2. Agricultural valorization

2.1 Regulations

French legislation on the land application of urban sludge is a good illustration of Europe's aim to preserve agricultural resources, without condemning this common-sense approach for most urban sludge or sludge from non-toxic industries. The main points are as follows:

• sludge producer responsibility ;

• principle of safety and agricultural interest (agronomic value of N, K ₂ O, P ₂ O ₅ , CaO, MgO, SO ₃ ; organic amendment...);

• lower thresholds for trace metallic and organic elements...