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Third Quarter 2001 Groundwater Monitoring Report �i Moore Petroleum Bulk Plant,5491 F Street,Banta,California Page 3 Apex submitted the Workplan for Limited Subsurface Investigation dated August 6, 1999, proposing the installation of four additional groundwater monitoring wells (MW-4A, MW-7, MW-8, and MW-9). During installation, well MW-8 was installed with the screen and filter pack extending well into the unsaturated zone for possible future use as a vapor extraction well. In addition, underground piping was installed from well MW-8 (VEW-3) to the former remediation compound(Figure 2). Apex submitted the Workplan for Limited Subsurface Investigation dated April 27, 2000, proposing the installation of three additional groundwater monitoring wells and one deep soil boring. On July 25 and 26, 2000 Apex personnel supervised the installation of three groundwater monitoring wells (MW-10, MW-11, and MW-12). The results of all soil and water sampling were documented in the report entitled Results Report for Limited Subsurface Investigation and Third Quarter 2000 Groundwater Monitoring Report dated August 25, 2000. Apex submitted the Workplan for Interim Remediation & 4rh Quarter 2000 Groundwater Monitoring Report dated November 17, 2000, proposing the installation of three recovery wells and one vapor extraction well using the three recovery wells for a pumping test. SJCEHD responded and only wanted one recovery well installed for the pumping test and depending on the results,more recovery wells could be installed. On January 8, 2001, Apex supervised the installation of one vapor extraction well (VEW-2) and one recovery well (RW-2). Results of the well installation can be found the report titled Results Report for Limited Subsurface Investigation and First Quarter 2001 Groundwater Monitoring Report, dated March 9, 2001. In March 2001, Apex performed a pumping test utilizing well RW-2. The results of the pumping test indicated that groundwater extraction was capable of controlling the off-site migration of petroleum contamination. However, low influent groundwater concentrations recorded during the test as a result of dilution of the plume with clean formation water make it a cost ineffective method for remediating the site. Apex recommended continuing groundwater monitoring to assure the plume is remaining stable and using vapor extraction to mitigate residual contamination in soil at the site. On August 24, 2001, Apex over drilled and reinstalled well MW-7 as a vapor extraction well. On September 12, 2001, Apex personnel installed the remediation piping connecting wells MW-7, VEW-2, and VEW-3 to the remediation compound.