Laserfiche WebLink
1 o9pM FROH HORIZON E!",NIPONIHENTL 9IG 939 2172 P. <br /> HORIZON ENVIRONMENTAL INC. <br /> 4WAWWM""W Spocialists in Site.'Avssossrnent,Pernedial Testing,Desi-,-j and Operation <br /> December 9, 1998 <br /> DEC 14 1998 <br /> tyls. Michelle Nukes <br /> A11.60CIIJOYOTCI ENVIRONMENTAL HEALTH <br /> 1810 Sonlersville Road PERMIT/SERVICES <br /> Antioch, Calif rnia 94-509 <br /> SubJect: Request for Sitc Closure <br /> Fc)n-n(-,r Discovery Chevrolet <br /> 1615 West I Ith Street, Tracy, C�jjij`oj-rjia. <br /> MS. N o k cs: <br /> 1.lorizon Environmental Inc. (Horizon) has reviewed the Fourth Quarter 1998 Status Report <br /> (Ge,ttler-Ryan, December 8, 1998) that summarizes the results oi' thc fourth quarter 1998 <br /> groundwater sampling and monitoring at the above-referenced site. Results of the <br /> groundwater sampling work performed by Gettler-.Ryan on December 7, 1993 indicate that <br /> concentrations of dissolved gasoline c-on.stitue-ilts in. monitoring \vell NIW-2, located <br /> immediately downgradient of the former underground storage tax.Lks cavity, are <br /> decreasing. The decreasing concentrations in well M'N'-2 demonstrate. the eff�cti.vencss of <br /> the overexcavation work- performed in August 1998 that removed gasoline-impacted soil and <br /> groundwater in the area of the tbrmer USTs cavity and fornner product pipeline area. <br /> As discussed in the Correclive fiction }'fan (Horizon, June 1998) and in the tkt»orl on <br /> C'orrec'tive Action,Activities (Horizon, September 1994:), if groundwater sampling performed <br /> after the remedial soil and groundwater work in6cated decreasing concentrations of <br /> gasoline hydrocarbons in groundwater, since the sources for hydrocarbons have been <br /> removed, it was 1-forizon's opinion that the remaining dissol <br /> ved hydrocarbons will naturally <br /> attenuate with time. Therefore, no further work to remediate hydrocarbons at this site <br /> should be necessary. Based on the latest verification sampling and since the approved <br /> corrective action has been 1-ompleted it is our opinion the site should be gr<U31cd CIOSUrc- <br /> After granting of site closure by the SXP1 IS-F,H.D ,-the remaining monitorinwells should <br /> be destroyed and no further remedial work related to the. former IaS'I's, former associated <br /> piping, and lion-ner dispenser should benecessary at thy: cite. j <br />