Nepal may be famous for its dangerous mountains, but stagnant water is a far greater threat to human life. It is one of the world’s poorest countries, and two-thirds of the population lives without toilets. Water pipes in major cities are old and crumbling — a bad situation made worse by the earthquake that devastated Kathmandu in April. Diarrhea has long been a major killer of Nepalese children, although the death rate was cut in half between 2000 and 2010. Much of the credit went to a newly recruited corps of “lady health workers” who taught basic hygiene such as the need to use latrines and to wash hands afterward. Also, local clinics began stocking packets of oral rehydration solution. The water problem is chronic, especially where sewage from one village washes downstream to foul the drinking water of others below. Some charities try to help by drilling wells. Last April’s Kathmandu earthquake was followed by dire predictions that a cholera epidemic would break out when the summer monsoons flooded the camps where many refugees lived in tents. Those fears stemmed from the experience of Haiti, where a massive earthquake in early 2010 was followed ten months later by a cholera epidemic that has since sickened 700,000 Haitians and killed 9,000 of them. However, they failed to note crucial differences between the countries: in 2010, Haiti had not had a case of cholera in decades, so no one in the population was immune. Cholera is endemic in Nepal, so many adults survived mild cases in childhood and have immunity. In fact, Haiti’s epidemic was blamed on Nepalese United Nations peacekeepers. The outbreak began in the Arbonite River near their encampment, which was leaking raw sewage, and the bacterial strain was identical to the Nepalese one. No major outbreaks of waterborne disease have happened as a result of earthquake damage, and well-run refugee camps have safe water, often trucked in by relief agencies. But serious outbreaks could still happen, particularly in hard-to-reach rural areas.