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CLEA Er_�.a� ER <br /> G R O U P <br /> Environmeetal Services <br /> discussion with Ms Lori Duncan of the SJC/SJC/EHD, Clearwater submitted the Workplan for <br />' Site Investigation dated November 18, 1998 An addendum to the workplan, dated December <br /> 10, 1998, was submitted in response to SJC/EHD comments The workplan and addendum were <br />' approved by the SJC/EHD on December 15, 1998 <br />' 1999 <br /> In January 1999, Clearwater supervised the installation of three additional groundwater- <br /> monitoring wells (MW-4 through MW-6) to delineate the extent of dissolved-phase <br /> contamination Concurrently, Clearwater also performed a sensitive receptor survey The results <br /> Iof the investigation indicated that the extent of sorbed-phase contamination was delineated and <br /> existed from approximately 10 to 25 feet bgs near the former USTs Analysis of the <br />' groundwater samples indicated that the extent of dissolved-phase contamination remained <br /> undelineated downgradient from the former UST system However, high contaminant <br /> concentrations in cross-gradient positioned wells suggested that off-site sources could be <br /> contributing to contamination detected beneath the site Inquiries suggested and later confirmed <br />' the existence of a fuel transport line in the area of the site The line was found to be filled with <br /> nitrogen gas Based on this information, Clearwater recommended additional investigation along <br /> ISouth Fresno Avenue to better understand the distribution of contamination and possible <br /> contribution from potential off-site sources The results of this phase of investigation were <br /> presented in Clearwater's Well Installation and Groundwater Monitoring Report - First Quarter <br /> 1999 <br /> I <br /> 2000 <br />' In March 2000, Clearwater supervised the completion of one hydropunch, six soil borings, the <br />' destruction of MW-5, and the installation of three additional monitoring wells (MW-5B, MW-7, <br /> and MW-8) in three of the soil borings All three wells were placed on the downgradient portion <br /> of the plume to help determine the downgradient extent of contaminants The hydropunch was <br /> • <br /> 4Q/04 Groundwater Monitoring Report 3 <br />