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Chevron Products Company 2 Chevron SerylCe Station 9-2396,25651 Hughway 99 North,Acampo,CA August 9.2002 Groundwater was encountered at approximately 74 feet bgs in each of the soil . borings Boring logs and well construction details are included in Attachment C • Soil Sampling and Analysis. Six to seven soil samples were collected from each of the soil borings and submitted to a California certified laboratory for chemical analysis Soil analytical results are summarized in Table 1 A copy of the laboratory analytical report and chain-of-custody documentation is Included in Attachment D Soil samples submitted for chemical analysis were analyzed for total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethylbenzene, and xylenes (BTEX), and methyl tertiary butyl ether (MtBE) Soil samples submitted for chemical analysis reported analyte concentrations below laboratory detection limits for TPHg, BTEX and MtBE • Groundwater Analytical Results. June 18, 2002, SECOR International, Inc developed and sampled MW-1, MW-2 and MW-3 Groundwater samples were submitted to a California state-certified laboratory and analyzed for the presence of TPHg, BTEX, and MtBE On June 20, 2002 Lancaster laboratories reported that the groundwater samples were received over 6° Celcius On June 24, 2002, monitoring wells MW-1 through MW-3 were re-sampled Groundwater analytical results are summarized in Table 2 Copies of field data sheets are included in Attachment E MtBE was detected in two groundwater samples at a concentration of 1 microgram per liter (µg/1) (MW-1) and 5 µg11 (MW-2) No other target analytes were detected .� above their respective method detection limits • Monitoring Well Survey and Groundwater Gradient Interpretation. The newly installed monitoring wells were surveyed within 0 01-foot accuracy relative to mean sea level (MSL) Based on depth to water measurements taken during the second quarter 2002, groundwater flow was to the south at a gradient of 0 002 foot per foot (ft/ft) Groundwater flow and gradient are shown graphically in Figure 2 RECOMMENDATION: Based on the data presented above, SECOR recommends the following • Implementing quarterly monitoring program, • Monitor and sample MW-1, MW-2 and MW-3 quarterly for 1 year to verify existing groundwater analytical results, • Annual monitoring and sampling of domestic well beginning third quarter 2002 I 1Chevron1923961Reportsl9 2396 2002 MW SA doe