Water, Sanitation and Hygiene
Access to drinking water and sanitation is reported on a service ladder, not as a single yes-or-no number. The difference between “improved,” “basic,” and “safely managed” is the difference between counting taps and counting whether the water from those taps is safe to drink without further treatment.
Last reviewed on 2026-04-27.
The JMP service ladders
Drinking water
The drinking-water ladder runs from open surface water at the bottom, through unimproved sources, limited service (improved source but more than a 30-minute round trip), basic service (improved source within 30 minutes), to safely managed (improved source on premises, available when needed, and free from faecal and priority chemical contamination). The jump from “basic” to “safely managed” is large in many countries — a household can have a tap and still receive water that is intermittent or microbiologically unsafe. Reports that quote only “improved water access” lump together the top three rungs and obscure that gap.
Sanitation
The sanitation ladder runs from open defecation, through unimproved facilities, limited service (improved facility but shared with other households), basic service (improved facility used only by one household), to safely managed (basic facility where waste is then either treated and disposed of in situ, emptied and treated, or transported and treated off-site). Open defecation has fallen sharply over the past two decades but remains the practice of a meaningful share of the population in parts of sub-Saharan Africa and South Asia. The transition from “basic” to “safely managed” depends on faecal-sludge management and wastewater treatment, both of which are weak in many countries.
Hygiene
Hygiene is the youngest of the three ladders, added when the SDGs replaced the Millennium Development Goals. The basic indicator is the presence of a handwashing facility with soap and water at home. Limited service is a facility without soap or water; no service is no facility at all. Hygiene data is patchier than water and sanitation data because the household-survey questions are newer and not yet asked everywhere.
Inequalities within countries
National headline figures hide large urban-rural and wealth-quintile gaps. The same country can show 95% basic water service nationally but 70% in the poorest rural quintile. The JMP publishes inequality breakdowns for this reason; comparisons that use only the national average tend to overstate progress for the populations the indicators were designed to track.
From access to health outcomes
Diarrhoeal disease
Unsafe water, sanitation and hygiene contribute to diarrhoeal disease, a leading cause of child mortality in low-income countries. The Global Burden of Disease project at IHME publishes attributable-mortality and DALY estimates for unsafe WASH; these estimates are built up the same way as those covered on the air pollution page — with exposure-response curves, counterfactual exposures, and population weighting. They are population-level inferences, not individual case attributions.
Stunting and intestinal infections
Recurrent infections in early childhood — including those linked to poor sanitation — are part of the chain that leads to chronic undernutrition and stunting, even when food intake is adequate. This is why nutrition programmes increasingly bundle WASH interventions, and why hygiene indicators sit alongside food-security indicators in international monitoring.
Schools and health facilities
The JMP also reports WASH in schools and in health-care facilities, separately from household coverage. A health facility without reliable water and sanitation is not in a position to provide safe care; school WASH affects girls’ attendance during menstruation. These “institutional WASH” series have grown considerably in coverage and now sit alongside household figures in major reports.
The infrastructure pipeline
Translating better infrastructure into better outcomes depends on operation, maintenance, water-quality testing, and behaviour change. Pipes and toilets fall out of use without those layers. Indicator dashboards typically measure infrastructure presence rather than the chain to outcomes; chart users should expect that the line from access to health gain is real but lossy.
Common pitfalls
“Improved” is not the same as “safely managed”
Older charts often show “improved water access” near saturation while safely managed coverage is much lower. Both numbers come from the same survey, but they answer different questions.
National averages versus the bottom quintile
Headline coverage rates are dominated by urban and wealthier populations. WASH equity charts that show the gap between the richest and poorest quintile within a country are often more informative than the national figure.
Watch the survey vintage
DHS and MICS surveys run on multi-year cycles. A country’s reported coverage may be three to five years old; trend lines can be flat or jagged for survey-availability reasons rather than real-world reasons.
Water quality is the missing piece
The “free from faecal and priority chemical contamination” criterion in the safely-managed rung is hard to test at scale. Many countries still report water quality from spot studies, not continuous monitoring; treat the safely-managed rung as the best available estimate, not a precise measurement.
Sources
The standard reference is the WHO/UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP), which compiles household, school and health-facility WASH coverage from DHS, MICS, national censuses and administrative sources. UN-Water’s SDG 6 reports synthesize the indicators tracked under SDG target 6.1 (drinking water) and 6.2 (sanitation and hygiene). For health-burden estimates linked to WASH, the IHME Global Burden of Disease results are the standard. Country statistical offices publish underlying survey data that the JMP harmonizes.
WASH connects to life expectancy, maternal health, and disease burden, and intersects with the supply-side discussion on water scarcity. The two water pages answer different questions: water-scarcity covers physical availability; this page covers safe access at the household level.