Skip to main content

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: 

 

Related Content

link
Harmful Algal Bloom (HAB) in a stream

Why are some lakes full of algae and thick plants?

Plants naturally grow in and around lakes, but sometimes lakes and ponds can get an overgrowth of plants, algae, or bacteria. In many cases, humans are responsible. Chemicals that are used on lawns and in agriculture (like nitrogen and potassium) wash into our water systems. Once there, plants and algae have a feast on this “food”.Sometimes overgrowths of cyanobacteria (called “blooms”) can make...

link

Why are some lakes full of algae and thick plants?

Plants naturally grow in and around lakes, but sometimes lakes and ponds can get an overgrowth of plants, algae, or bacteria. In many cases, humans are responsible. Chemicals that are used on lawns and in agriculture (like nitrogen and potassium) wash into our water systems. Once there, plants and algae have a feast on this “food”.Sometimes overgrowths of cyanobacteria (called “blooms”) can make...

Learn More
link
Image: The Department of Agriculture (South Building)

How does acid precipitation affect marble and limestone buildings?

When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive.You might expect that sheltered areas of stone buildings...

link

How does acid precipitation affect marble and limestone buildings?

When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive.You might expect that sheltered areas of stone buildings...

Learn More
link
Image: Lake Chandler. Acid Lake

Can lakes near volcanoes become acidic enough to be dangerous to people and animals?

Yes. Crater lakes atop volcanoes are typically the most acid, with pH values as low as 0.1 (very strong acid). Normal lake waters, in contrast, have relatively neutral pH values near 7.0.The crater lake at El Chichon volcano in Mexico had a pH of 0.5 in 1983 and Mount Pinatubo's crater lake had a pH of 1.9 in 1992. The acid waters of these lakes are capable of causing burns to human skin but are...

link

Can lakes near volcanoes become acidic enough to be dangerous to people and animals?

Yes. Crater lakes atop volcanoes are typically the most acid, with pH values as low as 0.1 (very strong acid). Normal lake waters, in contrast, have relatively neutral pH values near 7.0.The crater lake at El Chichon volcano in Mexico had a pH of 0.5 in 1983 and Mount Pinatubo's crater lake had a pH of 1.9 in 1992. The acid waters of these lakes are capable of causing burns to human skin but are...

Learn More
link
Image: Methane bubbles trapped in thermokarst lake ice

What is methane and why is it a safety concern?

Methane (a gas composed of carbon and hydrogen) is produced two ways:Through biologic decomposition of organic matter at shallow depths. Swamps, landfills, and even shallow bedrock are some settings where this occurs. Methane can also be derived over millions of years by high pressure and high temperature processes that produce fossil fuels deep underground. Examples include coal deposits and oil...

link

What is methane and why is it a safety concern?

Methane (a gas composed of carbon and hydrogen) is produced two ways:Through biologic decomposition of organic matter at shallow depths. Swamps, landfills, and even shallow bedrock are some settings where this occurs. Methane can also be derived over millions of years by high pressure and high temperature processes that produce fossil fuels deep underground. Examples include coal deposits and oil...

Learn More
link
Image: Hydraulic Gold Mining

How do we extract minerals?

The primary methods used to extract minerals from the ground are: Underground miningSurface (open pit) miningPlacer mining The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.Higher-grade metallic ores found in veins deep under the Earth’s surface...

link

How do we extract minerals?

The primary methods used to extract minerals from the ground are: Underground miningSurface (open pit) miningPlacer mining The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.Higher-grade metallic ores found in veins deep under the Earth’s surface...

Learn More
link
Image: Ross basin, upper Cement Creek in Watershed above North Fork Cement Creek
link
link
Image: Dried Acid Mine Drainage Residuals
link
USGS
link
USGS
link
View of Cement Creek, Colorado
link
Image: Sampling Acid Mine Drainage in Elk_County, PA
link
Image: Acid Mine Drainage Discharge Appalachian Stream
link
Extremely acid mine drainage on a wall
link
Image shows orange, discolored water in a small canyon
link

USGS National Water Quality Monitoring Network

What is the U.S. Geological Survey National Water Quality Monitoring Network?Understanding the water quality of U.S. streams and rivers requires consistent data collection and analysis over decades. The U.S. Geological Survey’s (USGS) National Water Quality Network (NWQN) was established to facilitate national-scale understanding of surface-water quality conditions through the collection of compar
By
Water Resources, New Jersey Water Science Center

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 usually contains elevated concentrations of sulfate,
By
Water Resources, Pennsylvania Water Science Center

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. Field-scale experiments during both low- and high-flo
By
Ecosystems, Toxic Substances Hydrology, Environmental Health Program, Colorado Water Science Center

Hands-on experiments to test for acid mine drainage

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 sources, with emphasis on historic hydraulic minin
By
Ecosystems, Toxic Substances Hydrology, Environmental Health Program

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 techniques to learn about the processes that form the acidic

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 zone, and upstream in both tributaries were compar
By
Ecosystems, Columbia Environmental Research Center
link

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...

Read Article
link

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...

Read Article

Related Content

  • FAQ
    link
    Harmful Algal Bloom (HAB) in a stream

    Why are some lakes full of algae and thick plants?

