PCB remediation is a form of environmental cleanup which is designed to remove or neutralize polychlorinated biphenyl (PCB), a class of chemicals which have been deemed hazardous to human and environmental health. PCBs were introduced in 1929 and widely used well into the second half of the 20th century before people began to recognize that they were extremely harmful. Production of PCB was banned in 1976. PCB remediation can involve environmental cleanup at a site known to be contaminated, removal of contaminated materials at a site which utilized PCBs, or containment of spills.
This chemical is viscous and very sticky, with a yellowish color and no odor or taste. PCB can accumulate with ease in the soil, and it penetrates a wide variety of barriers, including some types of protective garments. Exposure to PCB has been linked with the development of birth defects and a wide variety of other health problems, making cleanup and containment of this chemical a concern in many regions of the world were PCB was produced or used.
Before people realized how harmful PCBs were, many companies freely released them into the environment. Electric utilities, for example, dumped copious amounts into nearby rivers and streams. Early attempts at proper disposal such as landfilling also proved problematic, as few landfills were equipped to contain PCBs, which meant that contamination occurred both at the site of original use and in remote locations. The goal of PCB remediation is to remove PCB from vulnerable environments and to ensure that it is properly handled and disposed of.
Some sites are known sources of PCB contamination, while others may be suspected. The first step in PCB remediation is usually testing to determine the extent of the contamination, find out where it is concentrated, and to locate the source, if possible. Then, contaminated materials must be removed or sterilized. Equipment, for example, may be sterilized during PCB remediation, while contaminated soil can be dug up and backfilled with clean soil.
Remediation can involve chemical or microbial treatment of a site, with chemicals or microbes breaking down the PCB so that it is no longer harmful. Destruction can also be accomplished with several treatment methods, including exposure to very high heat. Under certain circumstances, contamination may also be left in situ and capped. During PCB cleanup, remediation services want to avoid creating another problem; for example, incomplete combustion can lead to the formation of dioxins, another contaminant of concern.