What started as a one time public education project in 1995 grew to building and operating several subsurface flow wetlands treating domestic wastewater in Wisconsin for: single residences, multiple (clustered) residences, and for commercial/ institutional concerns. This paper shares experiences gathered during five plus years of operating six wetland systems in central and southeastern Wisconsin. Three of these case studies are included herein.
Public education inspired building the first subsurface flow wetland at a nature center that averages three (3) busloads of school children per day and with seasonal peak usage as well. The children have an extensive curriculum of activities, some feature:
- Sustainable development
- The value of wetlands in cleaning water, and
- The water cycle (counteracting the out-of-sight, out-of-mind situation after flushing the toilet)
Subsurface flow wetlands show excellent removal qualities for nitrogen when compared to other passive treatment technologies. Five case studies are included in the paper, encompassing six wetland complexes. All include: varying methods of wastewater collection from small diameter to large diameter collectors, septic tanks from clustered to individual residential, and lined subsurface flow wetland cells followed by dispersal wetland cells (unlined). All five of these wetland systems were built under a State of Wisconsin, Department of Commerce (COMM 83) statute that allows experimentation with on-site systems. One requirement is quarterly testing of wastewater characteristics by a certified laboratory. These and other results are displayed in the paper. A number of challenges were overcome, including freezing of some components during harsh winter months. These experiences will be shared.