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• [US EPA], 1992). Air stripping is considered a viable alternative for ex-situ treatment of the groundwater impacts identified at the CHSL. Granular Activated Carbon (GAC) Adsorption: Viable—This technology involves adsorption of liquid phase VOCs on a granular activated carbon (GAC) media. During GAC adsorption, the carbon gradually becomes "spent" (saturated) by the adsorbed VOCs and requires replacement or reactivation. The spent GAC must be disposed of, or reactivated at an approved facility. This technology is also a commonly used technology for ex-situ treatment of VOCs (US EPA, 1992) and is considered a technically viable process for the treatment of chlorinated VOCs at the CHSL. GAC Fluidized Bed: Not Viable—An enhancement over the standard GAC adsorption process whereby nutrients and/or oxygen are added to a fluidized GAC vessel to provide favorable conditions for biodegradation of the organic compounds after they are adsorbed on the carbon. Biodegradation of the VOC entrapped in the GAC Fluidized Bed system is achieved by natural microorganisms, which usually operate under aerobic conditions. Unlike conventional activated carbon adsorption, GAC use and replenishment for this process is limited and substantial reductions in operating costs can result. • This system has not been successful in treating polychlorinated aliphatics such as PCE, which is a component of the contamination at the CHSL. Accordingly this process is considered not viable at the CHSL since PCE impacts are present at the site. Biological Treatment System: Not Viable— Biological treatment removes organic compounds (including chlorinated VOCs). This process is commonly used in treatment of municipal and industrial sewage where organic contaminants are present in high concentrations (parts-per- million range) in the waste stream. Unlike the in-situ process, the ex-situ biological treatment system cannot be sustained if only low concentrations of VOCs are present, such as those present in the shallow aquifer at the CHSL. Since organic constituents in the impacted aquifer at the CHSL are present at only low parts- per-billion concentrations, effective and efficient operation of a biological treatment system could not be maintained and this remediation technology is considered not viable. Chemical Oxidation: Not Viable — This treatment technology utilizes chemical oxidation, via ozone (03) and/or hydrogen peroxide (H2O2) treatment, sometimes coupled with Ultraviolet • (UV) radiation,to oxidize (destroy) organic compounds (such as VOCs) in water. Engineering Feasibility Study Geo-Logic Page ■ 19 Corral Hollow Sanitary Landfill A s s o c i w r e s January 25,2013