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Eric J Hepler

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Long-term monitoring of stream-bed sediments reveals spatial and temporal trends in metal concentrations. Here we use concentration gradient “heat maps” as a visualization tool to report annual mean arsenic, cadmium and copper concentrations along a contamination gradient in the Clark Fork River (CFR) in Western Montana. The CFR has been heavily impacted by large-scale mining operations since the 19th century. Legacy mine waste and tailings have been deposited within the streambed, banks, and floodplains more than 200 kilometers downstream. Sieved sediment samples (<63µm) have been collected at 10 stations along a 200 kilometer contamination gradient annually since 1996. Ongoing remediation activities in the upper...
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Legacy mine waste from the Clark Fork River in Western Montana has contributed 100 million tons of tailings into the watershed between 1880 and 1982 (E.D. Andrews, Longitudinal dispersion of metals in the Clark Fork River, Montana, Lewis Publishers, 1987). Tailings deposited along the floodplain, streambanks and river channel continue to contribute metal contaminated material into the river in the form of metal-enriched particulate matter or seston, comprising a mixture of organic and inorganic materials (J.N. Moore and S.N. Luoma, Hazardous wastes from large-scale metal extraction: A case study. Environmental Science and Technology, v.24:1278-1285, 1990). Metal enriched seston poses a dietary exposure risk to filter-feeding...
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Water, bed sediment, and invertebrate tissue were sampled in streams from Butte to near Missoula, Montana, as part of a monitoring program in the Clark Fork Basin. The sampling program was completed by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to characterize aquatic resources in the Clark Fork Basin and monitor trace elements associated with historical mining and smelting activities. Sampling sites were on the Clark Fork River and a subset of its tributaries. Water samples were collected periodically at 22 sites from October 2019 through September 2020. Bed-sediment and tissue samples were collected once at 12 sites during July 2020. Water-quality data included concentrations...
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The U.S. Geological Survey is monitoring concentrations of metals and other trace elements in water, streambed sediment, and aquatic invertebrates at 6 locations in the middle and lower portions of the mainstem Klamath River from below J.C. Boyle dam in Oregon to near the mouth on the northwestern coast of California. Included are 3 tributary monitoring sites, one each on the Scott, Salmon, and Trinity Rivers. This data release makes available major and minor trace element concentrations in surface water, bed sediment, and aquatic invertebrates collected in September 2018, and in bed sediment collected in September 2019.
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This USGS data release includes data from experiments conducted with two species of caddisflies (Hydropsyche californica and Arctopsyche grandis (Order: Trichoptera) to quantify copper and cadmium uptake and loss after dissolved and dietary exposures. Both Arctopsyche and Hydropsyche belong to the family Hydropsychidae (O: Trichoptera). They are relatively sessile, net-spinning filter feeders. Data from these experiments can be used to characterize physiological parameters used in a bioaccumulation dynamic model.
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