Frankfurt (dpa/lhe) - The Hessian Federation for the Environment and Nature Conservation Germany (BUND) has criticized the coverage of the summit area of the potash spoil heap at the Hattorf site of the Kassel-based fertilizer company K S as insufficient. It does not solve the sewage problem, said deputy managing director Thomas Norgall, according to a statement on Tuesday. "Since the salt heaps are expected to continue to grow, larger and larger amounts of saline waste water will be produced."
The summit coverage was approved by the Kassel regional council on Monday. The aim is to reduce the leaching of saline heap water, the authority said. The permit is said to cover 9.5 hectares of plastic sheeting, a drainage layer and soil with future green growth.
The now approved cover has been rejected by the State Agency for Nature Conservation, Environment and Geology because the heap will continue to deform for centuries, explained Norgall. "From October 2019 to April 2021 alone, there was a subsidence of around six meters in the coverage area." The cover and in particular the film cannot withstand these movements in the long term. "Only a consistent shipment of the huge salt residues as solids into the exploited mines can safely prevent the increase in saline wastewater."
K S disagrees. In the approval process, the suitability and long-term usability of the geomembranes were extensively examined and all the necessary proof of suitability was provided, spokesman Marcus Janz explained on Wednesday. "On this basis, the competent mining authority has granted approval for the plateau cover."
With the plateau covered by the end of 2024, the amount of saline water from the Hattorf heap will be reduced in a first step. "In the long term, covering the heap flanks will have an even greater effect, as they occupy a much larger area than the plateau." Preparations for the side cover are underway. According to Janz, it should be presented next year.