ARCHIVED REPORTS_THIRD QUARTER 2010 STATUS SUMMARY REPORT

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Stantec Third Quarter 2010 Status Summary Report Former Tosco Bulk Terminal No. 10013 October 26, 2010 Additional analyses include MTBE for MW-15 as well as TBA and MTBE for wells MW-16, MW- 17B, MW-18C, MW-20, MW-21B, and MW-22C. Groundwater monitoring activities were performed on August 30, 2010 by TRC Solutions Inc. (TRC). 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. Historical groundwater elevation data are provided in Appendix B. Historical groundwater gradient information is provided in Appendix C. Field data sheets for the groundwater monitoring event in the third quarter 2010 are provided in Appendix D. Groundwater elevation data for the third quarter 2010 monitoring event are included in Table 3. Depth to water ranged from 3.39 feet below TOC in MW-15 to 14.94 feet below TOC in MW-19C. Groundwater elevations during the third quarter 2010 event have decreased approximately 1.2 foot from those measured in the second quarter 2010. 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 third quarter 2010 was approximately 0.004 foot per foot (ft/ft) towards the southwest. Wells screened in the "B" water-bearing zone, approximately 30 to 50 feet bgs, include wells MW-14, MW-17B, and MW-21B. Groundwater elevations in the "B" water-bearing zone are shown on Figure 4. The B zone groundwater gradient during the third quarter 2010 was approximately 0.003 ft/ft to the 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 2010 was approximately 0.0002 ft/ft to the southwest. Groundwater Sampling and Analysis Wells were sampled and analyzed in accordance with the MRP following standard U.S. Environmental Protection Agency (EPA) protocol. Monitoring wells MW-2 through MW-4, MW-8, MW-14, MW-16, MW-17B, MW-18C, MW-20, MW-21B, and MW-22C were sampled for water quality parameters on August 30, 2010 by TRC. 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 3