ARCHIVED REPORTS_SEPARATE PHASE HYDROCARBON INVESTIGATION UNOCAL EXTRACTION WELL PILOT STUDY 2011

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Stantec Report of Findings for the Waterfront Towers Separate Phase Hydrocarbon Investigation and Unocal Extraction Well Pilot Study Waterfront Towers Parking Lot March 4, 2011 Approximately 3,041 gallons of purged groundwater from the pilot testing was temporarily stored in a double contained, above ground Baker Tank. Grab groundwater samples were taken from the tank and submitted under chain-of-custody to state-certified analytical laboratory for waste water profiling to determine feasibility of discharge through the on-site remediation system. Following laboratory analysis, the 3,041 gallons of water were treated with the existing L&M OU groundwater treatment system and discharged into the sanitary sewer on November 18, 2010. 4.3 PUMP TEST AND FEASIBILITY STUDY Pump test and feasibility studies were conducted to evaluate and record the following: 1. the potential GWE rates from GWE-1 and GWE-2; 2. the potential to implement SVE from GWE-1 and GWE-2; 3. the chemical concentrations in both mediums (vapor and liquid); and, 4. the quantification of chemical removal from both mediums. In addition, the observations and data collected will be used to determine the feasibility of incorporating GWE-1 and GWE-2 into the existing MPE system and groundwater/vapor • treatment system already operating on the L&M OU for ongoing and continuous extraction and treatment of the contaminated media (liquid and vapor phases) until it is no longer deemed feasible. The pump testing and feasibility study was accomplished employing two separate extraction mechanisms on each well independently. The first method was two-phase extraction (TPE) utilizing a single vacuum pump to extract both groundwater and soil vapor through a small diameter entrainment tube or pipe (stinger) inserted into the extraction well below the water surface. The second method was GWE utilizing a single downhole submersible pump to extract groundwater alone. The feasibility of incorporating GWE-1 and GWE-2 into the existing MPE system and groundwater/vapor treatment system already operating on the L&M OU is discussed below. Analytical data from the pilot study are included in Tables 2 through 7. 4.4 ANALYTICAL LABORATORY TESTING Groundwater samples from GWE-1 and GWE-2 were submitted to a state-certified laboratory, Kiff Analytical, under chain-of-custody procedures and sample preservation procedures for analysis of the following chemical constituents: • TPHg using EPA Method 8260B • TPHd using Modified EPA Method 8015 4.7