The objective of the project is to evaluate the bioavailability and degradability of organochlorine pesticides: aldrin, dieldrin, heptachlor and the like, in contaminated soil and groundwater. Also their degradability will be assessed, using methanogenic granular sludge. Pesticides availability will be studied conducting their extraction studies from contaminated soil to determine the bioavailable phase. Also tests with adding dissolved organic carbon (DOC) will be carried out to find if it is possible to increase their concentration in the water phase, thus if it is possible to increase the biodegradable fraction. Simultaneously, selected pesticides biodegradation will be studied in tests using granular sludge. Adaptation, degradation rate and pesticides metabolites will be investigated thoroughly. Based on the results obtained during the research in the above two phases, a biodegradation experiments with real contaminated soil will be made. Finally, a design of a treatment concept to be applied in practice will be prepared.