brownfields

Brownfields are previously developed lands that may be contaminated and are not currently in use or are underutilized, with redevelopment potential constrained by real or perceived environmental contamination. They are often located in urban areas, near infrastructure, and on sites formerly used for industry, commerce, or transportation. Contaminants commonly found include petroleum hydrocarbons, solvents, metals, asbestos, PCBs, and pesticides. Perceived contamination can also hinder redevelopment even when risks are low.

Assessment typically starts with a Phase I environmental site assessment to identify potential problems, followed by Phase II sampling and laboratory analysis. If contamination is present, a cleanup plan is prepared and implemented using risk-based methods and may include soil excavation, remediation, capping, in-situ treatment, or monitored natural attenuation. Institutional controls may limit future land use.

Redevelopment after cleanup can transform brownfields into residential, commercial, industrial, or mixed-use developments, often supported by incentives such as grants, tax incentives, or low-interest loans. Benefits include urban revitalization, job creation, and preservation of undeveloped land elsewhere; costs and liability, financing gaps, and technical challenges can be barriers.

Policy and governance vary by country but commonly involve regulatory frameworks for cleanup standards, liability relief for innocent landowners, and planning tools. In the United States, federal and state programs encourage cleanup and redevelopment of brownfields, while many European countries use public-private partnerships and planning incentives. The concept emphasizes sustainable land use by reusing existing sites rather than expanding into greenfields.