Water entering the wetland system has already been treated by conventional treatment. 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. In these ponds the water is allowed to flow through densely planted vegetation where nutrients and suspended solids are removed. 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. 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.