Tailigns dams are embankment dams constructed to contain and store waste (tailings) of mines. During mining, in order to separate the mineral or metal from the rock, mechanical and chemical processes are used to grind up rock into sand. The great amount of wastewater that is being mixed up with sand and chemicals is referred to as tailings. Tailings can be liquid, solid, or a slurry of fine particles, and are usually environmentally harmful. They are placed together, forming ponds and are supported by earth-filled dams. The solids settle to the bottom and the water that is gathered on top is being reclaimed for reuse in the mine. In most cases, tailing dams are made of mining waste products resulting in cheaper construction but also in unstable structures that are prone to leakage.