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HomeMy WebLinkAboutAppendix D_OMP_Geotechnical Feasibility Study Appendix D Preliminary Geotechnical Feasibility Study (Furgo Consultants, Inc. 2016). DRAFTDecember 01, 2016 Project No. 04.72160040 City of South San Francisco Engineering Division 315 Maple Avenue South San Francisco, California 94080 Attention: Mr. Sam Bautista Subject: Preliminary Geotechnical Feasibility Study, Proposed Orange Park Storm Water Capture Project, South San Francisco, California Dear Mr. Bautista: In accordance with your request, Fugro Consultants, Inc. (Fugro) is pleased to present the results of the preliminary geotechnical feasibility study for the proposed Orange Park Storm Water Capture Project (Project 1) to be on the south side of Colma Creek in Orange Memorial Park located at Orange Avenue and Tennis Drive in South San Francisco, California. 1 PROJECT DESCRIPTION Project 1 will consist of a subsurface infiltration chamber that will have a foot print of about ½ acre. The chamber will be constructed 15 feet below ground surface (bgs) with 3 feet of cover. 2 PRELIMINARY GEOTECHNICAL FEASIBILITY STUDY A preliminary study was conducted to determine the feasibility of the project site for the proposed storm water capture project from a geotechnical and environmental standpoint. The scope of our services consisted of the following: • We reviewed the geotechnical and geologic site conditions based on the subsurface data contained in our files, existing geologic and seismic hazard maps, and other generally available related materials. FUGRO CONSULTANTS, INC. With operating companies throughout the world 1777 Botehlo Drive Suite 262 Walnut Creek, California 94596 T +1 925 949 7100 F +1 925 949 7010 DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 2 • We performed a site reconnaissance to observe the existing site conditions from a geotechnical and geologic viewpoint, and drilled three exploratory borings between 20 and 25 feet deep. • We performed three field percolation tests at a depth of 15 feet. • Collected four (4) soil samples (two above the infiltration chamber and two below) from each boring for a total of 12 soil samples. Soil samples were obtained from the three (3) exploratory borings completed at the site. For the purposes of this preliminary project, it is assumed that the purpose of the testing is to preliminarily evaluate onsite soils for the presence of contaminants. Please note that the groundwater was not sampled or tested and the soil testing herein would not be sufficient to profile the soil for waste disposal acceptance or an unrestricted reuse scenario. Soil samples were tested for the following: o Total petroleum hydrocarbons as gasoline (TPHg) using EPA Method 8015m/8021, o Total petroleum hydrocarbons as diesel and motor oil (TPHd and TPHmo) using EPA Method 8015m with silica gel cleanup, o Volatile organic compounds (VOCs) using EPA Method 8260, o Semi-volatile organic compounds (SVOCs) using EPA Method 8270 SIM, o 17 Title 22 metals using EPA Methods 6020, o Organochlorine Pesticides using EPA Method 8081, o Polychlorinated Biphenyls (PCBs) using EPA Method 8082, and/or o Asbestos using CARB 435 Method with 400-point count. • Identify the geotechnical and geologic conditions (e.g., soil, groundwater, fill thickness, potential for compressible soils, and geologic hazards such as surface fault rupture, seismic shaking and liquefaction) that could impact the development of the specific proposed project. • We prepared this feasibility geotechnical report for the potential site, identifying the geotechnical, geologic, and environmental conditions that could impact the development of the specific proposed project. We note that the recommendations provided in this report are for preliminary feasibility level study only. A detailed geotechnical investigation will be required to develop recommendations for the design and construction of the structure once the site has been approved. DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 3 2.1 SITE CONDITIONS 2.1.1 Surface Conditions The proposed locations for the storm water collection chamber is on a trapezoidal shaped property adjacent to the north-west corner of the Orange Memorial Park. The site is currently covered by loose topsoil/fill and some vegetation. The site is bound to the north by the Colma Creek canal, on the east by Orange Memorial Park, and the south and west by apartment developments. 