The quality of raw water does not generally match the standards applicable to tap water.

Undesirable elements have to be removed, such as suspended solids, iron, manganese, nitrates, pesticides, sulphates, salinity, pathogenic germs, taste
or odours, etc.

A range of treatment processes, including physicochemical treatments, sand or activated carbon filtration, disinfection and remineralisation can be

The application of new membrane filtration techniques is very promising in this regard.

Treatment takes place in pressure or open filters.

In order to block the growth of micro-organisms such as bacteria, algae, viruses, etc., the water must be disinfected.

The filters may contain:

  • sand: for water with low levels of suspended solids or for the removal of iron and manganese;
  • activated carbon: to remove, by adsorption, the organic molecules that give unpleasant odours and flavours to the water;
  • ion-exchange for softening, demineralisation or nitrates removal;
  • a neutralising mass: to solve problems of calcocarbonic balance.