Table 1.

Uranium extracted from sediment samples in milligrams of U per kilograms of dry sediment

Sample	1 M HCO3 extraction, mg/kg	Aqua regia digestion, mg/kg	Total U concentration, mg/kg
P-101
Preamendment	NA	0.8 (0.13)	0.8 (0.13)
Top	NA	229 (2)*	229 (2)*
Bot	NA	190 (12)	190 (12)
P-102
Preamendment	NA	0.5 (0.10)	0.5 (0.10)
Top preaging	364 (25)*	121 (8)*	485 (33)*
Bot postaging	123 (8)*	131 (9)*	254 (17)*

“Top” and “bot” indicate effluent and influent ends of columns, respectively. Estimated SDs (ESDs) based on replicates and instrumental error are listed in parentheses. Total U is the sum of HCO₃ and aqua regia-extracted U (SI Text).

*ESDs for this data point are based on instrumental errors because a sufficient quantity of sediment was unavailable for replicates.