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S E C 0 R <br /> Mr Harlin Knoll <br /> March 30, 2006 <br /> Page 2 <br /> REPORT OF FINDINGS <br /> On January 26, 2006, G-R performed 1Q2006 groundwater monitoring and sampling at the <br /> site (Attachment A) Monitoring well samples collected by G-R were analyzed by a suite of <br /> analytical methods chosen to assess the presence of total petroleum hydrocarbons as <br /> diesel (TPHd), total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, <br /> ethylbenzene, and total xylenes (BTEX), and methyl tertiary butyl ether (MtBE) The <br /> analytes 1,2-DCA and EDB were added on February 27, 2006, after the 1Q2006 sampling <br /> event occurred The samples were no longer within their hold time at the laboratory, <br /> therefore, those analytes will be sampled for and reported starting with the 2Q2006 <br /> quarterly report <br /> G-R's standard operating procedures (SOPs) indicate that before sampling, each well is <br /> checked for the presence of separate-phase petroleum hydrocarbons If separate-phase <br /> petroleum hydrocarbons are not detected, then the depth to water and the total depth of ' <br /> each well is measured and recorded prior to sampling Groundwater elevations are <br /> calculated using the measured depths Groundwater elevations across the site ranged <br /> from 19 83 to 21 02 feet above mean sea level (msl), and decreased an average of 0 38 <br /> feet from the previous sampling event Groundwater flow was calculated to the northwest <br /> at an approximate hydraulic gradient of 0 007 ft/ft (Attachment A) <br /> A summary of TPHd, TPHg, BTEX, and MtBE laboratory analytical data are presented <br /> below <br /> ANALYTICAL METHODS <br /> Groundwater samples from wells MW-1, MW-2, MW-3, MW-4, MW-5, MW-6A, MW-613, and <br /> MW-7 were analyzed using the following parameters <br /> • BTEX and MtBE by EPA Method 826013, <br /> • TPHd as TPH-DRO by CA LUFT modified EPA Method 801513, and, <br /> • TPHg as TPH-GRO by CA LUFT modified EPA Method 80158 <br /> RESULTS <br /> Laboratory analytical results are summarized in Tables 1 and 2 of Attachment A The G-R <br /> report included as Attachment A <br /> Detected constituents in groundwater are summarized below <br /> N1FdeslProjectslChevron\Retaill#9-86321Periodic Monitonng1200611QMR2006 doc <br />