2.1.2 Subsurface Conditions At the location of our exploratory Borings B-01, B-02, and B-03, we generally encountered fill over native poorly-graded sands with clay and silty sands with clay over fat clay with sand. In Boring B-1, about 2 feet of poorly-graded sand with gravel and clay fill was encountered at the surface and overlaying approximately 18 feet of medium dense to dense poorly-graded sands and stiff to very stiff silty sands. Below 20 feet, very stiff fat clay was encountered to the termination depth of 26.5 feet below ground surface. In Boring B-2, about 1 foot of poorly-graded sand with gravel and silt fill was encountered at the surface and overlaying approximately 17.5 feet of medium dense to dense poorly-graded sands with silt. Below 17.5 feet, stiff fat clay was encountered to the termination depth of 21.5 feet below ground surface. In Boring B-3, about 2.5 feet of poorly-graded sand with gravel and silt fill was encountered at the surface and overlaying approximately 17.5 feet of medium dense poorly-graded sands with silt. Below 17.5 feet, stiff to very stiff fat clay was encountered to the termination depth of 21.5 feet below ground surface. The approximate locations of the borings can be found on Plate - 2, Site Plan. The boring logs and related information depict the depth at which specific subsurface conditions were encountered during our field investigation. The approximate locations of the borings were determined by using a measuring tape and should be considered accurate only to the degree implied by the method used. The log of borings referenced and shown on Plate - 2 can be found in appendix A. 2.2 GROUNDWATER Free groundwater was not encountered at the time of drilling. However, the borings were backfilled with lean cement grout on completion due to San Mateo County Environmental Health requirements. In addition, fluctuations in the groundwater level may occur due to change in seasons, variations in rainfall and other factors. The site is adjacent to Colma Creek canal and therefore, the groundwater level will be affected by the water level in the creek. DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 4 3 CONCLUSIONS AND PRELIMINARY RECOMMENDATIONS We believe that the project is feasible from a geotechnical and engineering geologic standpoint, provided that the conclusions and recommendations presented in this report are used solely as preliminary guidance for what could be expected. The principal geotechnical considerations are the potentially liquefiable layers, the soil percolation rate, and the soil contamination and are discussed in the following sections. 3.1 LIQUEFIABLE MATERIALS Seismic liquefaction is a phenomenon in which saturated (submerged), cohesionless soil experiences a temporary loss of strength due to buildup of excess pore water pressure during cyclic loading induced by an earthquake. The susceptibility of a soil to liquefaction is a function of the gradation, density, aging/cementation, and fines content of the soil. The Orange Memorial Park area has been geologically mapped as alluvium consisting of sand and silt but locally containing clay, gravel or boulders. Also, the site is mapped in an area that has a high potential for liquefaction and is adjacent to Colma which is within the FEMA 100-Year Flood Area. The subsurface conditions at the site consist primarily of sand / gravel and silty sand layers above the water table. However, those layers typically have relatively high blow counts. In addition, the layers generally appear to be at least clayey. Therefore, we anticipate limited to negligible liquefaction potential. Nonetheless, detailed liquefaction evaluation should be conducted for the project once site-specific geotechnical data are collected and seismic parameters are developed per the current building design code. 3.2 FIELD PERCOLATION TESTING We performed three (3) field percolation tests within the project site to evaluate subsurface soil permeability. The percolation test locations were all performed in the area of the proposed Storm Water Capture Chamber, as shown on the Site Plan - Plate 2. Exploration Geoservices, of San Joes, California, advanced the percolation test holes to a depth of about 15 feet below ground surface (bgs) with an 8-inch diameter hollow-stem auger. The augers were advanced to testing depth under rotary motion and imbedded approximately 1 to 2- inches into the native undisturbed soil at the bottom of the excavation. Before taking the readings of the percolation rate at each test location, water was poured into the auger for an initial soaking period of at least 60 minutes to saturate the soil within the test zone. Readings of the water level (head) drop after the soaking period were taken at multiple time intervals up to approximately 60 minutes, depending on test location We estimated soil permeability (K) using procedures recommended in the U.S. Department of the Interior’s Engineering Geology Field Manual (1998). Calculated soil permeability of the subsurface soils is presented in Table 1. Please note that the tests were performed below a depth of about 15 DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 5 feet bgs and these results may not be indicative of the soil characteristics at different depths, or at other portions of the site. At the time of