Cardinal worked with BHE Environmental, Inc on this project. Cardinal provided professional assessment, design, and construction plans for a four acre constructed treatment wetland at the Duck Spring Facility located in Alcoa, Tennessee. The wetland was constructed to treat free cyanide and iron-cyanide complexes. It treats flow diverted from a limestone groundwater spring impacted with waste leachate from an aluminum smelting facility. Primary emergent plant species at this wetland facility include river bulrush, softstem bulrush, sweet flag, common arrowhead, and American bur-reed. In addition, there are submergent species, such as coontail.