Principally Acid Mine Drainage or AMD is contaminated water caused by mining, whether it be open cut or underground mining.

Acid Mine Drainage is usually high in dissolved iron, aluminum and sulfuric acid.  When leaching to the surface AMD has colors varying  from yellow/orange - orange/red.

The colours come from the iron and the smell that is associated with it comes from the sulphur.   

It's the run off of this contaminated water that has a major impact on the environment. 

Acid Drainage is one of the biggest environmental problems today, affecting entire eco-systems either by reducing natural inhabitants or by destroying whole areas that previously flourished with plants and animals.

Destruction is usually in the forms of fish kills and land scalds.

Through mining operations the natural occurring deposits of sulfidic compounds and minerals in the soils  associated with some mining practises become exposed to the oxygen.  While undisturbed they are in an anaerobic state and quite harmless.  At the commencement of mining the natural balance shifts and these minerals and sulfidic compounds oxidize and react into different oxidised products.

It is this exposure to oxygen and water that creates a chemical reaction that filters into our waterways taking with it other harmful chemicals such as  copper, iron, aluminium, manganese, cadmium, zinc, lead, and arsenic.  pH readings around 3 or 4 are common in mining areas associated with Acid Mine Drainage.

Acid leachate can come from inside the mine on the walls of the tunnels or from the 'tailings' left from when the ore was extracted.

AMD can effect the environment by destroying the habitat in waterways - fish, crustaceans, frogs ect.  The effect on fish habitat that rely on the rivers to breed is enormous.  Acid Mine Drainage contaminates natural breeding grounds.

AMD can contaminate the food chain by the amount of heavy metals in solution in the water.  As the prey and predator cycle continue the amount of heavy metals accumulating in each animal can affect animals higher up the chain.

AMD can contaminate the drinking water that normally is used for water supplies in towns and cities.

Acid Mine Drainage is a huge ongoing environmental problem today, affecting entire eco-systems either by reducing natural inhabitants or by killing whole areas that previously flourished with plants and animals.