Nearly 25% of the global population (1.8 billion people in 2012) is consuming fecally-contaminated water. This water can contain bacteria, protozoa, and viruses that can cause a variety of diseases in humans, most notably gastroenteritis. The impact on public health is staggering. Unsafe water, inadequate sanitation, and poor hygiene are responsible for about 90% of diarrheal deaths worldwide. Not surprisingly, diarrhea is the second leading cause of death for children under the age of five globally (1.2 million deaths in 2012). In addition to the human cost, the World Bank estimates that lack of access to safe water and sanitation results in a global economic loss of US$260 billion annually.