Despite differences in aquatic life and toxic metals in streams across a broad region of the western United States, scientists found common responses to cleanup of acid mine drainage.
Many miles of streams and rivers in the United States and elsewhere are polluted by toxic metals in acidic runoff draining from abandoned mining sites, and major investments have been made to clean up acid mine drainage at some sites. A new study based on long-term monitoring data from four sites in the western United States shows that cleanup efforts can allow affected streams to recover to near natural conditions within 10 to 15 years after the start of abatement work.
The four mining-impacted watersheds—located in mountain mining regions of California, Colorado, Idaho, and Montana—were all designated as Superfund sites under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which helps fund the cleanup of toxic-waste sites in the United States. They are among the few acid mine drainage sites where scientists have conducted extended studies to monitor the effectiveness of the remediation efforts.
“The good news from them all is that Superfund investments can restore the water quality and ecological health of the streams,” said David Herbst, a research scientist at UC Santa Cruz and coauthor of a paper on the new findings to be published in the June issue of Freshwater Science, now available online.
Read more at University of California - Santa Cruz
Image: Leviathan Creek below an abandoned open pit mine, an EPA Superfund site in the Sierra Nevada, where iron oxide deposits coat the stream bottom. (Credit: David Herbst)