New York, July 17 -- The first time Loko Miyo used an ATM card, she wasn't withdrawing money. She was collecting water.

For years, Loko had never imagined that a simple tap of a card could replace the exhausting six-hour journey she made to fetch just one 20-litre jerrycan of water from a polluted river.

"It was very difficult to walk on the rocky road carrying a jerrycan full of water," she recalls. "I will never forget the day I fell. The jerrycan hit my neck, and I was in bed for days."

The long journey was only part of the struggle. The river was shared by people and livestock, making the water unsafe to drink. Her children repeatedly suffered from diarrhea and other waterborne diseases.

"Since the water from the river was dirty, ...