Water pollution statistics describe several related but different conditions: whether drinking water is safely managed, how wastewater is treated, what is measured in rivers and lakes, and how exposure affects health. The figures below identify the geography, measurement period, definitions and uncertainty behind each measure.
Key Water Pollution Statistics
The most broadly useful figures span household access, treatment, environmental monitoring and health:
- In 2022, at least 1.7 billion people worldwide used drinking-water sources contaminated with faeces.
- In 2022, 73% of the global population, about 6 billion people, used safely managed drinking water.
- In 2022, 2.2 billion people worldwide lacked safely managed drinking water.
- In 2022, 115 million people worldwide collected untreated surface water from lakes, ponds, rivers or streams.
- In 2022, 76% of total wastewater received some treatment in the 73 countries where the measure could be calculated.
- In 2022, 60% of total wastewater was safely treated in the 42 countries where the measure could be calculated.
- In 2022, 42% of household wastewater was not safely treated before discharge in the world estimate.
- In 2022, about 113 billion cubic metres of household wastewater were released with inadequate or no treatment in the world estimate.
- In 2023, 56% of water bodies in 120 reporting countries were classified as having good ambient water quality.
- By 2030, up to 4.8 billion people could face health and livelihood risks if monitoring and water quality do not improve, according to a scenario-based forecast.
- In the United States in 2018–2019, 28% of river and stream miles had healthy biological communities.
- In the United States in 2018–2019, 42% of river and stream miles were rated poor for excess phosphorus.
- In the United States in 2018–2019, 44% of river and stream miles were rated poor for excess nitrogen.
- In the United States, naturally occurring arsenic, manganese, strontium, radium and adjusted gross alpha collectively affected supplies serving more than 30 million people in the 2010–2020 assessment.
- Microbiologically contaminated drinking water is estimated to cause about 505,000 diarrhoeal deaths each year worldwide.
- Unsafe drinking water, sanitation and hand hygiene together are estimated to cause about 1 million diarrhoeal deaths each year worldwide.
Contents
- Global drinking-water safety and access
- Wastewater treatment and pollution flows
- Ambient water quality trends and monitoring
- U.S. rivers, streams, lakes and estuaries
- Groundwater contamination and drinking-water risks
- Health outcomes and exposure
Global Water Pollution Statistics and Drinking-Water Safety
The World Health Organization’s drinking-water figures distinguish service access from direct pollution measurements. “Safely managed” means an improved source on premises, available when needed and free from faecal and priority chemical contamination; it is therefore broader than a single laboratory result.
- In 2022, 73% of the global population, approximately 6 billion people, used safely managed drinking water. The estimate describes service-level conditions, not a chemical-pollution count.
- At least 1.7 billion people used a drinking-water source contaminated with faeces in 2022. WHO notes that source contamination does not mean every user’s household water was tested.
- 2.2 billion people lacked safely managed drinking water in 2022, including people whose sources met some but not all safely managed criteria.
- 1.5 billion people had only basic drinking-water services in 2022, meaning an improved source within a 30-minute round trip without all safely managed requirements.
- 292 million people used limited services requiring more than 30 minutes to collect water in 2022.
- 296 million people relied on unprotected wells and springs in 2022; this is a risk category rather than proof that every source sample was contaminated.
- 115 million people collected untreated surface water from lakes, ponds, rivers or streams in 2022. The estimate does not measure pollution levels in every water body.
Source: Drinking-water — World Health Organization.
Wastewater Treatment Statistics and Untreated Pollution Flows
UN-Water’s 2024 update shows why wastewater percentages must be read with their reporting coverage. In 2022, 107 countries reported some wastewater statistics, representing 73% of the world’s population, but the calculable treatment estimates used smaller subsets.
| Measure | Result | Coverage and period |
|---|---|---|
| Total wastewater receiving some treatment | 76% | 73 countries; 42% of world population; 2022 |
| Total wastewater safely treated | 60% | 42 countries; 12% of world population; 2022 |
| Industrial wastewater treated | 38% | 22 countries; 8% of world population; 2022 |
| Industrial wastewater safely treated | 27% | 22 countries; 8% of world population; 2022 |
Source: Progress on Wastewater Treatment – 2024 Update — UN-Water. These are not fully global treatment percentages; safe treatment means at least secondary treatment or compliance under the report’s concept.
The household wastewater model provides a broader world estimate:
- 42% of household wastewater was not safely treated before discharge in 2022.
- Approximately 268 billion cubic metres of household wastewater were generated in the 2024 dataset, described as a world-representative household estimate.
- Approximately 155 billion cubic metres were safely treated, while 113 billion cubic metres were not safely treated in the same 2022 household dataset.
- 45% of the inadequately treated household fraction was attributed to inadequate blackwater and greywater collection systems; this is not 45% of all wastewater.
The report also records reporting changes rather than a clean environmental trend. The 2024 monitoring dataset covered 85 countries reporting total wastewater generated, compared with 56 in the 2021 report; reported generation rose from 132 to 187 billion cubic metres, reported treatment from 42 to 220 billion cubic metres, and the share receiving any treatment from 32% to 76%.
Because country and population coverage changed, these values should not be interpreted as global treatment growth.
For industrial flows, the 2024 report recorded 36 billion cubic metres generated across 49 reporting countries, 8 billion cubic metres treated across 27 countries, and 3 billion cubic metres safely treated across 17 countries. The corresponding population coverage was 16%, 10% and 5%, respectively, while wastewater reuse was reported as 36 billion cubic metres from 59 countries.