testing, the Colma Creek water surface was approximately 8 to 10 feet below existing site grade. Table 1. Field Percolation Test Results Percolation Test Location Approximate Depth of Percolation Test from ground surface (feet) Subsurface Conditions at test location Water Level Drop (feet) Estimated Soil Permeability, K (in/hour) B-01B 15 greyish brown poorly-graded sand with silt and clay 9.3 (10 minutes) 3.4 B-02B 15 light brown silty sand with clay 4.8 (60 minutes) 0.3 B-03B 15 Light greyish brown silty clayey sand 4.3 (15 minutes) 1.0 3.3 LIMITED ENVIRONMENTAL ASSESSMENT Based on information provided by the City, environmental studies were conducted at the Site in 2010 and 2011 by CSS Environmental Services, Inc. (CSS)1 as part of a larger environmental assessment of a former nursery business which occupied parcels of land on both the north and south sides of Colma Creek. In CSS’ report, the Site is identified as the Southern Parcel, and was thought to have been first developed sometime between 1956 and 1965 as a carnation nursery. Aerial photographs reviewed online through Google Earth confirm that greenhouses were present onsite from at least 1993 until they were demolished in the mid-2000’s. Reports of the testing performed by CSS in 2010 and 2011, showed elevated concentrations of select organochlorine pesticides within onsite soils at depths between 1.5 to 4 feet bgs. Reportedly in 2011, a soil cap was placed over the Site. The soil cap comprises borrow soil from a local affordable housing development site in San Mateo. Based on CSS field investigations, the import fill cap varies from 2 feet thick near the center of the Site and tapers to 0 feet thick along the perimeter where natural grades were matched. As requested by the City, Fugro completed a limited environmental assessment of onsite soils concurrent with our geotechnical investigation in order to preliminarily evaluate onsite soils for the presence of contaminants above and below the proposed infiltration chamber. It should be noted that the testing performed was limited and was solely conducted to provide a preliminary evaluation of the general quality of the onsite soils within the proposed construction zone. The testing program discussed below may not be considered sufficient to profile the soil for waste disposal acceptance and it was not conducted to address an unrestricted reuse of t the Site 1 CSS Environmental, Inc. Site Assessment Report for Parcels Northwest of Orange Park, APNs 014-041-170 and -180, South of San Francisco, California, SMCo Site #559204, Global ID #T10000002366, dated April 16, 2012 DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 6 Field Activities From each exploratory boring, Fugro collected four (4) soil samples, with two (2) samples obtained from above the proposed infiltration chamber depth of 15 feet bgs and two (2) soil sample obtained below the proposed infiltration chamber. Accordingly, a total of twelve (12) soil samples were collected and analyzed during this investigation. Soil samples were retained in new stainless steel liners, sealed with Teflon sheeting and plastic end-caps. Each sample container was filled to avoid headspace. Samples were placed in a chilled ice-chest pending delivery to the chemical testing laboratory. Drilling and sampling equipment were decontaminated before and after each use. Chemical Testing Program A total of twelve (12) soil samples were transported under chain-of-custody documentation to McCampbell Analytical Inc., a State of California-certified testing laboratory. Soil samples were analyzed for the following: •Total petroleum hydrocarbons as gasoline (TPHg) using EPA Method 8015m/8021, •Total petroleum hydrocarbons as diesel and motor oil (TPHd and TPHmo) using EPA Method 8015m with silica gel cleanup, •Volatile organic compounds (VOCs) using EPA Method 8260, •Semi-volatile organic compounds (SVOCs) using EPA Method 8270 SIM, •17 Title 22 metals using EPA Methods 6020, •Organochlorine Pesticides using EPA Method 8081, •Polychlorinated Biphenyls (PCBs) using EPA Method 8082, and •Asbestos using CARB 435 Method with 400-point count. Results of Analyses Soil results were compared to the San Francisco Bay Regional Water Quality Control Board’s (SFRWQCB’s) Environmental Screening Levels (ESLs) for commercial/industrial soil exposure, as well as ESLs for Any Land Use/Any Soil Depth Exposure (Construction Worker)2. Results for heavy metals were also compared to Total Threshold Limit Concentrations (TTLCs) some of the criteria used to classify soil as hazardous waste. 