This part of the CEN Technical Report specifies a most probable number (MPN) method for the quantitative detection of Escherichia coli in sludges, soils, soil improvers, growing media and biowastes. It allows further differentiation within the test than part 2 of this standard. It is suitable to evaluate the log reduction of E.coli through treatment as well as the quality of the end product. The method is for material with dry residues of more than 10 %. For materials with dry residues less than 10 %, the procedure given in CEN/TR 15214-1 should be used.