SUBSURFACE INVESTIGATION REPORT BRADFORD STREET PARCELS REDWOOD CITY, CALIFORNIA PROJECT: B04086 NOVEMBER 26, 2004

Transcription

1 SUBSURFACE INVESTIGATION REPORT BRADFORD STREET PARCELS REDWOOD CITY, CALIFORNIA PROJECT: B04086 NOVEMBER 26, 2004 Richard A. Garlow, MS CA Registered Geologist, RG-7472 Green Environment inc.

2 Green Environment inc Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA TABLE OF CONTENTS Subject Page I. INTRODUCTION...1 II. BACKGROUND...1 III. IV. SCOPE OF WORK...2 PRE-FIELD ACTIVITIES...2 V. FIELD ACTIVITIES A. Soil Borings & Soil Sampling...3 B. Groundwater Sampling...5 VI. VII. VIII. IX. LABORATORY ANALYSES A. Soil Analytical Methodologies...6 B. Groundwater Analytical Methodologies...6 INVESTIGATION RESULTS A. Regional Geology/Hydrogeology...7 B. Subject Property Geology/Hydrogeology...7 C. Analytical Results for Soil Samples...8 D. Analytical Results for Groundwater Samples...9 E. Sample Data Comparison with RWQCB Environmental Screening Levels...10 CONCLUSIONS...12 RECOMMENDATIONS...14 X. REFERENCES...15

3 Green Environment inc Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA TABLE OF CONTENTS (CONTINUATION) FIGURES Figure 1 Project Site Location Figure 2 Site Plan Figure 3 Soil Analytical Results Figure 4 Groundwater Analytical Results TABLES Table 1 Table 2 Table 3 Organic Analytical Results for Soil Samples CAM 17 Metals Analytical Results for Soil Samples Analytical Results for Groundwater Samples ATTACHMENTS Attachment A County Health Agency Permit Attachment B Geoprobe Boring Logs Attachment C STL-San Francisco Laboratory Report

4 Green Environment inc. Page 1 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA I. INTRODUCTION Green Environment inc. (GEI) was retained by the City of Redwood City (Redwood City) to complete a subsurface investigation of a commercial property located near the intersection of Main Street and Bradford Streets in Redwood City, San Mateo County, California ( subject property ). The attached Figure 1 shows the general location of the subject property. The subject property consists of four (4) adjacent parcels, (APN # , , and ). The parcels ending with -170, 240, and -999 are undeveloped and contain portions of Redwood Creek on their eastern boundaries. A thin layer of gravel covers part of the parcel ending -170 and all of the parcels ending -240 and These parcels are currently used as a restricted parking area, and there is a temporary chain link fence restricting access to Redwood Creek. The parcel ending with -200 is developed with an office building and paved parking lot, and is addressed 707 Bradford Street. The subject property is bounded: to the north by a fuel service station at 990 Veterans Blvd, and an office building with an attached parking structure at 900 Veterans Blvd; to the south by Bradford Street and a gravel covered parking lot at the northwest corner of Bradford and Main Streets and a city owned storm water pump station; to the east by Main Street and a gravel covered parking lot at the northwest corner of Bradford and Main Streets; and to the west by a paved parking lot between 707 Bradford Street and 599 Jefferson Street. The attached Figure 2 is a plan view of the subject property. This report presents the activities and results of a subsurface investigation conducted at the subject property by GEI on October 7, II. BACKGROUND In June 2004, GEI completed a Phase I Environmental Site Assessment (Phase I ESA) of the subject property, documented in a separate report (GEI, September 2004). Based upon GEI s findings and guidelines published in ASTM E , GEI did not identify any recognized environmental conditions on the subject property. However, though not recognized environmental conditions, GEI identified the following conditions, that in GEI s opinion, pose some environmental concern. Petroleum hydrocarbons releases from the adjacent property at 900 Veterans Boulevard (formerly a fuel service station) may have impacted groundwater and groundwater-saturated soils beneath the subject property. Fill material was used on the subject property during the relocation of Redwood Creek on the subject property. The source(s) of the fill were not identified by GEI. The fill may contain petroleum hydrocarbons and/or chemicals and metals at significant concentrations.

5 Green Environment inc. Page 2 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA Based upon these findings, Redwood City contracted with GEI to investigate the subsurface of the subject property. Redwood City informed GEI that they were considering constructing a child day care and/or senior housing facility on the subject property. III. SCOPE OF WORK The scope of work for the subsurface investigation was as follows. Drilling on October 7, 2004 of six (6) Geoprobe borings on the subject property and the collection of one (1) soil and one (1) groundwater sample from each borings. The boring locations are shown on Figure 2. The six (6) soil samples were submitted to a California-certified analytical laboratory for analyses for total extractable petroleum hydrocarbons [TEPH], total petroleum hydrocarbons as gasoline [TPHg], the gasoline constituents benzene, toluene, ethylbenzene and xylenes [BTEX], the gasoline oxygenate methyl tertiary butyl ether [MTBE], volatile organic compounds (VOC s), semi-volatile organic compounds (SVOC s), polychlorinated biphenyls (PCB s), organochlorine pesticides and heavy metals (CAM 17). The six (6) groundwater samples were submitted for laboratory analyses for TEPH, TPHg, BTEX, MTBE, VOC s and SVOC s. Preparation of this investigation report. IV. PRE-FIELD ACTIVITIES Prior to field activities, GEI completed the following tasks in early October Submittal of a Subsurface Drilling Application with a Work Plan on September 29, 2004 to the County of San Mateo, Health Services Agency, Groundwater Protection Program (SMCoGPP). The SMCoGPP issued a drilling permit to GEI on September 30, A copy of the drilling permit is provided in Attachment A. Preparation of a Health & Safety Plan to protect the health and safety of GEI employees and subcontractors during performance of the field work. Marking planned boring locations in white paint, followed by contacting Underground Service Alert to mark public utilities in the vicinity of the boring locations, at least 72 hours prior to drilling on the subject property. Contracting with a private utility locating company, Subdynamic Locating Services of San Jose, California, to clear the planned boring locations prior to the start of drilling.

6 Green Environment inc. Page 3 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA V. FIELD ACTIVITIES GEI s field activities for this investigation were performed on October 7, A detailed description of GEI s field activities is provided below. A. Soil Borings & Soil Sampling A total of six (6) Geoprobe borings were drilled on the subject property on October 7, The six (6) borings were designated B-1 through B-6, respectively. Boring locations are shown in Figure 2, and are described below. Boring B-1 was drilled near the southern edge of the subject property, near Bradford Street. Boring B-1 was placed at a location believed to be to the east of the original location of Redwood Creek and may be indicative of the original native soil. Boring B-2 was drilled near the western boundary the subject property, adjacent to the two story office building at 707 Bradford Street. Boring B-2 was placed at a location believed to be near the eastern edge of the original location of Redwood Creek and may be indicative of either the native soil or non-native fill. Boring B-3 was drilled east of boring B-2, near the current location of Redwood Creek. Boring B-3 was placed at a location believed to be to the east of the original location of Redwood Creek and may be indicative of the native soil. Boring B-4 was drilled near the western side of the northern boundary of the subject property, at a location believed to be near the center of the original location of Redwood Creek, and may be indicative of non-native fill. This boring is also down gradient from reported unauthorized releases of petroleum hydrocarbons. Boring B-5 was drilled near the northern boundary of the subject property, at a location believed to be near the center of the original location of Redwood Creek, and may be indicative of non-native fill. This boring is also down gradient from reported unauthorized releases of petroleum hydrocarbons. Boring B-6 was drilled near the eastern side of the northern boundary of the subject property, at a location believed to be near the center of the original location of Redwood Creek, and may be indicative of non-native fill. This boring is also down gradient from reported unauthorized releases of petroleum hydrocarbons. Environmental Probing (EnProb) of Oroville, California was contracted by GEI to drill the soil borings under the direction of a GEI Registered Geologist. EnProb is a C-57 licensed driller (C-57 #777007). Soil borings were completed on October 7, 2004 with

