The integrated constructed wetlands (ICW) concept

Scholz, M; Harrington, R; Carroll, P; Mustafa, A

Abstract

The free surface flow Integrated Constructed Wetlands (ICW) concept explicitly combines the
objectives of cleansing and managing water flow from farmyards with that of integrating the wetland
infrastructure into the landscape and enhancing its biological diversity. This leads to system robustness
and sustainability. Hydraulic dissipation, vegetation interception, and evapotranspiration create an
additional freeboard at the outlet of each wetland segment and at the point of discharge, thus enhancing
hydraulic residence time and cleansing capacity during hydraulic fluxes. The principal design criteria
leading to adequate effluent water quality (i.e., molybdate reactive phosphorus less than 1 mg/l) from
ICWare that the wetland area needs to be sized by a factor of at least 1.3 times the farmyard area and the
aspect ratio for the individual wetland segments (i.e., approximately four cells) needs to be less than 1:2.2
(width to length). Within a year of ICW commissioning, approximately 75% of farmyard runoff was
intercepted, leading to improvements in the receiving surface waters of the catchment. Most of the
recorded phosphate concentrations after ICW treatment agreed with the Irish Urban Wastewater
Treatment Regulation 2001, which can be used as a benchmark to assess ICW treatment performance
and which is usually applied unofficially to ICWeven if it may appear to be too stringent. A case study of
13 ICWs suggested that phosphorus exported from an ICW system was similar to the typical background
concentrations of phosphorus export rates from land to water.

Citation

Scholz, M., Harrington, R., Carroll, P., & Mustafa, A. (2007). The integrated constructed wetlands (ICW) concept. Wetlands, 27(2), 337-354. https://doi.org/10.1672/0277-5212%282007%2927%5B337%3ATICWIC%5D2.0.CO%3B2

• Journal Article Type: Article
• Publication Date: Jan 1, 2007
• Deposit Date: Mar 21, 2012
• Journal: Wetlands
• Print ISSN: 0277-5212
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 27
• Issue: 2
• Pages: 337-354
• DOI: https://doi.org/10.1672/0277-5212%282007%2927%5B337%3ATICWIC%5D2.0.CO%3B2
• Publisher URL: http://dx.doi.org/10.1672/0277-5212(2007)27[337:TICWIC]2.0.CO;2