ARCHIVED REPORTS_FIRST QUARTER 2012 STATUS SUMMARY REPORT

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First Quarter 2012 Status Summary Report Former Tosco Bulk Terminal No.10013 April 30,2012 Groundwater Elevation Measurements and Flow Direction As specified in the MRP, depth to static water, depth to any free product present, and the depth of each well were measured before sampling. Groundwater measurements and well depths were taken at 19 monitoring wells. Depth measurements were measured from the top of casing (TOC) to the nearest 0.01 foot. Groundwater elevation data for the First Quarter 2012 monitoring event are included in Table 2. Depth to water ranged from 2.88 feet below TOC in ' MW-15 to 13.92 feet below TOC in MW-19C. Historical groundwater elevation data are provided in Table 3. ' Groundwater elevation contours in the shallow"A" water-bearing zone wells, screened at depths of approximately 10 to 25 feet below ground surface (bgs), are shown on Figure 3. The shallow groundwater at the site generally flows to the southwest. The groundwater gradient in the ' shallow zone during the First Quarter 2012 was approximately 0.003 towards the southwest. Wells screened in the "B" water-bearing zone, approximately 30 to 50 feet bgs, include wells MW-14, MW-1713, and MW-2113. Groundwater elevations in the "B" water-bearing zone are shown on Figure 4. The B zone groundwater gradient during the First Quarter 2012 was approximately 0.002 to the west-southwest. ' Monitoring wells screened in the "C' water-bearing zone (approximately 55 to 75 feet bgs) include wells MW-18C, MW-19C, and MW-22C. Groundwater elevations in the "C' water- bearing zone are shown on Figure 5. The "C"zone groundwater gradient during the First Quarter 2012 was approximately 0.0003 to the northwest. Historical groundwater gradient information is provided in Attachment B. Field data sheets for the groundwater monitoring event ' in the First Quarter 2012 are provided in Attachment C. Groundwater Sampling and Analysis ' Wells were sampled and analyzed in accordance with the MRP following standard U.S. Environmental Protection Agency(EPA) protocol. ' All monitoring wells, with the exception of MW-5, MW-6, and MW-10 (which are not required to be sampled by the MRP), were sampled for water quality parameters on March 5 and 6, 2012 by ATC. Prior to sampling, all wells were purged of three well volumes by using submersible ' pumps and disposable bailers, and water quality parameters were measured repeatedly until the readings stabilized. The Field Data Sheets for the First Quarter 2012 sampling event are presented in Attachment C. 1 BC Laboratories, Inc. (13C), accredited by the California Environmental Laboratory Accreditation Program, performed the analyses for this MRP. Samples submitted to BC were analyzed for the following analytes: 3