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National Irrigation Water Quality Program


In 1982, deformities, reproductive failures, and mortalities among waterfowl and shorebirds were discovered at Kesterson National Wildlife Refuge in the San Joaquin Valley of California. Studies during 1982-85 determined the cause to be elevated levels of selenium in irrigation drainwater discharged to the refuge. As a result of these studies, the U.S. Department of the Interior embarked on the National Irrigation Water Quality Program (NIWQP). The program is designed to determine whether other Department constructed or managed irrigation projects, national wildlife refuges, or other wetland areas in the Western United States might be experiencing similar or other irrigation-related problems for which the Department of the Interior may have responsibility.

The program has five-phase process:

  • Site Identification
  • Reconnaissance Investigations
  • Detailed Studies
  • Planning
  • Remediation

Projects conducted under the first three phases are carried out by interdisciplinary study teams composed of scientists from the U.S. Geological Survey, the U.S. Fish and Wildlife Service, the Bureau of Reclamation, and the Bureau of Indian Affairs. A U.S. Geological Survey hydrologist is the leader for each of the interdisciplinary study teams. The U.S. Geological Survey participates in the last two phases under a Memorandum of Understanding with the Bureau of Reclamation.

In studies completed in 26 areas, selenium is the trace element found most often at elevated concentrations in water, bottom sediment, and biota. Boron, arsenic, molybdenum, uranium, and pesticide residues have also been found at elevated levels in some areas. Bioaccumulation of constituents associated with irrigation drainage is common.

The NIWQP maintains a web site with a more complete Program description.


Other Information About this Project

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