2 Environmental Screening Levels, SFRWQCB, User's Guide: Derivation and Application of Environmental Screening Levels, Interim Final February 2016. Direct Exposure Human Health Risk Levels Commercial/Industrial Soil and Any Land Use/Any Soil Depth Exposure (Construction Worker) (Table S-1). DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 7 For the purposes of this report we present a separate discussion of the results for samples collected from above the proposed infiltration chamber and results for samples from below the depth of the proposed chamber (15 feet bgs). Results of analyses for soil samples are summarized in Table 2. Copies of the laboratory reports with chain-of-custody documentation are presented in Appendix C. Analytical Results – Soil Above In Filtration Chamber No TPHg, TPHmo, TPHd, VOCs, SVOCs, PCBs, or asbestos were detected in any of the soil samples analyzed from above the proposed infiltration chamber. Organochlorine pesticides were only detected in the soil samples collected from the three borings at depths between 2 and 3.5 feet bgs. This finding is consistent with known pesticide contamination at the Site. For these soil samples, analyses detected concentrations of DDD (at 0.0022 milligrams per kilogram [mg/kg]), DDE (up to 0.47 mg/kg), DDT (up to 0.38 mg/kg), and dieldrin (up to 0.17 mg/kg). Detected concentrations were at or below respective ESLs for commercial shallow soil exposure and Any Land Use/Any Soil Depth Exposure (Construction Worker). Concentrations of various metals detected in all 6 samples were all below their respective TTLCs. With the exception of arsenic, detected metals were also below respective ESLs for commercial shallow soil exposure and Any Land Use/Any Soil Depth Exposure (Construction Worker). Analyses detected total arsenic ranging from 1.7 mg/kg to 2.9 mg/kg for all 6 samples, exceeding the commercial shallow soil exposure ESL of 0.31 mg/kg and the Any Land Use/Any Soil Depth Exposure (Construction Worker) ESL of 0.94 mg/kg. These arsenic concentrations exceed commercial and construction worker ESLs, however throughout California arsenic levels have been found to be higher than ESLs due to historic chemical usage as well as its presence in local bedrock materials which have been used as import fill. The concentrations detected do not appear to be related to a source release and are most likely associated with areal background arsenic concentrations. Analytical Results – Soil Below Infiltration Chamber No TPHg, TPHmo, TPHd, VOCs, SVOCs, organochlorine pesticides, PCBs, or asbestos were detected in any of the soil samples analyzed from below the proposed depth of the infiltration chamber. Similar to samples collected from above the infiltration chamber, various metals were detected in all six (6) samples analyzed at concentrations below respective TTLC thresholds. Arsenic was detected at concentrations ranging from 1.0 mg/kg to 3.0 mg/kg, similar to areal background arsenic concentrations for California soils. DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 8 Recommendations Due to the presence of organochlorine pesticides and arsenic, and the planned construction activities, Fugro recommends that a Site Mitigation Plan (SMP) be prepared for the project. The purposes of a SMP are to 1) mitigate potential exposures due to dust emissions or contact with unsaturated soils containing detected analytes and 2) provide standard construction guidelines for dust control and routine soil handling procedures. The SMP should address potential risks to construction workers due to identified Site contaminant, and should include provisions for managing soil as part of construction, including but not limited to excavating, stockpiling for waste profile characterization, erosion control measures, transportation of waste, tracking, dust control measures, PPE and decontamination procedures. Copies of this report should be provided to the contractor working on the project. That contractor should prepare a Health and Safety Plan (HSP), which is reviewed and approved by a Certified Industrial Hygienist (CIH), and which notifies workers of the presence of detected chemicals at the Site. 4 CLOSING Based on the available geotechnical and limited environmental data, there does not appear to be limiting factors to determine the project as not being feasible. The percolation test results presented in this letter are meant to assist in the planning of the proposed project. The actual feasibility of the project should be determined by your engineering group and project team. The above conclusions presented in this letter are meant to assist in the planning and feasibility of the proposed Storm Water Collection Chamber. The preliminary conclusions presented in this report are based on the field explorations at the three locations. The conclusions and recommendations provided in this report are for preliminary feasibility level study only. Once the site is chosen for development, a detailed geotechnical investigation should be conducted and recommendations for the design and construction of the structure should be developed. DRAFTCity of South San Francisco December 01, 2016 (Project No. 