WHAT IS IT?
Chlorine is the most widely used disinfectant in drinking water. What we commonly refer to as chlorine is measured as the presence of residual chlorine in the water, that is, the concentration of unreacted chlorine.
IS THE CONCENTRATION OF FREE CHLORINE IN WATER REGULATED BY LEGISLATION RELATING TO WATER FOR HUMAN CONSUMPTION?
The presence of residual chlorine in water supply networks is established in national legislation concerning drinking water (Royal Decree 140/03). This legislation sets a maximum concentration of free chlorine in the supply network of 1 mg/l.
Chlorine is imperceptible to the eye at the concentrations in which it is present in drinking water; however, it does give the water a certain smell and taste.
HOW DOES CHLORINE DISINFECT?
Chlorine is used to eliminate bacteriological contamination and works by destroying organic matter through oxidation.
By ensuring a permanent presence of free chlorine, we indirectly control the presence of bacteriological contamination in the water.
The minimum chlorine content is established by each Autonomous Community in the regional developments of RD 140/03.
Below, we show as an example the lower chlorine limits established by the health authority in different communities:
– Valencian Community: 0.4 mg/l
– Castilla La Mancha: 0.2 mg/l
– Balearic Islands: 0.2 mg/l
– Aragon: 0.2 mg/l
WHY IS IT SO IMPORTANT TO DISINFECT WATER?
Water disinfection is a vital issue for public health as it combats the presence of bacteriological contamination.
Bacteriological contamination can be present in water without being detected by people (since it can be invisible, odorless and tasteless) and, if ingested, could cause illness in the population.
That is why it is of paramount importance to maintain constant control of the presence of residual disinfectant in the water, so that the concentrations are always within the limits stipulated by current legislation.
