ARCHIVED REPORTS_XR0002153 - Laserfiche WebLink

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Clayton I Executive SurnmaKy Cl Cyton CrivironmentA Consultants, Inc , was retained by Orchard Supply Hardware to distal] three monitoring wells to saniplc and analyze, soil and groundwater at the northeast corner of macArthur Drive and Grant 1 ine Road in Tracy, Calitornia 'flus study was authorized by Mr. Mile I aToc.rette, director of real estate for Orchard Supply Hardware The loLations of the three monitoring wells are shown in Figure 2 MW-3 was. installed adjacent to and down gradient of the former loLation of the gasoline underground storage tank (UST) (Figure 2) MW-1 was installed at the northwest corner of the property to monitor a UST located west of the sub1eLt site at L.epnno Cheese Company MW-2 was installed at the northeast corner of the property to complete the triangle so that groundwater gradient could be calculated Our findings and conclusions are as follows • Benzene was not detected in any of the soil or water samples • Pesticides and PCBs were below detection hmits in all three wells • Low levels of petroleum products were detected in soil in M%V-3 The maximums of these levels were - Total petroleum hydrocarbons (TPH) as gasoline 68 parts per million (ppm) - Toluene 50 parts per billion (ppb) - Xylenes 730 ppb - Ethylbenzene 350 ppb The groundwater in MW-3 is at 8 39 feet below ground surface and the soil samples are located less than 5 feet from the groundwater Due to the shuilow groundwater, Category 3 of the Leaking Underground Fuel Tank (LUFI') Field anual wouldtypically,apply Clayton will consult with the San Joaquin County, Environmental I�ealth Division, and with the Central Valley Regional Water Quality Control Board (RWQCB) on the status of this site • The concentration of hydrocarbon oil and grease was 250 parts per million (PPM) in a soil sample from MW-3 There are no set action levels for oil and grease however, when concentrations exceed 100 ppppm the RWQCB's Recommendations for the Evaluation and Investlption of U3Ts requires a soil/groundwater investigation This study satisfies the RWQCB requirements Z he 100 ppm level is not a cleanup level The cleanup level is detertnmed by assessing the potential for soil contamination to impact groundwater • H drocarbon oil and grease were also detected in soil samples from MW-1 and but are withui acceptable levels as determined by the RWQCB Oaytc-n speculates that the oil and grease found m MWA and MW-2 may have come from oil-based sprays apphed to the site for agricultural purposes • Low le%,els of gasoline and the volatile hydrocatbons ethylbenzene and rylenc were touiid to the water sample retrieved from MW-3 These levels do not exLeed the California Departinent of Health Services (DI1S) action levels -Iu-