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Corrective Action Plan Page 16 <br /> Total Xylenes EPA Method 8020 <br /> When the analytical results are received, the drill cuttings to the drums will be classified <br /> and, as necessary, a SJVUAPCD Authorization of Uncontrolled Soil Aeration will be <br /> obtained to permit on-site treatment of this material by aeration [Note A requirement to <br /> obtain a SJVUAPCD permit for aeration of this material will be determined based on the <br /> criterion established by that agency's Rule 4651 (Ref 4) that requires soil that envts more <br /> than 50 ppm of VQC when measured as hexane at a distance of 3 in above the surface <br /> with an organic vapor analyzer shall be treated as contaminated for the purposes of the <br /> applicable air-quality regulations ] <br /> When they are sufficiently dry, the drill cuttings will be spread, to a maximum thickness of <br /> 1 ft , over a secure, bermed area of the site that will be protected by two layers of plastic <br /> sheeting The spread material will be rototilled to induce decontamination by aeration <br /> When aeration has progressed to the point that no olfactory indicators of components of <br /> gasoline are present, three sample of the soil will be obtained from randomly selected <br />' locations by driving a brass sampling tube into the spread material so that soil from at least <br /> 3 in beneath the surface is recovered These samples will be managed and analyzed / <br /> according to the procedures specified above for the initial sample of the drill cuttings If <br /> no detectable concentrations of the analytes of concern are found in the samples, the drill <br /> cuttings will be loaded into a truck for off-site disposal as clean material If not, the spread <br /> of cuttings will be subjected to additional cycles of rototilling, aeration, and sampling until <br /> no detectable concentrations of contaminants are found in samples and their disposal as <br /> clean material is permissible <br /> Eumping Rates- Drawdown and 7one of Influence <br /> The groundwater recovery and treatment system will have a maximum capacity of 45 gpm <br /> and a normal operating throughput of 30 gpm These parameters provide appropriate <br /> operating flexibility and reserve capacity while remaining compatible with the restrictions <br /> imposed by the CRWQCB's consolidated NPDES Permit No CA0082929 that lints total <br /> discharge from the treatment system to 50 gpm The maximum process capacity of 45 <br /> gpm also allows utilization of industry-standard, modular-sized air-striping and carbon- <br /> adsorption equipment <br /> Based on the hydrostratigraphy, the characteristics of the groundwater-flow regime <br /> beneath and the distribution of contaminant concentrations in the subsurface, it is <br /> proposed that groundwater will initially be pumped at a rate of 10 gpm from each <br /> recovery well Tlus will produce a total flow of 30 gpm which matches the proposed <br /> nominal operating capacity of the groundwater treatment system However, as operating <br /> experienced is gained, it is expected that it may be advantageous to adjust the pumping <br /> rates from each individual well The pumping rate from any given well in the array may be <br /> adjusted downward to permit increased pumping from one or more of the other wells in <br /> response to empirically observed water-table drawdowns and the distribution of <br /> contaminant concentrations in the area around the wells This will pernut optimal recovery <br />