AMD - Acid Mine Drainage
What is AMD?
AMD or acid mine drainage/abandoned mine drainage, is acidic water ladened with metals such as iron, manganese and aluminum. Typically this water is created due to coming in contact with a mine. The exposed minerals react with oxygen and the water, which generates sulfuric acid. The acid then dissolves the metals into the water. Not all AMD is acidic. Some AMD is alkaline, hence the more general name of "abandoned mine drainage". This name is also appropriate because most of the environmental issues created by AMD come from old, abandoned mines. These were mined before laws and regulations required mining companies to treat their water. Modern science has resulted in mining practices that produce little to no AMD. When a discharge is not avoidable, the mining company treats the water before it enters the watershed.
AMD Treatment
There are two ways AMD can be treated, actively and passively. Active treatment is done through the active addition of chemicals which causes a chemical reaction that precipitates the metals out. Passive treatment accomplishes the same goal but uses a more natural materials like limestone and plants to help the chemical reactions along. The type of treatment you use depends on the specific AMD you are trying to treat. Systems can range from small wetlands to a simple caustic drip and all they way up to a large lime bin with a clarifier.
Our AMD
Five of our treatment sites are located in the Stonycreek River watershed and the other is in the Casselman River watershed. All six of our current treatment sites utilize passive treatment with one system also having a slip stream lime doser component. Our typical system consists of ponds containing limestone, compost and different plant species that all help to precipitate the metals as the water moves through the ponds. See the Properties tab for more detail of each system located at each property.
AMD Assistance
Need help with an AMD issue? Bottomlands can provide technical assistance for any AMD related activity such as consulting, engineering, operation and maintenance and much more. Give us a call at 814-445-4491 or send us an email at info@bottomlandsconservancy.org