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Global access

According to the World Health Organization (WHO), "access to safe drinking-water is essential to health, a basic human right and a component of effective policy for health protection." In 1990, only 76 percent of the global population had access to drinking water. By 2015 that number had increased to 91 percent. In 1990, most countries in Latin America, East and South Asia, and Sub-Saharan Africa were well below 90%. In Sub-Saharan Africa, where the rates are lowest, household access ranges from 40 to 80 percent. Countries that experience violent conflict can have reductions in drinking water access: One study found that a conflict with about 2,500 battle deaths deprives 1.8% of the population of potable water.

By 2015, 5.2 billion people representing 71% of the global population used safely managed drinking water services. As of 2017, 90% of people having access to water from a source that is suitable for drinking – called improved water source – and 71% of the world could access safely managed drinking water that is clean and available on-demand. Estimates suggest that at least 25% of improved sources contain fecal contamination. 1.8 billion people still use an unsafe drinking water source which may be contaminated by feces. This can result in infectious diseases, such as gastroenteritis, cholera, and typhoid, among others. Reduction of waterborne diseases and development of safe water resources is a major public health goal in developing countries. In 2017, almost 22 million Americans drank from water systems that were in violation of public health standards, which could contribute to citizens developing water-borne illnesses. Safe drinking water is an environmental health concern. Bottled water is sold for public consumption in most parts of the world.

Improved sources are also monitored based on whether water is available when needed (5.8 billion people), located on premises (5.4 billion), free from contamination (5.4 billion), and within a 30-minute round trip. While improved water sources such as protected piped water are more likely to provide safe and adequate water as they may prevent contact with human excreta, for example, this is not always the case. According to a 2014 study, approximately 25% of improved sources contained fecal contamination.

The population in Australia, New Zealand, North America and Europe have achieved nearly universal basic drinking water services.

Because of the high initial investments, many less wealthy nations cannot afford to develop or sustain appropriate infrastructure, and as a consequence people in these areas may spend a correspondingly higher fraction of their income on water. 2003 statistics from El Salvador, for example, indicate that the poorest 20% of households spend more than 10% of their total income on water. In the United Kingdom, authorities define spending of more than 3% of one's income on water as a hardship.