7 Green Environment inc. Page 4 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA the use of a truck-mounted Geoprobe System The Geoprobe system consists of direct-push technology with continuous soil sampling capabilities. A core sampler was used for continuous soil sampling. The sampler consisted of a cylindrical steel tube of four (4)-feet length and 2.25-inch outside diameter. The sampler housed replaceable inner sleeves to store the sample. Sample sleeves consisted of clear acetate tubes of 1.75-inch diameter. The final component of the system was a retractable drive point and piston, which remained stationary while driving, but was released to collect the sample. The sampler was driven into subsurface soils using the percussion of the direct push unit. The initial core sample was collected in the sleeve within the hollow sampler. After extracting the sampler from the boring, the sample sleeve was removed for soil inspection and field screened by the GEI Registered Geologist. A new sleeve was then placed in the pre-cleaned sample tube and the sampler was advanced to the next depth of penetration by adding a series of drive rods. Borings were logged according to the Unified Soil Classification System. Field screening of soil samples was performed using the MiniRAE 2000 Portable VOC Monitor, Model PGM 7600 PID. Field screening consisted of placing soil in a plastic ziplock bag, and measuring the total volatile organics (TVOs) concentration in the headspace of the bag sample. At all locations GEI s field TVO readings of soil samples were relatively low (less than 2 ppm TVOs), and not indicative of overt impact by volatile organic compounds. PID readings are summarized in boring logs prepared by GEI (Attachment B). The six (6) borings were advanced to depths of between 19 and 22.5 feet below ground surface (bgs) into the first or shallow water-bearing zone. One soil sample from each boring was selected for laboratory analyses. These samples were collected in shallow soils ranging in depths of 3.5 to 7.0 feet bgs, above the first encountered water-bearing zone. Soil sampling consisted of cutting the selected segment of the acetate sleeve, sealing the ends of the acetate tube with Teflon film and plastic end caps, labeling the sample appropriately, and then placing the sample in a cooler for preservation. The samples were transferred to a California-certified analytical laboratory following chainof-custody protocol. Soil cuttings generated from drilling Geoprobe borings were placed in one (1) Department of Transportation (DOT)-type drum of 55-gallon capacity. The drum was labeled, sealed and placed for temporary storage near the southeast corner of the subject property.

8 Green Environment inc. Page 5 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA B. Groundwater Sampling Immediately following drilling and soil sampling on October 7, 2004, screened PVC casing of 1-inch diameter was installed in each boring to facilitate the collection of groundwater samples. Depth-to-water data is included in the boring logs (Attachment B). A dedicated disposable bailer was lowered into the temporary PVC casing below the air-water interface. The groundwater was examined for the possible presence of a product sheen or free floating product. No sheen or free product was observed in any of the six (6) borings completed on the subject property. Groundwater samples were collected once sufficient volume of groundwater accumulated in the encased boreholes for the filling of sample containers. At some boring locations the relatively low permeability of soils encountered in the water-bearing zone penetrated by the borings as well as the small diameter of the bore hole resulted in slow accumulation of groundwater. The accumulation of a sufficient volume of groundwater for sampling purposes required more than two (2) hours in Borings B-2 and B-5. Collection of a groundwater sample from each borehole was performed as follows. A dedicated, disposable bailer was lowered into the PVC casing past the water-air interface. The bailer was retrieved and groundwater from the bailer was carefully transferred into laboratory-supplied, 40-milliliter (ml) volatile organic analyses vials (VOAs). After filling the VOAs, dedicated disposable tubing connected to a pneumatic pump was lowered into the groundwater in the borehole and used to fill the one (1)-liter amber glass bottles. The amber bottles contained no chemical preservatives. The groundwater samples were labeled, preserved in a cooler with ice, and transported to a California-certified analytical laboratory following chain-of-custody protocol. Immediately following groundwater sampling activities, the borings were backfilled by tremie with neat cement grout.

9 Green Environment inc. Page 6 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA VI. LABORATORY ANALYSES The soil and groundwater samples collected on October 7, 2004 at the subject property were submitted for laboratory analyses to Severn Trent Laboratories, Inc., San Francisco, (STL) which is located in Pleasanton, California. STL is certified with the Department of Health Services, Environmental Laboratory Accreditation Program, ELAP No Chain of custody records followed the samples from the field to laboratory. A. Soil Analytical Methodologies GEI directed STL to analyze each of the six (6) soil samples as follows: Total Extractable Petroleum Hydrocarbons (TEPH) by EPA Method 3550/8015M with a silica gel cleanup step quantified with respect to diesel (TEPHd), motor oil ( TEPHmo), kerosene (TEPHk), stoddard solvent (TEPHss) and hydraulic oil (TEPHho); Total Petroleum Hydrocarbons as Gasoline (TPHg) by EPA Method 8260B; Benzene, Toluene, Ethylbenzene and Total Xylenes (BTEX) and Methyl Tertiary Butyl Ether (MTBE) by EPA Method 8260B; Volatile Organic Compounds (VOCs) by EPA Method 8260B; Semivolatile Organic Compounds (SVOCs) by EPA Method 8270C; Polychlorinated Biphenyls (PCBs) and Organochlorine Pesticides by EPA Method 8081A and 8082; and CAM 17 Metals by EPA Method 6010B, 7470/ B. Groundwater Analytical Methodologies GEI directed STL to analyze each of the six (6) groundwater samples as follows: Total Extractable Petroleum Hydrocarbons (TEPH) by EPA Method 3550/8015M with a silica gel cleanup step quantified with respect to diesel (TEPHd), motor oil ( TEPHmo), kerosene (TEPHk), stoddard solvent (TEPHss) and hydraulic oil (TEPHho); Total Petroleum Hydrocarbons as Gasoline (TPHg) by EPA Method 8260B; Benzene, Toluene, Ethylbenzene and Total Xylenes (BTEX) and Methyl Tertiary Butyl Ether (MTBE) by EPA Method 8260B; Volatile Organic Compounds (VOCs) by EPA Method 8260B; and Semivolatile Organic Compounds (SVOCs) by EPA Method 8270C. STL s laboratory report is provided in Attachment C.

10 Green Environment inc. Page 7 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA VII. INVESTIGATION RESULTS The ensuing discussion presents the results of GEI s investigation of the subject property. A. Regional Geology/Hydrogeology The subject property is situated in Redwood City, San Mateo County, California. The San Francisco Bay is located approximately two to three miles to the northeast of the subject property. The geology of the San Mateo County area is summarized in Brabb & Pampeyan (1998), CDWR (1967) and Helley et al (1979). The subject property is located between the coast ranges to the southwest, and the San Francisco Bay to the northeast. Pleistocene age poorly consolidated alluvial fan deposits consisting mainly of gravel, sand, silt and clay underlie the subject property. These deposits are underlain by bedrock composed of the Franciscan Assemblage. The Franciscan Assemblage includes greywacke, chert, limestone, shale and altered ultramafic and volcanic rocks. These rocks are variably sheared and metamorphosed. The active San Andreas Fault Zone, which trends northwest, is located approximately 4.5 miles southwest of the subject property. Groundwater in the flatland areas of the San Francisco Bay region occurs in the Holocene through Pleistocene alluvial and stream channel deposits. The water bearing zones are generally discontinuous. Within the Bay region, higher water tables are found most commonly in tidal mudflats underlain by bay mud and in low flood basins at the outer margins of alluvial fans. The lower water tables occur in higher well-drained alluviated areas underlain by coarse-grained deposits. Recharge to the groundwater is accomplished through man-made percolation ponds, natural recharge basins, infiltration from surface waters (lakes and streams), or precipitation. The regional gradient in water-bearing zones is generally towards the San Francisco Bay. B. Subject Property Geology/Hydrogeology The subject property slopes gently from the north down to the south. The surface elevation of the subject property is approximately 5 feet above mean sea level (msl). GEI s borings completed on October 7, 2004 were drilled to a maximum depth of 22.5 feet bgs. The borings generally encountered what appeared to be a layer of fill material from surface to depths of 7.5 to 11.5 feet bgs. The fill consisted of sandy gravels, sandy clay and silty clays which were at some locations were damp. Underlying the fill was highly plastic, organic silty clay, underlain by silty clay to sandy clay to clayey sands to depths ranging from 15 to 21.5 feet bgs, where a sand to clayey sand layer was encountered. The layer of sands to clayey sands was observed to be wet and was interpreted as representing the water table. GEI s boring logs are provided in

