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30 July 2008 <br /> AGE-NC Project No . 99-0682 <br /> Page 3 of 13 <br /> 2. 1 .2 . Ground Water Sample Collection <br /> Grab ground water samples were collected from two separate soil borings advanced adjacent to each <br /> CPT sounding boring, and from two paired borings (B-5 and B-6) . Samples were collected utilizing <br /> the 25-ton truck-mounted CPT drill rig equipped with 1 .75-inch diameter hollow stem rods fitted <br /> with a HydroPunch ground water sampling assembly, which was pushed to specified sampling <br /> depths in each soil boring. <br /> Ground water samples were collected from specified depth intervals (zones) based on the acquired <br /> CPT lithology data indicating favorable conditions for sampling. To collect a grab ground water <br /> sample, a HydroPunch sampling tool was pushed into the specified zone, then withdrawn <br /> approximately three to four feet to expose an inlet screen; the interior of the sampling tool filled with <br /> water and a 1 -inch outer diameter (O.D.) stainless steel bailer was lowered and utilized to extract a <br /> ground water sample. Ten grab ground water samples were collected from the following intervals : <br /> • 72 to 75 feet bsg, and 125 to 130 feet bsg from two separate borings immediately adjacent <br /> to boring CPT-6; <br /> • 72 to 75 feet bsg, and 124 to 130 feet bsg from two separate borings immediately adjacent <br /> to boring CPT-7; <br /> • 67 to 70 feet bsg, and 125 to 130 feet bsg from two separate borings immediately adjacent <br /> to boring CPT4; <br /> • 67 to 70 feet bsg, and 125 to 130 feet bsg from paired boring B-5; and <br /> • 71 to 75 feet bsg, and 125 to 130 feet bsg from paired boring B-6 . <br /> Following sample collection, samples were placed in laboratory-supplied containers : three 40-m1 <br /> VOA vials without sample preservative and into one 1 -liter amber bottle without preservative and <br /> transported under chain of custody to Cal Tech Environmental Laboratories (CTEL), a California <br /> Department of Public Health (CDPH)-certified laboratory. All samples were analyzed for: <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in <br /> accordance with EPA Method 8015 Modified; and <br /> • Benzene, toluene, ethylbenzene, and total xylenes (BTEX), fuel oxygenates di-isopropyl <br /> ether (RIPE), methyl tertiary-butyl ether (MTBE), ethyl tertiary-butyl ether (ETBE), <br /> tertiary-amyl methyl ether (TAME) and tertiary-butyl alcohol (TBA), and lead scavengers <br /> 1 ,2-dichloroethane ( 1 ,2-DCA), and 1 ,2-dibromoethane (EDB) in accordance with EPA <br /> Method 8260B . <br /> Advanced GeoEnvironmental, Inc <br />