ARCHIVED REPORTS_XR0009338 - Laserfiche WebLink

Home Browse Search

1 samples collected at the south ends of the tanks where petroleum product odor was detected However, PI-ICs in the follow up samples collected approximately 5 feet below the initial samples, were significantly attenuated relative to the initial samples (Table 1) No EDB was detected in any of the samples Lead was detected at 6 to 12 4 mg/kg in the initial samples 1 from the north ends of both tanks, but was not detected in the follow up samples at 16 feet bgs (Table 1) 3.0 SUMMARY OF ACTIVITIES 1 Drilling and sampling services were performed by Fisch Environmental Exploration Services (Fisch) of Valley Springs California, a C-57 licensed drilling contractor Bonngs were 1 advanced using a Geoprobe8 Model 5400 equipped with a GH-40 Soil Probing Hammer. Prior to drilling operations, Fisch obtained an "Application for Well/Pump Permit" from PHS/EHD , to install the soil borings (Appendix A) The following sections describe drilling and sampling activities at each of the two sites. 1 3.1 SITE 2 1 Drilling and sampling activities at Site 2 were conducted on August 6, in general accordance with procedures described in the Work Plan. The initial boring (B2-1) was drilled to a total depth of 20 feet bgs and was located about 40 feet south of the former UST excavation, at the toe of the steeply-sloped, crushed rock and construction tile berm that borders the refrigeration dome (Figure 2). Per the Work Plan, continuous-core samples were collected from the initial 1 boring-using=a 4-foot=long,2=inch=diameter,—Macro-Core=Open Tube=Sampler=equipped-with = a_clear _plastc liner_Following extraction from the Macro-Core Sampler, core tubes were 1 typically cut in half, capped, labeled and temporarily stored in an ice-cooled chest A hthologic log was prepared-dunng drilling based on exammaton-of the soil cores and utilizing -_ the Unified Soil Classification System and generally accepted geologic interpretive descriptions 1 (Appendix A) Soli cores were examined for the presence of staining, discoloration, or odors indicative of petroleum hydrocarbon contamination. In addition, a photoionization detector (PID) was used to check for the presence of petroleum hydrocarbon vapors in the open ' borehole. No indications of petroleum hydrocarbons were detected during drilling of either of the two borings at the site Two soil samples at 15 and 20 feet bgs were prepared from the ' soil cores for submittal to the laboratory for PHC analysis Groundwater was present in the open borehole after the boring had been advanced to 12 feet 1 bgs. A groundwater sample was collected at this depth by inserting a 1-inch diameter polyvmylchlonde (PVC) tubing, machine slotted with 0.001-inch diameter openings, from the 4 98117\2WRYMS23uSrIN xrr 1