A brownfield is an abandoned or under-utilized former industrial or commercial parcel of land, with either real or perceived environmental contaminants. The pollution present, and the cost and difficulty of the required cleanup complicates the potential for land re-use. Legal liability for clean-up is most commonly placed on the owner of the site during the time the contamination occurred, and determining this is often a challenge that can further delay re-use, once the contamination is fully assessed. Examples of causes and land use types that have created brownfields include factories, certain industrial uses, dry cleaning establishments, gas stations, and steel mills.

Reuse of a brownfield site is often determined by several factors including type and extent of contamination, ability to determine liable entity, location, and availability of funds (such as federal or state grants) for clean-up. In addition, the type of development that can occur on a former brownfield is often limited, based on the clean-up method that is most cost- and environmentally-effective. For example, a former brownfield may become a paved parking lot if the cost of clean-up was prohibitive to more extensive clean-up and redevelopment, such as multi-family residential or commercial uses.

If not identified and properly cleaned up, brownfields can threaten water quality and limit potential for economic development. Indianapolis is located in the Rust Belt of the Midwest, an area of larger concentrations of brownfields than typical. For that reason, the City of Indianapolis is committed to providing programs and incentives to promote the clean-up and reuse of existing brownfields.