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•i Cone Penetrometer Testing Site Investigation - Fourth Quarter 2007 STRONG PROPERTY 5157 West Business Loop 205,Tracy,California lA. INTRODUCTION AND SCOPE OF WORK At the request of Messrs. Robert and Mike Strong,Advanced GeoEnvironmental, Inc. (AGE)has prepared this report of findings for 5157 West Business Loop 205, Tracy, California. The report documents procedures and results for cone penetrometer testing(CPT)conducted at the site during November 2007(fourth quarter). The site setting is illustrated on Figure 1. Site structure, CPT soil boring, and monitoring well locations are depicted on Figure 2. The objective of this fourth quarter 2007 investigation was to assess the vertical extent of dissolved petroleum hydrocarbons.This report has been prepared in accordance with guidelines issued by the Central Valley Regional Water Quality Control Board for the investigation of underground storage tank(UST)sites.A summary of previous investigation and background information for the site was included in the AGE-prepared Problem Assessment-Feasibility Study Report,dated 29 April 2005. Following the initial advancement of each CPT lithologic sounding,independent grab water samples were collected adjacent to each CPT boring location, at selected depths, from separate sample- borings, each located a few feet from the initial CPT lithologic boring. Each independent sample boring was given the same boring designation as the initial CPT lithologic boring. 2.0. CPT SOIL BORINGS On 09 November 2007,one soil boring,CPT-1,was advanced on-site approximately ten feet north of well MW-2A, utilizing CPT technology, to characterize the geological and hydrogeological framework and to identify potential contaminant-migration pathways. Based on CPT lithologic sounding data collected at CPT-1,two depth-discrete"grab"ground water samples were collected adjacent to CPT-1,with independent borings advanced within a few feet of the CPT sounding. 2.1. CPT LITHOLOGIC SOUNDINGS Soil boring CPT-1 was advanced vertically to a total depth of 110 feet below surface grade (bsg) utilizing a 25-ton truck-mounted CPT drill rig equipped with 2-inch diameter hollow-stem rods.A hydraulic ram was utilized to advance a cone penetrometer tip to total depth of each CPT boring.Soil parameters such as cone penetrometer tip resistance, sleeve friction, friction ratio (ratio between sleeve friction and tip resistance),and pore water pressure were continuously measured as the cone penetrometer was advanced to depth. A continuous boring log was generated utilizing the Hogentogler Co. CPT computer program.The Hogentogler Co. computer program utilized the CPT Advanced GeoEnvironmental,Inc.