||The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. (May 2011)|
Brownfields are abandoned or underused industrial and commercial facilities available for re-use. Expansion or redevelopment of such a facility may be complicated by real or perceived environmental contaminations.
In the United States, urban planning jargon, a brownfield site (or simply a brownfield) is land previously used for industrial purposes or some commercial uses. The land may be contaminated by low concentrations of hazardous waste or pollution, and has the potential to be reused once it is cleaned up. Land that is more severely contaminated and has high concentrations of hazardous waste or pollution, such as a Superfund site, does not fall under the brownfield classification. Mothballed brownfields are properties that the owners are not willing to transfer or put to productive reuse.
In the United Kingdom and Australia, the term applies more generally to previously used land or to sections of industrial or commercial facilities that are to be upgraded, although this usage is becoming more commonplace in the United States as well.
United States 
The term brownfields 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 Planning Commission. The United States Environmental Protection Agency selected Cuyahoga County as its first brownfield pilot project in September 1993.
Generally, brownfield sites exist in a city's or town's industrial section, on locations with abandoned factories or commercial buildings, or other previously polluting operations. Small brownfields also may be found in many older residential neighborhoods. For example, many dry cleaning establishments or gas stations produced high levels of subsurface contaminants during prior operations, and the land they occupy might sit idle for decades as a brownfield.
Typical contaminants found on contaminated brownfield land include hydrocarbon spillages, solvents, pesticides, heavy metals such as lead (e.g., paints), tributyltins, and asbestos. Old maps may assist in identifying areas to be tested.
Redevelopment strategies 
||This section needs additional citations for verification. (May 2011)|
A number of innovative financial and remediation techniques have been used in the U.S. in recent years to expedite the cleanup of brownfield sites. For example, some environmental firms have teamed up with insurance companies to underwrite the cleanup of distressed brownfield properties and provide a guaranteed cleanup cost for a specific brownfield property, to limit land developers' exposure to environmental remediation costs and pollution lawsuits. The environmental firm first performs an extensive investigation of the brownfield site to ensure that the guaranteed cleanup cost is reasonable and they will not wind up with any surprises.
After the dot-com bubble of 2000, many venture capital firms looking for new businesses in which to invest have done so in brownfields. Venture capital investments in brownfield-related businesses have included companies developing new cleanup technology, companies that do remediation, and development projects in brownfield lands.
Innovative remedial techniques used at distressed brownfields in recent years include bioremediation and in situ oxidation. Often, these strategies are used in conjunction with each other or with other remedial strategies such as soil vapor extraction. In this process, vapor from the soil phase is extracted from soils and treated, which has the effect of removing contaminants from the soils and groundwater beneath a site. Some brownfields with heavy metal contamination have even been cleaned up through an innovative approach called phytoremediation, which uses deep-rooted plants to soak up metals in soils into the plant structure as the plant grows. After they reach maturity, the plants – which now contain the heavy metal contaminants in their tissues – are removed and disposed of as hazardous waste. A newer technology for remediating brownfields involves an in situ injection of an iron-embedded organosilica material that creates a permanent soft curtain barrier underground. Groundwater passes through the barrier, which absorbs toxins and solvents while the iron dechlorinates them to non-toxic products.
Research is under way to see if some brownfields can be used to grow crops, specifically for the production of biofuels. Michigan State University, in collaboration with DaimlerChrysler and NextEnergy, has small plots of soybean, corn, canola, and switchgrass growing in a former industrial dump site in Oakland County, Michigan. The intent is to see if the plants can serve two purposes simultaneously: assist with phytoremediation, and contribute to the economical production of biodiesel and/or ethanol fuel.
Post-redevelopment uses 
||This section needs additional citations for verification. (June 2011)|
Some state governments restrict development of brownfield sites to particular uses in order to minimize exposure to leftover contaminants on-site after the cleanup is completed; such properties are deed-restricted in their future usage. Some legally require that such areas are reused for housing or for new commercial use in order not to destroy further arable land. The redevelopment of brownfield sites is a significant part of new urbanism, while some brownfields are left as green spaces for recreational uses.
For historical reasons, many brownfield sites are close to important thoroughfares such as highways and rivers; their reclamation can therefore be a major asset to a city. Portland, Oregon, has pioneered the use of road and rail infrastructure to support the cleanup and reuse of brownfield sites. Another example is the Atlantic Station project in Atlanta, the largest brownfield redevelopment in the United States. In Seattle, rusted remains of a gasworks were left in place to add character to Gas Works Park. Dayton, like many other cities in the region, is developing Tech Town in order to attract technology-based firms to Dayton and revitalize the downtown area.
But one of the most well-known areas in the United States for brownfield redevelopment is Pittsburgh, Pennsylvania, which has successfully converted numerous former steel mill sites into high-end residential, shopping and offices. Several examples of brownfield redevelopment in Pittsburgh include the following:
- In Homestead, Pennsylvania, the site once occupied by Carnegie Steel has been converted into a successful commercial center, The Waterfront.
- In Pittsburgh's Squirrel Hill neighborhood, a former slag dump for steel mills was turned into a $243 million residential development called Summerset at Frick Park.
- In Pittsburgh's South Side neighborhood, a former LTV Steel mill site was transformed into Southside Works, a mixed-use development that includes high-end entertainment, retail, offices, and housing.