04.72160040) G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\WORK IN PROGRESS\20161101_FEASIBILITY.DOC 9 The summarization of the geotechnical explorations contained within this data report were made in accordance with generally accepted local and current geotechnical engineering principles and practices are meant solely as an aide for planning the actual design of the proposed structures. We make no warranty, either express or implied. Should you have any questions or require additional information, please contact us. Sincerely, FUGRO CONSULTANTS, INC. Matthew J. Bajuniemi Ronald L. Bajuniemi, P.E., G.E. Project Engineer Principal Engineer MJB/RLB:mb Copies Submitted: (PDF) Addressee Attachments: Plate 1. Vicinity Map Plate 2. Site Plan Appendices DRAFT PLATES DRAFTPROJECT LOCATION VICINITY MAP Orange Memorial Storm Water Capture Project South San Francisco, CaliforniaG:\jobdocs\04.72160040 Orange Memorial Park Storm Water Capture Project\Drawings\A04.72160040_Plate01.dwg 11-15-2016 - 10:02amProject No. PLATE 1 04.72160040 City of South San Francisco BASE MAP SOURCE: Vicinity Map is based on an image downloaded from Google Earth Pro, dated 11/15/2016 NORTH 0 MILES 12 DRAFTNORTH SITE PLAN Orange Memorial Storm Water Capture Project South San Francisco, California LEGEND Approximate Boring Location Approximate Percolation Test LocationG:\jobdocs\04.72160040 Orange Memorial Park Storm Water Capture Project\Drawings\A04.72160040_Plate02.dwg 11-15-2016 - 10:47amProject No. PLATE 2 04.72160040 City of South San Francisco 0 FEET 50 BASE MAP SOURCE: Site Plan is based on an image downloaded from Google Earth Pro, dated 11/16/2016 DRAFT APPENDIX A FIELD EXPLORATIONS DRAFTCity of South San Francisco Project No. 04.72160040 Number of blows required to drive sampler each of three 6-in. intervals, as measured in the field (uncorrected). An SPT hammer ( 140 lb., falling 30-in.) was used unless otherwise noted on the boring log. For example: MAJOR GROUP NAMES AND MATERIAL SYMBOLS Rock Core (Rotary-cut) See log for size Soft Very Loose Loose Medium Dense APPARENT DENSITY 0.50 to 1.0 2.0 to 4.0 > 4.0 Dense CONSISTENCY SPT (Driven) 1-3/8" ID 2" OD Modified California (Driven) 2-3/8" ID 3" OD Modified California (Driven) 1-7/8" ID 2-1/2" OD Shelby Tube (Pushed) 2-7/8" ID 3" OD Liquid Limit Less than 50% Liquid Limit Greater than 50% 101 Geobarrel (Rotary-cut) 2-7/8" ID Pitcher Barrel (Rotary-cut) 2-7/8" ID Vibracore (Vibrated) See log for size Collected from Auger Note: Refer to text of report for additional details or other sampler types. Osterberg (Piston) 2-7/8" ID Other See log for details WOHWOH5 A-1 SILTS AND CLAYS SILTS AND CLAYS HIGHLY ORGANIC SOILS GW Peat or Highly Organic Soils Poorly Graded GRAVEL SILTY GRAVEL CLASSIFICATION AND MATERIAL SYMBOLS Blow Count Push-core (Pushed) See log for size Description WATER LEVEL SYMBOLS INCREASING MOISTURE CONTENT Dry Moist Wet Initial water level Seepage encountered OTHER TESTS UNDRAINED SHEAR STRENGTH CONSISTENCY OF COHESIVE SOIL APPARENT DENSITY OF COHESIONLESS SOIL N-VALUE BLOW COUNT SANDSMore than 50% retainedon the No. 200 sieveCOARSE-GRAINED SOILSGRAVELS FINE-GRAINED SOILSGM A value of undrained shear strength is reported. The value is followed by a letter code indicating the type of test that was performed, as follows: U - Unconfined Compression Q - Unconsolidated Undrained Triaxial T - Torvane P - Pocket Penetrometer M - Miniature Vane F - Field Vane R - R-value CLAYEY GRAVEL Well-Graded SAND Poorly Graded SAND SILTY SAND CLAYEY SAND SILT Lean CLAY ORGANIC SILT Elastic SILT Fat CLAY ORGANIC CLAY Debris or Mixed Fill 3550/3" 5, 7, and 8 blows for first, second, and third interval, respectively. MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE CL "WOH" indicates that the weight of the hammer was sufficient toadvance the sampler over the first two intervals. 5 blows wererequired to advance the sampler over the third interval. Very Soft Medium Stiff Note: In absence of test data, consistency has been estimated based on manual observation. UNDRAINED SHEAR STRENGTH (KIPS PER SQUARE FOOT) 0.25 to 0.50 1.0 to 2.0Stiff SP SM PT OL CH SW Clean gravels less than 5% fines Sands with more than 12% fines Gravels with more than 12% fines Pavement with Aggregate Base Clean sand less than 5% fines MAJOR DIVISIONS PER ASTM D2488-06 GC ML 35 blows for the first interval. 