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k" KLEINFELDER <br /> soil bonngs, B 1 and B2 (Plate 1) were advanced west of the existing underground storage tank to a <br /> depth of approximately 25 feet bgs in April of 1999 Groundwater was not encountered from either <br /> of the two borings Soil samples collected from approximate depths of 20 and 25 feet bgs <br /> respectively, were submitted for laboratory analysis from both soil borings TPH-G and TPH-D <br /> ' were detected from both borings from one or more of the samples collected <br /> Based upon these results Mr Harlin Knoll of the San Joaquin County PHS/EHD requested <br /> installation of a single morutonng well southwest of the existing UST The well location is based <br /> on previous assessments at the General Mills facility, which showed a localized southwest <br /> groundwater gradient Based upon PHS/EHD comments and desires, General Mills retained <br /> Kleinfelder to install the monitoring well <br /> A single momtonng well (MW-1) was subsequently installed on May 23, 2000 just southwest of an <br /> existing UST at the subject site During advancement of the soil boring, groundwater was <br /> encountered at approximately 34 feet bgs The monitoring well was advanced vertically to a depth <br /> of approximately 45 feet bgs and screened from 25 to 45 feet <br />' Soil samples were collected at 5-foot intervals beginning at 5 feet bgs A total of 9 soil samples <br /> were collected from boring MW-1 Petroleum-like odors were noted from soil samples collected at <br />' depths ranging from 15 to 40 feet bgs The soil samples submitted for analyses were collected at <br /> approximate depths of 20 and 30 feet bgs A total of 2 soil samples and a single groundwater <br /> sample collected from MW-1 were analyzed for TPH-D and BLTEX constituents <br /> Both of the soil samples collected at approximate depths of 20 and 30 feet bgs had reported <br /> concentrations of TPH-D at 3,770 mg/kg and 2,880 mg/kg, respectively (Carbon range C10 to <br /> C 16) BTEX constituents were not detected at or above laboratory reporting limits in these two soil <br /> samples The groundwater sample collected from MW-i was reported by the laboratory as having a <br />' TPH-D concentration of 46 8 milligrams/liter (mg/1) Two BTEX constituents, ethylbenzene and <br /> total xylenes were also detected in this groundwater sample at 4 88 and 4 17 micrograms/liter <br /> (µg/1),respectively <br /> Kleinfelder conducted groundwater sampling for the fourth quarter 2000 and the first quarter 2001 <br /> Two groundwater samples were collected from MW-1 during the October 2000 and January 2001 <br /> quarterly sampling events The samples were analyzed for extractable hydrocarbons and gasoline <br /> constituents, benzene, toluene, ethylbenzene, and total xylenes (BTEX), during both sampling <br /> events Purgeable hydrocarbons as referenced to gasoline were also analyzed during the January <br />' 2001 sampling event at the request of PHS/EHD <br /> TPH-D was detected in the groundwater samples collected from MW-1 during the October 2000 <br /> and January 2001 sampling events at concentrations ranging from 14 4 to 18 6 mg/1 BTEX were <br /> not detected from groundwater samples collected during these two sampling events TPH-G, which <br /> was analyzed for the first time in January 2001 was detected m the groundwater sample collected <br /> from MW-1 at 3 3 mg/1 <br /> 28209 T03/ST04R1402/DH 1v Page 4 of 11 <br />' ©2004,Klemfelder, Inc October 20,2004 <br />