Water treatment spans drinking-water access, wastewater processing, industrial discharge, and the infrastructure that moves and cleans water. The statistics below distinguish observed results from estimates and forecasts, and identify the population, geography, units, and measurement period behind each figure.
Contents
- Global access to safely managed drinking water
- Global wastewater treatment and safe discharge
- United States water withdrawals and use
- United States public-water-system compliance
- United States drinking-water infrastructure needs
- United States wastewater treatment and clean-water investment
Global access to safely managed drinking water
The World Health Organization defines safely managed drinking water using three conditions: an improved source must be accessible on premises, available when needed, and free from faecal and priority chemical contamination. This is a definition of service quality and access, not simply the presence of a water source. WHO metadata identifies 2019 as the most recent year for that definition’s indicator information. (WHO, “Proportion of population using safely managed drinking-water services (%)”)
In 2018, 71.0% of the global population had access to safely managed drinking-water services. The WHO’s 2024 annual report projected that the share would reach 87.3% by 2025. The 2025 figure is explicitly a projection, so it should not be read as a measured worldwide outcome. (WHO, “WHO global water, sanitation and hygiene: annual report 2024”)
The related sanitation figures show a different level of coverage. Safely managed sanitation reached 53% of the global population in 2018 and was projected at 80% by 2025. These drinking-water and sanitation measures describe different services, even though both are part of broader water, sanitation, and hygiene monitoring. (WHO, “WHO global water, sanitation and hygiene: annual report 2024”)
| Global WASH measure | 2018 observed | 2025 projection |
|---|---|---|
| Safely managed drinking water | 71.0% | 87.3% |
| Safely managed sanitation | 53% | 80% |
The time labels matter: 2018 values are reported observations, while the 2025 values are forecasts. The drinking-water definition also depends on contamination and availability, so a basic access statistic should not be substituted for the safely managed measure.
Global wastewater treatment and safe discharge
UN-Water’s 2024 update reported that 107 countries supplied some wastewater statistics in 2022, representing 73% of the world’s population. However, reporting some statistics did not mean that a treatment ratio could be calculated for every country. (UN-Water, “Progress on Wastewater Treatment – 2024 Update”)
Among 73 countries where the ratio could be calculated, an estimated 76% of total wastewater received some treatment in 2022. Coverage for that estimate was 42% of the global population. A narrower measure found that 60% of total wastewater was safely treated among 42 countries, with at least secondary treatment, but those countries represented only 12% of the global population.
The reporting base expanded between 2015 and 2022. The number of countries reporting some wastewater statistics rose from 69 to 107. The number for which the total-wastewater treatment ratio was calculable increased from 42 to 73, while the number for which the safely treated ratio was calculable rose from 15 to 42. Expanded reporting is not itself evidence that treatment performance improved.
Industrial wastewater had particularly limited coverage. In 2022, 22 countries reported industrial wastewater data, representing 8% of the global population. Among those reporting countries, 38% of industrial wastewater was reported as treated and 27% as safely treated. The latter measure required at least secondary treatment and was not a global estimate.
Household wastewater provides another global indicator. An estimated 42% of household wastewater was not safely treated before discharge in 2022. UN-Water estimated that 113 billion cubic metres of household wastewater were released with inadequate or no treatment. These figures concern household wastewater only, not all wastewater from every sector.
United States water withdrawals and use
The U.S. Geological Survey estimated total U.S. water withdrawals at about 322 billion gallons per day in 2015, 9% below 2010. Freshwater withdrawals were 281 billion gallons per day and saline-water withdrawals were 41.0 billion gallons per day. Freshwater therefore represented 87% of national withdrawals in 2015. These are national estimates for 2015, not current 2026 measurements. (USGS, “Estimated use of water in the United States in 2015”)
Fresh surface-water withdrawals were 198 billion gallons per day in 2015, down 14% from 2010. Fresh groundwater withdrawals were 82.3 billion gallons per day, about 8% above 2010. The difference illustrates why treatment planning must consider source type as well as total volume.
Irrigation withdrawals reached 118 billion gallons per day in 2015, 2% above 2010, and accounted for 42% of total U.S. freshwater withdrawals. About 63.5 million U.S. acres were irrigated, 2% more than in 2010. Sprinkler and microirrigation systems covered 63% of irrigated land. Irrigation consumptive use was 73.2 billion gallons per day, equal to 62% of irrigation withdrawals and reclaimed wastewater use.
| U.S. water-use measure | 2015 figure | Comparison or share |
|---|---|---|
| Total withdrawals | 322 billion gal/day | 9% below 2010 |
| Freshwater withdrawals | 281 billion gal/day | 87% of total withdrawals |
| Saline-water withdrawals | 41.0 billion gal/day | — |
| Irrigation withdrawals | 118 billion gal/day | 42% of freshwater withdrawals |
| Public-supply withdrawals | 39.0 billion gal/day | 7% below 2010 |
Public-supply withdrawals were 39.0 billion gallons per day in 2015, 7% below 2010. Public-supply facilities provided potable water to 283 million people, about 87% of the U.S. population. Self-supplied domestic withdrawals were 3.26 billion gallons per day, 8% below 2010, and more than 98% came from groundwater.
