nEWS TECHNOLOGY Contractors selected for NY/NJ sediment cleanup pilot Seven contractors have been selected to begin bench-scale tests of technologies to decontaminate dredged sediments from New York/ New Jersey Harbor. The harbor contains some of the world's most contaminated silt. Within a year, the technologies are to be examined at the pilot-scale level, and final selections will be made for the most effective ones, according to Department of Energy and EPA officials. By early 1997, a full-scale decontamination program is to be under way, removing contaminants from the millions of tons of harbor sediments that must be dredged to keep the busy port open, according to Eric Stern, program manager for EPA Region II, and Keith Jones, DOE program administrator. DOE Brookhaven National Laboratory, aided by several universities, is responsible for assessing the technologies and for issuing grants to fund the demonstration projects. In 1992, Congress provided $6.5 million for remediation demonstration projects and after several delays, the project is now under way (ES&T, April 1995, p. 169AJ. Stern and Jones said in late June that the seven contractors would be announced by the end of July. In all, 25 companies presented proposals to clean and reuse the contaminated sediments. Contaminants include dioxin, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, pesticides, mercury, chromium, and lead at levels that threaten the environment and human health as well as exceed ocean dumping standards. The selected technologies include vitrification, soil washing and separation, several forms of stabilization and solidification, low-temperature thermal desorption, solvent extraction, and thermo- and electrochemical techniques. Stern expected the technologies will be used as a "treatment train," removing pollutants in a series of operations. With ocean dumping no
longer permitted and land disposal sites hard to find, decontamination technologies, despite their price, are seen as a viable solution to a complex problem. In June, for instance, the Port Authority of New York and New Jersey and the State of New York paid $17.7 million to ship 150,000 cubic yards of contaminated sediments to a Utah landfill, far more than the $5-30 per cubic yard cost for ocean disposal. Stern predicted that the cost of decontamination would be less than $100 a cubic yard, making it cheaper than shipping the waste to Utah but much more expensive than dumping it. Jones said DOE's goal is to quickly go to full-scale cleanup. He also said DOE will seek funding in its 1997 appropriation to make the cleanup operation an "urban laboratory" to gain experience in sediment cleanups and to apply it to thousands of other U.S. sites. The sediments will be collected from highly contaminated Newtown Creek, Stern said. Vendors will receive a share of some 400 gallons of sediments for bench tests. The Port Authority and city of Newark, NJ, will provide a two-acre site where contractors will decontaminate 25 cubic yards at the pilot level. In their bids, vendors pro-
Arthur Kill, Newark Bay, and Newtown Creek are NY/NJ Harbor areas with high sediment contaminant concentrations. Because Newtown Creek has the highest levels of most pollutants, its sediments will be used for the pilot project.
posed "beneficial uses" for cleaned sediments, which included incorporation in asphalt, construction aggregate, landfill cover, and artificial reef blocks. However, because of the controversy over ocean dumping of sediments, which has pitted longshoremen and the Port Authority against fishermen, shore residents, and businesses, Stern said it was doubtful any of the dredge spoils would ever again touch the sea, even if decontaminated. —JEFF JOHNSON
Sustainable development plan due this fall Taxes on waste and consumption and a shift of responsibility for the fate of products to manufacturers are likely recommendations of a presidential task force examining sustainable development. In a preview of findings from the President's Council on Sustainable Development, co-chairs David Buzzelli, vice president of Dow Chemical Co., and Jonathan Lash, president of the World Resources Institute, explained the Council's approach and outlined some recommendations at a June Resources for the Future symposium. VOL.
