CONSTRUCTED WETLAND SYSTEM FOR WATER QUALITY IMPROVEMENT OF IRRIGATION WASTEWATER

Most farms use agri-chemicals in their operations to obtain maximum production from their crops. Not all of these chemicals are utilized by the crops. Irrigation wastewater and natural runoff can carry nutrients and agri-chemicals to an off-site waterbody. This contributes to non-point source pollution and can lead to eutrophication of streams, reservoirs, and other bodies of water. It can also contaminate groundwater. Eutrophication often results in undesirable aquatic plant growth (Hammer, 1989). However, the nutrient-laden water can be diverted into a relatively small area where a treatment system has been established. The system resembles and functions like a natural wetland to remove nutrients, sediment, and other contaminants before the water returns to surface or ground water. A Constructed Wetland System (CWS), sometimes referred to as a nutrient and sediment control system, is both a biological and a physiochemical treatment system that utilizes wetland plants and microbes to assimilate and break down excess nutrients and remove them from the irrigation wastewater (DuPoldt et al., 1993). It is a cost effective way to treat agricultural wastewater before it is returned to surface or groundwater. Few systems of this type that treat agricultural wastewater have been built, especially in the arid and semi-arid West. These ecoregions pos