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Wm. J. Hunter & Associate ; . 2220 Loma Vista Dr. Registered Geologists T I J Sacramento, CA 95825 Petroleum& Mineral Appraisers (916) 972-7941 r _- P,; ? FAX (916) 972-1683 March 30 , 1994 Linda Turkatte, REHS San Joaquin Co. PHS Environmental Health Division 445 No. San Joaquin Street Stockton, CA 95202 Ref : 2969 Loomis Road (Site Code 2015; ) Quarterly Report, monitoring well data Dear Ms. Turkatte; We have enclosed a copy of the field log, chain of custody form, and laboratory analysis of a water sample taken from MW #1 on January 31 , 1994 . Water level measurements were taken in all three wells as directed by your office, but water samples were / not collected from MW 02 or #3. The results of that anlysis �r shows that Benzene was detected at 0 . 75 ug/L, and TPH-D was measured at 0 . 21 mg/L; Ethylbenzene, Toluene, and Xylene were not recorded at a detection limit of 0 . 3 ug/L. The sample taken in September, 1993 showed only Benzene at 0 . 9 ug/L; in June the results were 2. 7 ug/L Benzene, 27 . 0 ug/L Xylene, and 3 . 0 mg/L of TPHG. Refer to TABLE 1 for a summary of water analyzes run to �..r date. A review of the water level measurements taken since monitoring began in April , 1992, reveals that the maximum fluctuation in depths, (MW-2 , ) is 4 . 44' , with an average for the three wells of 4 . 25' . The highest levels recorded were in April, 1992 , with the lowest measured in September, 1992 . The graph prepared by Del- Tech included in this report shows that there is a good corre- lation in changes in water levels in the three wells. Although the rate of recharge varies slightly between the three, they appear to be communication with each other_ We have also included an updated exhibit showing the directions of hydraulic gradients as indicated by the 17 water level measurements taken to date. They are labeled on the attached EXHIBIT A. The data continues to show that the direction of flow is not stable; it has been measured to date in a 360-degree radius with no consistent established pattern. About half of the measurements show a northerly direction, and about half to the south. An analysis of all of the data obtained to date indicates that either: ( 1 ) there are no withdrawal or injection points within the zone of influence, and that the variations in direction are 1