Horizontal Subsurface Flow Constructed Wetland

A horizontal subsurface flow constructed wetland is a large gravel and sand-filled basin that is planted with wetland vegetation. As wastewater flows horizontally through the basin, the filter material filters out particles and microorganisms degrade the organics. Compared to free-water surface flow constructed wetlands, horizontal sub-surface flow constructed wetlands have the advantage of better oxygen transmission reduced risk of mosquito breeding.