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i Former Beacon Station No. 474 May 15, 2000 Stockton, California Results of Additional Subsurface Investigation Dillard Environmental of Byron, California and disposed to TPS Technologies Inc. (TPS) of . Richmond, California. The TPS Non-Hazardous Soils manifest is contained in Appendix E. The monitoring wells were developed and sampled in accordance with Horizon's Field Methods and Procedures included in Appendix B. Field purge and sample data were recorded on the Monitoring Well Data Sheets contained in Appendix F. A well head survey was performed to establish the elevation of the top-of-casing (TOC) for the monitoring wells relative to the existing site wells. Well head elevation survey field data are contained Appendix G. Initial groundwater samples were collected from monitoring wells MW-10, MW-11 and MW-12 on October 26, 2000. The groundwater samples were submitted to Mff and analyzed for TPHg, BTEX, the seven oxygenates, 1,2-dichloroethane (EDC) and 1,2- dibromoethane (EDB) by EPA Method 826013. Groundwater analytical results for monitoring wells MW-10, MW-11 and MW-12 are summarized in Tables 3 and 3A, which also contain quarterly monitoring groundwater data since May 1998. Horizon performed soil vapor extraction and air sparge tests to evaluate soil and groundwater remedial alternatives. The results of the remedial testing was documented by Horizon in Vapor Extraction / Air Sparge Test Repo rt letter dated January 18, 2000. Test results indicate soil vapor extraction and air sparge are feasible soil and groundwater remedial methods. Test results are discussed in detail in the January 18, 2000 letter report. CONCLUSIONS Soil samples collected from the monitoring well MW-10 and MW-11 borings at depths of 30, 50, 65 and 70 feet were selected for analyses. .An ethanol concentration of 0.015 ppm was reported for the 70-foot sample from the monitoring well MW-10 boring; the reporting limit for ethanol was 0.010 ppm. No other gasoline constituents were reported in soil samples from the monitoring well MW-10 and MW-11 borings. 1474.22rpt 6 HORIZON ENVIRONMENTAL INC.