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I November 2005 AGr-NC Project No. 97-0327 Page 6 of 8 Historically, results of ground water monitoring events have detected 1.2-DCA from wells MW-1, MW-2,and MW-4,at concentrations ranging from 0.f5 pg/l(MW-1)to 12 µg/l(MW-4). However. the most recent ground water monitoring event(20 July 2005; see Table 2) detected 1.2-DCA only from well MW-4, the most southwestern of the monitoring wells on-site. Thus, in order to ensure that dissolved 1,2-DCA has not migrated off-site, the proposed CPT borings (CPT-1 and CPT-2) were selected to define the lateral and vertical extent of dissolved 1.2-DCA in ground water. Each of the proposed CPT locations will consist of multiple 13/4-inch boreholes.The first CPT boring at each location will be utilized for cone penetrometer testing; the CPT will acquire a continuous lithologic record to interpret the stratigraphic and hydrogeologic units. Based on interpreted lithologic data and assessment needs, additional 13/4-inch soil borings will be advanced adjacent to the first CPT boring (less than 2 feet) to acquire independent grab ground water samples in each targeted zone. Each CPT boring will be advanced to total depths of approximately 100 feet bsg; however, the total depths of borings may vary according to hydrogeologic conditions encountered during drilling activities. Additional CPT literature is included in Appendix A. While the primary contaminant of concern for this work plan is 1,2-DCA,ground water samples will be analyzed by a California Department of Health Services(DHS)-certified laboratory for all of the following: • TPH-g and TPH-d in accordance with EPA Method 8015 Modified; • BTEX constituents in accordance with EPA Method 826013; and • Methanol, ethanol, ethylene dibromide (EDB), 1,2-DCA, TBA, di-isopropyl ether(DIPE), ethyl tert butyl ether (ETBE), tent amyl methyl ether (TAME)and MTBE by EPA Method 8260B. Laboratory reports for soil and ground water analysis, testing methods, laboratory quality assurance/quality control (QA/QC) reports, and sample chain of custody documentation will be presented in a report of findings and recommendations. 4.3. REPORT PREPARATION Upon completion of field work and receipt of final laboratory analysis, a report will be prepared presenting the findings of the investigation. The report will include a description of the work performed and results of the sampling and analysis.Conclusions,applicable recommendations,maps and cross-sections will be included in the report. The report will be in a format acceptable to the EHD and CVRWQCB, and will be reviewed and signed by a California Professional Geologist. .advanced GeoEnviroamental,Inc.