PCBS, MINING, AND WATER POLLUTION

The presence of PCB-containing electrical equipment in underground mines has been documented during U.S. Environmental Protection Agency (EPA), Region 8, mine inspections conducted over the last 20 years. PCB-containing electrical equipment may be found in mines throughout the world because both electrical systems and mining methods follow the same general patterns. The abandonment of this equipment in underground mines is likely to present worldwide ground water contamination in mining districts.

Polychlorinated biphenyls (PCBs) are a group of man-made structurally-related chemicals manufactured in the United States between 1929 and 1977 when manufacture was voluntarily discontinued. In 1978, their manufacture was prohibited, and their use and disposal closely regulated, by the PCB regulations under the Toxic Substances Control Act (TSCA), the Act that regulates industrial chemicals in use, including the disposal of PCBs. PCBs have become a ubiquitous environmental contaminant that have been detected in air, water, soils, and biosystems worldwide where they present a threat to human health and the environment. Despite the fact that manufacture has been prohibited in the United States of America and many other countries, PCBs are still used in electrical equipment. Certain continuing uses have been authorized under the PCB regulations. The major use of PCBs authorized by the regulations as dielectric fluids (or contaminants in dielectric fluids) in transformers and capacitors. Because the mining industry has been an extensive user of PCB-containing electrical equipment, some of this equipment has been abandoned underground. Furthermore, PCB-containing electrical equipment remains in underground use today. Abandoned equipment can become irretrievable, and released PCBs create a threat to ground and surface waters.