News: Keep developing PCB, dioxin treatments, GAO report says

News: Keep developing PCB, dioxin treatments, GAO report says. Technology. Daniel Shannon. Environ. Sci. Technol. , 1996, 30 (3), pp 114A–114A...
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consists of dioxins, polychlorinated biphenyls, and a host of hydrocarbons and metals from Superfund sites and industries that have dumped waste into the harbor and upstream rivers {ES&T, August 1995, 353A). The program began last year when seven promising technologies were chosen, and vendors began working to decontaminate benchscale amounts of waste. Looking at preliminary results from those tests on three technologies, two were found to clean sediments to very low if not nondetectable levels, according to Eric Stern and Keith Jones, project officers for EPA and DOE, respectively. Beginning in April or May, the selected technologies will be used to attempt to clean 25 cubic yards (25 tons) of contaminated sediments. These pilot tests will be done on site in Newark, N.J., and should be completed by the end of summer, Jones said. The final report assessing all the technologies will be released before the end of the year. Once the report is completed, the next step may be the most difficult: determining who among interested parties—the New York/ , New Jersey Port Authority, indus> tries responsible for the pollution, and state and federal governments—will pay for the actual

Bench-scale vitrification heats sediments to 4200 °F, destroying organics and trapping metals in glasslike material. The product can be sold as rock wool insulation and construction aggregate, claims the vendor.

cleanup. Even if a capable technology is found, the cost of treating millions of tons of dredged sediments will be large. DOE's Brookhaven National Laboratory has final authority to select the technologies, according to Jones, but he said DOE staff confer with EPA, the Army Corps of Engineers, community groups, and others on its decision. On Jan. 25, for instance, DOE and EPA took

the program to the Ironbound section of Newark, where almost 100 community residents, politicians, and reporters attended a "meet the technologies day" program. Ironbound is a residential and industrial area in eastern Newark and home to a Superfund site responsible for much of the dioxin contamination. Community interest has driven this program from the beginning; pressure from New Jersey communities to treat the sediments instead of dumping them in the ocean led to the 1992 federal appropriation of $6.5 million that created the demonstration program. Technologies include vitrification, soil washing and separation, stabilization and solidification, low-temperature thermal desorption, solvent extraction, and thermo- and electrochemical techniques. The Army Corp of Engineers is also looking into several nonproprietary technologies, including "manufactured soil production" in which treated or untreated sediments are mixed with lawn clippings, sawdust, processed cow manure, and other organic materials and used for cover at Superfund sites. The Corp is also investigating the use of phytoremediation to remove the toxic materials from the sediments mix. —JEFF JOHNSON

Keep developing PCB, dioxin treatments, GAO report says Alternative treatments to incineration for Superfund sites contaminated with dioxin and polychlorinated biphenyls (PCBs) face several barriers and have met only limited success, according to a General Accounting Office report. But because of concerns about incineration expressed by community groups, EPA should continue its efforts to develop alternative technologies, GAO recommended. GAO said the agency has used incineration to establish technology-based treatment standards for PCBs and dioxin, even though communities often find it unacceptable. EPA has identified several technologies that could be used in the future. However, except when used on low contaminant concentrations under highly con-

trolled circumstances, the alternatives have not been as effective as incineration, GAO found, although most are still in early stages of development. But EPA has taken several steps to enhance the development and use of alternatives. The agency signed a cooperative agreement with Clean Sites, a nonprofit corporation that seeks improvements to hazardous waste cleanup. Clean Sites will conduct full-scale, on-site demonstrations of these alternatives and will provide cost and performance data needed for using a technology. EPA has proposed amendments to regulations that would increase the flexibility of cleanup standards for PCBs {Federal Register, 1994, 59, 62788), GAO reported. The amended regulations

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would allow cleanup standards based on risk rather than on the performance of a technology, namely incinerators. EPA will wait until the dioxin reassessment is completed before considering changes to dioxin standards. EPA proposed to revisit remedy decisions at several Superfund sites that could benefit from advanced technologies, the report said. In 1994 EPA revisited its remedy decision of incineration at the New Bedford Harbor, Mass., Superfund site because of growing community opposition. With the community's assistance, EPA has since narrowed a list of possible alternative remedies to three technologies: solidification/ stabilization, chemical destruction, and thermal desorption followed by chemical destruction. —DANIEL SHANNON