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i CECCIIAYI, CECCMAT,AND GIOVANNOM,FUELING ISL M 2.0 ENSTALLATEON (DIF HEW M(D=ORHHG WELLS Three additional monitoring wells were proposed by ESE to further monitor hydrocarbons in ground water beneath the fuel island in a workplan dated September 19, 1994 An addendum to the workplan dated January 24, 1995 was prepared to document changes location of the wells per a letter dated December 5, 1994 from Mr Michael Infurna of the SJCEHD. The permit for monitoring well installation approved on March 22, 1995. In EXPLORATORY IDIlgIIILILENG As described in the work plan, a mobil drill rig equipped with hollow-stem auger was used to make the three bore holes Work commenced on April 4, 1995 and was completed by April 5, 1995 Soil samples were collected at 5 foot intervals using a modified split-spoon sampler Soils were described using the Unified Soil Classification System (ASTM 2488-84) The exploratory boring UST-2 was located on the West side of the fuel island, exploratory boring UST-3 was located on the North side of the fuel island and exploratory boring UST-4 was located on the Southeast side of the fuel island Soil samples selected for laboratory analysis were capped, labeled and placed in an ice chest under chain-of-custody for transport to a California Certified Laboratory Soils were tested for Total Petroleum Hydrocarbons as Diesel (TPH-D) using EPA method 3553/8015 modified, for Total Petroleum Hydrocarbons as Gasoline (TPH-G) using EPA method 503018015, and for benzene, ethylbenzene, toluene, and xylenes (BTEX) using EPA method 5030/8020 The findings of these tests are presented in Section 4 Soils encountered in the three borings consist of interbedded fine materials ranging from silty sands to sandy silts to the depths explored From the surface, the soils consist of sandy silt (ML) to a depth of about 15 feet bgs Silty sand (SM) was logged between the depths of 15 feet bgs to 30 feet bgs Sandy silt (ML) was logged between 30 feet bgs and 65 feet bgs with increasing amounts of sand between 65 feet bgs and 80 feet bgs. A coarse poorly graded medium sand (SP) was encountered between 80 feet bgs and 85 feet bgs Detailed soil descriptions are given on each boring log presented in Appendix A 2.2 MOMTOWNG WELL CONS 'IlgUMON After the completion of the exploratory drilling, monitoring wells consisting of 2-inch diameter schedule 40 PVC casing were constricted in each bore hole The three monitoring wells were of similar construction Twenty feet of well screen with 0 02 inch machine slot was installed F W92540=QM95 RPT 2 Environmental Science&Engineenng,Inc