Lawrence Berkeley National Laboratory

Hazardous waste is one of the most pervasive, difficult, and expensive problems confronting human society in the twentieth century. Our lack of knowledge concerning the hazards of some chemicals, lack of disposal regulations, lack of regulation enforcement, expense of treatment processes, and poor understanding of fate and effect of contaminants in the environment has led to a subsurface legacy of environmental contamination that will haunt us for hundreds of years. About 72 million U.S. citizens live within 4 mi of a USEPA Superfund National Priority List Site and 4.4 million people live within 1 mi (Bakst and Devine, 1994). The National Priority List has 1192 of the worst toxic waste sites listed and new sites are being added several times faster than sites are being removed from the list. As of December 1993, 10,624 sites were awaiting review and only 55 sites have been cleaned up and removed from the list since 1980 (Bakst and Devine, 1994). The USEPA estimated in one survey that the U.S. had more than 5 million underground storage tanks. An inspection of just 12,000 tanks revealed that 30% currently were leaking, thus as many as 300,000 to 420,000 tanks may be leaking now or will be leaking in the near future, and will require mandatory action (USEPA, 1988).