The pressure in water mains typically forces water out through any leak – preventing any contaminants from getting in. However, a British study finds that if the damage leads to a significant pressure drop, dirty water surrounding the pipe can then get sucked in through breaks.
It was believed that only clean water from the leak would be sucked into a broken pipe, and that even if contaminants were also sucked in, they would be expelled once water pressure in the pipe returned to normal.
However, a team led by engineer Joby Boxall of the University of Sheffield discovered that groundwater from around the pipe – which is often contaminated – can be sucked into and remain in the pipe. It then travels through the water supply network, they said.
“Many of us will have had [an upset] tummy in the past that we couldn’t quite explain, often putting it down to something we’d eaten,” Boxall said. “It now seems possible that some of these illnesses could have been caused not by food, but by water.”
Study co-author Richard Collins said that the new “research shows that contaminants that enter through a leaking pipe could be reaching consumer’ taps, and although this will be at very low concentrations, it would fail the safety tests if detected.”
