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1 v <br /> RTC <br /> A S $ O C I ATE 5 I N C . <br /> 4 <br /> ' In August 2000, JPCA advanced three soil borings Bl, MW4, and MW5. The latter two wells <br /> were completed as monitoring wells. Soil boring B1 was advanced to a depth of 115 feet bgs and <br /> ' wells MW4 and MWS were installed to a depth of 75 feet bgs. Soil and groundwater samples <br /> were collected and analyzed. Site activities were summarized in JPCA's 2nd Phase II <br /> Environmental Assessment Report, dated October 25, 2000. <br /> ' in January 2003, GHH Engineering, Inc. (GHH) advanced three cone penetrometer borings and <br /> three soil borings to depths ranging from 104 feet bgs to 122 feet bgs. <br /> In May 2003 GHH advanced four soil borings, MW6a, MW6b, MW7a, and MW7b to the east of <br /> y � g <br /> the site. These borings were completed as well clusters with MW6 and MW7a advanced to a <br /> tdepth of approximately 75 feet bgs, and MW6b and MW7b advanced to a depth of <br /> approximately 94 feet bgs. GHH also installed well EW1 in the southeast portion of the site. <br /> ' Site activities were summarized in GHH's Second Quarter 2003 Groundwater Monitoring <br /> Report and Additional Assessment Report, dated June 2003. <br /> In January 2004, an ATC geologist supervised the installation of five injection wells (IW1 - <br /> IW5) associated with an ozone injection system. Each injection well has a shallow and deep <br /> spargepoint for the ozone. The shallow spargepoints were installed to a depth of approximately <br /> 74.0 feet bgs and the deep spargepoints were installed at a depth of approximately 107.7 feet bgs. <br /> From February 17 to approximately April 20, 2004, an ATC geologist supervised the installation <br /> ' of groundwater monitoring wells MW6c, MW7c, MW8, MW9a, MW9b, MW9c, MW10a, <br /> MW10b, and MW10c. The data for the well installation will be submitted separately in an <br /> ATC's report entitled Summary Report of Subsurface Investigation. <br /> 1 2.0 GROUNDWATER MONITORING ACTIVITIES <br /> During the March 16-17, 2005 event ATC personnel collected groundwater samples from MW I <br /> through MW5, MW6a, MW6b, MW6c, MW7a, MW7b, MW7c, MWS, MW9a, MW9b, MW9c, <br /> MW10a, MW10b, MW10c and EWL The locations of the wells are shown on Figure 2. <br /> ' The depth to water was measured in all wells prior to collection of groundwater samples. The <br /> pH, electrical conductivity, and temperature and were then measured in the groundwater purged <br /> ' from the monitoring wells and recorded. Turbidity was visually observed and recorded. A <br /> minimum of three well casing volumes were purged from each monitoring well prior to <br /> sampling. After samples were collected, dissolved oxygen (DO) concentrations were measured. <br /> The groundwater samples collected from each well were submitted to State-certified Argon <br /> Laboratories Inc. (Environmental Laboratory Accreditation Program Cert. No. 2359) in Ceres, <br /> California for chemical analyses of total petroleum hydrocarbons as gasoline (TPHg) and total <br /> petroleum hydrocarbons as diesel (TPHd) utilizing Environmental Protection Agency (EPA) <br /> Method 801513; benzene, toluene, ethylbenzene, and xylenes (BTEX) utilizing EPA Method <br /> 802113; and methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE) di-isopropyl <br /> 8:1268231QM reports12005 1 stQR.doc 2 <br /> 1 <br />