A brownfield site is land that was previously used for industrial purposes.
Examples of brownfield sites include abandoned factories, gas stations that have gone out of business or empty strip malls. Brownfield redevelopment can be cost-effective because access roads, sewer, water and perhaps even buildings are already in place. Brownfield site redevelopment can be complicated, however, by the presence of hazardous substances, pollutants or contaminants left behind by the previous tenant.
See also: greenfield site