Laserfiche WebLink
which time a catal tic oxidizer could be substituted for an additional period. With an <br /> Y <br /> estimated volume of 5,000 cubic yards, GeoAudit estimates that remediation could be <br /> complete within 24 months after start-up. <br />' TABLE 5 <br /> ANALYTICAL RESULTS OF AIR SAMPLES* <br /> December 17, 1993 <br />' SAMPLE ID TPH-g Benzene Toluene Ethyl- Xylene <br /> benzene <br />' VW-1/121793/215 6300 58 440 16 50 <br /> VW-111217931330 4200 38 200 5.6 17 <br />' VW-111217931515 5400 49 300 8.4 26 <br /> parts per million <br /> 6.2 Groundwater Remediation <br />' 6.2.1 Ex-situ Treatment Alternatives <br /> GeoAudit has considered two alternative methods of ex-situ groundwater remediation at this <br /> site. These methods involve pumping groundwater from extraction wells and treating or <br /> disposing of the purged water. These methods require one or more suitably placed large- <br /> diameter extraction wells. None of the wells currently on-site are suitable for extraction. <br /> To extract the contaminated water, a pneumatic pump system is usually employed. The <br />' pump system is controlled automatically to maintain capture characteristics in the aquifer <br /> and to assure process requirements are maintained. <br /> 6.2.1.1 Carbon Filtration <br /> 6.2.1.1.1 Principles <br />' One of the variants of pump-and-treat systems involves the use of activated carbon filters <br /> to remove hydrocarbons. Dissolved hydrocarbons become adsorbed onto carbon particles <br />' and are removed from the treated water. Extracted water passes through large canisters <br /> containing a carbon filter, and the treated water is then either discharged to a storm drain <br /> or re-injected back into the aquifer. Canister systems come in several designs, and are <br />' normally constructed to insure at least a 15-minute residence time for treated water. <br /> A„d„S--. 33 <br /> AAA PAPA49-M.47 <br />