Polychlorinated Biphenyls (PCBs)


Because of their non-flammability, chemical stability and electrical insulating properties, polychlorinated biphenyls (PCBs) are used in a variety of commercial applications. There have long been concerns about health issues associated with PCBs and thus their manufacture was banned in 1979. Because the U.S. Environmental Protection Agency (EPA) authorized their continued use in certain enclosed applications, PCBs may still be present in older electrical equipment, such as transformers and capacitors.

Thirty years ago, EPA determined that the use of PCBs in electrical equipment as authorized under its regulations does not present an unreasonable risk of injury to human health or the environment. EPA has not provided any evidence that the toxicity of PCBs is greater than was thought at the time of the original use authorization.

How it affects Great River Energy

PCBs can be found in some equipment on the Great River Energy system, such as transformers, capacitors and circuit breakers. Great River Energy has a policy to remove equipment that is found to contain PCBs; however, the full extent to which PCBs are present in our equipment is not entirely known. Some equipment is untestable and cannot be identified without the potential to cause significant damage to PCB and non-PCB equipment. In many cases, the process required to identify whether PCBs are present would necessitate widespread service disruptions, create possible North American Electric Reliability Corporation (NERC) violations, damage or destroy equipment, and present real and immediate risk to worker safety. All PCB-containing equipment has been removed from our high-voltage direct current system.

December 15, 2016

Download a PDF of Great River Energy’s PCBs Position Statement