11 Green Environment inc. Page 8 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA Attachment B. Groundwater on the subject property was first observed by GEI to be a wet, sand to clayey sand which was encountered at depths ranging from 15 to 21.5 feet bgs. In most of the borings, groundwater seepage into the boreholes was relatively slow and the boreholes tended to dewater several times during the bailing of groundwater to fill sample containers. These conditions suggest the water-bearing zone encountered in the borings has low hydraulic permeability and water yielding capacity. The groundwater flow direction and gradient have not been established for the subject property. Based on the topography and regional setting, GEI estimates that the regional groundwater flow direction in the vicinity of the subject property is northeast, towards San Francisco Bay. However, Redwood Creek, which flows across the subject property, is expected to have an affect on shallow groundwater flow direction beneath the subject property. Reports of shallow groundwater investigations on neighboring properties indicate widely fluctuating groundwater flow directions, varying from northwest to southeast. These observations indicate that Redwood Creek, which is influenced by tidal fluctuations in the San Francisco Bay, may act as a groundwater recharge source when the creek is high and a groundwater discharge point when the creek is low. C. Analytical Results for Soil Samples Soil analytical results are tabulated in the attached Tables 1 and 2. The attached Figure 3 also includes summary soil analytical results for non-metals. TEPHd range hydrocarbons were detected at concentrations ranging from 1.2 to 52.0 micrograms per kilogram (µg/kg) in soil samples collected from borings B-2, B-3, B-4, B-5 and B-6. TEPHd was not detected in the soil sample collected from B-1. TEPHmo was detected at concentrations of 140 and 110 µg/kg in soil samples collected from borings B-3 and B-4, respectively. TEPHmo was not detected in soil samples collected from borings B-1, B-2, B-5 and B-6. TEPHk, TEPHss and TEPHho were not detected in any of the soil samples submitted for analyses. TPHg, BTEX and MTBE were not detected in any of the soil samples at the lab reporting limits. The only VOC detected in any of the soil samples was acetone, detected at a concentration of 80 (µg/kg) in the soil sample collected from Boring B-3. With the exception of the soil sample collected from boring B-3, phenol, a SVOC, was detected in all of the soil samples ranging from 0.2 to 1.2 mg/kg. No other SVOCs were detected in any of the soil samples submitted for analyses, except at boring B-3. Acenaphthylene, anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, fluoranthene, fluorene,

12 Green Environment inc. Page 9 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA indeno(1,2,3,c,d)pyrene, naphthalene, phenanthrene and pyrene were detected in the soil sample collected from boring B-3 at concentrations ranging from 8.9 to 210 mg/kg. PCB s and organochlorine pesticides were not detected in any of the soil samples submitted for analyses. Table 2 presents the CAM 17 Metals analytical results for the six soil samples submitted for analyses. Table 2 includes background metal concentrations in soils based on research reported in the scientific literature. The background metal concentrations in soil for the subject property have not been established. The background concentrations of metals in soil are determined by a combination of complex natural factors including soil parent material, topography, climate and organic content. Research studies include Scott (1995) who investigated a suite of native soils from northern Santa Clara County and reported background levels for arsenic, beryllium, chromium, copper, nickel, lead and zinc. Bradford et al (1996) presents the results of metal analyses for fifty (50) benchmark soil samples from throughout California. The research by Schacklette & Boerngen (1984) provides upper concentration ranges for metals in soils. Inspection of Table 2 shows that the results of the CAM 17 Metals analyses for the six soil samples collected for analyses are within background ranges reported in the above references. D. Analytical Results for Groundwater Samples Groundwater analytical results are tabulated in the attached Table 3. The attached Figure 4 also includes summary groundwater analytical results. TEPHd range hydrocarbons were detected in two (2) of the groundwater samples collected from boring B-2 and boring B-4, at concentrations of 120 and 53 micrograms per liter (µg/l), respectively. TEPHmo was detected in one (1) groundwater sample, collected from boring B-2, at a concentration of 530 µg/l. TEPHk, TEPHss and TEPHho were not detected in any of the groundwater samples. TPHg, BTEX, MTBE and other VOCs were not detected in any of the groundwater samples. SVOCs were detected in one (1) groundwater sample, collected from boring B-4. Specifically, the groundwater sample contained acenaphthylene, benzo(g,h,i)perylene, benzo(a)pyrene, fluoranthene, indeno(1,2,3,c,d)pyrene and pyrene at concentrations ranging from 2.0 to 5.5 µg/l.

13 Green Environment inc. Page 10 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA E. Sample Data Comparison with RWQCB Environmental Screening Levels The San Francisco Bay, Regional Water Quality Control Board (RWQCB) document, Screening for Environmental Concerns at Sites With Contaminated Soil and Groundwater (Interim Final July 2003), presents a series of conservative risk-based environmental screening levels (ESLs) for soil and groundwater that can be directly compared to sample data collected at a site. In general, the presence of chemicals at concentrations above the ESLs does not necessarily indicate that a significant risk exists at the site. It does, however, indicate that additional investigation, remedial action and/or evaluation of potential risks are warranted. ESLs have been established by the RWQCB for both residential and commercial/ industrial land use scenarios in order to address environmental protection goals presented in the San Francisco Bay Region Water Quality Control Plan (Basin Plan, June 21, 1995). The goals include protection of drinking water resources, aquatic habitats, and human health, among others. In accordance with RWQCB (July 2003), the most conservative risk scenario is residential land use where groundwater is a current or potential source of drinking water. Sensitive receptors such as hospitals, child day care centers and senior citizen centers are included in the residential land use ESLs established by the RWQCB. ESLs are often higher (less risk) for sites where groundwater is not a current or potential source of drinking water. Such a designation typically takes place on a regional or sub-aquifer basis at the discretion of the RWQCB (RWQCB, July 2003). Redwood City plans to develop the subject property as a child day care and/or senior housing facility. For this reason, GEI has compared subject property soil and groundwater analytical data to ESLs established for a residential land use scenario. The subject property soil analytical data, as presented in Table 1, includes RWQCB ESLs for two (2) residential land use scenarios: where groundwater IS a current or potential source of drinking water (Table A); and where groundwater IS NOT a current or potential source of drinking water (Table B). A comparison of subject property soil analytical data generated in this investigation to RWQCB ESLs indicates the following. The concentrations of TEPHd range hydrocarbons detected in a majority of the soil samples (1.2 to 52 mg/kg) are below the RWQCB Residential Land Use Table A and Table B ESLs for TPH middle distillates, 100 and 500 mg/kg, respectively. The concentrations of TEPHmo detected in only two (2) of the soil samples (110 to 140 mg/kg) are below the RWQCB Residential Land Use Table A and Table B ESLs for TPH residual fuels, 500 mg/kg.

