Man-made biologically active systems such as bogs, swamps, or marshes that are characterized by saturated soil conditions and at least periodic surface or near-surface water designed specifically to treat contaminants in surface water, groundwater, or waste streams.  

Mining Waste (MW-1)
Constructed Treatment Wetland
Constructed treatment wetlands are man-made biologically active systems such as bogs, swamps, or marshes that are characterized by saturated soil conditions and at least periodic surface or near-surface water designed specifically to treat contaminants in surface water, groundwater, or waste streams.