News and Activities
Are Contaminants Harming Salmon Near Hanford Nuclear Reservation?
Date Posted: August 25, 2000The Service's Upper Columbia River Basin Field Office in Spokane, Washington is currently working with the U.S. Geological Survey to conduct laboratory studies assessing the effects of chromium contamination on threatened and endangered runs of salmon and trout. The information collected during these studies will assist the Hanford Natural Resource Trustee Council (HNRTC) in evaluating contaminant threats to fish at the 100 Area, one of four Environmental Protection Agency (EPA) Superfund (NPL) sites, on the Hanford Nuclear Reservation. This is the HNRTC’s first set of focused studies to assess the effects of 100 Area contaminants on aquatic resources of the Columbia River.
Past operations of nine nuclear reactors at the 100 Area NPL site resulted in the production and disposal of large quantities of wastes and widespread contamination of soils, groundwater, and the Columbia River. Hexavalent chromium is one of the major contaminants of concern. Chromium was added to cooling water to prevent corrosion and clogging of pipes in the nuclear reactors. The cooling water was discharged directly to the River and to trenches and holding ponds, which led to groundwater contamination. During low flow, contaminated groundwater discharges to the River. In the fall, during low river flow, chinook salmon spawn in shallow, near-shore areas. Some of these spawning areas are adjacent to groundwater seeps reaching the river. High concentrations of chromium have been found in the groundwater near salmon spawning areas.
Chinook salmon eggs and the resulting young salmon live in the sediments for about 5-7 months. This duration could increase the chance for possible long-term exposure of salmon to chromium-contaminated groundwater. Some possible adverse effects of chromium exposure include (1) failed eggs; (2) negative effects on the early life stage of salmon; (3) chronic effects on growth or health of young salmon (parr); and (4) avoidance of chromium-contaminated spawning areas, resulting in a loss of habitat.