United States public-water-system compliance
The U.S. Environmental Protection Agency counted 148,541 active public water systems in calendar year 2023. Of these, 107,559 systems, or 72%, had no reported drinking-water-standard violations. Another 40,982 systems, nearly 28%, violated at least one drinking-water standard. (EPA, “Providing Safe Drinking Water in America: 2023 National Public Water Systems Compliance Report”)
The compliance categories identify different reported conditions. In 2023, 6,045 systems, or 4%, had a health-based drinking-water violation, defined here as an exceedance or missed treatment technique. Separately, 29,703 systems, or 20%, missed at least one monitoring or reporting requirement. These percentages should be read with their category definitions rather than treated as one single outcome measure.
EPA identified 5,018 systems, or 3.4%, as enforcement priorities in at least one quarter of 2023. The priority score used seriousness and duration. Small systems serving 3,300 people or fewer accounted for 4,667 systems, or 93% of enforcement-priority systems.
Formal enforcement action began at 2,398 systems in 2023, while informal action began at 27,149. Together, these figures describe regulatory activity during the year; they do not quantify the volume of water treated or establish that every system had the same compliance profile.
United States drinking-water infrastructure needs
EPA’s 7th Drinking Water Infrastructure Needs Survey and Assessment estimated $625 billion in U.S. drinking-water infrastructure needs over a 20-year horizon. This is a projected need, not measured spending or completed treatment capacity. The estimate was 32% higher than the 6th DWINSA estimate of $472.6 billion. (EPA, “EPA’s 7th Drinking Water Infrastructure Needs Survey and Assessment”)
The 2023 survey covered 3,629 public water systems across all 50 states, Puerto Rico, the District of Columbia, and U.S. territories. Of those systems, 3,526 responded, a 97% response rate. Survey responses and extrapolation limit direct inference about every individual system. (EPA, “7th Drinking Water Infrastructure Needs Survey and Assessment April 2023”)
The assessment identified $422.9 billion for distribution and transmission improvements, $107 billion for treatment infrastructure, and $56.1 billion for storage infrastructure over 20 years. These categories describe eligible projected infrastructure needs, not annual budgets.
Lead-service-line projections changed with methods and inventories. The 2023 DWINSA projected 9.2 million lead service lines nationally. EPA’s updated 7th DWINSA page reported a current projection of 4.0 million lead service lines in a 2025 update. The updated assessment had responses from 67% of surveyed systems in 2024; it was not a complete inventory. (EPA, “EPA’s 7th Drinking Water Infrastructure Needs Survey and Assessment”)
United States wastewater treatment and clean-water investment
The 2022 Clean Watersheds Needs Survey reported $630.1 billion in U.S. clean-water infrastructure needs for 2022–2041, in January 2022 dollars. The estimate included $66.6 billion for secondary wastewater treatment, $83.6 billion for advanced wastewater treatment, $7.7 billion for water reuse, and $0.2 billion for desalination. The desalination figure was rounded. (EPA, “2022 Clean Watersheds Needs Survey Report to Congress”)
The same survey reported $115.3 billion for stormwater management, $94.4 billion for nonpoint-source control, and $74.7 billion for decentralized wastewater treatment systems for 2022–2041. These are planning estimates in January 2022 dollars, not measured spending or completed capacity. (EPA, “Clean Watersheds Needs Survey”)
As of January 2022, 17,544 publicly owned treatment works served 270.4 million Americans, or 82% of the U.S. population. The population served by publicly owned systems with advanced treatment rose from less than 4% in 1972 to about 42% in 2022. Over the same period, the population served by systems with less-than-secondary treatment fell from almost 28% in 1972 to an estimated 1% in 2022. The last figure is a CWNS estimate. (EPA, “2022 Clean Watersheds Needs Survey Fact Sheet”)
The global and U.S. figures therefore measure different parts of water treatment. WHO tracks safely managed drinking-water and sanitation services, UN-Water reports treatment and safe discharge with limited country coverage, USGS estimates withdrawals and uses, and EPA reports compliance and projected infrastructure needs. Keeping those definitions and periods separate is essential when comparing access, treatment, regulatory performance, and investment.