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David and Marianne Warwick Heritage Square UST Tank Closure Report Page 2 Soil Sampling and Field Observations On July 26, 2002, a Condor geologist was on site to supervise the advancement of angle borings to collect samples from beneath the UST. Prior to commencement of fieldwork, a tailgate safety meeting was held and a site-specific Health and Safety Plan was discussed with, and presented to, all field personnel for their signatures. The investigation included the advancement of two rotary-driven hollow stem auger angled soil borings (TB-1 and TB-2). The boring locations at the surface are shown in Figure 4. Two soil samples were collected from each'boring from depths of approximately 10 feet bgs and 15 feet bgs (the latter two feet below the bottom of the.UST). These depths corresponded to boring distances of approximately 15 feet and 21.5 feet, respectively. The approximate sample locations'are shown in Figures 4 and 5. Soil samples were collected from the borings using a 2-inch outside diameter, split spoon sampling rod fitted with a clean brass soil sample tube. The soil sampling equipment was cleaned prior to collecting each sample by washing in a solution of laboratory-grade, non-phosphate detergent and de-ionized water, and double-rinsing with de-ionized water. The soil samples were measured for volatile organic vapors with a photoionization detector (PID) L immediate[ after collection. The 10-foot bgs and 15-foot bgs samples from TB-1 TB-1 S-1-15' and TB- Y g g p ( , 1,S-2-21.5') had PID readings of 302 parts per million (ppm) and 683 ppm, respectively. The samples collected from TB-2 (TB-2,S-1-15' and TB-2,S-2-21.5') had PID measurements of'0 ppm. After PID screening, the soil samples were sealed with Teflon@ sheeting, capped, labeled, and placed in a cooler chilled with ice and delivered under chain-of-custody 'procedures to Argon Laboratories of Ceres, California, a California certified laboratory, for analyses. Upon completion of the drilling and sampling, the boreholes were backfilled with grout. Analytical Results The four discrete sail samples were analyzed for benzene, toluene, eth lbenzene, and total xylenes p Y Y Y (BTEX), and methyl tertiary-butyl ether (MTBE) by EPA Method 8020A; for total extractable petroleum hydrocarbons quantified as kerosene (TEPH-K), diesel (TEPH-D), and motor oil (TEPH-MO) by EPA Method 8015m; and for total lead by EPA Method 7420. The discrete soil sample with the highest detected contaminant concentrations (TB-1,S-2-21.5') was analyzed for polynuclear aromatic hydrocarbons (PNAs) by EPA Method 8270C and for 17 California Administrative Manual (CAM) metals by EPA Methods 6010B and 7471 A. The analytical data support the field observations that soil contamination is present at the sampling points in association with the UST. Tables 1 and 2 present the analytical results. Laboratory reporting sheets and the chain-of-custody form are attached. Table i s Summa of Anal3lical.Results for H drocarbon Constituents and Total Lead ` CONSTITUENT B T E X MTBE TEPH-K TEPH-D TEPH-MO Total Lead Analytical Method—+ 8020A 8020A 8020A 8020A 8020A 8015m 8015m 8015m 7420 Reporting Limit-4 0.005 0.005 0.005 0.010 5.0 5.0-100 5.0 20 /kg 5.0 mg m /k m Ik m Ik m /k m k m k m /k mg/kg q Simple ID Date TB-1,S-1-15' 7/26/02 <0.005 4.011 <0.005 4.066 <0,050 <50 560 71200 11 TB-1,S-2-21.5' 7126102 <0.005 0.025 0,013 0.14 1 <0.050 <100 2,600 19.000 9.0 TB-2,S-I-15' 7126102 <0.005 <0.005 <0.005 <0.010 1 <0.050 <5.0 <5.0 <20 12 TB-2,S-2-21.5' 7126/02 <0.005 <0.045 <4.005 <.0.010 <0.054 <5.0 <5.0 <20 9.0 Now mg/kg=milligrams per kilogram=parts per million(ppm) 1 IL 4 CONDOR i