Stock Photo - 13 September 2021, Thuringia, Merkers-Kieselbach: A sign with the inscription ""Start custody area"" hangs on the ceiling in the mine. The fertilizer producer K+S plans to permanently store saline waste water from the Werra plant in a disused part of the Merkers mine, the Springen mine field. On the one hand, this will serve to dispose of saline water from potash production and should contribute to improving the quality of the waters of the Werra and Weser. On the other hand, it is intended to remove a mining legacy that would otherwise jeopardise mining safety in the long term. The approval procedure for the stacking is currently underway with the competent authorities in Thuringia and Hesse. Photo: Martin Schutt/dpa-Zentralbild/dpa. - Merkers-Kieselbach/Thuringia/Germany