14 Green Environment inc. Page 11 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA The concentration of acetone detected in only one (1) of the soil samples (80 µg/kg) is below the RWQCB Residential Land Use Table A and Table B ESLs for acetone, 240 and 500 µg/kg, respectively. The concentrations of phenol detected in a majority of the soil samples (0.2 to 1.2 mg/kg) are above the RWQCB Residential Land Use Table A ESL for phenol (0.076 mg/kg) but below the Table B ESL for phenol (19 mg/kg). The Table A and Table B ESLs for phenol are based upon groundwater protection, and not human health or urban area ecotoxicity risks, which have much higher risk screening values, or 7300 and 40 mg/kg, respectively (RWQCB Tables A-1 and B-1, July 2003). The concentrations of acenaphthylene, anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, fluoranthene, fluorene, indeno(1,2,3,c,d)pyrene, naphthalene, phenanthrene and pyrene detected in only one (1) of the soil samples (8.9 to 210 mg/kg) equal or exceed both the RWQCB Residential Land Use Table A and Table B ESLs for these SVOC s. The ESLs (RWQCB Tables A-1 and B-1, July 2003) for the detected SVOC s, in some cases are based upon groundwater protection (acenaphthylene, anthracene, benzo(g,h,i)perylene, fluorene, naphthalene, phenanthrene and pyrene), in other cases on human health risks (benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, chrysene and indeno(1,2,3,c,d)pyrene), and in one case on urban area ecotoxicity risk (fluoranthene). The subject property groundwater analytical data as presented in Table 3 includes RWQCB ESLs for the scenario where groundwater IS a current or potential source of drinking water (Table A), the alternative scenario where groundwater IS NOT a current or potential source of drinking water (Table B), as well as established groundwater screening levels for the evaluation of potential indoor-air impacts (Table E-1a). A comparison of groundwater analytical data to RWQCB ESLs indicates the following. The concentration of TEPHd range hydrocarbons detected in the groundwater sample collected from boring B-4, (53 µg/l) is below the RWQCB Table A and Table B ESLs for TPH middle distillates, 100 and 640 µg/l, respectively. The concentration of TEPHd range hydrocarbons detected in the groundwater sample collected from boring B-2, (120 µg/l) is above the RWQCB Table A ESL for TPH middle distillates (100 µg/l) but below the Table B ESL for TPH middle distillates (640 µg/l). A groundwater screening level to evaluate potential indoor impact for TPH middle distillates has not been established by the RWQCB.

15 Green Environment inc. Page 12 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA The concentration of TEPHmo detected in the groundwater sample collected from boring B-2, (530 µg/l) is above the RWQCB Table A ESL for TPH middle distillates (100 µg/l) but below the Table B ESL for TPH middle distillates (640 µg/l). A groundwater screening level to evaluate potential indoor impact for TPH residual fuels has not been established by the RWQCB. The concentrations of acenaphthylene and fluoranthene detected in the groundwater sample collected from boring B-4, (2.4 and 4.2 µg/l, respectively) are below the RWQCB Table A and Table B ESLs for acenaphthylene (30 µg/l) and fluoranthene (8 µg/l). Groundwater screening levels to evaluate potential indoor impact for acenaphthylene and fluoranthene have not been established by the RWQCB. The concentrations of benzo(g,h,i)perylene, benzo(a)pyrene, indeno(1,2,3,c,d)pyrene and pyrene detected in the groundwater sample collected from boring B-4, (2.7, 2.4, 2.0 and 5.5 µg/l, respectively) are above the RWQCB Table A and Table B ESLs for benzo(g,h,i)perylene (0.1 µg/l), benzo(a)pyrene (0.014 µg/l), indeno(1,2,3,c,d)pyrene (0.029 µg/l) and pyrene (2.0 µg/l). Groundwater screening levels to evaluate potential indoor impact for benzo(g,h,i)perylene, benzo(a)pyrene, and indeno(1,2,3,c,d)pyrene have not been established by the RWQCB. The groundwater screening level to evaluate potential indoor impact for pyrene is 140 µg/l. VIII. CONCLUSIONS Based upon the sampling and analytical data generated in this subsurface investigation, and using RWQCB ESLs for risk screening purposes, GEI has prepared the following conclusions. With the exception of the soil sample collected from boring B-3, chemicals of concern were not detected in subject property soil samples at concentrations that would pose a significant risk to human health in a residential land use scenario, including a child day care and/or senior housing facility. The soil sample collected from boring B-3 contained certain SVOC s (benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, chrysene and indeno(1,2,3,c,d)pyrene) at concentrations that may pose a significant risk to human health in a residential land use scenario, including a child day care and/or senior housing facility. With the exception of the soil sample collected from boring B-3, chemicals of concern were not detected in subject property soil samples at concentrations that pose

16 Green Environment inc. Page 13 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA a significant risk to groundwater, assuming shallow groundwater beneath the subject property IS NOT a current or potential source of drinking water. GEI believes this assumption is valid given the apparent low permeability and yield of the shallow water bearing zone and apparent communication with water in the Redwood Creek, a creek that includes urban stormwater runoff. The soil sample collected from boring B-3 contained certain SVOC s (acenaphthylene, anthracene, benzo(g,h,i)perylene, fluorene, naphthalene, phenanthrene and pyrene) at concentrations that may pose a significant risk to groundwater, even assuming shallow groundwater beneath the subject property IS NOT a current or potential source of drinking water. The types and concentrations of chemicals of concern detected in shallow groundwater beneath the subject property do not pose a significant risk to human health in a residential land use scenario, including a child day care and/or senior housing facility. With the exception of the groundwater sample collected from boring B-4, chemicals of concern were not detected in subject property shallow groundwater samples at concentrations that pose a significant risk to groundwater, assuming shallow groundwater beneath the subject property IS NOT a current or potential source of drinking water. The groundwater sample collected from boring B-4 contained certain SVOC s (benzo(g,h,i)perylene, benzo(a)pyrene, indeno(1,2,3,c,d)pyrene and pyrene) at concentrations that may pose a significant risk to groundwater, even assuming shallow groundwater beneath the subject property IS NOT a current or potential source of drinking water.

17 Green Environment inc. Page 14 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA IX. RECOMMENDATIONS Based upon GEI s conclusions, GEI recommends the following. The lateral and vertical extent of SVOC impacted soil at the location of boring B-3 should be determined with additional sampling and analyses. SVOC impacted soil at concentrations exceeding RWQCB ESLs based upon risk to human health in a residential land use scenario or risk to groundwater assuming shallow groundwater beneath the subject property IS NOT a current or potential source of drinking water, should either be removed from the subject property, or be adequately encapsulated to protect against direct human contact and leaching to groundwater.

18 Green Environment inc. Page 15 Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA X. REFERENCES Brabb, E. E. and Pampeyan, E. H. (1998). Geologic Map of San Mateo County, California, U. S Geological Miscellaneous Investigations Series Map I-1257-A. Brabb, E. E. et. Al (1998). Geology of the onshore part of San Mateo County, California: A digital Database U.S. Geological Survey Open-File Report Bradford, G. R., Chang, A. C., Page, A. L., Bakhtar, D., Frampton, J. A. and Wright, H. (1996): "Background Concentrations of Trace and Major Elements in California Soils, Kearney Foundation Special Report, Kearney Foundation of Soil Science, Division of Agriculture and Natural Resources, University of California, March California Department of Water Resources (CDWR, 1967). Evaluation of Groundwater Resources South Bay: Appendix: Geology, California Department of Water Resources Bulletin No. 118-i. Green Environment inc. (GEI). Phase I Environmental Site Assessment, 501 Forbes Boulevard, South San Francisco, California. August, Helley, E. J. et al (1979). Flatland Deposits of the San Francisco Bay Region, California Their Geology and Engineering Properties and Their Importance to Comprehensive Planning, U. S. Geological Survey Professional Paper 943, 88 p. Regional Water Quality Control Board, San Francisco Bay Region (RWQCB, December 2001). A Comprehensive Groundwater Protection Evaluation for South San Francisco Bay Basins, Draft for Stakeholders Review. RWQCB (July 2003). Screening for Environmental Concerns at Sites With Contaminated Soil and Groundwater, Volumes I and II, Interim Final -July Scott, Christina M. (1995): Background Metal Concentrations in Soils in Northern Santa Clara County, California," in: Recent Geologic Studies in the San Francisco Bay Area, in: Sangines, E. M, Andersen, D. W., and Bruising, A. V. (editors), The Pacific Section of the Society of Economic Paleontologists and Mineralogists, Pacific Section Volume 76, May 3-5, Shacklette, H. T. and Boerngen, J. G. (1984): Element Concentrations in Soils and Other Surficial Materials, Conterminous United States," U. S. Geological Survey Professional Paper 1270.

