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• On 12 August 1999, three soil and one ground water sample was collected from soil probe boring P-10 (15, 20 and 25 feet) and well MW-4, respectively and analyzed for bio- enumeration and physicochemical characterization by A. Keith Kaufinan of Culver City. The ground water sample collected from well MW-4 was found to have concentrations of inorganic components nitrogen,potassium and phosphates sufficient to support a microfauna for bioremediation. In addition, the ground water sample collected from well MW-4 was reported with a moderate microbiological population as biodegraders (2.8 CFU X 103/gr) indicating possible bioattenuation of the contaminates is occurring; no biodegraders were reported presence in the soil samples collected at 15 and 20 feet bsg, but low populations were reported to be present at 25 feet bsg (0.8 CFU X 103/gr). • An ozone-sparging system for in-situ oxidation was installed at the site on 20 January 2003 and operated continually from 31 March to 10 July 2003. The ozone-sparging system consisted of three ozone sparging wells (OSP-1A and B, OSP-2A and B and OSP- 3A and B) individually plumed to a Criegee Oxidation (C-Sparge) ozone generator via a subsurface network of 318-inch polyethylene tubing. The generator produced gaseous ozone which was injected at 25 psi into the subsurface, via microsparge points at sparge wells OSP-lA and B, OSP-2A and B and OSP-3A and B, to extract and decompose dissolved petroleum hydrocarbon constituents. The frequency and duration of ozone injection periods were approximately 20 minutes, initiating with the first well and then cycled into each well. Ozone readily degrades to oxygen. In order to monitor the effectiveness of ozone sparging, a YSI-50 dissolved oxygen (DO) meter was utilized in the field to measure DO at each monitoring well during the monitoring events conducted at the site. A table of dissolved oxygen data collected from wells MW-1 through MW-5 from April to June 2003 is included at the end of this appendix. • The ozone-sparging system was shut down in July 2003 after significantly increasing concentrations of TPH-d were detected over two consecutive quarters in the monitoring well at the former UST location (MW-4) and off-site monitoring well MW-1. GROUND WATER DEPTH AND FLOW DIRECTION Since ground water depth measurement have been recorded at the site, the depth to water in the former UST area (MW-4) has varied from nearly 27 feet bsg (August 2005) to almost 16 feet bsg (June 1998). More recently during the period from April 2001 to May 2006, the depth to water has averaged approximately 24 feet bsg in the former UST area(MW-4). Ground water flow direction has occurred to all quadrants with predominant flow direction to the southeast and with slightly less occurrence of flow to the northwest and northeast. Advanced GeoEnvironmental,Inc.