This study is an evaluation of the potential environmentalimpacts of contaminated groundwater from the ASARCO metals refiningfacility adjacent to the Missouri River in Omaha, Nebraska. Surfacewaters, sediments, and sediment pore waters were collected from theBurt-Izard drain, which transects the facility, and from the Missouri Riveradjacent to the facility. Groundwater was also collected from thefacility. Waters and sediments were analyzed for inorganic contaminants,and the toxicity of the waters was evaluated with the Ceriodaphnia dubia7-day test. Concentrations of several elemental contaminants were highlyelevated in the groundwater, but not in river sediment pore waters. Leadconcentrations were moderately elevated in whole sediment at one site, butlead concentrations in pore waters were low due to apparent sequestrationby acid-volatile sulfides. The groundwater sample was highly toxic to C.dubia, causing 100% mortality. Even at the lowest groundwaterconcentration tested (6.25%) C. dubia survival was reduced; however, atthat concentration, reproduction was not significantly different fromupstream porewater reference samples. Sediment pore waters were not toxic,except reproduction in pore water collected from one downstream site wassomewhat reduced. The decrease in reproduction could not be attributed tomeasured elemental contaminants.
