Brownfield land

Brownfield is previously developed land that has been abandoned or underused, and which may carry pollution, or a risk of pollution, from industrial use. The specific definition of brownfield land varies and is decided by policy makers and land developers within different countries. The main difference in definitions of whether a piece of land is considered a brownfield or not depends on the presence or absence of pollution. Overall, brownfield land is a site previously developed for industrial or commercial purposes and thus requires further development before reuse.

Examples of post industrial brownfield sites include abandoned factories, ash ponds, landfills, dry cleaning establishments, and gas stations. Typical contaminants include hydrocarbon spillages, solvents and pesticides, asbestos, and heavy metals like lead.

Many contaminated post-industrial brownfield sites sit unused because the cleaning costs may be more than the land is worth after redevelopment. Previously unknown underground wastes can increase the cost for study and cleanup. Depending on the contaminants and damage present adaptive re-use and disposal of a brownfield can require advanced and specialized appraisal analysis techniques.

The Federal Government of Canada defines brownfields as "abandoned, idle or underused commercial or industrial properties [typically located in urban areas] where past actions have caused environmental contamination, but which still have potential for redevelopment or other economic opportunities."

The U.S. Environmental Protection Agency (EPA) defined brownfield as a property where expansion, redevelopment or reuse may be complicated by the presence or potential presence of a hazardous substance, pollutant or contaminant. This comports well with an available general definition of the term, which scopes to "industrial or commercial property".

The term brownfield first came into use on June 28, 1992, at a U.S. congressional field hearing hosted by the Northeast Midwest Congressional Coalition. Also in 1992, the first detailed policy analysis of the issue was convened by the Cuyahoga County, Ohio Planning Commission. EPA selected Cuyahoga County as its first brownfield pilot project in September 1993. The term applies more generally to previously used land or to sections of industrial or commercial facilities that are to be upgraded.

In 2002, President George W. Bush signed the Small Business Liability Relief and Brownfields Revitalization Act (the "Brownfields Law") which provides grants and tools to local governments for the assessment, cleanup, and revitalization of brownfields as well as unique technical and program management experience, and public and environmental health expertise to individual brownfield communities. The motivation for this act was the success of the EPA's brownfields program, which it started in the 1990s in response to several court cases that caused lenders to redline contaminated property for fear of liability under the Superfund. As of September 2023, the EPA estimates that the EPA Brownfields program has resulted in 134,414 acres of land readied for reuse.

Mothballed brownfields are properties that the owners are not willing to transfer or put to productive reuse.