During the second World War it was decided to produce oil through pyrolysis of alum shalegiving rise to waste products (coke and ash). Waste was deposited in the open pits and in a waste deposit.Due to the high remaining energy in the waste materials the waste deposit still today has significantlyelevated temperatures (above 500 °c). remaining pyrite in the waste material has also led to ArDwith elevated trace metal concentrations. the waste deposit is no great environmental problemtoday but as soon as the waste pile cools off both the volumes of drainage and concentrations oftrace metals will increase dramatically