ACID ROCK DRAINAGE AND THE POTENTIAL FOR IMPACTS AT SELECTED ABANDONED MINE SITES IN THE BLACK HILLS NATIONAL FOREST

摘要

Abandoned mines in parts of the Black Hills of South Dakotahave the potential for acid rock drainage. For this work, ten siteswere examined on Black Hills National Forest land or on private landwhose drainage could affect Forest Service land. Water samplesfrom all the sites had pH values less than 6. Results of analyses fromwater samples and rock samples showed a correlation between metalscontent and pH. Acid-base accounting was used to determineacid drainage potential of the sites. One site (King of the West Mine)had a high potential for acid generation; fortunately, little or no surfacerunoff leaves the mine site. Six sites appeared to have moderatepotential, including the Minnesota Ridge Mine, which currently isbeing remediated. Three of the sites had low acid drainage potential.