Universal access to safe drinking water is a fundamental need and human right. Securing access for all would go a long way in reducing illness and death, especially among children. In 2015, 91 per cent of the world’s population use improved drinking water sources, exceeding the 2015 Millennium Development Goal target of 88 per cent. Over the MDG period 2.6 billion people gained access to an improved drinking water source, of these 1.9 billion gained access to a piped supply on premises. Despite this enormous accomplishment, troubling disparities persist: 663 million people do not use an improved drinking water source, most of whom are poor and live in rural areas. Questions also remain about the safety of ‘improved’ drinking water sources that may not always be free of contaminants and may not provide a reliable supply of water throughout the year.

Drinking Water: Equity, safety and sustainability - 2011 Thematic Report
This thematic report on drinking water highlights the substantive challenges that remain in achieving safe, sustainable and equitable access to drinking water.

Progress on Drinking Water and Sanitation - 2014 Report
The world has made great strides in increasing access to drinking water and sanitation for billions of people but progress has been uneven.
This joint WHO/UNICEF report documents the gains that have been made since 1990 and highlights substantive disparities such as those between regions, rural and urban areas and for marginalized groups.

JMP Website
WHO and UNICEF have monitored access to drinking water and sanitation through the Joint Monitoring Programme (JMP) for Water supply and Sanitation since the early 90s.
Progress on Sanitation and Drinking Water 2015 Assessement and MDG update
Looking back on 25 years of water, sanitation and hygiene monitoring, the report provides a comprehensive assessment of progress since 1990. The MDG target for drinking water was achieved in 2010 but the world has missed the sanitation target by almost 700 million people. In 2015, 663 million people still lack improved drinking water sources, 2.4 billion lack improved sanitation facilities and 946 million still practice open defecation.
JMP Progress on Sanitation and Drinking Water 2015 data dashboard
WHO/UNICEF JOINT MONITORING PROGRAMME FOR WATER SUPPLY AND SANITATION
Since 1990, WHO and UNICEF have tracked progress on global water and sanitation goals through the Joint Monitoring Programme for Water Supply and Sanitation (JMP). The JMP monitors trends in coverage; helps build national monitoring capacity in developing countries; develops and harmonises questionnaires, indicators and definitions to ensure comparability of data over time and among countries; and informs policymakers of the status of the water supply and sanitation sector through annual publications. The JMP draws guidance from a technical advisory group of leading experts in water supply, sanitation and hygiene, and from institutions involved in data collection and sector monitoring. Further information about the JMP and its methodology can be found at the JMP website.
DATA SOURCES
The JMP estimates for handwashing are based on information collected in household surveys such as Multiple Indicator Cluster Surveys (MICS) and Demographic and Health Surveys (DHS). Household surveys are usually conducted by national institutes of statistics, carried out by trained national staff who collect information on a wide range of health and living conditions through face-to-face interviews. Nationally owned and independently verifiable, these data sources provide national governments with a periodic update of the status and progress with respect to handwashing. Increasingly household survey data allow for assessing disparities in access by marginalized populations and geographic areas.
DEFINITION OF HANDWASHING FACILITIES WITH SOAP AND WATER
The presence of soap and water at a designated place is used a proxy for handwashing behaviours. Households are considered to have access if enumerators observe a place for handwashing and both water and soap are available.