How does mine drainage occur?
Mine drainage is formed when pyrite (an iron sulfide) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of streams containing mine drainage. The acid runoff further dissolves heavy metals such as copper, lead, and mercury into groundwater or surface water. The rate and degree by which acid-mine drainage proceeds can be increased by the action of certain bacteria.
Problems associated with mine drainage include contaminated drinking water, disrupted growth and reproduction of aquatic plants and animals, and the corroding effects of the acid on parts of infrastructures such as bridges.
Learn more: USGS Mine Drainage Activities
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Acid mine drainage
Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage...
Bigham, Jerry M.; Cravotta, Charles A. An approach to quantify sources, seasonal change, and biogeochemical processes affecting metal loading in streams: Facilitating decisions for remediation of mine drainage
Historical mining has left complex problems in catchments throughout the world. Land managers are faced with making cost-effective plans to remediate mine influences. Remediation plans are facilitated by spatial mass-loading profiles that indicate the locations of metal mass-loading, seasonal changes, and the extent of biogeochemical processes....
Kimball, B.A.; Runkel, R.L.; Walton-Day, K.
Hands-on experiments to test for acid mine drainage
Robbins, Eleanora I.; McSurdy, Sandra L.; Craddock, Timothy
Mercury Contamination from Historic Gold Mining in California
Mercury contamination from historic gold mines represents a potential risk to human health and the environment. This fact sheet provides background information on the use of mercury in historic gold mining and processing operations in California, and describes a new USGS project that addresses the potential risks associated with mercury from these...
Alpers, Charles N.; Hunerlach, Michael P.
Microbial and spectral reflectance techniques to distinguish neutral and acidic drainage
Acid drainage from abandoned coal mines is affecting thousands of miles of rivers in the eastern United States. U.S. Geological Survey (USGS) scientists are finding that neutral drainage is sometimes being mistaken for acidic drainage because both involve the formation of iron oxide-rich materials. USGS scientists are adapting microbial...
Robbins, Eleanora I. Acute toxicity of an acid mine drainage mixing zone to juvenile bluegill and largemouth bass
The toxicity of an acid mixing zone produced at the confluence of a stream that was contaminated by acid mine drainage (AMD) and a pH-neutral stream was investigated in toxicity tests with juvenile bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides. Fish mortalities in instream cages located in the mixing zone, below the mixing...
Henry, T.B.; Irwin, E.R.; Grizzle, J.M.; Wildhaber, M.L.; Brumbaugh, W.G.
New USGS Filter Removes Phosphorus from Waste Water
A tabletop water filter demo designed to remove phosphorus from waste water has in five-years grown into a fully functional water treatment system capable of filtering more than 100-thousand gallons per day.
No Silver Bullet, But a Silver Lining
Once so cheap it was used for pennies, copper is now so valuable that pennies contain almost no copper and they still cost more than one cent to make.
PubTalk 7/2018— Extreme acid mine drainage at Iron Mountain California
Title: Iron Mountain, California: An Extreme Acid Mine Drainage Environment
- "The world's most acid water" — explaining negative pH
- Colorful mineral salts that store metals and acidity in underground mine workings
- Microbial iron oxidation and formation of pipe scale in the water treatment system
- Challenges and successes of
Cement Creek, Colorado, is a Site of USGS Investigations on the Fate of Acid Mine Drainage.
Cement Creek, Colorado, is a site of U.S. Geological Survey (USGS) investigations of the fate of acid mine drainage. USGS scientists are developing methods to characterize contaminated streams that can be used by water-resource managers to make better cleanup decisions.
Ross basin, upper Cement Creek in Watershed above North Fork Cement Creek
Western view toward the Red Mountains near Silverton, Colorado, taken just upstream from the North Fork Cement Creek drainage in 2006. The photo illustrates acidic drainage (red drainage at right) and less acidic drainage (white drainage at left of photo) that originates from altered rocks and mines in the watershed. Black rocks in foreground are mine waste clasts coated
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PubTalk 3/2015 — The Environmental Legacy of California's Gold Rush
by Andrea Foster, USGS Research Geologist & Christopher Kim, Associate Professor, Chapman University
- Why are arsenic and mercury associated with California's gold mines?
- What types of arsenic and mercury contamination can be directly related to historic mining?
- How are geochemists studying the distribution and
Dried Acid Mine Drainage Residuals
Dried acid mine drainage residuals that are formed during treatment of the drainage. The USGS has pioneered a new use for these residuals that are currently a disposal challenge, using them to filter phosphorus from agricultural and municipal wastewaters.
Tracking Mercury from Ore to Organisms
Mercury Cycling and Bioaccumulation In a Mine-Dominated Ecosystem.
Sampling Acid Mine Drainage in Elk_County, PA
Sampling acid mine drainage residuals in Elk County, Pennsylvania. The USGS has pioneered a new use for these residuals that are currently a disposal challenge, using them to filter phosphorus from agricultural and municipal wastewaters.
Acid Mine Drainage Discharge Appalachian Stream
An acid mine drainage discharge forms a plume in a stream in the Appalachian region.
Lead Queen mine tunnel precipitate
Orange, iron-rich precipitate (ochre) from outflow of Lead Queen mine tunnel, after late September 2014 monsoon storm. Photo by Glen E. "Gooch" Goodwin, Photographer - used with permission.