What is acid mine drainage?
Where is acid mine drainage a problem?
What have EPA, DEP studies concluded?
What irreversible problems has acid mine drainage brought to PA?
How can acid mine drainage be treated?

Acid mine drainage is the movement of acidic water from areas that have been mined for coal or other mineral ores. More specifically, acid mine drainage occurs when the mineral pyrite, found naturally in coal, is exposed to water and air. Sulfuric acid and iron hydroxide are the major products of this reaction. The presence of these compounds can be recognized by a bright orange, yellow, or red color. This byproduct of mining, in high concentrations, can destroy water resources and habitats by lowering pH (increasing acidity) and coating streambeds with iron hydroxide.

Acid drainage problems exist in Pennsylvania, West Virginia, Ohio, Kentucky, Maryland, Indiana, Illinois, Oklahoma, Iowa, Missouri, Kansas, Tennessee, Virginia, Alabama, and Georgia. Pennsylvania and Northern West Virginia, the two most extensively mined states in Appalachia, lack limestone formations, which could serve as a neutralizing agent and help curb severe acid drainage pollution.

Acid mine drainage was a significant problem in streams studied in EPA and DEP samplings. Pennsylvania DEP sampling suggested that nearly 10% of stream miles in PA are degraded or threatened. Mine drainage, acidic deposition, and contaminants in fish tissue were associated with 15% of Pennsylvanian stream miles according to a 2000 EPA study.

Due to Pennsylvania's coal heritage and unregulated mining activity before 1977, almost 3,000 miles of streams are nearly void of life and are unable to support fish or macro-invertebrates. Consequently, Pennsylvania loses approximately $67 million annually that could be generated if sport fishing were restored in the affected streams. The estimated cost for restoring the damaged watersheds is $5 billion to $15 billion.

There are active and passive procedures used to treat and mitigate acid mine drainage. In active approaches, water treatment plants can employ alkaline agents, which are added to water to increase its pH level (lower its acidity).

Passive treatments use aerobic wetlands, limestone drainage, or diversion wells to raise pH levels and precipitate heavy metals out of the water. Both passive and active treatments have yet to be perfected and proliferated.

To learn more about acid mine drainage, please visit the following sites:
http://www.dep.state.pa.us/dep/deputate/minres/bamr/amd/science_of_amd.htm
http://pa.water.usgs.gov/projects/amd/
http://www.enviroliteracy.org/article.php/1123.html