND 200 Sieve Fraction Passing Fines(appreciable Large Bag (Bulk)Sample Size on No.4 Sieve amount of fines) SC Clayey SAND Core Run ML SILT Fine Silt Non-standard Penetration Test Grained and Liquid Limit Less than 50% CL Lean CLAY Z (with split spoon sampler) Soils Clay _ OL Organic SILT/Organic CLAY COMPONENT PROPORTIONS 50%or More Silt Liquid Limit 111 MH Elastic SILT DESCRIPTIVE TERMS RANGE OF PROPORTION Passing and 50%or More CH Fat CLAY Trace 0 - 5% No.200 Sieve ay Few 5 - 10% Size % OH Organic SILT/Organic CLAY Little 15 - 25% Some 30 - 45% Highly Organic Soils PT PEAT Mostly 50 - 100% COMPONENT DEFINITIONS GROUNDWATER WELL COMPLETIONS Locking Well Security Casing COMPONENT SIZE RANGE Well Cap Boulders Larger than 12 in Concrete Seal Cobbles 3 in to 12 in Well Casing Gravel 3 in to No 4(4.5mm) Bentonite Seal Coarse gravel 3 in to 3/4 in Fine gravel 3/4 in to No 4(4.5mm) Q Groundwater Level (measured at Sand No.4(4.5 mm)to No.200(0.074 mm) time of drilling) Coarse sand No.4(4.5 mm)to No. 10(2.0 mm) 1 Groundwater Level(measured in Medium sand No. 10(2.0 mm)to No.40(0.42 mm) well after water level stabilized) Fine sand No.40(0.42 mml to No.200(0.074 mm) Slotted Well Casing Silt and Clay Smaller than No.200(0.074mm) Sand Backfill NOTES: Soil classifications presented on exploration logs are based on visual and laboratory observation in general accordance with ASTM D 2487 and ASTM D 2488. Soil descriptions MOISTURE CONTENT are presented in the following general order: DRY Absence of moisture,dusty, Density/consistency,color,modifier(if any)GROUP NAME,additions to group name(if any),moisture content. dry to the touch. Proportion,gradation,and angularity of constituents,additional comments. (GEOLOGIC INTERPRETATION) MOIST Damp but no visible water. Please refer to the discussion in the report text as well as the exploration logs for a more WET Visible free water,usually complete description of subsurface conditions. soil is below water table. LEGEND OF TERMS AND ir"M,I Bank Site Monitoring Well Installations SYMBOLS USED ON fiONGWEST Renton, Washington EXPLORATION LOGS &A S S O C I A T E S, INC. PROJECT NO.: H 91 9-300 FIGURE: Z LEGEND 89193 7/22/97 DRILLING COMPANY: Holocene LOCATION: See Figure 1 DRILLING METHOD: Track Mounted Mobile, 4-1/4" ID HSA DATE COMPLETED: 6/23/97 SURFACE ELEVATION: 16 t Feet LOGGED BY: Erik Andersen U) w Q w U M Z m w Q L U) Standard Penetration Resistance Z cA c w (140 lb. weight, 30" drop) m O0 w w co F— w Q A Blows per foot U J -j W y tr 22 2 w_ o a) Q DESCRIPTION U) u1 a U o_`n 0 10 20 30 40 50 0 0 SM Loose, olive brown, silty SAND, moist to wet. ..................._ .. _ .. . - 5 S-1 3-3-3 Some iron staining. - - - - - - - - - - - - - - - - - - - - - - - - - MIL Soft, gray SILT with sand, wet. 10 i E i..... ......c....... ............ —10 SP Loose,dark gray, poorly graded SAND, wet Fine to medium sand. 15 ..... ........... ...... . _ .. — 15 :.....•.. ..: S-3 2-2-3 ..... - - — — — — — — — — — — — — — — —— —— —— — — — ML Soft, gray SILT, wet. Bottom of boring at 16.5 feet Groundwater observed at 6 feet below the ground surface during drilling. 