19 Green Environment inc. Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA FIGURES

20 Green Environment inc Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA Figure 1 Site Location Map NORTH

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24 Green Environment inc. Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA TABLES

25 Table 1 - Organic Analytical Results for Soil Samples Sample Sample Date Sample Depth Total Purgable Petroleum Hydrocarbons, TPHg Benzene Toluene Ethylbenzene Volatile Organic Compounds, EPA 8260B VOC's Total Extractable Petroleum Hydrocarbons, TEPH Semi-Volatile Organic Compounds, EPA 8270C SVOCs Total Xylenes MTBE Acetone Other VOC's TEPHd TEPHmo TEPHk TEPHss TEPHho Phenol Naphthalene Acenaphthylene Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Chrysene Benzo(b)- Benzo(k)- fluoranthene fluoranthene Benzo(a)- pyrene Indeno(1,2,3- c,d) pyrene Benzo (g,h,i)- perylene Other SVOC's PCB's Organo-chlorine pesticides feet bgs mg/kg µg/kg µg/kg µg/kg µg/kg µg/kg ug/kg ug/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg ug/kg µg/kg µg/kg B /07/ to 6.0 ND (<1.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<50) ND (<5.0 to<50) ND (<1.0) ND (<50) ND (<1.0) ND (<1.0) ND (<50) 0.46 ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067 to <0.33) ND (<50) ND (<2.0 to <100) B /07/ to 5.0 ND (<1.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<50) ND (<5.0 to<50) 4.8 (6) ND (<50) ND (<1.0) ND (<1.0) ND (<50) 0.75 ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067 to <0.33) ND (<50) ND (<2.0 to <100) B /07/ to 7.0 ND (<1.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) 80 ND (<5.0 to<50) 52 (6) 140 ND (<1.0) ND (<1.0) ND (<50) ND (<6.7) ND (<6.7 to <33) ND (<50) ND (<10 to <500) B /07/ to 5.5 ND (<1.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<50) ND (<5.0 to<50) 12 (6) 110 ND (<1.0) ND (<1.0) ND (<50) 1.2 ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067 to <0.33) ND (<50) ND (<2.0 to <100) B /07/ to 4.0 ND (<1.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<50) ND (<5.0 to<50) 1.2 (6) ND (<50) ND (<1.0) ND (<1.0) ND (<50) 0.20 ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067 to <0.33) ND (<50) ND (<2.0 to <100) B /07/ to 5.5 ND (<1.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<5.0) ND (<50) ND (<5.0 to<50) 4.5 (6) ND (<50) ND (<1.0) ND (<1.0) ND (<50) 0.98 ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067) ND (<0.067 to <0.33) ND (<50) ND (<2.0 to <100) Total Number of Samples: 6 Table A RWQCB ESLs, residential land use (1) 100 (5) 44 2,900 3,300 1, Varies by compound 100 (3) 500 (4) 100 (3) 100 (3) 500 (4) Varies by compound 220 Varies by compound Table B RWQCB ESLs, residential land use (2) 100 (5) 180 9,300 4,700 1,500 2, Varies by compound 500 (3) 500 (4) 500 (3) 500 (3) 500 (4) Varies by compound 220 Varies by compound Table Notes: General Sample depth Sample depth in feet below ground surface, bgs mg/kg Milligrams per kilogram (parts per million equivalent) µg/kg Micrograms per kilogram (parts per billion equivalent) ND (<50) Not detected at or above the laboratory reporting limit NE Not determined/established TPHg Total purgeable petroleum hydrocarbons as gasoline by Environmental Protection Agency (EPA) Method 8260B VOCs Volatile organic compounds by EPA 8260B MTBE - Methyl tertiary butyl ether TEPH Total extractable petroleum hydrocarbons by EPA Method 8015M with silica gel cleanup step TEPHd - TEPH as diesel TEPHmo - TEPH as motor oil TEPHk - TEPH as kerosene TEPHss - TEPH as stoddard solvent TEPHho - TEPH as hydraulic oil PCBs Polychlorinated biphenyls by EPA Method 8082 Organochlorine pesticides by EPA Method 8081 Consultant: Green Environment inc., San Carlos, CA Laboratory: Severn Trent Laboratories, Inc., Pleasanton, California (CAELAP #2496) Detailed: 1 Environmental Screening Levels (ESLs) taken from the San Francisco Bay Region, Regional Water Quality Control Board (RWQCB): Screening for Environmental Concerns at Sites With Contaminated Soil and Groundwater, Interim Final July ESLs correspond to shallow soil under a residential land use scenario where groundwater IS a current or potential source of drinking water (Table A) 2 ESLs taken from the San Francisco Bay Region, RWQCB (July 2003): Screening for Environmental Concerns at Sites With Contaminated Soil and Groundwater. ESLs Correspond to shallow soil under a residential land use scenerio where groundwater IS NOT a current or porential source of drinking water (Table B) 3 Environmental screening level for TPH (middle distillates) 4 Environmental screening level for TPH (residual fuels) 5 Environmental screening level for TPH (gasoline) 6 According to laboratory, the hydrocarbon reported was in the late diesel range, and did not match the laboratory diesel standard

26 Table 2 - CAM 17 Metals Analytical Results for Soil Samples Sample Sample Date Sample Depth Antimony Arsenic Barium Beryllium Cadmium Chromium Cobalt Copper Lead Mercury Molybdenum Nickel Selenium Silver Thallium Vanadium Zinc feet bgs mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg B /07/ ND (<2.0) ND (<0.50) ND (<1.0) 74 ND (<2.0) ND (<1.0) ND (<1.0) B /07/ ND (<2.0) ND (<0.50) ND (<1.0) 47 ND (<2.0) ND (<1.0) ND (<1.0) B /07/ ND (<2.0) ND (<0.50) ND (<0.50) ND (<1.0) 140 ND (<2.0) ND (<1.0) ND (<1.0) B /07/ ND (<2.0) ND (<0.50) ND (<0.50) ND (<0.050) ND (<1.0) 36 ND (<2.0) ND (<1.0) ND (<1.0) B /07/ ND (<2.0) ND (<0.50) ND (<0.50) ND (<0.050) ND (<1.0) 29 ND (<2.0) ND (<1.0) ND (<1.0) B /07/ ND (<2.0) ND (<0.50) ND (<1.0) 33 ND (<2.0) ND (<1.0) ND (<1.0) Number of Samples: 6 Background Range Reference: Scott (1995) NE 0.2 to 5.5 NE 0.3 to 1.4 NE 30.5 to 72 NE 23.8 to to 16.1 NE NE 46.4 to 101 NE NE NE NE 47.7 to 82.8 Background Range Reference: Bradford et al (1996) 0.15 to to to 1,400 1 to to to 1, to to to to to to to to to to to 236 Background Range Reference: Shacklette & Boerngen (1984) , Table Notes: General: Mg/kg: Milligrams per kilogram (parts per million equivalent) ND (<2.0): Not detected at or above the laboratory reporting limit NE: Not established/not published Depth of sample in feet below ground surface (feet bgs) CAM 17 Metals analyzed by EPA Methods 3050B/6010B/7471A Consultant: Green Environment inc., San Carlos, CA Laboratory: Severn Trent Laboratories, Inc., Pleasanton, California (CAELAP #2496) Background References: Scott, Christina M. (1995): Background Metal Concentrations in Soils in Northern Santa Clara County, California," in: Recent Geologic Studies in the San Francisco Bay Area, Sangines, E. M, Andersen, D. W., and Bruising, A. V. (editors), The Pacific Section of the Society of Economic Paleontologists and Mineralogists, Pacific Section Volume 76, May 3-5, Bradford, G. R., Chang, A. C., Page, A. L., Bakhtar, D., Frampton, J. A. and Wright, H. (1996): "Background Concentrations of Trace and Major Elements in California Soils, Kearney Foundation Special Report, Kearney Foundation of Soil Science, Division of Agriculture and Natural Resources, University of California, March 1996 Shacklette, H. T. and Boerngen, J. G. (1984): Element Concentrations in Soils and Other Surficial Materials, Conterminous United States," U. S. Geological Survey Professional Paper Data represent upper estimate regional background.

