5. Surface water treatment plants

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

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

• common problems of natural origin (turbidity and SS, iron, manganese, aluminium, MON, bacteria, algae, low minerality);

• increasingly frequent problems of anthropogenic origin (nitrates, pesticides, pharmaceutical residues, endocrine disruptors and other organic micropollutants, metals, pathogenic bacteria and viruses, organic matter from urban and industrial waste, etc.);

• treatment and distribution problems (THMs, chlorites, bromates, lead, acrylamide,...