
Results of RCRA groundwater quality assessment program at the 216-U-12 crib
Author(s) -
Bruce A. Williams,
Charissa J. Chou
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/493373
Subject(s) - groundwater , environmental science , hydrology (agriculture) , nitrate , vadose zone , geological survey , water well , chemistry , geology , geotechnical engineering , organic chemistry , paleontology
The 216-U-12 crib has been in a Resource Conservation and Recovery Act of 1976 (RCRA) interim-status groundwater quality assessment program since the first quarter of 1993. Specific conductance measured in downgradient wells 299-W22-41 and 299-W22-42 exceeds its critical mean. This report presents the results and findings of Phases I and II of the assessment monitoring program, as required by 40 CFR 265.93. The elevated levels of specific conductance in the downgradient {open_quotes}triggering{close_quotes} wells are attributed to nitrate, the mobile anion released when nitric acid is diluted in water, and calcium which is released from the sediments as acid is neutralized. Technetium-99 levels have been elevated in these same downgradient wells since 1991. The source of these constituents is the 216-U-12 crib. Downward migration of nitrate and technetium-99 from the vadose zone (and continued elevated specific conductance in the two downgradient wells) is still occurring because the driving force is still present