Impacts of AMD
Acidification and Acid Impacts EPA's Region III treatment of AMD and acids.
Why Is AMD Harmful? Hedin Environmental
AMD is responsible for depositing a huge acid load to a large number of streams in Pennsylvania and throughout the coal producing regions. AMD is the single largest non-point source pollution in PA. This acid is responsible for lowering the pH and degrading the quality of the waterway. As the pH is lowered, less and less living things can tolerate these harsh conditions. At sufficiently low pH, a stream effectively is dead. AMD can work in concert with acid deposition (acid rain) to have devastating effects to waterways.
AMD is also responsible for depositing a large load of heavy metals into our waterways. Iron, aluminum, and manganese are the principal metals deposited as a result of coal mining activities, but others are also possible. The effects of iron are usually visible in a stream running orange or with an orange coating on the bottom. Here iron is present in the compound yellowboy smothering aquatic plant and animal life and disrupting the food chain. When present, aluminum may be seen as white compound called gibbsite. It is toxic to many aquatic organisms and humans. For some plants it limits or stops root development. As a result, plants cannot absorb water and nutrients, are stunted, and exhibit nutrient deficiency symptoms. Manganese can interfere with normal growth processes in the aerial plant parts, which stunts the plant, discolors it, and causes poor yields.
AMD through acid and metal loading can render a waterway unsuitable for a variety of uses including human, agricultural, industrial and recreational. It degrades and destroys habitats. It is aesthetically unappealing. It is often seen in economically depressed areas adding to a sense of hopelessness.