Laserfiche WebLink
URS <br /> Mr Mike Infurna Page 5 <br /> San Joaquin County Environmental Health Department <br /> June 6, 2003 <br /> over 1,000 feet from the site,URS concludes that the impacted groundwater at the site does not pose <br /> a threat to either of these municipal wells <br /> • Groundwater conditions at the site have benefited from the historical use of SVE and air infection <br /> SVE has contributed to the remediation of soil and groundwater by source removal Au-infection has <br /> contributed to the remediation of groundwater through the introduction of oxygen to the subsurface to <br /> encourage the growth of naturally occurring bacteria and associated aerobic biodegradation <br /> • The remaining hydrocarbon impacts identified in groundwater are in the vapor extraction wells in the <br /> vicinity of the USTs and dispenser islands,particularly in well VW-10,located approximately 10 feet <br /> south of the western dispenser island TPHg and benzene were reported at 14,000µg/kg and 2,800 <br /> [t&g in VW-10 during the December 2002 sampling event <br /> • Because of the relatively low permeability soils(predominantly silts)and the relatively low hydraulic <br /> gradient(approximately 0 0015 ft/ft),the remaining hydrocarbon impacted groundwater is unlikely to <br /> • migrate vertically or laterally to a significant extent <br /> If you have any questions or comments regarding this letter,please call Mr Vernon EIarth at(916)679-2299 <br /> Sincerely, <br /> URS Corporation Americas <br /> O GE0ZO <br /> ? U(41 061 <br /> X17 -A <br /> No 7120 <br /> * Exp t �� <br /> Scott Lookmgb Vernon Elarth, R G <br /> Project Geologist Project Manager >y <br /> DF CAOFOe' <br /> Attachments Figure 1 Site Location Map with Production Well Locations <br /> Figure 2 Site Plan <br /> Figure 3 Site Lithology <br /> Figure 4 TPHg Distribution in Soil at Depths of 15 to 40 Feet <br /> S\2130 Site Conceptual Model.doc <br />