27 Table 3 - Analytical Results for Groundwater Samples Sample Sample Date Total Purgeable Petroleum Hydrocarbons, TPHg Volatile Organic Compounds, EPA 8260B VOC's Benzene Toluene Ethylbenzene Total Xylenes MTBE Other VOC's TEPHd Total Extractable Petroleum Hydrocarbons, TEPH TEPHmo TEPHk TEPHss TEPHho Acenaphthylene Semi-Volatile Organic Compounds, EPA 8270C SVOC's Fluoranthene Pyrene Benzo(a)-pyrene Indeno(1,2,3- c,d) pyrene Benzo (g,h,i)- perylene Other SVOC's ug/l µg/l µg/l µg/l µg/l µg/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l GW-1 10/07/04 ND (<50) ND (<0.50) ND (<0.50) ND (<0.50) ND (<1.0) ND (<5.0) ND (<0.50 to 50) ND (<50) ND (<500) ND (<50) ND (<50) ND (<500) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0 to <10) GW-2 10/07/04 ND (<50) ND (<0.50) ND (<0.50) ND (<0.50) ND (<1.0) ND (<5.0) ND (<0.50 to 50) 120 (7) 530 ND (<50) ND (<50) ND (<500) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0 to <10) GW-3 10/07/04 ND (<50) ND (<0.50) ND (<0.50) ND (<0.50) ND (<1.0) ND (<5.0) ND (<0.50 to 50) ND (<50) ND (<500) ND (<50) ND (<50) ND (<500) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0 to <10) GW-4 10/07/04 ND (<50) ND (<0.50) ND (<0.50) ND (<0.50) ND (<1.0) ND (<5.0) ND (<0.50 to 50) 53 (7) ND (<500) ND (<50) ND (<50) ND (<500) ND (<2.0 to <10) GW-5 10/07/04 ND (<50) ND (<0.50) ND (<0.50) ND (<0.50) ND (<1.0) ND (<5.0) ND (<0.50 to 50) ND (<50) ND (<500) ND (<50) ND (<50) ND (<500) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0 to <10) GW-6 10/07/04 ND (<50) ND (<0.50) ND (<0.50) ND (<0.50) ND (<1.0) ND (<5.0) ND (<0.50 to 50) ND (<50) ND (<500) ND (<50) ND (<50) ND (<500) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0) ND (<2.0 to <10) Total Number of Samples: 6 Table A RWQCB ESLs (1) 100 (6) Varies by compound 100 (4) 100 (5) 100 (4) 100 (4) 100 (5) Varies by compound Table B RWQCB ESLs (2) 500 (6) ,800 Varies by compound 640 (4) 640 (5) 640 (4) 640 (4) 640 (5) Varies by compound Table E-1a (3) groundwater screening levels potential indoor air impacts residential Use soil gas 1, ,000 52, ,000 48,000 Varies by compound Use soil gas N/A Use soil gas Use soil gas N/A Use soil gas NE 140 NE NE NE Varies by compound Table Notes: General Sample depth mg/kg µg/kg N/A ND (<50) NE TPHg VOCs TEPH SVOCs Sample depth in feet below ground surface, bgs Milligrams per kilogram (parts per million equivalent) Micrograms per kilogram (parts per billion equivalent) Not applicable Not detected at or above the laboratory reporting limits Not determined/established Total purgeable petroleum hydrocarbons as gasoline by Environmental Protection Agency (EPA) Method 8260B Volatile organic compounds by EPA 8260B Total extractable petroleum hydrocarbons by EPA Method 8015M with silica gel cleanup step TEPHd - TEPH as diesel TEPHmo - TEPH as motor oil TEPHk - TEPH as kerosene TEPHss - TEPH as stoddard solvent TEPHho - TEPH as hydraulic oil Semi volatile organic compounds by EPA 8270C Consultant: Green Environment inc., San Carlos, CA Laboratory: Severn Trent Laboratories, Inc., Pleasanton, California (CAELAP #2496) Detailed: 1 Environmental Screening Levels (ESLs) taken from the San Francisco Bay Region, Regional Water Quality Control Board (RWQCB): Screening for Environmental Concerns at Sites With Contaminated Soil and Groundwater, Interim Final July 2003 including ESL updated and corrections ESLs correspond to scenario where groundwater IS a current or potential source of drinking water (Table A) 2 ESLs taken from the San Francisco Bay Region, RWQCB (July 2003): Screening for Environmental Concerns at Sites With Contaminated Soil and Groundwater. ESLs correspond to scenario where groundwater IS NOT a current or potential source of drinking water (Table B) 3 ESLs taken from the San Francisco Bay Region, RWQCB (July 2003): Screening for Environmental Concerns at Sites With Contaminated Soil and Groundwater. ESLs correspond d to groundwater screening levels for evaluation of potential indoor impacts (Table E-1a) 4 Environmental screening level for TPH (middle distillates) 5 Environmental screening level for TPH (residual fuels) 6 Environmental screening level for TPH (gasolines) 7 According to the laboratory, hydrocarbon reported was in the late diesel range, and did not match the laboratory diesel standard

28 Green Environment inc. Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA ATTACHMENT A County Health Agency Permit

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32 Green Environment inc. Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA ATTACHMENT B Geoprobe Boring Logs

33 Project: B04086 Drill Dates: October 7, 2004 Site: Bradford Street Parcels, Redwood City, CA Drill Times: 2:40 PM to 3:10 PM Driller: Environmental Probing, Enprob C Hole Depth: 20 feet below ground surface (bgs) Drill Rig: Geoprobe TM System 5410 Hole Diameter: 2.25 inches Method: Hydraulic direct-push probe Logged By: Richard A. Garlow, RG 7472 Sample Label Sample Depth Sample Date & Time Field PID PVC Pipe LOG OF BORING B-1 Depth, feet (bgs) Sample Interval USCS Description 0 2 Fill SILTY CLAY, medium to light brown with sands and gravels, dry to damp Fill SANDY CLAY, brown, fine grained sands, plant and shell 0.7 ppm 4 fragments, damp at 4 ft B ft 10/07/04, 2:50 PM 6 Fill SILTY CLAY, brown to yellow brown, some gravels, damp 0.7 ppm 8 at 8 ft Fill SILTY CLAY, dark brown, moderate plasticity, moist OH SILTY CLAY, dark brownish gray, moderate to high plasticity, 10 moist, organic odor CL SILTY CLAY, brown, moderate plasticity, damp to moist 1.5 ppm 12 at 12 ft OH SILTY CLAY, dark gray some gravels, moderate to high plasticity, moist, 14 CL SILTY CLAY, light brown, some fine grained sands, moderate plasticity, moist CL SANDY CLAY, light brown, fine grained sands, moderate 1.6 ppm 16 plasticity, moist at 16 ft 10/7/2004 SC CLAYEY SAND, brown, fine grained sands, wet 3:10 PM Increasing sands SC/SP CLAYEY SAND to SAND, brown, fine grained sands, wet END OF BOREHOLE AT 20 FEET BGS A core sampler consisting of a cylindrical steel tube of inch diameter was used for continuous soil sampling. Following soil sampling, the driller installed screened PVC casing of 1 inch diameter in the borehole. Depth-to-water was 17 feet bgs at 3:10 PM on 10/07/04. At 3:20 PM (10/07/04), a groundwater sample (Sample GW-1: 40-ml VOAs, 1-lt amber bottles) was collected by lowering a dedicated, disposable bailer into the PVC casing. However a pneumatic pump with dedicated disposable tubing was used to fill the 1-lt amber bottles. No sheen or floating product was noted in the groundwater at the time of sampling. The borehole was backfilled with neat cement.

