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v y I L 16 October 1996 AGE-NC Project No 96-0211 ' s Page 2 of 6 2 3 GROUND WATER DEPTH AND FLOW DIRECTION r I Based on data obtained from monitoring wells located on nearby properties, ground water depth in the area of the site is'approximate ly 5 to 6 feet below surface grade (bsg) Regional ground water ' flow direction is north or northeast, however, ground water flow direction can vary locally and seasonally ' 1 , 30. PROCEDURES 3 1 MONITORING WELL INSTALLATION ' 3 1 1 DRILLING AND SOIL SAMPLING On 02 July 1996, four soil borings were drilled on the site to a depth of fifteen feet bsg Boring B 1 ' was advanced west of the former UST dispensers and backfilled with grout to the surface A grab gourd water sample was collected from boring B 1 Boring B2 was advanced south of t1=c former UST dispensers and was converted to monitoring well MW-3 Boring B3 was advanced northeast of the,former UST dispensers and converted to monitoring well MW-2 Boring B4 was advanced on the northein edge of the site and completed as ground water monitoring well MW-1 The installation of MW-I through MW-3 was performed rising a truck-mounted CME 75=H I drill rig equipped with continuous Dight, eight inch hollow-stem augers Fhe drill rig and two-pian ci ew ' were supplied by Soils Exploration Services (SES) of Benicia, California' The locations of the borings are shown on Figure 2 Samples were collected in each boring using a split tube sampler loaded with three clean, 2- by 6- inch brass sleeves A 140-pound hammer was used to advance the sampler eighteen inches the p p g number of blows required to advance the sampler in six-inch increments was recorded on the boring ' logs All sampling equipment was washed in an Alconox solution and rinsed twice with water prior to each sampling run The leading soil-tilled sampling sleeve was preserved for laboratory analysis Both ends of the leading sleeve were covered with Teflon sheets, capped and sealed with tape The samples were ' labeled, stored in a chilled) container and transported under chain-of-custody to McCampbell r Analytical, Inc (MAI) in Pacheco, California F ' Selected samples were analyzed for total petroleum hydrocarbons quantified as gasoline (TPH-g), volatile aromatics (benzene, toluene, ethyl benzene and xylenes BTE&X) with methyl-tert-butyl ether(MTBE) in accordance with EPA methods 5030/8015m and 8020, respectively 1 4 I I ` I