Brownfield regulation and development

Brownfields are defined by the Environmental Protection Agency (EPA) as properties that are complicated by the potential presence of pollutants or otherwise hazardous substances. The pollutants such as heavy metals, polychlorinated biphenyls (PCB), poly- and per-fluoroalkyl substances (PFAS), and volatile organic compounds (VOCs) contaminating these sites are typically due to commercial or industrial work that was previously done on the land.

Source: Wikipedia — Brownfield regulation and development (CC BY-SA 4.0)