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WEISS ASSOCL47E5 <br /> ATTACHMENT D - <br /> PROPOSED SOIL AND GROUND WATER REMEDIATION <br /> i <br /> I. SOIL REMEDIATION <br /> High hydrocarbon concentrations are found only in unsaturated soil immediately <br /> adjacent to the present excavation. Since the affected soil can be easily accessed by <br /> excavators, the excavation and backfilling can be accomplished quickly, the total quantity <br /> of impacted soil appears to be moderate and there is ample room available on-site for <br /> treatment of the removed soil, we feel that excavation and subsequent on-site aeration of <br /> the hydrocarbon-impacted soil is the most most effective and cost-efficient remedial <br /> option for these soils. Therefore we propose to: <br /> r <br /> 1) Excavate all soil containing detectable hydrocarbons from the sides and floor of <br /> the excavation; adjacent to the concrete slab, and, once all soil containing <br /> identifiable hydrocarbons has been removed, collect soil samples from the sides <br /> and floor of the final excavation. One . sample will be collected per <br /> 15-ft-by-15-ft section of exposed wall and floor of the excavation. We will use <br /> a portable organic vapor analyzer (OVA) and observations of hydrocarbon <br /> staining and odor to determine the limits of excavation. <br /> 2) Analyze the samples for TFHC by EPA Method 8015, to confirm that remaining <br /> suit cuittalmi no hydrocarbons at concentrations above the detection limit of 10 <br /> Parts per million (ppm). If hydrocarbons are detected in the remaining soil, <br /> continue the excavation with subsequent confirmatory resampling, until no <br /> hydrocarbons are detected, <br /> 3) Backfill the excavation <br /> with clean sand or gravel and cover the backfilled <br /> excavation with impermeable asphalt or concrete. <br /> 4) Stockpile the removed soil at the rear of the Safeway facility with previously <br /> excavated material and aerate the soil according to SJLHD-Air Quality Control <br /> District guidelines. <br /> Leaving a ing the slab in place will not adversely affect the proposed excavation since no soil <br /> known to contain high hydrocarbon concentrations is covered by the slab. <br /> 1 <br /> f <br /> Ii <br /> 1 � <br />