Go with the flow: do you need to filter US tap water?

There’s no one-size-fits-all way to ensure your drinking water is safe, experts say. Photograph: Stefania Pelfini la Waziya/Getty Images

Americans have a lot of questions about their drinking water. How is it treated? What’s in it? Most importantly, is it safe?

“I’ve even been out to eat where people overhear me talking about my work and come over to ask me a question about their tap water,” said Kimberly Parker, an environmental engineer who studies chemical contaminants in drinking water at Washington University in St Louis.