The present paper focuses on conducting research, based on physical, chemical analysis of treated sludge from the waste water treating systems and on physical, chemical and pedological analyzes on sterile material (soil), achieved in order to turn both residues, by mixing and a mutual treatment, into an useful, friendly environmental material, useful for further cultivation. One determined in situ probes from the Lupeni sterile dumps different characteristics such as: thickness of the soil layer, its physiological width, structure and porosity, permeability, humidity, soil reaction, effervescence with HCl, the nature of humus, soil texture, the presence, nature and abundance of soluble salts. Further one researched on electrokinetic�s disintegrated sludge, and applying ultrasonic technology, and concluded about the possibility of using the sludge on the degraded lands of the Jiu Valley. The sludges from the purification contain: clay particles entrained by street water into the sewer network; organic substances from domestic sewage and human manure; soluble / insoluble salts; various species of cat-ions and an-ions retained by the colloidal fraction of organic or mineral nature and microorganisms. As result, the tests demonstrated the improved soil quality on degraded lands by fertilizing with purified sludge. The superior growth of platelets in sterile mixture vessels and 75 % fermented sludge, versus experimental samples with 75 % sterile material. The use of sludge treated in land conversion has a unit cost of 210 � 250 euros/ tonne dry substance (d.s.).