Tracking down three billion litres of lost water

You'd think that of all the leaks in the country, the one that pops up on the street where a professor of water systems lives would get fixed pretty quickly. But as Vanessa Speight will tell you, that's sadly not the case. "It just comes out of the pavement and runs down the road," says Prof Speight, an expert in drinking water quality at the University of Sheffield. It was roughly a year ago that she first reported the problem to her local water firm. Despite efforts to locate the source of the leak, the company has come up dry. "It's probably been six different times they've dug up the road," Prof Speight adds.