WORK PLANS - Laserfiche WebLink

Home Browse Search

• Fla Ci Shell#1003 Site History& Background g t ' New West Stations 6437 West Banner Street, Lodi, California On January 29, 2008, Closure Solutions submitted a Problem Assessment Report (PAR). In accordance ' with the Tri-Regional Guidelines, this report included: • The depth and extent of free product found, including an estimate of volume removed and ' volume remaining. • Figures delineating lateral and vertical extent of soil contamination, groundwater degradation ' plume(s), and vapor plumes as appropriate. • Tables summarizing analytical data such as compound concentrations found in soil and ' groundwater, and sample depth. • An evaluation of the physical and chemical characteristics of the hazardous substance or its ' constituents, including its toxicity,persistence and potential for migration in water, soil,and air. • An estimate of the mass of contaminants remaining in soil and groundwater. ' • Identification of applicable cleanup levels for affected or threatened groundwater and surface water, and a rationale for selecting these levels. • Cross sections based upon boreholes, monitoring wells, trenches, and supporting geological mapping logs. • A Site map showing sensitive receptors (i.e. local water supply wells, buildings or utilities ' impacted or potentially threatened. • Appropriate conclusions and recommendations for the next phase of work. • An updated Site Conceptual Model illustrating Site conditions showing the extent of known soil and groundwater impact relative to the leaking UST system and the relationship between ' contaminants and potential receptors. A Feasibility Study was prepared and submitted on March 19, 2008 in accordance with the Cleanup and ' Abatement Order No. R5-2007-0709 (CAO), dated May 1, 2007 that compared the following three remedial alternatives: Monitored and Natural Attenuation, Ozone Sparging and Groundwater Extraction. Closure Solutions recommended implementing Alternative 3 — Groundwater Extraction. Monitored ' Natural Attenuation was not recommended due to the lack of dissolved hydrocarbon plume control and the possible threat to nearby wells. Ozone Sparging was not recommended due to the lack of dissolved ' hydrocarbon plume control. Groundwater Extraction was considered to be a cost-effective remedial solution designed to adequately meet the technical, institutional,and environmental protection criteria and has already been shown to be effective at the Site. The RWQCB approved the Feasibility Study in a letter dated April 3, 2008. On May 9, 2008 Confluence repaired monitoring well MW-11 B. A letter documenting the repair was ' submitted to RWQCB on May 28, 2008. Page 6 of 7 Closure Solutions, Inc.