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elevations are discussed in Section 2 3, and the groundwater analytical results are discussed in Section 2 4 Groundwater level measurement and sampling methodology are described in Appendix A 2.1 DEPTH TO GROUNDWATER PROCEDURES On January 9 and July 23, 1998, depth to groundwater was measured, in feet below ground surface (bgs), in each of the five monitoring wells at the Site using an electronic water level indicator per the methodology specified in Appendix A 1 1 2.2 GROUNDWATER SAMPLING AND ANALYSIS PROCEDURES Groundwater samples were collected from site monitoring wells on July 23, 1998, per the methodology specified in Appendix A 1 Field parameters were recorded on Field Record of Water Sampling Forms, copies of which are presented in Appendix B A duplicate sample was collected from monitoring well DMW-2 and was identified as "DMW-20 " After collection, the samples were hand delivered under chain-of-custody to Quanterra Environmental Laboratories (Quanterra) in West Sacramento, California for analysis Quanterra is a State of California Department of Toxic Substances Control (DTSC) certified laboratory The chain-of-custody (Appendix 8) requested that the water samples be analyzed for total petroleum hydrocarbons as diesel (TPH-d) by EPA Method 8015 modified 2.3 GROUNDWATER ELEVATION AND GRADIENT Current and past groundwater elevation data are provided below in Table 1 Groundwater elevations rose approximately 9 45 feet from January 1998 to July 1998 These elevations are also higher than 1997 levels This increase in groundwater elevation is likely due to the greater than average rainfall during the 1997 — 1998 rainy season As shown in Figures 2 and 3, the groundwater direction was predominantly north-northwest with a gradient of 0 0009 and 0 0005 for January and July 1998, respectively 2 WM_SACI\SYS\WORDPROC1sac\044mt$C\9809_06 doc DAMES&MOORE