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i 25 August 1995 AGE-NC Project No, 95-0136 Page 3 of 4 ' measured at one-gallon intervals(Two gallon intervals for MW-1 on 22 June) using an ICM water analyzer. All purged water was placed in 55-gallon drums and stored on-site. Stabilization data and ' field logs are included in Appendix A. ' 3.2. COLLECTION OF GROUND WATER SAMPLES Water samples were collected from MW-1, MW4, and MW-5 using new disposable bailers. ' Immediately upon retrieval, the samples were transferred into 40-nt3 EPA vials preserved with hydrochloric acid and 1-liter amber bottles. All samples were transported in a chilled container under chain-of-custody to Alpha Analytical Laboratories(AAL) in Ukiah, and analyzed for TPH-g and. BTE&X in accordance with Methods 5030 and 602 respectively. 4.0. FINDINGS 4.1. RELATIVE GROUND WATER ELEVATION AND GRADIENT . The relative elevation of ground water in each well was calculated by subtracting the depth to water ' from the surveyed relative casing elevation (Table 1). Ground water rose.an average of 6.74 feet between December 1994 and May 1995 and dropped an average of.0.43 feet between May and June 1995. The significant rise in ground water at the site is most likely due to heavy winter rains received between January and March 1995. The ground water flow direction at the site in May was determined to be convex toward the northeast ' (Figure 3). The gradient was steeper than in previous monitorings. The June flow direction was concave toward the northeast, corresponding with previous monitoring events(Figure 4). 4.2. ANALYTICAL RESULTS OF GROUND WATER SAMPLES I No TPH-g or BTE&X were detected in samples collected during the May 1995 sampling. However, TPH-g and benzene were detected in the June 1995 water sample from monitoring well MW-1 at concentrations of 61 ppb and 2.6 ppb, respectively. Benzene was also detected in the 1 June 1995 sample from MW-4 at a concentration of 0.68. No other petroleum hydrocarbons were detected in the June 1995 samples. The analytical results of the ground water samples are summarized in Table 2. The laboratory reports and chain-of-custody forms are included in Appendix B.