|[[Image:Vertical_flow_constructed_wetland.png |right|300px]]
|}
----
[[Image:Icon_vertical_flow_constructed_wetland.png |right|95px]]
'''A Vertical Flow Constructed Wetland is a filter bed that is planted with aquatic plants. Wastewater is poured or dosed onto the wetland surface from above using a mechanical dosing system. The water flows vertically down through the filter matrix. The important difference between a vertical and horizontal wetland is not simply the direction of the flow path, but rather the aerobic conditions.'''
Pathogen removal is accomplished by natural decay, predation by higher organisms, and sedimentation.
{{procontable | pro=
- Constant source of electrical energy required. <br> - Not all parts and materials may be available locally. <br> - Requires expert design and supervision. <br> - Moderate capital cost depending on land, liner, etc.; low operating costs. <br> - Pre-treatment is required to prevent clogging. <br> - Dosing system requires more complex engineering.
}}
==Adequacy==
With time, the gravel will become clogged with accumulated solids and bacterial film. The material may have to be replaced every 8 to 15 or more years. Maintenance activities should focus on ensuring that primary treatment effectively lowers organics and solids concentrations before entering the wetland. Testing may be required to determine the suitability of locally available plants with the specific wastewater. The vertical system requires more maintenance and technical expertise than other wetland technologies.
==Acknowledgements=={{:Acknowledgements Sanitation}} ==References and external links==
* Crites, R. and Tchobanoglous, G. (1998). [http://books.google.com/books/about/Small_and_decentralized_wastewater_manag.html?id=yx9SAAAAMAAJ Small and Decentralized Wastewater Management Systems]. WCB and McGraw-Hill, New York, USA. pp 599–609. (Comprehensive summary chapter including solved problems.)
* Mara, DD. (2003). [http://www.pseau.org/outils/ouvrages/earthscan_ltd_domestic_wastewater_treatment_in_developing_countries_2003.pdf Domestic wastewater treatment in developing countries]. London, Earthscan, pp 85–187.
* Poh-Eng, L. and Polprasert, C. (1998). [http://books.google.com/books/about/Constructed_Wetland_for_Wastewater_Treat.html?id=uo5vNAAACAAJ Constructed Wetlands for Wastewater Treatment and Resource Recovery]. Environmental Sanitation Information Center, AIT, Bangkok, Thailand.
* Polprasert, C., et al. (2001). Wastewater Treatment II, Natural Systems for Wastewater Management. Lecture Notes. IHE Delft, The Netherlands. Chapter 6.
* Reed, SC. (1993). [http://water.epa.gov/type/wetlands/restore/upload/2003_07_01_wetlands_pdf_sub.pdf Subsurface Flow Constructed Wetlands For Wastewater Treatment, A Technology Assessment]. United States Environmental Protection Agency, USA. Available: [http://www.epa.gov ( Environmental Protection Agency], USA. Comprehensive design manual.) ==Acknowledgements=={{:Acknowledgements Sanitation}}
