Authorities have banned the drinking of public water supplies in 32 areas of Lazio, mainly in the Viterbo area north of Rome, due to a high presence of arsenic in the water. The order came into effect on 1 January after the arsenic levels breached the EU limit of 10 micrograms per litre of water.

The ban affects thousands of households who can no longer drink the water from their homes or from public fountains. The areas affected are Ardea, Anguillara Sabazia, Mazzano Romano, Velletri, Lanuvio and Civitavecchia Nord as well as 25 municipalities in the greater Viterbo region: Civita Castellana, Bagnoregio, Blera, Bolsena, Canino, Capodimonte, Capranica, Caprarola, Carbognano, Civitella D'Agliano, Fabrica di Roma, Grotte di Castro, Ischia di Castro, Lubriano, Marta, Montalto di Castro, Monte Romano, Piansano, Ronciglione, Villa S. Giovanni in Tuscia, Vetralla, Tuscania, Tessennano and Tarquinia.

Tankers have begun distributing water in the districts affected by the ban, while residents of Civitavecchia Nord have been issued with cards entitling them to collect up to 600 litres free of charge. Authorities have ordered the closure of the aqueducts Arsial 1, Arsial 2, Ponton dell'Elce and Colle Biadaro.

In addition to residents being prohibited from drinking the tap water, the law prohibits its use in cooking or preparation of food and beverages, although the washing of fruit and vegetables is permitted so long as they are rinsed with clean drinking water afterwards. The use of tap water for brushing teeth is prohibited, while its use for bathing purposes is allowed except in cases involving skin conditions such as eczema.

Residents of the affected areas may use the public water supply however to wash clothes and dishes, for household cleaning, flushing lavatories and in their heating systems.