SITE INFORMATION AND CORRESPONDENCE FILE 2

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December 12, 2007 Dear Resident/Business Owner: CLEANUP OF ENVIRONMENTAL IMPACTS RESULTING FROM LEAKING UNDERGROUND STORAGE TANKS LOCATED AT 16470 CAMBRIDGE DRIVE LATHROP, CA. EXECUTIVE SUMMARY The site is located on the northeast corner of Cambridge Drive and Louise Avenue in Lathrop, California and is an operating Circle K Mini Mart and service station. In 1997, during facility upgrades it was determined that petroleum impacts existed in soil and groundwater beneath the site. Between 1998 and 2006, sixteen geoprobe borings (GP- 1 to GP-14, DGP-1, and DGP-2) and twenty two monitoring wells (MW-1 to MW-22) have been installed to assess and monitor soil and groundwater conditions at the site. Quarterly monitoring and sample began in 1998 and continues today. Petroleum concentrations in groundwater are declining and impacts are fully assessed. Groundwater flow has generally been to the east-northeast with a gradient of 0.001 ft/ft. In 1999 and 2003, receptor surveys indicated 12 wells within a Y2-mile radius of the site. In 2002, interim remediation and feasibility testing (by dual phase extraction) were conducted to remove petroleum hydrocarbons from the subsurface and to test remedial technologies at the site. During the interim remediation and feasibility testing 305 pounds of TPHg, 1.3 pounds of benzene, and 0.07 pound of MTBE were extracted from the soil beneath the site. ConocoPhillips has submitted Revised Corrective Action Plan for ConocoPhillips, Circle K 01205, 16470 Cambridge Drive, Lathrop, California dated September 18, 2007 to propose site wide soil and groundwater remediation. PUBLIC NOTIFICATION ConocoPhillips and their consultants have proposed a corrective action plan (CAP) to cleanup the soil and groundwater impacts at the site referenced above. The San Joaquin County Environmental Health Department (SJC EHD) must review and approve the CAP prior to implementation of the plan. This notice is sent to advise you that the plan is available for review, and to advise you that SJC EHD is accepting public comment on the plan through January 12, 2008. The environmental impacts at the site resulted from a leaking underground fuel tank system. ConocoPhillips has investigated by installing monitoring wells, conducted quarterly sampling of the wells, conducted feasibility testing to institute cleanup efforts to limit the environmental impacts and protect the welfare of the public. ConocoPhillips now proposes a CAP to effectively cleanup the impacts. Assessment activities have been overseen by SJC EHD. The CAP proposes to remediate soil and groundwater impacts with the installation and operation of soil vapor extraction (SVE) and ozone sparge (OS) system. SVE is the removal of soil vapor from the subsurface for treatment and ozone sparge is for groundwater treatment. You may review a copy of the CAP, Revised Corrective Action CADocuments and Seftings\minfuma\Local Settings\Temporary Internet Files\OLKt\Circle K 1205 Cambridge Drive Lathrop-Public Notification and Executive Summary 12-11-2007.doc