Definition   A black water wetland is a constructed wetland that treats wastewater through the biological processes that are normally involved in a natural wetland environment. The amount of wastewater being treated can range from a single household to a town containing over 10,000 people. (A town may necessitate as much as 1200 acres of treatment wetlands.) Aesthetically, it can be nearly identical to a natural wetland minus some treatment structures. Blackwater wetlands may be geared towards multi-use, such as parks or wildlife refuges. In the future they may be seen as much more of an amenity, as compared to just a sewage treatment center.   Although the majority of on site systems in the United States are conventional septic systems, new interest in alternative on-site sewage systems has arisen over the last decade as a higher performing long-term solution for decentralized treatment.  The US EPA defines alternative treatment technologies as “environments (e.g., sand, peat, artificial media) that promote additional biological treatment and remove pollutants through filtration, absorption, and adsorption.”