REMOVAL_2007 - Laserfiche WebLink

Home Browse Search

GeoHydrologic Consultants, Inc. recollected in Mr. Infurna's presence on March 6,2008 just north of the previous sample location.A total often soil samples were collected from beneath the three 12,000-gallon gasoline USTs (UST1N-20.5, UST1M-21.5, USTIS-21, UST2N-20, UST2M-21.5, UST2S-21, UST3N-20, UST3S-20, UST3M-22, and UST3M-N-21) (Figure 2). These soil samples were collected at a depth of approximately 2 feet below the bottom of the pea gravel filled tank pit in native soil at depths that ranged from 20 to 22 feet bgs. Three soil samples were collected from beneath the gasoline dispensers(DI-10, D2-10, and D3-10)at a depth of approximately 10 feet below grade with the direct push rig angle boring, which corresponded to a depth of approximately 2 feet below the concrete dispenser slab which was approximately 8 foot thick(Figure 2). The soil borings were abandoned with bentonite grout. Mr. Michael Infurna of SJCEHD was present during sampling activities. Soil samples were collected for laboratory analysis and soil description. Soil types and other pertinent information were recorded on a field 'log in accordance with the Unified Soil Classification System. Vapor emissions from each soil sample were also measured by placing approximately one cubic inch of soil inside a sealed plastic bag, crumbling the soil sample and allowing it to off-gas in the bag for approximately three minutes, measuring the vapor concentration in the bag headspace using a portable Mini Rae photo- ionization detector(PID), and the resulting concentration on the field log was recorded. All soil samples were collected in an acetate sampling tube for the geoprobe borings or brass rings for the hollow-stern auger borings and capped with Teflon sheeting and plastic caps. Each sample was packaged, labeled, and placed in an ice-chilled cooler in preparation for delivery to Associated under strict chain-of-custody protocols. These soil samples were analyzed by Associated for TPHg by EPA Method 8015 Modified and BTEX, MTBE, DIPE, ETBE,TAME,and TBA by EPA Method 8260B. Soil samples results for the samples collected from beneath the gasoline USTs and dispensers did not contain detectable concentrations of any of the analytes of concern. These soil sample results are summarized in Table 1 and a copy of the laboratory report and chain-of-custody documents are included in Appendix D. 3.5 Reinstallation of Vapor and Groundwater Wells On January 2, 2008, GHC obtained well installation permits from the SJCEHD, and supervised the reinstallation of replacement wells for MW-1 I/VW-3 and MW-12. A copy of the signed off well permits is included in Appendix G. At the direction of SJCEHD inspector Michael Infurna, VW-3 was installed in a separate borehole approximately 3 feet southwest of well MW-I 1 instead of being nested as proposed because of issues raised regarding centering the wells in the borehole. Replacement wells MW-i 1, MW-12, and VW-3 were installed on February 7 and 8,2008, and placed approximately five feet from the abandoned MW-12 and MW-11/VW-3 well locations in the UST area(Figure 2) in order to avoid drilling through grouted soils. The wells were installed by Test America Drilling,a licensed C-57 contractor, using a drill rig equipped with continuous- flight hollow-stem augers. Vapor well VW-2-S/VW-2-D was not reinstalled due to low hydrocarbon concentrations detected during second quarter 2007 sampling events, and TOC 172 UST Removal Report Final Page I I