Longwall mining is a form of underground coal mining which removes the coal, and simply allows the overlying material to collapse into the vacated space.

This can cause:

• the land above to subside
• rock shelves to crack
• swamps, water courses and aquifers to drain away.

It can also cause:

• methane and other gases to be released
• minerals and chemicals to be released into swamps, water courses and aquifers.

Open Cut Mining is the removal of the surface soil or overburden from a huge area, down to the depth of the mineral deposit. This can be from a shallow depth of several metres up to 1000 metres deep. It forms a huge hole in the ground. Once exposed the mineral deposit is then mined by usually blasting and or digging.

It can cause the release of minerals, salts and other chemicals into -

• the surrounding ground waters or aquifers.
• the surrounding creeks and rivers.

It also releases dust into the air carrying these minerals, salts and chemicals for vast distances.

The piles of overburden are equally at risk of contaminating the waters and areas around them in wet times, as the rain water washes through the piles and runs away.