Brownfields by their very definition involve properties with environmental liability risk: A brownfield is a property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. USEPA The definition is broad and includes properties that may have contamination. It is a generally accepted principle that reusing a brownfield is preferable to developing greenspace for a host of reasons, but the top four include: 1.) Brownfields tend to be in urban or developed areas where there is demand for their space; 2.) Utility and access infrastructure usually already exists to support them, lowering development costs;