Proposed Research


Doctoral Research Proposal 

Ascertaining the factors influencing the acceptance or rejection of

Constructed Wetlands as an alternative form of wastewater treatment 


The ability to alter ecosystems to serve human needs has allowed homo sapiens to adapt far more rapidly to Earth’s diversity than any of his living counterparts. One such adaptation is the use of constructed or artificial wetlands to assimilate anthropogenic wastes. While used for century’s by eastern cultures to grow rice and other agricultural products, constructed wetlands have only recently been elevated to the status of an engineered technology in the west. Constructed wetlands (CWs) offer on-site handling and stabilization of biosolids, require minimal operations and maintenance (O&M) when compared to conventional brick and mortar treatment systems, and provide substantial improvement in the quality of effluents discharged. The use of CWs to treat domestic sewage has gained popularity in recent years as an alternative to centralized wastewater treatment systems. Industrial applications, such as the treatment of acid mine drainage, have implemented CWs as a cost-effective, efficient means of enhancing effluent quality.


In November, 2000 researchers and scientists attending the International Water Quality Associations Conference on Wetland Treatment of Polluted Waters. The conference, held in Orlando, Florida offers insight into the most recent research developments in CWs. Of the nearly 200 papers presented during the 5 day meeting, only a handful addressed the policy and public decision factors associated with the selection of CWs as an alternative form of wastewater treatment. One only needs to look at the proceedings Table of Contents to assess the areas of current research emphasis. Papers addressing parameter performance [phosphorous (27), nitrogen (22), and pathogen (17)], modeling (24), and ecological considerations (32) comprised the majority of papers. Application specific papers including sub-surface flow (26), free surface flow (27), industrial (33), agricultural (16), and storm water (14) comprise the balance of presentations. While a number of authors addressed policy and public decision-making factors associated with their specific project, only a handful of authors addressed the relation of these factors to overall policy development. Thus, it would appear that a gap in the state of knowledge currently exists regarding the CWs from a policy perspective.

This research endeavor seeks to quantify and qualify the factors influencing the acceptance or rejection of CWs as an alternative form of wastewater treatment. Considering the importance of this innovative technology, an awareness of the weight and influence that various factors play in decision making is an important component relative to the implementation of CWs.

Consider, for example, that land acquisition and land costs have historically been cited as the primary deterrent to selecting a CW for treatment. Recent requirements in public notification by publicly-owned treatment works regarding chlorine use has necessitated the development of emergency evacuation plans. In some cases, additional buffer zones have been suggested as a means to ameliorate or minimize evacuation areas. Such action increases the foot print of the facility and by default, increases the land acquisition of the facility. This introduced effect may have direct costs (land acquisition for buffers) or indirect costs (compensation for reduced neighboring home values) that asserts an externality on the true cost of wastewater treatment services. Thus, comparisons of CWs to conventional and alternative treatment systems at the public policy level, may not be reflecting the true costs and benefits associated with this ‘new’ adaptation of ecological engineering. Research that highlights the key factors involved in the decision-making process could prove invaluable in promoting CWs as an alternative treatment technology.


A survey form will be developed to ascertain the factors involved in the acceptance or rejection of CWs for wastewater treatment. Results from the survey will be entered into a relational database (Microsoft Access or similar) for analysis. An extensive review of published and gray literature sources will be conducted to develop the survey. The survey instrument will be further refined through the use of information interviews with appropriate personnel representing various perspectives (regulatory, utility, consultant) in the decision-making process. Finally, the capture of timely pertinent information by the survey will be reviewed through a peer-review process to ensure proper consideration of all factors involved in decision-making and policy development.

The survey will be distributed in three manners. First, a web-based survey form that will permit online, instant database entry of the information requested. The web-based survey form and database will be securely located at Second, a letter distributed by email and incorporating links to the aforementioned secure web page. Third, a printed version of the survey will be distributed, as needed, to contacts within the water quality community.

Typically response rates of 5% to 8% for surveys is considered a good outcome. However, web-based survey instruments targeted to a specific audience have frequently generated high levels of response. For example, a recent remote sensing study in Australia received a response rate of greater than 75%. The key factor to high response rates and quality information is a qualified list of online recipients. Correspondingly, requests for participation will be emailed to contacts qualified through list-serves, authors from relevant proceedings, appropriate IAWQ and SWS members, and participants in online forums such as Water Online. Furthermore, all State and Federal (EPA, DOA, DOI) and public utility contacts will be gleaned from agency web sites and contact information, including a current database of contacts for eastern US-based utilities.


Surveys will be proofed for accuracy of information and duplicative entrees. Survey information will then be entered into a relational database. The relational objects will then be analyzed using multivariate statistical methods. First, a principal component analysis will be conducted to highlight latent relationships. Second, a correlation cluster analysis will be performed to determine the relative weight of relational objects to acceptance or rejection of CWs as a treatment technology. Third, a two-way multivariate discriminate analysis will be conducted to determine the influence of individual and grouped factors relative to acceptance or rejection of CWs as discriminated from other forms of treatment technology.

Once completed, if sufficient factors exist relative to the decision-making process, a model will be developed as a tool for decision makers and the water quality community. The intended model would query the user for pertinent information and return an estimation of acceptance or rejection of a CW for a given situation. Furthermore, the model would present a weighted list of factors that the user should consider in evaluating CWs as a treatment method. Finally, the model would produce a list of key contacts and locations that reflected similar circumstances to assist the user in networking and communications to ensure an adequate outcome.


A formal publication, interactive web-site, relational database, and decision-making model will be made available for as tools for participants in the study. All participants will have an opportunity to request copies of the formal publication at the conclusion of their survey-entry submission. Dissemination of the products, information, and services available will be promoted through the Internet and authored papers and presentations at symposia and conferences both domestically and internationally.


It is anticipated that the written publication will be of sufficient quality to serve as a Doctoral Thesis. Intellectual property rights, royalties, and dissemination of products produced from this research may be offered through negotiation or as good will for water quality improvements at the sole discretion of the researcher and author.

Your comments and insight regarding this proposal are highly appreciated!

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