20 0 20 40 60 80 100 20 Water Content M Plastic Limit --0 Liquid Limit Natural Water Content NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated 1-1 and therefore may not necessarily be indicative of other times and/or locations. BORING: 131-1-1 Er"T",I Bank Site Monitoring Well Installations +IONGWEST Renton, Washington PAGE: 1 of 1 & ASSOCIATES, INC. PROJECT NO.: 8919-300 FIGURE: 3 PZO 89193 7122/97 DRILLING COMPANY: Holocene LOCATION: See Figure 1 DRILLING METHOD: Track Mounted Mobile, 4-1/4" ID HSA DATE COMPLETED: 6/23/97 SURFACE ELEVATION: 19 t Feet LOGGED BY: Erik Andersen N w U - I a a me LN. It Standard Penetration Resistance m J H Z N c w HH (140 lb. weight, 30" drop) m .tee, -1 O w uw N rc F— w Q ♦ Blows per foot = O a 0. "' w O w 22 m = F- a 2 F- 2 2 Z o = W v 2 a o U) Q DESCRIPTION ai U) a.0 O n.cn o 0 10 20 30 40 50 0 0 SP Medium dense, olive brown, poorly graded SM SAND with silt, moist to wet. Trace to few gravels. Fine to medium sand. 5 ......_...... ...;............_...... . _ .. _ . 5 S-1 5-5-6 SM Very loose, gray, silty SAND, wet Fine sand. Some iron staining. ;..... ........... .. -10 S-2 1-1-1 - - - - - - - - - - - - - - - - - - - - - - - - - ML Very soft to soft, gray SILT, wet. SP Medium dense, dark gray, poorly graded SAND, wet. Fine to medium sand. . _ 15 _...... _ . _ 15 S-3 6-6-9 ...... Bottom of boring at 16.5 feet Groundwater observed at 6 feet below the ground surface during drilling. 20 20 0 20 40 60 80 100 Water Content M Plastic Limit F-0 Liquid Limit Natural Water Content NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. BORING: 131-1-2 U=1 Bank Site Monitoring Well Installations flONGWEST Renton, Washington PAGE: 1 of 1 & A S S O C I A T E S, INC. PROJECT NO.: H 91 9-300 FIGURE: 4 PZO 89193 7/22/97 DRILLING COMPANY: Holocene LOCATION: See Figure 1 DRILLING METHOD: Track Mounted Mobile, 4-1/4" ID HSA DATE COMPLETED: 6/23/97 SURFACE ELEVATION: 17 t Feet LOGGED BY: Erik Andersen —7 1n w w vca z wo- Q s cn Standard Penetration Resistance ^ f- z c w � (140 lb. weight, 30" drop) a O w w w( "'Q A Blows per foot = m N a a- cc ° w Ow 22 = LU o crn Q DESCRIPTION uai (D a O a ) 0 10 20 30 40 50 0 0 SP Medium dense, gray, poorly graded SAND with 0 SM silt, moist. Fine to medium sand. Some iron staining. 5 .......*.._............_...... _ . ......_ . 5 S-1 9-6-6 10 - - - - - - - - - - - - - - - - - - - - - - - - - ... ...... . ...... . ...... _...... . - 10 MH Very soft, gray, elastic SILT, wet. S 2 0/12" 1 i E i SP Medium dense, dark gray, poorly graded SAND, wet. Fine to medium sand. 15 _ .. ......- 15 S-3 6-12-14 Bottom of boring at 16.5 feet Groundwater observed at 7.5 feet below the ground surface during drilling. 20 0 20 40 60 80 100 20 Water Content (%) Plastic Limit F---*---i Liquid Limit Natural Water Content NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be indicative of other times and/or locations. [FLVA I BORING: BH-3 Bank Site Monitoring Well Installations flONGWEST Renton, Washington PAGE: 1 of 1 & ASSOCIATES, INC. PROJECT NO.: 89 1 9-300 FIGURE: 5 PZO 89193 7/22197 r r i M i r r N i i 1 M 1 1 r