Investigation of the Strontium-90 Contaminant Plume along the Shoreline of the Columbia River at the 100-N Area of the Hanford Site

The U.S. Department of Energy Hanford Site, formerly used for nuclear weapons production, encompasses 1500 square kilometers in southeast Washington State along the Columbia River. A principle threat to the river are the groundwater plumes of hexavalent chromium (Cr(VI)), which affect approximately 9.8 square kilometers, and 4.1 kilometers of shoreline. Cleanup goals are to stop Cr(VI) from entering the river by the end of 2012 and remediate the groundwater plumes to the drinking water standards by the end of 2020. Five groundwater pump-and-treat systems are currently in operation for the remediation of Cr(VI). Since the 1990s, over 13.6 billion L of groundwater have been treated; over 1,435 kg of Cr(VI) have been removed. This paper describes the unique aspects of the site, its environmental setting, hydrogeology, groundwater-river interface, riverine hydraulic effects, remediation activities completed to date, a summary of the current and proposed pump-and-treat operations, the in situ redox manipulation barrier, and the effectiveness of passive barriers, resins, and treatability testing results of calcium polysulfide, biostimulation, and electrocoagulation, currently under evaluation.

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Four Decades of Environmental Change and Their Influence upon Native Wildlife and Fish on the Mid-Columbia River, Washington, USA

Environmental Conservation ◽

10.1017/s0376892900015976 ◽

1985 ◽

Vol 12 (3) ◽

pp. 241-248 ◽

Cited By ~ 8

Author(s):

William H. Rickard ◽

Donald G. Watson

Keyword(s):

Environmental Change ◽

Agricultural Practices ◽

Columbia River ◽

Livestock Grazing ◽

Irrigated Agriculture ◽

Hanford Site ◽

Bald Eagles ◽

The Past ◽

Riverine Habitats ◽

Hanford Reach

The Hanford Reach of the Columbia River has experienced a great deal of human-imposed environmental change within the past 40 years, as has much of the adjacent land. The major disturbances have been from hydroelectric dams' construction and an intensive expansion of irrigated agriculture. A notable exception to the steady expansion of agriculture and dam-building has been the 1,400 km2 Hanford Site, which was established in 1943. Today, the Hanford Site consists mostly of undeveloped land that still supports native vegetation. It is free from agricultural practices, and has also been essentially free from livestock grazing and the shooting of animal wildlife. This conservative land-use has favoured populations of native wildlife that use the riverine habitats of the Hanford Reach of the Columbia River—e.g. Mule Deer, Canada Goose, and Great Blue Heron, are notable instances.The Hanford Reach supports the only mainstem Chinook Salmon spawning habitat on the Columbia River. This population is maintained by a combination of natural spawning and artificial propagation in concert with a regulated harvest of returning adults. Numbers of mainstem spawning Salmon have increased markedly in the past 10 years, and this has attracted increasing numbers of wintering Bald Eagles to the Hanford Reach.

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