The leachate recycling at landfill sites constitutes a serious technical problem which occurs in the phase of designing and building a landfill site as well as during its operation and reclamation. The ecological aspect is of a great importance because leachates contain organic substances and inorganic salts which are toxic. The composition and quantity of the leachate deposit can vary depending on the seasons and atmospheric rainfall. In Poland, leachates are taken away by gully emptiers and disposed of in sewage treatment plants. However, as experts admit, this solution is a temporary one. In industrialized countries of Western Europe this solution is contrary to the current technological and legal conditions. Mixing landfill leachates and municipal sewage in sewage treatment plants leads only to the dilution of landfill leachates so as to comply with the norms concerning sewage treatment. It is important to notice that inorganic salts, including heavy metals, constitute about 80 % of leachate weight.
Biocoenoses of bacteria cannot remove inorganic substances which are contained in leachates. In the end, untreated inorganic substances go to the natural environment with partly purified sewages.
