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HYDROLOGY <br /> Ground water elevations at the site ranged between 5 and 6 feet <br /> below sea level from January 20, 1989 to April 18, 1989 . From <br /> April 18 , 1989 through September 13 , 1991, ground water <br /> elevations decreased an average of eight feet, to approximately <br /> 13 feet to 14 feet below sea level . This decrease may be <br /> attributed to both sampling time (summer vs . winter) as well as <br /> an effect of the continuing drought period. <br /> Ground water elevations increased approximately 1 to 1% feet <br /> since the last depth-to-water measurements on December 28, 1994 . <br /> This recharge is effecting the current ground water elevation <br /> gradient across the site and has increased from the slope of <br /> 0 . 006 from MW5 to MW7 and 0 . 004 from MW3 to MW2 during the <br /> December 28 , 1994 gauging to a slope of 0 . 003 ft/ft from MW1 to <br /> MW7 . The flow direction is to the south, southwest from MW1 to <br /> MW7, see Figure 4D. Unlike the previous ground water gauging <br /> period (Figure 4C) the hydraulic gradient across the site is <br /> relatively stable, indicating a condition where the inflow and <br /> outflow of water to the local aquifer have reached some kind of <br /> equilibrium. <br /> SITE INVESTIGATION <br /> Ground water sampling was conducted on March 30, 1995 in <br /> compliance with the quarterly monitoring requirements for this <br /> site . The various ground water parameters were determined by: 1) <br /> recording depth to water (by use of a resistivity meter) at each <br /> monitor well; 2) purging and containment of ground water from the <br /> wells; 3) collecting water samples from the wells; 4) submitting <br /> these water samples to a State Certified Analytical testing <br /> laboratory via established "chain of custody" procedures . <br /> The water samples were analyzed for Total Fuel Hydrocarbons (TFH) <br /> as gasoline and Volatile Aromatic Hydrocarbons (BTEX) using EPA <br /> Methods 5030 and 602, respectively. Laboratory detection limits <br /> are as follows : TFH is 0 . 05 mg/L and BTEX is 0 . 5 µg/L and 2µg/L <br /> for xylenes . <br /> Methods and Procedures <br /> The ground water was sampled in eight monitoring wells (MW1, MW2, <br /> MW3 , MW4 , MW5, MW6, MW7 and MW8) by a Western Geo-Engineers <br /> (WEGE) geotechnician working directly under the supervision of <br /> California Registered Geologist 43037 . Prior to sampling each <br /> y 3 USA 65 Mar. ' 95 Qtr Rpt <br />