ARCHIVED REPORTS XR0001302 - Laserfiche WebLink

Home Browse Search

Atlantic Richfield Company 4 Former ARCO#4493,205 North Center Street Stockton,CA August 22 2002 • and xylenes (BTEX) by the California Department of Health Services/Leaking Underground Fuel Tank (DHS/LUFT) method, and fuel oxygenates (methyl tert butyl ether [MtBE], tert-amyl methyl ether [TAME], di-isopropyl ether [DIPE], ethyl tert- butyl ether [EtBE], tert-butyl alcohol [TBA], 1,2-dlchloroethane [1,2-DCA], and ethylene dlbrorrnde [EDB]) by EPA Method 8260B Benzene and ethylbenzene were detected in soil samples from the boring for MW-9 at 42 feet below ground surface (bgs) at concentrations of 0 0072 milligrams per kilogram (mg/kg) and 0 024 mg/kg, respectively MtBE was also detected in soil samples from MW-9 at 25 feet bgs (0 020 mg/kg) and 42 feet bgs (0 026 mg/kg) Other fuel oxygenates were not detected in soil samples from the boring of MW-9 above the laboratory detection limit TPHg, BTEX, MtBE, and other fuel oxygenates were not detected in soil samples from the boring of MW-10 above the laboratory detection limit Soil analytical data are summarized in Table 2 Field and laboratory procedures are presented as Attachment D Certified laboratory analytical reports and chain-of-custody documentation are presented as Attachment F Well Development, Surveying,Monitoring and Sampling,and Analysis After installation, wells MW-8M/D, MW-9M/D, and MW-10MID were developed by Western Strata Exploration (Westex) on June 12, 2002, under the direction of SECOR staff The wells were rigorously surged over the length of the screen interval Approximately 10 casing volumes of water were bawled and pumped from each well at an approximate pumping rate of 10 gallon per minute (gpm) Monitoring well development and sampling field sheets are included in Attachment E Depth to water was also measured on June 12, 2002 and groundwater samples were collected from the newly installed groundwater monitoring wells Depth to water was approximately 14 to 19 feet bgs Groundwater samples from monitoring wells MW- 8M/D, MW-9M/D, and MW-1OM/D were analyzed for TPHg and BTEX by the DHSILUFT Method, and fuel oxygenates by EPA Method 8260B TPHg was detected in water samples from all six new wells at concentrations ranging from 87 parts per billion (ppb)(MW-10D) to 4,700 ppb (MW-8M) Benzene was detected in water samples from all six new wells at concentrations ranging from 19 ppb (MW-10D) to 70 ppb (MW-8D) Toluene was detected In water samples from five of the six new wells at concentrations ranging from 0 87 ppb (MW-10M) to 90 ppb (MW- 8M) Ethylbenzene was detected in water samples from four of the six new wells at concentrations ranging from 69 ppb (MW-9D) to 650 ppb (MW-8M) Xylenes were detected in water samples from five of the six new wells at concentrations ranging from 1 2 ppb (MW-IOM) to 490 ppb (MW-8M) MtBE was detected In water samples from . all six new wells at concentrations ranging from 3 1 ppb (MW-10D) to 46 ppb (MW- 8D) I\ARC0144931Reports\DualWell-Rpt doc