Cities bear rising cost of keeping water safe to drink

TOLEDO, Ohio (AP) Standing at the edge of the Great Lakes, the world's largest surface source of fresh water, this city of 280,000 seems immune from the water-supply problems that bedevil other parts of the country. But even here, the promise of an endless tap can be a mirage.

Algae blooms in Lake Erie, fed by agriculture runoff and overflowing sewers, have become so toxic that they shut down Toledo's water system in 2014 for two days. The city is considering spending millions of dollars to avoid a repeat.

Similar concerns about water quality are playing out elsewhere. Farm fertilizers, discarded pharmaceuticals, industrial chemicals and even saltwater from rising oceans are s