MILAN - Mineral water and tap water serve both to satisfy the need to quench one’s thirst, but there are some differences that, from legislation to composition, characterize them. Let us clarify a bit to help citizens to learn more.
The main element of differentiation lies precisely in the source. Natural mineral water may only come from deep groundwater, with geological characteristics that preserve it of course from risks of contamination. Tap water, distributed through the aqueducts and commonly defined as drinking water, instead, can also drift from superficial flaps and surface waters, as lakes or rivers, which may not be immune from contamination.
Treatments for tap water
Precisely for this reason, tap water is subjected to treatments of antibacterial disinfection. Most of the water distributed by the aqueducts on national territory is disinfected using as agents gaseous chlorine, sodium hypochlorite and chlorine dioxide. The correct dosage of the chlorination is precisely one of the most critical elements of tap water management: if a low dosage does not guarantee a sufficient downstream disinfection, a high dosage, vice versa, can determine the exceeding of the limits for certain substances harmful to the health, such as trihalomethanes (chloroform, bromoform). Other treatments may also be necessary to delete footsteps of chemical contamination or unwanted elements.
The quality of tap waters depends very much on the conditions of the water distribution network, which can also significantly vary from municipality to municipality; mineral waters, instead, arrive on the table in the same way they gush at source, without the intervention of any kind. The law, taking account of the particular characteristics of natural mineral waters and whereas the request of the consumer is to have available an unobjectionable product under the profile of guarantee of health and hygiene, has already long established 51 control parameters and their respective limits.
Tap water: surveillance and compliance
The operations of surveillance and monitoring in hygiene health of natural mineral waters shall be carried out by health authorities (ASL, ARPA laboratories, NAS). The inspections and taking samples to be subjected to analytical checks may be carried out at any time and along the whole chain of production and distribution (starting from sources, along the feeding hydraulic network, on plants in factory, in stores and warehouses, points of sale).
A judgement of qualitative non conformity on a natural mineral water implies the revocation of the Decree of ministerial recognition and authorization of its sale; for non-conformed tap water to the exceeding of limit of a parameter, instead, one can ask for exemptions.
di Alessandro Conte