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Mr Paul Supple Project 20805-140 006 <br /> January 28, 1998 <br /> Page 3 <br /> PREFIELD ACTIVITIES <br /> EMCON will obtam well perrruts from the SJCPHS, Environmental Health Division <br /> EMCON will also notify Underground Service Alert of its intent to drill at least 48 hours <br /> before drilling to identify the location of underground utilities A private utility-locating <br /> contractor will also be used to locate utilities or other subsurface obstructions. <br /> FIELD OPERATIONS <br /> EMCON field personnel will observe a licensed well driller drill up to three <br /> ? 1 18-mch-diameter soil borings at locations crossgradient to downgradient of the USTs (see <br /> ` <br /> Figure ) near the southeastern property boundary The borings will be drilled to depths of <br /> o approximately 50 feet bgs Groundwater is presently approximately 33 feet bgs and has <br /> � risen approximately 12 feet since 1993 If a 5-foot-thick clay layer is encountered less than `� <br /> 4 15 feet below static groundwater level, the drilling will be terminated within the clay unit Il J <br /> Field screening will be conducted using a portable photoionizanon detector ) to <br /> perform head space analysis Soil from each sampled interval will be placed in a Ziploc® <br /> • bag to allow volatilization of petroleum hydrocarbons. The PID will be used to measure <br /> the volatilized petroleum hydrocarbons, and readings will be entered on the boring logs at <br /> the respective depth intervals <br /> One 2-inch-diameter groundwater monitoring well (MW-7, MW-8, and MW-9) will be <br /> installed in each boring, if warranted If there is no evidence of groundwater impact <br /> during drilling and installation of MW-7, then wells MW-8 and MW-9 will not be <br /> installed The wells will be constructed using 20-foot sections of 0 02-inch slotted screen <br /> Number 3 sand will be used as the filter pack. <br /> Undisturbed soil samples will be collected from each soil boring using modified California <br /> split-spoon sampling equipment. A nu mum of two soil sam les fr each boring and a <br /> composite sample from the drill cuttangs will be submitted to an approved laboratory f <br /> certified by the state of California. The soil samples will be analyzed for TPHG and <br /> BTEX/methyl tert-butylether (MTBE) using modified U S Environmental Protection <br /> Agency (USEPA) Methods 8015 and 8020, respectively <br /> Drill cuttings will be stored on, and covered with, plastic pending characterization analysis <br /> and evaluation of disposal alternatives A four-point sample collected from the drill <br /> cuttings will be analyzed for TPHG and BTEX using USEPA Method 8015/8020 total <br /> lead using USEPA Method 7410 ARCO's waste transporter, Dillard Trucking, will <br /> transport soil cuttings to TPS for disposal <br /> • <br /> SA"VW805\08051400 6AS-99�cbell 2 <br />