Laserfiche WebLink
Groundwater quality in the site vicinity is poor The subject property is located within the plume <br /> of saline groundwater encroaching from the delta area to the west The nearest monitored <br /> production wells, located approximately 4,000 feet northeast of the site, contain chloride and total <br /> dissolved solids in excess of MCL's <br /> PROCEDURES <br /> Resources <br /> Excavation was conducted by Johnson Petroleum Construction, Inc Sean Garvey, a Ground <br /> Zero geologist, supervised excavation activities and sample collection Mr Michael Infurna with <br /> PHS/EHD observed field activities and conducted the site inspection McCampbell Analytical, <br /> Inc conducted the laboratory analysis Groundwater was pumped from the excavation by D A <br /> Parrish and was disposed of at the City of Stockton wastewater treatment facility Excavated soil <br /> was disposed of at Forward Landfill <br /> Soil Excavation and Sampling <br /> • Contarninated soil excavation and confirmation sampling occurred in two stages — the first on June 16 <br /> and the second on June 30, 1999 The additional excavation was conducted in order to remove a small <br /> volume of contaminated soil remaining after the first stage of work <br /> Initial Soil Excavation <br /> On June 16, 1999, approximately 200 cubic yards of contaminated soil and 20 yards of overburden <br /> was excavated by Johnson Petroleum within the vicinity of the existing tank pit The area excavated <br /> was irregular in shape and varied in depth Figure 3 depicts the excavated area <br /> The removal of soil began at the south center portion of the existing tank pit Overburden and <br /> potentially contaminated sort was segregated into separate spoil piles At a depth of approximately 8 to <br /> 9 feet, petroleum hydrocarbon odors were noted Groundwater became present at a depth of <br /> approximately 18 feet bgs Apparent discoloration of the soil became evident at a depth of <br /> approximately 15 feet and extended to 21 feet (subsequent analytical results suggest that the apparent <br /> discoloration was in fact natural soil color) <br /> Excavation proceeded laterally and vertically until lack of odor and significant flame ionization detector <br /> (FID) readings indicated that impacted soil had been removed in all quadrants except possibly in the <br /> vicinity of the west end of the former dispenser island Confirmation sample WCE-20-NC was <br /> collected at this location The excavated material was stockpiled on and covered by visqueen plastic <br /> pending disposal Field notes are included in Attachment A <br /> Woolsey/reports/soiNsum doc <br /> 3 <br />