Site Sampling and Treatability Studies for Demonstration of WasteChem’s Asphalt Encapsulation Technology Under EPA’s SITE Program

摘要

The U.S. Environmental Protection Agency (EPA) is conducting demonstrations of a number of innovative cleanup technologies at Superfund sites across the nation. Conducted under the Superfund Innovative Technology Evaluation (SITE) program, the purpose of these technology demonstrations is to evaluate the capabilities and costs of innovative technologies under actual field conditions. These technology demonstrations involve considerable planning and costs, both to EPA and to the technology developers. Therefore, it is important to select sites with adequate quantities of wastes at high enough concentrations to allow clear comparisons between the treated and untreated wastes. It is also important to conduct treatability studies before final selection of a site to determine if the technology to be demonstrated is effective in treating the wastes that are present and allow the technology developer to establish operating parameters for the demonstration. This paper presents a sampling approach that was used to determine whether there were adequate quantities and concentrations of wastes at the Woodland Township Route 532 Site for demonstration of an asphalt encapsulation technology developed by WasteChem Corporation. This paper also presents the result of a bench-scale treatability study conducted by the WasteChem Corporation on wastes from this site. The WasteChem Corporation later withdrew its plan to demonstrate its technology based on cost disadvantages in comparison to other cleanup technologies that involve solidification.The preliminary sampling and analysis confirmed most of the types of organic and inorganic contaminants found at the Woodland Township Route 532 site during the remedial investigation (RI). However, the contamination levels varied over relatively short distances across the site for some contaminants.The bench-scale treatability study indicated that, when compared with concentrations in the untreated waste, WasteChemu27s asphalt encapsulation technology reduced semivolatile organic compound (SVOC) concentrations in the toxicity characteristic leaching procedure (TCLP) extracts of treated wastes. The study also indicated that metals concentrations in the TCLP extracts were lower in the treated wastes than the untreated wastes in some samples and higher in others. Further studies would be required to explain these variations in leachable metals.