4. Treatment plants for groundwater or deep water

4.1 Main problems encountered in groundwater intended for drinking water supply

For groundwater, quality can be :

• excellent ;

• naturally deteriorated by episodic turbidity (water in karstic zones), by micro-organisms, by iron, manganese, ammonia, arsenic, selenium, fluorine, or too "hard" to be distributed;

• deteriorated by anthropogenic activities leading to the presence of nitrates, pesticides, chlorinated solvents, petroleum additives (MTBE) or other micropollutants.

The processes corresponding to these different qualities are described schematically below. For more detailed information on the processes used, please refer to "Water technologies",...