The work was carried out at the premises of the former sand quarry in the cadastral area of the municipality of Údlice as sludge from the Chomutov sewage treatment plant had been discharged into the extraction shaft of the quarry for many years. Within the project, a mobile sludge treatment plant was built on the edge of the former extraction shaft and the sludge water was gradually purified and drained. After draining the shaft and testing it for contaminated waste, the sediment was thickened and the shaft was subsequently backfilled. The whole area was then planted with trees and shrubs creating a small grove. The reclaimed area significantly contributes to increasing the quality of the environment because it has developed into a natural shelter for animals in the surrounding countryside which is used mainly for agricultural purposes.