5. Surface water treatment plants

5.1 Main problems encountered in surface water intended for drinking water supply

The quality of surface water (rivers and natural or dammed lakes) is very rarely excellent, and the problems encountered are of three types:

• common problems of natural origin: turbidity and suspended solids, iron, manganese, aluminum, natural organic matter, algal toxins, low mineral content;

• Increasingly frequent problems of anthropogenic origin: nitrates, pesticides and metabolites, pharmaceutical residues, per- and polyfluoroalkylated substances (PFAS), endocrine disruptors and other organic micropollutants, algal blooms, metals, microbiology (bacteria, viruses and pathogenic protozoa), organic matter from urban and...