ARCHIVED REPORTS XR0001439 - Laserfiche WebLink

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r, � 6ETTLER - RYAN INC. � Y WORK PLAN FOR ADDITIONAL SUBSURFACE ASSESSMENT At Former Unocal Service Station #0123 1034 Central Avenue Tracy, California Report No 240073 03 INTRODUCTION At the request of Unocal Corporation (Unocal), Gettler-Ryan Inc (GR) has prepared this Work Plan for additional subsurface assessment at the subject site The purpose of this investigation is to further evaluate the distribution of residual petroleum hydrocarbons in soil and groundwater downgradient of the subject site This work was requested by San Joaquin County Public Health Services Environmental Health Division (SJCPHS-EHD) The proposed scope of work includes obtaining the required boring and encroachment permits, advancing one soil boring to approximately 12 feet below ground surface (bgs), collecting soil and grab groundwater samples • for chemical analysis, analyzing the soil and grab groundwater samples, and preparing a report presenting the findings of the investigation The scope of work described in this Work Plan is intended to comply with the State of California Water Resources Control Board's Leaking Underground Fuel Tanks (LUFT) Manual, the California Regional Water Quality Control Board's (CRWQCB) Tri-Regional Board Staff Recommendations for Preliminary Investigation and Evaluation of Underground Tank Sites, and SJCPHS-EHD guidelines SITE DESCRIPTION The site is located on the southeast corner of the intersection of Central Avenue and 11th Street in Tracy, California (Figure 1) The site was reportedly an operating Unocal service station from 1920 through 1962 Two underground storage tank (UST) complexes have existed at the site A cluster of three USTs was located at the northern property boundary adjacent to l lth Street, and a second cluster of three tanks located to the south that was active at the time of closure in 1962 Other station facilities consisted of a station building, a dispenser island, and one waste oil UST The property was purchased by Bank of America in 1962 All subsurface and aboveground facilities have been demolished and removed from the site (except for one UST at the northern property boundary that was abandoned in place) The site is currently an asphalt-paved parking lot owned by and servicing the Wells Fargo Bank located immediately to the south Pertinent site features are shown on Figure 2 PREVIOUS ENVIRONMENTAL ACTIVITIES A limited subsurface investigation was conducted by L M Swift for Wells Fargo and is detailed in a Phase I Report dated March 29, 1994 The investigation included an underground electronic 6747 Sierra Court , Suite J a Dublin , California 94568 ( 925 ) 551 - 7555