Large scale soil contamination is a serious problem in many regions. The causes of pollution with heavy metals, organic compounds and other are manifold and overlap often: long term application of fertilizers and pesticides onto farmland soils, sewage farm lands and waste deposits, atmospheric deposition, landscapes under military use, flood events, environmental crime and war. Hazard estimations, redevelopment suggestions and conceptions of usage are needed to be developed. Conversely to small scaled and spatially less (bordered) dangerous waste residues (Altlasten) the investigation of large scale contaminated areas should be approached seperatly because of its dimension. Methodological experiences shall be presented within the paper, considering the practical, interdisciplinary work, which was done at the field under investigation by the author after the reunification. The procedure consisting of data collection and processing, validation, assessment and presentation of the results as well as recommendation of actions are discussed and given. On the hand of examples the problematic will be systematized. (1) sewage farm lands around Berlin; (2) flood plain soils after the extreme event 2002 at the river Elbe; (3) intensive used farmlands in Saxony; and (4) military training areas in conversation. The knowledge of precaution and sanitary from soils view and the society will be summarised at the end. How does the use regarding sanitary prove? Could the endanger from use and protection goods be averted? Is precaution enough with regard to diffuse, creeping soil change? References: (i) Grunewald, K. (1997) Großräumige Bodenkontaminationen - Wirkungsgefüge, Erkundungsmethoden und Lösungsansätze. Springer-Verlag, Berlin, Heidelberg, New York, 250 S. (Veröff. der Habilitation). (ii) Grunewald, K., C. Weber & K. Schröder (2005) Schadstoffbelastung und Auennutzung nach dem Elbehochwasser 2002 in Sachsen – eine Synopse. In: „Handbuch Angewandte Limnologie“, hrsg. von Steinberg/Calmano/Klapper/Wilken, 22. Erg.Lfg. 7/05, 42 S.