Reuse and Treatment Strategies for Agricultural Waste Waters

The charge of the United States Bureau of Reclamation (Reclamation) from its creation was to provide water to agriculture to the arid western states. As such, Reclamation began construction of large-scale water storage and delivery systems throughout the west. While drainage was an integral part of these irrigation systems, little thought was taken for the condition of the water drained from the land, nor its impact on the receiving stream. Now, in an era of greater environmental awareness and concern, the impact of agricultural waste waters on receiving streams has gained more, and more attention. As the primary steward of the nations waters, state governments have been required to take inventory of the rivers flowing through their states and assess and report the water quality of each. Additionally, the states have been required to develop plans for the improvement of the quality of water bodies not meeting water quality use standards through a process termed TMDL. The TMDL, or Total Maximum Daily Load, process is intended to define water pollution constituents of concern, and develop plans for the improvement of the quality of the state's waters. Part of the process is to look at the contribution of agricultural waste waters on the overall quality of the receiving streams. Reclamation has assisted the state of Idaho in the TMDL process for the Boise and Payette rivers. Options, ranging from water reuse to full-scale wetlands treatment systems, for the reduction of agricultural loading to these rivers were developed and presented as a partial solution.