I have read a wide variety of costs and effectiveness of these, as many fail to create wetlands.  There may be various reasons for construvting a wetland, and some of them have expectstions of pollutant reduction or habitat restoration.  Most cost effective is often restoring a drained wetland, plugging ditch and restoring hydrology.  If a wetland is created, it may take years to develop hydric soils and anoxic conditions and hydrophytic plant community natural or desired if that is intent.  Also size of wetland desired could vary, but alot will depend on the circumstances.  Some conditions do not lend themselves to wetland creation, and I say that because there have been so many failures or conditions that did not achieve design expectations.

I have read your answer and a lot of the information you tell me is something new to me. Thank you very much. However,you didnt answer my question. I need a cost evaluation method for how to cost a constructed wetland,and if it is possible for a CW treating wastewater from agricultural runoff. Since Im doing the economic part of the case study I need to know prices for the various tasks needed to be done for the construction and later for the maintenance. Thank you again

I recommend downloading the free software AMD Treat from the Office of Surface Mining in the USA.  See http://amd.osmre.gov/

The software was developed for CWs treating acidic water from coal mines but it could be adapted to agricultural runoff.  You will have to develop your own sizing criteria based on the flow rate and chemistry of the water requiring treatment in your wetland and you must input unit prices for construction that are specific to your site/locale, but it is a nice cost model for comparing alternative treatment strategies that should be suitable for your purpose.  The model also has modules for operation and maintenance that you will find helpful.  Be sure to read the user's guide, twice.

Unfortunately, many of the dimensional inputs are in English, not metric units.  Better have your conversion tables handy and double-check your entries.  All prices are in $US, but I'm sure you can adjust as needed to Euros, etc.  Good luck.

Hi Giannis,

maybe this can help: EPA Constructed Wetlands Treatment of Municipal Wastewater - you can googleit.... There is a section of capital and reccuring costs and case studies...

Good Luck

Dear  Giannis Kosmidis of 

Democritus University of Thrace,

CW can bio- remedy less pollutants w water. Pl. study my paper on the design of Dewats Technology to assess the mechanics of treatment from say higher BOD to lower BOD upto a level of 10 to 5 ppm.

Main criteria to follow would be HRT- say for a remediation of BOD 80- 100 ppm, would be 3 to 4 days.. with RBT also. Accordingly you can design for the flow.. with different plants/ roots/ reeds etc..

Well wishes,

Ajit Seshadri - [email protected] -