Historical Mining Impacts Decreasing in Some Stream Reaches in Upper Clark Fork Basin plus 1 more |
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Posted: 12 Mar 2014 09:00 AM PDT HELENA, Mont. – Streams in the Upper Clark Fork Basin have shown a decrease or no change in the occurrence of metals and arsenic associated with historical mining, according to a new U.S. Geological Survey report released today. The largest decreases were in areas targeted by remediation efforts. Contact Information: Steve Sando ( Phone: (406) 457-5928 ); Jill Frankforter ( Phone: (406) 457-5917 ); HELENA, Mont. – Streams in the Upper Clark Fork Basin have shown a decrease or no change in the occurrence of metals and arsenic associated with historical mining, according to a new U.S. Geological Survey report released today. The largest decreases were in areas targeted by remediation efforts. The USGS, in cooperation with the U.S. EPA, conducted the study to assess the effects of remediation efforts on mining contaminants in the Upper Clark Fork Basin. The USGS report analyzes data collected at 22 sites during 1996-2010 from streams in the Upper Clark Fork Basin. The study found that metals tended to enter waterways in larger quantities from areas where historical mining wastes had accumulated. A few of these stream reaches contributed most of the metals that entered into the entire Basin. Some of the metals evaluated, cadmium, copper, lead, and zinc, primarily move through streams attached to sediment. "Arsenic is different from the heavy metals because it was more widely distributed in the soils and groundwater, and is typically dissolved in the water rather than attached to sediment. So arsenic tends to enter streams more uniformly, rather than in localized areas," said Steve Sando, USGS hydrologist and lead author of the report. This difference is important because it shows the complexities involved in remediating the mining impacts. Federal, State, and local agencies, as well as the British Petroleum Company are involved in the massive clean-up efforts in the Basin. Although evaluating water quality with respect to regulatory standards was not the focus of the study, concentrations of metals and arsenic were compared to U.S. EPA aquatic life criteria and drinking-water standards. Historically, many of the streams have had concentrations of the contaminants that were higher than the standards. Some sites still have concentrations of some contaminants that exceed standards, but especially in sites with remediation, the water quality is substantially improving. The publication "Water-Quality Trends for Selected Sampling Sites in the Upper Clark Fork Basin, Montana, Water Years 1996–2010" is available online. | ||
| Land Use Impacts Aquatic Life in Illinois River Basin Posted: 12 Mar 2014 07:30 AM PDT This map of the Illinois River in northwest Arkansas shows the 18 sites at which this study was conducted. (High resolution image) LITTLE ROCK, Ark. – The biology of small streams in the Illinois River Basin has been disturbed by a mix of factors, according to a new U.S. Geological Survey report. Contact Information: James Petersen ( Phone: 501-228-3620 ); Christian Quintero ( Phone: 813-498-5019 );
LITTLE ROCK, Ark. – The biology of small streams in the Illinois River Basin has been disturbed by a mix of factors, according to a new U.S. Geological Survey report. Results from the study done on 18 sites on small streams in the Illinois River Basin in northwestern Arkansas show the biology of the tested sites is disturbed by how land in the area is used, wastewater treatment plants, shading, water quality, stream dimensions, sediment and road density. "Nutrients resulting from upstream land use practices or wastewater treatment plants can increase algae growth in the streams, which has an affect on aquatic insects and fish," said USGS hydrologist and lead author Jim Petersen. “When you add in other chemicals and sediment, changes in the amount of shade a stream receives, along with changes to streamflow patterns caused by urban and agricultural use, you get a complex system that can affect biological communities." The report looked at four biological groups that include macroalgae--visible floating mats of algae; periphyton--the coating of algae on rocks; macroinvertebrates--which include aquatic insects, crustaceans, and crayfish; and fish. Fish and macroinvertebrate communities downstream from areas with greater amounts of urban and agricultural land use and roads often were the most disturbed. Macroalgae amounts were highest at sites downstream from wastewater treatment plants and also increased as shading decreased. Total periphyton amounts were not associated with any environmental factors. "We know the quality of streams in this watershed is improving, and we think the change can be tied to wastewater treatment plant upgrades, stream bank restoration work, regional watershed protection efforts such as those by the Illinois River Watershed Partnership, and farmers' adherence to nutrient management plans," said Delia Haak, Executive Director of the Illinois River Watershed Partnership. "It will be important for the USGS to conduct future research to see how the improvements in northwestern Arkansas are impacting the Illinois River and other streams in the watershed." Water quality in the Illinois River Basin in northwestern Arkansas and northeastern Oklahoma has been a topic of interest for more than 30 years. Researchers and the general public can use this study to access information about how water quality and habitat affect biological communities. The report, "Effects of Land Use, Stream Habitat, and Water Quality on Biological Communities of Wadeable Streams in the Illinois River Basin of Arkansas, 2011 and 2012," by James C. Petersen, B. G. Justus, and Bradley J. Meredith, which was funded by the Illinois River Watershed Partnership through a grant from the Arkansas Natural Resources Commission and the U.S. Environmental Protection Agency, is available online. |
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