ARCHIVED REPORTS_MONITORING WELL INSTALLATION AND BIOSPARGE EVALUATION REPORT

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January 2009 — PSC performed the Soil Vapor Intrusion Survey. The report for the survey was submitted March 30, 2009. Current Activities Sara Lee along with the responsible parties (RPs) of the neighboring sites 1 entering into the California UST Fund CPA. A cost sharing agreement and CPA applications were submitted on November 20, 2009. Groundwater Monitorin¢ In accordance with the CVRWQCB request in their letter dated September 26, 2006, PSC ' initiated quarterly groundwater monitoring at the Site in January 2007. Prior to this, it appears as though MW-1 was sampled once in February 1996 and MW-7S and MW-7D were sampled once in October 1997. There is no record that VE-I was sampled prior to 2007. ' From January through May 25, 2007, approximately 500 milliliters (mL) of liquid-phase hydrocarbons (LPH) were removed from well VE-1. LPH has not been detected in well VE-I ' since April 2007. Consequently, VE-1 has been sampled during quarterly groundwater monitoring activities since July 2007. The CVRWQCB requested that well VE-1 be included in all subsequent quarterly monitoring events in a letter dated October 12, 2007. LPH has not been detected in the other wells installed at the Site on behalf of Sara Lee and its ' predecessors. As part of the coordinating efforts to obtain correlating data among the other LUST sites in ' the vicinity, the quarterly groundwater monitoring efforts have been scheduled to coincide with the adjacent properties. In addition, split samples are collected from the three Texaco wells (TX-MW-8-50, TX-MW-14-49, and TX-MW-21-80) which are located on the Colombo/Toscana Site. In consideration of State Water Resources Control Board Resolution 2009-0042, PSC ' requested that groundwater monitoring at the site be conducted on a semi-annual basis. This request was denied by the CVRWQCB in a letter dated July 13 2009. The CVRWQCB requested the continuation of quarterly monitoring during the evaluation of remedial technology and pending application to the Commingled Plume Account. 1.3 Local Geology and Hydrogeology The Site is located in the San Joaquin Sub-basin of the San Joaquin Valley Groundwater Basin. Shallow deposits in this sub-basin consist of alluvium, riverbank, and flood basin 1 deposits. Sediments encountered in these deposits consist of interbedded gravels, sands, silts, and clays of various thicknesses. Soil borings drilled on and near the Site found sediments indicative of the sub-basin. Primarily clay and silt with layers of sand, and gravel of varying thicknesses were encountered. Geologic Cross sections prepared from soil borings, CPT logs, ' and monitoring well installations drilled from 1996 through July 2009 depict a generalization of subsurface conditions. These cross sections are presented as Figures 4 through 7. ' Sandy gravel fill was encountered in the former UST excavation at the Site to depths of approximately 10 to 12 feet bgs. Fill was also encountered in borings drilled around the site to depths of 5 to 10 feet. Most of the fill material appeared to be reworked native soil and the Monitoring Well Installation and BioSparge Evaluation Report Prepared For:Sara Lee Bakery Group,Inc. 4 Prepared By:PSC Industrial Outsourcing,LP Sara Lee—Lincoln Street 200912_03-MW Installation&BioSparge Evaluation Report(Final).doc Report Date:December 3,2009