Formed two years ago to look into policies that foster sustainable development and economic vitality, the Council will forward its policy recommendations to the president this fall. The 25-member Council includes top corporate officials, environmentalists, cabinet members, and government and community leaders. At its first meeting in July 1993, the Council was termed a "linchpin" by Vice President Gore because of what he said was its role in developing (continued on next page)
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a plan to lead to economic progress without environmental destruction. The Council has held meetings around the country, heard from experts, and reviewed local projects with a sustainable development perspective. Speaking at the symposium, Lash discussed four policy recommendations in the manufacturing sector out of some 80 that, he said, would be issued by August. These included: • Establishment of performance-based comprehensive "environmental management systems" to replace federal, state, and local regulatory schemes. • A shift of focus from waste reduction, resource conservation, and pollution prevention to extended product responsibility; manufacturers assume responsibility for the life of a product. • Greater use of market incentives. • A revenue-neutral tax shift from taxing work and investments to taxing activities that lead to environmental damage, waste, and consumption. In his original charge to the Council, Gore urged that it "show what can be done" through demonstration projects. Although the Council has not originated such projects, according to Council staff, it has examined local projects. Buzzelli pointed to projects at a Dow Chemical facility at LaPorte, TX, and a Monsanto plant at Pensacola, FL, which are being overseen by representatives of industry and the Natural Resources Defense Council. The projects' goal is to see what "regulatory fixes" could provide greater environmental protection and better efficiency, according to Ric Olson, Dow Chemical senior environmental associate. An independent auditor is now conducting pollution prevention audits at the plants. That information will be coupled with an examination of regulations to see if barriers exist that block industry from achieving reductions, as industries contend, and if so, how regulations might be changed. —JEFF JOHNSON
Subsurface barrier trapped rapped diverse contaminants, let water ater through Two commercially available, inexpensive ingredients are the basis of a promising subsurface barrier material. In laboratory studies, the material trapped a surprising assortment of major organic and inorganic contaminants while allowing water to flow through, reported developer Robert Bowman at the American Geophysical Union meeting in June. A 15-month pilot-scale study to evaluate the permeable barrier material is planned for next year. Subsurface barriers limit the spread of mobile pollutants in contaminated soils, reducing cleanup costs and protecting downstream aquifers. Bowman's group at the New Mexico Institute of Mining and Technology (Socorro, NM) developed their barrier material by treating zeolites with the surfactant hexadecyltrimethylammonium (HDTMA), a commonly used chemical (see Bowman et al., ACS Symposium Series 594, 1995, p. 55). Using current prices, Bowman estimated that the modified zeolite could cost about $0.25/lb. The surfactant coats the surface, leaving the internal pores of the cagelike zeolites open for ion exchange. According to Bowman, the treated zeolites offer several mechanisms to trap diverse categories of pollutants. Inorganic cations such as Pb 2+ are trapped by ion exchange with the zeolite or surface complexation reactions, inorganic anions form a surface precipitate with the adsorbed alkylammonium ion, and nonpolar organics such as benzene or xylenes dissolve into the alkylammonium layer. One surprising, accidental discovery is that the modified zeolite traps normally difficult-to-treat chromate anions. Laboratory studies show that the HDTMA coating stays on zeolites in the presence of organic solvents, concentrated salt solutions, and solutions with pHs ranging from 3 to 13. "Long-term leaching studies show a slow bleed of the HDTMA [off the zeo-
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Surface-modified zeolite
Backfill
>..—_ Contaminated groundwater
Purified groundwater
lite]," said Bowman. But the surfactant should be reabsorbed by soils pretty quickly, he suspects. In recent years, several groups have investigated a suite of materials for permeable and impermeable subsurface barriers, but most are aimed at specific classes of contaminants. Bowman argued that because impermeable barriers restrict groundwater flow, they run the risk of building up hydraulic pressures on the upstream side, which could lead to water and contaminants flowing over or under the barrier. Jim Amonette, a senior research scientist working on barriers at Pacific Northwest Laboratories (Richland, WA), agreed but says that even permeable barriers can slow water flow, and therefore packing density will be a key issue. Combining permeable and impermeable barriers into a funnel and gate is "probably the best way to go," said Amonette. Other potential problems are the longterm stability of the barrier and competition with naturally occurring ions for exchange sites. According to Bowman, for applications as deep as 50 ft, the zeolite barrier would be poured as slurry into trenches dug by a backhoe. Deeper barriers may be possible by adapting existing technology, said Bowman. Commercial interests have contacted Bowman about using the modified zeolites for other purposes. "They could be used in a packed bed [to trap contaminants] as part of a pump-and-treat operation." —ALAN NEWMAN
