ARCHIVED REPORTS XR0003357 - Laserfiche WebLink

Home Browse Search

S E C 0 R 7-Eleven Store#14117 Work Plan for Additional Site Assessment July 27, 2004 Page 4 cleaned before drilling each borehole, and sampling equipment will be cleaned between each sampling interval Each soil sample will be screened for hydrocarbon vapors using a portable photolonization detector (PID) Soil samples retained for analysis will be sealed with Teflon® sheets and plastic caps, then labeled and placed on ice in an insulated container for delivery under chain of custody to Kiff Analytical LLC in Davis, California The sod encountered during drilling will be logged using the Unified Soil Classification System by a SECOR field geologist, working under the supervision of a California registered geologist GeoprobeTm Borings SECOR will supervise the drilling and advancement of three offsite GeoprobeT"soil borings (GP-1 through GP-3) at the locations shown on Figure 2 and summarized in Table 3 The borings will be advanced using a standard GeoprobeT"" sampling ng, and will be continuously cored with a 2-inch diameter Macro Core® sampling device from 5 to 15 feet bgs One sample per boring will be retained and analyzed for TPHg, BTEX, and MtBE using Environmental Protection Agency (EPA) Method 8260B (Table 4) Grab groundwater samples will be collected from temporary well casing installed into each boring using a slim hole disposable baiter The groundwater will be decanted from the bailer into 40-m1 volatile ' organic analysis (VOA) vials, and capped Each VOA vial will be checked to ensure no bubbles are present, labeled, placed on Ice, and transported to the laboratory under chain- of-custody documentation The grab groundwater samples collected from the Geoprobe borings will be analyzed for TPHg, BTEX, and fuel oxygenates using EPA Method 8260B Following collection of the water sample, each boring will be tremie grouted from 15 feet to grade with neat cement and finished at grade with concrete to match existing paving, CPT Borings SECOR will supervise the advancement of one onsite (CPT-1) and two offsite (CPT-2 and CPT-3) CPT borings to an approximate depth of 110 feet bgs at the locations shown on Figure 2 The borings will be advanced using a direct push CPT ng to log sod stratigraphy Based on the results of the CPT tests, three grab groundwater sample depth intervals near 70, 90, and 110 feet bgs will be Identified (e g high-permeable soil zone) for each CPT location Each grab groundwater sample will be collected from a separate and adjacent borehole using a modified HydroPunch®sampler Prior to sampling, a water level meter will be used to confirm that the drive rods do not contain water The sampler will be driven to approximately 3 feet below the desired sampling depth and retracted 3 feet to expose the disposable schedule 20 poiyvinyl chloride (PVC) screen and allow groundwater to enter the HydroPunch® sampler The water sample will be collected by lowering a 3/4'-diameter stainless steel bailer through the drive rods to groundwater The groundwater will be balled from the drive rods, decanted from the bailer into 40-ml VOA vials, and capped Each VOA vial will be checked to ensure no bubbles are present, labeled, placed on ice, and transported to the laboratory under chain-of-custody documentation The drive rods will be retracted, leaving the disposable drive tip and 4 foot length of PVC well screen in the hole • File 7-11/14117 WP for additional assessment(July 04)doe SECOR Intemebonal Incorporated