The last step in the flue gas purification is wet washing. In giant washing towers we spray the flue gases with plenty of water, allowing them to be purified even more and cooled to about 65?C. This is where the remainder of the dust particles disappear. The water we use in the washing towers comes from the nearby water treatment plant. All the water in our plants is also re-used, so that not a single drop of water goes down the drain.