Ambient Water Quality Statistics, Trends and Monitoring Gaps
Ambient water quality concerns the condition of water bodies themselves, rather than household service access or treatment at a wastewater plant. Under the SDG 6.3.2 framework, 56% of water bodies in 120 reporting countries had good ambient water quality in 2023, down from 57% in 2017.
The apparent change is small, but comparability depends on national monitoring and reporting. The number of countries reporting the indicator rose from 89 in 2022 to 120 in the 2023 data drive, and only 71 of those 120 countries had groundwater information.
- Up to 4.8 billion people could face health and livelihood risks by 2030 if monitoring and water quality are not improved. This is a scenario-based forecast, not a prediction that every person will be affected.
- The 2017–2023 decline from 57% to 56% is an observed indicator change among reporting countries, not a complete global time series.
- The groundwater reporting gap means the ambient indicator cannot be read as a comprehensive account of subsurface contamination.
Source: Progress on Ambient Water Quality – 2024 Update — UN-Water.
U.S. River, Stream, Lake and Estuary Pollution Statistics
The U.S. Environmental Protection Agency’s National Aquatic Resource Surveys use statistically representative national estimates, but their condition categories are not identical to state legal impairment listings. The surveys also cover different waterbody populations and years.
| U.S. assessment | Survey scope and period |
|---|---|
| Rivers and streams | 1,543,290 river miles; 2018–2019 |
| Lakes and reservoirs | 224,916 water bodies; 2017 |
| Wetlands | 95,694,241 acres; 2016 |
| Coastal estuaries | 27,479 square miles; 2015 |
| Great Lakes nearshore waters | 7,118 square miles; 2015 |
Source: National Water Quality Inventory: Report to Congress — U.S. EPA.
Key biological and chemical indicators show different dimensions of condition:
- Only 28% of U.S. river and stream miles had healthy biological communities in 2018–2019, based on EPA’s benthic macroinvertebrate index.
- 35% of sampled river and stream fish communities were in good condition in 2018–2019, while 54% of sampled lake zooplankton communities were in good condition in 2017.
- Across the most recent national surveys, good biological condition ranged from 28% to 71%, depending on waterbody type and indicator.
- 42% of river and stream miles were rated poor for excess phosphorus, and 44% were rated poor for excess nitrogen, in 2018–2019. “Poor” means exceeding the NARS benchmark, not necessarily legal impairment.
- Enterococci were at or below EPA’s benchmark in 78% of rivers and streams in 2018–2019 and 99% of assessed estuarine waters in 2015.
- Only 33% of U.S. estuarine area was rated good for eutrophication in 2015.
Groundwater Contamination Statistics and Drinking-Water Risks
Groundwater pollution statistics require particular care because contamination may be naturally occurring, linked to land use, or concentrated in sampled aquifers rather than distributed across every well. The U.S. Geological Survey’s 2010–2020 assessment found that five geogenic constituents—arsenic, manganese, strontium, radium and adjusted gross alpha—collectively affected drinking-water supplies serving more than 30 million people.
USGS trend data come from regional monitoring networks and selected chemicals, not a census of all wells:
- USGS groundwater monitoring has used 82 regional networks since 1988.
- Each network contains approximately 20–30 wells, reflecting a sampling design rather than the national well count.
- The trend analysis examined 28 chemicals: 6 pesticides, 6 volatile organic compounds, and 16 inorganic elements or compounds.
- Groundwater-quality changes were evaluated for more than 2,200 wells in 25 principal aquifers during 1988–2021.
- Repeated sampling occurred at approximately 10-year intervals, limiting the timing resolution of detected trends.
Sources: Status of water-quality conditions in the United States, 2010–20 and Three decades of groundwater-quality data across the nation — U.S. Geological Survey. An increasing concentration in one network is not proof of contamination in every U.S. well.
Water Pollution Health Outcomes and Exposure Statistics
The health burden includes direct drinking-water contamination and broader WASH risks. The estimates below should not be added together: they use different exposure definitions and some describe associated conditions rather than direct pollution attribution.
- Microbiologically contaminated drinking water is estimated to cause approximately 505,000 diarrhoeal deaths each year worldwide. WHO’s attribution concerns diarrhoeal deaths linked to contaminated drinking water, not all water-related deaths.
- Unsafe drinking water, sanitation and hand hygiene together are estimated to cause about 1 million diarrhoeal deaths annually worldwide.
- Addressing unsafe water, sanitation and hand hygiene risks could avoid 395,000 deaths among children under 5 each year worldwide, according to the cited preventable-fraction estimate.
- More than 251.4 million people required preventive treatment for schistosomiasis in 2021. This is a treatment-need measure associated with exposure to infested water, not a count of pollution cases.
- In acute-care hospitals, 7 of every 100 patients in high-income countries acquired at least one healthcare-associated infection during their stay, compared with 15 of every 100 patients in low- and middle-income countries. These are WASH-risk-context statistics, not direct measurements of hospital water contamination.
Source: Drinking-water — World Health Organization.
A separate WHO indicator for safely treated domestic wastewater had data for 115 countries covering 2019–2020. Regional aggregates may be imputed and require at least 50% data coverage, so indicator availability is itself part of interpreting global water pollution statistics.
Source: Proportion of safely treated domestic wastewater flows (%) — World Health Organization.