Water & Mining Legacies

Researchers examined the mobilization of arsenic from riverbank sediments affected by the gold mining legacy in north-central South Dakota. Mining waste from the Homestake Mine discharged into Whitewood Creek and the Cheyenne River, leaving sediments with high arsenic concentrations. Laboratory experiments showed that arsenic release was strongly influenced by bicarbonate and phosphate, offering insights into how ion displacement processes affect water quality for nearby communities.

This study investigated the mechanisms of uranium uptake by Tamarix (Salt Cedars) growing along the Rio Paguate, which flows through the Jackpile Mine near Pueblo de Laguna, New Mexico. Uranium was detected in both roots and shoots, with accumulation concentrated in root cortex cells. Controlled laboratory experiments confirmed that uranium precipitates in root cell walls, highlighting pathways of plant uptake in contaminated environments.

This study analyzed contaminated sediments collected from Cheyenne River Sioux Tribal lands in South Dakota to identify chemical and microbial processes that influence arsenic, iron, and manganese release. Experiments showed that anaerobic conditions with electron donors triggered the highest releases, driven by microbial reductive dissolution. Results reveal how redox transitions and microbial activity shape metal mobility, with implications for water and sediment quality.