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r. Underground Storage Tank Deline"31 n Sampling Using Cone Penetration Testing With An Ultra-Violet Optical Screening Tool Report 216 N.California Street Page 3 of 7 underground utilities until the first day of drilling and required positive location of lines by hand digging or vacuum excavation prior to drilling within 10 lateral feet of surface markings. This requirement made drilling in the traffic or parking lane of northbound California Street impractical during this phase of the investigation. Prior to initiating fieldwork at the Site, all field personnel were familiarized with the Site Specific Health and Safety Plan included in the Work Plan. 2.2 CONE PENERATION TEST FIELD PROCEDURES The CPT borings were hydraulically advanced using a 2-inch diameter conical bit in conjunction with a UVOST module. The soil behavior (tip pressure and sleeve friction) was logged as the probe was advanced. The ratio of soil behaviors was used to classify the penetrated soil by soil behavior type (SBT), which is similar to the Unified Soil Classification System (USCS). The UVOST module emitted _ ultra-violet light through a window in the module that caused hydrocarbon molecules to fluoresce. Fiber- optic cables transmit fluorescence data to the surface, where intensity and decay were recorded approximately every 2 inches. The UVOST data was correlated to the SBT data. Decay signatures indicated the type of hydrocarbon impact and the signal intensity indicated the location. Data logs were prepared containing observations including SBT, UVOST measurements, and the location of soil and groundwater samples. Soil and groundwater samples were collected from the borings for laboratory analyses based upon CPT and UVOST measurements. Discrete depth soil samples were collected from the borings with a 1-inch outside diameter (O.D.), 12-foot-long core barrel fitted with a clean, single use, stainless steel liner. The soil sampling equipment was`7c eaneTprior to collecting the samples. Soil samples were collected from selected borings and intervals for laboratory analyses. The liners were sealed at the ends with Teflon® sheeting, capped, and labeled. The samples were placed in a cooler with Blue Ice® and delivered under chain-of-custody procedures to a California-certified laboratory for analyses. The groundwater samples from the borings were collected using a push-type groundwater sampler. The .- sampler has a sealed, retrievable stainless steel screen. The sampler was pushed in a closed position to the desired sampling interval. The sampler push rod was then retracted exposing the inlet screen. Groundwater flowed hydrostatically from the formation into the inlet screen. A groundwater sample was retrieved from within the screen with a small diameter stainless steel bailer. The groundwater samples were discharged directly from the bailer into laboratory supplied sample containers. The sample containers were sealed, labeled, placed in a cooler with Blue Ice®, and delivered under chain-of-custody procedures. Upon completion of the borings and sampling, the borings were grouted with neat cement to the surface with SJCEHD observation and/or authorization. _ 3.0 SOIL AND GROUNDWATER INVESTIGATION Each CPT location consisted of one to four co-located but separate borings within a 4-foot radius. First, the CPT/UVOST testing probe was advanced to a depth of 100 feet bgs to evaluate the vertical extent of ■- soil contamination. Separate borings were advanced to collect each groundwater sample at selected depths after CPT/UVOST data and logs were analyzed. The last boring was advanced to collect the soil samples. CPT 1-1 was placed in the landscaped area, approximately 5 feet east of the former location of .. the UST and previously-advanced SB-1. Groundwater samples were collected at depths of 61 feet and 75 feet bgs from two separate borings, CPT 1-2 and 3, to minimize the potential for cross-contamination as directed in the contingent Work Plan approval letter from SJCEHD dated October 30, 2008. Four soil samples were then collected from a separate boring, CPT 1-4 at depths of approximately 60 feet, 72 feet, 80 feet, and 100 feet bgs,based upon indications of contamination from the UVOST tool. is CONDOR