Either through normal operation of an industrial site or following an accident, it is not uncommon for chemicals or other hazardous materials to impact the surrounding environment. In such cases, contamination remediation is required to restore the area to its original condition. Such remediation is often lengthy, complicated, and expensive. Many jurisdictions require contamination remediation to be monitored and evaluated by government officials before a site can be pronounced safe.
Contamination remediation is a relatively new term in industry, dating only to the 1960s and 70s. Before that time, the true consequences of environmental contamination were not understood, and little was done to clean up spills or limit the leaching of industrial waste. With advancing science in the field of environmental protection, people realized the amount of damage unmitigated chemicals were doing to the landscape near factories and power plants around the world.
There are two basic types of contamination remediation. In situ remediation attempts decontamination without removing the affected soil or water. Ex situ remediation involves excavating or pumping out the impacted area and treating it elsewhere. A common strategy for contamination remediation in a river or stream, for instance, is to dredge it and remove the dirty silt, mud, and nearby soil to a specially prepared landfill.
As technology evolves, new techniques and methods are implemented to better and more completely remediate contaminated areas. One such technology is known as bioremediation, which uses special micro-organisms that eat and metabolize toxic waste. Since the turn of the 21st century, bioremediation has made strides towards dealing with previously hard-to-treat heavy metals, such as cadmium.
Another benefit of advancing science in the field of contamination remediation is that old locations that were previously abandoned and cordoned off can be revisited and treated effectively. Many sites around the world that were left vacant for decades have been successfully treated, thanks to techniques that were previously unavailable. Such areas that are subsequently redeveloped and put to new use are known as brownfields.
The term brownfields was coined at a United States Congressional hearing in the early 1990s, but has gained widespread use throughout the developed world. In most jurisdictions, funding is provided in varying proportions by developers, insurance companies, and government sources. Common sites include former power and chemical plants as well as steel mills, fuel stations, and even dry cleaners. Many such sites are in historically good locations, and when remediated properly can become valuable economic drivers.