50 blows for the first 3 inches ofthe second interval. Lack of third value implies that driving wasstopped 3 inches into the second interval. MH OH GP SC MORE THAN 50% OF COARSE FRACTION PASSING NO. 4 SIEVE Very Stiff Hard50% or more passesthe No. 200 sievePLATE A-1TERMS AND SYMBOLS USED ON BORING LOGS SAMPLER TYPE 578 OTHER MATERIAL SYMBOLS 0 to 4< 0.25 Field or laboratory tests without a dedicated column on the boring log are reported in the Other Tests column. A letter code is used to indicate the type of test. For certain tests, a value representing the test result is also provided. Typical letter codes are as follows. Additional codes may be used. Refer to the report text and the laboratory testing results for additional information. k - Permeability (cm/s) Consol - Consolidation Gs - Specific Gravity MA - Particle Size Analysis EI - Expansion Index OVM - Organic Vapor Meter Notes: Classification of soils on the boring logs is in general accordance with ASTM D2488, or D2487 if appropriate laboratory data are available. The geologic formation is noted in bold font at the top of interpreted interval on the boring logs. 5 to 9 10 to 29 30 to 49 > 49 Well-Graded GRAVEL Final water level Very Dense N-VALUE The N-Value represents the blowcount for the last 12 inches of the sample drive if three 6-inch intervals were driven. N-value presented is independant of impact energy. If 50 hammer blows were insufficient to drive through either the second or the third interval, the total number of blows and total length driven are reported (excluding the first interval). "ref" (refusal) indicates that 50 blows were insufficient to drive through the first 6-inch interval. Parenthesis indicate that an approximate correction has been applied for non-SPT drive samplers. For example, a factor of 0.63 is commonly used to adjust blow counts obtained using a 3-inch outside diameter modified California sampler to correspond to Standard Peneteration Test. DRAFT18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" Poorly-graded SAND with SILT and GRAVEL (SP-SM): dense, light brown, dry, fine- to coarse-grained sand, gravel up to approx 2" diameter, with some wood debris [FILL] SILTY SAND (SM): medium dense, light brown, dry to moist, fine- to medium-grained sand Poorly-graded SAND with SILT (SP-SM): medium dense, light greyish brown, dry to moist, fine- to medium-grained sand fine- to coarse-grained sand with occaisional thin coarse sand lenses moist to wet SILTY SAND (SM): stiff to very stiff, brownish grey to dark grey, moist to wet, at approx. 17.5 feet: ~3" lense of Silty Fat Clay (CH-MH) then back to silty fine- to medium-grained sand Fat CLAY (CH): very stiff, black, wet, with trace organics (grass/roots/wood) slight sulphur odor NOTES: 1. Terms and symbols defined on Plate A-1. 162424 867 8810 6710 457 6718 121620 81628 14712 81214 8612 5611 30 13 11 11 12 25 23 28 19 16 18 11 MA MA 101 103 86 80 10 8 9 30 41 60 46 42 10 BORING DEPTH: 26.5 ft BACKFILL: Grout DEPTH TO WATER: Not Encountered FIELDWORK DATE: September 27, 2016 DRILLING METHOD: 8-in. dia. Hollow Stem Auger HAMMER TYPE: Downhole RIG TYPE: Mobile Drill B-53 DRILLED BY: Daniel Arballo LOGGED BY: K. Herr CHECKED BY: M. BajuniemiRECOVERYFCLP STANDARD LOG G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\FIELD\BORINGS\GINT\04.72160040_20160927.GPJ OGEM_LIB_JAN2012.GLB 11/15/16 03:55 pDEPTH, ftMATERIALSYMBOLMATERIAL DESCRIPTION 5 10 15 20 25 A-2N VALUEOR RQD%Sheet 1 of 1 SAMPLER TYPELOG OF BORING NO. B-01AOrange Memorial Park Storm Water Capture ProjectSouth San Francisco, CaliforniaBLOW COUNT ORPRESSURE, psiLOCATION: (Latitude, Longitude) City of South San Francisco Project No. 04.72160040 % PASSING#200 SIEVELIQUIDLIMIT, %PLASTICITYINDEXDRY UNITWEIGHT, pcfWATERCONTENT, %UNDRAINEDSHEARSTRENGTH, Su,ksfOTHER TESTS DRAFT18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 12 18" Poorly-graded SAND with SILT (SP-SM): medium dense to dense, light brown, dry, [FILL] Poorly-graded SAND with SILT (SP-SM): loose to medium dense, light brown, dry to moist, fine- to medium-grained sand SILTY SAND (SM): medium dense, light brown, dry to moist, fine- to coarse-grained sand moist, fine- to medium-grained sand with occaisional thin silty sand lenses and trace rounded pea-gravel up to approx 1/4" diameter Fat CLAY (CH): stiff, black, moist to wet NOTES: 1. Terms and symbols defined on Plate A-1. 111212 444 81112 667 6814 688 6810 81622 8912 15 8 14 13 14 16 18 24 13 MA 93 98 70 20 15 47 57 37 17 BORING DEPTH: 21.5 ft BACKFILL: Grout DEPTH TO WATER: Not Encountered FIELDWORK DATE: September 27, 2016 DRILLING METHOD: 8-in. dia. Hollow Stem Auger HAMMER TYPE: Downhole RIG TYPE: Mobile Drill B-53 DRILLED BY: Daniel Arballo LOGGED BY: K. Herr CHECKED BY: M. BajuniemiRECOVERYFCLP STANDARD LOG G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\FIELD\BORINGS\GINT\04.72160040_20160927.GPJ OGEM_LIB_JAN2012.GLB 11/15/16 03:55 pDEPTH, ftMATERIALSYMBOLMATERIAL DESCRIPTION 5 10 15 20 A-3N VALUEOR RQD%Sheet 1 of 1 SAMPLER TYPELOG OF BORING NO. B-02AOrange Memorial Park Storm Water Capture ProjectSouth San Francisco, CaliforniaBLOW COUNT ORPRESSURE, psiLOCATION: (Latitude, Longitude) City of South San Francisco Project No. 04.72160040 % PASSING#200 SIEVELIQUIDLIMIT, %PLASTICITYINDEXDRY UNITWEIGHT, pcfWATERCONTENT, %UNDRAINEDSHEARSTRENGTH, Su,ksfOTHER TESTS DRAFT18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" 18 18" Well-graded SAND with SILT and GRAVEL (SW-SM): medium dense, light brown, dry, fine- to medium-grained sand with gravel up to approx. 