Laserfiche WebLink
Banta Road - UPRR -2 - 16 November 2010 <br /> 'Tracy, San Joaquin County <br /> Tlie analytical results for water quality parameters for an onsite groundwater sample <br /> determined that total dissolved solids (TDS) at a concentration of 650 mg/L exceeded the <br /> California Department of Public Health Recommended Secondary Maximum Contaminant <br /> Level value (500 mg/L) for drinking water. In addition, several other constituents exceeded <br /> drinking water standards as well as some agricultural beneficial use criteria. Considering the <br /> nature of onsite groundwater quality and readily available municipal water supply, shallow <br /> groundwater at the Site is unlikely to be used as a source of drinking water. <br /> Based on the findings of the site investigations, Chevron was notified in September 2009 that <br /> crude oil affected soil and groundwater were delineated and a Human Health Screening <br /> Evaluation (Screening Evaluation) could be completed. A Screening Evaluation was <br /> submitted September 2009. In a 10 November 2009 Central Valley Water Board letter to <br /> Chevron that stated based on the findings, the site was a candidate for closure and a request <br /> for No Further Action Required determination could be prepared. <br /> Chevron's consultant queried the California Natural Diversity Database, maintained by the <br /> California Department of Fish and Game, to search for threatened, endangered, or sensitive <br /> species. None have been observed within one mile of the site. <br /> The environmental screening levels and/or the water quality constituent concentrations are <br /> used to assist in defining the extent of affected soil and groundwater, not to assess health, <br /> ecological risk, or to establish cleanup levels. The Screening Evaluation findings indicate that <br /> exposure to petroleum hydrocarbons chemical of potential concern present do not exceed <br /> respective environmental screening levels. The levels reported do not pose a threat to future <br /> commercial/trench maintenance workers or to potential ecological receptors at the Site. <br /> Central Valley Water Board staff received a copy of a site specific Soil and Groundwater <br /> Management Plan (SGMP), dated 22 March 2010. The SGMP designates Chevron as the <br /> responsible party for any issues that may arise related to the crude oil leaks encountered <br /> during future site excavation and/or maintenance activities. The SGMP was submitted to <br /> owners of property determined to overlie affected soil and groundwater including the San <br /> Joaquin County Environmental Health Department. <br /> Central Valley Water Board staff concurs that based on results of soil and groundwater <br /> investigations and the health risk screening evaluations, the presence of residual crude oil in <br /> soil and groundwater would not present a threat to human health for use as a future <br /> commercial site. <br /> Details of the site assessments are available to interested parties through the GeoTracker <br /> website (https //qeotracker.waterboards.ca.gov/search/casesearch.htm) and Central Valley <br /> Water Board case files. The Central Valley Water Board case number is 6L0607765026. <br /> Interested parties with questions or comments regarding the site or the proposed closure can <br /> provide written comments, or contact Dean Hubbard at the above address, by e-mail at <br /> dhubbard(c vvaterboards.ca.gov, or at (559) 445-5179 by 17 December 2010. <br />