Laserfiche WebLink
j <br /> Former Beacon Station No. _04)74 September 22,2005 <br /> Stockton California Work Plan for an Additional Subsurface Investigation <br /> SITE DESCRIPTION AND BACKGROUND <br /> The site is an operating gasoline service station located on the southwestern corner of the <br /> intersection of East Main Street and Broadway Avenue in Stockton, San Joaquin County as <br /> shown on Figure 1. Site facilities include a station building, two gasoline product dispenser <br /> islands located toward the northern property boundary, and three underground gasoline <br /> storage tanks (USTs) located toward the northeastern property boundary. A remediation <br /> system compound is located near the southeastern corner of the site. Locations of these and <br /> other pertinent site features are.shown on Figure 2. <br /> Previous environmental work at the site was conducted by Horizon and others. The previous <br /> work was summarized by Horizon in the Results of Additional Groundwater Assessment and <br /> Updated Site Conceptual Model dated June 7, 2005 that documented the performance and <br /> results of the most recent investigation. <br /> The most .recent investigation included the advancement of cone-penetrometer (CPT) and <br /> soil borings, collection of CPT-lithology logs, collection of soil and groundwater samples, <br /> and the installation and sampling of groundwater monitoring wells MW-13 through.MW-17. <br /> Recommendations for additional site characterization monitoring wells were presented in the <br /> June 7, 2005 report. Operation of a site remediation system was initiated in March 2005. <br /> Vapor extraction and groundwater air sparge systems are currently operating on an ongoing <br /> basis. <br /> The SJCEHD July 12, 2005 letter contained comments and requests for delineation of the <br /> vertical and lateral extent of groundwater impacted with hydrocarbons, primarily DCA, and <br /> to supplement existing characterization data for the central portion of the site. . The tasks <br /> proposed in this work .plan were developed on the basis of the SJCEHD requests and an <br /> evaluation of site conditions relative"to those requests. . ` <br /> 1474wp9-05 <br /> Project No. 1474.16 2 HORIZON ENVIRONMENTAL INC. <br />