Easy access to clean tap water is one of the unsung miracles of the modern world. A tap and a piece of soap in the kitchen, not to mention flush toilets, have arguably saved more human lives than many wonder drugs.

Yet while some 82% of North Koreans have access to tap water usable for basic sanitation, that water is not necessarily safe to drink: According to UNICEF, only 61% have access to safely managed water services. Another problem is even those with taps in their homes may not always have running water due to frequent power outages that shut off pumps.