• In this Tuesday, Sept. 1, 2015 photo, Ken Gibbons, a graduate research assistant at the University of Toledo Lake Erie Center, holds a sample of algae from Lake Erie in a lab in Oregon, Ohio. Algae blooms in Lake Erie, fed by agriculture runoff and overflowing sewer pipes, have become so toxic that they shut down Toledo's water system for two days in the summer of 2014 and have the city looking at spending millions to avoid a repeat. (AP Photo/Haraz N. Ghanbari)

    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.