Contamination hazards tagging

Is the use of hazard=contamination for tagging contaminated areas reserved for areas that are off-limits altogether due to contamination (the Love Canal landfill example, where the landfill itself is tagged that way), or should it be also used for areas where say the groundwater is contaminated, but the area is otherwise habitable? (for instance, the AMD 915 Superfund site in Santa Clara County, which has been redeveloped into housing as soil vapor intrusion can be controlled through fairly standard construction techniques and the polluted surficial aquifer isn’t going to pose a threat to the residents otherwise)