The role of alluvial aquifer sediments in attenuating a dissolved arsenic plume data release
In a crude-oil-contaminated sandy aquifer at the Bemidji site in northern Minnesota, biodegradation of petroleum hydrocarbons has resulted in release of naturally occurring As to groundwater under Fe-reducing conditions. This data set was collected for a study that used chemical extractions of aquifer sediments collected in 1993 and 2011-2014 to evaluate the relationship between Fe and As in different redox zones (oxic, methanogenic, Fe-reducing, anoxic-sub-oxic transition) of the contaminated aquifer over a twenty year period. The data presented showed that 1) the aquifer has the capacity to naturally attenuate the plume of dissolved As, primarily through sorption; 2) Fe and As are linearly correlated in sediment across all redox zones, and a regression analysis between Fe and As reasonably predicted As concentrations in sediment from 1993 using only Fe concentrations; 3) an As-rich iron curtain, associated with the anoxic-sub-oxic transition zone, migrated 30 m downgradient between 1993 and 2013 as a result of the hydrocarbon plume evolution; and 4) silt lenses in the aquifer preferentially sequester dissolved As, though As is remobilized into groundwater from sediment after reducing conditions are established.
Citation Information
Publication Year | 2017 |
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Title | The role of alluvial aquifer sediments in attenuating a dissolved arsenic plume data release |
DOI | 10.5066/F7K35RWK |
Authors | Brady A. Ziegler, Madeline E. Schreiber, Isabelle M Cozzarelli |
Product Type | Data Release |
Record Source | USGS Asset Identifier Service (AIS) |
USGS Organization | National Research Program |
Rights | This work is marked with CC0 1.0 Universal |