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1 <br /> was used to get the rods. <br />' Drilling resumed at 1330 hours, and the augers were advanced to <br /> 55' , at which point a clean core barrel was inserted into the <br /> flights and a core was taken from 55' --5fi' 6" . The drill returns <br />' had a petroleum odor, but no visible staining. Core recovery was <br /> 18" of slightly plastic silty clay, brown to grayish brown, with <br /> occassional root casts filled with a white mineral. The core had <br />' a definite petroleum odor, and portions were discolored, possibly <br /> due to contamination_ <br /> t The augers were advanced to 60' , at which point a clean core <br /> barrel was inserted and driven from 60-61 '6" . When the barrel <br /> was retrieved, it was very wet. Upon opening the barrel, only <br /> about 3" of core material was recovered; it consisted of very wet <br /> silty clay A very faint petroleum odor was noted, but no <br /> visible staining was evident. A metal tape was lowered into the <br /> augers, and indicated water to be at about 60' 6" This is the <br />' approximate depth to groundwater in this area based upon County <br /> Flood Control District maps _ A portion of the core was sealed & <br /> preserved for later analysis. <br /> Drilling activities stopped at this point while a meeting was <br /> held with the owner, the geologist, & the County representative <br /> to discuss options. Because of the apparent contamination <br />' encountered from 30 ' to 60' , a groundwater investigation would <br /> almost certainly be required. Although the soil boring may not <br /> be in the optimum location for monitoring purposes, the cost <br />' savings of completing it where it is appear to justify that <br /> option compared to plugging it and placing a new well in another <br /> position. Therefore, it was agreed by all parties to deepen the <br /> soil boring & complete it as a groundwater monitoring well. <br />' Augers were advanced to 70'bgl, approximately 10' below the water <br /> table. PLATE VIII gives details of lithology, blow counts, <br /> times, etc. <br /> While drilling crew returned to their yard to pick up pipe for <br /> ' completing the well, Mr. Hunter transported the preserved soil <br /> samples to FGL Laboratory under chain of custody. Instructions <br /> were given to test for BTEX, TPH-G, & waste oil as instructed by <br /> the San Joaquin EHD. Upon return to the site, Mr. Hunter <br /> ' observed the drilling crew making up & running 2" , flush screw- <br /> joint blank & slotted PVC into the hole. The bottom joint was <br /> fitted with a threaded cap, perforations consisted of 15 feet of <br /> ' 0 01" shop---made slots, with blank pipe above. After landing the <br /> casing on bottom at 70 ' , a total of 6 sacks of Lonestar #2/12 <br /> graded sand was poured down the annular space between the pipe <br /> and the augers. The casing was vibrated during this operation, <br /> and sand depth was continually checked with a weighted tape. As <br /> ' 7 <br />