ARCHIVED REPORTS_XR0007452 CASE 1

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' �'' ■ KLEINFELDER Total petroleum hydrocarbons as referenced to diesel (TPH-D) was detected in the groundwater samples collected from MW-1 during the October 2000 and January 2001 sampling events at concentrations ranging from 14 4 to 18 6 mg/1 Benzene, toluene, ethylbenzene, and total xylenes (BTEX) were not detected from groundwater samples collected during these two sampling events Total petroleum hydrocarbons as referenced to gasoline (TPH-G), which was analyzed for the first time in January 2001 was detected in the groundwater sample collected from MW-1 at 3 3 mg/1 The Central Valley Regional Water Quality Control Board (RWQCB) and PHS/EHD requested ' continued quarterly groundwater sampling, and a workplan to address the extent of the contamination in the vicinity of the subject site, including a sensitive receptor survey and estimates as to the amount of contamination in soil and groundwater ' At the request of General Mills, Kleinfelder installed three additional monitoring wells in the vicinity of the UST in January 2002 During the installation, soil samples were collected from the borings for laboratory analysis None of those samples contained detectable concentrations of TPH-G, TPH-D, nor BTEX, at or above laboratory reporting limits After development and ' purging, the three monitoring wells and one existing monitoring well were sampled No requested petroleum constituents, including TPH-D, TPH-G, BTEX nor the five oxygenates, were detected in the groundwater samples collected from the down-gradient monitoring wells MW-2, MW-3, and upgradient monitoring well MW-4 TPH-D and TPH-G were detected at concentrations of 13 mg/l and 2 5 mg/l, respectively, from the groundwater samples collected from MW-1 (located adjacent and southwest of the UST) Ethyl-benzene and total xylenes were also detected in the groundwater sample collected from MW-1 at 1 6 and 83 µg/1, respectively No additional requested analytes were detected, at or above laboratory reporting limits from the groundwater samples collected from MW-1 Kleinfelder submitted a proposal (File No 02001 PROP ENV/ST02P022, dated, June 19, 2002) to General Mills to conduct continued quarterly groundwater sampling from the four monitoring wells ' in the vicinity of the UST The following details Kleinfelder's findings for the second quarter 2002, based on the proposed scope of work ' 18748 T02/ST02R420 Page 5 of I I ©2002 Kleinfelder, Inc August 29,2002