ABSTRACT
Demonstration results to date indicate that a constructed wetlands treatment (CW) system can be designed, constructed, and operated to provide a very high-quality, secondary-level effluent for BOD (biochemical oxygen demand) and suspended solids removal and fecal coliform reduction. Design examples should not be used to “cookbook” a design. Designs must be coordinated with and approved by local and state officials. A CW can be either a surface flow system having visible standing water, a subsurface flow system containing porous substrate and designed and operated to prevent standing water, or a combination of the two. A small CW can be a single cell, two cells in series, or multiple cells in parallel and/or series. Water level control and adjustment is critical to establish and grow vegetation and prevent standing water. The cell discharge structure should incorporate water level control piping (swivel standpipe or flexible tubing) at the effluent end of the cell(s) for manipulating the water level.