34 Project: B04086 Drill Dates: October 7, 2004 Site: Bradford Street Parcels, Redwood City, CA Drill Times: 1:20 PM to 1:50 PM Driller: Environmental Probing, Enprob C Hole Depth: 20 feet below ground surface (bgs) Drill Rig: Geoprobe TM System 5410 Hole Diameter: 2.25 inches Method: Hydraulic direct-push probe Logged By: Richard A. Garlow, RG 7472 Sample Label Sample Depth Sample Date & Time Field PID PVC Pipe LOG OF BORING B-2 Depth, feet (bgs) Sample Interval USCS Description 0 2 Fill SILTY CLAY, brown to light brown, some sands and gravels 0.5 ppm 4 Fill CLAYEY SAND, light brown, slightly damp at 4 ft Fill SILTY CLAY, dark brown to gray, slightly damp B ft 10/07/04, 1:30 PM Fill SILTY CLAY, dark brown with white sandstone pebbles, damp 6 Fill SILTY CLAY, mottled brown and greenish brown, some fine grained sands, damp 0.3 ppm 8 OH SILTY CL;AY, dark gray,moderate to high plasticity, moist at 8 ft ppm 12 SP SAND, gray to light gray, moist at 12 ft CL SILTY CLAY, dark gray some fine grained sands, moderate plasticity, moist, ppm 16 at 16 ft CL CL CL SANDY CLAY, gray, fine grained sands, damp SILTY CLAY, mottled light brown and gray, moderate plasticity, moist to damp SILTY CLAY, dark gray, moderate plasticity, moist 18 10/7/2004 SP SAND, dark gray, fine grained sands, wet 1:50 PM OH SILTY CLAY, dark to medium gray, moderate to high 20 plasticity, moist END OF BOREHOLE AT 20 FEET BGS A core sampler consisting of a cylindrical steel tube of inch diameter was used for continuous soil sampling. Following soil sampling, the driller installed screened PVC 22 casing of 1 inch diameter in the borehole. Depth-to-water was 18 feet bgs at 1:50 PM on 10/07/04. At 2:00 PM (10/07/04), a groundwater sample (Sample GW-2: 40-ml VOAs, 1-lt amber bottles) was collected by lowering a dedicated, disposable 24 bailer into the PVC casing. However a pneumatic pump with dedicated disposable tubing was used to fill the 1-lt amber bottles. No sheen or floating product was noted in the groundwater at the time of sampling. The borehole was 26 backfilled with neat cement.

35 Project: B04086 Drill Dates: October 7, 2004 Site: Bradford Street Parcels, Redwood City, CA Drill Times: 12:00 PM to 12:30 PM Driller: Environmental Probing, Enprob C Hole Depth: 19 feet below ground surface (bgs) Drill Rig: Geoprobe TM System 5410 Hole Diameter: 2.25 inches Method: Hydraulic direct-push probe Logged By: Richard A. Garlow, RG 7472 Sample Label Sample Depth Sample Date & Time Field PID PVC Pipe LOG OF BORING B-3 Depth, feet (bgs) 0 2 Sample Interval USCS Fill Fill Fill Fill Description SANDY GRAVEL, gray, dry SILTY CLAY, brown, some sands and gravels, damp SANDY GRAVEL, light gray brown, damp SILTY CLAY, dark brown with white sandstone pebbles, damp to moist 0.4 ppm 4 Fill SILTY CLAY, dark gray to brown, moderate plasticity, moist at 4 ft B ft 10/07/04, 12:10 PM 6 some fine grained sands 1.0 ppm 8 at 8 ft Fill SANDY GRAVEL, up to 0.5 inches diameter, dry to damp 10 OH SILTY CLAY, dark gray, moderate to high plasticity, moist 1.1 ppm 12 at 12 ft 14 CL SILTY CLAY, mottled greenish gray to yellow brown, moderate plasticity, moist 0.9 ppm 16 SC CLAYEY SAND, yellow brown, moist at 16 ft OH SILTY CLAY, dark gray, brown, high plasticity, moist 10/7/2004 SC CLAYEY SAND, brown, fine grained sands, wet 12:30 PM 18 CL SILTY CLAY, yellow brown, moist SC CLAYEY SAND to SAND CLAY, very moist END OF BOREHOLE AT 19 FEET BGS 20 A core sampler consisting of a cylindrical steel tube of inch diameter was used for continuous soil sampling. Following soil sampling, the driller installed screened PVC casing of 1 inch diameter in the borehole. Depth-to-water was feet bgs at 12:30 PM on 10/07/04. At 12:40 PM (10/07/04), a groundwater sample (Sample GW-3: 40-ml VOAs, 1-lt amber bottles) was collected by lowering a dedicated, disposable bailer into the PVC casing. However a pneumatic pump with dedicated disposable tubing was used to fill the 1-lt 24 amber bottles. No sheen or floating product was noted in the groundwater at the time of sampling. The borehole was backfilled with neat cement. 26

36 Project: B04086 Drill Dates: October 7, 2004 Site: Bradford Street Parcels, Redwood City, CA Drill Times: 10:40 AM to 11:10 AM Driller: Environmental Probing, Enprob C Hole Depth: 22.5 feet below ground surface (bgs) Drill Rig: Geoprobe TM System 5410 Hole Diameter: 2.25 inches Method: Hydraulic direct-push probe Logged By: Richard A. Garlow, RG 7472 Sample Label Sample Depth Sample Date & Time Field PID PVC Pipe LOG OF BORING B-4 Depth, feet (bgs) Sample Interval USCS Description 0 2 Fill Fill Fill SANDY GRAVEL, gray, dry SILTY CLAY, gray brown sands and gravels, slightly damp SILTY CLAY, dark gray brown, some sands and gravels, Fill SILTY CLAY, yellow brown, gravels up to 1 inch diameter, 1.2 ppm 4 some fine grained sands, damp to moist at 4 ft B ft 10/07/04, 10:50 AM ppm 8 Fill GRAVELLY SAND to SANDY GRAVEL, dry at 8 ft Fill FRACTURED ROCK, dry 0.6 ppm 10 Fill SILTY CLAY, mottled brown gray to light brown, moist at 10 ft OH SILTY CLAY, mottled dark gray and brown, moderate to high plasticity, moist 12 OH SILTY CLAY, dark gray,moderate to high plasticity 1.2 ppm SP SAND, dark gray, fine grained sands, moist at 13 ft CL SILTY CLAY, dark gray, moist to very moist 14 SC CLAYEY SAND, dark gray, fine grained sands, moist OH SILTY CLAY, dark gray,brown, moderate to high plasticity, moist 1.0 ppm 16 at 16 ft SC CLAYEY SAND, gray, fine grained sands, moist OH SILTY CLAY, dark gray, moderate to high plasticity, shell fragments, moist 0.8 ppm 18 at 18 ft CL/SC SANDY CLAY to CLAYEY SAND, dark gray, fine grained sands, moist to very moist OH SILTY CLAY, dark gray, moist 0.6 ppm 20 SC CLAYEY SAND, brown to yellow brown, moist at 20 ft 10/7/2004 SC CLAYEY SAND, dark gray brown, fine grainded sands, wet 11:10 AM H 2 S odor 22 SP SAND, brown to light brown, wet END OF BOREHOLE AT 22.5 FEET BGS A core sampler consisting of a cylindrical steel tube of 2.25-inch diameter 24 was used for continuous soil sampling. Following soil sampling, the driller installed screened PVC casing of 1 inch diameter in the borehole. Depthto-water was 20.5 feet bgs at 11:10 AM on 10/07/04. At 11:20 AM (10/07/04), a groundwater sample (Sample GW-4: 40-ml VOAs, 1-lt 26 amber bottles) was collected by lowering a dedicated, disposable bailer into the PVC casing. However a pneumatic pump with dedicated disposable tubing was used to fill the 1-lt amber bottles. No sheen or floating product was noted in the groundwater at the time of sampling. The borehole was backfilled with neat cement. 28

