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I ' Chemical analyses were performed on soil samples obtained at depths of 21 . 5, 26 . 5 , and 81 . 5 feet below ground surface. TPHG I concentrations ranged from nondetectable at 81 . 5 feet to 27 , 000 ppm at 21 . 5 feet. Some BTEX compounds were detected in each sample analyzed. ' 3 . 1. 3 . 4 Monitoring Well Boring MW-4 Chemical analyses were performed on soil samples taken at 36 . 5 ' and 81 feet below ground surface. The sample collected at 36. 5 feet showed TPHG and BTEX constituents in the following concentrations: 330 ppm, . 600 ppm, 2 . 20 ppm, 1 . 30 ppm, and 6. 80 ppm, respectively. The sample taken at 81 feet was nondetectable ' for petroleum hydrocarbons . 3 . 1. 3 . 5 Monitoring Well Boring MW-5 ' Chemical analyses were conducted on soil samples collected at depths of 46. 5 and 81 . 5 feet below ground surface . TPHG and BTEX ' constituents were nondetectable for the samples tested. 3 . 2 Groundwater Investigation ' The following sections discuss groundwater monitoring well construction, well development and sampling procedures, and results of chemical analyses . Appendices G, H, and I document TPE' s protocols relative to groundwater monitoring well construction, development, and sampling procedures. ' 3 . 2 . 1 Monitoring Well Installation Monitoring well borings MW-1, MW-2 and MW-3 were drilled to a ' total depth of 91 feet below ground surface. Monitoring well borings MW-4 and MW-5 were each drilled to a total depth of 92 feet below grade. Each boring was converted to a monitoring well. The wells are all similar in details of construction (see ' Well Construction Details presented in Appendix E) . The exact depth of each boring and screen length were determined by the geologic profile and the occurrence of groundwater in each ' boring. Groundwater was encountered in each boring at a depth of approximately 80 feet below ground surface. The borings for all of the wells were terminated approximately 10 feet into the 1 uppermost aquifer. All wells were constructed under the supervision of a TPE California Registered geologist. All of the monitoring Wells were constructed using schedule 40, ' 4-inch diameter PVC well casing and screen. The screen and PVC casing were threaded together above ground and lowered inside the hollow-stem augers. The screen was designed to intersect the water table and account for seasonal variations ( 10 feet below and 10 feet above the water table) . No glue was used in this ' 5