    Plants naturally grow in and around lakes, but sometimes lakes and ponds can get an overgrowth of plants, algae, or bacteria. In many cases, humans are responsible. Chemicals that are used on lawns and in agriculture (like nitrogen and potassium) wash into our water systems. Once there, plants and algae have a feast on this “food”.Sometimes overgrowths of cyanobacteria (called “blooms”) can make...

    link

    Why are some lakes full of algae and thick plants?

    Plants naturally grow in and around lakes, but sometimes lakes and ponds can get an overgrowth of plants, algae, or bacteria. In many cases, humans are responsible. Chemicals that are used on lawns and in agriculture (like nitrogen and potassium) wash into our water systems. Once there, plants and algae have a feast on this “food”.Sometimes overgrowths of cyanobacteria (called “blooms”) can make...

    Learn More
    link
    Image: The Department of Agriculture (South Building)

    How does acid precipitation affect marble and limestone buildings?

    When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive.You might expect that sheltered areas of stone buildings...

    link

    How does acid precipitation affect marble and limestone buildings?

    When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive.You might expect that sheltered areas of stone buildings...

    Learn More
    link
    Image: Lake Chandler. Acid Lake

    Can lakes near volcanoes become acidic enough to be dangerous to people and animals?

    Yes. Crater lakes atop volcanoes are typically the most acid, with pH values as low as 0.1 (very strong acid). Normal lake waters, in contrast, have relatively neutral pH values near 7.0.The crater lake at El Chichon volcano in Mexico had a pH of 0.5 in 1983 and Mount Pinatubo's crater lake had a pH of 1.9 in 1992. The acid waters of these lakes are capable of causing burns to human skin but are...

    link

    Can lakes near volcanoes become acidic enough to be dangerous to people and animals?

    Yes. Crater lakes atop volcanoes are typically the most acid, with pH values as low as 0.1 (very strong acid). Normal lake waters, in contrast, have relatively neutral pH values near 7.0.The crater lake at El Chichon volcano in Mexico had a pH of 0.5 in 1983 and Mount Pinatubo's crater lake had a pH of 1.9 in 1992. The acid waters of these lakes are capable of causing burns to human skin but are...

    Learn More
    link
    Image: Methane bubbles trapped in thermokarst lake ice

    What is methane and why is it a safety concern?

    Methane (a gas composed of carbon and hydrogen) is produced two ways:Through biologic decomposition of organic matter at shallow depths. Swamps, landfills, and even shallow bedrock are some settings where this occurs. Methane can also be derived over millions of years by high pressure and high temperature processes that produce fossil fuels deep underground. Examples include coal deposits and oil...

    link

    What is methane and why is it a safety concern?

    Methane (a gas composed of carbon and hydrogen) is produced two ways:Through biologic decomposition of organic matter at shallow depths. Swamps, landfills, and even shallow bedrock are some settings where this occurs. Methane can also be derived over millions of years by high pressure and high temperature processes that produce fossil fuels deep underground. Examples include coal deposits and oil...

    Learn More
    link
    Image: Hydraulic Gold Mining

    How do we extract minerals?

    The primary methods used to extract minerals from the ground are: Underground miningSurface (open pit) miningPlacer mining The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.Higher-grade metallic ores found in veins deep under the Earth’s surface...

    link

    How do we extract minerals?

    The primary methods used to extract minerals from the ground are: Underground miningSurface (open pit) miningPlacer mining The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.Higher-grade metallic ores found in veins deep under the Earth’s surface...

    Learn More
  • Multimedia
    link
    Image: Ross basin, upper Cement Creek in Watershed above North Fork Cement Creek
    link
    link
    Image: Dried Acid Mine Drainage Residuals
    link
    USGS
    link
    USGS
    link
    View of Cement Creek, Colorado
    link
    Image: Sampling Acid Mine Drainage in Elk_County, PA
    link
    Image: Acid Mine Drainage Discharge Appalachian Stream
    link
    Extremely acid mine drainage on a wall
    link
    Image shows orange, discolored water in a small canyon
    link
  • Publications

    USGS National Water Quality Monitoring Network

    What is the U.S. Geological Survey National Water Quality Monitoring Network?Understanding the water quality of U.S. streams and rivers requires consistent data collection and analysis over decades. The U.S. Geological Survey’s (USGS) National Water Quality Network (NWQN) was established to facilitate national-scale understanding of surface-water quality conditions through the collection of compar
    By
    Water Resources, New Jersey Water Science Center

    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 usually contains elevated concentrations of sulfate,
    By
    Water Resources, Pennsylvania Water Science Center

    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. Field-scale experiments during both low- and high-flo
    By
    Ecosystems, Toxic Substances Hydrology, Environmental Health Program, Colorado Water Science Center

    Hands-on experiments to test for acid mine drainage

    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 sources, with emphasis on historic hydraulic minin
    By
    Ecosystems, Toxic Substances Hydrology, Environmental Health Program

    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 techniques to learn about the processes that form the acidic

    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 zone, and upstream in both tributaries were compar
    By
    Ecosystems, Columbia Environmental Research Center
  • News
    link

    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...

    Read Article
    link

    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...

    Read Article