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. . • <br /> Mr Ron Rowe Project 22611-100 001 <br /> October 7, 1996 <br /> Page 2 <br /> Task 1 - Pre-Field Activities <br /> EMCON will obtain drilling permits from the San Joaquin County Public Health Services <br /> EMCON will notify Underground Service Alert of its intent to drill at least 48 hours before <br /> drilling to identify the location of underground utilities <br /> Task 2 - Field Activities <br /> EMCON will contract a licensed well driller to drill two exploratory ,oil borings The <br /> exploratory borings will be drilled to depth of approximately 60 feet below ground surface <br /> (first-encountered groundwater) using 8-inch-diameter hollow-stern augers The purpose of <br /> these borings is to evaluate current (post vapor extraction) hydrocarbon concentrations and <br /> obtain geotechnical data on subsurface soil One proposed boring location is east of the vapor <br /> extraction well (VEW), and the second boring is north of monitoring well MW-5 Both borings <br /> will be located within the structure The soil borings will be backfilled with a c,ement/bentonite <br /> slurry In the event that field evidence (visual observation and photoionization readings) <br /> indicates elevated concentrations of residual hydrocarbons, the borings may be converted to <br /> vapor extraction wells for use during further remediation, of warranted <br /> Soil samples will be collected at 5-foot intervals and will be classified using visual and manual <br /> methods according to the Unified Soil Classification System Soil samples will be submitted <br /> to a California state-certified analytical laboratory and will be analyzed for total petroleum <br /> hydrocarbons as gasoline (TPHG), and benzene, toluene, ethylbenzene and total xylenes <br /> (BTEX) using USEPA Methods 8015 and 8020, respectively (three soil samples from each <br /> boring will be analyzed) In addition, soil samples collected at different stratigraphic units <br /> (EMCON is estimating three [3} different units) will be analyzed for permeability, moisture, <br /> saturation, bulk density, and total organic carbon This data will assist in performing the <br /> RBCA analysis <br /> All generated drill cuttings and excess soil samples will be stored on site and placed on and <br /> covered with visqueen Four soil samples will be collected from the -,oil cuttings and <br /> composited at a state-certified laboratory to determine the appropriate disposal method <br /> The composited soil sample will be analyzed for TPHG, BTEX, total lead, reactivity, <br /> corrosnvnty, and ignitabihty <br /> SAC N\P722611\26111000 1 A 96Npas i <br />