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3 October 1995 <br /> AGE-NC Project No 95-0103 <br /> Page 3 of 4 <br /> 3 3 GROUND WATER SAMPLE COLLECTION AND ANALYSIS <br /> Water samples were collected from MW-1 through MW4 using new disposable bailers The samples <br /> were transferred to 40-m1 EPA vials preserved with hydrochloric acid Each sample was logged on <br /> a chain-of-custody form, placed in a chilled container and transported to McCampbell Analytical Inc <br /> ' (MAI)in Pacheco, California <br /> The samples were analyzed for TPH-g and BTE&X in accordance with EPA methods 5030/8015 and <br /> 602, respectively The laboratory report and chain-of-custody are presented in Appendix B <br /> 4.0. FINDINGS <br /> 4 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT <br /> The relative elevation of ground water in each well was calculated by subtracting the ground water <br /> depth from the surveyed relative casing elevation (Table 1) The ground water elevation rose <br /> approximately one-half foot between April and July 1995 Free product thickness was measured at <br /> 0 01 inches in both MW-1 and MW-4 <br /> Ground water flow direction at the site is generally to the southwest with a gradient at approximately <br /> 0 0074 (Figure 3) However, a pronounced ridge is present between MW-1 and MW-3 The ridge <br /> was not noted during the sampling event in January 1995 <br /> 42 ANALYTICAL RESULTS <br /> TPH-g was detected to the water samples from MW-1, MW-3 and MW-4 at concentrations of <br /> 27,000 gg/l(parts per billion ppb), 2,800 ppb and 140,000 ppb, respectively BTE&X were detected <br /> in MW-1, MW-3 and MW-4 at concentrations up to 34,000 ppb (ethylbenzene in MW-4) No <br /> petroleum hydrocarbons were detected in the sample from MW-2 Analytical results of ground water <br /> samples are summarized in Table 2 The laboratory report and chain-of-custody are included in <br /> Appendix B <br /> 5.0. CONCLUSIONS & RECOMMENDATIONS <br /> 5 1 FREE PRODUCT <br /> Only 0 01 inches of free product was measured in July 1995 It appears that free product at the site <br /> is minimal and that removal performed in conjunction with standard quarterly monitoring is adequate <br />