1" diameter [FILL] SILTY SAND (SM): medium dense, light brown, dry, fine- to medium-grained sand light greyish brown, dry to moist from approx. 8.25 feet to 8.5 feet: trace organics (roots) at approx. 17 feet: with some silt and organics (roots/grass/wood) at approx. 17.5 feet: fine- to coarse-grained clean sand with organics Fat CLAY (CH): stiff to very stiff, black, moist to wet, with trace organics (roots/grass) at approx. 21 feet: gradual transition into and out of ~3" lense of fine- to medium-grained dark grey silty sand at approx. 23 feet: with fine- to medium-garined grey sand NOTES: 1. Terms and symbols defined on Plate A-1. 4815 171715 467 789 568 568 667 101017 121732 396 121623 23 20 13 17 9 14 13 27 31 15 24 97 66 89 4 3 32 36 21 21 16 BORING DEPTH: 23.0 ft BACKFILL: Grout DEPTH TO WATER: Not Encountered FIELDWORK DATE: September 27, 2016 DRILLING METHOD: 8-in. dia. Hollow Stem Auger HAMMER TYPE: Downhole RIG TYPE: Mobile Drill B-53 DRILLED BY: Daniel Arballo LOGGED BY: K. Herr CHECKED BY: M. BajuniemiRECOVERYFCLP STANDARD LOG G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\FIELD\BORINGS\GINT\04.72160040_20160927.GPJ OGEM_LIB_JAN2012.GLB 11/15/16 03:55 pDEPTH, ftMATERIALSYMBOLMATERIAL DESCRIPTION 5 10 15 20 A-4N VALUEOR RQD%Sheet 1 of 1 SAMPLER TYPELOG OF BORING NO. B-03AOrange Memorial Park Storm Water Capture ProjectSouth San Francisco, CaliforniaBLOW COUNT ORPRESSURE, psiLOCATION: (Latitude, Longitude) City of South San Francisco Project No. 04.72160040 % PASSING#200 SIEVELIQUIDLIMIT, %PLASTICITYINDEXDRY UNITWEIGHT, pcfWATERCONTENT, %UNDRAINEDSHEARSTRENGTH, Su,ksfOTHER TESTS DRAFT APPENDIX B LABORATORY TESTING DRAFTB-01A 2.5 3 SILTY SAND (SM), Olive Brown 10 42 M, S B-01A 10.5 10 Poorly-graded SAND with SILT (SP-SM), Olive Brown 108 101 8 T B-01A 16.0 13 Poorly-graded SAND with SILT (SP-SM), Olive Brown 113 103 9 10 T, S B-01A 20.5 15 SANDY SILT (ML), Very Dark Grayish Brown 112 86 30 T B-01A 25.5 18 Fat CLAY (CH), Black 113 80 41 60 46 T, A B-02A 8.5 6 Silty SAND (SM), Dark Yellwoish Brown 111 93 20 T B-02A 17.0 10 SILTY SAND (SM), Light Olive Brown 112 98 15 17 T, S B-02A 20.5 12 Fat CLAY with SAND (CH), Black 103 70 47 57 37 T, A B-03A 3.0 2 SILTY SAND (SM), Light Olive Brown 101 97 4 21 T, F B-03A 7.5 7 SILTY SAND (SM), Light Yellowish Brown 69 66 3 16 T, F B-03A 22.5 15 Lean CLAY (CL), Very Dark Gray 118 89 32 36 21 T, A So4 SAND EQUIVALENT(SE)M = Moisture Content T = Total & Dry Unit Weight S = Sieve Analysis FC = % Passing #200 Sieve H = Hydrometer Analysis A = Atterberg Limits P = Compaction Test R = Resistivity, ohm-cm, satur. pH = pH Cl = Chloride, ppm SO4 = Sulfate, ppm Qu = Unconfined Compression Su = Undrained Shear Strength u = Unconsolidated Undrained p = Pocket Penetrometer t = Torvane m = Miniature Vane DIRECTSHEARCompressive Strength Tests UWW = Unit Wet Weight UDW = Unit Dry Weight MC = Moisture Content Fines = % Passing #200 Sieve LL = Liquid Limit PI = Plasticity Index UWW pcf LL PI TESTLISTINGRSU(Cell Prs.)ksf MAX DD = Maximum Dry Density OPT MC = Optimum Moisture Content FINES % MATERIAL DESCRIPTION EXPANSION INDEXTest Listing Abbreviations D = Direct Shear Test C = Consolidation Test Co = Corrosivity Tests CU = CU Triaxial U = UU Triaxial R = R-Value SE = Sand Equivelant Cl DRILL HOLE R-VALUEpH Orange Memorial Park Storm Water Capture Project South San Francisco, California SUMMARY OF LABORATORY TEST RESULTSSUM-1 LAB_SUMMRY (G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\FIELD\BORINGS\GINT\04.72160040_20160927.GPJ) -VTA- 12/1/16 11:46 AMCORROSIVITY TESTS ATTERBURGLIMITSQu, ksf C = Assigned Cohesion, ksf PHI = Assigned Friction Angle, degrees Direct Shear Test PLATE B-1PHI deg Corrosivity Tests C ksf MAX DD pcf UDW pcf OPT MC %COMPACTIONTESTClassification Tests Compaction Test COMPRESSIVESTRENGTHTESTSMC%DEPTH, ftSAMPLE NUMBERCity of South San FranciscoProject No. 04.72160040 DRAFT0 10 20 30 40 50 60 70 80 90 100 0.0010.010.1110100 CoarsePERCENT FINER BY WEIGHTMedium FineCoarse GRAIN SIZE IN MILLIMETERS GRAVEL GRAIN SIZE CURVES PLATE B-2 SAND SILT or CLAY Fine Project No. 04.72160040 City of South San Francisco Orange Memorial Park Storm Water Capture Project South San Francisco, California GRAIN SIZE CURVES (G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\FIELD\BORINGS\GINT\04.72160040_20160927.GPJ)-VTA-12/1/16 11:45 a D10 D30 D60Cc 0.9 2.5 0.11 0.09 0.10 0.19 0.12 HYDROMETER ANALYSIS 20 LEGEND 10 40 SILTY SAND (SM), Olive Brown Poorly-graded SAND with SILT (SP-SM), Olive Brown SILTY SAND (SM), Light Olive Brown 1003 1.5 3/4 3/8 4 B-01A B-01A B-02A (location) US STD SIEVE SIZE INCHES 200 US STD SIEVE SIZE NUMBERS CLASSIFICATION Cu (depth,ft) 2.5 16.0 17.0 DRAFT0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 25.5 20.5 22.5 B-01A B-02A B-03A 60 57 36 CH or OH CL or OL ML or