There are many potentially hazardous substances in explosive materials. During manufacture; use and disposal there can be leaching to the surrounding environment; to the factory site and the waste water from the processes. Many of the explosives consist of organic substances which are possible to treat biologically. This means degradation by using micro organisms either in batch reactor systems or in continuous processes. The first has been tried out in the laboratory whereas the latter is a research idea which will be discussed in the present paper. Principally; the method is envisaged as flow through a filter column or box with an inert substrate well suited for a bio-film to grow on. Close to a free liquid surface; the environment is aerobic; with available oxygen At particle surfaces; however; the micro biological process consumes the oxygen and offers an anaerobic environment. The anaerobic environment is well suited for denitrification bacteria which together will work for a degradation of the nitric groups on the explosive substance molecule.