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25 September 1995 <br /> AGE-NC Project No 95-0137 <br /> Page 3 of 6 <br /> ' aromatic hydrocarbons(benzene, toluene,ethyl benzene BTE&X) in accordance with EPA methods <br /> 5030/8015-modified for fuels and 602, respectively Monitonng wells MW4 and MW-5 were <br /> installed on a later date and therefore could not be sampled during this sampling event <br /> 3 3 DRILLING AND SAMPLING <br /> ' On 14 August 1995, five soil borings were drilled at the site Each boring was drilled using a truck- <br /> mounted HT-55 drill ng equipped with hollow-stem augers The dnll ng and a two-man crew were <br /> ' supplied by Mitchell Dnihng Environmental, Inc of Sacramento, California Borings B9 and B 11 <br /> were advanced to depths of 35 feet,borings B 10,B 12 and B 13 were advanced to a depth of 20 feet <br /> ' Soil samples were collected ahead of the drill bit using a split-tube sampler loaded with three pre- <br /> cleaned 2-inch by 6-inch brass sleeves Samples were collected at five-foot intervals, using a 140- <br /> pound hammer to advance the sampler 18 inches The number of blows required to advance the <br /> sample in 6-mch increments was recorded on the boring log To avoid cross-contanunation, the <br /> sampling equipment was decontaminated in an alconox solution and rinsed twice with water prior to <br /> each sample run Augers were steam-cleaned between borings <br /> For each sample, both end f 1 <br /> p s h 1 o the lead sleeve were covered with Teflon sheets, capped and sealed <br /> with tape The samples were stored under ice and relinquished to Pan-Ag Laboratories for analysis <br /> Selected samples were analyzed for TPH-g, TPH-d and BTE&X in accordance with EPA methods <br /> 5030/8015m, 8020, respectively <br /> 1 <br /> 3 4 LOGGING <br /> ' During drilling, auger returns were monitored for the presence of organic vapors using a photo- <br /> ionizing detector (PID Thermo Environmental 580A, 10 OeV calibrated using isobutylene) <br /> Additionally, soil was extruded from the second brass sleeve and screened for the presence of organic <br /> vapors using a PID and the readings were recorded on the boring logs The soil was then described <br /> in accordance with the United Soil Classification System Boring logs are included in Appendix B <br /> 3 5 WELL COMPLETION <br /> ' Pnor to completion,water in B9 and B I 1 was allowed to stabilize to determine the g <br /> depth to round <br /> P <br /> water Subsequently,B9 and B11 were completed as 2-inch diameter ground water monitoring wells <br /> (MW-5 and MW-4, respectively), using PVC casing with 0 020 screen at a depth interval between <br /> 15 and 35 feet The filter pack(#3 sand) was installed from 14 to 35 feet and bentonite pellets were <br /> used to make a 3-foot plug to a depth of 11 feet The well was then grouted to the surface with <br />