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9 <br /> USA Petroleum has acquired 9 monitor wells i the course of the <br /> investigation of this site. Five of the wells are located <br /> within USA property and four wells are to the south in a <br /> downgradient direction (see Figure 3 ) . fter the existing wells <br /> were in place, a Problem Asse ort was prepared December <br /> 5, 1989 . This repo included in ndix A of the Quarterly <br /> Monitoring Report o September 24, 1992 . It presents Soil Boring <br /> analysis, Ground ter analysis, G d water flow direction, <br /> Aquifer test data with o transmissivi.ty and hydraulic <br /> conductivity, and an evaluation of the zero line of contamination. <br /> Geology <br /> The deposits under the site are Recent to Pleistocene age alluvium <br /> and consists of lenticular silt, sand, gravel and clay <br /> representing a heterogeneous fluvial environment. The Problem <br /> Assessment Report for this site (Appendix A of the Quarterly <br /> Monitoring Report for September 24, 1992 ) details the local and <br /> regional geology and hydrogeology. <br /> HYDROLOGY <br /> The ground water had maintained an elevation of between 5 and 6 <br /> feet below sea level from January 20, 1989 to April 18 , 1989 <br /> during a period of ground water elevation measurements following <br /> the installation of MW4, MW5 , MW6 and MW7 from January to March, <br /> 1989 . From April 18 , 1991 through September 13 , 1991, ground water <br /> elevation at the site decreased to approximately 13 ' to 14 ' below <br /> . sea level . This may be attributed to both sampling time ( summer <br /> vs . winter) as well as an effect of the continuing drought period. <br /> Since the last sampling round in September 1991, there has been an <br /> over all increase of approximately 1 . 5 ' in the ground water level <br /> at this site (see Table 1 ) . The present ground water flow <br /> direction, Figure 4B, is south to southeast. The hydauli.c gradient <br /> is fairly flat across the site from MW1 to MW7 at a slope of . 003 . <br /> SITE INVESTIGATION <br /> Ground water sampling was conducted on February 6, 1992 to comply <br /> with quarterly monitoring of this site. Various parameters of the <br /> ground water beneath the site were determined by: 1 ) recording <br /> depth to water (by use of a resistivity meter) for the monitor <br /> wells; 2) purging and containment of ground water from the well; <br /> 3 ) collecting water samples from the well; 4) submitting these <br /> water samples to a State Certified Analytical testing laboratory <br /> via established "chain of custody" procedures. The water was <br /> analyzed for Total Fuel Hydrocarbons (TFH) as gasoline and <br /> Volatile Aromatic Hydrocarbons (BTEX) using EPA Methods 5030 and <br /> 602, respectively. <br /> • <br /> 2 <br />