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i95ha%i itrh Nirtet fracc c t hebruarv1� 1994 ippro\imateh 0 003 vertical per horizontal feet According to site acuyity records the wells had not been Ssampled again until October 1993 when RRM initiated a new quarterly sampling program In October 1993 RRM performed quarterly groundwater sampling at monitor dells MWA through MW- 3 Ground%%ater samples were anahzed for TPHg and BTEX TPHg concentrations of 5,500 (5 5 ppm) and 2 900 (2 9 ppm) pans per billion (ppb)along with BTEX compounds were found at wells MW-2 and MW-3 respectively TPHg and BTEX were not detected in well MW-1 The average depth to groundwater was measured at approximately 8-feet below surface grade with an inferred groundwater flow direction to the north-east OBJECTIVES The*ectiv a of this second quarterly groundwater sampling event was to monitor the extent of petroleum hydrocarbon impacts to groundwater and to establish the current groundwater flow direction and gradient as required by the State of California Underground Storage Tank Regulations PROCEDURES Monitor wells MW-1, MW-2, and MW-3 were sampled on January 4, 1994 The locations of the wells are shown in Figure 2 Sampling activities consisted of a depth to water measurement,and then purging and sampling groundwater from each well Depth to water measurements were used to calculate the elevation of the groundwater level at each well to determine the groundwater gradient and flow direction Details of the sampling procedures are described below . 1 Measure the static depth to groundwater at each well using a Soling electronic water level indicator 2 Using a pre-cleaned Teflon bailer,purge each well a minimum of 5 well casing volumes,or until pH, conductivity, and temperature Ievels have stabilized 3 Following purging re-measure static depth to groundwater at each well to determine that groundwater has recovered to within 80%of the initial Iey el 4 Using a pre-cleaned Teflon bailer,collect a groundwater sample from each well and transfer the samples into preserved 40-m1 VOA sample vials 5 Seal and-label each sample and place into iced storage 6 Following chain of custody documentation, transport samples to a State Certified analytical laboratory All samples were submitted to Anametrix laboratories of San Jose, California for certified analyses for TPHg, and BTEX using modified EPA Methods 8015/8020 All sampling equipment was pre-cleaned before use using an Alconox soap solution and a distilled water nnse All liquid wastes denved during purging procedures were stored on-site in DOT rated 55-gallon drums contained on-site 2