The paper discusses the features that make constructed treatment wetlands a suitable solution in sustainable resources-oriented sanitation systems, the importance of system thinking for sustainability as well as key factors for sustainable implementation of constructed wetland systems. Constructed treatment wetlands meet the basic criteria of sustainable sanitation systems by preventing diseases, protecting the environment, being an affordable, acceptable, and simple technology.
This booklet focuses on treating domestic/municipal wastewater or greywater with subsurface flow constructed wetlands with coarse sand as a filter medium. The emphasis is on the application in developing countries and countries in transition. In the publication, an overview and basic guidance is provided on the design and maintenance of horizontal flow beds (HFBs), vertical flow beds (VFBs) and the “French System”. A description of the most common pre-treatment systems is also included due to their vital importance for the proper functioning of CWs.
This report compiles international experience in greywater management on household and neighbourhood level in low and middle-income countries. In urban areas of LMIC, greywater is commonly discharged untreated into drainage channels, use untreated greywater for agricultural purposes, thereby leading to environmental degradation and exposing the population to health risks. Though greywater is generally less polluted than domestic or industrial wastewater, it may still contain high levels of pathogenic microorganisms, suspended solids and substances such as oil, fat, soaps, detergents, and other household chemicals.