37 Project: B04086 Drill Dates: October 7, 2004 Site: Bradford Street Parcels, Redwood City, CA Drill Times: 8:00 AM to 8:40 AM Driller: Environmental Probing, Enprob C Hole Depth: 20 feet below ground surface (bgs) Drill Rig: Geoprobe TM System 5410 Hole Diameter: 2.25 inches Method: Hydraulic direct-push probe Logged By: Richard A. Garlow, RG 7472 Sample Label Sample Depth Sample Date & Time Field PID PVC Pipe LOG OF BORING B-5 Depth, feet (bgs) Sample Interval USCS Description 0 Fill SANDY GRAVEL, gray,dry Fill SILTY CLAY, light brown, sands and gravels up to 1 inch 2 diameter Fill SILTY CLAY, dark brown, some fine grained sands, damp B ft 10/07/04, 8:10 AM 0.2 ppm 4 at 4 ft Fill Fill SILTY CLAY, mottled light brown to brown, damp SILTY CLAY, dark brown, some fine grained sands, damp 0.9 ppm 6 at 6 ft Fill SANDY GRAVEL, light brown to light gray, gravel up to 1.5 inches diameter, damp Fill SILTY CLAY, mottled light and dark brown, moist to very moist 0.5 ppm 8 at 8 ft Fill SILTY CLAY, dark brown, moist to damp 0.8 ppm 10 at 10 ft Fill SANDY GRAVEL, light gray, damp 1.2 ppm 12 OH SILTY CLAY, dark brown to red brown, moderate to high at 12 ft plasticity, moist 1.5 ppm 14 at 14 ft 16 CL SILTY CLAY, mottled brown and gray brown, moderate plasticity, some fine grained sands, moist to very moist 0.3 ppm at 17 ft 10/7/2004 SC CLAYEY SAND, brown to grayish brown, fine grained to 8:30 AM medium grained sands, wet SP SAND, brown, fine grained sands, wet END OF BOREHOLE AT 20 FEET BGS A core sampler consisting of a cylindrical steel tube of inch diameter was used for continuous soil sampling. Following soil sampling, the driller installed screened PVC casing of 1 inch diameter in the borehole. Depth-to-water was 17 feet bgs at 8:30 AM on 10/07/04. At 8:40 AM (10/07/04), a groundwater sample (Sample GW-5: 40-ml VOAs, 1-lt amber bottles) was collected by lowering a dedicated, disposable bailer into the PVC casing. However a pneumatic pump with dedicated disposable tubing was used to fill the 1-lt amber bottles. No sheen or floating product was noted in the groundwater at the time of sampling. The borehole was backfilled with neat cement.

38 Project: B04086 Drill Dates: October 7, 2004 Site: Bradford Street Parcels, Redwood City, CA Drill Times: 9:20 AM to 9:50 AM Driller: Environmental Probing, Enprob C Hole Depth: 22.5 feet below ground surface (bgs) Drill Rig: Geoprobe TM System 5410 Hole Diameter: 2.25 inches Method: Hydraulic direct-push probe Logged By: Richard A. Garlow, RG 7472 Sample Label Sample Depth Sample Date & Time Field PID PVC Pipe LOG OF BORING B-6 Depth, feet (bgs) Sample Interval USCS Description Fill SANDY GRAVEL, gray, dry Fill SILTY CLAY, dark brown, some sands and gravels, slightly 2 damp Fill SANDY GRAVEL, light and slightly damp Fill SILTY CLAY, light brown, some fine grained sands, damp 0.3 ppm 4 at 4 ft Fill SILTY CLAY yellowish brown, some fine grained sands, moist B ft 10/07/04, 9:30 AM shell fragments 0.6 ppm 6 at 6 ft 0.8 ppm 8 at 8 ft OH SILTY CLAY, dark gray,some fine grained sands, moderate to 0.6 ppm 10 high plasticity, moist at 10 ft 0.7 ppm 12 at 12 ft 0.6 ppm at 14.5 ft OH SILTY CLAY, gray brown, moderate to high plasticity, moist- 14 damp 16 CL SILTY CLAY, dark gray, moderate plasticity, moist SC CLAYEY SAND, dark brownish gray, fine grained sands, very moist 0.8 ppm 18 at 18 ft CL SILTY CLAY brown to light brown, some fine grained sands, moist CL SANDY CLAY, mottled gray to brownish gray, fine grained 0.7 ppm 20 sands, moist at 20 ft 10/7/2004 9:50 AM 22 SC CLAYEY SAND, brown to dark brown, fine to medium grained sand, wet END OF BOREHOLE AT 22.5 FEET BGS A core sampler consisting of a cylindrical steel tube of 2.25-inch diameter was used for continuous soil sampling. Following soil sampling, the driller installed screened PVC casing of 1 inch diameter in the borehole. Depthto-water was 21.5 feet bgs at 9:50 AM on 10/07/04. At 10:00 AM (10/07/04), a groundwater sample (Sample GW-6: 40-ml VOAs, 1-lt amber bottles) was collected by lowering a dedicated, disposable bailer into the PVC casing. However a pneumatic pump with dedicated disposable tubing was used to fill the 1-lt amber bottles. No sheen or floating product was noted in the groundwater at the time of sampling. The borehole was backfilled with neat cement.

39 SOIL BORING KEY FOR GEOPROBE BORINGS LOG SYMBOLS DESCRIPTION Geological contact, approximate Termination of boring 10/07/04, 2:50 PM Field PID Depth-to-water with date and time of measurement Field screening results for total volatile organics (TVOs) measured with a portable photo-ionization detector (PID). TVOs measured in parts per million, ppm. PID = MiniRAE 2000 Portable VOC Monitor, Model PGM 7600 PID calibrated with 100 ppm isobutylene standard SAMPLE RECOVERY DESCRIPTION Tube sample retained for possible laboratory analyses Tube sample retrieved for field inspection No sample recovery SAMPLE LABEL DESCRIPTION B Soil Sample "B " was taken from Boring B-1 from the 5.5 to 6.0 feet depth interval and retained for possible laboratory analyses. Depth measured in feet below the top or ground surface. TEMPORARY CASING Solid PVC Casing Screened PVC Casing DESCRIPTION Following soil sampling, temporary polyvinyl chloride (PVC) casing of 1-inch diameter was installed in the borehole Page 1 of 1

40 Green Environment inc. Subsurface Investigation Report Bradford Street Parcels, Redwood City, CA ATTACHMENT C STL-San Francisco Laboratory Report

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