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Ground water elevations have dropped approximately 1% feet since <br /> the last depth-to-water measurements on July 28 , 1994 The <br /> current ground water elevation gradient across the site is fairly <br /> flat with an average slope of 0 002 (0 002 feet per linear foot) <br /> from MW1 toward MW6 and an overall flow direction to the south <br /> southeast, see Figure 4D Unlike the previous two ground water <br /> gauging periods (Figures 4B and 4C) the hydraulic gradient across <br /> the site is stable or consistent, this may reflect neither a <br /> drainage or recharge but a condition of equilibrium between the <br /> inflow and outflow of water to the local aquifer and is <br /> represented by less variation or differences of hydraulic <br /> conductivities from well to well <br /> SITE INVESTIGATION <br /> Ground water sampling was conducted on September 29, 1994 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 02 mg/L and BTEX is 0 5 pg/L, except <br /> where samples were diluted <br /> Methods and Procedures <br /> The ground water was sampled in seven monitoring wells (MW1, MW2 , <br /> MW4 , MW6 , MW7 and MW8) by a Western Geo-Engineers (WEGE) <br /> geotechnician working directly under the supervision of <br /> California Registered Geologist #3037 Prior to sampling each <br /> well, the WEGE geotechnician measured the depth to ground water <br /> using a resistance probe A ground water contour surface was <br /> later plotted from these depth-to-water measurements, ground <br /> water flow directions at the site were then inferred from the <br /> contour gradients This information is presented in Figure 4D <br /> 3 <br />