- In the Hazelwood (Pittsburgh) neighborhood, a former Jones and Laughlin steel mill site was transformed into a $104 million office park called Pittsburgh Technology Center.
- In Herr's Island, a 42-acre (170,000 m2) island on the western bank of the Allegheny River, a former rail stop for livestock and meatpacking was transformed into Washington's Landing, a waterfront center for commerce, manufacturing, recreation and upscale housing
In the United States, investigation and cleanup of brownfield sites is largely regulated by state environmental agencies in cooperation with the Environmental Protection Agency (EPA).The EPA, together with local and national government, can provide technical help and some funding for assessment and cleanup of designated sites. They can also provide tax incentives for cleanup that is not paid for outright; specifically, cleanup costs are fully tax-deductible in the year they are incurred. Many of the most important provisions on liability relief are contained in state codes that can differ significantly from state to state.
In the UK regulation of contaminated land comes from Part 2A of the Environment Act, responsibility falls on local authorities to create a "contaminated land register", sites with dubious past and present uses may be subject to a desktop study, which is sometimes implemented as a condition in planning applications.
Barriers to redevelopment 
||This section needs additional citations for verification. (May 2011)|
Many contaminated brownfield sites sit unused for decades because the cost of cleaning them to safe standards is more than the land would be worth after redevelopment. However, redevelopment has become more common in the first decade of the 21st century, as developable land grows less available in highly populated areas, and brownfields contribute to environmental stigma which can delay redevelopment. Also, the methods of studying contaminated land have become more sophisticated and established.
Many federal and state programs have been developed to help developers interested in cleaning up brownfield sites and restoring them to practical uses. Some states and localities have spent considerable money assessing the contamination on local brownfield sites, to quantify the cleanup costs in an effort to move the redevelopment process forward.
In the process of cleaning contaminated brownfield sites, surprises are sometimes encountered, such as previously unknown underground storage tanks, buried drums or buried railroad tank cars containing wastes. When unexpected circumstances arise, the cost for clean-up increases, and as a result, the cleanup work may be delayed or stopped entirely. To avoid unexpected contamination and increased costs, many developers insist that a site be thoroughly investigated (via a Phase II Site Investigation or Remedial Investigation) prior to commencing remedial cleanup activities.
Acquisition, adaptive re-use, and disposal of a brownfield site requires advanced and specialized appraisal analysis techniques. For example, the highest and best use of the brownfield site may be affected by the contamination, both pre- and post-remediation. Additionally, the value should take into account residual stigma and potential for third-party liability. Normal appraisal techniques frequently fail, and appraisers must rely on more advanced techniques, such as contingent valuation, case studies, or statistical analyses. Nonetheless, a University of Delaware study has suggested a 17.5:1 return on dollars invested on brownfield redevelopment.
See also 
- Brownfield regulation and development
- Brownfield status
- Greenfield land
- Greyfield land
- HUD USER
- Industrial nature
- Regulatory Barriers Clearinghouse
- Small Business Liability Relief and Brownfields Revitalization Act
- Brockton Brightfield (brownfield turned into a solar power plant)
- Rhizome Collective (brownfield-based radical urban sustainability collective)
- Redevelopment of Mumbai mills (unused mills being re-developed)
- Waste (law)
- "Glossary of Terms for Brownfields" (URL). Environmental Law Institute. Retrieved 2009-11-29.
- "Brownfields Showcase Community Fact Sheet" (URL). Environmental Protection Agency. Retrieved 2009-11-29.
- "Brownfields Program Achievements Linked to Early Success" (PDF). United States Environmental Protection Agency. October 2006. pp. 1–3. Retrieved 2012-04-10.
- "ANR Communications" (URL). Michigan State University. July 10, 2006. Retrieved 2009-11-29.[dead link]
- Building a City Within the City of Atlanta
- "Brownfields Tax Incentive" (URL). Environmental Protection Agency. Retrieved 2009-11-29.
- "Brownfields Overview Page" (URL). National Conference of State Legislatures. Retrieved 2009-11-29.
- Coming Back from Economic Despair Henry Mayer and Micheal Greenburg. Economic Development Quarterly, August 2001
- "John A. Kilpatrick Resume" (PDF). Greenfield Advisors. Archived from the original on 14 May 2011. Retrieved 2009-11-29. Article Author of "Valuation of Brownfields", Chapter 29 in Lexis-Nexis Matthew Bender's Brownfield Law and Practice, 2007.
- Montgomery, Jeff (14 May 2011). "Cleaning up contamination". The News Journal (New Castle, Delaware: Gannett). DelawareOnline. Archived from the original on 14 May 2011. Retrieved 14 May 2011. The first online page is archived; the page containing information related here is not in the archived version.
- Brownfield Land at the Open Directory Project
- Polluted and Dangerous: America's Worst Abandoned Properties and What Can Be Done About Them (University of Vermont Press).
- Parents Demand Curbs on Schools Built on Contaminated Land
- Brownfield Cleanup Legal Updates
- Photographies of French Brownfields.
- Photographies of German Brownfields.
- Brownfields memory with photographies in Europe.
- United States EPA, Brownfields and Land Revitalization
- National Brownfields Conference cosponsored by the U.S. EPA and ICMA
- Sustainability Toolkit: Environmental Models