The study of the effect of rhizosferical bacteries on bio mass production and the availability of metals to plants and thus the take in of heavy metals by plants - Analysis of the cost efficiency of fytoremediation with case study the with heavy metals polluted Noord-Kempen. - Prospection of the feasability until the realization of a specific project on soil rationalization - to bring together all relevant variables in a 'blueprint' cost-benefit model where the netto present value can be taken as a decision supporting criterium in the framework of durable soil management.