The expanding use of decentralized wastewater management has resulted in an increasing interest in small-scale wetland treatment systems. Until now, limited information has been available on the use and performance of these wastewater treatment systems. The just released design manual, Small-Scale Constructed Wetland Treatment Systems: Feasibility, Design Criteria, and O&M Requirements, by Scott Wallace, P.E., addresses this knowledge gap. Wallace is a leading authority on the topic and is currently senior vice president of North American Wetland Engineering, LLC in White Bear Lake, Minn.
Data from 1,640 small-scale treatment wetlands with different design parameters, loading rates and geographic locations from around the world was collected for this project. In addition, Wallace created and cataloged one of the largest resource libraries in existence on the subject of constructed wetlands. This data was used to develop sizing criteria for the two most common types of small-scale treatment wetlands: free water surface (FWS) wetlands and vegetated submerged bed (VSB) wetlands.
Published for the first time are confidence intervals for design criteria allowing designers to explicitly assign a factor of safety to a given wetland design. The book also provides basic information on wastewater generation, the feasibility of wetland technology and internal treatment processes in constructed wetlands. Important design issues including hydraulic considerations, cold-climate performance, operations and maintenance, vegetation establishment and construction costs are also presented in this informative and useful guide to incorporating wetland technology to solve future wastewater management challenges.
The design manual, published in August 2006 by the Water Environment Research Federation (WERF), is currently available only to WERF subscribers. It will be published for mass distribution by IWA Publishing Limited in late fall 2006 and will be available to all interested parties via their website.