ARCHIVED REPORTS_XR0007451 CASE 1

Home Browse Search

kT] KLEINIFELDER 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/l 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/l The C entral Valley Regional Water Quality Control B oard (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 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/1 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/l, respectively No additional requested analytes were detected, at or above laboratory reporting limits from the groundwater samples collected from MW-1 ' Klemfelder conductedgroundwater sampling for the second quarter 2002 Dunng that sampling g ' event, total petroleum hydrocarbons as referenced to diesel (TPH-D) were detected in the groundwater samples collected from MW-1 and MW-2 at concentrations of 27 mg/1 and 0 076 milligram / 1 iter (mg/1), respectively Total petroleum hydrocarbons as referenced to gasoline ' (TPH-G) were also detected in the sample from MW-I with a concentration of 1 7 mg/l, as well as ethylbenzene at 1 6 microgram / liter (µg/I) No petroleum constituents were detected in the groundwater samples collected from MW-3 or MW-4, during the second quarter 2002 sampling event ' Kleinfelder submitted a proposal (File No 02001PROP 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 third quarter 2002, ' based on the proposed scope of work ' 18748 T02/ST02R795 Page 5 of i l ' ©1011 Kleinfelder,Inc December 3, 2002