ARCHIVED REPORTS_XR0007365 - Laserfiche WebLink

Home Browse Search

ThirdQ uarter 2005 Thrifty#171 October 25, 2005 Page 3 Site Activities From November 18 through 21, 2003, Thrifty's consultant, AGE completed site assessment activities that consisted of dnlling three locations using cone penetrometer testing(CPT) A second boring was advanced at each CPT location to collect soil and groundwater samples The findings CPT/site assessment were summarized in the Cone Penetrometer Testing/Site Assessment Report prepared by AGE dated March 31, 2004, and provided to the SJCEHD on Apnl 12, 2004 On May 18, 2004 Thrifty visited the site and met with the SJCEHD to discuss the environmental status of the site and to collect data regarding sensitive receptors in the area Thrifty collected additional sensitive receptor data (production well data) from the State Department of Water Resources and contacted the Stockton Fire Department (SFD) and Stockton Building Department (SBD) regarding former gasoline service stations that bordered the site The SFD and SBD sent data to Thrifty indicating that service stations were previously located to the north and west of the site As requested by the SJCEHD, Thrifty prepared and submitted a Preliminary Site Conceptual Model(PSCM) dated September 17, 2004 The PSCM recommended that a workplan should be prepared to develop a scope of work to address groundwater contamination beneath the site including the installation of at least one groundwater extraction well The PSCM also recommended that the SJCEHD should require an assessment of a former service station site located upgradient and adjacent to Thrifty#171 Ina letter dated October 6, 2004, the SJCEHD agreed that a workplan should be prepared and also requested that existing well MW-5 be abandoned due to its long screen length In response, Thrifty prepared the Workplan for Well Abandonment/Installation of Groundwater Extraction Wells and Pilot Testing dated November 12, 2004 The workplan proposed to abandon well MW-5, install two groundwater extraction wells, and conduct remedial pilot testing In a letter dated December 7, 2004, the SJCEHD approved the workplan with conditions that included no well screens should extend beyond 85 feet bgs and to add 1,2-DCA, EDB, and lead to constituents to be analyzed in soil samples collected during well installation activities Thrifty retained GHC to conduct the well abandonment/installation activities and pilot testing From February through April 2005, GHC conducted well installation and abandonment activities and pilot testing activities, as described in the 1 st Quarter 2005 status report On August 2, 2005, Thrifty submitted the Remedial Pilot Testing Report and Remedial Action Plan (RAP) prepared by GHC dated July 29, 2005 GHC concluded that soil vapor extraction in conjunction with groundwater pump and treat will be an effective remedial approach at the site •