The traditional definition of a constructed wetland is given by (Hammer 1989) as “a designed and man-made complex of saturated substrates, emergent and submergent vegetation, animal life, and water that simulates natural wetlands for human use and benefits.” A wetland, constructed or otherwise, develops anaerobic conditions periodically and supports vegetation designed to thrive in oxygen-deficient soils.
Constructed Wetlands provide a highly effective and relatively inexpensive alternative to conventional wastewater treatment facilities.
The benefits of constructed wetlands for wastewater treatment are:
- They are relatively inexpensive to construct and operate.
- They are easy to maintain.
- They provide effective and reliable wastewater treatment
- They can tolerate both great and small volumes of water and varying contaminant levels.
- They can be aesthetically pleasing and provide habitat for wildlife and human enjoyment. (Hammer and Bastian, 1989).
The disadvantages of constructed wetlands for wastewater treatment are:
- Depending on the design, they may require a relatively large land area compared to a conventional facility.
- The design and operating criteria for this new science are not yet precise.
- The biological and hydrological processes within a constructed wetland are not yet well understood.
- There may be possible problems with pests. (Hammer and Bastian, 1989)