Supplemental groundwater remediation technologies to protect the Columbia River at Hanford, WA
- U.S. Department of Energy, Richland Operations Richland, WA (United States)
- Fluor Hanford, Inc., Richland, WA (United States)
- Pacific Northwest National Laboratory, Richland, WA (United States)
Nine projects have been recently selected by the US Department of Energy (EM-22) to address groundwater contaminant migration at the Hanford Site. This paper summarizes the background and objectives of these projects. Five of the selected projects are targeted at hexavalent chromium contamination in Hanford 100 Area groundwater. These projects represent an integrated approach towards identifying the source of hexavalent chromium contamination in the Hanford 100-D Area and treating the groundwater contamination. Currently, there is no effective method to stop strontium-90 associated with the riparian zone sediments from leaching into the river. Phyto-remediation may be a possible way to treat this contamination. Its use at the 100-N Area will be investigated. Another technology currently being tested for strontium-90 contamination at the 100-N Area involves injection (through wells) of a calcium-citrate-phosphate solution, which will precipitate apatite, a natural calcium phosphate mineral. Apatite will adsorb the strontium-90, and then incorporate it as part of the apatite structure, isolating the strontium-90 contamination from entering the river. This EM-22 funded apatite project will develop a strategy for infiltrating the apatite solution from ground surface or a shallow trench to provide treatment over the upper portion of the contaminated zone, which is unsaturated during low river stage. Uranium in groundwater at the Hanford 300 Area is another environmental concern. Preliminary laboratory tests indicate that it may be possible to inject water-soluble phosphate compounds into the uranium contamination to stabilize it. One of the projects will perform laboratory tests using long-chain polyphosphate materials. Then, a field test will be conducted to determine if it is possible to treat groundwater in the unconfined aquifer at the Hanford 300 Area using polyphosphate materials. The rates of abiotic hydrolysis of are key parameters needed to predict the movement of carbon tetrachloride and one of its reductive degradation products, chloroform, from the Hanford 200 West Area towards the Columbia River. Current values for these rates have high uncertainty associated with them because they are extrapolated from determinations made at high temperatures (>70 deg. C) to ambient groundwater temperatures ({approx}19 deg. C) and have ignored possible contributions from sorptive interactions with sediments. One of the EM-22 projects will improve this situation by measuring the hydrolysis rates at temperatures down to 20 deg. C and in contact with various sediment solids. (authors)
- Research Organization:
- WM Symposia, 1628 E. Southern Avenue, Suite 9 - 332, Tempe, AZ 85282 (United States)
- OSTI ID:
- 21290860
- Report Number(s):
- INIS-US-09-WM-07271; TRN: US10V0186038271
- Resource Relation:
- Conference: WM'07: 2007 Waste Management Symposium - Global Accomplishments in Environmental and Radioactive Waste Management: Education and Opportunity for the Next Generation of Waste Management Professionals, Tucson, AZ (United States), 25 Feb - 1 Mar 2007; Other Information: Country of input: France; 33 refs
- Country of Publication:
- United States
- Language:
- English
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