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' Mr.Marty Hartzell February 16,2001 Page 5 of 8 11- '. 4.2 Laboratory Analysis ' Selected soil samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) and diesel (TPHd) using EPA method 8015 modified; benzene, toluene, ethylbenzene and xylenes ' (BTEX) and methyl tert butyl ether (MTBE) using EPA method 8020; and total lead using EPA method 6010. In addition,the soil sample collected from SB1 at a depth of 25 feet was analyzed for oxygenated gasoline additives, including methanol and ethanol, and the lead scavengers 1,2- dichloroethane(1,2-DCA)and ethylene dibromide(EDB)using EPA method 8260. The groundwater samples collected from borings SB I and S134 were analyzed for the constituents ' listed above using methods 8015 modified, 8020, 8260, and 6010. The specific sampling intervals and analyses were determined in the field through discussions with ' Mr. Marty Hartzell of the CRWQCB, and Mr. Hartzell reviewed copies of chain-of-custody documents via facsimile prior to analyzing the samples. 4.3 Soil Analytical Results Petroleum hydrocarbon constituents were detected at elevated levels in soil samples collected at ' depths of 15, 25, and 40 feet bgs from boring SB 1, and at low levels in soil samples collected from SBI at 45 feet bgs and from SB3 at 40.5 feet bgs. Most notably, TPHg ranged from 960 ppm in SBI-15 to 31,000 ppm in SB 140, and benzene ranged from <5.0 ppm in SB1-15 to 70 ppb in SBI- 40. Sample SBI-45 contained only 1.6 ppm TPHg and <0.005 ppm benzene. No petroleum hydrocarbon constituents were detected in soil samples collected from SB 1 at depths of 50, 55, or 60 feet bgs except for xylenes, which ranged from 0,008-0.043 ppm within that interval. The soil ' sample collected from SB3 at 40 feet contained only TPHg, ethylbenzene, and xylenes at 1.4 ppm, 0.005 ppm, and 0.038 ppm, respectively. No petroleum hydrocarbon constituents were detected in any other soil sample collected from borings SB2, SB3, or SB4. No MTBE or other oxygenated gasoline additives were detected in any soil sample. TPHd was detected only in the sample collected from SBI at 15 feet bgs (630 ppm). Soil analytical results are summarized in Table 2. Laboratory reports are included in Attachment 2. ' 4.4 Groundwater Analytical Results ' Discrete groundwater samples were collected from borings SB 1 and SB4 at an interval of 60 to 65 feet bgs using a HydropunchTM sampling tool. No TPHd, TPHg, BTEX, oxygenated gasoline additives, or lead scavengers were detected in either groundwater samples. Total lead (unfiltered) detected in the groundwater water ranged from 0.029 to 0.12 ppm. Groundwater analytical results are summarized in Table 3. Laboratory reports and chain of custody documentation are included in Attachment 2. 4.5 Residual Contaminants in Soil ' The limits of impacted soil (zero line)was determined from evaluating analytical and lithology data collected during the field investigation. The maximum radius of impact was determined to be at a datslgtounaclgonzaleslsumrpt doc