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Constructed wetlands as a tool for sewage and stormwater pollution control.

Although traditionally surface water pollution control measures in many countries of the world have been restricted to sewage effluent discharges, now it has become necessary to apply control measures to stormwater pollution as well. Constructed wetlands are considered as natural systems that provide a low cost maintenance and low energy natural treatment option for sewage and stormwater. They are especially suited for polishing effluent from existing or new sewage treatment plants, or providing treatment for septic tank effluent, by removing organic matter, suspended solids, nutrients, pathogens and heavy metals. This paper describes some important issues relating to the design of constructed wetlands and provides a summary of a pilot study with constructed wetlands for sewage treatment.