Wonderful news! Water fountains are coming back. In an attempt to tackle plastic waste, the old municipal staple will be installed in public places in London so we can have a free drink and top up refillable bottles. But can we be sure the water is clean? If your lips touch the spout, will you get herpes or some other orally transmissible infection? Should you wipe the spout before drinking? Or perhaps do a sneaky inspection of the person in front of you to establish if their oral hygiene is up to scratch?

Water fountains have been a feature of cities since the ancient Greeks put them near temples and dedicated them to gods and heroes. Britain caught up in the mid-19th century, with the Metropolitan Free Drinking Fountain Association responsible for 800 drinking fountains in London alone. The technology used to help reduce the risk of infectious diseases has improved, including slanted jets of water, filters and better maintenance. But over the past 30 to 40 years, drinking fountains have been disappearing because of the marketing of bottled water, a lack of investment and maintenance by local authorities, and concern about health risks. So, how best to ensure a hygienic experience?

The main source of contamination is on the knobs and buttons of fountains; if you are going to wipe anything with a disinfectant, go for the knobs, not the spout.

The risk of getting herpes from the spout is almost negligible, but for those who feel queasy about any public amenities, it is best to drink from the flowing jet of water, rather than wrapping your lips round the spout.

Remember: disease outbreaks from municipal water fountains are extremely rare and tend to be isolated cases involving individuals with an impaired immune system.

Modern designs of water fountains are likely to pose a negligible risk to your health. And the benefits of access to free, clean water in city centres are enormous. Kids can have water instead of sugary drinks; older people can avoid dehydration; runners and cyclists can rehydrate without having to lug plastic bottles with them. The only downside will be for businesses that sell us expensive water in plastic bottles. Ah, well.