6.2 Swiss studies Water Sci and Tech. As of 1997, Switzerland had approximately 80 constructed wetlands. Between 1990 and 1995, its performance of the system was closely monitored and its efficiency examined. After 10 years of operation, performance had not shown any notable degradation. At Slimbridge in the UK, constructed wetlands have been exploited a tourist attraction.
Wetlands are a valuable habitat for wildlife, and can support many rare species.
Waste passes through a settlement pond and then into a series of three parallel wetland beds, one planted with phragmites one with mosaics, and the third with irises. All act to remove BOD etc, but by using different species, three quite different habitats are created for wildlife. After recombination the waste then flows through two polishing beds before leaving the system. As mentioned at the beginning of this report, constructed wetlands are not widely used in developing, tropical countries. However, this is the very environment in which such wetlands perform best.