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N ff A S S O C I A T E S I N C TPHd was reported at levels ranging from non-detected(less than 1.0 ppm)to 720 ppm in soil samples F r collected across the site. No TPHd was detected in borings SB-7 or MW-5. Results of laboratory Ff analyses of soil samples are summarized in Table 1. F Soil samples collected from depths greater than 11 feet below grade were within the saturated zone. Analytical results of those samples are more indicative of groundwater contamination rather than soil contamination. Results of soil samples collected in the vadose zone (less than 11 feet deep) suggest that shallow soil contamination is somewhat random and not laterally continuous across the site. Furthermore,no BTEX constituents are present at significant levels. , f 2.0 METHOD AND PROCEDURES 1 All work described herein was performed in accordance with ATC's Workplan for Subsurface Investigation, dated July 12, 1999, which was approved with minor modifications by PHS/EHD. The scope of work completed included obtaining permits, advancing three soil borings using direct push technology, soil and grab groundwater sampling, and the laboratory analysis of selected soil and groundwater samples. 2.1 Drilling Activities On September 17, 1999, a geologist from ATC Associates supervised the advancement of three soil borings to 30 feet bgs. A site plan showing soil boring locations is included as Figure 2. Fisch Environmental, California License C57 683865, advanced the borings using a truck mounted Geoprobe® narrow diameter rig employing direct push technology. Soil samples were collected in acetate sampling tubes beginning and were described according to the Unified Soil Classification System. Descriptions of soil types encountered and sample collection intervals are presented on the boring logs contained in Appendix A. 2.2 Soil Sampling Each soil sample was field screened with a Flame Ionization Detector (FID) for the presence of F volatile organic compounds. Petroleum hydrocarbons were observed during field activities in borings SB 11, SB 12, and SB 13 at depths ranging from 14 to 18 feet bgs. The maximum FID readings from each boring SB 11, SB 12, and SB 13 were 50, 30, and 100 ppm, respectively. F s Sample tubes were sealed at each end using Teflon tape and plastic end caps, labeled, and placed on ice. Selected soil samples were kept on ice and delivered under chain-of-custody documentation to a State-certified Argon Laboratories Inc. (DOHS Cert. No. 2359) for chemical ✓:, analysis. wA14991\14981tirepodslpsi.doc 3 f