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13 December 1999 AGE-NC Project No. 98-0433 Page 4 of 13 water monitoring wells. All of the soil boring were subsequently completed as ground water . I monitoring wells. Soil boring and monitoring well locations, shown on Figure 2, were located on the east portion of the site at and surrounding the approximate location of the former gasoline dispenser. Soil boring MW-I was advanced directly north of former UST location. Soil boring MW-2 was established in the southern portion of the former UST dispenser area,northwest of boring MW-1. Soil boring MW- 3 was established approximately 140 feet west of the former dispenser location, and soil boring MW- 4 was established north and west of the former UST dispensers. Soil boring MW-5 was established ' approximately 190 feet west of the former dispensers. Previously, in May 1998, three monitoring wells had been installed on the subject property as part of UST site investigation on the adjacent property occupied by Ripon Farm Services, Inc. The wells, MW-6, MW-7 and MW-8, were installed in pilot borings B-20, B-21 and B-22, respectively, as reported in Quarterly Report - May 1998, RIPON FARM SERVICE, 22871 South Highway 99, ' Ripon, California, prepared by AGE, dated 20 July 1998. Data obtained from the three wells are utilized in this report for the subject property. 3.5.1. SOIL SAMPLE COLLECTION AND ANALYSIS Each soil boring was advanced to a depth of 30 feet bsg These soil borings were advanced for collection of soil samples to characterize the subsurface soil profile and identify water-bearing units for monitoring well screen placement.Installation of the wells was performed using a truck-mounted CME 75-HT drill rig equipped with 8-inch continuous flight hollow-stem augers. The drill rig and two-man crew were supplied by Soil Exploration Services(SES)of Sacramento,California. Samples were collected from borings MW-2 through MW-5 at five-foot intervals using a California-modified split spoon sampler loaded with three clean, 2 X 6-inch brass sleeves. A 140-pound hammer was used to advance the sampler 18 inches; the number of blows required to advance the sampler over ' each 6-inch increment was recorded on the boring logs. Samples were.collected from boring MW-I using a five-foot soil core barrel set to advance with the I lead auger. Soil samples were collected in 2 X 6-inch brass sleeves at significant lithologic changes or at a minimum five-foot interval. All sampling equipment was washed in an Alconox solution and rinsed twice with water prior to each sampling run. Both ends of the soil sleeve of each sample collected for laboratory analysis were covered with Teflon sheets, capped and sealed with-tape. The selected samples were stored in a chilled container and transported under chain-of-custody to McCampbell Analytical, Inc. (MAI), a California Advanced GeoEnvironmental,Inc.