Laserfiche WebLink
cy/ <br /> yy <br /> . Quarterly Summary Report <br /> Fourth Quarter 1999 <br /> Tosco (Former Unocal) Service Station#4409 <br /> 1502 North El Dorado <br /> Stockton, California <br /> CITY Stockton <br /> COUNTY San Joaquin <br /> BACKGROUND <br /> The site is located on the northeast corner of Harding Way and El Dorado Street in Stockton, <br /> California. The site is a former Unocal service station that retailed gasoline and diesel fuel. On <br /> April 7, 1999, three 10,000 gallon capacity USTs were removed from the site. Two USTs <br /> contained gasoline and one contained diesel fuel. Initial remedial activities included source <br /> removal of obviously impacted soil to a depth of approximately 18 feet bgs beneath the center of <br /> the western fuel tank. Additional remedial activities included source removal of obviously <br /> impacted soil in the area beneath the former dispenser and product lines. A concrete pad <br /> restricted the lateral extent of excavation. During excavation of impacted soil; unidentified <br /> fiberglass piping was found. Additional excavation and sampling was completed on <br /> • April 8, 1999 to remove the unidentified piping. Samples were collected from the bottom and <br /> side walls of the excavated area. Following removal of the former station canopy, canopy <br /> footings and kiosk, additional over-excavation was completed in the dispenser area. Over- <br /> excavation was terminated when obviously impacted soil was removed, the structural integrity of <br /> the sidewalk was endangered, or groundwater was encountered. Residual hydrocarbons remain <br /> in the soil and groundwater. A total of approximately 1,707 tons of soil was transported offsite <br /> for disposal at the Forward Landfill in Manteca, California. <br /> RECENT QUARTER ACTIVITIES <br /> • Submitted Additional Assessment Work Plan on October 28, 1999. <br /> • Completed groundwater monitoring well installation on December 9 and 10, 1999. <br /> ANTICIPATED NEXT QUARTER ACTIVITIES <br /> • Sample and survey new groundwater monitoring wells. <br /> • Submit Additional Assessment Report. <br /> • Submit Quarterly Summary Report. <br /> 9110112A/4gsr99 2 01/18/00 <br />