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In August 2000,JPCA advanced three soil borings (BI, MW4, and MW5), MW4 and MW5 were
<br /> completed as monitoring wells BI was advanced to a depth of 115 feet bgs and MW4 and MW5
<br /> were installed to a depth of 75 feet bgs Soil and groundwater samples were collected and
<br /> analyzed Site activities were summarized in JPCA's 2'd Phase 11 Environmental Assessment
<br /> 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 MW6a, MW6b, MW7a, and MW7b to the east of the site These
<br /> borings were completed as well clusters with MW6a and MW7a advanced to a depth of
<br /> approximately 75 feet bgs, and MW6b and MW7b advanced to a depth of approximately 94 feet
<br /> bgs GHH also installed EW1 in the southeast portion of the site Site activities were
<br /> summarized in GHH's Second Quarter 2003 Groundwater Monitoring Report and Additional
<br /> 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 /> MW l Ob, and MW l Oc
<br /> 2.0 GROUNDWATER MONITORING ACTIVITIES
<br /> During the June 21-22, 2005 event ATC personnel collected groundwater samples from MW1
<br /> through MW5, MW6a, MW6b, MW6c, MW7a, MW7b, MW7c, MW8, MW9a, MW9b, MW9c,
<br /> MW10a, MW10b, MW10c and EW1 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 8015M, 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 /> ether (DIPE), tertiary amyl ether (TAME), tertiary butyl ether (TBA), 1,2-dichloroethane (1,2-
<br /> S 1268231QM reports12005 2ndQR doe 2
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