The Cause And Effects Of Acid Mine Drainage

The Cause and Effects of Acid Mine Drainage

INTRODUCTION

Imagine going fishing on a cool Autumn day, the trees are all different shades of orange, brown and red and the birds are singing their beautiful songs, but their is a serious problem because when you arrive at the river all plant and animal life are gone. This is by no means a recent phenomenon. This is due to the effects of acid rock drainage (ARD). This is a problem that has been occurring since ancient times, but it was not until the 1800's when fast growing industrialization and heavy mining that it caught alot of attention.

Acid rock drainage is the term used to describe leachate, seepage, or drainage that has been affected by the natural oxidation of sulfur minerals contained in rock which is exposed to air and water. The major components of

ARD formation are reactive sulfide minerals, oxygen, and water. Biological activity and reactions is what is responsible for the production of ARD. These reactions make low pH water that has the ability to mobilize heavy metals contained in geological materials with which it comes in contact. "ARD causes a devastating impact on the quality of the ground or surface water it discharges to. (Ellison & Hutchison)"

ACID MINE DRAINAGE

Within the mining process there are several sources that cause ARD. No matter what activities occur, ARD usually occurs when certain conditions are met.

These conditions are the factors that limit or accelerate the release of ARD.

The initial release of ARD can occur anywhere from a few months to many decades after the sulfide containing material is disturbed or deposited. ARD has been associated with mines since mining began. When ARD occurs due to the effects of mining it is called acid mine drainage, or AMD. The coal mining industry here in the eastern United States has been associated with a major source of AMD for decades. When water comes in contact with pyrite in coal and the rock surrounding it, chemical reactions take place which cause the water to gain acidity and to pick up iron, manganese and aluminum. Water that comes into contact with coal has a orange-red yellow and sometimes white color. The metals stay in the solution beneath the earth due to the lack of oxygen. When the water comes out of the mine or the bor...

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...ansform organic material and nutrients.(Bastian 1993) Natural and constructed wetland have been used to treat wastewater. The first one that was ever constructed was in 1982.

There are over 200 systems in Appalachia alone.(Bastian 1993)

Even though this is safer for the ecosystem it is found that at most sites, chemical treatment is still necessary to meet efficient standards, but the costs of chemical treatment is greatly reduced with the initial biological treatment. Most operators find that the costs of the construction of the wetlands are made up within one year due to the money saved on chemicals.

CONCLUSION

In conclusion, acid rock drainage is a big problem all throughout the world due to alot of industrialization and mining. This is not only a serious problem around the world, it touches home here, especially here in Appalachia, but it seems to be under or getting under control with all the new regulations and standards the EPA is setting. Low pH and a high acidity level is harmful to us our wildlife and our plants. With the help of more education and more research it will not have to be a problem for our future.