After leaving Clemson, I began my graduate career at Oregon State University. I have been pursuing a Masters of Science degree in Bioresouce Engineering and am in the final stages of completing my thesis project. While at OSU I have furthered my studies of natural treatment systems. Our department here is similar to the Biosystems Engineering department at Clemson; there are many different directions of study. In the OSU department, our program is interdisciplinary and my studies have included a broad range of disciplines, from Microbiology and Ecology to Vadose Zone Hydrology and Wastewater engineering.

Some of the projects that I have worked on here include:

• investigating a polluted stream site on the campus that led to major reforms in the OSU animal science center,
• working with communities through the OSU Cooperative Extension Service to educate people about septic field health, and
• educating youth from the community of Ashland, Oregon, regarding wetlands and wetland treatment systems and their benefits to the water system.
  

For my thesis project, I have been studying a natural water treatment system that was built to treat wastewater from the city of Ashland's wastewater treatment plant. Water entering the wetland system has already been treated by conventional treatment. The purpose of the wetland system is to do a "final polishing" of the wastewater before it is released into Bear Creek. The city is sponsoring the investigation to explore the possibilities of utilizing wetland treatment systems to help maintain water quality standards while growing as a metropolitan area.

The water is treated in the demonstration wetlands project at Ashland through three primary components. Initially, the water flows through three free water surface wetlands (FWSW), or open water wetland ponds. In these ponds the water is allowed to flow through densely planted vegetation where nutrients and suspended solids are removed. Secondly, the water is applied to two vertical flow wetlands (VFW). This type of treatment system is composed of a gravel bed that is approximately a meter deep and planted with common reed grass. Water is applied vertically to the beds. As it flows through the gravel it is further polished. In both of these systems the primary mechanisms of removal are breakdown by microorganisms and physical filtration of solids. The plants provide surface area for microorganism growth, a filtering surface in the open ponds, and supply oxygen in what would otherwise be anoxic environments.

Finally, the water flows through a set of rapid infiltration soil basins (RISB). This component of the system has been the primary focus of my thesis work. The purpose of these basins is to remove phosphorus from the waste stream through soil sorption processes. Wastewater that reaches these basins already meets all the other water quality standards for the discharge stream except the phosphorus standard (which is 0.08 mg P/L).

My research has indicated that the retention time within the basins was not adequate for all of the phosphorus removal mechanisms to take place. We therefore made modifications to operate the system on a fill and drain basis. This allows the retention within the cells to be increased from a few hours to 7 days. We are currently sampling the system to determine if the modifications do indeed increase removal.

While working on this project, I have worked with both consulting firms and city officials. It has also placed me in the role of educator within the community of Ashland through spreading information about the wetland project. All of these skills are preparing me for my future career where I would like to work as a consultant encouraging communities to utilize natural treatment systems in dealing holistically with their water issues.

Further information about Oregon State University and the Bioresource Engineering Department can be found at http://www.bre.orst.edu/.