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Mr. Kyle Christie December 7, 1994 Page 2 Results Water-level data collected August 30, 1994, is inconsistent with historical water-level data. Historically, changes in water levels in all of the monitoring wells had similar trends. During this sampling event, the water level increased in elevation in well AL-1, decreased in elevation in well AL-2, and did not change in well AL-4. Because of the anomalous nature of this data, water levels were remeasured by BC on November 4, 1994. The November data was used to determine hydraulic gradient and groundwater flow direction. The general groundwater flow direction on November 4, 1994, was to the southeast under a hydraulic gradient of approximately 0.0004. Historical gradients have ranged from 0,001 to 0.0005. On November 4, 1994, depth-to-water at the site ranged from 10.09 feet below ground surface (bgs) in well AL-2 to 11.32 feet bgs in well AL-1. Water-level data are shown in Table 1. Groundwater flow directions and gradients are shown in Table 2. Groundwater elevation contours and the groundwater flow direction for November 4, 1994, are shown on Figure 1. Analytical results from groundwater samples for this and previous quarters are summarized in Table 3. The August 30, 1994, analytical results are shown on Figure 2. The complete laboratory report for the August 30, 1994 sampling is presented in Exhibit A. BTEX and TPH-G were not detected in any of the wells during this sampling event. Discussion The direction of groundwater flow has changed since the last sampling event conducted in April 1992. However, it is consistent with flow directions reported during previous sampling events. The hydraulic gradient is approximately 0.0004, which is consistent with previous measurements. BTEX and TPH-G were not detected in any wells. BTEX and TPH-G have not been identified in any of the wells since sampling began in 1957 nor were any hydrocarbon constituents identified in hydropunch samples (HP-1,HP-2,HP-3)collected in March 1992. J Because groundwater is not impacted by hydrocaibQns, BC and ARCO requested closure of this site in a letter to San Joaquin County (Couniy) dated November 10, 1992. The County denied closure, stating that additional information was needed. Groundwater samples collected during this annual sampling event again do not indicate the presence of hydrocarbons at the site. It is the opinion of ARCO and BC that this site does not pose an environmental risk, therefore, closure of this site is requested. Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. 1730JZEP0RTS\ANNUAL94.RPT