Friday, August 28, 2015

EPA releases more docs - Sediment a "long term" concern in Colorado mine spill's wake

Environmental officials said Thursday their long-term concern after the 3 million-gallon Gold King Mine spill centers around the metallic sediment left in its wake. Specifically, the Environmental Protection Agency says it is worried about the potential stirring up of sediment during "high-water events" and the sludge's effect on people who are continually recreating for long periods — several weeks — of time. The EPA mentioned the concerns as part of a data release accompanying 77 pages of documents chronicling the minutes and hours before and after the agency-triggered spill. The Aug. 5 disaster sent yellow-orange sludge through three states and two American Indian tribes, prompting emergency declarations and leaving communities along hundreds of river miles angry.  The EPA says data, collected over the past two weeks, shows surface water metal levels at 24 sampling locations along the watershed below the spill are "trending toward pre-event conditions." Metal levels in the sediment, the EPA says, are below the agency's recreational screening level. However, the EPA says it is not certain there are no health risks from the sediment. "Risks to humans from metals in the sediments are based upon the total exposure a person may have over a given period of time," David Gray, an EPA spokesman, said. "Exposure from sediments would be from hand-to-mouth exposures. We want to ensure that the concentration of metals in the sediments are sufficiently low enough to ensure that a recreational person will not be exposed to harmful levels of metals."...more

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