brownfield

A brownfield is a site that was previously developed for industrial or commercial use and may be complicated by the presence or potential presence of hazardous substances, pollutants, or contaminants. Redevelopment or reuse of brownfields aims to convert underutilized properties into productive uses while managing environmental risk. The term is often contrasted with 'greenfield' sites, which are undeveloped land without contaminated conditions.

Contaminants commonly found on brownfields include petroleum hydrocarbons, solvents, heavy metals, asbestos, PCBs, and pesticides. Site owners typically undertake environmental assessment and remediation to acceptable standards before new development proceeds. Risk assessment, cleanup, and verification are guided by regulatory frameworks, which may set cleanup levels based on the intended end use.

Redevelopment typically involves due diligence, environmental site assessments (Phase I and Phase II), and, if needed, cleanup strategies such as removal, in-situ treatment, or containment. Public and private funding, tax incentives, grants, and liability relief programs are frequently used to offset remediation costs and reduce developer risk.

Benefits of brownfield redevelopment include revitalization of urban areas, preservation of undeveloped land, job creation, and increased tax revenue, while reducing pressure on greenfield sites. Challenges include high cleanup costs, technical complexity, uncertain property title or contamination scope, and the need for coordination among multiple stakeholders.

Globally, the concept is recognized in many countries with varying definitions and programs. In the United States, the Environmental Protection Agency defines a brownfield as real property where expansion or redevelopment may be complicated by the presence or potential presence of hazardous substances. In other regions, separate policies and agencies govern assessment and cleanup.