Superfund is a term used for the monies available to the U.S. Environmental Protection Agency (EPA) to clean up abandoned or inactive hazardous waste sites. Such sites may involve soil and/or groundwater contamination, and are often contaminated with heavy metals, such as arsenic, cadmium, chromium, lead, mercury, and zinc; pesticides, including aldrin, dieldrin, chlordane, and DDT ; and chlorinated solvents such as carbon tetrachloride, methylene chloride, and tetra and trichloroethylene. Polychlorinated biphenyls ( PCBs ), cyanide, benzene, toluene, vinyl chloride, and radionuclides, including strontium, plutonium, and uranium are also found at hazardous waste sites. The $1.8 billion Superfund was established in 1980 by federal legislation under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). It was created with taxes imposed by the federal government on major oil and chemical companies. At that time, common belief was that sufficient funds and technology existed to clean up all abandoned hazardous waste sites by 1985.
By 1985, although work had started at many sites, only approximately six sites had been completely remediated, and it soon became clear that revisions to legislation were needed to streamline cleanup efforts and additional taxes for Superfund were required to provide funding. In 1986 Superfund was replenished under the Superfund Amendments and Reauthorization Act (SARA). As a result of SARA, Superfund totaled $8.5 billion.
Under CERCLA and SARA, the EPA is given the authority and resources to clean up hazardous waste sites. EPA's priority is to identify responsible parties—those companies that have caused contamination—and require them to clean up, at their own expense, any corresponding hazardous waste sites. EPA thus reserves the use of Superfund monies for sites in which responsible parties are not identified or have claimed bankruptcy. As of 1999, responsible parties have contributed over $16 billion toward the cleanup of hazardous waste sites.
The EPA follows a detailed procedure to evaluate hazardous waste sites and ranks them according to the severity of risk to human health and the environment. The national priorities list (NPL) includes those sites that are deemed eligible for cleanup by Superfund. In 1987 it listed 1,187 sites and nearly 30,000 sites remained to be assessed. As of March 2002, 1,223 sites remained on the NPL and were eligible for cleanup under Superfund. In addition, 810 sites had achieved "construction completed" status which means that all the measures to clean up the sites, as outlined in the EPA Record of Decisions, have been taken.
Site Cleanup Remedies
Technologies employed to clean up sites include procedures that have been used for decades in treating water and air pollution; also, novel techniques
Contaminants that are biodegradable may be completely converted to environmentally acceptable products. An example of this would be using microorganisms to biodegrade gasoline components in water or soil to carbon dioxide and water. Alternatively, depending on cost and time constraints, other technologies are employed that transfer the contamination from one medium to another. Air stripping and soil vapor extraction are examples of such technologies. Air stripping involves spraying contaminated water into the top of a vertical tower while air is pumped from the bottom to the top of the tower. Chemicals that are volatile will be transferred in the tower from the water to the air. In soil vapor extraction, perforated pipes are drilled into contaminated subsurface soil and a vacuum is applied to encourage volatile chemicals to transfer from the soil to the air. Contaminants transferred to the air by these processes, such as benzene, toluene, and trichloroethylene are sometimes captured with activated carbon or destroyed by a combustion process, such as incineration. Air stripping was employed to clean ground-water contaminated with volatile organic chemicals, including trichloroethylene, benzene, toluene, and xylenes, at the General Mills/Henkel Superfund site, a former technical center and research laboratory in Minneapolis, Minnesota. The contaminants in the ground water have stabilized since the pump and treat system began in the early 1990s, with cleaned water being discharged to the Minneapolis storm sewer system.
Since the inception of SARA, the EPA has expressed a preference for cleanup remedies that destroy contamination rather than transfer it. Contaminants may be destroyed by microorganisms that biodegrade chemicals or by incineration processes that transform the chemical with extreme heat. One billion pounds of contaminated soil were incinerated at the Sikes Disposal Pits near Crosby, Texas, where hazardous waste from petrochemical companies had been dumped in unlined pits during the 1960s. The incineration was completed in 1994 and the site is now planted with local grasses. The excavation of contaminated soil for hauling to a landfill is an example of the removal and transfer of contamination to another area. The concern with "removal technologies" is that the contamination may create a future hazard to human health or the environment. For this reason, the EPA has come to discourage the use of removal technologies.
Pros, Cons, and Other Countries
Superfund's proponents argue that the EPA must have the authority and resources to clean up hazardous waste sites. Otherwise, reluctant responsible parties will have no incentive to bear the burden of cleanup. In such cases, the protection of public health and remediation of damages to the environment would be left for taxpayers to finance. Those against Superfund reauthorization claim that many industries are responsibly handling the matter of hazardous waste sites and have invested sizable resources to clean up such locations. Furthermore, these industries have a vested interest in achieving a cost-effective cleanup in a timely manner.
Many developed countries have implemented hazardous waste remediation programs. Some countries pay for site cleanup from general government revenues (taxes, etc.), whereas others rely on special taxes on industry (similar to Superfund).
LaGrega, Michael D.; Buckingham, Phillip L.; and Evans, Jeffrey C. (2001). Hazardous Waste Management, 2nd edition. New York: McGraw-Hill.
Watts, Richard J. (1997). Hazardous Wastes: Sources, Pathways, Receptors. New York: John Wiley & Sons.
Federal Remediation Technologies Roundtable. "Remediation Technology." Available from http://www.frtr.gov .
"Libby, Montana, Groundwater Contamination." Available from http://www.epa.gov/superfund .
Thomas D. DiStefano
SUPERFUND SITE IN LIBBY, MONTANA
In Libby, Montana, the remediation of soil and groundwater contaminated with pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAHs) has been under way since 1985. PCP and PAHs are chemicals used to preserve wood products such as telephone poles and railroad ties. The responsible party, Champion International Corporation, caused soil and groundwater contamination at its lumber and plywood mill in Libby. The EPA determined that wastewater and sludge from the wood-treating process were the sources of contamination. To address the issue of contamination, drinking water from a public water supply was provided to residents of the Libby area, and the use of private wells prohibited. Contaminated soil and groundwater are undergoing cleanup using bioremediation, a technology that employs microorganisms to transform hazardous chemicals into environmentally acceptable products.