A sample taken from the public fountain in via Carlo Cattaneo was enough to turn off the taps of half the city. The Municipality of Viterbo has signed a non-drinking ordinance for the areas served by the “Centro 480” water network, after the enterococci parameter was found to be beyond the legal limits. Arpa Lazio certified the non-compliance in its test report, sent on 4 June by the ASL to the Municipality and the manager Talete.
The affected areas
The provision concerns the areas supplied by the 480 reservoir, which include in whole or in part the Cappuccini, Murialdo, Pila, Barco, Grotticella, Mazzetta, Pietrare, Ponte dell’Elce districts, as well as the areas of Strada Cassia Sud, Strada Filante and Strada Buon Respiro. The exact perimeter does not always coincide with the boundaries of the neighborhoods, which is why we recommend consulting the map attached to the ordinance (which you will find at the bottom of the article) to understand whether or not your home falls within the area subject to the ban.
What can and cannot be done
In the areas involved, water cannot be drunk, use for domestic hygiene is permitted, with one exception, which should not be underestimated, which concerns brushing teeth, which is strictly excluded. To prepare and/or wash food, however, the water must first be boiled for at least 10-15 minutes.
Interventions and restoration
Talete, manager of the integrated water service of Ato 1 Viterbo, will have to urgently adopt the corrective measures necessary to bring the parameter back within the limits. The union ordinance n. 21 of 4 June 2026 will remain in force until compliance is restored, which must be confirmed by new favorable samples, then the lifting of the ban will be promptly communicated to the population.
Focus: what enterococci are
Enterococci are a group of bacteria that normally live in the intestines of humans and warm-blooded animals. Finding them in tap water, however, is far from normal and their possible presence is considered the primary indicator of recent fecal contamination. In simple words, if they appear in the analyses, it means that the water has come into contact with fecal material and could therefore carry other pathogenic microorganisms, viruses or parasites.
The regulatory framework is referenced in Legislative Decree 18/2023, which transposes European Directive 2020/2184 on water intended for human consumption, placing intestinal enterococci and Escherichia coli among the primary indicators of faecal contamination, real indicators of a potential health hazard. For both the parameter value is zero in 100 milliliters, therefore any presence therefore constitutes a non-conformity.
The dangers
Why so much attention on these bacteria in particular? For a couple of reasons:
It must be said that, in the absence of extraordinary events, it is unlikely that concentrations in mains water will reach such concentrations as to reach the infectious dose and this is exactly why ordinances such as the Viterbo one are precautionary in nature, because action is taken before the risk materializes, not after.
