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CSUS-Multi Campus Regional Center—Quarterly Groundwater Monitoring April 8,2003 Page 4 SUMMARY AND PROPOSED FUTURE WORK 11%.e The current quarterly monitoring data indicate that groundwater conditions at the site have remained relatively static. The laboratory analytical results of the current monitoring are generally consistent with the historical laboratory analytical results. The current groundwater gradient direction (southeast) has deviated from the gradient direction measured during the fourth quarter 2002 (northeast), however, the current gradient direction is similar to that measured during the second and third quarter of 2002 (June 28 and September 11, 2002,respectively). Condor prepared a Problem Assessment Work Plan (PAWP), dated January 23, 2003, at the request of David Rosso for the Trustees of the California State University in response to a letter dated April 26, 2002 from Rebecca Setliff of the San Joaquin County Environmental Health Department (SJCEHD). The purpose of the work is to further investigate the lateral and vertical extent of petroleum hydrocarbon contamination in groundwater at the site. The proposed work includes the installation of direct push borings to further evaluate the site hydrogeology and to collect discrete interval groundwater samples. Nuel Henderson of the SJCEHD approved the PAWP in a letter dated March 27, 2003. Five pairs of direct push borings will be installed at the site. One boring pair will be installed in the source area, three pairs will be installed downgradient of the source area, and one pair will be installed upgradient of the source area. Field observations for the borings will include inspection of an aliquot of the water sample for odor and organic vapor with a photoionization detector (PDI). The proposed boring pair locations are shown in Figure 4, attached. Fieldwork is scheduled to commence April 14, 2003. Condor prepared a Soil and Groundwater Remediation Work Plan, dated March 3, 2003, at the request of David Rosso. The scope of work described in the Work Plan included (1) groundwater dewatering with dewatering wells, groundwater treatment, and proper disposal of treated groundwater; (2) soil over- excavation, including transport and disposal of contaminated soil; and (3) in-situ groundwater remediation utilizing ozone sparging technology. In a letter dated March 27, 2003, Mr. Henderson of the SJCEHD approved the soil over-excavation portion of the Soil and Groundwater Remediation Work Plan as an interim remedial measure. However,Mr. Henderson also indicated that ozone sparging would not be considered by the SJCEHD until site characterization was complete. Condor anticipates that quarterly groundwater monitoring of MW-1, MW-2, and MW-3 will continue. The next groundwater sampling event is tentatively scheduled for June 2003. 4M N4� IL 41 CONDOR