Why copper should not be disposed of in landfill sites?

it's going to be a question in my exam but i don't get it.

Copper is a heavy metal that can harm many people. This process of heavy metals building in your body is called bioaccumulation and the process of this building in the food chain is called biomagnification. Its hard to rid of this heavy metal because it is very dense, therefore, cannot breakdown in our bodies. Heavy metals get consumed by producers and then reach to the top of the pyramid (us) so we have the highest risk of getting diseases and so on. Make sure you explain that heavy metals get passed from industrial purposes where companies do not dispose of waste properly.
Source: Exam as well
Good luck!  

What the guy above said, although he focuses more on the human side. In animals the bioaccumalation can cause toxicity and diseases within them too, and it can cause large loss of life. It also limits plant growth when in high doses, so new life can't grow in the area once the landfill is covered over