Environmental Impacts of Mining

Can you tell that this was a mine?

Mining can do a lot of damage to a region. Mining companies are now supposed to return the land to its natural state when they are done. Sometimes this works really well. It's hard to tell there was a mine here!

Mining and the Environment

Mining provides people with many resources they need. But mining can be hazardous to the environment. For surface mines, miners clear the land of soil and plants. Nearby lakes and streams may be inundated with sediment. The mined rock may include heavy metals. These also enter the sediment and water. Removing metals from rock may involve toxic chemicals. Acid flow from a mine site will change the chemistry of a nearby stream or lake.

Land Reclamation

U.S. law states that once mining is complete, the land must be restored to its natural state. This process is called reclamation. A pit may be refilled with dirt. It may be filled with water to create a lake. The pits may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. The land is reshaped. Native plants are planted.

Mine Pollution

Mining can cause pollution. Chemicals released from mining can contaminate nearby water sources. Pictured below is water that is contaminated from a nearby mine (Figure below). The United States government has mining standards to protect water quality.

Summary

• Surface mining clears the land. Rock, dirt, and plants are all disturbed.
• Mining releases pollutants from rock or as metals are removed from rock.
• Reclamation occurs when people attempt to return the mined land to its original state.

Review

1. What damage may be caused by mining?
2. Why is sediment considered a problem in mined areas?
3. How is the region where there is a surface mine reclaimed?