A brownfield site is an abandoned industrial property where the land may still contain hazardous contaminants, which will often dissuade potential developers. Pollution at brownfield sites, however, is considered low-grade and able to be cleaned up, thereby making these properties a prime target for redevelopment. Contaminants most commonly discovered at brownfield sites include solvents, pesticides, asbestos, and lead.
Brownfield sites are mostly found in older towns that once were booming industrial hubs. When the mills and factories faded, the land was abandoned and, in many cases, became overgrown and blighted. A brownfield site can also be identified, although less frequently, as land that once housed commercial ventures, such as gas stations, dry cleaners, or other businesses that utilized pollutants.
The clean-up and redevelopment of brownfield sites gained steam in the 1990s to coincide with the growing interest in environmental stewardship. In the United States (US), the federal Environmental Protection Agency (EPA) began a Brownfields Program in 1995 to erase the perceived inability to redevelop brownfield sites. More than $14 billion US Dollars (USD) have been poured into identifying brownfields, assessing brownfield site clean-up strategies, and encouraging potential investors to get these tracts of land back on the tax rolls.
Benefits of eradicating soil contamination at a brownfield site include the creation of jobs and an improved environment for local habitat. Redevelopment can also take advantage of existing infrastructure. Grant money typically is available to facilitate the clean-up and development of brownfield sites, as well as tax incentives. Several programs are offered to potential developers to assess the contamination and estimate a clean-up cost before a commitment is made to move forward. Land that contains a significant amount of pollutants is not considered a brownfield site.
Clean-up of brownfields has surged in modern times due in part to sheer practicality. In land-locked communities or those with increased population, less and less property is available for development. Brownfields usually are redeveloped with light manufacturing or industrial uses, but can also be made into residential areas.
Several techniques are used to pry contaminants from the toxic soil of brownfields. They include bioremediation, in situ oxidation, and soil vapor extraction. A unique cleaning strategy for land that is heavily polluted with metal is called phytoremediation, which uses plants to absorb the contaminants. When the plants are fully grown, they are weeded and dumped at hazardous waste depositories.
Some scientists hope that brownfields will be able to be used as alternative energy sources in the future. Researchers are experimenting with soybeans and switchgrass planted on once-toxic land. They hope that these plants can then be converted into biofuels.