Agricultural valorization
Final disposal of sludge.

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, K₂O, P₂O₅, CaO, MgO, SO₃; organic amendment...);

• lower thresholds for trace metallic and organic elements and compounds ;

• sludge traceability, which prohibits the mixing of sludge from different origins;

• for certain applications, hygienized sludge is required (absence of salmonella,...