ARCHIVED REPORTS_MONITORING WELL INSTALLATION AND BIOSPARGE EVALUATION REPORT

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' feed for shallow completions less than 30 foot bgs. The wells were finished at the surface with a flush-mounted traffic rated vault box secured in a concrete pad. The well was secured with an expandable locking J-Plug and padlock. t2.2.3 Post-Installation Monitoring Well Surveying Upon completion of the well installations and in accordance with the California GeoTracker requirements, the locations and elevations of the wells were surveyed. The survey was performed by PLS Surveys, Inc., a California-licensed Professional Land Surveyor. The survey included latitude, longitude, ground-surface elevation, and top-of-casing elevation for I each installed well. Latitude and longitude were referenced to the 1983 North American Datum (NAD83) and elevation was referenced to the 1988 North American Vertical Datum (NAVD88). A report of survey data was uploaded into the California GeoTracker database, ' This survey report is included as Appendix C. The surveyed data was used to prepare groundwater elevation maps for the Site by incorporating the newly installed wells. ' 2.3 Post-Installation Development and Sampling After a minimum of 72-hours had elapsed following the well installations, the wells were developed and purged in accordance with DWR. The depth to water and the total depth were measured in each well to the nearest 0.01 foot, using an electronic oil/water interface probe to check for free phase petroleum product. Development consisted of surging the screened intervals with a vented surge block of the same diameter as the casing for approximately 10 minutes. The wells were purged using a pump until at least 10 casing-volumes of groundwater were removed (where possible), the water was free of silt and apparent turbidity, and the water quality parameters for temperature, pH, specific conductance, dissolved oxygen ' (DO), and oxidation-reduction potential (ORP) stabilized. The purge water was contained in DOT-approved 55-gallon drums stored temporarily on-site until transported to an approved disposal facility in Fernley,Nevada by PSC. After a minimum of 48-hours elapsed following well development, the new wells were purged a minimum of three casing-volumes and post-development groundwater samples were collected in sample containers supplied by the laboratory. The sample containers were sealed, labeled, placed in an iced thermally-insulated cooler, and then transported under chain-of- custody protocol to Kiff Analytical. The new groundwater monitoring wells were incorporated into an existing quarterly groundwater-monitoring schedule at the Site after the initial sampling event was performed. Development water was stored in 55-gallon drums and placed on Site with drums of decon water, soil cuttings, and well installation debris. All ' investigation derived wastes (IDW) were sampled and analyzed for waste characterization. These waste materials were subsequently transported to a licensed waste disposal facility for proper disposal. 2.3.1 Deviations from the Work Plan ' PSC attempted to install a well in the "C" zone near CT-MW-8-87 and drilled the soil boring to a total depth of 130 feet bgs. Soils encountered to the depth of 80 feet bgs were similar to the soil encountered in adjacent well CT-MW-8-87, located approximately five feet east. A Monitoring Well installation and BioSparge Evaluation Report Prepared For:Sara Lee Bakery Group,Inc. 10 Prepared By:PSC Industrial Outsourcing,LP Sara Lee—Lincoln Street 2009_12_03-MW Installation&BioSparge Evaluation Report(Final).doc Report Date:December 3,2009