OL MH or OH LEGEND location LIQUID LIMIT (LL) PLASTICITYLIQUID LIMIT(LL) PLASTIC LIMIT(PL) Fat CLAY (CH), Black Fat CLAY with SAND (CH), Black Lean CLAY (CL), Very Dark Gray depth, ft ATTERBERG LIMITS TEST RESULTSPLASTICITY INDEX (PI)INDEX (PI)CLASSIFICATION CL-ML PLASTICITY CHART PLATE B-3 14 20 15 46 37 21 PLASTICITY CHART G:\JOBDOCS\04.72160040 ORANGE MEMORIAL PARK STORM WATER CAPTURE PROJECT\FIELD\BORINGS\GINT\04.72160040_20160927.GPJ 12/1/16 11:45 a Project No. 04.72160040 City of South San Francisco Orange Memorial Park Storm Water Capture Project South San Francisco, California DRAFT APPENDIX C ENVIRONMENTAL TESTING DRAFTNovember 2016 Project No. 04.72160040 Table 2 Summary of Analytical Results - Soil Orange Memorial Park Storm W ater Capture Project Oakland, California G:\jobdocs\04.72160040 Orange Memorial Park Storm Water Capture Project\Enviro Section\Orange Memorial Park table Page 1 of 1 Hydrocarbons TPHg mg/kg <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 3,900 2,700 NE TPHd mg/kg <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1,100 850 NE TPHmo mg/kg <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 <5.0 140,000 31,000 NE Volatile Organic Compounds VOCs mg/kg ND ND ND ND ND ND ND ND ND ND ND ND varies varies NE Semi-Volatile Organic Compounds SVOCs mg/kg ND ND ND ND ND ND ND ND ND ND ND ND varies varies varies Organochlorine Pesticides p,p-DDD mg/kg <0.020 <0.0010 <0.0010 <0.0010 0.0022 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 12 81 a1.0 p,p-DDE mg/kg 0.47 <0.0010 0.0038 <0.0010 0.035 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 8.5 57 a1.0 p,p-DDT mg/kg 0.38 <0.0010 0.0022 <0.0010 0.028 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 8.5 57 a1.0 Dieldrin mg/kg 0.17 <0.0010 0.032 <0.0010 0.043 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 <0.0010 0.17 1.1 8.0 Remaining Pesticides mg/kg ND ND ND ND ND ND ND ND ND ND ND ND varies varies varies Polychlorinated Biphenyls PCBs mg/kg ND ND ND ND ND ND ND ND ND ND ND ND 1.0 5.6 50 Metals Antimony mg/kg <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 470 140 500 Arsenic mg/kg 2.9 2.9 2.9 1.7 2.8 2.5 1.7 2.3 1.7 3.0 2.2 1.0 0.31 0.94 500 Barium mg/kg 28 32 30 16 22 34 1.7 63 20 69 18 62 220,000 2,900 10,000 Beryllium mg/kg <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 2,200 40 75 Cadmium mg/kg <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 580 41 100 Chromium+mg/kg 34 32 33 21 42 32 23 46 24 49 25 53 1,800,000#510,000#2,500+ Cobalt mg/kg 3.7 3.8 3.5 2.8 3.5 3.9 2.8 4.7 3.3 5.2 4.0 2.0 350 27 8,000 Copper mg/kg 5.7 4.5 4.6 2.5 4.5 4.3 2.6 9.9 2.9 9.0 2.9 5.9 47,000 14,000 2,500 Lead mg/kg 7.1 1.9 2.8 1.1 2.5 2.1 1.4 2.4 1.3 2.6 1.3 1.9 320 320 1,000 Mercury mg/kg 0.06 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 0.13 <0.050 0.054 <0.050 <0.050 190 42 20 Molybdenum mg/kg <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 5,800 1,700 3,500 Nickel mg/kg 22 26 23 15 20 25 17 32 18 43 20 19 11,000 83 2,000 Selenium mg/kg <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 0.52 <0.50 0.52 <0.50 0.52 5,800 1,700 100 Silver mg/kg <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 5,800 1,700 500 Thallium mg/kg <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 12 3.4 700 Vanadium mg/kg 23 24 24 17 20 23 16 27 18 27 18 22 600,000 600 2,400 Zinc mg/kg 28 18 21 11 19 19 12 23 12 25 13 13 350,000 100,000 5,000 Asbestos %ND ND ND ND ND ND ND ND ND ND ND ND NE NE 1.0 Notes: TPHg= Total Petroleum Hydrocarbons as gasoline TTLC = Total Threshold Limit Concentration TPHd= Total Petroleum Hydrocarbons as diesel ESL = Environmental Screening Levels, SFRWQCB, User's Guide: Derivation and Application of Environmental Screening Levels, Interim Final February 2016 TPHmo= Total Petroleum Hydrocarbons as motor oil Com/Ind: Shallow Soil Exposure and Direct Exposure Human Health Risk Levels Commercial/Industrial (Table S-1) Any Land Use/Any Soil Depth Exposure (Construction Worker) Detected Concentrations shown in Bold aTTLC's are cumulative for 4,4' -DDD, -DDE, -DDT <0.5 = Not detected above laboratory detection limit mg/kg = Milligrams per kilogram =Concentrations in exceedence of Com/Ind: Shallow Soil Exposure ESLs NE = Not Established =Concentrations in exceedence of Any Land Use/Any Soil Depth Exposure (CW) ESLs ND = Not detected =Concentrations in exceedence of TTLC + = Assumes Total Chromium = Concentration in exceedence of 2 or more regulatory criteria. # = Assumes Chromium III Com/Ind: Shallow Soil Exposure Any Land Use / Any Soil Depth Exposure (CW) B-03A@7 B-03A@18 B-03A@22 18 22 9/27/2016 9/27/2016 9/27/2016 9/27/2016 213.0 6.0 16.5Sample Depth ft 2.0 5.0 15.53.5 7.0 9/27/2016 9/27/2016 9/27/2016 9/27/2016Sample Date 9/27/2016 9/27/2016 9/27/2016 9/27/2016 Screening CriteriaSample ID ESLAnalyteB-01A@21 B-02A@[email protected]@2 B-01A@5 [email protected]@3 B-02A@6 [email protected] TTLC 20